Publications by authors named "Zhi Chen"

1,524 Publications

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The Heat Shock Repressor HspR Directly Controls Avermectin Production, Morphological Development, and HO Stress Response in .

Appl Environ Microbiol 2021 Jun 23:AEM0047321. Epub 2021 Jun 23.

State Key Laboratory of Agrobiotechnology and College of Biological Sciences, China Agricultural University, Beijing, China.

Heat shock response (HSR) is a universal cellular response that promotes survival following temperature increase. In filamentous , which account for ∼70% commercial antibiotic production, HSR is regulated by transcriptional repressors; in particular, the widespread MerR-family regulator HspR has been identified as a key repressor. However, functions of HspR in other biological processes are unknown. The present study demonstrates that HspR pleiotropically controls avermectin production, morphological development, and heat shock and HO stress responses in industrially important species . HspR directly activated structural genes (, ) and HO stress-related genes (, , , , , ), whereas it directly repressed heat shock genes (HSGs) ( operon, , , ) and developmental genes (, , ). HspR interacted with PhoP (response regulator of the widespread PhoPR two-component system) at to co-repress the important operon. PhoP exclusively repressed target HSGs (, , ) different from those of HspR (, , ). A consensus HspR-binding site, 5'-TTGANBBNNHNNNDSTSHN-3', was identified within HspR target promoter regions, allowing prediction of the HspR regulon involved in broad cellular functions. Taken together, our findings demonstrate a key role of HspR in coordination of a variety of important biological processes in species. Our findings are significant to clarify the molecular mechanisms underlying HspR function in antibiotic production, development, and HO stress responses through direct control of its target genes associated with these biological processes. HspR homologs described to date function as transcriptional repressors, but not as activators. Results of the present study demonstrate that HspR acts as a dual repressor/activator. PhoP was shown to crosstalk with HspR at to co-regulate HSR and have its exclusive target HSGs. The novel role of PhoP in HSR further demonstrates the importance of this regulator in . Overexpression of strongly enhanced avermectin production in wild-type and industrial strains. These findings provide new insights into the regulatory roles and mechanisms of HspR and PhoP, and facilitate methods for antibiotic overproduction in species.
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http://dx.doi.org/10.1128/AEM.00473-21DOI Listing
June 2021

Comparison of modified hand-assisted retroperitoneoscopic laparoscopic nephrectomy and open nephrectomy in patients with benign inflammatory non-functioning kidney diseases.

Transl Androl Urol 2021 May;10(5):2027-2034

Department of Urology, Xiangya Hospital, Central South University, Changsha, China.

Background: To assess the validity and feasibility of the modified hand-assisted retroperitoneoscopic laparoscopic nephrectomy (MHARLN) in patients with benign inflammatory non-functioning kidney diseases.

Methods: We retrospectively compared the data of 223 patients who underwent an MHARLN (n=142) or an open nephrectomy (ON) (n=81) with benign inflammatory non-functioning diseases between January 2014 and October 2019 at our hospital. Patients' demographic data, perioperative outcomes, preoperative and postoperative inflammatory data, and postoperative complications were reviewed.

Results: The basic demographic data of patients were similar between the 2 groups. The mean operative times for the MHARLN and the ON were 135 and 143 minutes (P=0.181), respectively. The first time at which postoperative ambulation occurred, the visual analog pain scale (VAS) score before discharge and the postoperative complication rate were similar in both groups. However, compared to the MHARLN, the ON was associated with a more severe inflammatory response on the first day after surgery (P=0.045), higher estimated blood loss (309.8 139.6 mL; P=0.036), more peritoneal ruptures (19.8% 9.2%; P=0.024), higher intraoperative transfusion (14.82% 4.93%; P=0.011), higher VAS scores 24 hours after surgery (5.9 5.2; P=0.002), additional analgesic use (35.8% 21.8%; P=0.024), and longer hospital stays (5.3 4.6 days; P=0.048). Before a liquid diet was commenced in the MHARLN and ON groups, the mean time was 1.2 and 1.5 days, respectively (P=0.004).

Conclusions: When performed by a skilled laparoscopic surgeon, the use of the MHARLN in patients with benign inflammatory non-functioning kidney diseases is reliable and safe. The MHARLN may help to treat challenging cases and result in less trauma successfully.
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http://dx.doi.org/10.21037/tau-21-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8185685PMC
May 2021

Cytomegalovirus Latency Exacerbated small-for-size Liver Graft Injury through Activation of CCL19/CCR7 in Hepatic Stellate Cells.

Transplantation 2021 Jun 2. Epub 2021 Jun 2.

1Department of Surgery, HKU-SZH & Faculty of Medicine, The University of Hong Kong, Hong Kong, China 2AIDS Institute and Department of Microbiology, Faculty of Medicine, The University of Hong Kong, Hong Kong, China 3Institute of Immunology, School of Medicine, Zhejiang Univerisity, Hangzhou, Zhejiang, China.

Background: The interplay between cytomegalovirus (CMV) latency and graft malfunction after living donor liver transplantation (LDLT) remains poorly defined due to the complexity of clinical confounding factors. Here, we aimed to investigate the effects of CMV latency on small-for-size graft injury and to get further insight on the pathogenic role of hepatic stellate cells (HSCs) in this process.

Methods: Rat orthotopic liver transplantation with small-for-size grafts was performed in a CMV latent model developed in immunocompetent Sprague Dawley (SD) rats using Priscott strain. Post-transplant graft injury including hepatocyte damage, stellate cell activation and fibrogenesis were evaluated. Differential gene expression of HSCs in response to CMV latency was screened by cDNA microarray. Clinical validation was further conducted in human biopsies.

Results: CMV latency aggravated hepatocyte apoptosis/necrosis in the early phase, enhanced HSC expansion and graft fibrosis during the middle-late phase in small-for-size liver grafts of the rat model. cDNA microarray mining revealed CCL19/CCR7 as one of the most noteworthy pathways bridging HSC activation and liver graft injury in the presence of CMV latency. Together with CCL19 upregulation, coherent overexpression of CCR7 in accumulated HSCs was confirmed in both rat and human CMV latent recipients. Moreover, addition of CCL19 in vitro promoted HSC migration by increasing the level of matrix metalloproteinase-2 (MMP2).

Conclusion: Our data demonstrated that CMV latency aggravated early/late phase liver graft damage and fibrogenesis via CCL19/CCR7/HSCs axis. Blockade of CMV latency-related stellate cell activation may shed light on the strategy of graft protection clinically.
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http://dx.doi.org/10.1097/TP.0000000000003846DOI Listing
June 2021

High Rate and Long Lifespan Sodium-Organic Batteries Using Pseudocapacitive Porphyrin Complexes-Based Cathode.

Nanomicro Lett 2021 Feb 14;13(1):71. Epub 2021 Feb 14.

Key Laboratory of Environmentally Friendly Chemistry and Application of Ministry of Education, Key Laboratory for Green Organic Synthesis and Application of Hunan Province, College of Chemistry, Xiangtan University, Xiangtan, 411105, People's Republic of China.

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http://dx.doi.org/10.1007/s40820-021-00593-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8187698PMC
February 2021

MV CBCT-Based Synthetic CT Generation Using a Deep Learning Method for Rectal Cancer Adaptive Radiotherapy.

Front Oncol 2021 31;11:655325. Epub 2021 May 31.

Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Shanghai, China.

Due to image quality limitations, online Megavoltage cone beam CT (MV CBCT), which represents real online patient anatomy, cannot be used to perform adaptive radiotherapy (ART). In this study, we used a deep learning method, the cycle-consistent adversarial network (CycleGAN), to improve the MV CBCT image quality and Hounsfield-unit (HU) accuracy for rectal cancer patients to make the generated synthetic CT (sCT) eligible for ART. Forty rectal cancer patients treated with the intensity modulated radiotherapy (IMRT) were involved in this study. The CT and MV CBCT images of 30 patients were used for model training, and the images of the remaining 10 patients were used for evaluation. Image quality, autosegmentation capability and dose calculation capability using the autoplanning technique of the generated sCT were evaluated. The mean absolute error (MAE) was reduced from 135.84 ± 41.59 HU for the CT and CBCT comparison to 52.99 ± 12.09 HU for the CT and sCT comparison. The structural similarity (SSIM) index for the CT and sCT comparison was 0.81 ± 0.03, which is a great improvement over the 0.44 ± 0.07 for the CT and CBCT comparison. The autosegmentation model performance on sCT for femoral heads was accurate and required almost no manual modification. For the CTV and bladder, although modification was needed for autocontouring, the Dice similarity coefficient (DSC) indices were high, at 0.93 and 0.94 for the CTV and bladder, respectively. For dose evaluation, the sCT-based plan has a much smaller dose deviation from the CT-based plan than that of the CBCT-based plan. The proposed method solved a key problem for rectal cancer ART realization based on MV CBCT. The generated sCT enables ART based on the actual patient anatomy at the treatment position.
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http://dx.doi.org/10.3389/fonc.2021.655325DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8201514PMC
May 2021

Study of an Online Plan Verification Method and the Sensitivity of Plan Delivery Accuracy to Different Beam Parameter Errors in Proton and Carbon Ion Radiotherapy.

Front Oncol 2021 28;11:666141. Epub 2021 May 28.

Department of Medical Physics, Shanghai Proton and Heavy Ion Center, Shanghai, China.

For scanning beam particle therapy, the plan delivery accuracy is affected by spot size deviation, position deviation and particle number deviation. Until now, all plan verification systems available for particle therapy have been designed for pretreatment verification. The purpose of this study is to introduce a method for online plan delivery accuracy checks and to evaluate the sensitivity of plan delivery accuracy to different beam parameter errors. A program was developed using MATLAB to reconstruct doses from beam parameters recorded in log files and to compare them with the doses calculated by treatment planning system (TPS). Both carbon ion plans and proton plans were evaluated in this study. The dose reconstruction algorithm is verified by comparing the dose from the TPS with the reconstructed dose under the same beam parameters. The sensitivity of plan delivery accuracy to different beam parameter errors was analyzed by comparing the dose reconstructed from the pseudo plans that manually added errors with the original plan dose. For the validation of dose reconstruction algorithm, mean dose difference between the reconstructed dose and the plan dose were 0.70% ± 0.24% and 0.51% ± 0.25% for carbon ion beam and proton beam, respectively. According to our simulation, the delivery accuracy of the carbon ion plan is more sensitive to spot position deviation and particle number deviation, and the delivery accuracy of the proton plan is more sensitive to spot size deviation. To achieve a 90% gamma pass rate with 3 mm/3% criteria, the average spot size deviation, position deviation, particle number deviation should be within 23%, 1.9 mm, and 1.5% and 20%, 2.1 mm, and 1.6% for carbon ion beam and proton beam, respectively. In conclusion, the method that we introduced for online plan delivery verification is feasible and reliable. The sensitivity of plan delivery accuracy to different errors was clarified for our system. The methods used in this study can be easily repeated in other particle therapy centers.
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http://dx.doi.org/10.3389/fonc.2021.666141DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8193983PMC
May 2021

Advanced maternal age causes premature placental senescence and malformation via dysregulated α-Klotho expression in trophoblasts.

Aging Cell 2021 Jun 9:e13417. Epub 2021 Jun 9.

International Collaborative Laboratory of Reproduction and Development of Chinese Ministry of Education, Chongqing Medical University, Chongqing, China.

Advanced maternal age (AMA) pregnancy is associated with higher risks of adverse perinatal outcomes, which may result from premature senescence of the placenta. α-Klotho is a well-known antiaging protein; however, its expression and effect on the placenta in AMA pregnancies have not yet been fully elucidated. The expression patterns of α-Klotho in mouse and human placentas from AMA pregnancies were determined by Western blotting and immunohistochemistry (IHC) staining. α-Klotho expression in JAR cells was manipulated to investigate its role in trophoblastic senescence, and transwell assays were performed to assess trophoblast invasion. The downstream genes regulated by α-Klotho in JAR cells were first screened by mRNA sequencing in α-Klotho-knockdown and control JAR cells and then validated. α-Klotho-deficient mice were generated by injecting klotho-interfering adenovirus (Ad-Klotho) via the tail vein on GD8.5. Ablation of α-Klotho resulted in not only a senescent phenotype and loss of invasiveness in JAR cells but also a reduction in the transcription of cell adhesion molecule (CAM) genes. Overexpression of α-Klotho significantly improved invasion but did not alter the expression of senescence biomarkers. α-Klotho-deficient mice exhibited placental malformation and, consequently, lower placental and fetal weights. In conclusion, AMA results in reduced α-Klotho expression in placental trophoblasts, therefore leading to premature senescence and loss of invasion (possibly through the downregulation of CAMs), both of which ultimately result in placental malformation and adverse perinatal outcomes.
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http://dx.doi.org/10.1111/acel.13417DOI Listing
June 2021

Abundance of solute carrier family 27 member 6 () in the bovine mammary gland alters fatty acid metabolism.

Food Funct 2021 Jun;12(11):4909-4920

Key Laboratory for Animal Genetics, Breeding, Reproduction and Molecular Design of Jiangsu Province, College of Animal Science and Technology, Yangzhou University, Yangzhou, Jiangsu 225009, China. and Joint International Research Laboratory of Agriculture & Agri-Product Safety, Ministry of Education, Yangzhou University, Yangzhou, Jiangsu 225009, China.

Milk fatty acid (FA) composition is associated with the nutritional value of milk and is known to vary with the stage of lactation. Although biochemical aspects controlling FA metabolism in the bovine mammary gland are well-established, less is known about the underlying molecular mechanisms. Thus, to address some of these shortcomings, the present study sought to evaluate milk FA composition and mammary transcriptome profiles at different stages of lactation. Compared with 90 d of lactation, at 315 d of lactation, there was an increase in the concentrations of C18:2, polyunsaturated fatty acids (PUFA), and short-chain fatty acids (SCFA), and a decrease in C16:0 and long-chain fatty acids (LCFA) in milk. To further identify candidate genes and pathways responsible for these phenotypic differences, the transcriptome of bovine mammary tissue at 90 d (peak) and 315 d (late) of lactation was profiled using RNA-seq. A total of 827 differentially expressed genes were identified. Bioinformatic analysis revealed that the major differentially modulated lipid metabolic pathways were the PPAR signaling pathway, alpha-linolenic acid metabolism and linoleic acid metabolism. Compared with peak lactation, the mammary tissue at late lactation had lower abundance of genes related to FA transport and activation (CD36, SLC27A6, ACSM1, FABP3 and FABP4). Thus, to further explore the role of FA transport into mammary cells, we knocked down fatty acid transport protein 6 (solute carrier family 27 member 6, SLC27A6) in the bovine mammary epithelial cells (BMECs) using siRNA. The knockdown of SLC27A6 dramatically downregulated the mRNA abundance of genes associated with FA activation (ACSL4), oxidation (CPT1A) and transport (CD36), while the abundance of genes associated with transcription regulation (PPARG), diacylglycerol acyltransferase 1 (DGAT1), FA binding (FABP3), and desaturation (FADS2) was upregulated. In addition, SLC27A6 silenced the intracellular content of triglyceride (TG) and the percentage of C18:1cis9 and C20:4cis5,8,11,14 was greater, whereas that of C16:0 and C18:0 was lower. Overall, in vivo results indicated that LCFA transport into mammary cells during late lactation partly explains the difference in the FA profiles. In vitro analyses underscored how FA transport via SLC27A6 could dictate in part the intracellular utilization of FA for TG synthesis versus oxidation. The data provide strong support for a central role of SLC27A6 in the regulation of FA metabolism in BMECs.
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http://dx.doi.org/10.1039/d0fo03289aDOI Listing
June 2021

Auricular acupressure for myopia prevention and control in children and its effect on choroid and retina: a randomized controlled trial protocol.

Trials 2021 Jun 7;22(1):387. Epub 2021 Jun 7.

Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China.

Background: Nowadays, because of the increasing incidence, the prevention and control of myopia has become an urgent issue. In China, auricular acupressure has been commonly used in the clinical treatment of myopia in children, but the exact effectiveness remains unproven. The purpose of this trial is to observe the efficacy of auricular acupressure in myopia prevention and control, as well as its effect on the choroidal and retinal thickness.

Method/design: A total of 480 subjects at 8-9 years old will be randomized in a 1:1 ratio to an intervention group versus a control group. The intervention group will receive auricular acupressure for 12 months, while the control group will be taken as a blank control. The primary and secondary outcomes will be measured at baseline, and again at 3, 6, 9, and 12 months after recruitment. The myopia incidence (spherical equivalent ≤ - 0.50 D) and the mean change of spherical equivalent will be taken as the primary variables; the secondary outcome measures include axial length, uncorrected visual acuity, and choroidal and retinal thickness.

Discussion: This trial aims to evaluate the effectiveness of auricular acupressure for myopia prevention and control with objective evidence and to preliminarily explore the plausible mechanism and provide reference for adopting this approach to retard the onset and control the progression of myopia.

Trial Registration: Chinese Clinical Trial Registry ChiCTR2000038456 . Registered on September 23, 2020.
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http://dx.doi.org/10.1186/s13063-021-05334-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8186104PMC
June 2021

The Emerging Role of Thymopoietin-Antisense RNA 1 as Long Noncoding RNA in the Pathogenesis of Human Cancers.

DNA Cell Biol 2021 Jun 4. Epub 2021 Jun 4.

State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.

Long noncoding RNAs (lncRNAs) play essential roles in the occurrence and development of multiple human cancers. An accumulating body of researches have investigated thymopoietin antisense RNA 1 (TMPO-AS1) as a newly discovered lncRNA, which functions as an oncogenic lncRNA that is upregulated in various human malignancies and associated with poor prognosis. Many studies have detected abnormally high expression levels of TMPO-AS1 in multiple cancers, such as lung cancer, breast cancer, colorectal cancer (CRC), hepatocellular carcinoma, CRC, gastric cancer, ovarian cancer, thyroid cancer, esophageal cancer, Wilms tumor, cervical cancer, retinoblastoma, bladder cancer, osteosarcoma, and prostate cancer. TMPO-AS1 has been subsequently demonstrated to play a pivotal role in tumorigenesis and progression. The aberrantly expressed TMPO-AS1 acts as a competing endogenous RNA (ceRNA) that inhibits miRNA expression, thus activating the expression of downstream oncogenes. This study comprehensively summarizes the aberrant expressions of TMPO-AS1 as reported in the current literature and explains the relevant biological regulation mechanisms in carcinogenesis and tumor progression. Corresponding studies have indicated that TMPO-AS1 has a potential value as a promising biomarker or a target for cancer therapy.
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http://dx.doi.org/10.1089/dna.2021.0024DOI Listing
June 2021

Sestrin protects Drosophila midgut from mercury chloride-induced damage by inhibiting oxidative stress and stimulating intestinal regeneration.

Comp Biochem Physiol C Toxicol Pharmacol 2021 Jun 2;248:109083. Epub 2021 Jun 2.

College of Biological Science and Agriculture, Qiannan Normal University for Nationalities, Duyun 558000, China. Electronic address:

Overproduction of the deleterious reactive oxygen species (ROS) is one of the major causes of mercury, a heavy metal with diverse applications and environmental presence, induced neuronal and gastrointestinal adversities in exposed organism including Drosophila melanogaster. Sestrin, an oxidative stress responsive gene, emerges as a novel player in the management of oxidative stress response. Due to limited information regarding the role of sestrin in mercury-induced gastrointestinal adversities, it was hypothesized that modulation of sestrin may improve the mercury-induced gastrointestinal adversities in Drosophila. Here, we fed Drosophila with 400 μM HgCl and found that sestrin transcriptional level was significantly increased in midguts. Sestrin knockdown in HgCl-exposed midguts decreased survival rates and climbing ability of flies, and inhibited superoxide dismutase and glutathione-S-transferase activities of midgut epithelieum. Meanwhile, sestrin knockdown in midgut aggravated the HgCl-induced disruption of intestinal organization by worsening ROS production and cell apoptosis. Immunohistochemical staining data revealed that sestrin knockdown inhibited intestinal stem cell division in HgCl-exposed midguts. Furthermore, JNK signaling was found to mediated sestrin expression in midgut. Taken together, the study demonstrated that sestrin protects Drosophila midgut from HgCl-induced oxidative damage by inhibiting ROS production and stimulating the tissue regeneration program under regulation of JNK signaling pathway. This work suggests therapeutic implications of sestrin against heavy metal-induced gastrointestinal adversities in mammals.
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http://dx.doi.org/10.1016/j.cbpc.2021.109083DOI Listing
June 2021

Experimental and Numerical Studies on the Direct Shear Behavior of Sand-RCA (Recycled Concrete Aggregates) Mixtures with Different Contents of RCA.

Materials (Basel) 2021 May 28;14(11). Epub 2021 May 28.

Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, China.

Recycled concrete aggregate (RCA) is a typical construction and demolition (C&D) material generated in civil engineering activities and has been widely used as the coarse-grained filler added to sand for roadbed fillings. The effect of RCA content on the mechanical behavior of sand-RCA mixtures is complicated and still not fully understood. To explore the effect of RCA content on the macroscale and microscopic behavior of the sand-RCA mixtures with various RCA contents, laboratory direct shear tests and numerical simulations using the 3D discrete element method were performed. Experimental direct shear tests on sand-RCA mixtures with different contents of RCA were first carried out. Numerical direct shear models were then established to represent the experimental results. The particle shape effect was also considered using a new realistic shape modeling method to model the RCA particles. Good agreement was observed between the DEM simulation and experimental results, verifying the ability of the numerical direct shear models to represent the direct shear behavior of sand-RCA mixtures. The macroscopic responses of both experimental and numerical tests showed that all samples presented an initial hardening followed by a post-peak strain softening. The peak-state friction angles increased with the RCA content for samples under the same vertical stress. The effect of RCA content on the microscopic behavior based on DEM simulation was also found. The microscopic properties of RCA-sand mixtures, such as coordination numbers, PDFs and contact force transformation features, were analyzed and related to the macroscopic results.
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http://dx.doi.org/10.3390/ma14112909DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8198910PMC
May 2021

In Situ Growth of Metallic 1T-MoS on TiO Nanotubes with Improved Photocatalytic Performance.

ACS Omega 2021 May 4;6(19):12787-12793. Epub 2021 May 4.

College of Materials and Chemistry, China Jiliang University, Hangzhou 310018, China.

1T-MoS is in situ grown on TiO nanotubes (TNTs) using a hydrothermal method, forming a [email protected] composite, which is confirmed by its physical characterization. The prepared composites show enhanced photocatalytic performance for the degradation of tetracycline hydrochloride under visible light, and the improved photocatalytic activity is closely related to the loaded amount of 1T-MoS. Therein, 0.5 wt % [email protected] can degrade 57% in 1 h, which is the highest photocatalytic efficiency observed in experiments so far. It is speculated that the introduction of 1T-MoS may optimize light absorption and charge separation/transport. The active species are identified and the reaction mechanism is proposed here.
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http://dx.doi.org/10.1021/acsomega.1c01068DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8154240PMC
May 2021

Mental Health Status of the Elderly Chinese Population During COVID-19: An Online Cross-Sectional Study.

Front Psychiatry 2021 12;12:645938. Epub 2021 May 12.

Department of Social Medicine of School of Public Health and Department of Pharmacy of the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.

COVID-19 not only threatened the public's physical health but also brought unbearable psychological pressure, especially for those vulnerable groups like the elderly. However, studies on the psychological status of older adults during this public health emergency remained scant. This study aims to investigate the mental health status among the elderly Chinese population during COVID-19 pandemic and determine the influencing factors of psychological symptoms. From February 19 to March 19, 2020, an online survey was administered to Chinese older adults using a convenience sampling method. Information on demographic data, health status and other epidemic related factors were collected. Specifically, the study defined the psychological status as five primary disorder-depression, neurasthenia, fear, anxiety, and hypochondria-which were assessed by the Psychological Questionnaire for Emergent Event of Public Health (PQEEPH). Standard descriptive statistics and multiple logistic regression analyses were conducted to analyze the data. Of 1,501 participants recruited from 31 provinces in China, 1,278 were valid for further analysis. Participants' scores on each sub-scale were described in median and interquartile [M(Q)]: depression [0.00 (0.33)], neurasthenia [0.00 (0.40)], fear [1.00 (0.83)], anxiety [0.00 (0.17)], hypochondria [0.00 (0.50)]. Chronic diseases (depression = 0.001; neurasthenia < 0.001; fear = 0.023; anxiety < 0.001; hypochondria = 0.001) and the BMI index (depression = 0.015; neurasthenia = 0.046; fear = 0.016; anxiety = 0.015; hypochondria = 0.013) had significant impacts on all of the five sub-scales. Specifically, the rural dwellers had a higher level of neurasthenia, fear, and hypochondria. Besides, education level ( = 0.035) and outbreak risk level ( = 0.004) had significant impacts on the depression. Higher household monthly income per capita ( = 0.031), and the community-level entry/exit control ( = 0.011) are factors against anxiety. Most elderly residents reported mild negative emotions during COVID-19 and more attention should be paid to the recognition and alleviation of fear. Our findings also identified factors associated with the mental health status of the elderly, which is of practical significance in the design and implementation of psychological interventions for this vulnerable population during COVID-19 and future emerging diseases.
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http://dx.doi.org/10.3389/fpsyt.2021.645938DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8149938PMC
May 2021

Leptospirosis with pulmonary haemorrhage and multiple organ failure: a case report and literature review.

J Int Med Res 2021 May;49(5):3000605211019665

Department of Emergency, Jiangxi Provincial People's Hospital Affiliated to Nanchang University, Nanchang, Jiangxi, China.

Pulmonary haemorrhage is an important complication of leptospirosis. We herein report an uncommon case of severe pulmonary haemorrhage and multiple organ failure caused by leptospirosis in a 49-year-old man who was previously healthy. He was a farm worker who was admitted to the hospital because of haemoptysis. He had worked in a paddy field 4 days prior to admission. Chest computed tomography revealed pulmonary haemorrhage, which rapidly deteriorated into haemorrhagic shock and multiple organ failure. Based on the patient's possible history of contact with contaminated water and the DNA sequence of detected in his bronchoalveolar lavage fluid, the patient was diagnosed with pulmonary haemorrhagic leptospirosis. Despite the administration of a fluid bolus, norepinephrine, broad-spectrum antibiotics, and haemostatics, and even with administration of a blood transfusion and extracorporeal life support, the pulmonary haemorrhage could not be controlled effectively. The patient eventually died of haemorrhagic shock. Leptospirosis can be a life-threatening disease despite aggressive treatment, even with extracorporeal life support. Next-generation sequencing can provide important diagnostic clues for patients with atypical leptospirotic symptoms.
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http://dx.doi.org/10.1177/03000605211019665DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8165534PMC
May 2021

[Discussion on the multi-disciplinary dimensional basic problems and methodology systems of macroecosystem science research.]

Ying Yong Sheng Tai Xue Bao 2021 May;32(5):1531-1544

Synthesis Research Center of Chinese Ecosystem Research Network/Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.

The urgent requirement of human society to solve major resource and environmental pro-blems at the regional and global scales promotes the rises of macroecosystem science (MES) and the multidisciplinary fusions of natural science and humanities. Furthermore, it facilitates the innovation of macroecosystem scientific theory, as well as the development of continental and global scale knowledge fusion methodology and key technology. With the aim to serve the construction and deve-lopment of continental and global scale knowledge fusion methodological system for the changes of ecosystem status and resource environmental effect studies, we systematically elaborated the multi-disciplinary dimensional basic scientific problems, logic relationships and frontiers in the macroecosystem science, discussed the ideology and content of constructing the continental and global scale research methodological system, proposed to develop the networked observation-networked experiment-numerical simulation-knowledge fusion four-in-one infrastructures. This study would provide theoretical references for the network design of ecosystem observation research in China and at the global scale.
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http://dx.doi.org/10.13287/j.1001-9332.202105.040DOI Listing
May 2021

[Biodegradation of Polystyrene by ].

Huan Jing Ke Xue 2021 Jun;42(6):3056-3062

College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China.

Biodegradation is the most sustainable treatment method for waste polystyrene (PS). Thermophiles possess highly efficient biotransformation capabilities that could enhance the biodegradation efficiency of organic solid wastes. However, detailed research on the degradation of PS plastics by thermophile is scarce. Here, the degradation performance of a strain of FAFU011 (FAFUA011) isolated from compost was examined. The results showed that strain FAFUA011 could utilize PS as the sole carbon source for growth and formed a stable biofilm on the surface of PS fragments. During 56 days of degradation, FAFU0011 caused a total mass loss of PS of 4.2% and decrease in molecular weight of 17.4%-18.2%. Based on SEM observations, FAFUA011 causes erosion hollows on the surface of PS, thus increasing the type and number of oxygen-containing structures that alter its hydrophilic properties. These changes facilitate the colonization of other microorganisms and further promote biodegradation. Based on 2D-COS analysis, the chronological order of the change in functional groups during the degradation process were identified as follows:1491 cm(C-H) > 1450 cm(C-H) > 1601 cm(C=C) > 1027 cm(C-O) > 1068 cm(C=O) > 1366 cm(C-OH). Overall, these results reveal that FAFU011 could promote the thermophilic bio-oxidative degradation of PS plastic.
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http://dx.doi.org/10.13227/j.hjkx.202009298DOI Listing
June 2021

Mitochondrial DNA leakage induces odontoblast inflammation via the cGAS-STING pathway.

Cell Commun Signal 2021 May 20;19(1):58. Epub 2021 May 20.

The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei- MOST) and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, China.

Background: Mitochondrial DNA (mtDNA) is a vital driver of inflammation when it leaks from damaged mitochondria into the cytosol. mtDNA stress may contribute to cyclic GMP-AMP synthase (cGAS) stimulator of interferon genes (STING) pathway activation in infectious diseases. Odontoblasts are the first cells challenged by cariogenic bacteria and involved in maintenance of the pulp immune and inflammatory responses to dentine-invading pathogens. In this study, we investigated that mtDNA as an important inflammatory driver participated in defending against bacterial invasion via cGAS-STING pathway in odontoblasts.

Methods: The normal tissues, caries tissues and pulpitis tissues were measured by western blotting and immunohistochemical staining. Pulpitis model was built in vitro to evaluated the effect of the cGAS-STING pathway in odontoblast-like cell line (mDPC6T) under inflammation. Western blot and real-time PCR were performed to detect the expression of cGAS-STING pathway and pro-inflammatory cytokines. The mitochondrial function was evaluated reactive oxygen species (ROS) generated by mitochondria using MitoSOX Red dye staining. Cytosolic DNA was assessed by immunofluorescent staining and real-time PCR in mDPC6T cells after LPS stimulation. Furthermore, mDPC6T cells were treated with ethidium bromide (EtBr) to deplete mtDNA or transfected with isolated mtDNA. The expression of cGAS-STING pathway and pro-inflammatory cytokines were measured.

Results: The high expression of cGAS and STING in caries and pulpitis tissues in patients, which was associated with inflammatory progression. The cGAS-STING pathway was activated in inflamed mDPC6T. STING knockdown inhibited the nuclear import of p65 and IRF3 and restricted the secretion of the inflammatory cytokines CXCL10 and IL-6 induced by LPS. LPS caused mitochondrial damage in mDPC6T, which promoted mtDNA leakage into the cytosol. Depletion of mtDNA inhibited the cGAS-STING pathway and nuclear translocation of p65 and IRF3. Moreover, repletion of mtDNA rescued the inflammatory response, which was inhibited by STING knockdown.

Conclusion: Our study systematically identified a novel mechanism of LPS-induced odontoblast inflammation, which involved mtDNA leakage from damaged mitochondria into the cytosol stimulating the cGAS-STING pathway and the inflammatory cytokines IL-6 and CXCL10 secretion. The mtDNA-cGAS-STING axis could be a potent therapeutic target to prevent severe bacterial inflammation in pulpitis. Video Abstract.
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http://dx.doi.org/10.1186/s12964-021-00738-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8136190PMC
May 2021

The long-term observation in Chinese children with monocular myelinated retinal nerve fibers, myopia and amblyopia.

Transl Pediatr 2021 Apr;10(4):860-869

Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China.

Background: The syndrome of monocular myelinated retinal nerve fibers (MRNF), myopia and amblyopia threatens visual development of infants and young children. The efficacy of part-time occlusion therapy remains controversial, and the long-term prognosis of the syndrome remains unclear.

Methods: Ten children (4.40±2.22 years, 4 boys and 6 girls) with monocular MRNF, myopia and amblyopia were recruited. Both the affected eyes (treatment group) and the fellow eyes (control group) underwent routine ophthalmic examinations, including AL, cycloplegic refraction, best-spectacles-corrected distance visual acuity (BSCDVA), cover test, simultaneous perception, corneal curvature, anterior segment and fundus examinations. Refractive error was corrected by either spectacles or rigid gas permeable (RGP) contact lenses. Part-time occlusion therapy was employed for amblyopia treatment. The retinal characteristics were examined only on the final visit with a Fourier-domain optical coherence tomography (FD-OCT). The speed of myopia progression and axial elongation were calculated. Statistical analysis was performed using SPSS 20 software. Cut-off P values were 0.05.

Results: On the final visit, six children had normal simultaneous perception but three had strabismus. The mean AL and spherical equivalent (SE) values of the affected eyes were 28.05±1.59 mm and -12.60±4.20 D, respectively, while those of the fellow eyes were 23.67±1.13 mm and -0.66±1.99 D, respectively. AL and SE were significantly different over time and between groups (P<0.0001), but no time*group interaction effect (P>0.05) was observed. The differences in the corneal curvature, mean speed of myopia progression, axial elongation, foveal thickness and parafoveal thickness between the two groups were not significant (P>0.05). However, the perifoveal thickness in the affected eyes was significantly higher than that of the control eyes (P=0.047). In the treatment group, the occlusion dosage positively correlated with the final BSCDVA (R=0.764, P=0.016) but did not correlate with the speed of myopia progression or axial elongation (both P values >0.05).

Conclusions: The affected eyes have longer AL, severer myopia and thicker perifoveal retina when compared with the fellow eyes. Both the affected and the fellow eyes have similar speed of myopia progression as well as that of axial elongation.
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http://dx.doi.org/10.21037/tp-20-452DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8107855PMC
April 2021

Air superhydrophilic-superoleophobic SiO-based coatings for recoverable oil/water separation mesh with high flux and mechanical stability.

J Colloid Interface Sci 2021 May 5;600:118-126. Epub 2021 May 5.

State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, No. 122, Luoshi Road, Wuhan 430070, PR China.

Due to the inherent differences in surface tension between water and oil, it is a challenge to fabricate air superhydrophilic-superoleophobic materials despite their promising potential in the field of oil/water separation. Herein, a facile approach is developed to fabricate air superhydrophilic-superoleophobic SiO coating by combination of controllable modifying SiO nanoparticle surface by both hydrophilic groups (i.e., -OH groups) and oleophobic groups (i.e., fluorinated groups) with constructing porous and hierarchical structures. Hydroxyl-modified SiO nanoparticles (NPs) are synthesized using a base-catalysed procedure in the presence of ammonia or NaOH. Chitosan quaternary ammonium salt (HACC) is introduced to bind SiO by forming a unique hydrogen bond between HACC and -OH, followed by adding pentadecafluorooctanoic acid (PFOA) to complex with HACC to form fluorinated groups. The SiO coatings are fabricated on various substrates (e.g., glass, foam and Cu mesh) by spraying procedure and characterized using SEM, FTIR, XPS, etc. The contact angles of oils (e.g., pump oil, castor oil, corn oil, hexadecane and bean oil) and water on the coatings are over 150° and close to 0°, respectively. By optimization, the representative SiO-coated Cu mesh displayed high-efficiency of 99.2% in separating water from mixture of water/pump oil, and high penetration flux of 1.41 × 10 L·m ·h. Besides, the coating maintains its superhydrophilic-superoleophobic properties even after 110 cycles of sandpaper abrasion or after being immersed in water for 3 h. After 20 cycles of oil/water separation, the coating retains separation efficiency up to 97.93%. This study provides a new and universal protocol to fabricate unique superwetting surfaces with effective oil/water separation performance, long-term durability and outstanding reusability.
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http://dx.doi.org/10.1016/j.jcis.2021.05.004DOI Listing
May 2021

A novel lncRNA SOX2OT promotes the malignancy of human colorectal cancer by interacting with miR-194-5p/SOX5 axis.

Cell Death Dis 2021 May 15;12(5):499. Epub 2021 May 15.

Department of Nephrology, First Hospital of Jilin University, Jilin, 130021, China.

Long noncoding RNAs (lncRNAs) show emerging roles in colorectal cancer (CRC) development and are considered to be involved in the potential mechanism of tumor malignancy. While Sox2 overlapping transcript (SOX2OT) has been implicated in the progression of multiple cancers, its role in CRC remains to be explored. In this study, in situ hybridization (ISH) and qRT-PCR were performed to establish the functional relationships between SOX2OT and CRC deranged in CRC tissue and cells. Subsequently, SOX2OT shRNAs vectors were transfected into CRC cells to performed loss-of-function assays to detect the potential role of SOX2OT on proliferation and metastasis in vitro and vivo. The results showed SOX2OT was an oncogene that was up-regulated in human CRC tissues and cell lines. SOX2OT silencing suppressed cell proliferation, migration, and invasion in CRC cells in vitro, and inhibited tumorigenesis in the mouse xenografts. Bioinformatic predictive analysis coupled with the dual-luciferase reporter, RNA immunoprecipitation (RIP), and functional rescue assay elucidated the mechanistic network of the SOX2OT-miR-194-5p-SOX5 axis in CRC. Mechanistically, SOX2OT acted as a competing endogenous RNA (ceRNA) to upregulate SOX5 by sponging miR-194-5p. Downregulated SOX2OT boosted miR-194-5p expression, thus decreased the protein level of SOX5, which suppresses tumorgenesis of CRC.
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http://dx.doi.org/10.1038/s41419-021-03756-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8124073PMC
May 2021

Transcriptome analysis of ovary tissues from low- and high-yielding Changshun green-shell laying hens.

BMC Genomics 2021 May 14;22(1):349. Epub 2021 May 14.

College of Animal Sciences, Zhejiang University, 310058, Hangzhou, China.

Background: Changshun green-shell laying hens are unique to Guizhou Province, China, and have high egg quality. Improving egg production performance has become an important breeding task, and in recent years, the development of high-throughput sequencing technology provides a fast and exact method for genetic selection. Therefore, we aimed to use this technology to analyze the differences between the ovarian mRNA transcriptome of low and high-yield Changshun green-shell layer hens, identify critical pathways and candidate genes involved in controlling the egg production rate, and provide basic data for layer breeding.

Results: The egg production rates of the low egg production group (LP) and the high egg production group (HP) were 68.00 ± 5.56 % and 93.67 ± 7.09 %, with significant differences between the groups (p < 0.01). Moreover, the egg weight, shell thickness, strength and layer weight of the LP were significantly greater than those of the HP (p < 0.05). More than 41 million clean reads per sample were obtained, and more than 90 % of the clean reads were mapped to the Gallus gallus genome. Further analysis identified 142 differentially expressed genes (DEGs), and among them, 55 were upregulated and 87 were downregulated in the ovaries. KEGG pathway enrichment analysis identified 9 significantly enriched pathways, with the neuroactive ligand-receptor interaction pathway being the most enriched. GO enrichment analysis indicated that the GO term transmembrane receptor protein tyrosine kinase activity, and the DEGs identified in this GO term, including PRLR, NRP1, IL15, BANK1, NTRK1, CCK, and HGF may be associated with crucial roles in the regulation of egg production.

Conclusions: The above-mentioned DEGs may be relevant for the molecular breeding of Changshun green-shell laying hens. Moreover, enrichment analysis indicated that the neuroactive ligand-receptor interaction pathway and receptor protein tyrosine kinases may play crucial roles in the regulation of ovarian function and egg production.
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http://dx.doi.org/10.1186/s12864-021-07688-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8122536PMC
May 2021

Bimetallic composite induced ultra-stable solid electrolyte interphase for dendrite-free lithium metal anode.

J Colloid Interface Sci 2021 Oct 17;599:819-827. Epub 2021 Apr 17.

School of Materials and Energy, University of Electronic Science and Technology of China (UESTC), Chengdu 611731, PR China. Electronic address:

Lithium metal is the most promising anode materials for the next generation lithium ion battery. However, the electrode polarization leads to the formation of dendrites and "dead lithium", which degrades the performance of lithium metal batteries and induce a variety of security risk. The electrode polarization and lithium dendrites can be suppressed by lithium metal composite electrode. Herein, a simple and effective strategy is adopted to construct nickel and lithium bimetallic composite (NiLi-BC) electrode by a double roll process. The Ni framework inside the electrode can optimize the electric field and Li distribution at the electrode/electrolyte interface and induce the uniform lithium deposition. As a result, the NiLi-BC exhibits a lithium dendrite-free feature and stable cycling performance under a low overpotential (<15 mV throughout 2180 h at 1 mA cm with a deposition capacity of 1 mAh cm). Moreover, the assembled NiLi-BC||LiFePO coin cell and pouch cell exhibit improved capability and stable cycling performance. Finally, the in-situ optical microscopy and in-situ Raman spectroscopy are employed to obtain a better understanding of the interfacial structure and chemical component during the Li plating and striping processes. The scheme of this study of the NiLi electrode has great practical application value.
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http://dx.doi.org/10.1016/j.jcis.2021.04.067DOI Listing
October 2021

Age- and sex-specific reference intervals for blood urea nitrogen in Chinese general population.

Sci Rep 2021 May 12;11(1):10058. Epub 2021 May 12.

Department of Nephrology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China.

Blood urea nitrogen (BUN) is a nitrogenous end product of protein metabolism. This study aims to explore the age- and sex-specific distribution of BUN among healthy Chinese adults. A total of 24,006 BUN values from healthy adults (14,148 males and 9858 females) were included in the cross-sectional study. Males had a higher median BUN value compared to females (4.6 mmol/L vs. 4.1 mmol/L). BUN values showed a positive correlation with body mass index (BMI), cholesterol, and blood sugar (P < 0.0001). However, eGFR showed a negative correlation with the BUN reference value (P < 0.0001) in both sexes. Multiple linear regression analysis confirmed that the positive associations of BUN levels and age were statistically significant after adjusting confounding factors (P < 0.001). Thus, the serum BUN values increased by 0.21 mmol/L for males and 0.282 mmol/L for females per 10 years. The BUN values corresponding to the 1st, 2.5th, 50th, 97.5th, and 99th percentiles for any specific age in both sex were also calculated. These results indicate that the serum BUN reference value is significantly affected by age and gender, and thus, its interpretation is age- and sex-dependent.
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http://dx.doi.org/10.1038/s41598-021-89565-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8115101PMC
May 2021

Ocular Anatomical and Functional Characteristics in Anisometropic Chinese Children.

Optom Vis Sci 2021 05;98(5):476-482

Department of Computer Science and Engineering, Southern University of Science and Technology, Shenzhen, China.

Significance: This research found that anterior and posterior biometrics differ in many aspects between fellow eyes of anisometropic children. This might shed light on the mechanisms underlying the onset and progression of anisometropia and myopia.

Purpose: This study aimed to investigate the ocular biometric parameters, peripheral refraction, and accommodative lag of fellow eyes in anisometropic children.

Methods: Anisometropic children were recruited. Axial length (AL), vitreous chamber depth (VCD), central corneal thickness, anterior chamber depth (ACD), lens thickness (LT), simulated K readings, central and peripheral refractive errors, and accommodative lag were measured in both eyes. The subfoveal choroidal thickness, average choroidal thickness, and choroid vessel density of the 6 × 6-mm macular area were measured by optical coherence tomography.

Results: Thirty-two children aged 11.1 ± 1.7 years were enrolled. The average degree of anisometropia was 2.49 ± 0.88 D. The AL, VCD, ACD, and simulated K reading values were significantly larger in the more myopic eyes, whereas the LT value was significantly smaller. Subfoveal choroidal thickness (P = .001) and average choroidal thickness (P = .02) were smaller in the more myopic eyes than in the contralateral eyes, whereas choroid vessel density (P = .03) was larger. The amount of anisometropia had a significant positive correlation with the difference in AL (r = 0.869, P < .001), VCD (r = 0.853, P < .001), and ACD (r = 0.591, P < .001) and a negative correlation with the difference in LT (r = -0.457, P = .009).

Conclusions: Ocular biometrics differ in many aspects between the fellow eyes of anisometropic Chinese children, and the difference is correlated with the degree of anisometropia.
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http://dx.doi.org/10.1097/OPX.0000000000001692DOI Listing
May 2021

[Expression and characterization of a novel halohydrin dehalogenase from Rhodospirillaceae bacterium].

Sheng Wu Gong Cheng Xue Bao 2021 Apr;37(4):1298-1311

School of Biotechnology, East China University of Science and Technology, Shanghai 200237, China.

As a class of multifunctional biocatalysts, halohydrin dehalogenases are of great interest for the synthesis of chiral β-substituted alcohols and epoxides. There are less than 40 halohydrin dehalogenases with relatively clear catalytic functions, and most of them do not meet the requirements of scientific research and practical applications. Therefore, it is of great significance to excavate and identify more halohydrin dehalogenases. In the present study, a putative halohydrin dehalogenase (HHDH-Ra) from Rhodospirillaceae bacterium was expressed and its enzymatic properties were investigated. The HHDH-Ra gene was cloned into the expression host Escherichia coli BL21(DE3) and the target protein was shown to be soluble. Substrate specificity studies showed that HHDH-Ra possesses excellent specificity for 1,3-dichloro-2-propanol (1,3-DCP) and ethyl-4-chloro-3-hydroxybutyrate (CHBE). The optimum pH and temperature for HHDH-Ra with 1,3-DCP as the reaction substrate were 8.0 and 30 °C, respectively. HHDH-Ra was stable at pH 6.0-8.0 and maintained about 70% of its original activity after 100 h of treatment. The thermal stability results revealed that HHDH-Ra has a half-life of 60 h at 30 °C and 40 °C. When the temperature is increased to 50 °C, the enzyme still has a half-life of 20 h, which is much higher than that of the reported enzymes. To sum up, the novel halohydrin dehalogenase from Rhodospirillaceae bacterium possesses good temperature and pH stability as well as catalytic activity, and shows the potential to be used in the synthesis of chemical and pharmaceutical intermediates.
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http://dx.doi.org/10.13345/j.cjb.200719DOI Listing
April 2021

The effect of microstructure on mechanical properties of corn cob.

Micron 2021 Jul 20;146:103070. Epub 2021 Apr 20.

Key Laboratory of Bionic Engineering, Ministry of Education, Jilin University, Changchun, 130025, China; College of Biological and Agricultural Engineering, Jilin University, Changchun, 130025, China.

As a natural biomass resource, corn cob has excellent mechanical properties and a special layered structure. To investigate the relationship between the mechanical properties and microstructure of corn cob, the ultra-deep field 3D microscope was used to characterize the macro geometric parameters, and the scanning electron microscopy (SEM) was observe the microstructure of the corn cob. The Fourier transform infrared spectrometer was used to analyze the fiber composition, revealing the contribution of fiber composition to the mechanical properties. Axial compression, radial compression, and three-point bending tests were performed on corn cob using a universal testing machine. Moreover, an impact testing machine was used for impact tests. The results show that a corn cob is structurally divided into the pith, woody ring, and glume, mainly composed of cellulose, hemicellulose, and lignin in fiber composition, respectively. The pith is a porous sponge-like tissue that has a greater bearing capacity while maintaining a low density. It is also a progressively hardening material with good buffering properties under impact loads. The woody ring is the primary source of mechanical strength, whose microstructure is a hollow tubular structure composed of cellulose and bonded by lignin. The internal microstructure of the glume is also porous and spongy, but the mechanical properties are mainly manifested in its macrostructure. The results of this study may provide a reference for the subsequent processing and industrial application of corn cob, and the unique structure of corn cob is also an excellent bionic prototype for lightweight design.
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http://dx.doi.org/10.1016/j.micron.2021.103070DOI Listing
July 2021

[CT and Magnetic Resonance Imaging Findings of the Intracranial Extra-cerebral Chondroma:A Case Report].

Zhongguo Yi Xue Ke Xue Yuan Xue Bao 2021 Apr;43(2):300-304

Department of Radiology,Hainan Hospital of Chinese PLA General Hospital,Sanya,Hainan 572013,China.

Intracranial intradural chondroma is a rare disorder,the imaging findings of which have been rarely reported.The current study reported a case of intracranial extra-cerebral chondroma and described the detailed CT and magnetic resonance imaging findings,which would provide valuable imaging evidence for the diagnosis of intracranial extra-cerebral chondroma.
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http://dx.doi.org/10.3881/j.issn.1000-503X.12506DOI Listing
April 2021

Switching the secondary and natural activity of Nitrilase from Acidovorax facilis 72 W for the efficient production of 2-picolinamide.

Biotechnol Lett 2021 May 7. Epub 2021 May 7.

State Key Laboratory of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, Shanghai, 200237, People's Republic of China.

Objectives: Catalytic promiscuity, or the ability to catalyze a secondary reaction, provides new opportunities for industrial biocatalysis by expanding the range of biocatalytic reactions. Some nitrilases converting nitriles to amides, referred to as the secondary activity, show great potential for amides production. And our goal was exploiting the amide-forming potential of nitrilases.

Results: In this study, we characterized and altered the secondary activity of nitrilase from Acidovorax facilis 72 W (Nit72W) towards different substrates. We increased the secondary activity of Nit72W towards 2-cyanopyridine by 196-fold and created activity toward benzonitrile and p-nitrophenylacetonitrile by modifying the active pocket. Surprisingly, the best mutant, W188M, completely converted 250 mM 2-cyanopyridine to more than 98% 2-picolinamide in 12 h with a specific activity of 90 U/mg and showed potential for industrial applications.

Conclusions: Nit72W was modified to increase its secondary activity for the amides production, especially 2-picolinamide.
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http://dx.doi.org/10.1007/s10529-021-03137-7DOI Listing
May 2021

Effect of biomass and insecticidal activity by cultivation with vegetable wastes.

R Soc Open Sci 2021 Mar 24;8(3):201564. Epub 2021 Mar 24.

College of Resources and Environmental Sciences, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, People's Republic of China.

(Bt) has been regarded as a biopesticide with high efficiency and safety, while it still cannot be popularized and mass-produced because of its high production costs. In the present study, we aimed to develop a cost-effective biopesticide via the secondary use of discharged vegetable wastes as the raw fermentation medium, and the insecticidal activity of Bt strain prepared by this cheap cultivation approach was evaluated. The suitable carbon source, nitrogen source additives and optimal metal ions were screened by the single-factor test, and the optimal combination of additives was determined by orthogonal test and ANOVA analysis. We found that soluble starch (6 g l), soya bean meal (6 g l), Al (0.4 g l) and Fe (0.4 g l) were the optimal exogenous additives, and the optimal fermentation conditions were as follows: pH 7.0, temperature of 35°C and aeration of 80 ml/250 ml. Meanwhile, the bioactivity test results showed that the Bt strain prepared by cheap cultivation still exhibited a good insecticidal effect on compared with the standard LB medium. Collectively, our findings provided a new strategy for vegetable waste utilization with less environmental impact and reduced production cost.
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http://dx.doi.org/10.1098/rsos.201564DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8074981PMC
March 2021