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991.
R Póvoa MT Bombing B Luna Filho M Sim?es A Costa N Murad C Ferreira C Ferreira Filho 《Canadian Metallurgical Quarterly》1998,17(10):803-807
The CARE study showed that the myocardial infarction recurrence rate in patients with moderate cholesterol blood level decreases early during pravastatin treatment. Our goal is to evaluate the possible role of pravastatin in preventing the myocardial lesions induced by cold stress. Twenty Wistar-EPM rats were divided into four groups: Control (CON); PR (Pravastatin) treated with 10 mg/kg/d for 15 days; S (Stress group) in which the rats were submitted to cold stress (-8 degrees C for four hours); and PR + S group treated with pravastatin like PR group and also submitted to the cold stress. The animals were sacrificed and heart fragments were removed for optic and electronic microscopic analysis. The variable considered was mitochondria abnormality (edema, lyses and vacuolization) that was interpreted as crystolyses indices (CI) (n degree of abnormal mitochondria/n degree total of mitochondria). The following crystolyses indices, were found for each group respectively: CON, 2.0%; S, 95.5%; PR, 19.9% and PR + S group, 27.7%*(*p < 0.01). In conclusion, pravastatin prevented myocardial lesions induced by cold stress significantly. 相似文献
992.
MT Alvarez-Martinez F Porte JP Liautard J Sri Widada 《Canadian Metallurgical Quarterly》1997,1339(2):331-340
We have previously shown that annexin I, a member of a family of calcium-dependent phospholipid and membrane binding proteins, interacts with profilin with high specificity and affinity. This finding further suggests that annexin I is involved through profilin in the regulation of membrane-cytoskeleton organization. We have investigated the consequences of a complex formed by these two proteins on the functions of both profilin and annexin I. Annexin I is able to modify the inhibitory effect of profilin on actin polymerization. This action is partial and the mechanism involved appears to be complex. On the other hand, the association between annexin I and profilin is sufficiently strong to inhibit the self-association of annexin I. The binding capacity of annexin I to liposomes containing phosphatidylserine, which mimics annexin I binding to membranes, is also decreased by profilin. This binding is nevertheless restored when phosphatidylinositol 4,5-biphosphate (PtdInsP2) is included in the liposomes. Finally, the capacity of annexin I to aggregate liposomes is also modified. It is worthwhile mentioning that the liposomes-binding and liposomes-aggregating activities of annexin I are independently regulated. The cell localization and functions of annexin I and profilin suggest that interaction between these two proteins may be directly implicated in the regulation of membrane-cytoskeleton. The phospholipid composition of membranes may be one of the modulating factors. 相似文献
993.
M Minervini A Atlante S Gagliardi MT Ciotti E Marra P Calissano 《Canadian Metallurgical Quarterly》1997,768(1-2):57-62
In addition to an antigen-specific signal, T cell activation requires an antigen-independent costimulatory signal provided by interaction of CD28 with B7 (CD80 and CD86) on the APC. By blocking B7 interactions, previous studies demonstrated the requirement for costimulation in the induction of experimental allergic encephalomyelitis (EAE). Recent studies suggest that unlike CD28, CTLA-4 (a second B7 ligand) delivers an inhibitory signal. To address the regulatory role of CTLA-4 in EAE, we used an antibody directed against CTLA-4 administered at the time of disease induction. This resulted in a significantly more severe clinical course and more inflammatory and demyelinating lesions in the CNS of anti-CTLA-4-treated mice. These data suggest that CTLA-4-mediated inhibitory signals can regulate the clinical severity and histologic parameters of neuroautoimmune disease. 相似文献
994.
JA Langlois CJ Rosen M Visser MT Hannan T Harris PW Wilson DP Kiel 《Canadian Metallurgical Quarterly》1998,83(12):4257-4262
Few studies of the GH axis and bone have focused specifically on elderly people. The objective of this study was to determine the association between insulin-like growth factor I (IGF-I) and bone mineral density (BMD) in 425 women and 257 men aged 72-94 who participated in the Framingham Osteoporosis Study component of the Framingham Heart Study in 1992-1993. Serum IGF-I level was determined by RIA. BMD at three femoral sites and the lumbar spine was determined by dual x-ray absorptiometry, and at the radius by single-photon absorptiometry. IGF-I level was positively associated with BMD at all five sites (Ward's area, femoral neck, trochanter, radius, and lumbar spine) in women after adjustment for weight loss and other factors (P < or = 0.01) and protein intake in a subset of participants (0.006 < P < 0.07). A threshold effect of higher BMD was evident at each of the 3 femoral sites and the spine (P < 0.03) but not at the radius for women in the highest quintile of IGF-I (> or = 179 g/liter) vs. those in the lowest four quintiles. IGF-I was not significantly associated with BMD in men. These results indicate that higher IGF-I levels are associated with greater BMD in very old women, and suggest that future clinical trials employing GH may have a role in the development of treatments for older women with osteoporosis. 相似文献
995.
996.
Soman (pinacolymethylphosphonofluoridate), a highly potent irreversible inhibitor of acetylcholinesterase (AChE), causes seizures and rapidly increases Fos and glial fibrillary acidic protein (GFAP) staining in piriform cortex (PC). This suggests that the inhibition of AChE by soman leads to increased acetylcholine (ACh) and neuronal excitability in PC. The sole source of cholinergic input to PC is from the nucleus of the diagonal band (NDB). To investigate the role of ACh in soman-induced seizures, we lesioned cholinergic neurons in NDB unilaterally with 192-IgG-saporin. By 10 d, saporin eliminated staining for choline acetyltransferase (ChAT), the synthetic enzyme for ACh, in NDB ipsilateral to the lesion. Staining for AChE, the degradative enzyme for ACh, was eliminated in PC ipsilateral to the lesioned NDB. By 45-60 min after soman, increased Fos and GFAP staining in PC was evident only ipsilateral to the unlesioned NDB. By 90-120 min after soman, Fos and GFAP staining increased bilaterally in PC. In a second experiment, electrical stimulation electrodes were implanted unilaterally in the NDB to activate focally the projections to PC in unanesthetized rats. Within 5 min of NDB stimulation, there were clear behavioral and EEG signs of convulsions. After 45-60 min of NDB stimulation, there was increased Fos and GFAP staining in layer II of PC ipsilateral to the stimulation site. Pretreatment with the selective muscarinic receptor antagonist scopolamine blocked the convulsions and prevented increased Fos and GFAP staining in PC. These results suggest that ACh release in PC triggers the initiation of seizures and gliosis after soman administration, predominantly by the activation of muscarinic receptors. 相似文献
997.
J Vila A Gene M Vargas J Gascon C Latorre MT Jimenez de Anta 《Canadian Metallurgical Quarterly》1998,47(10):889-891
Escherichia coli strains associated with diarrhoeal disease have been classified into several types according to the pathogenic mechanism. Among these, enteroaggregative E. coli strains (EAggEC) have been associated with persistent childhood diarrhoea. Some strains of EAggEC produce a heat-stable toxin (EAST-1) that differs from others described previously. The main goal of this case-control study was to determine the prevalence of EAggEC and EAST-1-producing E. coli strains as a cause of diarrhoea in children in Spain and to study their in-vitro susceptibility to 21 antimicrobial agents. In the case group (115 children) 22 (19%) isolates and four (3.5%) isolates were EAST-1-producing E. coli and EAggEC, respectively, whereas in the control group (79 children) four (5%) isolates produced EAST-1 (p = 0.005) and three (3.8%) isolates were EAggEC. The present study suggests that EAST-1-producing E. coli strains are associated with diarrhoeal diseases in Spanish children, whereas EAggEC strains are not. Moreover, EAST-1-producing E. coli strains showed a high susceptibility to all the antimicrobial agents tested except for ampicillin. 相似文献
998.
AC Palmer WF Blakemore RJ Franklin LM Frost RE Gough JC Lewis DF Macdougall MT O'Leary LR Stocker 《Canadian Metallurgical Quarterly》1998,143(20):550-552
Paraplegia affected 14 hedgehogs (Erinaceus europaeus) in a wildlife rescue hospital over a period of six months. Postmortem examination revealed demyelination in the brain and spinal cord and an inflammatory response in the meninges, choroid plexus and CNS. The peripheral nervous system was not affected. In the spleen, lungs and liver there was an accumulation of megakaryocytes and other evidence of extramedullary haemopoiesis, but there was no haematological evidence of anaemia. The pattern of disease incidence and the nature of the changes in the CNS suggest they were of viral origin, but no causal agent was isolated and the possibility of a neurotoxin cause cannot be ruled out. 相似文献
999.
DM Howarth MT Epstein PA Thomas LW Allen R Akerman L Lan 《Canadian Metallurgical Quarterly》1997,24(12):1465-1469
The efficacy of fractionated out-patient radioiodine therapy in 38 patients with compressive symptoms due to long-standing large multinodular goitres was assessed. The diagnosis was established by clinical assessment in addition to technetium-99m pertechnetate thyroid scan or computed tomography scan of the thyroid and mediastinum. Oral iodine-131 therapy was administered as a 2.22 GBq (60 mCi) cumulative dose over 4 months (555 MBq per month). All patients were monitored with serum thyroid-stimulating hormone and free thyroxine (+/- free tri-iodothyronine) assays before the treatment and after each dose fraction. Clinical and biochemical follow-up was performed on all patients and ranged from 6 to 45 months after therapy. The patients consisted of 35 female and three male patients with a median age of 59 years (range 37-87 years). Prior to treatment 20 patients were biochemically hyperthyroid and 18 were euthyroid. Overall, 71% of patients reported a subjective improvement in compressive symptoms and 29% reported no change. Clinically assessed reduction in goitre size occurred in 92% of patients while there was no change in 8%. At 3 months of follow-up, 31% of patients had become hypothyroid and at 18 months 66% were hypothyroid. Seven hyperthyroid patients (35%) became euthyroid and 13 hyperthyroid patients (65%) became hypothyroid. Three patients who became hypothyroid experienced neck soreness (transient in one patient, persistent in two patients). There were no differences in outcome between patients who were hyperthyroid and those who were euthyroid prior to treatment. Fractionated out-patient radioiodine therapy showed excellent short- and medium-term safety, was very well tolerated and offered a satisfactory alternative treatment to surgery. 相似文献
1000.
SE Carlson MT Clandinin HW Cook EA Emken LJ Filer 《Canadian Metallurgical Quarterly》1997,66(3):715S-736S
This review evaluates scientific data associated with the possibility that trans fatty acids compromise fetal and infant early development. Concerns have been triggered by research that has heightened our awareness of the importance of n-3 and n-6 fatty acids; shown that trans fatty acids inhibit delta6 desaturation of linoleic acid; identified trans fatty acid isomers in fetal, infant, and maternal tissues; and reported an inverse association between the trans fatty acid content of tissue lipids and measures of growth and development. Animal studies provide little evidence that trans fatty acids influence growth, reproduction, or gross aspects of fetal development. However, these models may not have been appropriate for addressing all the subtle effects that influence development of human infant retinal, neural, or brain function. Human studies are hampered by the complexity of the interrelations among nutritional, genetic, and environmental factors and by ethical considerations that constrain the research design. Existing data have not established a causal relation between trans fatty acid intake and early development. Conclusions cannot be drawn from the possible association found between trans fatty acid exposure and lower n-3 and n-6 long-chain polyunsaturated fatty acids and growth because of confounding factors. Few studies addressed the question of whether trans fatty acids adversely affect human fetal growth. One study reported a correlation between the trans fatty acid content of plasma and birth weight of preterm infants and one study reported a relation between preterm births and the trans fatty acid content of maternal plasma. Limited associative data have addressed whether trans fatty acids adversely affect fetal and infant neurodevelopment and growth. The interpretation of existing research and development of recommendations should be done cautiously. Suggestions for research to clarify these issues are made. 相似文献