全文获取类型
收费全文 | 14046篇 |
免费 | 1146篇 |
国内免费 | 75篇 |
专业分类
耳鼻咽喉 | 118篇 |
儿科学 | 532篇 |
妇产科学 | 331篇 |
基础医学 | 1775篇 |
口腔科学 | 216篇 |
临床医学 | 1553篇 |
内科学 | 2794篇 |
皮肤病学 | 444篇 |
神经病学 | 1350篇 |
特种医学 | 463篇 |
外科学 | 1818篇 |
综合类 | 350篇 |
一般理论 | 7篇 |
预防医学 | 1204篇 |
眼科学 | 257篇 |
药学 | 809篇 |
中国医学 | 4篇 |
肿瘤学 | 1242篇 |
出版年
2021年 | 162篇 |
2020年 | 101篇 |
2019年 | 180篇 |
2018年 | 209篇 |
2017年 | 161篇 |
2016年 | 182篇 |
2015年 | 187篇 |
2014年 | 274篇 |
2013年 | 416篇 |
2012年 | 563篇 |
2011年 | 632篇 |
2010年 | 321篇 |
2009年 | 338篇 |
2008年 | 587篇 |
2007年 | 602篇 |
2006年 | 569篇 |
2005年 | 611篇 |
2004年 | 543篇 |
2003年 | 504篇 |
2002年 | 498篇 |
2001年 | 482篇 |
2000年 | 510篇 |
1999年 | 428篇 |
1998年 | 172篇 |
1997年 | 162篇 |
1996年 | 109篇 |
1995年 | 126篇 |
1994年 | 114篇 |
1992年 | 358篇 |
1991年 | 351篇 |
1990年 | 367篇 |
1989年 | 350篇 |
1988年 | 264篇 |
1987年 | 299篇 |
1986年 | 304篇 |
1985年 | 305篇 |
1984年 | 201篇 |
1983年 | 229篇 |
1982年 | 124篇 |
1979年 | 203篇 |
1978年 | 140篇 |
1977年 | 124篇 |
1976年 | 138篇 |
1975年 | 133篇 |
1974年 | 144篇 |
1973年 | 136篇 |
1972年 | 107篇 |
1971年 | 101篇 |
1970年 | 119篇 |
1969年 | 104篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Joseph G Rajendran Darrell R Fisher Ajay K Gopal Lawrence D Durack Oliver W Press Janet F Eary 《Journal of nuclear medicine》2004,45(6):1059-1064
Radioimmunotherapy (RIT) using (131)I-tositumomab has been used successfully to treat relapsed or refractory B-cell non-Hodgkin's lymphoma (NHL). Our approach to treatment planning has been to determine limits on radiation absorbed dose to critical nonhematopoietic organs. This study demonstrates the feasibility of using CT to adjust for actual organ volumes in calculating organ-specific absorbed dose estimates. METHODS: Records of 84 patients who underwent biodistribution studies after a trace-labeled infusion of (131)I-tositumomab for RIT (January 1990 and April 2003) were reviewed. Serial planar gamma-camera images and whole-body NaI probe counts were obtained to estimate (131)I-antibody source-organ residence times as recommended by the MIRD Committee. The source-organ residence times for standard man or woman were adjusted by the ratio of the MIRD phantom organ mass to the CT-derived organ mass. RESULTS: The mean radiation absorbed doses (in mGy/MBq) for our data using the MIRD model were lungs = 1.67; liver = 1.03; kidneys = 1.08; spleen = 2.67; and whole body = 0.3; and for CT volume-adjusted organ volumes (in mGy/MBq) were lungs = 1.30; liver = 0.92; kidneys = 0.76; spleen = 1.40; and whole body = 0.22. We determined the following correlation coefficients between the 2 methods for the various organs: lungs, 0.49 (P = 0.0001); liver, 0.64 (P = 0.004); kidneys, 0.45 (P = 0.0004); spleen, 0.22 (P = 0.0001); and whole body, 0.78 (P = 0.0001), for the residence times. For therapy, patients received mean (131)I administered activities of 19.2 GBq (520 mCi) after adjustment for CT-derived organ mass compared with 16.0 GBq (433 mCi) that would otherwise have been given had therapy been based only using standard MIRD organ volumes-a statistically significant difference (P = 0.0001). CONCLUSION: We observed large variations in organ masses among our patients. Our treatments were planned to deliver the maximally tolerated radiation dose to the dose-limiting normal organ. This work provides a simplified method for calculating patient-specific radiation doses by adjusting for the actual organ mass and shows the value of this approach in treatment planning for RIT. 相似文献
22.
Jennifer Orlet Fisher Diane C Mitchell Helen Smiciklas-Wright Leann Lipps Birch 《Journal of the American Dietetic Association》2002,102(1):58-64
OBJECTIVE: To evaluate parents' fruit and vegetable intake and their use of pressure to eat in child feeding as predictors of their 5-year-old daughters' fruit and vegetable, micronutrient, and fat intakes. SUBJECTS: Data were obtained from 191 non-Hispanic white families with 5-year-old girls. DESIGN: Parent data included reports of pressure in child feeding and their own fruit and vegetable intake. Girls' intakes of fruits and vegetables, selected micronutrients, and fat were the main outcomes of interest. STATISTICAL ANALYSIS: Structural equation modeling was used to test a model describing relationships among parents' fruit and vegetable intake, parents' use of pressure in child feeding, and daughters' fruit and vegetable, micronutrient, and fat intakes. RESULTS: The model provided a good fit to the data, revealing that girls' fruit and vegetable intake was positively related to their parents' reported fruit and vegetable intake. Parents who consumed fewer fruits and vegetables tended to report greater pressure in child feeding and had daughters who consumed fewer fruits and vegetables. Girls' reported fruit and vegetable intakes were positively related to their micronutrient intakes and negatively associated with fat intake. APPLICATIONS/CONCLUSIONS: This research demonstrates that parents' own fruit and vegetable intake may encourage fruit and vegetable intake in their daughters, leading to higher micronutrient intakes and lower dietary fat intakes. Conversely, pressure to eat may discourage fruit and vegetable intake among young girls. 相似文献
23.
Ross W. James Peter A Howat K. John Fisher 《Australian and New Zealand journal of public health》1987,11(1):54-61
Health education campaigns which utilise the mass media generally employ advertising techniques. Television and print media are considered more influential, with radio being primarily used for awareness raising and campaign support messages. There is relatively little research into the effectiveness of radio talkback programs in promoting health or reducing illness. This paper argues a case for health and welfare professionals to utilise talkback radio as part of their health promotion activities. 相似文献
24.
25.
We report a rare example of bilateral primary malignant phyllodes tumours. The diagnosis was supported by the identification of a benign epithelial element in each lesion. The case illustrates the typical dimorphic features of malignant phyllodes tumours. A contralateral tumour should not be regarded as metastatic without histological confirmation. 相似文献
26.
Alfred E Buxton Hugh Calkins David J Callans John P DiMarco John D Fisher H Leon Greene David E Haines David L Hayes Paul A Heidenreich John M Miller Athena Poppas Eric N Prystowsky Mark H Schoenfeld Peter J Zimetbaum Paul A Heidenreich David C Goff Frederick L Grover David J Malenka Eric D Peterson Martha J Radford Rita F Redberg 《Journal of the American College of Cardiology》2006,48(11):2360-2396
27.
Daniel B. Costa Christopher A. Fisher Kenneth B. Miller German A. Pihan David P. Steensma Richard J. Gibbons Douglas R. Higgs 《European journal of haematology》2006,76(5):432-435
Abstract: We describe a patient with acquired alpha-thalassemia myelodysplastic syndrome (ATMDS). A previously healthy 66-year-old man presented with hemoglobin of 9.3 g/dL, mean corpuscular volume 59 fL, and a bone marrow aspirate with increased erythroid precursors and hypolobulated megakaryocytes. Hemoglobin H inclusions were seen in most red cells after 1% brilliant cresyl blue supravital stain of the peripheral blood. At the molecular level, we identified of a novel mutation in the most 3' exon of the ATRX gene ( C GA→ T GA substitution in codon 2407) resulting in a premature termination codon (p.R2407X). This case provides further evidence for a link between ATRX mutations and ATMDS, and suggests a possible role for the conserved Q-box element in ATRX function. 相似文献
28.
M. S. Levine A. M. Adinolfi R. S. Fisher C. D. Hull D. Guthrie N. A. Buchwald 《Brain research》1988,440(2):267-279
These studies provide information on the changes in the ultrastructure in the caudate nucleus of aged cats. The major findings was that there was a decrease in the density of synapses in caudate neuropil. This decrease occurred in animals after 3 years of age and remained relatively constant in older animals. In conjunction with this change a population of unusually long synapses also occurred. These larger synaptic appositions were associated with enlarged spine heads. The caudate also showed a number of qualitative ultrastructural alterations. Many neurons contained accumulations of lipofuscin or lipopigment granules in aged animals. These inclusions occurred in both soma and dendrites of neurons and all types of glial cells. A unique configuration of collapsed agranular cisterns also was observed in aged animals. The present results indicate that decreases in synaptic density may by one morphological event underlying functional alterations observed in caudate neurons in aged cats. 相似文献
29.
30.
Background: The gastric bypass operation has evolved since 1966 when it was first introduced. The purpose of this study was
to determine the present state of gastric bypass by consensus among the members of the American Society for Bariatric Surgery
(ASBS). Method: A questionnaire was sent to all members of the ASBS. Forty-three percent responded reporting over 41,200 cases.
Results: Results were analyzed by using χ2 tests with a null hypothesis. Surgeons agreed on several technical aspects, preferring a vertical to a horizontal stapleline;
estimating, rather than measuring, the pouch volume at an average of 22 cc. Few surgeons divide the short gastric vessels,
and only 25% of surgeons polled use a restrictive ring or band proximal to the gastroenterostomy. Most surgeons calibrate
the gastroenterostomy, reporting a preferred average diameter of 12.3 cm. There was no consensus regarding forming the gastroenterostomy,
58% preferring hand-sewn and 42% stapled anastomoses. There was no consensus regarding dividing the gastric pouch from the
bypassed stomach: Conclusion: The preferred gastric bypass is vertical, with the pouch estimated at 20-25 cc, and the gastroenterostomy
calibrated at 12 mm diameter. The short gastric vessels need not be divided, and restrictive bands or rings are not preferred.
This technique of gastric bypass should be used as the control procedure when modifications are tested in future trials. Randomized
prospective studies are suggested to probe the benefits of division of the stomach pouch from the bypassed stomach. 相似文献