全文获取类型
收费全文 | 1639篇 |
免费 | 182篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 10篇 |
儿科学 | 48篇 |
妇产科学 | 45篇 |
基础医学 | 280篇 |
口腔科学 | 33篇 |
临床医学 | 201篇 |
内科学 | 224篇 |
皮肤病学 | 7篇 |
神经病学 | 188篇 |
特种医学 | 81篇 |
外科学 | 231篇 |
综合类 | 23篇 |
一般理论 | 2篇 |
预防医学 | 163篇 |
眼科学 | 13篇 |
药学 | 148篇 |
中国医学 | 2篇 |
肿瘤学 | 124篇 |
出版年
2023年 | 10篇 |
2022年 | 16篇 |
2021年 | 40篇 |
2020年 | 29篇 |
2019年 | 35篇 |
2018年 | 52篇 |
2017年 | 30篇 |
2016年 | 25篇 |
2015年 | 36篇 |
2014年 | 56篇 |
2013年 | 66篇 |
2012年 | 87篇 |
2011年 | 83篇 |
2010年 | 62篇 |
2009年 | 46篇 |
2008年 | 72篇 |
2007年 | 63篇 |
2006年 | 81篇 |
2005年 | 85篇 |
2004年 | 78篇 |
2003年 | 65篇 |
2002年 | 61篇 |
2001年 | 37篇 |
2000年 | 27篇 |
1999年 | 41篇 |
1998年 | 35篇 |
1997年 | 15篇 |
1996年 | 16篇 |
1995年 | 18篇 |
1994年 | 10篇 |
1992年 | 23篇 |
1991年 | 37篇 |
1990年 | 39篇 |
1989年 | 28篇 |
1988年 | 22篇 |
1987年 | 44篇 |
1986年 | 19篇 |
1985年 | 20篇 |
1984年 | 35篇 |
1983年 | 15篇 |
1982年 | 13篇 |
1981年 | 11篇 |
1980年 | 12篇 |
1979年 | 14篇 |
1978年 | 10篇 |
1975年 | 6篇 |
1974年 | 13篇 |
1973年 | 13篇 |
1971年 | 10篇 |
1969年 | 8篇 |
排序方式: 共有1823条查询结果,搜索用时 15 毫秒
1.
Melanie Inkster Alan Montgomery Peter Donnan Tom MacDonald Frank Sullivan Tom Fahey 《The British journal of general practice》2005,55(521):931-937
BACKGROUND: Studies show that 60-75% of treated patients with hypertension in general practice, still do not reach the recommended blood pressure targets of <150/90 mmHg. AIM: To investigate aspects of hypertension management in relation to sociodemographic variables, antihypertensive drug treatment, and organisational factors in primary care. DESIGN OF STUDY: Observational study over 3 years. SETTING: Eight general practices in Tayside, UK. METHOD: Participants were 560 randomly selected patients aged 40-79 years receiving treatment for hypertension. The outcome measurement was blood pressure control, expressed in binary form based on the British Hypertension Society audit standard of <150/90 mmHg. RESULTS: Of 536 eligible patients, 261 (49%) were defined as having inadequate blood pressure control at the end of the study period. No significant associations were discovered with sex, age, deprivation score and comorbidity. In those patients with inadequate control, 30% had no modifications to their drug treatment during the study period. Blood pressure control at the end of the study period was not associated with number of antihypertensive drugs taken or number of antihypertensive drug modifications. The mean number of clinician contacts was 11 (standard deviation = 8), and mean continuity in primary care was high, although this was not associated with improved blood pressure control. A higher proportion of hypertension-related consultations were associated with increased odds of having inadequate blood pressure control. CONCLUSION: Achieving adequate blood pressure control continues to represent a substantial health problem in a significant proportion of the hypertensive population. Patient, physician and organisational elements play a role in ensuring effective delivery of hypertension care in the community. 相似文献
2.
Administered radiopharmaceutical doses in children: a survey of 13 pediatric hospitals in North America. 总被引:1,自引:0,他引:1
Universally applied standards for administering radiopharmaceutical doses in children do not presently exist. Hence, pediatric radiopharmaceutical dosimetry varies considerably from institution to institution and is generally based on the recommended adult dose adjusted for body mass. METHODS: We surveyed 13 pediatric hospitals in North America to obtain objective data on dosimetry practices for 16 pediatric nuclear medicine examinations, including the minimum total radiopharmaceutical administered dose per examination, the total administered dose based on body mass, and maximum total doses in children. RESULTS: The reported administered doses of radiopharmaceuticals to children vary over a relatively large range, especially with respect to minimum total administered doses. CONCLUSION: This survey has identified a broad range of administered doses directly leading to variability in radiation-absorbed doses to patients. The nuclear medicine community should develop pediatric standards for radiopharmaceutical administered doses and reduce radiation exposure in children, such as through the use of modern software reconstruction techniques. 相似文献
3.
Antibiotic prophylaxis diminishes bacterial translocation but not mortality in experimental burn wound sepsis 总被引:3,自引:0,他引:3
W G Jones A E Barber J P Minei T J Fahey G T Shires G T Shires 《The Journal of trauma》1990,30(6):737-740
Pseudomonas (PSA) burn wound sepsis results in prolonged bacterial translocation (BT) of enteric organisms such as E. coli to the mesenteric lymph nodes (MLN) and organs in rats. Intestinal decontamination with oral antibiotics may improve mortality after burn injury, perhaps due to decreased BT. To determine the effect of oral antibiotic prophylaxis effective against E. coli but not PSA on BT and subsequent mortality in a model of PSA burn wound sepsis, rats were given a 30% scald burn and wound inoculation with 10(8) PSA followed by randomization to either ampicillin (50 mg/kg/d) or saline gavage. Cultures of MLN, organs, blood, and cecal contents were obtained on days 1, 4, and 7 after injury, with additional animals observed for 14-day mortality. Although oral antibiotic prophylaxis resulted in increased cecal colony counts, the incidence of BT was unchanged. The number of organisms present in both the MLN and organs, however, was significantly reduced with prophylaxis, indicating cecal overgrowth by non-translocating bacteria. Reduction of the number of translocating organisms did not result in improved mean survival time after injury, suggesting that mortality from PSA burn wound sepsis occurs independently of bacterial translocation. 相似文献
4.
Harvey A Ziessman Frederic H Fahey Frank B Atkins Jonathan Tall 《Journal of nuclear medicine》2004,45(5):760-764
The purposes of this investigation were to standardize and validate a simple quantitative method for performing radionuclide solid gastric emptying that can be used for any dual-head gamma-camera and to establish reference values. METHODS: After eating a solid meal (egg sandwich) labeled with a radionuclide, 20 healthy volunteers (9 male, 11 female) underwent a 90-min gastric-emptying study performed with a triple-head gamma-camera. Two sets of 3 simultaneous projections were acquired sequentially for 30 s each: anterior, right posterior oblique (RPO), left posterior oblique (LPO), posterior, left anterior oblique (LAO), and right anterior oblique (RAO), and this sequence was repeated continuously for 90 min. Time-activity curves were generated using a gastric region of interest for each of the views as well as the conjugate-view geometric mean (GM) data for the anterior/posterior, LAO/RPO, and RAO/LPO combinations. Quantitative parameters were determined: percentage gastric emptying (%GE) at 90 min, half-time (min) based on an exponential fit, and clearance rate (%/min) based on a linear fit. Reference values were determined on the basis of a 95% confidence interval of the t distribution. The results were statistically analyzed and compared. RESULTS: The %GE reference values were greater for the anterior/posterior GM (>or=33%) than for the LAO (>or=31%) and anterior (>or=30%) GMs. The 3 %GE GM methods, the 3 exponential-fit GM methods, and the 3 linear-fit GM methods had high correlation coefficients (r >or= 0.874), and with only a single exception, there was no statistical difference among them. The LAO method and LAO/RPO GM mean method correlated strongly (r = 0.900) and had similar mean values (52% vs. 51%) and reference values (29% vs. 30%). All 3 methods of GM quantification also correlated strongly, and there was no significant difference among them. CONCLUSION: We have described and validated a simple method for radionuclide solid gastric emptying that can be used with a dual-head gamma-camera. We recommend the anterior/posterior GM method and have established reference values (>or=33%). 相似文献
5.
Calculation of a gallbladder ejection fraction: advantage of continuous sincalide infusion over the three-minute infusion method. 总被引:4,自引:0,他引:4
The purpose of this study was to investigate alternative methods of infusing sincalide for calculation of a gallbladder ejection fraction (GBEF) during cholescintigraphy (5 mCi 99mTc-mebrofenin). After gallbladder filling, three methods of infusion were compared in 23 normal volunteers: (1) 0.02 microgram/kg as a 3-min infusion, (2) 0.02 microgram/kg as a 30-min infusion, and (3) 0.01 microgram/kg as a 30-min infusion (14 subjects), all performed on separate days. With the 3-min infusion, the emptying pattern was usually exponential and completed in 15 min. The mean (GBEF) was 52% +/- 26% at 20 min and 56% +/- 27% at 30 min (range 0%-100%). GBEFs were less than 35% in six subjects and 35%-38% in four. Side effects were noted by 11/23 subjects. With the slow infusions, emptying was linear; no side effects were noted. With 0.02 microgram/kg, the mean GBEF was 50% +/- 27% at 20 min and 70% +/- 22% at 30 min (range 26%-95%). Similar results were seen with 0.01 microgram/kg, but the data were more limited. The 30-min infusion had a higher normalcy rate than the 3-min method (91% versus 74%). Females had significantly lower GBEFs than males (p less than 0.05%). We conclude that the slow infusion method is preferable; it is more physiological, results in more complete emptying, has no side effects, has less normal variability, and should improve the specificity of this test. The lower mean female GBEF may have pathophysiological significance. 相似文献
6.
This article describes recent developments in cardiology and cardiovascular disease that are likely to be relevant to primary healthcare professionals and their patients. The following subject areas are covered: Primary prevention: recent developments in pharmaco-logical interventions, drug interactions, and drugs that are likely to cause harm; cardiovascular risk estimation and shared decision making with patients; and new developments in 24-hour ambulatory blood pressure monitoring. Secondary prevention: new models of care, including nurse-led care for the provision of hypertension and secondary prevention clinics; new drugs for the treatment of angina and myocardial infarction; ambulatory electrocardiography for the diagnosis of arrhythmias in primary care; and new developments in the treatment of atrial fibrillation - direct thrombin inhibitors and implantable devices. Tertiary prevention: recent developments in cardiac rehabilitation; recent evidence concerning revascularisation procedures and appropriateness criteria for referral; and implantable defibrillators. 相似文献
7.
8.
Joanne Fielding Nellie Georgiou-Karistianis Lynette Millist Michael Fahey Owen White 《Journal of the International Neuropsychological Society》2006,12(4):455-464
Trajectories of saccadic eye movements can be modulated by the presence of a competing visual distractor. It is proposed that the superior colliculus (SC) controls the initial deviation through competitive lateral interactions. Given the ramifications of connections between basal ganglia (BG) thalamo-cortical circuitry and the SC, it was anticipated that this modulation would be differentially effected in those with Huntington's disease, which in its early stages is primarily a disorder of the BG. Horizontal deviation was determined for exogenously driven and endogenously driven vertical saccades in the presence of peripheral distractors. For neurologically healthy participants, the initial trajectories of both saccade types curved away from distractor locations, as predicted. However, for HD participants exogenous saccades consistently deviated leftwards, irrespective of distractor location. Endogenous saccades also revealed anomalous horizontal deviation, with significant leftward deviation evident for saccades directed upward and significant rightward deviation for saccades directed downward. Further, both groups generated a comparable proportion of erroneous responses to distractor stimuli, but only neurologically healthy participants demonstrated a response time advantage for compatible target/distractor presentation. These results suggest anomalous regulation of distractor-related activity in HD. 相似文献
9.
10.
Cyclophosphamide 'pulses' in chronic progressive multiple sclerosis. A preliminary clinical trial 总被引:1,自引:0,他引:1
L W Myers J L Fahey D J Moody M R Mickey M V Frane G W Ellison 《Archives of neurology》1987,44(8):828-832
To our knowledge, this is the first clinical trial in multiple sclerosis (MS) demonstrating the feasibility of directing immunomodulating therapy by monitoring immunologic results. Cyclophosphamide was administered at monthly intervals, escalating the dose until there was a significant reduction in both the number of blood B lymphocytes and helper/inducer (CD4) T cells of 14 patients with chronic progressive MS. The frequency and severity of adverse effects led us to conclude that the regimen is too toxic for the long-term treatment of patients with MS. 相似文献