Water in contact with the backside of a silicon substrate enables drilling of high-quality holes through the substrate using ultrashort laser pulses.

Holes through silicon substrates are used in silicon microsystems, for example in vertical electrical interconnects. In comparison to deep reactive ion etching, laser drilling is a versatile method for forming these holes, but laser drilling suffers from poor hole quality. In this article, water is used in the silicon drilling process to remove debris and the shape deformations of the holes. Water is introduced into the drilling process through the backside of the substrate to minimize negative effects to the drilling process. Drilling of inclined holes is also demonstrated. The inclined holes could find applications in radio frequency devices.

Reduced structural brain asymmetry during neonatal life is potentially related to autism spectrum disorders in children born extremely preterm.

Disruption of the normal patterns of structural brain asymmetry, and in language-related areas, has been reported in individuals with autism spectrum disorder (ASD). We tested the hypothesis that 16 children born extremely preterm (EPT), and diagnosed with ASD at 6.5 years of age (EPT-ASD), would have different patterns of brain structural asymmetry, particularly in language-related areas, to 21 EPT children without ASD and 15 term-born children. They all underwent neonatal magnetic resonance imaging scans at 40 weeks of gestation. ASD diagnoses and the Weschler Intelligence Scale for Children-Fourth Edition, were performed in the EPT children, but not in the term group. Asymmetry indices (AIs) were assessed at three levels: global (hemispheres), lobar (brain lobes), and modular (primary sensorimotor, unimodal, and higher-order association areas). AIs were also assessed in language-related regions and correlational analyses were performed between these AIs and verbal scores. The EPT-ASD group showed reduced structural asymmetry at the modular level, mainly involving the higher-order association cortices and the language-related areas. Predominant positive correlations between language functioning and leftward AIs in the inferior frontal gyrus (opercular) and supplementary cortices, and rightward asymmetry in the angular and supramarginal gyri, were identified in the EPT-ASD group. The overall results suggest that reduced brain structural asymmetry identified during the neonatal period would be a risk factor for the development of ASD in EPT infants. This finding could identify EPT children at risk at an early stage, so that tailored interventions could be used to optimize their functions and quality of life. Autism Res 2019, 12: 1334-1343. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Babies born before the expected date (preterm) are more likely to develop autism, due to abnormal brain development. Compared with children without autism, preterm children with autism did not display the important physical differences between the two sides of their brain that are needed for normal functioning. As this alteration was found just after birth, this information could be used to identify children who are likely to develop autism, so that they can get medical support at an earlier age.

Poor Brain Growth in Extremely Preterm Neonates Long Before the Onset of Autism Spectrum Disorder Symptoms.

Preterm infants face an increased risk of autism spectrum disorder (ASD). The relationship between autism during childhood and early brain development remains unexplored. We studied 84 preterm children born at <27 weeks of gestation, who underwent neonatal magnetic resonance imaging (MRI) at term and were screened for ASD at 6.5 years. Full-scale intelligence quotient was measured and neonatal morbidities were recorded. Structural brain morphometric studies were performed in 33 infants with high-quality MRI and no evidence of focal brain lesions. Twenty-three (27.4%) of the children tested ASD positive and 61 (72.6%) tested ASD negative. The ASD-positive group had a significantly higher frequency of neonatal complications than the ASD-negative group. In the subgroup of 33 children, the ASD infants had reduced volumes in the temporal, occipital, insular, and limbic regions and in the brain areas involved in social/behavior and salience integration. This study shows that the neonatal MRI scans of extremely preterm children, subsequently diagnosed with ASD at 6.5 years, showed brain structural alterations, localized in the regions that play a key role in the core features of autism. Early detection of these structural alterations may allow the early identification and intervention of children at risk of ASD.