首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   12471篇
  免费   1110篇
  国内免费   421篇
耳鼻咽喉   138篇
儿科学   233篇
妇产科学   212篇
基础医学   1701篇
口腔科学   178篇
临床医学   1470篇
内科学   2066篇
皮肤病学   582篇
神经病学   607篇
特种医学   602篇
外国民族医学   7篇
外科学   1192篇
综合类   997篇
现状与发展   1篇
一般理论   5篇
预防医学   776篇
眼科学   303篇
药学   1518篇
  5篇
中国医学   550篇
肿瘤学   859篇
  2024年   21篇
  2023年   153篇
  2022年   410篇
  2021年   510篇
  2020年   353篇
  2019年   414篇
  2018年   440篇
  2017年   393篇
  2016年   489篇
  2015年   691篇
  2014年   794篇
  2013年   760篇
  2012年   1125篇
  2011年   1041篇
  2010年   686篇
  2009年   633篇
  2008年   691篇
  2007年   632篇
  2006年   540篇
  2005年   503篇
  2004年   369篇
  2003年   374篇
  2002年   283篇
  2001年   171篇
  2000年   164篇
  1999年   180篇
  1998年   115篇
  1997年   146篇
  1996年   108篇
  1995年   94篇
  1994年   63篇
  1993年   51篇
  1992年   73篇
  1991年   54篇
  1990年   51篇
  1989年   43篇
  1988年   31篇
  1987年   47篇
  1986年   26篇
  1985年   19篇
  1984年   21篇
  1983年   25篇
  1981年   10篇
  1979年   15篇
  1975年   10篇
  1973年   13篇
  1970年   11篇
  1959年   10篇
  1958年   21篇
  1957年   13篇
排序方式: 共有10000条查询结果,搜索用时 79 毫秒
21.
KIR and HLA loci are both highly polymorphic, and some HLA class 1 products bind and trigger cell-surface receptors specified by KIR genes. We examined whether KIR genes act in concert with HLA-B locus to control HIV-1 infection in a sample of Zambian patients. DNA samples from 88 Zambian patients with HIV-1 were examined. Patients were classified as either slow progressors (SP; n = 54) or rapid progressors (RP; n = 34) to AIDS. All were typed for HLA-B and KIR genes. Our results reveal an association between B*57 supertype (B*57s, which includes B*57 and B*58 alleles) and delayed progression to AIDS (p = 0.0007 by pc = 0.015; OR = 5.25). We also observed an increase incidence of Bw4-I80 in patients with slow progression (p = 0.001 by pc = 0.003, OR = 5). This increase was found to be secondary to B*57s. The presence of both KIR3DL1 and B*57S has a significant effect on progression to AIDS (p = 0.0008; OR = 5.61). B*57s genotypes with another HLA-B allele different from those in the trans position, which also had a specificity different to Bw4-I80 (Bw4-T80 or Bw6), was also greater in the SP than in the RP group (p = 0.00003; OR = 10.11). The presence of the inhibitory allele KIR3DL1 in combination with the HLA-B*57s alleles that contain the Bw4-I80 epitope, has a highly protective effect against progression to AIDS in Zambian patients.  相似文献   
22.
Summary Some differences between gallbladder lithiasis and primary common bile duct lithiasis are described. Microbiological cultures and biochemical analyses were carried out on the bile of two groups of patients: 27 suffering from gallbladder and 5 from primary common duct lithiasis. The microstructure and composition of gallstones were also examined by polarized light microscopy and X-ray diffraction. Women predominated in gallbladder lithiasis but not in primary common duct lithiasis group (P<0.05) and body weight was higher in the former group (P<0.02). Primary common duct lithiasis patients had a higher, although not significant, incidence of duodenal diverticulosis (P=0.15), and a higher incidence ofE. coli-positive cultures in bile (P<0.001). No significant difference in the biochemical composition of the bile was found between the groups. Brown pigment stones predominated in primary common duct lithiasis, while cholesterol stones did in gallbladder and secondary common duct lithiasis (P<0.0001). Stones formed in the gallbladder generally show linear, radial growths of cholesterol crystals, while those from the common duct present a polystratified, concentric deposition of microgranules composed mainly of pigmentary salts.These differences should be taken into account as additional criteria in the differential diagnosis between primary and secondary common duct lithiasis, as the classical criteria for diagnosing of the former greatly underestimate its actual incidence. The distinction between primary and secondary common duct lithiasis is of practical significance, since each entity requires different treatment.Abbreviations CBD common bile duct - CBDL common bile duct lithiasis - ERCP endoscopic retrograde cholangiopancreatography - GBL gallbladder lithiasis - HDL high density lipoproteins - PCBDL primary common bile duct lithiasis - SCBDL secondary common bile duct lithiasis - SGOT serum glutamic-oxalacetic transaminase - SGPT serum glutamic-pyruvic transaminase  相似文献   
23.
Li  Chunjing  Guo  Liwen  Luo  Mi  Guo  Mingjuan  Li  Jierong  Zhang  Shilin  Liu  Guoqing 《International urology and nephrology》2021,53(10):1987-1993
International Urology and Nephrology - Ureteroscopy is widely applied in pregnant women with renal colic, but such patients are easy to experience uterine contraction after surgery. There are many...  相似文献   
24.
25.
Chromatographic conditions for the separation of five pairs of active compounds occuring in four ointment preparations and an aerosol one were elaborated. The ways of extraction of hydrocortisone esters (acetate and butyrate), chlorquinaldol, oxytetracycline base and oxytetracycline hydrochloride from the ointments as well as purification of the extracts prior to the HPLC analysis were described. The proposed analytical methods are for more specific and precise from those used until now in the home-made preparations quality control.  相似文献   
26.
用细胞培养、免疫细胞化学染色、图像分析及流式细胞术观察低氧和猪肺动脉缺氧内皮细胞条件培养液(HECCM)对体外培养的新生大鼠肺血管周细胞 (PC)α- SM- actin、 CD34 、 S- 10 0和 PCNA的表达及细胞周期的影响。结果发现 ,低氧和 HECCM可促进 PC表达α- SM- actin和 PCNA,而抑制 CD34 和 S- 10 0的合成 ,促进 PC由静止期 (G0 /G1 期 )进入 DNA合成期 (S期 )及有丝分裂期 (G2 M期 )。提示 ,低氧不仅能促进 PC增殖 ,而且还可促进其向平滑肌样细胞转化。故 PC是慢性低氧性肺动脉高压时无肌型细动脉肌化的重要细胞来源。  相似文献   
27.
性别异常的染色体组型分析   总被引:1,自引:0,他引:1  
为了进一步探讨性别异常发生的机制及染色体组型与表型性别的相关性 ,对 33例性别异常病人的染色体组型和临床资料进行分析。结果表明 :46XY男性假两性畸形占 5 7 5 7% ,46XX女性假两性畸形为 18 18% ,真两性畸形的组型有12 12 % ,其他组型为 12 12 %。含Y染色体组型的病人 88 8%可以找到睾丸 ,但 73 6 8%的病人表现为女性社会性别。性染色体与社会性别的相符率为 42 82 %。还发现 2例男性假两性畸形其性染色体正常 ,但常染色体分别为臂间倒位及 13和 14号染色体间的易位时 ,也可以导致性别异常。结论 :性染色体决定着性腺分化的方向 ,但成熟的性腺和正常的性别发育还需除性染色体之外的多条染色体、多个基因的参与。  相似文献   
28.
29.
Kong X  Zeng L  Xia T  Wang J  Mi P  Na Y  Xue Z  Pan B  Hao J  Gu F  Guo Y 《中华外科杂志》1999,37(4):231-234,I015
目的 探讨抑那通和缓退瘤联合治疗对正常前列腺,增生的前列腺(BPH)和前列腺癌以及睾丸的作用。方法 对16例接受联合内分泌治疗至少3个月且有治疗前后病理资料的前列腺癌患者的标本进行了系统的病理学检查。对内分泌治疗后的睾丸标本与同龄未接受治疗的进行对照研究。结果 14例内分泌治疗后的前列腺标本2例未见残存癌灶,9例对治疗有明显的反应;3例对治疗反应差,治疗并未降低前列腺癌的病理分期。3例内分泌治疗后  相似文献   
30.
Background: Most germs causing postoperative endophthalmitis derive from the conjunctival bacterial normal flora. Postoperative endophthalmitis is often induced by staphylococcal germs. The application of polyvidone-iodine solution to the conjunctiva is one possibility to reduce potential endophthalmitis-causing bacteria. The aim of this study was to evaluate the effectiveness of 1 % polyvidone-iodine solution concerning the reduction of colonization with staphylococci in the course of intraocular surgery. This is to evaluate the effectiveness of 1 % polyvidone-iodine solution concerning coagulase-negative and positive staphylococci.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号