全文获取类型
收费全文 | 14828篇 |
免费 | 1233篇 |
国内免费 | 58篇 |
专业分类
耳鼻咽喉 | 78篇 |
儿科学 | 693篇 |
妇产科学 | 365篇 |
基础医学 | 1732篇 |
口腔科学 | 402篇 |
临床医学 | 1552篇 |
内科学 | 3712篇 |
皮肤病学 | 282篇 |
神经病学 | 1315篇 |
特种医学 | 752篇 |
外国民族医学 | 8篇 |
外科学 | 1862篇 |
综合类 | 247篇 |
预防医学 | 1093篇 |
眼科学 | 304篇 |
药学 | 921篇 |
1篇 | |
中国医学 | 4篇 |
肿瘤学 | 796篇 |
出版年
2021年 | 197篇 |
2019年 | 214篇 |
2018年 | 244篇 |
2017年 | 199篇 |
2016年 | 189篇 |
2015年 | 235篇 |
2014年 | 310篇 |
2013年 | 443篇 |
2012年 | 619篇 |
2011年 | 642篇 |
2010年 | 357篇 |
2009年 | 370篇 |
2008年 | 532篇 |
2007年 | 616篇 |
2006年 | 614篇 |
2005年 | 581篇 |
2004年 | 601篇 |
2003年 | 549篇 |
2002年 | 500篇 |
2001年 | 470篇 |
2000年 | 412篇 |
1999年 | 431篇 |
1998年 | 222篇 |
1997年 | 227篇 |
1996年 | 228篇 |
1995年 | 169篇 |
1994年 | 198篇 |
1993年 | 192篇 |
1992年 | 350篇 |
1991年 | 329篇 |
1990年 | 328篇 |
1989年 | 346篇 |
1988年 | 279篇 |
1987年 | 285篇 |
1986年 | 282篇 |
1985年 | 293篇 |
1984年 | 209篇 |
1983年 | 170篇 |
1982年 | 117篇 |
1981年 | 119篇 |
1979年 | 222篇 |
1978年 | 157篇 |
1977年 | 162篇 |
1976年 | 132篇 |
1975年 | 151篇 |
1974年 | 166篇 |
1973年 | 142篇 |
1972年 | 154篇 |
1971年 | 119篇 |
1970年 | 114篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Many studies of joint replacement in the aged population include a wide spectrum of geriatric patients ranging from relative healthy and otherwise vigorous younger-elderly to small numbers of much older patients with many comorbid problems. To clarify the latter patient subset we assessed the results of total hip and knee arthroplasties done on a group of frail elderly patients. We retrospectively reviewed the preoperative and postoperative charts and radiographs of 130 patients who were at least 80 years when they had a total joint arthroplasty. One hundred arthroplasties (70 hips, 30 knees) were done. On a subjective grading scale, 95% of the patients were very satisfied, 5% reported satisfactory outcomes and no patients considered their results poor. After surgery, 90% of the patients became community walkers without assistance. The level of independent living was maintained in 97% of patients at long-term followup. Causes of morbidity included two infections, one dislocation, and one leg-length discrepancy. This study specifically addresses the outcomes of total joint replacement in elderly patients who are frail. We show that satisfactory and cost-effective health outcomes can be anticipated after total joint arthroplasties in this age group. 相似文献
992.
Friedrich J Charpentier K Marsh CL Bakthavatsalam R Levy AE Kuhr CS 《Transplantation proceedings》2004,36(10):3101-3104
BACKGROUND: Bladder drainage of the exocrine secretions of pancreas transplants has been the standard of practice as it affords the ability to monitor for rejection and is thought to be associated with decreased morbidity. Recently, there has been renewed interest in avoiding the urinary tract complications and metabolic derangements that accompany bladder drainage by draining pancreatic exocrine secretions into the jejunum (enteric drainage). We sought to determine whether enteric drainage of pancreas transplants is safe and offers advantages without compromise in graft function or longevity. METHODS: We retrospectively reviewed all pancreas transplants performed at the University of Washington between 2000 and 2003. Selection of the exocrine drainage method was based on the length of cold ischemia time and whether the pancreas was transplanted alone or in combination with a kidney. Pearson's chi-square and Fisher's Exact tests were used for statistical comparisons in complications or rejections between the groups. RESULTS: Thirty-four pancreas transplants were performed with exocrine drainage into the bladder used in 17 and enteric drainage in 17. The complication rate was 53% in the bladder-drained group and 41% (P=.49) in the enteric-drained group. The incidence of pancreas rejection was 24% in the bladder-drained versus 29% in the enteric-drained patients (P=.50). One graft failed, which was in the bladder cohort. CONCLUSIONS: We found comparable rejection and complication rates between groups. We conclude that enteric drainage is safe when used selectively, and entails no increased risks compared with bladder drainage. 相似文献
993.
Tasnim Sinuff Deborah J. Cook Graeme M. Rocker Lauren E. Griffith Stephen D. Walter Malcolm M. Fisher Peter M. Dodek Peter Sjokvist Ellen McDonald John C. Marshall Peter A. Kraus Mitchell M. Levy Neil M. Lazar Gordon H. Guyatt 《Journal canadien d'anesthésie》2004,51(10):1034-1041
Purpose
Setting treatment goals in the intensive care unit (ICU) often involves resuscitation decisions. Our objective was to study the rate of establishing do-not-resuscitate (DNR) directives, determinants, and outcomes of those directives for mechanically ventilated patients.Methods
In a multicentre observational study, we included consecutive adults with no DNR directives within 24 hr of ICU admission who were mechanically ventilated for at least 48 hr. We identified the rate with which DNR directives were established, and factors associated with these directives.Results
Among 765 patients, DNR directives were established for 231 (30.2%) patients; 143 (62.1%) of these were established within the first week. Factors independently associated with a DNR directive were: patient age [> 75 yr (hazard ratio [HR] 2.3, 95% confidence interval 1.5–3.4], 65 to 74yr(HR 1.8, 1.2–2.7), 50 to 64 yr (HR 1.4, 1.0–2.2) relative to < 50 yr); medical rather than surgical diagnosis (HR 1.8, 1.3–2.5); multiple organ dysfunction score (HR 1.7 for each five-point increment, 1.4–2.0); physician prediction of ICU survival [< 10% (HR 15.0, 6.7–33.6)], 10 to 40% [(HR 5.0, 2.3–11.2), 41 to 60% (HR 4.0, 1.8–9.0) relative to > 90%]; and physician perception of patient preference to limit life support (no advanced life support [(HR 5.8, 3.6–9.4) or partial advanced life support (HR 3.2, 2.2–4.6) compared to full measures].Conclusion
One third of mechanically ventilated patients had DNR directives established early during their ICU stay after the first 24 hr of admission. The strongest predictors of DNR directives were physician prediction of low probability of survival, physician perception of patient preference to limit life support, organ dysfunction, medical diagnosis and age. 相似文献994.
Levy JH 《Journal of cardiothoracic and vascular anesthesia》2004,18(2):129-130
995.
Clark DA Manuel J Lee L Chaouat G Gorczynski RM Levy GA 《American journal of reproductive immunology (New York, N.Y. : 1989)》2004,52(6):370-378
PROBLEM: Previous data have shown "danger" signals, such as bacterial lipopolysaccharide (LPS) acting via toll-like (tlr) receptors are required for early pregnancy failure in several murine abortion models. Indeed, the abortion rate increased in the CBA x DBA/2 model after a gestation day (gd) 7.5 injection of tumour necrosis factor (TNF)-alpha + interferon (IFN)-gamma only if the LPS-tlr signalling pathway was intact. High rates of cytokine-boosted abortion >80% loss can be achieved in certain animal colonies, that have a high endogenous (spontaneous) rate of resorption (30-50%). A specific role for LPS has been postulated to determine both the endogenous and cytokine-boosted losses. METHODS: To test the role of LPS in spontaneous and cytokine-boosted abortions, recombinant TNF-alpha + IFN-gamma, and LPS were injected in different doses and sequences intraperitoneally (i.p.) into CBA x DBA/2 mated mice in the Toronto General Research Institute animal facility where the endogenous abortion rate is <30%. The effects of poly IC, a tlr3 agonist that induces IFN-gamma that can reverse LPS-induced tolerance, and effects of anti-MD-1 on TNF-alpha induction by LPS, poly IC, CPG, or HSP in vitro were also examined. RESULTS: A high endogenous rate of loss similar to that seen in Clamart could be achieved by increasing exposure to LPS on the morning after mating (gd 0.5). The magnitude by which the abortion rate could be increased by an i.p. injection of 2000 u TNF-alpha + 1000 u IFN-gamma on gd 7.5 was independent of the endogenous rate of loss, and could not be increased by doubling the dose. One microgram of LPS given on day 7.5 achieved a similar rate of loss, and if given with the cytokines, synergistically boosted the rate of loss to near Clamart rates. LPS given 1 day prior to the cytokines abrogated the cytokine effect, whereas LPS given day 0.5 had no significant effect on the response to day 7.5 cytokine injection. Blocking MD-1 inhibited TNF-alpha stimulation by poly IC, LPS, CPG, or HSP in vitro, and reduced abortion rates. Poly IC did not avert LPS-type tolerance effects in vivo. CONCLUSIONS: High endogenous rates of abortion in the CBA x DBA/2 model may be explained by exposure to LPS at the time of mating. Increased rates of loss triggered by cytokines later in pregnancy may depend on increased absorption of LPS from intestinal flora. 相似文献
996.
Levy MM 《The New England journal of medicine》2004,351(4):389-391
997.
Renal failure is a common medical condition, and many patients have comorbid psychiatric disorders. In this review, which is intended as a resource for consultation psychiatrists, the authors discuss pharmacokinetic considerations and provide information about the use of individual psychotropic medications in patients with renal disease. Most psychotropic medications are fat soluble, easily pass the blood-brain barrier, are not dialyzable, are metabolized primarily by the liver, and are excreted mainly in bile. Consequently, the majority of these drugs can be safely used with the end-stage renal disease population. 相似文献
998.
Infection with a proposed new subspecies of Babesia canis, Babesia canis subsp. presentii, in domestic cats
下载免费PDF全文
![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Baneth G Kenny MJ Tasker S Anug Y Shkap V Levy A Shaw SE 《Journal of clinical microbiology》2004,42(1):99-105
Parasitemia with a large Babesia species was identified in two domestic cats from Israel. One cat, also coinfected with feline immunodeficiency virus and "Candidatus Mycoplasma haemominutum," had profound icterus and anemia which resolved after therapy, whereas a second cat was an asymptomatic carrier. Amplification and sequencing of the 18S rRNA gene, followed by phylogenetic analyses, indicated that infection was caused by Babesia canis. However, the sequences of the internal transcribed and 5.8S rRNA regions of the ribosomal operon used for subspeciation of B. canis were markedly different from the recognized subspecies of B. canis, which include B. canis vogeli, B. canis canis, and B. canis rossi. Based on phylogenetic comparisons of the 18S rRNA gene, 5.8S, and internal transcribed spacer sequences of the isolates from the cats and on the smaller sizes of the merozoite and trophozoite stages of this parasite, which distinguish it from the subspecies of B. canis present in dogs, we propose to identify the novel feline genotype of B. canis described in the present study as a new subspecies, B. canis subsp. presentii. 相似文献
999.
Potential screening assay for undetectable viruses on the basis of their capacity to induce alpha interferon production
下载免费PDF全文
![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
High interferon production by plasmacytoid dendritic cells (PDC) was unexpectedly noted after their coculture with CD4(+) cells from a healthy donor whose cells subsequently showed human herpesvirus type 6 and 7 infections. This release of interferon was not observed with uninfected normal CD4(+) cells. Induction of PDC interferon production could help screen for covert virus infections. 相似文献
1000.
Topical application of ocular drugs may cause serious adverse ocular or systemic side effects. Children are at greater risk for systemic side effects because ocular dosing is not weight-adjusted, and infants are especially vulnerable as a consequence of the inability to efficiently metabolize the drug, and/or an immature blood-brain barrier. Four pediatric patients are reported in whom treatment with topical brimonidine, a selective alpha-2 adrenoceptor agonist, indicated for the treatment of glaucoma, produced somnolence. Anti-glaucoma eyedrops that are not approved for use in children are still used frequently in pediatrics. Therefore, physicians should be aware of possible systemic side effects of ophthalmic drops. 相似文献