1,862 research outputs found

    In vivo characterization of early-stage radiation skin injury in a mouse model by two-photon microscopy

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    Ionizing radiation (IR) injury is tissue damage caused by high energy electromagnetic waves such as X-ray and gamma ray. Diagnosis and treatment of IR injury are difficult due to its characteristics of clinically latent post-irradiation periods and the following successive and unpredictable inflammatory bursts. Skin is one of the many sensitive organs to IR and bears local injury upon exposure. Early-stage diagnosis of IR skin injury is essential in order to maximize treatment efficiency and to prevent the aggravation of IR injury. In this study, early-stage changes of the IR injured skin at the cellular level were characterized in an in vivo mouse model by two-photon microscopy (TPM). Various IR doses were applied to the mouse hind limbs and the injured skin regions were imaged daily for 6 days after IR irradiation. Changes in the morphology and distribution of the epidermal cells and damage of the sebaceous glands were observed before clinical symptoms. These results showed that TPM is sensitive to early-stage changes of IR skin injury and may be useful for its diagnosis.1194Ysciescopu

    Effect of temperature anisotropy on various modes and instabilities for a magnetized non-relativistic bi-Maxwellian plasma

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    Using kinetic theory for homogeneous collisionless magnetized plasmas, we present an extended review of the plasma waves and instabilities and discuss the anisotropic response of generalized relativistic dielectric tensor and Onsager symmetry properties for arbitrary distribution functions. In general, we observe that for such plasmas only those electromagnetic modes whose magnetic field perturbations are perpendicular to the ambient magneticeld, i.e.,B1 \perp B0, are effected by the anisotropy. However, in oblique propagation all modes do show such anisotropic effects. Considering the non-relativistic bi-Maxwellian distribution and studying the relevant components of the general dielectric tensor under appropriate conditions, we derive the dispersion relations for various modes and instabilities. We show that only the electromagnetic R- and L- waves, those derived from them and the O-mode are affected by thermal anisotropies, since they satisfy the required condition B1\perpB0. By contrast, the perpendicularly propagating X-mode and the modes derived from it (the pure transverse X-mode and Bernstein mode) show no such effect. In general, we note that the thermal anisotropy modifies the parallel propagating modes via the parallel acoustic effect, while it modifies the perpendicular propagating modes via the Larmor-radius effect. In oblique propagation for kinetic Alfven waves, the thermal anisotropy affects the kinetic regime more than it affects the inertial regime. The generalized fast mode exhibits two distinct acoustic effects, one in the direction parallel to the ambient magnetic field and the other in the direction perpendicular to it. In the fast-mode instability, the magneto-sonic wave causes suppression of the firehose instability. We discuss all these propagation characteristics and present graphic illustrations

    Extrarenal multiorgan metastases of collecting duct carcinoma of the kidney: A case series

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    <p>Abstract</p> <p>Introduction</p> <p>Collecting duct carcinoma is a rare type of renal cell carcinoma. The primary is difficult to diagnose on imaging, and metastases are often present on initial presentation. Extensive multiorgan metastases can result in complex presentations that can be difficult to diagnose.</p> <p>Case presentation</p> <p>We present two case reports of multiorgan metastases of collecting duct carcinoma that were autopsy confirmed. The first case was a 55-year-old man who presented with fever and abdominal pain. Abdominal computed tomography showed enlargement of the right kidney. Pyelonephritis was considered on the basis of laboratory test results and imaging findings. However, multiple cavitary lesions were found on routine chest radiography. These lesions were biopsied, resulting in a histological diagnosis of metastatic adenocarcinoma. A renal tumor was considered. Transitional cell carcinoma was suspected, which proved to be misdiagnosed and chemotherapy was given accordingly. However, this was not effective and the patient died after 2 months. Autopsy demonstrated the primary tumor to be collecting duct carcinoma, with metastases to lung, liver, spleen, bone marrow, right adrenal gland, and para-aortic lymph node. Computed tomography done while the patient was alive detected lung, liver, and para-aortic lymph node metastases. The second case was a 77-year-old man who presented with fever. Pyelonephritis was considered on the basis of the laboratory test results and imaging findings. Antibiotic therapy improved his symptoms and laboratory indicators of inflammation. One year later, he developed backache. Computed tomography revealed a progressively enlarging right renal lesion, multiple liver masses, enlargement of the para-aortic lymph nodes, and multiple osteoblastic and osteoclastic lesions. A renal tumor with multiple metastases was diagnosed. Chemotherapy was given without effect, and the patient died of cardiac failure 1 year later. Autopsy revealed a primary tumor of collecting duct carcinoma with metastases to the liver, right adrenal gland, right upper ureter, bone marrow, para-aortic and mediastinal lymph nodes, and bone.</p> <p>Conclusion</p> <p>We present the radiological findings of lung, liver, lymph node, and bone metastases in two patients with collecting duct carcinoma.</p

    Atomic-scale combination of germanium-zinc nanofibers for structural and electrochemical evolution

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    Alloys are recently receiving considerable attention in the community of rechargeable batteries as possible alternatives to carbonaceous negative electrodes; however, challenges remain for the practical utilization of these materials. Herein, we report the synthesis of germanium-zinc alloy nanofibers through electrospinning and a subsequent calcination step. Evidenced by in situ transmission electron microscopy and electrochemical impedance spectroscopy characterizations, this one-dimensional design possesses unique structures. Both germanium and zinc atoms are homogenously distributed allowing for outstanding electronic conductivity and high available capacity for lithium storage. The as-prepared materials present high rate capability (capacity of similar to 50% at 20 C compared to that at 0.2 C-rate) and cycle retention (73% at 3.0 C-rate) with a retaining capacity of 546 mAh g(-1) even after 1000 cycles. When assembled in a full cell, high energy density can be maintained during 400 cycles, which indicates that the current material has the potential to be used in a large-scale energy storage system

    Global distribution and diversity of marine Verrucomicrobia

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    Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of Nature Publishing Group for personal use, not for redistribution. The definitive version was published in The ISME Journal 6 (2012): 1499-1505, doi:10.1038/ismej.2012.3.Verrucomicrobia is a bacterial phylum that is commonly detected in soil but little is known about the distribution and diversity of this phylum in the marine environment. To address this, we analyzed the marine microbial community composition in 506 samples from the International Census of Marine Microbes as well as eleven coastal samples taken from the California Current. These samples from both the water column and sediments covered a wide range of environmental conditions. Verrucomicrobia were present in 98% of the analyzed samples and thus appeared nearly ubiquitous in the ocean. Based on the occurrence of amplified 16S rRNA sequences, Verrucomicrobia constituted on average 2% of the water column and 1.4% of the sediment bacterial communities. The diversity of Verrucomicrobia displayed a biogeography at multiple taxonomic levels and thus, specific lineages appeared to have clear habitat preference. We found that Subdivision 1 and 4 generally dominated marine bacterial communities, whereas Subdivision 2 was confined to low salinity waters. Within the subdivisions, Verrucomicrobia community composition were significantly different in the water column compared to sediment as well as within the water column along gradients of salinity, temperature, nitrate, depth, and overall water column depth. Although we still know little about the ecophysiology of Verrucomicrobia lineages, the ubiquity of this phylum suggests that it may be important for the biogeochemical cycle of carbon in the ocean.We would like to thank the UCI Undergraduate Research Opportunity Program (S.F.), the National Science Foundation (OCE-0928544 and OCE-1046297, A.C.M.) and the Alfred P. Sloan Foundation (S.H., D.M.W., M.S.) for supporting the work

    Intraductal papillary mucinous tumor of bile ducts radiologic and pathologic features: a case report

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    We report a case of a 67-year-old Caucasian man with right upper quadrant abdominal pain. He underwent radiologic investigations that revealed a solid, focal mass, at the V hepatic segment. Because a definitive diagnosis, based on imaging appearance of the lesion, was impossible in our case, we performed a hystopathological investigation but the biopsies were inconclusive. So, the definitive diagnosis of intraductal papillary mucinous tumor of bile ducts was made on surgical resected material

    Significant associations of PAI-1 genetic polymorphisms with osteonecrosis of the femoral head

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    <p>Abstract</p> <p>Background</p> <p>The pathogenesis of osteonecrosis of the femoral head (ONFH) has been implicated in hypofibrinolysis and blood supply interruption. Previous studies have demonstrated that decreased fibrinolytic activity due to elevated plasminogen activator inhibitor-1 (PAI-1) levels correlates with ONFH pathogenesis. The -675 4G/5G single nucleotide polymorphism (SNP rs1799889) in the PAI-1 gene promoter is associated with PAI-1 plasma level. We investigated whether rs1799889 and two other SNPs of the PAI-1 gene (rs2227631, -844 G/A in the promoter; rs11178, +10700 C/T in the 3'UTR) are associated with increased ONFH risk.</p> <p>Methods</p> <p>Three SNPs in PAI-1 were genotyped in 206 ONFH patients and 251 control subjects, using direct sequencing and a TaqMan<sup>® </sup>5' allelic discrimination assay. We performed association analysis for genotyped SNPs and haplotypes with ONFH.</p> <p>Results</p> <p>The 4G allele of rs1799889, A allele of rs2227631, and C allele of rs11178 were significantly associated with increased ONFH risk (p = 0.03, p = 0.003, and p = 0.002, respectively). When we divided the population according to gender, an association between the three SNPs and increased risk of ONFH was found only in men. In another subgroup analysis based on the etiology of ONFH, rs2227631 (A allele) and rs11178 (C allele) in the idiopathic subgroup (p = 0.007 and p = 0.021) and rs1799889 (4G allele) and rs11178 (C allele) in the alcohol-induced subgroup (p = 0.042 and p = 0.015) were associated with increased risk of ONFH. In addition, a certain haplotype (A-4G-C) of PAI-1 was also significantly associated with ONFH (p < 0.001).</p> <p>Conclusion</p> <p>Our findings demonstrated that three SNPs (rs1799889, rs2227631, and rs11178) of the PAI-1 gene were associated with ONFH risk. This study also suggests that PAI-1 SNPs may play an important role in ONFH.</p
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