RESUMO
In this Letter, we design and experimentally demonstrate compact mode converters with a lightning-like and arrow-like polygonal subwavelength grating (SWG) structure on a silicon-on-insulator (SOI) platform, which can convert the TE0 mode to the TE1 and TE2 modes, respectively. The footprints of the proposed TE0-1 and TE0-2 mode converters are only 4.44 × 1.3 and 5.89 × 1.8â µm2, respectively. The experimental results show the mode converters have a low insertion loss (<1â dB) and a broad bandwidth (>50â nm). The measured cross talks of the TE0-1 and TE0-2 mode converters are -7.2â dB and -10.3â dB, respectively. In addition, the proposed mode converters with the SWG structure have the advantage in fabrication, since only a one-step full-etching process is required.
RESUMO
Vertebral artery dissection is a rare pathology that can cause ischemic stroke in young people. Cervical massage, especially improper pulling manipulation, is a cause of vertebral artery dissection. We present a case of 32-year-old woman who developed acute multiple posterior circulation ischemic cerebral infarctions as a result of left vertebral artery V4 segment dissection after receiving neck massage. She underwent emergency vertebral artery stent implantation at the site of the dissection. Symptoms were relieved the day after treatment. The patient recovered without adverse complications or endovascular restenosis in the following year.
Assuntos
Infarto Cerebral , Massagem , Stents , Dissecação da Artéria Vertebral , Humanos , Feminino , Dissecação da Artéria Vertebral/diagnóstico por imagem , Dissecação da Artéria Vertebral/etiologia , Dissecação da Artéria Vertebral/cirurgia , Adulto , Stents/efeitos adversos , Massagem/efeitos adversos , Infarto Cerebral/etiologia , Infarto Cerebral/diagnóstico por imagem , Artéria Vertebral/diagnóstico por imagem , Artéria Vertebral/cirurgiaRESUMO
Objective: This study investigated how anticipated instrumental support sources and intergenerational support influence depressive symptoms in older Chinese adults. Methods: We employed binary logistic regression on data from 7,117 adults aged ≥60 in the 2018 China Health and Retirement Longitudinal Study, controlling for gender, marital status, and self-rated health. Results: 38.89% of respondents exhibited depressive symptoms. Anticipated support from spouse and children, spouse only, children only, or other sources showed 52, 25, 46, and 40% lower odds of depression, respectively, compared with no anticipated support. Those providing financial support had 36% higher odds of depression than those without exchanges. However, those receiving financial support, receiving instrumental support, and receiving and providing financial and emotional support had 19, 14, 23, and 24% lower odds of depression. Conclusion: Different anticipated instrumental support sources and intergenerational support influenced depression odds in older adults, suggesting potential benefits in promoting such support systems.
Assuntos
Depressão , Aposentadoria , Criança , Humanos , Pessoa de Meia-Idade , Idoso , Depressão/epidemiologia , Depressão/psicologia , Estudos Longitudinais , China/epidemiologia , Modelos LogísticosRESUMO
The gut-brain axis, which includes gut microbiota and microbiome-derived metabolites, might be implicated in depression. We reported the sustained prophylactic effects of a new antidepressant arketamine in chronic restrain stress (CRS) model of depression. In this study, we investigated the role of gut-brain axis on the prophylactic effects of arketamine in the CRS (7 days) model. Pretreatment with arketamine (10 mg/kg, 1 day prior to the CRS onset) significantly prevented CRS-induced body weight loss, increased immobility time of forced swimming test, decreased sucrose preference of sucrose preference test, and reduced expressions of synaptic proteins (GluA1 and PSD-95) in the prefrontal cortex (PFC) in the male mice. Gut microbiota analysis showed that pretreatment with arketamine might restore altered abundance of gut microbiota in CRS-exposed mice. An untargeted metabolomics analysis revealed four metabolites (e.g., L-leucine, N-acetyl-l-glutamine, 2-(2,4-dichlorophenyl)-3-[4-(dimethylamino)phenyl]acrylonitrile, L-threonine amide) that were altered between control and CRS group; however, there were found to be altered between the saline + CRS group and the arketamine + CRS group. Network analysis demonstrated correlations among synaptic proteins in the PFC and certain microbiota, and blood metabolites. These findings suggest that gut-brain axis, including its metabolites, might partially contribute to the persistent prophylactic effects of arketamine in the CRS model.
Assuntos
Eixo Encéfalo-Intestino , Depressão , Camundongos , Masculino , Animais , Depressão/tratamento farmacológico , Depressão/prevenção & controle , Antidepressivos/farmacologia , Córtex Pré-Frontal/metabolismo , Sacarose/farmacologia , Estresse Psicológico/metabolismoRESUMO
Purpose: The regularity of epidemic prevention and control measures in China has meant that nursing students have been exposed to more electronic devices, while problematic smartphone use has increased. The purpose of this study is to determine the prospective associations among time management tendency, negative emotions, and problematic smartphone use in nursing students during the COVID-19 pandemic. Methods: A longitudinal study was conducted between November 2021 and May 2022. A total of 989 nursing students participated. The convenience sampling method was adopted and the following tools were used: the Adolescence Time Management Disposition Scale, the Depression Anxiety Stress Scales - 21, and the Mobile Phone Addiction Index. Multiple parallel mediation models were used by Mplus. Results: Time management tendency had a significantly negative effect on problematic smartphone use (p < 0.05). Further tests using mediation models showed that stress as a negative emotion mediated the relationship between time management tendency and problematic smartphone use (p < 0.05) over time. Conclusion: Nursing educators need to strengthen the stress resistance and time management ability of nursing students.
Assuntos
COVID-19 , Estudantes de Enfermagem , Adolescente , Humanos , Gerenciamento do Tempo , Estudos Longitudinais , COVID-19/epidemiologia , Pandemias , Smartphone , China/epidemiologia , EmoçõesRESUMO
To achieve high power conversion efficiency in perovskite/silicon tandem solar cells, it is necessary to develop a promising wide-bandgap perovskite absorber and processing techniques in relevance. To date, the performance of devices based on wide-bandgap perovskite is still limited mainly by carrier recombination at their electron extraction interface. Here, we demonstrate assembling a binary two-dimensional perovskite by both alternating-cation-interlayer phase and Ruddlesden-Popper phase to passivate perovskite/C60 interface. The binary two-dimensional strategy takes effects not only at the interface but also in the bulk, which enables efficient charge transport in a wide-bandgap perovskite solar cell with a stabilized efficiency of 20.79% (1 cm2). Based on this absorber, a monolithic perovskite/silicon tandem solar cell is fabricated with a steady-state efficiency of 30.65% assessed by a third party. Moreover, the tandem devices retain 96% of their initial efficiency after 527 h of operation under full spectral continuous illumination, and 98% after 1000 h of damp-heat testing (85 °C with 85% relative humidity).
RESUMO
Wide-bandgap (WBG) absorbers in tandem configurations suffer from poor crystallinity and weak texture, which leads to severe mixed halide-cation ion migration and phase segregation during practical operation. We control WBG film growth insensitive to compositions by nucleating the 3C phase before any formation of bromine-rich aggregates and 2H phases. The resultant WBG absorbers show improved crystallinity and strong texture with suppressed nonradiative recombination and enhanced resistance to various aging stresses. Perovskite/silicon tandem solar cells achieve power conversion efficiencies of 29.4% (28.8% assessed by a third party) in a 25-square centimeter active area and 32.5% in a 1-square centimeter active area. These solar cells retained 98.3 and 90% of the original efficiency after 1301 and 800 hours of operation at 25° and 50°C, respectively, at the maximum power point (AM 1.5G illumination, full spectrum, 1-sun) when encapsulated.