全文获取类型
收费全文 | 79742篇 |
免费 | 5808篇 |
国内免费 | 3290篇 |
专业分类
耳鼻咽喉 | 329篇 |
儿科学 | 1415篇 |
妇产科学 | 851篇 |
基础医学 | 13729篇 |
口腔科学 | 875篇 |
临床医学 | 6177篇 |
内科学 | 17449篇 |
皮肤病学 | 1324篇 |
神经病学 | 3493篇 |
特种医学 | 1374篇 |
外国民族医学 | 9篇 |
外科学 | 4511篇 |
综合类 | 11414篇 |
现状与发展 | 19篇 |
预防医学 | 6650篇 |
眼科学 | 652篇 |
药学 | 10114篇 |
21篇 | |
中国医学 | 4234篇 |
肿瘤学 | 4200篇 |
出版年
2024年 | 767篇 |
2023年 | 1131篇 |
2022年 | 2252篇 |
2021年 | 2717篇 |
2020年 | 2636篇 |
2019年 | 2809篇 |
2018年 | 2532篇 |
2017年 | 2510篇 |
2016年 | 2842篇 |
2015年 | 3133篇 |
2014年 | 4999篇 |
2013年 | 5276篇 |
2012年 | 5060篇 |
2011年 | 5415篇 |
2010年 | 4430篇 |
2009年 | 4210篇 |
2008年 | 4150篇 |
2007年 | 4005篇 |
2006年 | 3718篇 |
2005年 | 3135篇 |
2004年 | 2618篇 |
2003年 | 2301篇 |
2002年 | 1848篇 |
2001年 | 1628篇 |
2000年 | 1248篇 |
1999年 | 1113篇 |
1998年 | 1005篇 |
1997年 | 845篇 |
1996年 | 704篇 |
1995年 | 713篇 |
1994年 | 620篇 |
1993年 | 503篇 |
1992年 | 493篇 |
1991年 | 387篇 |
1990年 | 380篇 |
1989年 | 322篇 |
1988年 | 272篇 |
1987年 | 244篇 |
1986年 | 198篇 |
1985年 | 480篇 |
1984年 | 480篇 |
1983年 | 388篇 |
1982年 | 411篇 |
1981年 | 334篇 |
1980年 | 309篇 |
1979年 | 273篇 |
1978年 | 211篇 |
1977年 | 168篇 |
1976年 | 186篇 |
1975年 | 159篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
短暂性脑缺血发作患者血浆中TXB2和PGF1α含量检测 总被引:3,自引:0,他引:3
本文用放射免疫法测定47例短暂性脑缺血发作(TIA)患者血浆中血栓素B_2(TXB_2)和6酮-前列腺F_(1α)(PGF_(1α))的含量。结果发现TIA患者血浆中TXB_2含量增高,PGF_(1α)降低;头颅CT或MRI示有小灶性梗塞者及TIA发作持续时间长于30min者TXB_2升高和PGF_(1α)降低更显著。治疗3个月后,血浆PGF_(1α)显著增高。TXB_2和PGF_(1α)在体内的失平衡是急性脑血管疾病发病的重要机理之一。 相似文献
22.
We have analysed video recordings of 21 patients with cervical dystonia treated with botulinum toxin. Fourteen patients have a record both of their response shortly after injections were commenced and between four years five months and six years seven months later. Our analysis shows that the long term outcome is often better than the initial response. We suggest that chronic treatment with botulinum toxin allows different muscles to those initially injected to be identified as contributors to the dystonia. Subsequent injection of these muscles leads to further improvement. It implies that cervical dystonia is a more widespread disorder of motor control, rather than simply limited to a few muscles. 相似文献
23.
The normally expressed κ immunoglobulin light chain gene repertoire and somatic mutations studied by single-sided specific polymerase chain reaction (PCR); frequent occurrence of features often assigned to autoimmunity 下载免费PDF全文
L JUUL L HOUGS V ANDERSEN A SVEJGAARD T BARINGTON 《Clinical and experimental immunology》1997,109(1):194-203
The expressed human κ light chain gene repertoire utilized by healthy individuals was studied by two different single-sided specific PCR techniques to avoid bias for certain V genes. A total of 103 rearranged κ sequences from peripheral blood mononuclear cells from healthy individuals were cloned from cDNA and assigned to the Vκ and Jκ germ-line genes with the closest overall homology. The use of cDNA rather than genomic DNA focused the analysis on activated B cells rich in mRNA. Accordingly, the sequences represented the applied repertoire and almost all were somatically mutated. V genes from the Jκ-proximal duplication unit of the κ locus were almost exclusively used. A total of 65% of the sequences could be assigned to four or five genes: A27 (humkv325), L6 (Vg), L2 (humkv328), and A3 and/or A19. N additions and P nucleotides were quite common and found in 32% and 21% of the sequences, respectively. Extended CDR3s more than nine residues in length were found in 18% of the sequences, and in 71% of cases this was due to insertion of an extra proline residue. This proline was usually explained from the germ-line sequences involved. These results are in good agreement with those of previous repertoire studies using potentially V-gene-biased techniques. Thus, it is clear that restricted V-gene usage, common N and P additions, and extended CDR3 regions are normal features and not, as has been claimed, characteristics of pathological autoantibodies. 相似文献
24.
25.
Sherif M. Hassan Frans G.I. Jennekens George Wieneke Henk Veldman 《Neuromuscular disorders : NMD》1994,4(5-6):489-496
Changes in calcitonin gene-related peptide-like immunoreactivity (CGRP-LI) at the motor endplates of botulinum toxin-paralysed rat muscles were investigated using immunohistochemistry. One day following toxin injection, a dramatic increase in CGRP-LI was detected at the motor endplates and within preterminal axons of the soleus and gastrocnemius muscles. The upregulation of CGRP-LI persisted throughout the period during which muscle fibres were paralysed and new neuromuscular junctions were being formed by the growing sprouts. Decline of CGRP-LI at the motor endplates coincided with clinical recovery. Both up- and down-regulation of CGRP-LI took place earlier in the soleus than in the gastrocnemius muscle. Up-regulation of CGRP-LI was also detected in a subpopulation of motor axons in the sciatic nerves and in the spinal motor neurons innervating the paralysed muscles. These results indicate that levels of CGRP are regulated, at least partly, by changes in the target innervation. They also suggest an important role for CGRP in the regenerative processes following muscle paralysis. 相似文献
26.
Felipe Scalco Manzano DDSc Lucia Mercuri Granero MD Danilo Masiero MD Maria Teresa Botti Rodrigues dos Santos DDSc PhD 《Special care in dentistry》2004,24(4):235-239
This study was designed to verify the safety and efficacy of botulinum toxin type A (BTX-A) used as a neuromuscular block on spastic masticatory musculature of children with cerebral palsy. Six patients who had spastic-tetraplegic cerebral-palsy, aged 5 to 20 years were selected. All patients had spasticity of the jaw muscles, bruxism, lower lip trauma, limited mouth opening, and difficulties in cleaning the oral cavity. The patients were sedated under general anesthesia, while the dentist injected the masseter and temporalis muscles bilaterally with 150 and 75 units of BTX-A each. Clinical examinations were conducted at 7, 14, 30, and 90 days after the initial appointment. We found statistically significant decreases in muscle spasticity and bruxism ( p = 0.002), improved inter-incisal opening ( p = 0.002), improved oral hygiene ( p = 0.031), and less lower lip trauma ( p = 0.060) after the neuromuscular blocking. 相似文献
27.
28.
Light microscopy of GTP-binding protein (Go) immunoreactivity within the retina of different vertebrates 总被引:2,自引:0,他引:2
Toshio Terashima Toshiaki Katada Eikichi Okada Michio Ui Yoshiro Inoue 《Brain research》1987,436(2):384-389
To examine species differences in the distribution pattern of guanosine triphosphate (GTP)-binding protein (Go) within the vertebrate retina, paraffin-embedded retinae from a number of vertebrate species, including the goldfish, frog, turtle, chicken, monkey, and human, were immunohistochemically stained with affinity-purified antibody against the alpha-subunit of Go. Go-immunoreactive products were found to be located in the neuropil, but not in the cell bodies of neurons, in the retina of all these species. However, some species differences were observed. In the frog, monkey and human, the inner plexiform layer (IPL) was homogeneously stained with this antibody, but in the goldfish, turtle and chicken, the IPL was heterogeneously stained. In the frog, chicken, turtle and human, the outer plexiform layer (OPL) was densely stained with this antibody, but in the goldfish and monkey, the OPL was rather faintly immunoreactive to the antibody. In the goldfish, monkey and human, the outer nuclear layer (ONL) was not immunoreactive to the Go-antibody, whereas in the frog, turtle and chicken, the ONL was immunoreactive to it. The implications of these species differences in Go localization in the vertebrate retina are discussed. 相似文献
29.
SHIGEKI OCHI MORIKAZU ONJI KAZUHITO SHIRAISHI KYOKO OHTU TOMOHIRO AKAO YOSHITO YANO NOBUYUKI TAKEI HIKARU MATSUI YASUYUKI OHTA MASAKICHI UMEDA 《Journal of gastroenterology and hepatology》1991,6(6):599-602
To clarify the prevalence of concurrent infection with hepatitis C virus (HCV), hepatitis B virus (HBV) and human T cell leukaemia virus (HTLV), we measured HCV antibody in the population of a district endemic for HBV and HTLV infection. Blood samples were collected in June 1990 from 579 inhabitants of four islands of Uwa Bay in the southwest of Ehime Prefecture in Japan. Anti-HCV antibody against C100-3 protein was detected using an enzyme-linked immunosorbent assay kit (Ortho Diagnostics). Thirteen of the 579 inhabitants (2.2%) were positive for anti-HCV, and this prevalence rate was not significantly different from the frequency of anti-HCV in Tokyo blood donors. A total of 11% (64 of 579) of the subjects were positive for HBsAg and 3.3% (19 of 579) were positive for anti-HTLV. These frequencies of HBsAg and anti-HTLV positivity were distinctly higher than the respective means of Japanese. All anti-HCV positive individuals were negative for HBsAg and anti-HTLV, while 54% (7 of 13) had increased alanine aminotransferase levels. These data suggest that the prevalence of HCV infection is not high even in an area endemic for HBV and HTLV infection. 相似文献
30.