Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 3 de 3
Filtrar
Mais filtros












Base de dados
Intervalo de ano de publicação
1.
Light Sci Appl ; 13(1): 44, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38311617

RESUMO

Benefitting from narrow beam divergence, photonic crystal surface-emitting lasers are expected to play an essential role in the ever-growing fields of optical communication and light detection and ranging. Lasers operating with 1.55 µm wavelengths have attracted particular attention due to their minimum fiber loss and high eye-safe threshold. However, high interband absorption significantly decreases their performance at this 1.55 µm wavelength. Therefore, stronger optical feedback is needed to reduce their threshold and thus improve the output power. Toward this goal, photonic-crystal resonators with deep holes and high dielectric contrast are often used. Nevertheless, the relevant techniques for high-contrast photonic crystals inevitably complicate fabrication and reduce the final yield. In this paper, we demonstrate the first continuous-wave operation of 1.55 µm photonic-crystal surface-emitting lasers by using a 'triple-lattice photonic-crystal resonator', which superimposes three lattice point groups to increase the strength of in-plane optical feedback. Using this geometry, the in-plane 180° coupling can be enhanced threefold compared to the normal single-lattice structure. Detailed theoretical and experimental investigations demonstrate the much lower threshold current density of this structure compared to 'single-lattice' and 'double-lattice' photonic-crystal resonators, verifying our design principles. Our findings provide a new strategy for photonic crystal laser miniaturization, which is crucial for realizing their use in future high-speed applications.

2.
BMC Cardiovasc Disord ; 23(1): 293, 2023 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-37296380

RESUMO

BACKGROUND: In recent years, the incidence of diabetes mellitus has been increasing annually, and cardiovascular complications secondary to diabetes mellitus have become the leading cause of death in diabetic patients. Considering the high incidence of type 2 diabetes (T2DM) combined with cardiovascular disease (CVD), some new hypoglycemic agents with cardiovascular protective effects have attracted extensive attention. However, the specific role of these regimens in ventricular remodeling remains unknown. The purpose of this network meta-analysis was to compare the effects of sodium glucose cotransporter type 2 inhibitor (SGLT-2i), glucagon-like peptide 1 receptor agonist (GLP-1RA) and dipeptidyl peptidase-4 inhibitor (DPP-4i) on ventricular remodeling in patients with T2DM and/or CVD. METHODS: Articles published prior to 24 August 2022 were retrieved in four electronic databases: the Cochrane Library, Embase, PubMed, and Web of Science. This meta-analysis included randomized controlled trials (RCTs) and a small number of cohort studies. The differences in mean changes of left ventricular ultrasonic parameters between the treatment and control groups were compared. RESULTS: A total of 31 RCTs and 4 cohort studies involving 4322 patients were analyzed. GLP-1RA was more significantly associated with improvement in left ventricular end-systolic diameter (LVESD) [MD = -0.38 mm, 95% CI (-0.66, -0.10)] and LV mass index (LVMI) [MD = -1.07 g/m2, 95% CI (-1.71, -0.42)], but significantly decreased e' [MD = -0.43 cm/s 95% CI (-0.81, -0.04)]. DPP-4i was more strongly associated with improvement in e' [MD = 3.82 cm/s, 95% CI (2.92,4.7)] and E/e'[MD = -5.97 95% CI (-10.35, -1.59)], but significantly inhibited LV ejection fraction (LVEF) [MD = -0.89% 95% CI (-1.76, -0.03)]. SGLT-2i significantly improved LVMI [MD = -0.28 g/m2, 95% CI (-0.43, -0.12)] and LV end-diastolic diameter (LVEDD) [MD = -0.72 ml, 95% CI (-1.30, -0.14)] in the overall population, as well as E/e' and SBP in T2DM patients combined with CVD, without showing any negative effect on left ventricular function. CONCLUSION: The results of the network meta-analysis provided high certainty to suggest that SGLT-2i may be more effective in cardiac remodeling compared to GLP-1RA and DPP-4i. While GLP-1RA and DPP-4i may have a tendency to improve cardiac systolic and diastolic function respectively. SGLT-2i is the most recommended drug for reversing ventricular remodeling in this meta-analysis.


Assuntos
Doenças Cardiovasculares , Diabetes Mellitus Tipo 2 , Inibidores da Dipeptidil Peptidase IV , Humanos , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/tratamento farmacológico , Doenças Cardiovasculares/prevenção & controle , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Inibidores da Dipeptidil Peptidase IV/farmacologia , Receptor do Peptídeo Semelhante ao Glucagon 1/agonistas , Hipoglicemiantes/farmacologia , Metanálise em Rede , Inibidores de Proteases/farmacologia , Remodelação Ventricular
3.
Biomed Res Int ; 2014: 616018, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25243161

RESUMO

AIMS: To investigate the impact of blood type, functional polymorphism (T-1676C) of the COX-1 gene promoter, and clinical factors on the development of peptic ulcer during cardiovascular prophylaxis with low-dose aspirin. METHODS: In a case-control study including 111 low-dose aspirin users with peptic ulcers and 109 controls (asymptomatic aspirin users), the polymorphism (T-1676C) of the COX-1 gene promoter was genotyped, and blood type, H pylori status, and clinical factors were assessed. RESULTS: Univariate analysis showed no significant differences in genotype frequencies of the COX-1 gene at position -1676 between the peptic ulcer group and control group. Multivariate analysis revealed that blood type O, advanced age, history of peptic ulcer, and concomitant use of NSAID were the independent risk factors for the development of peptic ulcer with the odds ratios of the 2.1, 3.1, 27.6, and 2.9, respectively. CONCLUSION: The C-1676T polymorphism in the COX-1 gene promoter is not a risk factor for ulcer formation during treatment with low-dose aspirin. Blood type O, advanced age, history of peptic ulcer, and concomitant use of NSAID are of independent significance in predicting peptic ulcer development during treatment with low-dose aspirin.


Assuntos
Sistema ABO de Grupos Sanguíneos/fisiologia , Aspirina/efeitos adversos , Ciclo-Oxigenase 1/genética , Úlcera Péptica/epidemiologia , Polimorfismo Genético/genética , Regiões Promotoras Genéticas/genética , Idoso , Idoso de 80 Anos ou mais , Aspirina/uso terapêutico , Doenças Cardiovasculares/tratamento farmacológico , Doenças Cardiovasculares/prevenção & controle , Estudos de Casos e Controles , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Úlcera Péptica/induzido quimicamente , Úlcera Péptica/genética , Fatores de Risco
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...