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   2591篇
  免费   110篇
  国内免费   11篇
耳鼻咽喉   56篇
儿科学   36篇
妇产科学   18篇
基础医学   208篇
口腔科学   31篇
临床医学   117篇
内科学   710篇
皮肤病学   14篇
神经病学   242篇
特种医学   86篇
外科学   492篇
综合类   4篇
预防医学   65篇
眼科学   19篇
药学   174篇
中国医学   12篇
肿瘤学   428篇
  2023年   19篇
  2022年   40篇
  2021年   45篇
  2020年   16篇
  2019年   45篇
  2018年   54篇
  2017年   46篇
  2016年   50篇
  2015年   61篇
  2014年   76篇
  2013年   72篇
  2012年   95篇
  2011年   166篇
  2010年   116篇
  2009年   70篇
  2008年   125篇
  2007年   168篇
  2006年   156篇
  2005年   134篇
  2004年   175篇
  2003年   134篇
  2002年   143篇
  2001年   81篇
  2000年   68篇
  1999年   65篇
  1998年   28篇
  1997年   20篇
  1996年   17篇
  1995年   13篇
  1994年   10篇
  1993年   11篇
  1992年   45篇
  1991年   43篇
  1990年   39篇
  1989年   29篇
  1988年   31篇
  1987年   23篇
  1986年   29篇
  1985年   22篇
  1984年   17篇
  1983年   19篇
  1980年   7篇
  1979年   16篇
  1978年   9篇
  1977年   6篇
  1976年   5篇
  1974年   5篇
  1971年   9篇
  1970年   6篇
  1967年   5篇
排序方式: 共有2712条查询结果,搜索用时 31 毫秒
91.
92.
We retrospectively reviewed the imaging findings, indications, technique and clinical impact in children who had undergone chest CT while undergoing extra-corporeal membrane oxygenation (ECMO). Radiology and ECMO databases were searched to identify all 19 children who had undergone chest CT (20 scans in total) while on ECMO at our institution between May 2003 and May 2012. We reviewed all CT scans for imaging findings. Chest CT is performed in a minority of children on ECMO (4.5% in our series). Timing of chest CT following commencement of ECMO varied among patient groups but generally it was performed earlier in the neonatal group. Clinically significant imaging findings were found in the majority of chest CT scans. Many scans contained several findings, with most cases demonstrating parenchymal or pleural abnormalities. Case examples illustrate the spectrum of imaging findings, including underlying pathology such as necrotising pneumonia and severe barotrauma, and ECMO-related complications such as tension haemothoraces and cannula migration. The results of chest CT led to a change in patient management in 16 of 19 children (84%). There were no adverse events related to patient transfer. An understanding of scan technique and awareness of potential findings is important for the radiologist to provide prompt and optimal image acquisition and interpretation in appropriate patients.  相似文献   
93.
The purposes of this study were to establish normative data for mesiodistal tooth crown diameters and arch dimensions in Mongolian adults and to compare them with those of Japanese adults. The study materials comprised dental casts of 100 modern Mongolian and 100 Japanese subjects (50 males, 50 females for each) with Angle Class I normal occlusion. The mean ages were 20 years 8 months for the Mongolian subjects and 20 years 0 months for the Japanese subjects. On the dental casts, the mesiodistal tooth crown diameters (excluding wisdom teeth) and dental arch dimensions were measured. The following arch dimensions were measured: inter-canine lingual, inter-premolar lingual, inter-molar lingual, inter-molar central, coronal arch length, basal arch length, and basal arch width. In the Mongolian samples, significant sex differences were noted, and most of the items were significantly larger in males than in females. Significant differences between the Mongolian and Japanese samples were mainly noted in the premolar and molar regions, rather than in the anterior region, and were significantly smaller in the Mongolian samples. In the Mongolian samples, the molar section widths and basal arch width and length were significantly larger in males and females compared with the Japanese samples. These results suggest that the tooth crown size and arch dimensions in the Mongolian samples differed from those in the Japanese samples, and that establishment of the clinical norm for Mongolian adults might be helpful in formulating treatment plans for Mongolian patients, given that these parameters are the basic tools for diagnosis.  相似文献   
94.
95.
96.
Posterior reversible encephalopathy syndrome (PRES) is a neurological disorder characterized by seizures, altered mental status and visual disorders, along with characteristic radiological findings. It is strongly related to hypertension induced by steroids and other immunosuppressive agents. There are an increasing number of reports regarding PRES arising during the course of chemotherapy for hematological malignancies. To clarify the risk factors for this phenomenon, we retrospectively analyzed pediatric patients undergoing treatment for hematological malignancies. Of 161 patients, six patients (3.7 %) developed PRES with characteristic clinical and radiographic findings. Univariate analysis revealed that tumor lysis syndrome (TLS) was a significant risk factor for the onset of PRES. TLS is a significant risk factor for the development of PRES in pediatric patients receiving chemotherapy for hematological malignancies.  相似文献   
97.
The safety and efficacy of non-vitamin K oral anticoagulant (NOAC) compared with warfarin in treating patients with non-valvular atrial fibrillation (NVAF) who developed acute ischemic stroke or transient ischemic attack (AIS/TIA), particularly those receiving tissue-plasminogen activator (tPA) therapy, remains unclear. Between April 2012 and December 2014, we conducted a multicenter prospective cohort study to assess the current clinical practice for treating such patients. We divided the patients into two groups according to the administration of oral anticoagulants (warfarin or NOACs) and tPA therapy. The risk of any hemorrhagic or ischemic event was compared within 1 month after the onset of stroke. We analyzed 235 patients with AIS/TIA including 73 who received tPA therapy. Oral anticoagulants were initiated within 2–4 inpatient days. NOACs were administered to 49.8 % of patients, who were predominantly male, younger, had small infarcts, lower NIHSS scores, and had a lower all-cause mortality rate (0 vs. 4.2 %, P = 0.06) and a lower risk of any ischemic events (6.0 vs. 7.6 %, P = 0.797) compared with warfarin users. The prevalence of all hemorrhagic events was equivalent between the two groups. Early initiation of NOACs after tPA therapy appeared to lower the risk of hemorrhagic events, although there was no significant difference (0 vs. 5.6 %, P = 0.240). Although more clinicians are apt to prescribe NOACs in minor ischemic stroke, NOAC treatment may provide a potential benefit in such cases. Early initiation of NOACs after tPA therapy may reduce the risk of hemorrhagic events compared with warfarin.  相似文献   
98.
A flexible and wearable amperometoric glucose sensor was fabricated and tested. Also, the sensor was utilized to tear glucose monitoring. The sensor was constructed by immobilizing GOD onto a flexible oxygen electrode (Pt working electrode and Ag/AgCl counter/reference electrode), which was fabricated using “Soft-MEMS” techniques onto a functional polymer membrane. In purpose of bioinstrumentation, adhesive agents were not used for constructing the flexible biosensor. Linear relationship between glucose concentration and output current was obtained in a range of 0.025–1.475 mmol/l, with a correlation coefficient of 0.998. Current dependences on pH and temperature were also evaluated. The current was largest at pH 7.0 and the current increased when temperature increased. This indicates that the output current depends on enzyme activity. Based on the basic characteristics investigation, the glucose sensor was applied to measurement of glucose in tear fluids on an eye site of a Japan white rabbit. The change of tear glucose level induced by oral-administration of glucose was monitored as a current change of the sensor attached on the eye site. In this investigation, the tear glucose level varied from 0.16 to 0.46 mmol/l. Although there was a delay of several tens of minutes towards blood sugar level, it is considered to be possible that non-invasive continuous glucose monitoring can be realized using the flexible biosensor.  相似文献   
99.
Goals:We examined whether synbiotics enhance improvement by probiotics.Background:Probiotics, which are beneficial microbacteria, are a nutritional intervention for treatment of functional constipation or its tendency. Prebiotics, meanwhile, can promote the proliferation of probiotics in the gastrointestinal tract and enhance their beneficial effects. Synbiotics, a combination of probiotics and prebiotics, may be superior to probiotics in the treatment of defecation-related symptoms, but this requires elucidation.Study:This randomized, double-blind, placebo-controlled study enrolled 69 healthy adults with constipation tendency. Participants were allocated to either control, probiotics, or synbiotics groups and they recorded details of their defecations and their condition. The first 2 weeks were the observation period and the latter 2 weeks were the intervention period, in which participants took test foods. Probiotic foods included Bifidobacterium longum NT strain (1010 CFU/day), synbiotic foods included the NT strain (1010 CFU/day) and galactooligosaccharide (1 g/day). Placebo foods contained the vehicle only. Participants answered questionnaires (Patient Assessment on Constipation Symptoms [PAC-SYM], and one on dietary history) on the last day of each period.Results:Nine participants withdrew consent, and 2 of the remaining 60 had missing data. Age, body mass index, and sex were not significantly different between the 3 groups. Frequency of bowel movements in the fourth week, the primary endpoint, was not increased in the probiotics or synbiotics groups compared with the control group, and the frequency of bowel movements and days with defecation were not changed by probiotics or synbiotics during the intervention period. Probiotics and synbiotics did not improve stool conditions, although incomplete defecation was improved by probiotics but not by synbiotics compared with placebo. PAC-SYM indicated that stool condition and total scores were improved by probiotics but not by synbiotics during the intervention compared with placebo.Conclusion:The probiotic strain Bifidobacterium longum NT can improve constipation symptoms, especially stool condition, but it does not increase bowel movement frequency in healthy adults with constipation tendency. Synbiotics treatment seemed to diminish this improvement of constipation induced by probiotics. This study indicates the possibility of attenuation of beneficial effects from probiotics by the use of synbiotics, contrary to synbiotics theory.  相似文献   
100.

Background

Intraoperative identification of the difficult-to-spot parathyroid gland is critical during surgery for thyroid and parathyroid disease. Recently, intrinsic fluorescence of the parathyroid gland was identified, and a new method was developed for intraoperative detection of the parathyroid with an original fluorescent detection apparatus. Here, we describe a method for intraoperative detection of the parathyroid using a ready-made photodynamic eye (PDE) system without any fluorescent dye or contrast agents.

Methods

Seventeen patients who underwent surgical treatment for thyroid or parathyroid disease at Kagoshima University Hospital were enrolled in this study. Intrinsic fluorescence of various tissues was detected with the PDE system. Intraoperative in vivo and ex vivo intrinsic fluorescence of the parathyroid, thyroid, lymph nodes and fat tissues was measured and analyzed.

Results

The parathyroid gland had a significantly higher fluorescence intensity than the other tissues, including the thyroid glands, lymph nodes and fat tissues, and we could identify them during surgery using the fluorescence-guided method. Our method could be applicable for two intraoperative clinical procedures: ex vivo tissue identification of parathyroid tissue and in vivo identification of the location of the parathyroid gland, including ectopic glands.

Conclusion

The PDE system may be an easy and highly feasible method to identify the parathyroid gland during surgery.
  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