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1.
J Am Chem Soc ; 144(31): 14005-14011, 2022 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-35904545

RESUMEN

The carbon-carbon (C-C) bond formation is essential for the electroconversion of CO2 into high-energy-density C2+ products, and the precise coupling pathways remain controversial. Although recent computational investigations have proposed that the OC-COH coupling pathway is more favorable in specific reaction conditions than the well-known CO dimerization pathway, the experimental evidence is still lacking, partly due to the separated catalyst design and mechanistic/spectroscopic exploration. Here, we employ density functional theory calculations to show that on low-coordinated copper sites, the *CO bindings are strengthened, and the adsorbed *CO coupling with their hydrogenation species, *COH, receives precedence over CO dimerization. Experimentally, we construct a fragmented Cu catalyst with abundant low-coordinated sites, exhibiting a 77.8% Faradaic efficiency for C2+ products at 300 mA cm-2. With a suite of in situ spectroscopic studies, we capture an *OCCOH intermediate on the fragmented Cu surfaces, providing direct evidence to support the OC-COH coupling pathway. The mechanistic insights of this research elucidate how to design materials in favor of OC-COH coupling toward efficient C2+ production from CO2 reduction.

2.
Alcohol Clin Exp Res ; 44(2): 407-414, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31782159

RESUMEN

BACKGROUND: Repeated binge drinking is associated with reduced microvascular function. However, microvascular responses to pathophysiological stimulus such as high pressure as well as potential mechanisms that underlie binge-induced microvascular dysfunction are unknown. Therefore, using an ex vivo experimental model, we examined microvascular responses following a brief period of high intraluminal pressure in isolated arterioles from young adults who have a history of repeated binge drinking. In addition, we examined whether the application of the endothelial nitric oxide synthase cofactor, tetrahydrobiopterin, would restore microvascular function in response to flow and high intraluminal pressure in young adult binge drinkers. METHODS: Isolated subcutaneous adipose arterioles were obtained from young adult binge drinkers (BD; n = 14), moderate drinkers (MODs; n = 10), and alcohol abstainers (ABs; n = 12; mean age: 23.7 ± 0.5 years; and body mass index: 23.4 ± 0.4 kg/m2 ). Arteriolar flow-induced dilation (FID, pressure gradient: ∆10 to 100 cm H2 O) was measured before and after acute high intraluminal pressure with and without tetrahydrobiopterin. RESULTS: Before high pressure, FID at Δ60 and Δ100 cm H2 O pressure gradient in BDs was 14% lower and 18% lower, respectively, than ABs (p < 0.05), while MODs and ABs had similar FID across all pressure gradients (p ≥ 0.2). After high pressure, FID in BDs was further reduced by 10% (p < 0.0005) and this impairment was ameliorated by the treatment of tetrahydrobiopterin (4 to 26% higher, p < 0.005). In contrast, FID after high pressure did not change in MODs and ABs (p ≥ 0.5). CONCLUSIONS: Microvascular dysfunction in young adult binge drinkers may be exacerbated with acute pathophysiological stimulus. These binge-induced dysfunctions may be reversed by tetrahydrobiopterin, which suggests a role of oxidative stress and/or uncoupled endothelial nitric oxide synthase in binge drinking.


Asunto(s)
Abstinencia de Alcohol , Consumo Excesivo de Bebidas Alcohólicas/fisiopatología , Biopterinas/análogos & derivados , Microvasos/efectos de los fármacos , Microvasos/fisiopatología , Vasodilatación/efectos de los fármacos , Adolescente , Adulto , Consumo de Bebidas Alcohólicas/fisiopatología , Biopterinas/farmacología , Estudios Transversales , Femenino , Humanos , Masculino , Técnicas de Cultivo de Órganos , Vasodilatación/fisiología , Adulto Joven
3.
Med Sci Monit ; 26: e923934, 2020 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-32756534

RESUMEN

BACKGROUND Esophageal carcinoma (ESCA) is a health challenge with poor prognosis and limited treatment options. Our aim is to screen for hub genes and pathways associated with ESCA pathology as diagnostic or therapeutic targets. MATERIAL AND METHODS We downloaded 2 ESCA-related datasets from the Gene Expression Omnibus (GEO) database. Subsequently, differentially expressed genes (DEGs) of ESCA were determined by statistical analysis. Both Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of DEGs were performed using online analytic tools. Network analysis was employed to construct a protein-protein interaction (PPI) network and to filter hub genes. We evaluated the expression level and impact of hub genes on survival of ESCA patients using the OncoLoc webserver. RESULTS A total of 210 DEGs were identified. The GO analysis showed that the DEGs were enriched in cell division. The KEGG pathway analysis showed DEGs that were enriched in cell cycle regulation, known cancer pathways, the PI3K-Akt signaling pathway, and the cGMP-PKG signaling pathway. The top 10 hub genes were markedly upregulated in ESCA tissue compared with normal esophageal tissue. Moreover, the expression level of the hub genes was different at different pathological stages of ESCA. Further prognostic analysis identified that the top 10 hub genes were related to late survival of ESCA patients, while exhibiting few associations with early survival time. CONCLUSIONS The signaling pathways involving the DEGs probably represent the pathological mechanism underlying ESCA. The hub genes were associated with survival of ESCA patients, and as such have the potential to serve as diagnostic indicators and therapeutic targets.


Asunto(s)
Adenocarcinoma/genética , Adenocarcinoma/metabolismo , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/metabolismo , Carcinoma de Células Escamosas de Esófago/genética , Carcinoma de Células Escamosas de Esófago/metabolismo , Redes Reguladoras de Genes , Mapas de Interacción de Proteínas/genética , Adenocarcinoma/mortalidad , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Biología Computacional/métodos , Bases de Datos Genéticas , Neoplasias Esofágicas/mortalidad , Carcinoma de Células Escamosas de Esófago/mortalidad , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Ontología de Genes , Humanos , Fosfatidilinositol 3-Quinasas/genética , Fosfatidilinositol 3-Quinasas/metabolismo , Pronóstico , Mapeo de Interacción de Proteínas , Proteínas Proto-Oncogénicas c-akt/genética , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal/genética , Tasa de Supervivencia , Transcriptoma
4.
J Am Chem Soc ; 141(38): 14976-14980, 2019 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-31523954

RESUMEN

The traditional NH3 production method (Haber-Bosch process) is currently complemented by electrochemical synthesis at ambient conditions, but the rather low selectivity (as indicated by the Faradaic efficiency) for the electrochemical reduction of molecular N2 into NH3 impedes the progress. Here, we present a powerful method to significantly boost the Faradaic efficiency of Au electrocatalysts to 67.8% for the nitrogen reduction reaction (NRR) by increasing their electron density through the construction of inorganic donor-acceptor couples of Ni and Au nanoparticles. The unique role of the electron-rich Au centers in facilitating the fixation and activation of N2 was also investigated via theoretical simulation methods and then confirmed by experimental results. The highly coupled Au and Ni nanoparticles supported on nitrogen-doped carbon are stable for reuse and long-term performance of the NRR, making the electrochemical process more sustainable for practical application.

5.
Alcohol Clin Exp Res ; 42(2): 278-285, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29178290

RESUMEN

BACKGROUND: Binge drinking is associated with increased risk for cardiovascular (CV) disease. MicroRNA-21 (miR21) is up-regulated in the setting of excessive alcohol consumption and CV disease. Therefore, the goal of this study was to examine the vasodilatory responses to flow and acetylcholine (ACh) in the absence and presence of an anti-miR21 inhibitor in the microcirculation of young adult repeated binge drinkers (BDs). METHODS: Gluteal subcutaneous adipose tissue biopsies were obtained from young adults (18 to 30 years, n = 35 vessels from BDs and n = 28 vessels from abstainers). Resistance arteries (RAs) were isolated, incubated with anti-miR21 or a negative control (NC) to miR21 (12 hours; 50 nM), and lumen diameters measured with video microscopy. miR21 of adipose tissues was determined by quantitative polymerase chain reaction. RESULTS: Flow-induced dilation and ACh-induced dilation (AChID) were reduced in BDs as compared to abstainers. The miR21 inhibitor but not the NC abrogated these effects in BDs, but did not affect vasodilation in abstainers. Nitric oxide synthase inhibition with L-NAME reduced vasodilation in abstainers but not in BDs. In BDs, vasodilation was reduced by L-NAME in the presence of anti-miR21 but not the NC. Scavenging the reactive oxygen species, hydrogen peroxide with polyethylene glycol catalase reduced dilation in BDs but did not affect the restored dilation by the miR21 inhibitor. Maximum dilation to papaverine (endothelium independent) was similar between groups and unaffected by pharmacological inhibition. Finally, vascular endogenous miR21 was increased in BDs compared to abstainers. CONCLUSIONS: Endogenous miR21 is increased in RAs of young BDs, leading to reduced flow and AChID in the microcirculation.


Asunto(s)
Consumo Excesivo de Bebidas Alcohólicas/fisiopatología , MicroARNs/antagonistas & inhibidores , Microcirculación/efectos de los fármacos , Microvasos/efectos de los fármacos , Vasodilatación/efectos de los fármacos , Acetilcolina/farmacología , Adolescente , Adulto , Estudios de Casos y Controles , Catalasa/farmacología , Inhibidores Enzimáticos/farmacología , Femenino , Humanos , Peróxido de Hidrógeno , Masculino , MicroARNs/metabolismo , Microcirculación/fisiología , Microscopía por Video , Microvasos/fisiopatología , NG-Nitroarginina Metil Éster/farmacología , Óxido Nítrico Sintasa/antagonistas & inhibidores , Polietilenglicoles/farmacología , Grasa Subcutánea/irrigación sanguínea , Grasa Subcutánea/metabolismo , Vasodilatación/fisiología , Vasodilatadores/farmacología , Adulto Joven
6.
Angew Chem Int Ed Engl ; 57(10): 2697-2701, 2018 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-29341380

RESUMEN

Engineering the adsorption of molecules on active sites is an integral and challenging part for the design of highly efficient transition-metal-based catalysts for methanol dehydrogenation. A Mott-Schottky catalyst composed of Ni nanoparticles and tailorable nitrogen-doped carbon-foam (Ni/NCF) and thus tunable adsorption energy is presented for highly efficient and selective dehydrogenation of gas-phase methanol to hydrogen and CO even under relatively high weight hourly space velocities (WHSV). Both theoretical and experimental results reveal the key role of the rectifying contact at the Ni/NCF boundaries in tailoring the electron density of Ni species and enhancing the absorption energies of methanol molecules, which leads to a remarkably high turnover frequency (TOF) value (356 mol methanol mol-1 Ni h-1 at 350 °C), outpacing previously reported bench-marked transition-metal catalysts 10-fold.

7.
J Physiol ; 595(7): 2339-2364, 2017 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-27859264

RESUMEN

KEY POINTS: Endothelial inwardly rectifying K+ (Kir2.1) channels regulate flow-induced vasodilatation via nitric oxide (NO) in mouse mesenteric resistance arteries. Deficiency of Kir2.1 channels results in elevated blood pressure and increased vascular resistance. Flow-induced vasodilatation in human resistance arteries is also regulated by inwardly rectifying K+ channels. This study presents the first direct evidence that Kir channels play a critical role in physiological endothelial responses to flow. ABSTRACT: Inwardly rectifying K+ (Kir) channels are known to be sensitive to flow, but their role in flow-induced endothelial responses is not known. The goal of this study is to establish the role of Kir channels in flow-induced vasodilatation and to provide first insights into the mechanisms responsible for Kir signalling in this process. First, we establish that primary endothelial cells isolated from murine mesenteric arteries express functional Kir2.1 channels sensitive to shear stress. Then, using the Kir2.1+/- heterozygous mouse model, we establish that downregulation of Kir2.1 results in significant decrease in shear-activated Kir currents and inhibition of endothelium-dependent flow-induced vasodilatation (FIV) assayed in pressurized mesenteric arteries pre-constricted with endothelin-1. Deficiency in Kir2.1 also results in the loss of flow-induced phosphorylation of eNOS and Akt, as well as inhibition of NO generation. All the effects are fully rescued by endothelial cell (EC)-specific overexpression of Kir2.1. A component of FIV that is Kir independent is abrogated by blocking Ca2+ -sensitive K+ channels. Kir2.1 has no effect on endothelium-independent and K+ -induced vasodilatation in denuded arteries. Kir2.1+/- mice also show increased mean blood pressure measured by carotid artery cannulation and increased microvascular resistance measured using a tail-cuff. Importantly, blocking Kir channels also inhibits flow-induced vasodilatation in human subcutaneous adipose microvessels. Endothelial Kir channels contribute to FIV of mouse mesenteric arteries via an NO-dependent mechanism, whereas Ca2+ -sensitive K+ channels mediate FIV via an NO-independent pathway. Kir2 channels also regulate vascular resistance and blood pressure. Finally, Kir channels also contribute to FIV in human subcutaneous microvessels.


Asunto(s)
Arterias Mesentéricas/fisiología , Canales de Potasio de Rectificación Interna/fisiología , Vasodilatación/fisiología , Adulto , Animales , Células Endoteliales/fisiología , Humanos , Masculino , Ratones Transgénicos , Microvasos/fisiología , Persona de Mediana Edad , Canales de Potasio de Rectificación Interna/genética
8.
Am J Physiol Heart Circ Physiol ; 312(5): H896-H906, 2017 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-28235790

RESUMEN

High blood pressure has been shown to elicit impaired dilation in the vasculature. The purpose of this investigation was to elucidate the mechanisms through which high pressure may elicit vascular dysfunction and determine the mechanisms through which regular aerobic exercise protects arteries against high pressure. Male C57BL/6J mice were subjected to 2 wk of voluntary running (~6 km/day) for comparison with sedentary controls. Hindlimb adipose resistance arteries were dissected from mice for measurements of flow-induced dilation (FID; with or without high intraluminal pressure exposure) or protein expression of NADPH oxidase II (NOX II) and superoxide dismutase (SOD). Microvascular endothelial cells were subjected to high physiological laminar shear stress (20 dyn/cm2) or static condition and treated with ANG II + pharmacological inhibitors. Cells were analyzed for the detection of ROS or collected for Western blot determination of NOX II and SOD. Resistance arteries from exercised mice demonstrated preserved FID after high pressure exposure, whereas FID was impaired in control mouse arteries. Inhibition of ANG II or NOX II restored impaired FID in control mouse arteries. High pressure increased superoxide levels in control mouse arteries but not in exercise mouse arteries, which exhibited greater ability to convert superoxide to H2O2 Arteries from exercised mice exhibited less NOX II protein expression, more SOD isoform expression, and less sensitivity to ANG II. Endothelial cells subjected to laminar shear stress exhibited less NOX II subunit expression. In conclusion, aerobic exercise prevents high pressure-induced vascular dysfunction through an improved redox environment in the adipose microvasculature.NEW & NOTEWORTHY We describe potential mechanisms contributing to aerobic exercise-conferred protection against high intravascular pressure. Subcutaneous adipose microvessels from exercise mice express less NADPH oxidase (NOX) II and more superoxide dismutase (SOD) and demonstrate less sensitivity to ANG II. In microvascular endothelial cells, shear stress reduced NOX II but did not influence SOD expression.


Asunto(s)
Tejido Adiposo/irrigación sanguínea , Tejido Adiposo/fisiología , Ejercicio Físico/fisiología , Microvasos/fisiología , Estrés Oxidativo/fisiología , Bloqueadores del Receptor Tipo 2 de Angiotensina II/farmacología , Animales , Arterias/fisiología , Presión Sanguínea/fisiología , Células Endoteliales/efectos de los fármacos , Miembro Posterior/irrigación sanguínea , Humanos , Masculino , Glicoproteínas de Membrana/antagonistas & inhibidores , Glicoproteínas de Membrana/genética , Ratones , Ratones Endogámicos C57BL , NADPH Oxidasa 2 , NADPH Oxidasas/antagonistas & inhibidores , NADPH Oxidasas/genética , Superóxido Dismutasa/antagonistas & inhibidores , Superóxido Dismutasa/genética , Resistencia Vascular
9.
Biochem Biophys Res Commun ; 473(1): 1-7, 2016 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-26975472

RESUMEN

Vertebrate lens is one of the tissues with the highest soluble protein concentration. The predominant soluble proteins in lens fiber cells are crystallins, and among them, α-crystallins belong to the small heat shock protein family with chaperone-like activity. Although α-crystallins are highly soluble in waters, α-crystallins have been detected in the membrane-bound fraction of lens, which will increase in the aged or cataractous lens. In this research, we found αA-crystallin exhibited a complex thermal transition with remarkable changes in secondary and quaternary structures. Treatment of αA-crystallin at high temperatures induced larger oliogomers with higher hydrophobic exposure. Both heat-treated and untreated αA-crystallin could insert into lipid monolayer directly as revealed by monolayer surface pressure experiments. Heat-treatment facilitated the membrane insertion of αA-crystallin and increased the membrane-bound fraction in the cells. The membrane-binding ability of αA-crystallin could be altered by cataract-causing mutations R116C, R116H and Y118D. Our results suggested that the irreversible changes in oligomer size induced by various stresses might promote the membrane association of αA-crystallin and therefore might play a role in aged cataract. Alternations in the membrane binding ability of α-crystallins might be important to the understanding of both aged and congenital cataracts.


Asunto(s)
Membrana Celular/química , Cristalinas/química , 1,2-Dipalmitoilfosfatidilcolina/química , Animales , Catarata/metabolismo , Bovinos , Cromatografía , ADN Complementario/metabolismo , Células HeLa , Proteínas de Choque Térmico/química , Humanos , Lípidos/química , Microscopía Fluorescente , Mutación , Fosfatidilserinas/química , Presión , Unión Proteica , Estructura Cuaternaria de Proteína , Estructura Secundaria de Proteína , Albúmina Sérica Bovina/química , Temperatura
10.
Microcirculation ; 22(1): 44-53, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25155427

RESUMEN

BACKGROUND AND AIMS: The hypothesis of this study was that microvascular FID and AChID is impaired in visceral (VAT) compared to SAT arterioles in morbidly obese women. An Additional aim was to determine the mechanisms contributing to FID and AChID in VAT and SAT arterioles. METHODS AND RESULTS: Arterioles were obtained from SAT and VAT biopsies from women (BMI > 35 kg/m(2) ) undergoing bariatric surgery. Microvessels were cannulated for reactivity measurements in response to flow (pressure gradients of 10-100 cmH2 O) and to ACh (10(-9) -10(-4 ) M) with and without l-NAME, INDO, and PEG-catalase. NO and H2 O2 generation were detected in arterioles by fluorescence microscopy. FID and AChID of arterioles from VAT were reduced compared to SAT arterioles. In SAT arterioles, l-NAME, INDO, and PEG-catalase significantly reduced FID and AChID but had no effect individually on VAT arterioles' vasodilator reactivity. INDO +l-NAME reduced FID in VAT arterioles. NO-fluorescence was greater in arterioles from SAT compared to VAT arterioles. Vascular H2 O2 generation during flow was similar in both VAT and SAT. CONCLUSION: Our results suggest that VAT arterioles display reduced vasodilator reactivity to flow and ACh compared to SAT arterioles, mediated by different regulatory mechanisms in human obesity.


Asunto(s)
Acetilcolina/farmacología , Grasa Intraabdominal/irrigación sanguínea , Obesidad Mórbida/fisiopatología , Grasa Subcutánea/irrigación sanguínea , Vasodilatación/efectos de los fármacos , Vasodilatadores/farmacología , Adulto , Arteriolas/patología , Arteriolas/fisiopatología , Velocidad del Flujo Sanguíneo/efectos de los fármacos , Femenino , Humanos , Grasa Intraabdominal/patología , Grasa Intraabdominal/fisiopatología , Persona de Mediana Edad , Obesidad Mórbida/patología , Grasa Subcutánea/patología , Grasa Subcutánea/fisiopatología
11.
Nat Commun ; 15(1): 6435, 2024 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-39085303

RESUMEN

The direct co-conversion of methane and carbon dioxide into valuable chemicals has been a longstanding scientific pursuit for carbon neutrality and combating climate change. Herein, we present a photo-driven chemical process that reforms these two major greenhouse gases together to generate green methanol and CO, two high-valued industrial chemicals. Isotopic labeling and control experiments indicate an oxygen-atom-graft occurs, wherein CO2 transfers one O into the C-H bond of CH4 via photo-activated interfacial catalysis with AuPd nanoparticles supported on GaN. The photoexcited AuPd/GaN interface effectively orchestrates the CH4 oxidation and the CO2 reduction producing 13.66 mmol g-1 of CH3OH yield over 10 h. This design provides a solid scientific basis for the photo-driven oxygen-atom-grafting process to be further extended to visible light region.

12.
Front Cell Dev Biol ; 11: 1214450, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37675144

RESUMEN

Central nervous system disorders significantly affect the lives and health of millions of people worldwide. Despite many therapeutic drugs are available that could potentially target central nervous system disorders, their clinical utility is severely constrained by their inability to cross the blood-brain barrier (BBB). Fortunately, nanotechnology has been advanced to offers a solution to allow drugs reaching the targeted brain regions safely, efficiently, and precisely through nasal drug delivery system (NDDS), bypassing the BBB completely. This strategy can promote the drug accumulated in the targeted brain region, improve drug bioavailability, and minimal side effects and mucociliary clearance effectively. In this review, we elaborate recent advances in the use of lipid-based nanoparticles, involving liposomes, nanoemulsions, nanostructured lipid carriers, and solid lipid nanoparticles. Besides, we particularly introduced the nasal cavity physiological structure, and further summarized the nose-to-brain drug delivery pathways, including olfactory, trigeminal, and blood circulation pathway. Moreover, the mechanism and route of NDDS by various types of nanoparticles are also highlighted.

13.
iScience ; 26(2): 105942, 2023 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-36711239

RESUMEN

The direct and selective transformation of naturally abundant methane (CH4) into high-value-added oxygenates, e.g., methanol, ethanol, and formic acid, is one of the "Holy Grails" in chemistry and chemical productions. However, complex mixtures of products, often due to over-oxidations, make such transformations highly challenging. Herein, gallium nitride (GaN), a methane-active semiconductor, catalyzes the photooxidation of methane and empowers the fine-controlling of chemoselectivity toward methanol and formic acids, simply by regulating the O2 content in water. In contrast to previous methods, no overoxidation products (CO2 and CO) were observed in this process. Mechanistic investigations and the corresponding quantitative experiments indicated that the controllable generation of moderately reactive oxygen radicals (•OOH and •OH) in combination with the direct methane activation triggered by GaN is responsible for the highly selective reactivity and tunability through a photo-generated radical process.

14.
STAR Protoc ; 4(3): 102530, 2023 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-37656629

RESUMEN

Herein, we present a protocol for the on-demand preparation of methanol and formic acid via selective photo-oxidation of methane with H2O and O2 catalyzed by GaN. The detailed photosyntheses of methanol or formic acid from CH4/H2O or CH4/H2O/O2 are described, respectively. In addition, we provide experimental details for the accurate quantifications of the final gas/liquid products and photoexcited oxygenated radicals. Finally, we deliver the procedure for scaling up the transformation. For complete details on the use and execution of this protocol, please refer to Han et al. (2023).1.


Asunto(s)
Formiatos , Metanol , Metano
15.
Precis Chem ; 1(7): 437-442, 2023 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-37771514

RESUMEN

The decarboxylative Minisci reaction is a versatile tool for the direct C-H alkylation of heteroarenes, where stoichiometric amounts of oxidants or expensive, precious metal reagents are commonly used. Herein, we reported a photodriven decarboxylative Minisci reaction enabled by a gallium nitride-based heterogeneous photocatalyst under mild conditions. This method can be effectively applied to a broad substrate scope of acids, including primary, secondary, and tertiary carboxylic acids and N-heteroarenes effectively. The practicability and robustness of the approach are demonstrated for the functionalization of biologically active compounds.

16.
Commun Chem ; 6(1): 181, 2023 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-37658203

RESUMEN

Alkanes are naturally abundant chemical building blocks that contain plentiful C(sp3)-H bonds. While inert, the activation of C(sp3)-H via hydrogen atom abstraction (HAT) stages an appealing approach to generate alkyl radicals. However, prevailing shortcomings include the excessive use of oxidants and alkanes that impede scope. We herein show the use of gallium nitride (GaN) as a non-toxic, recyclable, heterogeneous photocatalyst to enable alkyl C(sp3)-H in conjunction with the catalytic use of simple photosensitizer, benzophenone, to promote the desired alkyl radical generation. The dual photocatalytic cycle enables cross-dehydrogenative Minisci alkylation under mild and chemical oxidant-free conditions.

17.
Clin Respir J ; 16(11): 717-731, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36181340

RESUMEN

OBJECTIVES: This study aimed to present a review on the general effects of different positive end-expiratory pressure (PEEP) levels during thoracic surgery by qualitatively categorizing the effects into detrimental, beneficial, and inconclusive. DATA SOURCE: Literature search of Pubmed, CNKI, and Wanfang was made to find relative articles about PEEP levels during thoracic surgery. We used the following keywords as one-lung ventilation, PEEP, and thoracic surgery. RESULTS: We divide the non-individualized PEEP value into five grades, that is, less than 5, 5, 5-10, 10, and more than 10 cmH2 O, among which 5 cmH2 O is the most commonly used in clinic at present to maintain alveolar dilatation and reduce the shunt fraction and the occurrence of atelectasis, whereas individualized PEEP, adjusted by test titration or imaging method to adapt to patients' personal characteristics, can effectively ameliorate intraoperative oxygenation and obtain optimal pulmonary compliance and better indexes relating to respiratory mechanics. CONCLUSIONS: Available data suggest that PEEP might play an important role in one-lung ventilation, the understanding of which will help in exploring a simple and economical method to set the appropriate PEEP level.


Asunto(s)
Atelectasia Pulmonar , Cirugía Torácica , Humanos , Rendimiento Pulmonar , Respiración con Presión Positiva/métodos , Mecánica Respiratoria , Atelectasia Pulmonar/prevención & control
18.
Nurse Educ Today ; 112: 105336, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35378416

RESUMEN

BACKGROUND: It is crucial to diversify the methods for clinical nurses to continue learning nursing ethics in that ethical decision-making ability in nursing is regarded as one of the core competencies in nursing practice. OBJECTIVE: In response to nurses' learning needs for nursing ethics, this study built an online learning platform for the pertinent topic, and tested its effect on improving nurses' ethical decision-making ability and critical thinking ability. DESIGN: A qualitative method was adopted to develop interventions, which were designed as a teaching practice research consisting of a study group and a control group. PARTICIPANTS: A total of 93 nurses, including 20 interviewees and 30 in the study group and 43 in the control group. METHOD: Qualitative methods were employed to understand the learning needs of nurses. The judgment about nursing decisions and the critical thinking disposition inventory, learning effectiveness questionnaire and learning software quality evaluation scale were used as research tools in this teaching practice research. The SPSS 25.0 was adopted to analyze data by paired sample t-test and independent sample t-test. RESULTS: In the measurement of the judgment about nursing decisions scale, the study group scored higher than the control group. The critical thinking disposition inventory scale identified a similar result in the total score incorporating the four dimensions, including analyticity, systematicity, critical thinking self-confidence, inquisitiveness. There is a correlation between learning software quality and learning effect, with a correlation coefficient of 0.640. CONCLUSION: The online learning platform of nursing ethics built in this study has positive learning effects, and it demonstrates effectiveness to improve nurses' abilities in nursing ethics, decision-making and critical thinking. It is expected to be a viable way to improve the continuity of nurses' study of ethics.


Asunto(s)
Educación a Distancia , Ética en Enfermería , Estudiantes de Enfermería , Humanos , Aprendizaje , Pensamiento
19.
J Tradit Chin Med ; 42(2): 242-249, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35473345

RESUMEN

OBJECTIVE: To assess the efficacy and safety of ginger-indirect moxibustion for chronic fatigue syndrome (CFS). METHODS: In this central randomized, controlled trial, 290 CFS participants were recruited and randomly allocated to group A (ginger-indirect moxibustion plus acupuncture) or group B (acupuncture alone). The study consisted of a treatment period of 8 weeks with a total of 24 treatments (3 sessions per week, every other day), and a follow-up period of 12 weeks. The outcome was measured by Fatigue Severity Scale (FSS), Psychological Health Report (SPHERE), the Self-rating depression scale (SDS) and the Hamilton anxiety scale (HAMA) at baseline, 2, 4, 6, 8, 12 and 20 weeks. RESULTS: With the treatment undergoing, the changes of FSS, SPHERE, SDS and HAMA scores in both groups increased gradually, and the effect maintained at the 12th week. Between groups, significantly higher score changes were seen in group A in FSS after 4 weeks treatment (11.94 9.12, 95%: 0.94, 4.7) and in SPHERE after 2 weeks treatment (3.7 2.27, 95%: 0.56, 2.31). But for SDS and HAMA, the improvement did not differ significantly between groups. No severe adverse events were reported. CONCLUSION: Ginger-indirect moxibustion is a safe and effective intervention to relieve fatigue and accompanying physical symptoms of CFS.


Asunto(s)
Terapia por Acupuntura , Síndrome de Fatiga Crónica , Moxibustión , Zingiber officinale , Terapia por Acupuntura/efectos adversos , Síndrome de Fatiga Crónica/diagnóstico , Síndrome de Fatiga Crónica/psicología , Síndrome de Fatiga Crónica/terapia , Humanos , Resultado del Tratamiento
20.
Biochim Biophys Acta ; 1804(4): 948-56, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20079887

RESUMEN

alpha-crystallin is a molecular chaperone that maintains the optical properties of the lens and delays the onset scattering caused by aging-related protein aggregation. In this research, we found that the missense mutation R116H resulted in an altered size distribution, impaired packing of the secondary structures and modified quaternary structure with great hydrophobic exposure. The mutant exhibited a substrate-dependent chaperone (aggregation-inhibition) or anti-chaperone (aggregation-promotion) effect. Equilibrium unfolding experiments indicated that the mutation stabilized an aggregation-prone intermediate which was not populated during the unfolding of the wild-type protein. The accumulation of this intermediate greatly promoted the formation of non-native large oligomers or aggregates during unfolding. These results suggested that both the aggregation of the mutant upon stress and co-deposition with the target proteins were likely to be responsible for the onset of cataract.


Asunto(s)
Catarata/congénito , Catarata/genética , Cristalinas/química , Cristalinas/genética , Proteínas Mutantes/química , Proteínas Mutantes/genética , Sustitución de Aminoácidos , Catarata/metabolismo , Dicroismo Circular , Cristalinas/metabolismo , Guanidina , Humanos , Técnicas In Vitro , Modelos Biológicos , Chaperonas Moleculares/química , Chaperonas Moleculares/genética , Chaperonas Moleculares/metabolismo , Peso Molecular , Proteínas Mutantes/metabolismo , Mutación Missense , Desnaturalización Proteica , Pliegue de Proteína , Multimerización de Proteína , Estabilidad Proteica , Estructura Cuaternaria de Proteína , Estructura Secundaria de Proteína , Estructura Terciaria de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Respuesta de Proteína Desplegada
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