Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 30
Filtrar
1.
Small ; : e2402537, 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38711307

RESUMO

Cu-based catalysts are the most intensively studied in the field of electrocatalytic CO2 reduction reaction (CO2RR), demonstrating the capacity to yield diverse C1 and C2+ products albeit with unsatisfactory selectivity. Manipulation of the oxidation state of Cu sites during CO2RR process proves advantageous in modulating the selectivity of productions, but poses a formidable challenge. Here, an oxygen spillover strategy is proposed to enhance the oxidation state of Cu during CO2RR by incorporating the oxygen donor Sb2O4. The Cu-Sb bimetallic oxide catalyst attains a remarkable CO2-to-CO selectivity approaching unity, in stark contrast to the diverse product distribution observed with bare CuO. The exceptional Faradaic efficiency of CO can be maintained across a wide range of potential windows of ≈700 mV in 1 m KOH, and remains independent of the Cu/Sb ratio (ranging from 0.1:1 to 10:1). Correlative calculations and experimental results reveal that oxygen spillover from Sb2O4 to Cu sites maintains the relatively high valence state of Cu during CO2RR, which diminishes the binding strength of *CO, thereby achieving heightened selectivity in CO production. These findings propose the role of oxygen spillover in CO2RR over Cu-based catalysts, and shed light on the rational design of highly selective CO2 reduction catalysts.

2.
Small ; 19(8): e2206478, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36504185

RESUMO

Platinum group metal (PGM)-free M-N-C catalysts have exhibited dramatic electrocatalytic performance and are considered the most promising candidate of the Pt catalysts in oxygen reduction reaction (ORR). However, the electrocatalytic performance of the M-N-C catalysts is still limited by their inferior intrinsic activity and finite active site density. Regulating the coordination environment and increasing the pore structure of the catalyst is an effective strategy to enhance the electrocatalytic performance of the M-N-C catalysts. In this work, the coordination environment and pore structure exquisitely regulated Fe-N-C catalyst exhibit excellent ORR activity and durability. With the enhanced intrinsic activity and increased active site density, the optimized Fe-N/S-C catalyst shows impressive ORR activity (E1/2  = 0.904 V vs reversible hydrogen electrode (RHE)) and superior long-term durability in an alkaline medium. As the advanced physical characterization and theoretical chemistry methods illustrate, the S-modified Fe-Nx (Fe-N3 /S-C) moiety is confirmed as the improved active center for ORR, and the increased active site density further improved ORR efficiency. Based on the Fe-N/S-C cathode, a Zn-air battery is fabricated and shows superior power density (315.4 mW cm-2 ) and long-term discharge stability at 20 mA cm-2 . This work would open a new perspective to design atomically dispersed iron-metal site catalysts for advanced electro-catalysis.

3.
Small ; 19(37): e2206477, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37147778

RESUMO

Oxygen electrocatalysis has aroused considerable interest over the past years because of the new energy technologies boom in hydrogen energy and metal-air battery. However, due to the sluggish kinetic of the four-electron transfer process in oxygen reduction reaction and oxygen evolution reaction, the electro-catalysts are urgently needed to accelerate the oxygen electrocatalysis. Benefit from the high atom utilization efficiency, unprecedentedly high catalytic activity, and selectivity, single-atom catalysts (SACs) are considered the most promising candidate to replace the traditional Pt-group-metal catalysts. Compared with SACs, the dual-atom catalysts (DACs) are attracting more attraction including higher metal loading, more versatile active sites, and excellent catalytic activity. Therefore, it is essential to explore the new universal methods approaching to the preparation, characterization, and to elucidate the catalytic mechanisms of the DACs. In this review, several general synthetic strategies and structural characterization methods of DACs are introduced and the involved oxygen catalytic mechanisms are discussed. Moreover, the state-of-the-art electrocatalytic applications including fuel cells, metal-air batteries, and water splitting have been sorted out at present. The authors hope this review has given some insights and inspiration to the researches about DACs in electro-catalysis.

4.
Opt Lett ; 47(10): 2450-2453, 2022 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-35561373

RESUMO

We develop a general methodology capable of analyzing the response of Weyl semimetal (WSM) photogalvanic networks. Both single-port and multiport configurations are investigated via extended versions of Norton's theorem. An equivalent circuit model is provided where the photogalvanic currents induced in these gapless topological materials can be treated as polarization-dependent sources. To illustrate our approach, we carry out transport simulations in arbitrarily shaped configurations involving pertinent WSMs. Our analysis indicates that the photogalvanic currents collected in a multi-electrode system directly depend on the geometry of the structure as well as on the excitation and polarization pattern of the incident light. Our results could be helpful in designing novel optoelectronic systems that make use of the intriguing features associated with WSMs.

5.
Opt Lett ; 45(18): 5097-5100, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32932462

RESUMO

An electrically driven dumbbell-shaped cavity semiconductor laser laterally confined by isolation and metal layers at 635 nm has been proposed. In the simulation, we systematically analyzed the Q-factors, mode intensity distributions, and directionality of the dumbbell-shaped cavity. A measured speckle contrast as low as 3.7%, emission divergence of 7.7°, and maximum output power of about 2.36 W were obtained in the experiment. Such a semiconductor laser with low coherence, high power, and high directivity may provide great potential application value in laser display and imaging.

6.
Nano Lett ; 16(7): 4624-9, 2016 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-27331618

RESUMO

Organic-inorganic lead halide perovskite semiconductors have recently reignited the prospect of a tunable, solution-processed diode laser, which has the potential to impact a wide range of optoelectronic applications. Here, we demonstrate a metal-clad, second-order distributed feedback methylammonium lead iodide perovskite laser that marks a significant step toward this goal. Optically pumping this device with an InGaN diode laser at low temperature, we achieve lasing above a threshold pump intensity of 5 kW/cm(2) for durations up to ∼25 ns at repetition rates exceeding 2 MHz. We show that the lasing duration is not limited by thermal runaway and propose instead that lasing ceases under continuous pumping due to a photoinduced structural change in the perovskite that reduces the gain on a submicrosecond time scale. Our results indicate that the architecture demonstrated here could provide the foundation for electrically pumped lasing with a threshold current density Jth < 5 kA/cm(2) under sub-20 ns pulsed drive.

7.
Yao Xue Xue Bao ; 51(9): 1368-77, 2016 09.
Artigo em Chinês | MEDLINE | ID: mdl-29924510

RESUMO

Human breast cancer resistance protein (BCRP), an ATP-binding cassette (ABC) efflux transporter, is mainly responsible for the transport of many endogenous and xenobiotics. BCRP is expressed in different tissues, such as placental, intestinal epithelium, endothelial cells of brain microvessels, and renal proximal tubular cells. BCRP is considered as one of the key factor for the drug-drug interaction and individual difference in drug therapy. The review will provide an overview of the current knowledge on the discovery of BCRP and its physical function, transport mechanism, substrate and inhibitors, as well as its effect on the drug pharmacokinetics.


Assuntos
Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/metabolismo , Neoplasias da Mama/metabolismo , Proteínas de Neoplasias/metabolismo , Transporte Biológico , Neoplasias da Mama/tratamento farmacológico , Interações Medicamentosas , Humanos , Xenobióticos
8.
Eur J Anaesthesiol ; 31(12): 663-8, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24752322

RESUMO

BACKGROUND: Propofol injection pain is a common and unsolved anaesthesia problem. OBJECTIVES: The present study attempted to confirm that the plasticiser di(2-ethylhexyl) phthalate in polyvinyl chloride (PVC) infusion tubes may increase propofol injection pain by increasing the aqueous propofol concentration. DESIGN: A randomised controlled study. SETTING: University teaching hospital, 1 April to 25 June 2013. PATIENTS: One hundred patients scheduled for elective surgery were allocated randomly to the PVC or the control (C) group. The PVC group received a propofol (Diprivan) infusion via a 1-m PVC infusion extension tube, whereas group C received propofol injected directly through the port of the cannula. INTERVENTION: After the syringe was loaded with propofol, air was expelled from the tube and the syringe was left standing for 5 min; intravenous propofol 0.5 mg kg was then injected either through the PVC tube or directly into the cannula. MAIN OUTCOME MEASURE: A verbal rating scale was used to evaluate the propofol injection pain in both groups. Di(2-ethylhexyl) phthalate and aqueous propofol concentrations were also measured in samples of propofol after simulated injection. To investigate whether the increase in aqueous propofol concentration was caused by leached di(2-ethylhexyl) phthalate, the same amount of di(2-ethylhexyl) phthalate as that measured in the PVC group was added to the samples (group D). RESULTS: The incidences of pain in groups PVC and C were 88 and 46%, respectively (P < 0.0001). The di(2-ethylhexyl) phthalate concentration in group PVC (1.01 ±â€Š0.07 µg ml) was greater than that in group C (lower than the detection limit of 0.03 µg ml). No significant difference was found between the aqueous propofol concentrations in groups PVC (25.9 ±â€Š1.8 µg ml) and D (24.4 ±â€Š1.1 µg ml) (P = 0.22), which were significantly higher than that in group C (14.3 ±â€Š1.0 µg ml) (P = 0.079). CONCLUSION: Propofol injection pain is increased by contact with PVC infusion tubing as a result of an increase in aqueous propofol concentration caused by di(2-ethylhexyl) phthalate leaching into the lipid emulsion. TRIAL REGISTRATION: chictr.org identifier: ChiCTR-TRC-12003170.


Assuntos
Dietilexilftalato/efeitos adversos , Dor/induzido quimicamente , Dor/diagnóstico , Plastificantes/efeitos adversos , Cloreto de Polivinila/efeitos adversos , Propofol/efeitos adversos , Adulto , Idoso , Dietilexilftalato/administração & dosagem , Feminino , Humanos , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade , Plastificantes/administração & dosagem , Cloreto de Polivinila/administração & dosagem , Propofol/administração & dosagem
9.
Yao Xue Xue Bao ; 49(9): 1279-88, 2014 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-25518327

RESUMO

The tumor multidrug resistance reversal effect of NPB304, a novel taxane, was studied. MTT assay was used to determine the IC50 of chemotherapy drugs. Western blotting assay was applied to analyze the expression of P-glycoprotein (P-gp). The effect of compounds on the P-gp function and P-gp ATPase activity was determined by rhodamine 123 (Rh123) accumulation assay and analysis kit, respectively. Molecular docking was employed to predict the binding force between compounds and P-gp. Transmembrane transport of NPB304 was analyzed using MDCK II and MDR1-MDCK II cell model. NPB304 displayed multidrug resistance reversal effect on KBV cells and MCF-7/paclitaxel cells, NPB304 collaborative with P-glycoprotein (P-gp) inhibitors verapamil enhanced the reversal activity, specifically, 10 µmol x L(-1) verapamil in combination with paclitaxel reversed resistance by 56.5-fold, while combined with NPB304 increased the reversal fold; NPB304 synergistically increased Rh123 accumulation in the resistant cells when combined with verapamil, and NPB304 at 0-1 µmol x L(-1) enhanced the ATPase activity activated by verapamil was observed. NPB304 existed the hydrophobic interactions with the TM regions of P-gp, and the binding force between NPB304 and the A chain of the TM region was stronger. P-gp ATPase activity assay demonstrated NPB304 at lower concentrations (0-1.5 µmol x L(-1)) could activate the P-gp ATPase, playing a role on inhibition of P-gp function. However, NPB304 did not have an obvious feature of P-gp substrate. NPB304 exerted itself and synergy with verapamil activity on reversing tumor resistance via inhibiting the P-gp function.


Assuntos
Antineoplásicos/farmacologia , Taxoides/farmacologia , Verapamil/farmacologia , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Transporte Biológico , Resistência a Múltiplos Medicamentos , Resistencia a Medicamentos Antineoplásicos , Sinergismo Farmacológico , Humanos , Células MCF-7 , Rodamina 123
10.
J Hazard Mater ; 470: 134221, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38615651

RESUMO

Constructed wetlands (CWs) are a promising approach for treating acid mine drainage (AMD). However, the extreme acidity and high loads of heavy metals in AMD can easily lead to the collapse of CWs without proper pre-treatment. Therefore, it is considered essential to maintain efficient and stable performance for AMD treatment in CWs. In this study, pre-prepared attapulgite-soda residue (ASR) composites were used to improve the substrate of CWs. Compared with CWs filled with gravel (CWs-G), the removal efficiencies of sulfate and Fe, Mn, Cu, Zn Cd and Pb in CWs filled with ASR composites (CWs-ASR) were increased by 30% and 10-70%, respectively. These metals were mainly retained in the substrate in stable forms, such as carbonate-, Fe/Mn (oxide)hydroxide-, and sulfide-bound forms. Additionally, higher levels of photosynthetic pigments and antioxidant enzyme activities in plants, along with a richer microbial community, were observed in CWs-ASR than in CWs-G. The application of ASR composites alleviated the adverse effects of AMD stresses on wetland plants and microorganisms. In return, the increased bacteria abundance, particularly SRB genera (e.g., Thermodesulfovibrionia and Desulfobacca), promoted the formation of metal sulfides, enabling the saturated ASR adsorbed with metals to regenerate and continuously capture heavy metals. The synergistic adsorption of ASR composites and microbial sulfate reduction maintained the stable and efficient operation of CWs. This study contributes to the resource utilization of industrial alkaline by-products and promotes the breakthrough of new techniques for low-cost and passive treatment systems such as CWs.


Assuntos
Compostos de Magnésio , Metais Pesados , Mineração , Compostos de Silício , Sulfatos , Poluentes Químicos da Água , Áreas Alagadas , Sulfatos/química , Metais Pesados/química , Adsorção , Poluentes Químicos da Água/química , Poluentes Químicos da Água/metabolismo , Compostos de Silício/química , Compostos de Magnésio/química , Ácidos/química , Oxirredução , Biodegradação Ambiental , Concentração de Íons de Hidrogênio
11.
Environ Pollut ; 344: 123337, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38266698

RESUMO

The in situ biosequestration of Cr(VI) in groundwater with molasses as the carbon source was studied based on column experiments and model simulation in this study. Compared with biological reduction, molasses-based chemical reduction did not cause significant Cr(VI) removal at molasses concentration as high as 1.14 g L-1. The molasses at a concentration as low as 0.57 g L-1 could support biofilm-based Cr(VI) sequestration under flow conditions and showed better sequestration performances than D-glucose and emulsified vegetable oil (8 g L-1). The existence of molasses (1.14 g L-1) decreased the pH of the effluent from 7.5 to 6.3 and the oxidation-reduction potential from 275 mV to 220 mV in the groundwater, which was responsible for reduction and thus the sequestration of Cr(VI). Advection-dispersion-reaction model well described the process of the Cr(VI) transport with biosequestration in the column (R2 ≥ 0.96). Owing to the Cr(VI) toxicity to the biofilms, the removal ratio decreased by 24% with a rise of Cr(VI) concentration from 8.6 to 43 mg L-1. The prolongation of hydraulic retention time could promote the performance of Cr(VI) biosequestration. The chemical form of Cr deposited as the product of bio-reduction was confirmed as Cr(OH)3·H2O and other complexes of Cr(III). Our work demonstrated the efficacy of molasses for in situ sequestration of Cr(VI) under the dynamic flow condition and provide some useful information for Cr-contaminated groundwater remediation.


Assuntos
Água Subterrânea , Poluentes Químicos da Água , Melaço , Água Subterrânea/química , Cromo/química , Carbono
12.
ACS Appl Mater Interfaces ; 16(10): 12398-12406, 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38412364

RESUMO

The metal-nitrogen-carbon (M-N-C)-based catalysts are promising to replace PGM (platinum group metal) to accelerate oxygen reduction reaction due to their excellent electrocatalytic performance. However, the inferior intrinsic activity and poor active site density confining further improvement in their performance. Modulating the electronic structure and reasonably designing the pore structure are widely acknowledged effective strategies to boost the activity of the M-N-C catalysts. However, it is a great challenge to form abundant pores to regulate the electronic structure via the facile method. Herein, a hierarchical, porous dual-atom catalyst FeNi-NPC-1000 has been architectured by the Na2CO3 template method and bimetallic doping modification strategy. Benefitting from the optimized pore and electronic structure, the as-prepared FeNi-NPC-1000 possesses a high specific surface area (1412.8 m2 g-1) and improved ORR activity (E1/2 = 0.877 V vs RHE), which is superior to that of Pt/C (E1/2 = 0.867 V vs RHE). With the evidence of AC-STEM, XAS, and DFT, the FeNi-N8-C moiety is proven to be the key active site to realize high-efficiency ORR catalysis. When assembled it as an air cathode of ZABs, FeNi-NPC-1000 displays superior discharge performance (Pmax = 367.1 mW cm-2) and a stable battery long-life. This article will provide a new strategy for designing dual-metal atomic catalysts applied in metal-air batteries.

13.
Sci Rep ; 14(1): 5007, 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38424313

RESUMO

It is of interest to develop wide-temperature domain damped hydrophobic materials. In this paper, we designed incorporating bio-based phenolic resin into the IIR matrix and introducing dibenzyl fork acetone (DBA) into the main chain structure with sodium hydroxide activation to construct three-dimensional network. In this paper, we designed incorporating bio-based phenolic resin into the IIR matrix and introducing dibenzyl fork acetone (DBA) into the main chain structure with sodium hydroxide activation to construct three-dimensional network. The added bio-based phenolic resin has reticulated structure blended with butyl rubber, combined with sodium hydride activation-modified IIR. The results show that sodium hydride activated modification of DBA is introduced into the main chain structure of IIR by infrared and 1H NMR analysis. The material hydrophobic is realized by the introduction of DBA with static water contact angle of 103.5°. The addition of 10phr lignin-based phenolic resin (LPF) is compatible with IIR, and the torque can reach 7.0 N-m. The tensile elongation of the modified butyl rubber composite can reach 2400% with tensile strength up to 11.43 MPa, while the damping factor can reach 0.37 even at 70 °C. The thermal stability of the composites is enhanced with mass retention rate of 28%. The bio-based PF/NaH activation-modified butyl rubber damping material has potential applications in damping hydrophobicity with wide temperature range.

14.
J Colloid Interface Sci ; 673: 444-452, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38878378

RESUMO

Electrocatalytic water splitting (EWS) for hydrogen production is considered an ideal strategy for utilizing renewable energy, reducing fossil fuel consumption, and addressing environmental pollution issues. Traditional noble metal electrocatalysts have excellent performance, but their cost is high. Developing efficient, stable, and relatively inexpensive dual functional electrocatalysts is crucial for promoting large-scale EWS hydrogen production processes. Herein, a simple one-step electrodeposition method was used to grow nickel-iron phosphorus-sulfides (NiFePS) on the surface of hydrophilic treated carbon cloth (CC). The resultant NiFePS/CC with a phosphorus to sulfur ratio of 1:4 exhibited the best electrocatalytic performance, requiring only -91 mV and 216 mV overpotentials to generate the current densities of 10 mA·cm-2 in hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively. When it was used as a bifunctional electrocatalyst to overall water splitting (OWS), a voltage of 1.536 V can generate a current density of 10 mA·cm-2. The excellent electrocatalytic performance can be ascribed to two factors: 1) the CC with excellent conductivity serves as a growth substrate, reducing the impedance of charge transfer from the electrode to the electrolyte and accelerating the electron transfer rate; 2) The large number of ultra-thin nanosheets formed on the surface of the catalyst increase the electrochemical specific surface area, expose more reaction sites, and thus improve the electrocatalytic reaction performance. This work provides a new approach for designing efficient non-noble metal electrocatalysts for water splitting.

15.
Curr Oncol ; 30(8): 7654-7671, 2023 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-37623036

RESUMO

This systematic review examined cancer care costs, the financial burden for patients, and their economic coping strategies in mainland China. We included 38 quantitative studies that reported out-of-pocket payment for cancer care and patients' coping strategies in English or Chinese (PROSPERO: CRD42021273989). We searched PubMed, Embase, Ovid, Web of Science, Cochrane, CNKI, and Wanfang Data from 1 January 2009 to 10 August 2022. We referred to the standards for reporting observational studies to assess the methodological quality and transparent reporting of the included studies and reported the costs narratively. Annual mean medical costs (including inpatient and outpatient costs and fees for self-purchasing drugs) ranged from USD 7421 to USD 10,297 per patient. One study investigated medical costs for 5 years and indicated that inpatient costs accounted for 51.6% of the total medical costs, followed by self-purchasing drugs (43.9%). Annual medical costs as a percentage of annual household income ranged from 36.0% to 63.1% with a metaproportion of 51.0%. The common coping strategies included borrowing money and reduction of household expenses and expenses from basic health services. Costs of inpatient care and self-purchasing drugs are major drivers of medical costs for cancer care, and many affected households shoulder a very heavy financial burden.


Assuntos
Estresse Financeiro , Neoplasias , Humanos , Neoplasias/terapia , China , Pacientes Internados , Adaptação Psicológica
16.
Int Breastfeed J ; 18(1): 40, 2023 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-37568207

RESUMO

BACKGROUND: The World Health Organization and the government of China have made many efforts to improve breastfeeding practices. The evidence of breastfeeding practices over the past decade in China is limited. The current study aimed to describe the current prevalence, variation trends, and determinants of breastfeeding practices in China using data from the National Household Health Service Surveys (NHHSS) in 2013 and 2018. METHODS: Women who had at least one live birth in the five years from the 2013 NHHSS numbered 10,544, and 12,766 women from the 2018 NHHSS were included in the current study. The rates of breastfeeding, early initiation of breastfeeding within the first hour after birth, exclusive breastfeeding for at least six months since birth, and continued breastfeeding accompanied by adequate complementary feeding for over two years were measured. Logistic regressions were performed to study the associations between breastfeeding practices and maternal-based, healthcare-based, and infant-based characteristics. RESULTS: In the 2018 survey, the rates of practiced any breastfeeding, early initiation of breastfeeding within the first hour after birth, exclusive breastfeeding for at least six months, and continued breastfeeding for over two years were 91.50%, 28.16%, 47.90%, and 4.78%, respectively, showing significant improvements compared to the 2013 survey period. Women who received high education, were from a household with high incomes, had more than one child, and had more antenatal and postnatal visits, were more likely to practice breastfeeding and initiate it within the first hour, but they were less likely to breastfeed the infants for two years. Births by caesarean section and low birthweight were associated with worse breastfeeding practices. CONCLUSIONS: The rates of practicing breastfeeding and exclusive breastfeeding for six months or more in China improved over the past decades, suggesting improved awareness and knowledge of breastfeeding among women. However, individual and social factors may impact practices of early initiation and continued breastfeeding. Strengthening breastfeeding support from family, community, and health professionals (e.g., family member engagement, friendly work environment, and professional consultation, etc.) during the postpartum and infant period may improve women's confidence in breastfeeding practices.


Assuntos
Aleitamento Materno , Serviços de Saúde Materna , Feminino , Humanos , Lactente , Gravidez , Cesárea , China/epidemiologia , Estudos Transversais , Prevalência
17.
J Multidiscip Healthc ; 16: 997-1010, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37056979

RESUMO

Background: In China, physicians have long faced long working hours, high stress levels, and tensions between physicians and patients, which can lead to negative behaviors. Understanding physicians' expectations and requirements of the hospital and increasing satisfaction with their psychological contract can help improve physician motivation and stabilize the hospital team. Aim: The study aims to analyze the relationship between physicians' psychological contract violations and different behavioral choices, encourage hospitals to conclude a balanced psychological contract with physicians, and provide governance and intervention strategies for hospital human resource management. Methods: Stratified cluster sampling was used to select 321 physicians from four public hospitals in Beijing for questionnaire surveys. Descriptive statistical analysis, t-test, ANOVA, correlation analysis, and regression models were performed using Stata 15.0 and SPSS 26.0 to analyze the relationship between psychological contract violations, physicians' EVLN behaviors and organizational justice. Results: Psychological contract violation had a positive effect on exit behavior and neglect behavior, and a negative effect on voice behavior and loyalty behavior. Organizational justice plays a mediating role between psychological contract violation and physicians' exit, voice and loyalty behaviors. Conclusion: Psychological contract violation can drive negative behavior among physicians, and organizational justice can play a mediating role in this. Public hospitals should establish a healthy psychological contract with physicians and place a premium on organizational justice to promote constructive behaviors and prevent destructive behaviors. This study constructs a more complete theoretical framework to explain physicians' behavior, and further dynamic tracking investigations are necessary because the evolution of physicians' behavior is a dynamic and long-term process.

18.
Sci Total Environ ; 903: 166601, 2023 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-37634714

RESUMO

Acid mine drainage (AMD) rich in arsenic (As) and antimony (Sb) is considered as a significant environmental challenge internationally. However, simultaneous removal of As and Sb from AMD is still inadequately studied. In this study, a highly effective and simple approach was proposed for mitigating As and Sb-rich AMD, which involves in-situ formation of layered double hydroxides (LDHs). Following the treatment, the residual concentrations of iron (Fe), magnesium (Mg), sulfate, As and Sb in field AMD were decreased from their initial concentrations of 1690, 1524, 2055, 7.8 and 10.6 mg L-1, respectively, to 1.3, 12.4, 623, 0.006 and 0.004 mg L-1, respectively. Chemical formula of the resulting As and Sb-loaded LDHs can be identified as Mg4.226Fe2.024OH2SO4AsSb0.006∙mH2O. The dissolution rates of metal(loid)s in As and Sb-loaded LDH were lower than 1% under strongly acidic and alkaline environments. In presence of the mixed adsorbates, the As immobilization capacity by LDHs was significantly decreased, with an apparent intervention from Sb. However, As did not have a significant effect on the immobilization of Sb by LDH. As was immobilized by LDHs through anion exchange and complexation with -OH groups, while Sb was captured by anion exchange and complexation with [Formula: see text] . Density functional theory (DFT) calculations further proved the above conclusions. This novel approach is effective and can be applied for in-situ AMD treatment from abandoned mines.

19.
J Med Chem ; 66(17): 12536-12543, 2023 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-37608596

RESUMO

In this study, we have investigated the potential of two classes of thioglucoside analogues of gliflozins as antidiabetic drugs, one with substitutions of S-atoms in meta-positions (similar to C-glucoside SGLT2 inhibitors, TAGs A, B, and C) and the other with substitutions of S-atoms in ortho-positions (similar to O-glucoside SGLT2 inhibitors, TAGs D, E, F, and G). These TAGs were confirmed to show good stability against ß-glucosidase and to have no acute toxicity to cultured cells. Most importantly, TAGs D, E, F, and G all showed high inhibitory activity against SGLT2 (IC50: 2.0-5.9 nM) and thus have great potential to be developed as new gliflozin drugs. Compared with the synthesis of C-glucoside gliflozins, the synthesis of TAGs is simple, efficient, and associated with low costs, high yields, and very mild reaction conditions.


Assuntos
Inibidores do Transportador 2 de Sódio-Glicose , Inibidores do Transportador 2 de Sódio-Glicose/farmacologia , Hipoglicemiantes/farmacologia , Glucosídeos/farmacologia , Tioglucosídeos
20.
Adv Sci (Weinh) ; 10(28): e2303726, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37530207

RESUMO

The recognition of the surface reconstruction of the catalysts during electrochemical CO2 reduction (CO2RR) is essential for exploring and comprehending active sites. Although the superior performance of Cu-Zn bimetallic sites toward multicarbon C2+ products has been established, the dynamic surface reconstruction has not been fully understood. Herein, Zn-doped Cu2 O nano-octahedrons are used to investigate the effect of the dynamic stability by the leaching and redeposition on CO2RR. Correlative characterizations confirm the Zn leaching from Zn-doped Cu2 O, which is redeposited at the surface of the catalysts, leading to dynamic stability and abundant Cu-Zn bimetallic sites at the surface. The reconstructed Zn-doped Cu2 O catalysts achieve a high Faradaic efficiency (FE) of C2+ products (77% at -1.1 V versus reversible hydrogen electrode (RHE)). Additionally, similar dynamic stability is also discovered in Al-doped Cu2 O for CO2RR, proving its universality in amphoteric metal-doped catalysts. Mechanism analyses reveal that the OHC-CHO pathway can be the C-C coupling processes on bare Cu2 O and Zn-doped Cu2 O, and the introduction of Zn to Cu can efficiently lower the energy barrier for CO2RR to C2 H4 . This research provides profound insight into unraveling surface dynamic reconstruction of amphoteric metal-containing electrocatalysts and can guide rational design of the high-performance electrocatalysts for CO2RR.

SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa