Caries and fluorosis prevalence in communities with different concentrations of fluoride in the water

The need to defluoridate and fluoridate the water supplies in areas with drinking water naturally containing above-optimal (>/=2.5 mg/l) and suboptimal (相似文献   

EFFECT OF MICROSTRUCTURE ON HYDROGEN DAMAGE OFJBK-75 PRECIPITATE-STRENGTHENED AUSTENITIC STEEL

1.IntroductionHydrogenembrittlement(HE)0rhydr0gendamage(HD)ofall0ysisnotonlyrelatedt0chemicalc0mpositionsbutals0c10selyt0microstructures.Thereweres0merep0rts0ntheeffect0fmicr0structures0nHD0fsingle-phaseausteniticsteels[1-3].Themicrostructuralreas0nsofHD0fprecipitate-strengthenedausteniticsteels(PSAS),however,havereceivedlessattenti0n.Single-phaseausteniticsteelshaveproveninseveralinstancestohaveg00dresistancet0HD,butaretypicallynostr0ngerthan450MPainyieldstrength.Thus,anausteniticmatri…     

Two Algorithms for Fast Polyhedron Ray-Tracing

ＴｗｏＡｌｇｏｒｉｔｈｍｓｆｏｒＦａｓｔＰｏｌｙｈｅｄｒｏｎＲａｙ－ＴｒａｃｉｎｇＺｈａｎｇＱｉａｎＳｈｉＪｉａｏｙｉｎｇＣａｉＨｏｎｇＣＡＤ＆ＣＧＳｔａｔｅＫｅｙＬａｂ．，ＺｈｅｊｉａｎｇＵｎｉｖｅｒｓｉｔｙ，３１００２７ＦｏｓｈａｎＥｎｔｅｒｐｒ...     

Preferential adsorption, internalization and resistance to degradation of the major isoform of the Alzheimer's amyloid peptide, A beta 1-42, in differentiated PC12 cells

A central question in Alzheimer's disease (AD) is the role of amyloid in pathogenesis. Recent discoveries implicating the longer A beta 1-42 form of amyloid in pathogenesis led us to characterize the interaction of A beta with cells to elucidate differences that might account for these observations. We characterized the adsorption, internalization and degradation of radiolabeled A beta in NGF-differentiated PC12 cells under conditions that are not acutely toxic. All A beta peptides examined absorb to the surface of PC12 cells and are internalized; however the adsorption and internalization of A beta 1-42 is significantly greater than that of A beta 1-40 and A beta 1-28. The adsorption of A beta 1-42 is decreased by treatment of the cells with neuraminidase, but not heparitinase. The fate of the internalized A beta 1-42 is also very different than shorter A beta peptides; a fraction of the internalized A beta 1-42 accumulates intracellularly and is resistant to degradation for at least 3 days while A beta 1-40 and shorter peptides are eliminated with a half life of about 1 h. A beta 1-42 does not appear to inhibit lysosomal hydrolases, since A beta 1-28 is degraded at the same rate in the presence or absence of A beta 1-42. The intracellular A beta 1-42 is located in a dense organellar compartment and colocalizes with the lysosomal markers Lucifer Yellow and horseradish peroxidase. These data indicate that there are significant differences in the cell surface adsorption, internalization and catabolism of A beta 1-42 compared to A beta 1-40 and A beta 1-28. These differences may be important for the preferential accumulation of the longer A beta 1-42 isoform and its association with AD pathogenesis.     

Antro-pyloric canal values from early prematurity to full-term gestational age: an ultrasound study

PURPOSE: To evaluate antro-pyloric canal dimensions from early prematurity to full-term gestational age. MATERIALS AND METHODS: Ninety infants with no signs of regurgitation or vomiting were studied 3-5 days after birth. Their gestational ages ranged from 26 to 41 weeks (mean 33.7 weeks) and the body weight from 670 to 4150 g (mean 2067 g). Antro-pyloric muscle thickness, canal length and canal width were measured. RESULTS: A positive correlation between gestational age, muscle thickness (R = 0.71, P < 0.001), length (R = 0.63, P < 0.001) and width (R = 0.42, P < 0.001) was found. Furthermore, a positive correlation between body weight, muscle thickness (R = 0.82, P < 0.001) length, (R = 0.67, P < 0.001) and width (R = 0.55, P < 0.001) was observed. CONCLUSIONS: This study shows that antro-pyloric canal dimensions increase with gestational age. Moreover, it provides normal values for muscle thickness, canal length and canal width from the early gestation to full term.