全文获取类型
收费全文 | 591篇 |
免费 | 60篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 6篇 |
妇产科学 | 6篇 |
基础医学 | 117篇 |
口腔科学 | 16篇 |
临床医学 | 64篇 |
内科学 | 160篇 |
皮肤病学 | 8篇 |
神经病学 | 59篇 |
特种医学 | 9篇 |
外科学 | 67篇 |
综合类 | 1篇 |
预防医学 | 20篇 |
眼科学 | 10篇 |
药学 | 41篇 |
中国医学 | 3篇 |
肿瘤学 | 58篇 |
出版年
2023年 | 2篇 |
2022年 | 5篇 |
2021年 | 12篇 |
2020年 | 11篇 |
2019年 | 20篇 |
2018年 | 17篇 |
2017年 | 23篇 |
2016年 | 20篇 |
2015年 | 24篇 |
2014年 | 28篇 |
2013年 | 41篇 |
2012年 | 53篇 |
2011年 | 60篇 |
2010年 | 33篇 |
2009年 | 27篇 |
2008年 | 43篇 |
2007年 | 39篇 |
2006年 | 33篇 |
2005年 | 36篇 |
2004年 | 32篇 |
2003年 | 28篇 |
2002年 | 33篇 |
2001年 | 5篇 |
2000年 | 5篇 |
1999年 | 3篇 |
1996年 | 1篇 |
1993年 | 2篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1980年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1972年 | 1篇 |
1970年 | 1篇 |
1960年 | 1篇 |
排序方式: 共有651条查询结果,搜索用时 14 毫秒
1.
Micro‐evolution of the hepatitis B virus genome in hepatitis B e‐antigen‐positive carriers: Comparison of genotypes B and C at various immune stages
下载免费PDF全文
![点击此处可从《Journal of gastroenterology and hepatology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
2.
3.
García-González M Abdulkader I Boquete AV Neo XM Forteza J Cameselle-Teijeiro J 《Virchows Archiv : an international journal of pathology》2005,447(1):12-17
This study was undertaken to investigate cyclooxygenase-2 (COX-2) expression in follicular cells of the human thyroid. COX-2 expression was studied immunohistochemically in a total of 174 samples. COX-2 immunoreactivity was confined to the cell cytoplasm with the nuclei remaining unlabelled. COX-2 expression was observed in five cases (17.2%) of normal follicular cells and in one case (16.6%) of solid cell nests. Follicular carcinoma expressed COX-2 more frequently than follicular adenoma (93.4% vs 21.1%) (p0.001). A higher percentage of cases of papillary microcarcinomas up-regulated COX-2 in comparison with all papillary carcinomas (p0.05). However, we could not establish any relationships among COX-2, patients ages or lymph node metastases in papillary carcinomas. COX-2 expression was found in 12 (92.3%) poorly differentiated carcinomas and in 13 (92.8%) undifferentiated carcinomas. We found that COX-2 is not always useful as a marker of malignancy. Our results suggest that COX-2 plays a role in progression of all thyroid carcinomas, but in papillary carcinomas, seems more important only in the early stages. COX-2 expression in the undifferentiated carcinoma deserves special consideration due to its prognosis and to the fact that selective COX-2 inhibitors were found to enhance tumour response to radiation in some studies. 相似文献
4.
Enrique Fernández-Caldas Jerónimo Carnés Víctor Iraola Miguel Casanovas 《Annals of allergy, asthma & immunology》2007,98(5):464-470
BACKGROUND: Numerous varieties of Olea europaea have been described in Mediterranean countries. OBJECTIVE: To investigate the immunochemical characteristics of 6 varieties of Olea europaea collected during 5 consecutive years. METHODS: The varieties Carrasquefio, Manzanillo, Acebuche (wild olive), Hojiblanco, Picual, and Nevado were analyzed. Pollen samples from each variety were collected for 5 consecutive years from the same cultivars by trained personnel. The antigenic and allergenic profiles of these extracts were evaluated by means of sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot using the serum of 29 O. europaea-allergic individuals. Ole e 1 was measured using enzyme-linked immunosorbent assay and purified Ole e 1 and rabbit polyclonal antibodies. Allergenic potency was determined using enzyme-linked immunosorbent assay inhibition and is expressed in histamine equivalent prick units per gram of raw material. RESULTS: Hojiblanco and Acebuche had the lowest mean +/- SD Ole e 1 content in the 5 years (0.045 +/- 0.029 and 0.059 +/-0.031 microg/microg of freeze-dried material, respectively). The variety with the highest mean +/- SD Ole e 1 content was Picual (0.19 +/-0.075 microg/microg). Hojiblanco had the lowest total biological potency throughout the study. A positive correlation was obtained between rainfall in the winter months and total allergenicity of the 6 varieties. CONCLUSIONS: The different varieties of O. europaea pollen demonstrated great differences in allergenic potency and Ole e 1 content. These differences were maintained throughout the study, suggesting that they are due to genetic differences intrinsic to the varieties, although certain climatic effects may also play a role. 相似文献
5.
Aberrant cellular retinol binding protein 1 (CRBP1) gene expression and promoter methylation in prostate cancer 总被引:3,自引:0,他引:3
下载免费PDF全文
![点击此处可从《Journal of clinical pathology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Jerónimo C Henrique R Oliveira J Lobo F Pais I Teixeira MR Lopes C 《Journal of clinical pathology》2004,57(8):872-876
AIMS: Retinoids are involved in cell growth, differentiation, and carcinogenesis. Their effects depend on cytosolic transport and binding to nuclear receptors. CRBP1 encodes a protein involved in this process. Because altered CRBP1 expression and promoter hypermethylation occur in several tumours, these changes were investigated in prostate tumorigenesis. METHODS: The CRBP1 promoter was assessed by methylation specific polymerase chain reaction on tissue samples from 36 radical prostatectomy specimens (paired normal tissue, adenocarcinoma, and high grade prostatic intraepithelial neoplasia (HGPIN)), 32 benign prostatic hyperplasias (BPHs), and 13 normal prostate tissue samples from cystoprostatectomies. Methylation of DNA extracted from microdissected tissue was examined blindly. CRBP1 expression was assessed by immunohistochemistry on formalin fixed, paraffin wax embedded tissue. RESULTS: Loss of CRBP1 expression was seen in 15 of 36 adenocarcinomas and 18 of 36 HGPINs. Fifteen adenocarcinomas and nine HGPINs showed overexpression, whereas the remainder showed normal expression. BPH displayed normal expression. No significant associations were found between CRBP1 expression and Gleason score or stage. CRBP1 promoter hypermethylation was found in 17 of 36 adenocarcinomas, three of 35 HGPINs, one of 36 normal prostate tissues from the same patients, none of 32 BPHs, and none of 13 normal prostate tissues from cystoprostatectomies. Loss of expression and hypermethylation of CRBP1 were not significantly associated. CONCLUSIONS: Altered CRBP1 expression and hypermethylation are common in prostate carcinoma, although CRBP1 hypermethylation is not an early event in tumorigenesis. Moreover, both adenocarcinoma and HGPIN show frequent CRBP1 overexpression. The molecular mechanisms underlying altered CRBP1 expression in prostate cancer deserve further study. 相似文献
6.
Thomas Tabourin Judith Sarfati Ugo Pinar Nicolas Beaud Jerôme Parra Christophe Vaessen Florie Gomez Daniel Benamran Geoffroy Canlorbe Jérémie Belghiti Emmanuel Chartier-Kastler Olivier Cussenot Thomas Seisen Morgan Roupret 《Urologic oncology》2021,39(5):298.e7-298.e11
ObjectivesTo assess potential nosocomial coronavirus disease-2019 (COVID-19) transmission in patients who underwent robot-assisted laparoscopic procedures during the pandemic.Material and methodsProspective study in patients undergoing robot-assisted laparoscopy in urology or gynaecology within 2 academic hospitals. Patients underwent local preoperative COVID-19 screening using a symptoms questionnaire. Patients with suspicious screening underwent coronavirus real time-polymerase chain reaction (RT-PCR) and were excluded from robotic surgery if positive. Patients with symptoms postsurgery were systematically tested for coronavirus by RT-PCR. One-month postsurgery, all patients had a telephone consultation to evaluate COVID-19 symptoms.ResultsSixty-eight patients underwent robotic surgery during the study period (median age: 63-years [IQR: 53–70], 1.8 male: female ratio). Oncology was the main indication for robotic surgery (n = 62, 91.2%) and 26 patients (38.2%) received a chest CT-scan prior to surgery. Eleven patients (16.2%) were symptomatic after surgery of whom only 1 tested positive for coronavirus by RT-PCR (1.5%) and was transferred to COVID-19 unit with no life-threatening condition. No attending surgeon was diagnosed with COVID-19 during the study.ConclusionsRobot-assisted laparoscopic surgery seemed safe in the era of COVID-19 as long as all recommended precautions are followed. The rate of nosocomial COVID-19 transmission was extremely low despite the fact that we only used RT-PCR testing in symptomatic patients during the preoperative work-up. Larger cohort is needed to validate these results. 相似文献
7.
8.
Leticia Fiss Maria de Lourdes Adrien Clairton Marcolongo-Pereira Nathalia D. Assis-Brasil Eliza S. V. Sallis Franklin Riet-Correa Jerônimo L. Ruas Ana Lucia Schild 《Parasitology research》2013,112(2):883-887
Eight outbreaks of acute and subacute fasciolosis are reported in sheep in the municipality of Santa Vitória do Palmar, southern Brazil, in areas used for irrigated rice cultivation, which are subject to frequent flooding. Two outbreaks occurred mid-winter during July and August, and six occurred during spring and early summer. Morbidity ranged from 3 to 66.7 %, and mortality ranged from 3 to 50 %. Clinical signs included weight loss, mucosal pallor, apathy, depression, muscle tremors, and drooling; these were followed by death within approximately 24 h. Some sheep were found dead. Gross lesions were characterized by an irregular liver capsule with fibrin deposition and hemorrhages. The liver parenchyma contained hemorrhagic tracts or irregular clear areas alternated with dark hemorrhagic areas. Histologically, hemorrhagic dark red tracts of necrotic liver parenchyma and an inflammatory infiltrate were noted; these lesions coincided with the presence of immature flukes. Langhans-type giant cells, fibrous tissue, and bile duct cell proliferation were observed in subacute cases. Chronic fasciolosis is a well-known disease to farmers in southern Brazil; nevertheless, acute and subacute fasciolosis, which are more difficult to diagnose and treat, may cause important economic losses. Efficient control of fasciolosis requires integration of measures to treat infections in the definitive host, to reduce the population of snails of the genus Lymnaea, and to avoid contact between the parasite and host by appropriate pasture management. 相似文献
9.
10.
María Eugenia Pachón-Ibáñez Jerónimo Pachón 《Expert review of anti-infective therapy》2016,14(2):153-155
The current antibiotic crisis to treat infections by Acinetobacter baumannii is linked with the increase of antimicrobial resistance and the lack of development of new antimicrobial drugs. For this reason, new alternatives for the treatment and control of infections by A. baumannii are necessary. Several studies have reported the effect of adjuvants to restore the efficacy of existing antimicrobial agents. Herein, we analyzed the main results on the development of adjuvant drugs, as monotherapy or in combination therapy with existing antimicrobial agents, which have shown promising results in vitro and in vivo. However, caution is needed and further extensive in vivo studies have to be performed to confirm the potential use of these adjuvants as true therapeutic alternatives. 相似文献