全文获取类型
收费全文 | 5165篇 |
免费 | 540篇 |
国内免费 | 28篇 |
专业分类
耳鼻咽喉 | 54篇 |
儿科学 | 175篇 |
妇产科学 | 80篇 |
基础医学 | 645篇 |
口腔科学 | 114篇 |
临床医学 | 705篇 |
内科学 | 1089篇 |
皮肤病学 | 104篇 |
神经病学 | 367篇 |
特种医学 | 369篇 |
外科学 | 605篇 |
综合类 | 44篇 |
一般理论 | 2篇 |
预防医学 | 719篇 |
眼科学 | 114篇 |
药学 | 238篇 |
中国医学 | 7篇 |
肿瘤学 | 302篇 |
出版年
2023年 | 91篇 |
2022年 | 76篇 |
2021年 | 164篇 |
2020年 | 139篇 |
2019年 | 166篇 |
2018年 | 198篇 |
2017年 | 139篇 |
2016年 | 146篇 |
2015年 | 169篇 |
2014年 | 272篇 |
2013年 | 337篇 |
2012年 | 351篇 |
2011年 | 348篇 |
2010年 | 211篇 |
2009年 | 198篇 |
2008年 | 226篇 |
2007年 | 265篇 |
2006年 | 214篇 |
2005年 | 175篇 |
2004年 | 166篇 |
2003年 | 129篇 |
2002年 | 127篇 |
2001年 | 74篇 |
2000年 | 86篇 |
1999年 | 64篇 |
1998年 | 93篇 |
1997年 | 111篇 |
1996年 | 93篇 |
1995年 | 74篇 |
1994年 | 74篇 |
1993年 | 62篇 |
1992年 | 48篇 |
1991年 | 28篇 |
1990年 | 42篇 |
1989年 | 63篇 |
1988年 | 57篇 |
1987年 | 52篇 |
1986年 | 47篇 |
1985年 | 58篇 |
1984年 | 26篇 |
1983年 | 27篇 |
1982年 | 34篇 |
1981年 | 41篇 |
1980年 | 19篇 |
1979年 | 22篇 |
1978年 | 10篇 |
1977年 | 20篇 |
1976年 | 22篇 |
1975年 | 15篇 |
1974年 | 11篇 |
排序方式: 共有5733条查询结果,搜索用时 15 毫秒
31.
Lindsey LA 《Journal of the Royal College of Surgeons of Edinburgh》1999,44(1):34-35
Surgeons' basic competency relies upon their ability to combine their existing knowledge and practical skills in the care of their patients, and also upon keeping up to date and encompassing change. We now live in a society which has become accustomed to receive a constant flow of up-to-date information about the world around it. With recent developments, including the Internet, the World Wide Web, and advances in personal computer systems, the pace of change of information technology (IT) has been increasing. These changes have had a significant impact upon surgery, and it is now becoming necessary to be able to make use of these new resources to function effectively in modern practice. This article will outline some of the more important topics relating to IT in surgical practice as an introduction to a series on this subject which will be appearing in forthcoming issues of the Journal. 相似文献
32.
The use of newly approved drugs for human immunodeficiency virus (HIV)-infected adults is limited in children until child-specific pharmacokinetic and safety data can be submitted to the Food and Drug Administration (FDA) to fulfill labeling requirements. Design of a clinical trial to assess drug safety in children requires a different set of issues from standard Phase II and III efficacy trials in adults. For example, Phase II trials in adults are done to collect preliminary efficacy information. In children, efficacy of the drug is assumed and only safety needs to be shown. As a result, control groups may not be required and it may not be necessary to show superiority of the new drug over a control. This paper describes these issues in some detail and gives examples of designs appropriate in different scenarios. 相似文献
33.
RINA SRIVASTAVA VW TILAK S MUKHERJEE JD YADAV 《Medical Journal Armed Forces India》1996,52(4):233-235
In a simulated field trial Bacillus thuringiensis var israelensis (BTI) pellet formulation exhibited an enhanced efficacy with increasing dose. A dosage of 1.0 and 1.5 ppm was most effective under simulated field conditions. In field trials persistence of BTI pellet (1.0 ppm) was observed for 35 days in moderately polluted water collection as compared to 21 days in highly polluted water bodies.KEY WORDS: Bacillus thuringiensis, Malaria, Mosquito control 相似文献
34.
This report describes a new technique for treatment of a segmental defect in long bones that uses a cylindrical titanium mesh cage, in combination with cancellous bone allograft and demineralized bone matrix putty (Grafton), stabilized with a statically locked intramedullary nail. Two clinical cases of tibia defects treated with this technique are presented. At the one-year follow-up, radiographically both cases demonstrated excellent limb alignment, stability, and bony healing. Immediate full weight-bearing was initiated in each case, and early limb functional recovery was achieved. Preliminary data suggest that this technique may be a reasonable alternative to currently used methods for management of select long bone segmental defects. 相似文献
35.
GA Smith SD Strausbaugh C Harbeck-Weber DM Cohen BJ Shields JD Powers 《Pediatrics》1997,100(5):825-830
OBJECTIVE: To compare the effectiveness of three new topical anesthetics that do not contain cocaine (prilocaine-phenylephrine, tetracaine-phenylephrine [tetraphen], and tetracaine-lidocaine-phenylephrine) to that of tetracaine-adrenaline-cocaine (TAC) during laceration repair in children. DESIGN: Prospective, randomized, double-blind clinical trial. SETTING: The emergency department of an urban children's hospital. PARTICIPANTS: Children 1 year of age or older with a laceration = 5 cm in length that required suturing. Intervention. A total of 240 children were randomly assigned to one of four treatment groups. OUTCOME MEASURES: Pain felt during suturing was scored by suture technicians, research assistants, parents, and patients >/= 5 years of age using a visual analogue scale (VAS). Suture technicians, research assistants, and parents also scored pain using a seven-point Likert scale. In addition, suture technicians completed an anesthetic effectiveness scale. RESULTS: There was consistently no difference demonstrated between the effectiveness of tetraphen and that of TAC for each outcome measure of each observer group. A statistically significant difference was seen among anesthetics when comparing VAS and Likert scale scores of suture technicians and Likert scale scores of research assistants. Based on post hoc analyses, these statistically significant differences were between TAC and prilocaine-phenylephrine (suture technician VAS and Likert scale) and between TAC and tetracaine-lidocaine-phenyl-ephrine (suture technician Likert scale), but not between TAC and tetraphen. When power analyses were performed using alpha = 0.05 and beta = 0.20, it was possible to detect a difference of 1.2 VAS units for each of the observer groups. Based on anesthetic effectiveness scale scores, the three new topical preparations collectively performed significantly better on the face and scalp than on the extremities (relative risk = 1.83; 95% confidence interval 1.20 < relative risk < 2.79). CONCLUSION: This study demonstrated the effectiveness and safety of three new non-cocaine-containing topical anesthetics. Consistently, there was no statistical difference demonstrated between the effectiveness of tetraphen and that of TAC for each outcome measure of each observer group. Tetraphen offers an effective alternative to TAC during laceration repair in children. 相似文献
36.
Hypospadias trends in two US surveillance systems 总被引:6,自引:0,他引:6
OBJECTIVE: Hypospadias is a common congenital anomaly, the cause of which is unknown. Unexplained increases in the rates of hypospadias occurred in five European countries in the 1970s and 1980s. We examined data from two birth defects surveillance systems in the United States for evidence of similar trends. METHODOLOGY: The Metropolitan Atlanta Congenital Defects Program (MACDP) provided birth prevalence rates from 1968 to 1993. The nationwide Birth Defects Monitoring Program (BDMP) provided rates from 1970 to 1993. MACDP data are population-based and could be categorized by the severity of the hypospadias. BDMP data allowed analysis of rate trends for the four census regions of the United States. RESULTS: Data from both surveillance systems showed an approximate doubling of hypospadias rates in the 1970s and 1980s. MACDP data showed that the rate of severe cases increased while the ratio of mild to severe cases decreased. BDMP data showed that hypospadias rates increased markedly in all four regions of the United States. CONCLUSIONS: The observed increases are unlikely to be attributable to increased sensitivity of the surveillance systems or the identification of more mild cases by physicians over time, because either trend would have increased rather than decreased the ratio of mild to severe cases. If real, these trends represent the largest number of cases and the first report of an increase in hypospadias rates outside of Europe. Additional investigation of a possible increase in hypospadias rates is warranted. 相似文献
37.
38.
Ventolini G Neiger R Mathews L Adragna N Belcastro M 《American journal of perinatology》2008,25(2):79-83
We studied the effect of antenatal corticosteroids on the incidence of respiratory disorders in singleton neonates born between 34 and 36 weeks of gestation. Retrospective analysis was conducted of the incidence of respiratory distress syndrome (RDS) and other respiratory disorders (need for mechanical ventilation, continuous positive airway pressure, and prolonged oxygen therapy) among singleton neonates delivered between 34 and 36 weeks of gestation who were exposed to antenatal corticosteroids, compared with neonates who were not exposed. Statistical analyses included two-tailed T tests, two-way analysis of variance for continuous data, and chi-square analysis for ratios. A probability of 0.05 was considered significant. Between January 1, 2000, and December 31, 2004, 1078 neonates were born between 34 and 36 weeks of gestation. Information regarding antenatal corticosteroids was available in 1044: 574 neonates (53.2%) were exposed to antenatal corticosteroids and 470 (43.6%) were not. One thousand and eighteen neonates were admitted to the neonatal intensive care unit. Respiratory disorders were diagnosed in 140 of those exposed to antenatal steroids (24.4%) and in 382 of the nonexposed (81.3%) ( P < 0.0001). Two hundred and ten neonates (20.6%) developed RDS: Of those, 43 were exposed to antenatal corticosteroids and 167 were not (incidence of RDS was 7.5% and 35.5%, respectively; P = 0.0001). The beneficial effects of corticosteroids were similar in both genders. It appears that the exposure of singleton pregnancies to antenatal corticosteroids between 24 and 34 weeks of gestation is associated with a significantly lower incidence of respiratory disorders among neonates born at 34 to 36 weeks of gestation. Further studies are needed to determine whether administering antenatal steroids to women experiencing preterm labor after 34 weeks of gestation would be associated with a similar beneficial effect. 相似文献
39.
Prevalence and Contributors to Low‐grade Inflammation in Three U.S. Populations of Reproductive Age Women 下载免费PDF全文