全文获取类型
收费全文 | 843篇 |
免费 | 89篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 48篇 |
妇产科学 | 10篇 |
基础医学 | 128篇 |
口腔科学 | 16篇 |
临床医学 | 74篇 |
内科学 | 146篇 |
皮肤病学 | 10篇 |
神经病学 | 36篇 |
特种医学 | 110篇 |
外科学 | 51篇 |
综合类 | 22篇 |
预防医学 | 67篇 |
眼科学 | 61篇 |
药学 | 27篇 |
肿瘤学 | 123篇 |
出版年
2021年 | 11篇 |
2020年 | 7篇 |
2019年 | 7篇 |
2018年 | 19篇 |
2017年 | 14篇 |
2016年 | 14篇 |
2015年 | 19篇 |
2014年 | 25篇 |
2013年 | 31篇 |
2012年 | 23篇 |
2011年 | 25篇 |
2010年 | 15篇 |
2009年 | 32篇 |
2008年 | 20篇 |
2007年 | 23篇 |
2006年 | 29篇 |
2005年 | 25篇 |
2004年 | 17篇 |
2003年 | 25篇 |
2002年 | 29篇 |
2001年 | 25篇 |
2000年 | 19篇 |
1999年 | 18篇 |
1998年 | 29篇 |
1997年 | 32篇 |
1996年 | 31篇 |
1995年 | 20篇 |
1994年 | 28篇 |
1993年 | 18篇 |
1992年 | 27篇 |
1991年 | 18篇 |
1990年 | 16篇 |
1989年 | 22篇 |
1988年 | 23篇 |
1987年 | 15篇 |
1986年 | 20篇 |
1985年 | 12篇 |
1983年 | 10篇 |
1982年 | 15篇 |
1981年 | 7篇 |
1980年 | 12篇 |
1979年 | 9篇 |
1977年 | 10篇 |
1976年 | 8篇 |
1975年 | 9篇 |
1974年 | 11篇 |
1971年 | 7篇 |
1970年 | 5篇 |
1967年 | 5篇 |
1966年 | 6篇 |
排序方式: 共有934条查询结果,搜索用时 15 毫秒
1.
2.
3.
W D Lovan R A Weaver R J Lentz J K Goodrum B F Withers 《Aviation, space, and environmental medicine》1986,57(4):370-375
The Naval Special Board of Flight Surgeons was established in 1956 for the evaluation of Navy, Marine Corps, and Coast Guard problem aeromedical cases. This paper examines a sample 248 of these cases for the period of 1974-83 with respect to the characteristics of those referred, their referral diagnostic category, and the recommendation of the Special Board regarding return to a flying status. Those cases with a referral diagnostic category of ENT and Ophthalmology were less likely to be returned to flight status. Older, more senior pilots, and pilots with more total flight time were less likely to be returned to unrestricted flying than were their younger, more junior, and less experienced counterparts. Otherwise, no significant difference in outcome based on age, rank, marital status, branch of service, specialty, or flight hours was detected. Overall, 61% of those evaluated by the SBFS were returned to flight status. 相似文献
4.
Benign intracranial hypertension and recombinant growth hormone therapy in Australia and New Zealand
PA Crock JD McKenzie AM Nicoll NJ Howard W Cutfield LK Shield G Byrne 《Acta paediatrica (Oslo, Norway : 1992)》1998,87(4):381-386
Benign intracranial hypertension (BIH) is reported in three children from Australia and one from New Zealand, who were being treated with recombinant human growth hormone (rhGH). Three males and one female, aged between 10.5 and 14.2 y, developed intracranial hypertension within 2 weeks to 3 months of starting treatment. A national database, OZGROW, has been prospectively collecting data on all 3332 children treated with rhGH in Australia and New Zealand from January 1986 to 1996. The incidence of BIH in children treated with growth hormone (GH) is small, 1.2 per 1000 cases overall, but appears to be greater with biochemical GHD (<10IUml -1 ), i.e. 6.5/1000 (3 in 465 cases), relative risk 18.4, 95% confidence interval 1.9-176.1, than in all other children on the database. The incidence in patients with Turner's syndrome was 2.3/1000 (1 in 428 cases). No cases in patients with partial GHD (10–20 IUml -1 ) or chronic renal failure were identified. Possible causative mechanisms are discussed. The authors'practice is now to start GH replacement at less than the usual recommended dose of 14IUm-2 week-1 in those children considered to be at high risk of developing BIH. Ophthalmological evaluation is recommended for children before and during the first few months following commencement of rhGH therapy and is mandatory in the event of peripheral or facial oedema, persistent headaches, vomiting or visual symptoms. The absence of papilledema does not exclude the diagnosis. 相似文献
5.
6.
Alteration in myelin-associated proteins following spinal cord irradiation in guinea pigs. 总被引:3,自引:0,他引:3
C S Chiang K A Mason H R Withers W H McBride 《International journal of radiation oncology, biology, physics》1992,24(5):929-937
The aim of this study was to investigate the pathological and cellular basis for radiation-induced myelopathy in guinea pigs by monitoring biochemical alterations in levels of myelin basic protein and 2',3'-cyclic nucleotide phosphohydrolase. Guinea pigs were irradiated to the lumbar region with various doses of neutrons or cobalt gamma irradiation. The ED50s for paralysis were 17.2 Gy and 67.5 Gy for neutron and cobalt irradiation, respectively, and was histologically associated with demyelination. In spinal cords taken from animals at the onset of paralysis myelin basic protein levels were decreased in direct relationship to the radiation dose. The lowest doses to cause paralysis led to a 25% decrease in MBP levels. In a separate experiment, alterations in MBP were measured in the spinal cords over the time period leading up to paralysis. Surprisingly, decreases in MBP were found immediately after the end of the 4 week irradiation period. These early changes in MBP were not markedly dose dependent and occurred with nonparalyzing doses. Dose-dependent decreases were found only just before the onset of paralysis. CNPase activity measured in the same specimens showed changes that were essentially similar to those for MBP. In the CSF, MBP levels were essentially constant until onset of paralysis. This study showed that demyelination, as assessed by the levels of the myelin-associated proteins MBP and CNPase, can occur soon after spinal cord irradiation but that profound dose-dependent changes are seen only immediately preceding the onset of paralysis. Although increases in MBP in the CSF were associated with the onset of radiation-induced myelopathy, its assay is unlikely to predict this complication of irradiation. 相似文献
7.
A new commercial kit, MEASLESTAT M (Whittaker Bioproducts, Inc.), was compared with the sucrose density gradient centrifugation-hemagglutination inhibition method for the detection of measles virus-specific immunoglobulin M. Overall agreement between the two procedures was 97.1% for 104 single and paired serum samples tested. The sensitivity and specificity of MEASLESTAT M were 98.4 and 95.2%, respectively. 相似文献
8.
9.
R. T. Withers N. O. Whittingham K. I. Norton J. La Forgia M. W. Ellis A. Crockett 《European journal of applied physiology》1987,56(2):169-180
Summary Ninety-one percent (n=182) of the female members of South Australian representative squads in 14 sports volunteered to act as subjects. Twenty-seven percent of them had represented Australia. The underwater weighing method together with the measurement of residual volume (RV) by helium dilution were used to determine body density (BD); the percent body fat (% BF) was then computed according to Siri.A stepwise multiple regression analysis yielded a correlation coefficient (R) of 0.863 between the criterion (BD) and the best weighted sum of predictors (anthropometric variables): BD (g·cm–3)=1.14075–0.04959 (log10 triceps, subscapular, supraspinale and calf skinfolds in mm)+0.00044 (age in decimal years)–0.000612 (waist girth in cm)+0.000284 (height in cm)–0.000505 (gluteal girth in cm)+0.000331 (breast girth in cm).Only those predictors which resulted in a statistically significant increase inR (p0.05) were included. The standard error of estimate of 0.00597 g · cm–3 was equivalent to 2.7% BF at the mean. This equation was shown to be largely population specific. There was a range of 7.6–35.8% of BF and the overall mean of 18.5% was significantly lower (p<0.001) than that of 23.4% obtained on a moderately active reference sample of similar age (n=135). If group sizes of only one or two are regarded as too small for meaningful comparison, then the lowest mean of 13.5% was achieved by the long-distance runners (n=14). The highest averages were registered by the heavyweight rowers (24.2%;n=7) and soccer players (22.0%;n=11). The overall average for games players (n=107) was 19.4%.This study was supported by a grant from the National Health and Medical Research Council of Australia 相似文献
10.