846 research outputs found
Formation mechanism of SiGe nanorod arrays by combining nanosphere lithography and Au-assisted chemical etching
The formation mechanism of SiGe nanorod (NR) arrays fabricated by combining nanosphere lithography and Au-assisted chemical etching has been investigated. By precisely controlling the etching rate and time, the lengths of SiGe NRs can be tuned from 300 nm to 1
μm. The morphologies of SiGe NRs were found to change dramatically by varying the etching temperatures. We propose a mechanism involving a locally temperature-sensitive redox reaction to explain this strong temperature dependence of the morphologies of SiGe NRs. At a lower etching temperature, both corrosion reaction and Au-assisted etching process were kinetically impeded, whereas at a higher temperature, Au-assisted anisotropic etching dominated the formation of SiGe NRs. With transmission electron microscopy and scanning electron microscopy analyses, this study provides a beneficial scheme to design and fabricate low-dimensional SiGe-based nanostructures for possible applications
Are associations of leisure-time physical activity with mortality attenuated by high levels of chronic ambient fine particulate matter (PM2.5) in older adults? A prospective cohort study
BACKGROUND AND PURPOSE: Although leisure-time physical activity (PA) has established health benefits in older adults, it is equivocal if exercising in environments with high levels of PM2.5 concentrations is equally beneficial for them. To explore the independent and joint associations of ambient PM2.5 and PA with all-cause mortality among adults aged 60 or older and to assess the modifying effect of age (60-74 years vs. 75+ years) on the joint associations. METHODS: A prospective cohort study based on the MJ Cohort repeat examinations (2005-2016) and the Taiwan Air Quality Monitoring Network and death registry linkages (2005-2022). We included MJ Cohort participants aged 60 or more at baseline who attended the health check-ups at least twice (n = 21,760). Metabolic equivalent hours per week (MET-h/week) of leisure-time PA were computed. Multivariable adjusted associations were examined using time-varying Cox proportional hazard models. RESULTS: There were 3539 all-cause deaths over a mean follow-up of 12.81 (SD = 3.67) years. Ambient PM2.5 and physical inactivity are both independently associated with all-cause mortality. The joint associations of PA and PM2.5 concentrations with all-cause mortality differed in the young-old (60-74 years) and the older-old (75+ years) (P for interaction = 0.01); Higher levels of long-term PM2.5 exposures (≥25 μg/m3) had little influence on the associations between PA and mortality in the young-old (HR = 0.68 (0.56-0.83) and HR = 0.72 (0.59-0.88) for participants with 7.5-<15 and 15+ MET-h/week respectively) but eliminated associations between exposure and outcome in the older-old (HR = 0.91 (0.69-01.21) and HR = 1.02 (0.76-1.38) for participants with 7.5-<15 and 15+ MET-h/week). CONCLUSION: Long-term exposures to higher PM2.5 concentrations may eliminate the beneficial associations of PA with all-cause mortality among adults aged 75 and over
Changes in physical activity and adiposity with all-cause, cardiovascular disease, and cancer mortality
BACKGROUND: The relationship between joint changes in physical activity and adiposity with mortality is not well understood. We examined the association of changes in these two established risk factors with all-cause (ACM), cardiovascular disease (CVD), and cancer mortality. METHODS: We used longitudinal data from Taiwan’s MJ Cohort, comprising 116,228 general population adults recruited from 1998-2013 with repeated measures 4.6 y (2.5) apart and followed up for mortality for 11.9 y (3.5). Physical activity, body mass index (BMI), waist circumference (WC), and body fat percentage (BF%) groups and changes were based on public health and clinical guidelines. RESULTS: Compared to stable-insufficient physical activity, increasing physical activity from any baseline level was associated with lower ACM (HR [95%CI]): 0.85 [0.74, 0.96]) and CVD mortality (0.72 [0.55, 0.93]) risk. This was approximately equal to meeting physical activity guidelines at both timepoints (eg: 0.71 [0.58, 0.88] for CVD mortality). Compared to stable-overweight/moderate adiposity, decreasing adiposity level attenuated but did not offset mortality risk for all three outcomes (eg: BMI = 0.95 [0.76, 1.16] for CVD mortality). Only maintaining a healthy adiposity level at both timepoints offset mortality risk (BMI = 0.75 [0.61, 0.89]) for CVD mortality). In the joint changes analyses, lower mortality risk was a consequence of increases in physical activity across adiposity change groups (eg: WC decrease = 0.57 [0.48, 0.67]; WC stability = 0.73 [0.66, 0.80], WC increase = 0.83 [0.72, 0.97] for ACM). Decreasing adiposity attenuated the negative associations of decreased physical activity (BF% = 1.13 [0.95, 1.35] for ACM). CONCLUSIONS: We found a lower risk for ACM, CVD, and cancer mortality from increasing physical activity and an attenuation from decreasing adiposity regardless of baseline levels. The beneficial associations of joint changes were primarily driven by physical activity, suggesting lower mortality risk may be more immediate through physical activity improvements compared to adiposity improvements alone
Yeast axial-element protein, Red1, binds SUMO chains to promote meiotic interhomologue recombination and chromosome synapsis
The synaptonemal complex (SC) is a tripartite protein structure consisting of two parallel axial elements (AEs) and a central region. During meiosis, the SC connects paired homologous chromosomes, promoting interhomologue (IH) recombination. Here, we report that, like the CE component Zip1, Saccharomyces cerevisiae axial-element structural protein, Red1, can bind small ubiquitin-like modifier (SUMO) polymeric chains. The Red1–SUMO chain interaction is dispensable for the initiation of meiotic DNA recombination, but it is essential for Tel1- and Mec1-dependent Hop1 phosphorylation, which ensures IH recombination by preventing the inter-sister chromatid DNA repair pathway. Our results also indicate that Red1 and Zip1 may directly sandwich the SUMO chains to mediate SC assembly. We suggest that Red1 and SUMO chains function together to couple homologous recombination and Mec1–Tel1 kinase activation with chromosome synapsis during yeast meiosis
Biomarkers in long COVID-19: A systematic review
PurposeLong COVID, also known as post-acute sequelae of COVID-19, refers to the constellation of long-term symptoms experienced by people suffering persistent symptoms for one or more months after SARS-CoV-2 infection. Blood biomarkers can be altered in long COVID patients; however, biomarkers associated with long COVID symptoms and their roles in disease progression remain undetermined. This study aims to systematically evaluate blood biomarkers that may act as indicators or therapeutic targets for long COVID.MethodsA systematic literature review in PubMed, Embase, and CINAHL was performed on 18 August 2022. The search keywords long COVID-19 symptoms and biomarkers were used to filter out the eligible studies, which were then carefully evaluated.ResultsIdentified from 28 studies and representing six biological classifications, 113 biomarkers were significantly associated with long COVID: (1) Cytokine/Chemokine (38, 33.6%); (2) Biochemical markers (24, 21.2%); (3) Vascular markers (20, 17.7%); (4) Neurological markers (6, 5.3%); (5) Acute phase protein (5, 4.4%); and (6) Others (20, 17.7%). Compared with healthy control or recovered patients without long COVID symptoms, 79 biomarkers were increased, 29 were decreased, and 5 required further determination in the long COVID patients. Of these, up-regulated Interleukin 6, C-reactive protein, and tumor necrosis factor alpha might serve as the potential diagnostic biomarkers for long COVID. Moreover, long COVID patients with neurological symptoms exhibited higher levels of neurofilament light chain and glial fibrillary acidic protein whereas those with pulmonary symptoms exhibited a higher level of transforming growth factor beta.ConclusionLong COVID patients present elevated inflammatory biomarkers after initial infection. Our study found significant associations between specific biomarkers and long COVID symptoms. Further investigations are warranted to identify a core set of blood biomarkers that can be used to diagnose and manage long COVID patients in clinical practice
Pathological granuloma fibrosis induced by agar-embedded Mycobacterium abscessus in C57BL/6JNarl mice
IntroductionPulmonary granuloma diseases caused by Mycobacterium abscessus (M. abscessus) have increased in past decades, and drug-resistance in this pathogen is a growing public health concern. Therefore, an animal model of chronic granuloma disease is urgently needed.MethodsIn this study, M. abscessus embedded within agar beads (agar-AB) was used to develop such a model in C57BL/6JNarl mice.ResultsChronic infection was sustained for at least 3 months after agar-AB infection, visible granulomas spread in the lungs, and giant cells and foamy cells appeared in the granulomas. More importantly, pulmonary fibrosis progressed for 3 months, and collagen fibers were detected by Masson trichrome staining. Further, inducible nitric oxide synthase (iNOS) was highly expressed within the alveolar space, and the fibrosis-mediator transforming growth factor beta (TGF-β) began to be expressed at 1 month. Hypoxia-inducible factor (HIF-1α) expression also increased, which aided in normalizing oxygen partial pressure.DiscussionAlthough the transient fibrosis persisted for only 3 months, and the pulmonary structure resolved when the pathogen was cleard, this pulmonary fibrosis model for M. abscessus infection will provide a novel test platform for development of new drugs, regimens, and therapies
Intensify the application of ZnO-based nanodevices in humid environment: O2/H2 plasma suppressed the spontaneous reaction of amorphous ZnO nanowires
[[abstract]]In this work, we have demonstrated that amorphous ZnO nanobranches (a-ZnO NBs) could spontaneously react from the crystalline ZnO NWs (c-ZnO NWs) at specific humid environment. The spontaneous reaction mechanism and result can be analyzed by humidity controlling and optical microscope (OM)/scanning electron microscope (SEM)/Kelvin probe force microscopy (KPFM)/transmission electron microscopy (TEM) system. We can make the c-ZnO NWs spontaneous reaction happen at different humid environments and suppress the a-ZnO NBs spontaneous reaction by oxygen/hydrogen plasma surface passivation. The hydrogen plasma surface treatment also can improve the UV sensing sensitivity more than twofold. This work provides the mechanism and methods of the a-ZnO NBs spontaneous growth and offers the passivation treatment for strengthening and enhancing ZnO-based nanodevice application in humid environment and UV light detection, respectively.[[notice]]補正完畢[[journaltype]]國外[[incitationindex]]SCI[[ispeerreviewed]]Y[[booktype]]電子版[[booktype]]紙本[[countrycodes]]DE
Association of Female Menopause With Atrioventricular Mechanics and Outcomes
BACKGROUND: Despite known sex differences in cardiac structure and function, little is known about how menopause and estrogen associate with atrioventricular mechanics and outcomes. OBJECTIVE: To study how, sex differences, loss of estrogen in menopause and duration of menopause, relate to atrioventricular mechanics and outcomes. METHODS: Among 4051 asymptomatic adults (49.8 ± 10.8 years, 35%women), left ventricular (LV) and left atrial (LA) mechanics were assessed using speckle-tracking. RESULTS: Post-menopausal (vs. pre-menopausal) women had similar LV ejection fraction but reduced GLS, reduced PALS, increased LA stiffness, higher LV sphericity and LV torsion (all p < 0.001). Multivariable analysis showed menopause to be associated with greater LV sphericity (0.02, 95%CI 0.01, 0.03), higher indexed LV mass (LVMi), lower mitral e’, lower LV GLS (0.37, 95%CI 0.04–0.70), higher LV torsion, larger LA volume, worse PALS (∼2.4-fold) and greater LA stiffness (0.028, 95%CI 0.01–0.05). Increasing years of menopause was associated with further reduction in GLS, markedly worse LA mechanics despite greater LV sphericity and higher torsion. Lower estradiol levels correlated with more impaired LV diastolic function, impaired LV GLS, greater LA stiffness, and increased LV sphericity and LV torsion (all p < 0.05). Approximately 5.5% (37/669) of post-menopausal women incident HF over 2.9 years of follow-up. Greater LV sphericity [adjusted hazard ratio (aHR) 1.04, 95%CI 1.00–1.07], impaired GLS (aHR 0.87, 95%CI 0.78–0.97), reduced peak left atrial longitudinal strain (PALS, aHR 0.94, 95%CI 0.90–0.99) and higher LA stiffness (aHR 10.5, 95%CI 1.69–64.6) were independently associated with the primary outcome of HF hospitalizations in post-menopause. Both PALS < 23% (aHR:1.32, 95%CI 1.01–3.49) and GLS < 16% (aHR:5.80, 95%CI 1.79–18.8) remained prognostic for the incidence of HF in post-menopausal women in dichotomous analyses, even after adjusting for confounders. Results were consistent with composite outcomes of HF hospitalizations and 1-year all-cause mortality as well. CONCLUSION: Menopause was associated with greater LV/LA remodeling and reduced LV longitudinal and LA function in women. The cardiac functional deficit with menopause and lower estradiol levels, along with their independent prognostic value post-menopause, may elucidate sex differences in heart failure further
Diagnostic Value of Nitroglycerin-Induced Headache as a Negative Predictor of Coronary Atherosclerosis
The purpose of the present study was to clarify the possible relationship between nitroglycerin (NTG)-induced headache and both vascular functional and organic atherosclerosis. The study included 96 patients with NTG-induced headache (group I: 54.7±9.5 years, 52 males) and 204 patients without headache (group II: 58.1±9.1 years, 127 males) who suffered from new-onset chest pain. Flow-mediated dilation and nitroglycerin-mediated dilation were significantly greater in group I than in group II (8.8±4.1% vs. 7.1±3.5%, p=0.001, and 23.1±7.3% vs. 17.1±11.8%, p<0.001, respectively). The carotid intima-media thickness was significantly smaller in group I than in group II (0.55±0.15 mm vs. 0.67±0.22 mm, p=0.001). Heart-carotid pulse wave velocity was significantly lower in group I than in group II (784.5±160.1 m/s vs. 979.1±215.6 m/s, p=0.003). In the multiple regression analysis, the absence of NTG-induced headache was a predictor of coronary artery disease (CAD) (odds ratio: 17.89, 95% confidence interval: 7.89-40.02, p<0.001). NTG-induced headache developed more frequently in patients with normal coronary arteries or minimal CAD than in patients with obstructive CAD. The presence of NTG-induced headache might be helpful and provide additional information in evaluating patients with chest pain syndrome
Risk groups defined by Recursive Partitioning Analysis of patients with colorectal adenocarcinoma treated with colorectal resection
<p>Abstract</p> <p>Background</p> <p>To define different prognostic groups of surgical colorectal adenocarcinoma patients derived from recursive partitioning analysis (RPA).</p> <p>Methods</p> <p>Ten thousand four hundred ninety four patients with colorectal adenocarcinoma underwent colorectal resection from Taiwan Cancer Database during 2003 to 2005 were included in this study. Exclusion criteria included those patients with stage IV disease or without number information of lymph nodes. For the definition of risk groups, the method of classification and regression tree was performed. Main primary outcome was 5-year cancer-specific survival.</p> <p>Results</p> <p>We identified six prognostic factors for cancer-specific survival, resulting in seven terminal nodes. Four risk groups were defined as following: Group 1 (mild risk, 1,698 patients), Group 2 (moderate risk, 3,129 patients), Group 3 (high risk, 4,605 patients) and Group 4 (very high risk, 1,062 patients). The 5-year cancer-specific survival for Group 1, 2, 3, and 4 was 86.6%, 62.7%, 55.9%, and 36.6%, respectively (p < 0.001). Hazard ratio of death was 2.13, 5.52 and 10.56 (95% confidence interval 1.74-2.60, 4.58-6.66 and 8.66-12.9, respectively) times for Group 2, 3, and 4 as compared to Group 1. The predictive capability of these grouping was also similar in terms of overall and progression-free survival.</p> <p>Conclusion</p> <p>The use of RPA offered an alternative grouping method that could predict the survival of patients who underwent surgery for colorectal adenocarcinoma.</p
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