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1.
Proc Natl Acad Sci U S A ; 119(37): e2121848119, 2022 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-36067324

RESUMEN

Refractory carbides are attractive candidates for support materials in heterogeneous catalysis because of their high thermal, chemical, and mechanical stability. However, the industrial applications of refractory carbides, especially silicon carbide (SiC), are greatly hampered by their low surface area and harsh synthetic conditions, typically have a very limited surface area (<200 m2 g-1), and are prepared in a high-temperature environment (>1,400 °C) that lasts for several or even tens of hours. Based on Le Chatelier's principle, we theoretically proposed and experimentally verified that a low-pressure carbothermal reduction (CR) strategy was capable of synthesizing high-surface area SiC (569.9 m2 g-1) at a lower temperature and a faster rate (∼1,300 °C, 50 Pa, 30 s). Such high-surface area SiC possesses excellent thermal stability and antioxidant capacity since it maintained stability under a water-saturated airflow at 650 °C for 100 h. Furthermore, we demonstrated the feasibility of our strategy for scale-up production of high-surface area SiC (460.6 m2 g-1), with a yield larger than 12 g in one experiment, by virtue of an industrial viable vacuum sintering furnace. Importantly, our strategy is  also applicable to the rapid synthesis of refractory metal carbides (NbC, Mo2C, TaC, WC) and even their emerging high-entropy carbides (VNbMoTaWC5, TiVNbTaWC5). Therefore, our low-pressure CR method provides an alternative strategy, not merely limited to temperature and time items, to regulate the synthesis and facilitate the upcoming industrial applications of carbide-based advanced functional materials.

2.
J Am Chem Soc ; 146(3): 2227-2236, 2024 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-38224553

RESUMEN

Charged microdroplets offer novel electrochemical environments, distinct from traditional solid-liquid or solid-liquid-gas interfaces, due to the intense electric fields at liquid-gas interfaces. In this study, we propose that charged microdroplets serve as microelectrochemical cells (MECs), enabling unique electrochemical reactions at the gas-liquid interface. Using electrospray-generated microdroplets, we achieved multielectron CO2 reduction and C-C coupling to synthesize ethanol using molecular catalysts. These catalysts effectively harness and relay electrons, enhancing the longevity of solvated electrons and enabling multielectron reactions. Importantly, we revealed the intrinsic relationship between the size and charge density of a MEC and its reaction selectivity. Employing in situ mass spectrometry, we identified reaction intermediates (molecular catalyst adducts with HCOO) and oxidation products, elucidating the CO2 reduction mechanism and the comprehensive reaction procedure. Our research underscores the promising role of charged microdroplets in pioneering new electrochemical systems.

3.
J Am Chem Soc ; 146(22): 15320-15330, 2024 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-38683738

RESUMEN

Palladium hydrides (PdHx) are pivotal in both fundamental research and practical applications across a wide spectrum. PdHx nanocrystals, synthesized by heating in dimethylformamide (DMF), exhibit remarkable stability, granting them widespread applications in the field of electrocatalysis. However, this stability appears inconsistent with their metastable nature. The substantial challenges in characterizing nanoscale structures contribute to the limited understanding of this anomalous phenomenon. Here, through a series of well-conceived experimental designs and advanced characterization techniques, including aberration-corrected scanning transmission electron microscopy (AC-STEM), in situ X-ray diffraction (XRD), and time-of-flight secondary ion mass spectrometry (TOF-SIMS), we have uncovered evidence that indicates the presence of C and N within the lattice of Pd (PdCxNy), rather than H (PdHx). By combining theoretical calculations, we have thoroughly studied the potential configurations and thermodynamic stability of PdCxNy, demonstrating a 2.5:1 ratio of C to N infiltration into the Pd lattice. Furthermore, we successfully modulated the electronic structure of Pd nanocrystals through C and N doping, enhancing their catalytic activity in methanol oxidation reactions. This breakthrough provides a new perspective on the structure and composition of Pd-based nanocrystals infused with light elements, paving the way for the development of advanced catalytic materials in the future.

4.
J Neuroradiol ; 51(1): 74-81, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37442272

RESUMEN

PURPOSE: Traditional flow diverters (FDs) for treating aneurysms at the fetal posterior communicating artery are unsatisfactory. Surpass Streamline is a novel FD with different mesh characteristics; however, the outcomes for such aneurysms remain unclear. This study aimed to compare hemodynamic alterations induced by Surpass Streamline, Pipeline Flex, and Tubridge devices and explore possible strategies for aneurysms at the fetal posterior communicating artery. METHODS: Two simulated aneurysms (Case 1, Case 2) were constructed from digital subtraction angiography (DSA). The three FDs were virtually deployed, and hemodynamic analysis based on computational fluid dynamics was performed. Hemodynamic parameters, including the sac-averaged velocity magnitude (Velocity), high-flow volume (HFV), and wall shear stress (WSS), were compared between each FD and the untreated model (control). Surpass Streamline was performed in real life for two aneurysms and the clinical outcomes were collected for analysis. RESULTS: Compared to the control, the Surpass resulted in the most significant reduction in flow. In Case 1, the Velocity, HFV, and WSS were reduced by 51.6%, 78.1%, and 64.3%, respectively. In Case 2, the Velocity, HFV, and WSS were reduced by 48.0%, 81.1%, and 65.3%, respectively. Tubridge showed slightly larger changes in hemodynamic parameters than Pipeline. In addition, our analysis suggested that metal coverage was correlated with the WSS, Velocity, and HFV. The postoperative DSA showed that the aneurysm was nearly occluded in Case 1 and decreased in Case 2. CONCLUSION: Compared to that with the Pipeline and Tubridge, the Surpass resulted in the greatest reduction in hemodynamic parameters and might be effective for aneurysms at the fetal posterior communicating artery. Virtual FD deployment and computational fluid dynamics analysis may be used to predict the treatment outcomes.


Asunto(s)
Aneurisma Intracraneal , Humanos , Aneurisma Intracraneal/terapia , Aneurisma Intracraneal/cirugía , Hemodinámica , Resultado del Tratamiento , Hidrodinámica , Arterias
5.
Angew Chem Int Ed Engl ; 63(20): e202403114, 2024 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-38488787

RESUMEN

The conversion of methane under ambient conditions has attracted significant attention. Although advancements have been made using active oxygen species from photo- and electro- chemical processes, challenges such as complex catalyst design, costly oxidants, and unwanted byproducts remain. This study exploits the concept of contact-electro-catalysis, initiating chemical reactions through charge exchange at a solid-liquid interface, to report a novel process for directly converting methane under ambient conditions. Utilizing the electrification of commercially available Fluorinated Ethylene Propylene (FEP) with water under ultrasound, we demonstrate how this interaction promote the activation of methane and oxygen molecules. Our results show that the yield of HCHO and CH3OH can reach 467.5 and 151.2 µmol ⋅ gcat -1, respectively. We utilized electron paramagnetic resonance (EPR) to confirm the evolution of hydroxyl radicals (⋅OH) and superoxide radicals (⋅OOH). Isotope mass spectrometry (MS) was employed to analyze the elemental origin of CH3OH, which can be further oxidized to HCHO. Additionally, we conducted density functional theory (DFT) simulations to assess the reaction energies of FEP with H2O, O2, and CH4 under these conditions. The implications of this methodology, with its potential applicability to a wider array of gas-phase catalytic reactions, underscore a significant advance in catalysis.

6.
J Am Chem Soc ; 145(23): 12717-12725, 2023 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-37268602

RESUMEN

Enhancing the catalytic activity of Ru metal in the hydrogen oxidation reaction (HOR) potential range, improving the insufficient activity of Ru caused by its oxophilicity, is of great significance for reducing the cost of anion exchange membrane fuel cells (AEMFCs). Here, we use Ru grown on Au@Pd as a model system to understand the underlying mechanism for activity improvement by combining direct in situ surface-enhanced Raman spectroscopy (SERS) evidence of the catalytic reaction intermediate (OHad) with in situ X-ray diffraction (XRD), electrochemical characterization, as well as DFT calculations. The results showed that the Au@Pd@Ru nanocatalyst utilizes the hydrogen storage capacity of the Pd interlayer to "temporarily" store the activated hydrogen enriched at the interface, which spontaneously overflows at the "hydrogen-deficient interface" to react with OHad adsorbed on Ru. It is the essential reason for the enhanced catalytic activity of Ru at anodic potential. This work deepens our understanding of the HOR mechanism and provides new ideas for the rational design of advanced electrocatalysts.

7.
Phys Chem Chem Phys ; 25(38): 26258-26269, 2023 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-37743787

RESUMEN

The excited state properties and deactivation pathways of two DNA methylation inhibitors, i.e., 5-azacytidine (5ACyd) and 2'-deoxy-5-azacytidine (5AdCyd) in aqueous solution, are comprehensively explored with the QM(CASPT2//CASSCF)/MM protocol. We systematically map the feasible decay mechanisms based on the obtained excited-state decay paths involving all the identified minimum-energy structures, conical intersections, and crossing points driving the different internal conversion (IC) and intersystem crossing (ISC) routes in and between the 1ππ*, 1nπ*, 3ππ*, 3nπ*, and S0 states. Unlike the 1nπ* state below the 1ππ* state in 5ACyd, deoxyribose group substitution at the N1 position leads to the 1ππ* state becoming the S1 state in 5AdCyd. In 5ACyd and 5AdCyd, the initially populated 1ππ* state mainly deactivates to the S0 state through the direct 1ππ* → S0 IC or mediated by the 1nπ* state. The former nearly barrierless IC channel of 1ππ* → S0 occurs ultrafast via the nearby low-lying 1ππ*/S0 conical intersection. In the latter IC channel of 1ππ* → 1nπ* → S0, the initially photoexcited 1ππ* state first approaches the nearby S2/S1 conical section 1ππ*/1nπ* and then undergoes efficient IC to the 1nπ* state, followed by the further IC to the initial S0 state via the S1/S0 conical intersection 1nπ*/S0. The 1nπ*/S0 conical intersection is estimated to be located 6.0 and 4.9 kcal mol-1 above the 1nπ* state minimum in 5ACyd and 5AdCyd, respectively, at the QM(CASPT2)/MM level. In addition to the efficient singlet-mediated IC channels, the minor ISC routes would populate 1ππ* to T1(ππ*) through 1ππ* → T1 or 1ππ* → 1nπ* → T1. Relatively, the 1ππ* → 1nπ* → T1 route benefits from the spin-orbit coupling (SOC) of 1nπ*/3ππ* of 8.7 cm-1 in 5ACyd and 10.2 cm-1 in 5AdCyd, respectively. Subsequently, the T1 system will approach the nearby T1/S0 crossing point 3ππ*/S0 driving it back to the S0 state. Given the 3ππ*/S0 crossing point located above the T1 minimum and the small T1/S0 SOC, i.e., 8.4 kcal mol-1 and 2.1 cm-1 in 5ACyd and 6.8 kcal mol-1 and 1.9 cm-1 in 5AdCyd, respectively, the slow T1 → S0 would trap the system in the T1 state for a while. The present work could contribute to understanding the mechanistic photophysics and photochemistry of similar aza-nucleosides and their derivatives.

8.
J Head Trauma Rehabil ; 38(4): E289-E298, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36730820

RESUMEN

BACKGROUND: Limited evidence has explored the impact of traumatic brain injury (TBI) on posttraumatic epilepsy with control cohort for comparison. In addition, we could not find any review to identify the effect of TBI on the outcomes. Thus, we conducted this study to compare the risk of epilepsy between individuals with TBI and without TBI. METHODS: Systematic and comprehensive search was carried out in the following databases and search engines: EMBASE, Cochrane, MEDLINE, ScienceDirect, and Google Scholar from 1954 until January 2022. The Newcastle Ottawa (NO) Scale was utilized to assess the risk of bias. Meta-analysis was carried out using the random-effects model, and pooled odds ratio (OR) along with 95% CI was reported. RESULTS: In total, we included 10 studies satisfying inclusion criteria. Most studies had good to satisfactory quality. The pooled OR was 4.25 (95% CI, 1.77-10.25; I2 = 100%), indicating that the individuals with TBI had 4.25 times higher risk of having epilepsy than individuals without TBI, and this association was statistically significant ( P = .001). Subgroup analysis based on the years of follow-up revealed that the patients within 5 years post-TBI had the highest risk of epilepsy (pooled OR = 7.27; 95% CI, 3.61-14.64). CONCLUSION: Individuals with TBI had a significantly higher risk of epilepsy than the individuals without TBI, irrespective of the duration of the injury. Hence, long-term follow-up of the individuals with TBI is necessary to prevent any adverse consequences.


Asunto(s)
Lesiones Traumáticas del Encéfalo , Epilepsia , Humanos , Lesiones Traumáticas del Encéfalo/complicaciones , Lesiones Traumáticas del Encéfalo/epidemiología , Epilepsia/epidemiología , Epilepsia/etiología
9.
Vascular ; : 17085381231164663, 2023 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-36946194

RESUMEN

BACKGROUND: Acute mesenteric ischemia (AMI) is a life-threatening surgical emergency with a poor prognosis. This study assessed the association of diffuse reduction of spleen density (DROSD) with postoperative complications and identified risk factors for adverse outcomes in AMI patients after surgery. METHODS: Patients who were diagnosed with AMI and underwent surgical operations between April 2006 and July 2021 were enrolled. Spleen density was assessed using preoperative non-enhanced computed tomography. The lowest quartile of spleen density in all patients was regarded as the cutoff value for DROSD. Univariate and multivariate analyses were performed to determine the risk factors related to postoperative outcomes after surgery. RESULTS: According to the diagnostic cutoff, patients with a spleen density ≤49.07 HU were defined as DROSD. In a cohort of 97 patients, 34.0% developed complications within 30 days of surgery. The multivariate analysis illustrated that DROSD was an independent risk factor for prognostic outcomes in AMI patients after surgery. CONCLUSION: Patients with low spleen density were prone to postoperative complications. As an imaging method, preoperative assessment of spleen density is a novel predictor that can be used clinically to identify high-risk AMI patients with poor prognosis.

10.
Angew Chem Int Ed Engl ; 62(21): e202300604, 2023 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-36949023

RESUMEN

Hydrogen peroxide (H2 O2 ) is an indispensable basic reagent in various industries, such as textile bleach, chemical synthesis, and environmental protection. However, it is challenging to prepare H2 O2 in a green, safe, simple and efficient way under ambient conditions. Here, we found that H2 O2 could be synthesized using a catalytic pathway only by contact charging a two-phase interface at room temperature and normal pressure. Particularly, under the action of mechanical force, electron transfer occurs during physical contact between polytetrafluoroethylene particles and deionized water/O2 interfaces, inducing the generation of reactive free radicals (⋅OH and ⋅O2 - ), and the free radicals could react to form H2 O2 , yielding as high as 313 µmol L-1 h-1 . In addition, the new reaction device could show long-term stable H2 O2 production. This work provides a novel method for the efficient preparation of H2 O2 , which may also stimulate further explorations on contact-electrification-induced chemistry process.

11.
J Sep Sci ; 45(2): 518-528, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34784088

RESUMEN

Juglandis Mandshuricae Cortex is the bark of Juglans mandshurica Maxim., which has been used as a folk medicine plant in China and India. In this study, an ultra-high performance liquid chromatography-quadrupole/orbitrap high-resolution mass spectrometry method was developed to clarify and quantify the chemical profiling of Juglandis Mandshuricae Cortex rapidly. A total of 113 compounds were characterized. Among them, seven flavonoids were simultaneously quantified in 15 min, including myricetin, myricetrin, taxifolin, kaempferol, quercetin, quercitrin, and naringenin. The method was validated for accuracy, precision, and the limits of detection and quantification. All calibration curves showed a good linear relationship (r > 0.9990) within test ranges. The intra- and inter-day relative standard deviations were less than 2.16%. Accuracy validation showed that the recovery was between 95.6 and 101.3% with relative standard deviation values below 2.85%. The validated method was successfully applied to determine the contents of seven flavones in Juglandis Mandshuricae Cortex from seven sources and the contents of these places were calculated respectively. This method provides a theoretical basis for further developing the medicinal value of Juglandis Mandshuricae Cortex.


Asunto(s)
Medicamentos Herbarios Chinos , Juglans , Cromatografía Líquida de Alta Presión/métodos , Medicamentos Herbarios Chinos/análisis , Flavonoides/análisis , Juglans/química , Espectrometría de Masas en Tándem/métodos
12.
Ann Vasc Surg ; 84: 298-304, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35247535

RESUMEN

BACKGROUND: The predictive values of the platelet to lymphocyte ratio (PLR) and red cell distribution width (RDW) have been demonstrated in different types of abdominal surgery. The aim of this study was to investigate the interest of the preoperative PLR and RDW as predictors of 30-day postoperative complications in patients with acute mesenteric ischemia (AMI). METHODS: Clinical data of 105 AMI patients were retrospectively reviewed. Postoperative complications were evaluated by the Clavien-Dindo classification. The cutoff values for neutrophil to lymphocyte ratio (NLR), PLR, and RDW were determined by receiver operating characteristic curves. Univariate and multivariate analyses evaluating the risk factors for postoperative complications were performed. RESULTS: In the univariate analyses, advanced age, female, anemia, high white blood cell (WBC), high PLR, high NLR, high RDW, Charlson comorbidity index (CCI) score ≥2, and bowel resection were associated with the postoperative complications. A multivariable analysis revealed that advanced age, high PLR, high RDW, and bowel resection were independent predictors of postoperative complications. CONCLUSIONS: The PLR and RDW might play important roles in evaluation of the risk of postoperative complications in AMI patients. The preoperative PLR and RDW are simple and useful predictors of postoperative complications in AMI patients.


Asunto(s)
Índices de Eritrocitos , Isquemia Mesentérica , Femenino , Humanos , Linfocitos , Isquemia Mesentérica/diagnóstico , Neutrófilos , Complicaciones Posoperatorias , Pronóstico , Estudios Retrospectivos , Resultado del Tratamiento
13.
Chem Soc Rev ; 50(19): 10983-11031, 2021 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-34617521

RESUMEN

Elemental two-dimensional (2D) materials have emerged as promising candidates for energy and catalysis applications due to their unique physical, chemical, and electronic properties. These materials are advantageous in offering massive surface-to-volume ratios, favorable transport properties, intriguing physicochemical properties, and confinement effects resulting from the 2D ultrathin structure. In this review, we focus on the recent advances in emerging energy and catalysis applications based on beyond-graphene elemental 2D materials. First, we briefly introduce the general classification, structure, and properties of elemental 2D materials and the new advances in material preparation. We then discuss various applications in energy harvesting and storage, including solar cells, piezoelectric and triboelectric nanogenerators, thermoelectric devices, batteries, and supercapacitors. We further discuss the explorations of beyond-graphene elemental 2D materials for electrocatalysis, photocatalysis, and heterogeneous catalysis. Finally, the challenges and perspectives for the future development of elemental 2D materials in energy and catalysis are discussed.

14.
Angew Chem Int Ed Engl ; 61(5): e202112749, 2022 Jan 26.
Artículo en Inglés | MEDLINE | ID: mdl-34806809

RESUMEN

Plasmonic metals under photoexcitation can generate energetic hot electrons to directly induce chemical reactions. However, the capability and fundamental insights of the transportation of these hot electrons at plasmonic metal-2D material interfaces remain unclear. Herein, hot-electron transfer at Au-graphene interfaces has been in situ studied using surface-enhanced Raman spectroscopy (SERS) with atomic layer accuracy. Combining in situ SERS studies with density functional theory calculations, it is proved that hot electrons can be injected from plasmonic Au nanoparticles to graphene and directly penetrate graphene to trigger photocatalytic reactions. With increasing graphene layers, the transportation of hot electrons decays rapidly and would be completely blocked after five layers of graphene. Moreover, the transfer of hot electrons can be modulated by applying an external electric field, and the hot-electron transfer efficiency under electrochemical conditions is improved by over three times in the presence of a monolayer of graphene.

15.
J Sep Sci ; 44(19): 3562-3579, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34358407

RESUMEN

Zilongjin tablets as a traditional Chinese medicine are widely used for primary lung cancer patients with deficiency of "qi " and "blood " syndrome undergoing chemotherapy. It is a compound preparation that consists of eight herbs. To clarify the chemical profiling of Zilong Jin tablets rapidly, a feasible and accurate strategy was developed by the ultra high performance liquid chromatography-quadrupole/orbitrap high resolution mass spectrometry. According to the accurate mass and fragment ion information provided by high resolution mass spectrometry, the compounds were reasonably identified. In total, 74 compounds were characterized, including 20 flavonoids, 14 quinones, 15 organic acids, 6 phthalide compounds, and 19 other compounds. Among them, 34 major compounds were unambiguously confirmed by comparing with reference standards. This study could provide an important scientific basis for further research on quality control, pharmacokinetics and pharmacodynamics, and clinical application of Zilong Jin tablets.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Medicamentos Herbarios Chinos/química , Espectrometría de Masas/métodos , Benzofuranos/análisis , Benzofuranos/química , Flavonoides/análisis , Flavonoides/química , Quinonas/análisis , Quinonas/química
16.
J Am Chem Soc ; 142(6): 2956-2967, 2020 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-31902206

RESUMEN

All-inorganic lead halide perovskite nanocrystals (NCs) are potential candidates for fabricating high-performance light-emitting diodes (LEDs) owing to their precisely tunable bandgaps, high photoluminescence (PL) efficiency, and excellent color purities. However, the performance of pure red (630-640 nm) all-inorganic perovskite LEDs is still limited by the halide segregation-induced instability of the electroluminescence (EL) of mixed halide CsPbI3-xBrx NCs. Herein, we report an effective approach to improving the EL stability of pure red all-inorganic CsPbI3-xBrx NC-based LEDs via the passivation of potassium bromide on NCs. By adding potassium oleate to the reaction system, we obtained potassium bromide surface-passivated (KBr-passivated) CsPbI3-xBrx NCs with pure red PL emission and a photoluminescence quantum yield (PLQY) exceeding 90%. We determine that most potassium ions present on the surface of NCs bind with bromide ions and thus demonstrate that potassium bromide surface passivation of NCs can both improve the PL stability and inhibit the halide segregation of NCs. Using KBr-passivated CsPbI3-xBrx NCs as an emitting layer, we fabricated stable and pure red perovskite LEDs with emission at 637 nm, showing a maximum brightness of 2671 cd m-2, maximum external quantum efficiency of 3.55%, and good EL stability. The proposed KBr-passivated NC strategy will open a new avenue for fabricating efficient, stable, and tunable pure color perovskite NC LEDs.

17.
J Am Chem Soc ; 142(8): 3686-3690, 2020 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-32045234

RESUMEN

Highly luminescent inks are desirable for various applications such as decorative coating, art painting, and anticounterfeiting, to name a few. However, present inks display low photoluminescent efficiency requiring a strong excitation light to make them glow. Here, we report a highly luminescent ink based on the copper-iodide/1-Propyl-1,4-diazabicyclo[2.2.2]octan-1-ium (Cu4I6(pr-ted)2) hybrid cluster with a quantum efficiency exceeding 98%. Under the interaction between the Cu4I6(pr-ted)2 hybrid cluster and polyvinylpyrrolidone (PVP), the highly luminescent Cu4I6(pr-ted)2/PVP ink can be facilely prepared via the one-pot solution synthesis. The obtained ink exhibits strong green light emission that originates from the efficient phosphorescence of Cu4I6(pr-ted)2 nanocrystals. Attractively, the ink displays high conversion efficiency for the ultraviolet light to bright green light emission due to its wide Stokes shift, implying great potential for anticounterfeiting and luminescent solar concentrator coating.

18.
Ann Vasc Surg ; 67: 105-114, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32240729

RESUMEN

BACKGROUND: This study was performed to determine the association of frailty and comorbidity status with postoperative morbidity and mortality in patients with acute mesenteric ischemia (AMI). METHODS: Patients diagnosed with AMI between April 2006 and September 2019 were enrolled in this study. Frailty was evaluated by sarcopenia which was diagnosed by third lumbar vertebra psoas muscle area (PMA). Comorbidity status was evaluated by the Charlson Comorbidity Index (CCI) score. Univariate and multivariate analyses evaluating the risk factors for postoperative morbidity and mortality were performed. RESULTS: Of the 174 patients, 86 were managed conservatively and 88 underwent surgery. In surgically managed patients, 39.8% developed complications within 30 days of surgery. Ten patients died within 30 days of the operation. In the univariate analyses, white blood cell >10 g/L, low PMA, CCI score ≥2, and bowel resection were associated with postoperative complications. Multivariate analysis revealed that low PMA, CCI score ≥2, and bowel resection were independent predictors of postoperative complications. CONCLUSIONS: This study demonstrated that low PMA, CCI score ≥2, and bowel resection were independent risk factors for postoperative complications in patients with AMI. Preoperative assessment of frailty using PMA and the evaluation of comorbidity status using CCI may serve as helpful tools in preoperative risk assessment and should be integrated into scoring systems for surgically treated AMI.


Asunto(s)
Reglas de Decisión Clínica , Tratamiento Conservador , Anciano Frágil , Fragilidad/diagnóstico por imagen , Isquemia Mesentérica/terapia , Oclusión Vascular Mesentérica/terapia , Músculos Psoas/diagnóstico por imagen , Sarcopenia/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Procedimientos Quirúrgicos Vasculares , Enfermedad Aguda , Adulto , Factores de Edad , Anciano , Composición Corporal , Toma de Decisiones Clínicas , Comorbilidad , Tratamiento Conservador/efectos adversos , Tratamiento Conservador/mortalidad , Procedimientos Quirúrgicos Electivos , Femenino , Fragilidad/mortalidad , Fragilidad/fisiopatología , Estado de Salud , Humanos , Masculino , Isquemia Mesentérica/diagnóstico por imagen , Isquemia Mesentérica/mortalidad , Oclusión Vascular Mesentérica/diagnóstico por imagen , Oclusión Vascular Mesentérica/mortalidad , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Músculos Psoas/fisiopatología , Medición de Riesgo , Factores de Riesgo , Sarcopenia/mortalidad , Sarcopenia/fisiopatología , Factores de Tiempo , Resultado del Tratamiento , Procedimientos Quirúrgicos Vasculares/efectos adversos , Procedimientos Quirúrgicos Vasculares/mortalidad
19.
BMC Fam Pract ; 21(1): 147, 2020 07 22.
Artículo en Inglés | MEDLINE | ID: mdl-32698768

RESUMEN

BACKGROUND: Epidemic chronic diseases pose significant challenges to the improvement of healthcare in China and worldwide. Despite increasing international calls for the inclusion of evidence-based decision-making (EBDM) processes in chronic disease prevention and control programming as well as policymaking, there is relatively little research that assesses the current capacity of physicians and the factors that influence that capacity in China. METHOD: This cross-sectional study was conducted in community health centres (CHCs) in Shanghai, China, using multistage cluster sampling. An evidence-based chronic disease prevention (EBCDP) evaluation tool was employed to assess physician EBCDP awareness, adoption, implementation and maintenance based on the Reach, Effectiveness, Adoption, Implementation and Maintenance (RE-AIM) framework and using a 7-point Likert scale. Linear regression analysis was used to assess associations between each EBCDP aspect and overall EBCDP status with participant characteristics or organizational factors. RESULT: A total of 892 physicians from CHCs in Shanghai, China, were assessed. The physicians perceived their awareness (mean = 4.90, SD = 1.02) and maintenance (mean = 4.71, SD = 1.07) of EBCDP to be relatively low. Physicians with relatively lower job titles and monthly incomes (> 9000 RMB) tended to have relatively higher scores for the awareness, adoption, and implementation of EBCDP (P < 0.05). Those who had participated in one program for chronic disease prevention and control were less likely to adopt (b = - 0.284, P = 0.007), implement (b = - 0.292, P = 0.004), and maintain (b = - 0.225, P = 0.025) EBCDP than those who had participated in more programs. Physicians in general practice (Western medicine) had a lower level of awareness of EBCDP than those in other departments (P < 0.0001). Physician from CHCs located in suburban areas had lower scores for awareness (b = - 0.150, P = 0.047), implementation (b = - 0.171, P = 0.029), and maintenance (b = - 0.237, P = 0.002) that those from urban CHCs. Physicians in CHCs affiliated with universities had higher scores on all four EBCDP aspects that those in CHCs not affiliated with a university. CONCLUSIONS: This study provides quantitative evidence illustrating EBCDP practices among physicians in CHCs with various personal and organizational characteristics, respectively. More methods should be provided to increase the awareness of such physicians regarding EBCDP to stimulate the use of EBCDP for their patients and in connection with other public health priorities.


Asunto(s)
Actitud del Personal de Salud , Enfermedad Crónica/prevención & control , Toma de Decisiones Clínicas , Práctica Clínica Basada en la Evidencia/estadística & datos numéricos , Médicos Generales/estadística & datos numéricos , Adulto , China , Centros Comunitarios de Salud , Estudios Transversales , Femenino , Humanos , Ciencia de la Implementación , Renta , Modelos Lineales , Masculino , Persona de Mediana Edad , Percepción
20.
J Am Chem Soc ; 141(35): 13977-13986, 2019 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-31436416

RESUMEN

The chemical reactivity and/or the diffusion of Ag atoms or ions during thermal processing can cause irreversible structural damage, hindering the application of Ag nanowires (NWs) in transparent conducting films and other applications that make use of the material's nanoscale properties. Here, we describe a simple and effective method for growing monolayer SnO2 on the surface of Ag nanowires under ambient conditions, which protects the Ag nanowires from chemical and structural damage. Our results show that Sn2+ and Ag atoms undergo a redox reaction in the presence of water. First-principle simulations suggest a reasonable mechanism for SnO2 formation, showing that the interfacial polarization of the silver by the SnO2 can significantly reduce the affinity of Ag to O2, thereby greatly reducing the oxidation of the silver. The corresponding values (for example, before coating: 17.2 Ω/sq at 86.4%, after coating: 19.0 Ω/sq at 86.6%) show that the deposition of monolayer SnO2 enables the preservation of high transparency and conductivity of Ag. In sharp contrast to the large-scale degradation of pure Ag-NW films including the significant reduction of its electrical conductivity when subjected to a series of harsh corrosion environments, monolayer SnO2 coated Ag-NW films survive structurally and retain their electrical conductivity. Consequently, the thermal, electrical, and chemical stability properties we report here, and the simplicity of the technology used to achieve them, are among the very best reported for transparent conductor materials to date.

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