Diabetes during Pregnancy: A Maternal Disease Complicating the Course of Pregnancy with Long-Term Deleterious Effects on the Offspring. A Clinical Review

In spite of the huge progress in the treatment of diabetes mellitus, we are still in the situation that both pregestational (PGDM) and gestational diabetes (GDM) impose an additional risk to the embryo, fetus, and course of pregnancy. PGDM may increase the rate of congenital malformations, especially cardiac, nervous system, musculoskeletal system, and limbs. PGDM may interfere with fetal growth, often causing macrosomia, but in the presence of severe maternal complications, especially nephropathy, it may inhibit fetal growth. PGDM may also induce a variety of perinatal complications such as stillbirth and perinatal death, cardiomyopathy, respiratory morbidity, and perinatal asphyxia. GDM that generally develops in the second half of pregnancy induces similar but generally less severe complications. Their severity is higher with earlier onset of GDM and inversely correlated with the degree of glycemic control. Early initiation of GDM might even cause some increase in the rate of congenital malformations. Both PGDM and GDM may cause various motor and behavioral neurodevelopmental problems, including an increased incidence of attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD). Most complications are reduced in incidence and severity with the improvement in diabetic control. Mechanisms of diabetic-induced damage in pregnancy are related to maternal and fetal hyperglycemia, enhanced oxidative stress, epigenetic changes, and other, less defined, pathogenic mechanisms.     

Metallurgical Features of Plasma Surfacing Repair of Magnesium Alloys

Metallurgist - Results are provided for studying formation of the structure and properties of products made of high-strength light alloy ML5 of the magnesium-aluminum-manganese-zinc system using...     

Thermal expansion of an SiC particle-reinforced aluminum composite

Using a push-rod dilatometer, we measured between 76 and 390 K the thermal expansion of a particle-reinforced-composite wrought plate obtained by powdermetallurgy methods. The particles, 30% by volume, consisted of monocrystals of -SiC with sizes near 10 m. The matrix consisted of a 6061 aluminum alloy with original particle sizes near 20 m. We found the perpendicular thermal expansivity, ₃, higher by 26% than the in-plane thermal expansivity, ₁-₂. These values differ from a rule-of-mixture prediction by –3 and –23%, respectively. All three _i, components lie outside the Rosen-Hashin bounds. Levin's isotropic model agrees within 10% with the ₁-₂-₃ average. Both the anisotropy and the bounds violation result from microstructural nonhomogeneity arising from processing. Rosen and Hashin's transverse-isotropicsymmetry relationships account approximately for these effects by introducing the anisotropic elastic constants. Using neutron diffraction, we determined that the SiC particles are textureless.Paper presented at the Tenth International Thermal Expansion Symposium, June 6–7, 1989, Boulder, Colorado, U.S.A.     

Adaptation of an automotive dialogue system to users’ expertise and evaluation of the system

Spoken dialogue systems (SDSs) can be used to operate devices, e.g. in the automotive environment. People using these systems usually have different levels of experience. However, most systems do not take this into account. In this paper, we present a method to build a dialogue system in an automotive environment that automatically adapts to the user’s experience with the system. We implemented the adaptation in a prototype and carried out exhaustive tests. Our usability tests show that adaptation increases both user performance and user satisfaction. We describe the tests that were performed, and the methods used to assess the test results. One of these methods is a modification of PARADISE, a framework for evaluating the performance of SDSs [Walker MA, Litman DJ, Kamm CA, Abella A (Comput Speech Lang 12(3):317–347, 1998)]. We discuss its drawbacks for the evaluation of SDSs like ours, the modifications we have carried out, and the test results.

Temperature stability of thin anodic oxide films in metal/insulator/metal structures: A comparison between tantalum and aluminium oxide

The dielectric breakdown of thin (d = 3–4 nm) aluminium and tantalum oxide films was investigated by means of current voltage plots in metal/insulator/metal systems. Dielectric breakdown field strengths, E_DB, of 0.6 GV m^− 1 were found for both oxide types at room temperature. Differences appear in the temperature dependence of E_DB. Tantalum oxide films show an unchanged breakdown behaviour for temperatures up to 420 K while aluminium oxide films lose already 80% of their E_DB value in the same temperature range. Time-resolved investigations of the electric breakdown revealed intermediate states of both oxide types which were stable for several ms being characterized by an enhanced tunnel current. The breakdown voltage clearly scales with the oxide thickness for both oxide types.     

Geometric adaption of biodegradable magnesium alloy scaffolds to stabilise biological myocardial grafts. Part I

Synthetic patch materials currently in use have major limitations, such as high susceptibility to infections and lack of contractility. Biological grafts are a novel approach to overcome these limitations, but do not always offer sufficient mechanical durability in early stages after implantation. Therefore, a stabilising structure based on resorbable magnesium alloys could support the biological graft until its physiologic remodelling. To prevent early breakage in vivo due to stress of non-determined forming, these scaffolds should be preformed according to the geometry of the targeted myocardial region. Thus, the left ventricular geometry of 28 patients was assessed via standard cardiac magnetic resonance imaging (MRI). The resulting data served as a basis for a finite element simulation (FEM). Calculated stresses and strains of flat and preformed scaffolds were evaluated. Afterwards, the structures were manufactured by abrasive waterjet cutting and preformed according to the MRI data. Finally, the mechanical durability of the preformed and flat structures was compared in an in vitro test rig. The FEM predicted higher durability of the preformed scaffolds, which was proven in the in vitro test. In conclusion, preformed scaffolds provide extended durability and will facilitate more widespread use of regenerative biological grafts for surgical left ventricular reconstruction.     

Pleiotropic,Unique and Shared Responses Elicited by IL-6 Family Cytokines in Human Vascular Endothelial Cells

Vascular endothelial cells express glycoprotein 130 (gp130), which is utilized as a signaling receptor by cytokines in the interleukin-6 (IL-6) family. Several IL-6 family cytokines can be found in the circulatory system during physiological or pathological conditions, and may influence endothelial function and response. This study evaluated and compared the cellular and molecular responses induced by IL-6 family cytokines in human endothelial cells. A proteomic analysis showed that IL-6 family cytokines induce the release of a range of proteins from endothelial cells, such as C-C motif chemokine ligand 23, hepatocyte growth factor, and IL-6. Pathway analysis indicated that gp130-signaling in endothelial cells regulates several functions related to angiogenesis and immune cell recruitment. The present investigation also disclosed differences and similarities between different IL-6 family cytokines in their ability to induce protein release and regulate gene expression and intracellular signaling, in regards to which oncostatin M showed the most pronounced effect. Further, this study showed that soluble gp130 preferentially blocks trans-signaling-induced responses, but does not affect responses induced by classic signaling. In conclusion, IL-6 family cytokines induce both specific and overlapping molecular responses in endothelial cells, and regulate genes and proteins involved in angiogenesis and immune cell recruitment.     

海绵负载纳米Al2O3复合吸附剂去除水中硒研究

研究制备了海绵负载纳米Al2O3微球的复合吸附剂(NAS),并用于对Se(Ⅳ)和Se(Ⅵ)的吸附。结果表明,合成的纳米Al2O3微球(NAO)的平均尺寸为200~400 nm,在海绵上负载NAO会使其分散性更好。当NAO负载量分别为80 mg/g和60 mg/g时,NAS对Se(Ⅳ)和Se(Ⅵ)的吸附性能为佳,分别需要60、120 min达到平衡,适应pH为2~5;两者均符合准2级动力学模型;NAS对Se(Ⅳ)、Se(Ⅵ)的最大吸附容量分别为137.2、143.9 mg/g,能很好地与Freundlich模型拟合,说明NAS表面不均匀,且属于多层吸附。经过2次的循环,对Se(Ⅳ)和Se(Ⅵ)的去除率有所降低,但均仍保持在一定的水平,说明NAS可再生循环利用。NAS作为一种新型吸附剂去除水中Se具有较好的应用前景。     

Protective effect of estrogens and catecholestrogens against peroxidative membrane damagein vitro

The antioxidant effects of natural estrogens (estrone E₁; 17β-estradiol), synthetic estrogens (17α-ethynylestradiol, EE₂; mestranol, MES; diethylstilbestrol, DES) and catechle-strogens (2-hydroxyestradiol; 4-hydroxyestradiol 4-OHE₂) on lipid peroxidation induced by different means in rat liver microsomes were investigated. The extent of lipid peroxidation was determined by measuring thiobarbituric acid reactive substances. Prooxidants included Fe³⁺/ADP/reduced NADPH, Fe²⁺/ascorbate,tert-butyl hydroperoxide (t-BOOH) and 2,2′-azobis (2-amidinopropane) (AAPH). Estrogens and catecholestrogens decreased lipid peroxidation in all four systems tested. In the iron/ascorbate model it was shown that (i)-OHE₂ and DES had analogous patterns of inhibition, irrespective of the presence of NADPH or the functional integrity of the microsómes, and (ii) the antioxidant activities of E₁, EE₂ and MES were dependent on the assay conditions with the activity being markedley higher when estrogen metabolism was favored. When peroxidation was initiated by the peroxyl radical generator AAPH, the inhibitory effects observed were least pronounced. Our data also showed that, in each of the systems, all inhibitors displayed the same order of inhibitory potency with DES and catecholestrogens being the most potent antioxidants under all experimental conditions used. The present results confirm earlier findings and point toward a link between estrogen metabolism and estrogen antioxidant activity. The data also indicate that estrogens and catecholestrogens interact with the peroxidative process at different levels with their interactions with iron or the metal-derived species being the most important modes of inhibition.