A Birth Cohort Follow-Up Study on Congenital Zika Virus Infection in Vietnam.

We assessed the development, sensory status, and brain structure of children with congenital Zika virus (ZIKV) infection (CZI) at two years and preschool age. CZI was defined as either ZIKV RNA detection or positive ZIKV IgM and neutralization test in the cord or neonatal blood. Twelve children with CZI born in 2017-2018 in Vietnam, including one with Down syndrome, were assessed at 23-25.

A self-adapting first-principles exploration on the dissociation mechanism in sodiated aldohexose pyranoses assisted with neural network potentials.

Understanding the mechanism of collision-induced dissociation (CID) in mono-saccharides with density functional theory (DFT) is challenging because of many possible reaction paths that originate from their high structural diversity. To search for the transition state (TS) from the huge number of conformers, we propose a three-step search scheme with the assistance of neural network potential (NNP). The search starts from a cross-checking of sugars, to a global search of all possible channels, and in the end, an exhaustive exploration around the low-lying channels.

Collision-induced dissociation of Na-tagged ketohexoses: experimental and computational studies on fructose.

Collision-induced dissociation tandem mass spectrometry (CID-MS) and computational investigation at the MP2/6-311+G(d,p) level of theory have been employed to study Na-tagged fructose, an example of a ketohexose featuring four cyclic isomers: α-fructofuranose (αFru), β-fructofuranose (βFru), α-fructopyranose (αFru), and β-fructopyranose (βFru). The four isomers can be separated by high-performance liquid chromatography (HPLC) and they show different mass spectra, indicating that CID-MS can distinguish the different fructose forms. Based on a simulation using a micro-kinetic model, we have obtained an overview of the mechanisms for the different dissociation pathways.

Toward Closing the Gap between Hexoses and -Acetlyhexosamines: Experimental and Computational Studies on the Collision-Induced Dissociation of Hexosamines.

Motivated by the fundamental difference in the reactivity of hexoses and -acetylhexosamines under collision-induced dissociation (CID) mass spectrometry conditions, we have investigated the CID of two hexosamines, glucosamine (GlcN) and galactosamine (GalN), experimentally and computationally. Both hexosamines undergo ring-opening and then dissociate via the A and the A (X) cross-ring cleavage channels. The preference for the ring-opening is similar to the behavior of -acetylhexosamines and explains why the two anomers of the same sugar give the same mass spectrum.

Unexpected Dissociation Mechanism of Sodiated N-Acetylglucosamine and N-Acetylgalactosamine.

The mechanism for the collision-induced dissociation (CID) of two sodiated N-acetylhexosamines (HexNAc), N-acetylglucosamine (GlcNAc), and N-acetylgalactosamine (GalNAc), was studied using quantum-chemistry calculations and resonance excitation in a low-pressure linear ion trap. Experimental results show that the major dissociation channel of the isotope labeled [1-O, D]-HexNAc is the dehydration by eliminating HDO, where OD comes from the OD group at C3. Dissociation channels of minor importance include the A cross-ring dissociation.

Collision-induced dissociation of sodiated glucose, galactose, and mannose, and the identification of anomeric configurations.

Collision-induced dissociation of sodiated α-glucose, β-glucose, α-galactose, β-galactose, α-mannose, and β-mannose was studied using electronic structure calculations and resonance excitation in a low-pressure linear ion trap. We made an extensive search of conformers and transition states in calculations to ensure the transition state with the lowest barrier height for each dissociation channel could be located. The major dissociation channels, in addition to desodiation, are cross-ring dissociation and dehydration.

Tuning the vibrational coupling of HO by changing its solvation environment.

This study demonstrates how the intermode coupling in the hydronium ion (HO) is modulated by the composition of the first solvation shell. A series of rare gas solvated hydronium ions (HORg, where Rg = Ne, Ar, Kr, and Xe) is examined via reduced-dimensional anharmonic vibrational (RDAV) ab initio calculations. We considered six key vibrational normal modes, namely: a hindered rotation, two H-O-H bends, and three O-H stretches.