全文获取类型
收费全文 | 639篇 |
免费 | 23篇 |
国内免费 | 1篇 |
出版年
2024年 | 1篇 |
2023年 | 3篇 |
2022年 | 4篇 |
2021年 | 12篇 |
2020年 | 12篇 |
2019年 | 11篇 |
2018年 | 10篇 |
2017年 | 11篇 |
2016年 | 19篇 |
2015年 | 27篇 |
2014年 | 37篇 |
2013年 | 45篇 |
2012年 | 76篇 |
2011年 | 69篇 |
2010年 | 36篇 |
2009年 | 24篇 |
2008年 | 39篇 |
2007年 | 39篇 |
2006年 | 39篇 |
2005年 | 32篇 |
2004年 | 27篇 |
2003年 | 23篇 |
2002年 | 15篇 |
2001年 | 5篇 |
1999年 | 5篇 |
1998年 | 8篇 |
1997年 | 3篇 |
1996年 | 2篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1984年 | 3篇 |
1982年 | 2篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1974年 | 1篇 |
排序方式: 共有663条查询结果,搜索用时 15 毫秒
131.
Recent evidence strongly suggests that both central and peripheral T-type Ca(2+) channels enhance somatic and visceral nociceptive inputs, as well as that regulation of T-type Ca(2+) channel function can result in significant changes of pain threshold in a variety of animal models. Therefore, T-type Ca(2+) channels in peripheral and central pain pathways, although previously unrecognized, may have great importance as targets for developing new therapies against pain. This is particularly critical in cases in which currently available treatments are limited due to serious side effects or are not consistently effective (e.g., chronic neuropathic pain). In this review, we summarize recent studies of the regulation of T-type channels in peripheral sensory neurons by means of redox agents and neuroactive steroids, as well as studies of the function of these channels in the pathophysiology of neuropathic pain. 相似文献
132.
Vasilijević A Buzadzić B Korać A Petrović V Janković A Mićunović K Korać B 《Comparative biochemistry and physiology. Toxicology & pharmacology : CBP》2007,145(4):641-647
Alterations of pancreatic antioxidative defense (AD) and possible nitric oxide (NO) role in AD organization of adult rats receiving l-arginine.HCl (2.25%) or N(omega)-nitro-l-arginine methyl ester (L-NAME.HCl, 0.01%) as drinking liquids and maintained at room (22+/-1 degrees C) or low (4+/-1 degrees C) temperature for 45 days were studied. For that purpose, copper, zinc- and manganese superoxide dismutase (CuZnSOD, MnSOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione S-transferase (GST) and glutathione reductase (GR) activities were determined. Cold-induced decrease of CuZnSOD was inhibited with L-NAME, while l-arginine produced the same effect as cold in both supplemented groups. Cold acclimation elevated GSH-Px activity. l-Arginine and L-NAME expressed no effect on GSH-Px in rats kept at room temperature. L-NAME additionally elevated cold-induced GSH-Px activity, l-arginine expressing a similar trend. Cold-induced increase in GST activity was inhibited by L-NAME, while l-arginine inhibited this enzyme in both supplemented groups. Cold acclimation increased GR activity in control and L-NAME-treated group and l-arginine expressed a similar trend. Neither of the treatments affected MnSOD and CAT activities. Cold-induced changes of pancreatic AD were additionally affected by the alterations in l-arginine-NO-producing pathway. Some AD changes in the same direction with l-arginine or L-NAME point to the complexity of nitrogen compounds metabolism and function, accompanied by tissue-specific response. 相似文献
133.
Zilberberg L Todorovic V Dabovic B Horiguchi M Couroussé T Sakai LY Rifkin DB 《Journal of cellular physiology》2012,227(12):3828-3836
Fibrillin microfibrils are extracellular matrix structures with essential functions in the development and the organization of tissues including blood vessels, bone, limbs and the eye. Fibrillin‐1 and fibrillin‐2 form the core of fibrillin microfibrils, to which multiple proteins associate to form a highly organized structure. Defining the components of this structure and their interactions is crucial to understand the pathobiology of microfibrillopathies associated with mutations in fibrillins and in microfibril‐associated molecules. In this study, we have analyzed both in vitro and in vivo the role of fibrillin microfibrils in the matrix deposition of latent TGF‐β binding protein 1 (LTBP‐1), ‐3 and ‐4; the three LTBPs that form a complex with TGF‐β. In Fbn1?/? ascending aortas and lungs, LTBP‐3 and LTBP‐4 are not incorporated into a matrix lacking fibrillin‐1 microfibrils, whereas LTBP‐1 is still deposited. In addition, in cultures of Fbn1?/? smooth muscle cells or lung fibroblasts, LTBP‐3 and LTBP‐4 are not incorporated into a matrix lacking fibrillin‐1 microfibrils, whereas LTBP‐1 is still deposited. Fibrillin‐2 is not involved in the deposition of LTBP‐1 in Fbn1?/? extracellular matrix as cells deficient for both fibrillin‐1 and fibrillin‐2 still incorporate LTBP‐1 in their matrix. However, blocking the formation of the fibronectin network in Fbn1?/? cells abrogates the deposition of LTBP‐1. Together, these data indicate that LTBP‐3 and LTBP‐4 association with the matrix depends on fibrillin‐1 microfibrils, whereas LTBP‐1 association depends on a fibronectin network. J. Cell. Physiol. 227: 3828–3836, 2012. © 2012 Wiley Periodicals, Inc. 相似文献
134.
Mahajan DT Masand VH Patil KN Ben Hadda T Jawarkar RD Thakur SD Rastija V 《Bioorganic & medicinal chemistry letters》2012,22(14):4827-4835
In present work, 53 synthetic prodiginines were selected to establish thriving CoMSIA (Comparative Molecular Similarity Indices Analysis) model to explore the structural features influencing their anti-malarial activity. POM (Petra/Osiris/Molinspiration) was carried out to get insight into requirements that can lead to the improvement of the activity of these molecules. The CoMSIA model, based on a combination of steric, electrostatic and H-bond acceptor/donor effects, is with R(2)(cv)=0.738 and R(2)=0.911. The analyses reveal that lipophilicity, hydrogen donor/acceptor and steric factors play crucial role. The study with constructive propositions could be useful for the design of new analogues with enhanced activity. 相似文献
135.
Jelka Pleadin Manuela Zadravec Nina Per?i Ana Vuli? Vesna Jaki Mario Mitak 《Mycotoxin Research》2012,28(3):157-162
The aim of this study was to investigate the contamination of pig feed with moulds and the occurrence of mycotoxins. A total of 30 feed samples were collected at different animal feed factories in the north-western part of Croatia. Mycological analysis showed that the total number of moulds ranged from 1?×?103 to 1?×?105?cfu/g with samples contaminated with Aspergillus spp. (63?%), Penicillium spp. (80?%), and Fusarium spp. (77?%). A determination of aflatoxin B1 (AFB1), ochratoxin A (OTA), zearalenone (ZEA), deoxynivalenol (DON), T-2 toxin (T-2) and fumonisin (FUM) concentration was done using the validated ELISA method. The mean concentrations of AFB1 (0.5?±?0.6???g/kg), OTA (1.53?±?0.42???g/kg) and FUM (405?±?298???g/kg) were below the maximum levels or recommended values in the EU in all the investigated samples. The observed results indicated an increased contamination of pig feed with Fusarium mycotoxins DON and ZEA with mean concentrations of 817?±?447 and 184?±?214???g/kg, higher than recommended in 40 and 17?% of the analysed samples, respectively. 相似文献
136.
The corpus callosum connects two cerebral hemispheres as the most voluminous fiber system in the human brain. The developing callosal fibers originate from immature pyramidal neurons, grow through complex pathways and cross the midline using different substrates in transient fetal structures. We analyzed cellular structures in the human corpus callosum on postmortem brains from the age of 18 weeks post conception to adult, using glial fibrillary acidic protein, neuron-specific nuclear protein, and chondroitin sulphate immunocytochemistry. We found the presence of transient cellular structures, callosal septa, which divide major fiber bundles and ventrally merge with subcallosal zone forming grooves for callosal axons. The callosal septa are composed of glial fibrillary acidic protein reactive meshwork, neurones and the chondroitin sulphate immunoreactive extracellular matrix. The developmental window of prominence of the callosal septa is between 18-34 weeks post conception which corresponds to the period of most intensive growth of callosal axons in human. During the early postnatal period the callosal septa become thinner and shorter, lose their neuronal and chondroitin sulphate content. In conclusion, transient expression of neuronal, glial and extracellular, growing substrate in the callosal septa, as septa itself, indicates their role in guidance during intensive growth of callosal fibers in the human brain. These findings shed some light on the complex morphogenetic events during the growth of the corpus callosum and represent normative parameters necessary for studies of structural plasticity after perinatal lesions. 相似文献
137.
As the other major European countries, Croatia has also seen a marked increase in the rate of caesarean sections. The aim of this study was to determine the most common reasons for caesarean section, to compare emergency and elective caesarean section in regard to intraoperative and postoperative complications in both mother and child, and to assess the decision-to-delivery interval (DDI) in our clinic in comparison to current recommendations. Analyzing the results of our research we can say that the new-borns in the group with the elective caesarean section had considerably better Apgar index score in the first minute (p = 0.00056) and in the fifth minute (p = 0.054) than the children born in the group with emergency caesarean section. Children from the group with elective caesarean section had also less frequent asphyxia (p = 0.02315) and considerably less frequent resuscitation (p = 0.0143) than the children from the group with emergency caesarean sections. Only 39.73% of the emergency caesarean sections were performed within the "golden standard" period of 30 minutes. Regarding the data from the literature our results are similar with the ones from developed countries and 30 minute current standard seem to be not achievable. 相似文献
138.
Ulrih NP Skrt M Veranic P Galvani V Vranac T Curin Serbec V 《Biochemical and biophysical research communications》2006,344(4):1320-1326
A specific monoclonal antibody (mAb) V5B2 that discriminates between brain tissue of Creutzfeldt-Jakob disease patients and that from normal controls without proteinase K digestion has been prepared using a 13-residue synthetic peptide P1 from the primary structure of human PrP. In the light of the specific interaction between mAb V5B2 and the pathological isoform of PrP (PrP(Sc)), we investigated the solution behavior of antigen P1 and its interactions with mAb V5B2. Our results show that V5B2 recognizes epitope P1 in dimeric/oligomeric forms in solution and in the fibril-like aggregates, as well as in PrP(Sc) aggregates, and demonstrate that the specific epitope is present in all of these forms, but not in PrP(C). 相似文献
139.
Popsavin M Torović L Svircev M Kojić V Bogdanović G Popsavin V 《Bioorganic & medicinal chemistry letters》2006,16(10):2773-2776
Two novel tiazofurin analogues 2 and 3 were synthesized starting from d-glucose. The key step of the synthesis was the efficient one-step hydrogen sulfide-mediated conversion of 2-azido-3-O-acyl-ribofuranosyl cyanides to the corresponding 2-amido thiocarboxamides. Compounds 2 and 3 were evaluated for their in vitro antiproliferative activity against certain human tumour cell lines. Remarkably, compound 2 was found to be 570-fold more potent than tiazofurin against MCF-7 cells, while compound 3 showed the most powerful cytotoxicity against HT-29 cancer cells, being almost 100-fold more active than tiazofurin. 相似文献
140.
Primo? Peterlin Vesna Arrigler Saša Svetina Peter Walde 《Chemistry and physics of lipids》2009,159(2):67-420
The interaction of two types of vesicle systems was investigated: micrometer-sized, giant unilamellar vesicles (GUVs) formed from 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and submicrometer-sized, large unilamellar vesicles (LUVs) formed from oleic acid and oleate, both in a buffered aqueous solution (pH 8.8). Individual POPC GUVs were transferred with a micropipette into a suspension of oleic acid/oleate LUVs, and the shape changes of the GUVs were monitored using optical microscopy. The behavior of POPC GUVs upon transfer into a 0.8 mM suspension of oleic acid, in which oleic acid/oleate forms vesicular bilayer structures, was qualitatively different from the behavior upon transfer into a 0.3 mM suspension of oleic acid/oleate, in which oleic acid/oleate is predominantly present in the form of monomers and possibly non-vesicular aggregates. In both cases, changes in vesicle morphology were observed within tens of seconds after the transfer. After an initial increase of the vesicle cross-section, the vesicle started to evaginate, spawning dozens of satellite vesicles connected to the mother vesicle with narrow necks or tethers. In 60% of the cases of transfer into a 0.8 mM oleic acid suspension, the evagination process reversed and proceeded to the point where the membrane formed invaginations. In some of these cases, several consecutive transitions between invaginated and evaginated shapes were observed. In the remaining 40% of the cases of transfer into the 0.8 mM oleic acid suspension and in all cases of vesicle transfer into the 0.3 mM oleic acid suspension, no invaginations nor subsequent evaginations were observed. An interpretation of the observed vesicle shape transformation on the basis of the bilayer-couple model is proposed, which takes into account uptake of oleic acid/oleate molecules by the POPC vesicles, oleic acid flip-flop processes and transient pore formation. 相似文献