全文获取类型
收费全文 | 3016篇 |
免费 | 200篇 |
出版年
2024年 | 2篇 |
2023年 | 48篇 |
2022年 | 89篇 |
2021年 | 149篇 |
2020年 | 101篇 |
2019年 | 133篇 |
2018年 | 138篇 |
2017年 | 131篇 |
2016年 | 149篇 |
2015年 | 226篇 |
2014年 | 177篇 |
2013年 | 220篇 |
2012年 | 254篇 |
2011年 | 222篇 |
2010年 | 149篇 |
2009年 | 99篇 |
2008年 | 144篇 |
2007年 | 123篇 |
2006年 | 115篇 |
2005年 | 94篇 |
2004年 | 87篇 |
2003年 | 73篇 |
2002年 | 68篇 |
2001年 | 22篇 |
2000年 | 31篇 |
1999年 | 17篇 |
1998年 | 8篇 |
1997年 | 10篇 |
1996年 | 9篇 |
1995年 | 15篇 |
1994年 | 6篇 |
1993年 | 3篇 |
1992年 | 15篇 |
1991年 | 13篇 |
1990年 | 11篇 |
1989年 | 13篇 |
1988年 | 7篇 |
1987年 | 4篇 |
1986年 | 5篇 |
1985年 | 3篇 |
1984年 | 5篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1979年 | 4篇 |
1976年 | 3篇 |
1975年 | 2篇 |
1973年 | 3篇 |
1961年 | 1篇 |
1953年 | 1篇 |
排序方式: 共有3216条查询结果,搜索用时 15 毫秒
11.
N A Sharif J L Nunes V Kalfayan D L McClelland R P Rosenkranz R M Eglen R L Whiting 《Neurochemistry international》1992,21(1):69-73
Binding of [3H]GBR12935 to homogenates of mouse and rat striatum and kidney was studied. [3H]GBR12935 bound to both tissue preparations with high affinity (mouse striatum Kd = 2.4 +/- 0.4 nM, n = 4; mouse kidney Kd = 3.8 +/- 0.9 nM, n = 4), in a saturable (striatal Bmax = 1.5 +/- 0.4 pmol/mg protein; kidney Bmax = 4.9 +/- 0.5 pmol/mg protein) and reversible manner. Saturation experiments revealed the presence of a single class of high affinity binding sites in both tissues of both species. Mouse kidney appeared to possess a greater density of [3H]GBR12935 binding sites than the striatum while the reverse situation prevailed for the rat. Although two dopamine uptake inhibitors, namely GBR12909 and benztropine, displaced [3H]GBR12935 binding from striatal and kidney homogenates with a similar affinity in both tissues of these species, unlabelled mazindol, (+/-)cocaine, nomifensine and amfonelic acid were significantly (P < 0.001-0.02) more potent inhibitors of [3H]GBR12935 binding in the striatum than in the kidney. While the pharmacological profile of [3H]GBR12935 binding in the rodent striatum compared well with that of the dopamine transporter reported previously, the pharmacology in the kidney was considerably different to that in the striatum. GBR12909 (1-30 mg/kg, i.p.), a close analog of GBR12935, induced significant antidiuretic and antinatriuretic effects in spontaneously hypertensive rats. These data suggest that while [3H]GBR12935 labels the dopamine uptake sites in the brain, it does not appear to label similar sites in the kidney. The mechanism of action of GBR12909 on sodium and water excretion remains to be determined. 相似文献
12.
Summary In the present work we have investigated the possible interaction between Bleomycin (B) and UV light or hyperthermia (HT) in the induction of lethal events in diploid yeast populations in the stationary phase of growth. UV and B acting as single agents determine sigmoid survival curves. The combination of UV + B produces different degrees of sensitization depending on dose ranges. For [B] = 7.5 µg/ml combined with different UV fluences an exponential course is observed, suggesting overlapping lesion specificity of the involved repair pathways (excision and recombination). The hyperthermia plus Bleomycin treatment produces different degrees of inactivation depending on the sequences. Maximal inactivation effect was obtained for the sequence B + HT. In the case of HT + B ([B] > 7.5 µg/ml) the obtained sensitization is lower. 相似文献
13.
14.
Determination of the spectrum of beta-thalassemia genes in Spain by use of dot-blot analysis of amplified beta-globin DNA. 总被引:3,自引:1,他引:2
下载免费PDF全文
![点击此处可从《American journal of human genetics》网站下载免费的PDF全文](/ch/ext_images/free.gif)
S Amselem V Nunes M Vidaud X Estivill C Wong L d''''Auriol D Vidaud F Galibert M Baiget M Goossens 《American journal of human genetics》1988,43(1):95-100
We have delineated the molecular lesions causing beta-thalassemia in Spain, a country that has witnessed the passage of different Mediterranean populations over the centuries, in order to evaluate the extent of heterogeneity of these mutations and to make possible simplified prenatal diagnosis of the disorder in that country. The use of the polymerase chain-reaction (PCR) technique to preferentially amplify beta-globin DNA sequences that contain the most frequent beta-thalassemia mutations in Mediterraneans enabled us to rapidly analyze 58 beta-thalassemia alleles in a dot-blot format either by hybridization with allele-specific radiolabeled oligonucleotide probes or by direct sequence analysis of the amplification product. The Spanish population carries seven different beta-thalassemia mutations; the nonsense codon 39 is predominant (64%), whereas the IVS1 position 110 mutation, the most common cause of beta-thalassemia in the eastern part of the Mediterranean basin, is underrepresented (8.5%). The IVS1 mutation at position 6 accounts for 15% of the defects and leads to a more severe form of beta+-thalassemia than originally described in most of the patients we studied. In this study, we demonstrate further the usefulness of the dot-blot hybridization of PCR-amplified genomic DNA in both rapid population surveys and prenatal diagnosis of beta-thalassemia. 相似文献
15.
The authors studied by means of sterological methods the volume density of syncytial sprouts in different cotyledonary regions of the human term placenta. The syncytial sprouts account for 4.92% of the placenta volume. Meanwhile, there were significant differences according to the site from which the sample was obtained. The lowest value (2.72%) corresponds to the central-parabasal zone of the cotyledon, close to the entry of the maternal blood into the intervillous space, whereas the highest values correspond to the "venous" regions. The results of the present study, as well as those reported by others, suggest that the lateral-subchorial zone would be the growing region of the cotyledon. 相似文献
16.
Oxygen consumption rates (QO2) of laboratory reared stage one zoeae of Pandalus borealis (Krøyer) at 1.5, 3, 4.5, 6, and 9°C were 1.5, 2.2, 2.6, 3.6 and 4.1μ O2 · mg?1 · h?1, respectively. These values of QO2 correspond to 0.26, 0.38, 0.44, 0.60, and 0.70 μl O2 · individual?1 · h?1. At 10.5 °C oxygen consumption rates decreased suggesting thermally induced respiratory stress.The equation log10QO2 = 0.55 log10T°C + 0.086 describes the relationship between QO2 (μl O2 · mg?1 · h?1) and sea-water temperature between 1.5 and 9°C. Corresponding values of QO2 for an individual (μl O2 · h?1) exhibited the relationship log10QO2 = 0.55 log10T°C ?0.686.The minimum daily metabolic caloric requirements for an individual zoea ranged from 0.04 at 3 °C to 0.07 calories per day at 8 °C. The number of calories ingested daily ranged from 0.4 to 0.5 at 3 to 8 °C. 相似文献
17.
Nunes V. Casals T. Gallano P. Giménez F. J. Kere J. Williamson R. Estivill X. 《Human genetics》1989,83(3):305-306
Summary We report a rare allele detected using pMP6d-9, a probe very closely linked to cystic fibrosis (CF), on digestion with MspI. This allele has been found in normal and CF chromosomes, and therefore cannot be related to the mutation causing the disease. 相似文献
18.
Fine mapping of the Autosomal Dominant Split Hand/Split Foot Locus on Chromosome 7, Band q21.3-q22.1 总被引:6,自引:3,他引:3
下载免费PDF全文
![点击此处可从《American journal of human genetics》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Stephen W. Scherer Parvoneh Poorkaj Todd Allen Julia Kim Dorrit Geshuri Mark Nunes Sylvia Soder Karen Stephens Roberta A. Pagon Michael A. Patton Mary Anne Berg Tim Donlon Horacio Rivera R. A. Pfeiffer Kenji Naritomi Helen Hughes Maurizio Genuardi Fiorella Gurrieri Giovanni Neri Everett Lovrein Ellen Magenis Lap-Chee Tsui James P. Evans 《American journal of human genetics》1994,55(1):12-20
Split hand/split foot (SHFD) is a human developmental defect characterized by missing digits, fusion of remaining digits, and a deep median cleft in the hands and feet. Cytogenetic studies of deletions and translocations associated with this disorder have indicated that an autosomal dominant split hand/split foot locus (gene SHFD1) maps to 7q21-q22. To characterize the SHFD1 locus, somatic cell hybrid lines were constructed from cytogenetically abnormal individuals with SHFD. Molecular analysis resulted in the localization of 93 DNA markers to one of 10 intervals surrounding the SHFD1 locus. The translocation breakpoints in four SHFD patients were encompassed by the smallest region of overlap among the SHFD-associated deletions. The order of DNA markers in the SHFD1 critical region has been defined as PON–D7S812–SHFD1–D7S811–ASNS. One DNA marker, D7S811, detected altered restriction enzyme fragments in three patients with translocations when examined by pulsed-field gel electro-phoresis (PFGE). These data map SHFD1, a gene that is crucial for human limb differentiation, to a small interval in the q21.3-q22.1 region of human chromosome 7. 相似文献
19.
Seed of Stlosanthes humilis both have hard integuments and display physiological dormancy, the latter being lost during post-harvest ageing. Ethrel and l-aminocyclopropane-1-carboxylic acid (ACC) partially released scarified young seed from physiological dormancy. Cobalt and silver ions and abscisic acid inhibited germination of scarified non-dormant seed. Abscisic acid also inhibited germination of voung seed promoted by ACC. Thiourea and ethrel plus benzyladenine showed the greatest efficacy in breaking seed dormancy. 相似文献
20.
Paula Tatiana Lopes Seixas Antonio Jacinto Demuner Luiz Claudio Almeida Barbosa Cristiane Isaac Cerceau Daiane Einhardt Blank Marcelo Henrique Dos Santos Elizeu de Sá Farias Marcelo Coutinho Picanço 《Journal of Applied Entomology》2023,147(2):116-125
Aedes aegypti L. (Diptera: Culicidae) is a vector for serious diseases in tropical regions. This pest is mainly controlled by commercial larvicides but the application of such products has led to environmental problems. Essential oils (EO) have been consistently reported as molecules with insecticidal activity and can be used to produce more environmentally friendly larvicides in the control of A. aegypti. In this study, the larvicidal effect of essential oils (EO) from the leaves of three Artemisia species was evaluated against A. aegypti. The oils were obtained from steam distillation and their chemical composition was determined by gas chromatography–mass spectrometry. The EO of Artemisia camphorata was the most active in the screening bioassay and presented LC50 and LC95 of 64.95 and 74.18 μg ml−1, respectively. In addition, we found that germacrene D-4-ol was the constituent responsible for the toxicity of this EO. Artemisia camphorata EO and its major constituent, germacrene D-4-ol, are promising for the development of natural larvicides against A. aegypti. 相似文献