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   40364篇
  免费   4615篇
  国内免费   3060篇
耳鼻咽喉   498篇
儿科学   357篇
妇产科学   318篇
基础医学   3938篇
口腔科学   645篇
临床医学   5095篇
内科学   5140篇
皮肤病学   480篇
神经病学   1785篇
特种医学   1764篇
外国民族医学   13篇
外科学   4941篇
综合类   8501篇
现状与发展   14篇
一般理论   2篇
预防医学   3158篇
眼科学   890篇
药学   4534篇
  37篇
中国医学   2892篇
肿瘤学   3037篇
  2024年   235篇
  2023年   900篇
  2022年   2124篇
  2021年   2585篇
  2020年   2075篇
  2019年   1529篇
  2018年   1547篇
  2017年   1551篇
  2016年   1359篇
  2015年   2069篇
  2014年   2450篇
  2013年   2549篇
  2012年   3352篇
  2011年   3634篇
  2010年   2636篇
  2009年   2143篇
  2008年   2376篇
  2007年   2286篇
  2006年   2031篇
  2005年   1857篇
  2004年   1233篇
  2003年   1014篇
  2002年   877篇
  2001年   669篇
  2000年   601篇
  1999年   563篇
  1998年   278篇
  1997年   282篇
  1996年   229篇
  1995年   196篇
  1994年   168篇
  1993年   84篇
  1992年   96篇
  1991年   89篇
  1990年   82篇
  1989年   62篇
  1988年   58篇
  1987年   36篇
  1986年   29篇
  1985年   11篇
  1984年   17篇
  1982年   11篇
  1981年   10篇
  1979年   6篇
  1978年   11篇
  1977年   5篇
  1975年   4篇
  1974年   4篇
  1973年   4篇
  1972年   7篇
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
91.
肩峰下空间在撞击综合征、肩关节炎等多种疾病的发病学中起重要作用.传统观点认为撞击综合征的潜在因素是肩峰下空间狭窄对冈上肌腱的刺激,最新研究发现这一解释并不全面.该文介绍了肩峰下空间的研究进展,如骨性距离测量、撞击综合征发病机制等.  相似文献   
92.
本文采用放射免疫法测定了144例恶性肿瘤患者血清CEA含量,并以同样条件测定了30例正常人作为对照。结果表明恶性肿瘤患者血清CEA含量显著高于健康人,均值为10.3±4.84ng/ml。不同肿瘤患者血清CEA升高的程度不等,其中以肺癌含量最高为14.7±7.83ng/ml。转移性肿瘤CEA含量高于144例肿瘤的平均水平。术后复发者含量不见下降。癌性胸腹水中CEA含量明显升高。因此,血清CEA的测定对恶性肿瘤的辅助诊断,评价疗效和判断预后具有重要的临床意义。  相似文献   
93.
中西医结合治疗股骨头缺血性坏死   总被引:1,自引:0,他引:1  
股骨头缺血性坏死是世界骨科难题之一。作者致力于中草药治疗本病的研究三十多年,近来又在手术治疗方面倾注心血,对该病的防治、康复创立了一整套中西医结合新方法,取得了满意效果。自1982年以来,共治疗各种股骨头坏死1101例,其中单纯中医治疗433例,手术配合中药治疗668例。按作者制定的百分评分法,总有效率98%,优良率84%,无一例需再作人工关节置换术。  相似文献   
94.
报告37例胆囊小隆起性病变,其中良性颈变34例,胆囊癌3例。结果:本组23例有临床症状,多表现为反复发作的右上腹疼痛或不适;病灶部位,大小,多少,有无合并胆石及病变性质与临床症状有关;B-us,OCG,CT的诊断符合率例如辚33/37,9/24和5/10(x^2=18.75,P<0.005)。认为对胆囊小隆起性病变的病灶≥10mm,有增大趋势,呈恶性图像,合并胆石或血清CEA升高的病例应及早手术治疗。  相似文献   
95.
小儿重肾31例分析   总被引:1,自引:0,他引:1  
目的 探讨小儿重肾的诊断及治疗。方法 对我院 1989~ 2 0 0 1年收治的 3 1例小儿重肾进行回顾性分析。结果  3 1例中有 2 3例患儿接受 2 6次手术 ,有 16例行上半重肾及输尿管切除 ,其中有 2例须处理输尿管残端及盲袋所致的梗阻。 2 2例手术后恢复较好 ,仅 1例伴有轻度的尿失禁。结论 对于重肾伴肾积水或发育不良所致的各种临床表现应首先考虑做上半肾及输尿管大部切除术。B超、CT及静脉肾盂造影术 (IVP)对诊断分型有意义。  相似文献   
96.
This investigation used a derivation of acoustic reflection (AR) technology to make cross-sectional measurements of changes due to aging in the oral and pharyngeal lumina of male and female speakers. The purpose of the study was to establish preliminary normative data for such changes and to obtain acoustic measurements of changes due to aging in the formant frequencies of selected spoken vowels and their long-term average spectra (LTAS) analysis. Thirty-eight young men and women and 38 elderly men and women were involved in the study. The oral and pharyngeal lumina of the participants were measured with AR technology, and their formant frequencies were analyzed using the Kay Elemetrics Computerized Speech Lab. The findings have delineated specific and similar patterns of aging changes in human vocal tract configurations in speakers of both genders. Namely, the oral cavity length and volume of elderly speakers increased significantly compared to their young cohorts. The total vocal tract volume of elderly speakers also showed a significant increment, whereas the total vocal tract length of elderly speakers did not differ significantly from their young cohorts. Elderly speakers of both genders also showed similar patterns of acoustic changes of speech production, that is, consistent lowering of formant frequencies (especially F1) across selected vowel productions. Although new research models are still needed to succinctly account for the speech acoustic changes of the elderly, especially for their specific patterns of human vocal tract dimensional changes, this study has innovatively applied the noninvasive and cost-effective AR technology to monitor age-related human oral and pharyngeal lumina changes that have direct consequences for speech production.  相似文献   
97.
目的 用高效液相色谱法(HPLC法)测定去氧氟尿苷的含量及其有关物质。方法 采用Diamonsil C—粒(250mm×4.6mm,5μm),流动相为乙腈-水(1:1),检测波长为269nm,流速为0.8mL/min。结果 去氧氟尿苷质量浓度在10.0~200.4μg/mL范围内与峰面积线性关系良好,r:0.9999(n:5),平均回收率为100.2%,RSD=0.14%。结论 HPLC法简便、准确,专属性好,灵敏度高,可用于去氧氟尿苷含量及有关物质的测定。  相似文献   
98.
Objective:To evaluate the feasibility and safety of prenatal diagnosis by traneabdominal chorionic villus sam-pling(TA-CVS)via the guidance of B-mode ultrasound in the first trimester of gestation.To explore the technique of long time culture and chromosome preparation of villi in early pregnancy.To evaluate the feasibility of the above techniques in the application of the prenatal cytogenetic diagnosis.Methods:One hundred and thirty-five singleton pregnancies at risk were referred from January 2001 to Decem-ber 2007.Results:The average maternal age was 35.2 years.TA-CVS was performed in the 10~13th weeks of gestation and the average gestational age was 10.89 weeks.All attempts at sampling were successful.The rate of operation-associated fetal loss was 0.74%.The failure rate of prenatal diagnosis because of inadequate amount of specimen was 0.The average culture time was 5-7 days.The success rate of the cell culture was 98.5%.No maternal con-temination and bacterial contamination happened.Fifteen cases of abnormal karyotype and one case of confined pla-cantel mosaiciem were diagnosed.Conclusion:TA-CVS appears to be safe and feasible and might to be offered in the prenatal diagnosis in the first trimester of gestation.The technique of long time culture and chromosome preparation of villi is stable and reliable.It is feasible to apply these techniques in the clinical practice of prenatal cytogenetic diagnose in the early pregnancy.  相似文献   
99.
血管内机械取栓是治疗大血管闭塞性急性缺血性卒中的有效治疗方法。应结合病史、发
病形式及影像学检查等综合判断病变性质;依据病变性质并参考手术路径,个性化选择支架取栓、
抽吸取栓、球囊/支架血管成形术、动脉溶栓任一种或多种方法联合取栓;并依据手术方式选择手
术材料,以快速高效地完成手术。  相似文献   
100.
Objective To observe the effect of pulmonary circulation by 6% hydroxyethyl starch 130/0.4 during induction period from epidural block combined with general anesthesia. Methods Twenty-six hepatobiliary surgical patients with ASA Ⅰ-Ⅱ, aged 32 y-59 y, weighing 54 kg-73 kg, were randomized into 2 groups(n=13): hydroxyethyl starch 130/0.4 group(HS)and complex acetic acid Ringer's solution (RL). Above-mentioned solutions were infused 7 ml/kg respectively before induction. The pulmonary circulation hemodynamic parameters such as pulmonary arterial systolic pressure (PASP), pulmonary arterial diastolic pressure (PADP), mean pulmonary artery pressure(MPAP), pulmonary artery wedge pressure(PAWP), pulmonary vascular resistance(PVR) and right ventricular stroke work(RVSW) were recorded at base value(T0), 10 min after infusion(T1), 5 min after induction(T2), 5 rain after intubation(T3), 10 rain after intubation(T4)and 20 min after intubation(T5). Results PASP、PADP、MPAP、PAWP and CVP were significantly higher in group HS at T, than the values at T0 (P<0.05); PVR in group HS was obviously lower from T1 to T5 than the value at To (P<0.05 or P<0.01); RVSW was significantly higher in two groups at T1 than base value (P<0.05), but that in group HS was lower than base value (P<0.05 or P<0.01); HR obviously decreased in two groups from T2 to T5 as compared with the value at T0 (P<0.05); MAP was lower from T3 to T5 than the value at To (P<0.05 or P<0.01). PVR was obviously lower in group HS from T1 to T5 than that in group RL (P<0.05 or P<0.01); MAP obviously increased from T2 to T5 in group HS as compared with the value in group RL(P<0.05 or P<0.01). Conclusion 6% hydroxyethyl starch 130/0.4 can obviously reduce PVR during induction pe-riod from epidural block combined with general anesthesia. In all, there is no effect on pulmonary circulation by 6% hydroxyethyl starch 130/0.4.  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