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   5877篇
  免费   293篇
  国内免费   49篇
耳鼻咽喉   41篇
儿科学   208篇
妇产科学   184篇
基础医学   867篇
口腔科学   125篇
临床医学   419篇
内科学   1228篇
皮肤病学   108篇
神经病学   466篇
特种医学   168篇
外国民族医学   1篇
外科学   703篇
综合类   165篇
预防医学   588篇
眼科学   39篇
药学   461篇
中国医学   42篇
肿瘤学   406篇
  2023年   31篇
  2022年   45篇
  2021年   88篇
  2020年   68篇
  2019年   94篇
  2018年   107篇
  2017年   77篇
  2016年   99篇
  2015年   134篇
  2014年   142篇
  2013年   180篇
  2012年   251篇
  2011年   273篇
  2010年   153篇
  2009年   138篇
  2008年   222篇
  2007年   266篇
  2006年   287篇
  2005年   258篇
  2004年   269篇
  2003年   291篇
  2002年   254篇
  2001年   235篇
  2000年   201篇
  1999年   175篇
  1998年   66篇
  1997年   49篇
  1996年   51篇
  1995年   54篇
  1994年   55篇
  1993年   40篇
  1992年   128篇
  1991年   87篇
  1990年   130篇
  1989年   141篇
  1988年   107篇
  1987年   103篇
  1986年   91篇
  1985年   96篇
  1984年   76篇
  1983年   42篇
  1982年   33篇
  1981年   31篇
  1980年   31篇
  1979年   60篇
  1978年   33篇
  1977年   38篇
  1976年   34篇
  1975年   31篇
  1972年   34篇
排序方式: 共有6219条查询结果,搜索用时 15 毫秒
111.
The aim of the present open prospective study is to evaluate the efficacy and safety profile of fosfomycin trometamol in the chemoprophylaxis of urinary tract infections following transurethral diagnostic and/or therapeutic manuvres. 712 patients were enrolled in 72 urological surgical centres. All the enrolled patients received an initial dose of fosfomycin trometamol (Monuril® sachet containing 3 g of active drug in powder) 3 h before and a second dose 24 h after the transurethral manuvres. Clinical and microbiological examinations were carried out before the intervention, and then on the second and seventh days after the manuvres. 94 patients with positive baseline tests were excluded from the microbiological follow-up for noncompliance with the main inclusion criteria. Out of 618 patients with sterile urine or with bacteriuria <>5 ml on baseline screening, 20 (3.2%) developed UTI on the second day and 22 (3.6%) on the seventh day after treatment. Clinical follow-up is in agreement with these microbiological data. Overall, a total of 24 side effects were observed (3.3%), 16 of which were associated with Monuril® treatment. The results of this open study agree with the preliminary observations in the controlled studies.In der vorliegenden Studie wurde die Wirksamkeit und Sicherheit von Fosfomycin Trometamol in der Chemoprophylaxe bei diagnostischen und therapeutischen transurethralen Eingriffen geprüft. In 72 urologischen Zentren wurden 712 Patienten in die Studie aufgenommen. Alle Patienten erhielten drei Stunden vor dem Eingriff eine initiale Einzeldosis von 3 g Fosfomycin Trometamol (Monuril® Beutel mit 3 g Wirkstoff in Pulverform). Nach 24 Stunden wurde eine zweite Dosis verabreicht. Vor dem Eingriff sowie am zweiten und siebten Tag nach dem Eingriff wurden die Patienten klinisch untersucht und mikrobiologische Tests durchgeführt. Wegen Verletzung der Einschlußkriterien wurden 94 Patienten mit positiven Befunden zu Studienbeginn aus der mikrobiologischen Verlaufsbeurteilung ausgeschlossen. 20 der 618 Patienten, die vor dem Eingriff einen sterilen Urin oder eine Bakteriurie mit weniger als 105 Keimen/ml hatten, wiesen am zweiten Tag eine Harnwegsinfektion auf (3,2%); am siebten Tag nach dem Eingriff waren 22 (3,6%) der Patienten an einer Harnwegsinfektion erkrankt. Diese mikrobiologischen Daten stimmen mit den klinischen Befunden bei den Verlaufskontrollen überein. Insgesamt traten in 24 Fällen unerwünschte Wirkungen auf (3,3%), davon wurden 16 mit Monuril® in Zusammenhang gebracht. Die Ergebnisse dieser offenen Studie stimmen mit vorläufigen Ergebnissen kontrollierter Studien überein.  相似文献   
112.
70 patients suffering from multiple myeloma were observed by authors in the last 15 years and three months. In the meantime fifty-two out of them have died, and 18 patients are under permanent care. 43 IgG, 17 IgA, 6 Bence-Jones, 2 IgD types were diagnosed according to the paraprotein distribution, one patient proved to be nonsecretory, and an other one to osteosclerotic form as well. The median survival time was 27 months in the group of deceased patients. In the group followed-up 50.8 months survival time was observed up to the closing of the study. Several prognostic factors were investigated. According to the classification by Durie and Salmon the survival time was 60 months in the patients with stage I, 33 months in stage II., and 9 months in stage III respectively. The prognosis is much poorer in patients into the "B" category: the survival time was 14 months. Classified in the basis of the type of the myeloma-cell, the cases with well matured cells have had the best prognosis with survival time of 46 months, while the most unfavourable prognosis was observed in patients with blast-cell type, with a median survival time of 10 months. The greatest number of patients suffered from multiple myeloma of IgG paraprotein type, in this group the serum IgA level was found to be significantly decreased in the patients died due to inevitable infections. The survival was injured significantly by the occurrence of concomitant severe diseases, to.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
113.
目的:检测急性白血病病人血淋巴细胞热休克蛋白70(HSP70)及其mRNA的表达。方法:ELISA法检测HSP70,RT-PCR法检测HSP70 mRNA。结果:化疗前急性白血病病人淋巴细胞HSP70及mRNA明显低于正常人;而化疗后,急性白血病病人淋巴细胞HSP70及mRNA明显高于正常人(P<0.01),结论:HSP70与急性白血病癌细胞关系密切,对癌细胞起保护作用。  相似文献   
114.
小鼠胚胎干细胞体外分化为神经前体细胞的研究   总被引:8,自引:1,他引:7  
目的 探索小鼠胚胎干细胞(Embryonic stem cell,ES cell)体外分化为神经前体细胞(Neural precursor cells,NPC)的无血清培养条件,比较人胚胎成纤维细胞(Human embryonic fibroblasts,HEF)与小鼠胚胎成纤维细胞(Mouse embryonic fibroblasts,MEF)对小鼠ES细胞生长的作用。方法 在MEF或HEF饲养层上培养ES细胞,培养液中含白血病抑制因子。采用无血清方法培养NPC,免疫组化方法检测巢蛋白(Nestin),用硝基四氮啖蓝/5-溴-4-氯-吲哚基磷酸(NBT/BCIP)显色检测碱性磷酸酶。结果 无血清培养可以获得86%的NPC。HEF与MEF-样能维持ES未分化状态。结论 无血清培养方法有利于ES细胞向NPC分化,HEF可用于小鼠ES细胞的培养,而且比MEF优越。  相似文献   
115.
长沙地区疱疹病毒性脑炎的病原研究   总被引:2,自引:0,他引:2  
目的 :探讨长沙地区病毒性脑炎与疱疹病毒感染的关系。方法 :应用间接免疫荧光技术 (IFA)检测病毒性脑炎患者脑脊液或血清中疱疹病毒特异性IgG ,IgM。结果 :92 1例病毒性脑炎患者中有 1 33例 (1 4 4% )诊断为单纯疱疹病毒性脑炎 ,1 0岁以下年龄为发病高峰 ,9例 (0 98% )诊断为巨细胞病毒性脑炎 ,1 2例 (1 3 % )为水痘 带状疱疹病毒性脑炎。结论 :长沙地区疱疹病毒性脑炎病原以单纯疱疹病毒最常见 ;IFA法对疱疹病毒性脑炎具有诊断价值  相似文献   
116.
不同来源精子单精子卵胞浆内注射治疗不育症   总被引:3,自引:0,他引:3  
目的:采用不同来源精子行单精子卵胞浆内注射术(ICSI)治疗不育症并进行疗效对比观察,方法:女性行常规超促排卵和经阴道超声引导下取卵。比较采用精液、附睾和睾丸精子行ICSI后的卵子损伤率、受精率、卵裂率、胚胎质量和临床妊娠率。结果:53对不育夫妇共行62仆ICSI周期。27例临床妊娠,周期临床妊娠率为43.5%,分别有36、12和14个周期采用精液、附睾和睾丸精子,三组的卵子损伤率、受精率、卵裂率  相似文献   
117.
118.
The cellular electrophysiological effects of dridocainide (EGIS-3966), a novel class I antiarrhythmic agent, was studied using conventional microelectrode techniques in canine cardiac Purkinje fibres and papillary muscle preparations obtained from humans and guinea-pigs. In each preparation, dridocainide (0.6–2 mol/l) decreased the maximum velocity of action potential upstroke (Vmax) in a frequency-dependent manner, although marked differences were observed in its effects in Purkinje fibre and ventricular muscle preparations. In canine Purkinje fibres, action potential duration measured at 50% and 90% of repolarization was decreased, while action potential duration measured at 10% of repolarization was increased by dridocainide. In addition, the plateau of the action potential was depressed by the drug. These changes in action potential configuration were not observed in guinea pig or human papillary muscles. The offset kinetics of the dridocainide-induced V max block were different in Purkinje fibres and in ventricular muscle: the slow time constant of recovery of V max was estimated to be 2.5 s in dog Purkinje fibre and 5–6 s in human and guinea-pig papillary muscle. In guinea-pig papillary muscle, the rate of onset of the V max block was 0.15 and 0.2 per action potential in the presence of 0.6 and 2 mol/l dridocainide, respectively. Dridocainide also decreased the force of contraction in this preparation. On the basis of the present results, dridocainide appears to posess mixed class LC and LA properties, with LC predominance in human and guinea-pig ventricular muscle. Present results also indicate that results of conventional classification of class I drugs may depend on the parameters chosen, as well as on the preparation selected.  相似文献   
119.
Prevalence of antibodies to variants HHV-6A and B as well as HHV-7, the time of primary infections are not know in Hungarian children. Therefore, antibodies to these viruses were studied in 21 healthy children aged between 6 and 18 months. Lymphoid cultures were infected with standard virus strains for indirect immunofluorescence. IgM, IgG and high avidity IgG after 8M urea treatment were quantified in serial dilutions of sera. It was established that, three of 13 boys had low level (1:20) IgG or IgM antibodies to HHV-6A, but all girls were negative. With exception of one girl and one boy, all had antibodies to HHV-6B in different titres (1:20 to 1:640 by immunofluorescence), in 9 cases only IgM, in further 4 cases only low avidity IgG were detected. Children studied gradually acquired symptom-free HHV-6B infection between age of 8 and 18 months. Antibodies to HHV-7 were found in 3 boys and one girl before their age of 12 months, but the majority were infected after that age. Approximately three quarters of children acquired either HHV-6B or HHV-7 before age of 18 months. More than half of the children were infected with HHV-6B prior to HHV-7. Antibody level to HHV-6B was slightly higher in boys, while that to HHV-7 was higher in girls. In Hungary, childhood infection with HHV-6A seems to be a very rare event. Epidemiology of HHV-6B primary infection is similar to that of industrial countries, while that of HHV-7 resembles data of developing world: onset of antibodies occurs 1 or 2 years earlier than in the industrial nations.  相似文献   
120.
Lozsádi K 《Orvosi hetilap》1999,140(50):2819-2820
  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