全文获取类型
收费全文 | 5419篇 |
免费 | 466篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 82篇 |
儿科学 | 105篇 |
妇产科学 | 164篇 |
基础医学 | 687篇 |
口腔科学 | 105篇 |
临床医学 | 724篇 |
内科学 | 1003篇 |
皮肤病学 | 77篇 |
神经病学 | 372篇 |
特种医学 | 220篇 |
外科学 | 651篇 |
综合类 | 133篇 |
一般理论 | 1篇 |
预防医学 | 657篇 |
眼科学 | 51篇 |
药学 | 427篇 |
中国医学 | 14篇 |
肿瘤学 | 421篇 |
出版年
2023年 | 36篇 |
2022年 | 83篇 |
2021年 | 128篇 |
2020年 | 76篇 |
2019年 | 106篇 |
2018年 | 97篇 |
2017年 | 88篇 |
2016年 | 83篇 |
2015年 | 103篇 |
2014年 | 152篇 |
2013年 | 180篇 |
2012年 | 321篇 |
2011年 | 342篇 |
2010年 | 154篇 |
2009年 | 156篇 |
2008年 | 225篇 |
2007年 | 281篇 |
2006年 | 293篇 |
2005年 | 249篇 |
2004年 | 244篇 |
2003年 | 220篇 |
2002年 | 175篇 |
2001年 | 137篇 |
2000年 | 146篇 |
1999年 | 123篇 |
1998年 | 60篇 |
1997年 | 54篇 |
1996年 | 39篇 |
1995年 | 46篇 |
1993年 | 40篇 |
1992年 | 111篇 |
1991年 | 101篇 |
1990年 | 79篇 |
1989年 | 72篇 |
1988年 | 84篇 |
1987年 | 81篇 |
1986年 | 72篇 |
1985年 | 80篇 |
1984年 | 53篇 |
1983年 | 52篇 |
1982年 | 36篇 |
1981年 | 33篇 |
1980年 | 43篇 |
1979年 | 51篇 |
1978年 | 32篇 |
1976年 | 32篇 |
1975年 | 34篇 |
1974年 | 37篇 |
1971年 | 31篇 |
1970年 | 33篇 |
排序方式: 共有5894条查询结果,搜索用时 0 毫秒
21.
P Daly 《The British journal of theatre nursing》1992,2(2):8-9
Perfusionists are highly skilled professionals providing essential life support, enabling patients to undergo open heart surgery. Although this is the main function at the Royal Liverpool Children's Hospital, Alder Hey, they also manage a Homograft bank. Also known as a heart valve bank, this is a completely independent branch of the perfusion department. 相似文献
22.
This paper presents a review of the extracranial evaluation and treatment of cerebrospinal fluid (CSF) rhinorrhea. Diagnosis with attention to a careful history and physical with maneuvers which exacerbate drainage and thorough physical exam along with imaging techniques are discussed. The common etiologies of CSF rhinorrhea including trauma, spontaneous leakage, tumor, and iatrogenic injury are included. Management consists of conservative measures including the avoidance of straining maneuvers which increases intracranial pressure. Periodic drainage of CSF via lumbar puncture or continuous drainage via flow-regulated systems may also be of benefit in attempts of conservative management. Failure of conservative management, constant leakage, pneumocephalus, and recurrent meningitis are indicators for surgical repairs. Ethmoid-cribiform plate region repairs are generally approached by external ethmoidectomy and the development of mucoperiosteal flaps from various donor sites which are then rotated to the leak area to seal the defect. Frontal sinus leaks are usually repaired via an osteoplastic flap technique with direct repair of the dural defect or the use of fascial graft tucked under the bony defect, then obliterated with abdominal fat. CSF rhinorrhea presents a diagnostic and surgical challenge to the otolaryngologist. After diagnosis and localization, operative repair using extracranial approaches is accepted as the initial method of intervention in these cases. 相似文献
23.
Background: There are few detailed nutritional studies analysing dietary intakes and weaning practices of inner city infants aged 0–12 months. Pasteurized cow's milk (PCM) is not recommended as a main drink until after 1 year of age, although early usage is still common. Premature introduction of pasteurized cow's milk is associated with increased risk of iron deficiency anaemia. Methods: We therefore prospectively examined the dietary effect of early introduction of pasteurized cow's milk on the nutritional intake of 100 infants (mean age at recruitment 7.8 months), whose mothers had already elected to introduce cow's milk before the recommended age of 12 months in a deprived inner city area. In addition, a retrospective questionnaire on feeding practices and food choices was administered and information on parental education and employment was collected, together with a 3-day dietary diary of weighed intakes at recruitment. Results: The results indicate that weaning practices are handed down from family and friends and are intuitive rather than informed. Over 80% of the infants had intakes of iron, zinc and vitamin D below the reference nutrient intake (RNI) and a further 41% had low vitamin C intakes. Prior to introduction of PCM, there was also misuse of infant formula. Twenty per cent added an extra scoop of powder to the feeds, 10% added milk powder to the bottle before addition of water and 30% used microwave ovens to heat the infant bottle. Conclusion: Feeding practices in a deprived inner city area differed substantially from guidelines and infants were at risk of developing nutrient deficiencies as well as poor feeding practices. 相似文献
24.
John F. Teare Roger W. Peterson Karen Authier Linda Schroeder Daniel L. Daly 《Child & youth care forum》1998,27(2):125-138
The purpose of this study was to examine the correlates of post-shelter maternal family satisfaction in a group of youth who
were reunified with their families following a shelter stay. Findings indicated that higher ratings of family satisfaction
were related to greater maternal problem solving skill and less family conflict. 相似文献
25.
26.
27.
Schecter AD Berman AB Yi L Ma H Daly CM Soejima K Rollins BJ Charo IF Taubman MB 《Journal of leukocyte biology》2004,75(6):1079-1085
Monocyte chemoattractant protein-1 (MCP-1, CCL2) is a mediator of inflammation that has been implicated in the pathogenesis of a wide variety of human diseases. CCR2, a heterotrimeric G-coupled receptor, is the only known receptor that functions at physiologic concentrations of MCP-1. Despite the importance of CCR2 in mediating MCP-1 responses, several recent studies have suggested that there may be another functional MCP-1 receptor. Using arterial smooth muscle cells (SMC) from CCR2(-/-) mice, we demonstrate that MCP-1 induces tissue-factor activity at physiologic concentrations. The induction of tissue factor by MCP-1 is blocked by pertussis toxin and 1,2-bis(O-aminophenyl-ethane-ethan)-N,N,N',N'-tetraacetic acid-acetoxymethyl ester, suggesting that signal transduction through the alternative receptor is G(alphai)-coupled and dependent on mobilization of intracellular Ca(2+). MCP-1 induces a time- and concentration-dependent phosphorylation of the mitogen-activated protein kinases p42/44. The induction of tissue factor activity by MCP-1 is blocked by PD98059, an inhibitor of p42/44 activation, but not by SB203580, a selective p38 inhibitor. These data establish that SMC possess an alternative MCP-1 receptor that signals at concentrations of MCP-1 that are similar to those that activate CCR2. This alternative receptor may be important in mediating some of the effects of MCP-1 in atherosclerotic arteries and in other inflammatory processes. 相似文献
28.
Andrew Daly Steven McAfee Bimal Dey Christine Colby Leah Schulte Beow Yeap Robert Sackstein Nancy J Tarbell David Sachs Megan Sykes Thomas R Spitzer 《Biology of blood and marrow transplantation》2003,9(6):373-382
Infections are a common complication of allogeneic bone marrow transplantation and the leading cause of transplantation-related mortality. It had been hypothesized that transplantation following nonmyeloablative preparative regimens would result in fewer infections by causing less mucosal injury, less graft-versus-host disease, and allowing earlier immune reconstitution. We have retrospectively reviewed the infectious complications of 65 consecutive patients with advanced hematologic malignancies who underwent bone marrow transplantation using a novel preparative regimen consisting of cyclophosphamide, thymic irradiation, and in vivo T-cell depletion. Cytomegalovirus (CMV) infection occurred in 52% of cases in which the donor or recipient had evidence of prior CMV exposure. Using a strategy of preemptive therapy and secondary prophylaxis with ganciclovir, no CMV disease occurred. Infections with gram-positive bacteria predominated over the first 100 days after bone marrow transplantation. Thereafter, the relative proportion of gram-negative infections increased without a significant increase in episodes of neutropenia. The rate of bacterial infections was not influenced by relapse of the underlying malignancy. Seven patients developed infections with Aspergillus species, which was the most common infectious cause of death in these patients. Infections with viruses other than CMV (n=10) and with protozoan organisms (n=2) also occurred. The use of HLA-mismatched donors, the occurrence of grade II-IV acute graft-versus-host disease, and treatment with corticosteroids did not influence the risk of CMV or bacterial or fungal infections in patients who underwent transplantation following this preparative regimen. Overall, the incidence and spectrum of infections in this series was similar to the reported incidence of infections following conventional myeloablative allogeneic stem cell transplantation. We conclude that a quantitative T-cell deficiency in these extensively T-cell depleted patients may be a risk factor for infection, even in the absence of graft-versus-host disease. 相似文献
29.
Comparison of single-shot localization methods (STEAM and PRESS) for in vivo proton NMR spectroscopy 总被引:3,自引:0,他引:3
C T Moonen M von Kienlin P C van Zijl J Cohen J Gillen P Daly G Wolf 《NMR in biomedicine》1989,2(5-6):201-208
Two single-shot localization techniques, STEAM and PRESS, are analyzed with regard to specifications for in vivo localized proton NMR. In particular, attention is paid to optimum signal intensity per unit volume, sensitivity to motion and diffusion, shortest attainable echo time, water suppression and editing possibilities. Experimental results are shown for cat brain at 4.7 T and human brain at 1.5 T. Both STEAM and PRESS are highly effective localization methods. For long echo times, PRESS is the method of choice, because it offers a factor of two gain in signal intensity. In addition, the method is less sensitive to motion and diffusion, and not susceptible to multiple-quantum effects. STEAM offers advantages for observation of (coupled) metabolites with short T2, because (a) shorter TEs can be attained and (b) effective water suppression sequences can be implemented without penalty in echo time. Differences relating to editing possibilities and B1 dependence, possibly important in choosing a method, are discussed. 相似文献
30.
Association of DLG5 R30Q variant with inflammatory bowel disease 总被引:6,自引:0,他引:6
Daly MJ Pearce AV Farwell L Fisher SA Latiano A Prescott NJ Forbes A Mansfield J Sanderson J Langelier D Cohen A Bitton A Wild G Lewis CM Annese V Mathew CG Rioux JD 《European journal of human genetics : EJHG》2005,13(7):835-839
Crohn's disease (CD) and ulcerative colitis (UC) are chronic inflammatory diseases of the gastrointestinal system known as the inflammatory bowel diseases (IBD). Recently, Stoll and colleagues reported a novel finding of genetic variation in the DLG5 gene that is associated with IBD (CD and UC combined). We present here a study of the genetic variation described in that report in two well-powered, independent case-control cohorts and one family-based collection, and confirm the proposed association between IBD and the R30Q variant of DLG5 in two of the three studies. We are, however, unable to replicate the other proposed association to the common haplotype described in Stoll et al and suggest that this other finding could conceivably have been partially a statistical fluctuation and partially a result of LD with the replicated R30Q association. This study provides support for the hypothesis that DLG5 constitutes a true IBD risk factor of modest effect. 相似文献