Emergence of Recombinant Subclade D3/Y in Coxsackievirus A6 Strains in Hand-Foot-and-Mouth Disease (HFMD) Outbreak in India, 2022.

Coxsackievirus-A6 (CV-A6) is responsible for more severe dermatological manifestations compared to other enteroviruses such as CV-A10, CV-A16, and EV-A71, causing HFMD in children and adults. Between 2005 and 2007, the recombinant subclade D3/RF-A started to expand globally, and a CV-A6 pandemic started. The study aimed to conduct whole-genome sequencing (WGS) of an isolated CV-A6 strain from currently circulating HFMD cases from India in 2022. Gene-specific RT-PCR and sequencing were used to perform molecular characterization of the isolated virus. Confirmation of these isolates was also performed by transmission electron microscopy and WGS. Among eleven positive clinical enterovirus specimens, eight CV-A6 strains were successfully isolated in the RD cell line. Isolates confirmed the presence of the CV-A6 strain based on VP1 and VP2 gene-specific RT-PCR. Sequences of isolates were clustered and identified as the novel CV-A6 strain of the D3/Y sub-genotype in India. The studies revealed that the D3/Y sub-genotype is being introduced into Indian circulation. The predicted putative functional loops found in VP1 of CV-A6 showed that the nucleotide sequences of the amino acid were a remarkably conserved loop prediction compatible with neutralizing linear epitopes. Therefore, this strain represents a potential candidate for vaccine development and antiviral studies.

Azadirachta indica (AI)leaf extract coated ZnO-AInanocore-shell particles for enhanced antibacterial activity against methicillin-resistantStaphylococcus aureus(MRSA).

With the rise in microbial resistance to traditional antibiotics and disinfectants, there is a pressing need for the development of novel and effective antibacterial agents. Two major approaches being adopted worldwide to overcome antimicrobial resistance are the use of plant leaf extracts and metallic nanoparticles (NPs). However, there are no reports on the antibacterial potential of NPs coated with plant extracts, which may lead to novel ways of treating infections. This study presents an innovative approach to engineer antibacterial NPs by leveraging the inherent antibacterial properties of zinc oxide NPs (ZnO NPs) in combination withAzadirachta indica(AI) leaf extract, resulting in enhanced antibacterial efficacy. ZnO NPs were synthesised by the precipitation method and subsequently coated withAIleaf extract to produce ZnO-AInanocore-shell structures. The structural and morphological characteristics of the bare and leaf extract coated ZnO NPs were analysed by x-ray diffraction and field emission scanning electron microscopy, respectively. The presence of anAIleaf extract coating on ZnO NPs and subsequent formation of ZnO-AInanocore-shell structures was verified through Fourier transform infrared spectroscopy and photoluminescence techniques. The antibacterial efficacy of both ZnO NPs and ZnO-AInanocore-shell particles was evaluated against methicillin-resistantStaphylococcus aureususing a zone of inhibition assay. The results showed an NP concentration-dependent increase in the diameter of the inhibition zone, with ZnO-AInanocore-shell particles exhibiting superior antibacterial properties, owing to the combined effect of ZnO NPs and the poly phenols present inAIleaf extract. These findings suggest that ZnO-AInanocore-shell structures hold promise for the development of novel antibacterial creams and hydrogels for various biomedical applications.

Infrared-to-visible conversion in strontium sulphate through a defect-based infrared stimulated visible emission phenomenon.

Strontium sulphate (SrSO4 ) is a defect-based photoluminescence material, generally used in thermoluminescence applications, and has been studied for infrared (IR) stimulated visible emission. The SrSO4 particles were synthesized using a precipitation method. The orthorhombic phase of SrSO4 was confirmed from the X-ray diffraction pattern and the formation of micron-sized particles was authenticated from field emission scanning electron micrographs. The elemental composition of oxygen and strontium was determined using energy-dispersive X-ray analysis measurement that confirmed the presence of V O • • and V Sr ' ' intrinsic defects in the material. Photoluminescence investigations showed the presence of various defect bands in the band gap giving rise to intrinsic luminescence in SrSO4 . The emission in the visible region was attributed to the defect band arising due to V O • • . Photoluminescence lifetime measurement confirmed the presence of stable defect states with a lifetime in microseconds. The SrSO4 sample was tested using IR lasers and a red-orange emission spot was observed from the powder sample when excited with IR lasers. The underlying principle for IR-to-visible conversion in the material is a defect-mediated phenomenon that has been described through the energy level diagram of the material.

Improvement in white light emission of Dy3+doped CaMoO4via Zn2+co-doping.

The research in developing a single ingredient phosphor for white-light emission is progressively increasing. It is well known that the4F9/2 â†’ 6H13/2(yellow) and4F9/2 â†’ 6H15/2(blue) transitions of Dy3+ions give near-white light emission. The white light emission of Dy3+ions can be enhanced via improving the crystallinity of the host phosphor via co-doping of transition metal ions. In this paper, we report a significant improvement in the white light emission of Dy3+doped CaMoO4by co-doping Zn2+ions. The x-ray diffraction pattern confirms the tetragonal phase of pure and doped CaMoO4phosphor. The peak broadening and a red-shift in the absorption peak are observed by UV-vis absorption analysis of Zn2+/Dy3+doped CaMoO4. From Photoluminescence studies, we have observed that in Dy3+doped CaMoO4, the 4% Dy3+doped CaMoO4exhibits maximum emission. The Zn2+ions are co-doped to further increase the luminescence intensity of CaMoO4:4%Dy3+and the maximum luminescence is obtained for 0.25% Zn2+concentration. Two intense emission peaks centered at 484 nm and 574 nm related to transitions4F9/2 â†’ 6H15/2and4F9/2 â†’ 6H13/2of Dy3+ion are observed for Dy3+doped phosphor. The4F9/2 â†’ 6H13/2transition is the forced electric dipole transition which is affected by its chemical environment. After Zn2+co-doping, the4F9/2 â†’ 6H13/2transition is affected due to a change in asymmetricity around the Dy3+ions. The 0.25% co-doping of Zn2+gives 34% enhancement in luminescence emission of 4% Dy3+doped CaMoO4. As a result, the CIE coordinates of chromaticity diagram and the color purity of the 0.25% Zn2+co-doped CaMoO4:4Dy3+show improvement in the overall white light emission. We have shown that with Zn2+co-doping, the non-radiative relaxations are reduced which results in improved white light emission of Dy3+ions.

Strain assisted magnetoelectric coupling in ordered nanomagnets of CoFe2O4/SrRuO3/(Pb(Mg1/3Nb2/3)O3-PbTiO3) heterostructures.

We have explored the electric field controlled magnetization in the nanodot CoFe2O4/SrRuO3/PMN-PT (CFO/SRO/PMN-PT) heterostructures. Ordered ferromagnetic CFO nanodots (∼300 nm lateral dimension) are developed on the PMN-PT substrate (ferroelectric as well as piezoelectric) using a nanostencil-mask pattering method during pulsed laser deposition. The nanostructures reveal electric field induced magnetization reversal in the single domain CFO nanodots through transfer of piezostrains from the piezoelectric PMN-PT substrate to the CFO. Further, electric field modulated spin structure of CFO nanomagnets is analyzed by using x-ray magnetic circular dichroism (XMCD). The XMCD analysis reveals cations (Fe3+/Co2+) redistribution on the octahedral and tetrahedral site in the electric field poled CFO nanodots, establishing the strain induced magneto-electric coupling effects. The CFO/SRO/PMN-PT nanodots structure demonstrate multilevel switching of ME coupling coefficient (α) by applying selective positive and negative electric fields in a non-volatile manner. The retention of two stable states ofαis illustrated for ∼106seconds, which can be employed to store the digital data in non-volatile memory devices. Thus the voltage controlled magnetization in the nanodot structures leads a path towards the invention of energy efficient high-density memory devices.

Spin reorientation transition and coupled spin-lattice dynamics of Sm0.6Dy0.4FeO3.

In this work, we have presented a solid-solution of Sm0.6Dy0.4FeO3 in the form of nano-particles having spin reorientation transition (SRT) at a temperature interval of 220-260 K. The lattice dynamics of Sm0.6Dy0.4FeO3 have investigated by temperature-dependent x-ray diffraction and Raman spectroscopy. A negative thermal expansion at low temperatures has observed, which might be due to the interaction between Sm3+ and Fe3+ sublattice. Anomalous behavior in lattice parameters, octahedral tilt angle, and bond lengths have observed in the vicinity of SRT, which confirms the existence of magneto-elastic coupling in the system. The strong anomaly has observed in linewidth and phonon frequencies of Raman modes around SRT, which may be related to the spin-phonon coupling in Sm0.6Dy0.4FeO3. The contribution of SRT in lattice change and the presence of spin-phonon coupling can help to understand the correlation between the magnetic and structural properties of orthoferrite.

Effect of Mg doping in Sr2 SiO4 :Eu2+ nanophosphors for blue and white emission at near-UV excitation.

Nanophosphors of (Sr0.98-x Mgx Eu0.02 )2 SiO4 (x = 0, 0.18, 0.38, 0.58 and 0.78) were prepared through low temperature solution combustion method and their luminescence properties were studied. The emission peak for Eu2+  -doped Sr2 SiO4 nanophosphor is observed at ~490 nm and ~553 nm corresponding to two Sr2+ sites Sr(I) and Sr(II) respectively for 395 nm excitation. However the addition of Mg2+ dopant in Sr2 SiO4 leads to suppression of ~553 nm emission peak due to absence of energy levels of Sr (II) sites which results in a single broad emission at ~460 nm. It was shown that the emission peak blue shifted with increase in Mg concentration which may be attributed to change in crystal field environment around Sr(I) sites. Therefore, the (Mg0.78 Sr0.20 Eu0.02 )2 SiO4 nanophosphor can be used for blue emission and the Sr2 SiO4 :Eu0.042+ for green-yellow emission at 395 nm excitations. The Commission International de L'Eclairage (CIE) chromaticity coordinates for mixed powders of (Mg0.78 Sr0.20 Eu0.02 )2 SiO4 and Sr2 SiO4 :Eu0.042+ (in a 1:1 ratio) fall in the white region demonstrating the possible use of the mixture in white light generation using near-UV excitation source.