全文获取类型
收费全文 | 640篇 |
免费 | 73篇 |
国内免费 | 3篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 10篇 |
妇产科学 | 11篇 |
基础医学 | 107篇 |
口腔科学 | 24篇 |
临床医学 | 69篇 |
内科学 | 121篇 |
皮肤病学 | 45篇 |
神经病学 | 34篇 |
特种医学 | 15篇 |
外科学 | 77篇 |
综合类 | 3篇 |
预防医学 | 44篇 |
眼科学 | 31篇 |
药学 | 53篇 |
中国医学 | 3篇 |
肿瘤学 | 64篇 |
出版年
2024年 | 1篇 |
2023年 | 14篇 |
2022年 | 25篇 |
2021年 | 54篇 |
2020年 | 40篇 |
2019年 | 49篇 |
2018年 | 47篇 |
2017年 | 41篇 |
2016年 | 41篇 |
2015年 | 36篇 |
2014年 | 40篇 |
2013年 | 42篇 |
2012年 | 60篇 |
2011年 | 62篇 |
2010年 | 27篇 |
2009年 | 22篇 |
2008年 | 19篇 |
2007年 | 28篇 |
2006年 | 18篇 |
2005年 | 13篇 |
2004年 | 6篇 |
2003年 | 7篇 |
2002年 | 9篇 |
2001年 | 2篇 |
1999年 | 2篇 |
1994年 | 1篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1989年 | 2篇 |
1974年 | 2篇 |
1971年 | 1篇 |
1969年 | 1篇 |
1968年 | 1篇 |
排序方式: 共有716条查询结果,搜索用时 328 毫秒
101.
Norikazu Matsutomo Saki Matsumoto Tomoaki Yamamoto Eisuke Sato 《Radiological physics and technology》2017,10(4):439-445
The present study aimed to validate the absolute quantitative accuracy of a calibration method for single-photon emission computed tomography (SPECT) using cross-calibration factor (CCF)- and system sensitivity-based calibration methods. The CCF obtained with different reconstruction parameters was evaluated using a cylindrical phantom (diameter 20 cm, height 20 cm). SPECT images were acquired with a positron emission tomography/computed tomography (CT) phantom. Subsequently, they were reconstructed by using ordered subset expectation maximization with resolution recovery, scatter, and CT-based attenuation correction. All reconstructed SPECT counts were converted to activity concentrations based on the CCF and system planar sensitivity. We placed 12 circular regions of interest, 37 mm in diameter, on the phantom background, and the converted activity concentration and relative measurement error were assessed. The CCF obtained using a cylindrical phantom was affected by the iterative update number and post-smoothing filter function. The activity concentration calibrated using the CCF showed over- and underestimation. However, the activity concentration obtained from the system planar sensitivity was similar to that gained using the phantom. The values obtained using the system planar sensitivity were within 10% of the activity concentrations obtained with the phantom. These findings demonstrated that the calibration method using system planar sensitivity provides accurate quantification within 10% of the true activity concentration. Further clinical examination is required to validate the present results. 相似文献
102.
Keely May McNamara Saki Oguro Fumiya Omata Kyoko Kikuchi Fouzia Guestini Koyu Suzuki Yang Yang Eriko Abe Hisashi Hirakawa Kristy A. Brown Ishida Takanori Noriaki Ohuchi Hironobu Sasano 《Breast cancer research and treatment》2017,161(2):213-227
Purpose
While triple-negative breast cancer (TNBC) is negative for estrogen receptor alpha, a substantial proportion of carcinomas express estrogen receptor beta (ERβ); consequently, estrogen actions and metabolism may be relevant in this cancer subtype.Methods
A cohort of 81 TNBC patients from Tohoku University Hospital, Japan were characterised with regard to the expression of estrogen receptor beta and enzymes known to modulate levels of estrogens in breast and other tissues (Aromatase, 17-beta- Hydroxysteroid dehydrogenases 1, 2 and 6). This was done at the protein level by means of immunohistochemistry. As this cohort has been previously characterised for androgens, this also allows for comparison between the expressions of estrogen-related proteins and of androgen-related proteins. Preliminary mechanistic studies in cell culture were also undertaken.Results
17βHSD2 was detected in the highest number of cases followed by 17βHSD1, 17βHSD6 and aromatase. When comparing the expression of ERβ with that of the enzymes, it was positively correlated with the expression of 17βHSD6 (p < 0.05) and trended towards correlation with dual expression of 17βHSD1 and 2 (p < 0.07). 17βHSD1 was associated with significantly reduced tumour volume (p = 0.0025), while ERβ was associated with a trend towards reduced lymphovascular invasion, (p < 0.061). Interestingly, in survival analysis, 17βHSD6 expression was the only one of these five factors that influenced survival, with positive samples being associated with longer disease-free survival compared to those that were negative for 17βHSD6 (p < 0.05). In assessing associations with expression of proteins in the androgenic pathway, expression of aromatase appeared to be associated with androgenic pathways in TNBC patients (p < 0.05). Due to this association and the potential relevance to androgen-directed therapies in TNBC, we evaluated this interaction in vitro. We observed androgen-dependent upregulation of aromatase and ERβ in a subset of AR expressing TNBC cell lines (MDA-MB-453, SUM-185-PE and MFM-223).Conclusion
Overall this study suggests the presence of, and a potential protective effect of estrogens in TNBC.103.
The present systematic review and meta-analysis was conducted to assess the effect of tocilizumab (TCZ) in patients with rheumatoid arthritis (RA). We systematically searched all potential articles in the main databases, including PubMed, Scopus, EMBASE, Web of Sciences (ISI), and Cochrane Center. The search was subsequently updated in December 2020. The initial review and extraction of information were performed independently by two authors to collect the first author and publication year; sample size; mean age of the intervention and control groups; the dose of TCZ, and the follow-up duration. Outcomes of interest include the ACR20, ACR50, ACR70, total complication rate, and the occurrence of remission. Any disagreements between the reviewers were resolved by discussion and re-check of the article and consultation with a third reviewer. After reviewing and culling, 15 clinical trials comparing the clinical efficacy of TCZ and its comparators in the treatment of patients with RA entered the qualitative and quantitative synthesis. Tocilizumab 8 mg was statistically better than 4 mg or placebo for ACR responses. Significant clinical adverse events in patients with RA treated with TCZ, such as abnormal liver function tests (LFTs) and infections, were more frequent than in comparator groups. This systematic review and meta-analysis suggest that the combination therapy of TCZ with other drugs such as methotrexate and disease-modifying antirheumatic drugs has been studied for various clinical effects concerning safety and clinically significant adverse events. Although the data are promising, long-term performance and safety data need to be fully identified, as well as the risks and benefits of TCZ, especially appropriate timing, dosage, and regimen. 相似文献
104.
105.
106.
Morteza Hosseinzadeh Afra Khosravi Kourosh Saki Reza Ranjbar 《Archives of Medical Science》2011,7(5):844-849
Introduction
Migraine can cause headache in different communities so that 12-15% are suffering worldwide. Recently the relationship between infectious diseases such as Helicobacter pylori infection and migraine headache has been the focus of many studies. The current study was designed to evaluate IgG and IgM antibodies to H. pylori in patients suffering from migraine headaches.Material and methods
Patients who had diagnostic criteria for migraine were chosen as cases compared to some healthy individuals as the control group amongst which immunoglobulin G (IgG), immunoglobulin M (IgM), age, job, gastro-intestinal (GI) disorders, history of migraine, special meals, medications, sleeping disorders, stress, environmental factors etc were analysed.Results
The prevalence of disease was 38.6%. Household women had the highest prevalence (40%). Among them menstruation was related to high prevalence of migraine. 75.6% of patients had gastrointestinal disorders of which the gastric reflux was the most important sign (47.1%). The mean optical density (OD) value of IgG and IgM antibody to H. pylori was 60.08 ±7.7 and 32.1 ±8.7 for the case group, 21.82 ±6.2 and 17.6 ±9.4 for the control group, respectively.Conclusions
There was a significant difference in mean OD value of both antibodies to H. pylori amongst the case and control groups. As a result, active H. pylori infection is strongly related to the outbreak and severity of migraine headaches, and H. pylori treatment reduces migraine headaches significantly. Hopefully, the definite treatment and eradication of this infection can cure or reduce the severity and course of migraine headaches significantly if not totally. 相似文献107.
108.
109.
110.
Yukako Murakami Saki Matsui Akiko Kijima Shun Kitaba Hiroyuki Murota Ichiro Katayama 《Allergology international》2011,60(3):397-400
We report a case of 7-year-old monozygotic twin patients with atopic dermatitis. The HLA haplotypes were HLA A2, A11, B27, B61, DR1, and DR4. Both serum IgE levels and cedar pollen radioallergosorbent test (RAST) scores were high in the twins (elder/younger sister: IgE: 5170/3980 IU/ml and Japansese cedar pollen: > 100/64.0) in contrast to low mite and food RAST scores (Dermatophagoides Pterygonium; 0.59/0.4 and egg white 9.24/4.6). The patients showed positive immediate (20 min in both sisters) and delayed (24 hours in elder sister, 24, 48, 72 hours in younger sister) reactions to a scratch test with Japanese cedar pollen. Skin lesions on the face were aggravated and extended to the trunk and extremities during the Japanese cedar pollen season and gradually subsided in summer. Oral provocation with egg white or cow milk showed no exacerbations, and topical corticosteroid did not improve the eczema. In contrast, successful protection from severe scratching behaviors was achieved by use of topical anti-allergic eye drops and wearing nightgowns made by the mother. 相似文献