全文获取类型
收费全文 | 941篇 |
免费 | 0篇 |
专业分类
化学工业 | 17篇 |
金属工艺 | 2篇 |
机械仪表 | 3篇 |
轻工业 | 3篇 |
石油天然气 | 2篇 |
无线电 | 2篇 |
一般工业技术 | 2篇 |
冶金工业 | 906篇 |
原子能技术 | 3篇 |
自动化技术 | 1篇 |
出版年
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2016年 | 1篇 |
2014年 | 1篇 |
2013年 | 2篇 |
2012年 | 1篇 |
2011年 | 1篇 |
2010年 | 2篇 |
2006年 | 1篇 |
2004年 | 1篇 |
2003年 | 2篇 |
2000年 | 2篇 |
1999年 | 16篇 |
1998年 | 256篇 |
1997年 | 167篇 |
1996年 | 97篇 |
1995年 | 63篇 |
1994年 | 49篇 |
1993年 | 54篇 |
1992年 | 10篇 |
1991年 | 8篇 |
1990年 | 11篇 |
1989年 | 7篇 |
1988年 | 17篇 |
1987年 | 9篇 |
1986年 | 7篇 |
1985年 | 2篇 |
1983年 | 4篇 |
1982年 | 8篇 |
1981年 | 6篇 |
1980年 | 10篇 |
1979年 | 1篇 |
1978年 | 6篇 |
1977年 | 34篇 |
1976年 | 72篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1971年 | 3篇 |
1969年 | 1篇 |
1966年 | 1篇 |
1955年 | 1篇 |
排序方式: 共有941条查询结果,搜索用时 15 毫秒
91.
Intravenous administration of 125I-hCG to 7-8 day pseudopregnant rats resulted in maximum uptake of radioactivity to corpora lutea 2 hours after treatment. At this time tissue/plasma radioactivity ratios on an equal weight basis were: corpora lutea, 70.2 +/- 12.8; ovarian interstitium, 4.6 +/- 0.2; kidney, 2.2 +/- 0.1. No appreciable uptake was seen by adrenals or liver. Radioactivity in corpora lutea was associated primarily with membranes which sedimented at 2000g and when released by heat it was more than 63% bound to luteal LH receptor preparation in vitro. Radioactivity in renal tissue was associated primarily with the 100,000g supernatant fraction and was bound less than 1% to luteal LH receptors in vitro. PGF2alpha significantly reduced uptake (p less than .001) of 125I-hCG by corpora lutea within 30 minutes (-63%) as well as at 1 (-64%), 2 (-75%), 4 (-68%) and 24 hours (-85%). No clear effect of PGF2alpha on uptake of 125I-hCG by ovarian interstitial tissue was seen. Plasma progesterone was significantly decreased (p less than .001) within 30 minutes (-47%; p less than .01) after PGF2alpha treatment and also at 1 (-65%), 2 (-82%), 4 (-68%) and 24 hours (-92%). Two hours after PGF2alpha treatment the content of progesterone in corpora lutea was depressed (-46%; p less than .001). It is suggested that the rapid inhibition of luteal progesterone production induced by PGF2alpha in vivo occurs through a block in gonadotropin uptake by corpora lutea. 相似文献
92.
93.
94.
95.
Non-Immunoglobulin Salivary Agglutinins (NIA) which directly bind to microbes [including HIV] were studied for their potential to activate the first complement component (C1). It was determined that NIA had the same specific activity as heat aggregated IgG in binding to C1q and in activating C1. In order to determine the region of C1q which bound to NIA, C1q globular heads and C1q stems (collagen-like regions) were prepared and separated via a Western blot procedure. NIA bound principally to the globular heads of C1q and weakly to the collagen-like stem region. NIA were also studied for their potential to activate native C1 in normal human serum. Heat-aggregated IgG and cardiolipin served as positive controls. It was observed that incubation of isolated NIA with fresh normal human serum resulted in the formation of sodium dodecyl sulfate (SDS)-irreversible complexes of activated C1r-C1 inhibitor and activated C1s-C1 inhibitor and in activated C1s mediated C4 conversion. This indicated that isolated NIA had the potential to directly and effectively mediate classical complement pathway activation. Preincubation of NIA with C1q, blocked NIA mediated C1r and C1s activation and C4 conversion. The concn of NIA required to activate C1r and C1s was similar to that of heat-aggregated human IgG. In kinetic ELISA, NIA or aggregated IgG (positive controls) were first immobilized on microtiter plates, blocked with gelatin then incubated with fresh human serum as a source of complement. Depositions of C4b, C3b and iC3b substantiated that the complement system was effectively activated by immobilized NIA. The optimal relative NaCl concn for C4b deposition was 0.11 M. While pre-incubation of NIA with C1q blocked the subsequent C1 fixing potential of NIA, pre-incubation of NIA with rgp160 [HIV-1] or fibronectin did not interfere with the potential of NIA to fix C1. 相似文献
96.
NS Abushov 《Canadian Metallurgical Quarterly》1998,(7):12-13
The results of application of temporary bypass in surgical treatment of injuries of large arteries of the limbs in 40 victims are analysed. The causes of thrombosis of temporary shunt are studied its wide use is thought unreasonable. Indications for the use of temporary bypass in patients with damages of large arteries of the limbs at the stages of qualified surgical and specialised angiosurgical care are determined. 相似文献
97.
OG Khatsenko NS Barteneva LM de la Maza Y Kikkawa 《Canadian Metallurgical Quarterly》1998,55(11):1835-1842
In this study, we attempted to determine the effect of a systemic infection with Chlamydia trachomatis on cytochrome P450(CYP)-dependent metabolism in mice. Furthermore, we wanted to assess if these effects were mediated through NO. BALB/c(H-2d) female mice were inoculated intraperitoneally with the C. trachomatis mouse pneumonitis (MoPn) biovar, and induction of NO synthase (NOS) was detected by measuring [NOx] levels and inducible NOS protein content in peritoneal macrophages by Western blotting. Recovery of C. trachomatis from liver, lung, and spleen peaked at 4 days postinfection. Following cotreatment with N(G)-nitro-L-arginine methyl ester (L-NAME), an inhibitor of NO synthase, there was a significant increase in the intensity and the length of the infection. Six days after inoculation with C. trachomatis, CYP1A- and CYP2B-mediated metabolism in the liver of the mice was diminished up to 49% of control levels. However, when animals were treated with N(G)-nitro-L-arginine methyl ester at days 4 and 6 postinfection, the decrease in the metabolism of CYP1A and CYP2B was largely blocked. These results suggest that C. trachomatis infection can depress cytochrome P450 in a manner similar to other types of infections and that NO is likely to be a mediator of this depression. This finding may be of significance to patients taking drugs that are metabolized by phase I enzymes during infections with some bacteria such as C. trachomatis. 相似文献
98.
99.
KL Fong DH Ho RS Benjamin NS Brown A Bedikian BS Yap CL Wiseman W Kramer GP Bodey 《Canadian Metallurgical Quarterly》1982,9(3):169-172
During the phase I clinical trial of a new antitumor agent, bruceantin, the pharmacology was studied in 18 cancer patients. The drug was infused intravenously (IV) for 3 h at doses ranging from 1 to 3.6 mg/m2 per day for 5 days. The plasma drug disappearance curves were biphasic, with a fast initial half-life of less than 15 min. The second half-life (t1/2 beta) varied from 0.7 to 38 h among different patients and was not dose-related. The difference between the t1/2 beta on day 1 and that on day 5 was not significant. In patients with normal liver function, the mean plasma concentration at the end of infusion was 22 ng/ml, and the value of the area under the concentration X time curve (AUC) was 111 (ng/ml)h. In contrast, in patients with abnormal liver function the corresponding values were 115 ng/ml and 830 (ng/ml)h, respectively. In addition, these patients had a slower elimination half-life of 10.9 h and a decreased total clearance of 157 ml/min/m2, as compared with 2.6 h and 671 ml/min/m2, respectively, for the normal group. All these differences were statistically significant. Patients with abnormal liver function developed more severe toxicity, including fever, severe nausea, vomiting, and hypotension. Two patients with severe hepatic dysfunction received a reduced dose and developed no toxicity. These results demonstrated the importance of the effects of liver dysfunction on drug disposition and showed that the dosage should be reduced in patients with hepatic dysfunction. 相似文献
100.