全文获取类型
收费全文 | 1031篇 |
免费 | 63篇 |
国内免费 | 9篇 |
学科分类
医药卫生 | 1103篇 |
出版年
2022年 | 6篇 |
2021年 | 12篇 |
2020年 | 7篇 |
2019年 | 5篇 |
2018年 | 10篇 |
2017年 | 9篇 |
2016年 | 11篇 |
2015年 | 13篇 |
2014年 | 33篇 |
2013年 | 32篇 |
2012年 | 43篇 |
2011年 | 32篇 |
2010年 | 37篇 |
2009年 | 32篇 |
2008年 | 39篇 |
2007年 | 39篇 |
2006年 | 37篇 |
2005年 | 37篇 |
2004年 | 18篇 |
2003年 | 34篇 |
2002年 | 18篇 |
2001年 | 32篇 |
2000年 | 32篇 |
1999年 | 25篇 |
1998年 | 30篇 |
1997年 | 32篇 |
1996年 | 45篇 |
1995年 | 42篇 |
1994年 | 38篇 |
1993年 | 22篇 |
1992年 | 14篇 |
1991年 | 17篇 |
1990年 | 13篇 |
1989年 | 26篇 |
1988年 | 28篇 |
1987年 | 26篇 |
1986年 | 19篇 |
1985年 | 22篇 |
1984年 | 14篇 |
1983年 | 12篇 |
1982年 | 9篇 |
1981年 | 8篇 |
1980年 | 13篇 |
1978年 | 7篇 |
1977年 | 8篇 |
1976年 | 10篇 |
1975年 | 10篇 |
1972年 | 6篇 |
1969年 | 8篇 |
1881年 | 6篇 |
排序方式: 共有1103条查询结果,搜索用时 0 毫秒
101.
BACKGROUND: Extramedullary hematopoiesis (EMH) is known to occur in myeloproliferative disorders and hemoglobinopathies and is usually seen in the spleen and liver. METHODS: We report the first case of EMH causing subglottic stenosis in a woman with postpolycythemia myeloid metaplasia (PPMM). A tracheotomy was performed to maintain the airway and local radiotherapy was given. RESULTS: Two months after the radiotherapy was completed laryngoscopy showed an unobstructed airway with no evidence of disease, and the patient was successfully decanulated. Magnetic resonance imaging 8 months after radiotherapy confirmed the absence of local disease. CONCLUSION: Consideration should be given to EMH as a possible cause of airway obstruction in the differential diagnosis of a patient with a history of PPMM. 相似文献
102.
Robinson JW Donnelly BJ Coupland K Siever JE Saliken JC Scott C Brasher PM Ernst DS 《Urologic oncology》2006,24(6):472-486
PURPOSE: Previous research has raised concerns that although salvage cryosurgery may be an effective treatment to prevent the progression of prostate cancer after radiotherapy failure, the quality of life cost many be so severe as to prevent its acceptance as a viable treatment. The present study's purpose was to further the understanding of the quality of life outcomes of salvage cryosurgery. MATERIALS AND METHODS: A total of 46 men with locally recurrent prostate cancer after radiotherapy were recruited to participate in a prospective Phase II clinical trial using salvage cryosurgery. There were 2 questionnaires (i.e., the European Organization of Research and Treatment of Cancer QLQ C30 and the Prostate Cancer Index) administered before cryosurgery, and at 1.5, 3, 6, 12, 18, and 24 months after treatment. RESULTS: Quality of life returned to preoperative levels by 24 months after cryosurgery in all domains, with the exception of urinary and sexual functioning. At 24 months, 29% of men reported urinary bother as a moderate-to-big problem, and 56% reported sexual bother as a moderate-to-big problem. CONCLUSIONS: To our knowledge, this is the first study to evaluate prospectively men's quality of life for 2 years after salvage cryosurgery for locally recurrent prostate cancer after radiotherapy. Long-term impairments in quality of life appear to be limited to the sexual and urinary function domains. Overall quality of life appears to be high. These results support salvage cryosurgery as a viable treatment option. 相似文献
103.
104.
Sarah E. Coupland Philip L. Penfold Francis A. Billson 《Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie》1994,232(3):182-191
The distributions of the hydrolases acid and alkaline phosphatase (AP and ALP), N-acetyl--l-glucosaminidase (NAG), -glucuronidase (-Gluc), -galactosidase (-Gal), non-specific esterase (UE), dipeptidylpeptidases II and IV (DPPII and DPPIV), aminopeptidases M and A (APM and APA), and -glutamyltransferase (GGT) were investigated in the human, pig and Lewis rat normal anterior segment by histochemical methods. The distribution of the above hydrolases, particularly that of proteases, varied between ocular tissues and between the three species. Lysosomal hydrolases together with GGT and ALP were consistently active in the corneal epithelium, stroma and endothelium in all three species; the corneal distribution and activity of -Gal, APM, APA and DPPIV, however, displayed interspecies variation. The angular tissues showed similarities for most hydrolases with the exceptions of -Gal, UE, APM, APA and DPPIV In all eyes examined strong ciliary epithelial activity for AP, -Gal, UE, GGT and ALP was observed in the pars plicata; only the pig eye also displayed strong DPPIV activity in this area. Regional differences in hydrolase distribution in the iris were observed in all species. A post-mortem freezing delay of longer than 24 h resulted in a decrease in hydrolase activity. 相似文献
105.
Sarah E. Coupland Lothar Krause Friedrich Hoffmann 《Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie》1996,234(2):116-124
Background: The presence of Ia-positive cells (MHC class II equivalent) has been previously reported in the iris and choroid of various species. They have been reported to have both round and dendritic morphologies; the latter may represent classic dendritic cells, potent antigen-presenting cells (APCs). It is possible that the dendritic-like cells play a important role in (auto)immune processes of uveal and other ocular tissues. Using the flat or whole mount technique, the distribution of Ia-positive cells in the rat iris and choroid was investigated following penetrating Keratoplasty (PKP) and following treatment with cyclosporin A (CsA). Methods: Lewis (LW) rats received corneal buttons from Lewis-Brown Norway (LW-BN) donors and were randomly assigned to the following groups: (i) operated, untreated (n=24); (ii) operated, CsA-treated (10 mg/kg i.m.;n=22). Controls were groups (iii) normal LW rats (n=13); (iv) unopcrated, CsA-treated (16 days' treatment;n=8); (v) anterior perforation of the anterior chamber (n=3); (vi) eight corneal sutures only (n=4); (vii) syngeneic operated (LW to LW;n=4). Animals of groups (i) and (ii) were killed on the 5th, 9th and 13th postoperative days and on appearance of the corneal rejection (group i, day 13; group ii, day 16). Both eyes were enucleated, immediately fixed, and iris-choroid flat mounts were examined for Ia-positive cells using APAAP immunohistochemistry. Results: In the normal Lewis rat iris, scattered Ia-positive cells of both nondendritic and dendritic morphology were observed. CsA treatment in the unoperated rat did not result in a significant decrease in the percentage of dendritic cells in the iris or choroid. Anterior chamber perforation, the placement of sutures in the cornea and syngeneic PKP resulted in a moderate increase in iris Ia-positive cells. Allogeneic transplantation resulted in a large increase in both types of Ia-positive cells, particularly on day 13 with corneal rejection. In group ii, an initial decrease in Ia-positive cells until day 13 was observed; upon rejection (day 16), the histological picture was similar to that of untreated animals. Alterations in the operated choroid were also apparent following CsA treatment. Conclusion: Corneal transplantation in the Lewis rat results in an increase in Ia-positive cells in the iris; CsA therapy can delay but not prevent this reaction. Changes in choroidal Ia-positive cells following PKP were not apparent, their numbers being affected only by CsA treatment following grafting. 相似文献
106.
107.
Structural and functional protection of photoreceptors from MNU-induced retinal degeneration by the X-linked inhibitor of apoptosis 总被引:2,自引:0,他引:2
Petrin D Baker A Coupland SG Liston P Narang M Damji K Leonard B Chiodo VA Timmers A Hauswirth W Korneluk RG Tsilfidis C 《Investigative ophthalmology & visual science》2003,44(6):2757-2763
PURPOSE: To evaluate the neuroprotective effects of adenoassociated virus delivery of XIAP in N-methyl-N-nitrosourea (MNU)-induced retinal degeneration in Sprague-Dawley rats. METHODS: Sprague-Dawley rats were injected subretinally with recombinant adenoassociated virus (rAAV) encoding either XIAP or green fluorescent protein (GFP; injection control). Six weeks after injection, the animals received an intraperitoneal injection of MNU, a DNA methylating agent, at a dose of 60 mg/kg. Electroretinograms (ERGs) were recorded at 0, 24, 48 and 72 hours and 1 week after MNU. The rats were killed after the ERG was performed and were perfused with 4% paraformaldehyde. Eyes were then enucleated and embedded for cryosectioning. Eye sections were analyzed by TUNEL and histologic techniques. Real-time PCR and Western analysis were performed to confirm the overexpression of XIAP in injected eyes. RESULTS: Real-time PCR and Western analysis confirmed the overexpression of XIAP in virus-injected eyes in comparison to uninjected control eyes. At 24 hours after MNU injection, fewer cells had undergone apoptosis in the XIAP-treated eyes in comparison with GFP-injected or uninjected eyes. Hematoxylin and eosin staining revealed that the uninjected and GFP-injected photoreceptors were destroyed by 72 hours after injection of MNU, whereas the AAV-XIAP-injected eyes showed structural protection of the photoreceptors at all time points throughout the 1-week sampling period. ERGs showed functional protection up to 1 week after MNU injection in the AAV-XIAP-injected eye, whereas no response was observed in the control eye. CONCLUSIONS: The results suggest that XIAP is protective against this potent chemotoxic agent and holds promise as a therapeutic agent in gene therapy approaches to treating retinitis pigmentosa. 相似文献
108.
109.
N. J. Coupland MB ChB J. E. Bailey S. J. Wilson R. Horvath MB ChB D. Nutt DM 《Clinical autonomic research》1995,5(3):171-177
This study assessed the effects of clonidine on blood pressure (BP) and heart rate responses to active standing, recorded continuously using a Finapres monitor. Ten subjects were given a placebo infusion over 1 h, followed by clonidine hydrochloride 1.5 µg/kg over 2 h. During placebo and at 1, 3 and 19 h following the clonidine infusion, heart rate and blood pressure were recorded during the second half of supine rest for 10 min, active standing and quiet standing for 7 min. Clonidine did not alter the size of immediate drop in BP on standing, although the nadir was lower. BP recovery was impaired, with a loss of the usual BP overshoot in most subjects and with delays in reaching supine levels of diastolic BP (6.1 versus 9.6 s; p < 0.01) and systolic BP (8.1 versus 12.3 s; p < 0.05). The compensatory initial heart rate rise was significantly increased from 47 to 53 beats/min (p < 0.05), athough the peak rate reached was reduced from 114 to 104 beats/min (p < 0.05). These results demonstrate that impairment of central sympathetic vasomotor drive leads to a delay in BP recovery and loss of initial BP overshoot immediately after standing, together with impaired maintenance of early steady-state BP. 相似文献
110.
Twenty-six patients over the age of 50 years with proven iron deficiency anaemia were identified, investigated and followed up in general practice over a five-year period. The anaemia was symptomatic in 50% of patients but only 20% had symptoms related to the gut. Faecal occult blood testing was positive in five patients only and negative tests occurred in three patients with significant disease, including one caecal carcinoma. All patients agreed to oesophagogastroduodenoscopy (OGD) and fibreoptic sigmoidoscopy carried out on the same occasion. In eight patients, significant abnormalities were found on OGD and in two patients on sigmoidoscopy. Four patients declined barium enema examinations, two of whom had significant OGD abnormalities. Barium enema examination of the other 22 patients showed polyposis of the colon and a caecal carcinoma and initially missed one carcinoma of the caecum which was found subsequently. The likelihood of finding significant disease in iron-deficient patients over 50 years of age is high and should be assumed to be due to blood loss into the gut. Investigation by OGD, sigmoidoscopy and barium enema in the first instance seems warranted and is a condition that can be safely managed by the GP. (Br J Clin Pract 1997; 51(2) : 78-80) 相似文献