全文获取类型
收费全文 | 3215篇 |
免费 | 209篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 31篇 |
综合类 | 13篇 |
化学工业 | 1135篇 |
金属工艺 | 56篇 |
机械仪表 | 37篇 |
建筑科学 | 122篇 |
矿业工程 | 8篇 |
能源动力 | 73篇 |
轻工业 | 461篇 |
水利工程 | 32篇 |
石油天然气 | 14篇 |
无线电 | 150篇 |
一般工业技术 | 516篇 |
冶金工业 | 392篇 |
原子能技术 | 4篇 |
自动化技术 | 383篇 |
出版年
2023年 | 58篇 |
2022年 | 201篇 |
2021年 | 248篇 |
2020年 | 111篇 |
2019年 | 99篇 |
2018年 | 127篇 |
2017年 | 94篇 |
2016年 | 123篇 |
2015年 | 116篇 |
2014年 | 127篇 |
2013年 | 220篇 |
2012年 | 184篇 |
2011年 | 260篇 |
2010年 | 148篇 |
2009年 | 146篇 |
2008年 | 145篇 |
2007年 | 141篇 |
2006年 | 128篇 |
2005年 | 114篇 |
2004年 | 101篇 |
2003年 | 58篇 |
2002年 | 69篇 |
2001年 | 31篇 |
2000年 | 43篇 |
1999年 | 20篇 |
1998年 | 21篇 |
1997年 | 21篇 |
1996年 | 29篇 |
1995年 | 25篇 |
1994年 | 26篇 |
1993年 | 24篇 |
1992年 | 18篇 |
1991年 | 7篇 |
1990年 | 18篇 |
1989年 | 10篇 |
1988年 | 7篇 |
1987年 | 13篇 |
1986年 | 11篇 |
1985年 | 11篇 |
1984年 | 6篇 |
1983年 | 5篇 |
1981年 | 8篇 |
1980年 | 3篇 |
1979年 | 8篇 |
1978年 | 4篇 |
1977年 | 4篇 |
1976年 | 8篇 |
1975年 | 6篇 |
1968年 | 3篇 |
1964年 | 2篇 |
排序方式: 共有3427条查询结果,搜索用时 15 毫秒
101.
Stefano J. Mandriota Mirna Tenan Adeline Nicolle Julia D. Jankowska Paolo Ferrari Jean-Christophe Tille Mary-Anne Durin Catherine M. Green Sebastien Tabruyn Daniela Moralli Andr-Pascal Sappino 《International journal of molecular sciences》2020,21(23)
Genomic instability is generally considered as a hallmark of tumorigenesis and a prerequisite condition for malignant transformation. Aluminium salts are suspected environmental carcinogens that transform mammary epithelial cells in vitro through unknown mechanisms. We report here that long-term culture in the presence of aluminium chloride (AlCl3) enables HC11 normal mouse mammary epithelial cells to form tumours and metastases when injected into the syngeneic and immunocompetent BALB/cByJ strain. We demonstrate that AlCl3 rapidly increases chromosomal structural abnormalities in mammary epithelial cells, while we failed to detect direct modulation of specific mRNA pathways. Our observations provide evidence that clastogenic activity—a well-recognized inducer of genomic instability—might account in part for the transforming abilities of aluminium in mammary epithelial cells. 相似文献
102.
Finn Edler von Eyben Glenn Bauman Rie von Eyben Kambiz Rahbar Cigdem Soydal Alexander R. Haug Irene Virgolini Harshad Kulkarni Richard Baum Giovanni Paganelli 《International journal of molecular sciences》2020,21(23)
The aim of the review was to evaluate patient and treatment characteristics for patients with metastatic castration-resistant prostate cancer (mCRPC) treated with PSMA radioligand therapy (PRLT) associated with above-average outcome. The systematic review and meta-analysis followed recommendations by the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA). We searched for publications in PubMed, Embase, and ClinicalTrials.gov up to 31 September 2020. Thirty-six publications and four duplicates reported 2346 patients. Nearly two-thirds of the patients had bone metastases. Median overall survival (OS) was 16 months. Asymptomatic patients and patients with only lymph node metastases lived longer than symptomatic patients and patients with more extensive metastases. Patients treated with an intensified schedule of 177Lu PRLT lived longer than those treated with a conventional schedule. Half of the patients obtained a PSA decline ≥ 50% and these patients lived longer than those with less PSA decline. Approximately 10% of the patients developed hematologic toxicity with anemia grade 3 as the most severe adverse effect. Characteristics for patients, cancer, restaging, and PRLT predict above average overall survival following treatment with PRLT. 相似文献
103.
Elisabetta Coppi Ilaria Dettori Federica Cherchi Irene Bulli Martina Venturini Daniele Lana Maria Grazia Giovannini Felicita Pedata Anna Maria Pugliese 《International journal of molecular sciences》2020,21(24)
Adenosine is a signaling molecule, which, by activating its receptors, acts as an important player after cerebral ischemia. Here, we review data in the literature describing A2BR-mediated effects in models of cerebral ischemia obtained in vivo by the occlusion of the middle cerebral artery (MCAo) or in vitro by oxygen-glucose deprivation (OGD) in hippocampal slices. Adenosine plays an apparently contradictory role in this receptor subtype depending on whether it is activated on neuro-glial cells or peripheral blood vessels and/or inflammatory cells after ischemia. Indeed, A2BRs participate in the early glutamate-mediated excitotoxicity responsible for neuronal and synaptic loss in the CA1 hippocampus. On the contrary, later after ischemia, the same receptors have a protective role in tissue damage and functional impairments, reducing inflammatory cell infiltration and neuroinflammation by central and/or peripheral mechanisms. Of note, demyelination following brain ischemia, or autoimmune neuroinflammatory reactions, are also profoundly affected by A2BRs since they are expressed by oligodendroglia where their activation inhibits cell maturation and expression of myelin-related proteins. In conclusion, data in the literature indicate the A2BRs as putative therapeutic targets for the still unmet treatment of stroke or demyelinating diseases. 相似文献
104.
Francesco Paolo Fiorentino Irene Marchesi Christoph Schrder Ronny Schmidt Jun Yokota Luigi Bagella 《International journal of molecular sciences》2020,21(24)
Small cell lung cancer (SCLC) is an aggressive type of lung cancer with high mortality that is caused by frequent relapses and acquired resistance. Despite that several target-based approaches with potential therapeutic impact on SCLC have been identified, numerous targeted drugs have not been successful in providing improvements in cancer patients when used as single agents. A combination of targeted therapies could be a strategy to induce maximum lethal effects on cancer cells. As a starting point in the development of new drug combination strategies for the treatment of SCLC, we performed a mid-throughput screening assay by treating a panel of SCLC cell lines with BETi or AKi in combination with PARPi or EZH2i. We observed drug synergy between I-BET762 and Talazoparib, BETi and PARPi, respectively, in SCLC cells. Combinatorial efficacy was observed in MYCs-amplified and MYCs-wt SCLC cells over SCLC cells with impaired MYC signaling pathway or non-tumor cells. We indicate that drug synergy between I-BET762 and Talazoparib is associated with the attenuation HR-DSBR process and the downregulation of various players of DNA damage response by BET inhibition, such as CHEK2, PTEN, NBN, and FANCC. Our results provide a rationale for the development of new combinatorial strategies for the treatment of SCLC. 相似文献
105.
106.
107.
108.
Antonela Taddia María Julia Boggione Gisela Tubio 《International Journal of Food Science & Technology》2019,54(4):1027-1035
Agroindustrial by-products are an abundant source of biocompounds that contain valuable nutrients, which are not exploited. In this work, lignocellulosic wastes (LW) were used in submerged fermentation (SmF) and solid-state fermentation (SSF) by Aspergillus niger NRRL3 to obtain valuable enzymes required in industries. SmF using soya bean hulls (SH), wheat bran (WB) and a by-product of wheat flour (F) produced the highest activities of endo-1,4-β-xylanase (Xyl) and endo-1,4-β-D-glucanase (EG) being at least 3 times lower than those obtained by SSF. The highest ratio of Xyl to EG was obtained in SmF with F. Xyl obtained by SmF with WB was the most thermally resistant. The enzymatic extract obtained in SmF using SH presented a high power of saccharification. The production of enzymes for further application such as bioethanol generation process revalue these LW and can help offset growing environmental problems. 相似文献
109.
Fresh and dry-cured porcine loins (Longissimus dorsi) were analysed for glutathione peroxidase (GSHPx) activity and acid reactive substances (TBARS) in order to assess the influence of meat quality and salt (NaCl) concentration on oxidative stability. The results showed lower GSHPx activity and higher TBA levels in normal meat than in PSE meat indicating a higher oxidative stress in normal meat quality. GSHPx remained active at the end of the curing process. Higher salt concentration led to lower enzyme activity and TBARS values prompted the thought of a double role of NaCl as an enzyme inhibitor and as an antioxidant molecule 相似文献
110.
María Julia Spotti Martina J. Perduca Andrea Piagentini Liliana G. Santiago Amelia C. Rubiolo Carlos R. Carrara 《Food Hydrocolloids》2013
The effect of Maillard reaction on the mechanical properties of whey protein isolate (WPI) heat-induced gels was evaluated. WPI and dextran (15–25 kDa) conjugates were obtained by controlled dry heating during storage at 60 °C and 63% relative humidity for 2, 5 and 9 days. Changes in browning intensity and content of free amino groups were used to estimate the Maillard reaction. A decrease in free amino groups of WPI was observed when increasing polysaccharide concentration and reaction time. An increase in both a* and b* CIE Lab colour parameters indicated the development of a reddish-brown colour, typical of the Maillard reaction. Uniaxial compression and stress relaxation tests were performed to measure the mechanical properties of mixed and conjugate gels. Maillard reaction significantly modified the mechanical properties of WPI/DX gels, and even prevented fracture when conjugate gels were subjected to 80% deformation in uniaxial compression test. 相似文献