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971.
Y Koutedakis L Myszkewycz D Soulas V Papapostolou I Sullivan N C Sharp 《International journal of sports medicine》1999,20(6):379-383
The purpose of this study was to assess the effects of a six-week summer break and of dance preparations at the beginning of the new season following the break, on selected physiological parameters. Seventeen professional ballerinas (mean age 27.2 +/- 1.4 years, mean height 160.2 +/- 6.2 cm) volunteered. They were assessed just before and immediately after their normal summer break, during which very little or no physical work was reported. Eight of these dancers were assessed for a third time, 2-3 months after the end of the break, while they were into preparing for the new season. More specifically, compared to pre-break data, the six-weeks of holiday was followed by a 15% overall increase in the three flexibility tests (from 334 to 386 degrees, P < 0.01), a 14% increase in peak anaerobic power (from 350 to 400 watts; P < 0.01), a 16% increase in leg strength (from 143 to 166 Nm; P < 0.01) (i.e. the mean performance of left and right knee extension added to the mean performance of left and right knee flexion), and a 10% increase in VO2max (from 41.2 to 45.2 ml/kg/min; P < 0.05). The third set of data, 2-3 months after the end of the break, revealed further significant increases by 24% in leg-strength (P < 0.005) and 17% in VO2max (P < 0.01) compared to pre-holiday data. Despite the lack of a control group, the present results fit with the hypothesis of a degree of "burnout" at the end of the season, which negatively affected the mechanisms of fitness and conditioning. A six-week summer-break can act as a restorer of these mechanisms. Two to three months into the new season, positive adaptations to exercise appeared to confirm recovery from the "burnout" or overtraining phenomenon. More research is required on the effects of demanding dance schedules on fitness and conditioning, and how such schedules might adversely affect dance performance and dancers' careers. 相似文献
972.
973.
RATIONALE AND OBJECTIVES: Auditing has received much attention recently as a method for radiologists to use to evaluate their interpretation of screening mammograms. U.S. Food and Drug Administration regulations require that some sort of audit be in place before a mammography screening facility can receive accreditation. Auditing presents a unique opportunity to monitor accuracy continually and identify problems early. Audit data present unique challenges, however, and appropriate methods must be used to control the risk of errors. MATERIALS AND METHODS: This article introduces a simple method for the task of deciding if a radiologist yields an acceptable positive predictive value based on audit. The method is based on "sequential" decision-making techniques that have found wide application in quality control problems. These techniques are developed for diagnostic radiology and embodied in an easy-to-use decision-making chart. RESULTS: Several examples, based on audit data from actual mammography facilities, provide insights into the use of these charts and the influence of (a) the selection of standards, (b) the selection of error risks, and (c) radiologist variability. The examples also serve to demonstrate another important property of this method--that is, it specifies the minimum amount of data that has to be collected before any decision can reliably be made. CONCLUSION: The chart presented in this article provides a method by which audit data can be used objectively to evaluate the accuracy of screening mammogram interpretation. The method controls the risk of either falsely accepting an unqualified radiologist or falsely rejecting a qualified radiologist. It should be a useful tool to radiologists who must evaluate their own practices. 相似文献
974.
In order to evaluate the effect of the introduction of recent similar guidelines on the treatment of acute urinary tract
infection (UTI) in children, and possible changes in its epidemiology, we analyzed the records of hospital discharge for acute
UTI under the age of 15 years in England and Wales between 1979 and 1993 and in Finland between 1978 and 1994. Cases were
defined by the ICD9 diagnostic codes 590.1 (acute pyelonephritis) and 599.0 (UTI, site not specified) for males and females
according to three age groups (0–4, 5–9, and 10–14 years). We also compared the registry data on kidney transplants due to
end-stage renal disease caused by recurrent pyelonephritis in the United Kingdom and Finland. In England the rate of attack
of symptomatic UTI per 1,000 girls under 15 years increased from 0.74 (95% confidence interval 0.71–0.76) in 1987 to 1.32
(1.29–1.35) in 1993 (P<0.001, test for trend). The respective figures for Finnish girls were 1.74 (1.62–1.86) in 1987 and 1.62 (1.51–1.74) in 1993
(P=0.72). In English boys, the increase in the attack rate was from 0.38 (0.36–0.40) in 1987 to 0.70 (0.68–0.73) in 1993 (P<0.001). In Finnish boys the respective figures were 0.74 (0.66–0.82) in 1987 and 0.88 (0.80–0.97) in 1993 (P<0.02). The observed increases in the attack rates of UTI most probably relate to increased referral of acute UTI patients
to hospitals for the recommended imaging studies rather than changing occurrence. Publication of guidelines for treatment
of UTI in children, consolidating more-general awareness, may have contributed to this. The mean annual numbers of kidney
transplants in the United Kingdom and Finland during 1989–1995 due to end-stage renal disease caused by pyelonephritis were
of similar magnitude, i.e., 1.9 (1.6–2.3) transplants per million inhabitants in the United Kingdom and 2.8 (1.5–4.7) transplants
per million inhabitants in Finland. The decreasing trend in these figures in both countries, although statistically significant
only in the United Kingdom (P<0.05, test for trend), suggests improved long-term outcome of these patients induced by better diagnosis and treatment of
pyelonephritis and the diseases related to it, such as congenital malformations. According to our data, valid clinical guidelines
are effective in changing clinical practice.
Received: 1 September 1997 / Revised: 29 April 1998 / Accepted: 29 April 1998 相似文献
975.
Antonio G. Carrizo 《Critical Reviews in Neurosurgery》1999,9(2):79-86
Female gender and cigarette smoking appear to be risk factors for the development of multiple intracranial aneurysms. An acquired nature is likely in this form. The mechanism of aneurysm formation in patients with sickle cell anemia is apparently different. These patients also present multiple aneurysms that show propensity for vertebrobasilar territory and appear at a younger age. Familial cerebral aneurysms are diagnosed once heritable connective tissue disorders have been excluded. The age of patients tends to be lower and the size of aneurysm to be smaller at the time of rupture in the familial form. These aneurysms are less frequently found in the anterior communicating artery than the sporadic aneurysms. A high incidence of asymptomatic familial aneurysms was detected in people with family histories of intracranial aneurysms studied by means of magnetic resonance angiography. Furthermore, familial aneurysms are more likely to rupture in families having members with aneurysmal subarachnoid hemorrhage (SAH) than in those without. The results of an interesting study using color "power" transcranial Doppler ultrasound in patients with aneurysmal SAH suggest that as the intracranial pressure diminished, the size of the aneurysm increased, and there was relatively little change between maximum and minimum dimensions during the cardiac cycle, i.e., the pulsatility is reduced. The use of postoperative angiography after clipping is a matter of debate. The indication more widely accepted is in large aneurysms with a wide neck, in which incomplete clipping can be suspected. Taking into account the current low risk of angiography in centers of excellence, its routine use may be recommended. Aneurysm remnants, vessel occlusion, vasospasm, and newly identified aneurysms are the main findings that were reported. 相似文献
976.
Ove Almkvist Bengt Winblad 《European archives of psychiatry and clinical neuroscience》1999,249(3):S3-S9
Alzheimer’s disease (AD) is common in elderly individuals; it causes distress for the patients and their relatives as well as large costs for the society. With the advent of symptomatic treatment at present and probable etiology-based cures in the future, it will be possible to relieve and put an end to these negative effects. Therefore, it is necessary to diagnose the disease as early as possible. In this review, we briefly summarize the state-of-the-art concerning various available clinical and biochemical methods for identifying AD. Increasing age, heritage, and presence of ApoE e4 allele have been confirmed as risk factors for AD as well as some putative factors (e.g., low education, hypertension, hypotension) based on epidemiological recent research. Selective impairment of episodic memory has been found to be a preclinical marker for future development of AD based on convergent data from asymptomatic AD-related mutation carriers, longitudinal studies of patients with mild cognitive impairment (MCI), and epidemiological studies of incident AD cases. Neurophysiological methods are inexpensive and useful for the identification of changes in brain dysfunction in AD and new promising methods are under development. Using magnetic resonance imaging (MRT), structural measurements of brain atrophy and specific brain structures such as the hippocampus have been reported to detect dementia development early in the course of disease. Similarly, functional measurements of brain activity (e.g., blood flow) have revealed that hypometabolism in bilateral parietotemporal brain areas early in the disease course. Finally, biochemical studies have demonstrated that certain proteins (e.g., tau the Aβ1-42/43 metabolite of the amyloid precursor protein) may be associated with the disease process in AD, although the specificity of these markers remains to be established. It is concluded that still no single marker of AD exists, which makes it necessary to rely on data from multiple sources in order to arrive at the best possible diagnosis of AD. 相似文献
977.
Waller SA Armstrong KJ McGrath AM Sullivan CL 《Journal of autism and developmental disorders》1999,29(6):485-490
This review summarizes subject selection and diagnostic procedures documented in the Journal of Autism and Developmental Disorders. One hundred forty-two empirical articles published between February 1993 and April 1997 were examined. Reviewers independently evaluated articles using a coding instrument developed by the authors. Results indicated that a majority of researchers reported the use of one or more standard diagnostic criteria in classifying their subjects. However, numerous studies did not report the methods by which the diagnostic criteria were quantified or applied. Additionally, there was a lack of clear specification of inclusion and exclusion criteria for comorbid disorders. Improving the documentation of diagnostic practices in research on autism will benefit researchers and practitioners. 相似文献
978.
979.
980.
R D Etzioni E J Feuer S D Sullivan D Lin C Hu S D Ramsey 《Journal of health economics》1999,18(3):365-380
Measurement of treatment costs is important in the evaluation of medical interventions. Accurate cost estimation is problematic, when cost records are incomplete. Methods from the survival analysis literature have been proposed for estimating costs using available data. In this article, we clarify assumptions necessary for validity of these techniques. We demonstrate how assumptions needed for valid survival analysis may be violated when these methods are applied to cost estimation. Our observations are confirmed through simulations and empirical data analysis. We conclude that survival analysis approaches are not generally appropriate for the analysis of medical costs and review several valid alternatives. 相似文献