2,851 research outputs found

    Increased expression of two alternative spliced variants of CD1d molecule in human gastric cancer

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    Background: CD1d presents glycolipid antigens to invariant natural killer T (iNKT) cells. The role of CD1d in the development of peptic ulcer and gastric cancer has not been revealed, yet. Objective: To clarify the expression of alternatively spliced variants of CD1d in peptic ulcer and gastric cancer. Methods: Patients with dyspepsia were selected and divided into three groups of non-ulcer dyspepsia (NUD), peptic ulcer disease (PUD), and gastric cancer (GC), according to their endoscopic and histopathological examinations. H. pylori infection was diagnosed by rapid urease test and histopathology. The expression levels of V2, V4, and V5 spliced variants of CD1d molecule were determined by quantitative Reverse Transcriptase PCR. Results: Relative gene expression levels of V4 were higher in GC patients (n=37) than those in NUD (n=49) and PUD (n=51) groups (p<0.05 and p<0.01, respectively). Moreover, GC patients showed higher expression levels of V5 compared to NUD and PUD groups (p<0.001 and p<0.001, respectively). Positive correlation coefficients were attained between V4 and V5 expression in patients with PUD (r=0.734, p<0.0001) and GC (r=0.423, p<0.01), but not in patients with NUD. Among NUD patients, the expression levels of V4, but not V5, were higher in H. pylori-positive patients than in H. pylori-negative ones (p<0.01). Conclusion: Collectively, both membrane-bound (V4) and soluble (V5) isoforms of CD1d were over-expressed in gastric tumor tissues, suggesting that they are involved in anti-tumor immune responses. © 2015, Shiraz University of Medical Sciences. All rights reserved

    Fastpass: A Centralized “Zero-Queue” Datacenter Network

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    An ideal datacenter network should provide several properties, including low median and tail latency, high utilization (throughput), fair allocation of network resources between users or applications, deadline-aware scheduling, and congestion (loss) avoidance. Current datacenter networks inherit the principles that went into the design of the Internet, where packet transmission and path selection decisions are distributed among the endpoints and routers. Instead, we propose that each sender should delegate control—to a centralized arbiter—of when each packet should be transmitted and what path it should follow. This paper describes Fastpass, a datacenter network architecture built using this principle. Fastpass incorporates two fast algorithms: the first determines the time at which each packet should be transmitted, while the second determines the path to use for that packet. In addition, Fastpass uses an efficient protocol between the endpoints and the arbiter and an arbiter replication strategy for fault-tolerant failover. We deployed and evaluated Fastpass in a portion of Facebook’s datacenter network. Our results show that Fastpass achieves high throughput comparable to current networks at a 240 reduction is queue lengths (4.35 Mbytes reducing to 18 Kbytes), achieves much fairer and consistent flow throughputs than the baseline TCP (5200 reduction in the standard deviation of per-flow throughput with five concurrent connections), scalability from 1 to 8 cores in the arbiter implementation with the ability to schedule 2.21 Terabits/s of traffic in software on eight cores, and a 2.5 reduction in the number of TCP retransmissions in a latency-sensitive service at Facebook.National Science Foundation (U.S.) (grant IIS-1065219)Irwin Mark Jacobs and Joan Klein Jacobs Presidential FellowshipHertz Foundation (Fellowship

    Effect of synthetic and algal astaxanthin levels on egg astaxanthin content of rainbow trout (Oncorhynchus mykiss)

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    This research was done in a trout farm in Kohkiloyeh and Boyer- Ahmad province. The main object of this study was comparing of two sources of astaxanthin (synthetic or algae) in feed on astaxanthin content of egg in rainbow trout. It was considered seven groups consisting six treatments (T1-T6) in two different astaxanthin sources and a control (C) (without astaxanthin). So, algal astaxanthin (haematococcus pluvialis) in the three levels of 2.67, 3.55 and 8gr/kg food (T1,T2, T3); and synthetic astaxanthin in three levels of 40, 80 and 120mg/kg food in diet (T4, T5, T6) examined on 140 trout broods (3-4 years) for 4 months, before the spawning season. Astaxanthin content of obtained eggs from all treatments in spawning season was measured by HPLC apparatus. The highest and the lowest amount of egg astaxanthin were observed in T3 and C respectively. In each astaxanthin group, a significant difference was obtained between averages in treatments (P <0.05), as T3 was the highest between them. No significant difference was observed between synthetic astaxanthin treatments (T4, T5 and T6) and T1 (the lowest level of algal astaxanthin). Treatments T2 and T6 also had the same function in term of saving astaxanthin in eggs. It also concluded that natural astaxanthin (Haematococcus pluvialis) for the reason that contains supplementary nutritious, is extraordinary preferable than synthetic astaxanthin to improve astaxanthin content of egg in rainbow trout

    Effect of solute content and temperature on the deformation mechanisms and critical resolved shear stress in Mg-Al and Mg-Zn alloys

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    The influence of solute atoms (Al and Zn) on the deformation mechanisms and the critical resolved shear stress for basal slip in Mg alloys at 298 K and 373 K was ascertained by micropillar compression tests in combination with high-throughput processing techniques based on the diffusion couples. It was found that the presence of solute atoms enhances the size effect at 298 K as well as the localization of deformation in slip bands, which is associated with large strain bursts in the resolved shear stress (τRSS\tau_{RSS})-strain (ϵ\epsilon) curves. Deformation in pure Mg and Mg alloys was more homogeneous at 373 K and the influence of the micropillar size on the critical resolved shear stress was much smaller. In this latter case, it was possible to determine the effect of solute content on the critical resolved shear stress for basal slip in Mg-Al and Mg-Zn alloys

    Evaluation of egg vitamins A and E content in rainbow trout (Oncorhynchus mykiss Walbaum, 1792) broodstock affected by different levels of synthetic and natural (Heamatococcus pluvialis) astaxanthin

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    In present research, effect of dietary astaxanthin levels in sources of synthetic and algal on vitamins A and E content of egg rainbow trout broodstock was investigated, totally for 120 days. It was considered seven groups consisting six treatments (T1-T6) in two different astaxanthin sources and control (C). According to experiment design, treatments were arranged as algal astaxanthin (Haematococcus pluvialis) in the three levels of 2.67, 3.55 and 8gr/kg food (T1, T2, T3); and synthetic astaxanthin in three levels of 40, 80 and 120mg/kg food (T4, T5, T6). Egg vitamins A and E content in obtained eggs from all treatments during spawning season was measured. The highest (280.88± 22.51 ng) and the lowest (147.82± 12.71ng) amount of vitamin A were observed in T2 and control group, respectively. The highest (19.71± 2.92µg) and the lowest (5.27± 0.51µg) amount of vitamin E were obtained in T3 and control group, respectively. By increasing level of astaxanthin in both sources of algal and synthetic, content of vitamin E in egg increased but the effect of algal source on these indices was more perfect. In general present study show that, feeding broodstock affected on quality content of egg, It also concluded that natural astaxanthin (Haematococcus pluvialis) for the reason that contains supplementary nutritious, is extraordinary preferable than synthetic astaxanthin to improve vitamins content of egg in rainbow trout

    The Role of Microgravity in Cancer: A Dual-edge Sword

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    Since human beings could travel beyond the earth atmosphere, scientists started to investigate the effect of microgravity on human cells. Microgravity has different effects on normal and cancer cells, but the related mechanisms are not well-known till now. The aim of the present review is to focus on the consequences of exposing the cancer cells to reduced gravity. Some cancer cells organize three-dimensional structures under microgravity. Obviously, microgravity is an external stress, which can affect cell proliferation, apoptosis, cytoskeleton and signaling pathways. In addition, it touches immune-related components, regulates immune responses, and implicates immune cell activation. Low mutation aggregation and cancer rate in astronauts may lead to use microgravity as a therapeutic approach. However, it reduces the invasion and migration in some types of cancer cells, triggers the oncogenic signaling pathways including KRAS, and inhibits proliferation in normal lymphocytes. In conclusion, using microgravity as a therapeutic method in cancer treatment needs to be more investigated on both cancer and normal cells, and might not become true in the near future

    In vitro propagation of four Iranian grape varieties: Influence of genotype and pretreatment with arbuscular mycorrhiza

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    There is a great demand for table grape saplings, mainly for commercial varieties indicating that micropropagation could be an effective method for their mass propagation. Internal contamination in woody plant species is an important problematic issue and arbuscular mycorrhizal fungi (AMF) have been known as potential plant biological protectors. In the present study, the glasshouse grown mother plants of four grape varieties ('Asgari', 'Khalili', 'Keshmeshi', and 'Shahroudi') were inoculated with AMF as pre-treatment. The fungi strains were Glomus mosseae, G. fasciculatum, G. intraradices and a mixture of all three species. The comparative in vitro performance of these genotypes was evaluated following optimization of in vitro growth conditions for each genotype. Furthermore, the positive effect of AMF inoculation of stock plant on micropropagation process was studied. Changes in biochemical features (total chlorophylls, total phenols and total sugars), growth parameters (root length and total leaf area) and in vitro behavior of AMF pretreated as well as control explants were recorded. The mycorrhizal association with grapevine roots was confirmed following root staining and evaluation of colonization rate. The results revealed a distinct difference and clear genotypic effect on various in vitro parameters of studied grape genotypes. The utilized inocula were found to have the capability of mycorrhizal association with grapevine roots, leading to enhancing phenolics as a defense mechanism, increasing sugars and chlorophyll and finally growth of whole plant corresponding to the grape variety and AMF strain. These results confirmed that health and physiological conditions of the stock plants are important parameters for in vitro grape culture establishment and suggest the integration of mycorrhizal technology with tissue culture to accomplish better results

    Quantitative phase evolution during mechano-synthesis of Ti-Ni-Cu shape memory alloys

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    Cataloged from PDF version of article.Ti-41Ni-9Cu shape memory alloy was synthesized by mechanical alloying of pure elemental Ti, Ni, and Cu powders using high-energy ball milling. The qualitative and quantitative phase analyses of the as-milled powders were done by X-ray diffraction (XRD) using Rietveld refinement and the alloys microstructure was studied by scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM). Concerning the results, by milling evolution, the dissolution of the primary materials occurred at different rates and a considerable amount of the amorphous phase as well as B19′-martensite and B2-austenite was created. The formation of Ni solid solution was also evidenced prior to its dissolution. It was found that at sufficient milling time, the mechano-crystallization of the amorphous phase occurred and at the end of milling, the B19′-martensite is the dominant phase of the structure. © 2012 Elsevier B.V. All rights reserve

    Effect of milling Time on the Structure, Micro-hardness, and Thermal Behavior of Amorphous/Nanocrystalline TiNiCu Shape Memory Alloys Developed by Mechanical Alloying

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    Cataloged from PDF version of article.In the present paper, the effect of milling process on the chemical composition, structure, microhardness, and thermal behavior of Ti-41Ni-9Cu compounds developed by mechanical alloying was evaluated. The structural characteristic of the alloyed powders was evaluated by X-ray diffraction (XRD). The chemical composition homogeneity and the powder morphology and size were studied by scanning electron microscopy coupled with electron dispersive X-ray spectroscopy. Moreover, the Vickers micro-indentation hardness of the powders milled for different milling times was determined. Finally, the thermal behavior of the as-milled powders was studied by differential scanning calorimetery. According to the results, at the initial stages of milling (typically 0-12 h), the structure consisted of a Ni solid solution and amorphous phase, and by the milling evolution, nanocrystalline martensite (B19') and austenite (B2) phases were initially formed from the initial materials and then from the amorphous phase. It was found that by the milling development, the composition uniformity is increased, the inter-layer thickness is reduced, and the powders microhardness is initially increased, then reduced, and afterward re-increased. It was also realized that the thermal behavior of the alloyed powders and the structure of heat treated samples is considerably affected by the milling time. (C) 2013 Elsevier Ltd. All rights reserved
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