首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   152篇
  免费   6篇
  国内免费   2篇
基础医学   18篇
临床医学   12篇
内科学   60篇
皮肤病学   1篇
神经病学   13篇
特种医学   3篇
外科学   31篇
预防医学   2篇
眼科学   1篇
药学   9篇
肿瘤学   10篇
  2024年   1篇
  2023年   4篇
  2022年   3篇
  2021年   12篇
  2020年   6篇
  2019年   3篇
  2018年   4篇
  2017年   1篇
  2016年   6篇
  2015年   6篇
  2014年   7篇
  2013年   4篇
  2012年   8篇
  2011年   6篇
  2010年   5篇
  2009年   6篇
  2008年   4篇
  2007年   9篇
  2006年   15篇
  2005年   15篇
  2004年   5篇
  2003年   6篇
  2002年   10篇
  2001年   1篇
  1998年   3篇
  1997年   2篇
  1996年   2篇
  1993年   2篇
  1992年   1篇
  1990年   1篇
  1989年   1篇
  1981年   1篇
排序方式: 共有160条查询结果,搜索用时 31 毫秒
1.
Despite the importance of short-chain fatty acids (SCFA) in maintaining the ruminant physiology, the mechanism of SCFA absorption is still not fully studied. The goal of this study was to elucidate the possible involvement of monocarboxylate transporter 1 (MCT1) in the mechanism of SCFA transport in the caprine rumen, and to delineate the precise cellular localization and the level of MCT1 protein along the entire caprine gastrointestinal tract. RT-PCR revealed the presence of mRNA encoding for MCT1 in all regions of the caprine gastrointestinal tract. Quantitative Western blot analysis showed that the level of MCT1 protein was in the order of rumen ≥ reticulum > omasum > caecum > proximal colon > distal colon > abomasum > small intestine. Immunohistochemistry and immunofluorescence confocal analyses revealed widespread immunoreactive positivities for MCT1 in the caprine stomach and large intestine. Amongst the stratified squamous epithelial cells of the forestomach, MCT1 was predominantly expressed on the cell boundaries of the stratum basale and stratum spinosum. Double-immunofluorescence confocal laser-scanning microscopy confirmed the co-localization of MCT1 with its ancillary protein, CD147 in the caprine gastrointestinal tract. In vivo and in vitro functional studies, under the influence of the MCT1 inhibitors, p -chloromercuribenzoate (pCMB) and p -chloromercuribenzoic acid (pCMBA), demonstrated significant inhibitory effect on acetate and propionate transport in the rumen. This study provides evidence, for the first time in ruminants, that MCT1 has a direct role in the transepithelial transport and efflux of the SCFA across the stratum spinosum and stratum basale of the forestomach toward the blood side.  相似文献   
2.
Sleep timing is influenced by the circadian system. Morningness-eveningness (ME) preference in humans is affected by the free-running period, which is determined by circadian clock-relevant genes. In this study, we investigated association between the 3111T/C polymorphism in the 3'-flanking region of hClock (Homo sapiens Clock homolog) and ME preference in 421 Japanese subjects. The Horne-Ostberg ME questionnaire (MEQ) scores showed normal distribution, with mean score of 51.2 +/- 1.4 (range, 25-73), and scores were positively correlated with sleep onset time (r = 0.541, P < 0.001) and wake time (r = 0.513, P < 0.001). MEQ scores were significantly lower in subjects with 3111C/C (n = 12) than in subjects with 3111T/C (n = 106, P < 0.001) or 3111T/T (n = 303, P < 0.001), suggesting a stronger eveningness preference in 3111C/C homozygotes. This group also showed significantly delayed sleep onset (P < 0.001), shorter sleep time (P < 0.001), and greater daytime sleepiness (P < 0.001) in comparison to parameters in the subjects with the 3111T allele. There was no significant difference in any of these parameters between the 3111C/T and 3111T/T genotypes. The influence of the 3111T/C polymorphism on ME preferences in Caucasian populations remains controversial. The present findings in a Japanese population sample, which should have a relatively low risk of population stratification effects, suggest the significance of the association of the 3111C/C allele of hClock with evening preference.  相似文献   
3.
One hundred and forty four patients with chronic hepatitis B were tested to identify new mutations associated with hepatitis B e antigen (HBeAg) negativity, using a full genome sequence analysis. All the patients were Chinese and had hepatitis B virus infection of genotype C. Patients with none of the pre-core or core promoter mutations were significantly (P < 0.001) less common in the group with anti-HBe (13%) than in the group with HBeAg (56%). The complete nucleotide sequence was determined in four anti-HBe-positive patients who had neither pre-core nor core promoter mutations and in five HBeAg-positive patients who also had neither of these mutations (the groups were matched for age and sex). Six mutations were found to be significantly more common in the former group than in the latter: G529A (3/4 vs. 0/5), C934A (4/4 vs. 1/5), A1053G (4/4 vs. 1/5), G1915T/A (4/4 vs. 0/5), T2005C/A (4/4 vs. 0/5), and C3026T (3/4 vs. 0/5). Three of the six mutations were significantly more common in the four anti-HBe-positive patients who had neither pre-core nor core promoter mutations, compared to 11 HBeAg-positive patients who had pre-core and core promoter mutations, and also compared to 15 anti-HBe-positive patients who had pre-core and core promoter mutations, suggesting further the specificity of these mutations. Of the six mutations, two resulted in amino acid substitution in the polymerase protein, and one is located near the enhancer I region. The results suggest that the six newly discovered mutations are associated with HBeAg negativity.  相似文献   
4.
5.
We classified ipsilateral breast tumor recurrences (IBTRs) based on strict pathological rules. Ninety‐six women who were surgically treated for IBTR were included. IBTRs were classified according to their origins and were distinguished based on strict pathological rules: relationship between the IBTR and the primary lumpectomy scar, surgical margin status of the primary cancer, and the presence of in situ lesions of IBTR. The prognosis of these subgroups were compared to that of new primary tumors (NP) in the narrow sense (NPn) that occurred far from the scar. Distant‐disease free survival of IBTR that occurred close to the scar with in situ lesions and a negative surgical margin of the primary cancer (NP occurred close to the scar, NPcs) was similar to that of NPn. In contrast, IBTR that occurred close to the scar without in situ lesions (true recurrence (TR) that arose from residual invasive carcinoma foci, TRinv) had significantly poorer prognosis than NPn. IBTR that occurred close to the scar with in situ lesions and a positive surgical margin of the primary cancer (TR arising from a residual in situ lesion, TRis) had more late recurrences than NPcs. Precise pathological examinations indicated four distinct IBTR subtypes with different characteristics.  相似文献   
6.
7.
Clinical Autonomic Research - Delayed orthostatic hypotension (DOH), a fall in blood pressure after a 3-min cutoff, is clinically meaningful. The aim of this study was to elucidate the clinical and...  相似文献   
8.
TRK‐100STP, a sustained‐release preparation of the orally active prostacyclin analogue beraprost sodium, targets renal hypoxia. This study aimed to show the superiority of TRK‐100STP over placebos in patients with chronic kidney disease (with either primary glomerular disease or nephrosclerosis) to determine the recommended dose. CASSIOPEIR (Chronic Renal Failure Asian Study with Oral PGI2 Derivative for Evaluating Improvement of Renal Function) was a randomized, double‐blind, placebo‐controlled study conducted at 160 sites in seven Asia‐Pacific countries and regions. Eligible patients (n = 892) were randomized to TRK‐100STP 120, 240 μg, or placebo for a treatment period of up to 4 years. The primary efficacy endpoint was time to first occurrence of a renal composite: doubling of serum creatinine or occurrence of end‐stage renal disease. No significant differences were observed in composite endpoints between TRK‐100STP and placebo (P = 0.5674). Hazard ratios (95% CI) in the TRK‐100STP 120 and 240 μg vs. placebo groups were 0.98 (0.78, 1.22) and 0.91 (0.72, 1.14), respectively. The overall incidence of adverse events and adverse drug reactions was comparable between treatment arms.  相似文献   
9.
Despite the development of effective chemotherapy and radiotherapy, surgery remains the mainstay treatment of many cancers, requiring anesthesia. Almost all cancer deaths after primary surgery are attributable to recurrence or metastases. Recently it has been hypothesized that the perioperative anesthetic management of cancer patients could potentially affect the risk of recurrence and metastases, which implies a key role for anesthesiologists in choosing anesthetic agents and techniques that optimize the balance between the metastatic potential of the tumor versus its elimination by antimetastatic immune defenses. This review summarizes available experimental information on the potential effects of common anesthetic agents and techniques on cancer metastases and the conflicting retrospective clinical data on regional anesthesia in various types of cancer. A number of prospective, randomized, multicenter, clinical trials are in progress, and their results are eagerly awaited.  相似文献   
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号