全文获取类型
收费全文 | 197篇 |
免费 | 10篇 |
国内免费 | 1篇 |
专业分类
208篇 |
出版年
2024年 | 1篇 |
2023年 | 4篇 |
2022年 | 6篇 |
2021年 | 17篇 |
2020年 | 3篇 |
2019年 | 5篇 |
2018年 | 8篇 |
2017年 | 5篇 |
2016年 | 9篇 |
2015年 | 14篇 |
2014年 | 15篇 |
2013年 | 13篇 |
2012年 | 8篇 |
2011年 | 11篇 |
2010年 | 7篇 |
2009年 | 4篇 |
2008年 | 11篇 |
2007年 | 11篇 |
2006年 | 7篇 |
2005年 | 10篇 |
2004年 | 5篇 |
2003年 | 8篇 |
2002年 | 5篇 |
2001年 | 5篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1992年 | 1篇 |
1991年 | 5篇 |
1984年 | 1篇 |
1981年 | 1篇 |
1978年 | 1篇 |
排序方式: 共有208条查询结果,搜索用时 15 毫秒
41.
We estimated growth parameters of Emys orbicularis and Mauremys rivulata in Mediterranean Turkey with the skeletochronological method, using specimens drowned in fyke nets. In adult E. orbicularis, the median age was 8 years in males and 10 years in females. The median age of adult M. rivulata was 10 years for both sexes. Both species reach sexual maturity at an age of 5–7 years. No difference was found in age composition between the sexes. 相似文献
42.
A. Ismen O. Ozen U. Altinagac U. Ozekinci A. Ayaz 《Zeitschrift fur angewandte Ichthyologie》2007,23(6):707-708
Weight–length relationships are presented for 63 fish species sampled with a commercial trawl vessel at depths ranging from 28 to 370 m between February 2005 and April 2006 in Saros Bay, Turkey. Saros Bay was closed to trawl fishery in 2000, thus, most of the demersal fish species sampled were relatively undisturbed. 相似文献
43.
Saeed Ahmad Sanaullah Khan Alam Zeb Syed Wadood Ali Shah Bashir Ahmad Ayaz Ali Khan Waqar Ali Nadir Zaman Khan Ghazala Yasmin Zamani 《Saudi Journal of Biological Sciences》2021,28(11):6352-6358
The analgesic, antidiarrheal, and neuro-pharmacological potentials of Medicago denticulata leaves extract were screened in animal models. Potential analgesic response was noted (*P < 0.05, **P < 0.01, ***P < 0.001) in formalin, acetic acid and heat-induced pain models in a dose-dependent manner. Maximum activity by means of writhing inhibition was documented for Medicago denticulata at 300 mg/kg that was found to be 71.79% (17.43 ± 1.31). In first phase, the Medicago denticulata at a dose of 150 and 300 mg/kg showed analgesic activity and reduced the pain by 54.18% (18.39 ± 1.67) and 62.90% (14.89 ± 1.56), respectively. In second phase, the Medicago denticulata at a dose of 150 and 300 mg/kg showed analgesic activity and reduced the pain by 69.48% (19.78 ± 1.44) and 70.89% (18.86 ± 1.58), respectively. In hot plate method, the Medicago denticulata at a dose of 150 and 300 mg/kg showed the maximum response of 61.16% (8.47 ± 1.23) and 67.39% (10.09 ± 1.04), respectively at 60 min. Scopolamine significantly reduces spontaneous alteration in Y-maze model for antiamnesic activity. Medicago denticulata significantly increased the discrimination index in a dose-dependent manner using novel object recognition test (NORT) model. Exploration time in sec for the novel object was increased significantly (P < 0.001) by donepezil decreased for familiar one with a discrimination index (DI) of 62.18%. Medicago denticulata significantly increased the discrimination index by 60.86% and 57.24% at 300 and 150 mg/kg b.w, respectively. The lowest DI of 53.80% at 75 mg/kg was observed in comparison to the amnesic group. The Medicago denticulata significant decreased the elevated levels of acetylcholinesterase (AChE) and malondialdehyde (MDA and enhancing level of acetylcholine (ACh), superoxide dismutase (SOD) and catalase (CAT) acting as an antioxidant agent. Medicago denticulata reduced the total number of diarrheal feces to lesser extent at dose-dependent manner. From the study results, it is suggested that the Medicago denticulata extract possess good analgesic and antiamnesic activity however the antidiarrheal effects of plant were negligible. In the current study, the traditional use of the plant as a source of medicine has been validated. 相似文献
44.
Incompatibility of Lactobacillus Vectors with Replicons Derived from Small Cryptic Lactobacillus Plasmids and Segregational Instability of the Introduced Vectors 总被引:3,自引:4,他引:3 下载免费PDF全文
M. Posno R. J. Leer N. van Luijk M. J. F. van Giezen P. T. H. M. Heuvelmans B. C. Lokman P. H. Pouwels 《Applied microbiology》1991,57(6):1822-1828
Three new Lactobacillus vectors based on cryptic Lactobacillus plasmids were constructed. The shuttle vector pLP3537 consists of a 2.3-kb plasmid from Lactobacillus pentosus MD353, an erythromycin resistance gene from Staphylococcus aureus plasmid pE194, and pUC19 as a replicon for Escherichia coli. The vectors pLPE317 and pLPE323, which do not contain E. coli sequences, were generated by introducing the erythromycin resistance gene of pE194 into a 1.7- and a 2.3-kb plasmid from L. pentosus MD353, respectively. These vectors and the shuttle vector pLP825 (M. Posno, R. J. Leer, J. M. M. van Rijn, B. C. Lokman, and P. H. Pouwels, p. 397-401, in A. T. Ganesan and J. A. Hoch, ed., Genetics and biotechnology of bacilli, vol. 2, 1988) could be introduced by electroporation into Lactobacillus casei, L. pentosus, L. plantarum, L. acidophilus, L. fermentum, and L. brevis strains with similar efficiencies. Transformation efficiencies were strain dependent and varied from 102 to 107 transformants per μg of DNA. Plasmid DNA analysis of L. pentosus MD353 transformants revealed that the introduction of pLP3537 or pLPE323 was invariably accompanied by loss of the endogenous 2.3-kb plasmid. Remarkably, pLPE317 could only be introduced into an L. pentosus MD353 strain that had been previously cured of its endogenous 1.7-kb plasmid. The curing phenomena are most likely to be explained by the incompatibility of the vectors and resident plasmids. Lactobacillus vectors are generally rapidly lost when cells are cultivated in the absence of selective pressure. However, pLPE323 is stable in three of four Lactobacillus strains tested so far. 相似文献
45.
There is an increasing demand for assay technologies that enable accurate, cost-effective, and high-throughput measurements of drug–target association and dissociation rates. Here we introduce a universal homogeneous kinetic probe competition assay (kPCA) that meets these requirements. The time-resolved fluorescence energy transfer (TR–FRET) procedure combines the versatility of radioligand binding assays with the advantages of homogeneous nonradioactive techniques while approaching the time resolution of surface plasmon resonance (SPR) and related biosensors. We show application of kPCA for three important target classes: enzymes, protein–protein interactions, and G protein-coupled receptors (GPCRs). This method is capable of supporting early stages of drug discovery with large amounts of kinetic information. 相似文献
46.
Serological antibody assays used in hepatitis C virus diagnosis have improved in sensitivity and specificity. However, detection of active viremia or monitoring levels of virus during or after patient treatment is most commonly undertaken using nucleic acid-based technologies. Advancements in diagnostic technologies and implications for managing patients with hepatitis C in various clinical settings are discussed. 相似文献
47.
Dinçer Ayaz Uwe Fritz Cemal Varol Tok Ahmet Mermer Murat Tosunoğlu Murat Afsar Kerim Çiçek 《Biologia》2007,62(2):225-227
Data on population size, adult sex ratio, body size and mass are provided for a population of the turtle Emys orbicularis near Pazara?aç (Afyonkarahisar/Turkey). Using the mark-recapture method (triple catch), a population size of 664 turtles was estimated (95% confidence interval, range 332–996), corresponding to a density of 83 turtles per hectare (range 41.5–124.5). The adult sex-ratio was significantly skewed in favor of males (2.02 males: 1 female; P < 0.001). Almost all recorded specimens were adult (98.1%). Mean straight carapace length (SCL) and body mass (BM) of adult turtles were: SCL = 128.65 mm, BM = 345 g for males (n = 168) and SCL = 135.37 mm, BM = 463 g for females (n = 83). 相似文献
48.
Ullah Mughal E Ayaz M Hussain Z Hasan A Sadiq A Riaz M Malik A Hussain S Choudhary MI 《Bioorganic & medicinal chemistry》2006,14(14):4704-4711
Synthesis of flavones, 4-thioflavones and 4-iminoflavones was carried out with the substitution of variable halogens, methyl, methoxy and nitro groups in the A, B and AB rings of the respective compounds and we also report here their antibacterial activity. Most of the synthesized compounds were found to be active against Escherichia coli, Bacillus subtilis, Shigella flexnari, Salmonella aureus, Salmonella typhi and Pseudomonas aeruginosa. Activity of 4-thioflavones and 4-iminoflavones was found to be higher than that of their corresponding flavone analogues. Investigated compounds having substituents like F, OMe and NO2 at 4'-position in ring-B exhibited enhanced activity and the presence of electronegative groups in the studied compounds showed a direct relationship to the antibacterial activity. 相似文献
49.
Ersen Kavak Ayaz Najafov Nuri Ozturk Tuncay Seker Kader Cavusoglu Tolga Aslan Adil Doganay Duru Tahsin Saygili Gerta Hoxhaj Mahmut Can Hiz Durisehvar Ozer Unal Necla Birgül-İyison Mehmet Ozturk Ahmet Koman 《Cellular signalling》2010,22(10):1523-1535
The Wnt signaling pathway is involved in many differentiation events during embryonic development and can lead to tumor formation after aberrant activation of its components. β-catenin, a cytoplasmic component, plays a major role in the transduction of canonical Wnt signaling. The aim of this study was to identify novel genes that are regulated by active β-catenin/TCF signaling in hepatocellular carcinoma-derived Huh7 cells with high (transfected) and low β-catenin/TCF activities. High TCF activity Huh7 cells led to earlier and larger tumor formation when xenografted into nude mice. SAGE (Serial Analysis of Gene Expression), genome-wide microarray and in silico promoter analysis were performed in parallel, to compare gene expression between low and high β-catenin/TCF activity clones, and also those that had been rescued from the xenograft tumors. SAGE and genome-wide microarray data were compared and contrasted. BRI3 and HSF2 were identified as novel targets of Wnt/β-catenin signaling after combined analysis and confirming experiments including qRT-PCR, ChIP, luciferase assay and lithium treatment. 相似文献
50.
Ayaz M Ozdemir S Yaras N Vassort G Turan B 《Biochemical and biophysical research communications》2005,327(1):163-173
In the present study, rats were treated with sodium selenite (5 micromol/kg body weight/day, ip) for 4 weeks and the parameters of contractile activity, action potential, L-type Ca2+-current (ICaL), as well as transient outward (Ito), inward rectifier (IK1), and steady state (Iss) K+-currents were investigated. Sodium selenite treatment increased rat blood glucose level and lowered plasma insulin level, significantly. This treatment also caused slightly prolongation in action potential with no significant effects on spontaneous contraction parameters and intracellular Ca2+ transients of the heart preparations. These effects were associated with marked alterations in the kinetics of both ICaL and Ito including a significant slowing in both inactivation time constants of ICaL and a significant shift to negative potential at half-inactivation of these channels without any change in the current density. Also, there was a significantly faster inactivation of Ito and no shift in half-inactivation of this channel without any change in its current density. Consequently, there was a approximately 50% increase in total charges carried by Ca2+ current and approximately 50% decrease in total charges carried by K+ currents of the treated rat cardiomyocytes. Additionally we observed a significant inhibition in IK1 density in treated rat cardiomyocytes. Oxidized glutathione level was significantly increased (70%) while the observed decrease in reduced glutathione was much less. Since a shift in redox state of regulatory proteins is related with cell dysfunction, selenium-induced increase in blood glucose and decrease in plasma insulin may correlate these alterations. These alterations, in the kinetics of the channels and in IK1 density, might lead to proarrhythmic effect of chronic selenium supplementation. 相似文献