全文获取类型
收费全文 | 4838篇 |
免费 | 275篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 90篇 |
儿科学 | 108篇 |
妇产科学 | 65篇 |
基础医学 | 736篇 |
口腔科学 | 77篇 |
临床医学 | 452篇 |
内科学 | 1039篇 |
皮肤病学 | 67篇 |
神经病学 | 393篇 |
特种医学 | 192篇 |
外科学 | 907篇 |
综合类 | 66篇 |
一般理论 | 5篇 |
预防医学 | 296篇 |
眼科学 | 80篇 |
药学 | 286篇 |
中国医学 | 8篇 |
肿瘤学 | 268篇 |
出版年
2023年 | 20篇 |
2022年 | 31篇 |
2021年 | 80篇 |
2020年 | 64篇 |
2019年 | 83篇 |
2018年 | 72篇 |
2017年 | 72篇 |
2016年 | 80篇 |
2015年 | 80篇 |
2014年 | 133篇 |
2013年 | 206篇 |
2012年 | 251篇 |
2011年 | 308篇 |
2010年 | 173篇 |
2009年 | 169篇 |
2008年 | 299篇 |
2007年 | 311篇 |
2006年 | 309篇 |
2005年 | 294篇 |
2004年 | 293篇 |
2003年 | 295篇 |
2002年 | 268篇 |
2001年 | 60篇 |
2000年 | 58篇 |
1999年 | 59篇 |
1998年 | 66篇 |
1997年 | 56篇 |
1996年 | 51篇 |
1995年 | 54篇 |
1994年 | 48篇 |
1993年 | 35篇 |
1992年 | 52篇 |
1991年 | 51篇 |
1990年 | 49篇 |
1989年 | 49篇 |
1988年 | 41篇 |
1987年 | 44篇 |
1986年 | 37篇 |
1985年 | 37篇 |
1984年 | 36篇 |
1983年 | 29篇 |
1982年 | 23篇 |
1981年 | 25篇 |
1980年 | 23篇 |
1979年 | 21篇 |
1978年 | 21篇 |
1975年 | 17篇 |
1974年 | 14篇 |
1973年 | 26篇 |
1969年 | 15篇 |
排序方式: 共有5135条查询结果,搜索用时 15 毫秒
1.
Georges Schüler 《International journal of public health》1986,31(1):39-41
This review on air pollution and lung cancer recapitulates the main issues in this field (urban-rural-gradients; experimental data and occupational epidemiology of exposure to PAH; smoking and occupation as confounders). Definite risk increases have been observed in the vicinity of point emission sources. Within Switzerland lung cancer shows an urban/rural gradient in both sexes. The geographical distribution of the male cases can hardly be explained only by the patterns of smoking alone. 相似文献
2.
The influence of sex steroids and the dopaminergic system on the in vivo modulation of prolactin (PRL) mRNA levels was investigated by quantitative in situ hybridization in the male rat anterior pituitary gland. In situ hybridization was performed using a [35S]-labeled cDNA probe encoding PRL. Orchiectomy performed 14 days earlier did not modify PRL mRNA levels. In orchiectomized rats treatment with the dopaminergic agonist bromocriptine for 14 days decreased PRL mRNA levels by 30%, while in intact animals the same treatment did not induce any changes in PRL mRNA levels. Administration of the dopamine D2 receptor antagonist haloperidol in both intact and orchiectomized rats induced a 4-fold increase in mRNA levels. Administration of dihydrotestosterone to orchiectomized animals which had been treated or not with haloperidol or bromocriptine did not modify PRL mRNA levels. In orchiectomized animals administration of 17ß-estradiol (0.25 μg twice daily) for 14 days caused a 4-fold increase in amounts of PRL mRNA. Administration of bromocriptine to 17ß-estradiol-treated animals induced a 15% decrease of PRL mRNA levels compared to those obtained by 17ß-estradiol administered alone. The concomitant administration of 17ß-estradiol and haloperidol resulted in a 50% increase in PRL mRNA levels compared to those measured in animals treated with haloperidol alone. The present results clearly demonstrate that in vivo estrogen as well as dopamine-mediated mechanisms play a regulatory role in PRL mRNA levels in the male rat. 相似文献
3.
Jehad Al Watban Georges Rodesch Hortensia Alvarez Pierre Lasjaunias 《Child's nervous system》1995,11(7):406-408
The authors present three cases of vein of Galen aneurysmal malformations (VGAMs) diagnosed in infancy and submitted by the referring teams for stereotactic radiosurgery as the initial therapy (therapeutic doses ranging between 20–25 Gy and 40–50 Gy to the peak dose). After the conventional follow-up of 18–24 months, no change could be detected in the angioarchitecture of the lesions. All three cases were then referred for endovascular treatment and underwent embolization by the transarterial route using liquid adhesives (N-butyl cyanoacrylate). This resulted in complete anatomical exclusion of the lesion. Regardless of the theoretical efficiency of radiosurgery in the management of brain arteriovenous malformations, the present authors believe that transarterial embolization remains the treatment of choice in VGAMs. It offers a high rate of morphological cure and the best chances for normal neurocognitive development. The time required by radiosurgery to achieve a significant result is too long for developing and maturing brain and may not prevent the negative effects of the lesion, mainly in regard to hemo- and hydrodynamic disorders (atrophy, subcortical calcifications, etc.) created by the VGAM, thus leading to irreversible mental retardation. 相似文献
4.
Marie-Francoise Dresse Michele David Heather Hume Herve Blanchard Pierre Russo Nicolas Van Doesberg Georges E. Rivard 《Pediatric hematology and oncology》1991,8(4):329-334
The Kasabach-Merritt syndrome is characterized by thrombocytopenia and localized coagulopathy associated with a hemangioma. Most techniques applied to eradicate the tumor or accelerate its involution (surgery, radiation therapy, embolization) are invasive and require transfusion of large amounts of blood products. In some cases, medical treatment is the only alternative. Efficacy of steroids and antifibronolytic agents has already been described, but even this approach is associated with the administration of blood products. We report two cases of infants with Kasabach-Merritt syndrome associated with cardiac and hepatic hemangiomas. At admission, both had signs of cardiac failure. They were successfully treated with prednisone and epsilon-aminocaproic acid (EACA). Blood products were not required once the diagnosis was made. These observations have important implications for the management of patients with Kasabach-Merritt syndrome because they show that even in severe cases blood transfusions can be avoided by the use of prednisone and EACA. 相似文献
5.
6.
7.
8.
Francoise Mouchet Valérie Hansen Inge Van Herreweghe Olivier Vandenberg Régine Van Hesse Michèle Gérard Michèle Toppet Maryse Wanlin Véronique Toppet Georges Casimir Dominique Haumont Jack Levy 《Infection control and hospital epidemiology》2004,25(12):1062-1066
OBJECTIVE: To assess the extent of nosocomial transmission of tuberculosis among infants, family members, and healthcare workers (HCWs) who were exposed to a 29-week-old premature infant with congenital tuberculosis, diagnosed at 102 days of age. DESIGN: A prospective exposure investigation using tuberculin skin test (IST conversion was conducted. Contacts underwent two skin tests 10 to 12 weeks apart. Clinical examination and chest radiographs were performed to rule out disease. Isoniazid prophylaxis was administered to exposed infants at higher risk. SETTING: A neonatal intensive care unit in an urban hospital in Brussels, Belgium. PARTICIPANTS: Ninety-seven infants, 139 HCWs, and 180 visitors. RESULTS: Newly positive TST results occurred in HCWs who had been in close contact with the infant. Six (19%) of 32 primary care nurses and physicians had TST conversions and received treatment. Among the 97 exposed infants, 85 were screened and 34 were identified as at higher risk of infection. Of these, 27 received preventive isoniazid. None of the infants and none of the 93 other infants' family members evaluated were infected. CONCLUSIONS: Congenital tuberculosis in an infant poses a risk for nosocomial transmission to HCWs. Delayed diagnosis of this rare disease and close proximity are the most important factors related to transmission. 相似文献
9.
Jansen Jacob G.; van Teijlingen Corrie M. M.; MOHN Georges R.; van Zeeland Albert A.; Vrieling Harry 《Mutagenesis》1994,9(5):417-421
Spectra of N-ethyl-N-nitrosourea (ENU)-induced mutations differwidely among various in vitro and in vivo mutational systems.To investigate possible reasons for these differences, a mutationalsystem is needed in which the same target gene is used for comparisonin the same type of cells in vitro and in vivo. In the presentstudy, this was achieved by analysing at the molecular level35 hprt mutant rat fibroblast clones obtained from cell populationsexposed in vitro to ENU and comparing the mutational spectrumwith the previously determined spectrum of ENU-induced hprtmutants in the same target cells exposed in vivo. Twenty-eightmutants contained a single base pair alteration in the hprtcoding sequence. Most of these changes were found at AT basepairs (19/28), the AT to TA transversion being the most frequentkind of mutation (12/19), which is probably caused by O2-ethylthymine.Transversions at AT base pairs showed all mutated T's to belocated in the nontranscribed strand of the hprt gene, suggestinga strand specific fixation of mutations induced by O2-ethylthymine,which appears to be a general feature of ENU- and ENNG-inducedhprt mutations in mammalian cells. GC to AT transitions, probablycaused by O6-ethylguanine, were detected at a lower frequency(7/28). This in vitro mutational spectrum was very similar tothat of the same target cells exposed in vivo to ENU. A comparisonof the mutational spectra in AGT-proficient and AGT-deficientrodent cells exposed to ethylating agents showed that in contrastto the situation in AGT-proficient rat fibroblasts, GC to ATbase pair changes (and not AT to TA) are the predominant mutationsin AGT-deficient hamster cells.
4To whom correspondence should be addressed 相似文献
10.
A Vassault B Cherruau D Labbe B Alabrune P Baltassat R Bonete G Carroger S Costantini P Georges C Giroud 《Annales de biologie clinique》1992,50(2):81-95
During a multicenter evaluation, 16 methods for creatinine measurement have been tested according to the guidelines of the Société fran?aise de biologie clinique (SFBC) protocol. Kinetic Jaffé methods, widely used in France, performed on different analytical systems (Astra Beckman, IL 508, RA 1000 Technicon, Hitachi 704, 705, 717 Boehringer, Fara Roche, Progress Kone, Kem-O-Mat Coulter, Perspective France Monitor) have been compared to a continuous flow method with aqueous standards, to enzymatic methods using creatinine amidohydrolase with a colorimetric measurement (Boehringer and Ektachem Kodak) and to an HPLC method. Reproducibility, estimated with four different control sera, proved to be unsatisfactory in some cases as compared to current criteria for imprecision (less than +/- 10 mumol/l for intralaboratory and less than +/- 20 mumol/l for interlaboratory imprecision). The same selected patients sera covering the whole range of physiopathological concentrations have been analyzed with each method, and compared with the continuous flow results. Differences are more dependent on the sample than on the calibrators. The influences of haemolysis, bilirubin, acetoacetate, albumin, lipids, glucose, and some cephalosporins have been evaluated with spiked human sera. Haemolysed, turbid and jaundiced patient samples have been analyzed as well. The results vary according to the analytical procedure. This study took place in the implementation of a selected method for routine purpose with special regards to interferences and an acceptable imprecision. The method must satisfy the physicians' demands in the renal function exploration, especially in kidney-transplant patients. 相似文献