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   2726篇
  免费   179篇
  国内免费   27篇
耳鼻咽喉   28篇
儿科学   97篇
妇产科学   94篇
基础医学   500篇
口腔科学   244篇
临床医学   182篇
内科学   486篇
皮肤病学   86篇
神经病学   182篇
特种医学   40篇
外科学   220篇
综合类   13篇
一般理论   1篇
预防医学   332篇
眼科学   61篇
药学   192篇
中国医学   15篇
肿瘤学   159篇
  2024年   3篇
  2023年   37篇
  2022年   83篇
  2021年   151篇
  2020年   70篇
  2019年   93篇
  2018年   136篇
  2017年   76篇
  2016年   91篇
  2015年   115篇
  2014年   150篇
  2013年   163篇
  2012年   223篇
  2011年   265篇
  2010年   147篇
  2009年   107篇
  2008年   162篇
  2007年   173篇
  2006年   133篇
  2005年   113篇
  2004年   125篇
  2003年   107篇
  2002年   80篇
  2001年   12篇
  2000年   5篇
  1999年   8篇
  1998年   12篇
  1997年   12篇
  1996年   7篇
  1995年   5篇
  1994年   7篇
  1993年   5篇
  1992年   3篇
  1991年   6篇
  1990年   4篇
  1989年   6篇
  1988年   2篇
  1987年   3篇
  1985年   3篇
  1984年   5篇
  1983年   6篇
  1981年   3篇
  1979年   3篇
  1978年   2篇
  1975年   1篇
  1974年   2篇
  1970年   1篇
  1968年   1篇
  1966年   1篇
  1965年   1篇
排序方式: 共有2932条查询结果,搜索用时 15 毫秒
11.
We report the spontaneous development of recurrent chyloperitoneum as a complication of peritoneal dialysis in a toddler. An 18-month-old boy with end-stage renal disease (ESRD) on continuous cycling peritoneal dialysis developed spontaneous chyloperitoneum. He was treated conservatively, with a low-fat diet supplemented with medium-chain triglycerides. The chyloperitoneum resolved within 2 days of his being on the low-fat diet, but it recurred after re-institution of regular feeds on four occasions. After 3 months, the chyle leak finally resolved after an extended period of low-fat feeds. Chyloperitoneum is a rare complication of peritoneal dialysis that can be confused with signs of peritonitis, and it is important to differentiate between the two so that appropriate management can be undertaken. This paper discusses the possible causes, management and complications of recurrent chyloperitoneum.  相似文献   
12.
We studied 278 adolescents (169 females) aged 13.0–18.5 years to elucidate whether an independent effect of physical fitness and lean mass in the differences between male and female bones can be detected. Lean and fat masses and bone mineral content (BMC) were measured with DXA. Physical fitness was evaluated with six different tests included in the EUROFIT test battery (flexibility, isometric, dynamic and endurance strength, speed, and cardiovascular fitness). To test the independent relationship between physical fitness and bone mass, multiple regression analysis was applied, including lean mass, age, and Tanner development as covariates. The males had a 43% lower fat mass and 40% and 16% higher lean mass and total BMC compared with the females (all P < 0.05). After adjustment for differences in body size and lean mass, the females exhibited a 7.4% higher BMC than the males (P < 0.05). The multiple regression analysis showed that lean mass had an independent relationship with bone mass (P < 0.001), explaining 67% of the total variance in whole-body BMC. In males, change in R 2 was 0.658 for hand grip and 0.035–0.151 for the rest of physical fitness-related variables; but 0.019–0.042 in females (all P–0.001); however, the independent relationships between physical fitness and bone disappeared after controlling for lean mass. In conclusion, it is likely the differences between male and female in bone mass could be explained by differences in lean mass and physical fitness.  相似文献   
13.
BACKGROUND: Keratinocyte cultures have been used for the treatment of severe burn patients. Here, we describe a new cultured bioengineered skin based on (1) keratinocytes and fibroblasts obtained from a single skin biopsy and (2) a dermal matrix based on human plasma. A high expansion capacity achieved by keratinocytes grown on this plasma-based matrix is reported. In addition, the results of successful preclinical and clinical tests are presented. METHODS: Keratinocytes and fibroblasts were obtained by a double enzymatic digestion (trypsin and collagenase, respectively). In this setting, human fibroblasts are embedded in a clotted plasma-based matrix that serves as a three-dimensional scaffold. Human keratinocytes are seeded on the plasma-based scaffold to form the epidermal component of the skin construct. Regeneration performance of the plasma-based bioengineered skin was tested on immunodeficient mice as a preclinical approach. Finally, this skin equivalent was grafted on two severely burned patients. RESULTS: Keratinocytes seeded on the plasma-based scaffold grew to confluence, allowing a 1,000-fold cultured-area expansion after 24 to 26 days of culture. Experimental transplantation of human keratinocytes expanded on the engineered plasma scaffold yielded optimum epidermal architecture and phenotype, including the expression of structural intracellular proteins and basement-membrane components. In addition, we report here the successful engraftment and stable skin regeneration in two severely burned patients at 1 and 2 years follow-up. CONCLUSIONS: Our data demonstrate that this new dermal equivalent allows for (1) generation of large bioengineered skin surfaces, (2) restoration of both the epidermal and dermal skin compartments, and (3) functional epidermal stem-cell preservation.  相似文献   
14.
Kolesnikov YA  Cristea M  Pasternak GW 《Anesthesia and analgesia》2003,97(4):1103-7, table of contents
Studies have revealed that lidocaine is an effective analgesic when applied topically to the tail of a mouse in the radiant heat tail-flick assay. In addition, the topical combination of lidocaine with morphine revealed synergistic interactions between the two drugs. In the current studies, we demonstrate that topical butamben, benzocaine, and bupivacaine are active in the radiant heat tail-flick assay. In this assay, topical lidocaine has a ceiling effect and displays a biphasic curve, with large doses markedly decreasing the responses almost to baseline levels. In contrast, butamben has an S-shape dose-dependent response in the assay and did not display a biphasic curve as seen with lidocaine, suggesting that topical butamben may have advantages over lidocaine. Both benzocaine and bupivacaine also showed dose-dependent analgesic activity in this model. Like lidocaine, butamben/morphine combinations displayed synergistic interactions. Indeed, the synergy appeared more prominent with a butamben/morphine combination. We also observed synergy between topical benzocaine and morphine. Although the bupivacaine/morphine combination was suggestive of synergy on isobolographic analysis, it did not achieve statistical significance. These studies indicate that a series of local anesthetics are all active topically in the radiant heat tail-flick assay in mice and that several interact synergistically with morphine. Of the local anesthetics tested, butamben seemed to have several pharmacological characteristics, alone and in combination with morphine, which suggest that it may be superior to the other local anesthetics. Together, these observations suggest that topical combinations of opioids and local anesthetics may prove clinically valuable. IMPLICATIONS: Topical administration of the opioid micro -agonist morphine and the sodium channel inhibitors butamben and benzocaine results in a synergistic interaction for antinociception in radiant heat tail-flick assay in mice, suggesting that the combination of these drugs will enhance rather than detract from the analgesia of either alone.  相似文献   
15.
This case series of 16 patients with autosomal dominant polycystic kidney disease (ADPKD) describes 4 girls who presented with a urinary tract infection (UTI). Radiological evaluation revealed that each of these patients had vesicoureteral reflux (VUR). The frequency of VUR was significantly higher in the patients with ADPKD compared with otherwise healthy age-matched children who underwent testing after a UTI (100% versus 15%, P<0.002). These findings suggest VUR is an associated somatic anomaly in children with ADPKD that may contribute to the occurrence of UTI in this patient population.  相似文献   
16.
Cutaneous diabetic wounds greatly affect the quality of life of patients, causing a substantial economic impact on the healthcare system. The limited clinical success of conventional treatments is mainly attributed to the lack of knowledge of the pathogenic mechanisms related to chronic ulceration. Therefore, management of diabetic ulcers remains a challenging clinical issue. Within this context, reliable animal models that recapitulate situations of impaired wound healing have become essential. In this study, we established a new in vivo humanised model of delayed wound healing in a diabetic context that reproduces the main features of the human disease. Diabetes was induced by multiple low doses of streptozotocin in bioengineered human‐skin‐engrafted immunodeficient mice. The significant delay in wound closure exhibited in diabetic wounds was mainly attributed to alterations in the granulation tissue formation and resolution, involving defects in wound bed maturation, vascularisation, inflammatory response and collagen deposition. In the new model, a cell‐based wound therapy consisting of the application of plasma‐derived fibrin dermal scaffolds containing fibroblasts consistently improved the healing response by triggering granulation tissue maturation and further providing a suitable matrix for migrating keratinocytes during wound re‐epithelialisation. The present preclinical wound healing model was able to shed light on the biological processes responsible for the improvement achieved, and these findings can be extended for designing new therapeutic approaches with clinical relevance.  相似文献   
17.
Ocular non-Hodgkin's lymphoma is a rare condition that can involve the retina, the vitreous and the optic nerve. It can occur alone or can be associated with lymphoma of the central nervous system and a frequent manifestation is a posterior uveitis of difficult treatment. This kind of ocular tumor is difficult and a challenge to diagnosis. We describe a case of non-Hodgkin's intraocular B-cell lymphoma in a 47-year-old woman who had a posterior uveitis as the first manifestation. We emphasize the importance of a careful investigation and of the general clinical examination since this is the most common type in the eye. We expect to call the attention to this disease that many times appears in an unspecific form with unspecific symptoms.  相似文献   
18.
19.
20.
Background The histopathological characteristics of Chagas disease (ChD) are: presence of myocarditis, destruction of heart fibers, and myocardial fibrosis. Galectin-3 (Gal-3) is a biomarker involved in the mechanism of fibrosis and inflammation that may be useful for risk stratification of individuals with ChD.Objectives We sought to evaluate whether high Gal-3 levels are associated with severe forms of Chagas cardiomyopathy (CC) and whether they are predictive of mortality.Methods We studied anti-T. cruzi positive blood donors (BD): Non-CC-BD (187 BD without CC with normal electrocardiogram [ECG] and left ventricular ejection fraction [LVEF]); CC-Non-Dys-BD (46 BD with CC with abnormal ECG but normal LVEF); and 153 matched serum-negative controls. This cohort was composed of 97 patients with severe CC (CC-Dys). We used Kruskall-Wallis and Spearman’s correlation to test hypothesis of associations, assuming a two-tailed p<0.05 as significant.Results The Gal-3 level was 12.3 ng/mL for Non-CC-BD, 12.0 ng/mL for CC-Non-Dys-BD, 13.8 ng/mL for controls, and 15.4 ng/mL for CC-Dys. LVEF<50 was associated with higher Gal-3 levels (p=0.0001). In our linear regression adjusted model, we found association between Gal-3 levels and echocardiogram parameters in T. cruzi-seropositive subjects. In CC-Dys patients, we found a significant association of higher Gal-3 levels (≥15.3 ng/mL) and subsequent death or heart transplantation in a 5-year follow-up (Hazard ratio – HR 3.11; 95%CI 1.21–8.04; p=0.019).Conclusions In ChD patients, higher Gal-3 levels were significantly associated with severe forms of the disease and more long-term mortality, which means it may be a useful means to identify high-risk patients. (Arq Bras Cardiol. 2021; 116(2):248-256)  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