全文获取类型
收费全文 | 407篇 |
免费 | 2篇 |
专业分类
综合类 | 2篇 |
化学工业 | 7篇 |
金属工艺 | 1篇 |
机械仪表 | 5篇 |
建筑科学 | 3篇 |
能源动力 | 2篇 |
轻工业 | 13篇 |
无线电 | 6篇 |
一般工业技术 | 30篇 |
冶金工业 | 336篇 |
自动化技术 | 4篇 |
出版年
2022年 | 1篇 |
2021年 | 3篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2016年 | 4篇 |
2015年 | 1篇 |
2014年 | 4篇 |
2013年 | 5篇 |
2012年 | 3篇 |
2011年 | 5篇 |
2009年 | 1篇 |
2008年 | 4篇 |
2007年 | 3篇 |
2006年 | 6篇 |
2005年 | 2篇 |
2004年 | 4篇 |
2003年 | 2篇 |
2002年 | 4篇 |
2001年 | 2篇 |
2000年 | 2篇 |
1999年 | 9篇 |
1998年 | 104篇 |
1997年 | 58篇 |
1996年 | 42篇 |
1995年 | 34篇 |
1994年 | 20篇 |
1993年 | 14篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1989年 | 3篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1982年 | 4篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1977年 | 14篇 |
1976年 | 26篇 |
1975年 | 1篇 |
1972年 | 2篇 |
1955年 | 1篇 |
1954年 | 1篇 |
排序方式: 共有409条查询结果,搜索用时 15 毫秒
141.
JH Hong CS Chiang IL Campbell JR Sun HR Withers WH McBride 《Canadian Metallurgical Quarterly》1995,33(3):619-626
PURPOSE: To investigate the in vivo acute phase molecular response of the brain to ionizing radiation. METHODS AND MATERIALS: C3Hf/Sed/Kam mice were given midbrain or whole-body irradiation. Cerebral expression of interleukins (IL-1 alpha, IL-1 beta, IL-2, IL-3, IL-4, IL-5, IL-6), interferon (IFN-gamma), tumor necrosis factors (TNF-alpha and TNF-beta), intercellular adhesion molecule-1 (ICAM-1), inducible nitric oxide synthetase (iNOS), von Willebrand factor (vWF), alpha 1-antichymotrypsin (EB22/5.3), and glial fibrillary acidic protein (GFAP) was measured at various times after various radiation doses by ribonuclease (RNase) protection assay. The effects of dexamethasone or pentoxifylline treatment of mice on radiation-induced gene expression were also examined. RESULTS: Levels of TNF-alpha, IL-1 beta, ICAM-1, EB22/5.3 and to a lesser extent IL-1 alpha and GFAP, messenger RNA were increased in the brain after irradiation, whether the dose was delivered to the whole body or only to the midbrain. Responses were radiation dose dependent, but were not found below 7 Gy; the exception being ICAM-1, which was increased by doses as low as 2 Gy. Most responses were rapid, peaking within 4-8 h, but antichymotrypsin and GFAP responses were delayed and still elevated at 24 h, by which time the others had subsided. Pretreatment of mice with dexamethasone or pentoxifylline suppressed radiation-induced gene expression, either partially or completely. Dexamethasone was more inhibitory than pentoxifylline at the doses chosen. CONCLUSIONS: The initial response of the brain to irradiation involves expression of inflammatory gene products, which are probably responsible for clinically observed early symptoms of brain radiotherapy. This mechanism explains the beneficial effects of the clinical use of steroids in such circumstances. 相似文献
142.
TE Thiele DJ Marsh L Ste Marie IL Bernstein RD Palmiter 《Canadian Metallurgical Quarterly》1998,396(6709):366-369
Genetic linkage analysis of rats that were selectively bred for alcohol preference identified a chromosomal region that includes the neuropeptide Y (NPY) gene. Alcohol-preferring rats have lower levels of NPY in several brain regions compared with alcohol-non-preferring rats. We therefore studied alcohol consumption by mice that completely lack NPY as a result of targeted gene disruption. Here we report that NPY-deficient mice show increased consumption, compared with wild-type mice, of solutions containing 6%, 10% and 20% (v/v) ethanol. NPY-deficient mice are also less sensitive to the sedative/hypnotic effects of ethanol, as shown by more rapid recovery from ethanol-induced sleep, even though plasma ethanol concentrations do not differ significantly from those of controls. In contrast, transgenic mice that overexpress a marked NPY gene in neurons that usually express it have a lower preference for ethanol and are more sensitive to the sedative/hypnotic effects of this drug than controls. These data are direct evidence that alcohol consumption and resistance are inversely related to NPY levels in the brain. 相似文献
143.
We investigated the effect of domoate, kainate and AMPA on 45Ca2+ uptake and on metabolic activity of cultured chick amacrine-like cells, as measured by reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Domoate and kainate stimulated 45Ca2+ uptake and decreased MTT reduction, in a LY 303070-sensitive manner. AMPA caused a small increase on 45Ca2+ uptake, but it was without effect on MTT reduction. AMPA reduced both the 45Ca2+ entry and neurotoxicity induced by kainate, and cyclothiazide enhanced both the 45Ca2+ entry and neurotoxicity induced by AMPA. The results indicate that the AMPA receptors are the non-NMDA glutamate receptors involved in excitotoxicity. 相似文献
144.
ES Avetisov A Alazme TP Kashchenko IL Smol''ianinova KA Mats NI Lokhtina 《Canadian Metallurgical Quarterly》1994,110(1):13-16
In Europe patients are increasingly entering the healthcare debate, demanding explanations and questioning medical practice and clinical nursing traditions, at a time when human and financial resources are short and the relevancy of standard setting and quality assurance activities are being questioned. Working on heavily loaded units, nurses may feel tempted to dismiss the need for systematic evaluation of their work. However, quality assurance may be the way to empower nurses, but only if done collectively. 相似文献
145.
146.
147.
TD Randall AW Heath L Santos-Argumedo MC Howard IL Weissman FE Lund 《Canadian Metallurgical Quarterly》1998,8(6):733-742
Dendrimers represent a new class of highly branched polymers whose interior cavities and multiple peripheral groups facilitate potential applications in biomedicine and bio-organic chemistry. Major advances in the past year were made in the synthesis and study of new carbohydrate, nucleic acid, and peptide dendrimers, as well as in the use of dendrimers as magnetic resonance imaging contrast agents, as agents for cellular delivery of nucleic acids, and as scaffolds for biomimetic systems. 相似文献
148.
TP Kogan B Dupré H Bui KL McAbee JM Kassir IL Scott X Hu P Vanderslice PJ Beck RA Dixon 《Canadian Metallurgical Quarterly》1998,41(7):1099-1111
Reports of a high-affinity ligand for E-selectin, sialyl di-Lewis(x) (sLe(x)Le(x), 1), motivated us to incorporate modifications to previously reported biphenyl-based inhibitors that would provide additional interactions with the protein. These compounds were assayed for the ability to inhibit the binding of sialyl Lewis(x) (sLe(x), 2) bearing HL-60 cells to E-, P-, and L-selectin fusion proteins. We report that dimeric or trimeric compounds containing multiple components of simple nonoligosaccharide selectin antagonists inhibit sLe(x)-dependent binding with significantly enhanced potency over the monomeric compound. The enhanced potency is consistent with additional binding interactions within a single selectin lectin domain; however, multivalent interaction with multiple lectin domains as a possible alternative cannot be ruled out. Compound 15e (TBC1269) showed optimal in vitro activity from this class of antagonists and is currently under development for use in the treatment of asthma. 相似文献
149.
150.