Physical, mental, spiritual and social wellbeing of urban population during the COVID-19 lockdown phases: a cross-sectional study

Background: COVID 19 pandemic created immense mental & physical agony among human beings worldwide. The present study was conducted to assess the physical, mental, social and spiritual wellbeing of young adults and the elderly, during the lock-down phase of COVID-19. Methods: The cross-sectional study was conducted among 227 healthy adults in Bhubaneswar, capital of Odisha. Data was collected using a self-administered questionnaire pertaining to the physical, mental, social and spiritual health of participants. Results: During the lockdown, around two-thirds (65.4%) of the participants reported feeling helpless. The elderly felt more helpless than the young adults. One-third (73, 32.6%) of the participants experienced health issues during the lockdown period. The majority of the study participants (83.8%) mentioned that their family members shared tasks during lockdown which was a very positive sign observed in this study. Faith in God for the elderly and family support for the young adults made them mentally stronger. Conclusion: Managing pandemic needs a multipronged approach. But focusing on psychosocial health will prevent future unseen mental health pandemics and improve the resilience of mankind

Growth of Open Access Law Research Articles seen through DOAJ: A Bibliometric Analysis

This study provides a bibliometric analysis of law literature published from 2015-2019. A total of 3001 articles were retrieved from DOAJ database for the study. The law literature has been further divided into two categories, i.e. Public law and Private law. This paper focuses on the journal-wise distribution of publications, subject-wise distribution of publications, annual growth rate as well as compound annual growth rate, relative growth rate (RGR) and doubling time (DT) of open access law literature. Various statistical tests and methods such as Student’s t test, Chi-square test and correlation studies have been applied to verify the significance difference between the public law and the private law literature. It is found that the mean RGR for public law and private law are 0.41% and 0.39 % respectively whereas the values of DT for public and private law are 2.03 years and 0.98 year respectively

Dilution does the trick: Role of mixed solvent evaporation in controlling nanoparticle self-assembly

An easy and convenient way to prepare superlattices of amine capped gold nanoparticles is presented. It is clearly established that solvent evaporation significantly influences the nature of resulting superlattices and critically governs whether monolayer or multilayer superlattices are formed. More specifically, it is demonstrated that dilution of the nanoparticle dispersion with a similar solvent (but with different vapour pressure) is an expedient handle to control the nature of self-assembly

Preparation of Ag_Shell–Au_Core nanoparticles by anti-Galvanic reactions: are capping agents the “real heroes” of reduction?

The formation of AgShell–AuCore nanoparticles by the reduction of Ag+ ions on preformed Au NPs, mediated by the capping agents like dodecylamine is described. We clearly established that while monodisperse AgShell–AuCore structures can be formed in presence of weak surface binding ligands such as amines, strong binding ligands such as thiols, lead to formation of separate monometallic Au and Ag particles. Apart from highlighting the influence of metal-ligand binding strength on the formation of core–shell nanoparticle architectures, our study also provides an easy means to produce AgShell–AuCore structures

Fine control of nanoparticle sizes and size distributions: temperature and ligand effects on the digestive ripening process

It is demonstrated that a fine control over the size and size distribution of nanoparticles could be achieved using digestive ripening at different temperatures. Such variations in size and size distributions hugely influence the self-assembled processes in nanoparticles, and result in superlattice structures that are controlled by subtle interplay between ligand orientational entropy and their interdigitation and the van der Waals attraction between the metal cores

Time and temperature effects on the digestive ripening of gold nanoparticles: is there a crossover from digestive ripening to ostwald ripening?

The effects of time and temperature on the gold nanoparticle sizes obtained by digestive ripening have been investigated. In digestive ripening, a polydisperse colloid, upon refluxing with a surface-active ligand in a solvent, gets converted to a nearly monodisperse one. In this study, a polydisperse gold nanoparticle system was heated in 4-tert-butyltoluene with hexadecanethiol at different temperatures, viz. 60, 90, 120, 150 and 180 °C for different time periods and the trends in particle size variations were recorded. At lower temperatures such as 60 and 90 °C, after the initial narrowing of the size distribution, the particle sizes remain constant even though the refluxing step is continued for 24 h, substantiating the prevalence of the digestive ripening process. However, at elevated temperatures (120, 150 and 180 °C) particle sizes grow continuously, indicating a deviation from the digestive ripening behavior to an Ostwald ripening-type phenomenon

Synthesis and in situ observation of 3D Superlattices of gold nanoparticles using oil-in-water emulsion

In this work oil-in-water emulsion has been successfully used as a confined environment to grow 3D superlattices of gold nanoparticles. The superlattices were grown from 5 nm uniform gold nanoparticles using slow destabilization method. The confined environment was created by forming a stable emulsion where the gold colloid suspended in toluene was used as oil phase. Superlattices were also formed in bulk solution using the same slow destabilization method. A comparative study reveals that compact superlattices form more readily inside the emulsion drops as compared to bulk precipitation. The unstable colloid (in bulk or as emulsion) was aged for various periods at 5 °C to form more compact superlattices. The best superlattices with sharp corners are observed when the superlattices are formed inside the emulsion and aged for a month. Two key parameters, the incubation temperature and anti-solvent concentration, are optimized to obtain larger superlattices with sharp features. A new method is also demonstrated for in situ observation of superlattice formation using an optical microscope

Time and Temperature Effects on the Digestive Ripening of Gold Nanoparticles: Is There a Crossover from Digestive Ripening to Ostwald Ripening?

The effects of time and temperature on the gold nanoparticle sizes obtained by digestive ripening have been investigated. In digestive ripening, a polydisperse colloid, upon refluxing with a surface-active ligand in a solvent, gets converted to a nearly monodisperse one. In this study, a polydisperse gold nanoparticle system was heated in 4-tert-butyltoluene with hexadecanethiol at different temperatures, viz., 60, 90, 120, 150, and 180 °C for different time periods, and the trends in particle size variations were recorded. At lower temperatures such as 60 and 90 °C, after the initial narrowing of the size distribution, the particle sizes remain constant even though the refluxing step is continued for 24 h, substantiating the prevalence of the digestive ripening process. However, at elevated temperatures (120, 150, and 180 °C) particle sizes grow continuously, indicating a deviation from the digestive ripening behavior to an Ostwald ripening-type phenomenon

Partial Chemicalization of Nanoscale Metals: An Intra‐Material Transformative Approach for the Synthesis of Functional Colloidal Metal‐Semiconductor Nanoheterostructures

Heterostructuring colloidal nanocrystals into multicomponent modular constructs, where domains of distinct metal and semiconductor phases are interconnected through bonding interfaces, is a consolidated approach to advanced breeds of solution-processable hybrid nanomaterials capable of expressing richly tunable and even entirely novel physical-chemical properties and functionalities. To meet the challenges posed by the wet-chemical synthesis of metal-semiconductor nanoheterostructures and to overcome some intrinsic limitations of available protocols, innovative transformative routes, based on the paradigm of partial chemicalization, have recently been devised within the framework of the standard seeded-growth scheme. These techniques involve regiospecific replacement reactions on preformed nanocrystal substrates, thus holding great synthetic potential for programmable configurational diversification. This review article illustrates achievements so far made in the elaboration of metal-semiconductor nanoheterostructures with tailored arrangements of their component modules by means of conversion pathways that leverage on spatially controlled partial chemicalization of mono- and bi-metallic seeds. The advantages and limitations of these approaches are discussed within the context of the most plausible mechanisms underlying the evolution of the nanoheterostructures in liquid media. Representative physical-chemical properties and applications of chemicalization-derived metal-semiconductor nanoheterostructures are emphasized. Finally, prospects for developments in the field are outlined