全文获取类型
收费全文 | 5742篇 |
免费 | 544篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 22篇 |
综合类 | 1篇 |
化学工业 | 1886篇 |
金属工艺 | 43篇 |
机械仪表 | 115篇 |
建筑科学 | 229篇 |
矿业工程 | 10篇 |
能源动力 | 159篇 |
轻工业 | 1883篇 |
水利工程 | 48篇 |
石油天然气 | 40篇 |
无线电 | 223篇 |
一般工业技术 | 715篇 |
冶金工业 | 262篇 |
原子能技术 | 11篇 |
自动化技术 | 643篇 |
出版年
2024年 | 16篇 |
2023年 | 68篇 |
2022年 | 252篇 |
2021年 | 400篇 |
2020年 | 216篇 |
2019年 | 240篇 |
2018年 | 248篇 |
2017年 | 242篇 |
2016年 | 285篇 |
2015年 | 210篇 |
2014年 | 324篇 |
2013年 | 463篇 |
2012年 | 434篇 |
2011年 | 459篇 |
2010年 | 349篇 |
2009年 | 328篇 |
2008年 | 295篇 |
2007年 | 273篇 |
2006年 | 197篇 |
2005年 | 143篇 |
2004年 | 142篇 |
2003年 | 96篇 |
2002年 | 94篇 |
2001年 | 49篇 |
2000年 | 55篇 |
1999年 | 57篇 |
1998年 | 77篇 |
1997年 | 53篇 |
1996年 | 38篇 |
1995年 | 22篇 |
1994年 | 28篇 |
1993年 | 21篇 |
1992年 | 15篇 |
1991年 | 10篇 |
1990年 | 5篇 |
1989年 | 20篇 |
1988年 | 8篇 |
1987年 | 11篇 |
1986年 | 6篇 |
1985年 | 6篇 |
1984年 | 8篇 |
1983年 | 3篇 |
1982年 | 4篇 |
1981年 | 1篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1978年 | 4篇 |
1977年 | 4篇 |
1976年 | 6篇 |
1971年 | 1篇 |
排序方式: 共有6290条查询结果,搜索用时 609 毫秒
991.
Mihaela Ionescu Anca Pantea Stoian Manfredi Rizzo Dragos Serban Domenico Nuzzo Laura Mazilu Andra Iulia Suceveanu Ana Maria Dascalu Irinel Raluca Parepa 《International journal of molecular sciences》2021,22(21)
The 2019 novel coronavirus, known as severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) or coronavirus disease 2019 (COVID-19), is causing a global pandemic. The virus primarily affects the upper and lower respiratory tracts and raises the risk of a variety of non-pulmonary consequences, the most severe and possibly fatal of which are cardiovascular problems. Data show that almost one-third of the patients with a moderate or severe form of COVID-19 had preexisting cardiovascular comorbidities such as diabetes mellitus, obesity, hypertension, heart failure, or coronary artery disease. SARS-CoV2 causes hyper inflammation, hypoxia, apoptosis, and a renin–angiotensin system imbalance in a variety of cell types, primarily endothelial cells. Profound endothelial dysfunction associated with COVID-19 can be the cause of impaired organ perfusion that may generate acute myocardial injury, renal failure, and a procoagulant state resulting in thromboembolic events. We discuss the most recent results on the involvement of endothelial dysfunction in the pathogenesis of COVID-19 in patients with cardiometabolic diseases in this review. We also provide insights on treatments that may reduce the severity of this viral infection. 相似文献
992.
993.
994.
995.
Sara Morais Mnica Pereira Catarina Lau Ana Gonalves Catarina Monteiro Marta Gonalves Jorge Oliveira Lurdes Moreira Eugnia Cruz Rosrio Santos Margarida Lima 《International journal of molecular sciences》2021,22(22)
RASGRP2 encodes the calcium and diacylglycerol (DAG)-regulated guanine nucleotide exchange factor I (CalDAG-GEFI) identified as a Rap1-activating molecule. Pathogenic variants previously identified in RASGRP2 allowed the characterization of CalDAG-GEFI deficiency as a non-syndromic, autosomal recessive platelet function disease. We report on the clinical manifestations and laboratory features of a Portuguese family with a likely pathogenic variant in RASGRP2 (c.999G>C leading to a p.Lys333Asn change in the CDC25 catalytic domain of CalDAG-GEFI) and discuss the contribution of this variant to the disease manifestations. Based on the study of this family with one homozygous patient and five heterozygous carriers and on a critical analysis of the literature, we challenge previous knowledge that CalDAG-GEFI deficiency only manifests in homozygous patients. Our data suggest that at least for the RASGRP2 variant reported herein, there is a phenotypic expression, albeit milder, in heterozygous carriers. 相似文献
996.
Xinyang Zhou Shehan M. Fernando Alexander Y. Pan Rebecca Laposa Kathryn R. Cullen Bonnie Klimes-Dougan Ana C. Andreazza 《International journal of molecular sciences》2021,22(22)
The NOD-, LRR-, and pyrin-domain-containing protein 3 (NLRP3) inflammasome is a node of intracellular stress pathways and a druggable target which integrates mitochondrial stress and inflammatory cascades. While a body of evidence suggests the involvement of the NLRP3 inflammasome in numerous diseases, a lack of reliable measurement techniques highlights the need for a robust assay using small quantities of biological samples. We present a literature overview on peripheral activation of the NLRP3 inflammasome in mood disorders, then outline a process to develop and validate a robust assay to measure baseline and activated intracellular levels of “apoptosis-associated speck-like protein containing a CARD” (ASC) as a key component of an inflammatory profile in peripheral blood mononuclear cells (PBMC). A consistent association between high NLRP3 mRNA levels and relevant cytokines was seen in the literature. Using our method to measure ASC, stimulation of PBMC with lipopolysaccharide and nigericin or adenosine triphosphate resulted in microscopic identification of intracellular ASC specks, as well as interleukin 1 (IL-1) beta and caspase-1 p10 in the periphery. This was abolished by dose-dependent pre-treatment with 100 nM MCC950. We also report the use of this technique in a small pilot sample from patients with bipolar disorder and depressive disorders. The results show that levels of intracellular ASC and IL-1 beta are sensitive to change upon activation and maintained over time, which may be used to improve the detection of NLRP3 activation and guide personalized therapeutic strategy in the treatment of patients. 相似文献
997.
Ana M Castrilln Pilar Navarro Esther Alvrez-Pontes 《Journal of the science of food and agriculture》1997,75(1):125-132
Modifications in proximate composition, fatty acids, amino acids and –SH groups content, as well as changes in solubility and nutritional quality of protein, were studied in fillets of sardine (Clupea pilchardus) that had been successively pan-fried, frozen stored and reheated by two different means, namely conventional oven and microwave oven. Upon pan-frying in olive oil the sardine absorbed C18: 1(n-9) and C18: 2(n-6) and lost saturated (SFA) and polyunsaturated fatty acids (PUFA); this loss continued upon reheating, and as a consequence the percentage of MUFA increased compared to the just-fried sardine. A loss of water was observed during all processes. Upon frying there was a decrease of cyst(e)ine. Upon reheating by both microwave and conventional oven, methionine decreased; however, cyst(e)ine only decreased with the use of a conventional oven. A loss of –SH groups was recorded during frying and this phenomenon continued upon reheating. Biological value (BV) together with net protein utilisation (NPU) decreased upon both frying and reheating. © 1997 SCI. 相似文献
998.
Kristina Dominko Ana Rastija Sandra Sobocanec Lea Vidatic Sarah Meglaj Andrea Lovincic Babic Birgit Hutter-Paier Alessio-Vittorio Colombo Stefan F. Lichtenthaler Sabina Tahirovic Silva Hecimovic 《International journal of molecular sciences》2021,22(24)
Niemann-Pick type C disease (NPC) is a rare inherited neurodegenerative disorder characterized by an accumulation of intracellular cholesterol within late endosomes and lysosomes due to NPC1 or NPC2 dysfunction. In this work, we tested the hypothesis that retromer impairment may be involved in the pathogenesis of NPC and may contribute to increased amyloidogenic processing of APP and enhanced BACE1-mediated proteolysis observed in NPC disease. Using NPC1-null cells, primary mouse NPC1-deficient neurons and NPC1-deficient mice (BALB/cNctr-Npc1m1N), we show that retromer function is impaired in NPC. This is manifested by altered transport of the retromer core components Vps26, Vps35 and/or retromer receptor sorLA and by retromer accumulation in neuronal processes, such as within axonal swellings. Changes in retromer distribution in NPC1 mouse brains were observed already at the presymptomatic stage (at 4-weeks of age), indicating that the retromer defect occurs early in the course of NPC disease and may contribute to downstream pathological processes. Furthermore, we show that cholesterol depletion in NPC1-null cells and in NPC1 mouse brains reverts retromer dysfunction, suggesting that retromer impairment in NPC is mechanistically dependent on cholesterol accumulation. Thus, we characterized retromer dysfunction in NPC and propose that the rescue of retromer impairment may represent a novel therapeutic approach against NPC. 相似文献
999.
Snia I. G. Fangaia Pedro M. G. Nicolau Fernando A. D. R. A. Guerra M. Melia Rodrigo Gianluca Utzeri Ana M. T. D. P. V. Cabral Artur J. M. Valente Miguel A. Esteso Ana C. F. Ribeiro 《International journal of molecular sciences》2021,22(24)
Metal ions such as cobalt (II) and chromium (III) might be present in the oral cavity, as a consequence of the corrosion of Co-Cr dental alloys. The diffusion of such metal ions into the organism, carried by saliva, can cause health problems as a consequence of their toxicity, enhanced by a cumulative effect in the body. The effect of the chlorhexidine digluconate, which is commonly used in mouthwash formulations, on the transport of these salts is evaluated in this paper by using the Taylor dispersion technique, which will allow an assessment of how the presence of chlorhexidine digluconate (either in aqueous solution or in a commercial formulation) may affect the diffusion of metal ions. The ternary mutual diffusion coefficients of metal ions (Co and Cr) in the presence of chlorhexidine digluconate, in an artificial saliva media, were measured. Significant coupled diffusion of CoCl2 (and CrCl3) and chlorhexidine digluconate is observed by analysis of the non-zero values of the cross-diffusion coefficients, D12 and D21. The observed interactions between metal ions and chlorhexidine digluconate suggest that the latter might be considered as an advantageous therapeutic agent, once they contribute to the reduction of the concentration of those ions inside the mouth. 相似文献