Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 42
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
BMC Cardiovasc Disord ; 22(1): 494, 2022 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-36404328

RESUMO

BACKGROUND: In patients with heart failure, anxiety disorder is common and associated with adverse prognosis. This study intended to find more confounding factors of Chinese heart failure patients. METHODS: We enrolled 284 hospitalized heart failure patients, whose New York Heart Association (NYHA) classed as II-IV and left ventricular ejection fraction (LVEF) ≤ 45%. All the patients were scaled in Hamilton Rating Scale for Anxiety (14-items) (HAM-A14). Ordinal logistic regression analysis was performed to examine the association of correlated factors with anxiety disorder. RESULTS: There were 184 patients had anxiety accounting for 64.8% of all 284 hospitalized heart failure patients. The neutrophilic granulocyte percentage, urea nitrogen, total bilirubin and brain natriuretic peptide were positively associated with HAM-A14 score, meanwhile, the hemoglobin, red blood cells counts, albumin and LVEF were negatively associated with HAM-A14 score (All P < 0.05). After the adjustments of sex, hemoglobin, urea nitrogen, total bilirubin, albumin and brain natriuretic peptide, the neutrophilic granulocyte percentage was significantly associated with anxiety (OR = 43.265, P = 0.012). The neutrophilic granulocyte percentage was 0.616 ± 0.111, 0.640 ± 0.102, 0.681 ± 0.106 and 0.683 ± 0.113 in heart failure patients with no anxiety, possible anxiety, confirmed anxiety and obvious anxiety, respectively. CONCLUSIONS: Neutrophilic granulocyte percentage as well as the traditional risk factors such as sex, urea nitrogen and brain natriuretic peptide is associated with anxiety in hospitalized heart failure patients.


Assuntos
Insuficiência Cardíaca , Peptídeo Natriurético Encefálico , Humanos , Volume Sistólico , Função Ventricular Esquerda , Insuficiência Cardíaca/diagnóstico , Transtornos de Ansiedade , Granulócitos/química , Bilirrubina , Albuminas/análise , Nitrogênio/análise , China/epidemiologia , Ureia
2.
Org Lett ; 24(35): 6449-6454, 2022 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-36040361

RESUMO

We report the (R)-3,3'-I2-BINOL-boron-complex-catalyzed asymmetric 1,3-dipolar cycloaddition of 2'-hydroxychalcones with N,N'-cyclic azomethine imines, providing the corresponding N,N'-bicyclic pyrazolidine derivatives with three contiguous tertiary stereocenters in high yields with excellent diastereo- and enantioselectivities (up to >99:1 diastereomeric ratio and >99% enantiomeric excess). This catalytic system exhibits advantages of mild reaction conditions, high efficiency, and broad substrate scopes.

3.
J Org Chem ; 87(14): 9197-9209, 2022 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-35749308

RESUMO

Herein, we report the enantioselective conjugate addition of organic boronic acids to α,ß-unsaturated 2-acyl imidazoles using (R)-3,3'-I2-BINOL as the catalyst. The catalytic system shows high efficiency and tolerance to alkenylboronic acids and heteroarylboronic acids. The corresponding Michael addition products were obtained in moderate to excellent yields and with moderate to excellent enantioselectivities (up to 97% ee). A gram-scale reaction was also conducted, and the desired product was obtained in high yield with no erosion in enantioselectivity. Finally, the synthetic utility of the methodology was demonstrated by transforming the 2-acyl imidazole moiety to the corresponding aldehyde, carboxylic acid, ester, and amide derivatives.


Assuntos
Ácidos Borônicos , Imidazóis , Catálise , Estrutura Molecular , Estereoisomerismo
4.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-934576

RESUMO

The present pandemic prevention and control of 2019 novel coronavirus diseases(COVID-19) is still severe in China and abroad, which is however witnessing a dimensional application and success of the information technology.For example, the remote consultation system of epidemic prevention and control had played a key role in Henan province in its fight against COVID-19. The architecture of the system was composed of software and hardware architecture, data exchange technology, security system design, and data collection specifications. By the end of September 2021, the audio and video systems of 147 designated hospitals for patients of COVID-19 had been constructed, and 98 of which had achieved clinical data sharing and interaction. The remote consultation system effectively guaranteed the real-time sharing of case data, saved diagnosis costs and treatment time, laying a solid foundation for the pandemic prevention and control of COVID-19.

5.
J Org Chem ; 86(24): 18211-18223, 2021 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-34818889

RESUMO

We report herein the (R)-3,3'-Br2-BINOL-catalyzed enantioselective conjugate addition of organic boronic acids to ß,γ-unsaturated α-ketoesters to generate the corresponding Michael addition products in moderate to high yields and with moderate to excellent enantioselectivities (up to 99% ee). This catalytic system features characteristics of mild reaction conditions, high efficiency, and tolerance to alkenylboronic acids and heteroarylboronic acids.


Assuntos
Ácidos Borônicos , Ésteres , Catálise , Estereoisomerismo
6.
Angew Chem Int Ed Engl ; 60(51): 26694-26701, 2021 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-34643975

RESUMO

It usually requires high temperature and high pressure to reform methanol with water to hydrogen with high turnover frequency (TOF). Here we show that hydrogen can be produced from alkaline methanol on a light-triggered multi-layer system with a very high hydrogen evolution rate up to ca. 1 µmol s-1 under the illumination of a standard Pt-decorated carbon nitride. The system can achieve a remarkable TOF up to 1.8×106  moles of hydrogen per mole of Pt per hour under mild conditions. The total turnover number (TTN) of 470 000 measured over 38 hours is among the highest reported. The system does not lead to any COx emissions, hence it could feed clean hydrogen to fuel cells. In contrast to a slurry system, the proposed multi-layer system avoids particle aggregation and effectively uses light and Pt active sites. The performance is also attributed to the light-triggered reforming of alkaline methanol. This notable performance is a promising step toward practical light-driven hydrogen generation.

7.
ChemSusChem ; 14(11): 2308-2312, 2021 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-33909345

RESUMO

Simultaneous reductive amination of C=O and C-OH in 5-hydroxymethylfurfural (HMF) into C-NH2 in 2,5-bis(aminomethyl)furan (BAMF) is challenging. In this work, reductive amination of C=O in HMF was firstly studied, in which HMF can be converted into 5-hydroxymethyl furfurylamine (HMFA) with a 99.5 % yield over Raney Co catalyst. BAMF was then directly synthesized with 82.3 % yield from HMF over Raney Ni catalyst at 160 °C for 12 h. An even higher yield of 88.3 % could be obtained through a stepwise reductive amination process, in which the reaction started at 120 °C for the first 2 h over Raney Co mainly for amination of C=O and then continued at 160 °C for another 10 h over Raney Ni mainly for amination of C-OH. Under optimized reaction conditions, the catalyst could be reused four times without obvious loss in catalytic performance. XRD and XPS characterization of the reused catalyst indicated that the formation of Ni3 N and the adsorption of alkyl amines could be the main reasons for the deactivation of the catalyst. Moreover, plausible reaction pathways were proposed to originate the detected by-products according to the kinetic profiles.

8.
Brain Res Bull ; 159: 53-60, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32272155

RESUMO

Sepsis-associated encephalopathy (SAE) often leads to cognitive impairments in the rest life of septic survivors. The potential pathological changes of SAE are complicated and have not been fully understood. Morin, a flavone compound exhibiting neuroprotective activity and anti-inflammation effect, was employed to treat with CLP-induced septic mice in our study. The data from a novel object recognition test and tail suspension test indicated that morin treatment reversed cognitive dysfunction and relieved depressive-like behaviors in septic mice. Morin down-regulated the expressions of IL-6, MCP-1, TNF-α and IL-10 in serum and diminished microglia activation in septic mice. Additionally, Western blot results showed that morin reduced the phosphokinase GSK3ß activity and elevated the phosphatase PP2A activity, which led to lower tau phosphorylation. Morin reduced Aß deposition and protected the synapse integrity, which might be the possible mechanism of protecting cognitive functions in septic mice. In conclusion, we identified that morin exerted anti-inflammation and anti-neurodegeneration effects in septic mice, and prevented further cognitive impairments.


Assuntos
Disfunção Cognitiva/prevenção & controle , Modelos Animais de Doenças , Flavonoides/uso terapêutico , Fármacos Neuroprotetores/uso terapêutico , Encefalopatia Associada a Sepse/prevenção & controle , Sepse/tratamento farmacológico , Animais , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/metabolismo , Flavonoides/farmacologia , Mediadores da Inflamação/antagonistas & inibidores , Mediadores da Inflamação/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Fármacos Neuroprotetores/farmacologia , Sepse/complicações , Sepse/metabolismo , Encefalopatia Associada a Sepse/etiologia , Encefalopatia Associada a Sepse/metabolismo
9.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-872317

RESUMO

Driven by demand and policy guidance, the construction of Internet hospitals is on a fast track mode in China. To address such a situation, the state requires that before Internet hospitals are admitted, the provincial health authorities should establish an Internet medical service supervision platform to interconnect with the Internet hospital information platform for real-time supervision. This study discussed and introduced the Internet medical service supervision platform in Henan province, covering its system architecture, functions, regulatory indicators and operation mode. The platform is officially in operation and has completed docking with 7 medical institutions. It can implement entire process supervision with a total of 186 indicators in five categories in Henan, providing a reference for the construction of Internet medical service supervision platforms in other provinces.

10.
Angew Chem Int Ed Engl ; 58(46): 16558-16562, 2019 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-31433100

RESUMO

The growing demand for perovskite nanocrystals (NCs) for various applications has stimulated the development of facile synthetic methods. Perovskite NCs have often been synthesized by either ligand-assisted reprecipitation (LARP) at room temperature or by hot-injection at high temperatures and inert atmosphere. However, the use of polar solvents in LARP affects their stability. Herein, we report on the spontaneous crystallization of perovskite NCs in nonpolar organic media at ambient conditions by simple mixing of precursor-ligand complexes without application of any external stimuli. The shape of the NCs can be controlled from nanocubes to nanoplatelets by varying the ratio of monovalent (e.g. formamidinium+ (FA+ ) and Cs+ ) to divalent (Pb2+ ) cation-ligand complexes. The precursor-ligand complexes are stable for months, and thus perovskite NCs can be readily prepared prior to use. Moreover, we show that this versatile synthetic process is scalable and generally applicable for perovskite NCs of different compositions.

11.
Science ; 361(6405): 904-908, 2018 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-30166487

RESUMO

The combination of hybrid perovskite and Cu(In,Ga)Se2 (CIGS) has the potential for realizing high-efficiency thin-film tandem solar cells because of the complementary tunable bandgaps and excellent photovoltaic properties of these materials. In tandem solar device architectures, the interconnecting layer plays a critical role in determining the overall cell performance, requiring both an effective electrical connection and high optical transparency. We used nanoscale interface engineering of the CIGS surface and a heavily doped poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) hole transport layer between the subcells that preserves open-circuit voltage and enhances both the fill factor and short-circuit current. A monolithic perovskite/CIGS tandem solar cell achieved a 22.43% efficiency, and unencapsulated devices under ambient conditions maintained 88% of their initial efficiency after 500 hours of aging under continuous 1-sun illumination.

12.
Adv Mater ; : e1801117, 2018 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-29870579

RESUMO

Self-assembly of nanoscale building blocks into ordered nanoarchitectures has emerged as a simple and powerful approach for tailoring the nanoscale properties and the opportunities of using these properties for the development of novel optoelectronic nanodevices. Here, the one-pot synthesis of CsPbBr3 perovskite supercrystals (SCs) in a colloidal dispersion by ultrasonication is reported. The growth of the SCs occurs through the spontaneous self-assembly of individual nanocrystals (NCs), which form in highly concentrated solutions of precursor powders. The SCs retain the high photoluminescence (PL) efficiency of their NC subunits, however also exhibit a redshifted emission wavelength compared to that of the individual nanocubes due to interparticle electronic coupling. This redshift makes the SCs pure green emitters with PL maxima at ≈530-535 nm, while the individual nanocubes emit a cyan-green color (≈512 nm). The SCs can be used as an emissive layer in the fabrication of pure green light-emitting devices on rigid or flexible substrates. Moreover, the PL emission color is tunable across the visible range by employing a well-established halide ion exchange reaction on the obtained CsPbBr3 SCs. These results highlight the promise of perovskite SCs for light emitting applications, while providing insight into their collective optical properties.

13.
Nat Commun ; 9(1): 1518, 2018 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-29666394

RESUMO

Multi-photon absorption and multiple exciton generation represent two separate strategies for enhancing the conversion efficiency of light into usable electric power. Targeting below-band-gap and above-band-gap energies, respectively, to date these processes have only been demonstrated independently. Here we report the combined interaction of both nonlinear processes in CsPbBr3 perovskite nanocrystals. We demonstrate nonlinear absorption over a wide range of below-band-gap excitation energies (0.5-0.8 Eg). Interestingly, we discover high-order absorption processes, deviating from the typical two-photon absorption, at specific energetic positions. These energies are associated with a strong enhancement of the photoluminescence intensity by up to 105. The analysis of the corresponding energy levels reveals that the observed phenomena can be ascribed to the resonant creation of multiple excitons via the absorption of multiple below-band-gap photons. This effect may open new pathways for the efficient conversion of optical energy, potentially also in other semiconducting materials.

14.
J Huazhong Univ Sci Technolog Med Sci ; 37(5): 642-648, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29058275

RESUMO

The purpose of this study was to investigate the existence and extent of cognitive impairment in adult diabetes mellitus (DM) patients with episodes of recurrent severe hypoglycemia, by using meta-analysis to synthesize data across studies. PubMed, EMBASE and Cochrane library search engines were used to identify studies on cognitive performance in DM patients with recurrent severe hypoglycemia. Random-effects meta-analysis was performed on seven eligible studies using an inverse-variance method. Effect sizes, which are the standardized differences between the experimental group and the control group, were calculated. Of the 853 studies, 7 studies met the inclusion criteria. Compared with control subjects, the adult DM patients with episodes of recurrent severe hypoglycemia demonstrated a significantly lowered performance on memory in both types of DM patients, and poor performance of processing speed in type 2 DM patients. There was no significant difference between adult DM patients with and those without severe hypoglycemia in other cognitive domains such as general intelligence, executive function, processing speed and psychomotor efficiency. Our results seem to confirm the hypothesis that cognitive dysfunction is characterized by worse memory and processing speed in adult DM patients with a history of recurrent severe hypoglycemia, whereas general intelligence, executive function, and psychomotor efficiency are spared.


Assuntos
Transtornos Cognitivos/etiologia , Diabetes Mellitus Tipo 2/complicações , Hipoglicemia/complicações , Adulto , Diabetes Mellitus Tipo 2/psicologia , Feminino , Humanos , Hipoglicemia/psicologia , Inteligência , Masculino , Memória , Testes Neuropsicológicos
15.
Adv Mater ; 29(23)2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28394472

RESUMO

Inorganic metal halide perovskite nanocrystals (NCs) have been employed universally in light-emitting applications during the past two years. Here, blue-emission (≈470 nm) Cs-based perovskite NCs are derived by directly mixing synthesized bromide and chloride nanocrystals with a weight ratio of 2:1. High-brightness blue perovskite light-emitting diodes (PeLEDs) are obtained by controlling the grain size of the perovskite films. Moreover, a white PeLED is demonstrated for the first time by blending orange polymer materials with the blue perovskite nanocrystals as the active layer. Exciton transfer from the blue nanocrystals to the orange polymers via Förster or Dexter energy transfer is analyzed through time resolved photoluminescence. By tuning the ratio between the perovskite nanocrystals and polymers, pure white light is achieved with the a CIE coordinate at (0.33,0.34).

16.
Nano Lett ; 17(4): 2328-2335, 2017 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-28248512

RESUMO

In planar n-i-p heterojunction perovskite solar cells, the electron transport layer (ETL) plays important roles in charge extraction and determine the morphology of the perovskite film. Here, we report a solution-processed carbon quantum dots (CQDs)/TiO2 composite that has negligible absorption in the visible spectral range, a very attractive feature for perovskite solar cells. Using this novel CQDs/TiO2 ETL in conjunction with a planar n-i-p heterojunction, we achieved an unprecedented efficiency of ∼19% under standard illumination test conditions. It was found that a CQDs/TiO2 combination increases both the open circuit voltage and short-circuits current density as compared to using TiO2 alone. Various advanced spectroscopic characterizations including ultrafast spectroscopy, ultraviolet photoelectron spectroscopy, and electronic impedance spectroscopy elucidate that the CQDs increases the electronic coupling between the CH3NH3PbI3-xClx and TiO2 ETL interface as well as energy levers that contribute to electron extraction.

17.
Adv Mater ; 29(4)2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27879016

RESUMO

A formamidinium(FA)-based perovskite showns superior optoelectronic properties including better stability than methylammonium-based counterparts. Pure FA-perovskite-based light-emitting diodes (LEDs) with high efficiency are reported. Interestingly, the LED clearly shows a sub-bandgap emission at 1.7 V (bandgap 2.3 eV). This important discovery provides further insights of the charge transport mechanism in perovskite-based optoelectronic devices.

18.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-333447

RESUMO

The purpose of this study was to investigate the existence and extent of cognitive impairment in adult diabetes mellitus (DM) patients with episodes of recurrent severe hypoglycemia,by using meta-analysis to synthesize data across studies.PubMed,EMBASE and Cochrane library search engines were used to identify studies on cognitive performance in DM patients with recurrent severe hypoglycemia.Random-effects meta-analysis was performed on seven eligible studies using an inverse-variance method.Effect sizes,which are the standardized differences between the experimental group and the control group,were calculated.Of the 853 studies,7 studies met the inclusion criteria.Compared with control subjects,the adult DM patients with episodes of recurrent severe hypoglycemia demonstrated a significantly lowered performance on memory in both types of DM patients,and poor performance of processing speed in type 2 DM patients.There was no significant difference between adult DM patients with and those without severe hypoglycemia in other cognitive domains such as general intelligence,executive function,processing speed and psychomotor efficiency.Our results seem to confirm the hypothesis that cognitive dysfunction is characterized by worse memory and processing speed in adult DM patients with a history of recurrent severe hypoglycemia,whereas general intelligence,executive function,and psychomotor efficiency are spared.

19.
Sci Rep ; 6: 38569, 2016 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-27929053

RESUMO

In this study, we present a broadband nano-photodetector based on single-layer graphene (SLG)-carbon nanotube thin film (CNTF) Schottky junction. It was found that the as-fabricated device exhibited obvious sensitivity to a wide range of illumination, with peak sensitivity at 600 and 920 nm. In addition, the SLG-CNTF device had a fast response speed (τr = 68 µs, τf = 78 µs) and good reproducibility in a wide range of switching frequencies (50-5400 Hz). The on-off ratio, responsivity, and detectivity of the device were estimated to be 1 × 102, 209 mAW-1 and 4.87 × 1010 cm Hz1/2 W-1, respectively. What is more, other device parameters including linear performance θ and linear dynamic range (LDR) were calculated to be 0.99 and 58.8 dB, respectively, which were relatively better than other carbon nanotube based devices. The totality of the above study signifies that the present SLG-CNTF Schottky junction broadband nano-photodetector may have promising application in future nano-optoelectronic devices and systems.

20.
J Huazhong Univ Sci Technolog Med Sci ; 36(6): 785-790, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27924507

RESUMO

Neurofibrillary pathology of abnormally hyperphosphorylated tau is a hallmark of Alzheimer's disease (AD) and other tauopathies. Phosphatidylinositol 3-kinase (PI3K)/Akt/glycogen synthase kinase-3 beta (GSK-3ß) signaling pathway is pivotal for tau phosphorylation. Inhibition of soluble epoxide hydrolase (sEH) metabolism has been shown to effectively increase the accumulation of epoxyeicosatrienoic acids (EETs), which are cytochrome P450 metabolites of arachidonic acid and have been demonstrated to have neuroprotective effects. However, little is known about the role of sEH in tau phosphorylation. The present study investigated the role of a sEH inhibitor, 1-(1-propanoylpiperidin-4-yl)-3-[4-(trifluoromethoxy)phenyl] urea (TPPU), on H2O2-induced tau phosphorylation and the underlying signaling pathway in human embryonic kidney 293 (HEK293)/Tau cells. We found that the cell viability was increased after TPPU treatment compared to control in oxidative stress. Western blotting and immunofluorescence results showed that the levels of phosphorylated tau at Thr231 and Ser396 sites were increased in H2O2-treated cells but dropped to normal levels after TPPU administration. H2O2 induced an obvious decreased phosphorylation of GSK-3ß at Ser9, an inactive form of GSK-3ß, while there were no changes of phosphorylation of GSK-3ß at Tyr216. TPPU pretreatment maintained GSK-3ß Ser 9 phosphorylation. Moreover, Western blotting results showed that TPPU upregulated the expression of p-Akt. The protective effects of TPPU were found to be inhibited by wortmannin (WT, a specific PI3K inhibitor). In conclusion, these results suggested that the protective effect of TPPU on H2O2-induced oxidative stress is associated with PI3K/Akt/GSK-3ß pathway.


Assuntos
Compostos de Fenilureia/farmacologia , Piperidinas/farmacologia , Processamento de Proteína Pós-Traducional , Transdução de Sinais , Proteínas tau/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Glicogênio Sintase Quinase 3 beta/metabolismo , Células HEK293 , Humanos , Peróxido de Hidrogênio/toxicidade , Estresse Oxidativo , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...