全文获取类型
收费全文 | 36991篇 |
免费 | 2260篇 |
国内免费 | 162篇 |
专业分类
耳鼻咽喉 | 508篇 |
儿科学 | 861篇 |
妇产科学 | 652篇 |
基础医学 | 4603篇 |
口腔科学 | 662篇 |
临床医学 | 3564篇 |
内科学 | 8710篇 |
皮肤病学 | 416篇 |
神经病学 | 3391篇 |
特种医学 | 1500篇 |
外国民族医学 | 1篇 |
外科学 | 6683篇 |
综合类 | 240篇 |
一般理论 | 18篇 |
预防医学 | 2110篇 |
眼科学 | 534篇 |
药学 | 2070篇 |
中国医学 | 46篇 |
肿瘤学 | 2844篇 |
出版年
2023年 | 187篇 |
2022年 | 394篇 |
2021年 | 904篇 |
2020年 | 559篇 |
2019年 | 917篇 |
2018年 | 1116篇 |
2017年 | 764篇 |
2016年 | 780篇 |
2015年 | 955篇 |
2014年 | 1401篇 |
2013年 | 1871篇 |
2012年 | 2744篇 |
2011年 | 2963篇 |
2010年 | 1698篇 |
2009年 | 1626篇 |
2008年 | 2541篇 |
2007年 | 2684篇 |
2006年 | 2486篇 |
2005年 | 2406篇 |
2004年 | 2197篇 |
2003年 | 2042篇 |
2002年 | 1849篇 |
2001年 | 319篇 |
2000年 | 219篇 |
1999年 | 297篇 |
1998年 | 417篇 |
1997年 | 327篇 |
1996年 | 233篇 |
1995年 | 235篇 |
1994年 | 193篇 |
1993年 | 187篇 |
1992年 | 114篇 |
1991年 | 122篇 |
1990年 | 99篇 |
1989年 | 86篇 |
1988年 | 75篇 |
1987年 | 72篇 |
1986年 | 74篇 |
1985年 | 84篇 |
1984年 | 99篇 |
1983年 | 93篇 |
1982年 | 90篇 |
1981年 | 88篇 |
1980年 | 74篇 |
1979年 | 45篇 |
1978年 | 40篇 |
1974年 | 35篇 |
1973年 | 31篇 |
1934年 | 34篇 |
1923年 | 40篇 |
排序方式: 共有10000条查询结果,搜索用时 234 毫秒
41.
Philip S Wells Josdalyne L Anderson Marc A Rodger Nancy Carson Rebecca L Grimwood Steve P Doucette 《Blood coagulation & fibrinolysis》2006,17(7):533-538
The substitution of leucine for valine at amino acid position 34 of the factor XIII gene is commonly referred to as FXIII Val34Leu polymorphism. The homozygous leucine/leucine genotype has been reported to confer protection against venous thromboembolism, but previous studies have not evaluated a population limited to those with idiopathic venous thromboembolism. The primary objective of the study was to determine whether the FXIII Val34Leu polymorphism is independently associated with the occurrence of idiopathic venous thromboembolism. We prospectively enrolled consecutive patients with at least one objectively confirmed idiopathic venous thromboembolism. Friends of cases were recruited as controls and matched to cases by sex, ethnicity, and age. All participants were tested for the FXIII Val34Leu polymorphism in addition to several well-known thrombophilias. Data from 309 cases and 306 controls were analyzed. The FXIII leucine/leucine genotype was present in 4.9% of cases and 6.5% of controls. An adjusted odds ratio of 0.59 (95% confidence interval, 0.25-1.38) was found for the recessive model and 0.69 (95% confidence interval, 0.46-1.02) for the dominant model. Our results do not support an independent association of the FXIII Val34Leu polymorphism with idiopathic venous thromboembolism in our Caucasian Canadian study population. 相似文献
42.
Rakel Kling Marc Corbière Rebecca Milord Janet G Morrison Kevin Craib Annalee Yassi Claire Sidebottom Catherine Kidd Victoria Long Sharon Saunders 《AAOHN journal》2006,54(11):481-487
This study examined the use and effectiveness of the Alert assessment form. The form is part of the Alert system, used by one large acute care hospital to identify patients with a propensity for violence. All reported incidents of patient violence from August 1, 2003, through December 31, 2004, were included in patient charts. One hundred seventeen violent patient charts were reviewed and compared with 161 non-violent patient charts, randomly chosen from the same time period. Overall use of the Alert assessment form for violent and non-violent patients was 75.7% and 35.4%, respectively. The assessment form was found to have moderate sensitivity (71%) and high specificity (94%). It is reasonably effective in identifying potentially violent or aggressive patients when it is used according to protocol. Efforts to improve the tool are warranted, as is evaluation of its benefit in settings with low prevalence of violence. Also, greater effort must be taken to prevent violence once an aggressive patient has been identified. 相似文献
43.
Serum and Cerebrospinal Fluid Pharmacokinetics of Intravenous and Oral Lamivudine in Human Immunodeficiency Virus-Infected Children 总被引:3,自引:3,他引:0
下载免费PDF全文
![点击此处可从《Antimicrobial agents and chemotherapy》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Brigitta U. Mueller Linda L. Lewis Geoffrey J. Yuen Maureen Farley Amy Keller Joseph A. Church Jonathan C. Goldsmith David J. Venzon Marc Rubin Philip A. Pizzo Frank M. Balis 《Antimicrobial agents and chemotherapy》1998,42(12):3187-3192
We studied the pharmacokinetics of intravenously and orally administered lamivudine at six dose levels ranging from 0.5 to 10 mg/kg of body weight in 52 children with human immunodeficiency virus infection. A two-compartment model with first-order elimination from the central compartment was simultaneously fitted to the serum drug concentration-time data obtained after intravenous and oral administration. The maximal concentration at the end of the 1-h intravenous infusion and the area under the concentration-time curve after oral and intravenous administration increased proportionally with the dose. The mean clearance of lamivudine (± standard deviation) in the children was 0.53 ± 0.19 liter/kg/h (229 ± 77 ml/min/m2 of body surface area), and the mean half-lives at the distribution and elimination phases were 0.23 ± 0.18 and 2.2 ± 2.1 h, respectively. Clearance was age dependent when normalized to body weight but age independent when normalized to body surface area. Lamivudine was rapidly absorbed after oral administration, and 66% ± 25% of the oral dose was absorbed. Serum lamivudine concentrations were maintained above 1 μM for ≥8 h of 24 h on the twice daily oral dosing schedule with doses of ≥2 mg/kg. The cerebrospinal fluid drug concentration measured 2 to 4 h after the dose was 12% (range, 0 to 46%) of the simultaneously measured serum drug concentration. A limited-sampling strategy was developed to estimate the area under the concentration-time curve for concentrations in serum at 2 and 6 h. 相似文献
44.
45.
Armin W. Geiger M.D. F.I.C.A. Alexander M. Zarubin Ph.D. Marc Hertel Anke Fahrenkamp M.D. Gert von Bally Hans H. Scheld M.D. F.I.C.A. 《The International journal of angiology》1995,4(1):46-50
Dysfunction of heart valve prostheses—mechanical as well as biological—is a common problem in cardiac surgery. The reasons for the valve failures are still not well understood. Biological valves especially have an unsatisfactory durability; degeneration and calcification very often lead to the failure of the valves. In our opinion, hidden defects present in the valve material prior to implantation of the valves is a plausible explanation for the dysfunction. Hitherto there has been no technique to detect these defects without destructing the specimen. Holographic interferometry proved to be applicable forin vitro evaluation of mechanical heart valve prostheses. In the present paper we describe application of this method to biological valves. Nine porcine bioprostheses and four fresh porcine aortic valves were investigated by means of holographic interferometry. In eight of nine bioprostheses, the results showed irregularities of the leaflet structure which depend on anomalies of the connective tissue of the leaflets of the valves. To make sure that these findings are not due to normal variations of the morphology, the investigations were carried out with fresh and unfixated porcine aortic valves. In the latter, no such anomalies of the structure were detected. The results obtained confirm the above hypothesis on the origin of the later valve dysfunction. Thus, holographic interferometry tests of bioprostheses prior to their implantation prevent the use of potentially dysfunctional valves.Presented at the 35th World Congress, International College of Angiology, Copenhagen, Denmark, July 1993 相似文献
46.
P. E. Wallemacq Raymond Reding Etienne M. Sokal Jean Ville de Goyet Stéphane Clement de Clety Véronique Van Leeuw Marc De Backer Jean-Bernard Otte 《Transplant international》1997,10(6):466-470
Pediatric liver transplant recipients constitute a population characterized by a particularly unpredictable and poor bioavailability
of cyclosporin (CyA). Even though several adult studies show that the new oral formulation of CyA, Neoral (NEO), produces
better bioavailability and blood level predictability, few data describe its pharmacokinetics in children. We performed a
complete analysis of the pharmacokinetics of NEO in ten small children after primary liver transplantation. Three pharmacokinetic
profiles were set up with data obtained from tests taken during i. v. administration of CyA, after the first oral NEO dose,
and after the last NEO dose before discharge from the hospital. The mean half-lives obtained were 8.1, 7.7, and 6.9 h, respectively,
and the bioavailabilities were 22 % and 21 % for the first and last NEO doses. A large interpatient variability was observed.
This was due, in part, to episodes of diarrhea that interfered with the pharmacokinetic evaluation and, in part, to the variability
of post-transplant hepatic function. There was a good correlation between CyA trough levels and their related AUCs for both
NEO profiles (r = 0.93 and r = 0.74, respectively). We conclude that, even though the pediatric OLT population remains more unpredictable than that of
adults, NEO has a relatively rapid half-life and a remarkably improved bioavailability.
Received: 29 November 1996 Received after revision: 10 April 1997 Accepted: 15 May 1997 相似文献
47.
Marc Ziegler Alexandre Castro-Caldas Susanna Del Signore Olivier Rascol 《Movement disorders》2003,18(4):418-425
Piribedil is a non-ergot D2/D3 agonist with a significant antagonist action on alpha2A and alpha2C adrenergic receptor subtypes. This double-blind placebo-controlled study was undertaken to confirm the efficacy of 150 mg/day piribedil po in improving motor symptoms of idiopathic Parkinson's disease (PD) in nonfluctuating patients insufficiently controlled by a stable daily dose of levodopa (L-dopa). Efficacy was assessed using the Unified Parkinson's Disease Rating Scale (UPDRS) III score as primary criterion over 4 months. A second comparison was planned at 6 months, after possible adjustment of L-dopa. At 4 months, the rate of response, defined as a 30% decrease from baseline on UPDRS III score, was significantly greater with piribedil compared with placebo (56.4% vs. 37.7%; P = 0.040). At 6 months, the better efficacy of piribedil was maintained (61.8% of responders vs. 39.6% on placebo; P = 0.020). The difference between groups on UPDRS III change from baseline reached statistical significance only at 6 months: -10.0 points in the piribedil group vs. -6.7 points in the placebo group (P = 0.037). Secondary end-points were not significantly different. The most frequently reported adverse events were gastrointestinal symptoms (27 of 61 patients in the piribedil group vs. 13 of 54 patients in the placebo group). In conclusion, a 6-month oral administration of 150 mg/day piribedil in combination with L-dopa is well tolerated, except for minor gastrointestinal symptoms at the beginning of the treatment and significantly improves motor symptoms compared with placebo in PD nonfluctuating patients. 相似文献
48.
Robert G. Frank Allyson E. Haut Megan Smick Marc W. Haut John M. Chaney 《Brain injury : [BI]》1990,4(3):289-295
Cognitive deficits associated with closed head injury (CHI) have been well studied. Less attention has been directed to the emotional consequences of CHI and subsequent attempts to cope with major life events. CHI typically constitutes a catastrophic injury, yet few studies have examined coping strategies used by individuals after CHI or the effects of CHI on family functioning that may mediate coping. Previous workers have speculated that time since injury is a crucial determinant of coping; however, this has not been investigated with regard to CHI. In this preliminary investigation, 40 patients with CHI were compared with 17 neurologically intact controls. The CHI group was divided into two groups according to time since injury. It was found that patients with CHI used information seeking as their most dominant coping strategy regardless of their time since injury. Patients with CHI had higher family cohesion scores than control subjects. Implications of these findings for psychological response to CHI are discussed. 相似文献
49.
M.D.Robert R. Bahnson M.D.B. Simon Slasky M.D.Marc S. Ernstoff M.D.Barbara F. Banner 《Urology》1990,35(6)
The ultrasonographic characteristics of an epidermoid cyst of the testicle are presented. Since these, findings are similar to other published case reports, preoperative sonographic diagnosis of this lagon may be possible. 相似文献
50.
Gunter Deppe M.D. Marc L. Kahn M.D. Vinay K. Malviya M.D. John M. Malone Jr. M.D. Carl W. Christensen M.D. Ph.D. 《Gynecologic oncology》1996,62(3):340-343
Experience with the P.A.S.-PORT, a peripherally implanted central venous access device, is evaluated in a retrospective review of 154 patients from July 1991 to June 1994. Blood could not be aspirated from six patients. Complications included temporary minor thrombophlebitis in seven patients (4.5%), symptomatic axillary or subclavian vein thrombosis in five patients (3.2%), clotted port in two patients (1.2%), port pocket cellulitis in two patients (1.2%), and fungal sepsis in two patients (1.2%). In six patients (3.8%) the P.A.S.-PORT had to be removed because of complications. The P.A.S.-PORT facilitated delivery of chemotherapy, parenteral nutrition, blood products, antibiotics, hydration, and blood sampling. It was demonstrated that the P.A.S.-PORT may be inserted and used with a low incidence of complications in gynecologic cancer patients. 相似文献