全文获取类型
收费全文 | 9237篇 |
免费 | 744篇 |
国内免费 | 54篇 |
专业分类
耳鼻咽喉 | 27篇 |
儿科学 | 320篇 |
妇产科学 | 202篇 |
基础医学 | 1175篇 |
口腔科学 | 367篇 |
临床医学 | 863篇 |
内科学 | 1551篇 |
皮肤病学 | 172篇 |
神经病学 | 874篇 |
特种医学 | 596篇 |
外科学 | 1122篇 |
综合类 | 208篇 |
一般理论 | 8篇 |
预防医学 | 841篇 |
眼科学 | 76篇 |
药学 | 654篇 |
1篇 | |
中国医学 | 4篇 |
肿瘤学 | 974篇 |
出版年
2021年 | 104篇 |
2020年 | 66篇 |
2019年 | 124篇 |
2018年 | 141篇 |
2017年 | 123篇 |
2016年 | 144篇 |
2015年 | 147篇 |
2014年 | 221篇 |
2013年 | 305篇 |
2012年 | 398篇 |
2011年 | 419篇 |
2010年 | 263篇 |
2009年 | 270篇 |
2008年 | 401篇 |
2007年 | 398篇 |
2006年 | 388篇 |
2005年 | 369篇 |
2004年 | 393篇 |
2003年 | 347篇 |
2002年 | 317篇 |
2001年 | 282篇 |
2000年 | 297篇 |
1999年 | 280篇 |
1998年 | 193篇 |
1997年 | 195篇 |
1996年 | 181篇 |
1995年 | 156篇 |
1994年 | 164篇 |
1993年 | 155篇 |
1992年 | 235篇 |
1991年 | 204篇 |
1990年 | 175篇 |
1989年 | 188篇 |
1988年 | 163篇 |
1987年 | 176篇 |
1986年 | 164篇 |
1985年 | 162篇 |
1984年 | 94篇 |
1983年 | 103篇 |
1982年 | 66篇 |
1981年 | 85篇 |
1980年 | 55篇 |
1979年 | 78篇 |
1978年 | 76篇 |
1977年 | 66篇 |
1976年 | 68篇 |
1974年 | 64篇 |
1973年 | 51篇 |
1972年 | 56篇 |
1971年 | 59篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Philip Peng FRCPC Manon Choiniere PhD Dominique Dion MD MSc Howard Intrater FRCPC Sandra LeFort PhD Mary Lynch FRCPC May Ong FRCPC Saifee Rashiq MSc DA FRCPC Gregg Tkachuk PhD Yves Veillette FRCPC 《Journal canadien d'anesthésie》2007,54(12):977-984
PURPOSE: The objective of this survey was to examine the services offered by multidisciplinary pain treatment facilities (MPTFs) across Canada and to compare access to care at these MPTFs. METHODS: A MPTF was defined as a clinic that advertised specialized multidisciplinary services for the diagnosis and management of patients with chronic pain, having a minimum of three different health care disciplines (including at least one medical speciality) available and integrated within the facility. The search method included approaching all hospital and rehabilitation centre administrators in Canada, the Insurance Bureau of Canada, the Workplace Safety and Insurance Board or similar body in each province. Designated investigators were responsible for confirming and supplementing MPTFs from the preliminary list for each province. Administrative leads at each eligible MPTF were asked to complete a detailed questionnaire regarding their MPTF infrastructure, clinical, research, teaching and administrative activities. RESULTS: Completed survey forms were received from 102 MPTFs (response rate 85%) with 80% concentrated in major cities, and none in Prince Edward Island and the Territories. The MPTFs offer a wide variety of treatments including non-pharmacological modalities such as interventional, physical and psychological therapy. The median wait time for a first appointment in public MPTFs is six months, which is approximately 12 times longer than non-public MPTFs. Eighteen pain fellowship programs exist in Canadian MPTFs and 64% engage in some form of research activities CONCLUSION: Canadian MPTFs are unable to meet clinical demands of patients suffering from chronic pain, both in terms of regional accessibility and reasonable wait time for patients' first appointment. 相似文献
22.
This case study highlights the important contribution of nursing in obtaining an accurate health history. The case discussed herein initially appeared to be neurogenic diabetes insipidus (DI) secondary to a traumatic brain injury. The nursing staff, by reviewing the patient's health history with his family, discovered a history of polydipsia and long-standing lithium use. Lithium is implicated in drug-induced nephrogenic DI, and because the patient had not received lithium since being admitted to the hospital, his treatment changed to focus on nephrogenic DI. By combining information from the patient history, the physical examination, and radiologic and laboratory studies, the critical care team demonstrated that the patient had been self-treating his lithium-induced nephrogenic DI and developed neurogenic DI secondary to brain trauma. Thus successful treatment required that nephrogenic and neurogenic DI be treated concomitantly. 相似文献
23.
Randall E Brand Henry T Lynch 《Endocrinology & Metabolism Clinics of North America》2006,35(2):405-15, xi
It is estimated that 5% to 10% of pancreatic cancer cases are attributable to hereditary factors. We believe that the number of cases that are genetic in etiology are even greater, however, based not on a classic autosomal dominant pattern of inheritance but rather when one takes into account low-penetrant inherited susceptibility factors. There is also a growing recognition that the development of pancreatic cancer in pancreatic cancer-prone families is dependent not only on genetic variables but on nongenetic factors. The aim of this article is to review the challenges in identifying pancreatic cancer-prone families and how environmental factors interact with genetic factors in these families. 相似文献
24.
Noah A Goldman Ellen B Katz Alan S Glenn Richard H Weldon Joan G Jones Uticia Lynch Melissa J Fezzari Carolyn D Runowicz Gary L Goldberg Maureen J Charron 《Modern pathology》2006,19(11):1429-1436
Glucose is provided to cells by a family of glucose transport facilitators known as GLUTs. These transporters are expressed in a tissue specific manner and are overexpressed in many primary tumors of these tissues. Regulation of glucose transport facilitator expression has been demonstrated in endometrial tissue and endometrial adenocarcinoma. The following experiments were conducted to quantify and localize the expression of GLUT1 and GLUT8 in benign endometrium and compare this expression to endometrial cancer. Endometrial tissue samples were obtained from random hysterectomy specimens of patients with benign indications for surgery and endometrial cancer. Immunoblot and immunolocatization studies were performed using GLUT1 and GLUT8 specific antisera. Endometrial samples from 65 women who had undergone hysterectomy were examined (n=38 benign, n=27 malignant). A 44 and a 35.4 kDa immunoreacive species was demonstrated in endometrium and endometrial cancer for GLUT1 and GLUT8, respectively. Upregulation of GLUT1 expression was demonstrated with increasing grade of tumors (P<0.002). GLUT8 expression was increased in all tumor subtypes compared to atrophic endometrium (P<0.001). Apical localization by GLUT1 and GLUT8 was demonstrated in endometrial glands. GLUT1 and GLUT8 demonstrated diffuse intracellular localization in the cancer subtypes. GLUT1 and GLUT8 are expressed in both human endometrium and endometrial cancer. There appears to be a step-wise progression in GLUT1 and GLUT8 expression as tumor histopathology worsens. GLUT1 and GLUT8 may be important markers in tumor differentiation, as well as providing energy to rapidly dividing tumor cells. 相似文献
25.
26.
27.
28.
29.
Scott A. Syverud MD J. Matthew Jenkins MD Robert A. Schwab MD Michael T. Lynch MD Kevin Knoop MD Alexander Trott MD 《Academic emergency medicine》1994,1(6):509-513
Objective: Mental nerve block is frequently used to aid repair of facial lacerations; both percutaneous and intraoral approaches to blocking this nerve are used, but have never been compared. The authors compared the two techniques for pain of administration and effectiveness of anesthesia. Methods: A prospective, randomized, single-blind, crossover study was conducted using ten healthy volunteers aged 22 to 33 years. Patients having prior experience with mental nerve blocks, lidocaine allergy, active oral/facial infection, or previous facial fractures were excluded. Bilateral mental nerve blocks were done using intraoral technique on one side and percutaneous technique on the other. Both techniques were used by the same investigator and were carried out with 27-gauge needles and 2.5 mL of 2% buffered lidocaine at room temperature injected over 20 seconds. The oral mucosa was topically anesthetized with viscous lidocaine for 1 minute prior to intraoral injection. The orders of the blocks and sides of the face anesthetized were randomized. Subjective and objective pain (visual-analog scale), efficacy (anesthesia of lower lip), time to onset, and duration of anesthesia were evaluated. Results: The intraoral technique was subjectively less painful than the percutaneous approach in nine of ten subjects (p = 0.02). Scores on the visual-analog pain scale were significantly lower for the intraoral technique (p = 0.03). Intraoral injection produced lower-lip anesthesia in 10/10 subjects versus 7/10 for percutaneous (p = 0.25). Times to onset (approximately 1–2 minutes) and durations of anesthesia (approximately one hour) were similar for the two techniques. Conclusion: The intraoral approach to the mental nerve block with adjunctive topical anesthesia was subjectively and objectively less painful than the percutaneous approach without adjunctive anesthesia. While the intraoral approach had a greater efficacy of lower-lip anesthesia and a longer duration of action, these differences were not statistically significant. 相似文献
30.
Time-dependent changes in mesolimbic dopamine (DA) function are believed to play a role in behavioral sensitization and drug craving experienced during withdrawal from chronic cocaine administration. The present study utilized intravenous (IV) cocaine self-administration coupled with intracranial microdialysis in rats to investigate time dependent changes during withdrawal from chronic cocaine exposure. Following 2 weeks of IV cocaine self-administration, rats were allowed contingent access to cocaine at 1 and 7 days of withdrawal while extracellular levels of DA were measured from the ventral striatum. A second group of animals received yoked, noncontingent cocaine for 2 weeks and were then administered noncontingent cocaine on days 1 and 7 of withdrawal. In addition, a third group of animals received 2 weeks of yoked saline followed by noncontingent cocaine 1 day after withdrawal. There were no significant differences between groups for the overall cocaine dosage or temporal pattern of infusions on days 1 and 7 of withdrawal. Basal extracellular DA concentrations did not differ between any treatment groups at either withdrawal time. Extracellular DA levels were increased throughout the session on both days; however, the increases at day 7 were significantly less than day 1 for both contingent and noncontingent conditions. DA overflow on day 1 did not differ between animals receiving chronic yoked cocaine or saline. These results suggest that tolerance-like attenuation to the DA-elevating effects of cocaine is not apparent early in withdrawal, but does develop by later time points. DA release in the ventral striatum may not be directly related to cocaine self-administration following withdrawal, since DA levels were attenuated after 7 days of withdrawal while responding for cocaine was unaltered. 相似文献