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1.
Nano Lett ; 24(1): 441-449, 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38109494

RESUMO

Conjugated polymer films are promising in wearable X-ray detection. However, achieving optimal film microstructure possessing good electrical and detection performance under large deformation via scalable printing remains challenging. Herein, we report bar-coated high-performance stretchable films based on a conjugated polymer P(TDPP-Se) and elastomer SEBS blend by optimizing the solution-processing conditions. The moderate preaggregation in solution and prolonged growth dynamics from a solvent mixture with limited dissolving capacity is critical to forming aligned P(TDPP-Se) chains/crystalline nanofibers in the SEBS phase with enhanced π-π stacking for charge transport and stress dissipation. The film shows a large elongation at break of >400% and high mobilities of 5.29 cm2 V-1 s-1 at 0% strain and 1.66 cm2 V-1 s-1 over 500 stretch-release cycles at 50% strain, enabling good X-ray imaging with a high sensitivity of 1501.52 µC Gyair-1 cm-2. Our work provides a morphology control strategy toward high-performance conjugated polymer film-based stretchable electronics.

2.
Small ; 20(4): e2306396, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37712176

RESUMO

Rechargeable zinc-air batteries (Re-ZABs) are one of the most promising next-generation batteries that can hold more energy while being cost-effective and safer than existing devices. Nevertheless, zinc dendrites, non-portability, and limited charge-discharge cycles have long been obstacles to the commercialization of Re-ZABs. Over the past 30 years, milestone breakthroughs have been made in technical indicators (safety, high energy density, and long battery life), battery components (air cathode, zinc anode, and gas diffusion layer), and battery configurations (flexibility and portability), however, a comprehensive review on advanced design strategies for Re-ZABs system from multiple angles is still lacking. This review underscores the progress and strategies proposed so far to pursuit the high-efficiency Re-ZABs system, including the aspects of rechargeability (from primary to rechargeable), air cathode (from unifunctional to bifunctional), zinc anode (from dendritic to stable), electrolytes (from aqueous to non-aqueous), battery configurations (from non-portable to portable), and industrialization progress (from laboratorial to practical). Critical appraisals of the advanced modification approaches (such as surface/interface modulation, nanoconfinement catalysis, defect electrochemistry, synergistic electrocatalysis, etc.) are highlighted for cost-effective flexible Re-ZABs with good sustainability and high energy density. Finally, insights are further rendered properly for the future research directions of advanced zinc-air batteries.

3.
Ren Fail ; 46(2): 2365396, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38874150

RESUMO

OBJECTIVE: The aim of this study was to investigate the potential importance of complement system activation, with particular emphasis on the complement alternative pathway (AP), in the pathogenesis of hypertensive renal damage. METHODS: Serum complement C3, complement Factor H (CFH) and AP activation were assessed in 66 participants with established essential hypertension with renal damage (RD). Fifty-nine patients with age- and sex-matched essential hypertension without renal damage (NRD) and 58 healthy participants (normal) were selected. RESULTS: Our study revealed that C3 and AP50 continuously increased from normal to NRD to RD (p < 0.05, respectively), while CFH was significantly lower than that in NRD and healthy participants (p < 0.05, respectively). After multifactorial logistic regression analysis corrected for confounders, elevated serum C3 (p = 0.001) and decreased CFH (p < 0.001) were found to be independent risk factors for hypertension in healthy participants; elevated serum C3 (p = 0.034), elevated AP50 (p < 0.001), decreased CFH (p < 0.001), increased age (p = 0.011) and increased BMI (p = 0.013) were found to be independent risk factors for the progression of hypertension to hypertensive renal damage; elevated serum C3 (p = 0.017), elevated AP50 (p = 0.023), decreased CFH (p = 0.005) and increased age (p = 0.041) were found to be independent risk factors for the development of hypertensive renal damage in healthy participants. CONCLUSION: Abnormal activation of complement, particularly complement AP, may be a risk factor for the development and progression of hypertensive renal damage.


Assuntos
Complemento C3 , Fator H do Complemento , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Estudos de Casos e Controles , Complemento C3/metabolismo , Complemento C3/análise , Fatores de Risco , Idoso , Adulto , Hipertensão/complicações , Hipertensão/sangue , Ativação do Complemento , Hipertensão Essencial/sangue , Hipertensão Essencial/complicações , Hipertensão Essencial/fisiopatologia , Modelos Logísticos , Via Alternativa do Complemento , Progressão da Doença
4.
Ren Fail ; 46(1): 2300314, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38189082

RESUMO

PURPOSE: To investigate the effects of canagliflozin (20 mg/kg) on Dahl salt-sensitive (DSS) rat gut microbiota and salt-sensitive hypertension-induced kidney injury and further explore its possible mechanism. METHODS: Rats were fed a high-salt diet to induce hypertension and kidney injury, and physical and physiological indicators were measured afterwards. This study employed 16S rRNA sequencing technology and liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based metabolic profiling combined with advanced differential and association analyses to investigate the correlation between the microbiome and the metabolome in male DSS rats. RESULTS: A high-salt diet disrupted the balance of the intestinal flora and increased toxic metabolites (methyhistidines, creatinine, homocitrulline, and indoxyl sulfate), resulting in severe kidney damage. Canagliflozin contributed to reconstructing the intestinal flora of DSS rats by significantly increasing the abundance of Corynebacterium spp., Bifidobacterium spp., Facklamia spp., Lactobacillus spp., Ruminococcus spp., Blautia spp., Coprococcus spp., and Allobaculum spp. Moreover, the reconstruction of the intestinal microbiota led to significant changes in host amino acid metabolite concentrations. The concentration of uremic toxins, such as methyhistidines, creatinine, and homocitrulline, in the serum of rats was decreased by canagliflozin, which resulted in oxidative stress and renal injury alleviation. CONCLUSION: Canagliflozin may change the production of metabolites and reduce the level of uremic toxins in the blood circulation by reconstructing the intestinal flora of DSS rats fed a high-salt diet, ultimately alleviating oxidative stress and renal injury.


Assuntos
Microbioma Gastrointestinal , Hipertensão , Toxinas Biológicas , Masculino , Animais , Ratos , Canagliflozina/farmacologia , Canagliflozina/uso terapêutico , Ratos Endogâmicos Dahl , Toxinas Urêmicas , Cromatografia Líquida , Creatinina , RNA Ribossômico 16S , Espectrometria de Massas em Tandem , Cloreto de Sódio , Dieta , Rim
5.
Biochem Biophys Res Commun ; 653: 53-61, 2023 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-36857900

RESUMO

Hypertensive nephropathy is characterized by long-term damage to renal tissues by chronic uncontrolled hypertension, and ultimately leads to the development of renal fibrosis. The epithelial-mesenchymal transition (EMT) potentially contributes to the promotion of renal fibrosis in chronic kidney disease (CKD). In this study, we investigated the potential roles of canagliflozin (Cana) on renal EMT and oxidative stress through its effects on sirtuin 3 (SIRT3) expression. High-salt diet (HSD)-induced Dahl salt-sensitive rats hypertensive renal injury led to decreased SIRT3 expression and an increase in EMT and oxidative stress. In contrast, Cana administration rescued SIRT3 expression, decreased both EMT and levels of oxidative stress, and ameliorated renal injury. Furthermore, we compared the antihypertensive and renoprotective properties of Cana when combined with irbesartan (Irb), a renin-angiotensin system (RAS) blocker. We concluded that administration of Cana in combination with Irb had a significantly greater effect in lowering systolic blood pressure when compared to Cana monotherapy. However, no statistical differences were observed between combined therapy and monotherapy groups with regards to the lowering of diastolic blood pressure and renoprotection. Utilizing the human renal proximal tubular epithelial cell line (HK-2), Angiotensin II (AngⅡ) induced HK-2 negatively regulated the expression of SIRT3, FOXO3a, catalase, and promoted EMT, all of which were reversed by Cana. Furthermore, SIRT3 silencing abolished Cana-mediated rescue of forkhead box O3a (FOXO3a) and catalase expression and Cana-mediated suppression of EMT in AngⅡ induced HK-2. Taken together, Cana acts as a renoprotective agent by suppressing EMT in the pathology of renal fibrosis via interaction with the SIRT3-FOXO3a pathway.


Assuntos
Hipertensão , Nefropatias , Sirtuína 3 , Animais , Humanos , Ratos , Canagliflozina/farmacologia , Canagliflozina/uso terapêutico , Catalase/metabolismo , Dieta , Transição Epitelial-Mesenquimal , Fibrose , Hipertensão/metabolismo , Irbesartana/metabolismo , Irbesartana/farmacologia , Rim/patologia , Nefropatias/patologia , Estresse Oxidativo , Ratos Endogâmicos Dahl , Sirtuína 3/genética , Sirtuína 3/metabolismo , Cloreto de Sódio na Dieta/efeitos adversos , Cloreto de Sódio na Dieta/metabolismo
6.
Small ; 19(36): e2301609, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37116125

RESUMO

NiFe-based (oxy)hydroxides are the benchmark catalysts for the oxygen evolution reaction (OER) in alkaline medium, however, it is still challenging to control their structures and compositions. Herein, molybdates (NiFe(MoO4 )x ) are applied as unique precursors to synthesize ultrafine Mo modified NiFeOx Hy (oxy)hydroxide nanosheet arrays. The electrochemical activation process enables the molybdate ions (MoO4 2- ) in the precursors gradually dissolve, and at the same time, hydroxide ions (OH- ) in the electrolyte diffuse into the precursor and react with Ni2+ and Fe3+ ions in confined space to produce ultrafine NiFeOx Hy (oxy)hydroxides nanosheets (<10 nm), which are densely arranged into microporous arrays and maintain the rod-like morphology of the precursor. Such dense ultrafine nanosheet arrays produce rich edge planes on the surface of NiFeOx Hy (oxy)hydroxides to expose more active sites. More importantly, the capillary phenomenon of microporous structures and hydrophilic hydroxyl groups induce the superhydrophilicity and the rough surface produces the superaerophobic characteristic for bubbles. With these advantages, the optimized catalyst exhibits excellent performance for OER, with a small overpotential of 182 mV at 10 mA cm-2 and long-term stability (200 h) at 200 mA cm-2 . Theoretical calculations show that the modification of Mo enhances the electron delocalization and optimizes the adsorption of intermediates.

7.
Small ; 19(47): e2303919, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37488691

RESUMO

Lithium-sulfur (Li-S) batteries hold great promise for widespread application on account of their high theoretical energy density (2600 Wh kg-1 ) and the advantages of sulfur. Practical use, however, is impeded by the shuttle effect of polysulfides along with sluggish cathode kinetics. it is reported that such deleterious issues can be overcome by using a composite film (denoted as V-CMP@MWNT) that consists of a conjugated microporous polymer (CMP) embedded with vanadium single-atom catalysts (V SACs) and a network of multi-walled carbon nanotubes (MWNTs). V-CMP@MWNT films are fabricated by first electropolymerizing a bidentate ligand designed to coordinate to V metals on self-standing MWNT films followed by treating the CMP with a solution containing V ions. Li-S cells containing a V-CMP@MWNT film as interlayer exhibit outstanding performance metrics including a high cycling stability (616 mA h g-1 at 0.5 C after 1000 cycles) and rate capability (804 mA h g-1 at 10 C). An extraordinary area-specific capacity of 13.2 mA h cm-2 is also measured at a high sulfur loading of 12.2 mg cm-2 . The underlying mechanism that enables the V SACs to promote cathode kinetics and suppress the shuttle effect is elucidated through a series of electrochemical and spectroscopic techniques.

8.
Chemistry ; 29(46): e202301124, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37296528

RESUMO

NiFe-layered double hydroxide (NiFe-LDH) is the benchmark catalyst for the oxygen evolution reaction (OER) in alkaline medium, however, it is still challenging to improve its activity and stability. Herein, NiFe-LDH macroporous array electrodes are demonstrated to significantly enhance the activity and stability for oxygen evolution reaction. The electrodes are fabricated by the chemical and electrochemical corrosion process of Ni foam induced by ferric nitrate, hydrochloric acid and oxygen. By optimizing the amount of iron salt and acid and selecting the appropriate reaction temperature and time, the NiFe-LDH electrodes only need the overpotential of 180 mV and 248 mV to reach the current density of 10 mA cm-2 and 500 mA cm-2 , respectively, and remain highly stable for 1000 h at 500 mA cm-2 . The unique macroporous array not only significantly increases the active area of NiFe-LDH catalyst, but also creates a stable nanostructure that avoids severe reconstruction.

9.
Pharmacology ; 108(5): 478-491, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37611563

RESUMO

INTRODUCTION: The aim of this study was to investigate the effect of canagliflozin (CANA) on ventricular remodeling in patients with preserved ejection fraction (HFpEF) heart failure and to further investigate its possible molecular mechanisms. METHODS: A high-salt diet was used to induce the formation of HFpEF model in salt-sensitive rats. The rats were fed with CANA and irbesartan, respectively. The mice were divided into control group, model group, CANA group, irbesartan group, and combined drug group. After 12 weeks of feeding, the rats were evaluated by measuring the relevant indexes and echocardiography for cardiac function. Histological analysis was performed using Masson trichrome staining and immunohistochemical staining. RT-qPCR and Western blot were used to quantify the relevant genes and proteins. RESULTS: In this study, CANA exhibited diuresis, decreased blood pressure, weight loss, and increased food and water intake. Following a high-salt diet, Dahl salt-sensitive rats developed hypertension followed by left ventricular diastolic dysfunction, myocardial fibrosis, and left ventricular remodeling. Myocardial hypertrophy and fibrosis were reduced, and left ventricular diastolic function and ventricular remodeling improved after CANA treatment. The combination of CANA and irbesartan was superior to monotherapy in reducing blood pressure and improving cardiac insufficiency and left ventricular diastolic dysfunction in rats. CANA improves myocardial fibrosis, left ventricular diastolic dysfunction, and ventricular remodeling by upregulating apelin, activating angiotensin-converting enzyme 2 (ACE2), and increasing ACE2/Ang (1-7)/MASR axis levels. CONCLUSION: CANA improves myocardial fibrosis, left ventricular diastolic dysfunction, and ventricular remodeling in HFpEF rats through upregulation of apelin/ACE2 signaling.


Assuntos
Insuficiência Cardíaca , Disfunção Ventricular Esquerda , Humanos , Ratos , Camundongos , Animais , Insuficiência Cardíaca/tratamento farmacológico , Insuficiência Cardíaca/metabolismo , Insuficiência Cardíaca/patologia , Remodelação Ventricular/fisiologia , Canagliflozina , Enzima de Conversão de Angiotensina 2 , Volume Sistólico/fisiologia , Irbesartana , Apelina , Ratos Endogâmicos Dahl , Fibrose
10.
Neural Plast ; 2023: 2382980, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37124873

RESUMO

Objective: Many stroke victims have severe swallowing problems. Previous neuroimaging studies have found that several brain regions scattered in the frontal, temporal, and parietal lobes, such as Brodmann's areas (BA) 6, 21, and 40, are associated with swallowing function. This study sought to investigate changes in swallowing function and resting-state functional magnetic resonance imaging (rs-fMRI) in stroke patients with dysphagia following action observation treatment. It also sought to detect changes in brain regions associated with swallowing in stroke patients. Methods: In this study, 12 healthy controls (HCs) and 12 stroke patients were recruited. Stroke patients were given 4 weeks of action observation therapy. In order to assess the differences in mfALFF values between patients before treatment and HCs, the fractional amplitude of low-frequency fluctuations (fALFF) in three frequency bands (conventional frequency band, slow-4, and slow-5) were calculated for fMRI data. The significant brain regions were selected as regions of interest (ROIs) for subsequent analysis. The mfALFF values were extracted from ROIs of the three groups (patients before and after treatment and HCs) and compared to assess the therapeutic efficacy. Results: In the conventional band, stroke patients before treatment had higher mfALFF in the inferior temporal gyrus and lower mfALFF in the calcarine fissure and surrounding cortex and thalamus compared to HCs. In the slow-4 band, there was no significant difference in related brain regions between stroke patients before treatment and HCs. In the slow-5 band, stroke patients before treatment had higher mfALFF in inferior cerebellum, inferior temporal gyrus, middle frontal gyrus, and lower mfALFF in calcarine fissure and surrounding cortex compared to HCs. We also assessed changes in aberrant brain activity that occurred both before and after action observation therapy. The mfALFF between stroke patients after therapy was closed to HCs in comparison to the patients before treatment. Conclusion: Action observation therapy can affect the excitability of certain brain regions. The changes in brain function brought about by this treatment may help to further understand the potential mechanism of network remodeling of swallowing function.


Assuntos
Transtornos de Deglutição , Acidente Vascular Cerebral , Humanos , Deglutição , Transtornos de Deglutição/diagnóstico por imagem , Transtornos de Deglutição/etiologia , Imageamento por Ressonância Magnética/métodos , Córtex Motor , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/terapia
11.
Zhongguo Yi Liao Qi Xie Za Zhi ; 47(6): 598-601, 2023 Nov 30.
Artigo em Zh | MEDLINE | ID: mdl-38086713

RESUMO

The composite material PLGA compounded with ß-tricalcium phosphate (ß-TCP) was prepared by melt blending method, and the absorbable interface screw was prepared by injection molding process. Prepare PBS buffer that simulates human body, conduct in vitro degradation experiments on interface screws according to relevant national and industry standards, then test and characterize interface screws at different time points for degradation of intrinsic viscosity, average molecular weight distribution, mass loss, mechanical properties and thermal properties. According to the degradation performance-time curve, determine the time node at which the interface screw loses the mechanical properties. In this paper, the in vitro degradation behavior of interfacial screws prepared from PLGA and ß-TCP composites was studied in detail, providing a reference and basis for the degradation behavior of absorbable products prepared from PLGA and ß-TCP composites.


Assuntos
Fosfatos de Cálcio , Poliésteres , Humanos , Teste de Materiais , Implantes Absorvíveis
12.
Small ; 18(18): e2107450, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35128790

RESUMO

Electrochemical CO2 reduction to valuable ethylene and ethanol offers a promising strategy to lower CO2 emissions while storing renewable electricity. Cu-based catalysts have shown the potential for CO2 -to-ethylene/ethanol conversion, but still suffer from low activity and selectivity. Herein, the effects of surface and interface structures in Cu-based catalysts for CO2 -to-ethylene/ethanol production are systematically discussed. Both reactions involve three crucial steps: formation of CO intermediate, CC coupling, and hydrodeoxygenation of C2 intermediates. For ethylene, the key step is CC coupling, which can be enhanced by tailoring the surface structures of catalyst such as step sites on facets, Cu0 /Cuδ+ species and nanopores, as well as the optimized molecule-catalyst and electrolyte-catalyst interfaces further promoting the higher ethylene production. While the controllable hydrodeoxygenation of C2 intermediate is important for ethanol, which can be achieved by tuning the stability of oxygenate intermediates through the metallic cluster induced special atomic configuration and bimetallic synergy induced the double active sites on catalyst surface. Additionally, constraining CO coverage by the complex-catalyst interface and stabilizing CO bond by N-doped carbon/Cu interface can also enhance the ethanol selectivity. The structure-performance relationships will provide the guidance for the design of Cu-based catalysts for highly efficient reduction of CO2 .

13.
J Environ Manage ; 324: 116298, 2022 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-36179473

RESUMO

This study investigated groundwater hexavalent chromium (Cr(VI)) decontamination by a biological permeable reactive barrier (bio-PRB), where a woodchip-elemental sulfur [S(0)] based mixotrophic process was established. 89.0 ± 0.27% of Cr(VI) was removed from the synthetic groundwater after 72 h at a concentration of 50 mg/L during the preliminary batch experiment. The impact of geochemical and hydrodynamic conditions Cr(VI) removal was investigated in the bio-PRB over 225 days. Although elevated Cr(VI) (i.e., 75 mg/L), addition of nitrate and short hydraulic retention time reduced the Cr(VI) removal, 87.2 ± 2.09% of Cr(VI) removal was accomplished. Characterization of the solids indicated that the soluble Cr(VI) was converted and immobilized as the insoluble trivalent chromium [Cr(III)]. 16S rRNA gene based sequencing results suggested that micromolecules produced by woodchip cellulose hydrolyzing- and sulfur oxidizing bacteria were further used by functional Cr(VI) removal bacteria (e.g., Geobacteraceae and Pseudomonas). The extracellular protein and humic-like substances in extracellular polymeric substances (EPS) can bind toxic Cr(VI) through carboxyl and hydroxyl groups, and reduce Cr(VI) in an enzymatic manner. The preliminary finding of this study provided a potential way to utilize agricultural waste for in-situ Cr(VI) contaminated-groundwater remediation.


Assuntos
Água Subterrânea , Poluentes Químicos da Água , RNA Ribossômico 16S , Poluentes Químicos da Água/análise , Água Subterrânea/química , Cromo/análise , Enxofre , Biotecnologia
14.
Small ; 17(23): e2008052, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33887101

RESUMO

Hydrogenation of diesters to diols is a vital process for chemical industry. The inexpensive Cu+ /Cu0 -based catalysts are highly active for the hydrogenation of esters, however, how to efficiently tune the ratio of Cu+ /Cu0 and stabilize the Cu+ is a great challenge. In this work, it is demonstrated that doped Ti ions can tune the ratio of Cu+ /Cu0 and stabilize the Cu+ by the TiOCu bonds in Ti-doped SiO2 supported Cu nanoparticle (Cu/Ti-SiO2 ) catalysts for the high conversion of dimethyl adipate to 1,6-hexanediol. In the synthesis of the catalysts, the Ti4+ OCu2+ bonds promote the reduction of Cu2+ to Cu+ by forming Ti3+ OV Cu+ (OV : oxygen vacancy) bonds and the amount of Ti doping can tune the ratio of Cu+ /Cu0 . In the catalytic reaction, the O vacancy activates CO in the ester by forming new Ti3+ δ OR Cu1+ δ bonds (OR : reactant oxygen), and Cu0 activates hydrogen. After the products are desorbed, the Ti3+ δ OR Cu1+ δ bonds return to the initial state of Ti3+ OV Cu+ bonds. The reversible TiOCu bonds greatly improve the activity and stability of the Cu/Ti-SiO2 catalysts. When the content of Ti is controlled at 0.4 wt%, the conversion and selectivity can reach 100% and 98.8%, respectively, and remain stable for 260 h without performance degradation.

15.
BMC Public Health ; 21(1): 117, 2021 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-33430851

RESUMO

BACKGROUND: The COVID-19 has caused a sizeable global outbreak and has been declared as a public health emergency of international concern. Sufficient evidence shows that temperature has an essential link with respiratory infectious diseases. The objectives of this study were to describe the exposure-response relationship between ambient temperature, including extreme temperatures, and mortality of COVID-19. METHODS: The Poisson distributed lag non-linear model (DLNM) was constructed to evaluate the non-linear delayed effects of ambient temperature on death, by using the daily new death of COVID-19 and ambient temperature data from January 10 to March 31, 2020, in Wuhan, China. RESULTS: During the period mentioned above, the average daily number of COVID-19 deaths was approximately 45.2. Poisson distributed lag non-linear model showed that there was a non-linear relationship (U-shape) between the effect of ambient temperature and mortality. With confounding factors controlled, the daily cumulative relative death risk decreased by 12.3% (95% CI [3.4, 20.4%]) for every 1.0 °C increase in temperature. Moreover, the delayed effects of the low temperature are acute and short-term, with the most considerable risk occurring in 5-7 days of exposure. The delayed effects of the high temperature appeared quickly, then decrease rapidly, and increased sharply 15 days of exposure, mainly manifested as acute and long-term effects. Sensitivity analysis results demonstrated that the results were robust. CONCLUSIONS: The relationship between ambient temperature and COVID-19 mortality was non-linear. There was a negative correlation between the cumulative relative risk of death and temperature. Additionally, exposure to high and low temperatures had divergent impacts on mortality.


Assuntos
COVID-19/mortalidade , Temperatura , China/epidemiologia , Humanos
16.
Sensors (Basel) ; 21(5)2021 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-33807795

RESUMO

The existing pedestrian detection algorithms cannot effectively extract features of heavily occluded targets which results in lower detection accuracy. To solve the heavy occlusion in crowds, we propose a multi-scale feature pyramid network based on ResNet (MFPN) to enhance the features of occluded targets and improve the detection accuracy. MFPN includes two modules, namely double feature pyramid network (FPN) integrated with ResNet (DFR) and repulsion loss of minimum (RLM). We propose the double FPN which improves the architecture to further enhance the semantic information and contours of occluded pedestrians, and provide a new way for feature extraction of occluded targets. The features extracted by our network can be more separated and clearer, especially those heavily occluded pedestrians. Repulsion loss is introduced to improve the loss function which can keep predicted boxes away from the ground truths of the unrelated targets. Experiments carried out on the public CrowdHuman dataset, we obtain 90.96% AP which yields the best performance, 5.16% AP gains compared to the FPN-ResNet50 baseline. Compared with the state-of-the-art works, the performance of the pedestrian detection system has been boosted with our method.

17.
Angew Chem Int Ed Engl ; 60(9): 4747-4755, 2021 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-33215803

RESUMO

A facile anisotropic surface modification and etching strategy is presented for the synthesis of hollow structured ZIF-67 nanoframes. The strategy uses structural and compositional distinctions between each crystallographic facet of truncated rhombic dodecahedrons ZIF-67 (tZIF-67 RDs) and the moderate coordinating and etching effects of cyanuric acid (CA). The CA can anisotropically modify and protect the {110} facets from etching, causing the six {100} facets be selectively etched via an inside-out manner, and finally forming the hollow nanoframes. The surface-modified hollow tZIF-67 RDs can be facet-selectively etched by metal salts in an outside-in manner to give metal-doped tZIF-67 nanoframes. After calcination, the metal-tZIF-67 hybrids are converted into metal-Co alloy/C composite catalysts with hollow nanoframed structures. The PtCo/C catalyst with only 5.9 wt % Pt exhibits high catalytic activities and stabilities in the hydrogen evolution reaction (HER) in acidic solutions.

18.
Chemistry ; 26(28): 6195-6204, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32077175

RESUMO

Developing efficient electrocatalysts for the hydrogen evolution reaction (HER) is crucial for establishing a sustainable and environmentally friendly energy system, but it is still a challenging issue. Herein, hierarchical tubular-structured CoS2 -MoS2 /C as efficient electrocatalysts are fabricated through a unique metal-organic framework (MOF) mediated self-sacrificial templating. Core-shell structured MoO3 @ZIF-67 nanorods are used both as a precursor and a sacrificial template to form the one-dimensional tubular heterostructure where vertically aligned two-dimensional CoS2 -MoS2 nanosheets are formed on the MOF-derived carbon tube. Trace amounts of noble metals (Pd, Rh, and Ru) are successfully introduced to enhance the electrocatalytic property of the CoS2 -MoS2 /C nanocomposites. The as-synthesized hierarchical tubular heterostructures exhibit excellent HER catalytic performance owing to the merits of the hierarchical hollow architecture with abundantly exposed edges and the uniformly dispersed active sites. Impressively, the optimal Pd-CoS2 -MoS2 /C-600 catalyst delivers a current density of 10 mA cm-2 at a low overpotential of 144 mV and a small Tafel slope of 59.9 mV/dec in 0.5 m H2 SO4 . Overall, this MOF-mediated strategy can be extended to the rational design and synthesis of other hollow heterogeneous catalysts for scalable hydrogen generation.

19.
Pharmacology ; 104(1-2): 7-20, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30947229

RESUMO

BACKGROUND: Ocotillol, RT5 and F11, the main active components of ocotillol type ginsenosides, have attracted a lot of attention due to their beneficial effects on neurodegenerative disease models of Alzheimer's disease. Pharmacokinetic (PK) is a bridge linking the herbal medicines and their pharmacological responses. However, few data are available regarding PK behaviors of ocotillol type ginsenosides. METHODS: The liquid chromatography-tandem mass spectrometry methods were developed and validated to calculate the concentrations of 3 ginsenosides in different biological matrices. Rat and beagle dog plasma samples were deproteinized with methanol and separated on Shim-pack GIST C18 column. All of the analytes were detected in positive ion mode using multiple reaction monitoring. RESULTS: The methods showed good linearity (r > 0.996) in the established concentration range. All validated data, such as specificity, intra- and inter-day precision, accuracy, extraction recovery, matrix effect, and stability were within required limits. The values of Cmax and AUC(0-t) indicated ocotillol type ginsenosides had low systemic exposure and poor absorption into blood. T1/2 and MRT(0-t) demonstrated the elimination process of ocotillol type ginsenosides might be slow. Double peaks were observed in the mean plasma concentration versus time profiles of ocotillol, RT5, and F11 after oral intake. CONCLUSIONS: This was the first PK investigation of the ocotillol type ginsenosides in rats and beagle dogs. The results we found here were helpful to our understanding of the absorption mechanism of ocotillol type ginsenosides and provided the scientific basis for further pre-clinical research.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Ginsenosídeos/farmacocinética , Fármacos Neuroprotetores/farmacocinética , Panax/química , Espectrometria de Massas em Tandem/métodos , Administração Oral , Animais , Cromatografia Líquida de Alta Pressão/métodos , Cães , Avaliação Pré-Clínica de Medicamentos , Feminino , Ginsenosídeos/administração & dosagem , Masculino , Fármacos Neuroprotetores/administração & dosagem , Ratos , Padrões de Referência , Reprodutibilidade dos Testes , Distribuição Tecidual
20.
Small ; 14(44): e1802442, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30286273

RESUMO

Highly efficient earth-abundant electrocatalysts for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are of great importance for renewable energy conversion systems. Herein, hollow porous heterometallic phosphide nanocubes are developed as a highly active and robust catalyst for electrochemical water splitting via one-step phosphidation of a NiCoFe Prussian blue analogue. Through modulation of the composition of metals in the precursors, the optimal NiCoFeP exhibiting increased electrical conductivity and abundant electrochemically active sites, leading to high electrocatalytic activities and outstanding kinetics for both HER and OER, is successfully obtained. NiCoFeP shows low overpotentials of 273 mV for OER and 131 mV for HER at a current density of 10 mA cm-2 and quite low Tafel slopes of 35 mV dec-1 for OER and 56 mV dec-1 for HER.

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