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111.
Schwannomas are common peripheral nerve sheath tumors that typically occur on the head, neck, trunk, or extremities. Intra-abdominal schwannomas, however, are rare. We describe a young woman who presented for imaging evaluation of suspected nephrolithiasis and was incidentally found to have a schwannoma centered within the pancreatic parenchyma. In addition, we detail the clinical, imaging, and histopathologic features of pancreatic schwannoma and summarize diagnosis and management of this rare clinical entity.  相似文献   
112.
The amino acid L-arginine is crucial for nitric oxide (NO) synthesis, an important molecule regulating vascular tone. Considering that vascular dysfunction precedes cardiovascular disease, supplementation with precursors of NO synthesis (e.g., L-arginine) is warranted. However, supplementation of L-citrulline is recommended instead of L-arginine since most L-arginine is catabolized during its course to the endothelium. Given that L-citrulline, found mainly in watermelon, can be converted to L-arginine, watermelon supplementation seems to be effective in increasing plasma L-arginine and improving vascular function. Nonetheless, there are divergent findings when investigating the effect of watermelon supplementation on vascular function, which may be explained by the L-citrulline dose in watermelon products. In some instances, offering a sufficient amount of L-citrulline can be impaired by the greater volume (>700 mL) of watermelon needed to reach a proper dose of L-citrulline. Thus, food technology can be applied to reduce the watermelon volume and make supplementation more convenient. Therefore, this narrative review aims to discuss the current evidence showing the effects of watermelon ingestion on vascular health parameters, exploring the critical relevance of food technology for acceptable L-citrulline content in these products. Watermelon-derived L-citrulline appears as a supplementation that can improve vascular function, including arterial stiffness and blood pressure. Applying food technologies to concentrate bioactive compounds in a reduced volume is warranted so that its ingestion can be more convenient, improving the adherence of those who want to ingest watermelon products daily.  相似文献   
113.
From 2010 to 2013, genotype I avian influenza A(H9N2) viruses of the G1-lineage were isolated from several poultry species in Egypt. In 2014, novel reassortant H9N2 viruses were detected in pigeons designated as genotype II. To monitor the subsequent genetic evolution of Egyptian A(H9N2) viruses, we characterized the full genomes of 173 viruses isolated through active surveillance from 2017 to 2022. In addition, we compared the virological characteristics and pathogenicity of representative viruses. Phylogenetic analysis of the HA indicated that all studied sequences from 2017–2021 were grouped into G1-like H9N2 viruses previously detected in Egypt. Phylogenetic analysis indicated that the Egyptian A(H9N2) viruses had undergone further reassortment, inheriting four genes (PB2, PB1, PA, NS) from genotype II, with their remaining segments deriving from genotype I viruses (these viruses designated as genotype III). Studying the virological features of the two most dominant genotypes (I and III) of Egyptian H9N2 viruses in vitro and in vivo indicated that both replicated well in mammalian cells, but did not show any clinical signs in chickens, ducks, and mice. Monitoring avian influenza viruses through surveillance programs and understanding the genetic and antigenic characteristics of circulating H9N2 viruses are essential for risk assessment and influenza pandemic preparedness.  相似文献   
114.
Serological assays capable of measuring antibody responses induced by previous infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been critical tools in the response to the COVID-19 pandemic. In this study, we use bead-based multiplex assays to measure IgG and IgA antibodies and IgG avidity to five SARS-CoV-2 antigens (Spike (S), receptor-binding domain (RBD), Nucleocapsid (N), S subunit 2, and Membrane-Envelope fusion (ME)). These assays were performed in several cohorts of healthcare workers and nursing home residents, who were followed for up to eleven months after SARS-CoV-2 infection or up to six months after vaccination. Our results show distinct kinetic patterns of antibody quantity (IgG and IgA) and avidity. While IgG and IgA antibody levels waned over time, with IgA antibody levels waning more rapidly, avidity increased with time after infection or vaccination. These contrasting kinetic patterns allow for the estimation of time since previous SARS-CoV-2 infection. Including avidity measurements in addition to antibody levels in a classification algorithm for estimating time since infection led to a substantial improvement in accuracy, from 62% to 78%. The inclusion of antibody avidity in panels of serological assays can yield valuable information for improving serosurveillance during SARS-CoV-2 epidemics.  相似文献   
115.
The article presents research on ergonomics, biophysical comfort and safety of protective clothing. The resistance of the structural, thermal and mechanical properties of five fabrics (CBXS400, GG200T, Twaron CT736, Dyneema HB26 and T1790C), differing in geometry and raw material composition used in space suits, to dangerous ionizing radiation (β and γ) occurring in space was tested. For both types of radiation, four identical one-time doses in the range of 25–100 kGy were used. The effect of the applied absorbed doses of β and γ radiation on the parameters of textiles influencing ergonomics and safety of the cosmonaut’s work was verified by structural tests (micro-computed tomography and optical microcopy), thermal resistance tests (sweating guarded-hotplate) and strength tests (tensile testing machine). Experimental studies of thermal properties are supplemented with heat transport simulations using the finite volume method performed with 3D models of real textiles. The greatest reduction of thermal resistance for Twaron CT736 (−0.0667 m2·°C·W−1 for 100 kGy of β-radiation) and Dyneema HB26 (−0.0347 m2·°C·W−1 for 50 kGy of β-radiation) is observed. Strength tests have shown that all tested textiles are resistant to both types of radiation. Three textiles were selected to create a three-layer assembly with potential application in a cosmonaut’s glove (Extravehicular Activity—EVA).  相似文献   
116.
Following a stroke, a patient may present with varying degrees of neurological impairment, depending on the area of the brain which is damaged. Specifically, damage to the left cortical hemisphere may result in aphasia. The characteristic speech in a patient with an aphasia caused by a stroke can be similar to the speech in some patients with schizophrenia or other psychotic disorders. In a new patient without a reliable history who presents with suspected aphasia, it is important to include psychotic disorders as part of the differential diagnosis. Failure to differentiate psychotic disorders from aphasia could result in either a lack of treatment that would improve the patient's thought process, thought content, or language, or in a delayed treatment for a stroke, respectively. While a number of psychotic disorders exist and must be differentiated from one another in accordance with DSM-IV guidelines, speech abnormalities in patients with schizophrenia are well described in the literature. For this reason, schizophrenia is the psychotic disorder of focus in this paper. This case report illustrates a clinical situation where a patient required both a psychiatric and neurological consultation in order to determine the etiology of his language disorder. The purpose of this paper is to emphasize the need to consider both psychiatric disorders and aphasia in patients with unknown histories who present with language abnormalities, and to help the clinician critically examine the patient's speech so that, in conjunction with other clinical data, the correct diagnosis can be made and appropriate treatment initiated.  相似文献   
117.
Nanotechnology experienced a great technological advance after the discovery of the graphene family (graphene – Gr, graphene oxide – GO, and reduced graphene oxide-rGO). Based on the excellent properties of these materials, it is possible to develop novel polymeric nanocomposites for several applications in our daily routine. One of the most prominent applications is for food packaging, offering nanocomposites with improved thermal, mechanical, anti-microbial, and barrier properties against gas and water vapor. This paper reviewed food packaging from its inception to the present day, with the development of more resistant and intelligent packaging. Herein, the most common combinations of polymeric matrices (derived from non-renewable and renewable sources) with Gr, GO, and rGO and their typical preparation methods are presented. Besides, the interactions present in these nanocomposites will be discussed in detail, and their final properties will be thoroughly analyzed as a function of the preparation technique and graphene family-matrix combinations.

Food packaging based on nanotechnology of polymeric nanocomposites of graphene and graphene oxide results in packaging with better thermal, mechanical, antimicrobial, electrical packaging, moisture barrier and gas properties.  相似文献   
118.
The process of platinum recovery from used car catalysts is highly desirable for both economic and environmental reasons. From the many available methods of processing used car catalysts, the article conducted both numerical and experimental studies using a device based on the collector metal method with lead as a modified medium through a magnetohydrodynamic pump for washing platinum from the channels of the ceramic catalyst carrier. It was assumed that lead alloys with the addition of lithium increase the extraction of platinum from thin catalytic layers and accelerate the platinum dissolution reaction in the Pb-Li alloy, which is the result of a greater affinity of lithium for platinum compared to lead. This assumption was verified by numerical simulations as well as laboratory tests. Tests were carried out for the secondary supply voltage range between 40 and 60 V and the catalyst flushing time between 240 and 480 s. Graphical results of the research were discussed.  相似文献   
119.
Berger AC  Watson JC  Ross EA  Zalatoris A  Hoffman JP 《The American surgeon》2004,70(2):169-73; discussion 173-4
Increased expression of vascular endothelial growth factor (VEGF) by pancreatic cancer correlates with poor survival. The significance of VEGF in biliary and pancreatic secretions in periampullary cancers is unknown. Bile and pancreatic juice samples were collected from patients undergoing pancreaticoduodenectomy (PD). All samples were frozen at -70 degrees C until subsequent analysis for VEGF concentration using enzyme-linked immunoabsorbent assay (ELISA). Plasma VEGF levels in pancreatic cancer patients were <10 pg/mL. The biliary VEGF concentration for patients with malignancy was significantly elevated compared to benign disease (P = 0.05). There was no difference in pancreatic VEGF concentrations between benign and malignant disease. Cancer patients undergoing preoperative chemoradiation (CRT) had lower biliary and pancreatic VEGF concentrations than those who did not. Preoperative biliary drainage (BD) was associated with decreased VEGF concentrations in bile (3500 pg/mL vs 7740 pg/mL, P = 0.027). Patients undergoing both CRT and BD had diminished biliary and pancreatic VEGF concentrations compared to those who had neither. This was statistically significant for pancreatic VEGF concentrations (917 pg/mL vs 4723 pg/mL, P = 0.044). VEGF is highly concentrated in bile and pancreatic juice compared to plasma. Preoperative CRT and BD significantly reduce these levels in patients with periampullary cancers. Antiangiogenic therapy aimed at interrupting the VEGF pathway appears to be a logical target in periampullary cancer.  相似文献   
120.
TGF-β Induces Foxp3 + T-Regulatory Cells from CD4 + CD25 − Precursors   总被引:2,自引:0,他引:2  
CD4 + CD25 + regulatory T cells (Tregs) are potent suppressors, playing important roles in autoimmunity and transplantation tolerance. Understanding the signals necessary for the generation and expansion of Tregs is important for clinical cellular therapy, but only limited progress has been made. Recent reports suggest a role for TGF-beta in the generation of Tregs from CD4 + CD25 - precursors, but the mechanism remains unknown. Here, we demonstrate that TGF-beta2 triggers Foxp3 expression in CD4 + CD25 - precursors, and these Foxp3 + cells act like conventional Tregs. The generation of Foxp3 + Tregs requires stimulation of the T-cell receptor, the IL-2R and the TGF-beta receptor. More importantly, strong costimulation through CD28 prevents Foxp3 expression and suppressive function in an IL-4-dependent manner. Furthermore, TGF-beta-driven Tregs inhibit innate inflammatory responses to syngeneic transplanted pancreatic islets and enhance islet transplant survival. Thus, TGF-beta is a key regulator of the signaling pathways that initiate and maintain Foxp3 expression and suppressive function in CD4 + CD25 - precursors. TGF-beta and signaling through TGF-beta receptor, CD28 costimulation and IL-4 may be key components for the manipulation of Treg. The de novo generation of Foxp3 + cells from CD4 + cells has the potential to be used for treatment of autoimmune diseases and induction of transplant tolerance.  相似文献   
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