In silico screening of the juvabione category of juvenile hormone analogues with juvenile hormone binding protein of Galleria mellonella – a docking study

Juvabione, dehydrojuvabione and their aromatic analogues act as juvenile hormone mimics against diverse strains of insect species. Large numbers of modified juvenoids containing the juvabione skeleton, with various structural variations, are synthesized. Some of these compounds exhibit a very high degree of juvenile hormone activity and are presently in use. In this paper we report a comparative molecular docking study of synthesized juvabione, natural juvenile hormone III and synthetic insect growth regulators (fenoxycarb, S-21149, Compound 1, pyriproxyfen) with the juvenile hormone binding protein of Galleria mellonella. The study clearly indicates a higher binding affinity of nitro-substituted juvabione over natural juvenile hormone III and synthetic insect growth regulators such as fenoxycarb and S-21149.     

A multi-criteria decision making approach for location planning for urban distribution centers under uncertainty

Location planning for urban distribution centers is vital in saving distribution costs and minimizing traffic congestion arising from goods movement in urban areas. In this paper, we present a multi-criteria decision making approach for location planning for urban distribution centers under uncertainty. The proposed approach involves identification of potential locations, selection of evaluation criteria, use of fuzzy theory to quantify criteria values under uncertainty and application of fuzzy TOPSIS to evaluate and select the best location for implementing an urban distribution center. Sensitivity analysis is performed to determine the influence of criteria weights on location planning decisions for urban distribution centers.The strength of the proposed work is the ability to deal with uncertainty arising due to a lack of real data in location planning for new urban distribution centers. The proposed approach can be practically applied by logistics operators in deciding on the location of new distribution centers considering the sustainable freight regulations proposed by municipal administrations. A numerical application is provided to illustrate the approach.     

s-Triazine: A Privileged Structure for Drug Discovery and Bioconjugation

This review provides an overview of the broad applicability of s-triazine. Our many years working with this intriguing moiety allow us to discuss its wide activity spectrum (inhibition against MAO-A and -B, anticancer/antiproliferative and antimicrobial activity, antibacterial activity against MDR clinical isolates, antileishmanial agent, and use as drug nano delivery system). Most of the compounds addressed in our studies and those performed by other groups contain only N-substitution. Exploiting the concept of orthogonal chemoselectivity, first described by our group, we have successfully incorporated different nucleophiles in different orders into s-triazine core for application in peptides/proteins at a temperature compatible with biological systems.     

Estimation of the Surface Tensions of Benzonitrile, Chlorobenzene, Benzyl Chloride and Benzyl Alcohol in Mixtures with Benzene by Associated and Non-associated Processes at 298.15, 303.15 and 313.15 K

Densities and surface tensions were measured for the binary liquid mixtures formed by benzonitrile, chlorobenzene, benzyl chloride and benzyl alcohol with benzene, at 298.15, 303.15 and 313.15 K and atmospheric pressure, over the whole composition range. The Prigogine?CFlory?CPatterson model (PFP), the Ramaswamy and Anbananthan (RS) model, the model derived by Glinski, the Sanchez equation, the Goldsack relation and Eberhart??s model were used to predict the associational behavior of weakly interacting liquids. The measured properties were fitted to the Redlich?CKister polynomial equation to estimate the binary coefficients and standard errors. Furthermore, the McAllister multi-body interaction model was also used to correlate the binary solution properties. These non-associated and associated models were compared and tested for different systems, showing that considering the association processes yields better agreement between theory and experiment as compared to non-associated processes.     

Working vacations queueing model with multiple types of server breakdowns

This paper deals with a single server working vacation queueing model with multiple types of server breakdowns. In a working vacations queueing model, the server works at a different rate instead of being completely idle during the vacation period; the arrival rate varies according to the server’s status. It is assumed that the server is subject to interruption due to multiple types of breakdowns and is sent immediately for repair. Each type of breakdown requires a finite random number of stages of repair. The life time of the server and the repair time of each phase are assumed to be exponentially distributed. We propose a matrix–geometric approach for computing the stationary queue length distribution. Various performance indices namely the expected length of busy period, the expected length of working vacation period, the mean waiting time and average delay, etc. are established. In order to validate the analytical approach, by taking illustration, we compute numerical results. The sensitivity analysis is also performed to explore the effect of different parameters.     

添加钙基膨润土对猪粪堆肥中水溶性有机物光谱特征的影响

为了探究添加钙基膨润土(CB)对猪粪好氧堆肥过程中水溶性有机物(DOC)动态变化的影响,向猪粪和木屑混合物料中添加不同质量比的CB,采用自制的强制通风好氧发酵装置,进行了为期60天的好氧堆肥试验。定期采集堆肥样品并进行冷冻干燥,通过紫外-可见光谱(UV-Vis),傅里叶变换红外光谱(FTIR)和荧光光谱(FS)相结合的方法,对堆肥样品中DOC光谱特征的变化进行研究。结果表明,在堆肥过程中DOC呈降低趋势,且随着CB添加量的增多,DOC的降解率为49.11%~62.92%;堆肥DOC相应的UV-Vis和FS光谱分析显示,类腐殖质的特征峰强度不断升高,而碳水化合物、类蛋白的特征峰强度逐渐降低;且与对照相比,添加钙基膨润土使类腐殖质特征峰的强度增大,峰位置红移。堆肥结束时,相较于对照,添加CB处理的光谱特征参数SUVA₂₅₄,SUVA₂₈₀和腐殖化系数分别增加了16.51%~47.72%,8.58%~44.02%和23.16%~88.22%,且5%添加比例最佳,这被FTIR解析峰密度进一步证实;相关性分析显示,SUVA₂₅₄与堆肥腐熟度呈极显著相关,可指示堆肥腐熟度。综上所述,随着堆肥的进行,有机物由非腐殖质向腐殖质转化,DOC的分子质量及芳构化程度逐渐增加,且添加CB对这一过程具有促进作用,并以5%添加比例最佳。     

Hump structure below Tc in the thermal conductivity of MgB2 superconductor

A reasonable cause of absence of hump structure in thermal conductivity of MgB₂ below the superconducting transition temperature (T_c) lies in the appearance of multigap structure. The gaps of lower magnitude can be suppressed by defects so that this system becomes effectively a single-gap superconductor. When such a situation is created, it is hoped that thermal conductivity (κ) will show hump below T_c. Proceeding along these lines, a sample of MgB₂ with a relatively higher residual resistivity ρ_o = 33.8 μΩ cm has been found to show a hump structure below T_c. The actual electronic thermal conductivity κ_el of this sample is less than that expected from the Wiedeman–Franz law by more than a factor of 2.6 in the considered temperature range.Modifying the Wiedeman–Franz law for the electronic contribution by replacing the Lorenz number L₀ = 2.45 × 10^?8 W Ω K^?2 by an effective Lorenz number L_eff (<L₀) we have obtained two sets of κ_el, namely those with L_eff = 0.1L₀ and 0.2L₀. Corresponding to these two sets of κ_el, two sets of the phonon thermal conductivity κ_ph are obtained. κ_ph has been analyzed in terms of an extended Bardeen–Rickayzen–Tewordt theory. The main result of this analysis is that the hump structure corresponds to a gap ratio of 3.5, and that large electron-point defect scattering is the main source of drastic reduction of the electronic thermal conductivity from that given by the usual Wiedeman–Franz law.     

Ultrasonic and IR study of intermolecular association through hydrogen bonding in ternary liquid mixtures

Complex formation in ternary liquid mixtures of dimethylsulfoxide (DMSO) with phenol and o-cresol in carbontetrachloride has been studied by measuring ultrasonic velocity at 2 MHz, in the concentration range of 0.019-0.162 (in mole fraction of DMSO) at varying temperatures of 20, 30 and 40 degrees C. Using measured values of ultrasonic velocity, other parameters such as adiabatic compressibility, intermolecular free length, molar sound velocity, molar compressibility, specific acoustic impedance and molar volume have been evaluated. These parameters have been utilized to study the solute-solute interactions in these systems. The ultrasonic velocity shows a maxima and adiabatic compressibility a corresponding minima as a function of concentration for these mixtures. The results indicate the occurrence of complex formation between unlike molecules through intermolecular hydrogen bonding between oxygen atom of DMSO molecule and hydrogen atom of phenol and o-cresol molecules. The excess values of adiabatic compressibility and intermolecular free length have also been evaluated. The variation of both these parameters with concentration also indicates the possibility of the complex formation in these systems. Further, to investigate the presence of O-HO bond complexes and the strength of molecular association with concentrations, the infrared spectra of both the systems, DMSO-phenol and DMSO-o-cresol, have been recorded for various concentrations at room temperature (20 degrees C). The results obtained using infrared spectroscopy for both the systems also support the occurrence of complex formation through intermolecular hydrogen bonding in these ternary liquid mixtures.     

Performance assessment of hybrid multiblock copolymers included with ionic liquid for fuel cell applications

To improve the proton conductivity and thermal stability of proton exchange membrane, hybrid poly (arylene ether) multiblock copolymers were synthesized by using 6F-bisphenol A monomer. The hydrophobic oligomers poly (arylene ether sulfone) containing 6F-bisphenol A with varying molecular weight were copolymerised with hydrophilic oligomer disulfonated poly (arylene ether ketone) containing pendant carboxylic acid group to prepare multiblock copolymers. For further enhancing the proton conductivity, ionic liquid is embedded into the synthesized multiblock copolymers to fabricate the hybrid multiblock membranes. The ¹H NMR studies confirmed the synthesis of oligomers and multiblock copolymers whereas the FT-IR spectra revealed the interaction of ionic liquid with the multiblock copolymers. The proton conductivity of the membranes has also been examined at different temperatures and the activation energy required for the proton transport was calculated by using Arrhenius equation. At 30 °C, the maximum proton conductivity of 0.14 S/cm were shown by hybrid membrane (with 50% ionic liquid, 6FB1/I.L-50%), which is of 3.5 times greater than that of pristine 6FB1 membrane. Compared with pristine membranes, the hybrid membranes exhibit improved oxidative, thermal and mechanical stability. Moreover, the scanning electron microscopy (SEM) investigation depicts better phase separation in hybrid membranes than pristine membranes by forming ionic clusters. The membranes have been tested in H₂/O₂ fuel cell and their performance is compared with the state-of-art Nafion 117 membrane.     

Supramolecular Control on the Optical Properties of a Dye-Polyelectrolyte Assembly

Control of fluorescent molecular assemblies is an exciting area of research with large potential for various important applications, such as, fluorescence sensing/probing, cell imaging and monitoring drug-delivery. In the present contribution, we have demonstrated control on the extent of aggregation of a dye-polyelectrolyte assembly using a macrocyclic host molecule, sulfobutylether-β-cyclodextrin (SBE-β-CD). Initially, a cationic molecular rotor based organic dye, Auramine-O (AuO), undergoes aggregation in the presence of an anionic polyelectrolyte, polystyrene sulfonate (PSS), and displays a broad intense new emission band along with large variation in its absorption features and excited-state lifetime. A manipulation of the monomer-aggregate equilibrium of the dye-polyelectrolyte assembly has been achieved by introducing a cyclodextrin based supramolecular host, SBE-β-CD, which leads to relocation of AuO molecules from polyelectrolyte (PSS) to supramolecular host cavity, owing to the formation of a host-guest complex between AuO and SBE-β-CD. A reversible control on this manipulation of monomer-aggregate equilibrium is further achieved by introducing a competitive guest for the host cavity i. e., 1-Adamantanol. Thus, we have demonstrated an interesting control on the dye-polyelectrolyte aggregate assembly using a supramolecular host molecule which open up exciting possibilities to construct responsive materials using a repertoire of various host-specific guest molecules.