Publications by authors named "Xian Chen"

492 Publications

Silica-confined Ru highly dispersed on ZrO with enhanced activity and thermal stability in dichloroethane combustion.

Nanoscale 2021 Jun 10. Epub 2021 Jun 10.

State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, No. 30 Puzhu South Road, Nanjing 211816, China.

An efficient strategy (spontaneous deposition to enhance noble metal dispersity and core-shell confinement to inhibit noble metal sintering) is presented to synthesize highly active and thermally stable Ru/[email protected] catalysts for dichloroethane combustion.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/d1nr01538aDOI Listing
June 2021

Combination of Anti-EGFR and Anti-VEGF Drugs for the Treatment of Previously Treated Metastatic Colorectal Cancer: A Case Report and Literature Review.

Front Oncol 2021 24;11:684309. Epub 2021 May 24.

Department of Oncology, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China.

The standard third-line treatment of metastatic colorectal cancer (mCRC) includes the small-molecule anti-vascular drugs (Regofenib and Fruquintinib) and the chemotherapy drug trifluridine and tipiracil hydrochloride (TAS-102). There is no standard treatment for mCRC if the third-line treatment failed. Therefore, it is a pressing need to develop new therapeutic approaches to improve the survival of patients who developed drug resistance to the third-line treatment. In this study, we report a case of mCRC with RAS/BRAF wild-type, who was successfully treated using cetuximab in combination with fruquintinib after resistance to chemotherapy, bevacizumab, cetuximab and regorafenib. This patient responded to this combination regimen. Then, we discuss the mechanisms of action of this combination. Furthermore, we introduce the clinical trials on the combination regimens of anti-EGFR with anti-vascular monoclonal antibodies. Finally, we discuss the clinical explorations of using combination of anti-EGFR with small-molecule anti-VEGF drugs and their potential benefits. The clinical effects of small-molecule anti-vascular drugs in combination with anti-EGFR in the treatment of CRC warrant further explored.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fonc.2021.684309DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8180844PMC
May 2021

Mixing during Trapping Enabled a Continuous-Flow Microfluidic Smartphone Immunoassay Using Acoustic Streaming.

ACS Sens 2021 Jun 8. Epub 2021 Jun 8.

State Key Laboratory of Precision Measuring Technology & Instruments and College of Precision Instrument and Opto-electronics Engineering, Tianjin University, Tianjin 300072, China.

Smartphone-enabled microfluidic chemiluminescence immunoassay is a promising portable system for point-of-care (POC) biosensing applications. However, due to the rather faint emitted light in such a limited sample volume, it is still difficult to reach the clinically accepted range when the smartphone serves as a standalone detector. Besides, the multiple separation and washing steps during sample preparation hinder the immunoassay's applications for POC usage. Herein, we proposed a novel acoustic streaming tweezers-enabled microfluidic immunoassay, where the probe particles' purification, reaction, and sensing were simply achieved on the same chip at continuous-flow conditions. The dedicatedly designed high-speed microscale vortexes not only enable dynamic trapping and washing of the probe particles on-demand but also enhance the capture efficiency of the heterogeneous particle-based immunoassay through active mixing during trapping. The enriched probe particles and enhanced biomarker capture capability increase the local chemiluminescent light intensity and enable direct capture of the immunobinding signal by a regular smartphone camera. The system was tested for prostate-specific antigen (PSA) sensing both in buffer and serum, where a limit of detection of 0.2 ng/mL and a large dynamic response range from 0.3 to 10 ng/mL using only 10 μL of sample were achieved in a total assay time of less than 15 min. With the advantages of on-chip integration of sample preparation and detection and high sensing performance, the developed POC platform could be applied for many on-site diagnosis applications.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acssensors.1c00602DOI Listing
June 2021

TF-PROTACs Enable Targeted Degradation of Transcription Factors.

J Am Chem Soc 2021 Jun 8;143(23):8902-8910. Epub 2021 Jun 8.

Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215, United States.

Transcription factors (TFs) represent a major class of therapeutic targets for the treatment of human diseases including cancer. Although the biological functions and even crystal structures of many TFs have been clearly elucidated, there is still no viable approach to target the majority of TFs, thus rendering them undruggable for decades. PROTACs (proteolysis targeting chimeras) emerge as a powerful class of therapeutic modalities, which rely on induced protein-protein interactions between the proteins of interest (POIs) and E3 ubiquitin ligases to aid the degradation of POIs by the ubiquitin-proteasome system (UPS). Here, we report the development of a platform termed TF-PROTAC, which links an DNA oligonucleotide to an E3 ligase ligand via a click reaction, to selectively degrade the TF of interest. The selectivity of these TF-PROTACs depends on the DNA oligonucleotides utilized that can be specific to the TFs of interest. We have developed two series of VHL-based TF-PROTACs, NF-κB-PROTAC (dNF-κB) and E2F-PROTAC (dE2F), which effectively degrade endogenous p65 and E2F1 proteins in cells, respectively, and subsequently display superior antiproliferative effects in cells. Collectively, our results suggest that TF-PROTACs provide a generalizable platform to achieve selective degradation of TFs and a universal strategy for targeting most "undruggable" TFs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/jacs.1c03852DOI Listing
June 2021

Mode of action and efficacy of quinolinic acid for the control of Ceratocystis fimbriata on sweet potato.

Pest Manag Sci 2021 Jun 4. Epub 2021 Jun 4.

School of Life Sciences, Nantong University, Nantong, 226019, People's Republic of China.

Background: Ceratocystis fimbriata is a hazardous fungal pathogen able to cause black rot disease on sweet potato. The management of C. fimbriata strongly relies on the use of toxic fungicides, and there is a lack of efficient alternative strategies.

Results: The antifungal properties of quinolinic acid (QA) were studied for the first time, indicating that QA shows selective antifungal activity against C. fimbriata. QA inhibited completely the mycelial growth of C. fimbriata at less than 0.8 mg/mL concentration (pH 4), and was able to produce alterations in the fungal cell wall, and to impede spore agglutination and mycelium formation. QA significantly reduced the concentration of ergosterol, and was able to associate to iron(II), suggesting that QA may be a lanosterol 14-α demethylase inhibitor. In preventive applications, QA reduced the disease incidence of C. fimbriata on sweet potato by 75%, achieving higher control efficacy in comparison with commercial fungicides prochloraz and carbendazim.

Conclusions: The first selective antifungal agent against C. fimbriata was discovered in this work, and showed suitable antifungal properties for the management of black rot disease. This article is protected by copyright. All rights reserved.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/ps.6495DOI Listing
June 2021

The role of decidual natural killer cell derived soluble factors in early pregnancy.

Am J Reprod Immunol 2021 May 29:e13477. Epub 2021 May 29.

Shenzhen Key Laboratory of Reproductive Immunology for Peri-implantation, Zhongshan Institute for Reproduction and Genetics, Fertility Center, Shenzhen Zhongshan Urology Hospital, 518045, Guangdong, China.

Decidual natural killer cell (dNK), the predominant decidual lymphocytes in early pregnancy, are primarily identified based on their CD56 CD16 phenotype and play an important role in maintaining immune tolerance at the maternal-fetal interface. dNK dysfunction reportedly leads to pathological pregnancy. Indeed, various dNK-derived soluble factors are involved in a series of key processes related to pregnancy outcomes. In this review, we summarize the roles of these dNK-derived factors in immune tolerance and embryonic development to improve the current understanding regarding the physiological and pathological mechanisms that occur during pregnancy, while potentially informing the development of effective therapeutics.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/aji.13477DOI Listing
May 2021

Activated low-grade phosphate rocks for simultaneously reducing the phosphorus loss and cadmium uptake by rice in paddy soil.

Sci Total Environ 2021 Aug 23;780:146550. Epub 2021 Mar 23.

College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China. Electronic address:

Cadmium (Cd) pollution and phosphorus (P) leaching in paddy soils has raised the global concern. In this study, two kinds of the low grade phosphate rocks activated by the sodium lignosulfonate (SL) and humic acid (HA) were fabricated for soil Cd passivation and reduction of the soil P leaching simultaneously. The mechanisms of the Cd adsorption and passivation by the activated phosphate rocks (APRs) were investigated through the batch experiment and the indoor culture test (i.e., incubation and pot experiments) in the Cd-polluted paddy soil. The effects of the APRs on the potted rice growth, uptake of Cd by rice and P loss were also studied. In comparison with the superphosphate treatment, the cumulative P loss from SL- and HA-APRs were reduced by the 65.2% and 65.3%. In terms of the Cd passivation, the Cd adsorbed on the APRs was through the chemical ways (i.e., ligand exchange and the formation of internal complexes). The application of the APRs significantly decreased the soil exchangeable Cd by 48.9%-55.0%, while the Fe/Mn oxides-bound Cd and residual Cd increased significantly by 19.6%-20.3% and 50.7%-69.4%, respectively. Pot experiment also suggested that both the APRs treatments (SL- and HA-APRs) significantly diminished soil Cd accumulation in rice (by 72.7% and 62.8%) coupling with the significantly decreased P leaching. These results provide a sustainable way to explore a novel cost-effective, high-efficient and bi-functional mineral-based soil amendments for environmental remediation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.scitotenv.2021.146550DOI Listing
August 2021

Topics in the mathematical design of materials.

Philos Trans A Math Phys Eng Sci 2021 Jul 24;379(2201):20200108. Epub 2021 May 24.

BCAM, Basque Center for Applied Mathematics, Alameda Mazarredo, 14 Bilbao 48009, Spain.

We present a perspective on several current research directions relevant to the mathematical design of new materials. We discuss: (i) design problems for phase-transforming and shape-morphing materials, (ii) epitaxy as an approach of central importance in the design of advanced semiconductor materials, (iii) selected design problems in soft matter, (iv) mathematical problems in magnetic materials, (v) some open problems in liquid crystals and soft materials and (vi) mathematical problems on liquid crystal colloids. The presentation combines topics from soft and hard condensed matter, with specific focus on those design themes where mathematical approaches could possibly lead to exciting progress. This article is part of the theme issue 'Topics in mathematical design of complex materials'.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1098/rsta.2020.0108DOI Listing
July 2021

Quantitative analysis of compatible microstructure by electron backscatter diffraction.

Philos Trans A Math Phys Eng Sci 2021 Jul 24;379(2201):20200112. Epub 2021 May 24.

Mechanical and Aerospace Engineering, Hong Kong University of Science and Technology, Hong Kong.

We propose a scheme for assigning the martensite variant using electron backscatter diffraction in a martensite material that undergoes a solid-solid phase transformation. Based on the solutions of the crystallographic equations of martensite, we provide an algorithm to assign martensite variants to a particular microscopic region, and to check the elastic compatibility of the microstructure corresponding to low hysteresis and high reversibility in shape memory alloys. This article is part of the theme issue 'Topics in mathematical design of complex materials'.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1098/rsta.2020.0112DOI Listing
July 2021

A novel shift in the glass transition temperature of polymer nanocomposites: a molecular dynamics simulation study.

Phys Chem Chem Phys 2021 Jun;23(21):12216-12225

Zhejiang Province Key Laboratory of Quantum Technology and Device, Department of Physics, Zhejiang University, Hangzhou 310027, China.

The effect of the loading of nanoparticles on the glass transition temperature, Tg, of polymer nanocomposites is studied by using molecular dynamics simulations. Tg is estimated from the variation of system volume with temperature and the temperature-dependent diffusion of the polymer described by the Vogel-Fulcher-Tammann law. The estimated values of Tg from the two methods are consistent with each other. Results show that Tg can be regulated by changing the volume fraction of nanoparticles, fNP. A novel shift in Tg is observed, that is, Tg increases with fNP at fNP < , while it decreases with increasing fNP at fNP > . The basic mechanism behind the novel shift in Tg is the competition between the attraction of nanoparticles towards polymer chains and the fast diffusion of nanoparticles. The increase in Tg at low fNP is due to the attraction of nanoparticles, whereas the decrease in Tg at high fNP is attributed to the fast diffusion of nanoparticles. The diffusion of the polymer above Tg is also investigated. The diffusion of the polymer decreases with increasing fNP below and increases with fNP above , in agreement with the variation of Tg.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/d1cp00321fDOI Listing
June 2021

A randomized controlled study on an integrated approach to prevent and treat re-adhesion after transcervical resection of moderate-to-severe intrauterine adhesions.

Clinics (Sao Paulo) 2021 5;76:e1987. Epub 2021 May 5.

Department of Obstetrics and Gynecology, Nanping People's Hospital to Fujian University of Traditional Chinese Medicine, Nanping 353000, Fujian, China.

Objectives: This study aims to compare the clinical efficacy of an integrated approach to prevent and treat the recurrence of moderate-to-severe intrauterine adhesions (IUA) after hysteroscopic transcervical resection of adhesion (TCRA).

Methods: The study included a total of 70 patients with moderate-to-severe IUAs who underwent TCRA. Patients were randomly divided into two groups: treatment group (n=35) and control group n=35). In the treatment group, patients underwent balloon uterine stent placement and artificial cycle as well as received intrauterine perfusion of Danshen injection and oral Chinese medicine. In the control group, patients underwent balloon uterine stent placement and artificial cycle as well as received hyaluronic acid sodium and intrauterine device (IUD). Follow-up was performed after treatment of uterine cavity, menstruation and pregnancy.

Results: After 3 months of treatment, we observed a significantly lower rate of intrauterine re-adhesion (45.71% versus 77.14%, p=0.044) and significantly higher clinical efficiency (82.86% versus 77.14%, p=0.025) in the treatment group than those in the control group. After 6 months of treatment, we observed a significantly higher clinical efficiency in the treatment group than that in the control group (88.57% versus 68.57%, p=0.039). During the follow-up period, the pregnancy rate was 45.71% and 37.14% in the treatment group and control group, respectively, although the difference was not statistically significant (p=0.628).

Conclusions: After surgical management of IUA, the integrated treatment combining a uterus stent placement and artificial cycle with Danshen injection and oral Chinese medicine can improve the condition of menstruation, and prevent and treat recurrence of IUA.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.6061/clinics/2021/e1987DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8075111PMC
May 2021

Large-scale growth of few-layer two-dimensional black phosphorus.

Nat Mater 2021 May 10. Epub 2021 May 10.

Department of Applied Physics, The Hong Kong Polytechnic University, Hong Kong, People's Republic of China.

Two-dimensional materials provide opportunities for developing semiconductor applications at atomistic thickness to break the limits of silicon technology. Black phosphorus (BP), as a layered semiconductor with controllable bandgap and high carrier mobility, is one of the most promising candidates for transistor devices at atomistic thickness. However, the lack of large-scale growth greatly hinders its development in devices. Here, we report the growth of ultrathin BP on the centimetre scale through pulsed laser deposition. The unique plasma-activated region induced by laser ablation provides highly desirable conditions for BP cluster formation and transportation, facilitating growth. Furthermore, we fabricated large-scale field-effect transistor arrays on BP films, yielding appealing hole mobility of up to 213 and 617 cm V s at 295 and 250 K, respectively. Our results pave the way for further developing BP-based wafer-scale devices with potential applications in the information industry.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41563-021-01001-7DOI Listing
May 2021

OsPHR2 modulates phosphate starvation-induced OsMYC2 signaling and resistance to Xanthomonas oryzae pv. oryzae.

Plant Cell Environ 2021 May 2. Epub 2021 May 2.

State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China.

Phosphate (Pi) and MYC2-mediated jasmonate (JA) pathway play critical roles in plant growth and development. In particular, crosstalk between JA and Pi starvation signaling has been reported to mediate insect herbivory resistance in dicot plants. However, its roles and mechanism in monocot-bacterial defense systems remain obscure. Here, we report that Pi starvation in rice activates the OsMYC2 signaling and enhances resistance to Xanthomonas oryzae pv. oryzae (Xoo) infection. The direct regulation of OsPHR2 on the OsMYC2 promoter was confirmed by yeast one-hybrid, electrophoretic mobility shift, dual-luciferase, and chromatin immunoprecipitation assays. Molecular analyses and infection studies using OsPHR2-Ov1 and phr2 mutants further demonstrated that OsPHR2 enhances antibacterial resistance via transcriptional regulation of OsMYC2 expression, indicating a positive role of OsPHR2-OsMYC2 crosstalk in modulating the OsMYC2 signaling and Xoo infection. Genetic analysis and infection assays using myc2 mutants revealed that Pi starvation-induced OsMYC2 signaling activation and consequent Xoo resistance depends on the regulation of OsMYC2. Together, these results reveal a clear interlink between Pi starvation- and OsMYC2- signaling in monocot plants, and provide new insight into how plants balance growth and defense by integrating nutrient deficiency and phytohormone signaling. This article is protected by copyright. All rights reserved.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/pce.14078DOI Listing
May 2021

Activation of Blood Vessel Development in Endometrial Stromal Cells In Vitro Cocultured with Human Peri-Implantation Embryos Revealed by Single-Cell RNA-Seq.

Life (Basel) 2021 Apr 21;11(5). Epub 2021 Apr 21.

Tongji Hospital, School of Medicine, Tongji University, Shanghai 200092, China.

In humans, the maternal endometrium participates in the physical and physiological interaction with the blastocyst to begin implantation. A bidirectional crosstalk is critical for normal implantation and then a successful pregnancy. While several studies have used animal models or cell lines to study this step, little knowledge was acquired to address the role of endometrial cells in humans. Here, we analyzed single-cell sequencing data from a previous study including 24 non-coculture endometrial stromal cells (EmSCs) and 57 EmSCs after coculture with embryos. We further explored the transcriptomic changes in EmSCs and their interactions with trophoblast cells after coculture. Differentially expressed gene (DEG) analysis showed 1783 upregulated genes and 569 downregulated genes in the cocultured embryos. Weight gene coexpression network and gene ontology analysis of these DEGs showed a higher expression of , , and in EmSCs after coculture, indicating the enrichment of biological processes in blood vessel development and female pregnancy. These data imply that EmSCs start blood vessel development at the implantation stage. Compared with endometrium data in vivo at the implantation window, key pathways including epithelial cell development and oxygen response were involved at this stage. Further analysis using CellphoneDB shed light on the interactions between EmSCs and embryonic trophoblasts, suggesting the important role of integrins and fibroblast growth factor pathways during implantation. Taken together, our work reveals the synchronization signaling and pathways happening at the implantation stage involving the acquisition of receptivity in EmSCs and the interaction between EmSCs and trophoblast cells.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/life11050367DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8143346PMC
April 2021

Identification of QTLs and a Candidate Gene for Reducing Pre-Harvest Sprouting in - Chromosome Segment Substitution Lines.

Int J Mol Sci 2021 Apr 2;22(7). Epub 2021 Apr 2.

School of Life Sciences, Henan University, Kaifeng 475001, China.

Wheat pre-harvest sprouting (PHS) causes serious losses in wheat yield. In this study, precise mapping was carried out in the chromosome segment substitution lines (CSSL) F population generated by a direct cross of Zhoumai 18 (PHS-sensitive) and accession T093 (highly PHS-resistant). Three -derived quantitative trait loci (QTLs), , , and , were detected on chromosome 3DL using four simple sequence repeats (SSR) markers and 10 developed Kompetitive allele-specific PCR (KASP) markers. Alongside these QTL results, the RNA-Seq and qRT-PCR analysis revealed expression levels of in the region that were significantly higher in CSSLs 495 than in Zhoumai 18 during the seed imbibition treatment. The cDNA sequencing results of showed two single nucleotide polymorphisms (SNPs), resulting in two changed amino acid substitutions between Zhoumai 18 and line 495, and the 148 nt amino acid substitution of , derived from T093, which may play an important role in the functioning of ubiquitin ligase enzymes 3 (E3) according to the homology protein analysis, which could lead to differential PHS-resistance phenotypes. Taken together, our results may foster a better understanding of the mechanism of PHS resistance and are potentially valuable for marker-assisted selection in practical wheat breeding efforts.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/ijms22073729DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8038248PMC
April 2021

Targeting Replicative Stress and DNA Repair by Combining PARP and Wee1 Kinase Inhibitors Is Synergistic in Triple Negative Breast Cancers with Cyclin E or Alteration.

Cancers (Basel) 2021 Apr 1;13(7). Epub 2021 Apr 1.

Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.

The identification of biomarker-driven targeted therapies for patients with triple negative breast cancer (TNBC) remains a major clinical challenge, due to a lack of specific targets. Here, we show that cyclin E, a major regulator of G1 to S transition, is deregulated in TNBC and is associated with mutations in DNA repair genes (e.g., ). Breast cancers with high levels of cyclin E not only have a higher prevalence of mutations, but also are associated with the worst outcomes. Using several in vitro and in vivo model systems, we show that TNBCs that harbor either mutations in or overexpression of cyclin E are very sensitive to the growth inhibitory effects of AZD-1775 (Wee 1 kinase inhibitor) when used in combination with MK-4837 (PARP inhibitor). Combination treatment of TNBC cell lines with these two agents results in synergistic cell killing due to induction of replicative stress, downregulation of DNA repair and cytokinesis failure that results in increased apoptosis. These findings highlight the potential clinical application of using cyclin E and BRCA mutations as biomarkers to select only those patients with the highest replicative stress properties that may benefit from combination treatment with Wee 1 kinase and PARP inhibitors.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/cancers13071656DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8036262PMC
April 2021

Sulfonic-Group-Grafted TiCT MXene: A Silver Bullet to Settle the Instability of Polyaniline toward High-Performance Zn-Ion Batteries.

ACS Nano 2021 May 29;15(5):9065-9075. Epub 2021 Apr 29.

College of Materials Science and Engineering, Shenzhen University, Shenzhen 518055, China.

Polyaniline (PANI) is a promising cathode material for Zn-ion batteries (ZIBs) due to its intrinsic conductivity and redox activity; however, the achievements of PANI in high-performance ZIBs are largely hindered by its instability during the repeated charge/discharge. Taking advantage of the high conductivity, flexibility, and grafting ability together, a surface-engineered TiCT MXene is designed as a silver bullet to fight against the deprotonation and swelling/shrinking issues occurring in the redox process of PANI, which are the origins of its instability. Specifically, the sulfonic-group-grafted TiCT(S-TiCT) continuously provides protons to improve the protonation degree of PANI and maintains the polymer backbone at a locally low pH, which effectively inhibits deprotonation and brings high redox activity along with good reversibility. Meanwhile, the conductive and flexible natures of S-TiCT assist the fast redox reaction of PANI and concurrently buffer its corresponding swelling/shrinking. Therefore, the S-TiCT-enhanced PANI cathode simultaneously achieves a high discharge capacity of 262 mAh g at 0.5 A g, a superior rate capability of 160 mAh g at 15 A g, and a good cyclability over 5000 cycles with 100% coulombic efficiency. This work enlightens the development of versatile MXene surface engineering for advanced batteries.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acsnano.1c02215DOI Listing
May 2021

Translocation of a looped polymer threading through a nanopore.

Soft Matter 2021 Apr;17(16):4342-4351

Department of Physics, Zhejiang University, Hangzhou 310027, China.

Recent experiments reported that the complicated translocation dynamics of a looped DNA chain through a nanopore can be detected by ionic current blockade profiles. Inspired by the experimental results, we systematically study the translocation dynamics of a looped polymer, formed by three building blocks of a loop in the middle and two tails of the same length connected with the loop, by using Langevin dynamics simulations. Based on two entering modes (tail-leading and loop-leading) and three translocation orders (loop-tail-tail, tail-loop-tail, and tail-tail-loop), the translocation of the looped polymer is classified into six translocation pathways, corresponding to different current blockade profiles. The probabilities of the six translocation pathways are dependent on the loop length, polymer length, and pore radius. Moreover, the translocation times of the entire polymer and the loop are investigated. We find that the two translocation times show different dependencies on the translocation pathways and on the lengths of the loop and the entire polymer.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/d1sm00007aDOI Listing
April 2021

Tensile mechanical analysis of anisotropy and velocity dependence of the spinal cord white matter: a biomechanical study.

Neural Regen Res 2021 Dec;16(12):2557-2562

Department of Orthopedic Surgery, Yamaguchi University Graduate School of Medicine, Minami-Kogushi, Ube, Yamaguchi, Japan.

In spinal cord injuries, external forces from various directions occur at various velocities. Therefore, it is important to physically evaluate whether the spinal cord is susceptible to damage and an increase in internal stress for external forces. We hypothesized that the spinal cord has mechanical features that vary under stress depending on the direction and velocity of injury. However, it is difficult to perform experiment because the spinal cord is very soft. There are no reports on the effects of multiple external forces. In this study, we used bovine spinal cord white matter to test and analyze the anisotropy and velocity dependence of the spinal cord. Tensile-vertical, tensile-parallel, shear-vertical, and shear-parallel tests were performed on the white matter in the fibrous direction (cranial to caudal). Strain rate in the experiment was 0.1, 1, 10, and 100/s. We calculated the Young's modulus of the spinal cord. Results of the tensile and shear tests revealed that stress tended to increase when external forces were applied parallel to the direction of axon fibers, such as in tensile-vertical and shear-vertical tests. However, external forces those tear against the fibrous direction and vertically, such as in tensile-parallel and shear-parallel tests, were less likely to increase stress even with increased velocity. We found that the spinal cord was prone to external forces, especially in the direction of the fibers, and to be under increased stress levels when the velocity of external forces increased. From these results, we confirmed that the spinal cord has velocity dependence and anisotropy. The Institutional Animal Care and Use Committee of Yamaguchi University waived the requirement for ethical approval.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4103/1673-5374.313059DOI Listing
December 2021

Mechanism for the Reaction of White Phosphorus with CpCr(CO) Leading Ultimately to the Triple-Decker Sandwich CpCr(μ-η,η-P): A Theoretical Study.

Inorg Chem 2021 Apr 9;60(8):5955-5968. Epub 2021 Apr 9.

Department of Chemistry and Center for Computational Chemistry, University of Georgia, Athens, Georgia 30602, United States.

The experimentally known reaction of CpCr(CO) with white phosphorus (P) to give CpCr(CO)(η-P), CpCr(CO)(μ-η,η-P), and the triple-decker sandwich CpCr(μ-η,η-P) is of interest since the P reactant having a tetrahedral cluster of four phosphorus atoms is converted to products having P, P, and P ligands. The mechanism of this obviously complicated reaction can be dissected into three stages using a coupled cluster theoretical method that has been benchmarked with the P, Mn(CO), and CpCr(CO) dimerization processes. The first stage of the CpCr(CO)/P reaction mechanism generates the unsaturated singlet intermediate CpCr(CO) that combines with the P reactant. Decarbonylation of the resulting CpCr(CO)(P) complex provides a singlet tetracarbonyl readily fragmenting into the stable triphosphacyclopropenyl complex CpCr(CO)(η-P) and the chromium phosphide CpCr(CO)(P). The isomeric triplet tetracarbonyl CpCr(CO)(P), readily fragments into CpCr(CO)(η-P), which can generate the stable diphosphaacetylene complex CpCr(CO)(η,η-P) as well as the pentamer [CpCr(CO)](P). Combination of the coordinately unsaturated CpCr(CO)(η-P) with CpCr(CO)(η-P) can lead to a ring expansion. This generates the P pentagonal ligand in a CpCr(CO)(P) precursor to the experimentally observed carbonyl-free triple-decker sandwich CpCr(μ-η,η-P) after three successive decarbonylations.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.inorgchem.1c00382DOI Listing
April 2021

The mental health status among nurses from low-risk areas under normalized COVID-19 pandemic prevention and control in China: A cross-sectional study.

Int J Ment Health Nurs 2021 Apr 2. Epub 2021 Apr 2.

Department of Cardiovascular Surgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.

This study aimed to investigate the mental health status of nurses from low-risk areas of novel coronavirus (COVID-19) pandemic, its potential impact factors, and the main stressors under the normalized prevention and control in China. A mobile phone app-based survey was conducted among registered nurses in Jiangsu province via a region-stratified sampling method. The questionnaire consisted of items on the demographic characteristics of the nursing staff and their Depression, Anxiety, Stress Scale-21 (DASS-21) along with questions for self-assessment of stressors that are associated with COVID-19. STROBE guideline was used. Among 1803 nurses who were working in the low-risk areas in Jiangsu, 22.0%, 29.8%, and 16.1% of them reported moderate to extreme levels of depression, anxiety, and stress, respectively. Having 11-15 years of working experience and being a fixed-term contract nurse were associated with experiencing worse mental health outcomes while supporting-Wuhan working experience and having mental health preparation course training were independent factors that had beneficial impact on their psychological well-being afterward. In terms of source of pressure, a key finding of this study is that the main stressor among these nurses was the lack of patient's understanding and cooperation (71.2%) which calls for better psychosocial communication between nurses and patients. The present findings would provide information for other regions at low risk of COVID-19 and may aid the provision of support and interventions for the benefit of the psychological well-being of nurses who are exposed to life-threatening occupational risks and are more vulnerable to the pandemic than others.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/inm.12852DOI Listing
April 2021

Increased structural defects of graphene oxide compromised reductive capacity of ZVI towards hexavalent chromium.

Chemosphere 2021 Aug 18;277:130308. Epub 2021 Mar 18.

College of Environmental Science and Engineering & Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou, 225127, PR China; Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China. Electronic address:

Graphene oxide (GO) was treated with irradiation beams to understand the defective degree of carbon structure of GO in relation to electron transfer property of impregnated zerovalent iron (ZVI). The GO-supported ZVI (ZVI/GO) was synthesized and then characterized by an X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. The results showed that the oxygen-bearing functional groups, oxygen content and structural disorder were increased as a function of irradiation beam intensity. ZVI was dominant in the composites, but proportion of iron oxide increased with greater oxygen content. Batch sorption revealed that Cr(VI) removal decreased from 20.11 g kg to 2.30 g kg as solution pH rose from 3 to 9. Cr(VI) removal capacity was 26.39 g kg, 23.12 g kg and 12.35 g kg for ZVI/GO, ZVI/GO and ZVI/GO, respectively. The reduction capacity of sorbents followed similar trends as Cr(VI) sorption as per desorption experiment, which accounted for a major Cr(VI) detoxification mechanism by ZVI/GO composites. The electrochemical tests demonstrated that unfavorable electron transfer rate of ZVI/GO composites was aggravated by greater structural disorder of GO. Thus, higher dose of irradiations could create more disorder in graphitic carbon and promote oxidation of ZVI, which hindered Cr(VI) reduction.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.chemosphere.2021.130308DOI Listing
August 2021

Multi-omics analyses reveal that HIV-1 alters CD4 T cell immunometabolism to fuel virus replication.

Nat Immunol 2021 04 25;22(4):423-433. Epub 2021 Mar 25.

Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.

Individuals infected with human immunodeficiency virus type-1 (HIV-1) show metabolic alterations of CD4 T cells through unclear mechanisms with undefined consequences. We analyzed the transcriptome of CD4 T cells from patients with HIV-1 and revealed that the elevated oxidative phosphorylation (OXPHOS) pathway is associated with poor outcomes. Inhibition of OXPHOS by the US Food and Drug Administration-approved drug metformin, which targets mitochondrial respiratory chain complex-I, suppresses HIV-1 replication in human CD4 T cells and humanized mice. In patients, HIV-1 peak viremia positively correlates with the expression of NLRX1, a mitochondrial innate immune receptor. Quantitative proteomics and metabolic analyses reveal that NLRX1 enhances OXPHOS and glycolysis during HIV-1-infection of CD4 T cells to promote viral replication. At the mechanistic level, HIV infection induces the association of NLRX1 with the mitochondrial protein FASTKD5 to promote expression of mitochondrial respiratory complex components. This study uncovers the OXPHOS pathway in CD4 T cells as a target for HIV-1 therapy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41590-021-00898-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8087183PMC
April 2021

Identification of the potential novel biomarkers as susceptibility gene for Wilms tumor.

BMC Cancer 2021 Mar 25;21(1):316. Epub 2021 Mar 25.

Department of Urology, The Second Hospital, University of South China, Hengyang, 421001, Hunan, China.

Background: Wilms tumor (WT) is the most common malignant renal tumor in children. The aim of this study was to identify potential susceptibility gene of WT for better prognosis.

Methods: Weighted gene coexpression network analysis is used for the detection of clinically important biomarkers associated with WT.

Results: In the study, 59 tissue samples from National Cancer Institute were pretreated for constructing gene co-expression network, while 224 samples also downloaded from National Cancer Institute were used for hub gene validation and module preservation analysis. Three modules were found to be highly correlated with WT, and 44 top hub genes were identified in these key modules eventually. In addition, both the module preservation analysis and gene validation showed ideal results based on other dataset with 224 samples. Meanwhile, Functional enrichment analysis showed that genes in module were enriched to sister chromatid cohesion, cell cycle, oocyte meiosis.

Conclusion: In summary, we established a gene co-expression network to identify 44 hub genes are closely to recurrence and staging of WT, and 6 of these hub genes was closely related to the poor prognosis of patients. Our findings revealed that those hub genes may be used as potential susceptibility gene for clinical diagnosis and prognosis of this tumor.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s12885-021-08034-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7992941PMC
March 2021

Differential expression of protein disulfide isomerase (PDI) in regulating endometrial receptivity in humans.

Reprod Biol 2021 Jun 4;21(2):100498. Epub 2021 Mar 4.

Department of Obstetrics and Gynaecology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region; Shenzhen Key Laboratory of Fertility Regulation, The University of Hong Kong-Shenzhen Hospital, Futian District, Shenzhen, China. Electronic address:

Estrogen and progesterone regulate the expression of endometrial proteins that determine endometrial receptivity for embryo implantation. The protein disulfide isomerase (PDI) family of proteins play a diverse role in regulating protein modification and redox function. Although the role of PDIs in cancer progression has been widely studied, their role in endometrial receptivity is largely unknown. We have focused on the expressions of PDIA1, PDIA2, PDIA3, PDIA4, PDIA5, and PDIA6 isoforms in endometrial epithelium under the influence of estrogen and progesterone and investigated their functional role in regulating endometrial receptivity. We found PDIA1-6 transcripts were expressed in endometrial epithelial Ishikawa, RL95-2, AN3CA, and HEC1-B cell lines. The expression of PDIA1 was low and PDIA5 was high in HEC1-B cells, whereas PDIA2 was high in both AN3CA and HEC1-B cells. In Ishikawa cells, estrogen (10 and 100 nM) upregulated PDIA1 and PDIA6, whereas estrogen (100 nM) downregulated PDIA4 and PDIA5; and progesterone (0.1 and 1 μM) downregulated transcript expressions of PDIA1-6. In human endometrial samples, significantly lowered transcript expressions of PDIA2 and PDIA5 were observed in the secretory phase compared with the proliferative phase, whereas no change was observed in the other studied transcripts throughout the cycle. Inhibition of PDI by PDI antibody (5 and 10 μg/mL) and PDI inhibitor bacitracin (1 and 5 mM) significantly increased the attachment of Jeg-3 spheroids onto AN3CA cells. Taken together, our study suggests a role of PDI in regulating endometrial receptivity and the possibility of using PDI inhibitors to enhance endometrial receptivity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.repbio.2021.100498DOI Listing
June 2021

Protocol for proteogenomic dissection of intronic splicing enhancer interactome for prediction of individualized cancer prognosis.

STAR Protoc 2021 Mar 11;2(1):100338. Epub 2021 Feb 11.

Department of Biochemistry & Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.

Inter- or intra-patient tumor heterogeneity hinders the discovery of biomarkers for predicting individualized prognosis. Here, we present a protocol for an alternative splicing activity-based proteogenomic approach for identification of candidate prognostic markers in cancer cell lines and human breast cancer specimens. The pull-down of protein complexes with intronic splicing enhancer (ISE) probes is followed by tandem mass spectrometry (MS/MS) peptide sequencing. The proteogenomic analysis of data from these ISE-MS/MS assays identifies new prognostic markers that can be utilized to stratify patients with poor prognosis. For complete details on the use and execution of this protocol, please refer to Wang et al. (2018).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.xpro.2021.100338DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7887646PMC
March 2021

Avibactam potentiated the activity of both ceftazidime and aztreonam against S. maltophilia clinical isolates in vitro.

BMC Microbiol 2021 02 22;21(1):60. Epub 2021 Feb 22.

Department of Clinical Laboratory Medicine, The First Affiliated Hospital of Chongqing Medical University, No. 1 Friendship Road, Yuzhong District, Chongqing, 400016, China.

Background: Treatment options for Stenotrophomonas maltophilia (S. maltophilia) infections were limited. We assessed the efficacy of ceftazidime (CAZ), ceftazidime-avibactam (CAZ-AVI), aztreonam (ATM), and aztreonam-avibactam (ATM-AVI) against a selection of 76 S. maltophilia out of the 1179 strains isolated from the First Affiliated Hospital of Chongqing Medical University during 2011-2018.

Methods: We investigated the antimicrobial resistance profiles of the 1179 S. maltophilia clinical isolates from the first affiliated hospital of Chongqing Medical University during 2011-2018, a collection of 76 isolates were selected for further study of microbiological characterization. Minimum inhibitory concentrations (MICs) of CAZ, CAZ-AVI, ATM and ATM-AVI were determined via the broth microdilution method. We deemed that CAZ-AVI or ATM-AVI was more active in vitro than CAZ or ATM alone when CAZ-AVI or ATM-AVI led to a category change from "Resistant" or "Intermediate" with CAZ or ATM alone to "Susceptible" with CAZ-AVI or ATM-AVI, or if the MIC of CAZ-AVI or ATM-AVI was at least 4-fold lower than the MIC of CAZ or ATM alone.

Results: For the 76 clinical isolates included in the study, MICs of CAZ, ATM, CAZ-AVI and ATM-AVI ranged from 0.03-64, 1-1024, 0.016-64, and 0.06-64 μg/mL, respectively. In combined therapy, AVI was active at restoring the activity of 48.48% (16/33) and 89.71% (61/68) of S. maltophilia to CAZ and ATM, respectively. Furthermore, CAZ-AVI showed better results in terms of the proportion of susceptible isolates (77.63% vs. 56.58%, P < 0.001), and MIC50 (2 μg/mL vs. 8 μg/mL, P < 0.05) when compared to CAZ. According to our definition, CAZ-AVI was more active in vitro than CAZ alone for 81.58% (62/76) of the isolates. Similarly, ATM-AVI also showed better results in terms of the proportion of susceptible isolates (90.79% vs.10.53%, P < 0.001) and MIC50 (2 μg/mL vs. 64 μg/mL, P < 0.001) when compared to ATM. According to our definition, ATM-AVI was also more active in vitro than ATM alone for 94.74% (72/76) of the isolates.

Conclusions: AVI potentiated the activity of both CAZ and ATM against S. maltophilia clinical isolates in vitro. We demonstrated that CAZ-AVI and ATM-AVI are both useful therapeutic options to treat infections caused by S. maltophilia.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s12866-021-02108-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7901100PMC
February 2021

Recent Advances in Developing Lanthanide Metal-Organic Frameworks for Ratiometric Fluorescent Sensing.

Front Chem 2020 25;8:624592. Epub 2021 Jan 25.

College of Materials Science and Engineering, Shenzhen University, Shenzhen, China.

Fluorescent probes have attracted special attention in developing optical sensor systems due to their reliable and rapid fluorescent response upon reaction with the analyte. Comparing to traditional fluorescent sensing systems that employ the intensity of only a single emission, ratiometric fluorescent sensors exhibit higher sensitivity and allow fast visual screening of analytes because of quantitatively analyzing analytes through the emission intensity ratio at two or more wavelengths. Lanthanide metal-organic frameworks (LnMOFs) are highly designable multifunctional luminescent materials as lanthanide ions, organic ligands, and guest metal ions or chromophores are all potential sources for luminescence. They thus have been widely employed as ratiometric fluorescent sensors. This mini review summarized the basic concept, optical features, construction strategies, and the ratiometric fluorescent sensing mechanisms of dual-emitting LnMOFs. The review ends with a discussion on the prospects, challenges, and new direction in designing LnMOF-based ratiometric fluorescent sensors.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fchem.2020.624592DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7868329PMC
January 2021

Manipulation of composting oxygen supply to facilitate dissolved organic matter (DOM) accumulation which can enhance maize growth.

Chemosphere 2021 Jun 23;273:129729. Epub 2021 Jan 23.

College of Natural Resources and Environment, South China Agricultural University, Guangzhou, 510642, PR China.

Promotion of crop yield by compost application is generally thought to be ascribed to a better supply of macro and micronutrients, however the importance of compost DOM on plant growth has not been well demonstrated. In this study, composting of chicken manure, spent mushroom and sawdust was conducted under aerobic or anaerobic condition to determine the effects of compost DOM on plant growth. It was found that dissolved organic matter (DOM) first increased and then decreased in compost, and DOM of anaerobic compost was slightly higher than that of aerobic compost. When compost extract was applied to maize, among N, P, K and DOM content, it was DOM content that was most significantly and strongly related to plant biomass (r = 0.843, p<0.001). Compost DOM was also strongly related to soil properties, the improvement of which can also promote plant growth. Compost application confirmed that higher compost DOM results in greater plant biomass. In order to facilitate compost DOM accumulation, we designed a novel composting process which combined aerobic and anaerobic treatments, and the resulting compost (A-Ana compost) with the highest amount of DOM displayed the best performance in promotion of plant growth. A-Ana compost was able to increase maize biomass by 32.71% and 12.40% compared with only anaerobic or aerobic compost, respectively. Therefore, DOM is a critical factor determining compost quality and it is feasible to manipulate composting oxygen supply condition to increase compost DOM, which will lead to increased plant yield.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.chemosphere.2021.129729DOI Listing
June 2021