全文获取类型
收费全文 | 2613篇 |
免费 | 223篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 22篇 |
儿科学 | 102篇 |
妇产科学 | 43篇 |
基础医学 | 401篇 |
口腔科学 | 69篇 |
临床医学 | 213篇 |
内科学 | 516篇 |
皮肤病学 | 40篇 |
神经病学 | 251篇 |
特种医学 | 53篇 |
外国民族医学 | 2篇 |
外科学 | 304篇 |
综合类 | 75篇 |
一般理论 | 2篇 |
预防医学 | 229篇 |
眼科学 | 35篇 |
药学 | 171篇 |
中国医学 | 45篇 |
肿瘤学 | 277篇 |
出版年
2023年 | 20篇 |
2022年 | 28篇 |
2021年 | 60篇 |
2020年 | 53篇 |
2019年 | 49篇 |
2018年 | 64篇 |
2017年 | 51篇 |
2016年 | 49篇 |
2015年 | 60篇 |
2014年 | 84篇 |
2013年 | 117篇 |
2012年 | 128篇 |
2011年 | 166篇 |
2010年 | 90篇 |
2009年 | 85篇 |
2008年 | 113篇 |
2007年 | 163篇 |
2006年 | 152篇 |
2005年 | 124篇 |
2004年 | 122篇 |
2003年 | 117篇 |
2002年 | 115篇 |
2001年 | 52篇 |
2000年 | 37篇 |
1999年 | 44篇 |
1998年 | 38篇 |
1997年 | 28篇 |
1996年 | 36篇 |
1995年 | 39篇 |
1994年 | 30篇 |
1993年 | 17篇 |
1992年 | 25篇 |
1991年 | 25篇 |
1990年 | 21篇 |
1989年 | 26篇 |
1988年 | 23篇 |
1987年 | 34篇 |
1986年 | 22篇 |
1985年 | 27篇 |
1984年 | 15篇 |
1982年 | 14篇 |
1981年 | 14篇 |
1980年 | 12篇 |
1979年 | 20篇 |
1978年 | 32篇 |
1977年 | 28篇 |
1976年 | 14篇 |
1973年 | 20篇 |
1972年 | 15篇 |
1971年 | 19篇 |
排序方式: 共有2850条查询结果,搜索用时 15 毫秒
1.
J. Savige L. Amos Frank Ierino H. G. Mack R. C. Andrew Symons P. Hughes 《Ophthalmic genetics》2016,37(4):369-376
Background: Dense deposit disease and atypical hemolytic uremic syndrome are often caused by Complement Factor H (CFH) mutations. This study describes the retinal abnormalities in dense deposit disease and, for the first time, atypical haemolytic uremic syndrome. It also reviews our understanding of drusen pathogenesis and their relevance for glomerular disease. Methods: Six individuals with dense deposit disease and one with atypical haemolytic uremic syndrome were studied from 2 to 40 years after presentation. Five had renal transplants. All four who had genetic testing had CFH mutations. Individuals underwent ophthalmological review and retinal photography, and in some cases, optical coherence tomography, and further tests of retinal function. Results: All subjects with dense deposit disease had impaired night vision and retinal drusen or whitish-yellow deposits. Retinal atrophy, pigmentation, and hemorrhage were common. In late disease, peripheral vision was restricted, central vision was distorted, and there were scotoma from sub-retinal choroidal neovascular membranes and atypical serous retinopathy. Drusen were present but less prominent in the young person with atypical uremic syndrome due to a heterozygous CFH mutation. Conclusions: Drusen are common in forms of C3 glomerulopathy caused by compound heterozygous or heterozygous CFH mutations. They are useful diagnostically but also impair vision. Drusen have an identical composition to glomerular deposits. They are also identical to the drusen of age-related macular degeneration, and may respond to the same treatments. Individuals with a C3 glomerulopathy should be assessed ophthalmologically at diagnosis, and monitored regularly for vision-threatening complications. 相似文献
2.
Amos Adler Na'ama Sturlesi Noga Fallach Deniz Zilberman-Barzilai Omar Hussein Shlomo E. Blum Eyal Klement Mitchell J. Schwaber Yehuda Carmeli 《Journal of clinical microbiology》2015,53(11):3515-3521
Our objectives were to study the prevalence, risk factors for carriage, and transmission dynamics of extended-spectrum-β-lactamase (ESBL)-producing Enterobacteriaceae (ESBLPE) in a national survey of cattle. This was a point prevalence study conducted from July to October 2013 in Israel. Stool samples were collected from 1,226 cows in 123 sections on 40 farms of all production types. ESBLPE were identified in 291 samples (23.7%): 287 contained Escherichia coli and 4 contained Klebsiella pneumoniae. The number of ESBLPE-positive cows was the highest in quarantine stations and on fattening farms and was the lowest on pasture farms (P = 0.03). The number of ESBLPE-positive cows was the lowest in sections containing adult cows (age, >25 months) and highest in sections containing calves (age, <4 months) (P < 0.001). Infrastructure variables that were significant risk factors for ESBLPE carriage included crowding, a lack of manure cleaning, and a lack of a cooling (P < 0.001 for each), all of which were more common in sections containing calves. Antimicrobial prophylaxis was given almost exclusively to calves and was associated with a high number of ESBLPE carriers (P < 0.001). The 287 E. coli isolates were typed into 106 repetitive extragenic palindromic (REP)-PCR types and mostly harbored blaCTX-M-1 or blaCTX-M-9 group genes. The isolates on the six farms with ≥15 isolates of ESBLPE were of 4 to 7 different REP-PCR types, with one dominant type being harbored by about half of the isolates. Fourteen types were identified on more than one farm, with only six of the farms being adjacent to each other. The prevalence of ESBLPE carriage is high in calves in cowsheds where the use of antimicrobial prophylaxis is common. ESBLPE disseminate within cowsheds mainly by clonal spread, with limited intercowshed transmission occurring. 相似文献
3.
Ullmann Yehuda MD Shoshani Oren MD Fodor Adriana MD Ramon Yitzhak MD Carmi Nurit PhD Eldor Liron MD Gilhar Amos MD 《Dermatologic surgery》2005,31(10):1304-1307
BACKGROUND: The use of suctioned fat grafts for correction of soft tissue defects is a widespread procedure in esthetic and reconstructive surgery. The main disadvantage of this simple and sensible procedure is the unpredictable absorption rate of the fat graft. A lot of research has been performed aiming for enhancement of the take of the fat grafts. OBJECTIVE: Our study was performed to find if there is any favorable donor site for fat harvesting. METHODS: This in vivo experiment using the nude mice model enables the study of the long-term survival of human fat in an animal model. The fat was harvested from three donor areas: the thigh, abdomen, and breast of a 48-year-old woman who came for an elective esthetic procedure. After centrifugation, 1 cc of fat was injected subcutaneously into the scalp of the nude mouse. There were 15 mice in each of the three groups, according to the selected donor sites. The animals were sacrificed 16 weeks after the procedure. The extracted fat was evaluated in terms of weight, volume, and six histologic parameters: integrity, vascularization, cyst formation, fibrosis, necrosis, and inflammation. RESULTS: This study could not find any statistically significant differences between the three investigated donor sites in the evaluated parameters. CONCLUSION: On the basis of this study, there is no favorable area for harvesting fat grafts. The donor site can be chosen according to the preference of the surgeon and the patient. 相似文献
4.
Using liposomes radiolabelled by the 99mTechnetium-stannous chloride technique we have investigated the effect of surface charge on the stability of the isotope in vitro and in vivo. Dialysis of 99mTc-labelled positive, negative and neutral liposomes, which had been incubated in either saline or normal rat serum showed no significant loss of the isotope from the liposome surface with only 2 per cent of the isotope dialysed. A comparison of gel chromatography with dialysis confirmed that most of the isotope remained attached to the liposome surface, but it did reveal greater loss of the isotope, between 15 and 23 per cent. The liposome clearance rates obtained from 125I-egg phosphatidylcholine (EPC) and 99mTc dual-labelled positive or neutral liposomes were significantly different. The 99mTc marker was cleared five times faster from the positive liposomes and twice as fast from the neutral liposomes as the 125I-EPC integral membrane marker. The 99mTc attached to liposomes with a negative surface charge was stable in vivo and had the same clearance rate from the circulation as the 125I-EPC marker. These results indicate that the commonly used in vitro techniques for assessing liposome radiolabel stability are unsuitable for predicting the stability of the 99mTc in vivo. 相似文献
5.
6.
The use of a subperiosteal tissue expander in rib reconstruction of an atrophic mandible 总被引:2,自引:0,他引:2
A technique is described that provides adequate coverage for rib grafts used in reconstruction of the atrophic mandible. The flaps are highly vascular and thick because of the fibrous capsule that forms around the tissue expander. A one-stage expansion technique is used that reduces the total time needed for reconstruction. 相似文献
7.
CM Reid M. Nelson P. Beckinsale P. Ryan LMH Wing LJ Beilin MA Brown GLR Jennings CI Johnston J. Marley JJ McNeil TO Morgan J. Shaw ID Steven MJ West 《Clinical and experimental pharmacology & physiology》1997,24(5):370-373
1. The present study aimed to determine the feasibility of conducting a 5 year cardiovascular outcome trial of the treatment of 6000 elderly hypertensive patients in Australian general practices. 2. General practitioners (GPs) were invited to participate by mail and personal follow-up. Patient records were reviewed to identify subjects for a blood pressure (BP) screening programme. Blood pressure was measured on three occasions and eligible subjects were included if the average BP was 160 mmHg systolic or 90 mmHg diastolic if systolic BP was 140 mmHg. 3. Seven hundred and forty-one GPs were approached and 89 were enrolled in the study (12% of mail invites and 75% of those receiving a personal contact). In 16 practices where screening was completed, 82 000 records were reviewed to identify 4% patients eligible for screening. Twenty-two per cent of eligible subjects attended screening. Of 1938 subjects screened, 180 (9%) had BP 5=160/90 mmHg. Forty-seven percent of subjects (n = 916) were receiving antihypertensive therapy and 184 (20%) were withdrawn from therapy. One hundred and sixteen (63%) of these subjects had BP return to study entry levels within 6 weeks. Fifty-seven newly diagnosed and 81 previously treated subjects were randomized (7% of the screened population). 4. Based on the high participation rate of GPs, the response rate of patients to attend a BP screening programme and the 7% randomization to screening ratio for entry into the study, the ANBP2 pilot study has demonstrated that it is feasible to recruit subjects from Australian general practices to a cardiovascular outcome trial. 相似文献
8.
9.
10.
Kirsty E Amos Shahram Anari Charlotte A Buswell Emma J McNeill Athanasia Printza Stephen J Ray Isam Rustom 《Annals of general psychiatry》2006,5(1):1-5