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排序方式: 共有2364条查询结果,搜索用时 15 毫秒
21.
Griefahn B Künemund C Blaszkewicz M Golka K Degen G 《International archives of occupational and environmental health》2002,75(3):171-178
OBJECTIVES: The present experiments concerned the hypothesis that an intermittent, strong and extremely low frequency magnetic field reduces salivary melatonin levels and delays consecutively the nadirs of rectal temperature and heart rate. METHODS: Twelve healthy young men (18-25 years) participated in three randomly permuted sessions, which were performed as constant routines. The participants kept a strict bed rest over 26 h, air temperature was 20 degrees C, illumination < 30 lx, and sound level < 50 dBA. Salivary melatonin levels were determined hourly, rectal temperature and heart rate were registered continuously throughout. An intermittent magnetic field was administered in one session from 6 p.m. to 2 a.m. at 16.7 Hz, 0.2 mT and alternating on/off-periods of 15 s. This situation was compared with a control session without any additional stress. Another session was performed to determine the participants' ability to respond to a well-known melatonin-suppressing stress, namely bright light (1,500 lx, 10 p.m.-2 a.m.). RESULTS: Bright light inhibited melatonin synthesis in all 12 participants and delayed the nadirs of rectal temperature and heart rate. The only significant alteration that was associated with exposure to the magnetic field was a delay in the heart rate nadir, which was not mediated by an accordingly altered melatonin profile. CONCLUSION: The fact that the circadian rhythm of only the heart rate was altered indicates an internal dissociation which might constitute a health risk in the long run and needs to be investigated more extensively. 相似文献
22.
Butchart EG Gohlke-Bärwolf C 《Journal of the American College of Cardiology》2004,44(5):1143-4; author reply 1144-5
23.
Filipek PA Juranek J Nguyen MT Cummings C Gargus JJ 《Journal of autism and developmental disorders》2004,34(6):615-623
A random retrospective chart review was conducted to document serum carnitine levels on 100 children with autism. Concurrently drawn serum pyruvate, lactate, ammonia, and alanine levels were also available in many of these children. Values of free and total carnitine (p < 0.001), and pyruvate (p=0.006) were significantly reduced while ammonia and alanine levels were considerably elevated (p < 0.001) in our autistic subjects. The relative carnitine deficiency in these patients, accompanied by slight elevations in lactate and significant elevations in alanine and ammonia levels, is suggestive of mild mitochondrial dysfunction. It is hypothesized that a mitochondrial defect may be the origin of the carnitine deficiency in these autistic children. 相似文献
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25.
Hoffman JR Greenberg JH Furuya D Craik RL Fanelli P Breslow S Sheehan S Ketschek A Damkaoutis C Reivich M Hand P 《Brain research》2003,965(1-2):91-99
Rats use their vibrissae for a variety of exploratory tasks including location of objects and discrimination of texture. This study examines recovery in vibrissal function following a unilateral ischemic injury to the somatosensory cortex. Vibrissal function was examined in adult food-restricted rats performing on a two-texture discrimination device. Animals were trained and tested until the criteria of >80% correct choices was demonstrated on three consecutive days. Ischemic rats were constrained to use the affected whiskers by clipping the ipsilateral vibrissae. One group was tested after ischemia, a second group was trained before ischemia and then tested, and a third group was pre-trained and received whisker stimulation and tested post-ischemia. Nai;ve animals recovering from ischemia took longer to reach criteria than intact or unilateral trimmed control animals. Pre-trained animals with compression ischemia receiving whisker stimulation with sucrose water completed the task to criteria in the fewest number of trials. The results indicate that recovery of vibrissal function occurs following a unilateral ischemic injury. Histological analysis in animals without whisker stimulation indicates that the number of normal appearing cortical barrels following ischemia was inversely correlated to the number of trials needed to complete the behavioral task. This suggests that the natural recovery of the ability to discriminate textures is related to the degree of damage to the barrel cortex. The relationship between cortical barrels and behavioral recovery did not hold for the ischemic animals receiving whisker stimulation. This latter group demonstrated recovery despite marked anatomical lesions suggesting that the intervention influenced reorganization. 相似文献
26.
Steinhausen HC Metzke CW 《Journal of child psychology and psychiatry, and allied disciplines》2003,44(5):677-686
BACKGROUND: Alcohol is the most frequently used substance among adolescents with different patterns of consumption. Various types of adolescent alcohol use have been proposed, but only a few studies have looked for external validation of these types. METHOD: Data from 794 adolescents participating in the Zurich Adolescent Psychology and Psychopathology Study (ZAPPS) were used to evaluate the discriminant validity of the classification of four types of adolescent drinkers: abstainers, social drinkers, heavy drinkers, and problem drinkers. Data were based on questionnaires dealing with substance abuse, emotional and behavioral problems, life events, coping capacity, self-related cognitions, perceived parental behavior, perceived school environment, and the social network. RESULTS: There was a clear differentiation of the problem drinkers' group on almost all dimensions of the emotional and behavioral problems questionnaires, with the heavy drinkers' profile situated in between on some dimensions, and the abstainers and social drinkers almost ideally meeting the expectation of a mean normal population profile. Problem drinkers were also marked by high life impact scores, low self-esteem, high self-awareness, low perceived parental acceptance and high amount of rejection by the parents, and various indicators of a stressful and less rewarding school environment. Again, the heavy drinkers were positioned on an intermediate level on some of these scales, whereas the abstainers and social drinkers scored more normally. CONCLUSION: These findings support the validity of the distinction of various adolescent alcohol use types. 相似文献
27.
Horsthemke B Lich C Buiting K Achmann R Aulehla-Scholz C Baumer A Bürger J Dworniczak B Gläser D Holinski-Feder E Janssen B Kleinle S Kochhan L Krasemann E Kraus C Kroisel P Plendl H Purmann S Sander G Skladny H Spitzer E Thamm-Mücke B Varon-Mateeva R Weinhäusel A Weirich H 《European journal of human genetics : EJHG》2003,11(12):913-915
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29.
Epileptic spasms and partial seizures as a single ictal event 总被引:2,自引:2,他引:0
PURPOSE: To investigate the phenomenon of epileptic spasms (ESs) associated with other seizure types in a single ictal event and to study the predictive value of this phenomenon regarding etiology and prognosis. METHODS: We selected retrospectively eight female and five male patients, who had ESs and other seizure types within a single seizure event and for whom a video-EEG recording of the phenomenon was performed in at least one situation. RESULTS: The seizure type associated with ESs was a partial seizure in all patients. We identified three groups with different seizure patterns regarding the temporal association of ES and partial seizures (PSs): (a) PS followed by ES; (b) PS appearing during a cluster of ESs without interrupting the cluster; and (c) complex seizure interaction with a succession of ESs and PSs in a close but variable temporal association. Underlying disorders included cortical dysplasia (three patients), complex cerebral malformations (two patients), and perinatal anoxic-ischemic injuries (two patients); four cases were classified as cryptogenic, and in two children, etiology was unknown, but prenatal origin was suspected. Outcome was poor in nine cases with intractable epilepsy; four cases had a favorable outcome, defined as complete cessation of epileptic seizures. CONCLUSIONS: The phenomenon of associated ESs and PSs as a single ictal event can be related to different etiologies and should not be considered distinctive for cortical malformations or severe brain damage. Different seizure patterns of associated ESs and PSs provide no hint for etiology or prognosis. Outcome is prevalently but not constantly unfavorable in patients with the phenomenon. 相似文献
30.
Streeck-Fischer A Kepper-Juckenack I Kriege-Obuch C Schrader-Mosbach H von Eschwege K 《Praxis der Kinderpsychologie und Kinderpsychiatrie》2003,52(8):620-638
Early maltreatment of children can lead to severe disorders in the regulation of behaviour and affect, alterations in awareness and distorted perception. In development-oriented psychotherapy, therapeutic interventions which are directed to regulating processes, decentration or mentalization, desomatization and symbolization of enacted messages play a central role. The results of early traumatization and of therapeutic interventions are portrayed, examining the multi-dimensional diagnosis and therapy of a dangerously aggressive 12-year-old boy as an example. From this, it becomes clear how, through new experiences with regulating others, he gradually surfaces from a world of annihilation and destruction and learns to survive and to live. 相似文献