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991.
目的利用卵巢切除大鼠建立骨质疏松骨折模型,研究低幅高频振动对骨质疏松性骨折愈合及患肢远端血供的作用。方法 32只6月龄雌性SD大鼠行卵巢切除术,3个月后构建右侧股骨干闭合性横行骨折合并股动脉损伤模型,术后随机平均分为振动组与对照组。每周摄股骨侧位X片以监测外骨痂尺寸及骨折愈合情况。第2、4、8周,应用脉冲多普勒超声测量患肢远端血流速度及阻力指数。Micro-CT扫描重建骨折部位,并作定性定量分析。结果超声检测发现,第2、4周振动组患肢股动脉远端收缩期峰值血流速度较对照组明显增高(P<0.05),阻力指数降低。X片及Micro-CT分析显示,振动组在愈合过程中,骨痂形成、矿化程度、重塑效果、桥接愈合率均显著优于对照组。结论低幅高频振动可有效改善患肢远端血供,促进骨质疏松性骨折愈合。 相似文献
992.
993.
目的 对于生物力学领域的研究者来说,计算仿真技术已成为一种不可或缺的工具。对于这种工具的性能,至关重要的一点在于其有效模拟个性化问题方面的能力。本文将阐述能将三维数字图像(由CT、超声机或MRI扫描仪生成的)直接转换生成高精度计算模型的一种独特的非常有效的方法。方法 采用的方法主要涉及:基于扫描的数据生成可输出到商业网格器中的表面模型-这种方法非常费时并且不是很精确,事实上对于复杂拓扑结构的影像数据这种方法很难处理:另外一种更加直接的方法是将几何模型的生成和网格划分一次性完成-这种方法先对感兴趣区域(三维图像分割)进行识别分割,然历直接生成基于一种由定义的边界分割的体素的体网格,这种方法被用来在整个体模型生成四面体和/或六面体单元,从而直接划分网格。结果 采用一种基于图像的网格方法来处理问题是非常先进的,也是非常精确有效的。这种基于图像自动生成的网格,其有限元单元模型区域边界正好在等值面上因此其考虑了局部体效应从而能保证局部体素的精确度。结论 对影像数据进行网格化是挑战也是机遇,这种与以往方法思想不一样的方法,在很多例子中,获得了更好的结果。这种能简易生成精确模型的方法,对于当前很多数值分析难以处理的问题诸如血液流体和病人个性化假体设计等提供了新的解决方案。 相似文献
994.
目的观察正常孕妇妊娠晚期和妊高征患者血小板参数的变化及临床意义。方法采用日本Sysmex KX-21型血液细胞分析仪分别对正常孕妇(118例)、妊高征患者(59例)及对照组(正常婚检妇女59例)的血液标本进行血小板(PLT)计数、平均血小板体积(MPV)、血小板分布宽度(PDW)的测定。结果妊高征组和正常孕妇组的MPV、PDW显著高于对照组(P〈0.01);妊高征组MPV、PDW明显高于正常孕妇组(P〈0.05);妊高征组的PLT显著低于对照组(P〈0.01)。结论妊高征患者由于血小板消耗和破坏增加,导致血小板减少,MPV、PDW明显增高,因此,检测血小板参数对预测妊高征的发生有一定的参考意义。 相似文献
995.
目的 对广州脐血库10年来保存的脐血人类白细胞抗原(human leukocyte antigen,HLA)等位基因及单倍型分布特征进行分析.方法 采用单克隆板,序列特异引物聚合酶链反应,PCR序列特异性寡核苷酸探针和DNA测序分型方法对广州脐血库内4194份脐带血进行HIA-A、B、DRB1等位基因分型.用Arlequm软件计算HLA基因频率和单倍型频率.结果 在广州脐血库中,HLA-A、B、DRB1等位基因型分别有18,43,13种.累积频率>50%的显著高频率等位基因是:A*11,A*02,A*24,A*33,B*40,B*15,B*46,B*13,DRB1*12,DRB1*15,DRB1*09,DRB1*04;最常见的单倍型为:A2-B46、B6-DR9、A11-DR12、A2-B6-DR9.结论 广州脐血库脐血捐献者HIA-A、B、DRB1等位基因型及单倍型分布具有典型南方人群的特点,此资料有助于为临床移植寻找合适匹配的供受对. 相似文献
996.
Changes in central artery blood pressure and wave reflection during a cold pressor test in young adults 总被引:1,自引:0,他引:1
The relative contribution of sympathetic nervous system (SNS)-induced increase in peripheral vascular resistance on central artery blood pressure (BP) and aortic wave reflection (augmentation index; AIx) is not completely understood. Central BP and wave reflection characteristics were measured using radial artery applanation tonometry before, during a 3-min cold pressor test (CPT), and 90 and 180-s post-CPT in 15 young, healthy adults (25 +/- 1 years). The CPT resulted in a greater magnitude of change in the estimated aortic systolic (31 vs. 23%, P < 0.05) and pulse (31 vs. 13%, P < 0.05) BP compared with the change in brachial artery BP. Additionally, the CPT resulted in an increased mean arterial pressure (MAP) (P < 0.05) and AIx (10 +/- 2 vs. 26 +/- 2%, P < 0.05). The change in MAP during the CPT was correlated to the change in AIx (r = 0.73, P < 0.01) and inversely related to roundtrip duration of the reflected wave to the periphery and back (r = -0.57, P < 0.05). The present study suggests that cold pressor testing results in a significant increase in arterial wave reflection intensity, possibly due to an increased MAP. However, the greater increase in systolic and pulse BP in the central compared with the peripheral circulation suggests that increased central artery wave reflection intensity contributes to increased left ventricular myocardial oxygen demand during CPT-induced hypertension. 相似文献
997.
Mühlbacher A Weber B Bürgisser P Eiras A Cabrera J Louisirirotchanakul S Tiller FW Kim HS v Helden J Bossi V Echevarria JM 《Medical microbiology and immunology》2008,197(1):55-64
In a multicenter study a new, fully automated Roche Diagnostics Elecsys HBsAg II screening assay with improved sensitivity to HBsAg mutant detection was compared to well-established HBsAg tests: AxSYM HBsAg V2 (Abbott), Architect HBsAg (Abbott), Advia Centaur HBsAg (Bayer) Enzygnost HBsAg 5.0 (Dade-Behring), and Vitros Eci HBsAg (Ortho). A total of 16 seroconversion panels, samples of 60 HBsAg native mutants, and 31 HBsAg recombinant mutants, dilution series of NIBSC and PEI standards, 156 HBV positive samples comprising genotypes A to G, 686 preselected HBsAg positive samples from different stages of infection, 3,593 samples from daily routine, and 6,360 unselected blood donations were tested to evaluate the analytical and clinical sensitivity, the detection of mutants, and the specificity of the new assay. Elecsys HBsAg II showed a statistically significant better sensitivity in seroconversion panels to the compared tests. Fifty-seven out of 60 native mutants and all recombinant mutants were found positive. Among 156 HBV samples with different genotypes and 696 preselected HBsAg positive samples Elecsys HBsAg II achieved a sensitivity of 100%. The lower detection limit for NIBSC standard was calculated to be 0.025 IU/ml and for the PEI standards ad and ay it was <0.001 and <0.005 U/ml, respectively. Within 2,724 daily routine specimens and 6.360 unselected blood donations Elecsys HBsAg II showed a specificity of 99.97 and 99.88%, respectively. In conclusion the new Elecsys HBsAg II shows a high sensitivity for the detection of all stages of HBV infection and HBsAg mutants paired together with a high specificity in blood donors, daily routine samples, and potentially interfering sera. 相似文献
998.
High dietary sodium intake is a risk factor for hypertension, and heart rate variability (HRV) is decreased in hypertension. Effects of dietary sodium intake on HRV of normotensive persons have not, however, been investigated to date. The present study examined effects of low and high sodium diets on blood pressure, heart rate, and HRV in 36 healthy, normotensive women, ages 40-70. Each was placed on a low sodium diet for 6 days followed by a high sodium diet for 6 days. The high salt diet increased mean systolic blood pressure, decreased heart rate, and increased high frequency HRV (HF). Cardiac vagal tone, estimated at baseline from heart period and a time domain estimate of respiratory sinus arrhythmia, was higher in salt-sensitive than salt-insensitive subjects. The finding of increased vagal tone in normotensive persons on high salt intake indicates that dietary sodium status should be considered in behavioral studies of HRV. 相似文献
999.
Guidetti L Emerenziani GP Gallotta MC Da Silva SG Baldari C 《European journal of applied physiology》2008,103(3):315-321
This study evaluated energy cost and energy sources of a ballet exercise (grand adage) in young female dancers with different technical ability, and then related the energy sources to the subject’s
and anaerobic threshold (IAT). Twenty-five dancers (13–16 years) were divided into two different technical ability groups:
low-level (n = 13) and high-level (n = 12). The overall energy requirement of dance exercise (VO2eq) was obtained by adding the amount of VO2 during exercise above resting (aerobic source or VO2ex) to the VO2 up to the fast component of recovery (anaerobic alactic source or VO2al) and to the energy equivalent of peak blood lactate accumulation (anaerobic lactic source or ) of recovery. VO2eq of exercise amounted to 81 ± 10 and 94 ± 9 ml kg−1 in low-level and high-level groups, respectively. VO2ex represented the higher fraction (65 ± 4% and 77 ± 5%) in low-level and high-level groups, respectively, of VO2eq in both the groups. In the low-level group the remaining fractions were: 23 ± 2 % for VO2al and 12 ± 1% for . In high-level group the remaining fractions were: 18 ± 2 % for VO2al and 4 ± 1% for . Between two groups, significant differences were found in VO2ex (P < 0.01), (P < 0.01), and VO2al (P < 0.05). IAT was 55 and 60% of for low-level and high-level dancers, respectively. Low-level dancers performed more exercise above IAT than high-level.
For these reasons, it should be better to define exercise intensity according to the IAT parameter and not only to 相似文献
1000.
利用重组的丙型肝炎病毒非结构区(HCVNS5)抗原建立了酶免疫试验(EIA),对25例输血后丙型肝炎进行了不同区抗体及丙氨酸转氨酶(ALT)的动态研究,同时对156例慢性丙型肝炎患者血清进行HCVRNA和抗-NS5平行检测,两者符合率为64.1%。抗-NS5抗体首次检出时间为30~575天(182.9±168.5),晚于ALT异常和其他区抗体的出现时间。在感染后1,3,6,12和24个月后抗-NS5的阳性率分别为28%,40%,52%,68%和76%。抗-NS5的动态变化类型为四种:一过性阳性、间歇性阳性、持续性阳性和2年内持续阴性 相似文献