全文获取类型
收费全文 | 265886篇 |
免费 | 22477篇 |
国内免费 | 9978篇 |
专业分类
耳鼻咽喉 | 2014篇 |
儿科学 | 5341篇 |
妇产科学 | 2846篇 |
基础医学 | 44932篇 |
口腔科学 | 4101篇 |
临床医学 | 20125篇 |
内科学 | 50703篇 |
皮肤病学 | 4283篇 |
神经病学 | 17671篇 |
特种医学 | 5264篇 |
外国民族医学 | 62篇 |
外科学 | 17244篇 |
综合类 | 35583篇 |
现状与发展 | 36篇 |
一般理论 | 6篇 |
预防医学 | 17720篇 |
眼科学 | 2726篇 |
药学 | 35923篇 |
75篇 | |
中国医学 | 11171篇 |
肿瘤学 | 20515篇 |
出版年
2024年 | 546篇 |
2023年 | 4385篇 |
2022年 | 9219篇 |
2021年 | 12967篇 |
2020年 | 10067篇 |
2019年 | 8661篇 |
2018年 | 8407篇 |
2017年 | 8528篇 |
2016年 | 8930篇 |
2015年 | 10296篇 |
2014年 | 15955篇 |
2013年 | 17465篇 |
2012年 | 15613篇 |
2011年 | 17818篇 |
2010年 | 14638篇 |
2009年 | 14595篇 |
2008年 | 14178篇 |
2007年 | 13301篇 |
2006年 | 11923篇 |
2005年 | 10472篇 |
2004年 | 8812篇 |
2003年 | 7800篇 |
2002年 | 6239篇 |
2001年 | 5361篇 |
2000年 | 4473篇 |
1999年 | 4045篇 |
1998年 | 3702篇 |
1997年 | 3488篇 |
1996年 | 3071篇 |
1995年 | 2757篇 |
1994年 | 2542篇 |
1993年 | 2190篇 |
1992年 | 1805篇 |
1991年 | 1648篇 |
1990年 | 1383篇 |
1989年 | 1179篇 |
1988年 | 1125篇 |
1987年 | 928篇 |
1986年 | 838篇 |
1985年 | 1316篇 |
1984年 | 1152篇 |
1983年 | 804篇 |
1982年 | 825篇 |
1981年 | 648篇 |
1980年 | 538篇 |
1979年 | 444篇 |
1978年 | 306篇 |
1977年 | 245篇 |
1976年 | 242篇 |
1975年 | 138篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
171.
Sodium-glucose cotransporter-2 inhibitors (SGLT2 inhibitors) are a new type of drug for the treatment of diabetes, and they have been proven to have a good hypoglycemic effect. Several lines of clinical evidence have shown that SGLT2 inhibitors can significantly reduce the risks of atherosclerosis, hospitalization for heart failure, cardiovascular death, and all-cause mortality and delay the progression of chronic kidney disease. Because of the protective effects of SGLT2 inhibitors on the heart and kidney, they are being studied for the treatment of heart failure and chronic kidney disease in patients without diabetes. Therefore, it is necessary for cardiologists, patients with diabetes, and nephrologists to fully understand this type of drug. In this review, we summarize the following three aspects of SGLT2 inhibitors: the recent clinical evidence of their cardiovascular benefits, their mechanisms of action, and their safety. 相似文献
172.
《The Journal of emergency medicine》2020,58(5):785-796
BackgroundBacteremia causes a major worldwide burden, in terms of financial and productivity costs, as well the morbidity and mortality it can ultimately cause. Proper treatment of bacteremia is a challenge because of the species-dependent response to antibiotics. The T2Bacteria Panel is a U.S. Food and Drug Administration–cleared and culture-independent assay for detection of bacteremia, including common ESKAPE pathogens—Escherichia coli, Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa—and provides species identification in as little as 3.6 h directly from blood.ObjectiveOur aim was to evaluate the T2Bacteria assay performance and potential to affect patient care in the emergency department (ED).MethodsED patients from a Louisiana and Florida center were enrolled as part of the T2Bacteria Panel clinical study, which was prospective and noninterventional. Blood samples for blood culture (BC) and T2Bacteria were matched in time and anatomic location.ResultsData from 137 ED patients were evaluated. Relative to BC, T2Bacteria showed 100% positive percent agreement and 98.4% negative percent agreement. In addition, for species on the T2Bacteria Panel, the T2Bacteria assay detected 25% more positives associated with infection, and on average identified the infectious species 56.6 h faster. The T2Bacteria assay covered 70.5% of all species detected by BC. Finally, relative to actual care, the T2Bacteria assay could have potentially focused therapy in 8 patients, reduced time to a species-directed therapy in 4 patients, and reduced time to effective therapy in 4 patients.ConclusionsIn this ED population, the T2Bacteria assay was a rapid and sensitive detector of bacteremia from common ESKAPE pathogens and showed the theoretical potential to influence subsequent patient therapy, ranging from antibiotic de-escalation to faster time to effective therapy. 相似文献
173.
174.
175.
Yaobin Ouyang Gongmeizi Liu Wenting Xu Zhen Yang Nianshuang Li Chuan Xie Chun Zhou Jiang Chen Yin Zhu Junbo Hong Nonghua Lu 《Oncology Letters》2021,21(2)
Helicobacter pylori (H. pylori) is a main risk factor for gastric cancer (GC). Epithelial-mesenchymal transition (EMT) is involved in the development and progression of H. pylori-associated GC. However, the exact molecular mechanism of this process remains unclear. The AKT/GSK3β signaling pathway has been demonstrated to promote EMT in several types of cancer. The present study investigated whether H. pylori infection induced EMT, and promoted the development and metastasis of cancer in the normal gastric mucosa, and whether this process was dependent on AKT activation. The expression levels of the EMT-associated proteins, including E-cadherin and N-cadherin, were determined in 165 gastric mucosal samples of different disease stages by immunohistochemical analysis. The expression levels of E-cadherin, N-cadherin, AKT, phosphorylated (p-)AKT (Ser473), GSK3β and p-GSK3β (Ser9) were further determined in H. pylori-infected Mongolian gerbil gastric tissues and cells co-cultured with H. pylori by immunohistochemical analysis and western blotting. The results indicated that the expression levels of the epithelial marker E-cadherin were decreased, whereas the expression levels of the mesenchymal marker N-cadherin were increased during gastric carcinogenesis. Their expression levels were associated with H. pylori infection. Furthermore, H. pylori infection resulted in downregulation of E-cadherin expression and upregulation of N-cadherin expression in Mongolian gerbils and GES-1 cells. In addition, an investigation of the associated mechanism of action revealed that p-AKT (Ser473) and p-GSK3β (Ser9) were activated in GES-1 cells following co-culture with H. pylori. Furthermore, following pretreatment of the cells with the AKT inhibitor VIII, the expression levels of E-cadherin, N-cadherin, p-AKT and p-GSK3β did not show significant differences between GES-1 cells that were co-cultured with or without H. pylori. The levels of p-AKT and p-GSK3β were increased in H. pylori-infected Mongolian gerbils. In conclusion, the present study demonstrated that H. pylori infection activated AKT and resulted in the phosphorylation and inactivation of GSK3β, which in turn promoted early stage EMT. These effects were AKT-dependent. This mechanism may serve as a prerequisite for GC development. 相似文献
176.
《Clinical Lymphoma, Myeloma & Leukemia》2020,20(8):e461-e467
IntroductionVon Willebrand factor (vWF) cleaving protease ADAMTS-13 has a key role for maintaining normal size of vWF. A deficiency or dysfunction of vWF cleaving protease is associated with ultra large vWF multimers and thrombotic microangiopathy. Patients with cancers have reduced levels of vWF cleaving protease. In this pilot study, we have evaluated whether or not deficiencies of ADAMTS-13 were present in myelodysplastic syndromes (MDS). Moreover, we assessed if a reduction in basal levels of ADAMTS-13 may play a role in the prognosis of MDS.Patients and MethodsWe measured and compared the levels of vWF cleaving protease ADAMTS-13 in 100 patients with MDS and 35 healthy controls. Patients were divided into 2 groups according to the International Prognostic Scoring System: group I consisting of 44 patients with low-risk MDS and group II of 56 patients with high-risk MDS. Patients with high-risk and low-risk MDS presented significantly lower levels of ADAMTS-13 than controls (P < .001 and P = .0177, respectively). High-risk patients had significantly lower levels of ADAMTS-13 when compared with the low-risk group (P < .001).ResultsWe found that reduced levels of ADAMTS-13 have a relationship with overall survival (P < .001). Statistical analysis showed that ADAMTS-13 correlates with cytogenetics (P < .001) and a tendency of slight correlation with platelet count and basal levels of ADAMTS-13 (R, 0.35; P value, 0.001). Moreover, we found that levels of ADAMTS-13 have correlation with response to treatment (P < .001).ConclusionsADAMTS-13 in MDS might represent a surrogate marker of prognosis, response to therapy, or disease progression. Further studies are needed. 相似文献
177.
178.
《Clinical oncology (Royal College of Radiologists (Great Britain))》2020,32(6):347-353
The current COVID-19 pandemic presents a substantial obstacle to cancer patient care. Data from China as well as risk models suppose that cancer patients, particularly those on active, immunosuppressive therapies are at higher risks of severe infection from the illness. In addition, staff illness and restructuring of services to deal with the crisis will inevitably place treatment capacities under significant strain. These guidelines aim to expand on those provided by NHS England regarding cancer care during the coronavirus pandemic by examining the known literature and provide guidance in managing patients with urothelial and rarer urinary tract cancers. In particular, they address the estimated risk and benefits of standard treatments and consider the alternatives in the current situation. As a result, it is recommended that this guidance will help form a framework for shared decision making with patients. Moreover, they do not advise a one-size-fits-all approach but recommend continual assessment of the situation with discussion within and between centres. 相似文献
179.
180.