Publications by authors named "Siyu Chen"

288 Publications

[Progress in the regulation of energy metabolic homeostasis by the SWI/SNF complex subunit Baf60a].

Sheng Wu Gong Cheng Xue Bao 2021 Feb;37(2):500-512

School of Life Science and Technology, China Pharmaceutical University, Nanjing 211198, Jiangsu, China.

Metabolic syndrome is a global chronic epidemic. Its pathogenesis is determined by genetic and environmental factors. Epigenetic modification is reported to regulate gene expression without altering its nucleotide sequences. In recent years, epigenetic modification is sensitively responded to environmental signals, further affecting the gene expression and signaling transduction. Among these regulators, chromatin remodeling SWI/SNF (SWItch/Sucrose non fermentable, SWI/SNF) complex subunit Baf60a plays an important role in maintaining energy homeostasis in mammals. In this paper, we described the pathophysiological roles of Baf60a in maintaining the balance of energy metabolism, including lipid metabolism, cholesterol metabolism, urea metabolism, as well as their rhythmicity. Therefore, in-depth understanding of Baf60a-orchestrated transcriptional network of energy metabolism will provide potential therapeutic targets and reliable theoretical supports for the treatment of metabolic syndrome.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.13345/j.cjb.200312DOI Listing
February 2021

The Impact of Particulate Matter (PM2.5) on Human Retinal Development in hESC-Derived Retinal Organoids.

Front Cell Dev Biol 2021 12;9:607341. Epub 2021 Feb 12.

Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing, China.

Increasing evidence demonstrated that PM2.5 could cross the placenta and fetal blood-brain barrier, causing neurotoxicity of embryonic development. The retina, an embryologic extension of the central nervous system, is extremely sensitive and vulnerable to environmental insults. The adverse effects of PM2.5 exposure on the retina during embryonic neurodevelopment are still largely unknown. Our goal was to investigate the effect of PM2.5 on human retinal development, which was recapitulated by human embryonic stem cell (hESC)-derived retinal organoids (hEROs). In the present study, using the hEROs as the model, the influences and the mechanisms of PM2.5 on the developing retina were analyzed. It demonstrated that the formation rate of the hERO-derived neural retina (NR) was affected by PM2.5 in a concentration dosage-dependent manner. The areas of hEROs and the thickness of hERO-NRs were significantly reduced after PM2.5 exposure at the concentration of 25, 50, and 100 μg/ml, which was due to the decrease of proliferation and the increase of apoptosis. Although we did not spot significant effects on retinal differentiation, PM2.5 exposure did lead to hERO-NR cell disarranging and structural disorder, especially retinal ganglion cell dislocation. Transcriptome analysis showed that PM2.5 treatment was significantly associated with the mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K)/AKT pathways and reduced the level of the fibroblast growth factors (FGFs), particularly FGF8 and FGF10. These results provided evidence that PM2.5 exposure potentially inhibited proliferation and increased apoptosis at the early development stage of the human NR, probably through the MAPK and PI3K/Akt pathway. Our study suggested that exposure to PM2.5 suppressed cell proliferation and promoted cell apoptosis, thereby contributing to abnormal human retinal development.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fcell.2021.607341DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7907455PMC
February 2021

DGKA Mediates Resistance to PD-1 Blockade.

Cancer Immunol Res 2021 Feb 19. Epub 2021 Feb 19.

State Key Laboratory of Oncology in Southern China, Sun Yat-sen University Cancer Center

Immunologic checkpoint blockade has been proven effective in a variety of malignancies. However, high rates of resistance have substantially hindered its clinical use. Understanding the underlying mechanisms may lead to new strategies for improving therapeutic efficacy. Although a number of signal pathways have been shown associated with tumor cell-mediated resistance to immunotherapy, T cell-intrinsic resistant mechanisms remain elusive. Here, we demonstrated that diacylglycerol kinase alpha (Dgka) mediated T-cell dysfunction during anti-PD-1 therapy by exacerbating the exhaustion of reinvigorated tumor-specific T cells. Pharmacological ablation of Dgka postponed T-cell exhaustion and delayed development of resistance to PD-1 blockade. Dgka inhibition also enhanced the efficacy of anti-PD-1 therapy. We further found that the expression of DGKA in cancer cells promoted tumor growth via the AKT signaling pathway, suggesting that DGKA might be a target in tumor cells as well. Together, these findings unveiled a molecular pathway mediating resistance to PD-1 blockade and provide a potential therapeutic strategy with combination immunotherapy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1158/2326-6066.CIR-20-0216DOI Listing
February 2021

Removal of roosters alters the domestic phenotype and microbial and genetic profile of hens.

Sci China Life Sci 2021 Feb 4. Epub 2021 Feb 4.

Guangdong Provincial Key Laboratory of Animal Molecular Design and Precise Breeding; School of Life Science and Engineering, Foshan University, Foshan, 528225, China.

Hens are raised apart from roosters in modern poultry production, a substantial change from their natural social structure. We compared productivity, injuries, behavior, physiology, microbiome and transcriptome of hens housed with (R+) or without (R-) roosters to quantify the effects of this change in social structure. Hens were raised free-range from 70 to 280 days when 30 birds per treatment were assigned to battery cages until Day 315 (R+C vs. R-C), while 30 birds per treatment remained in free-range pens (R+F vs. R-F). Response to a novel environment and object, behavioral time budgets, cecum microbiome, blood composition and transcriptomic sequencing of thigh muscle and spleen were analyzed. Hens housed without roosters showed better survival, consumed less food, produced more eggs and had better feed conversion. R+F hens clustered around the rooster and were less mobile in the novel environment and object tests. R+F hens displayed the richest microbiome, and the presence of roosters resulted in differentially expressed genes related to muscle development, cellular processes, environmental information processing and immune function. Removing roosters from housed hens intensified desirable characteristics favored by domestication probably operating by deprivation of mating behavior and reduced fear, along with altered microbial and genetic function.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11427-020-1770-1DOI Listing
February 2021

Clinical characteristics in patients with coronary slow flow phenomenon: A retrospective study.

Medicine (Baltimore) 2021 Feb;100(6):e24643

Department of Cardiology, the First Affiliated Hospital of Chongqing Medical University.

Abstract: Coronary slow flow phenomenon (CSFP) is a coronary artery disease in which coronary angiography shows no obvious stenosis, but there is a delay in blood flow perfusion. The etiopathogenic mechanisms of CSFP are still unclear. The aim of the present study was to investigate the role of clinical characteristics in patients with CSFP, and to provide a reference for exploring the potential mechanisms of CSFP. Patients with angiographically normal epicardial arteries were enrolled (145 patients with CSFP and 145 normal controls). Collected clinical information and laboratory indexes, which measured by peripheral venous blood samples before coronary angiography. Logistic regression analysis was performed for statistical analysis. The present study found 19 clinical and laboratory indexes with statistical differences between the two groups in univariate analysis. Multivariate analysis showed that monocyte count, haemoglobin, serum creatinine and globulin were independent predictors of CSFP. Moreover, the monocyte count, haemoglobin, creatinine and globulin levels were significantly higher in the CSFP patients than the controls, with positive associations between these parameters and the extent of CSFP. In addition, ROC analysis showed the diagnostic value of the above indexes for CSFP.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/MD.0000000000024643DOI Listing
February 2021

A STING-related prognostic score predicts high-risk patients of colorectal cancer and provides insights into immunotherapy.

Ann Transl Med 2021 Jan;9(1):14

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

Background: Targeted therapeutic strategies for advanced colorectal cancer (CRC) have been limited. STING is crucial to the antitumor immunotherapy, for it stimulates IFN signaling to mediate the crosstalk between innate and adaptive immune responses. Emerging evidence suggests that STING also contributes to the prognosis of CRC. However, prognostic models relating to STING have not yet been explored.

Methods: A total of 431 CRC samples from the TCGA database were analyzed to explore the prognostic value of STING-related genes. We trained prognostic models using the multivariate Cox regression. A STING-related prognostic score (SPS) was calculated as the gene expression multiplied by the corresponding coefficients of the final model. A backward stepAIC strategy was adopted to select the optimal model. A nomogram was used to personalize medical decisions for CRC.

Results: The expression level of STING was upregulated in the CMS1 subtype (P=0.036). Among STING-related genes, DHX9 (HR =0.72, P=0.01), IRF2 (HR =1.34, P=0.022), and POLR1D (HR =1.23, P=0.038) showed significant prognostic value. The SPS was proven to be an independent risk factor (training: HR =2.9, P=0.00013; validation: HR =3.02, P=0.01), and outperformed random classifiers in identifying high-risk CRC. The high SPS group was characterized by less genomic aberrations, upregulated IL6-JAK-STAT3 and IL2-STAT5 signaling pathways, increased expression of TIM-3, increased infiltration of regulatory T (Treg) cells and T helper 17 (Th17) cells, and decreased infiltration of M0 macrophages. Finally, the nomogram based on the SPS and clinical factors showed good performance in CRC.

Conclusions: SPS is an independent risk factor that could identify high-risk CRC. While ICBs may benefit patients of the CMS1 subtype, for the CMS2, CMS3, and CMS4 subtypes in the high SPS group, STING agonists and immunotherapies targeting the Th17 axis may be beneficial. Finally, the SPS-based nomogram could help advance personalized medical decisions for CRC.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.21037/atm-20-2430DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7859804PMC
January 2021

Serum fibroblast growth factor 23 (FGF-23): associations with hyperphosphatemia and clinical staging of feline chronic kidney disease.

J Vet Diagn Invest 2021 Feb 5:1040638720985563. Epub 2021 Feb 5.

College of Veterinary Medicine, China Agricultural University, Beijing, China.

Fibroblast growth factor 23 (FGF-23) is an independent monitor of the progression of chronic kidney disease (CKD) in human medicine, and FGF-23 may have value as a biomarker in feline CKD. We evaluated the relationship between serum FGF-23 and CKD stages, and the effect of age on FGF-23 in normal cats. We measured FGF-23 and intact parathyroid hormone (iPTH) concentrations by ELISA, with intra- and inter-assay CVs ≤ 15%. The percentage recovery of FGF-23 and iPTH remained stable for up to 7 d in samples stored at -20°C and -80°C. We measured FGF-23 in 304 cats, among which 196 were diagnosed with CKD. The 108 clinically healthy cats were divided into 5 subgroups based on growth stage (0-2 y, 3-6 y, 7-10 y, 11-14 y, ≥ 15 y). No statistical difference was found in FGF-23 among age groups ( = 0.15) or by sex in healthy subjects. Using the International Renal Interest Society guideline, 34 cats were defined as CKD stage 1, 74 stage 2, 51 stage 3, and 37 stage 4. FGF-23 was higher in cats in all CKD stages than in controls. Higher serum phosphorus was observed in stage 3 ( = 0.04) and 4 ( < 0.01) compared to controls. iPTH increased as CKD progressed. Pearson analysis indicated a positive linear relationship between FGF-23 and iPTH (control: = 0.70, < 0.01; CKD: = 0.46, = 0.02). FGF-23 may be a useful biomarker of feline CKD and may precede hyperphosphatemia in advanced feline CKD.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/1040638720985563DOI Listing
February 2021

OCT-OCTA segmentation: combining structural and blood flow information to segment Bruch's membrane.

Biomed Opt Express 2021 Jan 8;12(1):84-99. Epub 2020 Dec 8.

Pattern Recognition Lab, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, 91058, Germany.

In this paper we present a fully automated graph-based segmentation algorithm that jointly uses optical coherence tomography (OCT) and OCT angiography (OCTA) data to segment Bruch's membrane (BM). This is especially valuable in cases where the spatial correlation between BM, which is usually not visible on OCT scans, and the retinal pigment epithelium (RPE), which is often used as a surrogate for segmenting BM, is distorted by pathology. We validated the performance of our proposed algorithm against manual segmentation in a total of 18 eyes from healthy controls and patients with diabetic retinopathy (DR), non-exudative age-related macular degeneration (AMD) (early/intermediate AMD, nascent geographic atrophy (nGA) and drusen-associated geographic atrophy (DAGA) and geographic atrophy (GA)), and choroidal neovascularization (CNV) with a mean absolute error of ∼0.91 pixel (∼4.1 μm). This paper suggests that OCT-OCTA segmentation may be a useful framework to complement the growing usage of OCTA in ophthalmic research and clinical communities.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1364/BOE.398222DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7818963PMC
January 2021

Maximum a posteriori signal recovery for optical coherence tomography angiography image generation and denoising.

Biomed Opt Express 2021 Jan 7;12(1):55-68. Epub 2020 Dec 7.

Pattern Recognition Lab, Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany.

Optical coherence tomography angiography (OCTA) is a novel and clinically promising imaging modality to image retinal and sub-retinal vasculature. Based on repeated optical coherence tomography (OCT) scans, intensity changes are observed over time and used to compute OCTA image data. OCTA data are prone to noise and artifacts caused by variations in flow speed and patient movement. We propose a novel iterative maximum a posteriori signal recovery algorithm in order to generate OCTA volumes with reduced noise and increased image quality. This algorithm is based on previous work on probabilistic OCTA signal models and maximum likelihood estimates. Reconstruction results using total variation minimization and wavelet shrinkage for regularization were compared against an OCTA ground truth volume, merged from six co-registered single OCTA volumes. The results show a significant improvement in peak signal-to-noise ratio and structural similarity. The presented algorithm brings together OCTA image generation and Bayesian statistics and can be developed into new OCTA image generation and denoising algorithms.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1364/BOE.408903DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7818957PMC
January 2021

Ultrasensitive electrochemical immunosensor based on the signal amplification strategy of the competitive reaction of Zn and ATP ions to construct a "signal on" mode GOx-HRP enzyme cascade reaction.

Mikrochim Acta 2021 Jan 29;188(2):61. Epub 2021 Jan 29.

Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan, Engineering Research Center of Materials-Oriented Chemical Engineering of Xinjiang Production and Construction Corps, Key Laboratory of Materials-Oriented Chemical Engineering of Xinjiang Uygur Autonomous Region, School of Chemistry and Chemical Engineering, Shihezi University, Shihezi, 832003, People's Republic of China.

A GOx/HRP@ZIF-90 nanomaterial is proposed by coating GOx and HRP in ZIF-90 using a bio-simulated mineralization method to improve the tolerance of the enzyme to the external environment. In the detection process, the ZIF-90 is turned on under mild conditions by the competitive reaction of ATP with Zn and imidazole-2-carboxaldehyde (2-ICA), and the electrical signal of the system is amplified by the enzyme cascade reaction of GOx and HRP. Finally, based on the signal amplification strategy of the competitive reaction between Zn and ATP to construct a "signal on" mode, electrochemical immunosensor of GOx-HRP enzyme-linked cascade reaction was prepared. The proposed electrochemical immunosensor shows an excellent analytical performance when detecting CA-125, with good selectivity and stability, with a detection range of 0.1 pg mL-40 ng mL and a detection limit of 0.05 pg mL. The test has been performed using chronoamperometry under a constant voltage of -0.4 V. The immunosensor also shows an excellent performance when analysing human blood samples. The recovery of the immunosensor is 97.94-101.8%, with a relative standard deviation of 3.7-6.1%. The proposed sensor provides a novel idea for clinical use of GOx and HRP enzymes and a new method for the clinical detection of tumor markers.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00604-021-04720-5DOI Listing
January 2021

Uranyl-catalyzed hydrosilylation of -quinone methides: access to diarylmethane derivatives.

Org Biomol Chem 2021 Feb;19(7):1575-1579

Laboratory of Nuclear Energy Chemistry, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, P. R. China.

An efficient and convenient uranyl-catalyzed reductive hydrosilylation reaction of para-quinone methides (p-QMs) was developed by employing silane as the reductant. The hydrosilylation procedure using the UO2(NO3)2·6H2O/Et3SiH catalytic system proceeded smoothly and provided an expedient method for the construction of various diarylmethane derivatives in one step with good to excellent yields.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/d0ob02455dDOI Listing
February 2021

Simultaneously enhanced dielectric properties and through-plane thermal conductivity of epoxy composites with alumina and boron nitride nanosheets.

Sci Rep 2021 Jan 28;11(1):2495. Epub 2021 Jan 28.

State Key Laboratory of Electrical Insulation and Power Equipment, Center of Nanomaterials for Renewable Energy, Xi'an Jiaotong University, Xi'an, 710049, China.

Dielectric materials with good thermal transport performance and desirable dielectric properties have significant potential to address the critical challenges of heat dissipation for microelectronic devices and power equipment under high electric field. This work reported the role of synergistic effect and interface on through-plane thermal conductivity and dielectric properties by intercalating the hybrid fillers of the alumina and boron nitride nanosheets (BNNs) into epoxy resin. For instance, epoxy composite with hybrid fillers at a relatively low loading shows an increase of around 3 times in through-plane thermal conductivity and maintains a close dielectric breakdown strength compared to pure epoxy. Meanwhile, the epoxy composite shows extremely low dielectric loss of 0.0024 at room temperature and 0.022 at 100 ℃ and 10 Hz. And covalent bonding and hydrogen-bond interaction models were presented for analyzing the thermal conductivity and dielectric properties.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41598-021-81925-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7844292PMC
January 2021

Feed Restriction Induced Changes in Behavior, Corticosterone, and Microbial Programming in Slow- and Fast-Growing Chicken Breeds.

Animals (Basel) 2021 Jan 11;11(1). Epub 2021 Jan 11.

College of Animal Science and Technology, China Agricultural University, Beijing 100193, China.

This study aimed to explore the difference between two Chinese local broilers, one slow- and one fast-growing, in their response to a stress challenge. We conducted the study on slow- (Weining chicken) and fast-growing (Jinlinghua chicken) breeds, with 50 chickens from each breed either feed restricted to 70% for 30 days as a stress or given ad libitum to evaluate the effects on behavior, corticosterone, and microbial programming. Standing behavior was more frequent while exploration was less common in fast-growing breeds compared to slow-growing breeds. Food seeking and ingestion, exploration, and drinking increased, while resting decreased in the feed restricted treatments. There was no difference in corticosterone concentration between slow- and fast-growing chickens, but the level was affected by feeding treatments, and the interaction of breed and feed restriction. At the genus-level, the relative abundance of and was higher, while and was lower in the slow-growing breed compared to the fast-growing breed. Feed restricted birds had a higher abundance of , but lower abundance of , and . In conclusion, feed restriction to 70% for 30 days as a chronic stress stimulation caused more activity, elevated the stress response, and altered gut microbiota composition, but some changes were only evident in slow- or fast-growing chickens.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/ani11010141DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7827424PMC
January 2021

Recent advances in focused ion beam nanofabrication for nanostructures and devices: fundamentals and applications.

Nanoscale 2021 Jan;13(3):1529-1565

National Engineering Research Centre for High Efficiency Grinding, College of Mechanical and Vehicle Engineering, Hunan University, Changsha 410082, P. R. China.

The past few decades have witnessed growing research interest in developing powerful nanofabrication technologies for three-dimensional (3D) structures and devices to achieve nano-scale and nano-precision manufacturing. Among the various fabrication techniques, focused ion beam (FIB) nanofabrication has been established as a well-suited and promising technique in nearly all fields of nanotechnology for the fabrication of 3D nanostructures and devices because of increasing demands from industry and research. In this article, a series of FIB nanofabrication factors related to the fabrication of 3D nanostructures and devices, including mechanisms, instruments, processes, and typical applications of FIB nanofabrication, are systematically summarized and analyzed in detail. Additionally, current challenges and future development trends of FIB nanofabrication in this field are also given. This work intends to provide guidance for practitioners, researchers, or engineers who wish to learn more about the FIB nanofabrication technology that is driving the revolution in 3D nanostructures and devices.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/d0nr07539fDOI Listing
January 2021

Efficient and high-fidelity base editor with expanded PAM compatibility for cytidine dinucleotide.

Sci China Life Sci 2021 Jan 6. Epub 2021 Jan 6.

Laboratory of Zoonosis Research, Ministry of Education, College of Animal Science, Jilin University, Changchun, 130062, China.

Cytidine base editor (CBE), which is composed of a cytidine deaminase fused to Cas9 nickase, has been widely used to induce C-to-T conversions in a wide range of organisms. However, the targeting scope of current CBEs is largely restricted to protospacer adjacent motif (PAM) sequences containing G, T, or A bases. In this study, we developed a new base editor termed "nNme2-CBE" with excellent PAM compatibility for cytidine dinucleotide, significantly expanding the genome-targeting scope of CBEs. Using nNme2-CBE, targeted editing efficiencies of 29.0%-55.0% and 17.3%-52.5% were generated in human cells and rabbit embryos, respectively. In contrast to conventional nSp-CBE, the nNme2-CBE is a natural high-fidelity base editing platform with minimal DNA off-targeting detected in vivo. Significantly increased efficiency in GC context and precision were determined by combining nNme2Cas9 with rationally engineered cytidine deaminases. In addition, the Founder rabbits with accurate single-base substitutions at Fgf5 gene loci were successfully generated by using the nNme2-CBE system. These novel nNme2-CBEs with expanded PAM compatibility and high fidelity will expand the base editing toolset for efficient gene modification and therapeutic applications.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11427-020-1775-2DOI Listing
January 2021

Direct band gap and strong Rashba effect in van der Waals heterostructures of InSe and Sb single layers.

J Phys Condens Matter 2021 Jan 8. Epub 2021 Jan 8.

Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge, CB3 0FS, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND.

Van der Waals heterostructures formed by stacking different types of 2D materials are attracting increasing attention due to new emergent physical properties such as interlayer excitons. Recently synthesized atomically thin indium selenide (InSe) and antimony (Sb) individually exhibit interesting electronic properties such as high electron mobility in the former and high hole mobility in the latter. In this work, we present a first-principles investigation on the stability and electronic properties of ultrathin bilayer heterostructures composed of InSe and Sb single layers. The calculated electronic band structures reveal a direct band gap semiconducting nature of the InSe/Sb heterostructures independent of stacking pattern. Taking spin-orbit coupling into account, we find a large Rashba spin splitting at the bottom of conduction band, which originates from the atomic spin-orbit coupling with the symmetry breaking in the heterostructure. The strength of the Rashba spin splitting can be tuned by applying in-plane biaxial strain or an out-of-plane external electric field. The presence of large Rashba spin splitting together with a suitable band gap in InSe/Sb bilayer heterostructures make them promising candidates for spin field-effect transistor and optoelectronic device applications.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1088/1361-648X/abd9eeDOI Listing
January 2021

Disome-seq reveals widespread ribosome collisions that promote cotranslational protein folding.

Genome Biol 2021 Jan 5;22(1):16. Epub 2021 Jan 5.

State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100101, China.

Background: The folding of proteins is challenging in the highly crowded and sticky environment of a cell. Regulation of translation elongation may play a crucial role in ensuring the correct folding of proteins. Much of our knowledge regarding translation elongation comes from the sequencing of mRNA fragments protected by single ribosomes by ribo-seq. However, larger protected mRNA fragments have been observed, suggesting the existence of an alternative and previously hidden layer of regulation.

Results: In this study, we performed disome-seq to sequence mRNA fragments protected by two stacked ribosomes, a product of translational pauses during which the 5'-elongating ribosome collides with the 3'-paused one. We detected widespread ribosome collisions that are related to slow ribosome release when stop codons are at the A-site, slow peptide bond formation from proline, glycine, asparagine, and cysteine when they are at the P-site, and slow leaving of polylysine from the exit tunnel of ribosomes. The structure of disomes obtained by cryo-electron microscopy suggests a different conformation from the substrate of the ribosome-associated protein quality control pathway. Collisions occurred more frequently in the gap regions between α-helices, where a translational pause can prevent the folding interference from the downstream peptides. Paused or collided ribosomes are associated with specific chaperones, which can aid in the cotranslational folding of the nascent peptides.

Conclusions: Therefore, cells use regulated ribosome collisions to ensure protein homeostasis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s13059-020-02256-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7784341PMC
January 2021

Sex Disparities in the Clinical Characteristics, Synchronous Distant Metastasis Occurrence and Prognosis: A Pan-cancer Analysis.

J Cancer 2021 1;12(2):498-507. Epub 2021 Jan 1.

Department of Bone and Soft Tissue Tumours, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Tianjin 300060, China.

This study aims to assess the sex disparities in clinical characteristics and synchronous distant metastasis occurrence at diagnosis, as well as the subsequent prognosis in non-sex-specific cancers. The study included details from patients diagnosed with non-sex-specific cancers, during the period from 2010 to 2016, in the Surveillance, Epidemiology, and End Results (SEER) program. The distant metastasis prevalence and subsequent survival time were summarized in the total population and the population with specific cancers of different systems. The multivariable logistic and the Cox proportional hazards regressions were applied to evaluate the sex effect on distant metastasis occurrence and prognosis. The results were combined using meta-analysis. Across all non-sex-specific cancers, the pooled prevalence of distant metastasis was 15.2% (95% CI: 14.7-15.7%) and 7.1% (95% CI: 6.8-7.3%) for males and females, respectively. The pooled median survival time was 8.40 months (95% CI: 7.99-8.81) for male patients and 9.40 months (95% CI: 8.84-10.02) for female patients. After combining all non-sex-specific cancers, male patients displayed a higher distant metastasis occurrence than females (pooled OR=1.06, 95% CI: 1.04-1.08; 0.01), as well as worse overall survival after distant metastasis (pooled HR=1.08, 95% CI: 1.05-1.10; <0.01). The sex differences were more significant in patients younger than 65 years (0.01). Additionally, the sex influence on prognosis was most predominant amongst patients from Asian or Pacific Islander ethnic groups. Male gender appears to be an independent risk factor associated with the occurrence and prognosis of synchronous distant metastasis. Therefore, sex-specific preventions and treatments should become the focus of future research.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.7150/jca.50536DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7739003PMC
January 2021

Mapping the exposure and sensitivity to heat wave events in China's megacities.

Sci Total Environ 2021 Feb 6;755(Pt 1):142734. Epub 2020 Oct 6.

College of Applied Arts and Sciences, Beijing Union University, Beijing 100191, China.

The rising temperature makes the weather becoming more extreme. Understanding how extreme hot temperature-heat wave events (HWEs)-are likely to alter individual heat exposure and sensitivity is crucial for developing climate change mitigation and adaptation strategies. Despite the importance, little is known about the real-time impacts of HWEs on individual daily life in developing nations, like China. To fill this gap, we adopt over 1544 thousand Weibo (Chinese Twitter) social media data, coupled with meteorological conditions people face when posting, to assess the heat exposure and people's sensitivity to HWEs across 31 mega-cities in China. The results show the hotspot of Weibo heat is coincident with the extremely hot temperature, with a correlation of 0.7 (p < 0.05). The intensities, frequencies, and durations of HWEs in both geographical and social media space have high spatial heterogeneity. Its spatial variation can be explained by the type of climate zone and the unique geographical environment. The cities with extreme hot weather are more likely to adapt to the heatwave and less sensitivity to HWEs. The proposed framework, which integrates the real-time social media semantic analysis, statistical method, and spatial techniques, provides a new paradigm to assess the HWEs exposure and sensitivity analysis in China.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.scitotenv.2020.142734DOI Listing
February 2021

A novel, efficient and sustainable magnetic sludge biochar modified by graphene oxide for environmental concentration imidacloprid removal.

J Hazard Mater 2021 Apr 5;407:124777. Epub 2020 Dec 5.

Hubei Key Laboratory of Mineral Resources Processing and Environment, School of Resources and Environmental Engineering, State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan 430070, China; The James Hutton Institute, Craigiebuckler, Aberdeen AB15 8QH, UK. Electronic address:

Environmental concentration imidacloprid (IMI) has become a potential risk to ecological safety and human health, therefore an efficient, sustainable and environment friendly approach was urgently needed for its removal. In this study, a novel graphene oxide supported magnetic sludge biochar composite (GO/CoFeO-SBC) was first time synthesized and assessed for IMI removal at environmental concentration level. The maximum adsorption capacity of GO/CoFeO-SBC for IMI was 8.64 × 10 μg g. Physicochemical characteristics, kinetics (pseudo-second-order), isotherms (Freundlich and Temkin), thermodynamics and environmental factors analysis suggested that its outstanding adsorption performance was mainly attributed to pore filling, π-π conjugation and functional groups interaction. The mechanisms analysis indicated that intraparticle diffusion was the main rate-limiting step and its adsorption was a spontaneous, endothermic and randomness increased process. The magnetic sensitivity enabled it to be easily separated from water. The sustainable adsorption capacity (>90% of the initial adsorption capacity) of GO/CoFeO-SBC was well maintained by ethanol extraction even after five reuse cycles. GO/CoFeO-SBC also exhibited environmental security with its leaching concentrations of Fe and Co were below 0.5 mg L in a wide pH range. The performance of GO/CoFeO-SBC suggested that it could be served as a promising adsorbent for environmental concentration IMI removal.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jhazmat.2020.124777DOI Listing
April 2021

A novel method for determining the adequate dose of a chelating agent for phytoremediation of radionulides contaminated soils by M. cordata.

J Environ Radioact 2021 Feb 6;227:106468. Epub 2020 Dec 6.

Key Discipline Laboratory for National Defense for Biotechnology in Uranium, Mining and Hydrometallurgy, University of South China, Hengyang, 421001, China; Hunan Province Key Laboratory of Green Development Technology for Extremely Low Grade Uranium Resources, Hengyang, Hunan, 421001, China. Electronic address:

A chelating agent in an adequate dose used to enhance phytoremediation of radionuclide-contaminated soil should not inhibit the growth of the plant. If this constraint condition is satisfied, the total bioaccumulation amount (TBA) of radionuclide by the plant can be maximized. This is a constrained optimization problem to determine the adequate dose of the chelating agent for phytoremediation of radionuclide-contaminated soil. In this research, an adequate dose of a chelating agent for phytoremediation of radionuclide-contaminated soil was determined by a novel approach using pot experiments. The proposed approach was applied to specify the adequate doses of citric acid (CA) and S,S-ethylenediamine disuccinic acid (EDDS) for phytoremediation of uranium contaminated soil by M. Cordata. By using this method, the adequate doses of CA and EDDS for phytoremediation of U, Th and Ra contaminated soils by M. cordata were measures as 10.0 and 5.0 mmol kg, respectively. The results showed that the approach could be used to establish the adequate dose of a chelating agent for phytoremediation of radionuclide or other toxic heavy metal contaminated soil by a plant.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jenvrad.2020.106468DOI Listing
February 2021

ADM14 Induces Anti-Obesity Effects and Changes in Gut Microbiome in High-Fat Diet-Induced Obese Mice.

Nutrients 2020 Nov 30;12(12). Epub 2020 Nov 30.

Department of Food Science and Biotechnology, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon 16419, Korea.

The aim of our study was to evaluate the anti-obesity effects of () ADM14 administration in a high-fat diet-induced obese mouse model and the resulting changes in the intestinal microbiota. Prior to in vivo testing, ADM14 was shown to inhibit adipogenesis through in vitro test and genetic analysis. Subsequently, mice were orally administered 0.85% saline supplemented or not with ADM14 to high-fat diet group and normal diet group daily. The results showed that administration of ADM14 reduced weight gain, epididymal fat expansion, and total blood cholesterol and glucose levels, and significantly decreased expression of lipid-related genes in the epididymal fat pad. Administration of ADM14 showed improvement in terms of energy harvesting while restoring the Firmicutes to Bacteroidetes ratio and also increased the relative abundance of specific microbial taxa such as and , which are abundant in non-obese people. ADM14 affected the modulation of gut microbiota, altered the strain profile of short-chain fatty acid production in the cecum and enhanced the stimulation of butyrate production. Overall, ADM14 showed potential as a therapeutic probiotic supplement for metabolic disorders, confirming the positive changes of in vivo indicators and controlling gut microbiota in a high-fat diet-induced obese mouse model.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/nu12123703DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7761388PMC
November 2020

Characterization of rare earth elements present in coal ash by sequential extraction.

J Hazard Mater 2021 01 23;402:123760. Epub 2020 Aug 23.

Civil and Environmental Engineering, Konkuk University, 120 Neungdong-ro Gwangjin-gu, Seoul 05029, South Korea. Electronic address:

Although it has recently been reported that notable amounts of rare earth elements (REEs) are present in the residual coal ash, little is currently known regarding the association of these elements with the coal ash matrix, thereby limiting the potential for extraction of REEs from coal ash. In this study, we analyzed the binding characteristics of REEs within coal ash via sequential extraction and examined REE recovery during a coal ash recycling process. Major components of coal ash were found to be mineral oxides, mainly composed of Si, Fe, Al, and Ca, and residual carbons. Bottom and fly ashes were found to contain 185.8 mg/kg and 179.2 mg/kg of REEs, respectively. Tessier sequential extraction confirmed that 85 % of REEs are included in the residual fraction of both bottom and fly ashes. Furthermore, BCR sequential extraction revealed that 60-70 % of REEs are contained within the residual fraction, thereby indicating that REEs are strongly bound in both bottom and fly ashes and the use of very strong acids is required for the thorough extraction of REEs from coal ash. Additionally, it was found that 46.3 % of REEs can be recovered from the wastewaters produced during the process of coal ash-derived zeolite synthesis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jhazmat.2020.123760DOI Listing
January 2021

Desert dust as a significant carrier of atmospheric mercury.

Environ Pollut 2020 Dec 8;267:115442. Epub 2020 Sep 8.

State Key Laboratory of Cryospheric Science, Northeast Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China.

The atmospheric circulation plays a critical role in the global transport and deposition of atmospheric pollutants such as mercury (Hg). Desert dust emissions contribute to nearly 60-95% of the global dust budget and thus, desert dust may facilitate atmospheric Hg transport and deposition to the downwind regions worldwide. The role of desert dust in biogeochemical cycling of Hg, however, has not been well recognized by the Hg research community. In this study, we measured the concentration of particulate bound Hg (Hg) in total suspended particulate (TSP) collected from China's largest desert, Taklimakan Desert, between 2013 and 2017. The results show that Hg concentrations over the Taklimakan Desert atmosphere are remarkably higher than those observed from background sites in China and are even comparable to those measured in most of the Chinese metropolitan cities. Moreover, Hg concentrations in the Taklimakan Desert exhibit a distinct seasonal pattern peaking during dust storm outbreak periods in spring and summer (March to August). A preliminary estimation demonstrates that export of total Hg associated with atmospheric dust from the Taklimakan Desert could be 59.7 ± 60.3 (1SD) Mg yr. The unexpectedly high Hg concentrations during duststorms, together with consistent seasonal pattern of Hg revealed from the snow/ice, clearly demonstrate that Asian desert dust could act as a significant carrier of atmospheric Hg to the cryosphere of Western China and even can have further global reach.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.envpol.2020.115442DOI Listing
December 2020

Generative Adversarial Networks in Medical Image Processing.

Curr Pharm Des 2020 Nov 24. Epub 2020 Nov 24.

School of Computer Science, Chengdu University of Information Technology, Chengdu 610225. China.

Background: The emergence of generative adversarial networks (GANs) has provided a new technology and framework for the application of medical images. Specifically, a GAN requires little to no labeled data to obtain highquality data that can be generated through competition between the generator and discriminator networks. Therefore, GANs are rapidly proving to be a state-of-the-art foundation, achieving enhanced performances in various medical applications.

Methods: In this article, we introduce the principles of GANs and their various variants, deep convolutional GAN, conditional GAN, Wasserstein GAN, Info-GAN, boundary equilibrium GAN, and cycle-GAN.

Results: All various GANs have found success in medical imaging tasks, including medical image enhancement, segmentation, classification, reconstruction, and synthesis. Furthermore, we summarize the data processing methods and evaluation indicators. Finally, we note the limitations of existing methods and the existing challenges that need to be addressed in this field.

Conclusion: Although GANs are in initial stage of development in medical image processing, it will have a great prospect in the future.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2174/1381612826666201125110710DOI Listing
November 2020

A self-activating nanovesicle with oxygen-depleting capability for efficient hypoxia-responsive chemo-thermo cancer therapy.

Biomaterials 2021 Feb 18;269:120533. Epub 2020 Nov 18.

State Key Laboratory of High Performance Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, 200050, PR China; School of Chemistry and Materials Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, 310024, PR China. Electronic address:

Hypoxia-activated prodrugs (HAPs) promise to mitigate side effects of conventional chemotherapy and to enable precise medication treatment. One challenge facing HAPs-based chemotherapy is prodrug failure in normoxic tumor region. However, current strategies to enhance tumor hypoxia rely on delivery of oxygen-consuming agents and external stimulation, which can impede the optimal application of HAPs. Herein, a novel self-activating nanovesicle, TH-302@BR-Chitosan NPs, is constructed by assembling bilirubin-chitosan conjugate (named as BR-Chitosan) with a HAP, TH-302. It is interesting to find that the BR-Chitosan shows the inherent oxygen-depleting performance, especially in the presence of over expressed HO in tumor area, during which the BR-Chitosan can facily transform into biliverdin-chitosan (BV-Chitosan) and subsequently result in the disassembly of nanovesicles to release and activate the prodrug. Thus, this in situ strengthening hypoxia level of tumor can greatly promote the chemotherapy efficacy of HAPs. Moreover, as the oxidation derivatives of BR-Chitosan, BV-Chitosan exhibits intense absorbance at the range from long wavelength of visible region to near-infrared region, which can be acted as an effective photothermal agent for photothermal therapy (PTT). This biodegradable and self-activating nanovesicle with concise formulation demonstrates greatly enhanced synergistic therapeutic outcome in the activatable chemo-thermo combined therapy, showing much promising in future clinical transformation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.biomaterials.2020.120533DOI Listing
February 2021

Solvent-Induced Growth of Free-Standing 2D Si Nanosheets.

Small 2020 Dec 17;16(49):e2005426. Epub 2020 Nov 17.

Jiangsu Key Laboratory of New Power Batteries, Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing, 210023, P.R. China.

2D Si nanomaterials draw great interest owing to their fascinating properties and potential applications in electronic devices, catalysts, and energy storage and conversion devices. However, high-quality and large-scale synthesis of Si nanosheets remains a big challenge, despite the limited reports on their preparations via chemical exfoliation of layered Zintl silicide, magnesiothermic reduction of layered silicon oxide, and chemical vapor deposition. In this work, a facile, solution method to produce free-standing Si nanosheets in high yields and low cost, based on the reaction of commercial magnesium powder with trichlorosilane and tripropylamine in dichloromethane under mild conditions, is reported. The prepared Si nanosheets have an average thickness of ≈2 nm and show photoluminescence. Experiments demonstrate that the key to the formation of Si nanosheets is the use of dichloromethane as a solvent. This method can be used to prepare Si nanosheets in large scale for various potential applications and possibly Si crystals with specific crystal morphology.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/smll.202005426DOI Listing
December 2020

Successful therapy with interferon alpha-1b for a relapsing Epstein-Barr virus-positive mucocutaneous ulcer.

J Dermatol 2021 Jan 12;48(1):e3-e4. Epub 2020 Nov 12.

Department of, Dermatovenereology, West China Hospital, Sichuan University, Chengdu, China.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/1346-8138.15671DOI Listing
January 2021

Two-dimensional adaptive membranes with programmable water and ionic channels.

Nat Nanotechnol 2021 Feb 9;16(2):174-180. Epub 2020 Nov 9.

Centre for Advanced 2D Materials, National University of Singapore, Singapore, Singapore.

Membranes are ubiquitous in nature with primary functions that include adaptive filtering and selective transport of chemical/molecular species. Being critical to cellular functions, they are also fundamental in many areas of science and technology. Of particular importance are the adaptive and programmable membranes that can change their permeability or selectivity depending on the environment. Here, we explore implementation of such biological functions in artificial membranes and demonstrate two-dimensional self-assembled heterostructures of graphene oxide and polyamine macromolecules, forming a network of ionic channels that exhibit regulated permeability of water and monovalent ions. This permeability can be tuned by a change of pH or the presence of certain ions. Unlike traditional membranes, the regulation mechanism reported here relies on specific interactions between the membranes' internal components and ions. This allows fabrication of membranes with programmable, predetermined permeability and selectivity, governed by the choice of components, their conformation and their charging state.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41565-020-00795-yDOI Listing
February 2021

Integrating CRISPR-Cas12a with a DNA circuit as a generic sensing platform for amplified detection of microRNA.

Chem Sci 2020 Jul 19;11(28):7362-7368. Epub 2020 Jun 19.

State Key Laboratory of Chemo/Biosensing and Chemometrics , College of Chemistry and Chemical Engineering , Hunan Provincial Key Laboratory of Biomacromolecular Chemical Biology , Hunan University , Changsha 410082 , P. R. China . Email:

CRISPR-based diagnostics (CRISPR-Dx) has shown great promise in molecular diagnostics, but its utility in the sensing of microRNA (miRNA) biomarkers is limited by sensitivity, cost and robustness. Here, we describe a CRISPR-Dx method for the sensitive and cost-effective detection of miRNAs by rationally integrating CRISPR-Cas12a with DNA circuits. In this work, a modular catalytic hairpin assembly (CHA) circuit is designed to convert and amplify each target into multiple programmable DNA duplexes, which serve as triggers to initiate the -cleavage activity of CRISPR-Cas12a for further signal amplification. Such rational integration provides a generic assay for the effectively amplified detection of miRNA biomarkers. By simply tuning the variable regions in the CHA modules, this assay achieves sub-femtomolar sensitivity for different miRNA biomarkers, which improves the detection limit of CRISPR-Dx in the analysis of miRNA by 3-4 orders of magnitude. With the usage of the proposed assay, the sensitive assessment of miR-21 levels in different cancer cell lines and clinical serum samples has been achieved, providing a generic method for the sensitive detection of miRNA biomarkers in molecular diagnosis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/d0sc03084hDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7553042PMC
July 2020