1,016 research outputs found
A hybrid Si@FeSiy/SiOx anode structure for high performance lithium-ion batteries via ammonia-assisted one-pot synthesis
Synthesised via planetary ball-milling of Si and Fe powders in an ammonia (NH3) environment, a hybrid Si@FeSiy/SiOx structure shows exceptional electrochemical properties for lithium-ion battery anodes, exhibiting a high initial capacity of 1150 mA h g−1 and a retention capacity of 880 mA h g−1 after 150 cycles at 100 mA g−1; and a capacity of 560 mA h g−1 at 4000 mA g−1. These are considerably high for carbon-free micro-/submicro-Si-based anodes. NH3 gradually turns into N2 and H2 during the synthesis, which facilitates the formation of highly conductive FeSiy (y = 1, 2) phases, whereas such phases were not formed in an Ar atmosphere. Milling for 20–40 h leads to partial decomposition of NH3 in the atmosphere, and a hybrid structure of a Si core of mixed nanocrystalline and amorphous Si domains, shelled by a relatively thick SiOx layer with embedded FeSi nanocrystallites. Milling for 60–100 h results in full decomposition of NH3 and a hybrid structure of a much-refined Si-rich core surrounded by a mantle of a relatively low level of SiOx and a higher level of FeSi2. The formation mechanisms of the SiOx and FeSiy phases are explored. The latter structure offers an optimum combination of the high capacity of a nanostructural Si core, relatively high electric conductivity of the FeSiy phase and high structural stability of a SiOx shell accommodating the volume change for high performance electrodes. The synthesis method is new and indispensable for the large-scale production of high-performance Si-based anode materials
Toxoplasma gondii Inhibits Apoptosis in Infected Cells by Caspase Inactivation and NF-κB Activation
Our experiments aimed to clarify the mechanism by which host cell apoptosis is inhibited by infection with the intracellular protozoan parasite, Toxoplasma gondii (T. gondii). Mouse spleen cells were cultured in 6-well plates with RPMI 1640/10% FBS at 37℃, in a 5% CO2 atmosphere. Apoptosis of spleen cells was induced by actinomycin-D (AD) treatment for 1 h prior to infection with T. gondii. A variety of assays were used to assess the progression of apoptosis: DNA size analysis on agarose gel electrophoresis, flow cytometry with annexin V/PI staining, and analysis of expression levels of Bcl-2 family and NF-κB mRNA and proteins by RT-PCR, Western blotting, and EMSA. Additionally, transmission electron microscopy (TEM) was performed to observe changes in cell morphology. Fragmentation of DNA was inhibited in spleen cells treated with AD and T. gondii 5 h and 18 h post infection, respectively, and flow cytometry studies showed a decreased apoptotic rates in AD and T. gondii treated spleen cells. We observed decreased expression of Bax mRNA and protein, while levels of Bcl-2 mRNA remained constant in spleen cells treated with AD and T. gondii. Caspase 3 and PARP were inactivated in cells treated with AD and T. gondii, and increased levels of cleaved caspase 8 were also observed. Analysis of EMSA and Western blot data suggests that activation of transcription factor NF-κB may be involved in the blockade of apoptosis by T. gondii. TEM analysis showed nuclear fragmentation and chromatin condensation occurring in spleen cells treated with AD; however, such apoptosis-associated morphological changes were not observed in cells treated with both AD and T. gondii tachyzoites. Together, these data show that T. gondii infection inhibits AD induced apoptosis via caspase inactivation and NF-κB activation in mouse spleen cells
Detecting the Recurrence of Gastric Cancer after Curative Resection: Comparison of FDG PET/CT and Contrast-Enhanced Abdominal CT
The purpose of this study was to evaluate the value of fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) for detecting the recurrence of gastric cancer. We performed a retrospective review of 139 consecutive patients who underwent PET/CT and contrast-enhanced abdominal CT (CECT) for surveillance of gastric cancer after curative resection. Recurrence of gastric cancer was validated by histopathologic examination for local recurrence or serial imaging study follow-up with at least 1 yr interval for recurrence of distant metastasis form. Twenty-eight patients (20.1%) were confirmed as recurrence. On the patient based analysis, there was no statistically significant difference in the sensitivity, specificity and accuracy of PET/CT (53.6%, 84.7%, and 78.4%, respectively) and those of CECT (64.3%, 86.5%, and 82.0%, respectively) for detecting tumor recurrence except in detection of peritoneal carcinomatosis. Among 36 recurrent lesions, 8 lesions (22.2%) were detected only on PET/CT, and 10 lesions (27.8%) only on CECT. PET/CT had detected secondary malignancy in 8 patients. PET/CT is as accurate as CECT in detection of gastric cancer recurrence after curative resection, excepting detection of peritoneal carcinomatosis. Moreover, additional PET/CT on CECT could improve detection rate of tumor recurrence and provide other critical information such as unexpected secondary malignancy
Reference values for respiratory system impedance using impulse oscillometry in healthy preschool children
PurposeThe normal values for lung resistance and lung capacity of children, as determined by impulse oscillometry (IOS), are different for children of different ethnicities. However, reference values there is no available reference value for Korean preschool children have yet to be determined. The aim of the present study was to determine the normal ranges of IOS parameters in Korean preschool children.MethodsA total of 133 healthy Korean preschool children were selected from 639 children (aged 3 to 6 years) who attended kindergarten in Seongnam, Gyeonggi province, Korea. Healthy children were defined according to the European Respiratory Society (ERS) criteria. All subjects underwent lung function tests using IOS. The relationships between IOS value (respiratory resistance (Rrs) and reactance (Xrs) at 5 and 10 Hz and resonance frequency (RF)) and age, height, and weight were analyzed by simple linear and multiple linear regression analyses.ResultsThe IOS success rate was 89.5%, yielding data on 119 children. Linear regression identified height as the best predictor of Rrs and Xrs. Using stepwise multiple linear regressions based on age, height, and weight, we determined regression equations and coefficients of determination (R2) for boys (Rrs5=1.934-0.009×Height, R2=12.1%; Xrs5=0.774+0.006×Height-0.002×Age, R2=20.2% and for girls (Rrs5=2.201-0.012×Height, R2=18.2%; Xrs5=-0.674+0.004×Height, R2=10.5%).ConclusionThis study provides reference values for IOS measurements of normal Korean preschool children. These provide a basis for the diagnosis and monitoring of preschool children with a variety of respiratory diseases
Prognostic value of quality of life score in disease-free survivors of surgically-treated lung cancer
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the Creative Commons license, and indicate if changes were made.Abstract
Background
We aimed to evaluate the prognostic value of quality of life (QOL) for predicting survival among disease-free survivors of surgically-treated lung cancer after the completion of cancer treatment.
Methods
We administered the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30), the Quality of Life Questionnaire Lung Cancer Module (QLQ-LC13), Hospital Anxiety and Depression Scale (HADS), and Posttraumatic Growth Inventory (PTGI) to 809 survivors who were surgically-treated for lung cancer at two hospitals from 2001 through 2006. We gathered mortality data by linkage to the National Statistical Office through December 2011. We used Cox proportional hazard models to compute adjusted hazard ratios (aHRs) and 95 % confidence intervals (CIs) to estimate the relationship between QOL and survival.
Results
Analyses of QOL items adjusted for age, sex, stage, body mass index, and physical activity showed that scores for poor physical functioning, dyspnea, anorexia, diarrhea, cough, personal strength, anxiety, and depression were associated with poor survival. With adjustment for the independent indicators of survival, final multiple proportional hazard regression analyses of QOL show that physical functioning (aHR, 2.39; 95 % CI, 1.13–5.07), dyspnea (aHR, 1.56; 95 % CI, 1.01–2.40), personal strength (aHR, 2.36; 95 % CI, 1.31–4.27), and anxiety (aHR, 2.13; 95 % CI, 1.38–3.30) retained their independent prognostic power of survival.
Conclusion
This study suggests that patient-reported QOL outcomes in disease-free survivors of surgically-treated lung cancer after the completion of active treatment has independent prognostic value for long-term survival
The Role of 18F-FDG PET/CT in the Evaluation of Gastric Cancer Recurrence after Curative Gastrectomy
Acetylation changes tau interactome to degrade tau in Alzheimer’s disease animal and organoid models
© 2019 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.Alzheimer's disease (AD) is an age-related neurodegenerative disease. The most common pathological hallmarks are amyloid plaques and neurofibrillary tangles in the brain. In the brains of patients with AD, pathological tau is abnormally accumulated causing neuronal loss, synaptic dysfunction, and cognitive decline. We found a histone deacetylase 6 (HDAC6) inhibitor, CKD-504, changed the tau interactome dramatically to degrade pathological tau not only in AD animal model (ADLPAPT) brains containing both amyloid plaques and neurofibrillary tangles but also in AD patient-derived brain organoids. Acetylated tau recruited chaperone proteins such as Hsp40, Hsp70, and Hsp110, and this complex bound to novel tau E3 ligases including UBE2O and RNF14. This complex degraded pathological tau through proteasomal pathway. We also identified the responsible acetylation sites on tau. These dramatic tau-interactome changes may result in tau degradation, leading to the recovery of synaptic pathology and cognitive decline in the ADLPAPT mice11Nsciescopu
Challenges and recent advancements of functionalization of two-dimensional nanostructured molybdenum trioxide and dichalcogenides
Atomically-thin two-dimensional (2D) semiconductors are the thinnest functional semiconducting materials available today. Among them, both molybdenum trioxide and chalcogenides (MT&Ds) represent key components within the family of the different 2D semiconductors for various electronic, optoelectronic and electrochemical applications due to their unique electronic, optical, mechanical and electrochemical properties. However, despite great progress in research dedicated to the development and fabrication of 2D MT&Ds observed within the last decade, there are significant challenges affected their charge transport behavior, fabrication on a large scale as well as high dependence of the carrier mobility on thickness. In this article, we review the recent progress on the carrier mobility engineering of 2D MT&Ds and elaborate devised strategies dedicated to the optimization of MT&Ds properties. Specifically, the latest physical and chemical methods towards the surface functionalization and optimization of the major factors influencing the extrinsic transport at the electrode-2D semiconductor interface are discusse
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