全文获取类型
收费全文 | 498篇 |
免费 | 25篇 |
国内免费 | 4篇 |
学科分类
医药卫生 | 527篇 |
出版年
2023年 | 4篇 |
2022年 | 5篇 |
2021年 | 25篇 |
2020年 | 19篇 |
2019年 | 15篇 |
2018年 | 22篇 |
2017年 | 17篇 |
2016年 | 16篇 |
2015年 | 22篇 |
2014年 | 22篇 |
2013年 | 29篇 |
2012年 | 28篇 |
2011年 | 39篇 |
2010年 | 20篇 |
2009年 | 33篇 |
2008年 | 39篇 |
2007年 | 41篇 |
2006年 | 42篇 |
2005年 | 28篇 |
2004年 | 19篇 |
2003年 | 11篇 |
2002年 | 7篇 |
2001年 | 10篇 |
2000年 | 5篇 |
1999年 | 4篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1992年 | 1篇 |
1989年 | 1篇 |
排序方式: 共有527条查询结果,搜索用时 192 毫秒
1.
Ali Gürbüz Bilgin Emrecan Levent Yilik Ibrahim Ozs?yler Mert Kestelli Cengiz Ozbek Nagihan Karahan 《European journal of cardio-thoracic surgery》2006,29(2):186-189
OBJECTIVE: The purpose of this study was to evaluate whether intracoronary shunt usage reduced the myocardial damage on the basis of the cardiac markers when compared with the shuntless anastomosis in off-pump coronary artery bypass grafting (OPCABG) surgery of isolated left anterior descending artery lesions. METHODS: Forty patients who had stable angina with isolated left anterior descending (LAD) coronary artery lesion undergoing OPCABG surgery were randomized into two groups. Shunt group consisted of 20 patients who had OPCABG using intracoronary shunt, whereas the shuntless group consisted of 20 patients who underwent OPCABG without using intracoronary shunt. Cardiac troponin I, CK, and CK-MB before and 24h after the surgery were assessed in the groups. RESULTS: There were no deaths in the study. The two groups were similar with respect to sex and age. Duration of LIMA-LAD anastomosis was significantly higher in the shunt group (p=0.01). There was no significant difference between the groups concerning the preoperative and postoperative CK and CK-MB levels. The preoperative troponin I levels of the groups were not different (p=0.238; NS), whereas postoperative levels of this marker was significantly higher in the shuntless group (p=0.003). CONCLUSION: Intracoronary shunt reduced the postoperative troponin I levels significantly, so it may be indicated in the patients who are thought to be susceptible to transient ischemia. 相似文献
2.
Cigdem Kekik Cinar Sebahat Usta Akgul Sonay Temurhan Hayriye Senturk Ciftci Yeliz Ogret Gonca Emel Karahan Fatma Savran Oguz 《International journal of immunogenetics》2020,47(2):158-162
Istanbul Medical Faculty, Department of Medical Biology, as the first EFI‐accredited HLA laboratory in Turkey since 1999 has been organizing both national and international quality control tests for HLA typing under the banner of the “Balkan external proficiency testing (BEPT)” encompassing countries from EFI regions 8. The first round of BEPT in 2004 was organized for low‐resolution HLA‐A,‐B typing by molecular methods and 12 centres participated in the exercise. In 2005, low‐resolution HLA‐DR typing was added, and in 2007, low‐resolution HLA‐C and DQ typing were added to the exercise and 28 centres participated. In 2015, high‐resolution (four digits or higher typing) HLA‐A,‐B,‐C,‐DR and –DQ typing added to the exercise and 40 centres participated. In the last 2 years, 2017 and 2018, the number of participating centres increased to 48 and 52, respectively. When the distribution of low‐resolution typing methods applied in the exercises were investigated, it was found that 82% of the centres in the first round of BEPT in 2004 used PCR‐SSP, whereas in the last round in 2018, 26% of the centres preferred SSP, while the rest used SSO (50%) or SSP and SSO (24%) methods. Methods for high‐resolution typing were SBT (41%), NGS (18%), SSO (18%), SSP (6%), SBT + NGS (6%) and SBT + SSP (11%). In 15th trial for BEPT, nomenclature mistake rate was 12%, and erroneous result rate was 6% for HLA samples. The most common mistakes in the exercises were nomenclature mistakes. The EFI Standards Version 7.0 is stated "HLA type can be reported using a hyphen if homozygosity is not proven by family studies." In order to provide standard results among HLA laboratories and since accurate HLA typing leads to significant increase of graft and patient survival, quality control exercises should be performed in all HLA‐based tests periodically. 相似文献
3.
Karahan ZC Atalay F Uzun M Erturan Z Atasever M Akar N 《Microbial drug resistance (Larchmont, N.Y.)》2004,10(4):325-333
Drug-resistant tuberculosis is a serious problem throughout the world. Resistance to Rifampicin (RIF) is mainly caused by the mutations in the rpoB gene coding the beta-subunit of RNA polymerase. In this study, we aimed to detect the distribution of rpoB gene mutations in 80 RIF-resistant clinical Mycobacterium tuberculosis (MTB) isolates from Turkey. The rpoB gene was amplified by PCR and mutations leading to RIF resistance were determined by automated sequence analysis. A total of 72 of the 80 isolates (90%) were found to carry mutations in the amplified region, whereas eight isolates (10%) carried no mutations. Overall, 24 different missense mutations affecting 14 codons, and two deletion mutants were identified. Nine new mutations, six in the hot-spot region and three outside this region, were found. The codon numbers of the most frequently encountered mutations were 531 (51.4%), 526 (18.1%), 516 (13.9%), and 513 (12.5%). As a result, 90% of the RIF-resistant MTB isolates from the Turkish patients were found to carry a mutation in the rpoB gene, Ser531Leu being the most frequent one. Although molecular methods identify mutations leading to RIF resistance very quickly, results of the antimycobacterial susceptibility tests must be taken into consideration for the patients carrying no mutations in this region. 相似文献
4.
Cankal F Ugur HC Tekdemir I Elhan A Karahan T Sevim A 《Clinical anatomy (New York, N.Y.)》2004,17(2):118-122
The fossa navicularis is a relatively rare anatomic variation of the skull base. Awareness of its existence will avoid misinterpretations of radiological images and unnecessary investigations. This study describes the appearance of the fossa navicularis, and investigates its incidence and whether it is related to pathology at the basiocciput. We studied 492 dry human skulls and 525 computer tomography (CT) images of patients. Dry skulls showing a fossa navicularis were investigated by CT scan, whereas patients identified as having a fossa navicularis were further examined with magnetic resonance imaging (MRI). To document the position of the fossa more precisely, measurements were made between the fossa navicularis and certain anatomic landmarks such as the foramen ovale, the pharyngeal tubercle, the posterior border of the vomer, the foramen lacerum, the carotid canal, and the occipital condyle. Upon examination, 26 of 492 skulls (5.3%) were found to have a fossa navicularis. Twelve were <2 mm in depth and the other 14 had a depth of >/=2 mm. Of the 525 patients, 16 (3.0%) were identified as having a fossa navicularis in CT images. Evaluation of MRIs showed no soft tissue lesions in any of these patients. Comprehensive anatomic details of the fossa navicularis have not been reported in the literature. The results of this study may be useful to radiologists, anatomists, and surgeons interested in the skull base. 相似文献
5.
3-Hydroxysteroid-dehydrogenase (3-HSD) is an isoenzyme that catalyses an essential step in the synthesis of all classes of active steroid hormones. The presence of steroid hormones of the vertebrate type in invertebrates is acknowledged in addition to a group of steroid-like hormones called ecdysteroids that were present in arthropods and helminths. In the present study, 3-HSD was detected in the bradyzoites enclosed in sarcocysts of Sarcocystis spp. with immunohistochemistry. The results suggest that self-originating steroid hormones may play important roles in the development of Sarcocystis spp., and possibly in the regulation of the reciprocal immune interaction between the host and these parasites. 相似文献
6.
7.
8.
9.
10.