全文获取类型
收费全文 | 2819篇 |
免费 | 188篇 |
国内免费 | 5篇 |
专业分类
电工技术 | 13篇 |
综合类 | 2篇 |
化学工业 | 906篇 |
金属工艺 | 18篇 |
机械仪表 | 56篇 |
建筑科学 | 129篇 |
能源动力 | 56篇 |
轻工业 | 580篇 |
水利工程 | 36篇 |
石油天然气 | 9篇 |
无线电 | 135篇 |
一般工业技术 | 433篇 |
冶金工业 | 298篇 |
原子能技术 | 8篇 |
自动化技术 | 333篇 |
出版年
2024年 | 11篇 |
2023年 | 69篇 |
2022年 | 211篇 |
2021年 | 255篇 |
2020年 | 106篇 |
2019年 | 117篇 |
2018年 | 138篇 |
2017年 | 111篇 |
2016年 | 107篇 |
2015年 | 116篇 |
2014年 | 111篇 |
2013年 | 195篇 |
2012年 | 172篇 |
2011年 | 217篇 |
2010年 | 124篇 |
2009年 | 143篇 |
2008年 | 121篇 |
2007年 | 123篇 |
2006年 | 87篇 |
2005年 | 72篇 |
2004年 | 55篇 |
2003年 | 51篇 |
2002年 | 38篇 |
2001年 | 12篇 |
2000年 | 18篇 |
1999年 | 23篇 |
1998年 | 17篇 |
1997年 | 22篇 |
1996年 | 14篇 |
1995年 | 11篇 |
1994年 | 9篇 |
1993年 | 9篇 |
1992年 | 11篇 |
1990年 | 8篇 |
1989年 | 8篇 |
1988年 | 10篇 |
1987年 | 6篇 |
1986年 | 7篇 |
1985年 | 9篇 |
1984年 | 5篇 |
1983年 | 8篇 |
1982年 | 7篇 |
1981年 | 4篇 |
1977年 | 6篇 |
1976年 | 4篇 |
1975年 | 3篇 |
1973年 | 4篇 |
1972年 | 3篇 |
1964年 | 3篇 |
1958年 | 2篇 |
排序方式: 共有3012条查询结果,搜索用时 15 毫秒
51.
52.
Gaia Codolo Nicola Facchinello Nicole Papa Ambra Bertocco Sara Coletta Clara Benna Luigi DallOlmo Simone Mocellin Natascia Tiso Marina de Bernard 《International journal of molecular sciences》2022,23(3)
The Helicobacter pylori Neutrophil Activating Protein (HP-NAP) is endowed with immunomodulatory properties that make it a potential candidate for anticancer therapeutic applications. By activating cytotoxic Th1 responses, HP-NAP inhibits the growth of bladder cancer and enhances the anti-tumor activity of oncolytic viruses in the treatment of metastatic breast cancer and neuroendocrine tumors. The possibility that HP-NAP exerts its anti-tumor effect also by modulating the activity of innate immune cells has not yet been explored. Taking advantage of the zebrafish model, we examined the therapeutic efficacy of HP-NAP against metastatic human melanoma, limiting the observational window to 9 days post-fertilization, well before the maturation of the adaptive immunity. Human melanoma cells were xenotransplanted into zebrafish embryos and tracked in the presence or absence of HP-NAP. The behavior and phenotype of macrophages and the impact of their drug-induced depletion were analyzed exploiting macrophage-expressed transgenes. HP-NAP administration efficiently inhibited tumor growth and metastasis and this was accompanied by strong recruitment of macrophages with a pro-inflammatory profile at the tumor site. The depletion of macrophages almost completely abrogated the ability of HP-NAP to counteract tumor growth. Our findings highlight the pivotal role of activated macrophages in counteracting melanoma growth and support the notion that HP-NAP might become a new biological therapeutic agent for the treatment of metastatic melanomas. 相似文献
53.
54.
Katarina A. Jones Allison J. Richard J. Michael Salbaum Susan Newman Richard Carmouche Sara Webb Annadora J. Bruce-Keller Jacqueline M. Stephens Shawn R. Campagna 《International journal of molecular sciences》2022,23(7)
Herbal remedies are increasing in popularity as treatments for metabolic conditions such as obesity and Type 2 Diabetes. One potential therapeutic option is fenugreek seeds (Trigonella foenum-graecum), which have been used for treating high cholesterol and Type 2 diabetes. A proposed mechanism for these benefits is through alterations in the microbiome, which impact mammalian host metabolic function. This study used untargeted metabolomics to investigate the fenugreek-induced alterations in the intestinal, liver, and serum profiles of mice fed either a 60% high-fat or low-fat control diet each with or without fenugreek supplementation (2% w/w) for 14 weeks. Metagenomic analyses of intestinal contents found significant alterations in the relative composition of the gut microbiome resulting from fenugreek supplementation. Specifically, Verrucomicrobia, a phylum containing beneficial bacteria which are correlated with health benefits, increased in relative abundance with fenugreek. Metabolomics partial least squares discriminant analysis revealed substantial fenugreek-induced changes in the large intestines. However, it was observed that while the magnitude of changes was less, significant modifications were present in the liver tissues resulting from fenugreek supplementation. Further analyses revealed metabolic processes affected by fenugreek and showed broad ranging impacts in multiple pathways, including carnitine biosynthesis, cholesterol and bile acid metabolism, and arginine biosynthesis. These pathways may play important roles in the beneficial effects of fenugreek. 相似文献
55.
Sobia Noreen Sara Hasan Shazia Akram Ghumman Syed Nasir Abbas Bukhari Bushra Ijaz Huma Hameed Huma Iqbal Afeefa Aslam Mervat Abdelaziz Mohamed Elsherif Shazia Noureen Hasan Ejaz 《International journal of molecular sciences》2022,23(5)
The rapid progression in biomaterial nanotechnology apprehends the potential of non-toxic and potent polysaccharide delivery modules to overcome oral chemotherapeutic challenges. The present study is aimed to design, fabricate and characterize polysaccharide nanoparticles for methotrexate (MTX) delivery. The nanoparticles (NPs) were prepared by Abelmoschus esculentus mucilage (AEM) and chitosan (CS) by the modified coacervation method, followed by ultra-sonification. The NPs showed much better pharmaceutical properties with a spherical shape and smooth surface of 213.4–254.2 nm with PDI ranging between 0.279–0.485 size with entrapment efficiency varying from 42.08 ± 1.2 to 72.23 ± 2.0. The results revealed NPs to possess positive zeta potential and a low polydispersity index (PDI). The in-vitro drug release showed a sustained release of the drug up to 32 h with pH-dependence. Blank AEM -CS NPs showed no in-vivo toxicity for a time duration of 14 days, accompanied by high cytotoxic effects of optimized MTX loaded NPs against MCF-7 and MD-MBA231 cells by MTT assay. In conclusion, the findings advocated the therapeutic potential of AEM/CS NPs as an efficacious tool, offering a new perspective for pH-responsive routing of anticancer drugs with tumor cells as a target. 相似文献
56.
Raquel S. P. Hakes Sara E. Caton Daniel J. Gorham Michael J. Gollner 《Fire Technology》2017,53(2):475-515
Structure loss in wildland fires has significantly increased over the past few decades, affected by increased development in rural areas, changing fuel management policies, and climate change, all of which are projected to increase in the future. This paper is Part II of a two-part review, which presents a summary of fundamental and applied research on pathways to fire spread in the wildland urban interface. Part I discussed the fundamentals of wildland fire spread via radiative heat transfer, direct flame contact, and firebrand exposure. Here in Part II, we cover the response of building components and systems, as well as mitigation strategies used to prevent fire spread into and within communities in the United States. Post-fire investigations, full-scale structural testing, individual component testing, and combined systems or assembly testing have been used to identify building component and system vulnerabilities such as roofs, vents, siding, decks, fences, and mulch. Using results from these tests and investigations at different scales, some knowledge has been gained on specific vulnerabilities and the effectiveness of mitigation strategies, but a quantitative framework has not yet been established. On a community level, the layout of structures and the space between them has been shown to be incredibly important in mitigating wildfire risk. More locally, defensible space around homes has been effective in mitigating exposure from both radiation and direct flame contact. Firebrands still remain a challenge; however, many design recommendations have been proposed to harden structures against firebrand exposures. Recommendations for future research and development are also presented. 相似文献
57.
Bonzini S Verro R Otto S Lazzaro L Finizio A Zanin G Vighi M 《Environmental science & technology》2006,40(24):7561-7569
A GIS-based procedure for predicting pesticide exposure in surface waters has been applied on a pilot river basin characterized by intensive agricultural activity. The predictive approach has been validated through experimental monitoring, performed by collecting manual and automatic water samples during the productive season. Five active ingredients (terbuthylazine, metolachlor, alachlor, linuron, fenitrothion) were selected for analysis to validate the predictive approach. Comparison between predicted and experimental values showed good agreement for terbuthylazine and metolachlor (used in large volumes within the basin), demonstrating the reliability of the approach. However, some anomalous results were obtained for some of the other chemicals, which serve to highlight the difficulties in getting reliable input data, in particular on application patterns (rate and time). Furthermore, the value of mapping pesticide exposure on the medium-large scale is described, and the limitations of the reported predictive approach are discussed. 相似文献
58.
Wood Joanne V.; Heimpel Sara A.; Newby-Clark Ian R.; Ross Michael 《Canadian Metallurgical Quarterly》2006,90(6):ii
Reports an error in "Snatching Defeat From the Jaws of Victory: Self-Esteem Differences in the Experience and Anticipation of Success" by Joanne V. Wood, Sara A. Heimpel, Ian R. Newby-Clark and Michael Ross (Journal of Personality and Social Psychology, 2005[Nov], Vol 89[5], 764-780). There are typographical errors in Table 2 (certain values should not have been in bold face). The corrected table is provided in the erratum. (The following abstract of the original article appeared in record 2005-15658-009.) Successes--defined broadly as meeting important standards or receiving positive evaluations--are widely assumed to be enjoyed equally by people with high self-esteem (HSEs) and low self-esteem (LSEs). Three studies examined the contradictory hypothesis that HSEs react more favorably to success than do LSEs and that success brings about certain unfavorable consequences for LSEs. Undergraduate participants reacted to a laboratory-manipulated success (Studies 1 and 2) or imagined highly positive events in the future (Study 3). Self-esteem differences emerged in anxiety, thoughts about the self, and (in Study 3) thoughts about non-self-related aspects of the event. LSEs were more anxious than HSEs after succeeding, success improved HSEs' self-relevant thoughts but not LSEs', and LSEs focused more on success's negative aspects. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
59.
Alessia Mauri Alessandra Duse Giacomo Palm Roberto Previtali Stefania Maria Bova Sara Olivotto Sara Benedetti Francesca Coscia Pierangelo Veggiotti Cristina Cereda 《International journal of molecular sciences》2022,23(21)
GLUT1 deficiency syndrome (GLUT1DS1; OMIM #606777) is a rare genetic metabolic disease, characterized by infantile-onset epileptic encephalopathy, global developmental delay, progressive microcephaly, and movement disorders (e.g., spasticity and dystonia). It is caused by heterozygous mutations in the SLC2A1 gene, which encodes the GLUT1 protein, a glucose transporter across the blood-brain barrier (BBB). Most commonly, these variants arise de novo resulting in sporadic cases, although several familial cases with AD inheritance pattern have been described. Twenty-seven Italian pediatric patients, clinically suspect of GLUT1DS from both sporadic and familial cases, have been enrolled. We detected by trios sequencing analysis 25 different variants causing GLUT1DS. Of these, 40% of the identified variants (10 out of 25) had never been reported before, including missense, frameshift, and splice site variants. Their structural mapping on the X-ray structure of GLUT1 strongly suggested the potential pathogenic effects of these novel disease-related mutations, broadening the genotypic spectrum heterogeneity found in the SLC2A1 gene. Moreover, 24% is located in a vulnerable region of the GLUT1 protein that involves transmembrane 4 and 5 helices encoded by exon 4, confirming a mutational hotspot in the SLC2A1 gene. Lastly, we investigated possible correlations between mutation type and clinical and biochemical data observed in our GLUT1DS cohort, revealing that splice site and frameshift variants are related to a more severe phenotype and low CSF parameters. 相似文献
60.
Mohsen Akbarian Ali Khani Sara Eghbalpour Vladimir N. Uversky 《International journal of molecular sciences》2022,23(3)
Bioactive peptides are a group of biological molecules that are normally buried in the structure of parent proteins and become active after the cleavage of the proteins. Another group of peptides is actively produced and found in many microorganisms and the body of organisms. Today, many groups of bioactive peptides have been marketed chemically or recombinantly. This article reviews the various production methods and sources of these important/ubiquitous and useful biomolecules. Their applications, such as antimicrobial, antihypertensive, antioxidant activities, blood-lipid-lowering effect, opioid role, antiobesity, ability to bind minerals, antidiabetic, and antiaging effects, will be explored. The types of pathways proposed for bioactive applications will be in the next part of the article, and at the end, the future perspectives of bioactive peptides will be reviewed. Reading this article is recommended for researchers interested in various fields of physiology, microbiology, biochemistry, and nanotechnology and food industry professionals. 相似文献