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   4598篇
  免费   181篇
  国内免费   32篇
耳鼻咽喉   30篇
儿科学   49篇
妇产科学   36篇
基础医学   522篇
口腔科学   109篇
临床医学   318篇
内科学   1111篇
皮肤病学   82篇
神经病学   530篇
特种医学   147篇
外科学   952篇
综合类   13篇
预防医学   117篇
眼科学   32篇
药学   294篇
中国医学   2篇
肿瘤学   467篇
  2023年   22篇
  2022年   57篇
  2021年   72篇
  2020年   56篇
  2019年   72篇
  2018年   67篇
  2017年   57篇
  2016年   80篇
  2015年   76篇
  2014年   92篇
  2013年   121篇
  2012年   240篇
  2011年   267篇
  2010年   136篇
  2009年   110篇
  2008年   207篇
  2007年   253篇
  2006年   220篇
  2005年   241篇
  2004年   213篇
  2003年   249篇
  2002年   232篇
  2001年   120篇
  2000年   122篇
  1999年   123篇
  1998年   82篇
  1997年   36篇
  1996年   46篇
  1995年   53篇
  1994年   41篇
  1993年   38篇
  1992年   97篇
  1991年   73篇
  1990年   87篇
  1989年   83篇
  1988年   83篇
  1987年   76篇
  1986年   83篇
  1985年   58篇
  1984年   54篇
  1983年   34篇
  1982年   22篇
  1980年   22篇
  1979年   31篇
  1978年   19篇
  1976年   16篇
  1974年   16篇
  1970年   15篇
  1968年   16篇
  1967年   16篇
排序方式: 共有4811条查询结果,搜索用时 62 毫秒
1.
Despite a high prevalence of chronic muscle pain disorders such as fibromyalgia and regional myofascial pain, there is still limited knowledge about the factors that initiate and perpetuate these pain states. Although there are also likely to be downstream neuropathic changes in the central nervous system and spinal cord that sustain and exacerbate the pain states known as fibromyalgia, the focus of this critical review is on studies that examined the connection between both fibromyalgia and regional myofascial pain and sympathetic function. Specifically, we looked at studies that described Raynaud-like symptoms, cardiovascular dysfunction and altered intramuscular perfusion in chronic muscle pain. Our analysis showed that although the first 2 phenomena were intermittently present, a prominent and consistent feature for regional myofascial pain and to a lesser degree for fibromyalgia was intramuscular hypoperfusion. Several hypotheses can be offered why this hypoperfusion exists, and additional studies comparing and contrasting these theories are needed. This review focuses on one of these theories, namely, agonist-induced beta-adrenergic receptor desensitization as an explanatory model for hypoperfusion. What cannot be done at this time and is needed in the future is to compare and contrast to what degree the regional muscle pain disorder (myofascial) is similar or different from the more generalized disorder (fibromyalgia).  相似文献   
2.
3.
4.
Estramustine phosphate disodium (Estracyt) was used in the treatment of 38 patients with prostatic carcinoma for at least 1 year. Of these patients 37 patients were treated with Estracyt as primary treatment and 1 patient had been treated with another antiandrogenic therapy before the Estracyt treatment. Estracyt was given orally in a dose of 560 mg/day in divided oral doses. The clinical evaluation was done for the change of PAP, the relapse rate, the survival rate and the side effect. Among 22 cases which had shown abnormally high PAP values before the treatment started, the values decreased or normalized in 21 cases (95.5%) in the first year of administration of Estracyt. In 6 cases, however, the values increased again in the second year or later. Relapse was observed in 10 (26.3%) out of 38 cases. Relapse rate was 2.6%, 51.7%, and 51.7%, at the first, third, and fifth year, respectively. Survival rate was 97.4% at the first year, 88.5% at the third year, and 68.8% at the fifth year for the follow-up study. Side effects were observed in 14 (36.8%) out of 38 cases. The main side effect was gynecomastia. Gastro-intestinal disturbance and edema were also observed. However, there were only 2 cases (5.2%) in which administration of Estracyt had to be discontinued.  相似文献   
5.
A 72-year-old fisherman who was positive for the HCV antibody developed an annular, erythematous, infiltrated lesions on sun-exposed areas. The lesions were diagnosed as annular elastolytic giant cell granuloma both clinically and histologically. Topical corticosteroid and cryotherapy with liquid nitrogen for several months failed to improve the lesions. We then started dapsone, a known anti-oxidant, at 50 mg/day. A month later, the margins of the erythematous lesions faded, and the infiltration gradually decreased. No recurrence has been observed for one year after the start of the therapy. Anti-oxidative therapy appears to be effective for annular elastolytic giant cell granuloma and could be an alternate therapy for refractory granulomatous disease.  相似文献   
6.
Granular cell tumors (GCT) are rare neoplasms, and only 173 cases of benign GCT of the breast have been documented. We report herein the cases of two patients with this tumor and discuss the methods of diagnosis and treatment. The first patient was a 60-year-old woman who presented with a firm ill-defined mass in her left breast. Mammography showed a dense shadow with spicula and skin thickness, and ultrasonography revealed a hypoechoic mass with an irregular border. Radical mastectomy was performed under the wrong preoperative diagnosis of breast cancer. The second patient was a 31-year-old woman who presented with an elastic-hard mass in her left breast. Mammography showed a well-demarcated dense mass, and ultrasonography revealed a well-defined hypoechoic mass with a large depth-width ratio. Fine-needle aspiration cytology (FNAC) showed a large number of histiocytic cells with abundant granular cytoplasm. An excisional biopsy was performed, and histological examination confirmed a diagnosis of GCT. GCT is benign, but often misdiagnosed as breast cancer both clinically and radiologically. Therefore, histological examination is essential for making a correct diagnosis, while FNAC is also useful. Local resection is still the treatment of choice, and surgeons should do their utmost to avoid performing needless radical mastectomy.  相似文献   
7.
BACKGROUND: Glycogen synthase kinase-3 beta (GSK-3beta) is involved in many cellular processes, such as metabolism, apoptosis, differentiation and proliferation. Insulin-like growth factor-1 (IGF-1), which is well known to have a hypertrophic effect on cardiomyocytes, inactivates (phosphorylates) GSK-3beta in some cell types. The role of GSK-3beta in cardiomyocytes as a negative regulator of cardiac hypertrophy has been recently reported and the present study investigated the role of GSK-3beta in the cardiac hypertrophy of cultivated neonatal rat cardiomyocytes induced by IGF-1. METHODS AND RESULTS: First, the IGF-1 induced signal transduction leading to GSK-3beta in neonatal rat cardiomyocytes was examined. The phosphatidylinositol (PI) 3-kinase/Akt/GSK-3 beta signaling induced by IGF-1 was investigated using inhibitors of PI 3-kinase and Ad AktAA, a dominant negative form of Akt. Furthermore, using Ad MEK DN, a dominant negative form of MEK, it was found that MEK negatively regulates Akt phosphorylation upon IGF-1 stimulation. Next, it was examined whether GSK-3beta acts as a negative regulator in the cardiac hypertrophy induced by IGF-1. Sustained stimulation by IGF-1 caused cardiac hypertrophy in protein synthesis and cellular morphology, and overexpression of unphosphorylatable GSK-3beta (Ad GSK-3beta S9A) repressed these hypertrophic effects of IGF-1. CONCLUSIONS: GSK-3beta may play an important role as a negative regulator of cardiac hypertrophy induced by IGF-1.  相似文献   
8.
As an intraoperative chemotherapy treatment for the regional lymph nodes in resectable cases of pancreatoduodenal cancer, Neocarzinostatin (NCS) was administered in the duodenal subserosa and the NCS concentration was measured in the resected lymph nodes. Experiments: NCS 4,000 units (n = 4), or 10,000 units (n = 4) was administered into the duodenal subserosa of mongrel dogs, and 2 hours after administration, the lymph nodes of the mesentery root were resected. The NCS concentration in the lymph nodes was 0.21 U/g in the 4,000-U group and 1.39 U/g in the 10,000-U group. Clinical findings: NCS 10,000 U was administered into the duodenal subserosa in 6 cases of pancreatoduodenal cancer. The total number of resected lymph nodes was 49 and the mean NCS concentration was 5.65 U/g. According to site, the highest concentration was measured in lymph nodes from the anterior and posterior region of the pancreas head, which were near to the administration site. Also, NCS was well distributed in the lymph nodes in the hepatoduodenal ligament and mesentery root which lay in the direction of lymph flow. NCS concentration was high in lymph nodes resected 1 hour after administration. According to experimental reports of in vitro studies, an NCS concentration of more than 0.5 U/g is required to obtain an anticancer effect. This method is therefore considered to be useful as a form of intraoperative chemotherapy for the regional lymph nodes in pancreatoduodenal cancer.  相似文献   
9.
10.
Advanced glycation end products are the chemical modification of proteins induced by sugars in a hyperglycemic condition. Extracellular matrix proteins are prominent targets of nonenzymatic glycation because of their slow turnover rates. The aim of this study was to investigate the influence of nonenzymatic glycation of type I collagen on the migration of keratinocytes. The migration of keratinocytes was dramatically promoted on native type I collagen-coated dishes compared with that on uncoated dishes. When type I collagen was glycated with glycolaldehyde, large amounts of advanced glycation end products were produced; the glycated collagen I-coated dishes did not promote the migration of keratinocytes. Glycated collagen I did not affect the proliferative capacity of keratinocytes. However, the adhesion of keratinocytes to glycated collagen I was profoundly diminished in a glycation intensity-dependent manner. alpha2beta1 integrin is responsible for the migration and adhesion of keratinocytes to type I collagen. Pretreatment with glycated collagen I did not affect the expression level or functional activity of alpha2beta1 integrin on keratinocytes. These findings suggest that in the presence of glycated collagen I, keratinocytes lose their adhesive and migratory abilities. As the glycation did not modify the alpha2beta1 integrin on keratinocytes, it is suggested that glycation may diminish the binding capacity of type I collagen.  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