全文获取类型
收费全文 | 2473篇 |
免费 | 125篇 |
国内免费 | 23篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 175篇 |
妇产科学 | 23篇 |
基础医学 | 308篇 |
口腔科学 | 72篇 |
临床医学 | 237篇 |
内科学 | 530篇 |
皮肤病学 | 30篇 |
神经病学 | 81篇 |
特种医学 | 499篇 |
外科学 | 342篇 |
综合类 | 30篇 |
预防医学 | 63篇 |
眼科学 | 15篇 |
药学 | 90篇 |
中国医学 | 3篇 |
肿瘤学 | 120篇 |
出版年
2023年 | 7篇 |
2022年 | 18篇 |
2021年 | 28篇 |
2020年 | 17篇 |
2019年 | 21篇 |
2018年 | 34篇 |
2017年 | 27篇 |
2016年 | 49篇 |
2015年 | 47篇 |
2014年 | 66篇 |
2013年 | 93篇 |
2012年 | 69篇 |
2011年 | 62篇 |
2010年 | 109篇 |
2009年 | 73篇 |
2008年 | 84篇 |
2007年 | 70篇 |
2006年 | 60篇 |
2005年 | 61篇 |
2004年 | 49篇 |
2003年 | 40篇 |
2002年 | 45篇 |
2001年 | 53篇 |
2000年 | 45篇 |
1999年 | 56篇 |
1998年 | 140篇 |
1997年 | 124篇 |
1996年 | 132篇 |
1995年 | 98篇 |
1994年 | 80篇 |
1993年 | 87篇 |
1992年 | 35篇 |
1991年 | 36篇 |
1990年 | 30篇 |
1989年 | 69篇 |
1988年 | 53篇 |
1987年 | 60篇 |
1986年 | 53篇 |
1985年 | 53篇 |
1984年 | 30篇 |
1983年 | 37篇 |
1982年 | 36篇 |
1981年 | 21篇 |
1980年 | 36篇 |
1979年 | 14篇 |
1978年 | 18篇 |
1977年 | 21篇 |
1976年 | 23篇 |
1975年 | 26篇 |
1967年 | 5篇 |
排序方式: 共有2621条查询结果,搜索用时 15 毫秒
61.
Roberto Gasparini Maurizio Comanducci Daniela Amicizia Filippo Ansaldi Paola Canepa Andrea Orsi Giancarlo Icardi Emanuela Rizzitelli Gabriella De Angelis Stefania Bambini Monica Moschioni Sara Comandi Isabella Simmini Giueseppe Boccadifuoco Brunella Brunelli Marzia Monica Giuliani Mariagrazia Pizza Donatella Panatto 《Journal of clinical microbiology》2014,52(6):1901-1910
Neisseria meningitidis is an obligate human commensal that commonly colonizes the oropharyngeal mucosa. Carriage is age dependent and very common in young adults. The relationships between carriage and invasive disease are not completely understood. In this work, we performed a longitudinal carrier study in adolescents and young adults (173 subjects). Overall, 32 subjects (18.5%) had results that were positive for meningococcal carriage in at least one visit (average monthly carriage rate, 12.1%). Only five subjects tested positive at all four visits. All meningococcal isolates were characterized by molecular and serological techniques. Multilocus sequence typing, PorA typing, and sequencing of the 4CMenB vaccine antigens were used to assess strain diversity. The majority of positive subjects were colonized by capsule null (34.4%) and capsular group B strains (28.1%), accounting for 23.5% and 29.4% of the total number of isolates, respectively. The fHbp and nhba genes were present in all isolates, while the nadA gene was present in 5% of the isolates. The genetic variability of the 4CMenB vaccine antigens in this collection was relatively high compared with that of other disease-causing strain panels. Indications about the persistence of the carriage state were limited to the time span of the study. All strains isolated from the same subject were identical or cumulated minor changes over time. The expression levels and antigenicities of the 4CMenB vaccine antigens in each strain were analyzed by the meningococcal antigen typing system (MATS), which revealed that expression can change over time in the same individual. Future analysis of antigen variability and expression in carrier strains after the introduction of the MenB vaccine will allow for a definition of its impact on nasopharyngeal/oropharyngeal carriage. 相似文献
62.
63.
64.
J Tang DJ Humes E Gemmil NT Welch SL Parsons JA Catton 《Annals of the Royal College of Surgeons of England》2013,95(5):323-328
Introduction
The high mortality and morbidity associated with resection for oesophagogastric malignancy has resulted in a conservative approach to the postoperative management of this patient group. In August 2009 we introduced an enhanced recovery after surgery (ERAS) pathway tailored to patients undergoing resection for oesophagogastric malignancy. We aimed to assess the impact of this change in practice on standard clinical outcomes.Methods
Two cohorts were studied of patients undergoing resection for oesophagogastric malignancy before (August 2008 – July 2009) and after (August 2009 – July 2010) the implementation of the ERAS pathway. Data were collected on demographics, interventions, length of stay, morbidity and in-hospital mortality.Results
There were 53 and 55 oesophagogastric resections undertaken respectively for malignant disease in each of the study periods. The median length of stay for both gastric and oesophageal resection decreased from 15 to 11 days (Mann– Whitney U, p<0.001) following implementation of the ERAS pathway. There was no significant increase in morbidity (gastric resection 23.1% vs 5.3% and oesophageal resection 25.9% vs 16.7%) or mortality (gastric resection no deaths and oesophageal resection 1.8% vs 3.6%) associated with the changes. There was a significant decrease in the number of oral contrast studies used following oesophageal resection, with a reduction from 21 (77.8%) in 2008–2009 to 6 (16.7%) in 2009–2010 (chi-squared test, p<0.0001).Conclusions
The introduction of an enhanced recovery programme following oesophagogastric surgery resulted in a significant decrease in length of median patient stay in hospital without a significant increase in associated morbidity and mortality. 相似文献65.
Brunelli L Campagna R Airoldi L Cauli O Llansola M Boix J Felipo V Pastorelli R 《Metabolic brain disease》2012,27(1):37-49
Hepatic encephalopathy (HE) is a neurological disease associated with hepatic dysfunction. Current knowledge suggests that
hyperammonemia, related to liver failure, is a main factor contributing to the cerebral alterations in HE and that hyperammonemia
might impair signal transduction associated with post-translational modification of proteins such as tyrosine-nitration and
phosphorylation. However, the molecular bases of the HE remain unclear and very little is known about the occurrence of post-translational
modification on in vivo proteins. In this exploratory study we look for evidence of post-translation modifications of proteins
in the cerebellum of experimental HE rat models using a proteomic approach. For the first time we showed that hyperammonemia
without liver failure (HA rats) and experimental HE with liver failure due to portacaval shunt (PCS rats) lead to a reduced
protein nitration in rat cerebellum, where the undernitrated proteins were involved in energy metabolism and cytoskeleton
remodelling. Moreover we showed that tyrosine nitration loss of these proteins was not necessarily associated to a change
in their phosphorylation state as result of the disease. Interestingly the rat cerebellum phosphoproteome was mainly perturbed
in PCS rats, whereas HA rats did not shown appreciable changes in their phosphoprotein profile. Since the protein nitration
level decreased similarly in the cerebellum of both HA and PCS rats, this implies that the two disease models share common
effects but also present some differential signalling effects in the cerebellum of the same animals. This study highlights
the interest for studying the concerted action of multiple signalling pathways in HE development. 相似文献
66.
67.
68.
Morselli P Masciotra L Pinto V Zollino I Brunelli G Carinci F 《The Journal of craniofacial surgery》2007,18(6):1353-1358
This retrospective study was carried out to assess the prognostic value of three classification systems used for staging cutaneous head and neck malignant melanoma (CHNME). Fifty-three patients with histologically proven CHNME were analyzed. Thirty patients were never treated before admission, whereas 23 (43.4%) had a second radical resection of the primary tumor location, 9 (17%) had neck nodes, none had distant metastasis, and all had a minimum of 5 years of follow-up. Results show that T-stage is the most important clinical prognostic parameter, whereas Clark's and Breslow's classifications have lower impact in defining prognosis. Sites of primary tumor determines different clinical outcomes, but this does not reach statistically significant values. A second surgery on the primary tumor location is possible and is effective toward survival. No statistical differences were noted between the previously untreated and treated groups. Neck nodes have to be removed with neck dissection, and this regimen can improve the clinical outcome; however, only 40% of neck positive patients survive more than 5 years. 相似文献
69.
70.
巨噬细胞迁移抑制因子最初是由于能抑制体外巨噬细胞随机迁移而被发现,现在它作为一种重要的调节因子参与一系列炎症性疾病过程.我们最近发现,巨噬细胞迁移抑制因子的缺失使一些由炎症介质诱发的白细胞-内皮细胞相互作用减弱,提示巨噬细胞迁移抑制因子在炎症反应中起作用的机制之一是促进白细胞聚集.…… 相似文献