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   6746篇
  免费   314篇
  国内免费   114篇
耳鼻咽喉   60篇
儿科学   228篇
妇产科学   96篇
基础医学   1090篇
口腔科学   125篇
临床医学   1081篇
内科学   738篇
皮肤病学   38篇
神经病学   319篇
特种医学   248篇
外科学   996篇
综合类   788篇
预防医学   263篇
眼科学   305篇
药学   512篇
  3篇
中国医学   223篇
肿瘤学   61篇
  2023年   37篇
  2022年   85篇
  2021年   195篇
  2020年   134篇
  2019年   118篇
  2018年   138篇
  2017年   133篇
  2016年   156篇
  2015年   182篇
  2014年   377篇
  2013年   372篇
  2012年   313篇
  2011年   347篇
  2010年   304篇
  2009年   308篇
  2008年   294篇
  2007年   321篇
  2006年   287篇
  2005年   251篇
  2004年   232篇
  2003年   213篇
  2002年   186篇
  2001年   172篇
  2000年   157篇
  1999年   147篇
  1998年   137篇
  1997年   123篇
  1996年   150篇
  1995年   128篇
  1994年   140篇
  1993年   90篇
  1992年   92篇
  1991年   80篇
  1990年   64篇
  1989年   64篇
  1988年   70篇
  1987年   49篇
  1986年   63篇
  1985年   74篇
  1984年   52篇
  1983年   28篇
  1982年   39篇
  1981年   32篇
  1980年   44篇
  1979年   38篇
  1978年   21篇
  1977年   20篇
  1976年   32篇
  1975年   11篇
  1973年   23篇
排序方式: 共有7174条查询结果,搜索用时 86 毫秒
1.
刘俊  华自森  李诚诚  许静 《陕西中医》2020,(12):1759-1762
目的:探讨补阳还五汤重用伸筋草治疗脑梗死后痉挛型偏瘫的作用。方法:收集脑梗死后痉挛型偏瘫患者共88例,分为两组,对照组44例,西医治疗加康复训练和补阳还五汤治疗; 研究组44例,西医治疗加康复训练及补阳还五汤重用伸筋草治疗。比较治疗前后患者患侧上下肢肌张力、临床疗效、NIHSS、日常生活能力Barthel指数以及上下肢运动功能和不良反应发生率。结果:治疗后,两组患者患侧上下肢肌张力≤1级者占比均升高,且研究组中≤1级者占比均高于对照组,组间比较有统计学意义(P<0.05)。两组临床疗效等级分布和总有效率比较,差异有统计学意义(P<0.05)。治疗后两组患者NIHSS评分均降低,且研究组NIHSS评分低于对照组,治疗后两组患者Barthel指数和患侧上下肢FMA评分均升高,且研究组均高于对照组,组间比较有统计学意义(P<0.05)。两组不良反应发生率比较,差异无统计学意义(P>0.05)。结论:补阳还五汤重用伸筋草能够显著降低患者患侧上下肢肌张力,改善临床疗效和神经功能缺损,提高患者日常生活能力和患侧运动功能,且安全性良好。  相似文献   
2.
目的评价原位肝脏移植术(OLT)中持续输注多巴胺或多巴胺复合去甲肾上腺素对血液动力学、组织氧代谢和肾功能的影响。方法拟行OLT的患者30例,ASAⅢ或Ⅳ级,随机分为2组 (n=15)。A组:术中持续输注多巴胺,初始输注速率为1-3μg·kg-1·min-1;B组:术中持续输注多巴胺复合去甲肾上腺素,初始输注速率分别为1-3μg·kg-1·min-1和0.03μg·kg-1·min-1,多巴胺输注速率不超过5μg·kg-1·min-1;术中两组均调节输注速率维持MAP 60-80 mm Hg。分别于切皮前即刻、切肝期1 h、无肝期1 h、新肝期1h和术毕测定血液动力学、组织代谢和肾功能指标。结果两组HR、 MAP均维持较平稳。无肝期两组CVP、MPAP、PAWP、CO、CI、DO2、VO2降低(P<0.05);SVR和SVRI升高(P<0.05),但均在正常范围内。术中PVR、PVRI、pH及SvO2均较平稳。乳酸浓度增高并持续到术毕。两组术中Cr和BUN均在正常范围,B组总尿量高于A组(P相似文献   
3.
心肺转流时间对氧代谢的影响   总被引:1,自引:1,他引:0  
目的对心脏瓣膜手术病人麻醉与手术期间的氧代谢进行测定,探讨心肺转流(CPB)时间对其后氧代谢的影响。方法选择36例择期行心脏瓣膜手术病人,根据CPB时间,将病人分为S组(CPB≤150 min)和L组(CPB>150 min)。采用Swan-Ganz导管技术及反向Fick检测方法对麻醉手术期间的氧代谢进行测定。检测时点为麻醉前、CPB前、CPB停止10 min和60 min。结果麻醉前两组的pH、PaCO2、PaO2等血气参数维持在正常范围,但氧供(DO2)减少,氧摄取率(O2ER)增加。CPB前,两组病人DO2显著降低(P<0.05),S组的氧耗(VO2)显著降低(P<0.05)。CPB后10min到60 min期间,DO2、VO2显著增加(P<0.05),L组O2ER显著增加(P<0.05)。CPB后10 min和60 min,两组的pH、PaCO2及PaO2等虽与麻醉前比较有显著改变,但两组的变化是一致的。CPB后10 min两组的心指数(CI)较麻醉前和CPB前有极显著升高(P<0.01)。CPB后L组的VO2有增高趋势(P<0.05),O2ER明显大于S组。结论CPB对其后氧代谢有明显影响,随着CPB时间延长,CPB后氧代谢障碍更显著。  相似文献   
4.
Intraoperative and postoperative free flap monitoring by means of oxygen tension measurement was carried out in 11 patients. We used an invasive flexible microcatheter that allowed for measurement of oxygen tension in all types of free flaps. Two cases of the measured flaps were buried free flaps which do not allow monitoring by clinical assessment. All flaps monitored in this study survived. One case of displacement of the microcatheter occurred. In one patient, the tissue pO2 monitor successfully detected early vascular thrombosis with subsequent reoperation and salvage of the free flap.  相似文献   
5.
6.
Oxygen-sensitive F-19 magnetic resonance imaging of perfluorocarbon compounds requires that fluorocarbon T1 changes correlate with the local Po2 and not with the composition of the surrounding aqueous phase. The influence of various bioconstituents and paramagnetic ions within the aqueous phase on the F-19 fluorocarbon phase T1 for PFC emulsions was evaluated at 0.14 and 0.66 T. T1 was measured for FC-43, perflubron, and a fluorinated surfactant. Controlled variables introduced in the aqueous phase included annex solution constituents, blood, pH changes, and Gd-DTPA. For a constant Po2, the F-19 T1s were independent of the emulsion constituents, blood concentration, and pH. For FC-43 and perflubron, F-19 T1 was independent of the Gd-DTPA concentration, while the aqueous phase T1 decreased by more than an order of magnitude. XMO-10 (smallest emulsion particle size) showed a slight decrease in F-19 T1 with increasing Gd-DTPA concentration at 0.66 T.  相似文献   
7.
Heparin-induced Extracorporeal LDL-Precipitation (HELP) is an effective procedure for the elimination of both plasma LDL and fibrinogen. In 10 adult patients with severe type II hyperlipoproteinemia, a single HELP treatment of 3 1 plasma led to an acute decrease in the average plasma viscosity (PV) from 1.30 to 1.1 mPas. At the same time, an even more marked decrease in the mean erythrocyte aggregation rate from a pathological value of 7.9% to a value of 3.7% (normal range less than 5%) was observed. Long-term studies on five patients demonstrated a lasting improvement in these two haemorheological variables. The acute rheological changes were also accompanied by an improvement in polarographically determined muscle oxygen tension. Mean oxygen tension values measured in both the m.biceps brachii and the m.tibialis anterior in five patients before and after a single HELP treatment increased from 30 +/- 4 to 37 +/- 7 mmHg and from 27 +/- 2 to 31 +/- 3 mmHg respectively. These results may provide an explanation for the rapid improvement in patients' clinical symptoms such as angina pectoris and in stress electrocardiogram which have been observed during HELP therapy.  相似文献   
8.
The melt agglomeration process of lactose powder with hydrogenated cottonseed oil (HCO) as the hydrophobic meltable binder was investigated by studying the physicochemical properties of molten HCO modified by sucrose stearates S170, S770 and S1570. The size, size distribution, micromeritic and adhesion properties of agglomerates as well as surface tension, contact angle, viscosity and specific volume of molten HCO, with and without sucrose stearates, were examined. The viscosity, specific volume and surface tension of molten HCO were found to be modified to varying extents by sucrose stearates which are available in different HLB values and melt properties. The growth of melt agglomerates was promoted predominantly by an increase in viscosity, an increase in specific volume or a decrease in surface tension of the molten binding liquid. The agglomerate growth propensity was higher with an increase in inter-particulate binding strength, agglomerate surface wetness and extent of agglomerate consolidation which enhanced the liquid migration from agglomerate core to periphery leading to an increased surface plasticity for coalescence. The inclusion of high concentrations of completely meltable sucrose stearate S170 greatly induced the growth of agglomerates through increased specific volume and viscosity of the molten binding liquid. On the other hand, the inclusion of incompletely meltable sucrose stearates S770 and S1570 promoted the agglomeration mainly via the reduction in surface tension of the molten binding liquid with declining agglomerate growth propensity at high sucrose stearate concentrations. In addition to being an agglomeration modifier, sucrose stearate demonstrated anti-adherent property in melt agglomeration process. The properties of molten HCO and melt agglomerates were dependent on the type and concentration of sucrose stearate added.  相似文献   
9.
A recently introduced setup to measure the dynamic interfacial tension of expanding drops was used to compare the adsorption behaviour of a series of lipids at the electrified water∣dichloroethane interface. Phospholipids with saturated carbon chains of different length (DMPC, DPPC, DSPC, DAPC, DBPC), an unsaturated phospholipid (DOPC) and an ethanolamine (DSPE) were compared. It was found that the adsorption decreases with increasing chain length. Also, the increase of the flow rate reduces the degree of adsorption effectively. On the timescale of the experiments, the DSPE, DAPC and DBPC adsorption showed no potential dependence, whereas the adsorption of DOPC was stronger than that of the saturated lipids. Adsorption was modelled using the Langmuir adsorption isotherm; the potential dependence of adsorption is discussed.  相似文献   
10.
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