Search

The objectives of this study are to explore the activation ratios of implanted phosphorus dopants in polycrystalline silicon (poly-Si), and to reveal the role of grain boundary segregation in incomplete activation using atom probe tomography (APT) and differential Hall effect metrology (DHEM). After implantation and rapid thermal annealing, the results of APT revealed pronounced segregation toward grain boundaries that provides rapid diffusion paths for phosphorus. Peak concentrations of phosphorus segregations in the grain boundaries of the regrown and non-regrown regions were measured to be 4.38E21 and 2.17E21 atoms/cm³ that correspond to activation ratios of 6 % and 1 %, respectively. In contrast, phosphorus concentrations within grain interiors were found to be 6.86E20 and 1.72E19 atoms/cm³, corresponding to activation ratios of 39 % and nearly 100 % in the regrown and non-regrown regions, respectively. This research highlights a novel approach for evaluating site-specific activation ratios in poly-Si through the integrated use of DHEM and APT. [Display omitted] [ABSTRACT FROM AUTHOR]

Background and Purpose: Colorectal cancer is the third most common cancer worldwide. HER2 and HER3 are two members of human epidermal receptor family of tyrosine kinase receptors (RTKs) and associated with poor survival in colorectal cancer. They have been observed as important therapeutic targets in various types of cancer. Corosolic acid, a natural pentacyclic triterpene, has been demonstrated to have a significant anti‐cancer activity. However, the target of corosolic acid has not yet been explored. This study aimed to reveal the direct targets of corosolic acid underlying its anti‐cancer activities. Experimental Approach The targets of corosolic acid were revealed by the phospho‐RTK array, bio‐layer interferometry, co‐immunoprecipitation, and proximity ligation assay. The inhibitory action of corosolic acid on HER2/HER3 heterodimerization and related downstream signalling were investigated in HCT116 and SW480 cells. In addition, the chemo‐preventive effects of corosolic acid were validated in both HCT116 xenograft model and AOM/DSS model. Key Results: Our results demonstrated that corosolic acid could prevent NRG1‐induced HER2/HER3 heterodimerization and suppress the phosphorylation of both HER2 and HER3. Furthermore, HER2 and HER3 could regulate the downstream signalling pathways of RalA/RalBP1/CDK1 and PI3K/Akt/PKA, respectively, resulting in the changes in phosphorylation of Drp1 and mitochondrial dynamics. corosolic acid exhibited anti‐cancer activity in both HCT116 xenograft model and AOM/DSS model. Conclusions and Implications: Collectively, our results demonstrated corosolic acid directly targeted HER2 and HER3 heterodimerization and inhibited mitochondrial fission via regulating RalA/RalBP1/CDK1 and PI3K/Akt/PKA pathways, revealing a novel mechanism underlying the beneficial effects of corosolic acid on colorectal cancer. [ABSTRACT FROM AUTHOR]

CHCHD2 is the latest identified Parkinson's disease (PD)-causing gene, and previous studies have reported the same CHCHD2 variant (182C>T, Thr61Ile) in both PD and essential tremor (ET) patients. Whether CHCHD2 gene mutations are involved in both of these diseases remains unclear. We sequenced CHCHD2 gene in 171 familial ET patients, 133 autosomal dominant Parkinson's disease patients, and 211 normal controls. No pathogenic mutations were found, suggesting that CHCHD2 gene may not play a major role in our familial Chinese Han ET and PD patients. [ABSTRACT FROM AUTHOR]

Background: Renal cell carcinoma (RCC) is a clinically common tumor in the urinary system, showing an upward trend of both incidence and mortality. Apolipoprotein C1 (APOC1) has been identified as a vital regulator in tumor progression. This study aims to uncover the biological function of APOC1 in RCC process and the underlying mechanism. Methods: Differential levels of APOC1 in RCC samples and normal tissues in a downloaded TCGA profile and clinical samples collected in our center were detected by quantitative reverse transcription PCR (qRT-PCR). The prognostic value of APOC1 in RCC was assessed by depicting Kaplan–Meier survival curves. After intervening APOC1 level by transfection of sh-APOC1 or oe-APOC1, changes in phenotypes of RCC cells were examined through CCK-8, colony formation, Transwell assay and flow cytometry. Subsequently, protein levels of EMT-related genes influenced by APOC1 were determined by Western blot. The involvement of the Wnt3a signaling in APOC1-regulated malignant process of RCC was then examined through a series of rescue experiments. Finally, a RCC xenograft model was generated in nude mice, aiming to further clarify the in vivo function of APOC1 in RCC process. Results: APOC1 was upregulated in RCC samples. Notably, its level was correlated to overall survival of RCC patients, displaying a certain prognostic value. APOC1 was able to stimulate proliferative, migratory and invasive abilities in RCC cells. The Wnt3a signaling was identified to be involved in APOC1-mediated RCC process. Notably, Wnt3a was able to reverse the regulatory effects of APOC1 on RCC cell phenotypes. In vivo knockdown of APOC1 in xenografted nude mice slowed down the growth of RCC. Conclusions: APOC1 stimulates the malignant process of RCC via targeting the Wnt3a signaling. [ABSTRACT FROM AUTHOR]

Anesthetics are documented to affect tumors; therefore, we studied the antiglioma effect of propofol on proliferation and invasiveness of glioma cells and explored the underlying mechanism. C6 glioma cells were cultured and treated with propofol, and cell viability, invasiveness, and migration were measured. Glutamate release was measured using an enzyme-catalyzed kinetic reaction. xCT protein and α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptor GluR2 subunit protein expression was assessed with Western blot analysis and immunofluorescent staining. We observed that propofol significantly inhibited C6 glioma cell viability, invasiveness, and migration and decreased glutamate release. An agonist of the cystine/glutamate antiporter system (system x c − ), N -acetylcysteine (NAC), reversed propofol's effects, and propofol could inhibit C6 glioma cell proliferation by adding excess exogenous glutamate (100 μM). Finally, propofol increased the surface expression of GluR2, but decreased surface expression of xCT. The effects of propofol on surface expression of GluR2 and xCT could be rescued by (R, S)-AMPA, an agonist of Ca 2+ permeable AMPA receptor (CPAR). Thus, propofol can inhibit cell viability, invasiveness, and migration of C6 glioma cells, and the CPAR-system x c − pathway contributes to these events. [ABSTRACT FROM AUTHOR]

An increasing number of researchers have applied secondary-structure based multiple alignments of rDNA genes in phylogeny. These studies mostly depended on a few valuable divergent domains in LSU and SSU rDNA. Yet other divergent domains, e.g. D1, were poorly investigated and rarely used. However, these domains might contain additional evolutionary data and play a vital role in DNA-based phylogenetic study. Here, we investigated all available D1 sequences of Arachnida taxa and predicted corresponding secondary structures to help identify homologous positions in the D1 region. Long insertions were found exclusive to Eriophyoidea and folded into three newly proposed helices. Non-Acari taxa were all GC rich. In Acari, most Trombidiformes and all Mesostigmata (Parasitiformes) taxa were AT rich and Ixodida (Parasitiformes) GC rich; however there was no consistent base bias in Sarcoptiformes sequences. For Eriophyoid mites, genera Cecidophyopsis and Aceria were both well supported in MP, NJ, ME and ML tress based on D1 sequences, and clusters of Cecidophyopsis species were identical with former study. This demonstrated that the D1 region could act as a valuable molecular marker in phylogenetic reconstruction of Eriophyoidea. Additionally, D1 has been proven suitable in phylogenetic analysis at the family and genus level in Acari, but not in Opiliones. [ABSTRACT FROM AUTHOR]

Objective To find a feasible method for skill training of the microsurgical vasoepididymostomy in andrology by establishing a rabbit model of obstructive azoospermia. Methods According to age, weight and semen analysis, 38 healthy male California rabbits aged 5~6 months were selected as the experiment objects to establish a model of obstructive azoospermia by bilateral vasoligation. After 2 months, if no sperm was found in the sperm examination, rabbits were given the vas deferens epididymal duct microsurgical anastomosis. Within 2~4 months after surgery, rabbit semen was collected for a period of 3 months, with 3 times per month and the interval of 3 days. Semen was detected using SCA sperm quality analyzer and the main semen parameters were recorded. If there was no sperm, the semen samples were centrifuged and examined at high magnification for the final result. Results (1) During the establishment of the rabbit model of obstructive azoospermia, 1 case died of the necrosis of testis and epididymis and infection, and 1 case died of sudden cardiac arrest because the anesthetic injection was too fast. The establishment of obstruction model of the others 36 cases went well, no postoperative fever, diarrhea, etc. (2) As for the anastomosing site, two rabbits received unilateral anastomosis because the other proximal vas deferens dwindled and adhered to tunica vaginalis and spermatic cord severely, the others went well. (3) After four months of the operation, the results of semen analysis showed sperm in 23 male rabbits semen were detected, only a few sperm in 4 rabbits semen were found at high magnification after centrifuged without the results of semen analysis, sperm in 3 cases had been detected in midway but no sperm in the following experiment. Conclusion This study confirmed the feasibility of microsurgical vasoepididymostomy of animal experiment, which has the advantages of simplicity, minimal invasi and safety. The model can be used as a skills training platform for clinical doctors in andrology, and is worth further research and promotion. [ABSTRACT FROM AUTHOR]

Abstract: Micrometer Li1.05Mn1.95O4 has been synthesized by solid state reactions with the nano-Mn3O4 as a precursor. X-ray diffraction, scanning electron microscopy and laser particle sizer are employed to investigate the structures, morphologies and particle size distributions of the powder. The micrometer Li1.05Mn1.95O4 exhibits good rate performance at room temperature with a specific capacity of 98.4mAhg−1 at 5C. The Li1.05Mn1.95O4/Li half cell also shows good cycling performance at elevated temperature with 90.5% of its initial capacity retained after 100 cycles at 1C. At −20°C, the Li1.05Mn1.95O4 delivers a stable cycling performance with a specific capacity of 84.5mAhg−1, being 84.1% of the capacity at room temperature. The cyclic voltammetry (CV) and rate performance measurements illustrate an increasing polarization with decreasing the temperature. In addition, the diffusion coefficients of lithium ions in Li1.05Mn1.95O4 at various temperatures (25, 0, −10 and −20°C) are determined to be in the magnitude of 10−10 to 10−12 cm2 s−1 by cyclic voltammetry (CV) method. [Copyright &y& Elsevier]

Abstract: Among various anode materials for lithium ion batteries, MnO has attracted a wide-spread attention for its low charge potential (1.0V vs. Li/Li+) and high theoretical capacity (755mAhg−1). In this paper, we propose a facile way to synthesize carbon-coated nano-MnO powders (MnO/C). Mn3O4 nanoparticles with a particle size of about 20nm are firstly obtained in an alcoholysis process of manganese acetate tetrahydrate with diethylene glycol as the solvent. Then glucose is used as both a carbon source and a reducing agent to prepare MnO/C nanospheres. From the mixtures of Mn3O4 and glucose, nano-MnO/C composites with a carbon content up to 18.1wt% are obtained. X-ray diffraction and transmission electron microscopy are used to analyze the structures of the nano-Mn3O4 and nano-MnO/C composites. The electrochemical properties of the nano-MnO/C composites are also characterized. The electrode made from 10.7wt%-carbon-coated MnO/C shows very stable cycling performance with a high reversible capacity of 939.3mAhg−1 after 30 cycles at 0.1C. This electrode also shows favorable rate performance with specific capacities of 726.7, 686.8, 633.0 and 587.9mAhg−1 at 1C, 2C, 5C and 10C, respectively. [Copyright &y& Elsevier]

Abstract: Three-dimensional (3D) porous V2O5 and Fe0.1V2O5.15 thin films have been prepared by electrostatic spray deposition technique. X-ray diffraction, scanning electron microscopy and X-ray photoelectron spectroscopy are employed to investigate the structures and valence states of the films. Galvanostatic cell cycling, cyclic voltammetry and impedance spectroscopy are used to characterize their electrochemical properties. The Fe0.1V2O5.15 thin film shows much better cycling performance than the non-doped V2O5 thin film. Fe3+ can act as a stabilizing agent in the layered V2O5 and increase the reversibility of the charge and discharge processes towards deeper depth of lithium insertion/extraction. The dissolution of the active material in the electrolyte can also be significantly suppressed in the Fe-doped sample. Nevertheless, the Fe-doping causes a slight decrease in lithium ion diffusion coefficient. [Copyright &y& Elsevier]