首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   6030篇
  免费   498篇
  国内免费   9篇
耳鼻咽喉   31篇
儿科学   295篇
妇产科学   169篇
基础医学   786篇
口腔科学   122篇
临床医学   420篇
内科学   1235篇
皮肤病学   166篇
神经病学   1016篇
特种医学   344篇
外国民族医学   2篇
外科学   497篇
综合类   144篇
预防医学   695篇
眼科学   46篇
药学   315篇
中国医学   2篇
肿瘤学   252篇
  2021年   68篇
  2020年   60篇
  2019年   71篇
  2018年   85篇
  2017年   63篇
  2016年   72篇
  2015年   94篇
  2014年   112篇
  2013年   168篇
  2012年   288篇
  2011年   269篇
  2010年   163篇
  2009年   126篇
  2008年   259篇
  2007年   286篇
  2006年   245篇
  2005年   239篇
  2004年   245篇
  2003年   227篇
  2002年   212篇
  2001年   180篇
  2000年   165篇
  1999年   147篇
  1998年   68篇
  1997年   58篇
  1996年   50篇
  1995年   55篇
  1993年   60篇
  1992年   164篇
  1991年   139篇
  1990年   135篇
  1989年   148篇
  1988年   151篇
  1987年   133篇
  1986年   120篇
  1985年   116篇
  1984年   106篇
  1983年   84篇
  1982年   59篇
  1981年   56篇
  1980年   52篇
  1979年   91篇
  1978年   47篇
  1977年   69篇
  1975年   45篇
  1974年   64篇
  1973年   69篇
  1971年   47篇
  1970年   45篇
  1969年   52篇
排序方式: 共有6537条查询结果,搜索用时 15 毫秒
51.
OBJECTIVE: To utilize health services research techniques in developing an episode of care using an administrative data set. This method is demonstrated for an episodic clinical condition, migraine. DATA SOURCES: Medicaid administrative data set of 3,372 patients with a diagnosis of migraine (ICD-9-CM 346.0, 346.1) in the state of Pennsylvania between May 1990 and March 1992. STUDY DESIGN: The duration of a migraine episode was measured by assessing the magnitude of resource utilization and the proportion of patients with charges in the period after the index migraine as compared to the period before the index migraine. A confidence interval (CI) was developed around each measure using bootstrap techniques. DATA COLLECTION METHODS: All charge data were extracted daily for a 113-day observation period surrounding each index migraine in order to observe the duration of impact of a migraine diagnosis on resource utilization. PRINCIPAL FINDINGS: The lower limits of both the 95% and 99% CIs for the difference in charges are greater than 0 for three weeks. The lower limits of both CIs for the difference in the proportion of patients with charges are above 0 for six weeks. CONCLUSIONS: Our analysis demonstrates that a health services research framework can be used to define an episode of care for a chronic disease category such as migraine. This method can be used to evaluate episodes of care for clinical studies of limited or episodic conditions and to complement clinical expertise in developing time horizons for clinical trials.  相似文献   
52.
BACKGROUND: Opioid addiction therapy includes successful detoxification, rehabilitation, and sometimes methadone maintenance. However, the patient may have physical, mental, and emotional pain while trying to achieve abstinence. A new detoxification technique that incorporates general anesthesia uses a high-dose opioid antagonist to compress detoxification to within 6 h while avoiding the withdrawal. METHODS: After Institutional Review Board approval and detailed informed consent, 20 patients, American Society of Anesthesiologists status I-II, addicted to various opioids underwent anesthesia-assisted rapid opioid detoxification. After baseline hemodynamics and withdrawal scores were obtained, anesthesia was induced. After testing with 0.4 mg intravenous naloxone, 4 mg nalmefene, was infused over 2 to 3 h. After emergence, severity of withdrawal was scored before and after administration of 0.4 mg intravenous naloxone. After 24 h, patients began outpatient follow-up treatment while taking oral naltrexone. RESULTS: All 20 patients were successfully detoxified with no adverse anesthetic events. After the first post-treatment test dose of 0.4 mg naloxone, 13 of 20 patients had no signs of withdrawal and hemodynamic changes were minimal. Withdrawal scores were always very low and similar before and after detoxification. Three of 17 patients (18%) available for follow-up have remained abstinent from opioids since treatment (< or = 18 months). Four other patients are clean after brief relapses. CONCLUSIONS: Anesthesia-assisted opioid detoxification is an alternative to conventional detoxification.  相似文献   
53.
This research compared how over a three-month period Canadian and Israeli newspapers wrote about females and males with disabilities. The results showed that in both countries there was significantly greater coverage of males than females. In addition, different (and stereotypical) types of details were used to describe the two groups, and females were associated with different kinds of problems than males, including a higher incidence of violence and victimization. There were also some significant differences between the male and female journalists in this study, and evidence of sexism within the newspaper industry. This paper concludes with some ideas for altering the images of disabled women in the media.  相似文献   
54.
The "managed care backlash" arguably topped the list of media and policy concerns in 1998. Yet, against the background of the highly charged environment in which the future of our health care system continues to be debated, there is a dearth of concrete, "objective" facts on the nature of the changes, the reasons for them, and their meaning. An analysis of five important themes that emerged from a review of the recent literature on health system change concludes that an inherent tension exists between the interest in rapidly driving down health care costs through organizational change and the long time frames that are required to make fundamental changes in structure, process, and orientation. Unfortunately, in an environment in which purchasers are driven to seek cost savings and the political will supports a pluralistic and mixed public/private system, the health system may chart an alternative course, with the result that purchasers may rely increasingly on individual cost sharing and continue to cut back the amount of coverage they are willing to offer. The real challenge for public policy makers is to confront the issues directly, avoiding political incentives to adopt easy and fast solutions for these complex matters.  相似文献   
55.
56.
Growth of vascularized composite mandibular allografts in young rabbits   总被引:2,自引:0,他引:2  
Forty-one hemimandible allografts were transplanted in young rabbits immunosuppressed with cyclosporine. The majority of the grafts demonstrated normal wound healing, and growth of hair, bone, and teeth. The mandibular body and the premolars showed significant growth in length. The allografted mandibles functioned sufficiently that the rabbits took oral nourishment soon after surgery. Long-term survival was limited by a toxic "wasting syndrome" specific for rabbits under treatment with cyclosporine.  相似文献   
57.
In rats, circulating corticosterone and insulin are involved in regulation of the hypothalamic neuropeptide Y (NPY) system, which in turn, is involved in regulation of the hypothalamic-pituitary-adrenal (HPA) axis. Since the HPA axis and stress responsivity is altered in diseases such as depression, we investigated interactions between the effects of stress and antidepressant drug treatment on arcuate nucleus and locus coeruleus NPY mRNA expressions using in-situ hybridization histochemistry. After acute (2 h) and repeated immobilization (2 h daily, for 14 days), plasma concentrations of corticosterone increased, and those of insulin decreased. The expression of NPY mRNA was significantly increased in the arcuate nucleus, but was unchanged in the locus coeruleus following acute and repeated immobilization. Adrenalectomized rats with systemic corticosterone replacement (ADX+CORT), whose corticosterone concentration was maintained at approximately 50-100 ng/ml during repeated stress, showed a decrease in plasma insulin and an increase in arcuate nucleus NPY mRNA similar to that observed in sham rats, suggesting that changes in NPY mRNA levels are more closely tied to circulating insulin than to circulating corticosterone. In contrast, locus coeruleus NPY mRNA expressions in ADX+CORT rats were significantly higher than those in sham rats after repeated stress. Desmethylimipramine (DMI) treatment for 24 days did not affect basal plasma concentrations of corticosterone or insulin, or arcuate nucleus NPY mRNA expressions, but significantly decreased basal levels of locus coeruleus NPY mRNA compared to saline-treated rats. After repeated immobilization (2 h daily, for 4 days), DMI significantly reduced the stress-induced rise in locus coeruleus NPY mRNA levels, but potentiated the stress-induced rise in arcuate nucleus NPY mRNA expression. These results demonstrate that: (1) the increase in arcuate nucleus NPY mRNA expressions in stressed rats closely follows the decrease in plasma concentrations of insulin; (2) increases in NPY mRNA expressions occur in the absence of changes in plasma corticosterone; and (3) desipramine treatment potentiated the effect of stress on arcuate nucleus NPY mRNA expressions, but blocked the repeated stress-induced increase in locus coeruleus NPY mRNA expressions. Thus, NPY mRNA expression in the arcuate nucleus and the locus coeruleus is sensitive to the effects of stress and to the antidepressant drug desipramine, but the arcuate nucleus NPY system is regulated by different mechanisms than the locus coeruleus NPY system. The results provide further evidence for the importance of circulating insulin in the regulation of the arcuate nucleus NPY system.  相似文献   
58.
Cadet basic training: an ethnographic study of stress and coping   总被引:5,自引:0,他引:5  
Cadet basic training (CBT) at the U.S. Military Academy at West Point is an initial cadet experience designed to transition freshmen (new cadets) into the military. Challenge is an inherent component of CBT, and some challenging activities may be stressful. However, the nature and the impact of stress on health status have not been systematically investigated. An ethnographic technique, participant observation, was used to identify stressors and coping strategies among cadets aged 18 to 21 years participating in CBT. A company of 183 cadets, consisting of 123 new cadets and 60 supervising upperclass cadets from the U.S. Military Academy, was followed throughout the 6-week CBT in the summer of 1993. The investigator observed daily activities and participated in select field training experiences. Daily field observations were taped, and field notes were generated chronicling the experience. After CBT, 10 of the 60 upperclass cadets participated in a 20-minute structured interview. Field and interview notes were systematically reviewed to identify and categorize stressors and coping techniques. Stressors included anticipatory stress, time management pressures, sleep deprivation, performance evaluations, conflicts between teamwork and competitive grading, and inexperience in the leadership role. Coping techniques identified included perceiving social support, humor, and rationalization. Three new hypotheses were generated from the observations.  相似文献   
59.
The relationship between coercion strategies used by perpetrators of childhood sexual abuse (CSA) and elevations of CSA survivors on the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) was investigated. Participants were 151 women survivors of CSA in outpatient treatment at a university-based community mental health center. Scores on the MMPI-2 clinical scales and the Keane posttraumatic stress disorder (PTSD) scale were examined. Main effects were found for promised or received rewards on several clinical scales and the PTSD scale of the MMPI-2, independent of the presence of force. Specifically, the presence of such rewards was associated with significantly higher levels of symptomatology on Paranoia (Pa), Psychasthenia (Pt), Schizophrenia (Sc), and PTSD (Pk). There were no main or interaction effects noted for the presence of actual or threatened force on any of the scales.  相似文献   
60.
FL Porter  CM Wolf  J Gold  D Lotsoff  JP Miller 《Pediatrics》1997,100(4):626-632
BACKGROUND: Despite an increased awareness among clinicians regarding pain and pain management for infants undergoing surgery, pain associated with procedures performed outside the operating room may not be adequately managed. PURPOSE: To examine the beliefs and self-described behavior of physicians and nurses regarding the management of procedural pain in newborn infants. METHODS: A survey was distributed to 467 clinicians (nurses and physicians) working in 11 level II and 4 level III nurseries in a large metropolitan area. Respondents were asked to rate the painfulness of 12 common bedside nursery procedures and how often pharmacologic and nonpharmacologic (comfort) measures are currently used and should be used for those procedures. Demographic data were also collected. RESULTS: Surveys were completed by 374 clinicians (80% response rate). Physicians and nurses believe infants feel as much pain as adults and that 9 of the 12 listed procedures are moderately to very painful. Neither pharmacologic nor comfort measures are believed to be used frequently, even for the most painful procedures. Physicians and nurses believe both pharmacologic and comfort measures should be used more frequently, but nurses believe comfort measures should be used more frequently than do physicians. Beliefs about infant pain and procedural pain were related to pain management preferences. Physicians' but not nurses' ratings were associated with significant personal pain. CONCLUSIONS: Despite their beliefs that infants experience significant procedure-related pain, clinicians believe pain management for infants remains below optimal levels. Barriers to more consistent and effective pain management need to be identified and surmounted.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号