全文获取类型
收费全文 | 11040篇 |
免费 | 412篇 |
国内免费 | 62篇 |
专业分类
耳鼻咽喉 | 136篇 |
儿科学 | 162篇 |
妇产科学 | 106篇 |
基础医学 | 1486篇 |
口腔科学 | 222篇 |
临床医学 | 625篇 |
内科学 | 2642篇 |
皮肤病学 | 177篇 |
神经病学 | 906篇 |
特种医学 | 498篇 |
外科学 | 1657篇 |
综合类 | 26篇 |
预防医学 | 259篇 |
眼科学 | 402篇 |
药学 | 809篇 |
中国医学 | 22篇 |
肿瘤学 | 1379篇 |
出版年
2023年 | 40篇 |
2022年 | 108篇 |
2021年 | 159篇 |
2020年 | 74篇 |
2019年 | 120篇 |
2018年 | 198篇 |
2017年 | 157篇 |
2016年 | 223篇 |
2015年 | 196篇 |
2014年 | 272篇 |
2013年 | 376篇 |
2012年 | 552篇 |
2011年 | 615篇 |
2010年 | 367篇 |
2009年 | 328篇 |
2008年 | 650篇 |
2007年 | 729篇 |
2006年 | 722篇 |
2005年 | 740篇 |
2004年 | 727篇 |
2003年 | 651篇 |
2002年 | 698篇 |
2001年 | 208篇 |
2000年 | 187篇 |
1999年 | 204篇 |
1998年 | 183篇 |
1997年 | 175篇 |
1996年 | 138篇 |
1995年 | 120篇 |
1994年 | 128篇 |
1993年 | 113篇 |
1992年 | 119篇 |
1991年 | 107篇 |
1990年 | 93篇 |
1989年 | 88篇 |
1988年 | 69篇 |
1987年 | 82篇 |
1986年 | 99篇 |
1985年 | 68篇 |
1984年 | 62篇 |
1983年 | 55篇 |
1982年 | 54篇 |
1981年 | 49篇 |
1980年 | 50篇 |
1979年 | 48篇 |
1978年 | 33篇 |
1977年 | 45篇 |
1976年 | 31篇 |
1975年 | 22篇 |
1973年 | 27篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
Uchida Y Ohshima T Sasaki Y Suzuki H Yanai S Yamashita N Nakamura F Takei K Ihara Y Mikoshiba K Kolattukudy P Honnorat J Goshima Y 《Genes to cells : devoted to molecular & cellular mechanisms》2005,10(2):165-179
Collapsin response mediating protein-2 (CRMP2) has been identified as an intracellular protein mediating Semaphorin3A (Sema3A), a repulsive guidance molecule. In this study, we demonstrate that cyclin-dependent kinase 5 (Cdk5) and glycogen synthase kinase 3beta (GSK3beta) plays a critical role in Sema3A signalling. In In vitro kinase assay, Cdk5 phosphorylated CRMP2 at Ser522, while GSK3beta did not induce any phosphorylation of CRMP2. Phosphorylation by GSK3beta was exclusively observed in Cdk5-phosphorylated CRMP2, but barely in CRMP2T509A. These results indicate that Cdk5 primarily phosphorylates CRMP2 at Ser522 and GSK3beta secondarily phosphorylates at Thr509. The dual-phosphorylated CRMP2, but not non-phosphorylated or single-phosphorylated CRMP2, is recognized with the antibody 3F4, which is highly reactive with the neurofibrillary tangles of Alzheimer's disease. 3F4 recognized the CRMP2 in the wild-type but not cdk5-/- mouse embryonic brain lysates. The phosphorylation of CRMP2 at Ser522 caused reduction of its affinity to tubulin. In dorsal root ganglion neurones, Sema3A stimulation enhanced the levels of the phosphorylated form of CRMP2 detected by 3F4. Over-expression of CRMP2 mutant substituting either Ser522 or Thr509 to Ala attenuates Sema3A-induced growth cone collapse response. These results suggest that the sequential phosphorylation of CRMP is an important process of Sema3A signalling and the same mechanism may have some relevance to the pathological aggregation of the microtubule-associated proteins. 相似文献
43.
Kaburaki J Kuwana M Ikeda Y 《Rinsho byori. The Japanese journal of clinical pathology》2003,51(7):639-643
The concept of antiphospholipid syndrome(APS) has been widely accepted. Antiphospholipid antibodies originally included anticardiolipin antibodies and lupus anticoagulants as serological marker of APS. However, recent advances have shown that most pathogenic antiphospholipid antibodies are directed to phospholipid binding proteins such as beta 2-glycoprotein I and prothrombin as well as phospholipids. The preliminary classification criteria for definite APS have been advocated as the "Sapporo criteria". Further prospective investigations are required to re-evaluate the clinical significance of so-called antiphospholipid antibodies. 相似文献
44.
Yoshimitsu Fukushima Keiko Wakui Toshiro Nishida Yasuo Ueoka 《American journal of medical genetics. Part A》1991,40(4):485-487
We report on a boy with the blepharophimosis sequence and de novo, apparently balanced reciprocal translocation between 3q23 and 4p15.2 [46, XY,t(3;4)(q23;p15.2)de novo]. Possible assignment of this autosomal dominant disorder is discussed. A 3q23 band is a more preferable gene locus of the blepharophi mosis sequence, based on the comparison of clinical manifestations between 4p- and 3q-syndromes. 相似文献
45.
46.
M. Kohmoto T. Miyazawa E. Sato K. Uetsuka Y. Nishimura Y. Ikeda G. Inada K. Doi T. Mikami 《Archives of virology》1998,143(9):1839-1845
Summary. Following establishment, via the vaginal route, of infection with an AP-1 binding-site deleted mutant (ΔAP-1) of feline immunodeficiency
virus (FIV), cats were challenged with a homologous intact strain (TM2) of FIV. The cats were observed for 23 weeks to evaluate
the efficacy of the ΔAP-1 against the homologous TM2 strain challenge. These two viruses were differentiated by Southern blotting
after amplification of proviral DNA by semi-nested polymerase chain reaction in DNAs of peripheral blood mononuclear cells
and tissues. A TM2-specific band was detected in one cat exposed to but not infected with ΔAP-1, but not in two ΔAP-1-infected.
These results indicate that ΔAP-1 could protect against subsequent challenge with homologous FIV TM2 strain.
Received December 23, 1998 Accepted March 31, 1998 相似文献
47.
48.
Tumorous necrotic nodule in the liver: unexpected effect of the microwave tissue coagulator. 总被引:1,自引:0,他引:1 下载免费PDF全文
The microwave tissue coagulator (MTC) is used in hepatectomy because it provides excellent haemostasis during the procedure. A 59 year old man underwent partial hepatic lobectomy with MTC, for metastasis from colon cancer. A tumorous necrotic nodule was discovered in the liver. The nodule measured 2.5 cm at its largest diameter. Microscopically, it showed extensive coagulation necrosis and massive sinusoidal dilatation. To date, such a necrotic mass clinically mimicking neoplasm has not been reported as a complication of hepatectomy using MTC. Although it is unknown how the rounded necrotic nodule was formed in this case, clinicians should be aware of this phenomenon to avoid unnecessary operations. Likewise, pathologists should recognise such histological changes and review the clinical history of the patient when coagulation necrosis with massive sinusoidal dilatation is observed in a biopsy or hepatectomy specimen. 相似文献
49.
Inhibitory effect of antiserum to surface antigen P50 of Babesia gibsoni on growth of parasites in severe combined immunodeficiency mice given canine red blood cells 下载免费PDF全文
Fukumoto S Xuan X Takabatake N Igarashi I Sugimoto C Fujisaki K Nagasawa H Mikami T Suzuki H 《Infection and immunity》2004,72(3):1795-1798
The inhibitory effect of an antiserum to surface protein P50 of Babesia gibsoni on the growth of the parasite was determined with severe combined immunodeficiency mice given canine red blood cells. The antiserum to the recombinant P50 protein significantly inhibited the parasite growth, indicating that P50 might be a useful vaccine candidate. 相似文献
50.
Yasuo Saegusa Yasuhiro Ozeki Shigeo Harada Shigeo Nakamura 《Macromolecular chemistry and physics.》1994,195(9):3189-3198
A novel thermally stable and semiconducting polyheterocycle, poly(1,3,4-thiadiazole amine), was synthesized from 2-(p-aminophenyl)-1,3,4-oxadiazoline-5-thione via ring-opening. The polymer is a new class of ordered alternating copoly(aniline) containing 1,3,4-thiadiazole heterocyclic units. An investigation of the reaction of 2-phenyl-1,3,4-oxadiazoline-5-thione with aniline was conducted as a model reaction for the polymerization, and poly(phosphoric acid) (PPA) and phosphorus pentoxide/methanesulfonic acid (PPMA) were found to be favorable both as condensing agent and solvent for the formation of 2-anilino-5-phenyl-1,3,4-thiadiazole as a model compound. The polymerization was carried out both by two-step procedure that included ring-opening self-polyaddition giving poly(1-benzoylthiosemicarbazide), followed by cyclodehydration to poly(1,3,4-thiadiazole amine), and by a one-step procedure including cyclodehydration in situ. The poly(1-benzoylthiosemicarbazide) which was formed in the first step in m-cresol had reduced viscosities up to 0,42 dL·g?1, and it was converted to poly(1,3,4-thiadiazole amine) by treating in PPA or PPMA. Poly(1,3,4-thiadiazole amine) having reduced viscosities up to 0,25 dL·g?1 was also synthesized by the direct one-step polymerization in PPA or PPMA. The polymer is highly thermally stable and exhibited no weight loss up to 350°C under nitrogen. Its electric conductivity was less than 10?10 S·cm?1 at ambient temperature, but markedly increased to 2,9·10?7 S·cm?1 upon doping with iodine. 相似文献