全文获取类型
收费全文 | 6011篇 |
免费 | 369篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 49篇 |
儿科学 | 220篇 |
妇产科学 | 149篇 |
基础医学 | 792篇 |
口腔科学 | 287篇 |
临床医学 | 495篇 |
内科学 | 1217篇 |
皮肤病学 | 125篇 |
神经病学 | 525篇 |
特种医学 | 373篇 |
外国民族医学 | 1篇 |
外科学 | 875篇 |
综合类 | 40篇 |
预防医学 | 354篇 |
眼科学 | 55篇 |
药学 | 316篇 |
1篇 | |
中国医学 | 10篇 |
肿瘤学 | 511篇 |
出版年
2023年 | 37篇 |
2022年 | 48篇 |
2021年 | 128篇 |
2020年 | 103篇 |
2019年 | 147篇 |
2018年 | 178篇 |
2017年 | 124篇 |
2016年 | 132篇 |
2015年 | 161篇 |
2014年 | 200篇 |
2013年 | 232篇 |
2012年 | 306篇 |
2011年 | 284篇 |
2010年 | 210篇 |
2009年 | 194篇 |
2008年 | 229篇 |
2007年 | 244篇 |
2006年 | 217篇 |
2005年 | 225篇 |
2004年 | 203篇 |
2003年 | 211篇 |
2002年 | 208篇 |
2001年 | 148篇 |
2000年 | 147篇 |
1999年 | 139篇 |
1998年 | 105篇 |
1997年 | 114篇 |
1996年 | 86篇 |
1995年 | 81篇 |
1994年 | 96篇 |
1993年 | 92篇 |
1992年 | 106篇 |
1991年 | 98篇 |
1990年 | 104篇 |
1989年 | 118篇 |
1988年 | 97篇 |
1987年 | 108篇 |
1986年 | 84篇 |
1985年 | 87篇 |
1984年 | 51篇 |
1983年 | 59篇 |
1982年 | 34篇 |
1981年 | 41篇 |
1980年 | 34篇 |
1979年 | 40篇 |
1978年 | 33篇 |
1977年 | 28篇 |
1975年 | 28篇 |
1973年 | 27篇 |
1967年 | 25篇 |
排序方式: 共有6395条查询结果,搜索用时 296 毫秒
1.
J B Sherman M A Alexander D Gomez M Kim P Marole 《Journal of community health nursing》1992,9(3):183-190
The purpose of this study was to implement and evaluate a program for obese school children. A pretest-posttest design was utilized. Data was collected related to weight status, skinfold measurements, self-esteem, and nutritional knowledge. A convenience sample of 26 children, in the fourth to sixth grades, completed this 9-week program. The results indicate that self-esteem increased significantly (p less than .001) between the pretest and posttest interval. Weight status and nutritional knowledge showed no improvement. Exercise was difficult to assess on self-report, therefore no conclusions were were drawn in relation to this variable. Future research will be directed toward refining this intervention program. 相似文献
2.
Chronic morphine treatment produced increases in [3H]-flunitrazepam binding in some hippocampal areas of the rat brain. The differences in binding were statistically significant in some cases. Both morphine-dependent and morphine-deprived (abstinence syndrome) animals showed an identical response in binding, which confirms a real, although small, increase in benzodiazepine binding sites in the hippocampus after morphine treatment, that is not affected by a naloxone-induced abstinence syndrome under the conditions studied. These findings support the hypothesis of a morphine-induced up-regulation of benzodiazepine binding sites in the hippocampus. A possible different response in benzodiazepine binding sites 1 and 2 could explain the different findings reported in the literature. Our data suggest that the detected increase in benzodiazepine binding would be mainly due to type 2 binding sites, since the hippocampus has a higher density of this type of benzodiazepine binding sites. 相似文献
3.
Renato S. Gomez L. O. F. Andrade J. R. Rezende Costa 《Journal canadien d'anesthésie》1997,44(7):732-734
Purpose To present a case of brainstem anaesthesia as a complication of peribulbar anaesthesia.
Clinical features A 75-yr-old woman received peribulbar anaesthesia for cataract surgery. A few seconds after the block was performed, she had
a respiratory arrest, became unconscious, and developed hypertension and tachycardia followed by hypotension and bradycardia.
Ventilatory and haemodynamic support were performed before the patient regained adequate spontaneous breathing and normal
heart rate and blood pressure.
Conclusion Peribulbar anaesthesia generally cames a low risk of serious complications. However, respiratory arrest and brainstem anaesthesia
may occur as complications of peribulbar blocks.
Résumé Objectif Présenter un cas d’anesthésie du tronc cérébral compliquant une anesthésie péribulbaire. éléments cliniques Un bloc péribulbaire était réalisé chez une femine de 75 ans pour l’extraction d’une cataracte. Quelques secondes après l’injection, la patiente cessait de respirer et perdait conscience. Elle devenait hypertendue et tachycarde puts hypotendue et bradycarde. La ventilation et la circulation devaient être supportées jusqu’au retour spontané à la normale. Conclusion En général, l’anesthésie péribulbare comporte un faible risque de complications sérieuses. Un arrêt respiratoire par anesthésie du tronc cérébral est toujours possible.相似文献
4.
5.
Transformation of a Drosophila virilis white mutant host strain was attempted using a hobo vector containing the D. melanogaster mini-white+ cassette (H[w+, hawN]) and an unmodified or heat shock regulated hobo transposase helper. Two transformant lines were recovered with the unmodified helper (HFL1), one containing only the white+ marked vector, and a sibling line containing the vector as well as an HFL1 helper integration. An approximate total transformation frequency of 1% is deduced. A high frequency of wing and eye morphology mutants were also observed, suggesting that hobo may have mobilized a related element in D. virilis. The data reaffirms a relatively low transformation vector activity for the hobo transposon in D. virilis; however, nearly full interspecific expression of the white+ marker supports its possible function in other species as well. 相似文献
6.
7.
Andrew S. Fix Jeffrey W. Horn Lewis L. Truex Ronald A. Smith Ernesto Gomez 《Acta neuropathologica》1994,88(6):511-519
Cytoplasmic vacuoles appear in neurons of the posterior cingulate/retrosplenial cortex (PC/RS) of rats after treatment with N-methyl-d-aspartate (NMDA) receptor antagonists. Prominent dilatation of mitochondria and endoplasmic reticulum has been described within 2 h; however, the ultrastructural features of vacuole formation are unknown. To investigate this, the present study examined the PC/RS cortex of male rats (age 60–70 days) at 15, 30, 45, 60, 90, and 120 min after subcutaneous treatment with 1 mg/kg of the noncompetitive NMDA antagonist MK-801 (dizocilpine maleate, 5-methyl-10, 11-dihydro-5H-dibenzo [a,d] cyclohepten-5,10-imine). Subtle mitochondrial dilatation was identified in a few neurons as early as 15 min postdose (MPD). By 30 MPD, dilatation was more pronounced in mitochondria and also involved the endoplasmic reticulum and perinuclear space. Ribosomal disaggregation and degranulation were also evident by 30 MPD. At all subsequent time points, dilatation of mitochondria and endoplasmic reticulum progressed in severity. Although the relative involvement of mitochondria and endoplasmic reticulum varied, glia were not involved. These ultrastructural data suggest that after treatment with MK-801, mitochondrial dilatation precedes involvement of endoplasmic reticulum in vacuolization of susceptible PC/RS cortical neurons. The early mitochondrial effects identified in this study suggest an initial metabolic insult that rapidly progresses to affect endoplasmic reticulum and ribosomes. This strengthens the relationship between the ability of certain NMDA antagonists to induce energy perturbations and neuronal vacuoles in the same region of the rat cerebral cortex. 相似文献
8.
P C Njemanze C R Gomez S Horenstein 《Cortex; a journal devoted to the study of the nervous system and behavior》1992,28(1):69-75
Eight normal subjects were examined in dark, light and color conditions. Mean cerebral blood flow velocity (MBFV) were recorded almost simultaneously from their posterior cerebral arteries (PCA) using transcranial Doppler (TCD) ultrasound. The side-to-side difference was significant during the dark (p = 0.0159) and color stimulation (p = 0.0001) but not in light condition. This side-to-side difference in MBFV was used to characterize lateralization of color perception. This showed that the right PCA was always greater than the left during the presentation of color stimuli. Primary psychological colors (blue, yellow, red and green) induced greater lateralization as compared with color resulting from a mixed blue-green wavelength. This suggests that the right visual cortex is selectively sensitive to wavelengths. 相似文献
9.
We present a case of inflammatory bowel disease in which the diagnosis of pylephlebitis was made by ultrasonography. The patient was treated with antibiotics and aspirin and had an uneventful recovery. The sonographic findings are described. 相似文献
10.
The biomechanical and morphological changes in the medial collateral ligament of the rabbit after immobilization and remobilization 总被引:10,自引:0,他引:10
S L Woo M A Gomez T J Sites P O Newton C A Orlando W H Akeson 《The Journal of bone and joint surgery. American volume》1987,69(8):1200-1211
The effects of immobilization and remobilization on the biomechanical and morphological properties of the femur-medial collateral ligament-tibia complex and each of its components were investigated in the rabbit. Specimens that had been obtained after periods of unilateral immobilization of the knee and remobilization were evaluated for structural properties. In addition, the mechanical properties of the substance of the medial collateral ligament and the histological characteristics of both the substance of the ligament and its sites of insertion were evaluated. After immobilization, there were significant reductions in the ultimate load and energy-absorbing capabilities of the bone-ligament complex, and an increased number of failures occurred by tibial avulsion. The tissue of the medial collateral ligament also became less stiff as a result of immobilization. Histologically, the femoral and tibial insertion sites showed increased osteoclastic activity, resorption of bone, and disruption of the normal attachment of the bone to the ligament. With remobilization, the ultimate load and energy-absorbing capabilities of the bone-ligament complex improved but did not return to normal. Failure by tibial avulsion became less frequent, and the stress-strain characteristics of the medial collateral ligament returned to normal. Histologically, the sites of insertion of the ligament also showed evidence of recovery. 相似文献