全文获取类型
收费全文 | 46811篇 |
免费 | 3188篇 |
国内免费 | 1259篇 |
专业分类
耳鼻咽喉 | 631篇 |
儿科学 | 586篇 |
妇产科学 | 598篇 |
基础医学 | 7321篇 |
口腔科学 | 706篇 |
临床医学 | 4507篇 |
内科学 | 8103篇 |
皮肤病学 | 1447篇 |
神经病学 | 3436篇 |
特种医学 | 2621篇 |
外国民族医学 | 5篇 |
外科学 | 5627篇 |
综合类 | 2542篇 |
现状与发展 | 7篇 |
一般理论 | 11篇 |
预防医学 | 2334篇 |
眼科学 | 1260篇 |
药学 | 4434篇 |
15篇 | |
中国医学 | 1219篇 |
肿瘤学 | 3848篇 |
出版年
2024年 | 73篇 |
2023年 | 514篇 |
2022年 | 1438篇 |
2021年 | 1987篇 |
2020年 | 1157篇 |
2019年 | 1337篇 |
2018年 | 1544篇 |
2017年 | 1229篇 |
2016年 | 1662篇 |
2015年 | 2287篇 |
2014年 | 2721篇 |
2013年 | 2957篇 |
2012年 | 4204篇 |
2011年 | 4195篇 |
2010年 | 2538篇 |
2009年 | 2089篇 |
2008年 | 2757篇 |
2007年 | 2626篇 |
2006年 | 2293篇 |
2005年 | 2180篇 |
2004年 | 1679篇 |
2003年 | 1434篇 |
2002年 | 1228篇 |
2001年 | 865篇 |
2000年 | 860篇 |
1999年 | 672篇 |
1998年 | 322篇 |
1997年 | 276篇 |
1996年 | 194篇 |
1995年 | 193篇 |
1994年 | 160篇 |
1993年 | 119篇 |
1992年 | 201篇 |
1991年 | 197篇 |
1990年 | 169篇 |
1989年 | 131篇 |
1988年 | 105篇 |
1987年 | 103篇 |
1986年 | 81篇 |
1985年 | 56篇 |
1984年 | 52篇 |
1983年 | 48篇 |
1982年 | 40篇 |
1981年 | 32篇 |
1980年 | 29篇 |
1979年 | 38篇 |
1978年 | 27篇 |
1977年 | 21篇 |
1974年 | 21篇 |
1973年 | 16篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
901.
Hae Won Jung 《Medicine》2021,100(20)
Introduction:When a cancer patient presents with ST-segment elevation on an electrocardiogram (ECG), several causes including acute myocardial infarction (MI) should be considered. Myocardial metastasis is one of the rare causes of ST-segment elevation in cancer patients and its clinical silence makes it difficult to diagnose.Patient concerns:A 78-year-old man with lung cancer presented to the emergency room for chest pain. ECG revealed ST-segment elevation in inferior and lateral leads.Interventions:After emergent coronary angiography, percutaneous coronary intervention (PCI) on proximal right coronary artery was performed.Outcomes:Even 7 days after PCI, ST-segment elevation in inferior and lateral leads still existed. Cardiac markers continued to be within the normal range.Diagnosis:We found evidence of metastasis of lung cancer on the inferolateral wall of the myocardium by trans thoracic echocardiogram and positron emission tomography (PET)/computed tomography (CT). We diagnosed myocardial metastasis as the cause of ST-segment elevation in the patient.Conclusion:Myocardial metastasis is one of the differential diagnosis of ST-segment elevation in cancer patients. Periodic ECG is necessary for lung cancer patients and rapid cardiac work-up is recommended when ST-segment elevation is newly discovered. 相似文献
902.
Hwan Hee Lee Seulki Lee Kanghyo Lee Yu Su Shin Hyojeung Kang Hyosun Cho 《Daru : journal of Faculty of Pharmacy, Tehran University of Medical Sciences》2015,23(1)
Background
Cordyceps militaris has been used as a traditional medicine in Asian countries for a long time. Different types of Cordyceps extract were reported to have various pharmacological activities including an anti-cancer effect. We investigated the inhibitory effect of Cordyceps militaris ethanol extract on a human colorectal cancer-derived cell line, RKO.Methods
RKO cells were treated with various concentrations of nucleosides-enriched ethanol extract of Cordyceps militaris for 48 h and cytotoxicity was measured using a CCK-8 assay. Then, xenograft Balb/c nude mice were injected with RKO cells and subsequently orally administered with ethanol extract of Cordyceps militaris every day for 3 weeks to examine the inhibitory effect on tumor growth. Lastly, the effect of Cordyceps militaris on cell cycle as well as apoptosis was measured using flow cytometry. Also, the expression of p53, caspase 9, cleaved caspase-3, cleaved PARP, Bim, Bax, Bak, and Bad were detected using western blot assay.Results
RKO cells were highly susceptible to the ethanol extract of Cordyceps militaris (CME) and the growth of RKO cells-derived tumor was significantly delayed by the treatment of Cordyceps militaris. Cordyceps militaris induced cell cycle arrest in G2/M phase (untreated; 20.5 %, CME 100 μg/ml; 61.67 %, CME 300 μg/ml; 66.33 %) and increased early apoptosis (untreated; 1.01 %, CME 100 μg/ml; 8.48 %, CME 300 μg/ml; 18.07 %). The expression of p53, cleaved caspase 9, cleaved caspase-3, cleaved PARP, Bim, Bak, and Bad were upregulated by the treatment of Cordyceps militaris.Conclusion
Ethanol extract of Cordyceps militaris was highly cytotoxic to human colorectal carcinoma RKO cells and inhibited the growth of tumor in xenograft model. The anti-tumor effect of Cordyceps militaris was associated with an induction of cell cycle arrest and mitochondrial-mediated apoptosis. 相似文献903.
The central cholinergic system has been implicated in the pathophysiology of mood disorders. An imbalance in central cholinergic neurotransmitter activity has been proposed to contribute to the manic and depressive episodes typical of these disorders. Neuropharmacological studies into the effects of cholinergic agonists and antagonists on mood state have provided considerable support for this hypothesis. Furthermore, recent clinical studies have shown that the pan-CHRM antagonist, scopolamine, produces rapid-acting antidepressant effects in individuals with either major depressive disorder (MDD) or bipolar disorder (BPD), such as bipolar depression, contrasting the delayed therapeutic response of conventional mood stabilisers and antidepressants. This review presents recent data from neuroimaging, post-mortem and genetic studies supporting the involvement of muscarinic cholinergic receptors (CHRMs), particularly CHRM2, in the pathophysiology of MDD and BPD. Thus, novel drugs that selectively target CHRMs with negligible effects in the peripheral nervous system might produce more rapid and robust clinical improvement in patients with BPD and MDD. 相似文献
904.
Jung-min Kim Kyoung-pil Lee Soo-jin Park Saeromi Kang Jin Huang Jung-min Lee Koichi Sato Hae-young Chung Fumikazu Okajima Dong-soon Im 《Acta pharmacologica Sinica》2015,36(7):813-820
Aim:
Free fatty acid receptor 4 (FFA4; formerly known as GPR120) is the G protein-coupled receptor (GPCR) for omega-3 polyunsaturated fatty acids. FFA4 has been found to express in the small intestines and colons of mice and humans. In this study we investigate the effects of omega-3 polyunsaturated fatty acids on FFA4 in human colon epithelial cells in vitro.Methods:
HCT116 and HT-29 human colon epithelial cell lines endogenously expressing FFA4 were used. Intracellular Ca2+ concentration ([Ca2+]i) was measured in fura 2-AM-loaded cells with fluorescence spectrophotometry. RT-PCR and immunohistochemistry were used to detect FFA4.Results:
Ten to 100 μmol/L of omega-3 polyunsaturated fatty acids α-linolenic acid (αLA) or eicosapentaenoic acid (EPA) induced dose-dependent [Ca2+]i increase in HCT116 and HT-29 cells, whereas docosahexaenoic acid (DHA) had no effect. In addition, the omega-6 fatty acids linoleic acid and γ-linoleic acid also dose-dependently increase [Ca2+]i, but the mono-unsaturated fatty acid oleic acid and saturated fatty acids such as stearic acid and palmitic acid had no effect. In HCT116 and HT-29 cells, the αLA-induced [Ca2+]i increase was partially inhibited by pretreatment with EGTA, phospholipase C inhibitor edelfosine, cADPR inhibitors 8-bro-cADPR or DAB, and abolished by pretreatment with Ca2+ATPase inhibitor thapsigargin, but was not affected by Gi/o protein inhibitor PTX or IP3R inhibitor 2-APB.Conclusion:
Omega-3 and omega-6 long-chain polyunsaturated fatty acids (C18-20) induce Ca2+ mobilization responses in human colonic epithelial cells in vitro through activation of FFA4 and PTX-insensitive Gi/o protein, followed by Ca2+ release from thapsigargin-sensitive Ca2+ stores and Ca2+ influx across the plasma membrane. 相似文献905.
Alteration of brain connectivity in neurologically asymptomatic patients with chronic kidney disease
Yoo Jin Lee Eunjae Yoon Sihyung Park Yang Wook Kim Si Eun Kim Junghae Ko Jin Han Park Kang Min Park Il Hwan Kim Bong Soo Park 《Medicine》2021,100(16)
Our previous study demonstrated that patients with end-stage renal disease had decreased structural and functional brain connectivity, and there was a significant association between brain connectivity and cognitive function. The aim of this study was to evaluate the alterations of structural and functional connectivity using graph theoretical analysis in neurologically asymptomatic patients with relatively early-stage chronic kidney disease (CKD).We enrolled 18 neurologically asymptomatic patients with early CKD and 28 healthy controls. All the subjects underwent diffusion-tension imaging and resting functional magnetic resonance imaging. We calculated structural and functional connectivity based on diffusion-tension imaging and resting functional magnetic resonance imaging using a graph theoretical analysis. Then, we investigated differences of structural and functional connectivity between the CKD patients and the healthy controls.All the measures of structural connectivity were significantly different between the patients with CKD and healthy controls. The global efficiency, local efficiency, mean clustering coefficient, and small-worldness index were decreased, whereas the characteristic path length was increased in the patients with CKD compared with healthy controls. The structural betweenness centrality of the left calcarine and right posterior cingulum was also significantly different from that in healthy participants. However, all the measures of global functional connectivity in patients with CKD were not different from those in healthy controls. In patients with CKD, the functional betweenness centrality of the right insular cortex, right occipital pole, and right thalamus was significantly different from that in healthy participants.There are significant alterations of the global structural connectivity between the patients with CKD and the healthy subjects, whereas the global functional connectivity of the brain network is preserved. We find that the efficiency of the structural brain network is decreased in the patients with CKD. 相似文献
906.
Kyoungwon Jung Il Hyeong Choe Moo In Park Seun Ja Park Won Moon Sung Eun Kim Jae Hyun Kim Kwang Il Seo 《Medicine》2021,100(7)
Malignant gastric lymphoma (MGL) accounts for a small proportion (upto 5%) of gastric malignancies. However, unlike for advanced gastric cancer (AGC) that requires surgical treatment, the standard treatments for MGL are chemotherapy and radiotherapy. Hence, the initial impression of the endoscopist is critical for the differential diagnosis and for planning future treatment. The purpose of this study was to assess the endoscopic diagnostic accuracy and the possibility of distinguishing between AGC and MGL depending on the endoscopist''s experience.A total of 48 patients who had MGL, and 48 age and sex-matched patients who had AGC were assessed by endoscopic review at a tertiary referral hospital between June 2008 and February 2017. Two endoscopic specialists reviewed the endoscopic findings and divided these diagnoses into 5 groups: Borrmann type (1, 2, 3, and 4) and early gastric cancer-like type. After this, 7 experts and 8 trainees were asked to complete a quiz that was comprised of 6 images for each of the 96 cases and to provide an endoscopic diagnosis for each case. The test results were analyzed to assess the diagnostic accuracy according to the pathologic results, endoscopic subgroups, and endoscopists’ experience. For inter-observer agreement was calculated with Fleiss kappa values.The overall diagnostic accuracy of endoscopic findings by the experts was 0.604 and that by the trainees was 0.493 (P = .050). There was no significant difference in the diagnosis according to the final pathology (lymphoma cases, 0.518 vs 0.440, P = .378; AGC cases, 0.690 vs 0.547, P = .089, respectively). In the subgroup analysis, the experts showed significantly higher diagnostic accuracy for the endoscopic Borrmann type 4 subgroup, including lymphoma or AGC cases, than the trainees (P = .001). Inter-observer agreement of final diagnosis (Fleiss kappa, 0.174) and endoscopic classification groups (Fleiss kappa, 0.123–0.271) was slightly and fair agreement.The experts tended to have a higher endoscopic diagnostic accuracy. Distinguishing MGL from AGC based on endoscopic findings is difficult, especially for the beginners. Even if the endoscopic impression is AGC, it is important to consider MGL in the differential diagnosis. 相似文献
907.
Introduction: Hepatitis B virus (HBV) reactivation after ‘resolved’ infection can occur in the setting of immunosuppression, including iatrogenically induced by anti-CD20 antibodies. The presence of antibodies against the HBV core antigen (anti-HBc) is a marker of risk for this phenomenon. The risk of this occurring in patients with circulating HBV surface antigen (HBsAg) is well characterized, but is less well characterized in patients who are HBsAg negative.
Areas covered: This article reviews the literature regarding HBV reactivation in the context of rituximab therapy. We have limited our review to HBsAg-negative patients, and clinical outcomes following HBV reactivation.
Expert opinion: We have recommended prophylactic anti-viral therapy for all HBsAg-negative/anti-HBc-positive patients undergoing rituximab therapy in combination with other immunosuppressive therapy. 相似文献
908.
Jin Hee Ahn Ji Seon Jeong Se Hee Kang Ji Eun Yeon Eun A. Cho Gyu Sung Choi Jong Man Kim Gaab Soo Kim 《Medicine》2021,100(24)
Background:Supraglottic airway (SGA) devices do not definitively protect the airway from regurgitation of gastric contents. Increased gastric pressure and long operation time are associated with development of complications such as aspiration pneumonia. The aim of this study was to compare intragastric pressure between second-generation SGA and endotracheal tube (ETT) devices during long-duration laparoscopic hepatectomy.Methods:A total of 66 patients was randomly assigned to 2 groups; 33 patients each in the ETT and SGA groups. Intragastric pressure was continuously measured via a gastric drainage tube with a three-way stopcock connected to the pressure monitoring device. Normal saline was added to the end of the gastric drainage tube at each operation time point.Results:Intragastric pressure during pneumoperitoneum was no different between the 2 groups (P = .146) or over time (P = .094). The mean (standard deviation [SD]) pH of the SGA tip measured after operation was 6.7 (0.4), and a pH <4 was not observed. Relative risk of postoperative complications was significantly higher in the ETT group relative to the SGA group (sore throat, 5.5; cough,13.0).Conclusions:Use of SGA devices does not further increase intragastric pressure, even during prolonged upper abdominal laparoscopic surgery. Also, the frequency of postoperative sore throat and cough was significantly lower when the second-generation SGA device was used. 相似文献
909.
Kim Eun Soo Kim Kyeong Ok Jang Byung Ik Kim Eun Young Lee Yoo Jin Lee Hyun Seok Lee Joon Seop Kim Sung Kook Jung Yun Jin Kang Sang-Bum Agrawal Manasi Ungaro Ryan Colombel Jean-Frederic 《Digestive diseases and sciences》2022,67(7):2866-2875
Digestive Diseases and Sciences - Colectomy risk after acute severe ulcerative colitis (ASUC) has not been compared between Eastern and Western countries. We compared the 1-year colectomy risk... 相似文献
910.