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AbstractChorioamnionitis and intrauterine growth retardation (IUGR) are risk factors for cerebral palsy (CP). Common bacteria isolated in chorioamnionitis include group B Streptococcus(GBS) serotypes Ia and III. Little is known about the impact of placental inflammation induced by different bacteria, including different GBS strains. We aimed to test the impact of chorioamnionitis induced by two common GBS serotypes (GBSIa and GBSIII) on growth and neuromotor outcomes in the progeny. Dams were exposed at the end of gestation to either saline, inactivated GBSIa or GBSIII. Inactivated GBS bacteria invaded placentas and triggered a chorioamnionitis featured by massive polymorphonuclear cell infiltrations. Offspring exposed to GBSIII – but not to GBSIa – developed IUGR, persisting beyond adolescent age. Male rats in uteroexposed to GBSIII traveled a lower distance in the Open Field test, which was correlating with their level of IUGR. GBSIII-exposed rats presented decreased startle responses to acoustic stimuli beyond adolescent age. GBS-exposed rats displayed a dysmyelinated white matter in the corpus callosum adjacent to thinner primary motor cortices. A decreased density of microglial cells was detected in the mature corpus callosum of GBSIII-exposed males – but not females – which was correlating positively with the primary motor cortex thickness. Altogether, our results demonstrate a causal link between pathogen-induced acute chorioamnionitis and (1) IUGR, (2) serotype- and sex-specific neuromotor impairments and (3) abnormal development of primary motor cortices, dysmyelinated white matter and decreased density of microglial cells.

Laser wire deposits using Alloy 625 modified with 0.4 wt% B were manufactured on stainless steel 304 substrates. A layer boundary with a thickness of around 250 μm was formed between the layer cores during deposition. Results show that the solidification features in the layer boundary were coarser than the layer core due to the recalescence mechanism. Continuous eutectics were observed segregating the inter-dendritic regions in both the layer boundary and the layer core. The eutectics consisted of mainly Laves phase with a small amount of NbC precipitates. Solidification front velocities (SFV) were calculated from the Kurz-Giovanola-Trivedi (KGT) model. Results showed that they developed in the layer boundary and in the layer core at 0.06 m/s and 0.1 m/s respectively. Electron backscattered diffraction (EBSD) mapping revealed that small equiaxed grains nucleated in the layer boundary, while large columnar grains were prevalent in the layer core. Pole figures showed a strong oriented texture was present along the (100) plane. The columnar to equiaxed transition (CET) model developed by Hunts was considered and the results were in good agreement with the observed grain morphologies.

Linear friction welding (LFW), an emerging automated technology, has potential for solid-state joining of dissimilar materials (bi-metals) to enable tailoring of the mechanical performance, whilst limiting the assembly weight for increased fuel efficiency. However, bi-metallic welds are quite difficult to manufacture, especially when the material combinations can lead to the formation of intermetallic (brittle) phases at the interface, such as the case with assembly of Ti base alloys with Ni base superalloys. The intermetallic phase, once formed, lowers the performance of the as-manufactured properties and its growth during elevated temperature service can lead to unreliable performance. In this project, it was demonstrated that linear friction welding can be applied to join Ti-6%Al-4%V (workhorse Ti alloy) to INCONEL® 718 (workhorse Ni-base superalloy) with minimized interaction at the interface. Of particular merit is that no intermediate layer (between the Ti alloy and Ni-base superalloy) was needed for bonding. Characterization of the bi-metallic weld included macro-and microstructural examination of the flash and interface regions and evaluation of the hardness.

Abstract

Aluminum alloys are in high demand for additive manufacturing (AM) processing. However, the physical properties of Al alloys are less favorable for the production of repeatable and reliable parts, with factors such as surface oxide scales, high thermal conductivity, and large solidification shrinkage. Despite these characteristics, processing strategies have been developed to overcome these hurdles. The objective of this article is to highlight the different microstructure–processing–properties characteristics for the three main families of aluminum alloys: pure, casting, and wrought chemistries. The article focuses on AM processes involving solidification, including powder bed and direct energy deposition for both powder and wire feedstock.

A solid-state recycling route for processing aluminium alloy 7075 chips is proposed. This process involves pulverizing the chips using an industrial scale comminution line to produce a broad particle size distribution of granulated products and powders. Upon sieving, the −140 mesh fraction of the pulverised material was consolidated by spark plasma sintering into fully dense compacts, i.e. >99%. The properties of the pulverised powders and compacts were compared to commercially available aluminium alloy 7075 powder used in industrial press-sinter applications. The comminution line produced powder particles which possessed a 7·9 ± 0·6-nm thick native oxide layer with adhering exogenous contaminants, and aluminium oxide particles dispersed throughout the powder. The presence of the oxide layer and exogenous contaminants was found to be deleterious to the powder consolidation and mechanical properties. A flexural strength and strain and hardness of 94·7 ± 7·2 MPa, 2·1 ± 0·3% and 69·3 ± 5·2 HV were obtained, respectively.

The preparation and evaluation of a novel class of CB2 benzimidazole inverse agonists are reported. They showed binding affinities up to 0.7 nM towards CB2 with overall good selectivity over the CB1 receptor. They also reversed the effect of the cannabinoid agonist WIN55212-2 in competition assays showing Ki' values up to 1.2 nM.

This work demonstrates the possibility of using the Duane–Hunt limit of the bremsstrahlung to determine E2 values of Si3N4 and AlN ceramics. The EDHL versus E0 graph demonstrates that for conductive materials, the experimental curve is parallel to the theoretical (EDHL = E0), but both curves cross in the case of insulators. The intersection points (E2 value), are 3.01 keV for Si3N4 and 2.67 keV for AlN. Imaging of ceramic grain structure at high magnification was performed to demonstrate the validity of the calculated E2 values.

Concentrations of unconjugated and glucuronated C-21, C-19 and C-18 steroids have been measured in follicular fluid obtained from women hyperstimulated by a combination of clomiphene citrate, pergonal and hCG. Pregnenolone and its glucuronide are found at approximately 5% of the progesterone values (14 395 ± 2300 ng/ml). Concentrations of dehydroepiandrosterone glucuronide, androst-5-ene-3β,17β-diol glucuronide, dihydrotestosterone glucuronide, androstane-3α, 17β-diol glucuronide and androstane-3β, 17β-diol glucuronide are 2-6-fold higher than those of the related unconjugated steroids, while testosterone glucuronide levels are lower than those of testosterone. The concentrations of androsterone glucuronide reach almost 30-fold those of androsterone (2.56 ± 0.35 ng/ml). By contrast, estradiol and estrone concentrations are 10-20-fold higher than those of conjugated steroids. Measurement of plasma steroid glucuronides indicated that the concentrations in circulation are markedly lower than those detected in follicular fluid. Our data suggest that the ovary in humans may be a site of glucuronidation.