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   87476篇
  免费   8193篇
  国内免费   2433篇
耳鼻咽喉   666篇
儿科学   2252篇
妇产科学   659篇
基础医学   4974篇
口腔科学   542篇
临床医学   14596篇
内科学   21929篇
皮肤病学   519篇
神经病学   4740篇
特种医学   3082篇
外国民族医学   2篇
外科学   8743篇
综合类   15188篇
现状与发展   4篇
一般理论   1篇
预防医学   5153篇
眼科学   965篇
药学   7715篇
  111篇
中国医学   4825篇
肿瘤学   1436篇
  2024年   264篇
  2023年   1514篇
  2022年   2818篇
  2021年   4322篇
  2020年   4201篇
  2019年   3597篇
  2018年   3307篇
  2017年   3367篇
  2016年   3279篇
  2015年   3067篇
  2014年   6020篇
  2013年   5810篇
  2012年   4651篇
  2011年   4976篇
  2010年   4166篇
  2009年   3846篇
  2008年   4055篇
  2007年   4268篇
  2006年   3748篇
  2005年   3291篇
  2004年   2654篇
  2003年   2351篇
  2002年   2024篇
  2001年   1937篇
  2000年   1576篇
  1999年   1435篇
  1998年   1218篇
  1997年   1180篇
  1996年   993篇
  1995年   981篇
  1994年   894篇
  1993年   712篇
  1992年   754篇
  1991年   630篇
  1990年   540篇
  1989年   448篇
  1988年   435篇
  1987年   411篇
  1986年   349篇
  1985年   351篇
  1984年   351篇
  1983年   228篇
  1982年   249篇
  1981年   167篇
  1980年   135篇
  1979年   136篇
  1978年   127篇
  1977年   59篇
  1976年   68篇
  1975年   46篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
131.
海脉冲营养素对小鼠造血功能的影响   总被引:3,自引:3,他引:0  
通过与复方阿胶浆,施普端螺旋藻胶囊抗贫血功效的比较,研究了海脉冲营养素对小鼠造血功能的影响。结果表明,小鼠口服HMC500mg/(kg.d),对失血性贫血小鼠有提高,RBC的作用,对苯肼引起的溶血性贫血小鼠有升高Hb,RBC,WBC的作用,能促进由环磷酰胺所致骨髓抑制小鼠的骨髓有核细胞的增殖,增加脾脏重量,升高外周血中网织红细胞和WBC数量。  相似文献   
132.
棕榈油对成人血脂和血小板功能的影响   总被引:3,自引:0,他引:3  
张坚  王春荣 《营养学报》1997,19(2):186-190
报道了棕榈油(PA),花生油(PE)对血清总胆固醇水平(TC)在5.5~7.0mmol/L的受试者血脂和血小板功能的影响。51名受试者(男31人,女20人,年龄30~66岁之间)分为两组,一组男15人,女11人,称PE组;另一组男16人女9人,称PA组,预备期3周,膳食以当地日常食用的花生油烹调,实验期6周。PA组受试者食用以棕榈油烹调的实验膳;PE组受试者仍食花生油烹调的膳食。脂肪约占膳食能量的30%,其中60%~65%来自实验油。实验结果表明:与起始值相比,6周末PA组受试者血清TC,低密度脂蛋白胆固醇(LDL-C)和总胆固醇与高密度脂蛋白胆固醇比值(TC/HDL-C)显著下降,血浆血栓素B2(TXB2)/6-酮前列环素F1α、(6-keto-PGF1α)比值显著下降,全血血小板聚集率未见显著变化。PE组受试者的血脂、血浆TXB2、6-keto-PGF1α及全血血小板聚集率等指标均未出现显著变化。提示,棕榈油作为我国居民家庭烹调用油并不会增加发生心血管疾病的危险。  相似文献   
133.
AClinicalStudyofReversingLeftVentricularHypertrophyinHypertensivePatientsbyAdalatZhangFumin(张馥敏)XuDi(许迪)YongYonghong(雍永宏)Chen...  相似文献   
134.
李惠兰  缪鸿石 《中国康复》1993,8(3):122-124
观察了10项因素对偏瘫病人下肢功能康复的影响,其结果表明:①下肢功能水平;②平衡功能障碍;③足下垂内翻;④髋关节屈曲外旋挛缩;⑤深感觉障碍;⑥疼痛等几项因素对偏瘫病人下肢功能康复有显著的影响。  相似文献   
135.
本研究对30例三尖瓣返流患者同步进行了多普勒超声心动图和右心导管检查,应用计算机软件程序对三尖瓣返流频谱曲线进行微分处理。结果表明,两种技术测量的右室压力最大上升速率、右室心肌最大生理缩短速度、右室压力最大下降速率以及右室心肌松驰时间常数均高度相关(r分别为0.93,0.86,0.94,0.95),表明三尖瓣返流压差法能够无创性估测右室收缩和舒张功能,应用计算机软件程序能够使测量方法简便、准确。  相似文献   
136.
本研究观察国产雌二醇周效贴片(E2贴片)治疗因卵巢功能低落所致的主要临床表现的疗效,结合血FSH、LH、E2测定,阴道脱落细胞成熟指数和部分病例的子宫内膜活检,对E2贴片的疗效进行了综合评价。结果显示,雌二醇周效贴片对卵巢功能低落所致的潮热、出汗、失眠、情绪波动,眩晕和阴道干涩等有显著疗效,且疗效随用药时间的延长而递增,在用药140天时总有效率分别达98.9%,92.0%、91.4%、90.0%和78.0%,对LH、FSH的释放有抑制作用;血清E2水平属轻度升高,但趋于平稳;部分病例子宫内膜组织学检查未见雌激素作用所致的内膜增殖效应。用药期间部分病例出现周期性阴道出血,这对年轻卵巢功能早哀者在生理和心理上均有治疗意义,但对更年期患者会造成不便和不安感。约20%的病例贴片局部有轻微痒感,无其它不良反应。  相似文献   
137.
Professional exposure to vegetable dusts affect the respiratory function of the exposed subjects. A previous survey conducted in an industrial flour-mill demonstrated a higher frequency of respiratory symptoms in workers compared to a control group. Ten subjects employed in a work site particularly exposed to dust were studied. Each subject answered a questionnaire and performed on Mondays and Fridays, at the begenning and end of his work shift, a flow volume curve and an isocapnic hyperventilation test. The aerobiology of the professional environment was also measured. We noted: 1) in the flow volume curves: a drop in the FEV1 during the Monday morning shift, a significant difference between the FEV1 (p<0.05) and the MMEFR 25–75 (p<0.05) measured at 6 am on Monday and Friday, and between the MMEFR 25–75 values obtained at 12 noon on Monday and Friday (p<0.05). 2) after isocapnic hyperventilation, a significant drop in the MMEFR 25–75 at 6 am on Monday (p<0.01) and in the FEV1 and MMEFR 25–75 at 12 noon on Mondays (p<0.05), a significant drop in the FEV1 at 1 pm on Monday (p<0.01).  相似文献   
138.
OBJECTIVE: This study aimed to investigate the rate of occupational sensitization to horse hair in grooms and whether occupational exposure to horse hair increases respiratory and allergic symptoms and affects lung function in grooms or not. METHODS: This is a cross-sectional study. Two hundred grooms were randomly selected among 1000 grooms working in Veliefendi Hippodrome of Istanbul. One hundred and twenty-five subjects agreed to enter the study. Ninety-two workers who worked in the different parts of this hippodrome enrolled as the control group. A detailed questionnaire including respiratory and allergic symptoms was filled in, physical examination, skin prick tests and pulmonary function tests were performed. RESULTS: Sensitization to horse hair was 12.8% in grooms and 4.3% in controls. The difference was statistically significant (P = 0.0035). Asthma was found in 14.4% of the grooms and 5.4% of the controls, allergic rhinitis in 42.4% of the grooms and 18.4% of the controls, allergic conjunctivitis in 35.2% of the grooms and 15.2% of the controls, and allergic skin diseases in 32.8% of the grooms and 13% of the controls. The differences were statistically significant (P = 0.043, P = 0.0002, P = 0.001 and P = 0.0008, respectively). The means of FEV1, FEV1/FVC and FVC parameters were significantly lower in the groom group (P = 0.006, P = 0.001 and P = 0.003, respectively). In the multivariate analysis, being in the groom group and working years were found to be predictive factors for impairments of lung function (P < 0.001 and P = 0.002, respectively). CONCLUSION: Occupational exposure to horse increases the sensitization to horse hair, induces asthma and allergic symptoms and also impairs lung functions.  相似文献   
139.
BACKGROUND: Levels of an immunoregulatory and anti-inflammatory cytokine IL-10 are reduced in asthmatic airways, potentially contributing to more intense inflammation. Triamcinolone has anti-inflammatory properties and the anti-inflammatory effects of montelukast and formoterol have been discussed. OBJECTIVE: The purpose of this study was to define the effect of treatment with triamcinolone, montelukast and formoterol on the serum level of IL-10, eosinophil blood counts, eosinophil cationic response (ECP) and clinical parameters (symptom score, FEV1 and PC20H) in children with moderate asthma. METHODS: An 8-week, placebo-controlled and randomized, double-blind trial was carried out. The subjects were 91 children with moderate atopic asthma who were allergic to dust mite. Patients were randomly allocated to receive 400 microg triamcinolone (n = 19), 5 or 10 mg (according to age) montelukast (n = 18), 24 microg formoterol (n = 18) or placebo (n = 36). RESULTS: Seventy-nine children completed the study. After treatment with triamcinolone and montelukast the level of IL-10 in blood serum significantly increased, eosinophil blood counts and ECP levels significantly decreased and all clinical parameters improved; treatment with formoterol had no effect on IL-10 level, eosinophil blood counts in serum and bronchial hyper-reactivity; ECP level significantly decreased after treatment and asthma symptoms and FEV1 improved significantly. Mean IL-10 levels in serum before and after treatment with triamcinolone were 7.23 pg/mL with 95% CI, 6.74 -7.72% and 14.24 pg/mL with 95% CI, 11.6-16.88%, respectively (P < 0.001); with montelukast they were 6.59 pg/mL with 95% CI, 6.26-7.23% and 10.94 pg/mL with 95% CI, 8.24-12.65%, respectively (P < 0.002); with formoterol they were 7.06 pg/mL with 95% CI, 6.61-7.52% and 7.04 pg/mL with 95% CI, 6.15-7.93%. We found statistically significant correlations between serum level of IL-10 and serum level of ECP after treatment with triamcinolone and montelukast. CONCLUSION: This study demonstrates that one possible way by which triamcinolone and montelukast contribute to inhibition of inflammation is by increasing IL-10 levels.  相似文献   
140.
Summary The effects of sodium salts of various bile acids on the contractile force and the electrophysiological properties of rat ventricular muscle were studied in vitro. Primary, conjugated, and secondary bile acids were studied in a concentration range of 10–9–10–6 mol/l, which corresponds to concentrations found in the plasm of patients with cholestatic jaundice. In general, the bile acid induced a negative inotropic effect which was manifested as a reduction in active tension, maximum rate of tension activation, and maximum rate of tension relaxation. Twitch duration and time to peak tension were unaffected by the bile acids. The negative inotropism was associated with a reduction in ventricular action potential duration. Resting potential, action potential amplitude, and maximum upstroke velocity of phase 0 depolarization were unaffected. Voltage clamp experiments in rat ventricular myocytes demonstrated that sodium taurocholate decreased the slow inward current and slightly increased the outward potassium current. Hence, these effects on the membrane currents are probably responsible for the negative inotropic effect. Send offprint requests to O. Binah at the above address  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