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51.
正一款游戏鼠标一直都是众多玩家梦寐以求的产品,因为它不仅仅有着炫酷拉风的外观,能够向其他人证明自己是资深游戏玩家的证据,而且在同等水平的较量中,拥有一款好的外设产品,绝对能让你占得先机!笔者认识的玩电竞高手也都表示一款好的游戏鼠标绝对能给你带来很大的提升。总而言之一款出色的游戏鼠标是你想要玩好游戏的必要条件!那么作为一位游戏玩家一般都会买多少钱的游戏鼠标呢?由于价格因素,百元级的游戏鼠标才是最多用户选择的,本次横评也是看到了这一点,特意选出八个品牌的百元级主力游戏鼠标进行横评对比。 相似文献
52.
SA de Oliveira WN Soares MO Dalston MT de Almeida AJ Costa 《Canadian Metallurgical Quarterly》1995,28(4):339-343
Malignant mesothelioma is caused almost exclusively by occupational exposure to asbestos. During the past few years, however, increasing evidence has mounted that background exposure to asbestos could be sufficient to cause mesothelioma. Treatment of malignant mesothelioma remains a big problem. Some new approaches are on their way, and the most exciting ones are local immunotherapy in very early cases. Some success has been reported with local interferon treatment. As for treatment of metastatic pleural disease, the main purpose is symptomatic relief of dyspnea caused by fluid accumulation. The best way to achieve a lasting palliation is pleurodesis, and the most common way to do this, is by chemical means. The drug of choice in the United States has for many years been tetracycline, but since injectable tetracycline is no longer available, some substitute must be found. The substance that will "win" is not yet clear, but the two leading contestants are talc and doxycycline. Bleomycin also has its supporters, and a dark horse is quinacrine, which although not easily available in the United States, has been used in many European centers for decades. 相似文献
53.
Higher incidence of Gastrospirillum sp. in swine with gastric ulcer of the pars oesophagea 总被引:1,自引:0,他引:1
AJ Barbosa JC Silva AM Nogueira E Paulino Júnior CR Miranda 《Canadian Metallurgical Quarterly》1995,32(2):134-139
Gastric ulcer in swine is characterized by an area of acid-peptic digestion, occurs usually in the pars oesophagea of the stomach, and has unknown etiopathogenesis. The present work was carried out to investigate the prevalence of the newly described spiral-shaped microorganism Gastrospirillum sp. ("Gastrospirillum suis") in stomachs of abattoir pigs with and without gastric ulcer. Stomachs were removed from 32 consecutive pigs presenting apparently normal mucosa and from 32 additional consecutive pigs presenting frank, chronic gastric ulcer of the pars oesophagea. Fragments of antral, oxyntic, cardiac and pars oesophagea regions were taken from each stomach and processed for histology and for identification of Gastrospirillum sp. in tissue sections. The microorganisms were identified mainly in the mucous layer and in gastric foveolas of the antral and oxyntic mucosa. Forty pigs (62.5%) were positive for Gastrospirillum sp.; among them, 27 (67.5%) had gastric ulcer, and 13 (32.5%) had no ulcer. Twenty-four pigs (37.5%) were negative for Gastrospirillum sp.; among them, five (20.8%) presented with gastric ulcer, and 19 (79.2%) had no ulcer. There was a significant difference between pigs with and without gastric ulcer in regard to the presence of Gastrospirillum sp. (P < 0.01). The spiral-shaped microorganism Gastrospirillum sp. that inhabits the stomach of pigs should be considered a possible factor connected with the etiopathogenesis of swine gastric ulcer. 相似文献
54.
We have previously described in tuberous sclerosis (TSC) hamartomas the phenomenon of loss of heterozygosity (LOH) for DNA markers in the region of both the TSC2 gene on chromosome 16p13.3 and the TSC1 gene on 9q34. We now describe the spectrum of LOH in 51 TSC hamartomas from 34 cases of TSC. DNA was extracted from leucocytes or normal paraffin embedded tissue, and from frozen paraffin embedded hamartoma tissue from the same patient. The samples were analysed for 11 markers spanning the TSC1 locus and nine markers spanning the TSC2 locus. Twenty-one of 51 hamartomas showed LOH (41%). There was significantly more LOH on 16p13.3, with 16 hamartomas showing LOH around TSC2, and five in the vicinity of TSC1. No hamartoma showed LOH for markers around both loci. All the areas of LOH on chromosome 9 were large, but the smallest region of overlap lay between the markers D9S149 and D9S114, providing independent evidence for the localisation of the TSC1 gene. These data show that LOH is a common finding in a wide range of hamartomas, affecting the same TSC locus in different lesions from the same patient but not affecting both loci. These data support the hypothesis that both the TSC genes act as tumour suppressors and that the manifestations of TSC in patients with germline TSC mutations rise from "second hit" somatic mutations inactivating the remaining normal copy of the TSC gene. 相似文献
55.
Non-insulin-dependent (or type 2) diabetes mellitus is a common, underdiagnosed and growing disease in our society. It is responsible for increased morbidity and mortality and represents an important public health problem. This polygenic disease is often expressed late in life and its evolution is accelerated by environmental factors leading to obesity. It combines defects in both insulin secretion and insulin action, and such defects are present in various proportions according to the type of patient and the stage of the disease. Diet and physical activity recommendations are the basis of the treatment. Current pharmacological approaches aim at improving insulin secretion and/or insulin cellular action. After secondary failure to oral drugs, insulin therapy should be initiated, the patient becoming "insulin-requiring". A synergy should be searched in the combination of various therapeutic modalities in order to improve the glycaemic control. 相似文献
56.
Q Zhan S Fan ML Smith I Bae K Yu I Alamo PM O'Connor AJ Fornace 《Canadian Metallurgical Quarterly》1996,15(10):805-815
The tumor suppressor p53 is required for induction of its downstream effector genes such as GADD45 and CIP1/WAF1 by ionizing radiation (IR). This response is probably mediated through defined p53 binding sites located in the promoter of CIP1/WAF1 and in the third intron of GADD45. In contrast, the gadd gene stress response to base-damaging agents, such as methylmethane sulfonate (MMS) or UV radiation, or medium depletion (starvation) occurs in all mammalian cells examined to date regardless of p53 status for both GADD45 and also GADD153, which is not IR-responsive in many lines with functional p53. These agents strongly induce the p53 protein and raise the possibility that, although p53 is not required for the typical "gadd" response to these agents, p53 may contribute to these non-IR stress responses. This possibility was confirmed by the finding that disruption of p53 function by transfection with dominant-negative vectors expressing HPV E6, mutant p53, or SV40 T Ag reduced the induction of GADD45 and GADD153 as measured by increases in mRNA and protein levels in human lines with wild-type p53. Similarly, induction of these genes by MMS or UV radiation was consistently stronger in the parental mouse embryo fibroblasts compared to cells derived from mice where both p53 alleles had been deleted. Similar qualitative responses were also seen for CIP1/WAF1. In agreement with reduced induction of p53-regulated genes, the G1 checkpoint activated by MMS or UV radiation was markedly abrogated in p53-wt human MCF-7 breast carcinoma cells by E6 expression. Interestingly, induction of reporter constructs driven by the GADD45 or GADD153 promoters was substantially reduced in human cells transfected with mutant p53 or E6 expression vectors or in cells lacking p53 following treatment with MMS, UV radiation, or starvation. Because neither promoter is inducible by IR, and neither contains a strong p53 binding site, these results indicate that p53 has a synergistic or cooperative role in these non-IR stress responses for both GADD45 and GADD153, and that this role is not mediated through identifiable p53-binding sites. 相似文献
57.
Most migratory bird populations are composed of individuals that migrate and individuals that remain resident. While the role of ecological factors in maintaining this behavioral dimorphism has received much attention, the importance of genetic constraints on the evolution of avian migration has not yet been considered. Drawing on the recorded migratory activities of 775 blackcaps (Sylvia atricapilla) from a partially migratory population in southern France, we tested two alternative genetic models about the relationship between incidence and amount of migratory activity. The amount of migratory activity could be the continuous variable "underlying" the phenotypic expression of migratory urge, or, alternatively, the expression of both traits could be controlled by two separate genetic systems. The distributions of migratory activities in five different cohorts and the inheritance pattern derived from selective breeding experiments both indicate that incidence and amount of migratory activity are two aspects of one trait. Thus, all birds without measurable activity have activity levels at the low end of a continuous distribution, below the limit of expression or detection. The phenotypic dichotomy "migrant-nonmigrant" is caused by a threshold which may not be fixed but influenced both genetically and environmentally. This finding has profound implications for the evolution of migration: the transition from migratoriness to residency should not only be driven by selection favoring resident birds but also by selection for lower migratory activity. This potential for selection on two aspects, residency and migration distance, of the same trait may enable extremely rapid evolutionary changes to occur in migratory behavior. 相似文献
58.
Epistatic interactions between unlinked transgene loci in tobacco plants were studied following sexual crosses between different transgenic lines. Three potential "modifier" transgene loci, which were structurally similar but integrated at different chromosomal locations, were tested for their ability to influence the expression of a partially homologous "target" transgene locus. After introduction of an individual modifier locus, the target locus could be either unaffected, completely inactivated and methylated or differentially sensitive, showing more complete inactivation and methylation when homozygous than when hemizygous. The implications of these results for inbreeding depression in plants are discussed. 相似文献
59.
In an attempt to ascertain the value of extra- to intracranial arterial bypass for cerebrovascular disease, the general topic of bypass surgery is reviewed and the results of this procedure in 110 patients are analyzed. The feasibility of high patency rates of the anastomosis with acceptably low permanent morbidity and operative mortality rates is demonstrated. Lesions producing transient ischemic attacks which previously were considered to be inoperable or inaccessible can be bypassed by this procedure, and there appears to be a dramatic improvement in the symptomotology of virtually all patients. Patients with a mild stroke or "progressive stroke" also appear to benefit from bypass, but the erratic natural history of these entities precludes irrefutable substantiation of this conclusion. Patients with moderate-to-serve neurological deficits do not appear to be improved by this procedure. In our group of 20 patients presenting with transient ischemic attacks who have had more than 3 years of follow-up, only one patient has suffered a stroke and that was located in the opposite hemisphere. 相似文献
60.
The effect of actinomycin-D (AMD) on radiation damage repair was studied in plateau phase V79 Chinese hamster cells. Sublethal radiation damage repair, as demonstrated by survival fluctuations following two x-ray exposures separted by time, was observed in our plateau phase cells. Plateau phase cells exposed to 0.01-0.04 mug/ml AMD (a nontoxic regimen to 8 hours) between x-ray exposures were less able to repair sublethal damage. If plateau phase cells were plated at low dilutions into fresh medium (conditions for resuming exponential growth) immediately after the first x-ray dose, and exposed to 0.01--0.04 mug/ml AMD until the second dose, inhibition of sublethal damage repair and additional cell killing were observed particularly at 0.04 mug/ml AMD. It is suggested that radiation-drug damage interactions should be studied in plateau phase cells and in cells resuming exponential growth after plateau phase (possibly analogous to "recruitment"), as well as in exponential phase cultures. 相似文献