全文获取类型
收费全文 | 459篇 |
免费 | 39篇 |
国内免费 | 11篇 |
专业分类
儿科学 | 98篇 |
妇产科学 | 6篇 |
基础医学 | 85篇 |
口腔科学 | 8篇 |
临床医学 | 47篇 |
内科学 | 62篇 |
皮肤病学 | 5篇 |
神经病学 | 14篇 |
特种医学 | 19篇 |
外科学 | 29篇 |
综合类 | 9篇 |
一般理论 | 1篇 |
预防医学 | 87篇 |
眼科学 | 3篇 |
药学 | 10篇 |
中国医学 | 12篇 |
肿瘤学 | 14篇 |
出版年
2023年 | 3篇 |
2022年 | 3篇 |
2021年 | 5篇 |
2020年 | 6篇 |
2019年 | 7篇 |
2018年 | 7篇 |
2017年 | 6篇 |
2016年 | 6篇 |
2015年 | 5篇 |
2014年 | 13篇 |
2013年 | 11篇 |
2012年 | 25篇 |
2011年 | 13篇 |
2010年 | 20篇 |
2009年 | 14篇 |
2008年 | 13篇 |
2007年 | 20篇 |
2006年 | 21篇 |
2005年 | 19篇 |
2004年 | 30篇 |
2003年 | 23篇 |
2002年 | 16篇 |
2001年 | 22篇 |
2000年 | 13篇 |
1999年 | 14篇 |
1998年 | 17篇 |
1997年 | 13篇 |
1996年 | 11篇 |
1995年 | 8篇 |
1994年 | 10篇 |
1993年 | 6篇 |
1992年 | 11篇 |
1991年 | 9篇 |
1990年 | 3篇 |
1989年 | 4篇 |
1988年 | 6篇 |
1987年 | 7篇 |
1986年 | 2篇 |
1985年 | 7篇 |
1984年 | 4篇 |
1983年 | 4篇 |
1982年 | 9篇 |
1980年 | 6篇 |
1977年 | 5篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1974年 | 5篇 |
1971年 | 2篇 |
1961年 | 4篇 |
1921年 | 2篇 |
排序方式: 共有509条查询结果,搜索用时 31 毫秒
41.
Olsen A Thiong'o FW Ouma JH Mwaniki D Magnussen P Michaelsen KF Friis H Geissler PW 《Transactions of the Royal Society of Tropical Medicine and Hygiene》2003,97(1):109-114
A randomized, placebo-controlled, double-blind, two-by-two factorial trial was carried out among 977 schoolchildren from 19 primary schools in Nyanza Province, Kenya from February 1995 to February 1996. The interventions were multimicronutrient supplementation (vitamin A, 1000 micrograms; vitamin B1, 1.4 mg; vitamin B2, 1.6 mg; vitamin B6, 1.7 mg; vitamin B12, 2.0 micrograms; folate, 150 micrograms; niacin, 16 mg; vitamin C, 50 mg; vitamin D, 5 micrograms; vitamin E, 8 mg; iron, 18 mg; zinc, 20 mg; copper, 2.0 mg; iodine, 150 micrograms; selenium, 40 micrograms) and multihelminth chemotherapy (albendazole 600 mg in a single dose and/or praziquantel 40 mg/kg in a single dose). This paper reports the effects of the supplementation given on all school days on reinfection with hookworm, Ascaris lumbricoides, Trichuris trichiura and Schistosoma mansoni after 11 months. Baseline prevalence and geometric mean intensity for hookworm, A. lumbricoides, T. trichiura and S. mansoni in all children investigated were 54.7%, 13.8%, 45.6% and 70.0%, respectively and 8.6, 2.7, 5.9 and 19.4 eggs per gram (epg), respectively. Children received a mean of 2.3 multimicronutrient/placebo tablets per school week, giving a compliance rate of 46%. Children given multimicronutrients had a slightly, but significantly, lower intensity of S. mansoni reinfection compared with children given placebo (5.5 epg vs. 7.7 epg, P = 0.047). Multiple linear regression analyses controlling for baseline infection status confirmed this, as children who received micronutrients were reinfected with S. mansoni at only 69% of the intensity of those who received placebo. Multiple logistic regression analyses revealed that micronutrient supplementation was associated with a lower S. mansoni reinfection rate (odds ratio = 0.7) although this was only of borderline significance (P = 0.090). There were no significant differences in reinfection rates or intensities of hookworm, A. lumbricoides and T. trichiura. The effect on S. mansoni infection intensity is particularly interesting given the low compliance, suggesting that full micronutrient supplementation might have a role to play in S. mansoni control programmes. 相似文献
42.
0 引言 1989- 0 7全球首例活体肝部分移植术成功以来 ,这一手术先后在 30余个国家和地区开展 ,至 1996 - 0 8全球累计总例数已愈 70 0例 ,我院于 1997- 0 6 - 30在日本京都大学Tanaka Koichi教授的指导下 ,成功地开展了 1例活体肝部分移植术 ,至今患者已健康生存 1.5 a,现就其术后中长期管理结合文献总结如下 :1 临床资料1.1 病例 患者为 10岁女性 ,诊断为先天性弥漫性肝内胆管囊性扩张症、复发性胆管炎、肝硬变症 ,1997- 0 6 - 30在全麻下行活体肝部分移植术 ,供体为患儿 40多岁的父亲 ,手术顺利 ,术后早期临床资料已作过报告 [1 ] … 相似文献
43.
A retrospective study of 100 cerebral computed tomography scans interpreted as displaying subarachnoid hemorrhage was undertaken to determine the frequency of blood in the interpeduncular fossa as a useful radiographic sign. The results indicate that the interpeduncular fossa sign is second only to blood in the Sylvian fissure-circular sulcus area as a reliable indicator of subarachnoid hemorrhage on CT scans. 相似文献
44.
45.
46.
Williams AP Allen CD Millar CI Swetnam TW Michaelsen J Still CJ Leavitt SW 《Proceedings of the National Academy of Sciences of the United States of America》2010,107(50):21289-21294
In recent decades, intense droughts, insect outbreaks, and wildfires have led to decreasing tree growth and increasing mortality in many temperate forests. We compared annual tree-ring width data from 1,097 populations in the coterminous United States to climate data and evaluated site-specific tree responses to climate variations throughout the 20th century. For each population, we developed a climate-driven growth equation by using climate records to predict annual ring widths. Forests within the southwestern United States appear particularly sensitive to drought and warmth. We input 21st century climate projections to the equations to predict growth responses. Our results suggest that if temperature and aridity rise as they are projected to, southwestern trees will experience substantially reduced growth during this century. As tree growth declines, mortality rates may increase at many sites. Increases in wildfires and bark-beetle outbreaks in the most recent decade are likely related to extreme drought and high temperatures during this period. Using satellite imagery and aerial survey data, we conservatively calculate that ≈ 2.7% of southwestern forest and woodland area experienced substantial mortality due to wildfires from 1984 to 2006, and ≈ 7.6% experienced mortality associated with bark beetles from 1997 to 2008. We estimate that up to ≈ 18% of southwestern forest area (excluding woodlands) experienced mortality due to bark beetles or wildfire during this period. Expected climatic changes will alter future forest productivity, disturbance regimes, and species ranges throughout the Southwest. Emerging knowledge of these impending transitions informs efforts to adaptively manage southwestern forests. 相似文献
47.
BACKGROUND: A specific treatment for ongoing hemolytic disease of the fetus and newborn (HDFN) due to anti-D would be very attractive. One approach could be administration to the mother of nonhemolytic anti-D, which by crossing the placenta can block the binding of hemolytic maternal anti-D. STUDY DESIGN AND METHODS: Two anti-D immunoglobulin G3 (IgG3) heavy-chain mutants were expressed in Chinese hamster ovary cells. To investigate whether these anti-D IgG3 mutants could inhibit the red blood cell-destructive activity of recombinant human (rHu)IgG1 with identical antigen-binding region as well as polyclonal anti-D having multiple D epitope specificities, two assays were used, antibody-dependent cell-mediated cytotoxicity (ADCC) and a chemiluminescence (CL)-based method for detection of respiratory burst in peripheral blood monocytes. RESULTS: The two IgG3 anti-D heavy-chain mutants inhibited the ADCC and CL responses mediated by a rHuIgG1 anti-D with identical antigen-binding region as the mutant antibodies, as well as the destructive activity mediated by a polyclonal anti-D. CONCLUSION: The use of nonhemolytic anti-D may be an effective countermeasure against hemolysis in HDFN due to anti-D. 相似文献
48.
YL Cheng CC Shek FK Wong KS Choi KF Chau TS Ing CS Li 《American journal of kidney diseases》1998,31(6):986-990
In 22 hemodialysis patients, during a dialysis session, the solute removal index (SRI) for urea obtained from the use of a partial spent dialysate collection method was compared with that derived from the use of a total spent dialysate collection technique. The partial spent dialysate collection method was used to harvest a small representative sample of the total spent dialysate. The volumes of spent dialysate collected by the partial and the total spent dialysate collection methods were 1.7 +/- 0.4 L and 129.6 +/- 15.3 L, respectively. The total amount of urea nitrogen removed by dialysis as estimated by the partial spent dialysate collection method was similar to that determined by the total spent dialysate collection approach. As a result, the SRI value for urea obtained by the partial spent dialysate collection method (namely, 63% +/- 8%) correlated very well (r = 0.95, P < 0.001) with that derived by the total spent dialysate collection technique (namely, 62% +/- 8%). Our data suggest that it is feasible to use a simple partial spent dialysate collection method to obtain SRI results in patients treated with hemodialysis. 相似文献
49.
50.
An NMR-based metabonomic investigation on effects of milk and meat protein diets given to 8-year-old boys 总被引:1,自引:0,他引:1
Bertram HC Hoppe C Petersen BO Duus JØ Mølgaard C Michaelsen KF 《The British journal of nutrition》2007,97(4):758-763
The objective of the study was to investigate the ability of an NMR-based metabonomic approach, applied to biofluids, to explore and identify overall exogenous and endogenous biochemical effects of a short-time high intake of milk protein or meat protein given to prepubertal children, the aim being to compare relative differences and not an absolute quantification. A total of twenty-four 8-year-old boys were asked to take 53 g protein as milk (n 12) or meat daily (n 12). At baseline and after 7 d, urine and serum samples were collected and high-resolution 1H NMR spectra were acquired on these using a 800 MHz spectrometer. The milk diet reduced the urinary excretion of hippurate, while the meat diet increased the urinary excretion of creatine, histidine and urea. The NMR measurements on serum revealed minor changes in the lipid profile, which most probably should be ascribed to an increase in the content of SCFA in the blood after consumption of the milk diet. The meat diet had no effect on the metabolic profile of serum. The study for the first time demonstrates the capability of proton NMR-based metabonomics to identify the overall biochemical effects of consumption of different animal proteins. The urine metabolite profile is more susceptible to perturbations as a result of short diet interventions than the serum metabolite profile. The milk diet-induced reduction in urinary excretion of hippurate suggests alterations in gut microflora, which may be useful information for further studies elucidating the effects of bioactive components in milk. 相似文献