5,622 research outputs found

    Continuum understanding of twin formation near grain boundaries of FCC metals with low stacking fault energy

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    Deformation twinning from grain boundaries is often observed in face-centered cubic metals with low stacking fault energy. One of the possible factors that contribute to twinning origination from grain boundaries is the intergranular interactions during deformation. Nonetheless, the influence of mechanical interaction among grains on twin evolution has not been fully understood. In spite of extensive experimental and modeling efforts on correlating microstructural features with their twinning behavior, a clear relation among the large aggregate of grains is still lacking. In this work, we characterize the micromechanics of grain-to-grain interactions that contribute to twin evolution by investigating the mechanical twins near grain boundaries using a full-field crystal plasticity simulation of a twinning-induced plasticity steel deformed in uniaxial tension at room temperature. Microstructures are first observed through electron backscatter diffraction technique to obtain data to reconstruct a statistically equivalent microstructure through synthetic microstructure building. Grain-to-grain micromechanical response is analyzed to assess the collective twinning behavior of the microstructural volume element under tensile deformation. Examination of the simulated results reveal that grain interactions are capable of changing the local mechanical behavior near grain boundaries by transferring strain across grain boundary or localizing strain near grain boundary.116Ysciescopu

    Inflammatory cloacogenic polyps in children: diagnostic yield of rectal retroflexion during colonoscopy

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    Abstract Background and aims Inflammatory cloacogenic polyps (ICPs) are inflammatory lesions occurring around the anal transitional zone. These are rare in the pediatric population, and most reported cases are found in adults. Therefore, this study aimed to evaluate the usefulness of rectal retroflexion (RR) during colonoscopy in detecting ICPs in children. Methods A total of 1837 colonoscopies were performed in 1278 children between September 2003 and August 2020 at the Seoul National University Bundang Hospital. The laboratory test results and colonoscopic and histopathological findings were retrospectively reviewed. ICP was detected using the RR and was diagnosed based on the histologic findings of the polyp. Results A total of 69 patients were diagnosed with juvenile polyps (n = 62) or ICP (n = 7), with the latter being detected through RR. All children with ICP were diagnosed from 2013 onwards when RR during colonoscopy came to be routinely performed in our medical center. The patients with ICP were older at diagnosis and more associated with a family history of colorectal polyps than JP. Stool occult blood and the polyps endoscopic characteristics, such as number, location, volume, and shape, significantly varied between the two groups. Additionally, there was a statistically significant difference in the polypectomy method. During the long-term follow-up, there was no recurrence of ICP. Conclusions Due to their location at the anorectal junction, ICPs may be overlooked during colonoscopy, leading to misdiagnosis. Therefore, a retroflexion view during colonoscopy may help detect ICPs in pediatric patients, especially those presenting with hematochezia

    Separation of glycine-rich proteins from sea hare eggs and their anti-cancer activity against U937 leukemia cell line

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    The present study was designed to investigate the anti-cancer effects of Sea hare eggs (SE) in U937 cells and its major active components. The aqueous extract of SE (ASE), which contained the highest protein content, dosedependently inhibited the cancer cell’s growth (IC50 value, 10.42 ± 0.5 μg/mL). Additionally, ASE markedly caused DNA damage by inducing apoptotic body formation, DNA fragmentation, and accumulation of sub-G1 DNA contents. ASE induced apoptosis by activating caspase-3 and 9 and poly (ADP-ribose) polymerase (PARP) by regulating the expression of Bcl-2/Bax. Moreover, among its molecular weight fractions, the > 30 kDa fraction showed the highest cell-growth-inhibitory effects, which was inhibited by heat treatment. Furthermore, the > 30 kDa fraction had markedly higher glycine content than the ASE. The presence of two protein bands at around 16 and 32 kDa was identified. In addition, two fractions, F1 and F2, were obtained using anion-exchange chromatography, with the F1 having an improved cell-growth-inhibitory effect than the > 30 kDa fraction. Taken together, these results suggest that the ASE contains glycine-rich proteins, including the active 16 and 32 kDa proteins, which account for its anti-cancer effects by inducing apoptosis via regulation of the mitochondrial pathway

    Social Pressure-Induced Craving in Patients with Alcohol Dependence: Application of Virtual Reality to Coping Skill Training

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    OBJECTIVE: This study was conducted to assess the interaction between alcohol cues and social pressure in the induction of alcohol craving. METHODS: Fourteen male patients with alcohol dependence and 14 age-matched social drinkers completed a virtual reality coping skill training program composed of four blocks according to the presence of alcohol cues (x2) and social pressure (x2). Before and after each block, the craving levels were measured using a visual analogue scale. RESULTS: Patients with alcohol dependence reported extremely high levels of craving immediately upon exposure to a virtual environment with alcohol cues, regardless of social pressure. In contrast, the craving levels of social drinkers were influenced by social pressure from virtual avatars. CONCLUSION: Our findings imply that an alcohol cue-laden environment should interfere with the ability to use coping skills against social pressure in real-life situations.ope

    Limited type I interferons and plasmacytoid dendritic cells during neonatal respiratory syncytial virus infection permit immunopathogenesis upon reinfection

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    Respiratory syncytial virus (RSV) infection is the number one cause of bronchiolitis in infants, yet no vaccines are available because of a lack of knowledge of the infant immune system. Using a neonatal mouse model, we previously revealed that mice initially infected with RSV as neonates develop Th2-biased immunopathophysiologies during reinfection, and we demonstrated a role for enhanced interleukin-4 receptor α (IL-4Rα) expression on T helper cells in these responses. Here we show that RSV infection in neonates induced limited type I interferon (IFN) and plasmacytoid dendritic cell (pDC) responses. IFN alpha (IFN-α) treatment or adoptive transfer of adult pDCs capable of inducing IFN-α prior to neonatal RSV infection decreased Th2-biased immunopathogenesis during reinfection. A reduced viral load and downregulation of IL-4Rα on Th2 cells were observed in IFN- α-treated neonatal mice, suggesting dual mechanisms of action. © 2014, American Society for Microbiology

    Perturbative Expansion around the Gaussian Effective Potential of the Fermion Field Theory

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    We have extended the perturbative expansion method around the Gaussian effective action to the fermionic field theory, by taking the 2-dimensional Gross-Neveu model as an example. We have computed both the zero temperature and the finite temperature effective potentials of the Gross-Neveu model up to the first perturbative correction terms, and have found that the critical temperature, at which dynamically broken symmetry is restored, is significantly improved for small value of the flavour number.Comment: 14pages, no figures, other comments Typographical errors are corrected and new references are adde

    Genitourinary Rhabdomyosarcoma with Systemic Metastasis in a Young Dog

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    A 2-year-old intact female Golden Retriever presented due to rapidly progressing depression, ascites, dysuria, abdominal pain, and severe vaginal bleeding. At necropsy, the retroperitoneal space was expanded by multiple coalescing neoplastic nodules and the uterine wall was thickened with poorly defined neoplastic infiltrates. The urinary bladder was markedly thickened due to botryoid nodules exhibiting exophytic growth into the lumen. Metastases to lung, liver, kidney, and abdominal and thoracic lymph nodes were also noted. Microscopically, the genital tract and retroperitoneal masses were consistent with the alveolar subtype of rhabdomysarcoma, while the urinary bladder mass had characteristics of the embryonal subtype. Immunohistochemically, the neoplastic cells in all these tissue sites were intensely positive for desmin, sacromeric actin, and vimentin, while they were uniformly negative for cytokeratin and smooth muscle actin. Phosphotungstic acid hematoxylin stain revealed cross-striations in the cytoplasm of scattered neoplastic cells. Based on the gross findings, histopathology, and immunohistochemistry, genitourinary rhabdomyosarcoma with multisystemic metastases was made.This work was supported through the Brain Korea 21 Program for Veterinary Science and by Korean Research Foundation (KRF-2006-005-J02901). The authors thank Dr. Mac Law at North Carolina State University for critical review and comments and Sandra Horton (North Carolina State University) for expertise in staining

    Identification of Serum MicroRNAs as Novel Non-Invasive Biomarkers for Early Detection of Gastric Cancer

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    BACKGROUND: To investigate the potential of serum miRNAs as biomarkers for early detection of gastric cancer (GC), a population-based study was conducted in Linqu, a high-risk area of GC in China. METHODOLOGY/PRINCIPAL FINDINGS: All subjects were selected from two large cohort studies. Differential miRNAs were identified in serum pools of GC and control using TaqMan low density array, and validated in individual from 82 pairs of GC and control, and 46 pairs of dysplasia and control by real-time quantitative reverse transcription-polymerase chain reaction. The temporal trends of identified serum miRNA expression were further explored in a retrospective study on 58 GC patients who had at least one pre-GC diagnosis serum sample based on the long-term follow-up population. The miRNA profiling results demonstrated that 16 miRNAs were markedly upregulated in GC patients compared to controls. Further validation identified a panel of three serum miRNAs (miR-221, miR-744, and miR-376c) as potential biomarkers for GC detection, and receiver operating characteristic (ROC) curve-based risk assessment analysis revealed that this panel could distinguish GCs from controls with 82.4% sensitivity and 58.8% specificity. MiR-221 and miR-376c demonstrated significantly positive correlation with poor differentiation of GC, and miR-221 displayed higher level in dysplasia than in control. Furthermore, the retrospective study revealed an increasing trend of these three miRNA levels during GC development (P for trend<0.05), and this panel could classify serum samples collected up to 5 years ahead of clinical GC diagnosis with 79.3% overall accuracy. CONCLUSIONS/SIGNIFICANCE: These data suggest that serum miR-221, miR-376c and miR-744 have strong potential as novel non-invasive biomarkers for early detection of GC
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