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   98篇
  免费   2篇
儿科学   1篇
基础医学   8篇
口腔科学   29篇
临床医学   9篇
内科学   18篇
皮肤病学   3篇
神经病学   8篇
特种医学   3篇
外科学   17篇
预防医学   1篇
药学   3篇
  2024年   1篇
  2023年   3篇
  2022年   2篇
  2021年   3篇
  2020年   3篇
  2019年   3篇
  2018年   6篇
  2016年   3篇
  2015年   1篇
  2014年   1篇
  2013年   3篇
  2012年   6篇
  2011年   8篇
  2010年   2篇
  2009年   5篇
  2008年   3篇
  2006年   4篇
  2005年   2篇
  2004年   6篇
  2003年   4篇
  2002年   2篇
  2001年   1篇
  2000年   1篇
  1999年   2篇
  1998年   4篇
  1996年   1篇
  1992年   2篇
  1991年   6篇
  1990年   6篇
  1987年   1篇
  1985年   1篇
  1984年   1篇
  1983年   1篇
  1981年   1篇
  1979年   1篇
排序方式: 共有100条查询结果,搜索用时 15 毫秒
1.
In this study, we tested a new square wave microprocessor-controlled red laser with an extremely low peak power output (<3 mW; very low level laser therapy [vLLLT]) in experimental pain in the rat. Acute inflammation was induced by intraplantar injection of carrageenan, chronic inflammation was induced by complete Freund's adjuvant (CFA) and neuropathic pain was produced by sciatic nerve chronic constriction injury (CCI). In our study vLLLT was effective in reducing edema and hyperalgesia in acute and chronic inflammation if administered at the points usually selected for acupuncture. Moreover, spontaneous pain and thermal hyperalgesia were reduced in CCI rats treated with vLLLT In conclusion, vLLLT reduced edema and induced analgesia in experimental plantar pain in rats. We interpret this to mean that enkephalin mRNA level was strongly upregulated in the external layers of the dorsal horn of the spinal cord in CFA and CCI animals, and that vLLLT further increased the mRNA level in single neurons.  相似文献   
2.

Purpose

Diffuse remodeling of myocardial extra-cellular matrix is largely responsible for left ventricle (LV) dysfunction and arrhythmias. Our hypothesis is that the texture analysis of late iodine enhancement (LIE) cardiac computed tomography (cCT) images may improve characterization of the diffuse extra-cellular matrix changes. Our aim was to extract volumetric extracellular volume (ECV) and LIE texture features of non-scarred (remote) myocardium from cCT of patients with recurrent ventricular tachycardia (rVT), and to compare these radiomic features with LV-function, LV-remodeling, and underlying cardiac disease.

Procedures

Forty-eight patients suffering from rVT were prospectively enrolled: 5/48 with idiopathic VT (IVT), 23/48 with post-ischemic dilated cardiomyopathy (ICM), 9/48 with idiopathic dilated cardiomyopathy (IDCM), and 11/48 with scars from a previous healed myocarditis (MYO). All patients underwent echocardiography to assess LV systolic and diastolic function and cCT with pre-contrast, angiographic, and LIE scan to obtain end-diastolic volume (EDV), ECV, and first-order texture parameters of Hounsfield Unit (HU) of remote myocardium in LIE [energy, entropy, HU-mean, HU-median, standard deviation (SD), and mean absolute deviation (MAD)].

Results

Energy, HU mean, and HU median by cCT texture analysis correlated with ECV (rho?=?0.5650, rho?=?0.5741, rho?=?0.5068; p?<?0.0005). cCT-derived ECV, HU-mean, HU-median, SD, and MAD correlated directly to EDV by cCT and inversely to ejection fraction by echocardiography (p?<?0.05). SD and MAD correlated with diastolic function by echocardiography (rho?=?0.3837, p?=?0.0071; rho?=?0.3330, p?=?0.0208). MYO and IVT patients were characterized by significantly lower values of SD and MAD when compared with ICM and IDCM patients, independently of LV-volume systolic and diastolic function.

Conclusions

Texture analysis of LIE may expand cCT capability of myocardial characterization. Myocardial heterogeneity (SD and MAD) was associated with LV dilatation, systolic and diastolic function, and is able to potentially identify the different patterns of structural remodeling characterizing patients with rVT of different etiology.
  相似文献   
3.

Objective

This study evaluated the effect of root canal disinfectants on the elimination of bacteria from the root canals, as well as their effect on glass-fiber posts bond strength.

Material and Methods

Fifty-three endodontically treated root canals had post spaces of 11 mm in length prepared and contaminated with E. faecalis. For CFU/ml analysis, eight teeth were contaminated for 1 h or 30 days (n=4). Teeth were decontaminated with 5% NaOCl, 2% CHX, or distilled water. As control, no decontamination was conducted. After decontamination, sterile paper points were used to collect samples, and CFU/ml were counted. For push-out, three groups were evaluated (n=15): irrigation with 2.5% NaOCl, 2% CHX, or sterile distilled water. A bonding agent was applied to root canal dentin, and a glass-fiber post was cemented with a dual-cured cement. After 24 h, 1-mm-thick slices of the middle portion of root canals were obtained and submitted to the push-out evaluation. Three specimens of each group were evaluated in scanning electron microscopy (SEM). Data were analyzed with one-way ANOVA and Dunnett’s T3 test (α=0.05).

Results

The number of CFU/ml increased from 1 h to 30 days of contamination in control and sterile distilled water groups. Decontamination with NaOCl was effective only when teeth were contaminated for 1 h. CHX was effective at both contamination times. NaOCl did not influence the bond strength (p>0.05). Higher values were observed with CHX (p<0.05). SEM showed formation of resin tags in all groups.

Conclusion

CHX showed better results for the irrigation of contaminated root canals both in reducing the bacterial contamination and in improving the glass-fiber post bonding.  相似文献   
4.
Stiff left atrial (LA) syndrome is a distinct phenotype of heart failure with preserved ejection fraction, characterized by predominant high LA pressure. We describe the case of a middle‐aged woman who developed exertional breathlessness during low‐dose radiotherapy for right breast cancer and who was eventually found to be affected by stiff LA syndrome. Invasive hemodynamics allowed the recognition of pathognomonic tall V waves in the wedge position during exercise, in spite of inconclusive noninvasive investigations.  相似文献   
5.
Laccase-mediated intramolecular oxidative radical coupling of N-formyl-2-bromo-O-methylnorbelladine afforded a novel and isolable spirocyclohexadienonic intermediate of galantamine. High yield and conversion of substrate were obtained in the presence of the redox mediator 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO). This laccase procedure, with an overall yield of 34%, represents a scalable and environmentally friendly alternative to previously reported syntheses of galantamine based on the use of potassium ferricyanide as an unspecific radical coupling reagent.

Laccase-mediated intramolecular oxidative radical coupling of N-formyl-2-bromo-O-methylnorbelladine afforded a novel and isolable spirocyclohexadienonic intermediate of galantamine.  相似文献   
6.
This paper describes and discusses the multidisciplinary treatment involving a permanent maxillary lateral incisor fused to a supernumerary tooth, both presenting pulp necrosis and periapical lesion. A 15-year-old male patient sought treatment complaining of pain, swelling and mobility on the maxillary right lateral incisor. After clinical and radiographic examination, root canal preparation was performed according to the crown-down technique and a calcium hydroxide dressing was placed for 15 days. The patient returned and the definitive endodontic filling was done with thermomechanical compaction of gutta-percha and sealer. After 18 months, clinical and radiographic examinations were carried out and no pain or swelling was reported. Two years after endodontic treatment, the patient returned for periodontal and cosmetic treatments. Nine months later, a cone-beam computed tomography (CBCT) revealed that the previously detected periodontal defect and periapical lesion were persistent. Apical endodontic surgery was indicated. The supernumerary tooth was removed, the communicating distal surface was filled and the surgical site received bioactive glass and demineralized bovine organic bone. The pathological tissue was submitted to histopathological examination and the diagnosis was periapical cyst. One year after the apical endodontic surgery, CBCT showed bone formation at maxillary lateral incisor apical area. Two years after the surgery, the restoration was replaced due to aesthetic reasons and periapical radiograph showed success after 5 years of treatment. A correct diagnosis and establishment of an adequate treatment plan resulted in a successful management of the case.  相似文献   
7.
Role of short latency evoked potentials in the diagnosis of brain death.   总被引:7,自引:0,他引:7  
OBJECTIVE: The aim of this study is to confirm the effectiveness of auditory brain-stem responses (ABRs) and somatosensory evoked potentials (SEPs) in the diagnosis of brain death (BD). METHODS: ABRs and SEPs were recorded at the same session in 130 BD patients (age range 8-77 years, 81 male and 49 female). Twenty-four cases were submitted to serial recordings from preterminal conditions through BD. RESULTS: ABRs were absent in 92 cases (70.8%), only waves I or I-II were present in 32 cases (24.6%), while in the remaining 6 patients (4.6%) waves V and/or III were still present, excluding the death of the brain-stem. In 4 cases (3.1%) SEPs showed the absence of all components following the cervical N9, preventing the diagnosis of BD. Among 126 cases (96.9%) with preserved cervical N9-N13 SEPs confirmed the absence of brain-stem activity in 122 cases (93.7%), in whom no waves following P11 or P13 were recordable. SEPs excluded the diagnosis of BD in the remaining 4 cases (3.2%) showing preserved P14 and/or N18. In all pre terminal patients the far-field P14-N18 were present, and their disappearance was closely related to the onset of BD. CONCLUSIONS: The combined us of ABRs and SEPs was able to confirm BD in almost all patients, providing an objective confirmation of the diagnosis, and to exclude it in 7 cases, thus improving the reliability of diagnosis.  相似文献   
8.
Four hundred and thirty-nine carotid endarterectomies (CEAs) with routine use of patchgraft angioplasty were performed in 375 patients; the indwelling shunt was used only in patients showing clamp-related EEG abnormalities. Five patients showed EEG abnormalities just after head positioning, which reversed after removal of head hyperextension; three cases suffered EEG flattening due to severe bradycardia or cardiac arrest before carotid clamping, which promptly reversed after treatment. Clamp-related EEG abnormalities appeared in 106 operations (24.2%) and all reversed after the insertion of the indwelling shunt; patients with occlusion of the contralateral internal carotid artery showed a 68.8% rate of EEG clamp-related changes. The short term follow-up (one month after the operation) showed six minor strokes with complete recovery (1.37%), one intraoperative stroke (0.23%), three delayed major strokes (0.69%) and three neurological deaths (0.69%). The long-term follow-up over an average of 42 months showed a 3.7% rate of relevant neurological complications (ie permanent deficits + death) and a 3.16% rate significant restenosis or occlusion of the operated carotid artery. Our results show that the routine use of EEG monitoring and patch-graft angioplasty allow to perform CEAs with a very high degree of safety, improving the clinical course of the disease.  相似文献   
9.
Cavernous malformations are vascular lesions that occur in all parts of the central nervous system but most commonly in the cerebral hemispheres; unusually they may be found along the midline (basal ganglia, pineal region or brain stem), into the ventricle possibly encroaching upon the fourth and third ventricle. We report a case of midline cavernomas of the IV ventricle, that grew to large size in-time, demonstrating the capacity for rapid expansion.  相似文献   
10.
Motor evoked potentials (MEPs) following magnetic stimulation were recorded in 22 patients comatose as a result of head injury (13 cases), stroke (7 cases) or anoxia (2 cases). Somatosensory evoked potentials (SEPs) from median nerve were recorded as well in 19 cases in the same session. Thirteen patients died or remained vegetative (59.1%), 3 were severely disabled (13.6%) and 6 showed a good recovery (27.3%). MEPs were significantly related to the outcome; they appeared to be a more accurate prognostic indicator than the Glasgow Coma Scale (GCS). However, 1 out of 6 patients with bilaterally absent MEPs (16.7%) showed a good recovery. SEPs were significantly related to the outcome as well, but the combined use of SEP and MEP improved the outcome prediction, decreasing the rate of false negatives. Two patients had normal sensorimotor function, 13 a combined sensorimotor dysfunction, while 4 had a pure motor dysfunction. Our results suggest that SEPs and MEPs may improve the assessment of sensorimotor dysfunction in comatose patients. A significant relationship between MEPs and outcome appears to exist, but the assessment of MEP reliability requires further study.  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