全文获取类型
收费全文 | 16466篇 |
免费 | 1287篇 |
国内免费 | 404篇 |
专业分类
耳鼻咽喉 | 27篇 |
儿科学 | 180篇 |
妇产科学 | 130篇 |
基础医学 | 1052篇 |
口腔科学 | 702篇 |
临床医学 | 1633篇 |
内科学 | 1590篇 |
皮肤病学 | 514篇 |
神经病学 | 793篇 |
特种医学 | 766篇 |
外科学 | 1038篇 |
综合类 | 2045篇 |
一般理论 | 1篇 |
预防医学 | 3911篇 |
眼科学 | 114篇 |
药学 | 2066篇 |
9篇 | |
中国医学 | 1353篇 |
肿瘤学 | 233篇 |
出版年
2024年 | 24篇 |
2023年 | 178篇 |
2022年 | 308篇 |
2021年 | 658篇 |
2020年 | 550篇 |
2019年 | 514篇 |
2018年 | 450篇 |
2017年 | 508篇 |
2016年 | 581篇 |
2015年 | 567篇 |
2014年 | 1029篇 |
2013年 | 1222篇 |
2012年 | 1095篇 |
2011年 | 1382篇 |
2010年 | 967篇 |
2009年 | 803篇 |
2008年 | 798篇 |
2007年 | 814篇 |
2006年 | 682篇 |
2005年 | 593篇 |
2004年 | 518篇 |
2003年 | 469篇 |
2002年 | 397篇 |
2001年 | 373篇 |
2000年 | 290篇 |
1999年 | 224篇 |
1998年 | 217篇 |
1997年 | 203篇 |
1996年 | 183篇 |
1995年 | 151篇 |
1994年 | 167篇 |
1993年 | 127篇 |
1992年 | 123篇 |
1991年 | 108篇 |
1990年 | 84篇 |
1989年 | 95篇 |
1988年 | 77篇 |
1987年 | 85篇 |
1986年 | 56篇 |
1985年 | 94篇 |
1984年 | 68篇 |
1983年 | 60篇 |
1982年 | 58篇 |
1981年 | 44篇 |
1980年 | 29篇 |
1979年 | 37篇 |
1978年 | 20篇 |
1977年 | 24篇 |
1976年 | 14篇 |
1973年 | 10篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
接触镜与泪液形态关系的临床评价 总被引:1,自引:0,他引:1
目的 :观察配戴不同种类接触镜后眼表面泪膜的形态、稳定性及泪液量的变化。方法 :对日戴SCL、RGPCL和Ortho KCL的 2 14名近视患者 4 2 8只眼 ,利用表面泪膜观察装置 (DR 1)观察戴镜前后眼表泪液膜和戴镜状态下镜上泪液膜的形态分级 ,同时测定泪膜破裂时间 (BUT)。利用酚红染色棉丝测定SCL戴镜前后的泪液量 ,并用折射仪 (AtagoCL 1)测量SCL含水量的变化。结果 :SCL配戴者随戴镜时间延长 ,BUT明显缩短 (P <0 .0 1) ,RGPCL和Ortho KCL配戴者戴镜 5年以内 ,BUT无明显变化 (P >0 .0 5 )。戴镜后RGPCL ,Ortho KCL和非戴镜正常眼三组间眼表泪膜分级比例差异无显著性 ,SCL组Ⅰ级比例为 6 .5 % ,显著低于其他组(16 .1%~ 2 3.0 % )。镜上泪膜 ,SCL、RGPCL和Ortho KCL三组均以Ⅳ级为主 (分别占 5 4 .4 %、5 3.4 %和 5 1.5 % ) ,SCLⅠ级比例仅 1.9% ,显著低于另二组 (分别占 6 .2 %和 12 .4 % )。SCL配戴者随戴镜时间延长 ,泪液量轻度减少 ,SCL含水量在戴镜 1w后即显著降低。结论 :科学配戴接触镜对泪液膜质量无明显影响 ,但SCL长期使用可能对泪膜有一定干扰作用。 相似文献
32.
连续性静脉-静脉血液滤过联合机械通气治疗ARDS的临床观察 总被引:12,自引:5,他引:7
目的 观察连续性静脉 -静脉血液滤过 (CVVH)联合机械通气治疗ARDS患者的临床疗效。方法 选择入住ICU符合ARDS诊断标准的患者 4 0例 ,随机分为 2组 :A组 2 1例 ,采用常规治疗 +机械通气 ;B组 1 9例 ,采用常规治疗 +机械通气 +CVVH。分别观察 2组患者在使用呼吸机时间、氧合指数、吸入氧浓度、动脉血氧分压、PEEP水平、心率、血压及病死率等方面的差别。结果 A、B两组患者在病因、年龄、性别、APACHEⅡ评分及平均脏器功能障碍数等方面相似 ,B组患者加用CVVH后 ,各项指标经统计学处理显示 :病死率 ,B组与A组比较 ,差异有显著性意义 (P <0 0 5 ) :其他指标与A组比较 ,差异均有高度显著性意义 (P <0 0 1 )。结论 CVVH疗法可有效清除ARDS患者血管外肺水和各种应激激素、致炎介质 ,明显改善了ARDS患者肺部氧合功能及血流动力学指标 ,提高了抢救成功率 相似文献
33.
Hidero Minami Ryo Matsutani Atsushi Mizokami Mikio Namiki 《International journal of urology》2007,14(4):368-369
Abstract: A 19-year-old woman presented at our hospital with acute urinary retention in September 2005. She had experienced the same chief complaint twice previously. She had used non-steroidal anti-inflammatory drugs before acute urinary retention. The results of physical examinations were unremarkable, and her neurologic signs were not remarkable. The basic laboratory test values were all normal and a psychiatric assessment indicated that her symptoms were not psychogenic. Magnetic resonance imaging was carried out, but revealed only a slight bulging in the L3/L4/L5 disk. Water cystometry showed acontractile detrusor. We made a diagnosis of acute urinary retention as a result of non-steroidal anti-inflammatory drugs because of her use of such drugs before the development of symptoms on multiple occasions. This patient was regularly followed up as an outpatient, and she could void smoothly in February 2006. This is the first report which acute urinary retention associated with non-steroidal anti-inflammatory drugs in Japan. 相似文献
34.
Elemental composition and water content of myelinated axons and glial cells in rat central nervous system 总被引:1,自引:0,他引:1
The distribution of elements (e.g. Na, Cl, K) and water in CNS cells is unknown. Therefore, electron probe X-ray microanalysis (EPMA) was used to measure water content and concentrations (mmol/kg dry or wet weight) of Na, Mg, P, S, Cl, K and Ca in morphological compartments of myelinated axons and glial cells from rat optic nerve and cervical spinal cord white matter. Axons in both CNS regions exhibited similar water content ( 90%), and relatively high concentrations (wet and dry weight) of K with low Na and Ca levels. The K content of axons was related to diameter, i.e. small axons in spinal cord and optic nerve had significantly less (25–50%) K than larger diameter axons from the same CNS region. The elemental composition of spinal cord mitochondria was similar to corresponding axoplasm, whereas the water content (75%) of these organelles was substantially lower than that of axoplasm. In glial cell cytoplasm of both CNS areas, P and K (wet and dry weight) were the most abundant elements and water content was approximately 75%. CNS myelin had predominantly high P levels and the lowest water content (33–55%) of any compartment measured. The results of this study demonstrate that each morphological compartment of CNS axons and glia exhibits a characteristic elemental composition and water content which might be related to the structure and function of that neuronal region. 相似文献
35.
Alan T. Villavicencio MD Lloyd A. Hey MD Dhavalkumar Patel MD PhD Peter Bressler MD 《The Journal of allergy and clinical immunology》1997,100(6):853-854
J Allergy Clin Immunol 1997;100:853-4. 相似文献
36.
本文对我省56眼矿泉水的地理分布符合国家标准的情况及矿泉水水化学类型进行了统计分析,结果表明:56眼矿泉水基本遍布全省;其感官指标、污染物指标及微生物指标均符合国家标准;通过对限量指标分析,我省矿泉水属念锶或含偏硅酸或二者兼含;水化学分类以HCO3·Ca型居多,其次为HCO3-Ca·Na型。对影响卫生化学性能的决定因子进行相关分析表明:除Ca2+与Mg2+呈正相关外,K+与Na+及Sr与H2SiO3之间无相关性 相似文献
37.
本文于1993年4月调查了新疆拜城县重病区查尔齐农场中与中病区赛里木乡的饮水,土壤,粮食,学龄儿童头发中Zn,Cu,Mn,Ca,Li,Se6种元素无机元素的含量。结果表明,重病区小麦中Ca的含量显著高于中病区(P〈0.05),重病区饮水及小麦中Mn的含量显著低于中病区(P〈0.05)。这些结果揭示重病区查尔齐与中病区赛里木乡的病情相比较,除缺碘较为严重这一主要原因之外,高Ca,低Mn也可能与查尔齐 相似文献
38.
39.
Anxiolytic benzodiazepines have been shown to impair place learning in the Morris water maze. However, a clear-cut demonstration of a direct and specific effect on mnemonic processes has not yet been offered. In the present study, the effects of diazepam on place navigation in the Morris water maze were studied in rats. Three conditions were examined: learning, reversal learning and learning after familiarisation of animals with the maze. In view of the anxiolytic and sedative properties of diazepam, appropriate doses of the drug, i.e. those that produced an anxiolytic effect but no major motor impairment, were initially selected in the water-lick conflict and rotarod tests, respectively. Doses of 2.5 and 5 mg/kg PO increased punished drinking in the water-lick conflict test without significantly decreasing rotarod performance. These doses were then used to assess the effects of diazepam on spatial behaviour. Diazepam, at both doses, impaired place learning in behaviourally naive rats. Such an effect appeared to be transient: diazepam-treated rats eventually reached control performance. Moreover, analysis of the probe trial at the end of training revealed adoption of a spatial strategy to locate the submerged platform. Neither reversal learning nor learning after familiarisation was affected. These results do not replicate previous findings in the Morris water maze and provide some evidence that the diazepam-induced place learning deficit may be primarily anxiolytic in nature. 相似文献
40.