全文获取类型
收费全文 | 717篇 |
免费 | 75篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 10篇 |
儿科学 | 13篇 |
妇产科学 | 3篇 |
基础医学 | 76篇 |
口腔科学 | 60篇 |
临床医学 | 68篇 |
内科学 | 183篇 |
皮肤病学 | 3篇 |
神经病学 | 65篇 |
特种医学 | 15篇 |
外科学 | 99篇 |
综合类 | 8篇 |
一般理论 | 1篇 |
预防医学 | 47篇 |
眼科学 | 16篇 |
药学 | 58篇 |
中国医学 | 2篇 |
肿瘤学 | 71篇 |
出版年
2023年 | 13篇 |
2022年 | 12篇 |
2021年 | 24篇 |
2020年 | 12篇 |
2019年 | 28篇 |
2018年 | 33篇 |
2017年 | 37篇 |
2016年 | 29篇 |
2015年 | 26篇 |
2014年 | 16篇 |
2013年 | 38篇 |
2012年 | 48篇 |
2011年 | 48篇 |
2010年 | 46篇 |
2009年 | 21篇 |
2008年 | 37篇 |
2007年 | 57篇 |
2006年 | 40篇 |
2005年 | 36篇 |
2004年 | 32篇 |
2003年 | 24篇 |
2002年 | 29篇 |
2001年 | 10篇 |
2000年 | 8篇 |
1999年 | 10篇 |
1998年 | 5篇 |
1997年 | 10篇 |
1996年 | 4篇 |
1995年 | 8篇 |
1994年 | 7篇 |
1993年 | 3篇 |
1992年 | 8篇 |
1991年 | 5篇 |
1990年 | 6篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1987年 | 4篇 |
1986年 | 1篇 |
1985年 | 4篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1979年 | 4篇 |
1978年 | 6篇 |
1977年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有798条查询结果,搜索用时 15 毫秒
51.
This article focuses on the array of online benefits solutions offered by technology companies and reports the benefits to both employers and employees. Some of the benefits include reduced paperwork, reduced errors, and reduced administration costs. Companies that can deliver these benefits will be in great demand to help manage benefits programs and streamline the administrative processes. 相似文献
52.
Ala Addin Kandeel Mohamed Zeid Thomas Helm Madeline A. Lillie Eileen Donahue Julian L. Ambrus Jr. 《Journal of clinical immunology》2001,21(5):335-347
The coincidence of Hashimoto thyroiditis (HT) and chronic idiopathic urticaria (CIU) is a commonly observed phenomenon in western New York. Previous literature suggested that there may be a direct relationship between them. We undertook these studies to determine whether humoral or cell-mediated mechanisms might link HT and CIU.Skin biopsies from patients with CIU, with or without HT, were indistinguishable by light microscopy. No immune complex deposition was observed, although only the skin from patients with CIU and HT contained perivascular fibrin deposits. Similarly, immunohistochemical studies evaluating cellular expression of CD3, CD4, CD8, CD20, and CD68 failed to differentiate between CIU with or without HT. Analysis of V restriction in thyroid tissue of patients with HT and the skin of patients with CIU and HT by in situ polymerase chain reaction failed to reveal any oligoclonal T-lymphocyte subpopulations. In contrast, only patients with CIU and HT had anti-FcRI antibodies in their sera that could induce degranulation of normal basophils. Some sera from patients with CIU and HT caused degranulation of normal basophils in the absence of anti-FceRI. The factor causing basophil degranulation in these sera was not determined. Patients with CIU and HT failed to improve clinically with thyroid replacement therapy. All CIU patients were equally well managed with symptomatic therapies.In conclusion, HT likely represents a marker of other autoimmunity, rather than being a direct causative agent in CIU. Management of CIU, with or without HT and with or without anti-FceRI antibodies, should be the same. Future studies will have to examine whether cell-mediated responses participate in CIU, especially in association with HT. 相似文献
53.
Although head imaging studies are frequently used in the work-up of dementia, published criteria for the clinical diagnosis of Alzheimer's disease (AD) do not require them. Since our brain bank contains cases in which physicians had specifically diagnosed AD without using a head imaging study, we thought it of interest to investigate the accuracy of their clinical diagnoses. We retrospectively reviewed 911 consecutive dementia cases for those clinically diagnosed as either AD or senile dementia (SD). Twenty-one were identified in which head imaging studies had not been used, each diagnosed as AD or SD by a different physician. In only three had the physician reported a reason why a study was not done. In all 21 cases the primary neuropathological cause of the dementia was AD. Neuropathology in addition to AD was also noted, including cortical Lewy bodies in three, infarcts on gross examination in three, multiple microscopic infarcts in four, and multiple cerebral metastases in one. Acknowledging a number of study limitations, it is remarkable that the judgment of the physicians was correct regarding AD in all 21 cases. It is questionable if a head CT or MRI scan at time of diagnosis would have benefited any of the patients. 相似文献
54.
Obesity is a global health epidemic with considerable economic burden.Surgical solutions have become increasingly popular following technical advances leading to sustained efficacy and reduced risk.Sleeve gastrectomy accounts for almost half of all bariatric surgeries worldwide but concerns regarding its relationship with gastroesophageal reflux disease(GERD)has been a topic of debate.GERD,including erosive esophagitis,is highly prevalent in the obese population.The role of pre-operative endoscopy in bariatric surgery has been controversial.Two schools of thought exist on the matter,one that believes routine upper endoscopy before bariatric surgery is not warranted in the absence of symptoms and another that believes that symptoms are poor predictors of underlying esophageal pathology.This debate is particularly important considering the evidence for the association of laparoscopic sleeve gastrectomy(LSG)with de novo and/or worsening GERD compared to the less popular Roux-en-Y gastric bypass procedure.In this paper,we try to address 3 burning questions regarding the inter-relationship of obesity,GERD,and LSG:(1)What is the prevalence of GERD and erosive esophagitis in obese patients considered for bariatric surgery?(2)Is it necessary to perform an upper endoscopy in obese patients considered for bariatric surgery?And(3)What are the long-term effects of sleeve gastrectomy on GERD and should LSG be done in patients with pre-existing GERD? 相似文献
55.
Oncogenic targets Mmp7, S100a9, Nppb and Aldh1a3 from transcriptome profiling of FAP and Pirc adenomas are downregulated in response to tumor suppression by Clotam 下载免费PDF全文
56.
Influence of immediate and delayed post space preparation on sealing ability of resilon. 总被引:1,自引:0,他引:1
Emre Bodrumlu Umut Tunga Tayfun Ala?am 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2007,103(6):e61-e64
OBJECTIVE: The purpose of this study was to evaluate the effect of immediate and delayed post space preparation on the sealing ability of a new root canal filling material. STUDY DESIGN: Seventy-two extracted teeth were prepared and obturated with gutta-percha/AH-Plus and Resilon/Epiphany sealer by the lateral compaction technique. The teeth were divided randomly into 4 groups, and the post space was prepared either immediately after filling or after the obturated teeth had been stored in saline at 37 degrees C for a week. Leakage was determined by a fluid-transport device. RESULTS: The results showed that immediate post space preparation of the Resilon/Epiphany-filled group had a mean leakage value of 0.81 microL/h, whereas the delayed preparation had a mean leakage value of 0.75 microL/h. No difference (P > .05) in microleakage was found between gutta-percha/AH-Plus and Resilon/Epiphany-filled groups after immediate preparation. There was significant difference between gutta-percha/AH-Plus and Resilon/Epiphany groups in the delayed post space preparation (P < .05). CONCLUSION: Epiphany/Resilon obturation achieved better sealing than gutta-percha/AH-Plus at the apical end, especially in delayed post space preparation when mechanical techniques were used. 相似文献
57.
58.
Savaş Gürsoy Emin Erdal Hasan Herken Ercan Madenci Belgin Alaşehirli 《Rheumatology international》2001,21(2):58-61
Serotonin (5-HT) is a key neurotransmitter in the central nervous system. It is suggested that serotonergic dysfunction may be involved in the pathophysiology of fibromyalgia syndrome (FS). In this study, we aimed to investigate T102C polymorphism of the 5-HT2A receptor gene in FS. Fifty-eight patients with FS and 58 unrelated healthy volunteer controls were included in the study. In both groups, the C/C, C/T, and T/T genotypes of the 5-HT gene were represented in 31% (22.4% in controls), 50% (53.4%), and 19% (24.1%), respectively. The 5-HT2A receptor gene polymorphism results were not significantly different between patients and controls (chi squared test, P>0.05). There was a significant correlation between patients with the T/T genotype and the subgroup according to the SCL-90-R test, (analysis of variance, P<0.05). We also saw that patients with the T/T genotype had the lowest pain threshold. CONCLUSION. T102C polymorphism of the 5-HT2A receptor gene is not associated with the etiology of FS. Our results also indicate that the T/T genotype may be responsible for psychiatric symptoms of FS. 相似文献
59.
An indirect competitive enzyme-linked immunosorbent assay was developed using polyclonal antibody to detect extracellular polymeric secretions (EPS) produced by the marine stromatolite-forming cyanobacteria, Schizothrix sp. The cross-reactivity of this assay with other EPSs and polymers were low (< 0.5%). This assay can detect Schizothrix sp. EPS as low as 0.5 ng/mL. Intra-assay and inter-assay comparisons showed that coefficient variations were low, ranging from 3.34 to 10.30% and from 6.30 to 12.8%, respectively, for standards between 2 and 1000 ng/mL. Also, the seawater matrix effect was negligible. Our results indicated that this assay is a useful tool for quantification of Schizothrix sp. EPS in a range of ng/mL. 相似文献
60.
Ala S. Qutishat 《Clinical biochemistry》2009,42(4-5):256-258
ObjectivesTo investigate and describe the current status of quality regulations and accreditation standards in the medical laboratories in Jordan.Design and methodsDescribe the demography of Jordan. Classify the medical laboratories by health sectors. Describe the authority bodies in regard to health sectors and medical laboratories. Review the current by laws of licensing a medical laboratory, quality regulations, and accreditation projects currently active in Jordan.ResultsJordan is a developing country in the Middle East with limited resources, young population, but special success in education and health sectors. Medical laboratory services are being provided by many sectors. In regard to licensing to open a private laboratory, regulations are set and applied well. Regulations with regard to quality are set, but are not uniformly applied. Accreditation is a new concept, a voluntary process, and been granted to few laboratories by international accreditation bodies. Two local accreditation projects have started licensing to open a private laboratory is well regulated.ConclusionsQuality regulations are set, but not uniformly applied. Accreditation is a new concept and needs to be encouraged and improved. 相似文献