全文获取类型
收费全文 | 19801篇 |
免费 | 3723篇 |
国内免费 | 140篇 |
专业分类
耳鼻咽喉 | 526篇 |
儿科学 | 555篇 |
妇产科学 | 436篇 |
基础医学 | 1818篇 |
口腔科学 | 279篇 |
临床医学 | 4125篇 |
内科学 | 3547篇 |
皮肤病学 | 419篇 |
神经病学 | 1788篇 |
特种医学 | 669篇 |
外科学 | 2794篇 |
综合类 | 807篇 |
现状与发展 | 2篇 |
一般理论 | 9篇 |
预防医学 | 2900篇 |
眼科学 | 251篇 |
药学 | 968篇 |
1篇 | |
中国医学 | 104篇 |
肿瘤学 | 1666篇 |
出版年
2023年 | 461篇 |
2022年 | 176篇 |
2021年 | 372篇 |
2020年 | 590篇 |
2019年 | 311篇 |
2018年 | 743篇 |
2017年 | 721篇 |
2016年 | 751篇 |
2015年 | 869篇 |
2014年 | 936篇 |
2013年 | 1384篇 |
2012年 | 888篇 |
2011年 | 820篇 |
2010年 | 771篇 |
2009年 | 928篇 |
2008年 | 775篇 |
2007年 | 820篇 |
2006年 | 793篇 |
2005年 | 678篇 |
2004年 | 584篇 |
2003年 | 529篇 |
2002年 | 533篇 |
2001年 | 577篇 |
2000年 | 492篇 |
1999年 | 499篇 |
1998年 | 430篇 |
1997年 | 418篇 |
1996年 | 414篇 |
1995年 | 343篇 |
1994年 | 290篇 |
1993年 | 242篇 |
1992年 | 365篇 |
1991年 | 315篇 |
1990年 | 306篇 |
1989年 | 333篇 |
1988年 | 264篇 |
1987年 | 253篇 |
1986年 | 217篇 |
1985年 | 235篇 |
1984年 | 184篇 |
1983年 | 177篇 |
1982年 | 120篇 |
1981年 | 107篇 |
1979年 | 125篇 |
1978年 | 107篇 |
1977年 | 104篇 |
1976年 | 106篇 |
1974年 | 103篇 |
1973年 | 94篇 |
1972年 | 96篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Will Managed Care Ever Deliver on Its Promises? Managed Care, Public Policy, and Consumers of Mental Health Services 总被引:1,自引:1,他引:0
Ross EC 《Administration and policy in mental health》2000,28(1):7-22
Advocates of managed care have promised to greatly improve delivery of services to persons with serious mental illness by focusing on effectiveness and accountability. With the exception of a few beacons of success, experience shows that managed care has not delivered on its promises. This article examines several areas of the public mental health system that still have major flaws, hindering adequate provision of services. Such flaws include the absence of integration of Medicaid and the public mental health system; general lack of publicly documented performance measurements that demonstrate accountability; absence of meaningful and authentic consumer, family, and enrollee participation in service planning, implementation, and evaluation; among others. Are we ready to replicate the lessons from the few beacons of success, or will we just continue to fail persons with the most serious mental illnesses? 相似文献
992.
Smith ML Saltzman J Klim P Hanley WB Feigenbaum A Clarke JT 《American journal of mental retardation : AJMR》2000,105(2):69-80
Whether specific cognitive deficits related to frontal-lobe dysfunction that have been reported in individuals with phenylketonuria (PKU) are also characteristic of mild hyperphenylalaninemia (MHP) was investigated. Tests of executive function and control tasks not assessing executive function were administered to a group of individuals with MHP and a group without MHP, similar in age, gender, and IQ. Tests of academic skills and behavior-rating questionnaires were also administered to the group with MHP. No group differences were found for any measure, suggesting that the mild elevations of phenylalanine in individuals with MHP are not sufficient to produce behavioral and cognitive impairments characteristic of PKU. 相似文献
993.
994.
Cox DJ Gonder-Frederick LA Kovatchev BP Clarke WL 《Diabetes research and clinical practice》2001,54(1):17-26
OBJECTIVE: While it is clear that progressive diabetic hypoglycemia leads to neuroglycopenia, which impairs driving, it is not clear what contributes to patients' detection and subsequent self-correction of hypoglycemia/driving impairments. Drivers with Type 1 Diabetes Mellitus (T1DM) who did and did not engage in self-treatment during experimental hypoglycemia driving are compared physiologically and psychologically. METHOD: 38 drivers with T1DM drove a sophisticated driving simulator during euglycemia and progressive hypoglycemia. Subjects were continually monitored for driving performance, EEG activity and whether they self-treated with a glucose drink. Every 5 min measures were taken of blood glucose (BG) and epinephrine levels, perceived neurogenic and neuroglycopenic symptoms and driving ability. For the four weeks prior to this hospital study, subjects participated in a field study. Using a hand-held computer just prior to routine self-measurements of BG, subjects rated neurogenic and neuroglycopenic symptoms and made judgements about BG level and ability to drive as they did in the hospital. RESULTS: Drivers who did and did not self-treat did not differ in terms of their pre-hospital exposure to hypoglycemia, their depth and rate of BG fall during experimental testing, or their epinephrine response to hypoglycemia. Subjects who self-treated detected more neurogenic and neuroglycopenic symptoms than those who did not self-treat. They also experienced less EEG defined neuroglycopenia during the progressive hypoglycemic drive as compared to those who did not self-treat. Perceived need to self-treat and EEG parameters correctly classified 88% of those who did treat from those who did not self-treat. Further, subjects who self-treated were more aware of hypoglycemia and when not to drive while hypoglycemic in the field study. CONCLUSION: There is a narrow window between a patient's detection of hypoglycemic symptoms and the need to self-treat, and neuroglycopenia, which impairs self-treatment. Consequently, drivers with T1DM should be vigilant for signs of hypoglycemia and driving impairment (e.g. trembling, uncoordination, visual difficulties) and encouraged to treat themselves immediately when they suspect hypoglycemia while driving. 相似文献
995.
In anesthetized spinalized rat, electrical stimulation of the nucleus tractus solitarius (NTS) synchronizes the EEG by increasing the power of 4-6-Hz waves (>100%; P<0.01), and elevates cerebral blood flow (rCBF) by 18+/-5% (P<0.05). The coordinated response appears within seconds, is global, reversible, graded, evoked from the commissural sub-nucleus, and replicated by L-glutamate. The responses are markedly reduced by bilateral lesions or muscimol microinjections restricted to a region of ventral medullary reticular formation, the medullary cerebral vasodilator area (MCVA), a region from which stimulation elicits identical responses and mediates the comparable responses to hypoxic/ischemic excitation of sympathoexcitatory neurons of rostral ventrolateral medulla (RVLM). We conclude that: (a) excitation of intrinsic neurons of commissural NTS synchronizes the EEG and coordinately elevates rCBF; (b) the responses are mediated by excitation of neurons in MCVA; (c) the MCVA may be a common final pathway mediating cerebrovascular and EEG responses from multiple areas of CNS; and (d) the NTS-MCVA pathway may be a part of the anatomical substrate for behaviors, including slow-wave sleep and seizure suppression evoked by stimulation of visceral afferents terminating in NTS. 相似文献
996.
Mitchell MB Maharajh GS Bielefeld MR DeGroff CG Clarke DR 《The Annals of thoracic surgery》2001,72(1):251-253
Mitral valve replacement in small children imposes significant clinical difficulties because of the relatively small mechanical prosthetic valves required and the need for lifelong anticoagulation therapy. A child weighing 10.4 kg presented with thrombosis of her 19-mm mechanical mitral prosthesis 4 weeks after implantation despite appropriate oral anticoagulation therapy. An emergency mitral valve replacement with a pulmonary autograft was successfully performed with encouraging short-term results. 相似文献
997.
Expression of gastrin in developing gastric adenocarcinoma 总被引:14,自引:0,他引:14
BACKGROUND: A stepwise progression through premalignant stages has been identified for the intestinal type of gastric carcinoma. As gastrin has been identified as a growth factor for the intestinal type of gastric adenocarcinoma, the aim of this study was to investigate whether gastrin is expressed in premalignant gastric conditions. METHODS: Ninety archival samples of atrophic gastritis, intestinal metaplasia, mild gastric epithelial dysplasia, moderate gastric epithelial dysplasia, severe gastric epithelial dysplasia and intestinal-type gastric adenocarcinoma were obtained. Immunocytochemistry was performed using antibodies directed against gastrin and its post-translational precursors, and the gastrin/cholecystokinin B receptor. Positive staining was identified using the avidin--biotin immunoperoxidase method and quantified using an image analysis system. RESULTS: Gastrin and its receptor were shown to be expressed in specimens of atrophic gastritis, intestinal metaplasia, epithelial dysplasia and the intestinal type of gastric carcinoma. CONCLUSION: Gastrin seems to be an important growth factor in gastric carcinogenesis. 相似文献
998.
999.
To date, 118 loci have been associated with photoreceptor degenerative disease. In this review, we will discuss recent advances in the identification of genes that cause progressive photoreceptor cell death when mutated. We will focus on 12 genes isolated within the last two years that have been shown to be photoreceptor-specific, or that have provided insight into photoreceptor biology and the mechanisms of photoreceptor cell death. To aid in understanding the biologic basis for these diseases, we also briefly review photoreceptor biology. Finally, we report on recent advances towards the treatment of these disorders. 相似文献
1000.
Goldberg L MacKinnon DP Elliot DL Moe EL Clarke G Cheong J 《Archives of pediatrics & adolescent medicine》2000,154(4):332-338
BACKGROUND: Use of alcohol and other illicit drugs by adolescent male athletes is a significant problem. Participation in sports may encourage use of drugs that enhance athletic performance, especially anabolic steroids (AS). Because, to our knowledge, no other intervention has successfully altered substance abuse by athletes, we developed and assessed the efficacy of a team-centered, sex-specific education program designed to reduce adolescent athletes' intentions to use and use of AS and alcohol and other illicit drugs. METHODS: We studied 31 high school football teams that comprised 3207 athletes in 3 successive annual cohorts (1994-1996). The intervention included interactive classroom and exercise training sessions given by peer educators and facilitated by coaches and strength trainers. Program content included discussion of sports nutrition, exercise alternatives to AS and sport supplements, and the effects of substance abuse in sports, drug refusal role-playing, and the creation of health promotion messages. Questionnaires assessing AS, the use of sport supplements and alcohol and other illicit drugs, and potential risk and protective factors were administered before and after the intervention (before and after the football season) and up to 1 year after the program. RESULTS: At season's end, intentions to use (P<.05) and actual AS use (P<.04) were significantly lower among students who participated in the study. Although AS reduction did not achieve significance at 1 year (P<.08), intentions to use AS remained lower (P = .02). Illicit drug use (marijuana, amphetamines, and narcotics) was reduced at 1 year, whether alcohol was included (P = .04) or excluded (P = .02) from the index. Other long-term effects included fewer students reporting drinking and driving (P = .004), less sport supplement use (P = .009), and improved nutrition behaviors (P<.02). CONCLUSIONS: Use of alcohol and other illicit drugs and associated harmful activities can be prevented with a sex-specific, team-centered education. School athletic teams provide an optimal environment in which to provide drug prevention and health promotion education. 相似文献