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   6510篇
  免费   486篇
  国内免费   31篇
耳鼻咽喉   42篇
儿科学   172篇
妇产科学   78篇
基础医学   844篇
口腔科学   131篇
临床医学   496篇
内科学   1615篇
皮肤病学   231篇
神经病学   681篇
特种医学   231篇
外科学   940篇
综合类   31篇
预防医学   222篇
眼科学   146篇
药学   500篇
中国医学   15篇
肿瘤学   652篇
  2024年   8篇
  2023年   136篇
  2022年   287篇
  2021年   527篇
  2020年   223篇
  2019年   283篇
  2018年   318篇
  2017年   237篇
  2016年   247篇
  2015年   255篇
  2014年   286篇
  2013年   325篇
  2012年   516篇
  2011年   505篇
  2010年   273篇
  2009年   209篇
  2008年   342篇
  2007年   304篇
  2006年   315篇
  2005年   279篇
  2004年   276篇
  2003年   217篇
  2002年   180篇
  2001年   74篇
  2000年   58篇
  1999年   39篇
  1998年   34篇
  1997年   31篇
  1996年   18篇
  1995年   14篇
  1994年   17篇
  1993年   18篇
  1992年   28篇
  1991年   14篇
  1990年   26篇
  1989年   15篇
  1988年   11篇
  1987年   9篇
  1986年   6篇
  1985年   6篇
  1984年   5篇
  1983年   5篇
  1982年   4篇
  1981年   6篇
  1977年   5篇
  1975年   4篇
  1974年   4篇
  1972年   4篇
  1968年   4篇
  1967年   3篇
排序方式: 共有7027条查询结果,搜索用时 15 毫秒
111.
112.
Pd nanoparticles were electrochemically immobilized on a Pt surface in the presence of sodium dodecyl sulfate (SDS) molecules to study the electrokinetics of arsenite oxidation reactions and the corresponding sensing activities. The X-ray photoelectron spectroscopy (XPS) analysis showed that on the Pt surface, Pd atoms exist as adatoms and the contents of Pd(0) and Pd(ii) were 75.72 and 24.28 at%, respectively, and the particle sizes were in the range of 61–145 nm. The experimental results revealed that the catalytic efficiency as well as the charge transfer resistance (at the redox potential of the Fe(ii)/Fe(iii) couple) increased in the order of Pt < Pt–Pd < Pt–Pdsds. A Pt–Pdsds electrode exhibited an open circuit potential (OCP) of 0.65 V in acidic conditions; however, when 50.0 mM NaAsO2 was present, the OCP value shifted to 0.42 V. It has been projected that the As(iii) oxidation proceeds using a sequential pathway: As(iii) → As(iv) → As(v). After optimization of the square wave voltammetric data, the limits of detection of As(iii) were obtained as 1.3 μg L−1 and 0.2 μg L−1 when the surface modification of the Pt surface was executed with Pd particles in the absence and presence of the SDS surfactant, respectively. Finally, real samples were analyzed with excellent recovery performance.

Amplification of true surface area can be improved when Pd particles are deposited on a substrate in the presence of sodium dodecyl sulfate (SDS) surfactant. In acidic medium, As(iii) undergoes a two-step oxidation process.  相似文献   
113.
At present, vancomycin (VCM) and metronidazole (MNZ) are used for the first-line standard treatment of Clostridioides difficile infection (CDI). However, their differential use has not been sufficiently investigated. In this study, a meta-analysis on differences in the efficacy for CDI between VCM and MNZ was performed. Reports of randomized controlled studies using VCM or MNZ to treat CDI were surveyed. Meta-analysis was performed using the Mantel-Haenszel method and random-effects model, and the risk ratio and 95% confidence interval were calculated. Excluding overlapping reports, 1043 reports were extracted and 5 randomized controlled studies were extracted. There was no difference in therapeutic effects for CDI between VCM and MNZ (RR = 1.08, 95% CI (0.99–1.17), p = 0.09, I2 = 37%). On subgroup analysis by the severity, there was no difference in the clinical effects for CDI between VCM and MNZ in non-severe cases (risk ratio: 1.09, 95% confidence interval: 1.00–1.19, p = 0.06), but the clinical effects of VCM were significantly higher than those of MNZ in severe cases (risk ratio: 1.19, 95% confidence interval: 1.02–1.39, p = 0.03). No significant difference was noted in the recurrence rate, incidence of adverse event, time to exhibit therapeutic effects, or judgment of the bacteriological effects. As the therapeutic effects of VCM were superior in severe CDI cases, VCM should be considered first in severe cases.  相似文献   
114.
Hepatic abscess in chronic granulomatous disease (CGD) is very refractory and frequently requires multiple surgeries with frequent morbidities. Although surgical interventions are often required, patients are often not able to have surgery for various reasons. We present the case of a 21-year-old man with recurrent hepatic abscess in CGD. We could not provide surgical interventions due to the lack of a fluid cavity and the patient's refusal, and therefore we administered transcatheter arterial antimicrobial and steroid therapy. He did not have any exacerbation for more than 18 months after the final transcatheter treatment. This is the first reported case of successful transcatheter arterial antimicrobial and steroid therapy for refractory hepatic abscess in CGD. Although the patient's burden and medical cost were not inconsequential, this case shows that the transcatheter arterial antimicrobial and steroid therapy may be a treatment option for patients who are not candidates for surgical interventions.  相似文献   
115.
Mycotic aneurysm is a rare but life-threatening disease that warrants an integrated therapeutic approach involving surgical intervention and prolonged antibiotic use. However, the causative organisms are often unidentified because antibiotics started empirically render blood and tissue cultures negative. Molecular diagnosis has been reported to be useful in such culture-negative cases. We report a case of a culture-negative mycotic aortic aneurysm due to Haemophilus influenzae, diagnosed by direct 16S rRNA polymerase chain reaction (PCR) and sequencing of the resected aneurysm tissue. PCR for serotype revealed type b, and PCR and sequencing of the ftsI gene revealed alterations in penicillin-binding protein 3, suggesting resistance to ampicillin. Multilocus sequence typing demonstrated that the isolate belonged to sequence type 54.  相似文献   
116.
Long-term, low-dose erythromycin monotherapy, based on the anti-inflammatory effects of macrolides, has been reported to have the potential to suppress the exacerbation of Mycobacterium avium complex (MAC) lung disease with less toxicity. It remains unclear whether erythromycin monotherapy induces cross-resistance to clarithromycin, a key drug for MAC. To clarify this point, we conducted a retrospective, single-center, case-series study on patients with MAC lung disease who underwent erythromycin monotherapy for at least 6 months. Drug susceptibility tests, before and after erythromycin treatment initiation, were analyzed. Thirty-three patients were included in our study. All 33 patients showed susceptibility to clarithromycin for MAC both before and after erythromycin monotherapy. There was no significant difference in clarithromycin minimum inhibitory concentrations between before and after erythromycin treatment (median difference = 0 μg/ml; P = .313, Wilcoxon's signed-rank test). We conclude that erythromycin monotherapy for MAC lung disease may not induce cross-resistance to clarithromycin.  相似文献   
117.

Background

Bleeding from hemorrhagic shock can be immediately controlled by blocking the proximal part of the hemorrhagic point using either resuscitative thoracotomy for aortic cross-clamping or insertion of a large-caliber (10–14Fr) resuscitative endovascular balloon occlusion of the aorta (REBOA) device via the femoral artery. However, such methods are very invasive and have various complications. With recent progress in endovascular treatment, a low-profile REBOA device (7Fr) has been developed.

Objective

The objective of this study was to report our experience of this low-profile REBOA device and to evaluate the usefulness of emergency physician?operated REBOA in life-threatening hemorrhagic shock.

Methods

Ten patients with refractory hemorrhagic shock underwent REBOA using this device via the femoral artery. All REBOA procedures were performed by emergency physicians. The success rate of the insertion, vital signs, and REBOA-related complications were evaluated.

Results

Median age was 54 years (interquartile range 33–78 years). The causes of hemorrhagic shock were trauma (n = 4; 1 blunt and 3 penetrating), ruptured abdominal aortic aneurysm (n = 3), and obstetric hemorrhage (n = 3). Two patients had cardiopulmonary arrest upon arrival. REBOA procedure was successful in all patients, and all became hemodynamically stable to undergo definitive interventions after REBOA. There were no REBOA-related complications. The mortality rate within 24 h and 30 days was 40%.

Conclusions

This REBOA device was useful for emergency physicians in life-threatening hemorrhagic shock because of its ease in handling and low invasiveness.  相似文献   
118.

Context

The achievement of a personalized pain goal (PPG) is advocated as an individualized pain relief indicator.

Objectives

Pain relief indicators, including PPG, pain intensity (PI), and interference with daily activities (interference), were compared herein.

Methods

This was a single-center cross-sectional study. Adult patients with cancer on opioid medications who visited the outpatient clinic at the National Cancer Center Hospital East between March and September 2015 were consecutively enrolled. Patients conducted a self-report questionnaire, including reports of average PI, interference, PPG, and the need for further analgesic treatment. We compared the proportion of patients achieving PPG (PI ≤ PPG) and other pain relief indicators including PI ≤3 or interference ≤3 and the percentage of patients who did not need further analgesic treatment among those who fulfilled each pain relief indicator.

Results

A total of 347 patients (median age 64; 38% females) were analyzed. Median (interquartile range [IQR]) of PPG, PI, and interference was 2 (IQR 1–3), 2 (IQR 1–4), and 2 (IQR 0–5), respectively. The proportion of patients achieving PPG was 45.3% and significantly lower than those with PI ≤3 (69.0%; P < 0.001) and interference ≤3 (70.2%; P < 0.001). Eighty percent of patients achieving PPG did not need further analgesic treatment, whereas 70.8% of patients with PI ≤3 (P < 0.001) and 73.3% with interference ≤3 did need further analgesic treatment (P < 0.001).

Conclusion

The achievement of PPG was a stricter pain relief indicator than PI and interference and may reflect a real need for pain control.  相似文献   
119.
120.
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