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   8851篇
  免费   1017篇
  国内免费   185篇
耳鼻咽喉   80篇
儿科学   23篇
妇产科学   25篇
基础医学   280篇
口腔科学   86篇
临床医学   411篇
内科学   210篇
皮肤病学   23篇
神经病学   123篇
特种医学   103篇
外国民族医学   1篇
外科学   324篇
综合类   1031篇
预防医学   160篇
眼科学   6191篇
药学   705篇
  4篇
中国医学   163篇
肿瘤学   110篇
  2024年   29篇
  2023年   152篇
  2022年   228篇
  2021年   356篇
  2020年   297篇
  2019年   282篇
  2018年   361篇
  2017年   324篇
  2016年   394篇
  2015年   362篇
  2014年   561篇
  2013年   657篇
  2012年   584篇
  2011年   647篇
  2010年   493篇
  2009年   491篇
  2008年   414篇
  2007年   463篇
  2006年   429篇
  2005年   319篇
  2004年   298篇
  2003年   224篇
  2002年   167篇
  2001年   166篇
  2000年   171篇
  1999年   125篇
  1998年   114篇
  1997年   81篇
  1996年   57篇
  1995年   73篇
  1994年   56篇
  1993年   55篇
  1992年   72篇
  1991年   39篇
  1990年   40篇
  1989年   50篇
  1988年   25篇
  1987年   26篇
  1986年   16篇
  1985年   76篇
  1984年   48篇
  1983年   43篇
  1982年   46篇
  1981年   42篇
  1980年   47篇
  1979年   14篇
  1978年   14篇
  1977年   8篇
  1976年   6篇
  1972年   3篇
排序方式: 共有10000条查询结果,搜索用时 156 毫秒
51.
Pattern electroretinograms (PERGs) in response to 8.3 Hz alternating gratings (16.6 rev/sec) of different spatial frequencies were recorded in normal subjects as well as in patients affected by early glaucoma and ocular hypertension. In normal subjects the PERG response is spatially tuned, with a maximum at about 1.5 cycles/deg and attenuation at higher and lower spatial frequencies. In all cases of early glaucoma and in the great majority of cases of ocular hypertension the PERG was reduced, as compared with that of normal subjects, mainly in the medium range of spatial frequencies (at which the PERG has its maximal amplitude).  相似文献   
52.
目的:探讨小梁切除联合丝裂霉素术后晚期滤泡相关并发症的发生率及处理。 方法:1994-05/2000.05接受小梁切除手术联合丝裂霉素治疗青光眼65例65眼,采用Kaplan-Meier生存分析法估计晚期滤过泡渗漏、滤泡炎、眼内炎的发生概率。 结果:随访2.5~7.1(平均5.6)a,发生滤过泡渗漏16眼(16/65,24.6%),出现滤泡炎5眼(5/65,7.7%),发生眼内炎1眼,出现复合性滤泡并发症1眼,出现持久性低眼压9眼(9/65,13.8%)。Kaplan-Meier生存分析法估计晚期滤泡并发症5a发生概率为40.0%。多数眼通过门诊处理获得成功,部分眼需手术治疗。 结论:小梁切除联合丝裂霉素术后晚期滤泡相关并发症的发生率可高达40.0%,单纯滤过泡渗漏是一相对良性的状况,只要及时处理,可被修复,滤泡炎或眼内炎可以被控制,而获得正常眼内压。一相对良性的状况,只要及时处理,可被修复,滤泡炎或眼内炎可以被控制,而获得正常眼内压。  相似文献   
53.
The literature suggests that visual field defects may be more common in people who experience migraine. The Humphrey frequency doubling (FDT) visual field instrument selectively examines the magnocellular visual pathway, but has not previously been used to investigate visual function in migraine. In a masked controlled study we compared Humphrey FDT and Humphrey Swedish Interactive Threshold Algorithm fields of 25 migraine sufferers with 25 age- and gender-matched controls. Although both mean deviation and pattern standard deviation were a little worse in the migraine group, these differences did not reach statistical significance. There were no inter-eye visual field differences in the migraine group compared with controls. Comparing the mean of all the contrast thresholds in each hemisphere, there were no more inter-hemifield visual field differences in the migraine group compared with controls. There was no significant difference between the migraine and control groups in intra-ocular pressures. The visual field parameters were not correlated with the interval since the last migraine headache, the severity of migraine headache, the duration of migraine headache or the number of migraine headaches per annum. In our data, there was no evidence of visual field deficits, a magnocellular deficit, or indications of glaucomatous pathology.  相似文献   
54.
目的 :观察丝裂霉素C(MMC)在抗青光眼手术中应用的近期及远期效果。方法 :4 2只复发性青光眼在二次手术中一次性应用MMC术后观察及随访。结果 :术前眼压 34.0 5± 4 .0 5mmHg ,明显高于随访半年期 13.13± 3.30mmHg以及随访 2年期 14 .33± 3.30mmHg ,差异有显著性 (P <0 .0 1)。术后近期眼压 6 .75± 1.4 3mmHg ,明显低于随访半年期 (P <0 .0 1)。功能性滤过泡所占比率为 95 .2 %。结论 :术中一次性应用MMC ,远期观察其降压效果明显 ,且无严重并发症发生  相似文献   
55.
目的 研究非穿透性小梁切除术治疗开角型青光眼的手术效果。方法 对20例26眼开角型青光眼行非穿透性小梁切除术,术后观察眼压、结膜滤枕及前房反应等情况,随访1~12个月。结果 术后各期平均眼压均低于术前平均眼压,差异有显著性(P<0.05)术。前平均眼压26.26mmHg,术后3个月、6个月、9个月、12个月平均眼压分别为15.47mmHg、16.89mmHg、19.14mmHg、18.50mmHg。16眼结膜形成滤性手术典型滤过泡,10眼结膜疏松无滤过泡形成。26眼均无前房出血,术后前房反应轻。结论 非穿透性小梁切除术能有效地降低开角型青光眼的眼压,术后并发症少,可作为此类青光眼病人手术的选择。  相似文献   
56.
Summary It is widely accepted that a disturbed blood supply of the optic disc may cause (in addition with an increased intraocular pressure) optic nerve fibre damage. Therefore we measured ocular perfusion pressures in 79 healthy subjects. In 18 patients with low tension glaucoma, in 27 patients suffering from ocular hypertension and in 49 glaucoma (OAG) patients. For measuring perfusion pressures we used the technique of oculooscillo-dynamography (OODG) as described by Ulrich. Additionally we measured intraocular pressure and systemic blood pressure. In OODG the IOP is simultaneously increased in both eyes by application of a suction cup. After increase of the IOP the negative pressure in the suction cup is slowly and linearly decreased. During this decrease the pulse-depending oscillations of each eye are recorded on a strip-chart-recorder. By means of this method retinal and ciliary perfusion pressures can be separated. As a result we could show that mean arterial blood pressure and systolic retinal perfusion pressure were comparable and not statistically significantly different between the groups examined. The systolic ocular perfusion pressures in patients with low tension glaucoma showed a highly statistically significant reduction compared with the other groups. Between healthy subjects, OAG-patients and patients suffering from ocular hypertension there was no difference in systolic ciliary perfusion pressure detectable.  相似文献   
57.
The local mean and the average difference of four pairs of test locations within the 26° visual field, situated above and below the horizontal nasal meridian, were used to predict the global field indices MD and CLV of the Gl glaucoma program. Out of 539 examinations (194 eyes suspected of having glaucoma), the local indices NDIFF (describing asymmetrical behavior around the nasal horizontal meridian), ND0 (the mean defect in the nasal region), and the global indices MD and CLV were calculated. Seven hundred fifty-five examinations (446 normal eyes) served as a control group. First and second examinations of 146 glaucoma suspect eyes were used to calculate the retest reliability scores for the indices in question. When analyzing the glaucoma suspects, the local index NDIFF, together with the local mean defect, ND0, yielded highly reliable estimates of the global indices MD and CLV, with a retest correlation r = 0.86 for NDIFF, and r = 0.96 for ND0. The covariance of NDIFF with CLV was r = 0.67, while the co-variance of MD with ND0 was r = 0.95.The ranges of the local indices ND0 and NDIFF were each classified into normal range and range of suspected pathology, in analogy to the normal and pathological ranges of the global field indices. Equivalence of the local indices with the corresponding ranges of MD and CLV was investigated and the results are shown. The establishment of local indices may prove to be a powerful tool in early detection of glaucomatous damage.  相似文献   
58.
目的分析白内障伴青光眼患者术后胰岛素抵抗及炎症因子水平变化与视觉质量的关系。 方法选取47例(47眼)白内障伴青光眼患者为研究对象,均接受超声乳化+小梁切除术治疗。术前、术后7天、术后3个月检测患者客观散射指数(OSI)、点扩散函数(PSF)、调制传递函数截止频率(MTF cutoff)、胰岛素敏感指数及白细胞介素(IL)-1β、IL-10、IL-2水平。采用Pearson法分析视觉质量参数与胰岛素抵抗情况及炎症因子的相关性。 结果与术前比较,术后7天和术后3个月最佳校正视力、MTF cutoff及胰岛素敏感指数升高,且术后3个月更高(P<0.05);与术前比较,术后7天和术后3个月眼压、角膜内皮细胞计数、PSF、OSI及血清IL-1β、IL-2、IL-10水平降低,且术后3个月更低(P<0.05)。Pearson分析显示,术前、术后7天和术后3个月,白内障伴青光眼患者OSI与胰岛素敏感指数呈负相关(P<0.05),与血清IL-1β、IL-2、IL-10水平呈正相关(P<0.05);MTF cutoff与胰岛素敏感指数呈正相关(P<0.05),与血清IL-1β、IL-2、IL-10水平呈负相关(P<0.05);PSF与血清IL-1β水平呈负相关(P<0.05)。术后7天和3个月,PSF与胰岛素敏感指数呈正相关(P<0.05),与血清IL-2、IL-10水平呈负相关(P<0.05)。 结论超声乳化联合小梁切除术对视觉质量的改善可能与胰岛素抵抗及炎症因子变化密切相关。  相似文献   
59.
One hundred cases of recalcitrant glaucoma were operated with a long tube single-plate Molteno implant (LSMI). At the median follow-up of 15 months an intraocular pressure of 19 mm Hg was obtained in 64 of the 87 eyes (73%) which have a minimum follow-up of 6 months (secondary non-neovascular glaucomas=19; congenital glaucomas=26; secondary neovascular glaucomas=12). The interval probability (percentage±standard error) of obtaining a successful result (IOP19 mmHg) was 79% (±13) at twelve months from surgery, and 53% (±24) at the eighteen month interval. The least favorable results were obtained in the secondary non-neovascular glaucomas. Complications observed included choroidal detachment (24%), tube exposure (4%), tube-endothelium contact (6%), plus band keratopathy, fibrous ingrowth, traction retinal detachment and corneal ulcers.Seventeen cases needed repeate surgery for the management of complications. In order to decrease the post-operative hypotony, we have been using a tourniquet suture around the tube at the time of implantation to occlude it temporarily and limit the outflow.  相似文献   
60.
目的探讨高眼压状态下青光眼手术方法的安全性和效果。方法对32例药物降压无效的青光眼患者进行青光眼手术,术后观察出血、滤过泡、前房、眼压及视力的变化。结果术后1月视力提高的21只眼(65.63%);保持不变的11只眼(34.38%);眼压术后≤21mmHg者28只眼(87.5%);用药物控制的4只眼(12.5%)。结论高眼压状态采取手术治疗是安全有效的。  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