Investigating CO2 storage properties of C2N monolayer functionalized with small metal clusters

By using first principles calculations based on density functional theory (DFT), we studied a mechanism for the efficient capture of multiple CO2 molecules on TMn doped C2N monolayer (TMn = Tin and Scn with n = 1–3). A comprehensive analysis revealed that all the metal clusters bind strongly to C2N monolayer; however the bindings of Scn are stronger than those of Tin clusters. On the basis of electronic structure calculations, it was found that uniformly distributed metal clusters transformed the semiconducting C2N monolayers into metal. The magnetic states of C2N also changed from non-magnetic to magnetic upon the introduction of metal dopants. We found that a maximum of six CO2 molecules could be adsorbed on C2N doped with dimers and trimers of both Sc and Ti clusters. Our van der Waals corrected DFT calculations showed that the average binding energies per CO2 molecule decreased with the increase in the number of incident CO2 molecules to metal functionalized C2N. Overall, Scn doped C2N monolayer anchored the CO2 molecules stronger than that of Tin doping. We believe that these findings would pave the way for the synthesis of efficient CO2 capture medium

Carbon Nitride Monolayers as Efficient Immobilizers toward Lithium Selenides: Potential Applications in Lithium-Selenium Batteries

The low cost, high energy density, and nontoxic nature have made lithium-selenium batteries (LiSeBs) a promising option for large-scale energy storage applications. However, the issue of capacity loss during consecutive charge/discharge cycles has put a serious question mark on the commercialization of LiSeBs. In a quest to suppress the issue of capacity loss due to the dissolution of active lithium polyselenides (Li2Sen, n = 1-8) into the electrolyte, the so-called shuttle effect, we have employed first-principles density functional theory calculations to study the anchoring properties of two carbon nitrides monolayers, namely, nitrogenated holey graphene (C2N) and carbon nitride (C3N). We find that the presence of nitrogen (N) atoms, in both C2N and C3N, enable them to bind Li2Sen clusters stronger than that of graphene. We further discover that the anchoring properties of C2N (-2.03 to -3.82 eV) are stronger than that of C3N (-1.21 to -1.30 eV) due to higher concentrations of N atoms and relatively bigger pore size in the former than the later. In addition to the appropriate bindings, improved conductivities upon the adsorption Li2Sen further reinforce the promise of C2N and C3N as potential anchoring materials for LiSeBs. We believe that our computational results would pave the way toward the experimental synthesis of efficient anchoring materials based on the studied systems

Biotransformation studies of textile dye Remazol Orange 3R

In the present study, biotransformation of Remazol Orange 3R (RO3R) was studied using well-known bacterial isolate Pseudomonas aeruginosa strain BCH. The dye was decolorized up to 98 % within 15 min. The induction in the level of various oxidoreductive enzymes viz. laccase, tyrosinase, veratryl alcohol oxidase and DCIP reductase were observed in the cells obtained after decolorization of RO3R, which supports their role in decolorization. The metabolites of RO3R obtained after biodegradation were identified and characterized by various analytical techniques viz, HPLC, FTIR, and GC–MS. The RO3R was transformed to the N-(7 amino 8 hydroxy-napthalen-2yl) actamide (m/z, 198), Acetamide (m/z, 59) and Napthalen-1-ol (m/z, 144)

STUDY ON ACUTE ADVERSE DRUG REACTIONS OF ANTISNAKE VENOM IN A RURAL TERTIARY CARE HOSPITAL

  Objective: Snake bite is a major occupational hazard especially in rural areas. Majority of the anti-venom reactions are wrongly attributed to envenomation. There is inadequate reporting of anti-venom reactions leading to the paucity of true data of morbidity and mortality. The aim was to evaluate the adverse drug reaction (ADR) profile of anti-snake venom serum (ASV) in a rural tertiary care hospital.Methods: A prospective, observational study was conducted. A total number of 50 indoor cases of snake bites from May 2012 to January 2013 was included in the study, and the anti-venom reactions were assessed. In addition, basic epidemiological data and prescribing practices of ASV were also analyzed.Results: The incidence of snake bite was more in males (64%) as compared to females (36%) attributed to their out dwelling lifestyle. Vasculotoxic snake bites were more common (46%) than neuroparalytic ones (44%). Mild envenomation was the most common presentation. A total of 31 (62%) patients who received ASV suffered from anti-venom reactions. The most common nature of the reaction was chills, rigors (23.53%) followed by hypotension (21.57%). 52.94% cases of adverse reactions were of early anaphylactic type followed by 45.1% cases of pyrogenic reactions. 43.14% of cases of anti-venom reactions were probable in nature, and 13.73% were certain in nature with World Health Organization-Uppsala Monitoring Centre classification of ADRs. By using modified Hartwig Seigel scale, 70.59% cases were mild in severity, and 5.88% were severe in nature. Most of the reactions were classified as not preventable with the Schumock Thornton criteria. All the reactions were classified as hypersensitivity reactions with Karch and Lasanga classification.Conclusions: Present study showed a higher incidence of reactions to ASV at our institute. There was an inadequate documentation of clinical findings, investigations, and adverse reactions in most of the case papers.Keywords: Anti-snake venom, Adverse drug reactions, Pharmacovigilance, Snake bite.Â

Prediction of the Interfacial Properties of High-Performance Polymers and Flattened CNT-Reinforced Composites Using Molecular Dynamics

The next generation of ultrahigh-strength composites for structural components of vehicles for manned missions to deep space will likely incorporate flattened carbon nanotubes (flCNTs). With a wide range of high-performance polymers to choose from as the matrix component, efficient and accurate computational modeling can be used to efficiently downselect compatible resins and provide critical physical insight into the flCNT/polymer interface. In this study, molecular dynamics simulation is used to predict the interaction energy, frictional sliding resistance, and mechanical binding of flCNT/polymer interfaces for epoxy, bismaleimide (BMI), and benzoxazine high-performance resins. The results indicate that BMI has a stronger interfacial interaction and transverse tension binding with flCNT interfaces, while benzoxazine demonstrates the strongest levels of interfacial friction resistance

Exceptional anoxia resistance in larval tiger beetle, Phaeoxantha klugii (Coleoptera : Cicindelidae)

The tiger beetle Phaeoxantha klugii inhabits Central Amazonian floodplains, where it survives the annual inundation period in the third-instar larval stage submerged in the soil at approximately 29 degreesC for up to 3.5 months. Because flooded soils quickly become anoxic, these larvae should be highly resistant to anoxia. The survival of adult and larval P. klugii was therefore tested during exposure to a pure nitrogen atmosphere in the laboratory at 29 degreesC. Adult beetles were not resistant (< 6 h). Survival of larvae decreased over time, maximum survival was 15 days, whereas time to 50% mortality was 5.7 days (95% confidence interval 3.8-7.9). Anoxia resistance was additionally tested in third-instar larvae submerged within sediment for 40 days before anoxia exposure in the laboratory. Anoxia resistance was greatly enhanced in these larvae, showing a survival rate of 50% after 26 days of anoxia exposure. It appears that the gradual flooding process and/or the submersion phase induced a physiological alteration, most probably a strong depression in metabolic rate, which requires some days for induction. The degree of anoxia resistance in larval P. klugii is remarkable among terrestrial arthropods worldwide, even more so considering the high ambient temperatures. The species is well-suited to serve as a model organism for studying the physiological mechanisms of anoxia and submersion resistance in terrestrial arthropods inhabiting tropical floodplains

Mechanical response of polymer/BN composites investigated by molecular dynamics method

Boron nitride (BN) nanomaterials are being proposed as reinforcement materials in the next-generation structural composite materials for aerospace applications. Considering that the polymer/reinforcement interface characteristics can significantly affect the bulk-level properties, we focus on the representative cases of cyanate esters, epoxy, and bismaleimide (BMI) resins forming interfaces with a bilayer BN. While the fluorinated cyanate ester interface demonstrates lower interaction energy than non-fluorinated cyanate ester due to steric hindrance provided by fluorine groups, BMI shows higher interaction energy than epoxy because of the planarity of BMI. Calculations simulating pull-apart transverse tension experiments using molecular dynamics find that the non-fluorinated ester interface exhibits higher peak strength and stiffness than the fluorinated interface. On the other hand, the epoxy/BN interface is predicted to have significantly lower toughness than the BMI/BN interface. The results based on interaction energy and pull-apart transverse tension show that the BMI with BN can be considered superior to epoxy and ester polymers with BN. Graphical abstract: [Figure not available: see fulltext.

Identification, Synthesis, and Strategy For Minimization of Potential Impurities Observed In Raltegravir Potassium Drug Substance

Multiple sources of anticipated degradation and process impurities of raltegravir potassium drug substance observed during the laboratory optimization and later during its bulk synthesis are described in this article. The impurities were monitored by UPLC, and their structures are tentatively assigned on the basis of fragmentation patterns in LC–MS and NMR spectroscopy. Most of the impurities are synthesized, and their assigned constitutions were confirmed by co-injection in UPLC. In addition to the formation, synthesis, and characterization, strategy for minimizing these impurities to the level accepted by ICH is also described. We feel that our study will be helpful to the generic industry for obtaining chemically pure raltegravir potassium