Interaction of Anagrelide drug molecule on pristine and doped boron nitride nanocages: a DFT, RDG, PCM and QTAIM investigation.

Nowadays, a nanostructure-based drug delivery system is one of the most noticeable topics to be studied, and in this regard, boron nitride nanoclusters are promising drug carriers for targeted drug delivery systems. In this article, the interaction mechanism of Anagrelide (AG) drug with B12N12 and Al- and Ga-doped B12N12 nanocages have been investigated using DFT with B3LYP/6-31 G (d, p) method in both gas and water media. All our studied complexes are thermodynamically stable, and doped nanocage complexes have higher negative adsorption energy (EAd.) and negative solvation energy than AG/B12N12 complexes which correspond to the stability of these systems in both media. The negative highest EAd value is 64.98 kcal/mol (63.17 kcal/mol) and 65.69 kcal/mol (65.11 kcal/mol) in gas (water) media for complex F (AG/AlB11N12) and complex I (AG/GaB11N12) respectively, which refers to the highest stability of these systems. The enhanced values of dipole moment (from 12.40 (12.65) Debye to 17.21 (17.69) Debye in complex F (complex I)) also confirm their stability. The QTAIM and RDG analysis endorse the strong adsorption nature of the AG drug onto the AlB11N12, and GaB11N12 nanocages, which is consistent with the adsorption energy as chemisorption occurs for these complexes. According to the electronic properties, doped nanocages show high sensitivity that infers their promising nature for drug delivery purposes. Thus, complex F and complex I are promising drug delivery systems, and doped nanocages (AlB11N12 and GaB11N12) are better carriers than pristine nanocages for the AG drug delivery system.Communicated by Ramaswamy H. Sarma.

Salinity extrusion and resilience of coastal aquaculture to the climatic changes in the southwest region of Bangladesh.

The southwest coastal belt of Bangladesh is characterized by a fresh and saline water interaction which gives rise to a discrete inter-saline freshwater convergence zone (ICZ). Hydrology and farming along this transition zone is influenced by upstream and downstream abiotic factors including salinity intrusion and water flow. To better understand the changing geography of the transitional ICZ line and the relative influence of these hydrological events on farming therein, the recent study compared relative changes from 2010 to 2014 based on qualitative and quantitative survey work with 80 households of 4 villages (Shobna, Faltita, Badukhali and Rudaghora) from Khulna and Bagerhat district. Contrary to the conventional hotcake climate change induced salinity intrusion the study found a significant decrease in saltwater influx and increased freshwater volume in the ICZ villages, reflecting a seaward movement trend. Farmer perception shifted to low saline and freshwater in many areas where it was high saline and medium saline in 2010. The factual and perceived salinity were varied from 1 ± 0.44 to 2 ± 0.77 ppt in the studied villages. To confront the condition farmer diversified their farming pattern from single crop like either only shrimp or prawn culture to concurrent culture of shrimp-prawn, shrimp, prawn and rice with an increased production of (68-204 kg/ha), finfish (217-553 kg/ha) and dyke crop (92-800 kg/ha). Thus, affecting the socioeconomic condition of the farmer with an increase in average monthly income, reported for the better-off classes in 2014, ranged from 14,300 to 51,667 BDT and for the worse-off ranged from 5000 to 9900 BDT. In contrast, this average monthly income was 9500- 27,000 for better-off and 3875 - 8600 for worse-off classes, reported in 2010. Besides, farming areas (average 17% for better-off and -0.5% for worse-off) and land leasing (average increment rate per ha 50%) also increased among the surveyed farmers, reported in 2014 compared to 2010. In addition, several adaptation strategies like unrefined salt use, change of water use, diversification through prawn, finfish and dyke crops along with traditional shrimp and overall land use change have a positive impact on farmer's economic and nutritional security as well as farming intensity. The study showed a unique attributes of salinity extrusion in micro-level of ICZ line where farmers intensified farming system with indigenous knowledge to secured their livelihoods.

Functionalized metal-organic framework-derived carbon: Effective adsorbent to eliminate methylene blue, a small cationic dye from water.

Elimination of organic dyes from wastewater is very important for our safe environment and sound health. In this work, adsorptive removal of cationic dyes, especially small ones, was investigated with carbonaceous materials to develop a competitive adsorption technology. To improve the performance of metal-organic framework (MOF)-derived carbons (MDCs) in dye adsorption, an MDC, derived from a MOF (MAF-6), was oxidatively functionalized with ammonium persulfate solutions (APSs). Although the porosity of pristine MDC decreased with functionalization via oxidation, functionalized MDCs (FMDCs), especially FMDC(1.0) that was obtained via treating MDC with APS (1.0 M), showed remarkable performances in the adsorption of small cationic dyes like methylene blue (MB) and azure B. For example, FMDC(1.0) had the maximum adsorption capacity (Qo) of 625.0 mg/g (for MB) which is larger than any reported value with carbonaceous materials. Moreover, the obtained Qo was around 4 and 2 times that of activated carbon with Qo of 160 mg/g and MDC with Qo of 298 mg/g, respectively. On the contrary, oxidative treatment of MDC was negative in adsorption of an anionic dye such as methyl orange. Moreover, the functionalized MDC was not very effective in the adsorption of cationic dyes with large sizes (like brilliant green, crystal violet, Janus green B, and rhodamine B) because of the limited pore size of the studied adsorbent FMDC(1.0). The remarkable adsorption of MB over FMDC(1.0) could be explained by electrostatic and π-π interactions. Finally, the facile recyclability of the FMDC(1.0) in MB adsorption was confirmed via successive adsorptions, FT-IR, and nitrogen adsorption; therefore, FMDC(1.0) can be suggested as a potential adsorbent to remove cationic dyes, especially with small molecular sizes.

Role of metal and anions in organo-metal halide perovskites CH3NH3MX3 (M: Cu, Zn, Ga, Ge, Sn, Pb; X: Cl, Br, I) on structural and optoelectronic properties for photovoltaic applications.

Methylammonium metal halide perovskites have recently been explored for new uses due to their unique and exciting optoelectronic properties. Their exceptional electronic properties have often been attributed to the overlap between the metal cation s and halogen p states. In this study, density functional theory calculations have been carried out based on the orthorhombic phase of the organometal trihalide perovskite CH3NH3MX3 (M: Cu, Zn, Ga, Ge, Sn, Pb; X: Cl, Br, I) to systematically investigate the effects of the metal cation and halogen anion on the structural, electronic, and optical properties for solar cell applications. The calculated lattice parameters agree well with previously obtained experimental and theoretical results. All of these perovskites are direct band gap compounds at the G symmetry point, except CH3NH3GaX3. The band gap increases from iodide to chloride and also with the metal cation size, from Ge to Pb or Cu to Zn. Furthermore, metal halide perovskites show blue shifts in their optical absorption spectra with an increase in metal cation size. Among the studied examples, CH3NH3GaBr3 and CH3NH3CuCl3 absorb a wide range of light, from UV to the visible region, and possess very unusual high dielectric constants and refractive indices. Our calculations reveal that CH3NH3SnI3, CH3NH3GeI3, and CH3NH3ZnI3 are favorable candidates for lead-free photovoltaic applications.

The computational quantum mechanical investigation of the functionalized boron nitride nanocage as the smart carriers for favipiravir drug delivery: a DFT and QTAIM analysis.

Favipiravir (FPV) is an antiviral drug used for the cure of Influenza virus, Ebola virus, Lassa virus etc. because it has excellent preventing ability of entry/exit of the virus into/from the human cells. Boron nitride nanocages have already drawn enormous attention as the delivery vehicle of various drug molecules for their nontoxicity and other lucrative properties. In this research, we have scrutinized the adsorption mechanism of FPV molecule on the exterior surface of pristine, Zn functionalized, and Ni functionalized B12N12 (BN, Zn f-BN, and Ni f-BN) nanocages by applying the DFT/QTAIM method and B3LYP/6-31G(d,p) approach. The adsorption energy (EAd) data reveal that the functionalized BN adsorbents can adsorb FPV drug very efficiently compared with the pristine adsorbent (Highest EAd is -56.40 kcal/mol for FPV adsorbed Ni f-BN complex). The reduction of the HOMO-LUMO gap up to 67.79% indicates that this drug can be detected by the produced electrical signal very promisingly in the case of f-BN nanocages. The topological parameters also validate the ability of the f-BN nanocages to adsorb the FPV molecule. The effect of the biological environment of our investigated structures has been studied by using water as a solvent, and spontaneous adsorption with high solubility is observed in our calculations. This analysis also reveals that f-BN nanocages can be a potential nanocarrier for the delivery of FPV drug molecule.Communicated by Ramaswamy H. Sarma.

Nutritional profile of wild, pond-, gher- and cage-cultured tilapia in Bangladesh.

The proximate, minerals, amino acid and fatty acid composition of wild, pond-, gher- and cage-cultured tilapia in Bangladesh were evaluated and varied significantly (p < 0.05). The major component of the tilapia was moisture (79.12%-81.36%), followed by protein (14.93%-16.03%), lipid (0.59%-2.35%), carbohydrate (1.23%-1.51%), fibre (0.47%-0.88%), ash (0.31%-0.53%); the energy value was between 97.62 and 126.73 kcal/100 g. Macro-nutrients and micro-nutrients were detected in following order: K > Na > Mg > Ca and Fe > Mn, respectively in all the tilapia and the ratio of Na/K was <1. Essential amino acids, leucine (1.47-1.56 g/100 g) and lysine (1.66-1.74 g/100 g), were the predominant amino acids in tilapia, followed by non-essential amino acids, aspartic acid (1.72-1.84 g/100 g) and glutamic acid (2.88-3.07 g/100 g). Saturated palmitic acid (25.4%-35.54%), monounsaturated elaidic acid (31.51%-35.63%) and polyunsaturated linolenic acid (17.69%-22.57%) were the main fatty acids found in tilapia. The desirable protein percentage, Na/K ratio, the presence of essential amino acids, leucine and lysine, n-3 and n-6 fatty acid contents proved that the consumption of wild, pond-, gher- and cage-cultured tilapia are beneficial to human health and could be recommended to prevent different diseases particularly of cardiovascular type.

A DFT study on the geometrical structures, electronic, and spectroscopic properties of inverse sandwich monocyclic boron nanoclusters ConBm (n = 1.2; m = 6-8).

Recent photoelectron spectroscopy and computational studies have shown that boron ring-centered transition metal-doped inverse sandwich complexes prefer planar or quasi-planar structures which could be a potential building blocks for designing better nanosystems with tailored properties. Due to promising technological applications of different boron nanoclusters, we present a study on the structural, electronic, magnetic, and spectroscopic properties of Co-centered inverted sandwich monocyclic boron nanoclusters with pyramidal, CoBn, and bi-pyramidal, Co2Bn (n = 6-8) shapes. The investigations have been carried out on previously reported stable hexa-, hepta-, and octagonal hole containing pyramidal and bi-pyramidal boron clusters by employing density functional theory calculations with B3LYP hybrid exchange-correlation functional. Our calculation suggests that all the global minima structures have stable planar or quasiplanar symmetrical cyclic motif. The structural stability of clusters has been investigated by analyzing binding energy, thermodynamical parameters, vibrational spectra etc. All parameters indicate that the bi-pyramidal structures (Co2B6, Co2B7, and Co2B8) are more stable than both pristine and singly doped boron nanoclusters. On the contrary, the bi-pyramidal cluster is chemically less stable than the pyramidal clusters (except CoB7) which is supported by the ionization potential, electron affinity, energy gap, and global indices calculations. Molecular electrostatic potential surface and HOMO-LUMO analysis have been carried out to understand the thermodynamically stable clusters that arises due to specific inter/intra-molecular interactions. The presence of magnetic element (Co) in the clusters induces ferromagnetic properties which have been found by investigating the magnetic moment, spin density, and DOS spectra analysis. Size and geometry-dependent properties of boron nanoclusters have been observed as evident from the energy gap and optical absorptions analysis.

Extraction, optical properties, and aging studies of natural pigments of various flower plants.

In this paper, we reported the extraction process of five different flowering plants utilizing different dye extraction methods and solvents (ethanol and water) to choose the best dye removal process. The FTIR spectra revealed the presence of several clear functional groups for all five natural dyes. The analytical studies such as UV spectroscopy, column chromatography, and vacuum evaporation were performed to isolate the dyes from their solutions. The UV-Vis studies on the pigments of flower extracts indicated broad absorption peaks in the visible region including clear bandgaps. Among the studied pigments, Alternanthera ficoidea showed the lowest direct bandgap of 1.69 eV and an Urbach energy value of 6.33 meV. The dye extraction yield rate improvement was extended from 11.7 to 24.7% (water solvent) and 11.3-32.4% (ethanol solvent). Throughout the studies, it was observed that ethanol produced a better extraction for organic dyes than water as a solvent. Aging studies revealed that all the dyes at the room temperature showed better stability with minor changes in the observed optical parameters in oxygen-rich conditions; however, these parameters have shown significant variations at a 60 °C temperature.