Defining the Effect of the 16p11.2 Duplication on Cognition, Behavior, and Medical Comorbidities.

IMPORTANCE: The 16p11.2 BP4-BP5 duplication is the copy number variant most frequently associated with autism spectrum disorder (ASD), schizophrenia, and comorbidities such as decreased body mass index (BMI). OBJECTIVES: To characterize the effects of the 16p11.2 duplication on cognitive, behavioral, medical, and anthropometric traits and to understand the specificity of these effects by systematically comparing results in duplication carriers and reciprocal deletion carriers, who are also at risk for ASD. DESIGN, SETTING, AND PARTICIPANTS: This international cohort study of 1006 study participants compared 270 duplication carriers with their 102 intrafamilial control individuals, 390 reciprocal deletion carriers, and 244 deletion controls from European and North American cohorts. Data were collected from August 1, 2010, to May 31, 2015 and analyzed from January 1 to August 14, 2015. Linear mixed models were used to estimate the effect of the duplication and deletion on clinical traits by comparison with noncarrier relatives. MAIN OUTCOMES AND MEASURES: Findings on the Full-Scale IQ (FSIQ), Nonverbal IQ, and Verbal IQ; the presence of ASD or other DSM-IV diagnoses; BMI; head circumference; and medical data. RESULTS: Among the 1006 study participants, the duplication was associated with a mean FSIQ score that was lower by 26.3 points between proband carriers and noncarrier relatives and a lower mean FSIQ score (16.2-11.4 points) in nonproband carriers. The mean overall effect of the deletion was similar (-22.1 points; P < .001). However, broad variation in FSIQ was found, with a 19.4- and 2.0-fold increase in the proportion of FSIQ scores that were very low (≤40) and higher than the mean (>100) compared with the deletion group (P < .001). Parental FSIQ predicted part of this variation (approximately 36.0% in hereditary probands). Although the frequency of ASD was similar in deletion and duplication proband carriers (16.0% and 20.0%, respectively), the FSIQ was significantly lower (by 26.3 points) in the duplication probands with ASD. There also were lower head circumference and BMI measurements among duplication carriers, which is consistent with the findings of previous studies. CONCLUSIONS AND RELEVANCE: The mean effect of the duplication on cognition is similar to that of the reciprocal deletion, but the variance in the duplication is significantly higher, with severe and mild subgroups not observed with the deletion. These results suggest that additional genetic and familial factors contribute to this variability. Additional studies will be necessary to characterize the predictors of cognitive deficits

Boron nitride nanotube growth via boron oxide assisted chemical vapor transport-deposition process using LiNO 3 as a promoter

High-purity straight and discrete multiwalled boron nitride nanotubes (BNNTs) were grown via a boron oxide vapor reaction with ammonia using LiNO 3 as a promoter. Only a trace amount of boron oxide was detected as an impurity in the BNNTs by energy-dispersive X-ray (EDX) and Raman spectroscopies. Boron oxide vapor was generated from a mixture of B, FeO, and MgO powders heated to 1,150 °C, and it was transported to the reaction zone by flowing ammonia. Lithium nitrate was applied to the upper side of a BN bar from a water solution. The bar was placed along a temperature gradient zone in a horizontal tubular furnace. BNNTs with average diameters of 30–50 nm were mostly observed in a temperature range of 1,280–1,320 °C. At higher temperatures, curled polycrystalline BN fibers appeared. Above 1,320 °C, the number of BNNTs drastically decreased, whereas the quantity and diameter of the fibers increased. The mechanism of BNNT and fiber growth is proposed and discussed. [Figure not available see fulltext.] © 2015, Tsinghua University Press and Springer-Verlag Berlin Heidelberg

Boron nitride nanotube growth via boron oxide assisted chemical vapor transport-deposition process using LiNO 3 as a promoter

International audienceHigh-purity straight and discrete multiwalled boron nitride nanotubes (BNNTs) were grown via a boron oxide vapor reaction with ammonia using LiNO 3 as a promoter. Only a trace amount of boron oxide was detected as an impurity in the BNNTs by energy-dispersive X-ray (EDX) and Raman spectroscopies. Boron oxide vapor was generated from a mixture of B, FeO, and MgO powders heated to 1,150 °C, and it was transported to the reaction zone by flowing ammonia. Lithium nitrate was applied to the upper side of a BN bar from a water solution. The bar was placed along a temperature gradient zone in a horizontal tubular furnace. BNNTs with average diameters of 30–50 nm were mostly observed in a temperature range of 1,280–1,320 °C. At higher temperatures, curled polycrystalline BN fibers appeared. Above 1,320 °C, the number of BNNTs drastically decreased, whereas the quantity and diameter of the fibers increased. The mechanism of BNNT and fiber growth is proposed and discussed. [Figure not available see fulltext.] © 2015, Tsinghua University Press and Springer-Verlag Berlin Heidelberg

Synthesis of boron nitride nanostructures from borates of alkali and alkaline earth metals

International audienceReactions of borates of alkali and alkaline earth metals with ammonia in a temperature range of 950-1250 °C are explored with respect to the nano-boron nitride syntheses. M 2 O(MO)·nB 2 O 3 borates, where M 2 = Li, Na, K, and M = Mg, Ca, Sr, Ba are studied for a molar ratio n = 0.5-5.0. It is found that various boron nitride (BN) nanostructures such as BN-nanotubes (BNNTs), graphene-like BN petals (BNGPs), and columnar porous BN (BNP) flakes grow depending on the borate composition and synthesis temperature. Both morphology and yield of BN-nanostructures depend on the basicity of the metal oxide and its fraction in the precursor borate. Borates of Li, Mg, and Ca demonstrate the highest ability to produce BNNTs. Borates of Na and K produce BNGPs in the whole range of investigated n values and temperatures. BNP flakes with pores of 10-100 nm are formed from Mg-borates with n andgt; 3. © 2015 The Royal Society of Chemistry

Synthesis of boron nitride nanostructures from borates of alkali and alkaline earth metals

Reactions of borates of alkali and alkaline earth metals with ammonia in a temperature range of 950-1250 °C are explored with respect to the nano-boron nitride syntheses. M 2 O(MO)·nB 2 O 3 borates, where M 2 = Li, Na, K, and M = Mg, Ca, Sr, Ba are studied for a molar ratio n = 0.5-5.0. It is found that various boron nitride (BN) nanostructures such as BN-nanotubes (BNNTs), graphene-like BN petals (BNGPs), and columnar porous BN (BNP) flakes grow depending on the borate composition and synthesis temperature. Both morphology and yield of BN-nanostructures depend on the basicity of the metal oxide and its fraction in the precursor borate. Borates of Li, Mg, and Ca demonstrate the highest ability to produce BNNTs. Borates of Na and K produce BNGPs in the whole range of investigated n values and temperatures. BNP flakes with pores of 10-100 nm are formed from Mg-borates with n andgt; 3. © 2015 The Royal Society of Chemistry

Growth of spherical boron oxynitride nanoparticles with smooth and petalled surfaces during a chemical vapour deposition process

International audienceA rich variety of hollow and solid (without internal hollow spaces) spherical boron oxynitride nanoparticles (BNO-NPs) with smooth or petalled surfaces were synthesized during a boron oxide-assisted chemical vapour deposition (BOCVD) process. Diverse BNO-NPs were obtained while utilizing different precursors, gas flow rates and synthesis temperatures in the range of 1200-1430 °C. The BNO-NP morphologies, atomic structures and spatially-resolved chemical compositions were studied by scanning (SEM) and transmission electron microscopy (TEM), X-ray diffraction (XRD), energy-dispersive X-ray, Fourier-transform infrared and confocal Raman spectroscopy. Particle size distributions were measured using dynamic light scattering under visual microscopic control. A growth model of different spherical BNO-NP types based on the detailed analysis of physical-chemical processes at different BOCVD stages was proposed. A new type of spherical BNO-NPs of "hedgehog" morphologies with BN nanowires on their surfaces was first predicted in accordance with the designed model and then experimentally verified. © 2016 The Royal Society of Chemistry

Fabrication, characterization, and mechanical properties of spark plasma sintered Al-BN nanoparticle composites

International audienceFabrication of high strength yet light and low cost composite materials with good mechanical properties at room and elevated temperatures is a challenge that metallurgy and materials science communities are facing for many years, and no "dream material" has been developed so far. The primary goal of this study was to fabricate, characterize, and to carry out tensile tests on Al-based composite materials strengthened with commercially-available BN nanoparticles (BNNPs). The composites were fabricated by spark plasma sintering (SPS) technique. The structures of powder mixtures and composite materials, as well as their fracture surfaces, were studied by scanning and transmission electron microscopy. The influence of BNNPs content (0.5, 1.5, 3, 4.5, 6, and 7.5. wt%) and holding times (5, 60, and 300. min) at 600. °C during SPS on the tensile strength was investigated. A maximum increase in strength was observed for Al-based composites with 4.5. wt% of BNNPs. The sample demonstrated a 50% increase in tensile strength compared with pristine Al. Although the tensile tests performed at 300. °C revealed that the tensile strength became 20% lower than the strength at room temperature, it was, however, still 75% higher compared with that of the pure Al at 300. °C. In addition, at 300. °C the Al-BNNPs composites demonstrated a much higher value of yield stress, about 115. MPa, which is 190% higher than that of pure Al at the same temperature. The damping properties of Al-BNNPs composites were evaluated by temperature dependent internal friction (TDIF) measurements. The obtained results are discussed based on structural analysis and the TDIF data. © 2015 Elsevier B.V

Fabrication, characterization, and mechanical properties of spark plasma sintered Al-BN nanoparticle composites

International audienceFabrication of high strength yet light and low cost composite materials with good mechanical properties at room and elevated temperatures is a challenge that metallurgy and materials science communities are facing for many years, and no "dream material" has been developed so far. The primary goal of this study was to fabricate, characterize, and to carry out tensile tests on Al-based composite materials strengthened with commercially-available BN nanoparticles (BNNPs). The composites were fabricated by spark plasma sintering (SPS) technique. The structures of powder mixtures and composite materials, as well as their fracture surfaces, were studied by scanning and transmission electron microscopy. The influence of BNNPs content (0.5, 1.5, 3, 4.5, 6, and 7.5. wt%) and holding times (5, 60, and 300. min) at 600. °C during SPS on the tensile strength was investigated. A maximum increase in strength was observed for Al-based composites with 4.5. wt% of BNNPs. The sample demonstrated a 50% increase in tensile strength compared with pristine Al. Although the tensile tests performed at 300. °C revealed that the tensile strength became 20% lower than the strength at room temperature, it was, however, still 75% higher compared with that of the pure Al at 300. °C. In addition, at 300. °C the Al-BNNPs composites demonstrated a much higher value of yield stress, about 115. MPa, which is 190% higher than that of pure Al at the same temperature. The damping properties of Al-BNNPs composites were evaluated by temperature dependent internal friction (TDIF) measurements. The obtained results are discussed based on structural analysis and the TDIF data. © 2015 Elsevier B.V