全文获取类型
收费全文 | 1200篇 |
免费 | 41篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 25篇 |
妇产科学 | 21篇 |
基础医学 | 128篇 |
口腔科学 | 15篇 |
临床医学 | 74篇 |
内科学 | 404篇 |
皮肤病学 | 34篇 |
神经病学 | 79篇 |
特种医学 | 53篇 |
外科学 | 174篇 |
综合类 | 6篇 |
预防医学 | 70篇 |
眼科学 | 13篇 |
药学 | 96篇 |
中国医学 | 2篇 |
肿瘤学 | 46篇 |
出版年
2022年 | 12篇 |
2021年 | 12篇 |
2020年 | 11篇 |
2019年 | 12篇 |
2018年 | 26篇 |
2017年 | 16篇 |
2016年 | 20篇 |
2015年 | 20篇 |
2014年 | 26篇 |
2013年 | 42篇 |
2012年 | 61篇 |
2011年 | 63篇 |
2010年 | 33篇 |
2009年 | 31篇 |
2008年 | 66篇 |
2007年 | 61篇 |
2006年 | 42篇 |
2005年 | 53篇 |
2004年 | 63篇 |
2003年 | 67篇 |
2002年 | 50篇 |
2001年 | 43篇 |
2000年 | 33篇 |
1999年 | 46篇 |
1998年 | 18篇 |
1997年 | 13篇 |
1996年 | 15篇 |
1995年 | 9篇 |
1994年 | 7篇 |
1992年 | 14篇 |
1991年 | 21篇 |
1990年 | 17篇 |
1989年 | 20篇 |
1988年 | 14篇 |
1987年 | 13篇 |
1986年 | 9篇 |
1985年 | 16篇 |
1984年 | 11篇 |
1983年 | 8篇 |
1982年 | 11篇 |
1981年 | 8篇 |
1980年 | 5篇 |
1979年 | 8篇 |
1978年 | 10篇 |
1977年 | 15篇 |
1976年 | 6篇 |
1975年 | 19篇 |
1974年 | 5篇 |
1972年 | 9篇 |
1970年 | 6篇 |
排序方式: 共有1247条查询结果,搜索用时 15 毫秒
121.
Marco Mainardi Gaia Scabia Teresa Vottari Ferruccio Santini Aldo Pinchera Lamberto Maffei Tommaso Pizzorusso Margherita Maffei 《Proceedings of the National Academy of Sciences of the United States of America》2010,107(38):16673-16678
Western lifestyle contributes to body weight dysregulation. Leptin down-regulates food intake by modulating the activity of neural circuits in the hypothalamic arcuate nucleus (ARC), and resistance to this hormone constitutes a permissive condition for obesity. Physical exercise modulates leptin sensitivity in diet-induced obese rats. The role of other lifestyle components in modulating leptin sensitivity remains elusive. Environmentally enriched mice were used to explore the effects of lifestyle change on leptin production/action and other metabolic parameters. We analyzed adult mice exposed to environmental enrichment (EE), which showed decreased leptin, reduced adipose mass, and increased food intake. We also analyzed 50-d-old mice exposed to either EE (YEE) or physical exercise (YW) since birth, both of which showed decreased leptin. YEE mice showed no change in food intake, increased response to leptin administration, increased activation of STAT3 in the ARC. The YW leptin-induced food intake response was intermediate between young mice kept in standard conditions and YEE. YEE exhibited increased and decreased ratios of excitatory/inhibitory synapses onto α-melanocyte-stimulating hormone and agouti-related peptide neurons of the ARC, respectively. We also analyzed animals as described for YEE and then placed in standard cages for 1 mo. They showed no altered leptin production/action but demonstrated changes in excitatory/inhibitory synaptic contacts in the ARC similar to YEE. EE and physical activity resulted in improved insulin sensitivity. In conclusion, EE and physical activity had an impact on feeding behavior, leptin production/action, and insulin sensitivity, and EE affected ARC circuitry. The leptin-hypothalamic axis is maximally enhanced if environmental stimulation is applied during development. 相似文献
122.
123.
124.
Di Matteo FM Sorrenti S De Stefano M Palermo S Biancafarina A Guarino S Giusti D Savino G Di Marco C Catania A 《Il Giornale di chirurgia》2008,29(6-7):291-294
In this study on 28 operated patients, the Authors show that total thyroidectomy with elective central neck dissection and ipsilateral neck dissection is the most appropriate surgical treatment for medullary thyroid carcinoma. Pathologic study on lymph nodes removed in central and in latero-cervical compartments showed malignancy respectively in 75% and in 70% of the cases. However the role of elective ipsilateral lateral neck dissection remains controversial. 相似文献
125.
Di Matteo FM De Stefano M Vanni B Palermo S Biancafarina A Giusti D Savino G Di Marco C Casalvieri L De Antoni E 《Il Giornale di chirurgia》2008,29(5):238-241
The Authors present a rare case of voluminous retroperitoneal tumor in a 41 years old woman. CT scan showed a solid abdominal expansive mass, with compression and displacement of the left lobe of the liver, spleen, stomach, pancreas, and left kidney. The patient underwent surgery for excision of a giant retroperitoneal mass. Surgery was uneventful. The patients recovered well. Histology showed a mixed liposarcoma and angiosarcoma with high grade of malignancy and positivity for vimentin, factor VIII, CD34, CD31 and negativity for S-100, CD68, AMS, AML. The prognosis of these tumours is closely related to local recurrence, histological type, size and radical surgery. A low-grade malignancy tumor, small sized and completely resected leads to a good prognosis. Radiation therapy and chemotherapy do not seem to have a strong influence on the prognosis. An aggressive surgical approach is the first choice for the treatment of such tumors. The resection of adjacent organs may be required for radical surgery. 相似文献
126.
Di Matteo FM Sorrenti S Palermo S De Stefano M Biancafarina A Di Battista L Savino G Giusti D Casalvieri L Catania A 《Il Giornale di chirurgia》2008,29(4):159-161
The Authors describe two cases of simultaneous association of papillary and medullary thyroid carcinoma. They emphasize the treatment of these cases stressing the correlation between the therapeutic criteria and the malignancy of medullary carcinoma. 相似文献
127.
128.
TrkA activation in the rat visual cortex by antirat trkA IgG prevents the effect of monocular deprivation 总被引:1,自引:0,他引:1
Tommaso Pizzorusso Nicoletta Berardi Francesco M. Rossi Alessandro Viegi Kristine Venstrom Louis F. Reichardt Lamberto Maffei 《The European journal of neuroscience》1999,11(1):204-212
It has been recently shown that intraventricular injections of nerve growth factor (NGF) prevent the effects of monocular deprivation in the rat. We have tested the localization and the molecular nature of the NGF receptor(s) responsible for this effect by activating cortical trkA receptors in monocularly deprived rats by cortical infusion of a specific agonist of NGF on trkA, the bivalent antirat trkA IgG (RTA-IgG). TrkA protein was detected by immunoblot in the rat visual cortex during the critical period. Rats were monocularly deprived for 1 week (P21–28) and RTA-IgG or control rabbit IgG were delivered by osmotic minipumps. The effects of monocular deprivation on the ocular dominance of visual cortical neurons were assessed by extracellular single cell recordings. We found that the shift towards the ipsilateral, non-deprived eye was largely prevented by RTA-IgG. Infusion of RTA-IgG combined with antibody that blocks p75NTR (REX), slightly reduced RTA-IgG effectiveness in preventing monocular deprivation effects. These results suggest that NGF action in visual cortical plasticity is mediated by cortical TrkA receptors with p75NTR exerting a facilitatory role. 相似文献
129.
Davide Silvestri Niccoletta Barbani Caterina Cristallini Paolo Giusti 《Drug delivery》2013,20(2):116-124
The aim of the present work is the modification of a hydrophobic polymeric macromolecule, polymethylmethacrylate, by introducing hydrophilic moieties of 2-hydroxyethyl methacrylate within the polymer chain. Synthesis, characterization, and drug delivery control capabilities exerted on a highly hydrophobic drug (Paclitaxel) are illustrated. In particular, the dependency of the drug delivery kinetic on the fraction of hydrophilic units inserted in the copolymer chain was studied. Results showed that it is possible to have an increase of the kinetic delivery introducing hydrophilic units. In addition, a double control, diffusive and due to the relaxation of the molecules, on drug delivery was obtained. 相似文献
130.
M Giusti G Marini L Traverso P Cavagnaro L Granziera G Giordano 《Journal of endocrinological investigation》1990,13(2):127-132
The effect of short-term pulsatile LHRH administration was studied in 8 healthy subjects ranging from 60 to 81 yr to see if the decrease of pituitary gonadal function could be in part due to changes in the discharge of LHRH from the hypothalamus. Gonadotropin and testosterone (T) secretion was evaluated two weeks before and during LHRH (122-160 ng/kg bw every 120 min sc) infusion. In addition, a bolus dosage of LHRH (50 mu iv) was given both at the beginning and at the end of pulsatile LHRH administration in order to test gonadotrophs sensitivity. A significant increase in gonadotropin levels from day 0 to day 4 was found, and was followed by a subsequent decrease from day 7 to day 14. A slight significant increase in T levels was observed during LHRH administration (p less than 0.01). LH pulses were identified in 5 out of 8 subjects on day 0. On day 14, all the exogenous LHRH pulses were followed by significant LH bursts. There was not a significant decrease in the pituitary LH responsiveness to LHRH test from day 0 to day 14. Our study seems to indicate that pituitary - gonadal unit in normal elderly men can be modulated by pulsatile administration of LHRH. A pulse frequency of LHRH which is probably similar to the physiological one, could induce a slight increase in T levels via qualitative changes in LH activity. We can assume that clinical changes in gonadal activity might also be connected to some disturbances in endogenous LHRH pulsar. 相似文献