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Cotton is one of the most important cash crop grown for its fibre, which is the raw material for the textile industry. In India, the average yield and profitability of cotton cultivation are low as compared to developing countries. The main reason for this is hand picking of bolls, which is labour intensive resulting into low income of cotton growers. Furthermore, in India, most of the cotton varieties are indeterminate where the bolls do not mature at the same time and thus requires repeated hand pickings. Whereas the developed countries have 100% mechanized cotton picking due to determinate or semi-determinate plant types. Adoption of mechanical harvesting in India is dependent upon the availability of suitable cotton varieties as well as defoliants, desiccants, boll openers, growth hormones and re-growth inhibitors (Thatikunta et al., 2018). Defoliation before cotton harvesting is very important to maintain the quality of produce. In this paper, a comprehensive review is presented on effect and timing of application of defoliants on physiological characteristics of cotton. This will help in developing further research proposals to develop plant types for mechanical harvesting and use of defoliates to produce good fiber quality and increased farm income. [ABSTRACT FROM AUTHOR]

The bumper is an automotive part act as a protective shield in the vehicle. It bears and absorbs the load when the vehicle incurs a collision. If the bumper has got more weight it leads to more fuel consumption and decreases the fuel efficiency of the vehicle. This problem can be overcome by reducing the weight of the bumper without compromising its performance. The main objective in bumper design and fabrication is that it should possess less weight and at the same time, it should withstand the higher load during a collision. In this paper, the properties and performance of the developed bumper composite are compared with the existing bumper. The bumper performance is optimized using a finite element analysis with ANSYS R15.0. From the cost analysis, it has been observed that the weight and cost of the Basalt composite bumper is 49% and 56% lesser than the steel bumper. The Impact strength and Factor of Safety values of the Basalt fabric composite bumper is 47.6% and 32.5% higher than the steel bumper. The total deformation of the Steel bumper is 15.7 mm, and the Basalt composite bumper is 32 mm, which shows 51% higher deformation than steel. [ABSTRACT FROM AUTHOR]

Background: The cotton growing farmers in India are facing major problem at the time of harvest due to labor shortages, asynchronized boll opening, leaf trash in the cotton, which is reducing the boll picking efficiency and fiber quality. Presently, the Indian cotton industry is moving towards mechanical harvesting by cotton harvester. Defoliation or leaf abscission is induced in cotton as a natural physiological process which usually is inadequate for a complete mechanical harvest of cotton. Defoliation before harvest is often induced by managing the plants so that senescence, abscission (separation) layer development and leaf drop are encouraged. Chemical defoliants induce leaf abscission, hasten mature boll dehiscence and inhibit regrowth. Selection of appropriate defoliants is one of the critical decisions in cotton production. Their use can result in increased manual as well as machine harvest efficiency, reducing boll rot and the trash in seed cotton. The physiological basis of defoliation in cotton is essential to understand the role of appropriate defoliant with time of application. Hence, the objective of the study was to evaluate the defoliation efficiency, boll opening percentage and to know the physiological basis of defoliation in response to different defoliants and time of application in high density Cotton cultivation which eases the mechanical harvesting. Methods: In this field investigation during 2018 - 2019 at Department of Crop Physiology, Tamil Nadu Agricultural University, Coimbatore was carried with seven different defoliants and three different time of defoliants application were fixed based on crop maturity and duration of the crop. In this study, high density cotton variety CO 17 was used as experimental material. A series of lab and field analysis were determined on defoliation process, physiological attributes, boll opening percentage and seed yield and quality. The collected data were subjected to statistical analysis. Result: Our investigation exploring the effect of different defoliants on physiological, biochemical, yield and quality parameters of high density Cotton. Among the different defoliants and time of applications, two defoliants and two times of applications works better in terms of better defoliation, boll opening rate, physiology, yield and quality. The physiological and biochemical effects of defoliants on defoliation process were discussed. The present work will be useful for mechanized picking with these effective defoliants without loss of yield and quality loss in cotton. [ABSTRACT FROM AUTHOR]

So as to conquer the environmental problems raised due to the concrete production and their ingredients production, there has been a want to discover the alternative substances to replace the components together with cement and coarse combination. This study has an interest to investigate the utilisation of lightweight aggregate in M30 grade self-compacting concrete (SCC) containing lime. Initially in SCC, cement was replaced with lime by 5, 10, 15, 20, 25, 30, 35, 40 and 45% and optimised the replacement based on the mechanical properties. The coarse aggregate was replaced with a light weight steel slag (SS) aggregate at the percentage of 10, 20, 30 and 40% individually in the above optimised replacement of cement with lime. With each mix, to enhance the binding and mechanical properties, a constant percentage (5%) of epoxy resin (EPR) was added as additive. To enhance the workability and to found the optimum dosage, the superplasticiser conplast SP430 was added in distinctive chances of water cement ratio and the workability tests have been completed. And then mechanical properties and durability properties were compared with controlled SCC and their enhancement in properties were discussed. [ABSTRACT FROM AUTHOR]

This article focuses on the investigation of properties of Phoenix sp. fiber based geopolymer composites. Control samples (0 wt.%) and fiber reinforced samples (1, 2, 3, and 4 wt.%) with different quantities were produced and determined their physical, mechanical, morphological, ultrasonic pulse velocity, water absorption, thermal conductivity and fracture toughness properties. The outcomes show that the incorporation of Phoenix sp. fibers to geopolymer improved the splitting tensile (1.28–2.35 MPa), compressive (27.85–32.18 MPa) and flexural strengths (3.34–6.53 MPa). By contrast, as the fiber loading increased to 4 wt.%, the workability and bulk density of geopolymer decreased to 86% and 13%, respectively. Furthermore, a linear relationship was evidenced between the bulk density and thermal conductivity, as well as ultrasonic pulse velocity and compressive strength. Due to the hydrophilic character of Phoenix sp. fibers, the water absorption increased as the fiber content increases. Due to the local mechanisms that control the bridging activity, the addition of Phoenix sp. fibers improved the fracture toughness of the composites. [ABSTRACT FROM AUTHOR]

In the current research work steel mill scales, waste from steel industries has been tested out as a fractional replacement for sand. Steel mill scale is a waste product obtained from the steel production industries and it has an adverse effect on the environment. Steel mill scale has become a good substitute for fine aggregates in the construction industry. The experimental parameter was the percentage of steel mill scale substitution (0%, 20%, 40%, 60%, 80% and 100%) by weight to fine aggregate content in M30 grade concrete and the results obtained from those mixes are compared with original M30 grade concrete. Compressive strength, split tensile strength, flexural strength and micro-structural characters of such concrete were evaluated. The interaction of steel mill scale within the concrete has been methodically investigated using micro-structural studies. It was found that very small particle size of steel mill scale fills the voids between the fine and coarse aggregate thus makes dense concrete. The test outcomes suggest that recycling steel mill scale by utilizing as a fractional replacement for fine aggregate offers a viable cost effective and environmentally friendly solution at 60% replacement. [ABSTRACT FROM AUTHOR]

Misfolding of the cellular prion protein (PrPC) into β-sheet-rich scrapie form (PrPSc) is associated with transmissible spongiform encephalopathies. A point mutation F198S is responsible for the development of a rare inherited Gerstmann-Straussler-Scheinker disease caused by the aggregation of PrPC. Thus, identification and the structural characterization of aggregation-prone regions are essential to delineate the conversion of PrPC to the disease-associated PrPSc upon F198S mutation. In the present study, molecular dynamics simulations on the wild-type PrP (WT-PrP) and its mutant were performed to explore the structural basis responsible for aggregation driven by the mutation. Secondary structure analysis revealed that the mutant exhibited a partial unfolding on α2 and the complete distortion in the 3 10 -helix of the β2-α2 loop. Remarkably, the β2-α2 loop is in proximity to α3 attributed by the long-range hydrophobic interactions and such structural intimacy is not observed in the WT-PrP. Owing to this, the β1-α1-β2 regions have separated from α2-α3 domain resulting in the impairment on the hydrogen bond between α1 and α3. Thus, the present study provides a detailed structural description of the F198S mutant in line with previous experimental results and delivers insights into the structural basis responsible for the conversion of PrPC to the disease-associated PrPSc. • The mutant F198S endured a partial unfolding on α2 • The β2-α2 and α2-α3 loops are completely distorted in the single mutant • The long-range hydrophobic interactions are favored in proximity of the β2-α2 loop and α3 • Domain disassociations are occurred by breaking a hydrogen bond between α1 and α3 could be the basis for the conformational conversion of PrPC into PrPSc [ABSTRACT FROM AUTHOR]

Proteins are usually dynamic biological macromolecules, thereby exhibiting a large number of conformational ensembles which influence the association with their neighbours and interacting partners. Most of the side‐chain atoms and a few main‐chain atoms of the high‐resolution crystal structures deposited in the Protein Data Bank adopt alternate conformations. This kind of conformational behaviour prompted the authors to explore the relationship, if any, between the alternate conformations and the function of the protein molecule. Thus, a knowledge base of the alternate conformations of the main‐ and side‐chain atoms of protein structures has been developed. It provides a detailed description of the alternate conformations of various residues for more than 60 000 high‐resolution crystal structures. The proposed knowledge base is very user friendly and has various flexible options. The knowledge base will be updated periodically and can be accessed at http://iris.physics.iisc.ac.in/acms. [ABSTRACT FROM AUTHOR]

Nowadays automotive industries altered their core on the custom-made result. They are making medium and small batch production by covering an increasing offer, that the sheet metal forming dies are cost-effective manufacturability. Replete polymers undertake capabilities to fulfil such vital parts in the boundary of prototype tools manufacturing or in the small set production of sheet metal components. For sheet metal forming this paper declares investigations distribute tool designing and tribological form of using some materials like polymeric materials. Two polymer composites i.e. friction and wear on sheet metal simulated materials have been investigated, strip, drawing test testability is discussed and presented using the linear wear distance relation W1/s measured with the new testing method to anticipate lifetime of polymeric stamping dies using sheet materials with structured surfaces. A meaningful improvement in wear and friction performance of polymer or polymer composite has been observed and abstract model for rough wear and friction of polymer blend is given. Sheet metal counter material combination has been developed, based on the after effect accomplished by measurement of wear and friction. [ABSTRACT FROM AUTHOR]

The oral route of drug administration is mostly preferred by paediatric and geriatric patients. Patient non-compliance due to poor taste and swallowing problems are major issues in paediatric and geriatric drug therapy. Lack of age-appropriate formulations, inadequate labelling instructions, non-compatible and non-palatable medicines are the main reasons for medication errors in paediatric patients. This review mainly highlights major issues of paediatric and geriatric drug therapy and provides the design of oral flexible formulations as an alternative formulation design for age appropriate formulation development. Development of solid oral flexible formulations as an alternative to existing marketed formulations such as conventional tablets, orally disintegrating tablets, chewable and dispersible tablets for paediatric and geriatrics patients is described. Details about drug properties, excipient selection and taste masking approaches were described. The need for bioavailability and bioequivalence studies for flexible formulations also described. Development of flexible formulations as an alternative to marketed different formulations of the same drug would reduce the cost of the formulation for patients particularly developing countries where accessibility to various types of formulations is less. Flexible tablet formulations can be conveniently used by the patients as orally swallowable, orally disintegrating, chewable and as dispersible tablets. Sprinkle formulations such as pellets, granules packed in capsules or sachets can be conveniently used by paediatric and geriatric patients. Properly designed and developed flexible formulations for new chemical entities and off-patent drugs are need of the hour to provide better treatment to varying age groups of paediatrics and geriatrics. [ABSTRACT FROM AUTHOR]

The present study aims to investigate the influence of the size of the spherical capsule on the solidification characteristics of water as the PCM (phase change material) filled with 90% of its full volume. The experiments were conducted with three different sizes of stainless steel spherical capsules filled with PCM up to 90% of its full volume, maintained at various bath temperatures. It was observed that the capsule size had a significant influence on subcooling at lower temperature driving potential and was totally eliminated at higher temperature potential, for all the capsule sizes. The freeze front moved at a faster rate in the larger capsule than in the smaller capsule till the solidification of 75% mass of PCM. This effect was more pronounced at a higher temperature driving potential. Increasing the temperature potential was not beneficial for the 74 mm capsule due to insignificant increase in heat flux. However, the increased temperature potential significantly enhanced the heat flux by several folds for the higher diameter capsules during the solidification of 75% of mass. Considering the larger size capsule with sufficient temperature potential would hence be the optimal way of designing an increased energy efficient CTES (Cool thermal energy storage) system with rapid charging and discharging. [ABSTRACT FROM AUTHOR]

The complexes [Pt(mdt)2] (4; mdt = methyl dithiolene, [Me2C2S2]n-), [Pt(adt)2] (5; adt = p-anisyldithiolene, [(MeO-p-C6H4)2C2S2]2-), and [Pd(adt)2] (10) have been prepared in yields of ≥ 90% via transmetalation reactions with the corresponding [R2Sn(S2C2R'2)] complexes (R = "Bu, R' = Me; R = Me, R' = C6H4-p-OMe, 3). Intrahgand C--S and C--CchclaIe bond lengths (~1.71 and ~1.40 A, respectively) obtained by X-ray crystallography show these compounds to be comprised of radical monoanions mdt*- and adt*- . The six-coordinate octahedral adducts [Pt(adt)2(dppe)J [6; dppe = 1,2-bis(diphenylphosphino)ethane], trans-[Pt(adt)2(PMe3)2] (8), and frans-[Pt(mdt)2(PMe3)2] (9) have also been prepared, and crystal structures reveal dithiolene ligands that are fully reduced ene-l,2-dithiolates (C--S and C--Cchelate = ~1.77 and 1.35 A, respectively). Reduction of the dithiolene ligand thus occurs to accommodate the +IV oxidation state typical of octahedral sixcoordinate platinum. The cyclic voltammogram of 5 shows twofully reversible reductions at --0.11 and --0.84 V in CH2C12 (vs Ag/AgCl), attributed to successive (adt*- + e- → adt2-) processes, and a reversible oxidation at +1.01 V. The cyclic voltammogram of 9 shows two reversible oxidations at +0.38 and +0.86 V, which are assigned as successive (adt2- &#8594 adt*- + e-) oxidations. Consistent with their formulation as having fully reduced dithiolene ligands, the UV--vis spectra for 6, 8, and 9 show no low-energy absorptions below 700 nm, and the S K-edge XAS spectra of 6 and 8 show dithiolene sulfur that is reduced relative to that in 5. The introduction of PMe3 to 10 did not produce the palladium analogue of 8 but rather [Pd(adt)(PMe3)2] (11) . The reaction of [PdCl2(PPh3)2] with Li2(mdt) produced a mixture of [Pd(mdt)(PPh3)2] (12, 20%) and [(Ph3P)Pd(p-l,2-mdt- S,S':S)2Pd(PPh3)] (13, 28%), with the latter having C2 symmetry with a Pd2S2 core structure folded along the S…S axis. [ABSTRACT FROM AUTHOR]

The present study aims to investigate the solidification characteristics of water based NFPCM (nanofluid phase change material). The NFPCM was prepared by dispersing copper oxide nanoparticles and a nucleating agent in the base PCM (phase change material). The experiments were conducted at various bath temperatures and the NFPCM exhibited a significant reduction in solidification time of about 35% due to enhanced heat transport properties. Further, 50% of total mass solidified during 25% of total solidification time in both PCM and NFPCM. The presence of nucleating agent eliminated the ramifying problem of subcooling in the PCM and this will allow the evaporator to operate at a higher temperature in a chiller. The enhanced heat transfer rate of the NFPCM without subcooling is advantageous for many CTES (cool thermal energy storage) applications. It is construed from the experimental results that considerable energy saving potential is possible in the CTES system by operating the evaporator at a higher temperature. [ABSTRACT FROM AUTHOR]

Background: Blackgram [Vigna mungo (L.) Hepper] has significant agronomic and nutritional significance. Its productivity is insufficient to fulfil the expanding local demand in India. Increasing its productivity using appropriate agronomic practices is crucial. With this background, an experiment was conducted to study the effect of foliar application of liquid organic bio-stimulants on development, production and physiological characteristics of blackgram under irrigated conditions. Methods: Seven treatments comprising recommended dose of fertilizers (RDF) with foliar spray of dhasagavya, liquid rhizobium, fish amino acid, panchagavya, PPFM and seaweed extract at 1% and 3%, respectively were tested in randomised block design with three replications. The dimension of blackgram quantitative characters, viz., grain yield, plant height, number of branches per plant, dry matter production (DMP), leaf area index (LAI), number of pods per plant, number of seeds per pod, pod weight per plant, pod length, crop growth rate, total chlorophyll content, soluble protein content and nitrate reductase activity were reduced using principal component analysis (PCA). Result: The PCA was performed on all the attributes as correlation between the quantitative characters was found to be stronger among most of the biometric observations. It was noticed that almost 67% of the data's total variability, as reflected by the first two principal components. It demonstrated that grain production, DMP, nitrate reductase activity, pods per plant and leaf area index were the primary contributors. [ABSTRACT FROM AUTHOR]

Background: The productivity of blackgram is not adequate to meet the domestic demand of the growing Indian population. Consequently, there is an urgent need for enhancement of productivity through proper management practices. With this background, a research experiment was conducted to investigate the effect of liquid rhizobium with organic bio-stimulants on physiological and biochemical characters, antioxidant enzymes and yield of blackgram. Methods: A field experiment was laid out in randomized block design with three replications during 2021 (Kharif and Rabi) season. The treatments include 100% recommended dose of NPK along with foliar application of dasagavya, liquid rhizobium, fish amino acid, panchagavya, pink pigmented facultative methylotrophs (PPFM) and Sea weed extract with different concentration (1% and 3%, respectively) in addition to control. Organic bio stimulants were sprayed at 30 and 45 days after the sowing of blackgram. Result: The experiment results revealed that the application of 100% RDF+Liquid Rhizobium @ 1% registered maximum physiological and biochemical characters viz., CGR, total chlorophyll content, soluble protein content, nitrate reductase activity, catalase activity, peroxidase activity and number of root nodules plant-1, yield attributes viz., number of pods plant-1, number of seeds pod-1, grain yield (kg ha-1), haulm yield (kg ha-1). Correlation and Regression analysis also indicated that the yield attributes had a positive impact on the grain yield. [ABSTRACT FROM AUTHOR]

Abstract: This study aimed to investigate the thermal performance of nanofluid phase change material (NFPCM) for cool thermal energy storage (CTES) system. The NFPCM was prepared by suspending 0.1 wt. % multiwall carbon nanotubes (MWCNT) in deionized water (DI water) along with pseudomonas as a nucleating agent. The experiments were conducted at various surrounding bath temperatures with the NFPCM. The results evidently showed that the freezing duration was reduced by 25% in the case of NFPCM along with the elimination of subcooling compared to that of DI water. Further, the fraction of mass solidified at various time intervals revealed that 50% of phase change material (PCM) was frozen in 25% of the total freezing time for both the water PCM and NFPCM. The enhanced heat transport properties of the NFPCM along with the elimination of subcooling and accelerating charging will be very useful in designing energy efficient CTES system. [Copyright &y& Elsevier]

A series of reports describing the syntheses and structures of [MCl2(diazadiene)] (M = Cr, Mo, W) complexes is reassessed in the context of known chemistry of low-valent Group VI metal complexes, crystallographic trends such as M--CI bond lengths and unit cell volumes, and calculated metal--ligand bond lengths. Crystallographic data and computational results are inconsistent with any of these species being second or third row transition metal complexes. A review of the crystallographic information files accompanying the [MCl2(diazadiene)] (M = Mo, W) published structures reveals that the metal atoms were inappropriately treated with partial site occupancy factors (0.775 for Mo; 0.4005 and 0.417 for W), the effect of which was to manifest lighter-element behavior and better refinement in accord with the metal atoms' correct identity. A deliberate synthesis and characterization by X-ray diflraction of [ZnCl2(MesdadMe)] (MesdadMe = l,4-bis(2,4,6-trimethylphenyl)-2,3-dimethyl-l,4-diaza-1,3-butadiene) are reported. Refinement of this structure with the same combination of second or third row metal and offsetting partial site occupancy is shown to provide final refinement statistics essentially the same as with the correct model employing M = Zn at site occupancy 1.00. Use of the published method for synthesis of [WCl2(diazadiene)] with MesdadMe and [WBr4(MeCN)2] in lieu of [WCl4MeCN2] is shown to produce [ZnBr2(MesdadMe)], which has also been characterized by X-ray diffraction. It is concluded that the unusual putative 12-electron [MCl2(diazadiene)] (M = Cr, Mo, W) complexes are in all cases the corresponding [ZnCl2(diazadiene)] complexes, Zn having been commonly employed as reducing agent in their synthesis. [ABSTRACT FROM AUTHOR]

Highlights: [•] The Zn1− x Mg x O nanocrystals were synthesised from low temperature sol–gel process. [•] The structural properties of the nanocrystals were studied by XRD. [•] Enhanced deep level emission was observed for the Zn1−xMg x O. [•] The deep level emission mechanism was discussed based on the XPS results. [ABSTRACT FROM AUTHOR]

Abstract: This present study presents the solidification behavior of water based nanofluid phase change material encapsulated in a spherical container. The nanofluid phase change material (NFPCM) was prepared by dispersing the multi wall carbon nanotubes (MWCNT) with volume fractions of 0.15%, 0.3%, 0.45%, and 0.6% in de-ionized (DI) water as the base phase change material. The solidification experiments were conducted with DI water and the NFPCM and maximum reductions of 14% and 20.1% were observed in the solidification time with the NFPCMs at surrounding bath temperature of −9 °C and −12 °C respectively. The presence of MWCNT also acted as nucleating agent that caused appreciable reduction in the subcooling. The enhanced thermal transport properties of the NFPCM are very useful to operate the cool thermal energy storage (CTES) system at higher operating temperature of the secondary refrigerant. It is predicted that there is a possible energy saving potential of approximately 6–9% in the CTES using the NFPCMs. [Copyright &y& Elsevier]

In order to assess the sensitivity and complementarity of X-ray absorption and emission spectroscopies for determining changes in the metal ligation sphere, a systematic experimental and theoretical study of iron model complexes has been carried out. A series of high-spin ferrous complexes, in which the ligation sphere has been varied from a three-coordinate complex, [LtBuFe(SPh)] (1) (where LtBu = bulky β-diketiminate ligand; SPh = phenyl thiolate) to four-coordinate complexes [LtBuFe(SPh)(X)] (where X = CNtBu (2); 1-methylimidazole (3); or N,N-dimethylformamide (DMF) (4)), has been investigated using a combination of Fe K-edge X-ray absorption (XAS) and Kβ X-ray emission (XES) spectroscopies. The Fe K XAS pre-edge and edge of all four complexes are consistent with a high-spin ferrous assignment, with the largest differences in the pre-edge intensities attributed to changes in covalency of the fourth coordination site. The X-ray emission spectra show pronounced changes in the valence to core region (V2C) as the identity of the coordinated ligand is varied. The experimental results have been correlated to density functional theory (DFT) calculations, to understand key molecular orbital contributions to the observed absorption and emission features. The calculations also have been extended to a series of hypothetical high-spin iron complexes to understand the sensitivity of XAS and XES techniques to different ligand protonation states ([LtBuFeII(SPh)(NHn)]3-n (n = 3, 2, 1, 0)), metal oxidation states [LtBuFe(SPh)(N)]n- (n = 3, 2, 1), and changes in the ligand identity [LtBuFeIV(SPh)(X)]n-(X = C4-, N3-, O2-; n = 2, 1, 0). This study demonstrates that XAS pre-edge data have greater sensitivity to changes in oxidation state, while valence to core (V2C) XES data provide a more sensitive probe of ligand identity and protonation state. The combination of multiple X-ray spectroscopic methods with DFT results thus has the potential to provide for detailed characterization of complex inorganic systems in both chemical and biological catalysis. [ABSTRACT FROM AUTHOR]

Abstract: Control of the nanostructure and optical properties of ZnO nanoparticles are studied by using various capping agents. The uncapped and capped ZnO nanoparticles were synthesised from sol–gel process by reacting zinc acetate dehydrate with NaOH in deionised water at 70°C. Various capping agents such as Ethylene diamine tetra acetic acid (EDTA), Triethanolamine (TEA) and Tetraethylammonium Bromide (TEABr) were used as capping agents to control the size and morphology of the ZnO nanoparticles. The size and morphological changes of ZnO nanoparticles were investigated by using Transmission electron microscopy (TEM) and UV–Vis optical absorption spectroscopy. The XRD spectra of the synthesised samples confirmed that the synthesised products were ZnO nanoparticles with wurtzite structure. The presence of capping agents were analysed by Fourier transform infrared (FT-IR) spectroscopy. The morphology of the synthesised particles was changed with capping agents. Moreover, the capping mechanism is discussed based on the chemical reaction between the ZnO nanoparticles and the functional groups of the various capping agents. [Copyright &y& Elsevier]

In recent years, a number of high-valent iron intermediates have been identified as reactive species in iron-containing metalloproteins. Inspired by the interest in these highly reactive species, chemists have synthesized Fe(iv) and Fe(v) model complexes with terminal oxo or nitrido groups, as well as a rare example of an Fe(vi)-nitrido species. In all these cases, X-ray absorption spectroscopy has played a key role in the identification and characterization of these species, with both the energy and intensity of the pre-edge features providing spectroscopic signatures for both the oxidation state and the local site geometry. Here we build on a time-dependent DFT methodology for the prediction of Fe K- pre-edge features, previously applied to ferrous and ferric complexes, and extend it to a range of Fe(iv), Fe(v) and Fe(vi) complexes. The contributions of oxidation state, coordination environment and spin state to the spectral features are discussed. These methods are then extended to calculate the spectra of the heme active site of P450 Compound II and the non-heme active site of TauD. The potential for using these methods in a predictive manner is highlighted. [ABSTRACT FROM AUTHOR]

A new, high yield synthesis of [Ni(S[sub2]C[sub2]Me[sub2])[sub2]] (3) is described using 4,5-dimethyl-1 ,3-dithiol-2-one, Me[sub2]C[sub2]S[sub2]C==O (1), as dithiolene ligand precursor. Reaction of (Me[sub2]C[sub2]S[sub2])Sn[supn]Bu[sub2], 2, with WCI[sub6] produces tris(dithiolene) [W(S[sub2]C[sub2]Me[sub2])[sub3]] (6) and demonstrates the potential synthetic utility of this compound in metallodithiolene synthesis. The series of compounds [W(S[sub2]C[sub2]Me[sub2])[subx](CO)[sub6-2x]] (x = 1 -3), obtained as a mixture via the reaction of [Ni(S[sub2]C[sub2]Me[sub2])[sub2]] with [W(MeCN)[sub3](CO)[sub3]], has been characterized structurally. A trigonal prismatic geometry is observed for [W(S[sub2]C[sub2]Me[sub2])(CO)[sub4]) (4) and confirmed by a DFT geometry optimization to be lower in energy than an octahedron by 5.1 kcal/mol. The tris(dithiolene) compound [W(S[sub2]C[sub2]Me[sub2])[sub3]] crystallizes in disordered fashion upon a 2-fold axis in C2/c, a different space group than that observed for its molybdenum homologue (P¯1), which is attributed to a slightly smaller chelate fold angle, α, in the former. The reactivity of 4 and [W(S[sub2]C[sub2]Me[sub2])[sub2](CO)[sub2]] (5) toward PMe[sub3] has been examined. Compound 4 yields only [W(S[sub2]C[sub2]Me[sub2])(CO)[sub2](PMe[sub3])[sub2]] (7), while 5 produces either [W(S[sub2]C[sub2]Me[sub2])[sub2](CO)(PMe[sub3])] (8) or [W(S[sub2]C[sub2]Me[sub2])[sub2](PMe[sub3])[sub2]] (9) depending upon reaction conditions. Crystallographic characterization of 5, 8, and 9 reveals a trend toward greater reduction of the dithiolene ligand (i.e., more ene1 ,2-dithiolate character) across the series, as manifested by C-C and C-S bond lengths. These structural data indicate a profound effect exerted by the π-acidic CO ligands upon the apparent state of reduction of the dithiolene ligand in compounds with ostensibly the same oxidation state. [ABSTRACT FROM AUTHOR]

Abstract: Mononuclear complexes of cyclodiphosphazane with an uncoordinated phosphorus centre [RuCl2(η6-cymene){l-κP}] (1a) (L= cis-{(o-MeOC6H4O)P(μ-N t Bu)}2) and [PdCl2(PEt3){l-κP}] (1b) react with 1equiv. of [AuCl(SMe2)] to afford RuII/AuI and PdII/AuI heterodinuclear complexes [RuCl2(η6-cymene){μ-l-κP,κP}AuCl] (2) and [PdCl2(PEt3){μ-l-κP,κP}AuCl] (3), respectively. Heterotrinuclear complexes [PdCl2{μ-l-κP,κP}2(AuCl)2] (4), [PtCl2{μ-l-κP,κP}2(AuCl)2] (5) and [CuI{μ-l-κP,κP}2(AuCl)2] (6) containing PdII/2AuI, PtII/2AuI and CuI/2AuI metal centers have been synthesized from the reactions of trans-[PdCl2{l-κP}2] (1c), cis-[PtCl2{l-κP}2] (1d) and [CuI{{ l-κP}2] (1f) respectively, with 2equiv. of [AuCl(SMe2)]. Molecular structures of complexes 2, 3 and 4 were established by single crystal X-ray diffraction studies. [Copyright &y& Elsevier]

Abstract: Cyclodiphosphazanes having donor functionalities such as cis-[ t BuNP(OR)]2 (R=C6H4OMe-o (2); R=CH2CH2OMe (3); R=CH2CH2SMe (4); R=CH2CH2NMe2 (5)) were obtained in good yield by reacting cis-[ t BuNPCl]2 (1) with corresponding nucleophiles. The reactions of 2–5 with [RuCl2(η6-cymene)]2, [MCl(COD)]2 (M=Rh, Ir), [PdCl2(PEt3)]2 and [MCl2(COD)] (M=Pd, Pt) result in the formation of exclusively monocoordinated mononuclear complexes of the type cis-[{ t BuNP(OR)}2MLn-κP] irrespective of the reaction stoichiometry and the reaction conditions. In contrast, 2–5 react with [RhCl(CO)2]2, [PdCl(η3-C3H5)]2, CuX (X=Cl, Br, I) to give homobinuclear complexes. Interestingly, CuX produces both mono and binuclear complexes depending on the stoichiometry of the reactants and the reaction conditions. The mononuclear complexes on treatment with appropriate metal reagents furnish heterometallic complexes. [Copyright &y& Elsevier]

The reactions of cyclodiphosphazane cis-[tBuNP(OC6H4OMe-o)]2 (1) with 2 equiv of CuX in acetonitrile afforded one-dimensional CuI coordination polymers [Cu2X2{tBuNP(OC6H4OMe-o)}2]n (2, X = Cl; 3, X = Br; 4, X = I). The crystal structures of 2 and 4 reveal a zigzag arrangement of [P(μ-N)2P] and [Cu(u-X)2Cu] units in an alternating manner to form one-dimensional CuI coordination polymers. The reaction between 1 and CuX in a 2:1 ratio afforded mononuclear tricoordinated copper(l) complexes of the type [CuX{(tBuNP(OC6H4OMe-o))2}2] (5, X = Cl; 6, X = Br; 7, X = I). The single-crystal structures were established for the mononuclear copper(l) complexes 5 and 6. When the reactant ratios are 1:1, the formation of a mixture of polymeric and mononuclear products was observed. The CuI polymers (2-4) were converted into the mononuclear complexes (5-7) by reacting with 3 equiv of 1 in dimethyl sulfoxide. Similarly, the mononuclear complexes (5-7) were converted into the corresponding polymeric complexes (2-4) by reacting with 3 equiv of copper(l) halide under mild reaction conditions. [ABSTRACT FROM AUTHOR]

Ether- and thioether-functionalized cyclodiphosphazanes cis-[tBuNP(OCH2CH2EMe)]2 (E = O, 1; E = S, 2) react with 2 equiv of elemental sulfur or selenium to produce dichalcogenides cis-[tBuNP(E)(OCH2CH2EMe)]2 (4-6), whereas the similar reaction of amine-functionalized cyclodiphosphazane cis-[tBuNP(OCH2CH2NMe2)12 (3) with elemental chalcogen results in the formation of thio- or selenophosphates trans-[tBuNP(O)(ECH2CH2NMe2)]2 (E = 5, 7; E = Se, 8) through [1,3]-sigmatropic rearrangement. The X-ray crystal structure of 8 confirms the rearranged product as the trans isomer with a planar P2N2 ring. The equimolar reaction of P(OCH2CH2OMe)3 (9) with elemental sulfur or selenium produces the simple sulfide and selenide E=P(OCH2CH2OMe)3 (E = 5, 11; E = Se, 12) derivatives, respectively. In contrast, the reaction between P(OCH2CH2NMe2)3 (10) and S or Se furnishes the rearranged products (13 and 14). The rearrangement reaction was monitored by 31PNMR spectroscopy, which confirms the formation of selenophosphinic acid as the first step of the rearrangement. The [1,3]-sigmatropic rearrangement presumably takes place through chalcogen-nitrogen interactions. [ABSTRACT FROM AUTHOR]

Cyclodiphosphazanes having hemilabile ponytails such as cis-[tBuNP(OC6H4OMe-o)]2 (2), cis-[tBuNP(OCH2CH2-OMe)]2 (3), cis-[tBuNP(OCH2CH2SMe)]2 (4), and cis-[tBuNP(OCH2CH2NMe2))2 (5) were synthesized by reacting cis-[tBuNPCl]2 (1) with corresponding nucleophiles. The reaction of 2 with [M(COD)Cl2] afforded cis-[MCl2(2)2] derivatives (M = Pd (6), Pt (7)), whereas, with [Pd(NCPh)2C]2], trans-[MCl2(2)2] (8) was obtained. The reaction of 2 with [Pd(PEt3)Cl2]2, [Ru(η6p-cymene)Cl2]2, and [M(COD)Cl]2 (M = Rh, Ir) afforded mononuclear complexes of Pd(II) (9), Ru(II) (11), Rh(I) (12), and Ir(l) (13) irrespective of the stoichiometry of the reactants and the reaction condition. In the above complexes the cyclodiphosphazane acts as a monodentate ligand. The reaction of 2 with [PdCl(η³-C3H5))2 afforded binuclear complex [(PdCl(η³-C3H5))2{(tBuNP(OC6H4OMe-o))2-κP}] (10). The reaction of ligand 3 with [Rh(CO)2Cl]2 in 1:1 ratio in CH3CN under reflux condition afforded tetranuclear rhodium(1) metallamacrocycle (14), whereas the ligands 4 and 5 afforded bischelated binuclear complexes 15 and 16, respectively. The crystal structures of 8, 9, 12, 14, and 16 are reported. [ABSTRACT FROM AUTHOR]

The synthesis and coordination chemistry of bis- and tris(phosphines) with P&z.sbnd;Si&z.sbnd;P, P&z.sbnd;O&z.sbnd;Si&z.sbnd;O&z.sbnd;P and P&z.sbnd;C&z.sbnd;Si&z.sbnd;C&z.sbnd;P linkages is reviewed. The catalytic reactions involving organometallic complexes of silylphosphines are presented. The silylbis- and tris(phosphines) show remarkable versatility in their coordination behavior with transition metals. The improved solubility of these ligands and their complexes facilitated spectroscopic studies to compliment the structural information obtained via single crystal X-ray diffraction studies. The syntheses and reactivity of other related acyclic and cyclic systems with P&z.sbnd;N&z.sbnd;Si&z.sbnd;N&z.sbnd;P and P-aryl&z.sbnd;Si-aryl&z.sbnd;P linkages are also briefly described. [Copyright &y& Elsevier]

• Fluorescent N-CNDs obtained from sprout extract of B. flabllifer is reported. • The average size of the spherical shaped N-CNDs was 2.47 nm. • N-CNDs act as proficient green catalyst for reduction of Congo red by NaBH 4. • The reduction of Congo red was completed in 10 min by green catalyst N-CNDs. Here, we have demonstrated a facile hydrothermal carbonization pathway for the fabrication of luminescent nitrogen doped carbon nanodots (N-CNDs). The sprout extract of Borassus flabellifer (B. flabellifer) and aquous ammonia (aq.NH 3) were utilized as a source of carbon and nitrogen, respectively. Using diverse microscopic and spectroscopic methods, the fabricated N-CNDs were characterized and reported. The excitation dependant emission and absorbance features of the prepared N-CNDs were studied using fluorescence and UV–Visible spectroscopic methods. When excited at 320 nm the obtained N-CNDs exposed deep blue emission at 405 nm. The quantum yield (QY) for the synthesized N-CNDs was found to be 41%. The HR-TEM results confirmed the spherical shape and the size of the prepared N-CNDs to be 2.37 nm. The amorphous character of the synthesized N-CNDs was revealed by SAED pattern, XRD and Raman spectroscopic studies. Doping of nitrogen over surface of the CNDs was examined and confirmed through FT-IR, XPS and EDS analyses. XPS and FT-IR studies also exposed the presence of –COOH, NH 2 , OH and C O functional groups over the N-CNDs surface. The synthesized N-CNDs were found to have profound catalytic effect on the reduction of congo red by NaBH 4. Thus the study has unravelled the nature and utility of N-CNDs from B. flabellifer. [ABSTRACT FROM AUTHOR]

Abstract: The 1:2 and 1:1 reactions of cis-[ t Bu(H)NP(μ- t BuN)]2 (1) with paraformaldehyde afforded α-aminophosphonates, cis-[ t Bu(H)NCH2(O)P(μ- t BuN)]2 (2) and cis-[ t Bu(H)NP(μ- t BuN)2P(O)CH2N(H) t Bu] (3), respectively, through the insertion of a methylene moiety into the P–N bonds. The X-ray crystal structure of 2 reveals that the insertion reaction occurs selectively at the exocyclic P–N bonds of bis(amido)cyclodiphosphazane. [Copyright &y& Elsevier]

In this study, the cardioprotective effects of partially purified phenolic fraction of Kedrostis foetidissima leaves (PFK) were evaluated in isoproterenol (ISO)‐induced myocardial infarction rat model. ISO induction to experimental rats for two consecutive days significantly increased the levels of triglycerides, cholesterol, phospholipids, free fatty acids, low‐density lipoproteins, and cardiac biomarker enzymes, and decreased the levels of high‐density lipoproteins and antioxidant enzyme activity. Pretreatment of experimental rats with PFK for 45 days led to a significant elevation in antioxidant enzyme activity. PFK‐pretreated rats exhibited significantly reduced levels of circulating lipids and cardiac‐specific biomarker enzymes compared to ISO‐treated rats. Thus, the present study demonstrated that PFK ameliorated ISO‐induced cardiotoxicity through the augmentation of the endogenous cardiac antioxidant system, thereby modulating the lipid peroxidation caused by ISO‐induced free radicals, and prevented the myocardial damage, which was confirmed through histopathological analysis. Practical applications: Kedrostis foetidissima is edible medicinal plant and phenolic fraction extracted from the leaves of this plant may help the common man in the protection of heart. The phenolic fraction shows significant antioxidant activity, so this might be referred to as dietary supplement and also helps to develop new pharmaceutical formulations. [ABSTRACT FROM AUTHOR]

Highlights: [•] Simple route was prepared CuO nanoparticles. [•] Observed the good crystalline nature of the synthesized particles. [•] Particle size is very small at the range of 3–8nm. [•] Capping agent acting as the good size controller and for surface modifier. [Copyright &y& Elsevier]

• Synthesis, crystallographic analysis, and computational assessment of a new racetam derivative, designated as LIG. • The compound (LIG) exhibits significant drug-like characteristics similar to levetiracetam (LEV), an approved anti-epileptic drug (AED). • Molecular docking and molecular dynamic simulations (MDS) were employed to establish the binding affinity with SV2A (Synaptic vesicle 2A) protein. • This study identifies the compound (LIG) to be a promising lead molecule for the treatment of epilepsy. The present investigation illustrates the conceptualization, synthesis, crystallographic analysis, and computational assessment of a new racetam derivative with a pyrrolidone ring as the pharmacophore. The compound demonstrates drug-like characteristics similar to LEV, an approved anti-epileptic drug, indicating its potential for developing novel epilepsy drugs. Molecular docking and molecular dynamic simulations were used to evaluate the binding affinity between the compound and SV2A, a protein-ligand complex. The protein-ligand complex attained structural equilibrium in the final 50 nanoseconds of the 200 nanosecond molecular dynamics simulation. The analysis reveals that regions with higher flexibility are primarily located in the extramembrane regions of the protein. Intermolecular contact analysis reveals hydrogen bonding and hydrophobic interactions as the primary types of interactions. The Molecular Mechanics Poisson-Boltzmann Surface Area (MMPBSA) calculation highlights the energetic aspects of ligand binding and the participation of important residues in the binding pocket. Unique interactions like those involving bifurcated hydrogen bonding, and novel pi-anion interaction makes the study significant. Quantum chemical calculations for the compound (LIG) done using DFT corroborates the protein-ligand interactions on the basis of Molecular Electrostatic Potential (MEP) maps. The study establishes the structure-activity relationship (SAR) of the newly developed pyrrolidone-based compound, identifying it as a promising lead molecule for epilepsy treatment. [Display omitted] [ABSTRACT FROM AUTHOR]

Dimetallic compounds I(P-P)M(S2C6H2S2)M(P-P)] (M=Ni, Pd; P-P=chelating bis(phosphine), 3a-3f) are prepared from OCS2C6H2S2CO or nBu2SnS2C6H2S2SnnBu2, which are protected forms of 1,2,4,5-benzenetetrathiolate. Selective monodeprotections of OCS2C6H2S2CO or nBu2SnS2C6H2S2SnnBu2 lead to [(P-P)Ni(S2C6- H2S2CO)] or [(P-P)Ni(S2C6H2S2SnnBu2)]; the former is used to prepare trimetallic compounds [(dcpe)Ni(S2C6H2S2)M(S2C6H2S2)Ni(dcpe)] (M = Ni (6a) or Pt (6b); dcpe = 1 ,2-bis(dicyclohexylphosphino)ethane). Compounds 3a-3f are redox active and display two oxidation processes, of which the first is generally reversible. Dinickel compound [(dcpe)Ni(S2C6H2S2)Ni(dcpe)] (3d) reveals two reversible oxidation waves with ΔE½=0.66 V, corresponding to κC of 1.6 x 1011 for the mixed valence species. Electrochemical behavior is unstable to repeated scanning in the presence of [Bu4N][PF6] electrolyte but indefinitely stable with Na[BArF24] (BArF24 = tetrakis(3, 5-bis(frifluoromethyl)phenyl)borate), suggesting that the radical cation generated by oxidation is vulnerable to reaction with PF6-. Chemical oxidation of 3d with [Cp2Fe][BArF24] leads Information of [3d][BArF24]. Structural identification of [3d][BArF24] reveals appreciable shortening and lengthening of C-S and C-C bond distances, respectively, within the tetrathioarene fragment compared to charge neutral 3d, indicating this to be the redox active moiety. Attempted oxidation of [(dppb)Ni(S2C6H2S2)Ni(dppb)] (3c) (dppb = 1 ,2-bis(diphenylphosphino)benzene) with AgBArF24 produces [[(dppb)Ni(S2C6H2S2)Ni(dppb)]2(μ-Ag2)][BArF24]2, [4c][BArF24]2, in which no redox chemistry has occurred. Crystal structures of bis(disulfide)-linked compounds [(P-P)Ni(S2C6H2(u-S2)2C6H2S2)Ni(P-P)] are reported. Near IR spectroscopy upon cationic [3d]+ and neutral 6a reveals multiple intense absorptions in the 95O-14OO nm region. Time-dependent density functional theory (DFT) calculations on a 6a model compound indicate that these absorptions are transitions between ligand-based π-type orbitals that have significant contributions from the sulfur p orbitals. [ABSTRACT FROM AUTHOR]

Glaucoma is the second leading cause of blindness after cataract and is heterogeneous in nature. Employing a genetic approach for the detection of the diseased condition provides an advantage that the gene responsible for the disease can be identified by genetic test. The availability of predictive tests based on the published literature would provide a mechanism for early detection and treatment. The genotype and phenotype information could be a valuable source for predicting the risk of the disease. To this end, a web server has been developed, based on the genotype and phenotype of myocilin mutation, which were identified by familial linkage analysis and case studies. The proposed web server provides clinical data and severity index for a given mutation. The server has several useful options to help clinicians and researchers to identify individuals at a risk of developing the disease. Glaucoma Pred server is available at http://bioserver1.physics.iisc.ac.in/myocilin. • Features of Glaucoma Pred: To help clinicians and researchers to identify individuals at a risk of developing the disease • Severity Index: Genotype-phenotype correlations aids in predicting the range of phenotypic variation of a specific mutation. • Myoilin: All the nucleotide changes and clinical information were collected from available literature for myocilin gene. • Population based analysis: Genotypic data based on ethnicity and type of glaucoma is given in the population based analysis. [ABSTRACT FROM AUTHOR]

The π-extended TTF derivative (III) containing fused acenaphthene moieties was synthesized by the P(OMe) 3 mediated coupling reaction of acenaphtho[1, 2- d ][1, 3]dithiol-8-one (II). Compound II was obtained in 51% yield from 1( 2 H )-acenaphthylenone (I) in a single step. Crystal structures of compounds I and II reveal the presence of extended intermolecular π-π stacking interactions in the crystal lattice. TTF derivative III reacted with 7,7,8,8-tetracyanoquinodimethane (TCNQ) to form a charge-transfer complex that exhibited absorption bands at 762 and 859 nm. A simplified molecular orbital diagram for III was established using density functional theory (DFT) to understand electronic transitions. [ABSTRACT FROM AUTHOR]

Heteroleptic bis(dithiolene)-phosphine iron and cobalt complexes [Fe(adt) 2 (PMe 3 )] ( 1 ) and [Co(adt) 2 (PMe 3 )] ( 2 ) (adt = para -anisyldithiolene) have been synthesized from corresponding bis(dithiolene) dimers [M 2 (adt) 4 ] 2 (M = Fe, Co) by reacting with excess PMe 3 in dichloromethane. Solid-state structures of 1 and 2 have been determined by single crystal X-ray crystallography, and the dithiolene ligands C S (≈1.72 Å) and C C (≈1.37 Å) bond distances reveal the coordination of π-radical monoanionic dithiolene (adt• 1− ) ligands to metal centers. Intense low energy ligand-to-ligand-charge transfer (LLCT) absorption band (743 nm for 1 ; 905 nm for 2 ) in UV–vis spectra and characteristic ν (C S•) (1168 cm −1 for 1 ; 1170 cm −1 for 2 ) in IR spectra affirms coordination of π-radical monoanionic dithiolenes to divalent metal ions. The cyclic voltammogram of 1 and 2 shows reversible oxidation and reduction waves attributed to M II → M III + e − (+0.52 V for 1 ; +0.29 V for 2 ) and adt• 1− + e − → adt 2− (−0.63 V for 1 ; −0.46 V for 2 ) redox process respectively. Comprehensive structural and spectroscopic investigations conclude, [M 2 III (adt 2− ) 2 (adt• 1- ) 2 ] → 2 [M II (adt• 1- ) 2 (PMe 3 )] intramolecular redox interplay during phosphine coordination induced cleavage of homoleptic bis(dithiolene) dimers to produce square pyramidal complexes. [ABSTRACT FROM AUTHOR]