Controversy exists regarding the preventive effect of probiotics on the development of eczema or atopic dermatitis. We investigated whether supplementation of probiotics prevents the development of eczema in infants at high risk. In a randomized, double-blind, placebo-controlled trial, 112 pregnant women with a family history of allergic diseases received a once-daily supplement, either a mixture of Bifidobacterium bifidum BGN4, B. lactis AD011, and Lactobacillus acidophilus AD031, or placebo, starting at 4-8 wks before delivery and continuing until 6 months after delivery. Infants were exclusively breast-fed during the first 3 months, and were subsequently fed with breastmilk or cow's milk formula from 4 to 6 months of age. Clinical symptoms of the infants were monitored until 1 yr of age, when the total and specific IgE against common food allergens were measured. A total of 68 infants completed the study. The prevalence of eczema at 1 yr in the probiotic group was significantly lower than in the placebo group (18.2% vs. 40.0%, p=0.048). The cumulative incidence of eczema during the first 12 months was reduced significantly in probiotic group (36.4% vs. 62.9%, p=0.029); however, there was no difference in serum total IgE level or the sensitization against food allergens between the two groups. Prenatal and postnatal supplementation with a mixture of B. bifidum BGN4, B. lactis AD011, and L. acidophilus AD031 is an effective approach in preventing the development of eczema in infants at high risk of allergy during the first year of life.

The equilibrium electrical conductivity of polycrystalline, calcium-doped BaTiOJ was studied over the oxygen partial pressure range to lo5 Pa and the temperature range 800" to 1000°C. There is little effect if CaO is substituted for a corresponding amount of BaO, i.e., Bal-,Ca,TiOJ. If CaO is substituted for a corresponding amount of the TiOz content, i.e., BaTi1-,Ca,O3-,, the equilibrium conductivity shows strong evidence of acceptor-doped behavior. If the corresponding amount of excess CaO is added to stoichiometric BaTiOJ, i.e., BaCa,Ti03+,, the conductivity profiles are very close to those for samples with TiOt replaced by CaO, and show highly acceptor-doped behavior. This is in agreement with the replacement of a small amount of Ti by Ca2+ on the octahedral B-sites of BaTi03, where it acts as an acceptor center, Ca%.

The role of friction between the microhardness indenter and the test specimen is addressed through the analysis of dry (unlubricated) and lubricated tests on iron by Atkinson and Shi. Quantitative evaluation through a proportional specimen resistance model accurately describes the results. It suggests that friction is a major portion of the observed hardness increase at low test loads, the indentation size effect. The ISE is related to the surface-area-to-volume ratio of the indentation, which is inversely related to the indentation dimension.

Heparin lyase I (heparinase I) specifically depolymerizes heparin, cleaving the glycosidic linkage next to iduronic acid. Here, we show the crystal structures of heparinase I from Bacteroides thetaiotaomicron at various stages of the reaction with heparin oligosaccharides before and just after cleavage and product disaccharide. The heparinase I structure is comprised of a ␤-jellyroll domain harboring a long and deep substrate binding groove and an unusual thumb-resembling extension. This thumb, decorated with many basic residues, is of particular importance in activity especially on short heparin oligosaccharides. Unexpected structural similarity of the active site to that of heparinase II with an (␣/␣) 6 fold is observed. Mutational studies and kinetic analysis of this enzyme provide insights into the catalytic mechanism, the substrate recognition, and processivity.Heparin and heparan sulfate are linear, negatively charged polymers consisting of repeating units of 134-linked uronic acid (L-iduronic acid (IdoA) 4 and D-glucuronic acid (GlcA)) and glucosamine (1). Heparin consists of a high proportion of IdoA (ϳ90%) and is highly sulfated. It is widely used as an anticoagulant based on its binding to antithrombin, leading to the accelerated inhibition of the blood coagulation cascade (2). Heparin interacts with a variety of proteins, such as growth factors and chemokines, suggesting its relevance in various physiological and pathological processes (2, 3).Glycosaminoglycans in general, and heparin in particular, can be degraded by two mechanisms: hydrolysis and lytic elimination (4). Glycosaminoglycan hydrolases, present in eukaryotes and prokaryotes, break the glycosidic bond to the nonreducing end of the glucosamine, whereas glycosaminoglycan lyases, found only in prokaryotes, break the glycosidic linkage to the nonreducing end of uronic acid (5). The lyases that cleave chondroitin sulfate and hyaluronan have been extensively studied, structurally and biochemically. All of these lyases share a common fold, (␣/␣) 5 barrel, and antiparallel ␤-sheet, and have similar catalytic mechanisms (6 -8). In contrast, dermatan sulfate (chondroitin B) lyase has a completely different fold as a parallel ␤-helix, similar to pectate lyases, and employs very different catalytic machinery (9).The eliminative depolymerization of heparin/heparan sulfate affording unsaturated oligosaccharide products is carried out by three families of enzymes (10). Their primary sequences show no recognizable similarity, and they have distinct specificities (11). Thus, heparinase I is specific for heparin cleaving the glycosidic linkage to the nonreducing end of IdoA, heparin lyase III (heparinase III) cleaves the heparan sulfate next to glucuronic acid, and heparin lyase II (heparinase II) can depolymerize both of these substrates (see Fig. 1A). Structural information on the heparin degrading enzymes is limited to the Pedobacter heparinus (formerly Flavobacterium heparinum) heparinase II, which adopts an overall fold similar to chondroitin and hy...

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Electrical properties of acceptor (Mn, Mg or Mn + Mg)-doped BaTiO 3 ceramic have been studied in terms of oxygen vacancy concentration, various doping levels and electrical degradation behaviors. The solubility limit of Mn on Ti sites was confirmed to be close to or less than 1.0 mol%. Oxygen vacancy concentration of Ba(Ti 0.995−x Mg 0.005 Mn x )O 2.995−y (x = 0, 0.005, 0.01) was estimated to be ∼50 times greater than that of the un-doped BaTiO 3 . The leakage current of 0.5 mol% Mn-doped BaTiO 3 was stable with time, which was much lower than that of the un-doped BaTiO 3 . The BaTiO 3 specimen co-doped with 0.5 mol% Mg and 1.0 mol% Mn showed the lowest leakage current below 10 −10 A. It was confirmed that leakage currents of Mg-doped and un-doped BaTiO 3 under dc field are effectively suppressed by Mn co-doping as long as the Mn doping level is greater than Mg contents.

Degradation behaviors of Mg-doped BaTiO3 have been studied in terms of oxygen vacancy concentration and microstructural development. Mg-doped BaTiO3 powders were precisely synthesized by the Pechini method. As MgO content was increased to 1.0 mol%, Curie points moved to lower temperatures and dielectric constants decreased. The specimens doped with MgO showed higher leakage currents under the continuously applied dc field at a high temperature (100°C) during the aging process, compared with the undoped BaTiO3. With low levels of MgO (<1.0 mol%), the microstructure is similar to that of undoped BaTiO3, whereas a significant reduction in grain size was observed with higher levels (>2.0 mol%).