全文获取类型
收费全文 | 6957篇 |
免费 | 411篇 |
国内免费 | 43篇 |
专业分类
耳鼻咽喉 | 53篇 |
儿科学 | 175篇 |
妇产科学 | 151篇 |
基础医学 | 989篇 |
口腔科学 | 182篇 |
临床医学 | 533篇 |
内科学 | 1685篇 |
皮肤病学 | 137篇 |
神经病学 | 866篇 |
特种医学 | 205篇 |
外科学 | 1134篇 |
综合类 | 22篇 |
预防医学 | 300篇 |
眼科学 | 73篇 |
药学 | 444篇 |
中国医学 | 16篇 |
肿瘤学 | 446篇 |
出版年
2023年 | 44篇 |
2022年 | 122篇 |
2021年 | 209篇 |
2020年 | 123篇 |
2019年 | 165篇 |
2018年 | 227篇 |
2017年 | 162篇 |
2016年 | 207篇 |
2015年 | 191篇 |
2014年 | 282篇 |
2013年 | 329篇 |
2012年 | 506篇 |
2011年 | 504篇 |
2010年 | 290篇 |
2009年 | 247篇 |
2008年 | 416篇 |
2007年 | 402篇 |
2006年 | 380篇 |
2005年 | 366篇 |
2004年 | 356篇 |
2003年 | 346篇 |
2002年 | 250篇 |
2001年 | 126篇 |
2000年 | 124篇 |
1999年 | 119篇 |
1998年 | 53篇 |
1997年 | 42篇 |
1996年 | 42篇 |
1995年 | 26篇 |
1994年 | 20篇 |
1993年 | 16篇 |
1992年 | 81篇 |
1991年 | 69篇 |
1990年 | 53篇 |
1989年 | 62篇 |
1988年 | 42篇 |
1987年 | 44篇 |
1986年 | 37篇 |
1985年 | 39篇 |
1984年 | 23篇 |
1983年 | 22篇 |
1982年 | 20篇 |
1980年 | 19篇 |
1979年 | 34篇 |
1978年 | 12篇 |
1977年 | 15篇 |
1974年 | 11篇 |
1973年 | 12篇 |
1967年 | 10篇 |
1966年 | 15篇 |
排序方式: 共有7411条查询结果,搜索用时 0 毫秒
1.
2.
Rocco Spagnuolo Alessandro Corea Mariantonietta Blumetti Alessia Giovinazzo Massimiliano Serafino Caterina Pagliuso Raffaele Pagnotta Grazia Curto Cristina Cosco Vincenzo Cosco Rosellina Margherita Mancina Pietro Garieri Anna Papaleo Laura Grande Anna Barilaro Eugenio Garofalo Andrea Bruni Patrizia Doldo 《Journal of advanced nursing》2020,76(11):2993-3002
3.
4.
Background:
The results of a pilot colorectal cancer screening programme by biennial immunochemical faecal occult blood test (FOBT) are reported.Methods:
All residents aged between 50 and 69 years in the Italian province of Lecco were invited to have a FOBT. Those with a positive result were offered colonoscopy. FOBT uptake and compliance with colonoscopy were assessed. Detection rate and positive predictive value (PPV) for cancer and adenoma were calculated. Tumour stages were compared between screen‐detected cancers and other colorectal cancers diagnosed within the target age group.Results:
Some 38 693 (49·6 per cent) of 78 083 individuals had a FOBT and 2392 (6·2 per cent) had a positive result. Colorectal cancer was diagnosed in 4·6 per cent and advanced adenoma in 32·7 per cent. PPVs were 4·0 per cent for cancer, 28·1 per cent for advanced adenoma and 36·6 per cent for any adenoma. There was a significant difference in incidence of stage III/IV disease between screened and non‐screened cohorts. Compliance for colonoscopy was 92·0 per cent. Major determinants of compliance were age less than 59 years, female sex, high education level and non‐manual work.Conclusion:
These results justify extension of colorectal cancer screening to other regions of Italy. Copyright © 2009 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. 相似文献5.
Vigilio Ballabeni Massimiliano Tognolini Simona Bertoni Renato Bruni Alessandra Guerrini Gabriela Moreno Rueda Elisabetta Barocelli 《Pharmacological research》2007,55(1):23-30
Ocotea quixos essential oil was shown to possess significant inhibitory activity of platelet aggregation and clot retraction in rodent plasma. This study is aimed at fully characterizing the antiplatelet activity of the whole essential oil and its main components trans-cinnamaldehyde and methyl cinnamate also in human plasma, at investigating the mechanism underlying such activity and at evaluating the potential antithrombotic activity of subacute treatment of mice with Ocotea essential oil. In vitro Ocotea essential oil and trans-cinnamaldehyde inhibited arachidonic acid-, U46619-, ADP-, phorbol12-myristate13-alcetate-, collagen-induced platelet aggregation and thrombin-induced clot retraction in human and rodent plasma; Ocotea oil and trans-cinnamaldehyde competitively antagonized contractions induced by thromboxane A2 receptor agonist U46619 in rat isolated aortic ring (K(B) = 18 and 3.2 microg ml(-1), respectively). In vivo Ocotea oil, orally administered in a subacute treatment (30-100 mg kg(-1) day(-1) for 5 days) to mice, prevented acute thrombosis induced by collagen-epinephrine intravenous injection. This antithrombotic activity was not accompanied by pro-haemorragic side effect, as detected by the inactivity in bleeding test, thus showing a favourable safety profile compared to the conventional antiplatelet agent, acetylsalicylic acid. Present findings indicate that Ocotea essential oil possesses potent and safe antithrombotic activity attributable to its antiplatelet and vasorelaxant effects. The main constituent trans-cinnamaldehyde seems to be the primary responsible for this activity through a putative mechanism involving the inhibition of thromboxane A2 receptors. 相似文献
6.
D M Morris R Haskins A A Marino R P Misra S Rogers S Fronczak J A Albright 《Surgery》1990,107(6):627-631
Carbon in the form of 8-micron fibers induces growth of connective tissue. The purpose of this study was to measure and histologically characterize tissue ingrowth occurring in carbon fibers implanted for up to 12 months in abdominal-wall defects in rats, compared with polypropylene mesh. Carbon fibers induced significantly more tissue ingrowth than polypropylene mesh at 6 to 12 months postoperatively. The predominant tissues associated with carbon fibers and polypropylene mesh were dense connective tissue and fat, respectively. Fragmentation of the implants did not occur, and implant debris was not found in the regional lymph nodes. Carbon fibers are potentially useful for reinforcing abdominal-wall defects. 相似文献
7.
F. Marino M. Cosentino F. De Ponti C. Giaroni L. Somaini R. Bombelli M. Ferrari A.J. Aasen S. Lecchini G. Frigo 《Autonomic & autacoid pharmacology》1997,17(6):365-372
1 The present study examined the role of muscarinic receptors in the modulation of noradrenaline (NA) release in the guinea-pig isolated distal colon. The spontaneous endogenous NA overflow assayed by HPLC-ED was taken as an index of NA release from enteric noradrenergic nerve terminals. 2 Physostigmine (10 μm ) significantly enhanced spontaneous endogenous NA overflow. Hyoscine (muscarinic antagonist), (R)-(-)-trihexyphenidyl and telenzepine (M1-selective antagonists), and 11[[2-[(diethylamino)methyl]-1-piperydil]acetyl]-5,11-dihydro-6H-pyrido[2,3-b][1,4]benzodiazepine-6-one (AF-DX 116, M2-selective antagonist) inhibited NA overflow in a concentration dependent manner, with the following EC50 values: 131.74 (18.19–953.96), 101.62 (58.83–175.60), 150 (60–330), 30 (5–170) nm , respectively. 4-diphenylacetoxy-N-methylpiperidine methiodide (4-DAMP, M1- and M3- selective antagonist) had no significant effect up to 100 μm . 3 The muscarinic agonist oxotremorine inhibited NA overflow in a concentration dependent manner, with an EC50 value of 0.67 (0.30–1.51) μm . The response to oxotremorine was inhibited by muscarinic antagonists with the following order of potency: hyoscine = (R)-(-)-trihexyphenidyl = telenzepine > 4-DAMP >> AF-DX 116. 4 In the presence of 3 μm tetrodotoxin (TTX), the effect of oxotremorine and 4-DAMP was unchanged, while hyoscine, (R)-(-)-trihexyphenidyl, telenzepine and AF-DX 116, instead of inhibiting, significantly enhanced NA overflow. 5 The present results indicate that, in the guinea-pig colon, endogenous acetylcholine sustains spontaneous NA release by activating muscarinic receptors possibly located on interneurones. In addition, inhibitory muscarinic receptors may exist on adrenergic terminals. 相似文献
8.
Palliation of cardiac malformations associated with right isomerism (asplenia syndrome) in infancy 总被引:1,自引:0,他引:1
R Di Donato D di Carlo C Squitieri E Rossi A Ammirati B Marino C Marcelletti 《The Annals of thoracic surgery》1987,44(1):35-39
Right isomerism is characterized by the combination of an obstructed pulmonary outflow tract and a total anomalous pulmonary venous connection (TAPVC), which is obstructed in nearly half of the patients. Fourteen patients less than 2 years of age with right isomerism have been seen in our unit. Thirteen of them underwent palliation consisting of a systemic-pulmonary shunt (10 patients) or a combination of shunt and TAPVC repair (3). There were 7 hospital deaths (54%). The presence of obstructed pulmonary venous drainage was the major risk factor in the surgical treatment of these complex cardiac anomalies (p less than .02). Guidelines for the palliative management of right isomerism are suggested. 相似文献
9.
10.
Impact of pediatricians' attire on children and parents 总被引:1,自引:0,他引:1
R V Marino W Rosenfeld P Narula M Karakurum 《Journal of developmental and behavioral pediatrics : JDBP》1991,12(2):98-101
To evaluate perceptions of a pediatrician's attire, 50 children and parents in an outpatient facility were shown five photographs of a female or a male physician dressed differently (formal to informal). A list of positive and negative attributes was presented to the parents and children who were to match each picture to the attributes. Parents had a strong positive preference for the formally dressed female (short white coat and skirt), and the formally dressed male (short white coat and tie). More than 50% of the parents least preferred the most informal attire. Children had no clear preferences for males and preferred the female in the blouse and skirt. Children assigned negative attributes to informal attire but not to the same degree as did their parents. This study demonstrates that parents have stronger preferences than do their children. Although children had no strong positive preferences, they may feel negatively about informal attire. 相似文献