全文获取类型
收费全文 | 2034篇 |
免费 | 180篇 |
国内免费 | 67篇 |
专业分类
耳鼻咽喉 | 36篇 |
儿科学 | 96篇 |
妇产科学 | 13篇 |
基础医学 | 162篇 |
口腔科学 | 51篇 |
临床医学 | 251篇 |
内科学 | 232篇 |
皮肤病学 | 13篇 |
神经病学 | 36篇 |
特种医学 | 86篇 |
外科学 | 166篇 |
综合类 | 493篇 |
预防医学 | 247篇 |
眼科学 | 11篇 |
药学 | 162篇 |
2篇 | |
中国医学 | 125篇 |
肿瘤学 | 99篇 |
出版年
2023年 | 14篇 |
2022年 | 40篇 |
2021年 | 50篇 |
2020年 | 55篇 |
2019年 | 32篇 |
2018年 | 32篇 |
2017年 | 54篇 |
2016年 | 38篇 |
2015年 | 54篇 |
2014年 | 99篇 |
2013年 | 131篇 |
2012年 | 171篇 |
2011年 | 187篇 |
2010年 | 187篇 |
2009年 | 156篇 |
2008年 | 177篇 |
2007年 | 155篇 |
2006年 | 90篇 |
2005年 | 80篇 |
2004年 | 62篇 |
2003年 | 58篇 |
2002年 | 23篇 |
2001年 | 36篇 |
2000年 | 17篇 |
1999年 | 13篇 |
1997年 | 9篇 |
1996年 | 8篇 |
1995年 | 7篇 |
1994年 | 5篇 |
1992年 | 5篇 |
1990年 | 6篇 |
1989年 | 10篇 |
1988年 | 11篇 |
1987年 | 17篇 |
1986年 | 10篇 |
1985年 | 12篇 |
1984年 | 15篇 |
1983年 | 5篇 |
1982年 | 9篇 |
1981年 | 7篇 |
1980年 | 9篇 |
1979年 | 13篇 |
1977年 | 5篇 |
1974年 | 6篇 |
1965年 | 5篇 |
1958年 | 5篇 |
1957年 | 7篇 |
1956年 | 9篇 |
1955年 | 7篇 |
1954年 | 8篇 |
排序方式: 共有2281条查询结果,搜索用时 15 毫秒
1.
ROLF HULTCRANTZ BO ANGELIN KURT EINARSSON LEIF FRIMAN 《Journal of internal medicine》1987,221(5):503-507
ABSTRACT. Hultcrantz R, Angelin B, Einarsson K, Friman L (Departments of Internal Medicine and Roentgenology, Serafimer Hospital, and Department of Internal Medicine, Huddinge University Hospital, Karolinska Institute, Stockholm, Sweden). Spontaneous regression of Budd-Chiari syndrome (hepatic venous occlusion) in a young female. Acta Med Scand 1987; 221:503–7. A case of occlusion of the hepatic veins in an 18-year-old girl is presented. The onset was sudden with massive ascites and markedly impaired general condition. The diagnosis was based on liver biopsy and angiograms of the caval and hepatic veins as well as of the celiac artery. No predisposing factors could be found. The patient was treated conservatively with laparo-centesis and diuretics. Clear improvement was seen after two weeks, and after four weeks she had no ascites and could be discharged. All liver function tests were then normalized. After three months, all diuretics could be withdrawn, and in the following 11 years she has remained completely recovered. The case illustrates that also widespread thrombi of the hepatic veins may sometimes rapidly dissolve spontaneously, with apparent total reconstitution of hepatic function. This case is unusual since previously reported cases have had high mortality rates and, in surviving cases, operative procedures or large doses of diuretics have been required to control the ascites. 相似文献
2.
SUNG-GOO CHANG CHUL-SOO KIM SEUNG HYUN JEON YOUN-WHA KIM BO YOUL CHOI 《International journal of urology》2006,13(2):122-126
AIM: To evaluate the cause of elevated prostate-specific antigen (PSA) in patients with transrectal needle biopsy negative for prostate cancer. METHODS: Serum PSA concentration, prostate volume, and pathologic findings were examined in 223 patients with negative biopsy for prostate cancer. The degree of prostate inflammation was determined by the extent and degree of inflammation shown by biopsy specimens and is expressed as an inflammation score (range: 0-36). RESULTS: A significant correlation was found between PSA concentration and prostate total volume (P=0.0001). Prostate chronic inflammation showed no correlation with PSA concentration (P=0.485, F=0.488). After allocating patients to normal PSA (4 ng/mL) groups, we found that serum PSA concentrations in both groups were predominantly affected by prostate total volume. CONCLUSIONS: An increase in prostate volume appears to be the major contributor to a high serum PSA concentration in patients with negative biopsy for prostate cancer. However, in contrast to previous reports, there was no correlation between the degree of prostate chronic inflammation and serum PSA concentrations. 相似文献
3.
NATURE AND HEALING OF TIBIAL SHAFT FRACTURES IN ALCOHOL ABUSERS 总被引:3,自引:1,他引:2
NYQUIST FREDRIK; BERGLUND MATS; NILSSON BO E.; OBRANT KARL J. 《Alcohol and alcoholism (Oxford, Oxfordshire)》1997,32(1):91-95
Alcohol abuse is associated with an increased risk of osteopeniaand fractures. Previous histomorphometric studies on iliac crestbone have found decreased bone formation and increased boneresorption in alcohol abusers but it has not been establishedwhether alcohol abuse has any effect on the anatomical locationor the healing time of tibial shaft fractures. We studied, retrospectively,199 adult male patients hospitalized for isolated tibial shaftfracture in the city of Malmö, Sweden, between 1980 and1990. Forty-nine of the patients had earlier been registeredat the Department of Alcohol Diseases and were judged to beproblem drinkers. Abusers sustained their tibial shaft fracturesmore often by falling at ground level (P<0.0001) or froma higher level (P=0.009) and the fractures were more often obliquethan transverse (P=0.002) as compared with non-abusers. Healingtime was impaired in abusers who had sustained a transversefracture (P=0.035), but no difference was observed in healingtime in those with an oblique fracture. We found no differencebetween the abusers and the non-abusers regarding duration ofhospital stay, fracture location, amount of displacement, occurrenceof open fractures or the rate of complications. 相似文献
4.
The magnetic resonance (MR) images of six patients with thrombosis of a dural sinus were reviewed. The diagnosis had been verified by computed tomographic scans in three patients and arteriograms in two; in the sixth patient, only MR imaging was used to confirm the clinical syndrome. In all patients, high-intensity signal was seen from the thrombus within the affected dural sinus on all echoes. This persistent signal intensity allowed intravascular clot to be distinguished from normal causes of increased signal such as flow-related enhancement (entry phenomenon) and even-echo rephasing. MR imaging demonstrated the cause of the thrombosis in three patients: two were secondary to adjacent tumors, and one was secondary to unsuspected mastoiditis. Complications such as infarction were also demonstrated. Using MR imaging, one can easily and safely diagnose thrombosis of a dural sinus. MR should be the imaging method of choice in patients suspected of having thrombosis of a dural sinus. 相似文献
5.
目的:探讨糖尿病周围神经病(DPN)患者的临床特征与神经电生理变化。方法:分析97例DPN患者的临床特征,比较DPN组和对照组的神经传导速度(NCV)、远端潜伏期、远端波幅3个参数。结果:①临床特征以肢体麻木(59%)最多见、其次为疼痛(42%)。②患者组NCV、远端波幅值低于对照组,远端潜伏期比对照组延长;两组3个参数比较,除腓总神经远端波幅、尺神经感觉传导速度和正中、尺、腓肠神经远端潜伏期外,差异均有统计学意义(P<0.05)。结论:①DPN患者临床特征以肢体麻木和疼痛最多见;②检测NCV、远端潜伏期、远端波幅,能较早发现临床患者。 相似文献
6.
在156例先天性心血管畸形标本的观察和测量中,检出先天性三尖瓣畸形25例(16.02%),其中Ebstein's畸形6例,三尖瓣发育不良14例,三尖瓣缺如1例,三尖瓣瓣叶或/和腱索骑跨4例。用测量及比较解剖学的方法探求三尖瓣畸形与其功能的影响。结果显示:Ebstein's畸形和三尖瓣发育不良的心脏构筑都有明显的变化,而且两者存在一定的差异,同时明确了Ebstein's畸形的病理诊断标准和三尖瓣发育不良的分类。 相似文献
7.
NILS DAHLGREN BENGT NILSSON TAKEFUMI SAKABE BO K. SIESJ
《Acta physiologica (Oxford, England)》1981,111(4):475-485
The effect of the fatty acid cyclo-oxygenase inhibitor indomethacin on cerebral blood flow (CBF) and the metabolic rate for oxygen (CMRO2) was studied in paralyzed and artificially ventilated rats. In normocapnic animals, the drug (10 mg·kg-1i. v.) reduced CBF to 50% of control without a measurable effect on CMRO2. During hypercapnia (PaCO2 70–80 mmHg) the increase in CBF was reduced by about 80% but CMRO2 remained unchanged. Autoradiographic evaluation of local CBF in 20 brain structures indicated that the reduction in CBF was relatively uniform throughout the brain. Dose response curves showed that an effect on CBF was evident already at an indomethacin dose of 1 mg·kg-1 and maximal effects were obtained with 3–5 mg·kg-1. Following i. v. injection of the drug reduction in CBF was observed already after 10 s and the full response occurred after 1–2 min. It is concluded that metabolites of arachidonic acid, possibly mainly prostacyclin, are powerful modulators of normal cerebrovascular tone, and help to mediate the CBF response to increased CO2 tensions. However, since indomethacin does not modify the circulatory response in other conditions with increased CBF these substances do not qualify as general coupling factors controlling CBF in physiological or pathological states. 相似文献
8.
目的:鉴定并研究半夏AP2/ERF转录因子的功能,为推进半夏品种的遗传改良提供理论依据。方法:该文基于半夏三代转录组数据鉴定了半夏中AP2/ERF家族成员,并对其进行系统的生物信息学分析,同时利用实时荧光定量聚合酶链式反应(Real-time PCR)检测半夏AP2/ERF在不同组织及不同胁迫条件下的表达情况。结果:通过转录组数据共筛选出8个全长AP2/ERF转录因子家族成员,归为AP2、ERF和DREB 3个亚家族;半夏AP2/ERF的氨基酸数目为251~512个,等电点为5.29~11.72,不稳定指数为45.90~82.41,且主要定位于细胞核中;半夏AP2/ERF基因的结构域和Motifs相对保守。组织特异性表达模式分析显示,半夏AP2/ERF基因在不同组织部位中具有不同的表达模式,且主要在叶中表达。逆境胁迫应答分析表明,PtERF1主要响应NaCl的胁迫诱导;PtERF2和PtERF4在低温和聚乙二醇(PEG)胁迫下表达量均有较大幅度的上调;PtERF3同时响应低温和NaCl两种逆境的诱导;PtERF5同时响应高温、低温、NaCl、PEG胁迫诱导;PtERF7在高温胁迫下表达... 相似文献
9.
益气活血药对低氧性肺动脉高压大鼠神经肽Y、降钙素基因相关肽的影响 总被引:9,自引:0,他引:9
目的:探讨由黄芪、川芎组方的益气活血药对低氧性肺动脉高压大鼠神经肽Y(NPY)、 降钙素基因相关肽(CGRP)的影响。方法:采用常压低氧21天复制大鼠肺动脉高压模型,应用放射免疫技术测定大鼠血浆、肺组织中NPY、CGRP的含量变化。结果:益气活血药可降低肺动脉压,改善心功能及血液流变学。益气活血药中剂量组血浆及肺组织中NPY含量与缺氧组比较明显降低;而CGRP含量较缺氧组有所回升,肺组织中CGRP含量与缺氧组比较则趋于下降。结论:益气活血药可防止低氧性肺动脉高压的形成,也提示益气活血药的降压作用可能通过影响NPY、CGRP的含量来调节肺血管舒缩,从而降低肺动脉压。 相似文献
10.
目的 研究^131I治疗GD前后甲状腺激素动态变化规律及甲状腺功能变化的关系。方法:对33例GD患一次性给予^131I 13.5mci-7.0mic(平均4.8mic)治疗。于治疗后1、3、6、12mo定期复诊,化验TT3、TT4、FT3、FT4、TSH,并与治疗前及25例对照比较研究,以TT3、TT4、FT3、FT4,TSH的动态变化作为观察^131I治疗前后甲状腺功能变化的指标。结果:TT3、TT4、FT3FT4变化:治疗前及治疗后1mo最高,二相差无显性(P<0.05),治疗后3mo显性低于治疗前(P<0.05),但较对照组为高(P<0.05),治疗后6mo及12mo较治疗前显减低(P<0.01)但与寻照组相差无显性(P>0.05)。②TSH变化:治疗前及治疗后1月最低,二相差无显性(P>0.05)。治疗后3mo显高于治疗前及对照组(P<0.05),治疗后6mo及12mo明显高于治疗前及对照组(P<0.01)。③治疗后12mo治愈率为90.91%,总有效率为100%,治疗后3月及6mo共发生甲减5例,占15.15%。结论:^131I治疗GD安全有效,副作用小。动态检测甲状腺激素变化可以反映甲状腺功能恢复情况及有无并发症发生。 相似文献