全文获取类型
收费全文 | 11579篇 |
免费 | 677篇 |
国内免费 | 39篇 |
专业分类
耳鼻咽喉 | 147篇 |
儿科学 | 301篇 |
妇产科学 | 267篇 |
基础医学 | 1494篇 |
口腔科学 | 349篇 |
临床医学 | 1046篇 |
内科学 | 2101篇 |
皮肤病学 | 92篇 |
神经病学 | 1398篇 |
特种医学 | 265篇 |
外科学 | 1314篇 |
综合类 | 149篇 |
一般理论 | 27篇 |
预防医学 | 1191篇 |
眼科学 | 331篇 |
药学 | 919篇 |
中国医学 | 28篇 |
肿瘤学 | 876篇 |
出版年
2022年 | 42篇 |
2021年 | 134篇 |
2020年 | 77篇 |
2019年 | 153篇 |
2018年 | 204篇 |
2017年 | 150篇 |
2016年 | 165篇 |
2015年 | 180篇 |
2014年 | 289篇 |
2013年 | 487篇 |
2012年 | 677篇 |
2011年 | 746篇 |
2010年 | 410篇 |
2009年 | 399篇 |
2008年 | 788篇 |
2007年 | 837篇 |
2006年 | 802篇 |
2005年 | 876篇 |
2004年 | 846篇 |
2003年 | 851篇 |
2002年 | 832篇 |
2001年 | 95篇 |
2000年 | 55篇 |
1999年 | 101篇 |
1998年 | 153篇 |
1997年 | 143篇 |
1996年 | 133篇 |
1995年 | 109篇 |
1994年 | 94篇 |
1993年 | 109篇 |
1992年 | 77篇 |
1991年 | 64篇 |
1990年 | 55篇 |
1989年 | 55篇 |
1988年 | 56篇 |
1987年 | 39篇 |
1986年 | 49篇 |
1985年 | 65篇 |
1984年 | 117篇 |
1983年 | 79篇 |
1982年 | 110篇 |
1981年 | 119篇 |
1980年 | 88篇 |
1979年 | 51篇 |
1978年 | 51篇 |
1977年 | 45篇 |
1976年 | 39篇 |
1975年 | 38篇 |
1974年 | 39篇 |
1973年 | 28篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
51.
缺血性卒中或短暂性脑缺血发作患者的卒中预防指南 总被引:8,自引:0,他引:8
Ralph L.Sacco Robert Adams Grge Albers Mark J.ALBERTS Oscar Benavente Karen Furie Larry B.Goldstein Philip Gorelick Jonathan Halperin Robert Harbaugh S.Claiborne Johnston Irene Katzan Margaret Kelly-Hayes Edgar J.Kenton Michael Marks Lee H.Schwamm Thomas Tomsick 曹勇军 《中华脑血管病论坛》2006,4(1):21-66
这份新声明旨在为缺血性卒中或短暂性脑缺血发作存活者的缺血性卒中预防提供全面和及时的循证推荐,循证推荐包括对危险因素的控制,动脉粥样硬化性疾病的干预措施,心源性栓塞的抗栓治疗以及非心源性卒中抗血小板药的应用。另外,还为其他多种特殊情况下复发性卒中的预防提供了推荐、包括动脉夹层分离、卵圆孔未闭、高同型半胱氨酸血症、高凝状态、镰状细胞病、脑静脉窦血栓形成、女性卒中(特别是与妊娠和绝经后激素替代治疗相关卒中),脑出血后肮凝药的应用,以及该指南在高危人群中执行和应用的特殊措施。 相似文献
52.
Larry W. Figgs Mustafa Dosemeci Aaron Blair 《American journal of industrial medicine》1995,27(6):817-835
Death certificates from 23,890 male and female non-Hodgkin's lymphoma (NHL) cases and 119,450 noncancer controls from 24 states for the period 1984-1989 were used to generate hypotheses regarding occupational associations. Cases were frequency matched by age, race, and gender with five controls per case. Odds ratios were calculated for 231 industries and 509 occupations. Significant associations were observed for a variety of white-collar professionals (i.e., real estate agents, secretaries, bookkeepers, teachers, postal employees, business agents, engineers, chemists, and medical professionals) and blue-collar occupations (i.e., firefighters, farm managers, aircraft mechanics, electronic repairers, mining machine operators, and crane and tower operators). © 1995 Wiley-Liss, Inc. 相似文献
53.
David D. Dean Zvi Schwartz Ofelia E. Muniz Ruben Gomez Larry D. Swain David S. Howell Barbara D. Boyan 《Calcified tissue international》1992,50(4):342-349
Summary This study examined the presence of extracellular matrix processing enzymes in matrix vesicles produced by rat costochondral resting zone and growth zone chondrocytes in culture. Optimum procedures for the extraction of each enzyme activity were determined. Enzyme activity associated with chondrocyte plasma membrane microsomes was used for comparison. There was a differential distribution of the enzyme activities related to the cartilage zone from which the cells were isolated. Acid and neutral metalloproteinase (TIMP), plasminogen activator, and betaglucuronidase were highest in the growth zone chondrocyte (GC) membrane fractions when compared with matrix vesicles and plasma membranes isolated from resting zone chondrocyte (RC) cultures. There was a threefold enrichment of total and active acid metalloproteinase in GC matrix vesicles, whereas no enrichment in enzyme activity was observed in RC matrix vesicles. Total and active neutral metalloproteinase were similarly enriched twofold in GC matrix vesicles. TIMP, plasminogen activator, and betaglucuronidase activities were highest in the plasma membranes of both cell types. No collagenase, lysozyme, or hyaluronidase activity was found in any of the membrane fractions. The data indicate that matrix vesicles are selectively enriched in enzymes which degrade proteoglycans. The highest concentrations of these enzymes are found in matrix vesicles produced by growth zone chondrocytes, suggesting that this may be a mechanism by which the more differentiated cell modulates the matrix for calcification. 相似文献
54.
Antagonists of the N-methyl-D-aspartate (NMDA) type of excitatory amino acid (EAA) receptors blocked cocaine-induced stereotypy, locomotor stimulation and convulsions. These effects in general appear to involve selectively NMDA type of receptors. The results suggest that NMDA-activated systems are an integral component in the reaction sequences involved in the expression of several behavioral effects of cocaine. 相似文献
55.
Larry J Oesterle Sheldon M Newman W Craig Shellhart 《American journal of orthodontics and dentofacial orthopedics》2002,122(3):242-250
Light curing of composite resin material beneath orthodontic brackets is common in clinical orthodontics. Experiences with composite resins and high-intensity lights indicate some advantages to staged curing of the composite. In this study, the shear/peel bond strength of orthodontic brackets bonded to bovine enamel and cured with a pulsed xenon plasma arc light was compared with that of bonds cured with a conventional tungsten-quartz-halogen light and a nonpulsed xenon plasma arc light. The pulsed light provided less light energy than the nonpulsed lights. A small and a larger light-guide tip were used with the pulsed xenon plasma arc light. Three different orthodontic composite resin adhesives were tested with each light. The pulsed xenon plasma arc light resulted in either the same or decreased shear/peel bond strength when compared with the nonpulsed lights. There appeared to be no advantage to the use of a pulsed xenon plasma arc light in bonding orthodontic brackets. Results from using either a small or a large light-guide tip varied with the adhesive tested. 相似文献
56.
57.
58.
Michael J. LaRouere John J. Zappia Harvey I. Wilner Malcolm D. Graham Larry B. Lundy 《Skull base》1994,4(1):21-25
Four patients with grade C or D1 glomus jugulare tumors who underwent preoperative highly selective embolization followed by infratemporal fossa removal of their tumors were compared to three patients undergoing surgery alone with respect to intraoperative blood loss, operative time, cranial nerve palsy, length of hospitalization, and perioperative complications. Embolized patients demonstrated a marked reduction in blood loss (650 vs 1375 cc) compared with the nonembolized group. Operative time was shortened (by 51 minutes). Facial nerve function did not appear related to embolization but was directly related to intraoperative nerve manipulation. Hospital stay, perioperative complications, and lower cranial nerve palsies were not related to embolization. 相似文献
59.
Dr. Douglas N. Fish Pharm. D. Dr. Stephen C. Piscitelli Pharm. D. Dr. Larry H. Danziger Pharm. D. 《Pharmacotherapy》1995,15(3):279-291
The incidence of emergent resistance and clinical factors affecting its development were evaluated by retrospective review of 173 studies encompassing over 14,000 patients. Eight antibiotic classes and 225 individual treatment regimens were evaluated. Emergent resistance occurred among 4.0% of all organisms and 5.6% of all infections treated. It appeared to be significantly more frequent with penicillin and aminoglycoside monotherapy, with significantly lower rates associated with imipenem-cilastatin, aztreonam, and combination therapy. Clinical failure also appeared to be significantly more likely to occur after emergence of resistance among organisms treated with fluoroquinolones or aminoglycosides. Infections associated with higher resistance rates were cystic fibrosis, osteomyelitis, and lower respiratory tract infections. Resistance was most common in patients in intensive care units or receiving mechanical ventilation. It was also significantly frequent among studies performed in university or teaching hospitals. Organisms associated with high resistance rates were Pseudomonas aeruginosa, Serratia, Enterobacter, and Acinetobacter sp. Factors such as infection type, underlying diseases, type of institution, and specific pathogens warrant consideration when examining emergent resistance. 相似文献
60.
Deborah D Albright Diane Jordan-Wagner Diane C Napoli Amy L Parker Fonzie Quance-Fitch Bonnie Whisman Jacob W Collins Larry L Hagan 《Annals of allergy, asthma & immunology》2006,97(4):521-527
BACKGROUND: Multicolored Asian lady beetles (Harmonia axyridis) have been used as a biological control agent against crop-destroying aphids in the United States. Outside their natural habitat, H. axyridis seeks refuge in homes during fall and winter, leading to patient complaints and symptoms of rhinitis, wheezing, and urticaria on exposure to the beetles. OBJECTIVE: To gain a better understanding of the character and spectrum of allergic disease provoked by exposure to home-infesting lady beetles. METHODS: Eight patients with allergic symptoms suspected of being caused by H. axyridis and consistent with an IgE-mediated process were identified and interviewed. A whole-body extract from H. axyridis was prepared. Western blots using the patients' serum identified specific IgE antibodies in the extract. Through a novel technique, immunohistochemical analysis using beetle sections overlayed with patient serum was performed. A random survey of allergists from across the United States was also performed to evaluate experience with cases of lady beetle allergy. RESULTS: Western blots revealed IgE binding to 5 proteins with molecular weights of approximately 8.6, 21, 28, 31, and 75 kDa. Specific IgE bound to proteins localized in the beetle's mouth and leg areas. The allergist survey revealed positive responses in North Central, Mid-Atlantic and New England states. CONCLUSION: In 8 patients with allergic symptoms on exposure to high levels of lady beetles, specific IgE bound to proteins from H. axyridis. There was also an increased frequency of suspected cases of lady beetle allergy in endemic areas. 相似文献