188 research outputs found
Group III-V Nanowire Growth and Characterization
Electronic and optical devices typically use bulk or quantum wells today, but nanowires are promising building blocks for future devices, due to their structural characterizations of larger aspect ratio and smaller volume. In situ growth of semiconductor devices is extremely attractive, as it doesn’t require expensive lithography treatment. Over the past ten years, a great deal of work has been done to explore NW, incorporation of group III-V materials and band engineering for the electronic and optoelectronic devices. Because pseudo one-dimensional heterostructures may be grown without involving lattice mismatch defects, NWs may give rise to superior electronic, photonic, and magnetic performances as compared to conventional bulk or planar structures
Ten Years of the Sino-European Strategic Partnership: Achievements and Problems
Ten years after the establishment of the strategic partnership between China and the EU, this relationship has continued to flourish. However, publicly they have often been at odds, and even created doubts about the real existence of the comprehensive strategic partnership. The drawbacks of this relationship in recent years are mainly caused by the increased competitiveness in economy and trade, and the outbreak of quarrels concerning human rights and other areas. Since Sino-EU relations are very important for both parties and the world in general, both sides should find ways to control their conflicts and thus pave the way for their comprehensive strategic partnerships to further flourish
Active beam steering enabled by photonic crystal surface emitting laser
Emitting light towards on-demand directions is important for various
optoelectronic applications, such as optical communication, displaying, and
ranging. However, almost all existing directional emitters are assemblies of
passive optical antennae and external light sources, which are usually bulky,
fragile, and with unendurable loss of light power. Here we theoretically
propose and experimentally demonstrate a new conceptual design of directional
emitter, by using a single surface-emitting laser source itself to achieve
dynamically controlled beam steering. The laser is built on photonic crystals
that operates near the band edges in the continuum. By shrinking laser sizes
into tens-of-wavelength, the optical modes quantize in three-dimensional
momentum space, and each of them directionally radiates towards the far-field.
Further utilizing the luminescence spectrum shifting effect under current
injection, we consecutively select a sequence of modes into lasing action and
show the laser maintaining in single mode operation with linewidths at a
minimum of MHz and emitting power of ten milliwatts, and we
demonstrate fast beam steering across a range of in
a time scale of nanoseconds. Our work proposes a novel method for on-chip
active beam steering, which could pave the way for the development of
automotive, industrial, and robotic applications.Comment: 23 pages, 5 figure
Comparative efficacy of different exercise methods to improve cardiopulmonary function in stroke patients: a network meta-analysis of randomized controlled trials
BackgroundAlthough some studies have shown that exercise has a good effect on improving the cardiopulmonary function of stroke patients, it still needs to be determined which exercise method does this more effectively. We, therefore, aimed to evaluate the effectiveness of different exercise methods in improving cardiovascular function in stroke patients through a network meta-analysis (NMA), providing a basis to select the best treatment plan for stroke patients.MethodsWe systematically searched CNKI, WanFang, VIP, CBM, PubMed, Embase, Web of Science, and The Cochrane Library databases from establishment to 30 April 2023. Randomized controlled trials (RCTS) on exercise improving cardiopulmonary function in stroke patients were included, and we screened the included articles and extracted the relevant data. RevMan (version 5.4) and Stata (version 17.0) were used for data analysis.ResultsWe included 35 RCTs and a total of 2,008 subjects. Intervention measures included high-intensity interval training (HIIT), aerobic training (AT), resistance training (RT), combined aerobic and resistance exercise (CE), and conventional therapy (CT). In the network meta-analysis, the surface under the cumulative ranking area (SUCRA) ranking result indicated that HIIT improved peak oxygen uptake (VO2peak) and 6 mins walking distance (6MWD) optimally, with rankings of HIIT (100.0%) > CE (70.5%) > AT (50.2%) > RT (27.7%) > CT (1.6%), and HIIT (90.9%) > RT (60.6%) > AT (48.9%) > RT (48.1%) > CT (1.5%), respectively. The SUCRA ranking result showed that CE improved systolic blood pressure (SBP) and diastolic blood pressure (DBP) optimally, with rankings of CE (82.1%) > HIIT (49.8%) > AT (35.3%) > CT (32.8%), and CE (86.7%) > AT (45.0%) > HIIT (39.5%) > CT (28.8%), respectively.ConclusionWe showed that exercise can effectively improve the cardiopulmonary function of stroke patients. HIIT was the most effective in improving VO2peak and 6MWD in stroke patients. CE was the most effective in improving SBP and DBP in stroke patients. However, due to the limitations of existing clinical studies and evidence, larger sample size, multi-center, and high-quality RCTs are needed to verify the above conclusions in the future.Systematic review registrationhttps://www.crd.york.ac.uk/prospero/, identifier [CRD42023436773]
Age-Specific Prevalence of Visual Impairment and Refractive Error in Children Aged 3-10 Years in Shanghai, China
Changes in Cortical Thickness in Patients With Early Parkinson’s Disease at Different Hoehn and Yahr Stages
Objectives: This study was designed to explore changes in cortical thickness in patients with early Parkinson’s disease (PD) at different Hoehn and Yahr (H-Y) stages and to demonstrate the association of abnormally altered brain regions with part III of the Unified Parkinson’s Disease Rating Scale (UPDRS-III).Materials and Methods: Sixty early PD patients and 29 age- and gender-matched healthy controls (HCs) were enrolled in this study. All PD patients underwent comprehensive clinical and neuropsychological evaluations and 3.0 T magnetic resonance scanning. Patients with H-Y stage ≤1.5 were included in the mild group, and all other patients were included in the moderate group. FreeSurfer software was used to calculate cortical thickness. We assessed the relationship between UPDRS-III and regional changes in cortical thinning, including the bilateral fusiform and the temporal lobe.Results: The average cortical thickness of the temporal pole, fusiform gyrus, insula of the left hemisphere and fusiform gyrus, isthmus cingulate cortex, inferior temporal gyrus, middle temporal cortex and posterior cingulate cortex of the right hemisphere exhibited significant decreasing trends in HCs group and PD groups (i.e., the mild group and moderate group). After controlling for the effects of age, gender, and disease duration, the UPDRS-III scores in patients with early PD were correlated with the cortical thickness of the left and right fusiform gyrus and the left temporal pole (p < 0.05).Conclusion: The average cortical thickness of specific brain regions reduced with increasing disease severity in early PD patients at different H-Y stages, and the UPDRS-III scores of early PD patients were correlated with cortical thickness of the bilateral fusiform gyrus and the left temporal pole
Identification of a six-gene signature to predict survival and immunotherapy effectiveness of gastric cancer
BackgroundGastric cancer (GC) ranks as the fifth most prevalent malignancy and the second leading cause of oncologic mortality globally. Despite staging guidelines and standard treatment protocols, significant heterogeneity exists in patient survival and response to therapy for GC. Thus, an increasing number of research have examined prognostic models recently for screening high-risk GC patients.MethodsWe studied DEGs between GC tissues and adjacent non-tumor tissues in GEO and TCGA datasets. Then the candidate DEGs were further screened in TCGA cohort through univariate Cox regression analyses. Following this, LASSO regression was utilized to generate prognostic model of DEGs. We used the ROC curve, Kaplan-Meier curve, and risk score plot to evaluate the signature’s performance and prognostic power. ESTIMATE, xCell, and TIDE algorithm were used to explore the relationship between the risk score and immune landscape relationship. As a final step, nomogram was developed in this study, utilizing both clinical characteristics and a prognostic model.ResultsThere were 3211 DEGs in TCGA, 2371 DEGs in GSE54129, 627 DEGs in GSE66229, and 329 DEGs in GSE64951 selected as candidate genes and intersected with to obtain DEGs. In total, the 208 DEGs were further screened in TCGA cohort through univariate Cox regression analyses. Following this, LASSO regression was utilized to generate prognostic model of 6 DEGs. External validation showed favorable predictive efficacy. We studied interaction between risk models, immunoscores, and immune cell infiltrate based on six-gene signature. The high-risk group exhibited significantly elevated ESTIMATE score, immunescore, and stromal score relative to low-risk group. The proportions of CD4+ memory T cells, CD8+ naive T cells, common lymphoid progenitor, plasmacytoid dentritic cell, gamma delta T cell, and B cell plasma were significantly enriched in low-risk group. According to TIDE, the TIDE scores, exclusion scores and dysfunction scores for low-risk group were lower than those for high-risk group. As a final step, nomogram was developed in this study, utilizing both clinical characteristics and a prognostic model.ConclusionIn conclusion, we discovered a 6 gene signature to forecast GC patients’ OS. This risk signature proves to be a valuable clinical predictive tool for guiding clinical practice
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