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Photocatalytic nitrogen reduction reaction (NRR) is a sustainable process for ammonia synthesis under mild conditions. However, photocatalytic NRR activity and are generally limited by inefficient carrier separation and transfer. Therefore, parallel engineering of bulk phase doping and surface coupling is critical to achieving the goal of efficient NRR. In this study, Cl doped BiOBr nanosheet assemblies (BiOBr/Cl) were constructed in delicately designed deep eutectic solvents (DESs), combined with ionothermal methods at low temperatures and Bi3+ exsolution reduction strategy at high temperatures. The unique liquid state and reducibility of DESs induce the reduction of Bi3+ and the in situ coupling of Bi quantum dots at the surface of BiOBr/Cl nanosheets along with the construction of Bi-BiOBr/Cl nanosheet assemblies. The experimental results show that Cl doping could reduce the exciton dissociation energy and promote its dissociation to free carriers. Bi quantum dots could form tightly coupled Schottky junction with BiOBr/Cl enabling the efficient and unidirectional transmission of photogenerated electrons from BiOBr/Cl to metal Bi. The formed electron deficient region at Schottky interface promotes the adsorption and activation of N2. The hierarchical structure of Bi-BiOBr/Cl nanosheet assembly benefits to providing more N2 adsorption active sites. The DFT calculation shows that the accumulation of high concentration of active hydrogen in Bi-BiOBr/Cl leads to a significant decrease of energy barrier of the first step hydrogenation of N2. Bi-BiOBr/Clis more inclined to adsorb nitrogen for NRR in comparison with H* for hydrogen production. The synergistic effect of Cl doping and Bi coupling result in a high NRR activity of Bi-BiOBr/Cl photocatalyst of 6.67 mmol·g-1·h-1, which was 11.3 times higher than that of initial BiOBr. This study provides a promising strategy for designing highly active NRR photocatalysts with high efficiency carrier dissociation and transport.
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Main group Bi-based materials have gained popularity as N2 reduction reaction (NRR) photo/electrocatalysts due to their ability to inhibit competitive H2 evolution reactions (HER) and the unique N2 adsorption activities. The introduction of defects in Bi-based catalysts represents a highly effective strategy for enhancing light absorption, promoting efficient separation of photogenerated carriers, optimizing the activity of free radicals, regulating electronic structure, and improving catalytic performance. In this review, we outline the various applications of state of the defect engineering in Bi-based catalysts and elucidate the impact of vacancies on NRR performance. In particular, the types of defects, methods of defects tailoring, advanced characterization techniques, as well as the Bi-based catalysts with abundant defects and their corresponding catalytic behavior in NRR were elucidated in detail. Finally, the main challenges and opportunities for future development of defective Bi-based NRR catalysts are discussed, which provides a comprehensive theoretical guidance for this field.
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Photothermal conversion has garnered significant attention due to its potential for efficient energy conversion and application in targeted therapies. However, controlling photothermal properties at the atomic level remains a challenge in current materials synthesis. In this study, we report the synthesis and structural determination of a phosphine and mercaptan co-protected Au5Ag12(SR)9(dppf)4 (Au5Ag12) nanocluster with an extremely low quantum yield (â¼0%). For comparative purposes, we synthesized three alloy nanoclusters of similar size. Notably, Au5Ag12 demonstrates a remarkably superior photothermal conversion performance, significantly outperforming the other clusters. We investigated this variance from both absorption and emission perspectives. This research not only opens new avenues for the application of clusters with extremely low quantum yields, but also provides experimental evidence for understanding the photothermal conversion properties of cluster materials at the atomic level.
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Nanostructured electrocatalysts with unique surfaces and interfaces for hydrogen evolution reaction (HER) are crucial for achieving high performance in universal pH water and natural seawater. Herein, a supramolecular liquid precursor was designed and applied to grow NixCo4-xN/N-doped carbon (NC) ultrathin nanosheet arrays (NixCo4-xN/NC) on carbon cloth through one-step pyrolysis. According to the X-ray absorption spectra, Ni was successfully alloyed into Co4N to form NixCo4-xN/NC, which regulates the intrinsic electronic structure and optimizes the adsorption/desorption energy of the catalyst. The unique structure of NixCo4-xN anchored on NC can increase the electron transport efficiency and protect the catalyst from corrosion in the extreme corrosive electrolytes. As a result, the NixCo4-xN/NC catalyst exhibits excellent electrocatalytic HER activity over a wide pH range requiring only 46, 75, and 55 mV at 10 mA/cm2 in the acidic, neutral, and alkaline electrolytes, respectively. Interestingly, the catalyst also shows outstanding HER performance in the natural seawater. This work provides an alternative option for the rational design of efficient electrocatalysts for universal pH water/seawater splitting.
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Cáusticos , Água , Hidrogênio , Pirólise , Carbono , Água do Mar , Concentração de Íons de HidrogênioRESUMO
Multiple surface/interface engineering is an effective approach to develop efficient electrocatalysts for promoting the practical application of electrocatalysis and achieving carbon neutrality. Herein, a deep eutectic liquid precursor containing phosphorus was designed. The self-supported three-dimensional (3D) cobalt-doped Ni12P5/Ni3P nanowire networks coated with a thin layer of carbon (Co-NixP@C) were prepared by using an in-situ one-step pyrolysis method. The as-obtained Co-NixP@C hybrid possesses a superaerophobic/superhydrophilic surface, which could promote electrolyte diffusion and enhance bubble release. Density functional theory (DFT) calculations reveal that Co-doping in NixP@C can promote the adsorption and activation of 5-hydroxymethylfurfural (HMF) molecules, and optimize the energy barrier of H* absorption. The self-supported Co-NixP@C was used as an efficient bifunctional electrocatalyst for HMF oxidation coupled with hydrogen evolution reaction (HER) in a 1.0 M KOH solution. A nearly 100 % yield of 2,5-furandicarboxylic acid (FDCA) was achieved. The self-supported Co-NixP@C displayed high activity and stability for both HER and HMF conversion. The HMF oxidation coupled with HER can be efficiently driven by a 1.5 V commercial photovoltaic panel under sunlight. This study lays the foundation for large-scale industrialization in sustainable fine-chemical and energy engineering.
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The emerging S-scheme heterojunction shows a particular superiority in enhancing the efficiency of charge separation in photocatalyst. Herein, a Ni11(HPO3)8(OH)6/CdS heterojunctions (NiPO/CdS) are constructed for the first time by loading open framework structure NiPO on the surface of CdS nanoparticles (CdS NPs). The built-in electric field generated at the interface promotes the directional migration of photogenerated electrons from NiPO to CdS. This S-scheme pathway achieves a strong redox capacity and efficient carrier separation. More importantly, the unique triangular and hexagonal channels of NiPO facilitate the exposure of CdS active sites for proton adsorption, H2 production and escape. The hydrogen evolution rate of NiPO/CdS is 39 mmol g-1 h-1 under visible light irradiation, which is 6.5 times higher than that of pure CdS. The NiPO/CdS heterojunction also exhibits remarkable long-term stability. This study provides a new strategy for the ingenious design of S-scheme photocatalysts with excellent photocatalytic performance.
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Constructing photocatalysts with high activity and anti-photocorrosion is a key to harvesting hydrogen energy from seawater efficiently. Herein, graphene oxide closely coupled high-index facets CdZnS with rich sulfur vacancies (Vs-CZS@GO) has been successfully synthesized via one-pot sulfidation accompanied pyrolysis. DFT calculation confirmed the delicate surface/interface/defect engineering endowed high-index facets Vs-CZS@GO with a lower ΔGH* value and significant charge transfer behavior for efficient H2-generation. The synergistic effect of sulfur vacancy, high-index facets, and tightly coupling interface not only enhanced intrinsic active sites and carrier separation efficiencies, but also greatly promoted H2 evolution rate and stability. Consequently, Vs-CZS@GO displayed a significantly high H2-generation rate of 23.2 mmolâg-1âh-1 in natural seawater under visible-light irradiation, which is up to 82% of that in pure water. This work provides deeply insight into the synergistic regulation of electronic structure for exposed high-index facets photocatalysts via defect engineering and interface engineering for synergistic boosting visible-light-to-H2 evolution.
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Hidrogênio , Processos Fotoquímicos , Grafite , Hidrogênio/química , Água do Mar , EnxofreRESUMO
Atomically precise nanoclusters (NCs) provide opportunities for correlating the structure and electrocatalytic properties at atomic level. Herein, we report the single-atom doping effect and ligand effect on CO2 electroreduction (eCO2RR) by comparing monogold-doped Au1Cu24 and homocopper Cu25 NCs protected by triphenylphosphine or/and tris(4-fluorophenyl)phosphine. Catalytic results revealed that the electronic distribution of Cu25 NCs is enormously contracted by doping Au atoms, entitling it to exhibit the unique inhibition of hydrogen evolution reaction. And the inductive effect of ligand strongly favors the formation of formate in eCO2RR. Overall, this work will provide guidance for the rational design of the copper-based catalysts in the eCO2RR.
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Using the panel data of 280 prefecture-level cities in China from 2004 to 2014, this paper examines the effects of high-speed rail opening on health care environment based on Difference-in-Differences method (DID). Through an empirical analysis, the results proved that high-speed rail opening can significantly promote the health care environment and this effect is different in regions with different levels of economic development. Finally, we tested the mechanisms of how the high-speed rail opening affects the healthcare environment. High-speed rail opening improves the healthcare environment by increasing road accessibility and promoting economic development. Our results support the view that high-speed rail opening has an important contribution to the improvement of health care conditions.
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Atenção à Saúde , Desenvolvimento Econômico , China/epidemiologia , CidadesRESUMO
BACKGROUND: The purpose of this study is to explore the association between extravascular lung water (EVLW) and prognosis of sepsis (PS). METHODS: We will carry out comprehensive literature search in electronic databases (PUBMED/MEDLINE, EMBASE, CENTRAL, WorldSciNet, PsycINFO, Allied and Complementary Medicine Database, CBM, and CNKI) and additional sources. All electronic databases will be searched from their initial to the present without language restrictions. Case-controlled studies reporting the association between EVLW and PS will be evaluated for inclusion. Outcomes of interest will include mortality rate, extravascular lung water index, pulmonary vascular permeability index, blood lactate clearance, oxygenation index, blood gas analysis, PaO2/FiO2, cardiac output index, global end diastolic volume index, intrathoracic blood volume index, systemic resistance index, acute physiology and chronic health scoring system II, and infection-related organ failure scoring system. Study quality will be evaluated using Newcastle-Ottawa Tool, and statistical analysis will be performed utilizing RevMan 5.4 software. RESULTS: This study will summarize the most recent evidence to investigate the association between EVLW and PS. CONCLUSIONS: The results of this study will provide an exhaustive view of the association between EVLW and PS. STUDY REGISTRATION OSF: osf.io/vhnxw.
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Água Extravascular Pulmonar/metabolismo , Sepse/mortalidade , Sepse/fisiopatologia , APACHE , Gasometria , Pressão Sanguínea , Permeabilidade Capilar , Débito Cardíaco , Estudos de Casos e Controles , Humanos , Ácido Láctico/sangue , Escores de Disfunção Orgânica , Consumo de Oxigênio , Prognóstico , Circulação Pulmonar , Projetos de Pesquisa , Medição de Risco , Fatores de Risco , Revisões Sistemáticas como AssuntoRESUMO
RATIONALE & OBJECTIVE: Patients receiving maintenance hemodialysis (MHD) are highly vulnerable to infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The current study was designed to evaluate the prevalence of SARS-CoV-2 infection based on both nucleic acid testing (NAT) and antibody testing in Chinese patients receiving MHD. STUDY DESIGN: Cross-sectional study. SETTING & PARTICIPANTS: From December 1, 2019, to March 31, 2020, a total of 1,027 MHD patients in 5 large hemodialysis centers in Wuhan, China, were enrolled. Patients were screened for SARS-CoV-2 infection by symptoms and initial computed tomography (CT) of the chest. If patients developed symptoms after the initial screening was negative, repeat CT was performed. Patients suspected of being infected with SARS-CoV-2 were tested with 2 consecutive throat swabs for viral RNA. In mid-March 2020, antibody testing for SARS-CoV-2 was obtained for all MHD patients. EXPOSURE: NAT and antibody testing results for SARS-CoV-2. OUTCOMES: Morbidity, clinical features, and laboratory and radiologic findings. ANALYTICAL APPROACH: Differences between groups were examined using t test or Mann-Whitney U test, comparing those not infected with those infected and comparing those with infection detected using NAT with those with infection detected by positive serology test results. RESULTS: Among 1,027 patients receiving MHD, 99 were identified as having SARS-CoV-2 infection, for a prevalence of 9.6%. Among the 99 cases, 52 (53%) were initially diagnosed with SARS-CoV-2 infection by positive NAT; 47 (47%) were identified later by positive immunoglobulin G (IgG) or IgM antibodies against SARS-CoV-2. There was a spectrum of antibody profiles in these 47 patients: IgM antibodies in 5 (11%), IgG antibodies in 35 (74%), and both IgM and IgG antibodies in 7 (15%). Of the 99 cases, 51% were asymptomatic during the epidemic; 61% had ground-glass or patchy opacities on CT of the chest compared with 11.6% among uninfected patients (P<0.001). Patients with hypertensive kidney disease were more often found to have SARS-CoV-2 infection and were more likely to be symptomatic than patients with another primary cause of kidney failure. LIMITATIONS: Possible false-positive and false-negative results for both NAT and antibody testing; possible lack of generalizability to other dialysis populations. CONCLUSIONS: Half the SARS-CoV-2 infections in patients receiving MHD were subclinical and were not identified by universal CT of the chest and selective NAT. Serologic testing may help evaluate the overall prevalence and understand the diversity of clinical courses among patients receiving MHD who are infected with SARS-CoV-2.
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Anticorpos Antivirais/análise , Betacoronavirus/imunologia , Infecções por Coronavirus/diagnóstico , Falência Renal Crônica/terapia , Pneumonia Viral/diagnóstico , Diálise Renal , COVID-19 , China/epidemiologia , Comorbidade , Infecções por Coronavirus/epidemiologia , Estudos Transversais , Feminino , Humanos , Falência Renal Crônica/epidemiologia , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/epidemiologia , Prevalência , Estudos Retrospectivos , SARS-CoV-2 , Testes Sorológicos/métodos , Tomografia Computadorizada por Raios XRESUMO
Oxygen vacancy (Vo) creation and morphology controlling make significant contributions to the electronic and structural regulation of metal oxide semiconductors, yet an investigation about convenient approaches for fabricating hierarchical catalyst with abundant oxygen vacancies still has significant challenges. Here, we report a unique method to create abundant oxygen vacancies in hierarchical Ag/TiO2 nanoflowers during photocatalytic reaction, which is accompanied by light absorption variation and surface plasmon resonance (SPR) enhancement. Its high efficiency of photocatalytic H2 evolution (the highest apparent quantum yield reaches 3.2% at 365 nm) and rhodamine B degradation can be considered as benefits from the synergistic effects of the well-arranged hierarchical structure, the photogenerated oxygen vacancies, and the SPR of cocatalyst Ag. This work proposes an effective strategy to optimize the synthesis of regular hierarchical structures and enriches the research on the vital function of oxygen vacancies in photocatalytic reactions.
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A facile and effective method for preparing bifunctional electrocatalysts with enhanced activity and stability is desired for hydrogen and oxygen production. In this paper, ion-liquid-like (ILL) nickel-urea (Ni-U) was designed and applied to prepare 2D N-doped carbon/NiS2 (N-C/NiS2) nanohybrids by a one-step in situ pyrolysis synthesis strategy. The fluidity of ILL Ni-U benefits the interface coupling of the 2D N-C/NiS2 nanohybrid. Due to the synergistic effect between NiS2 and N-carbon with high conductivity, the H2O splitting performance of 2D N-C/NiS2 nanohybrids was significantly enhanced in alkaline media. The corresponding two-electrode cell only needed 1.53 V to undertake 10 mA cm-2 for H2O splitting. Moreover, the resultant 2D N-C/NiS2 nanohybrids exhibited lasting electrochemical endurance with the maintenance of its stability for more than 48 h. The synthetic strategy not only provides a simple and scalable route for constructing 2D hybrid electrocatalysts, but also paves a way to improve the HER/OER activity of sulphides via the surface/interface engineering strategy.
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Coronary stents made of zinc (Zn)-0.8 copper (Cu) (in wt%) alloy were developed as biodegradable metal stents (Zn-Cu stents) in this study. The mechanical properties of the Zn-Cu stents and the possible gain effects were characterized by in vitro and in vivo experiments compared with 316L stainless steel stents (316L stents). Young's modulus of the as-extruded Zn-0.8Cu alloy and properties of the stents, including their intrinsic elastic recoil, stent trackability were evaluated compared with 316L stents. In vivo study was also conducted to evaluate restoration of pulsatility of vessel segment implanted stents. Both Zn-Cu stents and 316L stents have good acute lumen gain. By comparison, the advantages of Zn-Cu stents are as follows: (I) Zn-Cu stents have less intrinsic elastic recoil than 316L stents; (II) stent trackability indicates that Zn-Cu stents have a smaller push force when passing through curved blood vessels, which may cause less mechanical stimulation to blood vessels; (III) in vivo study suggests that Zn-Cu stents implantation better facilitates the recovery of vascular pulsatility.
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Ligas/química , Materiais Biocompatíveis/química , Stents , Zinco/química , Módulo de Elasticidade , Aço InoxidávelRESUMO
OBJECTIVES: The aim of this study is to improve local-drug delivery efficiency and tissue absorption using the ultrasound (US)-responsible drug coating based on a newly developed US-controlled paclitaxel release balloon. BACKGROUND: Low availability of the drug coating remains a major concern of the current drug coated balloon (DCB). The goal of this study is to develop a method to use an US-responsible paclitaxel-loaded microcapsules (PM) as the main content of balloon drug coating to enhance bioavailability of DCB. METHODS: An US-controlled paclitaxel release balloon is designed and fabricated based on the US-responsible paclitaxel-loaded poly (lactic-co-glycolic acid) (PLGA) microcapsules. Rapid exchange percutaneous transluminal coronary angioplasty (PTCA) balloon catheters were coated with the PM. The deployment processes of the paclitaxel-loaded microcapsules coated balloons (PMCB) under US, PMCB without US and a homogenous matrix of paclitaxel and iopromide coated balloon (PICB) were then placed in healthy and stent implanted porcine coronary arteries. RESULTS: In vitro release assay demonstrated an ability of US (1 MHz, 1.22 W/cm2 , 1 minute) to affect the release kinetics of paclitaxel from PM by inducing a 76 ± 5.4% increase in the rate of release. The paclitaxel content in target vessels are 203 ± 37 µg/g for PMCB under US, 85 ± 23 µg/g for PMCB without US, and 107 ± 31 µg/g for PICB 1-hr post-surgery. The availability of the drug for the PMCB reaches 27% under US. CONCLUSIONS: The US-controlled paclitaxel release balloon significantly improved the drug content of the target vessels in the porcine model.
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Angioplastia Coronária com Balão/instrumentação , Cateteres Cardíacos , Fármacos Cardiovasculares/administração & dosagem , Materiais Revestidos Biocompatíveis , Vasos Coronários/metabolismo , Paclitaxel/administração & dosagem , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Ondas Ultrassônicas , Animais , Fármacos Cardiovasculares/química , Fármacos Cardiovasculares/farmacocinética , Preparações de Ação Retardada , Portadores de Fármacos , Liberação Controlada de Fármacos , Masculino , Paclitaxel/química , Paclitaxel/farmacocinética , Solubilidade , Sus scrofaRESUMO
OBJECTIVE: We aimed to conduct a network meta-analysis of treatments for small vessels coronary artery disease between drug-eluting balloon (DEB) and drug-eluting stent (DES). METHOD: A meta-analysis comparing DEB and DES outcomes was performed using the Medline, Embase, and Cochrane databases. The primary outcome was target lesion revascularization (TLR) or target vessel revascularization (TVR), and myocardial infarction (MI), death and major adverse cardiovascular events (MACE) were secondary outcomes. A total of six studies on 1813 patients were included. RESULTS: There was no significant difference in rates of TLR or TVR in the patients treated with the DEB strategy compares with the DES strategy [odds ratio (OR) = 0.96, 95% confidence interval (CI) 0.57-1.61, P = 0.89] within a follow-up period of 9-24 months. There was a significant reduction in rates of MI and death in the patients treated with a DCB strategy compared with those treated with a DES strategy (3.7%, 17 of 460 vs 6.1%, 36 of 595; 2.4%, 11 of 460 vs 6.1%, 36 of 595, respectively), and this difference was statistically significant (OR = 0.53, 95% CI 0.29-0.96, P = 0.04; OR = 0.44, 95% CI 0.22-0.88, P = 0.02, respectively). There was no difference between DEB and DES strategies in rates of MACE (OR = 0.94, 95% CI 0.66-1.33, P = 0.73). CONCLUSION: In summary, this study demonstrates that treatment of small vessel (diameter ≤ 3 mm) coronary artery disease (CAD) with DEB may lead to improving outcomes compared with the use of DES within a follow-up period of 9-24 months. Further large clinical trials are needed to verify this conclusion.
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Angioplastia Coronária com Balão/instrumentação , Antineoplásicos/administração & dosagem , Doença da Artéria Coronariana/terapia , Stents Farmacológicos , Intervenção Coronária Percutânea/métodos , Angioplastia Coronária com Balão/métodos , Humanos , Mortalidade , Infarto do Miocárdio/epidemiologia , Revascularização Miocárdica/estatística & dados numéricos , Neointima/prevenção & controle , Metanálise em RedeRESUMO
The Cordimax stent has proved non-inferior to the Cypher Select durable polymer sirolimus-eluting stent for the primary endpoint of angiographic in-stent late luminal loss and in-stent mean diameter stenosis at 9 months. The trial was designed to compare the efficacy and safety of the Cordimax stent with the Xience V stent in patients undergoing coronary revascularization. This randomized, multicenter trial enrolled 3697 patients treated with Cordimax stent (2460 patients) and Xience V stent (1237 patients). The primary efficacy endpoint was a target-lesion failure (TLF) at 1 year and the primary safety endpoint was a composite of death or myocardial infarction (MI) at 3 years. 3399 patients (91.9%) completed 3-year follow-up. At 1 year, the primary efficacy endpoint occurred in 86 (3.5%) patients in the Cordimax group versus 40 (3.2%) patients in the Xience V group (0.3% absolute risk difference, 95% CI -1.0-1.5%, Pnon-inferiority < 0.0001). At 3 years, the primary safety endpoint occurred in 39 (1.6%) patients in the Cordimax group versus 19 (1.5%) patients in the Xience V group (0.05% absolute risk difference, 95% CI -0.8-0.9%, Pnon-inferiority < 0.0001). The incidence of target lesion revascularization was low in Cordimax group compared with Xience V group (3.6% versus 5.1%, P = 0.03). There were no differences between Cordimax and Xience V in terms of Cardiac death (0.3% versus 0.4%, P = 0.70), myocardial infarction (1.2% versus 0.9%, P = 0.37), and the stent thrombosis (0.4% versus 0.6%, P = 0.61). In conclusion, safety and efficacy outcomes of Cordimax stent were non-inferior to the Xience V stent 3 years after stent implantation.
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Estenose Coronária/terapia , Stents Farmacológicos/efeitos adversos , Everolimo/administração & dosagem , Intervenção Coronária Percutânea/instrumentação , Sirolimo/administração & dosagem , Implantes Absorvíveis/efeitos adversos , Assistência ao Convalescente , Idoso , Estenose Coronária/complicações , Estenose Coronária/mortalidade , Preparações de Ação Retardada/administração & dosagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/epidemiologia , Infarto do Miocárdio/etiologia , Intervenção Coronária Percutânea/efeitos adversos , Polímeros/química , Trombose/epidemiologia , Trombose/etiologia , Resultado do TratamentoRESUMO
In the present study, a novel biodegradable Zn-0.8Cu coronary artery stent was fabricated and implanted into porcine coronary arteries for up to 24â¯months. Micro-CT analysis showed that the implanted stent was able to maintain structural integrity after 6â¯months, while its disintegration occurred after 9â¯months of implantation. After 24â¯months of implantation, approximately 28⯱â¯13â¯vol% of the stent remained. Optical coherence tomography and histological analysis showed that the endothelialization process could be completed within the first month after implantation, and no inflammation responses or thrombosis formation was observed within 24â¯months. Cross-section analysis indicated that the subsequent degradation products had been removed in the abluminal direction, guaranteeing that the strut could be replaced by normal tissue without the risk of contaminating the circulatory system, causing neither thrombosis nor inflammation response. The present work demonstrates that the Zn-0.8Cu stent has provided sufficient structural supporting and exhibited an appropriate degradation rate during 24â¯months of implantation without degradation product accumulation, thrombosis, or inflammation response. The results indicate that the Zn-0.8Cu coronary artery stent is promising for further clinical applications. STATEMENT OF SIGNIFICANCE: Although Zn and its alloys have been considered to be potential candidates of biodegradable metals for vascular stent use, by far, no Zn-based stent with appropriate medical device performance has been reported because of the low mechanical properties of zinc. The present work presents promising results of a Zn-Cu biodegradable vascular stent in porcine coronary arteries. The Zn-Cu stent fabricated in this work demonstrated adequate medical device performance both in vitro and in vivo and degraded at a proper rate without safety problems induced. Furthermore, large animal models have more cardiovascular similarities as humans. Results of this study may provide further information of the Zn-based stents for translational medicine research.
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Implantes Absorvíveis , Vasos Coronários , Teste de Materiais , Stents , Tomografia de Coerência Óptica , Animais , Cobre/química , Cobre/metabolismo , Vasos Coronários/diagnóstico por imagem , Vasos Coronários/cirurgia , Suínos , Fatores de Tempo , Zinco/química , Zinco/metabolismoRESUMO
Developing earth-abundant electrocatalysts for high-efficiency hydrogen evolution reaction (HER) has become one of the leading research frontiers in energy conversion. Here, the design and in situ growth of Ag nanodots decorated Cu2 O porous nanobelts networks on Cu foam (denoted as Ag@Cu2 O/CF) are carried out via a simple one-pot solution strategy at room temperature. Serving as self-supporting electrocatalysts, Ag@Cu2 O porous nanobelts provide plentiful active sites, and the 3D hybrid foams provide fast transportation for electrolyte and short diffusion path for newly formed H2 bubbles, which result in excellent electrocatalytic HER activity and long-term stability. Owing to the synergistic effect between Ag nanodots and Cu2 O porous nanobelts and CF, the hybrid electrocatalyst exhibits a low Tafel slope of 58 mV dec-1 , a small overpotential of 108 mV at 10 mA cm-2 , and high durability for more than 20 h at a potential of 200 mV for HER in 1.0 mol L-1 KOH solution.
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Drug eluting stents are one of the main devices of coronary intervention, which play a therapeutic role through the combination of medical devices. Drug is an important part of the drug eluting stents. The loading method, the type of carrier, drug and carrier interaction and the preparation process of the drug directly affect the drugs release kinetics characteristics of the device and the final treatment. According to the characteristics of the drug coating, drug coated stents can be divided into non-degradable polymers drug coated stents, biodegradable polymers drug coated stents and polymer-free drug eluting stents. This article discussed the stent coating process and drug release kinetics of the three types of drug eluting stent.