全文获取类型
收费全文 | 22259篇 |
免费 | 1483篇 |
国内免费 | 46篇 |
专业分类
耳鼻咽喉 | 532篇 |
儿科学 | 540篇 |
妇产科学 | 681篇 |
基础医学 | 286篇 |
口腔科学 | 1107篇 |
临床医学 | 3608篇 |
内科学 | 6661篇 |
皮肤病学 | 444篇 |
神经病学 | 851篇 |
特种医学 | 320篇 |
外科学 | 1934篇 |
综合类 | 26篇 |
现状与发展 | 2篇 |
一般理论 | 1篇 |
预防医学 | 3450篇 |
眼科学 | 235篇 |
药学 | 400篇 |
中国医学 | 11篇 |
肿瘤学 | 2699篇 |
出版年
2024年 | 211篇 |
2023年 | 1183篇 |
2022年 | 475篇 |
2021年 | 769篇 |
2020年 | 1267篇 |
2019年 | 480篇 |
2018年 | 1173篇 |
2017年 | 1214篇 |
2016年 | 1469篇 |
2015年 | 1397篇 |
2014年 | 2001篇 |
2013年 | 2194篇 |
2012年 | 741篇 |
2011年 | 698篇 |
2010年 | 1151篇 |
2009年 | 1563篇 |
2008年 | 667篇 |
2007年 | 448篇 |
2006年 | 757篇 |
2005年 | 355篇 |
2004年 | 290篇 |
2003年 | 207篇 |
2002年 | 174篇 |
2001年 | 274篇 |
2000年 | 233篇 |
1999年 | 249篇 |
1998年 | 331篇 |
1997年 | 255篇 |
1996年 | 240篇 |
1995年 | 197篇 |
1994年 | 156篇 |
1993年 | 113篇 |
1992年 | 113篇 |
1991年 | 91篇 |
1990年 | 108篇 |
1989年 | 86篇 |
1988年 | 67篇 |
1987年 | 50篇 |
1986年 | 58篇 |
1985年 | 45篇 |
1984年 | 43篇 |
1983年 | 40篇 |
1982年 | 15篇 |
1980年 | 16篇 |
1979年 | 10篇 |
1978年 | 14篇 |
1977年 | 18篇 |
1976年 | 11篇 |
1975年 | 18篇 |
1972年 | 15篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Many care-dependent elderly individuals live in nursing homes and must depend on nursing home aides for oral hygiene care. It is generally agreed that the level of oral hygiene care among care-dependent nursing home residents is less than optimal. Two reasons are time constraints and the difficulty involved in brushing other individuals' teeth. The identification of effective and efficient plaque-removal devices for use by care-providers should make it easier for nursing home aides to incorporate effective oral hygiene care into their daily routines. This pilot study was undertaken to determine the relative effectiveness of four plaque removal devices with different basic designs when used by a non-professional careprovider on 10 healthy volunteers. A brush with curved bristles on the lateral aspect of the brush head and short straight bristles in the center (Collis-curve) and an electric toothbrush with tuffs that rotate reciprocally (Interplak) were the most effective, a conventional brush (Oral-B) was somewhat less effective, and a disposable foam brush (Abco) was least effective and similar to the prebrushing plaque score (baseline). All the volunteers reported that the Collis-curve as the most comfortable brush, and the care-provider reported that it was the easiest to use. 相似文献
12.
13.
14.
Fukui K Kominami R Kaneuji A Matsumoto T Shinohara H 《Okajimas folia anatomica Japonica》2004,81(4):57-62
We report a new method of perfusion fixation for the proximal one-third of the femur of the Japanese white rabbit. Fluids to flush the blood and fix the marrow were injected into the abdominal aorta and drained from the stump of the femur. The oozing of the fluids from the stumps guaranteed complete flushing and fixation. The new method facilitated fixation and decreased the volume of necessary fluids. Scanning electron microscopy (SEM) images of bone marrow fixed using the new method and using the conventional method did not differ. Large fat globules were not observed in the SEM specimens produced using either the new or the conventional method. 相似文献
15.
Yamada A 《Shinrigaku kenkyu : The Japanese journal of psychology》2004,75(2):134-141
This study investigated the effects of repeated exposures to male and female targets on trait impressions and the role of stereotyped knowledge for the target's social category in impression formation process. The participants were repeatedly exposed to slides of male and female faces for subliminal durations. For each of 12 pairs containing both previously presented slide and newly presented slide, the participants made forced-choice liking judgments (Experiment 1), trait judgments (Experiment 2) and recognition judgments (Experiments 1 and 2). It was found that participants' attitude toward the targets became more positive, even though target recognition was not significantly greater than the chance level. Yet, when the dimension of judgment was stereotypically associated with the target's social category, exposure effects were obtained for the targets whose social category and its dimension were inferentially matched, but not obtained for the targets whose social category and its dimension were not inferentially matched. Some theoretical implications of the role of social category information in the mere exposure phenomenon are discussed. 相似文献
16.
A Parasyn R M Hanson MBBCh MPH MRACMA FRACP FACEM J K Peat M De Silva 《Journal of digital imaging》1998,11(1):45-49
Picture Archiving and Communication Systems (PACS) make possible the viewing of radiographic images on computer workstations located where clinical care is delivered. By the nature of their work this feature is particularly useful for emergency physicians who view radiographic studies for information and use them to explain results to patients and their families. However, the high cost of PACS diagnostic workstations with fuller functionality places limits on the number of and therefore the accessibility to workstations in the emergency department. This study was undertaken to establish how well less expensive personal computer-based workstations would work to support these needs of emergency physicians. The study compared the outcome of observations by 5 emergency physicians on a series of radiographic studies containing subtle abnormalities displayed on both a PACS diagnostic workstation and on a PC-based workstation. The 73 digitized radiographic studies were randomly arranged on both types of workstation over four separate viewing sessions for each emergency physician. There was no statistical difference between a PACS diagnostic workstation and a PC-based workstation in this trial. The mean correct ratings were 59% on the PACS diagnostic workstations and 61% on the PC-based workstations. These findings also emphasize the need for prompt reporting by a radiologist. 相似文献
17.
S. J. Rosansky MD R. Rhinehart MD D. Whittman MPH S. J. Menachery 《Clinical autonomic research》1995,5(3):151-154
In published studies of chronic haemodialysis patients, the frequency of autonomic dysfunction varies widely. One reason for the variation may be the time of testing with respect to time of dialysis. The current study tests the hypothesis that autonomic function — as measured by heart rate responses to the Valsalva manoeuvre (Valsalva ratio) and 30:15 electrocardiogram (ECG) R—R interval to upright posture (postural ratio) — is different when patients are above dry weight (predialysis) than when they are at or below dry weight (postdialysis). The study also reviews available literature to analyze other factors that may affect the results of autonomic testing in this population. A total of 25 chronic haemodialysis patients underwent standard Valsalva and 30:15 R—R interval postural autonomic testing prior to and after haemodialysis. In addition, pre- and postdialysis orthostatic responses were measured and compared with a control population. The 30:15 ratio increased after dialysis (p = 0.001). The Valsalva ratio did not change with dialysis. Out of 25 subjects, seven had an abnormal 30:15 ratio prior to dialysis decreasing to two out of 25 patients postdialysis (p < 0.03). Orthostatic responses predialysis did not differ from those in the control group. Review of the literature shows great variability in definition of normal Valsalva and postural (30:15 R—R interval) ratios. Diabetic patients in the current and prior studies were more likely to have abnormal responses. In conclusion, the prevalence of autonomic dysfunction in chronic dialysis patients as determined by Valsalva and 30:15 ECG postural ratios may be influenced by the following factors: when subjects are studied with respect to their dialysis treatment; the number of subjects with diabetes; and the cut-off point used to define abnormal test results. Abnormal Valsalva ratios are less frequent when measured postdialysis. 相似文献
18.
John William Hayden MD FACEP Claudette Laney RN CCHP&#x; Arthur L Kellermann MD MPH FACEP
《Annals of emergency medicine》1995,26(6)
Study objective: The alteration of a knee immobilizer into a sharp weapon by a prisoner prompted us to survey neighboring penal institutions to determine the frequency of such events. Design: We mailed a nine-item survey to all detention facilities in Tennessee, Arkansas, and Mississippi. A second survey was sent to nonresponding institutions 6 weeks after the initial mailing. Setting: The Regional Medical Center at Memphis, the designated facility for evaluation and treatment of prisoners from the county jail and state penitentiary. Participants: Survey respondents included 25 state penitentiaries, 31 county jails, 1 state minimum-security facility, 1 state maximum-security facility, 1 work-release center, 1 county detention center for drunken-driving offenders, and 1 federal penitentiary. Results: Of the 81 institutions surveyed, 77% responded to one of the two mailings. Forty percent responded in the affirmative when asked whether stolen or unauthorized medical equipment from outside their institutions had been discovered among inmates. When respondents were questioned as to whether medical equipment, prescribed or not, had been used or altered in a criminal manner, 34% responded "yes." Medications and medical appliances were listed in the responses. Conclusion: A survey of 81 local and neighboring penal institutions in a three-state area revealed that the illicit use of medicine and medical devices by prisoners is a legitimate safety concern of prison personnel and health care workers when medical care for inmates must be sought outside the security of their institutions. The modification of medical equipment into weapons by incarcerated patients, although clearly recognized as a security and safety problem by police authorities, appears to be unappreciated by health care workers providing episodic care to inmates. [Hayden JW, Laney C, Kellermann AL: Medical devices made into weapons by prisoners: An unrecognized risk. Ann Emerg Med December 1995;26:739-742.] 相似文献
19.
Drs. Christopher Williams PhD Ms. Jennifer A. Epstein PhD Gilbert J. Botvin PhD Michelle Ifill-Williams MPH 《Journal of urban health》1999,76(1):85-101
Youths residing in public housing developments appear to be at markedly heightened risk for drug use because of their constant
exposure to violence, poverty, and drug-related activity. The purpose of this study was to develop and test a model of marijuana
etiology with adolescents (N=624) residing in public housing. African-American and Hispanic seventh graders completed questionnaires
about their marijuana use, social influences to smoke maijuana, and sociodemographic and psychosocial characteristics. Results
indicated that social influences, such as friends' marijuana use and perceived ease of availability of marijuana, significantly
predicted both occasional and future use of marijuana. Individual characteristics such as antimarijuana attitudes and drug
refsul skills also predicted marijuana use. The findings imply that effective prevention approaches that target urban youths
residing in public housing developments should provide them with an awareness of social influences to use marijuana, correct
misperceptions about the prevalence of marijuana smoking, and train adolescents in relevant psychosocial skills. 相似文献
20.
Background: The complications of the gastric pouch in gastric bypass surgery are well known. Since the first report of this
surgery 30 years ago, new technical aspects that make it safer and more effective have been implemented. Methods: As a modification
of gastric bypass, the authors have performed 305 vertical banded gastroplasty-gastric bypass procedures. Two groups of patients
underwent the procedure: Group I (n = 206) without a limb of jejunum interposed between the gastric pouch and the excluded
stomach, and Group II (n = 99) with a limb of jejunum interposed between the pouch and the stomach. The results regarding
excess weight loss and complications of the gastric pouch during the first year after surgery were compared. Results: Age,
sex, initial weight, body mass index, and percentage of ideal weight were similar in both groups. Excess weight loss was also
similar. The complications in Group I were 1 leak, 3 left subphrenic abscesses, 2 erosive gastritis with bleeding, 1 stenosis
of the gastrojejunostomy, 1 perforated ulcer, and 4 marginal ulcers with bleeding. Two patients in Group II developed bleeding
from the staple-line. Conclusions: These preliminary data suggest that complications of the gastric pouch can be reduced by
interposing a limb of jejunum between the pouch and the excluded stomach. This is an early experience; long-term results are
pending. 相似文献