全文获取类型
收费全文 | 32631篇 |
免费 | 2722篇 |
国内免费 | 1377篇 |
专业分类
耳鼻咽喉 | 395篇 |
儿科学 | 652篇 |
妇产科学 | 573篇 |
基础医学 | 3967篇 |
口腔科学 | 571篇 |
临床医学 | 3484篇 |
内科学 | 5471篇 |
皮肤病学 | 763篇 |
神经病学 | 2139篇 |
特种医学 | 1220篇 |
外国民族医学 | 13篇 |
外科学 | 4117篇 |
综合类 | 4060篇 |
现状与发展 | 4篇 |
一般理论 | 19篇 |
预防医学 | 1944篇 |
眼科学 | 1161篇 |
药学 | 2595篇 |
19篇 | |
中国医学 | 1085篇 |
肿瘤学 | 2478篇 |
出版年
2024年 | 62篇 |
2023年 | 434篇 |
2022年 | 935篇 |
2021年 | 1396篇 |
2020年 | 1032篇 |
2019年 | 974篇 |
2018年 | 1101篇 |
2017年 | 966篇 |
2016年 | 966篇 |
2015年 | 1262篇 |
2014年 | 1559篇 |
2013年 | 1513篇 |
2012年 | 2312篇 |
2011年 | 2349篇 |
2010年 | 1377篇 |
2009年 | 1158篇 |
2008年 | 1667篇 |
2007年 | 1697篇 |
2006年 | 1662篇 |
2005年 | 1684篇 |
2004年 | 1214篇 |
2003年 | 1031篇 |
2002年 | 925篇 |
2001年 | 791篇 |
2000年 | 801篇 |
1999年 | 784篇 |
1998年 | 477篇 |
1997年 | 407篇 |
1996年 | 321篇 |
1995年 | 323篇 |
1994年 | 272篇 |
1993年 | 203篇 |
1992年 | 314篇 |
1991年 | 301篇 |
1990年 | 283篇 |
1989年 | 273篇 |
1988年 | 260篇 |
1987年 | 222篇 |
1986年 | 212篇 |
1985年 | 178篇 |
1984年 | 112篇 |
1983年 | 73篇 |
1981年 | 61篇 |
1979年 | 78篇 |
1978年 | 56篇 |
1977年 | 58篇 |
1976年 | 56篇 |
1974年 | 65篇 |
1973年 | 60篇 |
1972年 | 63篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
不同类型高危儿早期干预的临床研究 总被引:4,自引:0,他引:4
目的 探索早期干预对窒息、高胆、早产三类高危儿智力发育改善的效果,寻找更合适的早期干预措施。方法 将三类高危儿分为干预组及对照组,同时随机选取正常对照组进行随访。干预组采用鲍秀兰教授“0~3岁”早期干预方案训练,各组均在6个月、1岁时分别采用婴幼儿智能发育量表(CDCC)进行智力发育测评,结果用MDI、PDI表示。结果 (1)6个月龄时MDI各干预组与对照组间有显著性差异,窒息组、早产组与正常组间亦有显著性差异;高胆组与正常组间无差异;PDI窒息组中干预组与对照组之间有显著差异(P<0.01),高胆组、早产组均无差异(P>0.05)。(2)1岁时MDI和PDI结果一致,干预组与对照组间比较窒息组、高胆组有显著差异,早产组无差异;窒息组、高胆组干预组与正常组比较无差异,对照组和早产组与正常组比较均有显著差异(P<0.01)。(3)所有干预组测评分值均高于对照组,6个月与1岁之间比较有显著差异,各观察组间比较有显著性差异(P<0.01)。结论 三类高危儿早期干预效果差异较大,干预组均较对照组分值高,早期干预有改善智力发育的作用;三类高危儿中,窒息组、高胆组效果最好,均达到或超过正常水平。所有未干预组均不及正常水平;早期干预对足月高危儿效果显著,对早产儿欠佳,远期效果尚需进一步随访观察。 相似文献
52.
目的 探讨肺炎衣原体感染与慢性稳定性心绞痛患者血中炎症标志物之间的关系。方法 采用微量免疫荧光法 (MIF)和酶联免疫法 (ELISA)对 5 2例经冠状动脉造影证实的慢性稳定心绞痛患者 (CSA)血中肺炎衣原体IgG抗体 (CpIgG)和肿瘤坏死因子 α(TNF α)、白细胞介素 6 (IL 6 )、C 反应蛋白 (CRP)进行检测。结果 在慢性稳定性心绞痛患者组中CpIgG阳性率为 5 5 .77% ;而CpIgG滴度与TNF α、IL 6和CRP单因素及多因素回归分析发现只有CpIgG与TNF α显著相关 (P <0 .0 5 ) ,但与IL 6和CRP之间无显著相关性 (P <0 .0 5 )。在慢性稳定性心绞痛患者中肺炎衣原体感染可能促进TNF α的升高 ,但肺炎衣原体的感染不是导致斑块不稳定的主要因素 相似文献
53.
Liu Wenen Tang Yin Wang Lange Tan Deming Xiangya Hospital Central South University Changsha 《中国现代医学杂志》2003,13(8):18-20
Extended -spectrum β -lactamases(ESBLs)aremainlyproducedbymembersofthefamilyEnter obacteriaceaewhichcanhydrolyzeβ -lactamantibi oticsincludingthethird - generationcephalosporinandaztreonam ,theESBLs- producingbacillishowedmedian -highresistancetoceftazidimeandaztreonamparticularly[1] .NowadaystheprevalenceofESBLs -producingstrainshavebeenreportedinmanyareasaroundtheworld[2 ] .ButthereisfewinformationabouttherelationshipbetweentheuseofantibioticandtheproductionofESBLs .Weperformedastud… 相似文献
54.
Eight patients who developed severe ovarian hyperstimulation syndrome (OHSS) were identified among 1302 patients undergoing in-vitro fertilization (IVF) over a 1 year period (prevalence of 0.6%); 63% had ultrasonically diagnosed polycystic ovaries (PCO) and 75% were undergoing their first attempt at IVF. Pretreatment with a superactive luteinizing hormone-releasing hormone (LHRH) analogue significantly increased the prevalence of severe OHSS (1.1% versus 0.2%, P less than 0.05) compared with ovarian stimulation with clomiphene citrate and human menopausal gonadotrophin (HMG). The mean serum oestradiol concentration on the day of human chorionic gonadotrophin (HCG) administration was 8200 +/- 2300 pmol/l. A mean of 19.6 +/- 6.8 follicles had been aspirated and 13.1 +/- 7.7 oocytes recovered at transvaginal ultrasound-directed oocyte recovery. All patients had an embryo transfer and luteal support in the form of HCG. The clinical pregnancy rate was 88%, multiple pregnancy rate 71% and implantation rate 63.5 +/- 41.3%. In a group of seven patients who were hospitalized for moderate OHSS during the same period, peak oestradiol levels were significantly lower than in those with severe OHSS (P less than 0.05). Of the group with moderate OHSS, 57% had PCO, the clinical pregnancy rate was 100% and multiple pregnancy rate 43%. Patients with ultrasound-diagnosed PCO have an increased risk of developing OHSS and the dose of HMG administered to them should be minimized. In patients at risk of developing OHSS, progesterone instead of HCG should be used for luteal support. Transfer of a maximum of two embryos or freezing all embryos for transfer in a subsequent cycle may reduce the likelihood of multiple pregnancy. 相似文献
55.
Omeprazole May Kill Helicobacter pylori 总被引:2,自引:0,他引:2
K. L. Goh M.D. K. K. Tan M.D. P. E. Anderson M.D. 《The American journal of gastroenterology》1991,86(1):124-124
56.
The hepatitis B immunization programme in Singapore 总被引:2,自引:0,他引:2
K T Goh S Doraisingham K L Tan C J Oon M L Ho A J Chen S H Chan 《Bulletin of the World Health Organization》1989,67(1):65-70
A voluntary immunization programme to prevent perinatal transmission of hepatitis B virus (HBV) infection in Singapore was implemented on 1 October 1985 as an integral component of the national childhood immunization programme. Up to April 1988, a total of 68,845 mothers who attended government maternal and child health clinics were screened for the disease. Of these, 2432 (3.5%) were positive for hepatitis B surface antigen (HBsAg) and 904 (1.3%) for hepatitis B e antigen (HBeAg). Virtually all the babies born to carrier mothers completed the full immunization schedule; and in addition, those of HBeAg-positive mothers were given a dose of hepatitis B immunoglobulin at birth. The hepatitis B immunization programme was extended on 1 September 1987 to cover all newborns. About 90% of the 15,943 babies delivered in government institutions from September 1987 to April 1988 were immunized at birth, with the subsequent doses being administered at maternal and child health clinics at 4-6 weeks and 5 months later. More than 85% of the children given the full course of plasma-derived and yeast-derived hepatitis B vaccine from birth continued to have protective antibody to HBV two years after immunization. The programme is being closely monitored to assess the duration of immunity and the need for booster doses, while seronegative adults are also being encouraged to be vaccinated. 相似文献
57.
The most outstanding pathological changes of perinatal babies and children, based on the review of the autopsy files in the 1st Affiliated Hospital of West China University of Medical Sciences, are lymphocytic depletion, and reticuloepithelial cell swelling and/or fusiform malformation in the cortex, while in the medulla apoptosis is more prominent. We suppose that these alterations are due to immaturity of cortical thymocytes, and in the diseased condition, they are easily affected by extraordinary factors, especially the influence of corticosterone inducing acute severe necrosis, so the number of lymphocytes are obviously diminished. But, in the medulla, as intact mature lymphocytes exist, physiological phenomenon such as apoptosis is rather prominent in it. While in the medulla, Hassall's corpuscles have various characteristic changes, such as cornification, calcification, fusion, cystic change and disintegration. Besides, we observed a new alteration in the thymus defined as vacuolization. All the above pathological changes reached the peak in the 28- day group; there after, they might become either worse or better according to the condition of the disease and growth of the body. However, these are still problems to be further studied separately. 相似文献
58.
59.
60.
Two fast magnetic resonance (MR) imaging techniques, advanced Fourier and partial-flip imaging, were used at 0.35 T to examine 21 patients with suspected intracranial lesions; the results were quantitatively compared with a conventional spin-echo study. Both of the fast MR techniques yielded a fourfold reduction in imaging time per section. The advanced Fourier sequence showed contrast that was identical to the conventional spin-echo study with signal-to-noise ratios of 58% and 57% for the first and second echoes, respectively. The partial-flip sequence showed a contrast of 109% and 57% for lesions versus substantia alba, and 107% and 78% for substantia grisea versus substantia alba relative to the first and second echoes of the conventional spin-echo study. The partial-flip sequence was particularly sensitive to magnetic susceptibility; this produced artifacts that may undermine the usefulness of partial flip for routine screening in certain parts of the brain. However, this susceptibility significantly improved the detection of intracranial hemorrhage when compared with the spin-echo sequence, particularly when combined with phase mapping of the partial-flip study. 相似文献