全文获取类型
收费全文 | 9307篇 |
免费 | 454篇 |
国内免费 | 32篇 |
专业分类
耳鼻咽喉 | 109篇 |
儿科学 | 770篇 |
妇产科学 | 372篇 |
基础医学 | 946篇 |
口腔科学 | 151篇 |
临床医学 | 469篇 |
内科学 | 1661篇 |
皮肤病学 | 178篇 |
神经病学 | 299篇 |
特种医学 | 293篇 |
外科学 | 1823篇 |
综合类 | 517篇 |
一般理论 | 2篇 |
预防医学 | 357篇 |
眼科学 | 569篇 |
药学 | 464篇 |
中国医学 | 21篇 |
肿瘤学 | 792篇 |
出版年
2023年 | 63篇 |
2022年 | 148篇 |
2021年 | 273篇 |
2020年 | 135篇 |
2019年 | 190篇 |
2018年 | 274篇 |
2017年 | 191篇 |
2016年 | 240篇 |
2015年 | 236篇 |
2014年 | 316篇 |
2013年 | 374篇 |
2012年 | 537篇 |
2011年 | 548篇 |
2010年 | 393篇 |
2009年 | 300篇 |
2008年 | 470篇 |
2007年 | 517篇 |
2006年 | 495篇 |
2005年 | 397篇 |
2004年 | 340篇 |
2003年 | 307篇 |
2002年 | 267篇 |
2001年 | 234篇 |
2000年 | 236篇 |
1999年 | 221篇 |
1998年 | 127篇 |
1997年 | 102篇 |
1996年 | 98篇 |
1995年 | 72篇 |
1994年 | 62篇 |
1993年 | 43篇 |
1992年 | 102篇 |
1991年 | 100篇 |
1990年 | 78篇 |
1989年 | 76篇 |
1988年 | 86篇 |
1987年 | 83篇 |
1986年 | 90篇 |
1985年 | 111篇 |
1984年 | 66篇 |
1983年 | 60篇 |
1982年 | 46篇 |
1981年 | 41篇 |
1979年 | 80篇 |
1978年 | 47篇 |
1977年 | 51篇 |
1976年 | 41篇 |
1974年 | 42篇 |
1973年 | 48篇 |
1972年 | 46篇 |
排序方式: 共有9793条查询结果,搜索用时 15 毫秒
41.
42.
D. Gupta V. K. Singh J. Rajasingh T. Shinohara R. Misra S. S. Agarwal 《Immunologic research》1996,15(1):74-83
The objective of this study was to determine the proliferative responses of peripheral blood lymphocytes of ocular antigens like retinal S-antigen, peptides M and G of S-antigen, yeast histone H3 peptide 106–121 homologous to peptide M and peptide R16 of interphotoreceptor retinoid binding protein (IRBP) in children with juvenile chronic arthritis (JCA). We have studied the in vitro proliferative response of peripheral blood lymphocytes from 41 patients with JCA (10 with and 31 without uveitis) and 23 healthy controls against the above antigens. The responders were retested after 1 or 6 months. Fifty (5/10) and 9.7% (3/31) of JCA patients with and without uveitis, respectively, responded (stimulation index >3) to S-antigen or one of its peptide listed above or yeast histone H3 peptide or R16 of IRBP. None of the healthy controls responded to any of these antigens. The difference in the frequency of responders (SI>3) between JCA associated with uveitis and healthy controls was statistically significant (p=0.001). Similarly, the difference between JCA with and without uveitis was also significant (p=0.013). Our findings suggest that these antigens may have a role in the pathogenesis of uveitis in a subset of patients with JCA. 相似文献
43.
44.
Bajaj P Agarwal K Niveditha SR Pathania OP 《Indian journal of pathology & microbiology》2001,44(2):145-146
Benign and malignant soft tissue tumors of the paratesticular region i.e. those arising from the testicular tunics, epididymis and spermatic cord are uncommon. Of these, leiomyosarcoma arising from the tunica vaginalis is extremely rare. On extensive computerised search, a single case has been reported till date in the literature. We hereby report one such case because of its rarity. 相似文献
45.
The mechanical impedance of the ankle joint during electrical stimulation of the soleus is studied by applying constant-velocity
10° angular perturbations to the ankle and measuring the resultant torque. Both neurologically intact subjects and spinal
cord injured subjects are tested. Lumped, piecewise linear models are developed to predict the torque from the measured displacement
and acceleration signals. The commonly used second-order mass-spring-dashpot model fails to predict the changes in torque
that occur following imposed movements. A fiveelement, directionally-dependent piecewise linear model is much better at predicting
the measured responses for velocities up to 50° s−1. Numerical least squared error indentification techniques are used to estimate the model parameters for three neurologically
intact and three spinal cord injured subjects. The average error between the model’s response and the measured response across
all subjects is 10·9%. There is some evidence that a velocity-dependent non-linear model could produce better results than
the directionally-dependent piecewise linear model. 相似文献
46.
47.
One of the first useful products from the human genome will be a set of predicted genes. Besides its intrinsic scientific interest, the accuracy and completeness of this data set is of considerable importance for human health and medicine. Though progress has been made on computational gene identification in terms of both methods and accuracy evaluation measures, most of the sequence sets in which the programs are tested are short genomic sequences, and there is concern that these accuracy measures may not extrapolate well to larger, more challenging data sets. Given the absence of experimentally verified large genomic data sets, we constructed a semiartificial test set comprising a number of short single-gene genomic sequences with randomly generated intergenic regions. This test set, which should still present an easier problem than real human genomic sequence, mimics the approximately 200kb long BACs being sequenced. In our experiments with these longer genomic sequences, the accuracy of GENSCAN, one of the most accurate ab initio gene prediction programs, dropped significantly, although its sensitivity remained high. Conversely, the accuracy of similarity-based programs, such as GENEWISE, PROCRUSTES, and BLASTX was not affected significantly by the presence of random intergenic sequence, but depended on the strength of the similarity to the protein homolog. As expected, the accuracy dropped if the models were built using more distant homologs, and we were able to quantitatively estimate this decline. However, the specificities of these techniques are still rather good even when the similarity is weak, which is a desirable characteristic for driving expensive follow-up experiments. Our experiments suggest that though gene prediction will improve with every new protein that is discovered and through improvements in the current set of tools, we still have a long way to go before we can decipher the precise exonic structure of every gene in the human genome using purely computational methodology. 相似文献
48.
49.
High throughput parallel analysis of hundreds of patient samples for more than 100 mutations in multiple disease genes 总被引:5,自引:0,他引:5
Shuber AP; Michalowsky LA; Nass GS; Skoletsky J; Hire LM; Kotsopoulos SK; Phipps MF; Barberio DM; Klinger KW 《Human molecular genetics》1997,6(3):337-347
As more mutations are identified in genes of known sequence, there is a
crucial need in the areas of medical genetics and genome analysis for
rapid, accurate and cost-effective methods of mutation detection. We have
developed a multiplex allele-specific diagnostic assay (MASDA) for analysis
of large numbers of samples (> 500) simultaneously for a large number of
known mutations (> 100) in a single assay. MASDA utilizes
oligonucleotide hybridization to interrogate DNA sequences. Multiplex DNA
samples are immobilized on a solid support and a single hybridization is
performed with a pool of allele-specific oligonucleotide (ASO) probes. Any
probes complementary to specific mutations present in a given sample are in
effect affinity purified from the pool by the target DNA. Sequence-specific
band patterns (fingerprints), generated by chemical or enzymatic sequencing
of the bound ASO(s), easily identify the specific mutation(s). Using this
design, in a single diagnostic assay, we tested samples for 66 cystic
fibrosis (CF) mutations, 14 beta-thalassemia mutations, two sickle cell
anemia (SCA) mutations, three Tay-Sachs mutations, eight Gaucher mutations,
four mutations in Canavan disease, four mutations in Fanconi anemia, and
five mutations in BRCA1. Each mutation was correctly identified. Finally,
in a blinded study of 106 of these mutations in > 500 patients, all
mutations were properly identified. There were no false positives or false
negatives. The MASDA assay is capable of detecting point mutations as well
as small insertion or deletion mutations. This technology is amenable to
automation and is suitable for immediate utilization for high-throughput
genetic diagnostics in clinical and research laboratories.
相似文献
50.
The t(X;1)(p11.2;q21.2) translocation in papillary renal cell carcinoma fuses a novel gene PRCC to the TFE3 transcription factor gene 总被引:4,自引:2,他引:4