全文获取类型
收费全文 | 935篇 |
免费 | 0篇 |
专业分类
化学工业 | 10篇 |
金属工艺 | 2篇 |
机械仪表 | 1篇 |
建筑科学 | 1篇 |
能源动力 | 1篇 |
轻工业 | 8篇 |
水利工程 | 1篇 |
石油天然气 | 2篇 |
无线电 | 8篇 |
一般工业技术 | 8篇 |
冶金工业 | 890篇 |
自动化技术 | 3篇 |
出版年
2022年 | 1篇 |
2021年 | 2篇 |
2020年 | 2篇 |
2019年 | 3篇 |
2018年 | 4篇 |
2017年 | 3篇 |
2016年 | 1篇 |
2014年 | 2篇 |
2013年 | 4篇 |
2012年 | 3篇 |
2011年 | 2篇 |
2010年 | 1篇 |
2009年 | 1篇 |
2008年 | 2篇 |
2006年 | 2篇 |
2005年 | 1篇 |
2004年 | 7篇 |
2003年 | 2篇 |
2002年 | 1篇 |
1999年 | 34篇 |
1998年 | 291篇 |
1997年 | 168篇 |
1996年 | 117篇 |
1995年 | 64篇 |
1994年 | 59篇 |
1993年 | 41篇 |
1992年 | 9篇 |
1991年 | 12篇 |
1990年 | 8篇 |
1989年 | 18篇 |
1988年 | 13篇 |
1987年 | 9篇 |
1986年 | 4篇 |
1985年 | 2篇 |
1983年 | 2篇 |
1982年 | 5篇 |
1981年 | 4篇 |
1980年 | 5篇 |
1978年 | 1篇 |
1977年 | 9篇 |
1976年 | 14篇 |
1975年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有935条查询结果,搜索用时 15 毫秒
161.
P Graber D Gretener S Herren JP Aubry G Elson J Poudrier S Lecoanet-Henchoz S Alouani C Losberger JY Bonnefoy MH Kosco-Vilbois JF Gauchat 《Canadian Metallurgical Quarterly》1998,28(12):4286-4298
To study the expression of IL-13 receptor alpha1 (IL-13Ralpha1), specific monoclonal antibodies (mAb) were generated. Surface expression of the IL-13Ralpha1 on B cells, monocytes and T cells was assessed by flow cytometry using these specific mAb. Among tonsillar B cells, the expression was the highest on the IgD+ CD38- B cell subpopulation which is believed to represent naive B cells. Expression was also detectable on a large fraction of the IgD-CD38- B cells but not on CD38+ B cells. Activation under conditions which promote B cell Ig class switching up-regulated the expression of the receptor. However, the same stimuli had an opposite effect for IL-13Ralpha1 expression levels on monocytes. While IL-13Ralpha1 mRNA was clearly detectable in T cell preparations, no surface expression was detected. However, permeabilization of the T cells showed a clear intracellular expression of the receptor. A soluble form of the receptor was immunoprecipitated from the supernatant of activated peripheral T cells, suggesting that T cell IL-13Ralpha1 might have functions unrelated to the capacity to form a type II IL-4/IL-13R with IL-4Ralpha. 相似文献
162.
ML Doong CC Lu MM Kau SC Tsai YC Chiao JJ Chen JY Yeh H Lin SW Huang TS Chen FY Chang PS Wang 《Canadian Metallurgical Quarterly》1998,124(6):1123-1130
1. The effect of amphetamine on gastrointestinal (GI) transit and the plasma levels of cholecystokinin (CCK) were studied in male rats. 2. Gastric emptying was inhibited both acutely and chronically by the administration of amphetamine. GI transit was decreased by the acute administration of amphetamine but not affected by the chronic administration of amphetamine. 3. Plasma CCK levels were increased dose-dependently by amphetamine. 4. Proglumide, a CCK receptor antagonist, prevented amphetamine-induced inhibition of gastric emptying and the decrease in GI transit in male rats. 5. The selective CCK(A) receptor antagonist, lorglumide, dose-dependently attenuated the amphetamine-induced inhibition of gastric emptying in male rats. In contrast, the selective CCK(B) receptor antagonist, PD 135,158, did not reverse the effect of amphetamine on gastric emptying. 6. Both lorglumide and PD 135,158 reversed the inhibitory effect of amphetamine on GI transit in male rats. 7. These results suggest that amphetamine-induced inhibition of gastric emptying and intestinal transit is due in part to a mechanism associated with the hypersecretion of endogenous CCK. 相似文献
163.
Y Bouhnik M Lémann JY Mary G Scemama R Ta? C Matuchansky R Modigliani JC Rambaud 《Canadian Metallurgical Quarterly》1996,347(8996):215-219
BACKGROUND: Crohn's ulcerative gastrointestinal disease is presently managed through a variety of medical interventions, including-according to severity of illness-anti-inflammatory, immunosuppressive, and corticosteroid agents; and with remedial surgery to correct anatomical abnormalities caused by disease processes. The immunosuppressant azathioprine (or its metabolite, 6-mercaptopurine) is considered an efficient maintenance therapy for Crohn's, but there is always concern about bone-marrow suppression, liver damage, and other adverse effects. For how long persons with this disease should be given these drugs has not been determined. METHODS: Patients who were treated with azathioprine or 6-mercaptopurine for more than 6 months, and who were in prolonged clinical remission (> 6 months without steroids) were followed. The time-to-relapse was analysed in those on treatment, in those who stopped treatment for reasons other than a relapse, and in the whole sample, taking into account that they could be treated with the drugs or not, as a function of time. The influence of concomitant variables on time-to-relapse rate was examined using the Cox proportional hazard model. FINDINGS: In the 157 patients who continued to take the therapy, cumulative probabilities of relapse at 1 and 5 years were 11% and 32% respectively. Female gender, younger age, and a time for achieving remission more than 6 months were associated with a higher risk of relapse. In 42 patients who stopped therapy, probabilities of relapse at 1 and 5 years were 38% and 75%, respectively. Male gender, younger age and duration of remission less than 4 years were associated with a higher risk of relapse. After 4 years of remission on these drugs, the risk of relapse appeared to be similar, whether the therapy was maintained or stopped. INTERPRETATION: Taking into account the potential risks of long-term immunosuppressive therapy, the usefulness of maintaining azathioprine or 6-mercaptopurine in patients who have been in remission for more than 4 years is questionable. 相似文献
164.
C de Chillou P Riff N Sadoul G Ethevenot L Feldmann K Isaaz JP Simon M Boursier K Khalifé JY Thisse E Aliot 《Canadian Metallurgical Quarterly》1996,27(7):1662-1668
OBJECTIVES: This study sought to determine whether the reopening of the infarct-related vessel is related to clinical characteristics or cardiovascular risk factors, or both. BACKGROUND: In acute myocardial infarction, thrombolytic therapy reduces mortality by restoring the patency of the infarct-related vessel. However, despite the use of thrombolytic agents, the infarct-related vessel remains occluded in up to 40% of patients. METHODS: We studied 295 consecutive patients with an acute myocardial infarction who underwent coronary angiography within 15 days (mean [+/- SD] 6.7 +/- 3.2 days) of the onset of symptoms. Infarct-related artery patency was defined by Thrombolysis in Myocardial Infarction trial flow grade > or = 2. Four cardiovascular risk factors--smoking, hypertension, hypercholesterolemia and diabetes mellitus--and eight different variables-age, gender, in-hospital death, history of previous myocardial infarction, location of current myocardial infarction, use of thrombolytic agents, time interval between onset of symptoms, thrombolytic therapy and coronary angiography--were recorded in all patients. RESULTS: Thrombolysis in current smokers and anterior infard location on admission were the three independent factors highly correlated with the patency of the infarct-related vessel (odds ratios 3.2, 3.0 and 1.9, respectively). In smokers, thrombolytic therapy was associated with a higher reopening rate of the infard vessel, from 35% to 77% (p < 0.001). Nonsmokers did not benefit from thrombolytic therapy, regardless of infarct location. CONCLUSIONS: These observational data, if replicated, suggest that in patients with acute myocardial infarction, thrombolytic therapy may be most effective in current smokers, whereas nonsmokers and ex-smokers may require other management strategies, such as emergency percutaneous transluminal coronary angioplasty. 相似文献
165.
166.
The Pseudomonas aeruginosa PAO1 phage F116 was used to investigate the viricidal activity and the mechanism of action of sodium hypochlorite. The bacteriophage was inactivated with a low concentration (0.0005% available chlorine) of the biocide prepared in tap water but it was less sensitive to a sodium hypochlorite solution prepared in ultra-pure water (0.0075% available chlorine). For all the effective concentrations of sodium hypochlorite (i.e. producing at least 4 log reduction in phage titre), F116 was readily inactivated within 30 s. Electron microscopical investigations of the phage particles challenged with sodium hypochlorite showed a wide variety of deleterious effects, some of which have not been previously observed with other biocides. The wide range of structural alterations observed suggested that sodium hypochlorite has multiple target sites against F116 bacteriophage. A 30 s exposure to sodium hypochlorite (0.001% available chlorine) produced severe damage, the number and severity of which increased with a higher concentration (0.0075% available chlorine) and with a longer contact time. These observations suggested that sodium hypochlorite inactivated F116 bacteriophage by causing structural alterations to the phage head, tail and overall structure, hence possibly releasing the viral genome from damaged capsids in the surrounding media. 相似文献
167.
IO Song SR Hong Y Huh KJ Yoo MK Koong JY Jun IS Kang 《Canadian Metallurgical Quarterly》1998,40(1):26-31
Tuberculosis is a continuous threat for health in all parts of the world. In industrialized centers an emerging increase of tuberculosis is observed due to low health standards, poor health education and control, increasing migration and the HIV epidemic. This should alert the pediatrician, since most tuberculosis infections in childhood start with contacts of infected adults with children. There is still a good response to most drugs against tuberculosis, but in some parts of the world the resistance to conventional treatment is an emerging problem. In general incidence, morbidity and mortality of tbc in children of the western world is low and has good prognosis. However, the diagnostic principles and the education of pediatricians for recognizing tbc is still of utmost importance. 相似文献
168.
169.
IS Bhullar YS Li H Miao E Zandi M Kim JY Shyy S Chien 《Canadian Metallurgical Quarterly》1998,273(46):30544-30549
Vascular endothelial cells (ECs), forming a boundary between the circulating blood and the vessel wall, are constantly subjected to fluid shear stress due to blood flow. The aim of this study was to determine the role of the recently identified IkappaB kinases (IKKs) in shear stress activation of NF-kappaB and to elucidate the upstream signaling mechanism that mediates IKK activation. Our results demonstrate that IKKs in ECs are activated by shear stress in a rapid and transient manner. This IKK activation is followed by IkappaB degradation and NF-kappaB translocation into the nucleus. Transfection of plasmids encoding catalytic inactive mutants of IKKs, i.e. hemagglutinin (HA)-IKKalpha(K44M) and HA-IKKbeta(K44A), inhibits shear stress-induced NF-kappaB translocation. In addition, constructs encoding antisense IKKs, i.e. HA-IKKalpha(AS) and HA-IKKbeta(AS), attenuate shear stress induction of a promoter driven by the kappaB enhancer element. Preincubation of the EC monolayer with a monoclonal anti-alphavbeta3 integrin antibody (clone LM609) attenuates shear stress induction of IKK. Inhibition of tyrosine kinases by genistein causes a similar down-regulating effect. These results suggest that the integrin-mediated signaling pathway regulates NF-kappaB through IKKs in ECs in response to shear stress. 相似文献
170.
UE Pallonen WF Velicer JO Prochaska JS Rossi JM Bellis JY Tsoh JP Migneault NF Smith AV Prokhorov 《Canadian Metallurgical Quarterly》1998,33(4):935-965
The impact of adolescent smoking cessation clinics has been disappointing due to low participation rates, high attrition, and low quit rates. This paper describes two computerized self-help adolescent smoking cessation intervention programs: 1) a program utilizing the expert system which is based on the transtheoretical model of change and 2) a popular action-oriented smoking cessation clinic program for teens which was modified for computer presentation. High participation rates in the program among 132 smokers demonstrate the high feasibility and acceptability of the programs. Quit rates of up to 20% were observed during the intervention, and an additional 30% made unsuccessful quit attempt(s). The 6-month follow-up findings indicated that adolescents were poorly prepared to maintain abstinence. 相似文献