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   424篇
  免费   27篇
  国内免费   2篇
耳鼻咽喉   3篇
儿科学   8篇
妇产科学   3篇
基础医学   42篇
口腔科学   9篇
临床医学   38篇
内科学   109篇
皮肤病学   2篇
神经病学   48篇
特种医学   9篇
外科学   71篇
预防医学   42篇
眼科学   7篇
药学   30篇
肿瘤学   32篇
  2024年   1篇
  2023年   4篇
  2022年   9篇
  2021年   16篇
  2020年   14篇
  2019年   18篇
  2018年   14篇
  2017年   16篇
  2016年   12篇
  2015年   11篇
  2014年   15篇
  2013年   25篇
  2012年   35篇
  2011年   16篇
  2010年   20篇
  2009年   9篇
  2008年   20篇
  2007年   26篇
  2006年   20篇
  2005年   18篇
  2004年   14篇
  2003年   19篇
  2002年   16篇
  2001年   5篇
  2000年   5篇
  1999年   9篇
  1998年   5篇
  1997年   5篇
  1996年   6篇
  1995年   3篇
  1994年   3篇
  1993年   4篇
  1992年   5篇
  1991年   4篇
  1990年   8篇
  1989年   3篇
  1988年   5篇
  1987年   3篇
  1986年   2篇
  1985年   1篇
  1982年   1篇
  1979年   1篇
  1978年   1篇
  1977年   1篇
  1975年   1篇
  1974年   1篇
  1970年   1篇
  1969年   1篇
  1924年   1篇
排序方式: 共有453条查询结果,搜索用时 15 毫秒
1.
In this study, we analyzed the spatiotemporal expression patterns of the high-molecular weight (MAP2a and b) and low-molecular weight (MAP2c and d) cytoskeletal microtubule-associated protein-2 (MAP2) isoforms with Western blotting, and the cellular localization of the high-molecular weight MAP2 isoforms with immunocytochemistry in the hippocampi of 1- to 21-day-old rats. Moreover, the temporal profile (from 30 min to 1 week) of MAP2 isoform reactivity to kainic acid-induced status epilepticus was studied in P9 rats. During development, the expression of the high-molecular weight MAP2 isoforms significantly increased, while the low-molecular weight isoforms decreased, the most prominent changes occurring during the second postnatal week. This developmental increase in the high-molecular weight MAP2 expression was also confirmed with immunocytochemistry, which showed increased immunoreactivity, particularly in the molecular layers of the dentate gyrus, and in CA1 and CA3 stratum radiatum. In 9-day-old rats, status epilepticus resulted in a rapid transient increase (about 210%) in the high-molecular weight MAP2 expression, without any effect on the low-molecular weight MAP2. Moreover, disturbed dendritic structure in the CA1 and CA3 stratum radiatum was manifested as formation of varicosities 3h after the kainic acid treatment. The strictly developmentally regulated MAP2 isoform expression suggests different functional roles for these proteins during the postnatal development in the rat hippocampus. Moreover, high-molecular weight MAP2s may play a role in nerve cell survival during cell stress.  相似文献   
2.
This article details a 7- to 12-year follow-up of seven young male baseball players with osteochondritis dissecans of the capitellum that we treated using closed-wedge osteotomy. This procedure was established by Yoshizu in 1986 for the treatment of "Little League elbow." The bone of the capitellum was revascularized and remodeled within 6 months in all seven patients. Six of the patients were able to return to full athletic activity and continued to play baseball. Radiographic assessment during the follow-up study revealed minimal osteoarthritic change and suggests that the treatment is useful for such an injury.  相似文献   
3.
Mobile technology has been increasingly adopted in promotion of mental health among older people. This study assessed the feasibility of a mobile mental wellness training application for individual use and for group work from the perspectives of older adults and social care professionals. The older individuals recruited for the study were participants in a Circle of Friends group and family caregivers' peer support group offered by the communal senior services. The qualitative and quantitative results of interviews, questionnaires, observation, and application usage were reported. Seven older adults started using the application independently at home in parallel with the group activity. This study revealed new information regarding the barriers to the older adults' full adoption of such mobile technologies. The results indicated that there may be potential in the incorporation of mobile technologies in promotion of mental health of older people at group settings.  相似文献   
4.
ObjectivesWe investigated the relationship between pyramidal tract evaluation indexes (i.e., diffusion tensor imaging, transcranial magnetic stimulation (TMS)-induced motor-evoked potential (MEP), and central motor conduction time (CMCT) on admission to the recovery rehabilitation unit) and motor functions at discharge in patients with ischemic or hemorrhagic stroke.Materials and MethodsSeventeen patients were recruited (12 men; 57.9 ± 10.3 years). The mean fractional anisotropy (FA) values of the right and left posterior limbs of the internal capsule were estimated using a computer-automated method. We determined the ratios of FA values in the affected and unaffected hemispheres (rFA), TMS-induced MEP, and the ratios of CMCT in the affected and unaffected hemispheres (rCMCT) and examined their association with motor functions (Fugl–Meyer Assessment (FMA) and Action Research Arm Test (ARAT)) at discharge.ResultsHigher rFA values of the posterior limb of the internal capsule on admission to the recovery rehabilitation unit led to a better recovery of upper limb function (FMA: r = 0.78, p < 0.001; ARAT: r = 0.74, p = 0.001). Patients without MEP had poorer recovery of upper limb function than those with MEP (FMA: p < 0.001; ARAT: p = 0.001). The higher the rCMCT, the poorer the recovery of upper limb function (ARAT: r = ?0.93, p < 0.001). However, no association was observed between the pyramidal tract evaluation indexes and recovery of lower limb motor function.ConclusionsEvaluating the pyramidal tract is useful for predicting upper limb function prognosis, but not for lower limb function prognosis.  相似文献   
5.
6.
PURPOSE: We examined the survival benefit of pelvic exenteration for locally advanced colorectal cancer with lymph node metastases, because this issue remains controversial. METHODS: Medical records of 50 patients who underwent curative pelvic exenteration for colorectal cancer were reviewed retrospectively. Nodal metastases were examined by the clearing method in 29 patients and by the conventional manual method in 21 patients. RESULTS: Invasion to contiguous pelvic organs was present in 40 patients (80 percent) and absent in 10 patients (20 percent). Node metastases were present in 33 patients (66 percent). Operative morbidity and mortality rates were 22 percent (11 patients) and 6 percent (3 patients), respectively. Respective five-year survival rates were 60 and 80 percent in the groups with and without organ invasion (no significant difference). Five-year survival rates in patients with nodal metastases was 54.6 percent but was significantly higher, 82.4 percent, in patients without nodal metastases. Five-year survival in 28 patients with both organ invasion and nodal metastases was 53.6 percent. CONCLUSIONS: Long-term survival was afforded by pelvic exenteration for locally advanced colorectal cancer with nodal metastases.  相似文献   
7.

Objectives

To examine and compare the prevalence of use of vitamins, minerals, and fish-oil products (VMFO) in Finnish community-dwelling older people at two time points over a decade, and to explore the associated factors with the VMFO use.

Methods

A postal survey was sent to people aged 75, 80, 85, 90, and 95 years living in Helsinki, Finland in 1999 (N=3219) and in 2009 (N=2247). The response rates were 78% (n=2511) and 73% (n=1637), respectively. The surveys included items on demographic and health related factors, used medication and self-reported supplemental use of vitamins or minerals, and natural products.

Results

The proportion of respondents using at least one VMFO was 49.8% in 1999 and 66.8% in 2009 (p<0.001). The proportion using vitamin D (RR 4.58, 95% CI 3.89 to 5.40; p<0.001), calcium (RR 2.47, 95% CI 2.18 to 2.80; p<0.001), magnesium (RR 1.47, 95% CI 1.17 to 1.85; p<0.001), and fish-oil/omega3 products (RR 3.66, 95% CI 2.41 to 5.55; <0.001) was higher in 2009 than in 1999, even when adjusted for age, gender, living conditions, education and comorbidities, whereas that of other vitamins and fish-liver-oil products was lower. At both time points the use of VMFO was associated with female gender and higher number of used medications. In 1999, higher education was associated with VMFO-use while age and comorbidities was not. In 2009 higher age and comorbidities was associated with VMFO-use.

Conclusions

The use of VMFO is common among communitydwelling older people and it has significantly increased over ten years. The increase was mainly due to the use of vitamin D and calcium. The consumption of other vitamin supplements has decreased. Education was no longer associated with use of VFMO in 2009 where as age and comorbidities were.  相似文献   
8.
Genome-wide association studies (GWAS) and linkage studies have had limited success in identifying genome-wide significantly linked regions or risk loci for diabetic nephropathy (DN) in individuals with type 1 diabetes (T1D). As GWAS cohorts have grown, they have also included more documented and undocumented familial relationships. Here we computationally inferred and manually curated pedigrees in a study cohort of >6,000 individuals with T1D and their relatives without diabetes. We performed a linkage study for 177 pedigrees consisting of 452 individuals with T1D and their relatives using a genome-wide genotyping array with >300,000 single nucleotide polymorphisms and PSEUDOMARKER software. Analysis resulted in genome-wide significant linkage peaks on eight chromosomal regions from five chromosomes (logarithm of odds score >3.3). The highest peak was localized at the HLA region on chromosome 6p, but whether the peak originated from T1D or DN remained ambiguous. Of other significant peaks, the chromosome 4p22 region was localized on top of ARHGAP24, a gene associated with focal segmental glomerulosclerosis, suggesting this gene may play a role in DN as well. Furthermore, rare variants have been associated with DN and chronic kidney disease near the 4q25 peak, localized on top of CCSER1.  相似文献   
9.
Information on dietary adequacy is needed to assess food and nutrition security in a modern society, especially in the transition towards climate-friendly food systems. In this study, differences in the nutritional adequacy of diets among Finnish adults were evaluated in population groups of different education, income and urbanisation levels. The study used data from the FinDiet 2017 Survey (n = 1655, 18–74 years). Modelled usual intakes of foods and nutrients were evaluated relative to food-based dietary guidelines issued by the National Nutrition Council of Finland (FNNC) and with respect to nutrient adequacy following the Nordic Nutrition Recommendations and FNNC. For about half of the nutrients studied, intakes were found to be adequate. Intakes of protein, fat, saturated fatty acids and salt were estimated to be high. By contrast, inadequate intakes were seen in folate and vitamins A, D, B1, B2 and C in almost all groups studied. Groups with a higher education and income, groups that lived in urban areas and, in particular, women adhered more closely to recommended food consumption and nutrient intakes than others. However, major challenges posed by the Finnish diet are common to all groups studied, and only certain dietary features evaluated in view of nutritional adequacy are associated with socioeconomic differences.  相似文献   
10.
Black-pigmented, asaccharolytic Bacteroides strains, which positively reacted with anti-Bacteroides gingivalis (now reclassified as Porphyromonas gingivalis) serum, were isolated from beagle dogs, and their characteristics were studied and compared with those of P. gingivalis. The strains from dogs were different from P. gingivalis in their catalase activity, nutritional requirements and oxygen tolerance, and double-immunodiffusion tests showed serological dissimilarity between the strains from dogs and P. gingivalis. However, the strains from dogs had guanine-plus-cytosine contents of 49.0 to 49.3 mol %, which were very similar to P. gingivalis, and they showed strong DNA-DNA hybridization with P. gingivalis. These results indicated that beagle dogs had Porphyromonas species analogous to P. gingivalis in their oral cavities.  相似文献   
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