首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   117篇
  免费   8篇
  国内免费   1篇
电工技术   1篇
化学工业   39篇
机械仪表   6篇
建筑科学   1篇
能源动力   6篇
轻工业   7篇
无线电   7篇
一般工业技术   13篇
冶金工业   34篇
自动化技术   12篇
  2023年   2篇
  2022年   6篇
  2021年   4篇
  2020年   1篇
  2019年   3篇
  2018年   1篇
  2017年   2篇
  2016年   4篇
  2015年   4篇
  2014年   6篇
  2013年   6篇
  2012年   3篇
  2011年   9篇
  2010年   2篇
  2009年   3篇
  2008年   7篇
  2007年   4篇
  2006年   4篇
  2005年   5篇
  2004年   5篇
  2003年   2篇
  2002年   3篇
  2001年   4篇
  1998年   10篇
  1997年   8篇
  1996年   4篇
  1995年   4篇
  1994年   2篇
  1993年   3篇
  1992年   1篇
  1990年   2篇
  1988年   2篇
排序方式: 共有126条查询结果,搜索用时 15 毫秒
51.
Hypoxia is a key component of the tumor microenvironment (TME) and promotes not only tumor growth and metastasis, but also negatively affects infiltrating immune cells by impairing host immunity. Dendritic cells (DCs) are the most potent antigen-presenting cells and their biology is weakened in the TME in many ways, including the modulation of their viability. RNASET2 belongs to the T2 family of extracellular ribonucleases and, besides its nuclease activity, it exerts many additional functions. Indeed, RNASET2 is involved in several human pathologies, including cancer, and it is functionally relevant in the TME. RNASET2 functions are not restricted to cancer cells and its expression could be relevant also in other cell types which are important players in the TME, including DCs. Therefore, this study aimed to unravel the effect of hypoxia (2% O2) on the expression of RNASET2 in DCs. Here, we showed that hypoxia enhanced the expression and secretion of RNASET2 in human monocyte-derived DCs. This paralleled the HIF-1α accumulation and HIF-dependent and -independent signaling, which are associated with DCs’ survival/autophagy/apoptosis. RNASET2 expression, under hypoxia, was regulated by the PI3K/AKT pathway and was almost completely abolished by TLR4 ligand, LPS. Taken together, these results highlight how hypoxia- dependent and -independent pathways shape RNASET2 expression in DCs, with new perspectives on its implication for TME and, therefore, in anti-tumor immunity.  相似文献   
52.
The aim of this study was to research decarboxylating bacterial strains and biogenic amine content in a typical Italian goat cheese (Robiola di Roccaverano). The study was performed on fresh and ripened samples of goat cheese manufactured from industrial and artisanal producers. Sixty-seven bacterial strains isolated showed decarboxylating activity, and Enterococcus faecalis was the most widespread decarboxylating species in all artisanal and industrial products. Pediococcus acidilactici and Enterococcus malodoratus were also identified as biogenic amine producers in Robiola di Roccaverano cheese. All the E. faecalis strains isolated in this study were able to decarboxylate tyrosine. Tyramine was the most abundant biogenic amine in cheese samples, while histamine was the most widespread. High amounts of these two biogenic amines were found in ripened samples (up to 2,067 mg/kg for tyramine and 1,786 mg/kg for histamine), whereas 2-phenylethylamine and tryptamine were present in almost all ripened cheeses at low concentrations. The detection of strains producing biogenic amines and the high concentrations of tyramine and histamine found in ripened Robiola di Roccaverano could represent a potential risk to the consumer.  相似文献   
53.
The aim of this study was the microbiological characterisation of a typical Italian cheese “Robiola di Roccaverano” with Protected Designation of Origin (PDO). Fresh and ripened robiola samples were collected from four artisanal and one industrial producer. Artisanal producers used raw goat's milk and natural fermentation, whilst the industrial producer used mixed cow–goat's milk and selected starters. The microbial communities were monitored during different seasons and ripening times with PCR–DGGE and culture-dependent methods.The cluster analysis showed that the DGGE bacterial patterns were related to the different manufacturing and climatic conditions, revealing the occurrence of species associated to Robiola di Roccaverano. The DGGE profiles of yeasts were affected by ripening in summer season.Moreover, the results obtained allowed the identification of microbial species such as Lactococcus lactis subsp. lactis, Geotricum spp. and Kluyveromyces lactis that are related to the production of this typical cheese.  相似文献   
54.
Heterogeneous Photooxidation of Phenol by Catalytic Membranes   总被引:1,自引:0,他引:1  
In this work the heterogenization in polymeric membranes of decatungstate, a photocatalyst for oxidation reactions, was reported. Solid state characterization techniques confirmed that the catalyst structure was preserved within the polymeric membranes. The catalytic membranes were successfully applied in the aerobic photo-oxidation of phenol, one of the main organic pollutants in wastewater, providing stable and recyclable photocatalytic systems. The dependence of the phenol degradation rate by the catalyst loading and transmembrane pressure was shown. By comparison with homogeneous reaction, the catalyst heterogenised in membrane appears to be more efficient concerning the rate of phenol photodegradation and mineralization.  相似文献   
55.
Atopic dermatitis (AD) is a chronic inflammatory skin disorder characterized by relapsing eczematous injuries and severe pruritus. In the last few years, the AD prevalence has been increasing, reaching 20% in children and 10% in adults in high-income countries. Recently, the potential role of probiotics in AD prevention has generated considerable interest. As many clinical studies show, the gut microbiota is able to modulate systemic inflammatory and immune responses influencing the development of sensitization and allergy. Probiotics are used increasingly against AD. However, the molecular mechanisms underlying the probiotics mediated anti-allergic effect remain unclear and there is controversy about their efficacy. In this narrative review, we examine the actual evidence on the effect of probiotic supplementation for AD prevention in the pediatric population, discussing also the potential biological mechanisms of action in this regard.  相似文献   
56.
57.
58.
59.
Over a period of ten years (1980-1989) 528 patients with colon cancer were treated at one institution. One hundred seventy nine (33.9%) were obstructed (O) and underwent emergency surgery, while 349 received elective (E) treatment; of these 363 had one-stage curative treatment. Operative mortality was 10.3% (O) and 3.5% (E) respectively (p < .0.5). Three hundred forty three patients survived surgery and entered follow-up: 96 were O (M:F, 54:42) and 247 E (M:F, 119:128, p = N.S.). Their mean age was 69.5 and 64.4 (p < .001), respectively. Dukes' stage and histological grading were evenly distributed within the two groups, but sites of the primary were not (p < .001). During the follow-up local recurrence occurred in 40 patients (13 O, 27 E, p = N.S.) and metastatic disease in 78 (28 O, 50 E, p < .05, Life Table Analysis) including liver recurrence in 17 O and 30 E (p = .063). Five year crude survival (51%) was significantly worse in obstructed patients. Multivariate analysis showed that Dukes' stage and obstruction were the only prognostic factors of recurrent disease, while survival was affected by the same variables and age over 70. When recurrent disease was introduced in the model survival depended on Dukes' stage, site of the primary and age over 70 and the variable obstruction disappeared as prognostic factor. Right sided tumours showed a better and those at the splenic flexure a worse prognosis. Despite one-stage curative treatment obstruction carries a significantly higher risk of developing metastatic disease, suggesting that obstruction enhances cancer cell dissemination. These patients might benefit from per-operative intra-portal and post-operative systemic adjuvant chemotherapy.  相似文献   
60.
The in-use adhesion characteristics of polycrystalline cubic silicon carbide (poly-SiC) films when used as a substrate material in MEMS applications are investigated using micromachined polycrystalline Si (poly-Si) cantilever beam arrays. The detachment lengths greater than 1500 μm are obtained, corresponding to an apparent work of adhesion of less than 0.006 mJ/m2. This is to be compared to the detachment lengths of less than 200 μm when poly-Si substrate is used, corresponding to the apparent work of adhesion of greater than 20 mJ/m2. To help understand the mechanism leading to the significant reduction in in-use adhesion, the poly-SiC surfaces are characterized by X-ray photoelectron spectroscopy, atomic force microscopy, and contact angle measurement. Based on the data, it is suggested that the topography as well as the slower oxidation rate of poly-SiC films may be responsible for the observed adhesion reduction.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号