SARS-CoV-2 coronavirus has been recognized the causative agent of the recent and ongoing pandemic. Effective and specific antiviral agents or vaccines are still missing, despite a large plethora of compounds have been proposed and tested worldwide. New compounds are requested urgently and virtual screening can offer fast and robust predictions to investigate. Moreover, natural compounds were shown to exert antiviral effects and can be endowed with limited side effects and wide availability. Our approach consisted in the validation of a docking protocol able to refine the most suitable candidates, within the 31000 natural compounds of the natural product activity and species source (NPASS) library, interacting with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike glycoprotein. After the refinement process two natural compounds, castanospermine and karuquinone B, were shown to be the best-in-class derivatives in silico able to target an essential structure of the virus and to act in the early stage of infection.

In recent decades, quantum dots (QDs) with tunable bandgap, large absorption coefficient, high quantum yield, multiexciton effect, and easy solution processing have unparalleled advantages in photoelectric conversion. Optoelectronic devices based on QDs of different composition have made great progress. However, there is still a lack of reviews on comparing the optoelectronic application level of semiconductor quantum dots (SQDs), perovskite quantum dots (PQDs), and carbon quantum dots (CDs), and also rarely providing a comprehensive summary of photocatalysis. First, this review almost completely summarizes advantages and disadvantages of common synthesis methods for QDs, especially pointing out the importance of optimization strategies for preparing high‐quality QDs such as ligand engineering, ion exchange, and purification separation. Then, compositions of SQD, PQD, CD, and corresponding optoelectronic properties are introduced, respectively. Next, the strengths and weaknesses of the four QDs structures are compared in detail. Finally, the flourishing development in various optoelectronic applications is separately demonstrated, and development degree of SQDs, PQDs, and CDs is compared to discover the most suitable application scenarios for each. On these bases, bottlenecks and opportunities are also put forwarded, hoping to stimulate more breakthroughs in this field.

This study describes the adsorption of Cu (II), Co (II) and Ni (II) ions from wastewater on Vigna radiata husk biomass. The ability of adsorbent to capture the metal ions has been found to be in the order of Ni (II)>Co (II) and Cu (II) depending upon the size and nature of metal ions to be adsorbed. It has been observed that percentage removal of Cu (II), Co (II) and Ni (II) ions increases with increase of adsorbent dosage, contact time and pH of the medium but up to a certain extent. Maximum adsorption capacity (qmax) for Cu (II), Co (II) and Ni (II) ions has been found to be 11.05, 15.04 and 19.88 mg/g, respectively, under optimum conditions of adsorbent dosage, contact time and pH of the medium. Langmuir model best fits the adsorption process with R2 value approaches to unity for all metal ions as compared to other models because adsorption sites are seemed to be equivalent and only monolayer adsorption may occur as a result of binding of metal ion with a functional moiety of adsorbent. Pseudo second order kinetic model best interprets the adsorption process of Cu (II), Co (II) and Ni (II) ions. Thermodynamic parameters such as negative value of Gibbs energy (∆G°) gives information about feasibility and spontaneity of the process. Adsorption process was found to be endothermic for Cu (II) ions while exothermic for Co (II) and Ni (II) ions as signified by the value of enthalpy change (∆H°). Husk biomass was recycled three times for removal of Ni (II) from aqueous medium to investigate its recoverability and reusability. Moreover V. radiata husk biomass has a potential to extract Cu (II) and Ni (II) from electroplating wastewater to overcome the industrial waste water pollution.

A coronavirus disease pandemic (COVID-19) is still a global problem with not sufficient evidence of a declining pattern caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It is generally accepted that normal life is impeded by securing a reliable vaccine strategy. Many countries have accelerated the process of clinical trials to create effective treatment with COVID-19. More than 200 candidate vaccines have been started for SARS-CoV-2 testing. This review attempts to provide an overview of the currently emerging COVID-19 vaccine types, address the theoretical and practical challenges of vaccines for COVID-19 and discuss possible strategies to help vaccine design succeed. The first move was to take out papers using the initial keyword "pandemics, vaccines and vaccine types". A total of 63,538 results (including 1,200 journals; 16,875 books; and 12,871 web pages), with the initial keyword, searched for in the Scopus database. Further improvements were searched on keywords such as "pandemic and vaccine types" (711 newspapers and 5,053 webpages). This review attempts to overview the historical and important basic information about the pandemics viz. history, virological characteristics, structure, origin and physio-chemical properties. The second phase includes the vaccination types and strategies in depth. It includes the diagnosis, virology and pathogenesis of SARS-CoV-2 and SARS-COV-2/COVID-19 vaccines. The development, planning strategies, types, cost and current scenarios of COVID-19 vaccines are depicted in detail. The pandemic COVID-19 as it continues, is a global problem. Vaccination seems to be an efficient and economical way to mitigate and control the epidemic. This requires a mass production of successful COVID-19 vaccines.

Mamyshev oscillators (MOs) have attracted significant attention given their potential in yielding ultrafast lasers with high peak power. Based on step‐like saturable absorbers and self‐similar evolution in the gain fiber, MO technology features an advanced system capable of generating ultrastable femtosecond pulses with ultrahigh peak power. In this review, the principle of MO is presented in terms of their transmission function and tolerance to nonlinear phase shift and recent progress is reported in the advanced output performance of MO, manifested through high peak power, few‐cycles, high repetition rate, and supercontinuum generation. MO with various operation wavelengths (1, 1.5, and 2 μm) are examined, and MO starting methods are fully discussed, followed by a detailed account of diverse potential applications in areas such as biomedical imaging and material processing. Based on current progress, the prospective challenges and future directions of MO are highlighted and discussed.

The room temperature and task‐specific ionic liquids nowadays have been investigated widely for the removal of sulfur compounds from the natural gas streams. However, the major challenge is the recovery of the desulfurized ionic liquids, which need some significant developments. In this study, two magnetic ionic liquids including the 1‐butyl‐3‐methylimidazolium tetrachloroferrate [Bmim][FeCl4] and 1‐butyl‐3‐methylimidazolium thiocyanate [Bmim][SCN] were investigated for their interaction with the sulfur‐rich compound, that is, dibenzothiophene. The ionic liquids samples were desulfurized and then regenerated with the co‐solvent hexane. The samples were characterized and investigated with the analytical techniques including the Fourier‐transform infrared spectroscopy, ultraviolet–visible absorption analysis, thermogravimetric analysis, and detailed analysis by Raman spectroscopy. The desulfurization results demonstrated that there is no significant influence of the dibenzothiophene molecules on the basic structures of ionic liquids. The regeneration results revealed that the high polarity of the co‐solvent hexane successfully dissolve the dibenzothiophene and efficiently separated from the ionic liquids. Hence, the work present here in this study could be applied for the extractive removal of sulfur compounds from ionic liquids for their regeneration using high polarity co‐solvent hexane.

Fighting external pathogens relies on the tight regulation of the gene expression of the immune system. Ferroptosis, which is a distinct form of programmed cell death driven by iron, is involved in the enhancement of follicular helper T cell function during infection. The regulation of RNA is a key step in final gene expression. The present study aimed to identify the expression level of antisense lncRNAs (A2M-AS1, DBH-AS1, FLVCR1-DT, and NCBP2AS2-1) and FLVCR1 in COVID-19 patients and its relation to the severity of the disease. COVID-19 patients as well as age and gender-matched healthy controls were enrolled in this study. The expression level of the antisense lncRNAs was measured by RT-PCR. Results revealed the decreased expression of A2M-AS1 and FLVCR1 in COVID-19 patients. Additionally, they showed the increased expression of DBH-AS1, FLVCR1-DT, and NCBP2AS2. Both FLVCR1-DT and NCBP2AS2 showed a positive correlation with interleukin-6 (IL-6). DBH-AS1 and FLVCR1-DT had a significant association with mortality, complications, and mechanical ventilation. A significant negative correlation was found between A2M-AS1 and NCBP2AS2-1 and between FLVCR1 and FLVCR1-DT. The study confirmed that the expression level of the antisense lncRNAs was deregulated in COVID-19 patients and correlated with the severity of COVID-19, and that it may have possible roles in the pathogenesis of this disease.

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