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Low-dimensional semiconductor nanostructures, particularly in the form of nanowire configurations with large surface-to-volume-ratio, offer intriguing optoelectronic properties for the advancement of integrated photonic technologies. Here, a bias-controlled, superior dual-functional broadband light detecting/emitting diode enabled by constructing the aluminum-gallium-nitride-based nanowire on the silicon-platform is reported. Strikingly, the diode exhibits a stable and high responsivity (R) of over 200 mAW-1 covering an extremely wide operation band under reverse bias conditions, ranging from deep ultraviolet (DUV: 254 nm) to near-infrared (NIR: 1000 nm) spectrum region. While at zero bias, it still possesses superior DUV light selectivity with a high off-rejection ratio of 106. When it comes to the operation of the light-emitting mode under forward bias, it can achieve large spectral changes from UV to red simply by coating colloid quantum dots on the nanowires. Based on the multifunctional features of the diodes, this study further employs them in various optoelectronic systems, demonstrating outstanding applications in multicolor imaging, filterless color discrimination, and DUV/NIR visualization. Such highly responsive broadband photodetector with a tunable emitter enabled by III-V nanowire on silicon provides a new avenue toward the realization of integrated photonics and holds great promise for future applications in communication, sensing, imaging, and visualization.
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Single-photon detector (SPD), an essential building block of the quantum communication system, plays a fundamental role in developing next-generation quantum technologies. In this work, we propose an efficient modeling workflow of nanowire SPDs utilizing avalanche breakdown at reverse-biased conditions. The proposed workflow is explored to maximize computational efficiency and balance time-consuming drift-diffusion simulation with fast script-based post-processing. Without excessive computational effort, we could predict a suite of key device performance metrics, including breakdown voltage, dark/light avalanche built-up time, photon detection efficiency, dark count rate, and the deterministic part of timing jitter due to device structures. Implementing the proposed workflow onto a single InP nanowire and comparing it to the extensively studied planar devices and superconducting nanowire SPDs, we showed the great potential of nanowire avalanche SPD to outperform their planar counterparts and obtain as superior performance as superconducting nanowires, i.e. achieve a high photon detection efficiency of 70% with a dark count rate less than 20 Hz at non-cryogenic temperature. The proposed workflow is not limited to single-nanowire or nanowire-based device modeling and can be readily extended to more complicated two-/three dimensional structures.
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AIM: To explore the actual experience of psychological distress of adult women of reproductive age at different stages after breast cancer diagnosis. DESIGN: Qualitative. METHODS: Eighty-one patients with breast cancer-related distress thermometer scores >4 were selected using a purposive sampling method. Patients were divided into newly diagnosed and 1-, 3-, 6-, 9- and 12-month groups according to time since diagnosis and then interviewed. A phenomenological approach was adopted to analyse interview content, and different themes were extracted. RESULTS: Women exhibited different levels of psychological distress depending on the time since diagnosis, with newly diagnosed patients showing the highest distress. Within 1 year post-diagnosis, different events caused patients distress. Themes extracted at new diagnosis and 1-, 3-, 6-, 9- and 12 months post-diagnosis included sadness and disbelief, loss of control, optimistic but concerned, physical and mental exhaustion, difficulties returning to society and limited sexual intimacy, respectively; all groups expressed reproductive concerns. CONCLUSION: Clinical nurses should focus on different psychologically distressing events to provide targeted interventions at distinct phases. For women of childbearing age, clinical nurses should pay particular attention to patients' marriage and reproductive concerns. IMPLICATIONS FOR THE PROFESSION AND/OR PATIENT CARE: During the year after a breast cancer diagnosis, patients of childbearing age experience events that cause psychological distress that differ depending on time since diagnosis. Nurses should focus on core stressful events and perform specific nursing interventions. IMPACT: To provide holistic care, nurses should consider the psychological and emotional changes patients may undergo. For women of childbearing age, clinical nurses should pay particular attention to patients' marriage and fertility concerns, and be able to provide evidence-based professional guidance on reproductive preservation techniques. REPORTING METHOD: The study was reported using the consolidated criteria for reporting qualitative research guidelines. PATIENT OR PUBLIC CONTRIBUTION: Patients contributed to data collection through interviews.
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Neoplasias da Mama , Angústia Psicológica , Adulto , Humanos , Feminino , Neoplasias da Mama/psicologia , Pesquisa Qualitativa , Reprodução , CasamentoRESUMO
This study aims to summarize the changes of functional diffusion kurtosis imaging (DKI) parameters in the bilateral hippocampal CA1 region of the hemorrhagic shock reperfusion (HSR) model of rats and their correlation with cognitive dysfunction. Adult male Sprague-Dawley rats (9-10 weeks of age, weighing 350-400 g) were randomized into the HSR group (n = 30) and the sham-operated group (Sham) (n = 30). Rats in the HSR group and the Sham group were subdivided into five time points (1, 2, 4, 8, and 12 weeks) for examination. Diffusion kurtosis imaging (DKI) was performed. Cognitive dysfunction was analyzed by the Morris Water Maze. The correlation between the DKI parameters and cognitive dysfunction was analyzed by the Spearman correlation. In the HSR group, the values of axial kurtosis (Ka), radial kurtosis (Kr), and mean kurtosis (MK) in the bilateral hippocampal CA1 of rats at 1, 2, 4, 8 and 12 weeks after the surgery were significantly higher. The rats in the HSR group had significantly longer escape latency than in the Sham group. The rats in the HSR group had significantly shorter time and shorter distance in target quadrant than those in the Sham group. The escape latency had positive correlation with MK, Ka, and Kr. The distance and the time in target quadrant had negative correlation with MK, Ka, and Kr. The parameters get from the DKI could accurately evaluate the abnormal blood perfusion and microstructure changes in hippocampal CA1 area of the incomplete cerebral ischemia reperfusion rats induced by HSR. MK, Ka, and Kr values could reflect the decreased learning and memory ability in HSR rat model.
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Isquemia Encefálica , Disfunção Cognitiva , Ratos , Masculino , Animais , Ratos Sprague-Dawley , Reperfusão , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/etiologia , Região CA1 Hipocampal/diagnóstico por imagem , Imagem de Difusão por Ressonância MagnéticaRESUMO
Today, agricultural irrigation consumes the largest amount of freshwater globally, while humans are threatened by water scarcity. To eliminate the trade-off between hunger and thirst, here, we show off-grid maritime agriculture based on a floating solar-driven agro-desalination wooden dome. In this dome, part of the visible light is transmitted for photosynthesis, and the remaining solar energy drives solar desalination, providing enough water (>4 mm day-1) for irrigation. Based on this water-food synergy, the stages of germination and growth are demonstrated. This technology can, to a large extent, support food security and sustainable agriculture and, in principle, be used to create self-circulation systems at sea to help humans survive weather extremes such as floods and droughts.
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Agricultura , Abastecimento de Água , Humanos , Fazendas , Água , Oceanos e MaresRESUMO
PURPOSE: The aim of this study was to explore how family resilience and individual resilience reduce perceived stress and psychological distress in young female breast cancer survivors with fertility intention. METHODS: From June 2020 to June 2021, female breast cancer survivors were selected from the cancer centers of 10 tertiary Level A general hospitals in five cities of Sichuan Province. The survivors completed the Chinese versions of the Family Resilience Assessment Scale, Connor-Davidson Resilience Scale, Perceived Stress Scale, and a self-report distress thermometer. A multiple mediation effects test and structural equation modeling were used to explore the relationships among family resilience, individual resilience, perceived stress, and psychological distress. RESULTS: The direct effect of family resilience on perceived stress was ß = -0.320 (95% confidence interval -0.365, -0.271, P < 0.01). The direct effect of family resilience on psychological distress was ß = -0.263 (95% confidence interval -0.363, -0.153, P < 0.001). The direct effect of family resilience on individual resilience was ß = 0.593 (95% confidence interval 0.542-0.640, P < 0.001). The indirect effect of family resilience on psychological distress was ß = -0.322 (95% confidence interval -0.373, -0.274, P < 0.001). Both perceived stress and individual resilience mediated the relationship between family resilience and psychological distress. Furthermore, a partial mediating effect of perceived stress and individual resilience on family resilience and psychological distress was observed. CONCLUSION: Young female breast cancer survivors in China experience moderate levels of psychological distress.
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Neoplasias da Mama , Sobreviventes de Câncer , Resiliência Psicológica , Humanos , Feminino , Neoplasias da Mama/psicologia , Estudos Transversais , Sobreviventes de Câncer/psicologia , Saúde da Família , Sobreviventes/psicologia , Estresse Psicológico/etiologia , Estresse Psicológico/psicologiaRESUMO
BACKGROUND: An accurate assessment of teaching needs is necessary to ensure targeted teacher training programs are developed and implemented to improve teaching outcomes. The assessment of teaching needs from different perspectives helps to identify teaching needs more accurately. Therefore, based on the different perspectives of teachers and students, this study aimed to identify and evaluate the needs of community practice teachers by measuring discrepancies between perceived teaching importance and actual teaching performance, with a focus on the influencing factors. METHODS: A survey was circulated to 220 teachers in 36 community health service centers and 695 students in 6 medical schools in Southwest China. The participants anonymously completed the teacher or student version of the Chinese version of the Teacher Teaching Needs Questionnaire, which is predominantly used to assess the teaching needs of teachers. Both versions of the questionnaire include 27 items, covering 3 dimensions (including teaching skills, teaching environments, and teaching contents). The ordinal logistic regression was conducted to explore the factors that influenced teaching needs. RESULTS: The teachers and students produced overall self-evaluated teaching needs scores of 0.61 and 0.62 respectively. The teachers from provincial capital cities and low-educated teachers had teaching needs that are lower (OR = 0.641,95% CI: 0.461-0.902, OR = 15.352, 95% CI: 1.253-26.815, separately). Teachers with < 3 years of teaching experience had higher teaching needs (OR = 3.280, 95% CI: 1.153-10.075) than those with > 10 years of experience. Compared with teachers who self-evaluated their teaching outcomes as poor, those who reported extremely excellent (OR = 0.362, 95% CI: 0.220-0.701), excellent (OR = 0.638, 95% CI: 0.426-1.102), and ordinary (OR = 0.714, 95% CI: 0.508-1.034) teaching outcomes had lower teaching needs. Compared with teachers who self-evaluated their teaching abilities as poor, those who reported extremely excellent (OR = 0.536, 95% CI: 0.313-0.934), excellent (OR = 0.805, 95% CI: 0.518-1.269), and ordinary (OR = 0.737, 95% CI: 0.413-1.322) teaching abilities had lower teaching needs. CONCLUSIONS: Greater assistance should be provided to teachers with lower levels of education, fewer than three years of teaching experience, and who are located in non-capital cities, as these individuals require additional efforts to strengthen competencies. The education department should pay more attention to teacher feedback on practical outcomes and teaching abilities, as this can be used to devise the best teacher development plans. TRIAL REGISTRATION: Not applicable.
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Pessoal de Educação , Estudantes , Humanos , Estudos Transversais , Escolaridade , Serviços de Saúde ComunitáriaRESUMO
AIMS AND OBJECTIVES: This study examines the effects of family beliefs and family strength on individual resilience and quality of life among young breast cancer survivors and determines whether family strength mediates the effect of family beliefs on individual resilience and quality of life. BACKGROUND: Family beliefs and family strength are meaningful protective factors that help individuals maintain physical and mental health. However, few studies have explored their impact on individual resilience and quality of life. DESIGN: This study was conducted using a cross-sectional survey with a three-stage, stratified, convenience sampling approach following the STROBE guideline. METHODS: From August 2020 to May 2021, participants completed the shortened Chinese version of the Connor-Davidson Resilience Scale, the Chinese version of the Family Beliefs Scale, the Family Strength Scale and the Functional Assessment of Cancer Therapy-Breast scale. Structural equation modelling and multiple mediation effects test were used to explore the relationships among family beliefs, family strength, individual resilience and quality of life. RESULTS: The final model accounted for 44.5% and 78.1% of the total variance of individual resilience and quality of life, respectively. Family beliefs had an indirect effect on both individual resilience and quality of life through family strength. Family strength had a direct effect on individual resilience and had both a direct and an indirect effect on quality of life. Family strength mediated the correlations of family beliefs with individual resilience and quality of life. CONCLUSION: Mobilising family resources to establish healthy family beliefs and exert positive family strength will help increase young breast cancer survivors' individual resilience and improve quality of life. RELEVANCE TO CLINICAL PRACTICE: This study confirms the importance for clinical nursing practice to mobilise family resources and develop interventions centred on family beliefs and family strength.
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Neoplasias da Mama , Sobreviventes de Câncer , Resiliência Psicológica , Humanos , Feminino , Sobreviventes de Câncer/psicologia , Estudos Transversais , Neoplasias da Mama/psicologia , Qualidade de Vida , Inquéritos e QuestionáriosRESUMO
We report a simple and facile integration strategy of a laser source in passive photonic integrated circuits (PICs) by deterministically embedding semiconductor nanowires (NWs) in waveguides. InP NWs laid on a SiN slab are buried by a polymer layer which also acts as an electron-beam resist. With electron-beam lithography, hybrid polymer-SiN waveguides are formed with precisely embedded NWs. The lasing behavior of the waveguide-embedded NWs is confirmed, and more importantly, the NW lasing mode couples into the hybrid waveguide and forms an in-plane guiding mode. Multiple waveguide-embedded NW lasers are further integrated in complex photonic structures to illustrate that the waveguiding mode supplied by the NW lasers could be manipulated for on-chip signal processing, including power splitting and wavelength-division multiplexing. This integration strategy of an on-chip laser is applicable to other PIC platforms, such as silicon and lithium niobate, and the top cladding layer could be changed by depositing SiN or SiO2, promising its CMOS compatibility.
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Nanoscale fabrication and characterization techniques critically underpin a vast range of fields, including nanoelectronics and nanobiotechnology. Focused ion beam (FIB) techniques are appealing due to their high spatial resolution and widespread use for processing of nanostructured materials. Here, we introduce FIB-induced fluorescence spectroscopy (FIB-FS) as a nanoscale technique for spectroscopic detection of atoms sputtered by an ion beam. We use semiconductor heterostructures to demonstrate nanoscale lateral and depth resolution and show that it is limited by ion-induced intermixing of nanostructured materials. Sensitivity is demonstrated qualitatively by depth profiling of 3.5, 5, and 8 nm quantum wells and quantitatively by detection of trace-level impurities present at parts-per-million levels. The utility of the FIB-FS technique is demonstrated by characterization of quantum wells and Li-ion batteries. Our work introduces FIB-FS as a high-resolution, high-sensitivity, 3D analysis and tomography technique that combines the versatility of FIB nanofabrication techniques with the power of diffraction-unlimited fluorescence spectroscopy.
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Nanoestruturas , Microscopia Eletrônica de Varredura , Espectrometria de Fluorescência , Íons , TomografiaRESUMO
Cirsium japonicum DC. var. australe Kitam. has been used as an herbal remedy and often involves using the whole plant or roots. However, the bioactivities of different parts of the plant have been far less explored. This study aimed to evaluate the antioxidative ability of methanol extracts from the flowers, leaves, stems, and roots of the Cirsium plant and their possible active components against juglone-induced oxidative stress in the nematode Caenorhabditis elegans. The results showed that the highest dry weight (12.3 g per plant) was observed in leaves, which was followed by stems (8.0 g). The methanol extract yields from the flowers, leaves, and roots were all similar (13.0-13.8%), while the yield from stems was the lowest (8.6%). The analysis of the silymarin contents in the extracts indicated that the flowers, leaves, stems, and roots contained silychristin and taxifolin; however, silydianin was only found in the leaves, stems, and roots. The flower, leaf, and stem extracts, at a concentration of 10 mg/L, significantly reduced juglone-induced oxidative stress in C. elegans, which was potentially due to the presence of silychristin and taxifolin. Overall, C. japonicum DC. var. australe Kitam. contains a significant amount of silymarin and exhibits in vivo antioxidative activity, suggesting that the prospects for the plant in terms of health supplements or as a source of silymarin are promising.
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Cirsium , Silimarina , Animais , Caenorhabditis elegans , Flavonoides/farmacologia , Extratos Vegetais/farmacologia , Metanol , Estresse Oxidativo , Antioxidantes/farmacologiaRESUMO
Stroke is one of the leading causes of death and disability worldwide. NLRP3 inflammasome has an essential role in the neuropathology of stroke. Recent studies report that shifting the microglial M1 phenotype to the M2 phenotype protects against ischemic stroke. In the present study, the precise effects of Tranilast, a NLPR3 inflammasome inhibitor, on stroke were evaluated. We established a murine model of distal middle cerebral artery occlusion (dMCAO) and administered Tranilast to dMCAO-induced stroke mice. The NLRP3 level, caspase 1 activity, and infarct volume stroke mice were measured. The sensorimotor function, pro-inflammatory cytokine production, and M1/M2 marker expression were measured. The M1 phenotype was induced by treatment of BV2 microglia with lipopolysacharide and interferon γ, and these BV-2 cells were further treated with Tranilast. The expression of CD16 and CD206 was monitored. dMCAO increased the NLRP3 expression and enhanced caspase 1 activity. Tranilast treatment significantly decreased the infarct volume, improved sensorimotor function, and suppressed the production of inflammatory cytokines in stroke mice. Moreover, Tranilast decreased the M1 marker level while promoting the expression of M2 markers. In summary, our findings suggest that Tranilast ameliorates ischemic stroke through stimulating M2 polarization of microglia.
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Isquemia Encefálica , AVC Isquêmico , Acidente Vascular Cerebral , Animais , Isquemia Encefálica/tratamento farmacológico , Isquemia Encefálica/metabolismo , Caspase 1/genética , Caspase 1/metabolismo , Caspase 1/farmacologia , Modelos Animais de Doenças , Humanos , Infarto da Artéria Cerebral Média/tratamento farmacológico , Infarto da Artéria Cerebral Média/metabolismo , Infarto da Artéria Cerebral Média/patologia , Inflamassomos/metabolismo , Inflamassomos/farmacologia , Macrófagos/patologia , Camundongos , Camundongos Endogâmicos C57BL , Microglia/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , FenótipoRESUMO
Highly compact, filter-free multispectral photodetectors have important applications in biological imaging, face recognition, and remote sensing. In this work, we demonstrate room-temperature wavelength-selective multipixel photodetectors based on GaAs0.94Sb0.06 nanowire arrays grown by metalorganic vapor phase epitaxy, providing more than 10 light detection channels covering both visible and near-infrared ranges without using any optical filters. The nanowire array geometry-related tunable spectral photoresponse has been demonstrated both theoretically and experimentally and shown to be originated from the strong and tunable resonance modes that are supported in the GaAsSb array nanowires. High responsivity and detectivity (up to 44.9 A/W and 1.2 × 1012 cm âHz/W at 1 V, respectively) were obtained from the array photodetectors, enabling high-resolution RGB color imaging by applying such a nanowire array based single pixel imager. The results indicate that our filter-free wavelength-selective GaAsSb nanowire array photodetectors are promising candidates for the development of future high-quality multispectral imagers.
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Nanofios , Diagnóstico por ImagemRESUMO
Hot carrier harvest could save 30% energy loss in solar cells. So far, however, it is still unreachable as the photoexcited hot carriers are short-lived, â¼1 ps, determined by a rapid relaxation process, thus invalidating any reprocessing efforts. Here, we propose and demonstrate a feasible route to reserve hot electrons for efficient collection. It is accomplished by an intentional mix of cubic zinc-blend and hexagonal wurtzite phases in III-V semiconductor nanowires. Additional energy levels are then generated above the conduction band minimum, capturing and storing hot electrons before they cool down to the band edges. We also show the superiority of core/shell nanowire (radial heterostructure) in extracting hot electrons. The strategy disclosed here may offer a unique opportunity to modulate hot carriers for efficient solar energy harvest.
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It is essential to understand the failure modes and the failure moments of curved stems since trees could be damaged and may cause severe loss of life and property in urban. In our previous papers, the cracking failure mechanism of hollow erect and curved trunks under bending moment was clarified and we also found that the mechanism of cracking failure of solid trunk is different from the hollow one. While the existing equation to calculate the transverse stress of a solid curved stem under a bending moment is approximate and may cause considerable errors when the initial curvature of stem is small. To solve this problem, a series of novel equations were derived in this study. Among these newly derived equations, 3 of them are especially practical in the assessment of the risk of urban tree for both safety and environment management which are Mc, cminR and ccriR. The equation of Mc is to calculate the bending moment for a solid curved trunk at which the cracking failure is initiated and this equation is more accurate than the existing equation. The equation of cminR is to calculate the minimum cR (c: curvature, R: radius of trunk) below which cracking failure will not occur, and the equation of ccriR is to calculate the critical cR which represents equal opportunities for cracking and bending failure of the stem to occur. To exert our model to practice, the equations derived in this paper were applied to literature data (Wood handbook, 1999). From the data of 41 species of softwood and 48 species of hardwood, statistically, hardwoods have larger average values of cminR and ccriR than softwoods which means that hardwoods are more resistant to cracking failure than softwoods.
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Árvores , Madeira , Estresse MecânicoRESUMO
Semiconductor nanowire arrays have been demonstrated as promising candidates for nanoscale optoelectronics applications due to their high detectivity as well as tunable photoresponse and bandgap over a wide spectral range. In the infrared (IR), where these attributes are more difficult to obtain, nanowires will play a major role in developing practical devices for detection, imaging and energy harvesting. Due to their geometry and periodic nature, vertical nanowire and nanopillar devices naturally lend themselves to waveguide and photonic crystal mode engineering leading to multifunctional materials and devices. In this paper, we computationally develop theoretical basis to enable better understanding of the fundamental electromagnetics, modes and couplings that govern these structures. Tuning the photonic response of a nanowire array is contingent on manipulating electromagnetic power flow through the lossy nanowires, which requires an intimate knowledge of the photonic crystal modes responsible for the power flow. Prior published work on establishing the fundamental physical modes involved has been based either on the modes of individual nanowires or numerically computed modes of 2D photonic crystals. We show that a unified description of the array key electromagnetic modes and their behavior is obtainable by taking into account modal interactions that are governed by the physics of exceptional points. Such models that describe the underlying physics of the photoresponse of nanowire arrays will facilitate the design and optimization of ensembles with requisite performance. Since nanowire arrays represent photonic crystal slabs, the essence of our results is applicable to arbitrary lossy photonic crystals in any frequency range.
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Cinnamomum plants (Lauraceae) are a woody species native to South and Southeast Asia forests, and are widely used as food flavors and traditional medicines. This study aims to evaluate the chemical constituents of Cinnamomum osmophloeum ct. linalool leaf oil, and its antidepressant and motor coordination activities and the other behavioral evaluations in a rodent animal model. The major component of leaf oil is linalool, confirmed by GC-MS analysis. Leaf oil would not induce the extra body weight gain compared to the control mice at the examined doses after 6 weeks of oral administration. The present results provide the first evidence for motor coordination and antidepressant effects present in leaf oil. According to hypnotic, locomotor behavioral, and motor coordination evaluations, leaf oil would not cause side effects, including weight gain, drowsiness and a diminishment in the motor functions, at the examined doses. In summary, these results revealed C. osmophloeum ct. linalool leaf essential oil is of high potential as a therapeutic supplement for minor/medium depressive syndromes.
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Monoterpenos Acíclicos/farmacologia , Antidepressivos/farmacologia , Cinnamomum/química , Atividade Motora/efeitos dos fármacos , Óleos Voláteis/farmacologia , Extratos Vegetais/farmacologia , Folhas de Planta/química , Animais , Cromatografia Gasosa-Espectrometria de MassasRESUMO
Congenital hypothyroidism is one of the common diseases causing delayed intelligence development and growth retardation in children. In 2021, the ENDO-European Reference Network updated the practice guidelines for the diagnosis and management of congenital hypothyroidism. The guidelines give a comprehensive and detailed description of the screening, diagnosis, and management of congenital hypothyroidism in neonates. This article gives an interpretation of the guidelines in order to provide a reference for clinicians in China.
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Hipotireoidismo Congênito , Criança , China , Hipotireoidismo Congênito/diagnóstico , Consenso , Humanos , Recém-Nascido , Triagem Neonatal , TireotropinaRESUMO
Surface passivation of semiconductor nanowires (NWs) is important for their optoelectronic properties and applications. Here, the in situ passivation effect of an epitaxial InP shell and the corresponding photodetector performance is experimentally studied. Compared with the unpassivated GaAs1- x Sb x core-only NWs, the GaAs1- x Sb x /InP core/shell NWs have shown much stronger photoluminescence and cathodoluminescence intensities. Correspondingly, the fabricated single GaAs1- x Sb x /InP core/shell NW photodetector shows a responsivity of 325.1 A W-1 (@ 1.3 µm and 1.5 V) that is significantly enhanced compared to that of single GaAs1- x Sb x core-only NW photodetectors (143.5 A W-1), with a comparable detectivity of 4.7 × 1010 and 5.3 × 1010 cmâHz/W, respectively. This is ascribed to the enhanced carrier mobility and carrier concentration by the in situ passivation, which lead to both higher photoconductivity and dark-conductivity. Our results show that in situ passivation is an effective approach for performance enhancement of GaAs1-x Sb x NW based optoelectronic devices.
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We report multiwavelength single InGaAs/InP quantum well nanowire light-emitting diodes grown by metal organic chemical vapor deposition using selective area epitaxy technique and reveal the complex origins of their electroluminescence properties. We observe that the single InGaAs/InP quantum well embedded in the nanowire consists of three components with different chemical compositions, axial quantum well, ring quantum well, and radial quantum well, leading to the electroluminescence emission with multiple wavelengths. The electroluminescence measurements show a strong dependence on current injection levels as well as temperatures and these are explained by interpreting the equivalent circuits in a minimized area of the device. It is also found that the electroluminescence properties are closely related to the distinctive triangular morphology with an inclined facet of the quantum well nanowire. Our study provides important new insights for further design, growth, and fabrication of high-performance quantum well-based nanowire light sources for a wide range of future optoelectronic and photonic applications.