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As a kind of reactive oxygen species, peroxynitrite is related to various diseases closely such as cancer and neurodegenerative diseases. Constructing probes with highly specific ability and a wide linear detection range for peroxynitrite detection is crucial for understanding the pathogenesis of related diseases and optimizing treatments. In this work, we developed a novel luminescent ratiometric fluorescence nanoprobe (PC-CDs) based on carbon dots and phycocyanin. PC-CDs are constructed by amidation reaction between carbon dots and phycocyanin. The nanoprobe we obtained has a good ability of distinguishing peroxynitrite from other reactive oxygen species and interfering substances. Moreover, the linear range of the nanoprobe is 0.5-100 μM and the limit of detection is 0.5 μM when detecting peroxynitrite. In the spiked recovery experiments under phosphate buffered saline (PBS) environment, our nanoprobe has a good recovery performance and the recovery is 99% - 104%, which will be beneficial to the further development of peroxynitrite testing and the research progress of related diseases. Finally, we discuss the quenching mechanism of peroxynitrite for nanoprobe, and found that there is the combination of dynamic and static quenching in the quenching process.

Objective. The aim of this study is to investigate the effect of paclitaxel combined with doxorubicin hydrochloride liposome injection (DHLI) in the treatment of osteosarcoma and the MRI changes before and after treatment. Methods. A total of 108 osteosarcoma patients treated in our hospital (January 2020–April 2022) were selected to carry out a single-center retrospective study. Among them, 54 patients receiving the combination chemotherapy (MDT) with high-dose methotrexate, ifosfamide, cisplatin, and ADM were selected as the control group (COG), while 54 patients receiving MDT with high-dose methotrexate, ifosfamide, cisplatin, paclitaxel, and DHLI were chosen as the study group (STG). The COG and STG had the same dose intensity and chemotherapy cycles, and clinical and MRI evaluations were performed after treatment. Results. The evaluation of postoperative clinical efficacy showed that the disease control rate (DCR) of the STG was markedly higher than that of the COG ( P < 0.05 ). The incidence of cardiac toxicity was remarkably lower in the STG than that in the COG ( P < 0.05 ), with no between-group differences in the incidence of fever, abnormal liver function, myelosuppression, stomatitis, and alopecia ( P > 0.05 ). Obvious differences were found in the semiquantitative parameters of MRI in the STG before and after chemotherapy ( P < 0.05 ) and were also found in the SImax, TTP, SEE, PPE, WOR, and R values in the COG before and after chemotherapy ( P < 0.05 ). After chemotherapy, statistical differences were observed in the semiquantitative parameters of MRI between the two groups, with lower parameters such as Slope, SImax, SEE, and R values and higher parameters such as TTP, PPE, and WOR values in the STG than those in the COG ( P < 0.05 ). Conclusion. Paclitaxel combined with DHLI has definite efficacy in osteosarcoma chemotherapy, which is conducive to narrowing the lesion, controlling the disease, and reducing the occurrence of cardiac-related risk events. In addition, the semiquantitative parameters of dynamic contrast-enhanced MRI (DCE-MRI) have a high predictive value for the efficacy of chemotherapy, which can reflect the degree of tumor necrosis and contribute to a timely and objective assessment of the efficacy of osteosarcoma chemotherapy.

The key intermediate NH2-Ile-Thr(Bzl)-Asn-Cys(Bzl)-Pro-COOH of Atosiban was prepared from N-Boc-S-Bzl-cysteine by the stepwise lengthening of the chain according to the repetitive N,O-bis(trimethylsilyl)acetamide/N-hydroxysuccinimide ester (BSA/NHS) strategy. This synthetic route required no chromatography purification and can be readily performed, yielding a highly pure pentapeptide compound.

Nonoxidative coupling of methane (NOCM) is a highly important process to simultaneously produce multicarbons and hydrogen. Although oxide-based photocatalysis opens opportunities for NOCM at mild condition, it suffers from unsatisfying selectivity and durability, due to overoxidation of CH

In recent years, Janus two-dimensional (2D) materials have received extensive research interests because of their outstanding electronic, mechanical, electromechanical, and optoelectronic properties. In this work, we explore the structural, electromechanical, and optoelectronic properties of a novel hypothesized Janus InGaSSe monolayer by means of first-principles calculations. It is confirmed that the Janus InGaSSe monolayer indeed show extraordinary charge transport properties with intrinsic electron mobility of 48 139 cm2/(V·s) and hole mobility of 16 311 cm2/(V·s). Both uniaxial and biaxial strains can effectively tune its electronic property. Moreover, the Janus InGaSSe monolayer possesses excellent piezoelectric property along both in-plane and out-of-plane directions. The results of this work imply that the Janus InGaSSe monolayer is in fact an efficient photocatalyst candidate, and may provide useful guidelines for the discovery of other new 2D photocatalytic and piezoelectric materials.

Doping perovskite oxide with different cations is used to improve its electro‐catalytic performance for various energy and environment devices. In this work, an activated lattice oxygen activity in Pr0.4Sr0.6Co x Fe0.9− x Nb0.1O3− δ (PSCxFN, x = 0, 0.2, 0.7) thin film model system by B‐site cation doping is reported. As Co doping level increases, PSCxFN thin films exhibit higher concentration of oxygen vacancies (Vo••) as revealed by X‐ray diffraction and synchrotron‐based X‐ray photoelectron spectroscopy. Density functional theory calculation results suggest that Co doping leads to more distortion in Fe—O octahedra and weaker metal—oxygen bonds caused by the increase of antibonding state, thereby lowering Vo•• formation energy. As a consequence, PSCxFN thin film with higher Co‐doping level presents larger amount of exsolved particles on the surface. Both the facilitated Vo•• formation and B‐site cation exsolution lead to the enhanced hydrogen oxidation reaction (HOR) activity. Excessive Co doping until 70%, nevertheless, results in partial decomposition of thin film and degrades the stability. Pr0.4Sr0.6(Co0.2Fe0.7Nb0.1)O3 with moderate Co doping level displays both good HOR activity and stability. This work clarifies the critical role of B‐site cation doping in determining the Vo•• formation process, the surface activity, and structure stability of perovskite oxides., An activated lattice oxygen activity in Pr0.4Sr0.6Co x Fe0.9− x Nb0.1O3− δ (PSCxFN, x = 0, 0.2, 0.7) thin film model system by B‐site cation doping is reported. Co doping in PSCxFN facilitates oxygen vacancy formation and promotes B‐site cation exsolution, thereby enhances the electrochemical performance at elevated temperatures. Excessive Co doping until 70%, nevertheless, results in partial decomposition of the materials and degrades the stability.

Using co-hydrolysis of graphite oxide and cellulose in sulphate solution, nanocellulose (NC)/graphene oxide (GO) nanocomposite aqueous solution was prepared. The results of product size distribution showed that NC was well combined with GO in the NC/GO composite and better than the sample prepared by blending NC and GO solutions. The results from infrared spectroscopy and Raman spectroscopy showed that intense hydrogen bonds between NC and GO presented in NC/GO composite, while none were found in the mixture solution. The zeta potential results showed that the sample of NC/GO composite solution possessed higher stability than the sample prepared by the mixing method. The aqueous solution containing nanocomposite can be used to prepare NC/GO composites with high dispersibility.

Developing highly active and low cost catalysts for oxygen reduction is crucial for the commercialization of advanced energy systems. In this work, a mesoporous carbon was fabricated through a simple pyrolysis procedure by using 4′4-bipyridyl, FeCl3 and SBA-15 as the precursors and templates, respectively. The catalyst exhibits rather high ORR performance, with a half-wave potential of 0.906 V (vs. RHE). The catalyst also demonstrates outstanding stability, excellent methanol tolerance and high selectivity towards the four-electron path. The air electrode fabricated by using the catalyst can enable a zinc–air battery to deliver a specific capacity of 815.6 mA h gZn−1 and a maximum power density of 196.3 mW cm−2, which are among the highest values recently reported, to our knowledge. By comparing the catalysts obtained at different temperatures, we found that the increased graphitic N content together with the higher surface area should be the reasonable origins of the outstanding performance.

This article presents a semianalytical solution to a half-plane contact problem subjected to an arbitrarily distributed surface traction. The half-plane boundary is treated as a material surface of the Steigmann–Ogden type. Under the assumption of plane strain condition, the problem is formulated by coupling the methods of an Airy stress function and Fourier integral transforms. Stresses and displacements in the form of semi-infinite integrals are derived. A non-classical Flamant solution that is able to simultaneously account for the surface tension, membrane stiffness, and bending rigidity of the half-plane boundary is derived through limit analysis on the half-plane contact problem owing to a uniform surface traction. The fundamental Flamant solution is further integrated for tackling two half-plane contact problems owing to classical contact pressures corresponding to a rigid cylindrical roller and a rigid flat-ended punch. The resultant semi-infinite integrals are integrated by the joint use of the Gauss–Legendre numerical quadrature and the Euler transformation algorithm. Extensive parametric studies are conducted for comparing and contrasting the effects of Gurtin–Murdoch and Steigmann–Ogden surface mechanical models. The major observations and conclusions are two-fold. First, the introduction of either surface mechanical model results in size-dependent elastic fields. Second, the incorporation of the curvature-dependent nature of the half-plane boundary leads to bounded stresses and displacements in the fundamental Flamant solution. This is in contrast to the otherwise singular classical and Gurtin–Murdoch solutions. For all four case studies, the Steigmann–Ogden surface model also results in much smoother displacement and stress variations, indicating the significance of surface bending rigidity in nanoscale contact problems.

As a primary component of cell walls of plants, algae, bacteria, and other natural biomaterials, cellulose has attracted research attention and is the key to effective conversion of natural biomate...

Oxidative dehydrogenation of ethane (ODE) is limited by the facile deep oxidation and potential safety hazards. Now, electrochemical ODE reaction is incorporated into the anode of a solid oxide electrolysis cell, utilizing the oxygen species generated at anode to catalytically convert ethane. By infiltrating gamma-Al2O3 onto the surface of La0.6Sr0.4Co0.2Fe0.8O3-delta-Sm0.2Ce0.8O2-delta (LSCF-SDC) anode, the ethylene selectivity reaches as high as 92.5 %, while the highest ethane conversion is up to 29.1 % at 600 degrees C with optimized current and ethane flow rate. Density functional theory calculations and in situ X-ray photoelectron spectroscopy characterizations reveal that the Al2O3/LSCF interfaces effectively reduce the amount of adsorbed oxygen species, leading to improved ethylene selectivity and stability, and that the formation of Al-O-Fe alters the electronic structure of interfacial Fe center with increased density of state around Fermi level and downshift of the empty band, which enhances ethane adsorption and conversion.

This study examines how sampled Chinese and U.S. third and fourth grade students (NChina = 167, NUS = 97) understand the commutative, associative, and distributive properties. These students took b...

Nano-ZnO/regenerated cellulose (NZRC) films were prepared via the formation of Zn5(OH)8Cl2·H2O/regenerated cellulose (ZHCRC) film from cellulose-ZnCl2 aqueous solution by using NaOH aqueous solution as both the regeneration agent and the reactant, and the subsequent transformation of the Zn5(OH)8Cl2·H2O into nano-ZnO at a low hydrothermal temperature of 100 °C. The morphology of nano-ZnO changed from hexagonal nanosheets to nanorods as the hydrothermal treatment extending from 0.5 to 4 h. The NZRC films exhibited excellent photocatalytic degradation efficiency for methyl orange and 1.53 × 10−5 mol methyl orange was completely degraded in 40 min by using 1 g of hexagonal catalyst. The NZRC film photocatalytic composites can be applied in the large-scale industrial treatment for degrading organic dye wastewater with good prospects.

Developing highly efficient and low-cost catalyst to replace platinum (Pt) is a key task for the commercialization of advanced energy systems, e.g., proton exchange membrane fuel cells, direct meth...

This work aims to investigate the effects of a radially graded sphere on the reduction of stress concentrations in homogeneous hollow spheres. Both hydrostatic boundary pressures and a uniaxial outer tension are considered. For the spherically symmetric loading, closed-form solutions were successfully developed by assuming a power-law gradation in shear modulus and a constant Poisson’s ratio. For the case of uniaxial tension, the problem is tackled by discretizing the graded sphere into a number of homogeneous sublayers and by solving a simultaneous system about the series coefficients in Boussinesq displacement potentials. The sensitivity of the semianalytical solutions on the number of discretized sublayers is first assessed. Stress distributions and concentration factors are subsequently evaluated for a representative geometry and a few power-law gradation indices. Optimal indices are also identified, for which the stress concentration factors at the inner surface of the graded reinforcement sphere and the reinforcement/matrix interface become well balanced. Wherever possible, finite element solutions are also presented for the purpose of verification and validation. When the outer radius of the homogeneous hollow sphere is beyond four times that of its inner surface, the solutions well approximate the limiting case of an infinite matrix. Both the semianalytical and finite element solutions suggest the promising means of tailoring stress concentrations in thick-walled spheres through internally coating a thin layer of graded reinforcement.

Carboxymethyl cellulose (CMC) is a cellulose derivative that can be obtained from wood, bamboo, rattan, straw, and other cellulosic materials. CMC can be used to produce biofilms for many purposes, but the properties of these resulting films make them unsuitable for some applications. The effects of three kinds of plant fiber addition on CMC film properties was investigated using CMC derived from eucalyptus bark cellulose. Tensile strength (TS) and elongation at break (EB) of CMC/sodium alginate/glycerol composite films were 26.2 MPa and 7.35%, respectively. Tensile strength of CMC composite films substantially increased, reaching an optimum at 0.50 g of fiber. The enhancement due to industrial hemp hurd fiber on CMC composite films was more obvious. Pretreatment with hydrogen peroxide (H2O2) and glacial acetic acid (CH3COOH) produced films with a TS of 35.9 MPa and an EB of 1.61%. TS values with pectinase pretreated fiber films was 41.3 MPa and EB was 1.76%. TS of films pretreated with pectinase and hemicellulase was 45.2 MPa and EB was 4.18%. Chemical and enzymatic treatment both improved fiber crystallinity, but film tensile strength was improved to a greater extent by enzymatic treatment. Surface roughness and pyrolysis residue of the film increased after fiber addition, but Fourier transform infrared spectroscopy (FTIR), opacity, and water vapor transmission coefficients were largely unchanged. Adding fiber improved tensile strength of CMC/sodium alginate/glycerol composite films and broadened the application range of CMC composite films without adversely affecting film performance.

In this study, a novel electrifying mode (divided power-on and power-off stage) was applied in the system of BDD activate sulfate to degrade tetracycline hydrochloride (TCH). The BDD electrode could activate sulfate and H

Background: Globally, healthcare associated infections (HAI) are the most frequent adverse outcome in healthcare delivery. Although bacterial biofilms contribute significantly to the incidence of HAI, few studies have investigated the efficacy of common disinfectants against dry surface biofilms (DSB). The objective of this study was to evaluate the bactericidal efficacy of seven disinfectants against DSB of Staphylococcus aureus and Pseudomonas aeruginosa. We hypothesized that overall, hydrogen peroxides, sodium dichloro-s-triazinetrione and quaternary ammonium compounds plus alcohol disinfectants will be more bactericidal against DSB than quaternary ammonium. We also hypothesized that regardless of differences in product chemistries, higher bactericidal efficacies against DSB will be exhibited after 24 h of dehydration compared to 72 h.Methods: Wet surface biofilms of S. aureus and P. aeruginosa were grown following EPA-MLB-SOP-MB-19 and dehydrated for 24 h and 72 h to establish DSB. Seven EPA-registered disinfectants were tested against dehydrated DSB following EPA-MLB-SOP-MB-20. Results: Overall, quaternary ammonium plus alcohol, sodium dichloro-s-triazinetrione, and hydrogen peroxide products were more efficacious against DSB than quaternary ammoniums for both tested strains. While there was no significant difference in biofilm killing efficacies between 24 h and 72 h S. aureus biofilms, significantly higher log10 reductions were observed when products were challenged with 24 h P. aeruginosa DSB compared to 72 h P. aeruginosa DSB. Conclusion: Strain type, active ingredient class, and dry time significantly impact disinfectant efficacy against DSB of S. aureus or P. aeruginosa.

As the coronavirus disease 2019 (COVID-19) spreads globally, people are at risk of developing disinhibited eating behaviors. This study aimed to examine whether perceived mortality threat and negative affect mediate the relationship between trait self-control and disinhibited eating during the pandemic. A longitudinal survey was administered to a sample of college students (N = 634) before the outbreak (September 2019, T1), during the mid-term (February 2020, T2), and in the later stage of the pandemic (April 2020, T3). Self-report measures of trait self-control (T1), perceived mortality threat (T2, T3), negative affect (T2, T3), and disinhibited eating (T2, T3) were successively completed. Trait self-control was found to be negatively associated with negative affect, perceived mortality threat, and disinhibited eating during the mid-term and later stage of the pandemic. Disinhibited eating was positively associated with negative affect and perceived mortality threat. The longitudinal mediation results demonstrated that trait self-control (T1) could negatively predict disinhibited eating (T3) through negative affect (T2) rather than through perceived mortality threat. These findings suggest that trait self-control is of great importance in regulating psychological discomfort and disinhibited eating during stressful periods and that negative affect might be the main psychological mechanism underlying the relationship between self-control ability and disinhibited eating.

The observation of hydride species in reduced ceria has triggered recent interest, because the formation of hydrides in solid catalysts has been limited although hydrides are widely explored in homogeneous catalysis as active species for hydrogenation reactions. Here, we proposed a strategy to enhance the formation and activity of surface hydrides on oxide-based catalysts via the construction of metal-oxide interface. Specifically, during the reaction with H2, Cu supported on CeO2 nano-rods (NRs) were found to enhance the formation of hydride species, with the capacity more than an order of magnitude higher than that of CeO2 NRs. Moreover, sub-nanometer clusters (sub-NCs) of Cu supported on CeO2 NRs could enhance the formation and activity of surface hydrides, much more superior than that of Cu nanoparticles (NPs) on CeO2 NRs. A combination of ambient pressure photoelectron spectroscopy (AP-PES) techniques has enabled in-situ measurements of hydrogen interaction and as such, to correlate directly the electronic structures of solid catalysts with their activity. A strong metal-support interaction between under-saturated Cu clusters with CeO2 was found to account for the enhanced stability and reactivity of surface hydrides at the (sub-NCs) Cu-CeO2 interface, which provides insight for the design of highly efficient catalysts for catalytic hydrogenation reactions.

In recent years, photocrosslinked alginate hydrogel has been widely studied in bone tissue engineering, owing to its numerous advantages. However, there are still some shortcomings like insufficient mechanical strength and lack of bone induction. To compensate for these deficiencies, in this work, a novel doped strontium (Sr) photocrosslinked methacrylated alginate (Sr-PMA) hydrogel was developed. Photocrosslinked alginate hydrogel fabricated via crosslinking methacrylate-modified alginate under ultraviolet (UV) light was placed into strontium solutions to prepare Sr-PMA gel by chelating reaction. The chemical structures, swelling behaviors, degradation profiles, elastic moduli, Sr2+ ion release and surface morphology of the Sr-PMA hydrogel were characterized, and we found that physical properties of the gels can be tailored by varying concentration of Sr2+ ions. And MC3T3-E1 cell viability, proliferation and mineralization outside the hydrogel were also investigated. Further research on cell survival, multiplication, osteogenic differentiation of the cells encapsulated in Sr-PMA hydrogels were explored. In vitro studies of biological properties revealed that incorporation of Sr2+ into photocrosslinked alginate gels significantly improved osteogenic differentiation capabilities and mineralization via stimulating expression of osteogenesis related genes and proteins of the cells compared to strontium-free photocrosslinked alginate gels. The research demonstrates that the innovative Sr-PMA hydrogels possessing adjustable physical performances, excellent biocompatibility and osteogenic differentiation capabilities could be potentially applied to bone tissue engineering and regenerative medicine. Meanwhile, it also provides a reference for the modification of biological properties of biomaterials.

Due to the abundant priori information and the widespread applications, multi-shot based person re-identification has drawn increasing attention in recent years. In this paper, the high labeling cost and the huge unlabeled data motivate us to focus on the unsupervised scenario and a unified coarse-to-fine framework is proposed, named by Dynamic Bi-directional Normalized Sparse Representation (DBNSR). Specifically, the method designs an alternatively iterative mechanism to dynamically update the estimated cross-camera labels and progressively learn a discriminative metric. In each iteration, a Bi-directional Normalized Sparse Representation (BNSR) model is applied to estimate the label for each pair of cross-camera person sequences with bi-directional probabilities defined to encode their mutual correlation. With the estimated labels, we learn a keep-it-simple-and-straight-forward metric (KISSME) to further make BNSR model available in a more discriminative and lower-dimensional subspace. Extensive experiments on PRID 2011, iLIDS-VID and MARS three benchmarks show that our method performs favorably against state-of-the-arts.

Background Bacterial biofilms persistent on dry environmental surfaces in healthcare facilities play an important role in the occurrence of healthcare associated infections (HAI). Compared to wet surface biofilms and planktonic bacteria, dry surface biofilms (DSB) are more tolerant to disinfection. However, there is no official method for developing DSB for in vitro disinfectant efficacy testing. The objectives of this study were to (i) develop an in vitro model of DSB of S. aureus and P. aeruginosa for disinfectant efficacy testing and (ii) investigate the effect of drying times and temperatures on DSB development. We hypothesized that a minimum six log10 density of DSB could be achieved on glass coupons by desiccating wet surface biofilms near room temperatures. We also hypothesized that a DSB produced by the model in this study will be encased in extracellular polymeric substances (EPS). Methods S. aureus ATCC-6538 and P. aeruginosa ATCC-15442 wet surface biofilms were grown on glass coupons following EPA MLB SOP MB-19. A DSB model was developed by drying coupons in an incubator and viable bacteria were recovered following a modified version of EPA MLB SOP MB-20. Scanning electron microscopy was used to confirm the EPS presence on DSB. Results Overall, a minimum of six mean log10 densities of DSB for disinfectant efficacy were recovered per coupon after drying at different temperatures and drying times. Regardless of strain, temperature and dry time, 86% of coupons with DSB were confirmed to have EPS. Conclusion A rapid model for developing DSB with characteristic EPS was developed for disinfectant efficacy testing against DSB.

Background: Disinfectant products are used frequently on environmental surfaces (e.g. medical equipment, countertops, patient beds) and patient care equipment within healthcare facilities. The purpose of this study was to assess the risk of cross-contamination of Staphylococcus aureus and Pseudomonas aeruginosa during and after disinfection of predetermined surface areas with ready-to-use (RTU) pre-wetted disinfectant towelettes. Methods: This study tested six disinfectant towelette products against S. aureus ATCC CRM-6538 and P. aeruginosa strain ATCC-15442 on Formica surfaces. Each disinfectant was evaluated on a hard nonporous surface and efficacy was measured every 0.5 m2 using a modified version of EPA MLB SOP-MB-33 to study the risk of cross-contamination. Results: We found that all of the wipes used in this study transferred P. aeruginosa and S. aureus from an inoculated surface to previously uncontaminated surfaces. Disinfectant towelettes with certain chemistries also retained a high level of viable bacteria after disinfection of the surface area. The cross-contamination risk also varied by product chemistry and bacterial strain. Conclusion: Disinfectant wipes can cross-contaminate hard nonporous surfaces and retain viable bacterial cells post-disinfection, especially over larger surface areas. This highlights a need to further investigate the risk disinfectant wipes pose during and post-disinfection and guidance on maximum surface areas treated with a single towelette.

The aim of the present study was to investigate relationships among epidemic risk perception, perceived stress, mental health (depression and anxiety), future time perspective, and confidence in society during the novel coronavirus disease (COVID-19) pandemic in China. Especially, we wonder that whether perceived stress mediates associations between epidemic risk perception and mental health and that whether future time perspective and confidence in society moderate the link between perceived stress and mental health. This cross-sectional study was conducted among 693 Chinese adults aged 18–60 years. The results showed that epidemic risk perception was positively related to perceived stress, depression, and anxiety. The correlations between epidemic risk perception and depression and anxiety were reduced when perceived stress was included, suggesting that perceived stress mediated these relationships. Moreover, the boundary conditions for the associations among perceived stress, depression, and anxiety were found in the study. Specifically, positive future time perspective could buffer the negative effects of perceived stress on depression, and confidence in society could weaken the negative effects of perceived stress on anxiety. Based on these findings, practical guidance and theoretical implications are provided for the public to maintain mental health during COVID-19 pandemic. Limitations and future directions are also discussed.

2D ZnO nanosheets-regenerated cellulose (ZNSRC) photocatalytic composite thin films were prepared from ZnCl2 by using a two–step synthesis method at room temperature. The results show that during the formation of ZNSRC composite thin film, ZnCl2 first reacted with NaOH to form Zn5(OH)8Cl2·H2O which was then converted to ZnO. The 2D ZnO nanosheets are 350–450 nm in transverse size and 80 nm in thickness, dispersed on both the surface and inside of the ZNSRC thin films. The ZNSRC prepared by 13 h of reaction time has a characteristic of nanoporous 2D ZnO nanosheets and exhibits the best photocatalytic activity, as 1.53 × 10−5 mol methyl orange was completely degraded in 50 min by using 1 g catalyst. Thus, we can conclude that the ZNSRC photocatalytic composite thin films can be very useful for degrading organic dye wastewater.

Methylphosphonic acid (MPn) is an intermediate in the synthesis of the phosphorus-containing nerve agents, such as sarin and VX, and a biosynthesis product of marine microbes with ramifications to global climate change and eutrophication. Here, we applied the multi-labeled water isotope probing (MLWIP) approach to investigate the C–P bond cleavage mechanism of MPn under UV irradiation and density functional theory (DFT) to simulate the photo-oxidation reaction process involving reactive oxygen species (ROS). The results contrasted with those of the addition of the ROS-quenching compounds, 2-propanol and NaN3. The degradation kinetics results indicated that the extent of MPn degradation was more under alkaline conditions and that the degradation process was more rapid at the initial stage of the reaction. The phosphate oxygen isotope data confirmed that one exogenous oxygen atom was incorporated into the product orthophosphate (PO4) following the C–P bond cleavage, and the oxygen isotopic composition of this free PO4 was found to vary with pH. The combined results of the ROS-quenching experiments and DFT indicate that the C–P bond was cleaved by OH−/˙OH and not by other reactive oxygen species. Based on these results, we have established a mechanistic model for the photolysis of MPn, which provides new insights into the fate of MPn and other phosphonate/organophosphate compounds in the environment.

Background: Pre-wetted disinfectant wipes are increasingly being used in healthcare facilities to help address the risk of healthcare associated infections (HAI). However, HAIs are still a major problem in the US with Clostridioides difficile being the most common cause, leading to approximately 12,800 deaths annually in the US. An underexplored risk when using disinfectant wipes is that they may cross-contaminate uncontaminated surfaces during the wiping process. The objective of this study was to determine the cross-contamination risk that pre-wetted disinfectant towelettes may pose when challenged with C. difficile spores. We hypothesized that although the tested disinfectant wipes had no sporicidal claims, they will reduce spore loads. We also hypothesized that hydrogen peroxide disinfectant towelettes would present a lower cross-contamination risk than quaternary ammonium products. Methods: We evaluated the risk of cross-contamination when disinfectant wipes are challenged with C. difficile ATCC 43598 spores on Formica surfaces. A disinfectant wipe was used to wipe a Formica sheet inoculated with C. difficile. After the wiping process, we determined log10 CFU on previously uncontaminated pre-determined distances from the inoculation point and on the used wipes. Results: We found that the disinfectant wipes transferred C. difficile spores from inoculated surfaces to previously uncontaminated surfaces. We also found that wipes physically removed C. difficile spores and that hydrogen peroxide disinfectants were more sporicidal than the quaternary ammonium disinfectants. Conclusion: Regardless of the product type, all disinfectant wipes had some sporicidal effect but transferred C. difficile spores from contaminated to otherwise previously uncontaminated surfaces. Disinfectant wipes retain C. difficile spores during and after the wiping process.

Objectives To evaluate skeletal muscle mass in patients with both type 2 diabetes mellitus (T2DM) and concomitant lower extremity arterial disease (LEAD) and determine the contribution of skeletal muscle mass to macrovascular diseases. Methods In total, 112 patients with T2DM were divided into the T2DM and T2DM + LEAD groups. Hepatic function, renal function, uric acid, blood glucose, and glycated hemoglobin (HbA1C) were measured. Dual-energy X-ray absorptiometry was used to measure visceral fat area and skeletal muscle mass index (SMI). Results Waist-to-hip ratio, uric acid, and body fat percentage were significantly higher in the T2DM+LEAD group than in the T2DM group; SMI was significantly lower in the T2DM+LEAD group than in the T2DM group. There were no significant differences in albumin, creatinine, fasting blood glucose, HbA1C, or blood lipids. Uric acid, SMI, and body fat percentage were significantly positively correlated with T2DM and concomitant LEAD. Logistic regression analyses suggested that SMI is an independent risk factor for LEAD in T2DM (odds ratio = 1.517; 95% confidence interval: 1.082–2.126). Conclusions Skeletal muscle mass is lower in patients with T2DM and concomitant LEAD than in patients with T2DM who do not exhibit LEAD. SMI is an important risk factor for LEAD.

A facile and effective approach was developed for the preparation of mesoporous Fe-NC by pyrolyzing the mixture of FeCl2, urea, (NH4)2MoO7, phthalic anhydride and SBA-15, during which the in-situ formation of iron phthalocyanine is confirmed. The obtained catalyst exhibits high catalytic activity towards ORR, whose half-wave potential can be 53 mV more positive than that of commercial Pt/C catalyst. Besides, the catalyst also exhibits high selectivity of four electron path, along with excellent stability and methanol tolerance in alkaline media. Based on the characterization results, we suggest, the higher surface areas, highly porous structures induced by SBA-15 addition, as well as high graphitic N content should be the proper origins for its outstanding catalytic performance.

Previous studies demonstrate that, for nanostructures under transverse bending, the effective Young modulus is appreciably greater (in magnitude) than that of the same elements under axial loads. Therefore, in addition to the conventional residual surface tension and membrane stiffness, the curvature dependence of surface energy is desired for inhomogeneously strained nanostructures. In this paper, we aim to reevaluate the size-dependent nanoindentation hardness of an elastic half-space subjected to nanosized frictionless traction, through the use of both the curvature-independent Gurtin–Murdoch and the curvature-dependent Steigmann–Ogden models of surface elasticity. The nanoindentation problem is solved by the integration of Boussinesq’s method of displacement potentials and Hankel integral transforms. As examples, the effects of residual surface tension, membrane stiffness, and bending rigidity of the half-space boundary are parametrically analyzed in detail for a uniform circular pressure and a concentrated normal force. The observations in semianalytical calculations suggest a significant difference in the nanoindentation hardnesses predicted from the two popular models of surface mechanics. In most cases, the inclusion of bending rigidity results in smaller displacements and stresses, and therefore higher indentation hardness. Based on physically interpretable numerical values of surface material properties, we show that a curvature-dependent model of surface elasticity is required in order to characterize the size-dependent feature of nanoindentation problems correctly.

Background Disinfectant products are often used on environmental surfaces (e.g. countertops, patient beds) and patient care equipment in healthcare facilities to help prevent the transmission of healthcare-associated infections. Ready-to-use (RTU) disinfectants in the form of pre-wetted towelettes are increasingly popular among healthcare facilities. Currently, the EPA does not require disinfectant manufacturers to include a recommended maximum surface area per towelette on their product labels. The objective of this study was to investigate the efficacy of disinfectant towelette products on a hard non-porous surface across different coverage areas using a quantitative EPA method. We hypothesized that there would be significant differences in the efficacy of disinfectant towelette products, and that the greater surface area(s) wiped would result in reduced bactericidal efficacy. Methods This study tested ten disinfectant towelette products against Staphylococcus aureus strain ATCC CRM-6538 and Pseudomonas aeruginosa strain ATCC 15442 on Formica surfaces. Defined surface areas were wiped and the towelette weighed before and after wiping to determine the amount of liquid released. Bactericidal efficacy testing was also performed after wiping following standard EPA protocols. Results We found that disinfectant product, area of surface wiped, and strain impacted the bactericidal efficacy achieved. Disinfectant product type and area of surface wiped significantly impacted the percent of liquid released per ft2from the towelette. Conclusion Overall, bactericidal efficacy varied by towelette product, surface area wiped, and strain. This study also found that wiping larger surface areas may lead to decreased bactericidal efficacy. Further research is needed to test its implication.