Publications by authors named "Xuefei Zhang"

105 Publications

Identification of active sites of B/N co-doped nanocarbons in selective oxidation of benzyl alcohol.

J Colloid Interface Sci 2021 Nov 4. Epub 2021 Nov 4.

Fujian Provincial Key Laboratory of Electrochemical Energy Storage Materials, College of Chemistry, Fuzhou University, Fuzhou 350116, China; State Key Laboratory of Photocatalysis on Energy and Environment, Fuzhou University, Fuzhou 350116, China. Electronic address:

Developing highly active and stable nanocarbon catalysts for selective oxidation reactions has attracted much attention due to their potential as an alternative to traditional metal-based or noble metal catalysts. However, the nature of active sites and the reaction mechanism of nanocarbon catalysts for oxidation reactions still remains largely unknown, which hinders the rational design and development of highly efficient carbon-based catalysts. Here we report a facile strategy for the synthesis of boron and nitrogen co-doped carbon nanosheet material (BNC), which exhibits excellent catalytic activity with 91% conversion and 99% selectivity in selective oxidation of benzyl alcohol into benzaldehyde, superior to those of traditional carbon materials (oxidized carbon nanotubes, graphites and commercial nanocarbons). Structural characterizations and kinetic measurements are studied to clarify the active site, in which phenolic hydroxyl on BNC is responsible for the production of benzaldehyde. Meanwhile, we put forward a possible reaction mechanism and point out the key factors in determining the reactivity for this reaction. Therefore, the present work provides new insight into structure-function relationships, paving the way for the development of highly efficient nanocarbon catalysts.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jcis.2021.11.001DOI Listing
November 2021

Prevalence of Echinococcus Species in Wild Foxes and Stray Dogs in Qinghai Province, China.

Am J Trop Med Hyg 2021 Nov 15. Epub 2021 Nov 15.

National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research), NHC Key Laboratory of Parasite and Vector Biology, WHO Collaborating Center for Tropical Diseases, National Center for International Research on Tropical Diseases, Shanghai, China.

Echinococcosis is a zoonotic parasitic disease that is highly endemic to the Qinghai province of China. Limited data are available on the prevalence of the causal pathogen, Echinococcus spp., in definitive hosts in this region. Thus, the aim of this study was to evaluate the prevalence of Echinococcus spp. in wild foxes and stray dogs in Qinghai province. Five hundred and twenty-eight feces from wild foxes and 277 from stray dogs were collected from 11 counties in the Golog, Yushu, and Haixi prefectures and screened for Echinococcus spp. using copro-DNA polymerase chain reaction (PCR). In total, 5.5% of wild foxes and 15.2% of stray dogs tested positive for Echinococcus spp. The prevalence rates of Echinococcus spp. in wild foxes in Golog, Yushu, and Haixi were 7.3%, 5.2%, and 1.9%, respectively. In stray dogs, these rates were 13.3%, 17.3%, and 0%, respectively. Sequencing analysis determined that Echinococcus multilocularis was the most prevalent species, occurring in 4.0% and 12.6% of wild foxes and stray dogs, respectively. Echinococcus shiquicus was observed in 1.5% of wild foxes and 0.7% of stray dogs. Echinococcus granulosus was observed only in wild dogs, with a prevalence rate of 1.8%. To our knowledge, this is the first report on the prevalence of E. shiquicus in dogs in Qinghai province. The current results improve our understanding of the transmission and dissemination of human echinococcosis and suggest that exposure to the eggs of E. multilocularis harbored by wild foxes and stray dogs may pose a great risk of alveolar echinococcosis to humans in Qinghai province.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4269/ajtmh.21-0622DOI Listing
November 2021

Analysis of Correlation Between White Matter Changes and Functional Responses in Post-stroke Depression.

Front Aging Neurosci 2021 11;13:728622. Epub 2021 Oct 11.

Department of Rehabilitation, Zhujiang Hospital, Southern Medical University, Guangzhou, China.

: Post-stroke depression (PSD) is one of the most common neuropsychiatric symptoms with high prevalence, however, the mechanism of the brain network in PSD and the relationship between the structural and functional network remain unclear. This research applies graph theory to structural networks and explores the relationship between structural and functional networks. : Forty-five patients with acute ischemic stroke were divided into the PSD group and post-stroke without depression (non-PSD) group respectively and underwent the magnetic resonance imaging scans. Network construction and Module analysis were used to explore the structural connectivity-functional connectivity (SC-FC) coupling of multi-scale brain networks in patients with PSD. : Compared with non-PSD, the structural network in PSD was related to the reduction of clustering and the increase of path length, but the degree of modularity was lower. : The SC-FC coupling may serve as a biomarker for PSD. The similarity in SC and FC is associated with cognitive dysfunction, retardation, and desperation. Our findings highlighted the distinction in brain structural-functional networks in PSD. : https://www.clinicaltrials.gov/ct2/show/NCT03256305, NCT03256305.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fnagi.2021.728622DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8542668PMC
October 2021

Sulbactam Enhances in vitro Activity of β-Lactam Antibiotics Against .

Infect Drug Resist 2021 28;14:3971-3977. Epub 2021 Sep 28.

Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, People's Republic of China.

Purpose: To evaluate in vitro activities of β-lactam antibiotics alone and in combination with sulbactam at different ratios against clinical strains from China.

Methods: A total of 300 clinical isolates of were collected from 29 hospitals across China in 2018. Susceptibility to common antibiotics was assessed, and β-lactamase genes were detected. In vitro activity of ampicillin, cefoperazone and imipenem was tested alone and in combination with sulbactam at the ratios of 2:1, 1:1, 1:1.5, 1:2, 1:2.5 and 1:3.

Results: High resistant rates for common antibiotics were observed except tigecycline and polymyxin B. Among carbapenem-resistant , 97.3% isolates harbored . MIC and MIC values for sulbactam were 32 mg/L and 64 mg/L, respectively. High resistant rates for ampicillin, cefoperazone and imipenem were observed (92.3%, 93% and 85.3%, respectively). A stepwise increase in the ratio of sulbactam to partner β-lactam antibiotics led to a stepwise decrease in the MICs and a stepwise increase in the susceptible rates. The susceptible rates for imipenem-sulbactam 1:3, ampicillin-sulbactam 1:3 and cefoperazone-sulbactam 1:3 reached 16.3%, 58.3% and 91%, respectively.

Conclusion: The increasing proportion of sulbactam could enhance antimicrobial activities of imipenem-sulbactam, ampicillin-sulbactam and cefoperazone-sulbactam combinations against clinical strains in China, with cefoperazone-sulbactam as the most potent compound.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2147/IDR.S332160DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8487265PMC
September 2021

Construction of BiOI/TiO flexible and hierarchical S-scheme heterojunction nanofibers membranes for visible-light-driven photocatalytic pollutants degradation.

Sci Total Environ 2022 Feb 30;806(Pt 3):150698. Epub 2021 Sep 30.

Innovation Platform of Intelligent and Energy-Saving Textiles, School of Textile Science and Engineering, Tiangong University, Tianjin 300387, China; Department of Bioinformatics and Medical Engineering, Asia University, Taichung 41354, Taiwan; Department of Medical Research, China Medical University Hospital, China Medical University, Taichung, Taiwan. Electronic address:

Water was the source of life, in order to solve the serious water pollution problem facing the world, researchers have proposed many solutions. Among them, photoelectric catalytic technology based on semiconductor materials was an ideal and sustainable solution. Herein, by combining successive ionic layer adsorption and reaction (SILAR) with sol-gel electrospinning two strategies, a novel S-scheme heterojunction based on flexible and hierarchical BiOI/TiO nanofibrous membranes (BiOI/TiO NFM) was fabricated. The degradation rates of tetracycline (TC) and Rhodamine B (RHB) were 98.7% and 95.6%, respectively, under visible light irradiation. The main reason, except for the benefits offered by the hierarchical nanofiber structure, such as the large surface area, tightly connected interfaces and more exposed active sites, other advantages derived from photogenerated carrier transfer and superior redox ability were also momentous. To reveal the formed S-scheme heterojunction, a variety of test methods were used to characterize and test. These studies showed a significant increase in charge separation efficiency in the BiOI/TiO NFM, and the charge transport of S-scheme heterojunction was demonstrated. This study may offer new design ideas for the design and construction of novel structures of S-scheme heterojunctions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.scitotenv.2021.150698DOI Listing
February 2022

Characterization of the novel plasmid-encoded MBL gene blaAFM-1, integrated into a blaIMP-45-bearing transposon Tn6485e in a carbapenem-resistant Pseudomonas aeruginosa clinical isolate.

J Antimicrob Chemother 2021 Sep 17. Epub 2021 Sep 17.

Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China.

Objectives: To characterize the novel subclass B1 MBL AFM-1, encoded by a blaIMP-45-bearing megaplasmid from a carbapenem-resistant Pseudomonas aeruginosa (CRPA) clinical isolate.

Methods: CRPA HS17-127 and its transconjugant were discovered to carry blaAFM-1 in our previous study. blaAFM-1 and blaNDM-1 were cloned and expressed in Escherichia coli TOP10 and P. aeruginosa PAO1, respectively, to test the resistance phenotype. Kinetic studies were performed to elucidate the biochemical characteristics of the AFM-1 enzyme. Comparative genomic analysis was applied to investigate the genetic context of blaAFM-1.

Results: PAO1 transconjugant TcHS17-127 exhibited carbapenem resistance with an imipenem MIC of 64 mg/L. E. coli transformants with cloned blaAFM-1 or blaNDM-1 had increased MICs of all β-lactams tested (except aztreonam) and imipenem MICs of 4-8 mg/L. Kinetic studies showed that AFM-1 had greater catalytic efficiency against cephalosporins than carbapenems. blaAFM-1 was located on a 486 963 bp IncP-2 plasmid, pHS17-127, containing a 57.3 kb MDR Tn1403-derivative transposon, Tn6485e, which is genetically closest to the blaIMP-45-bearing Tn6485 transposon but has acquired an extra ISCR27n3-blaAFM-1 module. Multicentre surveillance of 605 P. aeruginosa clinical isolates identified three blaAFM carriers from different STs. Two of them co-carried blaAFM-1 and blaIMP-45. A BLAST search against the NCBI database showed six blaAFM carriers on various plasmids and the chromosomes of different Gram-negative species.

Conclusions: The blaAFM-1 gene confers carbapenem resistance and has been captured in distinct species of non-fermenters. Co-carriage of blaAFM-1 and blaIMP-45 in an MDR transposon on a conjugative plasmid can be expected to promote further dissemination of blaMBLs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/jac/dkab342DOI Listing
September 2021

Topoisomerase I inhibition and peripheral nerve injury induce DNA breaks and ATF3-associated axon regeneration in sensory neurons.

Cell Rep 2021 Sep;36(10):109666

F.M. Kirby Neurobiology Center, Program in Neurobiology, Boston Children's Hospital, Boston, MA 02115, USA; Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA; Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA. Electronic address:

Although axonal damage induces rapid changes in gene expression in primary sensory neurons, it remains unclear how this process is initiated. The transcription factor ATF3, one of the earliest genes responding to nerve injury, regulates expression of downstream genes that enable axon regeneration. By exploiting ATF3 reporter systems, we identify topoisomerase inhibitors as ATF3 inducers, including camptothecin. Camptothecin increases ATF3 expression and promotes neurite outgrowth in sensory neurons in vitro and enhances axonal regeneration after sciatic nerve crush in vivo. Given the action of topoisomerases in producing DNA breaks, we determine that they do occur immediately after nerve damage at the ATF3 gene locus in injured sensory neurons and are further increased after camptothecin exposure. Formation of DNA breaks in injured sensory neurons and enhancement of it pharmacologically may contribute to the initiation of those transcriptional changes required for peripheral nerve regeneration.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.celrep.2021.109666DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8462619PMC
September 2021

Cisplatin nanoparticles possess stronger anti-tumor synergy with PD1/PD-L1 inhibitors than the parental drug.

Acta Biomater 2021 11 14;135:543-555. Epub 2021 Aug 14.

Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, PR China; Jilin Biomedical Polymers Engineering Laboratory, Changchun 130022, PR China.

Programmed cell death protein 1 (PD1)/programmed death-ligand 1 (PD-L1) inhibitors provide an evolution in the field of cancer therapy. This results in unprecedented rates of long-lasting tumor responses, once cancer patients respond to PD1/PD-L1 inhibitors. However, the response rate of most cancers is not greater than 30%, which results in a limited therapeutic efficacy. Therefore, the increase of the therapeutic efficacy of PD1/PD-L1 inhibitors is of utmost importance. Hence, this study demonstrated that the sustained increase of tumor PD-L1 levels induced by long-tumor retaining cisplatin (Cis) nanoparticles improved the therapeutic outcomes of PD1/PD-L1 inhibitors. Cis-loaded poly(-glutamic acid)-graft-methoxy poly(ethylene glycol) complex nanoparticle (Cisplatin nanoparticle, P-Cis) caused tumor PD-L1 overexpression in a time dependent manner in vitro and amplified tumor PD-L1 signals at 72 h post treatment in vivo. Synergistic tumor inhibition was achieved when P-Cis was combined with PD1/PD-L1 inhibitors, such as BMS-202 and anti-PD1 antibody (aPD1), and a significantly superior tumor inhibition rate was observed in the combination group (P-Cis plus aPD1). In addition, when mice were treated with a single dose of P-Cis plus aPD1, its synergistic anti-tumor effect was much stronger than that of a single dose of Cis plus aPD1, as their Q values were 1.15 and 1.05 in the Lewis lung carcinoma (LLC) tumor model, and 1.92 and 0.95 in the B16F10 tumor model, respectively. The single dose of P-Cis could increase tumor PD-L1 expression at 72 h post injection, while a single-dose of Cis did not, thus the sustained tumor PD-L1 overexpression induced by P-Cis was essential for enhancing aPD1 therapy. The sustained tumor PD-L1 overexpression highlighted the involvement of PD1/PD-L1 pathway in tumor cell proliferation and CD8 T cell weakening and increased the role and possibility of PD1/PD-L1 inhibitors to block the PD1/PD-L1 pathway. Collectively, this study identified a potential clinical treatment with P-Cis plus PD1/PD-L1 inhibitors. STATEMENT OF SIGNIFICANCE: Programmed cell death protein 1 (PD1)/programmed death-ligand 1 (PD-L1) inhibitors provide an evolution in the field of cancer therapy. However, the response rate of most cancers is not greater than 30%, which results in a limited therapeutic efficacy. Therefore, the increase of the therapeutic efficacy of PD1/PD-L1 inhibitors is of utmost importance. Here, Cisplatin (Cis) loaded poly(-glutamic acid)-graft-methoxy poly(ethylene glycol) complex nanoparticle (P-Cis) is found to improve the therapeutic outcomes of PD1/PD-L1 inhibitors via sustained increase of tumor PD-L1 levels, and P-Cis possesses stronger anti-tumor synergy with PD1/PD-L1 inhibitors than the parental drug. This identifies a potential clinical treatment with P-Cis plus PD1/PD-L1 inhibitors.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.actbio.2021.08.013DOI Listing
November 2021

Epidemiological and genomic characteristics of Acinetobacter baumannii from different infection sites using comparative genomics.

BMC Genomics 2021 Jul 12;22(1):530. Epub 2021 Jul 12.

School of Pharmacy & Minhang Hospital, Fudan University, 826 Zhang Heng Rd, 201203, Shanghai, China.

Background: Acinetobacter baumannii is a common nosocomial pathogen that poses a huge threat to global health. Owing to the severity of A. baumannii infections, it became necessary to investigate the epidemiological characteristics of A. baumannii in Chinese hospitals and find the reasons for the high antibiotic resistance rate and mortality. This study aimed to investigate the epidemiologic and genetic characteristics of A. baumannii isolated from patients with hospital acquired pneumonia (HAP), bloodstream infection (BSI) and urinary tract infection (UTI) in China and uncover potential mechanisms for multi-drug resistance and virulence characteristics of A. baumannii isolates.

Results: All isolates were classified into two primary clades in core gene-based phylogenetic relationship. Clonal complex 208 (CC208) mainly consisted of ST195 (32 %) and ST208 (24.6 %). CC208 and non-CC208 isolates had carbapenem resistance rates of 96.2 and 9.1 %, respectively. Core genes were enriched in 'Amino acid transport and metabolism', 'Translation', 'Energy production and conversion', 'Transcription', 'Inorganic ion transport and metabolism' and 'Cell wall/membrane/envelope synthesis'. Most isolates possessed virulence factors related to polysaccharide biosynthesis, capsular polysaccharide synthesis and motility. Eleven isolates belong to ST369 or ST191 (oxford scheme) all had the virulence factor cap8E and it had a higher positive rate in UTI (35.3 %) than in BSI (18.9 %) and HAP (12.9 %). ABGRI1 antibiotic resistance islands were responsible for streptomycin, tetracycline and sulfonate resistance. The bla gene was the most probable cause for carbapenem resistance, although the bla gene with nonsynonymous SNPs (F82L, I129L) was not.

Conclusions: A. baumannii is a genomically variable pathogen that has the potential to cause a range of infectious diseases. There is high proportion of carbapenem resistance in isolates from all three infection sites (HAP, BSI and UTI), which can be attributed to the bla gene. CC208 is the predominant clone in bla-carrying A. baumannii that should be monitored. Virulence factors involving bacteria motility and polysaccharide biosynthesis which are widespread in clinical A. baumannii strains deserve our attention.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s12864-021-07842-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8272988PMC
July 2021

Single-atom cobalt-fused biomolecule-derived nitrogen-doped carbon nanosheets for selective oxidation reactions.

Phys Chem Chem Phys 2021 Jul;23(26):14276-14283

State Key Laboratory of Photocatalysis on Energy and Environment, Fujian Provincial Key Laboratory of Electrochemical Energy Storage Materials, Fuzhou University, 2 Xueyuan Road, Fuzhou 350016, China.

Non-noble metal single-atom catalysts hold great promise in selective oxidation reactions, although the progress is still unsatisfactory because of the synthesis challenge and the lack of mechanistic interpretations. Herein, we develop a biomolecule-based strategy to synthesize isolated Co single atom site catalysts by one-step pyrolysis of guanosine and Co precursors. Due to the abundant hydrogen bonding and π-π interaction of guanosine, the as-synthesized Co-N-C catalysts present a hierarchical porous two-dimensional (2D) nanostructure with an ultrahigh specific surface area, large pore volume, and high density of cobalt single atoms. Aberration-corrected electron microscopy and X-ray photoelectron spectroscopy reveal that Co species are present as isolated single sites and stabilized by nitrogen-doped carbon nanosheets. These characteristics make Co-GS-900 suitable as an efficient catalyst for selective oxidation of aromatic alkanes. For oxidation of ethylbenzene, Co-GS-900 exhibits a superior performance f with 91% conversion and 98% selectivity of acetophenone.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/d1cp01113hDOI Listing
July 2021

Molecular Characteristics of Causing Bloodstream Infections During 2010-2015 in a Tertiary Hospital, Shanghai, China.

Infect Drug Resist 2021 3;14:2079-2086. Epub 2021 Jun 3.

Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, People's Republic of China.

Background: The bloodstream infections (BSI) caused by pose a serious threat to human health. To explore molecular characteristics of causing BSI, we collected isolates causing BSI in Huashan Hospital, Shanghai, China during 2010-2015.

Methods: In all isolates causing BSI collected from this study, polymerase chain reaction (PCR) was used to detect ESBLs and carbapenemase genes, and minimum inhibitory concentrations (MICs) were determined with agar dilution method. Outer membrane proteins were examined by SDS-PAGE in carbapenem-resistant strains. The genetic background of gene was investigated by combining next-generation sequencing with a PCR mapping approach. Conjugation and transformation experiments were performed to verify the mobilization of . The transcription levels of the gene were measured by RT-PCR.

Results: During 2010-2015, a total of 207 BSI strains were isolated. The positive rates of β-lactamase resistant genes were 0.48% ( ), 57% ( ), 23.67% ( ), 18.84% ( ), and 1.93% ( ). High rates of , and were consistent with the poor activity of third-generation cephalosporins and aztreonam in vitro, except for carbapenem and β-lactamase inhibitor combinations. Low susceptibility rates were observed for piperacillin (25.1%) in contrast to the increased susceptibility when combined with β-lactamase inhibitors, namely piperacillin-tazobactam (90.8%). Only one KPC-producing strain was detected. Despite the combination of OmpC loss, the low expression level of KPC may be responsible for its lower resistance to carbapenems compared to DH5α (pKP12-100).

Conclusion: strains isolated from BSI were still highly susceptible to carbapenems and β-lactamase inhibitor combinations, and was the dominant genotype of ESBLs. The low expression of may be the reason for the low resistance to carbapenems.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2147/IDR.S305281DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8185459PMC
June 2021

Identification of and , New Transferable Quinolone Resistance Family Genes Originating from Enterobacter mori and Enterobacter asburiae, Respectively.

Antimicrob Agents Chemother 2021 07 16;65(8):e0045621. Epub 2021 Jul 16.

Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China.

The family was designated in 2017. To date, two alleles have been discovered that are carried by plasmids. Here, we identified a new quinolone resistance gene, , in the chromosome of Enterobacter mori clinical isolate 08-091 in China. conferred decreased susceptibility to fluoroquinolones, similar to and . To investigate the precise origin of , , and , 79 -bearing strains producing 30 variants were retrieved from the NCBI database. Phylogenetic analysis illustrated two major clusters, QnrE and QnrE, produced mainly by the and strains, respectively. Comparison of the genetic context of alleles demonstrated that and alleles presumably were captured by ISE and mobilized from the and strains to the and Escherichia coli strains, respectively. was proposed to be named , since it has spread to another genus. All the alleles were harbored by the Enterobacter species, except those captured by ISE and mobilized into other species of . is probably the source of to alleles, and is the reservoir of .
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1128/AAC.00456-21DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8284476PMC
July 2021

A novel mechanism of streptomycin resistance in Yersinia pestis: Mutation in the rpsL gene.

PLoS Negl Trop Dis 2021 04 22;15(4):e0009324. Epub 2021 Apr 22.

National Institute for Communicable Disease Control and Prevention, China CDC, Changping, Beijing, China.

Streptomycin is considered to be one of the effective antibiotics for the treatment of plague. In order to investigate the streptomycin resistance of Y. pestis in China, we evaluated streptomycin susceptibility of 536 Y. pestis strains in China in vitro using the minimal inhibitory concentration (MIC) and screened streptomycin resistance-associated genes (strA and strB) by PCR method. A clinical Y. pestis isolate (S19960127) exhibited high-level resistance to streptomycin (the MIC was 4,096 mg/L). The strain (biovar antiqua) was isolated from a pneumonic plague outbreak in 1996 in Tibet Autonomous Region, China, belonging to the Marmota himalayana Qinghai-Tibet Plateau plague focus. In contrast to previously reported streptomycin resistance mediated by conjugative plasmids, the genome sequencing and allelic replacement experiments demonstrated that an rpsL gene (ribosomal protein S12) mutation with substitution of amino-acid 43 (K43R) was responsible for the high-level resistance to streptomycin in strain S19960127, which is consistent with the mutation reported in some streptomycin-resistant Mycobacterium tuberculosis strains. Streptomycin is used as the first-line treatment against plague in many countries. The emergence of streptomycin resistance in Y. pestis represents a critical public health problem. So streptomycin susceptibility monitoring of Y. pestis isolates should not only include plasmid-mediated resistance but also include the ribosomal protein S12 gene (rpsL) mutation, especially when treatment failure is suspected due to antibiotic resistance.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1371/journal.pntd.0009324DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8096067PMC
April 2021

An IncP-2 plasmid sublineage associated with dissemination of among carbapenem-resistant .

Emerg Microbes Infect 2021 Dec;10(1):442-449

Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, People's Republic of China.

IMP-45, a variant of IMP-9, is one of the dominant metallo-β-lactamases (MBLs) in clinical carbapenem-resistant (CRPA) isolates in China. The aim of this study was to investigate the distribution and mechanism of dissemination of . MBL genes were detected by PCR in 173 non-duplicate CRPA isolates collected from Hospital HS in Shanghai and 605 isolates from a multicenter surveillance of in China. In total, 17 IMP-45-producers (14 from Hospital HS and 3 from other hospitals) were identified. Molecular typing identified an outbreak of 11 IMP-45-producing ST508 CRPA in the ICU of Hospital HS. Conjugation assays and whole genome sequencing were conducted among IMP-45-producers. Genomic comparison revealed that 16 -carrying plasmids (9 from this study and 7 from GenBank) shared a similar backbone with IncP-2 -carrying plasmid pOZ176 but lacked -- region. gene was presented in pOZ176, -carrying plasmids (17 from this study and 7 from GenBank) and 15 megaplasmids from GenBank. Phylogenetic analysis of showed that most -carrying plasmids were clustered into a sublineage separate from the one containing pOZ176. This IncP-2 plasmid sublineage contributed to the dissemination of among genetically diverse and recruited multiple resistance genes during its evolution.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/22221751.2021.1894903DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7971254PMC
December 2021

Loop extrusion mediates physiological Igh locus contraction for RAG scanning.

Nature 2021 02 13;590(7845):338-343. Epub 2021 Jan 13.

Howard Hughes Medical Institute, Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA, USA.

RAG endonuclease initiates Igh V(D)J recombination in progenitor B cells by binding a J-recombination signal sequence (RSS) within a recombination centre (RC) and then linearly scanning upstream chromatin, presented by loop extrusion mediated by cohesin, for convergent D-RSSs. The utilization of convergently oriented RSSs and cryptic RSSs is intrinsic to long-range RAG scanning. Scanning of RAG from the DJ-RC-RSS to upstream convergent V-RSSs is impeded by D-proximal CTCF-binding elements (CBEs). Primary progenitor B cells undergo a mechanistically undefined contraction of the V locus that is proposed to provide distal Vs access to the DJ-RC. Here we report that an inversion of the entire 2.4-Mb V locus in mouse primary progenitor B cells abrogates rearrangement of both V-RSSs and normally convergent cryptic RSSs, even though locus contraction still occurs. In addition, this inversion activated both the utilization of cryptic V-RSSs that are normally in opposite orientation and RAG scanning beyond the V locus through several convergent CBE domains to the telomere. Together, these findings imply that broad deregulation of CBE impediments in primary progenitor B cells promotes RAG scanning of the V locus mediated by loop extrusion. We further found that the expression of wings apart-like protein homologue (WAPL), a cohesin-unloading factor, was low in primary progenitor B cells compared with v-Abl-transformed progenitor B cell lines that lacked contraction and RAG scanning of the V locus. Correspondingly, depletion of WAPL in v-Abl-transformed lines activated both processes, further implicating loop extrusion in the locus contraction mechanism.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41586-020-03121-7DOI Listing
February 2021

Physiological role of the 3'IgH CBEs super-anchor in antibody class switching.

Proc Natl Acad Sci U S A 2021 01;118(3)

Howard Hughes Medical Institute, Boston Children's Hospital, Boston, MA 02115;

IgH class switch recombination (CSR) replaces Cμ constant region (C) exons with one of six downstream Cs by joining transcription-targeted double-strand breaks (DSBs) in the Cμ switch (S) region to DSBs in a downstream S region. Chromatin loop extrusion underlies fundamental CSR mechanisms including 3'IgH regulatory region (3'IgHRR)-mediated S region transcription, CSR center formation, and deletional CSR joining. There are 10 consecutive CTCF-binding elements (CBEs) downstream of the 3'IgHRR, termed the "3'IgH CBEs." Prior studies showed that deletion of eight 3'IgH CBEs did not detectably affect CSR. Here, we report that deletion of all 3'IgH CBEs impacts, to varying degrees, germline transcription and CSR of upstream S regions, except that of Sγ1. Moreover, deletion of all 3'IgH CBEs rendered the 6-kb region just downstream highly transcribed and caused sequences within to be aligned with Sμ, broken, and joined to form aberrant CSR rearrangements. These findings implicate the 3'IgH CBEs as critical insulators for focusing loop extrusion-mediated 3'IgHRR transcriptional and CSR activities on upstream C locus targets.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1073/pnas.2024392118DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7826415PMC
January 2021

Association of vitamin D status at birth with pulmonary disease morbidity in very preterm infants.

Pediatr Pulmonol 2021 05 23;56(5):1215-1220. Epub 2020 Dec 23.

Division of Neonatology, Department of Pediatrics, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China.

Objective: We aimed to assess whether serum 25-hydroxyvitamin D (25(OH)D) levels at birth are associated with pulmonary disease morbidities in very preterm infants.

Methods: This prospective cohort analysis included 93 infants born before 32 weeks of gestation in the Second Xiangya Hospital of Central South University between March 2016 and February 2017. Participants were classified into three groups according to their 25(OH)D levels at birth. The groups were compared in terms of demographic variables and pulmonary disease morbidities.

Results: The mean serum 25(OH)D level at birth was 35.7 ± 19.1 nmol/L, and 38 (40.9%), 31 (33.3%), and 24 (25.8%) infants had 25(OH)D levels of less than 25 nmol/L, 25-50 nmol/L, and more than or equal to 50 nmol/L, respectively. There was a statistically significant difference in neonatal respiratory distress syndrome (RDS) rates among the three groups (43.6% vs. 35.9% vs. 20.5%, p = .029). The rates of bronchopulmonary dysplasia, apnea, respiratory failure, persistent pulmonary hypertension, and pulmonary hemorrhage did not differ significantly among the groups. Logistic analysis, adjusted for gestational age and birth weight, showed that a low serum 25(OH)D level (<50 nmol/L) was a risk factor for RDS (odds ratio, 0.195; p = .017).

Conclusion: There was a high prevalence of low 25(OH)D levels (<50 nmol/L) and an association between vitamin D status and RDS in very preterm infants. However, more research on this association is required.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/ppul.25233DOI Listing
May 2021

Activatable Polymeric Nanoprobe for Near-Infrared Fluorescence and Photoacoustic Imaging of T Lymphocytes.

Angew Chem Int Ed Engl 2021 03 1;60(11):5921-5927. Epub 2021 Feb 1.

School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore, 637457, Singapore.

Development of real-time non-invasive imaging probes to assess infiltration and activation of cytotoxic T cells (CTLs) is critical to predict the efficacy of cancer immunotherapy, which however remains challenging. Reported here is an activatable semiconducting polymer nanoprobe (SPNP) for near-infrared fluorescence (NIRF) and photoacoustic (PA) imaging of a biomarker (granzyme B) associated with activation of CTLs. SPNP comprises a semiconducting polymer (SP) conjugated with a granzyme B cleavable and dye-labeled peptide as the side chain, both of which emit NIRF and PA signals. After systemic administration, SPNP passively targets the tumor and in situ reacts with granzyme B to release the dye-labeled peptide, leading to decreased NIRF and PA signals from the dye but unchanged signals from the polymer. Such ratiometric NIRF and PA signals of SPNP correlate well with the expression level of granzyme B and intratumoral population of CTLs. Thus, this study not only presents the first PA probes for in vivo imaging of immune activation but also provides a molecular design strategy that can be generalized for molecular imaging of other immune-related biomarkers.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/anie.202015116DOI Listing
March 2021

Dual-Shell Photothermoelectric Textile Based on a PPy Photothermal Layer for Solar Thermal Energy Harvesting.

ACS Appl Mater Interfaces 2020 Dec 30;12(49):55072-55082. Epub 2020 Nov 30.

Innovation Platform of Intelligent and Energy-Saving Textiles, School of Textile Science and Engineering, Tiangong University, Tianjin 300387, China.

To simply and effectively enhance the conversion capability of wearable thermoelectric textiles, a two-step in situ method is adopted to fabricate dual-shell photothermoelectric textiles which is made of polypropylene fibers with a photo-thermal layer (PPy) and a thermoelectric layer (PEDOT:Tos). The PPy is tailored to achieve high temperature and photothermoelectric effects. The PPy layer can significantly increase the photothermal conversion efficiencies of as-prepared fabric. The optimized photothermoelectric fabric can improve the generated voltage output from 294.13 to 536.47 μV under the infrared light, and its power density is up to 13.76 nW·m. A flexible photothermoelectric strip composed of as-prepared fabric coated with Ag particles and textile substrates with low thermal conductivity shows a voltage output of 2.25, 0.677, and 0.183 mV and a power output of 0.7031, 0.0636, and 0.0049 nW under IR light, sunlight, and on the arm, respectively. The photothermoelectric fabrics display potential as to a new smart wearable device for converting light and electricity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acsami.0c16401DOI Listing
December 2020

Dynamic evaluation on the energy and environmental performance of China's transportation sector: a ZSG-MEA window analysis.

Environ Sci Pollut Res Int 2021 Mar 29;28(9):11454-11468. Epub 2020 Oct 29.

Academy of Mathematics and Systems Science, Chinese Academy of Science, Beijing, 100190, China.

The transportation sector is one of the important energy consumption and carbon emission sources. This paper extends the multi-directional efficiency analysis (MEA) to zero-sum game MEA (ZSG-MEA) with considering the CO emission as a fixed-sum undesirable output to measure the energy and environmental performance (EEP) of the transportation sector. The ZSG-MEA window analysis is applied to dynamically evaluate the EEP of China's transportation sector in 30 provincial-level regions during 2008-2017. Some interesting findings are obtained: (i) the EEP of the transportation sector in most regions has not been performed well but the average EEP of the transportation sector in most regions has been gradually improved since 2011. A general trend is that the transportation sector in the east area wins the best average EEP, and the average EEP of the central area is better than that of the west area, but their gap is narrowing from 2012. (ii) The EEP fluctuation verifies the greatest imbalance of EEP among the east area's regions. Both the east area and the central area are narrowing the imbalance in recent years, but the west area has an inverse trend. (iii) The performance of CO emissions is better than that of energy consumption in all three areas, which implies that China's transportation sector seems to have paid more attention on emission reduction than energy conservation. Besides, the east area has the best performance of energy consumption and CO emissions from an overall perspective. And the energy consumption and CO emissions in the central area perform better than the west area before 2013, but then shows an entangled state from 2013. (iv) From the average variable specific ZSG-MEA efficiency, the industrial added value of transportation sector performs better than other variables in the east area and central area, but the situation in the west area is inverse. Some useful insights are provided according to these findings.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11356-020-11314-wDOI Listing
March 2021

Magnesium Trisilicate Coated Fe₃O₄ Nanoparticles as Prompt and Efficient Lactic Acid Removers Potential for Exercise-Induce Fatigue Prevention.

J Biomed Nanotechnol 2020 Apr;16(4):531-537

Exercise-induced fatigue is accumulated when lactic acid cannot be timely eliminated after intensive exercise, resulting in sport injuries. Traditional lactic acid removal methods are limited in timeliness, metabolic burden, and potential toxicity. To solve the thorny problems, in this study, nanomedicine was introduced for lactic acid removal. Magnesium trisilicate was coated on the surface of magnetic nanoparticles. These nanoparticles exhibited a prompt and efficient lactic acid adsorbing behavior. Moreover, they have favorable magnetic properties and good biocompatibility. The results showed that the prepared nanoparticles hold great potential in the removal of lactic acid for preventing exercise-induced fatigue.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1166/jbn.2020.2903DOI Listing
April 2020

Effects of Random Measurement Error on Lung Cancer Screening Decisions: A Retrospective Cohort-Based Microsimulation Study.

Chest 2021 02 14;159(2):853-861. Epub 2020 Sep 14.

VA Ann Arbor Center for Clinical Management Research and University of Michigan Medical School, University of Michigan, Ann Arbor, MI; Institute for Health Policy Innovation, University of Michigan, Ann Arbor, MI; Michigan Integrated Center for Health Analytics and Medical Prediction, University of Michigan, Ann Arbor, MI.

Background: Self-reported tobacco pack-year history plays a large role in decisions about low-dose CT screening for lung cancer, yet is challenging to measure accurately.

Research Question: To what extent does random measurement error in pack-year information impact screening decisions and screening effectiveness?

Study Design And Methods: Retrospective cohort study of 10,449 patients with pack-year history documented at least twice between October 2013 and July 2017 across 8 academic Veterans Affairs sites. Outcome measures included (1) observed reliability of pack-year information based on all repeat measures for the study population and (2) each person's statistically "true" pack-year information based on best linear unbiased predictor from a multilevel linear random effects model. To examine how unreliability leads to misclassification of screening eligibility and inaccuracy in estimating lung cancer risk, we simulated pack-year observations for each person, first comparing simulated pack-year and lung cancer risk values with true values, then comparing outcomes when basing screening decisions on unreliable pack-year information vs true information.

Results: Reliability of assessing pack-year information in routine practice varied across sites. Thus, we examined the clinical impact of two different levels of reliability, based on the range of intraclass correlation coefficients observed. Using a ≥ 30-pack-year threshold led to a high rate of eligibility misclassifications (48.1% misclassified with higher reliability pack-year information and 60.7% misclassified with lower reliability information). However, using a lung cancer risk threshold leads to fewer misclassifications (47.3%-49.7% misclassified when using lower reliability pack-year information) and maintains screening effectiveness better when using unreliable pack-year information.

Interpretation: Random error in real-world pack-year assessments leads to a substantial rate of misclassifying who should be offered CT screening if a ≥ 30-pack-year criterion is used. However, using a lung cancer risk threshold mitigates the impact of unreliable pack-year information. Decision-makers concerned about the impact of unreliable pack-year information should consider using risk-based approaches to CT screening.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.chest.2020.08.2112DOI Listing
February 2021

Evolution of CTX-M-215, a Novel Narrow-Spectrum β-Lactamase in an Escherichia coli Clinical Isolate Conferring Resistance to Mecillinam.

Antimicrob Agents Chemother 2020 10 20;64(11). Epub 2020 Oct 20.

Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China

Here, we report a novel narrow-spectrum β-lactamase CTX-M-215 identified in an clinical isolate in China and conferring high-level resistance to mecillinam but not to cefotaxime. CTX-M-215 differed from CTX-M-125, a CTX-M extended-spectrum β-lactamase (ESBL), by an N132D substitution, which decreased hydrolytic activities toward penicillins and cephalosporins except for mecillinam. High similarity was observed between CTX-M-215- and CTX-M-125-bearing plasmids, carried by different isolates in the same patient, indicating evolution of CTX-M-215 from CTX-M-125.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1128/AAC.00562-20DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7577136PMC
October 2020

Tackling COVID-19: Insights from the Qinghai Province plague prevention and control (PPC) model.

Biosaf Health 2020 Dec 5;2(4):187-192. Epub 2020 Aug 5.

Health Commission of Qinghai Province, Xining 810001, China.

Plague, caused by , is a natural focus infectious disease. In China, plague is classified as category A, with the highest risk and hazard among the infectious diseases. Qinghai used to be considered as one of the most serious areas of plague in China. In recent years, thank to the measures in eight aspects summarized as the "Qinghai model" which were adopted to prevent and control the human plague in Qinghai, Qinghai has not experienced any plague case reported for eight years. In early 2020, coronavirus disease 2019 (COVID-19) outbroke in China. The Qinghai model on plague was employed to deal with the COVID-19 emergency in Qinghai Province. The Qinghai Center for Disease Control and Prevention (Qinghai CDC) and hospitals, along with the departments of public security, animal husbandry and other departments, quickly tracked and treated the patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and started surveillance programs on close contacts timely. At present, the cure rate of patients has reached 100%, and close contacts have been effectively quarantined and tested to avoid the spread of COVID-19. The findings from the study suggest that the prevention and control measures undertaken in Qinghai Province might be effective in dealing with the category A infectious diseases such as COVID-19 and other diseases.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bsheal.2020.08.001DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7403129PMC
December 2020

Small-Baseline Approach for Monitoring the Freezing and Thawing Deformation of Permafrost on the Beiluhe Basin, Tibetan Plateau Using TerraSAR-X and Sentinel-1 Data.

Sensors (Basel) 2020 Aug 10;20(16). Epub 2020 Aug 10.

Faculty of Information Engineering, China University of Geosciences, 388 Lumo Road, Wuhan 430074, China.

The dynamic changes of the thawing and freezing processes of the active layer cause seasonal subsidence and uplift over a large area on the Qinghai-Tibet Plateau due to ongoing climate warming. To analyze and investigate the seasonal freeze-thaw process of the active layer, we employ the new small baseline subset (NSBAS) technique based on a piecewise displacement model, including seasonal deformation, as well as linear and residual deformation trends, to retrieve the surface deformation of the Beiluhe basin. We collect 35 Sentinel-1 images with a 12 days revisit time and 9 TerraSAR-X images with less-than two month revisit time from 2018 to 2019 to analyze the type of the amplitude of seasonal oscillation of different ground targets on the Beiluhe basin in detail. The Sentinel-1 results show that the amplitude of seasonal deformation is between -62.50 mm and 11.50 mm, and the linear deformation rate ranges from -24.50 mm/yr to 5.00 mm/yr (2018-2019) in the study area. The deformation trends in the Qinghai-Tibet Railway (QTR) and Qinghai-Tibet Highway (QTH) regions are stable, ranging from -18.00 mm to 6 mm. The InSAR results of Sentinel-1 and TerraSAR-X data show that seasonal deformation trends are consistent, exhibiting good correlations 0.78 and 0.84, and the seasonal and linear deformation rates of different ground targets are clearly different on the Beiluhe basin. Additionally, there are different time lags between the maximum freezing uplift or thawing subsidence and the maximum or minimum temperature for the different ground target areas. The deformation values of the alpine meadow and floodplain areas are higher compared with the alpine desert and barren areas, and the time lags of the freezing and thawing periods based on the Sentinel-1 results are longest in the alpine desert area, that is, 86 days and 65 days, respectively. Our research has important reference significance for the seasonal dynamic monitoring of different types of seasonal deformation and the extensive investigations of permafrost in Qinghai Tibet Plateau.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/s20164464DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7472081PMC
August 2020

Sedimentary and geochemical characteristics of Triassic new type of polyhalite potassium resources in Northeast Sichuan and its genetic study.

Sci Rep 2020 08 11;10(1):13528. Epub 2020 Aug 11.

Key Laboratory of Metallogeny and Mineral Assessment, Ministry of Natural Resources, Beijing, 100037, China.

Polyhalite has been discovered for years in the Triassic of the Sichuan Basin. However, it is difficult to exploit and utilize such polyhalite because of its deep burial depth and its coexistence with anhydrite or dolomite. Therefore, it has always been regarded as "dead ore". Based on slice identification, X-powder diffraction, chemical analysis, REEs analysis and strontium isotope test on halite samples from the fourth and fifth member of Jialingjiang Formation to Leikoupo Formation of Wells ZK601 and ZK001 in Xuanhan area, Northeast Sichuan Basin, this paper discovers thick layers of granular polyhalite associated with halite and the polyhalite content accounts for 10-30%. These deep polyhalites can be obtained by water-soluble mining and utilized, so they are called "new type polyhalite potash deposits". The deposit is deep buried at 3,000 m underground, and the thickness of a single layer can be more than 30 m. It is stable in regional distribution. The discovery of the "new type polyhalite potash deposits" has "activated" polyhalite, which has been considered as deep "dead ore" and has great significance for potash prospecting in China.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41598-020-69063-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7419550PMC
August 2020

A pH-responsive polymer linked with immunomodulatory drugs: synthesis, characteristics and in vitro biocompatibility.

J Appl Toxicol 2021 05 9;41(5):724-735. Epub 2020 Aug 9.

Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education and Key Laboratory of Polymeric Materials & Application Technology of Hunan Province, Key Laboratory of Advanced Functional Polymer Materials of Colleges and Universities of Hunan Province, College of Chemistry, Xiangtan University, Xiangtan, China.

Cancer immunotherapy is a promising method for cancer therapy. Imiquimod (R837) is a molecule that could activate immune systems for cancer immunotherapy, but an easily manufactured biocompatible carrier to deliver R837 may be needed to overcome the disadvantages of R837. Micelles formed by biocompatible copolymers have been widely used to deliver chemotherapeutic drugs but not immunotherapeutic drugs. In this study, R837 was linked to an amphiphilic biodegradable copolymer mPEG-b-PLA via acid-sensitive Schiff bases. The molecular structures were investigated by H nuclear magnetic resonance, gel permeation chromatography and Fourier transform infrared spectroscopy. The product could be self-assembled into micelles with R837 content as high as 22.4%. Owing to acid-cleavable Schiff bases, the release of R837 from micelles was markedly accelerated under acidic media. Consequently, the micelles linked with R837 stimulated the expression of major histocompatibility complex II-stimulating molecules on the surface of RAW 264.7 macrophages at pH 6.5 but not pH 7.4. By using human umbilical vein endothelial cells as the in vitro model, it was shown that the polymer carriers and R837-linked micelles were minimally cytotoxic and did not induce the activation of endothelial cells under physiological pH, which suggested the relatively high biocompatibility. In conclusion, this study successfully developed pH-responsive immunotherapeutic drug-loaded micelles that could activate macrophages at acidic pH in vitro. The high biocompatibility of the micelles to endothelial cells also indicated the potential uses under in vivo conditions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/jat.4042DOI Listing
May 2021

Wheat straw components fractionation, with efficient delignification, by hydrothermal treatment followed by facilitated ethanol extraction.

Bioresour Technol 2020 Nov 21;316:123882. Epub 2020 Jul 21.

Department of Chemical Engineering, University of North Dakota, Grand Forks, ND 58202, USA. Electronic address:

Lignocellulosic biomass fractionaion into its three major components is critically important for efficient feedstock utilization. The hydrothermal-ethanol method has broad application as its first step, hydrothermal treatment, provides high hemicellulose separation efficiency. However, it severely inhibits the delignification on the subsequent ethanol extraction. In this study, the second step, ethanol extraction, was facilitated by the addition of 3% NaOH and 3% HO, resulting in a significant improvement of lignin separation (by 48.2%). SEM, AFM, XPS, and XRD were used to characterize the surface composition of the remaining solids (crude cellulose) while the structure of isolated lignin was characterized by FT-IR, CP/MAS 13C NMR, GPC and TGA. The lignin samples isolated with both facilitated and non-facilitated ethanol extraction were compared to elucidate the lignin removal mechanism. The results showed that lignin degradation and crosslinking/polymerization occur in parallel during both the hydrothermal treatment and ethanol extraction.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.biortech.2020.123882DOI Listing
November 2020

Crosstalk between noncoding RNAs and ferroptosis: new dawn for overcoming cancer progression.

Cell Death Dis 2020 07 24;11(7):580. Epub 2020 Jul 24.

Department of Ultrasonography, Harbin Medical University Cancer Hospital, 150 Haping Road, 150040, Harbin, China.

Cancer progression including proliferation, metastasis, and chemoresistance has become a serious hindrance to cancer therapy. This phenomenon mainly derives from the innate insensitive or acquired resistance of cancer cells to apoptosis. Ferroptosis is a newly discovered mechanism of programmed cell death characterized by peroxidation of the lipid membrane induced by reactive oxygen species. Ferroptosis has been confirmed to eliminate cancer cells in an apoptosis-independent manner, however, the specific regulatory mechanism of ferroptosis is still unknown. The use of ferroptosis for overcoming cancer progression is limited. Noncoding RNAs have been found to play an important roles in cancer. They regulate gene expression to affect biological processes of cancer cells such as proliferation, cell cycle, and cell death. Thus far, the functions of ncRNAs in ferroptosis of cancer cells have been examined, and the specific mechanisms by which noncoding RNAs regulate ferroptosis have been partially discovered. However, there is no summary of ferroptosis associated noncoding RNAs and their functions in different cancer types. In this review, we discuss the roles of ferroptosis-associated noncoding RNAs in detail. Moreover, future work regarding the interaction between noncoding RNAs and ferroptosis is proposed, the possible obstacles are predicted and associated solutions are put forward. This review will deepen our understanding of the relationship between noncoding RNAs and ferroptosis, and provide new insights in targeting noncoding RNAs in ferroptosis associated therapeutic strategies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41419-020-02772-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7381619PMC
July 2020
-->