Publications by authors named "H Henry Li"

72,296 Publications

Aquaculture drug degradation in persulfate by PANI-based microparticles controlled via ultrasonic field: Forced motion of "burning hot micromotors".

Chemosphere 2021 Feb 23;275:130098. Epub 2021 Feb 23.

School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, 264209, China.

The triphenylmethane derivative malachite green (tpm) despite repeated prohibitions but is frequently detected in aquatic environment and draws emerging attention because of the potential poisonous effects. The polyaniline/persulfate with ultrasound catalysis (US/PANI-PS) was developed for tpm removal. The effects of 12 factors and the optimization by response surface methodology (RSM) for tpm removal were evaluated based on the pseudo-first-kinetics (k). From free radical inhibition, the ratios of active species in US/PANI-PS (δ = 0.355, δ = 0.593) were close to that in US-PS (δ = 0.346, δ = 0.586) and different to that in PANI-PS and PS systems. A possible degradation pathway (hydroxylation, N-demethylation, deamination, and open-benzene ring) was explored by gas chromatography-mass spectrometer (GC/MS) and high performance liquid chromatography-mass spectrometer (HPLC-MS). The designed reactor involving the US-driven PANI was simulated by acoustic-piezoelectric interaction. From cavitation calculations, the estimated effective-mean temperature at bubble-water interface had little increasing (from 704 K to 711 K) after adding the PANI, however, the adsorption capacity of tpm in reactive zone decreased from 0.0891 μM to 0.0787 μM. The mechanism (PANI hot turbo-micromotors) with US/PANI-PS was proposed. The tpm was removed with a low treatment cost of 2.81 $⋅m (the EE/O value 18.29 kWh⋅m) by US/PANI-PS, presenting a cost-effective treating process. The reusability tests and characterizations (contact angle, X-ray diffraction (XRD), and scanning electron microscope (SEM)) further confirmed the stability of PANI.
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http://dx.doi.org/10.1016/j.chemosphere.2021.130098DOI Listing
February 2021

Prevalence and factors associated with anxiety and depressive symptoms among patients hospitalized with hematological malignancies after chimeric antigen receptor T-cell (CAR-T) therapy: A cross-sectional study.

J Affect Disord 2021 Feb 18;286:33-39. Epub 2021 Feb 18.

Xuzhou Medical University, Jiangsu, China. Electronic address:

Background: We conducted a survey to investigate the prevalence and factors associated with anxiety and depressive symptoms among patients hospitalized with hematological malignancies after chimeric antigen receptor T-cell (CAR-T) therapy.

Methods: In total, 130 eligible patients completed the Self-Rating Anxiety Scale and Self-Rating Depression Scale at week 4 after CAR-T cell infusion. We collected sociodemographic information during the same period. We studied factors associated with anxiety and depressive symptoms using logistic regression analysis.

Results: The prevalence of anxiety and depressive symptoms at week 4 after infusion were 13.8% and 40.0%, respectively. A cutoff value of 50 or above indicates significantly anxiety and depressive symptoms. Binary logistic regression analysis showed that high school education and above (OR = 0.22, 95% CI = 0.06-0.78) and middle age (OR = 0.16, 95% CI = 0.03-0.90) were associated with lower risk of anxiety symptoms, and increased odds of depressive symptoms was associated with old age (OR = 11.39, 95% CI = 2.50-51.88), non-manual occupations before illness (OR = 3.72, 95% CI = 1.20-11.58), and higher healthcare expenditure (OR = 3.93, 95% CI = 1.50-10.33), while lower risk of depressive symptoms was associated with rural household location (OR = 0.25, 95% CI = 0.08-0.76) and being cared for by spouse (OR = 0.12, 95% CI = 0.02-0.63).

Conclusions: Patients receiving CAR-T therapy with lower education background, old ages, urban household location, or who used to work as non-manual workers require more attention and psychological care. Support from a spouse and medical expense deductions from the government may help patients develop positive attitudes.
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http://dx.doi.org/10.1016/j.jad.2021.02.041DOI Listing
February 2021

Effects of polycyclic aromatic hydrocarbons and multiple metals co-exposure on the mosaic loss of chromosome Y in peripheral blood.

J Hazard Mater 2021 Feb 24;414:125519. Epub 2021 Feb 24.

Department of Occupational and Environmental Health, State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China. Electronic address:

Mosaic loss of chromosome Y (mLOY) is an indicator of genome instability, but the environmental stressors of mLOY remained largely unknown. In this study, we detected the internal exposure levels of 11 polycyclic aromatic hydrocarbon (PAH) metabolites and 22 metals among 888 coke-oven workers, and calculated their blood mLOY based on genome-wide SNP genotyping data and presented as median log R ratio (mLRR-Y). The generalized linear model (GLM), LASSO, and Bayesian kernel machine regression (BKMR), were used to select mLOY-relevant chemicals. The results of these models consistently suggested the negative dose-response relationships of urinary 1-hydroxynaphthalene (1-OHNa), antimony (Sb), and molybdenum (Mo) with mLRR-Y. There were no pairwise interactions between these three chemicals (P > 0.05), but subjects with high exposure to ≥ 2 kinds of these chemicals showed reducing mLRR-Y [β(95%CI) = - 0.015(- 0.023, - 0.008)], increasing oxidative DNA damage (marked by 8-hydroxydeoxyguanosine) [β(95%CI) = 0.625(0.454, 0.796)] and chromosome damage (marked by micronucleus frequency in lymphocytes) [frequency ratio (FR) and 95%CI = 1.146(1.047, 1.225)] than those with low exposure to all these chemicals. The combined effects of 1-OHNa, Sb, and Mo on elevating DNA damage may partly explain their joint effects on increased blood mLOY. These results provided a new insight into environmental hazards co-exposure on chromosome-Y deletions.
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http://dx.doi.org/10.1016/j.jhazmat.2021.125519DOI Listing
February 2021

Comparative toxicity of multiple exposure routes of pyraclostrobin in adult zebrafish (Danio rerio).

Sci Total Environ 2021 Feb 27;777:145957. Epub 2021 Feb 27.

Key Laboratory of Pesticide Toxicology & Application Technique, Shandong Agricultural University, Tai'an, Shandong 271018, PR China; College of Plant Protection, Shandong Agricultural University, Tai'an, Shandong 271018, PR China; Research Center of Pesticide Environmental Toxicology, Shandong Agricultural University, Tai'an, Shandong 271018, PR China. Electronic address:

Pyraclostrobin, one of the most widely used fungicides globally, is highly toxic to aquatic organisms, which restricts its application in paddy fields. Most studies have focused on the molecular mechanism of pyraclostrobin toxicity; however, the exposure routes and target organs of pyraclostrobin in fish are poorly known. Here, we found that the lethal effects of aquatic exposure, head immersion, trunk immersion and oral exposure on the toxicity and accumulation of pyraclostrobin in adult zebrafish were different. The major pathway leading to pyraclostrobin accumulation, followed by high hazard to fish, was crossing over the gill rather than the intestine or skin. Additionally, serious histological abnormalities, mitochondrial dysfunction, energy deficiency and respiratory impairment occurred in the gills, while no overt change was observed in the heart and brain at the organic and cellular levels. This result suggested that the gill is the dominant portal and target organ of pyraclostrobin in fish, a fact that has been further verified by intravenous injection. The differences in the toxicity and translocation factor of crystalline and dissolved pyraclostrobin in fish demonstrated that reducing the concentration in the branchial environment is a vital direction for the future design of an effective toxicity regulation strategy to protect key sites from pyraclostrobin attack.
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http://dx.doi.org/10.1016/j.scitotenv.2021.145957DOI Listing
February 2021

Integrated omics and bioinformatics analyses for the toxic mechanism and material basis of Sophorae Tonkinensis radix et rhizome-induced hepatotoxicity.

J Pharm Biomed Anal 2021 Feb 26;198:113994. Epub 2021 Feb 26.

College of Pharmacy, Guizhou University of Traditional Chinese Medicine, Guian New Area, 550025, PR China. Electronic address:

In traditional Chinese medicine theory, Sophorae Tonkinensis radix et rhizome (ST) has the effects of treating tonsillitis, sore throats, and heat-evil-induced diseases. However, the utilization of ST is relatively restricted owing to its toxicity. The previous studies have made some progress on the mechanism and material basis of ST-induced hepatotoxicity, but there is still no significant breakthrough. In this study, integrated omics and bioinformatics analyses were used to investigate the mechanism and material basis of ST-induced hepatotoxicity. Integrated omics were used to analyze the differentially expressed proteins and metabolites, based on which the significantly dysregulated pathways were analyzed by using MetaboAnalyst. Bioinformatics was applied to screen the toxic targets and material basis. Integrated omics revealed that 254 proteins and 42 metabolites were differentially expressed after the treatment with ST, out of which 7 proteins were significantly enriched in 3 pathways. Bioinformatics showed that 20 compounds may interfere with the expression of 7 toxic targets of ST. Multiple toxic targets of ST-induced hepatotoxicity were found in the study, whose dysregulation may trigger hepatocyte necrosis/apoptosis, liver metastasis, and liver cirrhosis. Multiple compounds may be the toxic material basis in response to these effects.
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http://dx.doi.org/10.1016/j.jpba.2021.113994DOI Listing
February 2021

Computerized spermatogenesis staging (CSS) of mouse testis sections via quantitative histomorphological analysis.

Med Image Anal 2020 Oct 10;70:101835. Epub 2020 Oct 10.

State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 211166, China; Department of Neurology, Center for Reproductive Sciences, Northwestern University Feinberg School of Medicine, IL 60611, USA. Electronic address:

Spermatogenesis in mammals is a cyclic process of spermatogenic cell development in the seminiferous epithelium that can be subdivided into 12 subsequent stages. Histological staging analysis of testis sections, specifically of seminiferous tubule cross-sections, is the only effective method to evaluate the quality of the spermatogenic process and to determine developmental defects leading to infertility. Such staging analysis, however, is tedious and time-consuming, and it may take a long time to become proficient. We now have developed a Computerized Staging system of Spermatogenesis (CSS) for mouse testis sections through learning of an expert with decades of experience in mouse testis staging. The development of the CSS system comprised three major parts: 1) Developing computational image analysis models for mouse testis sections; 2) Automated classification of each seminiferous tubule cross-section into three stage groups: Early Stages (ES: stages I-V), Middle Stages (MS: stages VI-VIII), and Late Stages (LS: stages IV-XII); 3) Automated classification of MS into distinct stages VI, VII-mVIII, and late VIII based on newly developed histomorphological features. A cohort of 40 H&E stained normal mouse testis sections was built according to three modules where 28 cross-sections were leveraged for developing tubule region segmentation, spermatogenic cells types and multi-concentric-layers segmentation models. The rest of 12 testis cross-sections, approximately 2314 tubules whose stages were manually annotated by two expert testis histologists, served as the basis for developing the CSS system. The CSS system's accuracy of mean and standard deviation (MSD) in identifying ES, MS, and LS were 0.93 ± 0.03, 0.94 ± 0.11, and 0.89 ± 0.05 and 0.85 ± 0.12, 0.88 ± 0.07, and 0.96 ± 0.04 for one with 5 years of experience, respectively. The CSS system's accuracy of MSD in identifying stages VI, VII-mVIII, and late VIII are 0.74 ± 0.03, 0.85 ± 0.04, and 0.78 ± 0.06 and 0.34 ± 0.18, 0.78 ± 0.16, and 0.44 ± 0.25 for one with 5 years of experience, respectively. In terms of time it takes to collect these data, it takes on average 3 hours for a histologist and 1.87 hours for the CSS system to finish evaluating an entire testis section (computed with a PC (I7-6800k 4.0 GHzwith 32GB of RAM & 256G SSD) and a Titan 1080Ti GPU). Therefore, the CSS system is more accurate and faster compared to a human histologist in staging, and further optimization and development will not only lead to a complete staging of all 12 stages of mouse spermatogenesis but also could aid in the future diagnosis of human infertility. Moreover, the top-ranking histomorphological features identified by the CSS classifier are consistent with the primary features used by histologists in discriminating stages VI, VII-mVIII, and late VIII.
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http://dx.doi.org/10.1016/j.media.2020.101835DOI Listing
October 2020

SATB2 overexpression promotes oral squamous cell carcinoma progression by up-regulating NOX4.

Cell Signal 2021 Mar 3:109968. Epub 2021 Mar 3.

Jiangsu Key Laboratory of Oral Disease,Nanjing Medical University, Nanjing 210029,China; Depatment of Oral and Maxillofacial Surgery, The Affiliated Stomatological Hospital of Nanjing Medical University, Nanjing 210029, China. Electronic address:

While atypical expression of special AT-rich sequence-binding protein 2 (SATB2) has been approved associated with tumor progression, metastasis and unfavourable prognosis in various carcinomas. However, in oral squamous cell carcinoma (OSCC), both the expressive state and associated functions of SATB2's are still undefined. Here we show that, in clinical samples from a retrospective cohort of 58 OSCC patients, high expression of SATB2 is associated with poor prognosis of OSCC patients. In this study, we investigated SATB2 is highly expressed in OSCC tissues and cell lines, which can promote OSCC cells' proliferation, migration, invasion and tumor growth. According to sequencing results based on previous literature, we identified NOX4 is a bona fide downstream target of SATB2, when it was knockdown, OSCC's proliferation can be partially suppressed. Furthermore, NOX4 knockdown inhibits tumorigenicity, which can be rescued partially by ectopic expression of SATB2 in HNSCC cell line, and vice versa. Collectively, our findings not only indicate overexpression of SATB2 triggers the proliferative, migratory and invasive mechanisms which are important in the malignant phenotype of OSCC, but also identify NOX4 as the downstream gene for SATB2. These findings indicate that SATB2 may play a key role in OSCC tumorigenicity and may be a future target for the development of new therapeutic regimens.
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http://dx.doi.org/10.1016/j.cellsig.2021.109968DOI Listing
March 2021

New limonoids and quinolone alkaloids with cytotoxic and anti-platelet aggregation activities from Evodia rutaecarpa (Juss.) Benth.

Fitoterapia 2021 Mar 3:104875. Epub 2021 Mar 3.

School of Medicine, Kunming University, Kunming, PR China. Electronic address:

One new limonoid, named 19-hydroxy methyl isoobacunoate diosphenol (1); one new degraded limonoid, named 9α-methoxyl dictamdiol (9); two new quinolone alkaloids, 1-methyl-3-[(7E,9E,12Z)-7,9,12-pentadecadienyl]-4(1H)-quinolone (11) and 1-methyl-3-[(7E,9E,11E)-7,9,11-pentadecadienyl]-4(1H)-quinolone (12), along with eight known compounds, evodol (2), 7β-acetoxy-5-epilimonin (3), rutaevine (4), 6β-acetoxy-5-epilimonin (5), limonin (6), obacunone (7), clauemargine L (8), hiiranlactone E (10) were isolated from the fruits of Evodia rutaecarpa (Juss.) Benth.. Structures of the four new compounds were elucidated on the basis of extensive spectroscopic techniques, including 1D and 2D NMR techniques. Compounds 3, 5, 9, 11 and 12 showed obviously cytotoxic activity against six human tumor lines, while compounds 11, 12 displayed anti-platelet aggregation induced by ADP at 50 μM and 100 μM.
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http://dx.doi.org/10.1016/j.fitote.2021.104875DOI Listing
March 2021

LncRNA DLEU2 promotes cervical cancer cell proliferation by regulating cell cycle and NOTCH pathway.

Exp Cell Res 2021 Mar 3:112551. Epub 2021 Mar 3.

Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing, China. Electronic address:

Long noncoding RNAs (lncRNAs) are known to play a crucial role in the onset and progression of cervical cancer (CC). Here, the results of RNA microarray and RNA-sequencing dataset analysis showed that lncRNA DLEU2 was significantly upregulated in CC tissues. Clinicopathologic analysis indicated that lncRNA DLEU2 was closely related to tumor topography. Functional experiments and bioinformatics analysis revealed that lncRNA DLEU2 promoted CC cell proliferation and accelerated the cell cycle. Mechanistically, lncRNA DLEU2 promoted the progression of the cell cycle and inhibited the activity of the Notch signaling pathway by inhibiting p53 expression. Additionally, lncRNA DLEU2 probably interacted with ZFP36 Ring Finger Protein (ZFP36) to inhibit the expression of p53. In conclusion, this study revealed the function of lncRNA DLEU2 in CC tumorigenesis, suggesting new therapeutic targets in CC.
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http://dx.doi.org/10.1016/j.yexcr.2021.112551DOI Listing
March 2021

Cucurbitacin B exhibits antitumor effects on CD133+ HepG2 liver cancer stem cells by inhibiting JAK2/STAT3 signaling pathway.

Anticancer Drugs 2021 Mar 5. Epub 2021 Mar 5.

Department of Cancer, Hospital of Chengdu University of Traditional Chinese Medicine Clinical School of Medicine, Chengdu University of Traditional Chinese Medicine Basic School of Medicine, Southwest Jiaotong University College of Pharmacy, Chengdu Medical College Cancer Center, The General Hospital of Western Theater Command, Chengdu, China.

Cancer stem cells (CSCs), a crucial cancer cell subpopulation, possess stemness phenotypic characteristics. Cucurbitacin B (CuB), a tetracyclic triterpenoid isolated from Cucurbitaceae, exerts widely pharmacological activities in many diseases. The aim of this study was to enrich, identify liver CSCs and investigate antitumor effects of CuB as well as explore the underlying molecular mechanisms in these liver CSCs. HepG2 cell lines were used for the enrichment of liver CSCs by serum-free medium culture and magnetic-activated cell sorting. The CSC characteristics were analyzed by immunofluorescent staining, sphere-forming, western blot and xenograft tumorigenicity assay. CuB' antitumor effects and underlying molecular mechanism were measured by cell counting kit-8, colony formation, sphere-forming, cell cycle, xenograft and western blot assay. Our results showed that we could enrich 97.29% CD133+ HepG2 cells, which possessed CSC characteristics including re-renewal capacity, proliferative ability, sorafenib resistance, overexpressed stemness-related molecules and enhanced tumorigenic potential. Furthermore, we also found that CuB inhibited cell viability, sphere formation, colony formation and arrested cell cycle at G2/M phase as well as sensitized CD133+ HepG2 cells to sorafenib in vitro and in vivo. Western blot assay indicated that CuB inhibited expression levels of cyclin B1, CDK1, CD133, p-JAK2 and p-STAT3. In conclusion, our findings indicated that CuB could exhibit antitumor effects on CD133+ HepG2 CSCs by inhibiting the Janus kinase 2/signal transducers and activators of transcription-3 signaling pathway, expanding basic and preclinical investigations on liver CSCs.
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http://dx.doi.org/10.1097/CAD.0000000000001062DOI Listing
March 2021

Giant calcified pseudoplasm of the nerve axis of the temporal lobe: a case report and review of the literature.

Acta Neurol Belg 2021 Mar 6. Epub 2021 Mar 6.

Department of Neurosurgery, West China Hospital, Sichuan University, 37 Guo Xue Xiang, Wu Hou District, Chengdu, 610041, Sichuan, People's Republic of China.

Calcifying pseudoneoplasms of the neuraxis (CAPNONs) are rare and can occur along the neural axis. The pathogenesis of these masses is still unknown, and they are diagnosed by histopathological analysis. We report the largest CAPNON in the temporal lobe reported to date and a review of the literature on all previously reported CAPNON cases located in the temporal lobe. According to the literature review, prior to 2020, the largest CAPNON in the temporal lobe that had ever been reported measured 30 × 30 × 20 mm (Mohapatra et al.). However, we report a larger temporal lobe CAPNON (45 × 35 × 35 mm) in a female patient admitted to our hospital. In addition, among 22 patients with CAPNONs aged from 6 to 62 years, 45.5% were female and 54.5% were male. A total of 72.8% of patients presented with seizures, 9.1% had pituitary dysfunction and 9.1% did not have symptoms. Of the cases in the patients with seizures, 83.2% were completely surgically resected, 5.6% were partially surgically resected, and one was treated medically; one patient refused treatment. Except for one patient who had multiple lesions, all patients who underwent surgery exhibited improved or the disappearance of symptoms of epilepsy. The patient in whom epilepsy resolved had undergone total resection. CAPNON is a rare benign lesion that occurs throughout the nervous system, and the pathogenesis remains unclear. Although the hardness of these lesions vary, surgery is still the preferred treatment and yields good results, and total resection is recommended for patients with epilepsy in the temporal lobe.
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http://dx.doi.org/10.1007/s13760-021-01641-1DOI Listing
March 2021

Phytochelatins formation kinetics and Cd-induced growth inhibition in Lolium perenne L. at elevated CO level under Cd stress.

Environ Sci Pollut Res Int 2021 Mar 6. Epub 2021 Mar 6.

Rural Energy & Environment Agency, Ministry of Agriculture and Rural Affairs, P.R.C., Beijing, 100125, China.

Elevated CO levels may alleviate toxicities induced by environmental stresses in plants, such as heavy metals. To assess this possibility, seedlings of Lolium perenne L. were exposed to different Cd stress and CO levels during hydroponic culture. The kinetics of growth, Cd accumulation, and thiol formation were investigated. Elevated CO levels increased the growth rate from 30 to 75%, and decreased the Cd accumulation rate from 36 to 42%, leading to a decrease of Cd content in root and shoot. However, an increase in Cd transport from root to shoot was observed at elevated CO under Cd stress. The production of phytochelatins (PCs) occurred earlier at elevated CO level than at ambient CO level after exposure to Cd stress. The mean SH/Cd ratio was relatively higher at elevated CO level, but elevated CO level significantly decreased thiol contents. The reduction of Cd contents, earlier production of PCs, and relatively higher SH/Cd ratio at the elevated CO level alleviated Cd toxicity in root and shoot to some extent, causing significant yield increase of L. perenne after exposure to Cd stress. This study could provide an important data support and theoretical basis in understanding the effects of elevated CO on plant growth, heavy metal accumulation, and thiol formation.
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http://dx.doi.org/10.1007/s11356-021-12883-0DOI Listing
March 2021

Outcomes of arteriovenous fistula in elderly patients on maintenance haemodialysis.

Int Urol Nephrol 2021 Mar 6. Epub 2021 Mar 6.

Department of Renal Medicine, Singapore General Hospital, Singapore, Singapore.

Background: The optimal vascular access strategy in elderly patients receiving haemodialysis (HD) remains controversial. We aim to report the outcomes of arteriovenous fistula (AVF) in elderly patients initiated on maintenance HD in our centre.

Methods: Medical records of 688 incident patients initiated on HD from 2010 to 2012 in a tertiary centre were retrospectively reviewed. Patients' characteristics and AVF outcomes were compared among those < 65 years (non-elderly), ≥ 65-75 years (early elderly) and ≥ 75 years (late elderly).

Results: There were 418 non-elderly, 184 early elderly and 86 late elderly patients. There is a higher proportion of brachiocephalic and brachiobasilic fistula created in the late elderly (24.9% vs. 37.0% vs. 41.8%, p = 0.001). The outcomes of accesses created were comparable in the 3 age groups with similar proportions of functional AVFs (80.4% vs. 79.3% vs. 75.6%, p = 0.832) and comparable 1-, 3- and 5-year primary and secondary patency rates (p = 0.351 and 0.282, respectively). However, a longer maturation time (2.78 vs. 2.86 vs. 3.72 months, p = 0.010) and a higher mean number of interventions to assist maturation of the first AVF were required in late elderly patients (0.19 vs. 0.22 vs. 0.35, p = 0.014). Following AVF creation, median patient survival in the non-elderly, early and late elderly was 65.2 vs. 55.1 vs. 49.8 months respectively.

Conclusion: AVFs created in elderly patients have comparable outcomes compared to non-elderly patients although more interventions are required to assist maturation with a longer maturation time necessitating early access creation to allow for time needed due to maturation delay.
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http://dx.doi.org/10.1007/s11255-021-02822-wDOI Listing
March 2021

Clostridium butyricum Supernatant Regulates the Expression of RORγt in HCT-116 Cells by Inhibiting the TLR2/MyD88/NF-κB Signaling Pathway.

Curr Microbiol 2021 Mar 6. Epub 2021 Mar 6.

Department of Gastroenterology, Shengjing Hospital of China Medical University, No. 36 Sanhao Street, Shenyang, 110004, Liaoning, China.

In this study, we treated HCT-116 cells with Clostridium butyricum (C. butyricum) supernatant and observed its effects on the TLR2/MyD88/NF-κB signaling pathway and RORγt, to further explore the possible immune regulatory mechanism of C. butyricum. Our results showed that C. butyricum supernatant downregulated the mRNA and protein levels of TLR2, MyD88, NF-κBp65, and RORγt in HCT-116 cells and the protein levels of phospho-NF-κBp65. Partial blockage of TLR2 by CD282 weakened the inhibitory effects of C. butyricum supernatant on the above pathway components. Those component levels were still inhibited by C. butyricum supernatant after Pam3CSK4 activation of TLR2. In summary, C. butyricum supernatant can inhibit the TLR2/MyD88/NF-κB signaling pathway and the expression of RORγt in HCT-116 cells. These effects are at least partly achieved through inhibition of TLR2.
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http://dx.doi.org/10.1007/s00284-021-02392-1DOI Listing
March 2021

Chiral voltammetric sensor for tryptophan enantiomers by using a self-assembled multiwalled carbon nanotubes/polyaniline/sodium alginate composite.

Chirality 2021 Mar 6. Epub 2021 Mar 6.

College of Petrochemical Technology, Lanzhou University of Technology, Lanzhou, China.

Due to the crucial role of amino acids in life sciences and pharmaceutics, identification of optical amino acid molecules is of great significance. In this study, the two materials (CNT and PANI) were combined together to obtain the magnification of electrochemical signal by substrate material (CNT/PANI). Then a self-assembled multiwalled carbon nanotubes/polyaniline/sodium alginate (CNT/PANI/SA) nanocomposite with chiral sites and conductive material was synthesized as the electrochemical sensing interface. Next, a novel electrochemical sensing interface was fabricated via modifying the as-prepared chiral material on a polished glassy carbon electrode (CNT/PANI/SA/GCE) for precisely, efficiently, and rapidly differentiation of tryptophan (Trp) enantiomers. It was observed that CNT/PANI/SA/GCE showed desirable stereoselective recognition effect in the variety of signal strength to peak current (Ip) to the different optical activity of Trp enantiomers. In the case of optimal conditions, the peak current ratio in the solution of l-Trp and d-Trp (I /I ) was observed to be 2.1 at CNT/PANI/SA/GCE by differential pulse voltammogram (DPV). UV-visible spectroscopy further showed that CNT/PANI/SA had a greater binding energy to l-Trp. Also different factors affecting the enantioselectivity of CNT/PANI/SA/GCE, such as the incubation time, pH, and dropcoating volume of CNT/PANI/SA were optimized. Moreover, the proposed CNT/PANI/SA/GCE showed excellent specific stereoselectivity and anti-interference ability. Besides, the proposed chiral sensing platform can be effectively applied in real samples to detect Trp enantiomers sensitively. This work inspires us a new path for the preparation of substrate material with excellent electrical conductivity, as well as extend its application potential in chiral recognition.
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http://dx.doi.org/10.1002/chir.23305DOI Listing
March 2021

Brain Function in Children with Obstructive Sleep Apnea: A Resting-State fMRI Study.

Sleep 2021 Mar 1. Epub 2021 Mar 1.

Beijing Advanced Innovation Center for Big Data-Based Precision Medicine, School of Medicine and Engineering, Beihang University, Beijing, People's Republic of China.

Objective: To explore the neural difference between children with obstructive sleep apnea (OSA) and healthy controls, together with the relation between this difference and cognitive dysfunction of children with OSA.

Methods: Twenty children with OSA (7.2 ± 3.1 years, apnea hypopnea index (AHI): 16.5 ± 16.6 events/h) and 29 healthy controls (7.7 ± 2.8 years, AHI: 1.7 ± 1.2 events/h) were recruited and matched with age, gender, and handedness. All children underwent resting-state fMRI (rs-fMRI) and T1-wighted imaging. Some children were sedated for MRI scanning. We compared amplitude of low frequency fluctuation (ALFF) and regional homogeneity (ReHo) of children with OSA with those of healthy controls. During resting-state, the former reflects the intensity of the spontaneous neural activities, whereas the latter reflects temporal similarity of the spontaneous neural activities within a local brain region. Pearson correlation analysis was performed between these features of rs-fMRI and cognitive scores among children with OSA.

Results: Compared with controls, children with OSA showed decreased ALFF in the left angular gyrus but increased ALFF in the right insula, and decreased ReHo in the left medial superior frontal gyrus, right lingual gyrus and left precuneus. Additionally, among children with OSA, the ReHo value in the right lingual gyrus was negatively correlated with FIQ and VIQ, whereas that in the left medial superior frontal gyrus was positively correlated with VIQ.

Conclusions: Children with OSA presented abnormal neural activities in some brain regions and impaired cognitive functions with the former possibly being the neural mechanism of the latter.
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http://dx.doi.org/10.1093/sleep/zsab047DOI Listing
March 2021

Mesenchymal Stem Cell-Based Therapy for Diabetes Mellitus: Enhancement Strategies and Future Perspectives.

Stem Cell Rev Rep 2021 Mar 5. Epub 2021 Mar 5.

Department of Plastic and Reconstructive Surgery, Shanghai Institute of Precision Medicine, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200125, China.

Diabetes mellitus (DM), a chronic disorder of carbohydrate metabolism, is characterized by the unbridled hyperglycemia resulted from the impaired ability of the body to either produce or respond to insulin. As a cell-based regenerative therapy, mesenchymal stem cells (MSCs) hold immense potency for curing DM duo to their easy isolation, multi-differentiation potential, and immunomodulatory property. However, despite the promising efficacy in pre-clinical animal models, naive MSC administration fails to exhibit clinically satisfactory therapeutic outcomes, which varies greatly among individuals with DM. Recently, numbers of innovative strategies have been applied to improve MSC-based therapy. Preconditioning, genetic modification, combination therapy and exosome application are representative strategies to maximize the therapeutic benefits of MSCs. Therefore, in this review, we summarize recent advancements in mechanistic studies of MSCs-based treatment for DM, and mainly focus on the novel approaches aiming to improve the anti-diabetic potentials of naive MSCs. Additionally, the potential directions of MSCs-based therapy for DM are also proposed at a glance.
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http://dx.doi.org/10.1007/s12015-021-10139-5DOI Listing
March 2021

Prevalence of pediatric Kashin-Beck disease in Tibet.

Clin Rheumatol 2021 Mar 5. Epub 2021 Mar 5.

Arthritis Clinic and Research Center, Peking University People's Hospital, No. 11 Xizhimen South Road, Xicheng District, Beijing, 100044, China.

Introduction: To estimate the prevalence of Kashin-Beck disease (KBD) among children in 2017 in Changdu of Tibet.

Methods: We adopted a four-step recruitment to include children aged 7-12 years from seven identified historically endemic counties in Changdu. Posterior-anterior radiographs of right hand and wrist were taken and were graded at four sites (metaphysis, epiphysis, and bony end of phalanges and metacarpal and carpal bones). Two trained researchers independently read the films. Inter-rater reliability was assessed using weighted Kappa and percentage agreement. We fitted logistic regression model to examine the association of age, sex, and altitude of residential village with prevalence of KBD. We examined association between site involvement and severity of KBD using chi-square test.

Results: We recruited 13,573 children (mean age = 9.3 years, 48.40% girls) with a response rate of 95.81%. The overall prevalence of radiographic KBD was 0.26%. Luolong County had the highest prevalence (0.69%), followed by Bianba (0.26%), Basu (0.24%), Mangkang (0.14%), Zuogong (0.14%), Dingqing (0.07%), and Chaya (0.00%). A higher risk of radiographic KBD was associated with older age (P for trend <0.001) and girls (OR=1.86, 95% CI: 0.94, 3.70), but not the altitude of residential village (P for trend=0.957). Metaphysis was involved in all cases of KBD while lesions in epiphysis and bony end of phalanges and metacarpals were only observed in severe cases.

Conclusions: The prevalence of radiographic KBD among children aged 7-12 years was low in Changdu compared with previous census data, suggesting the effectiveness of preventative measures. Key Points • In this study, 13,573 Tibetan children were taken X-ray films of their hands and wrists. • The prevalence of radiographic KBD among children aged 7-12 years was low in Changdu of Tibet. • The preventative measures against KBD launched by Chinese government were effective in decreasing new onsets of KBD among Tibetan children.
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http://dx.doi.org/10.1007/s10067-021-05669-9DOI Listing
March 2021

Outcome of endovascular treatment within and beyond 6 h without perfusion software.

Sci Rep 2021 Mar 5;11(1):5342. Epub 2021 Mar 5.

Department of Neurology, Clinical Neuroscience Institute, The First Affiliated Hospital of Jinan University, Guangzhou, China.

Endovascular treatment (EVT) has been accepted as the standard of care for patients with acute ischemic stroke. The aim of the present study was to compare clinical outcomes of patients who received EVT within and beyond 6 h from symptom onset to groin puncture without perfusion software in Guangdong district, China. Between March 2017 and May 2018, acute ischemic stroke patients who received EVT from 6 comprehensive stroke centers, were enrolled into the registry study. In this subgroup study, we included all patients who had acute proximal large vessel occlusion in the anterior circulation. The demographic, clinical and neuroimaging data were collected from each center. A total of 192 patients were included in this subgroup study. They were divided into two groups: group A (n = 125), within 6 h; group B (n = 67), 6-24 h from symptom onset to groin puncture. There were no substantial differences between these two groups in terms of 90 days favorable outcome (modified Rankin scale [mRS] ≤ 2, P = 0.051) and mortality (P = 0.083), and the risk of symptomatic intracranial hemorrhage at 24 h (P = 0.425). The NIHSS (median 16, IQR12-20, group A; median 12, IQR8-18, group B; P = 0.009) and ASPECTS (median 10, IQR8-10, group A; median 9, IQR8-10, group B; P = 0.034) at baseline were higher in group A. The anesthesia method (general anesthesia, 21.3%, group A vs. 1.5% group B, P = 0.001) were also statistically different between the two groups. The NIHSS and ASPECTS were higher, and general anesthesia was also more widely used in group A. Clinical outcomes were not significantly different within 6 h versus 6-24 h from symptom onset to groin puncture in this real world study.
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http://dx.doi.org/10.1038/s41598-021-84857-8DOI Listing
March 2021

Hsa_circ_0110757 upregulates ITGA1 to facilitate temozolomide resistance in glioma by suppressing hsa-miR-1298-5p.

Cell Death Dis 2021 Mar 5;12(3):252. Epub 2021 Mar 5.

Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha, 410008, China.

Temozolomide (TMZ) is the internationally recognized and preferred drug for glioma chemotherapy treatment. However, TMZ resistance in glioma appears after long-term use and is an urgent problem that needs to be solved. Circular RNAs (circRNAs) are noncoding RNAs and play an important role in the pathogenesis and progression of tumors. Hsa_circ_0110757 was identified in TMZ-resistant glioma cells by high-throughput sequencing analysis and was derived from reverse splicing of myeloid cell leukemia-1 (Mcl-1) exons. The role of hsa_circ_0110757 in TMZ-resistant glioma was evaluated both in vitro and in vivo. It was found that hsa_circ_0110757 and ITGA1 are more highly expressed in TMZ-resistant glioma than in TMZ-sensitive glioma. The overexpression of hsa_circ_0110757 in glioma patients treated with TMZ was obviously associated with tumor invasion. This study indicates that hsa_circ_0110757 inhibits glioma cell apoptosis by sponging hsa-miR-1298-5p to promote ITGA1 expression. Thus, hsa_circ_0110757/hsa-miR-1298-5p/ITGA could be a potential therapeutic target for reversing the resistance of glioma to TMZ.
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http://dx.doi.org/10.1038/s41419-021-03533-xDOI Listing
March 2021

Robust and ultralow-energy-threshold ignition of a lean mixture by an ultrashort-pulsed laser in the filamentation regime.

Light Sci Appl 2021 Mar 5;10(1):49. Epub 2021 Mar 5.

CAS Center for Excellence in Ultra-intense Laser Science, 201800, Shanghai, China.

Laser ignition (LI) allows for precise manipulation of ignition timing and location and is promising for green combustion of automobile and rocket engines and aero-turbines under lean-fuel conditions with improved emission efficiency; however, achieving completely effective and reliable ignition is still a challenge. Here, we report the realization of igniting a lean methane/air mixture with a 100% success rate by an ultrashort femtosecond laser, which has long been regarded as an unsuitable fuel ignition source. We demonstrate that the minimum ignition energy can decrease to the sub-mJ level depending on the laser filamentation formation, and reveal that the resultant early OH radical yield significantly increases as the laser energy reaches the ignition threshold, showing a clear boundary for misfire and fire cases. Potential mechanisms for robust ultrashort LI are the filamentation-induced heating effect followed by exothermal chemical reactions, in combination with the line ignition effect along the filament. Our results pave the way toward robust and efficient ignition of lean-fuel engines by ultrashort-pulsed lasers.
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http://dx.doi.org/10.1038/s41377-021-00496-8DOI Listing
March 2021

Recent advances in cellulose and its derivatives for oilfield applications.

Carbohydr Polym 2021 May 6;259:117740. Epub 2021 Feb 6.

Tianjin Key Laboratory of Pulp and Paper, Tianjin University of Science and Technology, Tianjin, 300457, China. Electronic address:

The purpose of this review is to summarize and discuss the recent developments in exploring cellulose and its derivatives in the applications of oilfield chemicals for petroleum drilling and exploiting. We begin with a brief introduction of cellulose and its common water-soluble derivatives, such as the carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methylcellulose, and amphoteric cellulose. Afterwards, the applications of cellulose derivatives in different petroleum exploitation processes, such as drilling, cementing, and fracturing, are set out in detail. Finally, the application perspectives and challenges of cellulose derivatives for oilfield applications are presented. This work demonstrates that cellulose derivatives have wide application prospects in oilfield industry in the future.
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http://dx.doi.org/10.1016/j.carbpol.2021.117740DOI Listing
May 2021

The role of mRNA in the development, diagnosis, treatment and prognosis of neural tumors.

Mol Cancer 2021 Mar 5;20(1):49. Epub 2021 Mar 5.

Department of Anesthesiology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, People's Republic of China.

Neural tumors can generally be divided into central nervous system tumors and peripheral nervous tumors. Because this type of tumor is located in the nerve, even benign tumors are often difficult to remove by surgery. In addition, the majority of neural tumors are malignant, and it is particular the same for the central nervous system tumors. Even treated with the means such as chemotherapy and radiotherapy, they are also difficult to completely cure. In recent years, an increasingly number of studies have focused on the use of mRNA to treat tumors, representing an emerging gene therapy. The use of mRNA can use the expression of some functional proteins for the treatment of genetic disorders or tissue repair, and it can also be applied to immunotherapy through the expression of antigens, antibodies or receptors. Therefore, although these therapies are not fully-fledged enough, they have a broad research prospect. In addition, there are many ways to treat tumors using mRNA vaccines and exosomes carrying mRNA, which have drawn much attention. In this study, we reviewed the current research on the role of mRNA in the development, diagnosis, treatment and prognosis of neural tumors, and examine the future research prospects of mRNA in neural tumors and the opportunities and challenges that will arise in the future application of clinical treatment.
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http://dx.doi.org/10.1186/s12943-021-01341-7DOI Listing
March 2021

Culture, Thinking Styles and Investment Decision.

Psychol Rep 2021 Mar 5:33294121997778. Epub 2021 Mar 5.

Guanghua School of Management, Peking University, China.

Past research suggests that people with different thinking styles show different cognitive processes. Accordingly, we test how thinking style and advice jointly affect investment decision. We conduct three experiments with 530 participants. In Study 1, coin, card and stamp investors who had high levels of holistic thinking and made decisions on their own obtained the lowest returns. In Study 2, participants who used analytic thinking to make decisions on their own in the Balloon Analog Risk Task (BART) earned the most. In Study 3, Westerners who made decisions on their own using analytic thinking had the highest incomes, while Easterners using holistic thinking and listening to others also had positive returns. The results support the framing effect in investment decisions, and the two simulation paradigms are presented for future studies and to confirm the impacts of thinking styles.
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http://dx.doi.org/10.1177/0033294121997778DOI Listing
March 2021

Evolution of the Gut Microbiota and Its Fermentation Characteristics of Ningxiang Pigs at the Young Stage.

Animals (Basel) 2021 Feb 27;11(3). Epub 2021 Feb 27.

College of Animal Science and Technology, Hunan Agricultural University, Changsha 410128, China.

The current study aimed to investigate the evolution of gut microbiota and its influencing factors for NXP in youth. The results showed that Shannon index increased from d 21 to d 28 whereas the ACE index increased from d 21 until d 60. Firmicutes, mainly Lactobacillus dominated on d 21. The Bacteroides and Spirochetes showed highest relative abundance on d 28. Fiber-degrading bacteria, mainly , , , , and , dominated the microbial communities at d 28 and d 35. The microbial communities at d 60 and d 75 contained more , and than other ages, which had significantly positive correlations with acetate and total SCFAs concentration. In conclusion, the evolution of gut microbiota was mainly adapted to the change of dietary factors during NXP growth. The response of fiber-degrading bacteria at different stages may help NXP better adapt to plant-derived feeds.
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http://dx.doi.org/10.3390/ani11030638DOI Listing
February 2021

Experimental Study on Optimization of Phosphogypsum Suspension Decomposition Conditions under Double Catalysis.

Materials (Basel) 2021 Feb 27;14(5). Epub 2021 Feb 27.

College of Materials Science and Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.

Phosphogypsum (PG) is not only a solid waste discharged from the phosphate fertilizer industry, but also a valuable resource. After high-temperature heat treatment, it can be decomposed into SO and CaO; the former can be used to produce sulfuric acid, and the latter can be used as building materials. In this paper, the catalytic thermal decomposition conditions of phosphogypsum were optimized, and the effects of the reaction temperature, reaction atmosphere, reaction time and carbon powder content on the decomposition of phosphogypsum were studied. The research shows that the synergistic effect of carbon powder and CO reducing atmosphere can effectively reduce the decomposition temperature of phosphogypsum. According to the results of the orthogonal test under simulated suspended laboratory conditions, the factors affecting the decomposition rate of phosphogypsum are temperature, time, atmosphere and carbon powder content in turn, and the factors affecting the desulfurization rate are time, temperature, atmosphere and carbon powder content in turn. Under laboratory conditions, the highest decomposition rate and desulfurization rate of phosphogypsum are 97.73% and 97.2%, and the corresponding reaction conditions are as follows: calcination temperature is 1180 °C, calcination time is 15 min, carbon powder content is 4%, and CO concentration is 6%. The results of thermal analysis of phosphogypsum at different temperature rising rates show that the higher the temperature rising rate, the higher the initial temperature of decomposition reaction and the temperature of maximum thermal decomposition rate, but the increase in the temperature rising rate will not reduce the decomposition rate of phosphogypsum.
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http://dx.doi.org/10.3390/ma14051120DOI Listing
February 2021

Lipidomics Revealed Aberrant Metabolism of Lipids Including FAHFAs in Renal Tissue in the Progression of Lupus Nephritis in a Murine Model.

Metabolites 2021 Feb 27;11(3). Epub 2021 Feb 27.

Barshop Institute for Longevity and Aging Studies, San Antonio, TX 78229, USA.

Lupus nephritis (LN) is an inflammatory renal disease of patients with systemic lupus erythematosus with lots of immune complexes deposited in kidneys. Accumulated studies have demonstrated the close relationships among dyslipidaemia, inflammation, and autoimmune response, and oxidative stress in the patients. Lipids play numerous important roles in biological process and cellular functions. Herein, shotgun lipidomics was employed to quantitatively analyze cellular lipidomes in the renal tissue of MRL/lpr mice in the progression of LN (including pre-LN and LN state) with/without treated with glucocorticoids (GCs). The levels of cytokines (i.e., TNF-α (Tumor necrosis factor alpha) and IL-6 (Interleukin 6)) in the serum were measured by ELISA (enzyme-linked immunosorbent assay) kits. Renal histopathological changes and C3 deposition in the glomeruli of the mice were also determined. Lipidomics analysis revealed that the ectopic fat deposition and the aberrant metabolism of lipids that were relevant to oxidative stress (e.g., 4-hydroxyalkenal, ceramide, lysophospholipid species, etc.) always existed in the development of LN. Moreover, the anti-inflammatory FAHFA (fatty acid ester of hydroxyl fatty acid) species in the kidney tissue could largely reflect the severity of LN. Thus, they were a potential early biomarker for LN. In addition, the study also revealed that treatment with GCs could prevent the progression of LN, but greatly aggravate the aberrant metabolism of the lipids, particularly when used for a long time.
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http://dx.doi.org/10.3390/metabo11030142DOI Listing
February 2021

A Novel Ferroptosis-Related Gene Signature Predicts Overall Survival of Breast Cancer Patients.

Biology (Basel) 2021 Feb 14;10(2). Epub 2021 Feb 14.

Department of Medical Oncology, Sun Yat-sen University Cancer Center, Guangzhou 510060, Guangdong, China.

Breast cancer is the second leading cause of death in women, thus a reliable prognostic model for overall survival (OS) in breast cancer is needed to improve treatment and care. Ferroptosis is an iron-dependent cell death. It is already known that siramesine and lapatinib could induce ferroptosis in breast cancer cells, and some ferroptosis-related genes were closely related with the outcomes of treatments regarding breast cancer. The relationship between these genes and the prognosis of OS remains unclear. The data of gene expression and related clinical information was downloaded from public databases. Based on the TCGA-BRCA cohort, an 8-gene prediction model was established with the least absolute shrinkage and selection operator (LASSO) cox regression, and this model was validated in patients from the METABRIC cohort. Based on the median risk score obtained from the 8-gene model, patients were stratified into high- or low-risk groups. Cox regression analyses identified that the risk score was an independent predictor for OS. The findings from CIBERSORT and ssGSEA presented noticeable differences in enrichment scores for immune cells and pathways between the abovementioned two risk groups. To sum up, this prediction model has potential to be widely applied in future clinical settings.
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http://dx.doi.org/10.3390/biology10020151DOI Listing
February 2021

SARS-CoV-2 RNA Detection with Duplex-Specific Nuclease Signal Amplification.

Micromachines (Basel) 2021 Feb 14;12(2). Epub 2021 Feb 14.

State-Key Laboratory of Analog and Mixed-Signal VLSI, Institute of Microelectronics, University of Macau, Macau 999078, China.

The emergence of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a zoonotic pathogen, has led to the outbreak of coronavirus disease 2019 (COVID-19) pandemic and brought serious threats to public health worldwide. The gold standard method for SARS-CoV-2 detection requires both reverse transcription (RT) of the virus RNA to cDNA and then polymerase chain reaction (PCR) for the cDNA amplification, which involves multiple enzymes, multiple reactions and a complicated assay optimization process. Here, we developed a duplex-specific nuclease (DSN)-based signal amplification method for SARS-CoV-2 detection directly from the virus RNA utilizing two specific DNA probes. These specific DNA probes can hybridize to the target RNA at different locations in the nucleocapsid protein gene (N gene) of SARS-CoV-2 to form a DNA/RNA heteroduplex. DSN cleaves the DNA probe to release fluorescence, while leaving the RNA strand intact to be bound to another available probe molecule for further cleavage and fluorescent signal amplification. The optimized DSN amount, incubation temperature and incubation time were investigated in this work. Proof-of-principle SARS-CoV-2 detection was demonstrated with a detection sensitivity of 500 pM virus RNA. This simple, rapid, and direct RNA detection method is expected to provide a complementary method for the detection of viruses mutated at the PCR primer-binding regions for a more precise detection.
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http://dx.doi.org/10.3390/mi12020197DOI Listing
February 2021

Mechanism Identification and Kinetics Analysis of Thermal Degradation for Carbon Fiber/Epoxy Resin.

Polymers (Basel) 2021 Feb 14;13(4). Epub 2021 Feb 14.

College of Airworthiness, Civil Aviation University of China, Tianjin 300300, China.

For carbon fiber epoxy resin used in aerostructure, thermal degradation mechanism and kinetics play an important role in the evaluation of thermal response and combustion characteristics. However, the thermal decomposition process and mechanism are difficult to unify strictly due to the complexity of the components from different suppliers. In the present study, a product of carbon fiber epoxy resin made by AVIC (Aviation Industry Corporation of China) composite corporation is examined to identify its thermal degradation mechanism and pyrolysis products by measurements, including simultaneous thermal analysis, Fourier transform infrared spectroscopy and mass spectrometry, establish the kinetic model by Kissinger/Friedman/Ozawa/Coats-Redfern methods. The results show thermal degradation occurs in three steps under the inert atmosphere, but in four steps under air atmosphere, respectively. The first two steps in both environments are almost the same, including drying, carbon dioxide escape and decomposition of the epoxy resin. In the third step of inert atmosphere, phenol is formed, methane decreases, carbon monoxide basically disappears and carbon dioxide production increases. However, in air, thermal oxidation of the carbonaceous residues and intermolecular carbonization are observed. Furthermore, thermal degradation reaction mechanism submits to the F model. These results provide fundamental and comprehensive support for the application of carbon fiber epoxy resin in aircraft industry.
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http://dx.doi.org/10.3390/polym13040569DOI Listing
February 2021