全文获取类型
收费全文 | 639篇 |
免费 | 36篇 |
国内免费 | 45篇 |
专业分类
儿科学 | 39篇 |
妇产科学 | 3篇 |
基础医学 | 80篇 |
口腔科学 | 13篇 |
临床医学 | 90篇 |
内科学 | 141篇 |
皮肤病学 | 9篇 |
神经病学 | 49篇 |
特种医学 | 130篇 |
外科学 | 28篇 |
综合类 | 18篇 |
预防医学 | 26篇 |
眼科学 | 6篇 |
药学 | 70篇 |
中国医学 | 1篇 |
肿瘤学 | 17篇 |
出版年
2022年 | 2篇 |
2021年 | 4篇 |
2019年 | 2篇 |
2018年 | 5篇 |
2016年 | 2篇 |
2015年 | 4篇 |
2014年 | 9篇 |
2013年 | 15篇 |
2012年 | 5篇 |
2011年 | 10篇 |
2010年 | 25篇 |
2009年 | 26篇 |
2008年 | 9篇 |
2007年 | 35篇 |
2006年 | 13篇 |
2005年 | 13篇 |
2004年 | 7篇 |
2003年 | 10篇 |
2002年 | 6篇 |
2001年 | 8篇 |
2000年 | 15篇 |
1999年 | 16篇 |
1998年 | 44篇 |
1997年 | 35篇 |
1996年 | 39篇 |
1995年 | 27篇 |
1994年 | 19篇 |
1993年 | 21篇 |
1992年 | 21篇 |
1991年 | 12篇 |
1990年 | 28篇 |
1989年 | 37篇 |
1988年 | 36篇 |
1987年 | 28篇 |
1986年 | 24篇 |
1985年 | 17篇 |
1984年 | 13篇 |
1983年 | 13篇 |
1982年 | 9篇 |
1981年 | 6篇 |
1980年 | 7篇 |
1979年 | 3篇 |
1978年 | 7篇 |
1977年 | 11篇 |
1976年 | 6篇 |
1975年 | 5篇 |
1971年 | 2篇 |
1967年 | 2篇 |
1966年 | 2篇 |
1965年 | 1篇 |
排序方式: 共有720条查询结果,搜索用时 15 毫秒
21.
22.
23.
Susan Minson Marina Muñoz Inés Vergara Martin Mraz Robert Vaughan Lesley Rees Jonathon Olsburgh Francis Calder Rukshana Shroff 《Pediatric nephrology (Berlin, Germany)》2013,28(8):1299-1305
Background
There are no guidelines for the removal of a failed renal allograft, and its impact on subsequent dialysis and retransplantation has not yet been described.Methods
We performed a 10-year review of allograft failure to study the factors that determined an outcome of transplant nephrectomy and choice of subsequent renal replacement therapy in children with or without nephrectomy.Results
A total of 34 children developed graft failure over the 10-year study period, of whom 18 (53 %) required transplant nephrectomy. The median graft survival was 1.1 (range 0.2–10.6) versus 7.5 (1.5–15.0) years in the nephrectomy and non-nephrectomy groups, respectively (p?=?0.011). Children with graft failure within 1 year of transplantation were four-fold more likely to require transplant nephrectomy than those with graft failure after 1 year (p?=?0.04). Renal biopsy performed at ≤8 weeks prior to graft loss showed Banff grade II acute rejection in 13 of the 18 children who required subsequent nephrectomy versus three of the 13 children who did not need nephrectomy (p?=?0.01). Inflammation (fever, graft tenderness and raised C-reactive protein (CRP) in the 2 weeks preceding graft failure) was seen in 66 % of nephrectomized children, but not in any in the non-nephrectomy group (p?=?0.0003 for CRP between groups). Banff II rejection, an inflammatory response and the time post-transplantation significantly and independently predicted the outcome of nephrectomy (p?=?0.008, R 2?=?67 %). Human leukocyte antigen (HLA) antibody levels after graft failure were higher in the nephrectomy group (p?=?0.0003), but there was no difference between groups in terms of the presence or class of donor-specific antibodies. Of the children with graft failure, 82 % required dialysis (61 % hemodialysis) and 35 % have to date been successfully retransplanted.Conclusions
Children with Banff II rejection, an inflammatory response and early graft loss are more likely to require transplant nephrectomy. Nephrectomy may be associated with higher circulating HLA antibody levels. 相似文献24.
In this case, a male patient presented with a clinically and radiographieally unstable slipped capital femoral epiphysis (SCFE) as well as slipped calcaneal epiphysis years. Subsequent thorough at the age of 23 work-up revealed that he had some features of rickets and labo- ratory test demonstrated he had hypophos- phatemia (2.3mg/dl), normocalcemia, normal vi- tamin D metabolite levels, and secondary hy- perparathyroidism. 相似文献
25.
Comparison of the subacute toxicity and efficacy of 3-hydroxypyridin-4- one iron chelators in overloaded and nonoverloaded mice 总被引:3,自引:1,他引:3
Five orally effective iron chelators of the 3-hydroxypyridin-4-one series have been administered intraperitoneally to iron-overloaded and nonoverloaded male mice at a dose of 200 mg/kg/24 h for a total of 60 days to investigate the effect on iron loading and toxicity. There was a significant reduction in hepatic iron at the end of the study in the iron-overloaded mice with all compounds studied using chemical iron quantitation (P less than .001) and with Perls' stain (P less than .01). Liver iron removal with the hydroxypyridinones ranged from 37% with CP20 to 63% with CP51, compared with 46% removal for desferrioxamine (DFO). There was no significant reduction in splenic or cardiac iron with any chelator. There were no deaths in iron-overloaded animals receiving any of the hydroxypyridin-4-ones, but significantly more deaths in the nonoverloaded groups as a whole (P less than .03). No weight loss was observed with any chelator. Significant reductions in hemoglobin and white cell count were observed with CP20(L1). No histologic abnormalities of kidney, spleen, bone marrow, or stifle joints were observed. Intracytoplasmic inclusion bodies were observed in the centrilobular hepatocytes of animals administered each of the hydroxypyridin-4-ones, while the DFO-treated and control groups showed no such changes. 相似文献
26.
Detection of anti-HTLV-I Tax antibodies in HTLV-I enzyme-linked immunosorbent assay-negative individuals 总被引:10,自引:0,他引:10
Ehrlich GD; Glaser JB; Abbott MA; Slamon DJ; Keith D; Sliwkowski M; Brandis J; Keitelman E; Teramoto Y; Papsidero L 《Blood》1989,74(3):1066-1072
The HTLV-I tax gene protein (Tax) is not packaged within the mature viral particle from which the proteins for the commercially available enzyme-linked immunosorbent assay (ELISA) are derived. Screening of 162 individuals within a cohort of white intravenous (IV) drug abusers, previously identified as having an increased incidence of HTLV-I infection, demonstrated that seven of them had antibodies to the HTLV-I Tax protein but tested negative in HTLV-I ELISAs and Western blots prepared from purified virion proteins. Three out of 35 individuals in other behaviorally defined high-risk groups also displayed this limited pattern of reactivity to HTLV-I proteins. The presence of the anti-HTLV- I p40/Tax antibodies was determined by radioimmunoprecipitation assay (RIPA), which also revealed low levels of anti-env reactivity. The specificity of the anti-p40 reactivity was confirmed on specific Tax ELISAs and Western blots prepared from recombinantly produced Tax. In vitro gene amplification by the polymerase chain reaction (PCR) was used to establish the presence of sequences homologous to HTLV-I proviral DNA in four/four of these HTLV-I ELISA negative, Tax ELISA/Tax western blot/RIPA positive individuals. These data suggest that the true incidence of HTLV-I infection within high-risk cohorts is greater than previously reported. 相似文献
27.
EG Burden RW Walker DJ Ferguson AMF Goubran JR Howell JB John F Khan JS McGrath JP Evans 《Annals of the Royal College of Surgeons of England》2021,103(3):173
IntroductionWith the emergence of the COVID-19 pandemic, all elective surgery was temporarily suspended in the UK, allowing for diversion of resource to manage the anticipated surge of critically unwell patients. Continuing to deliver time-critical surgical care is important to avoid excess morbidity and mortality from pathologies unrelated to COVID-19. We describe the implementation and short-term surgical outcomes from a system to deliver time-critical elective surgical care to patients during the COVID-19 pandemic.Materials and methodsA protocol for the prioritisation and safe delivery of time-critical surgery at a COVID-19 ‘clean’ site was implemented at the Nuffield Health Exeter Hospital, an independent sector hospital in the southwest of England. Outcomes to 30 days postoperatively were recorded, including unplanned admissions after daycase surgery, readmissions and complications, as well as the incidence of perioperative COVID-19 infection in patients and staff.ResultsA total of 128 surgical procedures were performed during a 31-day period by a range of specialties including breast, plastics, urology, gynaecology, vascular and cardiology. There was one unplanned admission and and two readmissions. Six complications were identified, and all were Clavien-Dindo grade 1 or 2. All 128 patients had preoperative COVID-19 swabs, one of which was positive and the patient had their surgery delayed. Ten patients were tested for COVID-19 postoperatively, with none testing positive.ConclusionThis study has demonstrated the implementation of a safe system for delivery of time-critical elective surgical care at a COVID-19 clean site. Other healthcare providers may benefit from implementation of similar methodology as hospitals plan to restart elective surgery. 相似文献
28.
PURPOSE: The type and number of drug-related problems that commonly occur in hospitalized patients with HIV were studied. METHODS: The medical records of HIV-infected patients who were receiving antiretroviral therapy at the time of hospital admission between January 1, 2005, and August 31, 2006, were reviewed. Patients age 18 years or older who had received at least one dose of an antiretroviral for an HIV-related indication during their hospitalization were included in the study. Patients' medical records were evaluated to identify drug-related problems and adverse drug events secondary to antiretroviral therapy. RESULTS: Eighty-three patients were eligible for study inclusion. A total of 176 drug-related problems were identified. The most common drug-related problem identified among medication orders reviewed was inappropriate dosing. Of the 251 orders for antiretroviral agents, 57 drugs were inappropriately dosed. The most common drug-related problems among patients were drug-drug interactions and incomplete antiretroviral regimens. There was no significant difference in the mean length of stay between patients with or without drug-related problems. Admission by physicians who were not infectious diseases specialists was an independent risk factor for having at least one drug-related problem during hospitalization (odds ratio, 3.83; 95% confidence interval, 1.08-13.54). CONCLUSION: A majority of HIV-infected patients at one institution had at least one drug-related problem at hospital admission. The most common problem observed among the medication orders reviewed was inappropriate dosing. The most common drug-related problems observed among patients were drug-drug interactions and incomplete antiretroviral regimens. 相似文献
29.
M McCarthy JB Yuan A Campbell NP Lenzo K Butler‐Henderson 《Journal of Medical Imaging and Radiation Oncology》2008,52(6):564-569
18F‐fluorodeoxyglucose positron emission tomography (FDG‐PET) scans in the first 49 patients referred with either possible brain tumour or brain tumour recurrence were reviewed. FDG‐PET imaging was reported with reference to anatomical imaging. Based on the report the FDG study was classified as either positive or negative for the presence of tumour. Thirty‐eight cases were included in the analysis, 21 having pathological data and 17 with diagnostic clinical follow up. Eleven were excluded, as they had inadequate follow‐up data. Of the 21 cases with pathology, 18 were shown to have tumour. In this group there were five false‐negative scans and two false‐positive PET scans. Seventeen cases were assessed by clinical follow up, nine were considered to have been tumour. There were two false negatives with one false positive. The overall sensitivity, specificity and positive and negative predictive values were 74, 73, 87 and 53% respectively. This is similar to figures previously quoted in published work. Despite relatively limited numbers, the utility of FDG PET imaging in our hands is similar to published reports. With a positive predictive value of 87%, a positive FDG study indicates a high likelihood that there is brain tumour present. A negative study does not exclude the presence of tumour. 相似文献
30.
Sympathetic preganglionic neurons (SPN) in rat spinal cord were activated by the reflex stimulation of bulbospinal sympathetic neuronal pathways after a nitroprusside-induced hypotension. Hypotension-sensitive SPN, identified by immunoreactivity (IR) to the product of the immediate early gene c-fos and to choline acetyltransferase, were localized in the intermediolateral cell column of thoracic and upper lumbar cord, particularly middle to lower thoracic cord. Putative neurotransmitters, or their markers, in varicose fiber networks around SPN were identified. Nearly all hypotension-sensitive (Fos-IR) SPN were apposed by varicose fibers immunoreactive for tyrosine hydroxylase, serotonin, substance P, or enkephalin. Neuropeptide Y (NPY)- or phenylethanolamine-N-methyl transferase (PNMT)-IR varicose fibers apposed Fos-IR SPN in the upper and middle thoracic spinal cord, but in lower thoracic segments some Fos-IR SPN lacked these appositions. In thoracic segment 12, 51% +/- 5% of Fos-IR SPN (n = 9 rats) lacked PNMT contacts and 25% +/- 3% of Fos-IR SPN (n = 8 rats) lacked NPY contacts. In contrast to other chemically defined afferents, galanin-IR varicose fibers apposed fewer than half of the Fos-IR SPN in the middle to lower thoracic cord. Neurotransmitters/neuromodulators that might influence the activity of SPN acting in the baroreflex-mediated control of blood pressure have been identified. Uniformity in the neurochemistry of some fibers making connections with Fos-IR SPN, regardless of their segmental origin, suggests that common sets of neurons provide convergent inputs to all hypotension-sensitive SPN. Other fibers show topographic differences in their contacts with Fos-IR SPN, suggesting that subgroups of hypotension-sensitive SPN are targeted by particular neuron groups. 相似文献