Ga-In Alloy Segregation within a Porous Glass as Studied by SANS.

Nanolattices can play the role of templates for metals and metallic alloys to produce functional nanocomposites with particular properties affected by nanoconfinement. To imitate the impact of nanoconfinement on the structure of solid eutectic alloys, we filled porous silica glasses with the Ga-In alloy, which is widely used in applications. Small-angle neutron scattering was observed for two nanocomposites, which comprised alloys of close compositions. The results obtained were treated using different approaches: the common Guinier and extended Guinier models, the recently suggested computer simulation method based on the initial formulae for neutron scattering, and ordinary estimates of the scattering hump positions. All of the approaches predicted a similar structure of the confined eutectic alloy. The formation of ellipsoid-like indium-rich segregates was demonstrated.

Magnetic Studies of Superconductivity in the Ga-Sn Alloy Regular Nanostructures.

For applications of nanolattices in low-temperature nanoelectronics, the inter-unit space can be filled with superconducting metallic alloys. However, superconductivity under nanoconfinement is expected to be strongly affected by size-effects and other factors. We studied the magnetic properties and structure of the Ga-Sn eutectic alloy within regular nanopores of an opal template, to understand the specifics of the alloy superconductivity. Two superconducting transitions were observed, in contrast to the bulk alloy. The transitions were ascribed to the segregates with the structures of tetragonal tin and a particular gallium polymorph. The superconducting-phase diagram was constructed, which demonstrated crossovers from the positive- to the common negative-curvature of the upper critical-field lines. Hysteresis was found between the susceptibilities obtained at cooling and warming in the applied magnetic field.

SANS Studies of the Gallium-Indium Alloy Structure within Regular Nanopores.

Potential applications of nanolattices often require filling their empty space with eutectic metallic alloys. Due to confinement to nanolattices, the structure of phase segregates in eutectic alloys can differ from that in bulk. These problems are poorly understood now. We have used small angle neutron scattering (SANS) to study the segregation in the Ga-In alloy confined to an opal template with the regular pore network, created by a strict regularity of opal constituents in close similarity with nanolattices. We showed that SANS is a powerful tool to reveal the configuration of segregated phases within nanotemplates. The In-rich segregates were found to have specific structural features as small sizes and ordered arrangement.

Phase 3, open-label, Russian, multicenter, single-arm trial to evaluate the immunogenicity of varicella vaccine (VARIVAX™) in healthy infants, children, and adolescents.

Varicella (chickenpox) is a common, highly contagious disease caused by primary infection with varicella zoster virus (VZV), which can result in bacterial superinfection, central nervous system complications, and hospitalization. Stage 2 of this Phase 3 open-label study (ClinicalTrials.gov identifier: NCT03843632) enrolled 100 healthy infants, children, and adolescents (12 months-6 years, n = 37; 7-12 years, n = 33; 13-17 years, n = 30) without a clinical history of varicella. Participants aged 12 months-12 years were administered 1 dose of VARIVAX™ 0.5 mL (Varicella Virus Vaccine Live [Oka/Merck]) and adolescents aged 13-17 years were administered 2 doses 6 weeks apart. For participants seronegative at baseline (VZV antibody titer <1.25 glycoprotein enzyme-linked immunosorbent assay [gpELISA] units/mL), immunogenicity was assessed by seroconversion (VZV antibody titer ≥5 gpELISA units/mL) and VZV antibody geometric mean titers 6 weeks after the final dose. For participants who were VZV seropositive at baseline (VZV antibody titer ≥1.25 gpELISA units/mL), immunogenicity was assessed by antibody titer geometric mean fold rise and percentage of participants with ≥4-fold rise in antibody titer 6 weeks after the final dose. A Vaccine Report Card was used to report solicited and unsolicited adverse events through 42 days post-vaccination. After series completion among seronegative participants across age groups (n = 74), 98.6% demonstrated seroconversion 6 weeks post-vaccination; among seropositive participants (n = 26), 65.4% had ≥4-fold rise in antibody titer 6 weeks post-vaccination. No new safety signals were observed. Administering VARIVAX to infants, children, and adolescents resulted in an acceptable immune response with a safety profile consistent with the licensed product.

Phase 3, open-label, Russian, multicenter, single-arm trial to evaluate the immunogenicity of varicella vaccine (VARIVAX™) in healthy adults.

Varicella (chickenpox) is a common, highly contagious disease caused by primary infection with varicella zoster virus (VZV). Adults typically experience more severe symptoms than children and have a higher risk of developing complications. Stage 1 of this Phase 3 open-label study enrolled healthy adults in Russia aged 18-75 years without a clinical history of varicella infection. Eligible participants (n = 50) were administered 2 doses of VARIVAX™ (Varicella Virus Vaccine Live [Oka/Merck]) 0.5 mL 6 weeks apart. For participants seronegative at baseline (VZV antibody titer <1.25 glycoprotein enzyme-linked immuno-sorbent assay [gpELISA] units/mL), immunogenicity was assessed by seroconversion (VZV antibody titer ≥5 gpELISA units/mL) and assessment of geometric mean titers of VZV antibody as measured by gpELISA 6 weeks after Dose 2. For VZV seropositive participants at baseline (VZV antibody titer ≥1.25 gpELISA units/mL), immunogenicity was assessed by geometric mean fold rise in antibody titer and percentage of participants with a ≥ 4-fold rise in antibody titer 6 weeks after Dose 2. A Vaccine Report Card was used to record solicited and unsolicited adverse events through 42 days post-vaccination. All participants who were seronegative (n = 26) at baseline demonstrated seroconversion 6 weeks after Dose 2. Among participants who were seropositive at baseline (n = 23), 60.9% had a ≥4-fold rise in antibody titer 6 weeks after Dose 2. Vaccination was generally well tolerated, with no new safety signals identified. Administration of 2 doses of VARIVAX in adults in Russia results in acceptable immune responses with safety data consistent with the licensed product (Clinicaltrials.gov identifier: NCT03843632).