A preliminary comparison of the mechanical properties of chemically cured and ultrasonically cured glass ionomer cements, using nano-indentation techniques

There is a requirement for a dental cement with properties comparable or superior to conventional glass ionomer cements (GICs) but with the command set properties of the resin-modified GICs. The objective of this work was to show that the application of ultrasound to conventional Fuji IX commercial glass ionomer cement imparts a command set, whilst improving the short-term surface mechanical properties. Nano-indentation techniques were employed to highlight the improvements in hardness and creep resistance imparted to the cement through the application of ultrasound. The instant set imparted by the application of ultrasound provides improved surface hardness and creep, particularly within the first 24 h after setting. The surface hardness of the chemically cured Fuji IX (176 M Pa) increased by an order of magnitude when set ultrasonically (2620 M Pa), whilst creep reduced to a negligible amount. Rapid setting allows for shorter chair time and an improved clinical technique, making restorations more convenient for both the patient and clinician.     

1型糖尿病研究新进展

40年前创立的青少年糖尿病研究基金会((JDRF)是一个致力于通过支持研究来探寻1型糖尿病(TIDM)及其并发症治疗方法的组织.20世纪70年代有学者提出,TIDM和2型糖尿病(T2DM)的发病机制有根本的不同,T1DM与主要组织相容性复合体的人白细胞抗原(HLA)有独特相关性,有胰岛细胞自身抗体.     

Strangulation in child abuse: CT diagnosis

The central nervous system is commonly affected in child abuse. Between April 1985 and July 1986 three infants were identified in whom the primary mode of injury had been strangulation. In each case computed tomography (CT) demonstrated a large cerebral infarction confined to vascular territories associated with small subdural hematomas. There was no history or visible evidence of significant head trauma. Autopsy of one infant confirmed the presence of a hemispheric infarct, thin subdural hematoma, and an area of subintimal hemorrhage in the carotid artery ipsilateral to the infarct. The remaining two patients survived with residual hemiparesis. CT findings of a large cerebral infarction with an associated subdural hematoma in an infant without a history of a significant trauma should suggest the possibility of child abuse and may be the primary manifestation of abuse in some patients.     

Intracranial abnormalities in infants treated with extracorporeal membrane oxygenation: imaging with US and CT

Findings at neuroimaging in 100 consecutive infants treated with extracorporeal membrane oxygenation (ECMO) are presented. Imaging in these infants consisted of pretreatment cranial ultrasonography (US), daily US studies while on ECMO, and follow-up cranial computed tomography (CT) after treatment. There were findings of abnormalities in 43 patients. Thirty had intracranial bleeding, often of unusual extent and distribution. Thirteen additional infants had nonhemorrhagic abnormalities alone. Bleeding considered to be major was seen in 12% of infants. Large parenchymal hemorrhages and infarcts, cerebellar hemorrhages, and diffuse edema were the most significant abnormalities, with a 50% mortality (eight of 16 patients). No lateralization was noted with respect to distribution of bleeding sites or areas of nonhemorrhagic abnormalities. US was a sensitive but imperfect screening tool for intracranial abnormalities. Abnormalities missed with US included peripheral and small parenchymal lesions, subarachnoid hemorrhage, cerebral atrophy, and sagittal sinus thrombosis.