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11.
This article describes the association between previous infection and/or vaccination and the development of optic neuritis (ON) in 18 children. Ten of these children subsequently developed clinically definite multiple sclerosis (MS), while in 8 patients a clinically definite etiology could not be confirmed. Vaccination preceded the first ON attack in 6 patients, all but one of whom subsequently developed MS. It also preceded subsequent demyelinating events in 6 patients. Ten of the patients had a bacterial or viral infection within the 2 weeks prior to the first symptoms of ON. Intrathecal antibody synthesis against 2 or more viruses could be shown in 5 out of 8 patients studied; 5 out of 6 patients had oligoclonal antibodies in CSF and 12 out of 16 patients a high IgG index. Neither intrathecal antibody synthesis against 2 or more viruses nor elevated IgG indexes could be found in the control patients. Measles and mumps occurred at a significantly later age in the children who subsequently developed MS than in the control children, and these patients had significantly more events that might have impaired the blood-brain barrier than the controls. These results indicate that immunological events leading to MS may be triggered during childhood. Vaccination and infection often precede ON in childhood. Intrathecal viral antibody production can occur already in childhood at the time of the first symptoms of MS.  相似文献   
12.
While much time has been spent deliberating about the definition of play, little emphasis has been placed on what children themselves perceive as play. The aim of the present study was to examine social context as a cue for children's perceptions of play and learning. Ninety-two children aged between four and six years (mean four years nine months) participated in the study and completed the Activity Apperception Story Procedure. Children were asked to sort photographic stimuli into those they believed depicted play/not play and learning/not learning. Each of the stimuli were identified by independent raters as containing one of the following social cues; teacher absence (solitary activity, parallel activity or cooperative activity) or teacher presence (teacher involved activity or teacher directed activity). Findings revealed that children associated teacher absence with play. More specifically, children made links between play and the presence of peers (parallel and cooperative activity). Findings are discussed in relation to play in the early years curriculum, differences in children's early educational experiences and the importance of understanding children's perceptions of play.  相似文献   
13.
Two samples of kindergarten children's representation and understanding of written number symbols were examined in two time points in one academic year. About 85% of Chinese five year olds (mean = 5 years 10 months) were able to use conventional number symbols to represent the quantity of 30 or larger. At the end of the kindergarten year, 94% of Chinese six year olds (mean = 6 years 4 months) were able to use conventional number symbols to represent the quantity of 100 or larger. Some Chinese six year olds had problems in representing written addition and subtraction tasks. Children's ability to represent written number symbols, ability to represent written addition and subtraction formula and their performance on written addition and subtraction were closely related. The performance of children in a university-affiliated childcare center was better than that of the center serving working-class families in Time 1, but the performance reversed at the end of the kindergarten year.  相似文献   
14.
The study explored the counterfactual thinking that women with chronic and widespread pain showed in response to what they themselves considered to be particularly stressful situations. Counterfactual thinking in 125 women sick‐listed due to chronic and widespread pain was investigated in terms of structure, function and control focus. The women were asked, for each of three types of problems that they indicated in a questionnaire to affect them most strongly, to describe a typical occurrence of it and to complete a counterfactual sentence in connection with it of the type ‘If only . . .’. The majority of counterfactuals pertained to predominantly somatic problems (e.g. musculo‐skeletal problems, pain and fatigue) classified as being affective rather than preparative and self‐focused rather than external, whereas in counterfactuals relating to predominantly psychological/psychosocial problems a preparative function and an external focus were more prominent. The numbers of problems listed and the numbers of situations responded to counterfactually were positively correlated. The counterfactuals, although often related to somatic problems, generally concerned psychological or psychosocial matters such as finances and paid or unpaid work. A contextual approach to elucidating counterfactual thinking based on subjects' own experiences is seen as providing valuable insight into what bothers them most. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   
15.
In order to make effective use of the statistical theory of design of clinical trials for chronic diseases such as periodontal disease, certain issues must be considered. Any clinical trial requires that the disease definition be well-specified; that patient eligibility be explicit; that the observation times be explicit; that the duration and endpoint of therapy be specified; that the duration of subsequent followup observation be specified; and that the unit of observation (e.g., tooth, set of teeth, patient) be defined. In a chronic disease, the potential biases that can readily be introduced by self-selection of patients who enter the trial and/or who return for subsequent observation become more important, because subjects are required to remain on treatment and/or observation for prolonged periods. Further, the cyclical nature of some chronic diseases may require special attention to baseline definitions of active disease and disease outcome. These issues are illustrated with examples from clinical trials of hypertension, breast cancer screening, and Polycythemia Vera. Implications for periodontal disease are discussed.  相似文献   
16.
M.A. Sabbahi  E.M. Sedgwick   《Brain research》1987,423(1-2):125-134
The H-reflex of 120 soleus motoneurons was recorded using fibre EMG. The recovery profile of these motoneurons was studied during monitoring surface H-reflex records in 28 adult subjects. The spectrum of motoneurons tested was homogeneous with two extremes of neurons having different characteristics. A motoneuron population (forming about 69% of our sample) had a high threshold level for electrical stimuli, short recovery time, and short recovery fringe time (called type A). A second population of motoneurons (forming about 20-30% of our sample) had a low threshold level for electrical stimuli, long recovery fringe time (called type B). During an isometric muscle contraction every motoneuron showed an early shift in recovery time (i.e. each had a shorter recovery time) with shortened recovery fringe time. These changes were larger for motoneurons type B than motoneurons type A. With paired identical electrical stimuli of varying interstimulus intervals a motoneuron may fire in response to the conditioning and test stimuli giving an H2, but not in response to both stimuli. This occurred for interstimulus intervals of 4-11 ms. A strong inhibition period was recorded with interstimulus intervals of 12-80 ms in which all motoneurons did not show any recovery. Most motoneurons recovered in orderly fashion between 80 and 300 ms of interstimulus interval, and this recovery coincided with the fast recovery recorded in surface H-reflex. All motoneurons were recovered by 3000 ms of interstimulus intervals. These findings emphasize the importance of eliciting the H-reflex every 3-5 s in H-reflex methodology in order to be assured that all excited motoneurons have been recovered.  相似文献   
17.
Pathophysiological aspects of brain edema   总被引:16,自引:0,他引:16  
Summary Two mayor types of brain edema, related to two different pathomechanisms, can be recognized: 1)cytotoxic type-where the main feature is the swelling of cellular elements of brain parenchyma and 2)vasogenic type-where an increased vascular permeability leading to accumulation of edema fluid inthe extracellular spaces plays the principal role. In this type of edema, there is a close interrelationship between extravasation of serum proteins and retention of water in the brain tissue. In theischemic brain edema both cytotoxic and vasogenic mechanisms are involved. A biphasic opening of the blood-brain barrier, associated with vasogenic edema, is observed following release of major cerebral artery occlusion. The first opening of the barrier is related to a reactive hyperemia which follows promptly recirculation. The second opening, recognizable after a delay, is associated with a severe ischemic brain tissue injury.Dedicated to Prof. F. Seitelberger on the occasion of his seventieth birthday  相似文献   
18.
19.
Summary This paper deals with a particular aspect of speech motor control in patients suffering from apraxia of speech. Three experiments are reported concerning the phase relations between individual speech gestures. These include the timing of laryngeal, velar and labial movements relative to lingual gestures.A total of 8 patients and 12 normal controls were examined using speech material which was designed according to appropriate phonetic paradigms. Evaluation was performed on the basis of speech signal parameters referring to the kinematics of inter-articulatory phasing. Deviations of the patient group were found in all three experiments. This suggests that disturbed phase relations of individual speech movements are a general feature of apraxic speech. It is further hypothesized that the described motor symptoms are the origin of a variety of phonemic errors. Support for this view is provided by appropriate examples which refer to the examined paradigms. By this argument, much of the disturbed phonemic structure of apraxic speech may be accounted for by timing deficits.  相似文献   
20.
AIMS: The aim of this study is to compare PUMA curves with different pathologic conditions causing bladder dysfunction in 158 men and 83 women. METHODS: PUMA results in terms of bladder outlet obstruction and detrusor contractility were compared in 92 men with benign prostatic hypertrophy (BPH) and p(ves) congruent with p(det) (i.e., p(abd) congruent with 0) with the results of the urodynamics operator's opinion, the provisional International Continence Society method, Abrams and Griffith's diagram, urethral resistence factor (URA), Sch?fer's diagram, and Watt factor. PUMA curves correlated reliably with different pathologic conditions such as obstructive BPH, orthotopic bladder, cystocele, the neurological bladder, and bladder diverticulum. Statistical analysis indicated excellent agreement between PUMA and URA; agreement with other methods was good in cases of obstruction and nonobstruction. In doubtful cases, as diagnosed by standard methods, PUMA agreed only with the Abrams and Griffith's diagram. PUMA and Wmax were in good agreement on detrusor con traction force. Agreement between PUMA and Sch?fer's diagram was excellent for patients with detrusor hypercontractility and good for patients with detrusor hypocontractility and normocontractility. PUMA is the only method applicable to women. It is easy to perform. When integrated with other diagnostic tests, it provides realistic data for diagnosis, medical or surgical therapy, and outcome.  相似文献   
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