全文获取类型
收费全文 | 10283篇 |
免费 | 497篇 |
国内免费 | 115篇 |
专业分类
耳鼻咽喉 | 54篇 |
儿科学 | 249篇 |
妇产科学 | 299篇 |
基础医学 | 1130篇 |
口腔科学 | 138篇 |
临床医学 | 756篇 |
内科学 | 2568篇 |
皮肤病学 | 274篇 |
神经病学 | 1017篇 |
特种医学 | 410篇 |
外科学 | 1880篇 |
综合类 | 28篇 |
一般理论 | 1篇 |
预防医学 | 331篇 |
眼科学 | 140篇 |
药学 | 646篇 |
中国医学 | 27篇 |
肿瘤学 | 947篇 |
出版年
2024年 | 10篇 |
2023年 | 69篇 |
2022年 | 189篇 |
2021年 | 294篇 |
2020年 | 187篇 |
2019年 | 216篇 |
2018年 | 289篇 |
2017年 | 200篇 |
2016年 | 264篇 |
2015年 | 341篇 |
2014年 | 420篇 |
2013年 | 555篇 |
2012年 | 853篇 |
2011年 | 814篇 |
2010年 | 539篇 |
2009年 | 437篇 |
2008年 | 709篇 |
2007年 | 722篇 |
2006年 | 643篇 |
2005年 | 630篇 |
2004年 | 600篇 |
2003年 | 479篇 |
2002年 | 453篇 |
2001年 | 59篇 |
2000年 | 46篇 |
1999年 | 51篇 |
1998年 | 91篇 |
1997年 | 60篇 |
1996年 | 61篇 |
1995年 | 55篇 |
1994年 | 63篇 |
1993年 | 45篇 |
1992年 | 44篇 |
1991年 | 49篇 |
1990年 | 34篇 |
1989年 | 35篇 |
1988年 | 32篇 |
1987年 | 26篇 |
1986年 | 28篇 |
1985年 | 17篇 |
1984年 | 33篇 |
1983年 | 24篇 |
1982年 | 16篇 |
1981年 | 12篇 |
1980年 | 12篇 |
1979年 | 7篇 |
1978年 | 12篇 |
1977年 | 8篇 |
1974年 | 8篇 |
1969年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 921 毫秒
21.
Vincenzo Arizza Nicol Parrinello Sandra Schimmenti 《Developmental and comparative immunology》1991,15(4):219-226
-Lactose specific lectins are released from Phallusia mamillata hemocytes during short-term cultures. The molecular weight of the subunits, the immunological cross-reaction and the sugar specificity suggest that the released lectins are similar to those isolated from the sonicated hemocytes. Because lectin release appears to take place independently of active protein synthesis, the possibility exists that lectins are pre-formed, stored in hemocytes and released when in vitro conditions stimulate the cells. 相似文献
22.
Vincenzo La Milia Salvatore Di Filippo Monica Crepaldi Simeone Andrulli Lucia Del Vecchio Pietro Scaravilli Giovambattista Virga Francesco Locatelli 《Nephrology, dialysis, transplantation》2004,19(7):1849-1855
BACKGROUND: Sodium removal (NaR) may have a major impact on the survival of peritoneal dialysis patients. The dialysate/plasma sodium concentration ratio (D/P(Na)) is an indirect index of transcellular water transport by aquaporin channels, and thus of ultrafiltration. Sodium concentration can be assessed by means of flame photometry (F), and direct (D-ISE) or indirect ion-selective electrodes (I-ISE), but these methods have different properties. I-ISE is being used increasingly in clinical laboratories. The aim of this study was to evaluate NaR and D/P(Na) using the three different measurement methods. METHODS: We performed peritoneal equilibration tests (PETs) in 44 peritoneal dialysis patients and calculated the NaR. We also calculated D/P(Na) during the test; plasma and dialysate sodium concentrations were measured by F, D-ISE and I-ISE. RESULTS: NaR was lower (P<0.001) with D-ISE (69+/-29 mmol) than with F (81+/-29 mmol) or I-ISE (79+/-28 mmol). D/P(Na) was also lower at baseline (0.92+/-0.02 vs 0.95+/-0.02 and 0.95+/-0.02; P<0.001), after 60 min (0.87+/-0.03 vs 0.90+/-0.03 and 0.90+/-0.03; P<0.001) and at the end of PET (0.88+/-0.04 vs 0.92+/-0.04 and 0.92+/-0.04; P<0.001) when measured by D-ISE in comparison with F and I-ISE, respectively. CONCLUSIONS: NaR and D/P(Na) were lower when measured by the D-ISE method compared with the F and I-ISE methods. NaR and D/P(Na) were similar when measured by F or I-ISE. I-ISE can be used reliably in the evaluation of NaR and D/P(Na) in everyday clinical practice of peritoneal dialysis. 相似文献
23.
Risk of death from acute pancreatitis 总被引:5,自引:0,他引:5
Giorgio Talamini Claudio Bassi Massimo Falconi Nora Sartori Luca Frulloni Vincenzo Di Francesco Sergio Vesentini Paolo Pederzoli Giorgio Cavallini 《Journal of gastrointestinal cancer》1996,19(1):15-24
Summary
Conclusions
The analysis of all the data available in 192 patients at 24 h from admission shows that only serum glucose above 250 mg/dL
(13.88 mmol/L) and serum creatinine above 2 mg/dL (176.8 μmol/L) are prognostic factors of death (P<0.0001). When, however, pathological chest X-rays are also considered in a subset of 149 patients, these and serum creatinine
are prognostic factors of death with odds ratios of 2.9 (95% CL 1.3–6.3) and 9.4 (95% CL 2.2–40.7), respectively (P<0.0001).
Background In patients suffering from acute pancreatitis, neither Ranson scores nor Glasgow criteria evaluation at 24 h yield a sufficiently
reliable prognosis of the risk of death from the first acute attack.
Methods After excluding posttraumatic, postsurgical, and post-ERCP acute pancreatitis, we selected 192 consecutive patients admitted
in the first instance to our center for a first attack, distinguishing between patients who died and patients who survived.
We used Cox's model to analyze the prognostic weight of variables available within 24 h of admission (sex, age, alcohol intake,
smoking habits, 17 biochemical tests, body mass index, chest X-rays, body temperature, and shock status).
Results Seventeen (8.8%) patients died; mortality showed a decreasing trend over the period of years considered and was correlated,
among other things, with necrotizing type of pancreatitis, idiopathic etiology, and shock status on admission. 相似文献
24.
25.
Paolo Cossu Rocca Matteo Brunelli Stefano Gobbo Albino Eccher Emma Bragantini Maria M Mina Vincenzo Ficarra Filiberto Zattoni Alberto Zamò Maurizio Pea Aldo Scarpa Marco Chilosi Fabio Menestrina Franco Bonetti John N Eble Guido Martignoni 《Modern pathology》2007,20(7):722-728
S100A1 is a calcium-binding protein, which has been recently found in renal cell neoplasms. We evaluated the diagnostic utility of immunohistochemical detection of S100A1 in 164 renal cell neoplasms. Forty-one clear cell, 32 papillary, and 51 chromophobe renal cell carcinomas, and 40 oncocytomas, 164 samples of normal renal parenchyma adjacent to the tumors and 13 fetal kidneys were analyzed. The levels of S100A1 mRNA detected by quantitative RT-PCR analysis of frozen tissues from seven clear cell, five papillary, and six chromophobe renal cell carcinomas, four oncocytomas, and nine samples of normal renal tissues adjacent to neoplasms were compared with the immunohistochemical detection of protein expression. Clear cell and papillary renal cell carcinomas showed positive reactions for S100A1 in 30 out of 41 tumors (73%) and in 30 out of 32 (94%) tumors, respectively. Thirty-seven renal oncocytomas out of 40 (93%) were positive for S100A1, whereas 48 of 51 (94%) chromophobe renal cell carcinomas were negative. S100A1 protein was detected in all samples of unaffected and fetal kidneys. S100A1 mRNA was detected by RT-PCR in all normal kidneys and renal cell neoplasms, although at very different levels. Statistical analyses comparing the different expression of S100A1 in clear cell and chromophobe renal cell carcinomas observed by immunohistochemical and RT-PCR methods showed significant values (P<0.001), such as when comparing by both techniques the different levels of S100A1 expression in chromophobe renal cell carcinomas and oncocytomas (P<0.001). Our study shows that S100A1 protein is expressed in oncocytomas, clear cell and papillary renal cell carcinomas but not in chromophobe renal cell carcinomas. Its immunodetection is potentially useful for the differential diagnosis between chromophobe renal cell carcinoma and oncocytoma. Further, S100A1 protein expression is constantly detected in the normal parenchyma of the adult and fetal kidney. 相似文献
26.
Simona Cabib Claudio Castellano Vincenzo Cestari Umberto Filibeck Stefano Puglisi-Allegra 《Psychopharmacology》1991,105(3):335-339
Pretreament with small, per se ineffective doses of the selective D1 antagonist SCH 23390 inhibited hyperactivity induced by cocaine. On the other hand, the classic neuroleptic haloperidol and the selective D2 antagonist metoclopramide prevented the stimulatory effects of cocaine on locomotion only at hypokinetic doses, while the atypical neuroleptic (–)-sulpiride, a selective D2 antagonist, did not produce significant effects when administered at the hypokinetic dose of 12 mg/kg. Finally, at low doses (–)-sulpiride dose-dependently potentiated the locomotor-stimulating effects of cocaine, an effect that is not shared either with haloperidol or with metoclopramide. These results are discussed in terms of different roles of DA receptor subtypes in the modulation of the stimulant effects of cocaine on locomotion. 相似文献
27.
28.
VincenzoRochira LuciaZirilli BrunoMadeo AntonioBalestrieri CesareCarani AntonioR.M.Granata 《生殖与避孕(英文版)》2004,15(2):65-80
This review focuses on estrogen role on human male physiology. Biological estrogen actions on male reproductive system are summarized with particular regard to the effects of congenital estrogen deprivation in men. The effects of estrogen on spermatogenesis, hormonal secretion and gonadotropin feedback and on sexual behavior are discussed. It is remarked that the role of estrogens in male reproduction is a very recent acquisition in reproductive endocrinology, but it promises new future fields of research to be investigated as well as the possible disclosure of new strategies in clinical practice. 相似文献
29.
V. Belcastro C. Costa F. Galletti F. Pisani P. Calabresi L. Parnetti 《European journal of neurology》2007,14(10):1176-1178
Levetiracetam (LEV) monotherapy was investigated in 25 patients with advanced Alzheimer's disease (AD) and new-onset epileptic seizures in a prospective open-label study. At a daily dose of 1000–1500 mg, 72% were seizure-free for at least one year; 16% discontinued for untolerability; 8% were unresponsive; 4% were lost to follow-up. These results suggest the need for controlled studies to confirm if LEV can be a first-choice drug in AD. 相似文献
30.
Jamie C. Day Pier Vincenzo Piazza Michel Le Moal Stefania Maccari 《The European journal of neuroscience》1997,9(6):1130-1136
An influence on drug-taking behaviours of the stress-related hypothalamo-pituitary-adrenal (HPA) axis and its final hormonal mediator, corticosterone, has previously been demonstrated. A role for cortically projecting cholinergic neurons in these behaviours can also be proposed. The experiments presented here examine the effect of the drug of abuse cocaine (15 mg/kg) on the release of acetylcholine (ACh) in the cortex of freely moving rats, using the technique of in vivo microdialysis. To assess a possible modulatory influence of the HPA axis via its final hormonal mediator corticosterone, the cocaine-induced effect on cortical ACh release in intact rats was compared to that in adrenalectomized (ADX) rats, which thus lacked their endogenous source of corticosterone, and in ADX rats in which the cocaine-induced corticosterone peak and/or the basal circadian concentrations of serum corticosterone were simulated by replacement treatments. The results reported here demonstrate that cortical ACh release is greatly increased by cocaine in intact rats; ADX prolongs the return to basal levels of cortical ACh, and the chronic replacement of circadian levels of corticosterone normalizes this effect. In contrast, during the plateau period of cocaine-induced increased cortical ACh release, where no effect of ADX is evident, rats with chronic replacement of corticosterone show an attenuated cocaine-induced cortical ACh release, and the acute replacement of the cocaine-induced corticosterone secretion further attenuates this response. These results demonstrate that cocaine stimulates cortically projecting cholinergic neurons, and that the HPA hormone corticosterone modulates this interaction in a complex manner which merits further investigation. 相似文献