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   45018篇
  免费   3552篇
  国内免费   1356篇
耳鼻咽喉   349篇
儿科学   256篇
妇产科学   214篇
基础医学   2641篇
口腔科学   655篇
临床医学   4079篇
内科学   2911篇
皮肤病学   466篇
神经病学   1734篇
特种医学   1413篇
外国民族医学   7篇
外科学   2843篇
综合类   10124篇
现状与发展   5篇
预防医学   5445篇
眼科学   678篇
药学   8679篇
  501篇
中国医学   4908篇
肿瘤学   2018篇
  2024年   160篇
  2023年   623篇
  2022年   1423篇
  2021年   1942篇
  2020年   2088篇
  2019年   1115篇
  2018年   1158篇
  2017年   1629篇
  2016年   2237篇
  2015年   1997篇
  2014年   4172篇
  2013年   3819篇
  2012年   3319篇
  2011年   3115篇
  2010年   2376篇
  2009年   2034篇
  2008年   1912篇
  2007年   1995篇
  2006年   1756篇
  2005年   1507篇
  2004年   1136篇
  2003年   1058篇
  2002年   894篇
  2001年   793篇
  2000年   634篇
  1999年   573篇
  1998年   460篇
  1997年   393篇
  1996年   358篇
  1995年   350篇
  1994年   309篇
  1993年   240篇
  1992年   257篇
  1991年   223篇
  1990年   200篇
  1989年   206篇
  1988年   194篇
  1987年   145篇
  1986年   144篇
  1985年   180篇
  1984年   142篇
  1983年   95篇
  1982年   106篇
  1981年   75篇
  1980年   60篇
  1979年   78篇
  1978年   55篇
  1977年   60篇
  1976年   40篇
  1975年   36篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
Two experiments investigated the effects of haloperidol (0.1 mg/kg) on the partial reinforcement extinction effect (PREE). In experiment 1 two groups of rats were trained to run in a straight alley using six trials/day with an intertrial interval (ITI) of 5–8 min. The continuously reinforced (CRF) group received food reward on every trial. The partially reinforced (PRF) group was rewarded on a quasi-random 50% schedule. All animals were then tested in extinction. Haloperidol was administered in a 2 × 2 design, i.e., drug-no drug in acquisition and drug-no drug in extinction. In experiment 2 two groups of rats were trained to press a lever in an operant chamber using a discrete trial procedure of ten trials/day with an ITI of 60 s. The CRF group was rewarded on each trial and the PRF group was rewarded on a quasi-random 50% schedule. Haloperidol was administered for 22 days prior to the start of the PREE procedure as well as throughout acquisition and extinction. The PREE, i.e., increased resistance to extinction of PRF as compared to CRF animals, was obtained in both experiments in all drug conditions. In both experiments haloperidol increased the rate of extinction. Experiment 1 revealed that this effect was entirely dur to the administration of the drug in extinction, independently of the drug condition in acquisition. In contrast to previous results in a one trial/day procedure, the administration of haloperidol to CRF animals did not increase resistance to extinction, failing to support the notion that neuroleptics attenuate the rewarding properties of reinforcement.  相似文献   
52.
阔筋膜皮瓣移植修复手前臂巨大创面   总被引:4,自引:0,他引:4  
报道采用吻合血管的阔筋膜皮瓣移植,修复手、前臂巨大创面11例,均获成功,其优点:①阔筋膜长而坚韧,内面光滑,覆盖关节、骨、肌腱粘连轻,尤其利于肌腱滑动,是修复手、前臂的最佳皮瓣。②皮肤与肌腱同时缺损时,利用阔筋膜修复肌腰,一期完成肌腱及皮肤的修复。③股外侧皮神经长而粗,分支多,适合手部感觉修复。④供区隐蔽,皮下组织簿,血运丰富,供皮及阔筋膜面积大。  相似文献   
53.
A 9-year-old boy presented with a subacute history of optic neuritis followed by brainstem involvement, with fever and a lymphocytic pleocytosis in the cerebrospinal fluid. Gadolinium-enhancing ring lesions were demonstrate in the white matter of the cerebrum, brainstem and cerebellum on day 17 of the illness, all appearing simultaneously as part of a monophasic illness. A parietal lesion exerted mass effect. Needling and biopsy yielded no evidence of a pyogenic lesion, tumour or tuberculosis and showed vasculitis. There was insufficient material for myelin staining. Dexamethasone therapy lead to rapid improvement of the radiological lesions: MRI and CT on day 34 of the illness showed complete clearing of the lesions except for residual abnormality at the biopsy site.  相似文献   
54.
66例成人原发肾病综合征临床治疗与病理分析   总被引:1,自引:0,他引:1  
刘然  田松 《北京医学》1995,17(4):217-220
本对66例原发肾病综合征患进行病理类型与临床疗效分析。最常见病理类型为系膜增殖性肾炎,占42.5%,其次为膜性肾病,占32.5%,IgA肾病占15.0%。微小病变型及系膜增殖性肾炎对激素及免疫抑制剂治疗效果好,膜性肾病治疗效果差。不同病理类型患病理损害程度与疗效相关。伴肾小管间质病变治疗效果差(P〈0.05)。NSⅠ型疗效明显优于NSⅡ型(P〈0.05)。50岁以下原发肾病综合征(PNS)  相似文献   
55.
Late Effects of Childhood Acute Leukemia and Its Treatment   总被引:1,自引:0,他引:1  
Late effects of childhood acute leukemia and its treatment were studied in 766 patients (684 ALL, 73 ANLL, and 9 others) in Japan who had remained in remission for more than 1 year after their first complete remission. Delayed adverse sequelae involve a wide variety of organs and their functions. Short stature was present in 2.61%, obesity in 3.79%, abnormalities of growth hormone secretion in 1.5%, delayed secondary sex characteristics in 1.5% of males and 0.6% of females, motor disturbances in 1.17%, sensory disturbances in 0.91%, intellectual and learning disabilities in 2.48%, abnormal findings in routine neurologic examinations in 1.31%, EEG abnormalities in 4.30%, brain CT abnormalities in 5.09% and cardiac dysfunction in 1.07%. Various other disorders were seen in 20 patients. Many of these delayed adverse sequelae are caused by or related to central nervous system prophylaxis and systemic combination chemotherapy. The results suggest that it is needed to improve therapeutic methods through the stratification of patients by risk factors and detailed analysis of prognostic factors. Moreover it is important to render medical and psychosocial support to long-term survivors of childhood leukemia through interactions between the patient, parents and medical staff.  相似文献   
56.
卒中急性期病人中医综合康复护理效果观察   总被引:2,自引:1,他引:1  
[目的]探讨中医综合康复护理对卒中急性期病人神经功能缺损及日常生活能力(ADL)的影响。[方法]选择2004年9月-2006年9月在3家协作医院住院的卒中急性期238例病人为研究对象,随机分为实验组和对照组,两组药物治疗基本相同。实验组按中医综合康复护理方案进行护理.对照组采用卒中护理常规进行护理。对入选的病人在入院第1周内和4周后进行神经功能缺损及ADL的评定。[结果]4周后实验组在临床神经功能缺损、ADL等方面明显优于对照组,差异有统计学意义(P〈0.01)。[结论]中医综合康复护理可促进肢体的功能恢复,提高病人的ADL。  相似文献   
57.
8-硝基白杨素的合成及其抗肿瘤作用   总被引:5,自引:0,他引:5  
目的 探讨 8-硝基白杨素的抗肿瘤活性。方法 荷Lewis肺癌雄性小鼠 5 0只 ,随机分为5组 (NS对照组 ,环磷酰胺组 ,低、中、高剂量 8-硝基白杨素组 ) ,每组 1 0只 ,均采用腹腔注射给药。末次给药 2 4h后 ,颈椎脱位处死小鼠 ,观察各组瘤重减轻情况及转移结节数。结果 低、中、高剂量 8-硝基白杨素均能明显抑制肿瘤的生长和肿瘤转移结节的数 (阳性药对照组和各处理组与对照组相比 ,P均<0 .0 1 ) ,高剂量 ( 5 0mg kg) 8-硝基白杨素与 1 0 0mg kg的环磷酰胺的抗肿瘤作用相当 (P >0 .0 5 )。结论  8-硝基白杨素作为一种新黄酮衍生物 ,具有良好的抗肿瘤作用。  相似文献   
58.
目的 探讨舒肤特对座疮的治疗作用。 方法 病人随机分为治疗组和对照组。治疗组 45例 ,男 2 8例 ,女 17例 ;对照组 45例 ,男 2 5例 ,女 2 0例。年龄 14~ 42岁 ,平均 2 4岁。病程 2周~ 6年。治疗组用舒肤特 ,对照组用2 5 %氯霉素酊 ,每日 2次 ,4~ 8周为 1疗程。每周复诊 1次。 结果 治疗组痊愈率 3 7 8% ,总有效率 84 5 % ,对照组痊愈率 17 8% ,总有效率 62 2 % ,治疗组痊愈率优于对照组 ( χ2 =10 0 2 ,P <0 0 1) ,两组总有效率差异有显著性 ( χ2=11 42 8,P <0 0 1) , 结论 舒肤特是中西药复方制剂 ,其用于治疗痤疮效果较好 ,无明显副作用。  相似文献   
59.
茶氨酸对脑缺血再灌注损伤保护作用的实验研究   总被引:13,自引:0,他引:13  
目的观察茶氨酸对脑缺血再灌注损伤的保护作用,为临床脑缺血再灌注损伤的预防和治疗提供实验依据。方法将24只健康家兔随机分为四组:假手术组、脑缺血组、茶氨酸予处理组和茶氨酸治疗组。麻醉后分离血管,采用基底动脉、双侧颈总动脉结扎法制备急性全脑缺血再灌注动物模型。假手术组仅分离动脉不结扎,予处理组在缺血前应用茶氨酸,治疗组在缺血后应用茶氨酸,缺血组不作特殊药物处理。各组分别在规定时间点即缺血前、再灌注后30min、1h、2h采血测定神经特异性烯醇化酶(NSE)含量,取脑组织活检观察超微结构,处死动物测定脑含水量。结果茶氨酸予处理组和治疗组以上各项指标均较脑缺血组有显著的改善,提示茶氨酸具有神经保护作用。实验还显示茶氨酸予处理组在再灌注30min时NSE含量与假手术组比较无差异,提示用茶氨酸予处理后可能使缺血后脑损害的发生延迟,为进一步的治疗争取了宝贵时间。结论茶氨酸对脑缺血再灌注损伤有保护作用,值得进一步研究。  相似文献   
60.
BACKGROUND: Microbial skin colonization with Staphylococcus aureus is known to play an important role in atopic eczema (AE). Recently, an antibacterial effect of silver-coated textiles on S. aureus colonization has been demonstrated. OBJECTIVES: To investigate clinical efficacy and functionality of silver-coated textiles in AE, a multicentre, double-blind, placebo-controlled trial was conducted. PATIENTS/METHODS: From November 2001 to August 2002, 68 consecutive outpatients clinically diagnosed with generalized AE were included in the study. Inclusion criteria were the clinical diagnosis of AE with a moderate severity as measured by the scoring of atopic dermatitis (SCORAD) index with at least 20. Patients were instructed to wear either silver-coated (verum, 35 patients + 2 dropouts) or cotton garments (placebo, 22 patients + 9 dropouts) directly on the skin for 2 weeks. Only basic skin care and ongoing therapy with topical steroids or oral antihistamines was permitted. Clinical severity was assessed using the 'SCORAD' before, during and at the end of study. Quality of life (QOL), wearing comfort (WC) and functionality (FU) of study clothes were measured in parallel. Patients documented their subjective and objective symptoms daily. RESULTS: In the verum group, eczema improved significantly after 1 week with further enhancement until the end of study (P = 0.03 and P < 0.001). Silver-coated textiles were comparable to cotton in WC and FU. Pruritus and self-assigned skin condition improved significantly more than with placebo (P < 0.001 and P = 0.003). CONCLUSIONS: In conclusion, silver-coated textiles are able to improve objective and subjective symptoms of AE significantly within 2 weeks, showing a good wearing comfort and functionality comparable to cotton.  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