全文获取类型
收费全文 | 13918篇 |
免费 | 1243篇 |
国内免费 | 1043篇 |
专业分类
耳鼻咽喉 | 60篇 |
儿科学 | 222篇 |
妇产科学 | 151篇 |
基础医学 | 1643篇 |
口腔科学 | 201篇 |
临床医学 | 1740篇 |
内科学 | 2065篇 |
皮肤病学 | 168篇 |
神经病学 | 589篇 |
特种医学 | 671篇 |
外国民族医学 | 3篇 |
外科学 | 1306篇 |
综合类 | 2347篇 |
现状与发展 | 3篇 |
一般理论 | 2篇 |
预防医学 | 1021篇 |
眼科学 | 392篇 |
药学 | 1473篇 |
18篇 | |
中国医学 | 652篇 |
肿瘤学 | 1477篇 |
出版年
2024年 | 30篇 |
2023年 | 179篇 |
2022年 | 528篇 |
2021年 | 629篇 |
2020年 | 514篇 |
2019年 | 430篇 |
2018年 | 445篇 |
2017年 | 406篇 |
2016年 | 419篇 |
2015年 | 638篇 |
2014年 | 698篇 |
2013年 | 635篇 |
2012年 | 875篇 |
2011年 | 940篇 |
2010年 | 547篇 |
2009年 | 457篇 |
2008年 | 566篇 |
2007年 | 722篇 |
2006年 | 674篇 |
2005年 | 618篇 |
2004年 | 592篇 |
2003年 | 651篇 |
2002年 | 596篇 |
2001年 | 470篇 |
2000年 | 412篇 |
1999年 | 362篇 |
1998年 | 264篇 |
1997年 | 281篇 |
1996年 | 222篇 |
1995年 | 226篇 |
1994年 | 183篇 |
1993年 | 133篇 |
1992年 | 125篇 |
1991年 | 98篇 |
1990年 | 70篇 |
1989年 | 94篇 |
1988年 | 83篇 |
1987年 | 85篇 |
1986年 | 54篇 |
1985年 | 58篇 |
1984年 | 37篇 |
1983年 | 35篇 |
1982年 | 27篇 |
1981年 | 26篇 |
1980年 | 30篇 |
1979年 | 6篇 |
1978年 | 8篇 |
1977年 | 10篇 |
1976年 | 4篇 |
1975年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
41.
Silber SJ; Nagy Z; Devroey P; Tournaye H; Van Steirteghem AC 《Human reproduction (Oxford, England)》1997,12(11):2422-2428
The aim of the study was to determine whether a prior diagnostic testicle
biopsy can predict success or failure of testicular sperm extraction (TESE)
with intracytoplasmic sperm injection (ICSI) in patients with
non-obstructive azoospermia caused by testicular failure, and what is the
minimum threshold of sperm production in the testis which must be surpassed
for spermatozoa to reach the ejaculate. Forty- five patients with
non-obstructive azoospermia caused by testicular failure underwent
diagnostic testicle biopsy prior to a planned future TESE-ICSI procedure.
The diagnostic testicle biopsy was analysed quantitatively, and correlated
with the quantitative findings of spermatogenesis in patients with normal
spermatogenesis, as well as with the results of subsequent attempts at
TESE-ICSI. Men with non- obstructive azoospermia caused by germinal failure
had a mean of 0-6 mature spermatids/seminiferous tubule seen on a
diagnostic testicle biopsy, compared to 17-35 mature spermatids/tubule in
men with normal spermatogenesis and obstructive azoospermia. These findings
were the same for all types of testicular failure whether Sertoli cell
only, maturation arrest, cryptorchidism, or post-chemotherapy azoospermia.
Twenty-two of 26 men with mature spermatids found in the prior testis
biopsy had successful retrieval of spermatozoa for ICSI, 12 of their
partners became pregnant, and are either ongoing or delivered. The study
suggests that 4-6 mature spermatids/tubule must be present in the testis
biopsy for any spermatozoa to reach the ejaculate. More than half of
azoospermic patients with germinal failure have minute foci of
spermatogenesis which are insufficient to produce spermatozoa in the
ejaculate. Prior diagnostic testicle biopsy analysed quantitatively (for
the presence of mature spermatids) can predict subsequent success or
failure with TESE-ICSI. Incomplete testicular failure may involve a sparse
multi-focal distribution of spermatogenesis throughout the entire testicle,
rather than a regional distribution. Therefore, it is possible that massive
testicular sampling from many different regions of the testes may not be
necessary for successful TESE-ICSI.
相似文献
42.
β-Lactoglobulin was isolated from infant formulae that were ultra high temperature (UHT) -treated, sterilized or spray-dried. The effect of the isolated β-lactoglobulin on SfaII-fimbriae-mediated adhesion of Escherichia coli to human ileostomy glycoproteins was studied in vitro. β-Lactoglobulin isolated from sterilized formulae was found to perform significantly less well than preparations from spray-dried formulae (p = 0:05). Great heterogeneity was observed in the adhesion inhibitory capacity of β-lactoglobulin isolated from UHT-treated formulae. Therefore, no significant difference was observed between UHT-treated and sterilized formulae or spray-dried formulae (p < 0:10). It can be hypothesized that β-lactoglobulin from spray-dried and some UHT-treated infant formulae may affect the colonization of mucous membranes by E. coli strains causing neonatal septicaemia and meningitis. 相似文献
43.
44.
中国内部审计协会2003年发布的《内部审计具体准则》中明确指出,所谓“内部审计与外部审计的协调”,就是指内部审计机构与会计师事务所、国家审计机关在审计工作中的沟通与合作,现就医院内部审计与外部审计协调的必要性和可能性等进行探讨。 相似文献
45.
微量注射大豆皂甙(Ts)到下丘脑后核(PHN)能引起平均动脉压(MAP)升高,心率加快,其效应与向PHN内注入神经肽Y(NPY)相似。分别注入不能引起血压、心率发生明显变化的微量Ts、NPY,如果合并注入PHN则可引起血压、心率的显著变化,表明二者互有加强作用。Atropine可以对抗Ts、NPY或Ts+NPY同时注入PHN的升压效应,提示NPY是通过激活脑内M受体而实现升压效应的,而Ts的心血管效应又可能是经过脑内NPY介导和加强的。 相似文献
46.
Jian-ya Zhou Fa-di Tang Guo-gen Mao Jie Shao Yan Wang Ru-lian Bian 《浙江大学学报(医学版)》2003,32(4):315-8, 326
OBJECTIVE: To study the effect of eucalyptus globulus oil on the activity of nuclear factor-kappaB(NF-kappaB) in THP-1 cell line. METHODS: THP-1 cells were cultured with or without eucalyptus globulus oil at different concentrations (1, 10, 100 mg x L(-1), 30 min) before being stimulated with lipopolysaccharide (LPS, 1 mg x L(-1), 30 min). The location of NF-kappaB p65 subunit (NF-kappaB/p65) in THP-1 cells was detected by indirect immunofluorescence and laser scanning confocal microscope. The expression of NF-kappaB/p65 in nuclei was measured by Western-blot analysis. RESULT: The FITC-label NF-kappaB/p65 was mainly located in the nuclei after THP-1 cells were stimulated with LPS. Whereas, no fluorescence were seen in the nuclei of cells pretreated with eucalyptus globulus oil. This effect on NF-kappaB/p65 nuclear translocation was in a concentration dependent manner. CONCLUSION: Eucalyptus globulus oil inhibits the nuclear translocation of NF-kappaB induced by LPS in THP-1 cells. 相似文献
47.
Xin-ping Tang Kang Zeng Guan-hua Chen Long-yan Bi Long-zhong Fan Chang-fa Shao 《第一军医大学学报》2003,23(8):870-872
OBJECTIVE: To investigate the association of Malassezia furfur with chronic urticaria in the crew members of ships. METHODS: A comparative mycological study of 126 crew members of ships with chronic urticaria and 45 normal control subjects was carried out. The 82 urticaria patients identified as positive for Malassezia furfur were divided into groups A and B to receive treatment with antihistaminics (group A) and antihistaminics combined with 2% ketoconazole shampoo(group A). RESULTS: The carrier rates of Malassezia furfur were significantly higher in urticaria patients than in the normal control subjects (P<0.01), but in view of the case ratios of the final cure or improvement, no significant difference was observed between the two groups by the end of the treatment courses (P>0.05). But 6 to 8 weeks from the end of the treatment course, better therapeutic effect was noted in group B (P<0.01), with higher rate of negative Malassezia furfur findings (P<0.01). CONCLUSION: Malassezia furfur may play an important role in the prevalence of chronic urticaria among the crew members, and anti-fungal treatment may produce better long-term therapeutic effect. 相似文献
48.
准分子激光角膜原位磨镶术治疗近视合并中度以上散光疗效观察 总被引:1,自引:0,他引:1
目的 :评价小光斑飞点扫描准分子激光系统应用于准分子激光原位角膜磨镶术 (LASIK)治疗近视合并中度以上散光的疗效。 方法 :对 96例患者 14 4只眼按术前屈光度分成三组 ,Ⅰ组 75只眼 ,近视 0~ - 6D ,散光 - 2~ - 4DC ;Ⅱ组 5 7只眼 ,近视 - 6 .2 5~ 10 .0 0D ,散光 - 2~ - 4DC。Ⅲ组 12只眼 ,近视 - 10 .2 5D以上 ,散光 - 2~- 4DC ;术后随访半年以上 ,并将结果进行比较分析。 结果 :术后 1个月裸眼视力达到 0 .6以上者 ,Ⅰ组为5 .3% ,Ⅱ组为 15 .8% ,Ⅲ组为 6 6 .7% ;术后 1个月裸眼视力达到 1.0以上者 ,Ⅰ组为 94 .7% ,Ⅱ组为 84 .2 % ,Ⅲ组为 33.3%。术后半年裸眼视力达到 0 .6以上者 ,Ⅰ组为 4 % ,Ⅱ组为 14 % ,Ⅲ组为 75 % ;术后半年裸眼视力达到 1.0以上者 ,Ⅰ组为 96 % ,Ⅱ组为 86 % ,Ⅲ组为 2 5 %。术后屈光度在± 1.0D以内者 ,Ⅰ组中为 8% ,Ⅱ组为 14 % ,Ⅲ组为 5 8.3%。术后屈光度在± 0 .5 0D以内者 ,Ⅰ组为 92 % ,Ⅱ组为 86 % ,Ⅲ组为 4 1.7%。术后散光度在± 1.0DC以内者 ,Ⅰ组为 8% ,Ⅱ组为 10 .5 % ,Ⅲ组为 5 0 %。术后散光度在± 0 .5 0DC以内者 ,Ⅰ组为 92 % ,Ⅱ组为 89.5 % ,Ⅲ组为 5 0 %。平均实际切削区直径为 (8.0 2± 0 .0 6 9)mm。 结论 :使用小光斑飞点显像LASIK治疗低 相似文献
49.
目的 探索如何抑制嗜酸细胞的趋化作用,选择β-趋化因子巨噬细胞炎性蛋白4(MIP4)的突变性(Met-MIP4)作为趋化因子受体3的拮抗剂,将Met-MIP4基因在原核细胞中进行表达。方法 设计MIP4基因的PCR引物并进行氨基酸突变,将MIP4N末端的丙氨酸突变为蛋氨酸,以正常人肺酸突变,将MIP4N末端的丙氨酸突变为蛋氨酸。以正常人肺cDNA文库为模板,PCR方法获取Met-MIP4基因,克隆入载体pUC19,测序验证序列已得到突变,将正确的基因插入到GST融合表达载体pGEX-4T中,以IPTG诱导表达。结果 PCR产物为220bp左右的片段,连接入pUC19质粒后测序验证获得正确突变,构建的pGEX-4T融合表达载体在大肠杆菌中表达,经SDS-PAGE凝胶电泳显示有大小约34kU的新生融合蛋白表达。结论 成功突变并克隆了β-趋化因子MIP4基因,SDS-PAGE表明,与GST融合的Met-MIP4突变体已得到表达,为进一步研究其生物学活性奠定了基础。 相似文献
50.