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   1749篇
  免费   68篇
  国内免费   12篇
耳鼻咽喉   45篇
儿科学   25篇
妇产科学   25篇
基础医学   177篇
口腔科学   29篇
临床医学   116篇
内科学   665篇
皮肤病学   7篇
神经病学   127篇
特种医学   69篇
外科学   254篇
综合类   4篇
预防医学   72篇
眼科学   13篇
药学   78篇
中国医学   1篇
肿瘤学   122篇
  2023年   23篇
  2022年   30篇
  2021年   62篇
  2020年   31篇
  2019年   43篇
  2018年   39篇
  2017年   26篇
  2016年   24篇
  2015年   24篇
  2014年   30篇
  2013年   42篇
  2012年   69篇
  2011年   68篇
  2010年   42篇
  2009年   26篇
  2008年   53篇
  2007年   55篇
  2006年   65篇
  2005年   49篇
  2004年   58篇
  2003年   64篇
  2002年   76篇
  2001年   78篇
  2000年   77篇
  1999年   65篇
  1998年   27篇
  1997年   15篇
  1996年   16篇
  1994年   15篇
  1993年   10篇
  1992年   47篇
  1991年   53篇
  1990年   47篇
  1989年   36篇
  1988年   29篇
  1987年   42篇
  1986年   19篇
  1985年   30篇
  1984年   26篇
  1983年   17篇
  1982年   11篇
  1981年   13篇
  1980年   11篇
  1979年   22篇
  1978年   12篇
  1977年   11篇
  1975年   10篇
  1974年   11篇
  1973年   12篇
  1969年   9篇
排序方式: 共有1829条查询结果,搜索用时 15 毫秒
21.
To clarify the role of the Fas-Fas ligand (FasL) system in the peripheral blood from patients with various renal diseases, the Fas and FasL expression on mononuclear cells (MNCs) and serum levels of soluble Fas (sFas) and soluble FasL were investigated. Patients were selected from those with various types of glomerular diseases showing various degrees of renal function. Fas expression on MNCs was analyzed by a FACScan, sFas and soluble FasL were measured with an ELISA kit, and FasL expression on MNCs was counted using a FACScan after a bioassay. Fas-positive MNCs and sFas increased with statistical significance concomitantly with deterioration in renal function. Moreover, there was a significant correlation between them. sFas- and FasL-positive MNCs were significantly correlated with proteinuria. However, the Fas expression percentage on MNCs and/or serum levels of sFas did not correlate with the number of TUNEL-positive cells in the glomeruli. Also, there was no disease specificity in the activation of Fas. These results indicate that Fas expression on MNCs is activated in accordance with the deterioration in renal function without disease specificity, corresponding to the elevation of serum sFas levels to protect against Fas-mediated apoptosis.  相似文献   
22.
Calpain inhibitor inhibits secretory granule maturation and secretion of GH   总被引:2,自引:0,他引:2  
Clathrin- and AP-1-coated buds are present on immature secretory granules of endocrine cells that mature into clathrin-uncoated granules. The mechanism of clathrin and adaptor protein uncoating has remained obscure. Benzyloxycarbonyl-L-leucyl-L-leucinal (ZLLal), a calpain inhibitor, reduced growth hormone (GH) secretion with intracellular accumulation, in a GH-secreting rat pituitary tumor cell. Pulse and chase demonstrated that ZLLal retarded the turnover of clathrin (Clt.H) and adaptins. ZLLal-treatment co-immunoprecipitated the increased amounts of GH with Clt.H and adaptins compared to control cells, suggesting the intracellular accumulation of immature secretory granules. Clt.H and adaptins were limited-proteolyzed by m-calpain in vitro, indicating that calpain may be involved partly in the maturation of secretory granules in endocrine cells via the process of clathrin uncoating.  相似文献   
23.
BackgroundAlveolar air leakage from a pleural defect around the staple line is one of the complications after wedge resection of the lung. An intraoperative closure of the pleural defect by suturing can cause additional pleural rupture due to tension of the pleura adjacent to staple lines. Therefore, we have introduced a novel closure method for pleural defect adjacent to the staple line, named the double stapling method. This study compared the efficacy of two closure methods; the double stapling method and conventional suturing method with pledgets using ex vivo porcine lungs.MethodsThe double stapling method involves closing the pleural defect by suturing the two parallel staple lines at both sides of the pleural defect. This method was developed to distribute the pleural tension around the needle holes of suturing. As a model of pleural defect adjacent to the staple line after wedge resection, wedge resection of the caudal lobe of left porcine lungs was performed, and a superficial square pleural defect (10 mm × 10 mm) adjacent to the staple line was made by scalpel. The defect was closed using the following two methods: (I) suturing with pledgets (n=10); and (II) double stapling method (n=10). The lobe was inflated in water at an airway pressure of 20, 25, and 30 cmH2O; closure success or failure was judged by the absence or presence of air leakage.ResultsThe closure success was confirmed in 2 (20%) out of 10 cases in the suturing with pledgets group and 9 (90%) out of 10 in the double stapling method group (P=0.007). In 4 out of 10 cases in the suturing with pledgets group, new pleural clefts longer than 3 mm were created around the needle holes of suturing.ConclusionsEx vivo experiments have suggested the superiority of the double stapling method for the intraoperative closure of alveolar air leakage adjacent to the staple line after wedge resection, compared to conventional suturing with the pledget method.  相似文献   
24.
Vasospasm, initial neurological damage, rebleeding, and periprocedural complications are associated prognostic factors for clinical outcomes after aneurysmal subarachnoid hemorrhage (SAH). In this study, factors related to delayed ischemic neurological deficit (DIND) are evaluated using data from our institute for the last 18 years. Data from 2001 to 2018 of patients with aneurysmal SAH who underwent surgical clipping (SC) or endovascular coiling (EC) within 7 days of onset were retrospectively analyzed. Cases of mortality within 5 days after treatment were excluded. Multivariate analysis was used to identify the risk factors for DIND. In total, 840 cases of SAH were assessed; among these cases, 384 (45.7%) and 456 (54.3%) were treated with SC and EC, respectively. The frequency of DIND in the EC group was significantly less than that in the SC group (11.8% vs. 17.7%; p = 0.016). In the results of multivariate analysis, internal carotid artery (ICA) aneurysm and hemorrhagic complications were the risk factors for DIND. Cilostazol administration and EC were significant factors for vasospasm prevention after aneurysmal SAH (odds ratio of ICA aneurysm: 1.59, hemorrhagic complications: 1.76, SC: 1.51, and cilostazol administration: 0.51, respectively). Cilostazol administration was also a significant factor in patients who were treated with EC. ICA aneurysm, treatment strategy, hemorrhagic complications, and cilostazol administration were associated with DIND. Oral administration of cilostazol and avoiding hemorrhagic complications were effective in DIND prevention. If both treatments are available for ruptured aneurysms, clinicians should choose EC on the basis of its ability to prevent DIND.  相似文献   
25.
Gamma-aminobutyric acid (GABA) is present in the mammalian brain as the main inhibitory neurotransmitter and in foods. It is widely used as a supplement that regulates brain function through stress-reducing and sleep-enhancing effects. However, its underlying mechanisms remain poorly understood, as it is reportedly unable to cross the blood–brain barrier. Here, we explored whether a single peroral administration of GABA affects feeding behavior as an evaluation of brain function and the involvement of vagal afferent nerves. Peroral GABA at 20 and 200 mg/kg immediately before refeeding suppressed short-term food intake without aversive behaviors in mice. However, GABA administration 30 min before refeeding demonstrated no effects. A rise in circulating GABA concentrations by the peroral administration of 200 mg/kg GABA was similar to that by the intraperitoneal injection of 20 mg/kg GABA, which did not alter feeding. The feeding suppression by peroral GABA was blunted by the denervation of vagal afferents. Unexpectedly, peroral GABA alone did not alter vagal afferent activities histologically. The coadministration of a liquid diet and GABA potentiated the postprandial activation of vagal afferents, thereby enhancing postprandial satiation. In conclusion, dietary GABA activates vagal afferents in collaboration with meals or meal-evoked factors and regulates brain function including feeding behavior.  相似文献   
26.
Open in a separate window OBJECTIVESTotal arch replacement (TAR) using an endovascular approach has been initially introduced as the frozen elephant trunk technique (FET). In our institute, TAR using the FET with Frozenix has been used as the first-line treatment for distal aortic arch aneurysms since 2014. This study aimed to evaluate the early and long-term outcomes and demonstrate the efficacy of this procedure.METHODSBetween 2014 and 2021, 121 consecutive patients were treated with TAR using the FET with Frozenix for distal aortic arch aneurysms. Early and long-term outcomes were retrospectively analysed.RESULTSThe 30-day mortality rate was 2.5% (3/121). Of postoperative complications, paraplegia due to spinal cord injury occurred in 2 (1.7%) patients, stroke in 12 (9.9%) and acute renal failure in 10 (8.3%). At follow-up, 23 secondary aortic interventions were required and 8 (6.6%) patients underwent intended secondary thoracic endovascular aortic repair for residual descending aortic aneurysm. Late and aortic-related deaths occurred in 16 (13.2%) and 4 (3.3%) patients, respectively. The overall long-term survival rates at 1, 3 and 5 years were 87.6%, 83.1% and 65.4%, respectively, while the rates of freedom from aortic-related death at 1, 3 and 5 years were 95.7%, 95.7% and 84.8%, respectively.CONCLUSIONSTAR using the FET with Frozenix for distal aortic arch aneurysms has acceptable early mortality and morbidity. Spinal cord injury and paraplegia occur less frequently than previously reported. The technique has satisfactory long-term survival and freedom from aortic-related death.  相似文献   
27.
Objective Peripherally inserted central catheters (PICCs) are widely used in patients with hematologic malignancies. However, the risks of PICC-related complications during chemotherapy for acute myeloid leukemia (AML) are not fully understood. Methods We conducted a retrospective review of 128 adult patients with AML who received induction therapy by way of PICC insertion between 2012 and 2019. Results The median duration of PICC insertion was 30 days. The incidence rate of catheter-related bloodstream infection (CRBSI) was 2.4% at 30 days, and women were more likely to suffer from CRBSI than men. Local reactions at the insertion site were observed in 56 patients; however, these events did not predict CRBSI. The incidence rates of catheter-related thrombosis (CRT) were 1.6% at 30 days. Obesity put patients at an increased risk for CRT. Unexpected PICC removal occurred in 59 patients, and women were at a higher risk of catheter removal than men. Conclusion Low PICC-related complication rates, possibly associated with high rates of catheter removal, were observed during intensive chemotherapy for AML. Women and obese patients require careful monitoring of their PICC. Procedures to achieve appropriate PICC removal without increasing the complication rate need to be considered.  相似文献   
28.
OBJECTIVES: The aim of this study is to evaluate the usefulness of gastroesophageal reflux (GER) scintigraphy using the knee-chest (KC) position for the diagnosis of gastroesophageal reflux disease (GERD). METHODS: The study subjects were 37 patients with GERD and 8 healthy volunteers (control group). Endoscopically observed esophageal mucosal breaks were evaluated with the Los Angeles classification. For GER scintigraphy, the subjects ingested liquid yogurt labeled with 99mTc-diethylene triamine pentaacetic acid (99mTc-DTPA) and water. Imaging was performed in the supine and KC position, and GER was graded as 1-4 according to the extent of GER assessed by scintigraphy. RESULTS: GER scintigraphy revealed no reflux in the control group (specificity: 100%). In the supine position, gastroesophageal reflux was observed in 49% of the patients with GERD, compared to 76% in the KC position. 21 of 23 (91%) patients with erosive esophagitis were shown to have GER with scintigraphy. GER scintigraphy revealed severe reflux (grade 3 or 4) (83%, 10/12) in the patients who had severe mucosal breaks (LA grade C or D). GER scintigraphy detected grade 1 or 2 reflux in 7 of the 14 patients who were endoscopically negative. There was a correlation between the endoscopically determined severity of mucosa and the reflux grade which was determined with GER scintigraphy. CONCLUSION: GER scintigraphy can detect gastroesophageal reflux with a high sensitivity in the KC position and might be a useful method in the screening and assessment of the severity of this disease. This method would be useful for the diagnosis of GERD in endoscopically negative patients.  相似文献   
29.
30.

Background and Aims

Sodium-dependent glucose transporter-2 (SGLT-2) inhibitors, which are anti-diabetic drugs, reportedly decrease the incidence of cardiovascular events in high-risk patients with cardiovascular diseases, and thus chronic heart failure (CHF). SGLT-2 inhibitors also decrease albuminuria in patients with type 2 diabetes mellitus (T2D). Since albuminuria is a biomarker of not only chronic kidney disease but also cardiovascular events, we hypothesized that, among T2D patients with CHF, SGLT-2 inhibitors will decrease the extent of albuminuria and also improve CHF concomitantly.

Methods

DAPPER (UMIN000025102) is a multicenter, randomized, open-labeled, parallel-group, standard treatment-controlled study, which is designed to evaluate whether dapagliflozin, one of the SGLT-2 inhibitors, decreases albuminuria in T2D patients with CHF and exerts cardioprotective effects on the failing heart. The patients are randomized to either of the dapagliflozin (5 or 10 mg, once daily orally) or control group (administration of anti-diabetic drugs administered other than SGLT 2 inhibitors). The estimated number of patients that need to be enrolled is 446 in total (223 in each group). The primary objective is the changes in the urinary albumin-to-creatinine ratio from the baseline after 2-year treatment. The key secondary objectives are (1) the safety of dapagliflozin and (2) the cardiovascular and renal efficacies of dapagliflozin.

Conclusion and Perspectives

DAPPER study investigates whether dapagliflozin decreases albuminuria and exerts beneficial effects on the failing heart in T2D patients. (UMIN000025102).
  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