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41.
The feeding behavior of rats sympathectomized by neonatal administration of guanethidine (GUA) and/or adult adrenal demedullation (MDL) was investigated. GUA treatment tended to decrease body weight gain and food intake, chiefly by decreasing meal size and increasing satiety ratios. It also attenuated the increase in food intake caused by 2-deoxy-D-glucose (2DG; 150, 300, 450 mg/kg, IP) but not by insulin (3, 6, 9 U/kg, IP). MDL altered meal patterns in the same manner as GUA treatment but the effects were of smaller magnitude. It did not influence the response to either glucoprivic challenge. Combined GUA treatment and MDL generally produced additive effects. These results suggest that the major sympathetic influence on feeding is through adrenergic innervation and not circulating catecholamines. The hypothesis that the alteration in feeding patterns produced by ventromedial hypothalamic lesions is due to decreased sympathetic activity was not supported. 相似文献
42.
Michael Rossdale Terry Kemple Sarah Payne Michael Calnan Rosemary Greenwood 《The British journal of general practice》2007,57(535):152-154
Out-of-hours organisations are responsible for the care of patients 70% of the time, and their GPs act as gatekeepers to secondary care services. This observational study identifies the variations in GPs' out-of-hours referral rates to secondary care and factors that could explain these variations. One hundred and forty-nine GPs who worked in one UK general practice out-of-hours cooperative which served 19 practices with 167 000 registered patients. Data on patients who accessed the out-of-hours service over 3 years (2001-2004) were examined. Factors thought to be predictors of variation in referral rates were investigated using logistic regression analysis. There was a fivefold difference in referral rates between the lowest and highest referring quartiles of GPs (OR [odds ratio] = 4.56, CI [confidence interval] = 3.86 to 5.38). The sex (female) of the clinician, the time of the consultation (11 pm to 7 am), and the place of the consultation (home visit) accounted for some, but not all, of the increased referral rates. A doctor working out-of-hours disproportionately influences the fate of the patient, the number of hospital admissions, and extra costs to the health service. There is a need for follow-up studies to investigate the factors associated with referral behaviour, and how the variation relates to patient factors and the resources available. These findings could be used when planning the staffing of out-of-hours services to optimise appropriate care and minimise patients' exposure to unnecessary intrusive and expensive hospital care. 相似文献
43.
J. Gordon C. Ghez 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》1984,55(1):167-171
Summary We studied the EMG activity of biceps and triceps in human subjects during isometric force adjustments at the elbow. Rapid targeted force pulses exhibited stereotyped trajectories in which peak force was a linear function of the derivatives of force and the time to peak force was largely independent of its amplitude. These responses were associated with an alternating triphasic pattern of EMG bursts in agonist and antagonist muscles similar to that previously described for rapid limb movements. When the instructions demanded rapid force pulses, initial agonist bursts were of constant duration, and their magnitude was strongly related to peak force achieved. The timing of EMG bursts in antagonist pairs was closely coupled to the dynamics of the force trajectory, and the rising phase of the force was determined by both agonist and antagonist bursts. When peak force was kept constant and rise time systematically varied, the presence and magnitude of antagonist and late agonist bursts were dependent on the rate of rise of force, appearing at a threshold value and then increasing in proportion to this parameter. It is proposed that antagonist activity compensates for nonlinearity in muscle properties to enable the linear scaling of targeted forces which characterizes performance in this task.Supported by the Dystonia Medical Research Foundation and NS 19205 相似文献
44.
Rats were fed either a cereal-based or a purified casein-based diet in a foraging paradigm in which the costs of procurement and consumption were varied. The group offered the cereal-based diet consumed about 10% more calories than the group offered the casein-based diet, but both groups grew at the same rate. The intake of a control group offered a choice between the two diets was approximately 80% from the casein diet, and the growth of this group did not differ from that of the experimental groups. Variations in the cost of procurement and the cost of consumption affected the patterning of meals differentially for the two diets: changes in meal patterns tended to control the time and/or energy spent feeding. These results show that (1) meal patterns in the foraging paradigm are sensitive to subtle differences in diets, and (2) the amount of diet consumed (acceptance) and the choice between diets (preference) are determined by the economics of feeding and the nutritive quality of the foods, as well as by their palatability. 相似文献
45.
根据下頜光弹的等倾线图,描绘出主应力迹线规迹。在下颌侧位X线照片和去除唇侧及颊侧密质骨板的标本上,观察骨密质和松质的配布,以及骨小梁的排列和方向,试行探讨骨小梁方向与主应力迹线的关系。用光弹法求得的主应力迹线有两个系列:S_1系在下颌体近水平方向,在下颌支近垂直方向分布;S_2系力线与S_1系诸力线呈正交。在标本和X线照片上,主应力迹线规迹不同程度地在骨小梁的排列上有所反映。 相似文献
46.
Kerry B. Jedele Virginia V. Michels 《American journal of medical genetics. Part A》1991,39(2):201-203
Urticaria in response to various physical stimuli has been reported in sporadic and familial patterns. The most common of these physical urticarias, dermographism, is a localized urticarial response to stroking or scratching of the skin and has not been reported previously to be familial. A four-generation family with dermographism, probably inherited as an autosomal dominant trait, is presented along with a discussion of sporadic dermographism and other types of familial physical urticarias. 相似文献
47.
Mats Fredrikson Tomas Danielssons Bernard T. Engel Marianne Frisk-Holmberg Gunnar Ström Örjan Sundin 《Psychophysiology》1985,22(2):167-174
The aim of the present research was to study individual response specificity in 22 male patients having essential hypertension (HT) and to compare these patients with age-matched male normotensive controls (NT). Four stimuli, letter identification, mental arithmetic, cold pressor and isometric exercise, were administered while recordings were made of: systolic and diastolic blood pressures, heart rate, respiration, forearm and hand blood flows, and skin conductance level and fluctuations. After each session urine samples were collected and epinephrine and norepinephrine levels were analyzed. Twelve subjects in the HT group were given beta-adrenergic blocking agents and retested 1 to 21 months (X?= 12 months) after the first session. Each response was standardized, using NT as the reference group. Intraclass correlations were computed to evaluate whether HT males reacted with a more consistent hierarchy of responses than did NT. Intraclass correlations were significantly higher among the patients than in the control group, regardless of whether the blood pressure response was included or excluded in the computation of the intraclass correlations. Thus, we conclude that male HT patients show more individual response specificity than NT controls. Beta-adrenergic receptor antagonists reduced levels of cardiovascular activity and attenuated reactivity but did not affect amount of specificity. Thus, intraclass correlations provide unique and useful information, since they are not related to blood pressure reactivity or to urinary catecholamine levels, nor affected by beta-adrenergic blockade. 相似文献
48.
Spontaneous meal sizes, intermeal intervals, and 24 hr feeding rhythms were monitored in normal and 60 day recovered vagotomized rabbits fed solid laboratory chow. Mean sizes of meals and intermeal intervals, and the circadian distribution of food intake did not differ between the two groups, but vagotomy was associated with increased frequencies of both smaller and larger than average meals. Positive meal to postmeal interval correlations were evident in intact but not vagotomized animals, whereas vagotomized animals displayed a meal to premeal interval correlation in the light phase that was not present in normal rabbits. 相似文献
49.
Laser Doppler flowmetry with optical-fibre beam transmission is a sensitive fast and convenient method of measuring tissue
blood flow. However, its sensitivity can also be a problem because of movement artefacts. This study applies some basic considerations
of fibre optics and Rayleigh light scattering to the field of laser Doppler blood flow meters. Practical suggestions are given
by which movement arterfacts can be reduced by choice of optical fibres, attention to probe geometry, cladding the fibres
to reduce their movements and in the method of application. Experiments which test the normalisation circuitry of laser Doppler
instruments are described and the effects of movement artefacts on the interpretation of the pulsatile component of laser
Doppler records are also discussed. Probe and fibre line movements cause high-frequency intensity fluctuations due to speckle
movement. The intensity fluctuations produce an apparent Doppler shift much greater than the Doppler shift produced by the
relative movements of probe and tissue. It has been found that it is important to ensure that the fields of view of the illuminating
and detecting fibres do not overlap at the skin surface and that probe contact with the skin surface should be maintained. 相似文献
50.
A monitoring system to continuously record the daily pattern of drinking and eating of rats is described. This system, based on a North Star microcomputer, can record the amount of food ingested with a temporal resolution of +/- 1.0 second and quantitative accuracy within +/- 5%. Drinking behavior is detected using a drinkometer which also has a temporal resolution of +/- 1.0 second. Data are analyzed by computer to determine absolute amounts of consumption and patterns of intake. The patterns of feeding and drinking recorded by this system are similar to those observed using other monitoring devices. 相似文献