Search

Today, the rail traffic as a large capacity public transportation way gets rapid development in the world, in order to guarantee the trains safety, people use train network to monitor the trains real time status. But with the developing of safety requirement, the traditional MVB networks low transmission rate has been unable to meet the train safety monitorings large capacity data transmission requirement, so people put forward the idea of industrial Ethernet. Industrial Ethernet although can meet the requirement of large capacity, high rate transmission requirement, but still in the initial development stage, there has no unified transmission protocol and interface specification, so research on transmission standard of train safety monitoring network with great data transmission capacity has become the new development direction.

In order to improve the diagnostic accuracy of digital circuit, the fault diagnosis method based on support vector machines (SVM) is proposed. The input is fault characteristics of digital circuit; the output is the fault style. The connection of fault characteristics and style was established. Network learning algorithm using least squares, the training sample data is formed by the simulation, the test sample data is formed by the untrained simulation. The method achieved the classification of faulted digital circuits, and the results show that the method has the features of fast and high accuracy.

For the muzzle velocity measurement of high firing rate artillery, a novel time-frequency analysis method based on short-time Fourier transform (STFT) is proposed and the design principles of critical parameters are provided in this article. Measured data verifies the feasibility of this method, which provides useful references for engineering application and lays foundation for further noise reduction and muzzle velocity extrapolation.

We propose a scheme to deterministically generate Greenberger–Horne–Zeilinger states of N≥3 atoms trapped in spatially separated cavities connected by optical fibers. The scheme is based on the technique of fractional stimulated Raman adiabatic passage, which is a one-step technique in the sense that one needs only to wait for the desired entangled state to be generated in the stationary regime. The parametrized shapes of the Rabi frequencies of the classical fields that drive the two end atoms are chosen appropriately to realize the scheme. We also show numerically that the proposed scheme is insensitive to fluctuations of the pulses’ parameters and, at the same time, that it is robust against decoherence caused by the dissipation due to fiber decay. Moreover, a relatively high fidelity can be obtained even in the presence of cavity decay and atomic spontaneous emission.

AbstractPlasmid-mediated quinolone resistance (PMQR) determinants were widely distributed among Enterobacteriaceae. The objectives of the present study were to analyze PMQR-positive Escherichia coliisolates from pigs, and to investigate the association between these determinants and other resistant genes. A total of 129 porcine E. coliisolates were included in this study. The presence of PMQR, floR, blaCTX-M-14, and blaTEM-1genes were detected by polymerase chain reaction (PCR) amplification and confirmed by subsequent sequencing. The PMQR-positive isolates were subjected to plasmid profiling, and transformation experiments were conducted to identify the quinolone resistance plasmids. The qnrS1region of a quinolone resistance plasmid was cloned and sequenced. Among the 129 E. coliisolates, the positive rate for PMQR determinants was 42.6%, and the prevalence of qnrgenes, aa(6')-Ib–cr,and qepAwere 23.3%, 18.6%, and 0.8%, respectively. A qnrS1-carrying plasmid of 81 kb, named plasmid T078 (pT078), was detected from one multidrug-resistant isolate. Hybridization and PCR analysis confirmed that floR, blaCTX-M-14, and blaTEM-1genes were also located on this plasmid. Sequence analysis identified the qnrS1gene flanked by a truncated transposase gene. Moreover, complete tetracycline resistance genes tet(A) and tet(R) were found upstream of the qnrS1gene, and floRgene was found downstream of the qnrS1gene on the plasmid pT078. To our knowledge, this is the first study demonstrating the occurrence of qnrS1, floR, blaCTX-M-14, blaTEM-1, and tet(A) on one plasmid in E. coliisolated from food animals.

Tribromoacetic acid (TBAA), one of the typically recalcitrant and toxic chlorine disinfection byproducts (DBPs), is widespread in the drinking water and threating human health. The environment-friendly technology, UV irradiation, could efficiently destruct TBAA. The present study investigated the removal efficiency, photodegradation kinetics, and photodegradation mechanism of TBAA under UV irradiation. It revealed that the photodegradaton process of TBAA agreed well with the pseudo-first order kinetics, with the rate constant of 1.084 min-1 and half-time of 0.64 minutes. Further study on intermediate products formation and mass balance indicated that complete debromination and detoxification were obtained with almost all the bromine atoms released as bromide ions, and suggest that the cleavage of three C-Br bonds concurrently occurred during the photolysis of one TBAA molecule. It will provide some guidance for efficient treatment of brominated contaminants in water.

Chlorophenols (CPs), a group of recalcitrant and toxic pollutants, are widespread in the environment and threating human health. The environment-friendly technology, UV irradiation, could efficiently destruct CPs. The study investigated the influence of solution pH and positions and number of substituted chlorine atoms on photodegradation process of CPs, and also studied the photodegradation pathway. It found that the photodegradaton process of CPs was highly dependent on solution pH, and higher pH favored the degradation. The photodegradation processes agreed well with the pseudo-first order kinetics, and para- and ortho- positions and lower chlorination degree were more favorable for photodegradation of CPs. Most of the chlorine atoms were released as chloride ions, and suggest that the cleavage of the C-Cl bond occurred during the photodegradation process. It will provide some guidance for efficient treatment of CPs in water.

For the initial lining structure of tunnel , constructing an consider integrated safety factor function.Consider the initial shotcrete tunnel support structure as a series system, using the interval estimation of the "wide boundaries of law" system of tunnel lining structure analysis, on this basis to determine the system failure mode. Using the limit displacement under the condition of axial force and bending moment of the corresponding displacement and construction monitoring of displacement are analyzed, considering the material properties, geometry and random effects. Using the Monte Carlo finite element method, combined with a typical project example to tunnel structural system reliability index were calculated. The calculation results show that in the engineering example, tunnel lining structure in some local section of the reliability index is smaller, but the whole support system reliability indexes meet the design requirements, the whole tunnel lining structure in a safe state.

The stratum uneven settlement of tunnel is main factors that cause damage of tunnel longitudinal structure. a 3d numerical model is established for the force and deformation calculation of tunnel structure based on the elastoplastic theory. In the model, soil material is elastoplastic, and its constitutive model is Mohr Coulomb, the element type of soil is a three-dimensional solid, the element type of tunnel lining structure is space shell element, and tunnel settlement joint is three-dimensional linear spring. Calculation shows that, this calculation model is able to fully consider the impact of tunnel uneven settlement in all factors, and can simulate the vertical force and deformation behavior of tunnel structure in complex ground formation conditions. Research conclusion gives the vertical force and deformation of the tunnel structure under the condition of the stratum uneven settlement. It is very important reference for the longitudinal design and calculation of the tunnel lining structure.

The introduction of can reasonable description of transversely isotropic soil micro-element strength parameters - damage variable, according Mohr-Coulomb strength theory and soil micro-element theory of geotechnical failure to obey normal distribution characteristic,the damage variables can true reflection of transversely isotropic soil softening characteristics.Based on the uniaxial stress-strain curve of the geotechnical rupture process of statistical damage constitutive model of geotechnical, statistical damage variable is adjusted, establishing the reflect the complete process of geotechnical failure of 3D statistical damage constitutive model.Model is simple, easy to use, can better reflect the actual.The model reflects the failure process of geotechnical damage not only with geotechnical micro-unit strength changes, and the effect of geotechnical stress state.

This paper analyzes the tunnel rock ultimate displacement,proposes using acceleration to determine the tunnel surrounding rock stability.Acceleration compared to determine the stability of surrounding rock ultimate displacement method obtained consistent results.Acceleration improved the ultimate displacement method to determine the shortcomings are difficult to quantify.Acceleration of rock deformation by the positive and negative judgments, rock deformation can clearly reflect the trends and status, you can clearly see which one works in a specific state of rock a dangerous warning signal.With a typical project examples validate the method used to determine the displacement acceleration stability of surrounding rock is accurate, feasible.Research and analysis to help build a tunnel surrounding rock stability analysis of the forecasting system.

To make a top local adding stories of “L” flat facade irregular frame structure with good resistance to twist and integrity, can better satisfy the requirements of local seismic fortification intensity,using metal damper to this after-adding-stories framework model for processing. Using SAP2000 finite element analysis software modeling and in its install metal damper dynamic time-history analysis before and after. Results show that the structure using metal consumption technology in consume earthquake input energy at the same time can enhance structure rigid and floor wrest resistant and strengthen the lateral stiffness integral structure seismic performance.

ABSTRACTTo truly transform the landscape of tuberculosis treatment, novel regimens containing at least 2 new drugs are needed to simplify the treatment of both drug-susceptible and drug-resistant forms of tuberculosis. As part of an ongoing effort to evaluate novel drug combinations for treatment-shortening potential in a murine model, we performed two long-term, relapse-based experiments. In the first experiment, TMC207 plus pyrazinamide, alone or in combination with any third drug, proved superior to the first-line regimen including rifampin, pyrazinamide, and isoniazid. On the basis of CFU counts at 1 month, clofazimine proved to be the best third drug combined with TMC207 and pyrazinamide, whereas the addition of PA-824 was modestly antagonistic. Relapse results were inconclusive due to the low rate of relapse in all test groups. In the second experiment evaluating 3-drug combinations composed of TMC207, pyrazinamide, PA-824, moxifloxacin, and rifapentine, TMC207 plus pyrazinamide plus either rifapentine or moxifloxacin was the most effective, curing 100% and 67% of the mice treated, respectively, in 2 months of treatment. Four months of the first-line regimen did not cure any mice, whereas the combination of TMC207, PA-824, and moxifloxacin cured 50% of the mice treated. The results reveal new building blocks for novel regimens with the potential to shorten the duration of treatment for both drug-susceptible and drug-resistant tuberculosis, including the combination of TMC207, pyrazinamide, PA-824, and a potent fluoroquinolone.

AbstractThe objective of the present study was to examine whether the expression of qnrAmay contribute to a high level of resistance among parent and induced strains of Kluyveraspp. Two clinical isolates of ciprofloxacin-resistant Kluyveraspp. were obtained from livers of diseased chickens, and upon induction with ciprofloxacin, six strains with increased resistance were produced. Point mutations in qnrA, aac(6')-Ib-cr, gyrA, gyrB, parC, and parEwere investigated by polymerase chain reaction (PCR) amplification and DNA sequencing, and expression levels of acrABand qnrAin all strains were investigated by quantitative real-time PCR (qRT-PCR). The induced strains contained the same mutations in quinolone resistance-determining region as those of the parent strains. qRT-PCR showed that the expression of the acrAgene was not detected in any strain and acrBgene expression was unchanged between induced and parental strains. However, difference in expression of qnrAwas observed, which correlated well with the level of quinolone resistance in the parent and induced strains. The induced high resistance was not affected by mutations in qnrAand aac(6')-Ib-cr, by new mutations in the quinolone resistance-determining region of gyrA, gyrB, parC, and parE, or by the expression level of acrAB. These data suggest that the expression of qnrAmay be a factor contributing to the high level of resistance among parent and induced strains of Kluyveraspp.

With a view of simulating the dimensional changes during sintering of rectangle green bodies, the thermo-mechanical behavior of zirconium powder compacts at high temperature is investigated. In order to better describe the behavior of anisotropic shrinkage, the revised Master Sintering Curve is modified. Finite element calculations are then carried out on the green body according to the modified equation with the different shrinkages coefficients at the different stages of sintering. The possible causes of the anisotropic shrinkage are explained by macro-surface energy model. Numerical shape predictions have been compared with experimental data, which are considered to be in good agreement.

ABSTRACTMycobacterium ulceranscauses Buruli ulcer, a potentially disabling ulcerative skin disease. Only recently was antimicrobial therapy proven effective. Treatment for 2 months with rifampin plus streptomycin was first proposed after experiments in the mouse footpad model demonstrated bactericidal activity. This treatment is now considered the treatment of choice, although larger ulcers may require adjunctive surgery. Shorter, oral regimens are desired, but evaluating drug activity in mice is hampered by the very slow growth of M. ulcerans, which takes 3 months to produce countable colonies. We created a recombinant bioluminescent M. ulceransstrain expressing luxABfrom Vibrio harveyifor real-time evaluation of antimicrobial effects in vivo. Mouse footpads were injected with wild-type M. ulcerans1059 (WtMu) or the recombinant bioluminescent strain (rMu). Two weeks later, mice received rifampin plus streptomycin, kanamycin alone (to which rMu is resistant), or streptomycin alone for 4 weeks and were observed for footpad swelling (preventive model). Untreated controls and kanamycin-treated rMu-infected mice received rifampin plus streptomycin for 4 weeks after developing footpad swelling (curative model). Compared to WtMu, rMu exhibited similar growth and virulence in vivoand similar drug susceptibility. A good correlation was observed between luminescence (measured as relative light units) and number of viable bacteria (measured by CFU) in footpad homogenates. Proof of concept was also shown for serial real-time evaluation of drug activity in live mice. These results indicate the potential of bioluminescence as a real-time surrogate marker for viable bacteria in mouse footpads to accelerate the identification of new treatments for Buruli ulcer.

Three kinds of phenols, namely gallic acid, syringal alcohol and ferulic acid, were selected as laccase natural mediator to investigate the changes of fiber surfaces, morphological properties of fibers, kappa number and physical properties of OCC (Old Corrugated Containers) pulp with laccase/ natural mediator system treatment. It was illustrated that condensation reaction of phenols could be occured by catalytic oxidation of laccase. The results of fiber quality analysis and SEM observation showed that after treated using laccase/ natural mediator system, the resultantly yielded OCC pulp had much smoother surface, larger fibers coarseness, higher kappa number, and the auto-adhesion of fibers could be observed in the fibers. In additon, the wet strength of handsheets, especially the wet ring crush strength, was improved obviously, compared with control sample.

AbstractTo evaluate the temporal change in the plasmid-mediated quinolone resistance (PMQR) determinants from 2001 to 2007 in chicken, a total of 532 chicken Escherichia coliisolates were screened for PMQR determinants by polymerase chain reaction and sequencing. The prevalence of qnrgenes, aa(6′)-Ib-cr, and qepAwere 9.8%, 11.7%, and 0.75%, respectively. Among the qnrdeterminants, qnrA-, qnrB-, and qnrS-type genes were detected in 4 (0.75%), 21 (3.9%), and 27 (5.1%) of the examined isolates, respectively. None of the isolates carried qnrCgene. Ciprofloxacin resistance increased over time (p< 0.01), and a clear trend of increase in the prevalence of qnrand aac(6′)-Ib-crgenes among the isolates was shown from 2001 to 2007 (p< 0.01). Pulsed-field gel analysis showed that the PMQR-positive isolates were not clonally related and genetically diverse. Quinolone resistance was transferred by conjugation from qnrB-, qnrS-, and aac(6′)-Ib-cr–positive isolates to recipient E. coli. The qnrBand aac(6′)-Ib-cralleles were located on the plasmids with the size of 49 and 50 kb, respectively. However, the qnrSalleles were located on different plasmids with sizes from 57.4 to 88.6 kb, indicating diverse genetic backgrounds. The increasing frequency of ciprofloxacin resistance in E. coliwas associated with increasing prevalence of qnrgenes and aac(6′)-Ib-cr(rs= 0.964, p= 0.00045). This survey showed that PMQR determinants were highly prevalent in chicken E. coliisolates in China with a trend of increase from 2001 to 2007. Horizontal transfer and widespread use of quinolone antimicrobials may have contributed to the spread of PMQR determinants in the poultry production system. The widespread dissemination of PMQR could potentially fuel the rapid development of fluoroquinolones resistance.

Sensitive imaging of intracellular microRNA (miRNA) in living cells is of great significance. Isothermal hybridization chain reaction (HCR)-based methods, although have been widely used to monitor intracellular low-abundance miRNA, are still subjected to the challenges of limited signal amplification efficiency and compromised imaging resolution. In this work, we design a light-controlled recruitable HCR (LCR-HCR) strategy that enables us to well overcome these limitations. Exosomes as delivery and recruitment vehicles are modified with three cholesterol-modified hairpins (H1, H2, and H3), in which H1is for anchoring target miRNA and H2and H3with photocleavable linkers (PC-linkers) are designed for spatiotemporal HCR. By controllably releasing probes with high local concentrations to efficiently trigger HCR and further recruiting the generated double-stranded DNA (dsDNA) polymers instead of dispersion in the cytoplasm, the LCR-HCR method can significantly improve the imaging contrast by confining all of the reactants on exosome vehicles. For a proof-of-concept demonstration, the miR-21 was analyzed by LCR-HCR with a limit of detection (LOD) down to 3.3 pM (corresponding to 165 amol per 50 μL) in vitro and four times higher response than traditional HCR in vivo. In general, the LCR-HCR method provides a powerful tool for sensitive miRNA imaging in living cells and cancer diagnosis.

Vertically aligned carbon nanotubes (VACNTs), a unique classification of CNT, highly oriented and normal to the respective substrate, have been heavily researched over the last two decades. Unlike randomly oriented CNT, VACNTs have demonstrated numerous advantages making it an extremely desirable nanomaterial for many biomedical applications. These advantages include better spatial uniformity, increased surface area, greater susceptibility to functionalization, improved electrocatalytic activity, faster electron transfer, higher resolution in sensing, and more. This Review discusses VACNT and its utilization in biomedical applications particularly for sensing, biomolecule filtration systems, cell stimulation, regenerative medicine, drug delivery, and bacteria inhibition. Furthermore, comparisons are made between VACNT and its traditionally nonaligned, randomly oriented counterpart. Thus, we aim to provide a better understanding of VACNT and its potential applications within the community and encourage its utilization in the future.

The adjuvant treatment of patients with resected lung adenocarcinoma (LUAD) remains unstandardized. We analyzed the survival outcomes of these patients based on EGFRmutation status and adjuvant chemotherapy treatment.

5-Hydroxymethylcytosine (5hmC), an intermediate product of DNA demethylation, is important for the regulation of gene expression during development and even tumorigenesis. The challenges associated with determination of 5hmC level include its extremely low abundance and high structural similarity with other cytosine derivatives, which resulted in sophisticated treatment with large amount of sample input. Herein, we developed a primer-initiated strand displacement amplification (PISDA) strategy to quantify the global 5hmC in genomic DNA from mammalian tissues with high sensitivity/selectivity, low input and simple operation. This sensitive fluorescence method is based on 5hmC-specific glucosylation, primer ligation and DNA amplification. After the primer was labeled on 5hmC site, DNA polymerase and nicking enzyme will repeatedly act on each primer, causing a significant increase of fluorescence signal to magnify the minor difference of 5hmC content from other cytosine derivatives. This method enables highly sensitive analysis of 5hmC with a detection limit of 0.003% in DNA (13.6 fmol, S/N = 3) from sample input of only 150 ng, which takes less than 15 min for determination. Further determination of 5hmC in different tissues not only confirms the widespread presence of 5hmC but also indicates its significant variation in different tissues and ages. Importantly, this PISDA strategy exhibits distinct advantages of bisulfite-free treatment, mild conditions and simple operation without the involvement of either expensive equipment or large amount of DNA sample. This method can be easily performed in almost all research and medical laboratories, and would provide a promising prospect to detect global 5hmC in mammalian tissues.

•Predictive power of PD response for ICIs was superior than traditional biomarkers;•Predictive efficacy was improved by integrating tumor-immune-related features;•When tumor-specific feature was replaced, the model has pan-cancer applicability.•NRAS and PDPK1 have the potential to induce primary resistance to ICIs.

Low molecular weight poly(butylene adipate) (PBA) was synthesized by melt polycondensation. The chain extension of the prepolymers was carried out using 2,2’-(1,4-phenylene)-bis(2-oxazoline) (PBOX) as chain-extender. The influencing factors including reaction temperature, oxazoline/-COOH molar ratio, and the molecular weight of prepolymers were studied. At the optimal chain-extending condition, PBA with Mn of 38583 and Mw of 125497 was prepared. The structure of the chain-extended PBA was also characterized by the FTIR and 1H NMR.

ABSTRACTTo understand the prevalence and evolution of drug resistant HIV strains in Henan China after the implementation of free antiretroviral therapy for AIDS patients. 45 drug naïve AIDS patients, 118 AIDS patients who received three months antiretroviral therapy and 124 AIDS patients who received six months antiretroviral treatment were recruited in the southern part of Henan province. Information on general condition, antiretroviral medicines, adherence and clinical syndromes were collected by face to face interview. Meanwhile, 14ml EDTA anticoagulant blood was drawn. CD4/CD8 T cell count, viral load and genotypic drug resistance were tested. The rates of clinical improvement were 55.1% and 50.8% respectively three months and six months after antiretroviral therapy. The mean CD4 cell count after antiretroviral therapy was significantly higher than in drug naïve patients. The prevalence rate of drug resistant HIV strains were 13.9%, 45.4% and 62.7% in drug naïve patients, three month treatment patients and six month treatment patients, respectively. The number of resistance mutation codons and the frequency of mutations increased significantly with continued antiretroviral therapy. The mutation sites were primarily at the 103, 106 and 215 codons in the three-month treatment group and they increased to 15 codon mutations in the six-month treatment group. From this result, the evolution of drug resistant strains was inferred to begin with the high level NNRTI resistant strain, and then develop low level resistant strains to NRTIs. The HIV strains with high level resistance to NVP and low level resistance to AZT and DDI were highly prevalent because of the AZT+DDI+NVP combination therapy. These HIV strains were also cross resistant to DLV, EFV, DDC and D4T. Poor adherence to therapy was believed to be the main reason for the emergence and prevalence of drug resistant HIV strains. The prevalence of drug resistant HIV strains was increased with the continuation of antiretroviral therapy in the southern part of Henan province. Measures, that could promote high level adherence, provide new drugs and change ART regimens in failing patients, should be implemented as soon as possible.

ABSTRACTTo understand the prevalence and evolution of drug resistant HIV strains in Henan China after the implementation of free antiretroviral therapy for AIDS patients. 45 drug naïve AIDS patients, 118 AIDS patients who received three months antiretroviral therapy and 124 AIDS patients who received six months antiretroviral treatment were recruited in the southern part of Henan province. Information on general condition, antiretroviral medicines, adherence and clinical syndromes were collected by face to face interview. Meanwhile, 14ml EDTA anticoagulant blood was drawn. CD4/CD8 T cell count, viral load and genotypic drug resistance were tested. The rates of clinical improvement were 55.1% and 50.8% respectively three months and six months after antiretroviral therapy. The mean CD4 cell count after antiretroviral therapy was significantly higher than in drug naïve patients. The prevalence rate of drug resistant HIV strains were 13.9%, 45.4% and 62.7% in drug naïve patients, three month treatment patients and six month treatment patients, respectively. The number of resistance mutation codons and the frequency of mutations increased significantly with continued antiretroviral therapy. The mutation sites were primarily at the 103, 106 and 215 codons in the three-month treatment group and they increased to 15 codon mutations in the six-month treatment group. From this result, the evolution of drug resistant strains was inferred to begin with the high level NNRTI resistant strain, and then develop low level resistant strains to NRTIs. The HIV strains with high level resistance to NVP and low level resistance to AZT and DDI were highly prevalent because of the AZT+DDI+NVP combination therapy. These HIV strains were also cross resistant to DLV, EFV, DDC and D4T. Poor adherence to therapy was believed to be the main reason for the emergence and prevalence of drug resistant HIV strains. The prevalence of drug resistant HIV strains was increased with the continuation of antiretroviral therapy in the southern part of Henan province. Measures, that could promote high level adherence, provide new drugs and change ART regimens in failing patients, should be implemented as soon as possible.Cell Research (2005) 15, 843–849. doi:10.1038/sj.cr.7290356

Abstract: Objective: To explore the expression and significance of heparanase in non-small cell lung cancer (NSCLC) regarding prognosis and clinicopathological parameters. Methods: The expression of heparanase was assessed using immunohistochemistry staining and Western blot in 122 paraffin-embedded specimens and 38 freshly taken tissues. The relationship between heparanase expression and the clinicopathological factors was analyzed by Chi-square test, multivariate analysis and Kaplan-Meier method. Results: In the immunoreactive cells, staining was mainly located in cytoplasma and membrane. Human heparanase was highly expressed in lung cancer tissue (78.7%, 96/122) while negative in epithelia of normal lung tissues. The level of heparanase was remarkably higher in NSCLC than that in normal tissue (P=0.043). Expression of heparanase significantly correlated with TNM stage (P=0.025), lymphatic metastasis (P=0.002) and vascular invasion (P=0.0003). The patients with positive heparanase expression had a significantly shorter survival than those with negative heparanase expression (P=0.0006). In multivariate analysis, only p-TNM stage, lymphatic metastasis and vascular invasion could be considered as prognostic factors. Conclusion: Elevated level of heparanase in human non-small cell lung cancer tissues correlates with the TNM stage, invasion, metastasis and prognosis. However, heparanase expression is not an independent prognostic factor.

Developing high-performance warmth retention materials to protect humans from the harm causing by extra cold conditions is remained challenging. Herein, we firstly fabricate fibrous sponges tailored by interlocking double-networks to serve as novel warmth retention materials. Polymethyl methacrylate (PMMA) microfibers build the three-dimensional (3D) skeleton and polyurethane (PU) nanofibers are introduced into the skeleton to improve the mechanical property and warmth retention. The PMMA/PU fibrous sponge (PMMA/PUFS) has a high tensile stress of 159.02 kPa, large tensile elongation of 65.85%, and good resilience after bearing nearly complete deformation, as well as ultralight property (7.38 mg cm−3) and effective warmth retention (25.28 mW m−1 K−1). The successful fabrication of PMMA/PUFS may provide a new vision for creating functional materials with good mechanical properties.

Nano-structured membranes with great properties are promising alternatives for water purification. However, it remains a challenge to develop such materials, especially for purifying water contaminated by pathogenic microbes. In this work, a newly-designed nanofibrous membrane with rechargeable biocidal function was prepared through grafting poly(vinyl alcohol-co-ethylene) (EVOH) with poly[5,5-dimethyl-3-(3′-triethoxysilylpropyl)-hydratoin] (PSPH) in the form of electrospun nanofibers. The proposed strategy intrinsically allows the N-halamine compounds to homogeneously and covalently integrate with EVOH nanofibers, bringing the membranes efficiently antimicrobial capability and durability. Moreover, the resultant chlorinated membranes exhibit characteristics of good mechanical property, superior hydrophilicity, renewable chlorination activity (>4000 ppm) and outstanding microbicidal performance (>99.999%), suggesting the composite materials could be used as filtration layers for bacteria-contaminated water disinfection with a favorable flux (>2000 L m−2 h−1). The successful fabrication strategy provides innovative insights into exploring other antifouling nanofibrous materials in a renewable way.

A novel poly(styrene-co-acrylonitrile)-graft-polyethylene glycol copolymer was synthesized as new solid–solid phase change materials, which have high enthalpy and great heat storage durability.

Advanced warming materials integrating functions of reducing heat loss and providing extra heat for the body have attracted much attention. In this work, an ultralight and superelastic fibrous sponge serving as novel warmth retention materials was obtained by assembling the fibers contained zirconium carbide nanoparticles (ZrC NPs) into three-dimension (3D) configuration and creating the semi-interpenetrating polymer networks (semi-IPNs) within fibers via humidity-induced electrospinning and the thermal crosslinking technology. The resulting fibrous sponge (PCFS-12) exhibits high heat preservation ability (~25.2 mW m−1 K−1) and effective photo-thermal conversion performance that could improve the temperature of PCFS-12 to 70.3 °C under the sunlight irradiation. Moreover, the PCFS-12 showed a low density of 2.8 mg cm−3, low-temperature superelasticity with minor plastic deformation after 1000 compression, and good hydrophobic property (WCA = 132°). This work provides a novel approach to develop high-performance warmth retention materials for personal cold protection.

Health risks are more likely to occur in cold environments, making warm equipment highly in demand. Fluffy fibrous sponge obtained from direct electrospinning exhibited a great application prospect in heat retention fields but are often hampered by their weak mechanical stability and flammability used in high-temperature environments. How to create such materials having the robust mechanical property, flame retardancy and efficient thermal insulation simultaneously was a huge challenge. Herein, we report on a one-step method to manufacture superelastic and lightweight 3D fibrous sponge with antiflame function. The premise of this strategy is that polysulfone (PSU) can form a stable fluffy structure in a high-humidity environment, while polyurethane (PU) can absorb deformation energy caused by external forces. By adding OP-100A, the carbonization speed of PSU/PU fibrous sponge was increased and the antiflaming property was improved. Thanks to the polymer combination strategy, the fibrous sponge prepared has excellent tensile properties with the elongation at break reaching 160%, and unique elastic energy of compression with almost no plastic deformation after 100 compressions tests. Furthermore, the fibrous sponge also has obvious advantages in ultralight property, flame retardant property and heat retention property. The successful preparation of fibrous sponge opens a new way for the development of superelastic, lightweight, and flame-retardant heat retention materials.

Respiratory diseases, particularly which are highly infectious, have become a severe public health concern. Presently available masks used to prevent infections typically lack antibacterial activity. Herein, an eco-friendly 5-bromosalicylic acid/polyvinyl butyral nanofibrous membranes (BSA/PVB NMs) with high interception efficiency and antimicrobial property is reported. The membrane design uses green materials and electrospinning technique, making the entire process environmentally friendly. The resulting BSA/PVB NMs possess intriguing features, such as high filtration efficiency (>99%) at an airflow velocity of 85 L min−1, superior bactericidal activity (>99.999%) when in contact with bacteria for 10 min, and excellent bacterial filtration efficiency (BFE) (>99.9%) when combined with non-woven fabric to form a mask. The preparation of BSA/PVB NMs are completely up to the requirements of the core layer of N95 grade personal protective mask, making it a new choice of multi-functional bioprotective masks.

It is an urgent need to develop an effective and advanced technique to degrade mercaptan, a kind of pollution gas with bad odor, which seriously endangers human health and living environment. However, this is still a huge challenge. Here, we have prepared amide-halamine/silica composite nanofibrous membranes possessing rechargeable chlorination capacity via the combination of electrospinning and grafting reaction. The resultant chlorinated composite membranes are endowed with great structural stability attributed to covalent binding between amide-halamine compound and silica nanofibers, and exhibit the intriguing properties of renewable chlorination performance, high active chlorine content and good water swelling resistance, which are highly capable for degrading mercaptan in sewage with high degradation efficiency and large processing flux. More importantly, the successful fabrication of the amide-halamine/silica composite nanofibrous membranes with excellent properties will open a new approach for the design and development of a potential mercaptan degrading materials in wastewater treatment.

Although the unfolding and refolding of proteins have been extensively studied in the literature, relatively few attempts have been made to see how many residues of the total residues of a certain amino acid in an enzyme can be modified without seriously affecting its folding. Based on a statistical analysis of the quantitative relationship between the extent of modification of protein functional groups and the decrease in their biological activity, a method proposed by Tsou (Sci. Sin. 1962, 11, 1535–1558) is widely used to determine the number of residues essential for the catalytic activity of modified proteins. In the present paper, Tsou's method is applied to determine the number of cysteine residues essential for the folding of creatine kinase. The thiol groups of the cysteine residues in fully unfolded creatine kinase were modified by 2-chloromercuri-4-nitrophenol (MNP). The relationship between the number of MNP-groups introduced and the recovery of activity after refolding was determined. Quantitative treatment of the data by Tsou's plot shows that among the cysteine residues modified in each subunit of creatine kinase, only three are essential for its folding.

The conformational changes of the active site of creatine kinase (ATP: creatine N‐phosphotransferase EC 2.7.3.2.) during thermal denaturation was followed by changes in fluorescence at the active site of the enzyme labeled by o‐phthalaldehyde. Conformational changes of the active site occurred at the same time as inactivation of the enzyme. The active site changes occurred before the denaturation of the enzyme molecule as a whole was detected. The above results showed that the thermal inactivation of the creatine kinase was due to the conformational changes of its active sites.

The recent outbreak of a coronavirus disease (COVID-19) has posed a great threat to public health and financial system. Most current masks used to prevent the spread of COVID-19 are typically absence of biocidal properties. We designed a novel polymer, polystyrene grafted by 5, 5-dimethylhydantoin and trimethylamine (PSDT), which possesses halamine site and cationic quaternary ammonia salt site. Furthermore, PSDT/PU nanofiber@net membranes (PSDT/PU NNMs) were obtained by electrospinning technology. Our strategy enables inherent N-halamine and quaternary ammonia salt (QAS) group to be covalently integrated into membranes, realizing the efficient and stable biocidal properties. Meanwhile, the introduction of nanonets endows electrospun membranes with prominent air filtration performance. The resulting membranes exhibit integrated properties of high interception of fine particles (96.7%) and low pressure drop (95.4 Pa). Besides, chlorinated PSDT/PU nanofiber@net membranes (with active chlorine content of 0.60 wt% and quaternary ammonia salt content of 2.20 wt%) exhibited superior bactericidal (>99.9999%) and virucidal (>99.999%) efficiency in a short time (2 min), which enables chlorinated PSDT/PU NNMs to be served as the filtration material by providing bacterial interception (99.77%) and contact killing against pathogens. The successful synthesis of PSDT/PU NNMs provide innovative insights for exploring filtration materials in a nanonet and biocidal form.

5-Hydroxymethylcytosine (5hmC) and 5-formylcytosine (5fC) are key intermediates of active DNA demethylation, for which the global detection methods are still restricted by high cost and long operation time. Here, we demonstrate a pearl necklacelike strategy to accurately quantify global 5hmC and 5fC in genomic DNA. In this method, the metal–organic framework (MOF), [Cu3(BTC)2] (denoted as HKUST-1, H3BTC = 1,3,5-benzenetricarboxylic acid), with a diameter of ∼30 nm that contains ∼15 000 copper ions (Cu2+) as the “super label” was in situgrown in the carboxylated 5hmC and 5fC loci of genomic DNA via the coordination between Cu2+and the carboxyl group. After the acid digestion of MOF, the concentration of Cu2+, which has a quantitative relationship with the 5hmC/5fC content, was measured by inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The metal element enrichment during MOF growth has amplified the signal by 4 orders of magnitude, realizing sensitive and accurate quantification of global 5hmC and 5fC in different tissues with a detection limit of 0.031% and 0.019‰ in DNA, respectively. The bisulfite- and mass spectrometry-free strategy is easily performed in almost all research and medical laboratories and would provide potential capability to quantify other candidate modifications in nucleotides.

Chemical warfare agents (CWAs) pose huge threats to ecological environments, agriculture, and human health due to the turbulent international situation in contemporary society. Zirconium hydroxide (Zr(OH)4) has captured the prime focus as an effective candidate for CWA decomposition but is often hindered by the isolated powder form. Here, we demonstrate a scalable three-dimensional space-confined synthetic strategy to fabricate nanoflake-engineered zirconic fibrous aerogels (NZFAs). Our strategy enables the stereoscopic Zr(OH)4nanoflakes vertically and evenly in situgrown on the interconnected fibrous framework, remarkably enlarging the surface area and providing rich active sites for CWA catalysis. The as-synthesized NZFAs exhibit intriguing properties of ultralow density (>0.37 mg cm–3), shape-memory behavior under 90% strain, and robust fatigue resistance over 106compression cycles at 40% strain. Meanwhile, the high air permeability, prominent adsorptivity, and reusability make them state-of-the-art chemical protective materials. This work may provide an avenue for developing next-generation aerogel-based catalysts and beyond.

Sufficient and clean freshwater is still out of reach for billions of people around the world. Solar desalination from brine is regarded as one of the most promising proposals to solve this severe crisis. However, most of the reported evaporators to date still suffer from the decreasing evaporation rate caused by salt crystallization accumulated on their surface. Here, inspired by the vascular tissue structure, transpiration, and antifouling function of reed leaves, we design biomimetic hierarchical nanofibrous aerogels with parallel-arranged vessels and hydrophobic surfaces for highly efficient and salt-resistant solar desalination. Foldable vessel walls and flexible silica nanofibers give the reed leaf-inspired nanofiber aerogels (R-NFAs) excellent mechanical properties and enable them to withstand repeated compression. Besides, the R-NFAs can efficiently absorb sunlight (light absorption efficiency: 94.8%) and evaporate the brine to vapor, similar to reed leaves (evaporation rate: 1.25 kg m–2h–1under 1 sun). More importantly, enabled by the hydrophobic surfaces and parallel-arranged vessels, the R-NFAs can work stably in high-concentration brine (saturated, 26.3 wt %) under high-intensity light (up to 6 sun), demonstrating potent salt resistance. It is expected that R-NFAs with combined antisalt pore and surface structures will provide a designed concept for salt-resistant solar desalination.

Traditional fresh produce washing systems mainly rely on mechanical forces and usage of chlorine bleach solutions to aid in removal and sanitization of microorganisms attached on surfaces of fresh produce during washing processes. Frequent outbreaks of foodborne diseases from ready-to-eat produce indicate insufficient sanitization of the washing processes. Herein, we present a scalable methodology for creating antimicrobial and chlorine rechargeable hydrogel beads using an in situformed network of polyacrylamide and natural polysaccharide alginate through an emulsion polymerization. The resulting hydrogel beads exhibited robust mechanical strength, rechargeable chlorination capability, rapid up to 99.99% bacterial killing efficiency, and high produce sanitizaiton efficiency, enabling the hydrogel beads as a promising additive in chlorine sanitization to effectively sanitize the produce and automatically being recharged and reused.

Dynamic imaging of cell surface pH is extremely challenging due to the slight changes in pH and the fast diffusion of secreted acid to the extracellular environment. In this work, we construct a novel metal–organic framework (MOF)-shell-confined i-motif-based pH probe (MOFC-i) strategy that enables sensitive and dynamic imaging of cell surface pH. The CY3- and CY5-labeled i-motif, which is hybridized via its short complementary chain with two-base mismatches, is optimized for sensing at physiological pH. After efficiently anchoring the optimized pH probes onto the cell membrane with the aid of cholesterol groups, a biocompatible microporous MOF shell is then formed around the cell by cross-linking ZIF-8 nanoparticles via tannic acid. The microporous MOF shell can confine secreted acid without inhibiting the normal physiological activities of cells; thus, the MOFC-i strategy can be used to monitor dynamic changes in the cell surface pH of living cells. Furthermore, this method can not only clearly distinguish the different metabolic behaviors of cancer cells and normal cells but also reveal drug effects on the cell surface pH or metabolism, providing promising prospects in pH-related diagnostics and drug screening.

A visible-light-induced decarboxylation reaction was developed for the synthesis of alkylated benzimidazo[2,1-a]isoquinoline-6(5H)-ones and indolo[2,1-a]isoquinolin-6(5H)-ones under metal-free conditions. Impressively, metal catalysts and traditionally volatile organic solvents could be effectively avoided.

Clean and renewable energies are highly desired to replace traditional fossil fuels, and the electrocatalytic hydrogen evolution reaction (HER) has been regarded as an environment-friendly way to generate hydrogen. Transition metal sulfides have proven to be promising electrocatalysts; however, their HER performance is still unsatisfactory. Herein, we demonstrate enhanced HER activity can be achieved in ZnIn2S4(ZIS) nanosheets coupled to TiO2nanofibers by boron doping for the first time. The introduction of B significantly increases the sulfur vacancies, and thus, is favorable for enhancing the HER activity of ZIS@TiO2. Moreover, the well-matched band alignment between B doped ZIS and TiO2results in promoted charge transfer at the interface, further contributing to the enhanced electrocatalytic activity.

Pathogenic microbial contamination poses serious threats to human healthcare and economies worldwide, which instigates the booming development of challenging antibacterial materials. N-halamine fibrous materials (NFMs), as an important part of antibacterial materials, featuring structural continuity, good pore connectivity, rapid sterilization, rechargeable bactericidal activity, and safety to humans and environment, have received significant research attention. This review aims to present a systematic discussion of the recent advances in N-halamine antibacterial fibrous materials. We firstly introduce the chemical structures and properties of N-halamine materials. Subsequently, the developed NFMs can be categorized based on their fabrication strategies, including surface modification and one-step spinning. Then some representative applications of these fibrous materials are highlighted. Finally, challenges and future research directions of the materials are discussed in the hope of giving suggestions for the following studies.

ABSTRACTA multidrug resistance gene, cfr, and a phenicol resistance gene, fexA, were detected in a Bacillusstrain, BS-01, isolated from swine feces. The cfrgene was carried on a novel 16.5-kb plasmid, designated pBS-01. A complete Tn917structure, which harbors the macrolide-lincosamide-streptogramin B resistance gene erm(B), was located downstream of the cfrgene. The fexAgene was discovered in the chromosomal DNA of the BS-01 strain and identified in a Tn558variant.