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1.
M Z Atassi M Yoshioka G S Bixler Jr 《Proceedings of the National Academy of Sciences of the United States of America》1989,86(17):6729-6733
Processing of a protein antigen into fragments is believed to be a prerequisite for its presentation by the antigen-presenting cell to the T cell. This model would predict that, in oligomeric proteins, T cells prepared with specificity for regions that are buried within subunit association surfaces should recognize the respective regions in vitro equally well on the isolated subunit or on the oligomer. Three hemoglobin (Hb) alpha-chain synthetic peptides, corresponding to areas that are situated either completely [alpha-(31-45)] or partially [alpha-(41-45) and alpha-(81-95)] within the interface between the alpha and beta subunits of Hb, and a fourth peptide representing a completely exposed area in tetrameric Hb were used as immunogens in SJL/J (H-2s) mice. Peptide-primed T cells were passaged in vitro with the respective peptide to obtain peptide-specific T-lymphocyte lines. T-cell clones were isolated from these lines by limiting dilution. T-cell lines and clones that were specific for buried regions in the subunit association surfaces recognized the free peptide and the isolated subunit but not the Hb tetramer. On the other hand, T cells with specificity against regions that are not involved in subunit interaction and are completely exposed in the tetramer recognized the peptide, the isolated subunit, and the oligomeric protein equally well. The responses of the T-cell lines and clones were major histocompatibility complex-restricted. Since the same x-irradiated antigen-presenting cells were employed, the results could not be attributed to differences or defects in Hb processing. The findings indicate that in vitro the native (unprocessed and undissociated) oligomeric protein was the trigger of major histocompatibility complex-restricted T-cell responses. 相似文献
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OBJECTIVE: The differential diagnosis of primary (idiopathic) vs. psychiatric hypersomnia is challenging because of the lack of specific clinical or laboratory criteria differentiating these two disorders and the frequent comorbidity of mental disorders in patients with primary hypersomnia. The aim of this study was to assess whether polysomnography aids in the differential diagnosis of these two disorders. METHODS: After excluding patients taking medication and those with an additional diagnosis of sleep-disordered breathing, we compared the nocturnal and daytime sleep of 82 consecutive patients with a diagnosis of either primary hypersomnia (N = 59) or psychiatric hypersomnia (N = 23) and normal control subjects (N = 50). RESULTS: During nocturnal sleep, patients with psychiatric hypersomnia showed significantly higher sleep latency, wake time after sleep onset, and total wake time and a significantly lower percentage of sleep time than patients with primary hypersomnia and control subjects (p < .05). In addition, the daytime sleep of patients with psychiatric hypersomnia was significantly higher in terms of sleep latency, total wake time, and percentage of light (stage 1) sleep and lower in terms of percentage of sleep time and stage 2 sleep than in patients with primary hypersomnia and control subjects (p < .05). The daytime sleep of patients with primary hypersomnia as compared with that of control subjects was characterized by lower sleep latency and total wake time and a higher percentage of sleep time (p < .05). Finally, a sleep latency of less than 10 minutes or a sleep time percentage greater than 70% in either of the two daytime naps was associated with a sensitivity of 78.0% and a specificity of 95.7%. CONCLUSIONS: Our findings indicate that psychiatric hypersomnia is a disorder of hyperarousal, whereas primary hypersomnia is a disorder of hypoarousal. Polysomnographic measures may provide useful information in the differential diagnosis and treatment of these two disorders. 相似文献
4.
X-linked cleft palate 总被引:2,自引:0,他引:2
D Bixler 《American journal of medical genetics》1987,28(2):503-505
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On the classification of the acrocephalosyndactyly syndromes 总被引:2,自引:0,他引:2
This report describes a family in which two different types of acrocephalosyndactyly (ACS) were clinically identified. The proband presented with the classic stigmata of Pfeiffer syndrome, while her cousin was considered to be a typical case of Apert syndrome. Seven other family members also have unusually shaped heads and the facial appearance reminiscent of Crouzon disease.
Observations made in this family and from previous reports in the literature, we feel there is substantial reason to re-evaluate the ACS classification and to consider that the Apert and Pfeiffer types of ACS may be one and the same. 相似文献
Observations made in this family and from previous reports in the literature, we feel there is substantial reason to re-evaluate the ACS classification and to consider that the Apert and Pfeiffer types of ACS may be one and the same. 相似文献
7.
C. Dawn DeLozier Ray M. Antley Rick Williams Neil Green Richard M. Heller David Bixler Eric Engel John M. Optiz 《American journal of medical genetics. Part A》1980,7(3):391-403
Described here are two patients with a newly recognized syndrome of bone and cartilage maldevelopment which, we believe, results from a single embryonic defect, probably of genetic origin. The cardinal manifestations of this association are craniosynostosis, radiohumeral synostosis (RHS), and femoral bowing. Specific secondary defects include midface hypoplasia with characteristic facial appearance and ears, neonatal femoral fractures, and multiple minor anomalies of the limbs. Though the differential diagnosis includes such disorders as the campomelic syndrome, osteogenesis imperfecta (OI) and certain of acrocephalosyndactyly syndromes, the unique combination of clinical and radiographic abnormalities allows ready differentiation. The cause cannot be determined from these two cases. 相似文献
8.
Royden Stanford Danae Lowell Rajeeva Raju Shylaja Arya 《The Journal of foot and ankle surgery》2012,51(4):475-478
We report on a 79-year-old man with a chronic venous stasis ulceration of >20 years' duration in the left medial leg presenting to our clinic after admission for bleeding and suspected infection of his ulceration. This lesion had been biopsied in 1999 and was found to be a benign, chronic venous insufficiency ulceration. Plain film radiographs as well as a bone scan did not identify osteomyelitis. Because of the hypertrophic, nodular appearance of this ulceration, it was the clinicians' discretion to perform a repeat biopsy of the lesion. Biopsy revealed invasive, well-differentiated squamous cell carcinoma. A computed tomography scan subsequently identified a suspicious inguinal lymph node, and an ultrasound-guided needle aspiration revealed metastatic squamous cell carcinoma of the biopsied lymph node. Above-knee amputation was indicated at this time and was performed in conjunction with local superficial inguinal lymph node resection, after which the patient was discharged from our service. 相似文献
9.
Morphology of the uvula in obstructive sleep apnea 总被引:12,自引:0,他引:12
J L Stauffer M K Buick E O Bixler F E Sharkey A B Abt E K Manders A Kales R J Cadieux J D Barry C W Zwillich 《The American review of respiratory disease》1989,140(3):724-728
Alterations in pharyngeal structure and function are considered fundamental in the pathogenesis of obstructive sleep apnea (OSA). However, little is known about morphologic features of the pharynx in patients with OSA. We therefore studied the tissue composition of the uvula (midsagittal section) in patients with OSA, using a quantitative, morphometric point-counting technique. Uvula tissue was obtained by uvulopalatopharyngoplasty (UPPP) in 33 patients (mean number of apneas per hour of sleep = 32.7 +/- 5.2) and by autopsy in 22 normal subjects not known to have OSA. All statistical comparisons were controlled for differences caused by age and body mass index. Patients with OSA had a significantly greater percentage of muscle in the uvula (18.1 +/- 1.9% versus 9.3 +/- 2.1%, p = 0.02) than did normal subjects. A significant difference in fat content was also found (9.5 +/- 1.4% in patients versus 4.0 +/- 1.0% in normal subjects, p less than 0.02). These differences between patients with OSA and control subjects could not be accounted for by anthropometric or sex differences. The percentage of uvula fat tissue was significantly related to the frequency of apneas and hypopneas in sleep (r = 0.43, p less than 0.01). Uvula morphology in 6 nonapneic snorers undergoing UPPP was similar to that of patients with OSA. We conclude that the uvula in patients with OSA contains more muscle and fat than the uvula in control subjects, possibly contributing to pharyngeal narrowing in OSA. 相似文献
10.
Marked decrease in sleepiness in patients with sleep apnea by etanercept, a tumor necrosis factor-alpha antagonist 总被引:9,自引:0,他引:9
Vgontzas AN Zoumakis E Lin HM Bixler EO Trakada G Chrousos GP 《The Journal of clinical endocrinology and metabolism》2004,89(9):4409-4413
The proinflammatory cytokines, TNFalpha and IL-6, are elevated in obstructive sleep apnea (OSA) and have been proposed as mediators of excessive daytime sleepiness in humans. We tested the effects of etanercept, a medication that neutralizes TNFalpha and is approved by the FDA for the treatment of rheumatoid arthritis, in eight obese male apneics. These patients participated in a pilot, placebo-controlled, double-blind study during which nighttime polysomnography, multiple sleep latency test, and fasting blood glucose and plasma levels of IL-6, C-reactive protein, insulin, and adiponectin were obtained. There was a significant and marked decrease in sleepiness by etanercept, which increased sleep latency during the multiple sleep latency test by 3.1 +/- 1.0 min (P < 0.05) compared with placebo. Also, the number of apneas/hypopneas per hour was reduced significantly by the drug compared with placebo (52.8 +/- 9.1 vs. 44.3 +/- 10.3; adjusted difference, -8.4 +/- 2.3; P < 0.05). Furthermore, IL-6 levels were significantly decreased after etanercept administration compared with placebo (3.8 +/- 0.9 vs. 1.9 +/- 0.4 pg/ml; adjusted difference, -1.9 +/- 0.5; P < 0.01). However, no differences were observed in etanercept vs. placebo in the levels of fasting blood glucose and plasma C-reactive protein, insulin, and adiponectin. We conclude that neutralizing TNFalpha activity is associated with a significant reduction of objective sleepiness in obese patients with OSA. This effect, which is about 3-fold higher than the reported effects of continuous positive airway pressure on objective sleepiness in patients with OSA (0.9 vs. 3.1 min), suggests that proinflammatory cytokines contribute to the pathogenesis of OSA/sleepiness. 相似文献