全文获取类型
收费全文 | 420299篇 |
免费 | 38947篇 |
国内免费 | 29042篇 |
专业分类
耳鼻咽喉 | 3216篇 |
儿科学 | 5761篇 |
妇产科学 | 4672篇 |
基础医学 | 45255篇 |
口腔科学 | 6877篇 |
临床医学 | 59247篇 |
内科学 | 56261篇 |
皮肤病学 | 4629篇 |
神经病学 | 19870篇 |
特种医学 | 15194篇 |
外国民族医学 | 241篇 |
外科学 | 36623篇 |
综合类 | 79766篇 |
现状与发展 | 90篇 |
一般理论 | 34篇 |
预防医学 | 31796篇 |
眼科学 | 11664篇 |
药学 | 46590篇 |
474篇 | |
中国医学 | 27994篇 |
肿瘤学 | 32034篇 |
出版年
2024年 | 1437篇 |
2023年 | 6003篇 |
2022年 | 16020篇 |
2021年 | 20293篇 |
2020年 | 16054篇 |
2019年 | 12940篇 |
2018年 | 13506篇 |
2017年 | 13105篇 |
2016年 | 11955篇 |
2015年 | 18809篇 |
2014年 | 23533篇 |
2013年 | 21670篇 |
2012年 | 32257篇 |
2011年 | 36092篇 |
2010年 | 24749篇 |
2009年 | 20185篇 |
2008年 | 24452篇 |
2007年 | 23965篇 |
2006年 | 22779篇 |
2005年 | 21539篇 |
2004年 | 14303篇 |
2003年 | 13634篇 |
2002年 | 11137篇 |
2001年 | 9467篇 |
2000年 | 9129篇 |
1999年 | 9153篇 |
1998年 | 5709篇 |
1997年 | 5561篇 |
1996年 | 4280篇 |
1995年 | 3980篇 |
1994年 | 3363篇 |
1993年 | 2185篇 |
1992年 | 2621篇 |
1991年 | 2298篇 |
1990年 | 1926篇 |
1989年 | 1688篇 |
1988年 | 1382篇 |
1987年 | 1304篇 |
1986年 | 1035篇 |
1985年 | 739篇 |
1984年 | 423篇 |
1983年 | 301篇 |
1982年 | 167篇 |
1981年 | 200篇 |
1980年 | 138篇 |
1979年 | 173篇 |
1978年 | 98篇 |
1977年 | 69篇 |
1976年 | 46篇 |
1974年 | 55篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
目的 探讨脑梗死后抑郁与负性生活事件的关系。方法 将脑梗死患者按是否受负性生活事件影响分为 A(n=75 )、B(n=73)两组。采用抑郁自评量表 (SDS)及 Hamilton抑郁量表筛查 ,对两组进行比较分析 ,并观察其治疗效果。结果 A、B两组脑梗死后抑郁的发生率分别为 5 6 %、38.4 % ,两者比较差异显著 (P<0 .0 5 ) ;百忧解可显著改善或治愈脑梗死后抑郁 ,总有效率 6 1.7%。结论 脑梗死后抑郁发生与负性生活事件相关。百忧解治疗有效 相似文献
62.
目的 为探讨各种类型新生儿颅内出血的早期诊断方法,明确其临床特点与CT的关系。方法 对176例经CT证实有颅内出血新生儿的临床资料进行回顾性分析。结果 176例患儿中缺氧所致123例(72.6%),产伤21例(11.9%),新生儿出血症22例(12.5%),早产儿10例。患儿有意识障碍者156例(88.6%),惊厥98例(55.68%),肌张力改变113例(64.2%),原始反射减弱或消失104例(59%),贫血16例。CT示:SAH121例。占68.75%,为NICH最常见类型;SDH17例,IPH13例,IVH5例,混合性出血20例。结论 根据临床表现考虑NICH者应做头颅CT或头颅B超检查。Cr是确诊的最佳手段,能正确显示出血部位、范围、程度及区分各种类型,头颅B超对早产儿、低出生体重儿的IVH、IPH检出率高。 相似文献
63.
64.
65.
A difference spectrophotometric procedure is described for the assay of nitrazepam in tablet formulations. The method is based on the measurement of absorbance at 282 nm of a solution of the tablet extract in 0.1 M hydrochloric acid (pH 1) relative to that of an equimolar solution in 0.1 M sodium hydroxide (pH 13). The method is precise and selective for nitrazepam in the presence of the tablet excipients and 2-amino-5-nitrobenzophenone, the principal hydrolysis product of nitrazepam. The absence of a constant isosbestic point in the difference spectrum of nitrazepam during hydrolysis in alkaline solution indicates the presence of a previously unrecognized intermediate hydrolysis product. 相似文献
66.
豚鼠内耳磁微粒栓塞缺血模型初探 总被引:3,自引:0,他引:3
OBJECTIVE: To set up an inner ear ischemic model in guinea pig with ferromagnetic embolism. METHODS: A magnet was fitted in the external auditory canal and carbonyl iron filings (1%, 1 ml/kg) was injected into jugular, then the inner ear vessels were obstructed by ferromagnetic spheres. Cochlear blood flow (CBF) and number of red blood cells in the stria vessels were used to detect the model's ischemia of cochleae. The slice of temple bone and basal membrane stained by silver nitrate were used for inner ear's histopathological observations. RESULTS: The iron spheres were amassed in the one and two-day-later's model of inner ear vessels, which resulted in embolism. The number of red blood cells in the stria vessels decreased and then recovered to normal level after 4 days, but the CBF decreased to 50% +/- 10% of basic level immediately and recovered to 99% +/- 41% 4 days later. Scattered lesion of out hair cell cilium could be seen in cochleae in eight-day-later's model, and degenerations in different degree were found in vascular stria. CONCLUSION: The methods of inner ear ischemic model with ferromagnetic embolism could be practical and the decrease of CBF was reversible, so it may be an ideal model for studying some ischemic inner ear diseases and evaluating the effects of therapeutic drugs. 相似文献
67.
本文报道给家兔注入不同剂量的~3H-α-第二丁基对羟基苄醇,观察该药在其体内的药物动力学。结果表明,血中分布相快,消除相慢,消除半衰期T_1/1β为12h。经F值检验和理论计算值与实测值的契合程度比较,表明该药在兔体内的运转符合二室开放模型的动力学方程。 相似文献
68.
儿童青光眼作为一种严重的潜在性致盲眼病,因儿童患者的特殊性,治疗困难,效果不佳.近年来,随着阀门植入手术的日益开展,有关青光眼阀门应用于儿童青光眼治疗的相关报道日渐增多.与其他手术方式相比,阀门植入手术对婴幼儿难治性青光眼显示出较好的疗效和安全性,表现在结膜下瘢痕较小,滤过泡壁纤维化少、渗透性更好,从而能够长期有效地控制眼压.它能够很好避免因瘢痕形成所致的滤过失败,并且滤过泡渗漏和感染等严重并发症的发生率也明显降低.但目前还缺乏有关于此的大样本、长期疗效和安全性研究. 相似文献
69.
The effects of localized gamma-irradiation on the in vivo 31P NMR spectra of RIF-1 tumors grown subcutaneously in C3H/HeN mice have been examined before and during the week after treatment. Increases in the ratio of phosphocreatine (PCr) to inorganic phosphate (Pi) and in tumor pH, and decreases in the ratio of Pi to the beta phosphorus resonance of the nucleotide triphosphates (beta NTP) were observed in irradiated tumors. The time course of changes in the 31P spectrum following treatment was the opposite of the pattern during untreated growth, and the magnitude and duration of the changes increased with increasing radiation dose, decreasing clonogenic cell survival and increasing growth delay. To examine the possibility that nontherapeutic systemic effects of the tumor irradiation were responsible for the changes observed, a number of animals bearing two tumors were examined. One tumor on each mouse was selectively irradiated. Changes in tumor volume, Pi/beta NTP, PCr/Pi, the ratio of phosphomonoesters to beta NTP, and tumor pH were all significantly different in the treated compared to the untreated tumor on each animal, indicating that these changes in 31P NMR spectra were a response to radiation therapy and not a systemic response to radiation toxicity. 相似文献
70.
The historical review and the necessity of establishment of the Chinese Classification of Diseases (CCD) and Coding System are described. The content, terms used for unified and standardized nomenclatures, coding system including diagnostic terms of traditional Chinese medicine and other codings are introduced. The utility of the CCD system in medical record face sheet management, national native medical statistics, consultative retrieval from terms and codes of diseases, the development and practical trial of ICD-9 CCD is also discussed. Finally, the position and prospect of CCD system in international informatics communication is emphasized. 相似文献