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   45972篇
  免费   2623篇
  国内免费   427篇
耳鼻咽喉   724篇
儿科学   1773篇
妇产科学   723篇
基础医学   5907篇
口腔科学   1001篇
临床医学   3368篇
内科学   10463篇
皮肤病学   1359篇
神经病学   3533篇
特种医学   1342篇
外国民族医学   1篇
外科学   6038篇
综合类   1251篇
现状与发展   4篇
一般理论   17篇
预防医学   3994篇
眼科学   1319篇
药学   3026篇
  8篇
中国医学   599篇
肿瘤学   2572篇
  2024年   69篇
  2023年   386篇
  2022年   482篇
  2021年   1318篇
  2020年   745篇
  2019年   1365篇
  2018年   2095篇
  2017年   1302篇
  2016年   1145篇
  2015年   1064篇
  2014年   1272篇
  2013年   2025篇
  2012年   3481篇
  2011年   3976篇
  2010年   1908篇
  2009年   1149篇
  2008年   2931篇
  2007年   3014篇
  2006年   2736篇
  2005年   2812篇
  2004年   2513篇
  2003年   2435篇
  2002年   2185篇
  2001年   1500篇
  2000年   1934篇
  1999年   1058篇
  1998年   296篇
  1997年   206篇
  1996年   187篇
  1995年   172篇
  1994年   133篇
  1993年   114篇
  1992年   95篇
  1991年   94篇
  1990年   77篇
  1989年   80篇
  1988年   73篇
  1987年   49篇
  1986年   49篇
  1985年   67篇
  1984年   53篇
  1983年   45篇
  1982年   39篇
  1981年   34篇
  1980年   37篇
  1978年   30篇
  1977年   18篇
  1975年   23篇
  1974年   20篇
  1973年   18篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.

Background

Since recent reports have shown that (-)-Epigallocatechin-3-gallate (EGCG) could be used for treating proliferative and inflammatory disorders, we explored its use for the management of corneal chemical burns.

Materials and methods

Initially, EGCG was assayed on the rabbit corneal epithelial cell line RCE1(5T5) to establish the best testing conditions, and to avoid unwanted outcomes in the experimental animals. Then, we studied its effects on cell proliferation, cell cycle progression and cell differentiation. Afterwards, we instilled EGCG in experimental grade II corneal alkali burns in mice, three times a day up to 21 days, and evaluated by slit lamp examination and histological sections of corneal epithelial, corneal endothelial and stromal edema, as well as the presence of inflammatory cells and neovascularization.

Results

EGCG reduced cell growth and led to a decline in the proportion of proliferative cells in a concentration dependent manner. At 10 μM, EGCG promoted cell differentiation, an effect not related with apoptosis or cytotoxicity. When 10 μM EGCG was instilled in corneal alkali burns in mice three times a day up to 21 days, EGCG significantly reduced corneal opacity and neovascularization. The improved clinical appearance of the cornea was associated to a controlled epithelial growth; epithelial morphology was similar to that observed in normal epithelium and contrasted with the hyperproliferative, desquamating epithelium observed in control burn wounds. EGCG reduced corneal, stromal and endothelial edema, and wound inflammation.

Conclusion

This work constitutes the first evidence for the use of EGCG in the acute phase of a corneal alkali burn, representing a possible novel alternative to improve patient outcomes as an add-on therapy.  相似文献   
2.
ABSTRACT

This study closely examines 51 breast cancer narratives Latina and Spanish women wrote for other patients to illuminate how they conceptualize their health, with insights for addressing health disparities. Using discourse analysis of the role of language and culture in health care communication, this study focuses on the use of metaphors in the narratives. This provides revelations about the cultural and linguistic aspects of how the writers conceptualize their disease. Building on past research on metaphor use in cancer discourse in the English language, this study reveals the prevalence of metaphors comparing cancer to combat, or more generally, violence (e.g., “my battle against cancer”), or a journey (e.g., “my path with cancer”). Writers used this metaphorical language to offer advice to others with cancer and to mark their membership in a larger community of people with cancer. We also find that Spanish women use metaphors more frequently than Latinas and that they differed in their metaphorical portrayals of cancer. This research uncovers culturally embedded themes that are central to how women with cancer think about the disease, such as the prominence of spirituality in Latinas’ metaphorical constructions, a pattern not evident in Spanish women’s narratives.  相似文献   
3.
Purpose

Robotic approaches have been steadily replacing laparoscopic approaches in metabolic and bariatric surgeries (MBS); however, their superiority has not been rigorously evaluated. The main goal of the study was to evaluate the 5-year utilization trends of robotic MBS and to compare to laparoscopic outcomes.

Methods

Retrospective analysis of 2015–2019 MBSAQIP data. Kruskal-Wallis test/Wilcoxon and Fisher’s exact/chi-square were used to compare continuous and categorical variables, respectively. Generalized linear models were used to compare surgery outcomes.

Results

The use of robotic MBS increased from 6.2% in 2015 to 13.5% in 2019 (N= 775,258). Robotic MBS patients had significantly higher age, BMI, and likelihood of 12 diseases compared to laparoscopic patients. After adjustment, robotic MBS patients showed higher 30-day interventions and 30-day readmissions alongside longer surgery time (26–38 min).

Conclusion

Robotic MBS shows higher intervention and readmission even after controlling for cofounding variables.

Graphical Abstract
  相似文献   
4.
The effect of proteases inhibitors, epsilon-amino-caproic acid and gordox, on reproduction of rotavirus SA-11 in MA-104 cells was studied by enzyme immunoassay. These inhibitors were shown to exert an inhibiting effect on rotavirus reproduction.  相似文献   
5.
Graft-versus-host disease (GvHD), a major complication of allogeneic bone marrow transplantation, has been ascribed to mature T cells in the graft. Because T cells play an important role in engraftment of the bone marrow and decrease the probability of relapse of leukemia, a treatment strategy was developed to preserve the benefits of T cells in the graft and to control the severe complications of GvHD. This can be accomplished by the genetic modification of donor T cells with a suicide gene that allows their selective in vivo elimination and subsequently the abrogation of GvHD. For clinical benefit the alloreactivity of herpes simplex virus thymidine kinase (HSV-TK) gene-transduced T cells should be retained. Therefore, we investigated the influence of gene transduction and the selection procedure on T cells. We demonstrated that activation and culturing of T cells reduce their capacity to induce lethal GvHD in an allogeneic rat bone marrow transplantation model. Furthermore, positive immunomagnetic selection of gene-transduced T cells resulted in loss of the GvHD-inducing capacity of HSV-TK(+) T cells directly after MACS (magnetic cell sorting) selection; this loss could be recovered by a 1-day expansion of the selected T cells. No effect on alloreactivity was observed to be caused by the gene transduction procedure. Our study resulted in the development of an optimized culture and gene transduction protocol with preservation of T cell alloreactivity. Treatment of transplanted rats with ganciclovir resulted in a rapid reduction in the number of HSV-TK(+) T cells in the peripheral blood and in increased survival of the animals.  相似文献   
6.
Salmon calcitonin (SCT) is a well-tolerated peptide drug with a wide therapeutic margin and is administered parenterally for long-term treatments of bone diseases. Its clinical usefulness would be enhanced by the development of an orally active formulation. In this randomized crossover double-blinded phase I trial, controlled by both a placebo and a parenteral verum, we have tested a new oral formulation of SCT associated with a caprylic acid derivative as carrier. Eight healthy volunteers received single doses of 400, 800, and 1200 microg of SCT orally, a placebo, and a 10-microg (50 IU) SCT intravenous infusion. SCT was reliably absorbed from the oral formulation, with an absolute bioavailability of 0.5-1.4%, depending on the dose. It induced a marked, dose-dependent drop in blood and urine C-terminal telopeptide of type I collagen (CTX), a sensitive and specific bone resorption marker, with the effects of 1200 microg exceeding those of 10 microg intravenously. It also decreased blood calcium and phosphate, and increased the circulating levels of parathyroid hormone (PTH) and, transiently, the urinary excretion of calcium. It was well-tolerated, with some subjects presenting mild and transient nausea, abdominal cramps, diarrheic stools, and headaches. This study shows that oral delivery of SCT is feasible with reproducible absorption and systemic biological efficacy. Such an oral formulation could facilitate the use of SCT in the treatment of osteoporosis and other bone diseases.  相似文献   
7.
成人成骨细胞与珊瑚羟基磷灰石的体外生物相容性   总被引:13,自引:2,他引:11  
目的:研究成人骨髓成骨细胞与珊瑚羟基磷灰石(carolline hydroxyapatite,CHA)在体外培养条件下的生物相容性。方法:抽取健康成人骨髓组织,置于含体积分数为10%胎牛血清的DMEM培养基中培养,传代后改用含地塞米松、β-甘油磷酸钠和维生素C的条件培养基培养,分为CHA复合细胞组和单纯细胞组,不同时间用倒置相关显微镜,HE染色光镜及扫描电镜观察,MTT法进行细胞增殖测定,并进行细胞微量蛋白含量和碱性磷酸酶的定量检测,结果:成人骨髓成骨细胞体外培养时复合或不复合CHA均生长良好,表现出典型成骨细胞的形态特征和生物学特性,CHA利于细胞的贴附,生长与增殖,并对细胞的功能无不良影响,结论:CHA是较理想的骨组织工程支架材料,成骨细胞复合CHA用于骨缺损的修复,具有广阔的临床应用前景。  相似文献   
8.
9.
PurposeTo analyze the electroclinical features, aetiology and outcome in patients with normal neurological examination and psychomotor development who presented seizures during a mild gastroenteritis (MG).Patients and methodsEvaluation of the clinical charts of 22 patients who were assessed in the Neurology Department, Hospital Nacional de Pediatría Prof. Dr. JP Garrahan between 1999 and 2007.ResultsTwelve patients were boys and 10 were girls, the age of onset ranged from 5 to 26 months, and the median age was 10 months. Rotavirus antigen test in stool was positive in 9 of 18 studied patients. The seizures were brief, focal with secondary generalization in 15 patients (68.5%), apparently generalized in 5 (22.5%) and focal in two (9%). Seven of the patients (35%) had more than one seizure in 24 h. The interictal EEG was normal in all patients. Neuroradiological studies were performed in 19 patients with a normal result. No patient was put on long-term treatment with antiepileptic drugs. Four patients had subsequent mild gastroenteritis and two of them presented convulsions during the disease. After between 12 and 67 months of follow-up, all patients had normal psychomotor development and neurological examination.ConclusionsIn this study we confirmed the association of benign infantile seizures (BIS) and MG with or without rotavirus. The identification of this entity allows avoiding unnecessary complementary studies and treatment with antiepileptic drugs.  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