Synthesis,characterization and Hirshfeld surface analysis of a mixed-ligand copper (II) coordination polymer from 1,4,8,11-tetraazacyclotetradecane and pyromellitic dianhydride

Transition Metal Chemistry - One pot synthesis of a new mixed-ligand coordination polymer has been carried out by combining copper salt, macrocyclic ligand 1,4,8,11-tetraazacyclotetradecane...     

What is the probability an automorphism fixes a group element?

Extending the notion of probability to the automorphisms of a group, we find the probability of an arbitrarily chosen automorphism of a group fixing an arbitrary element of the group.     

Suzuki–Miyaura coupling of quinazolines containing an unprotected NH2 group: Synthesis and biological testing of quinazoline derivatives

A robust approach to 4-amino quinazoline bi-aryl compounds was developed through Suzuki–Miyaura coupling reaction of quinazoline containing an unprotected NH₂ group and arylboronic acids. Pd(dcpf)Cl₂ was found to be an efficient catalyst for the reaction. All the compounds were evaluated for antimicrobial activity against gram-positive and gram-negative bacteria and fungi. One of the compounds, 3l, found to be more active against Candida albicans than the standard Miconazole.     

Continuous dielectrophoretic cell separation microfluidic device

We present a prototype microfluidic device developed for the continuous dielectrophoretic (DEP) fractionation and purification of sample suspensions of biological cells. The device integrates three fully functional and distinct units consisting of an injector, a fractionation region, and two outlets. In the sheath and sample injection ports, the cell sample are hydrodynamically focused into a stream of controlled width; in the DEP fractionation region, a specially shaped nonuniform (isomotive) electric field is synthesized and employed to facilitate the separation, and the sorted cells are then delivered to two sample collection ports. The microfluidic behavior of the injector region was simulated and then experimentally verified. The operation and performance of the device was evaluated using yeast cells as model biological particles. Issues relating to the fabrication and operation of the device are discussed in detail. Such a device takes a significant step towards an integrated lab-on-a-chip device, which could interface/integrate to a number of other on-chip components for the device to undertake the whole laboratory procedure.     

A decision support system for selection of tractor-implement system used on Indian farms

The selection of tractor and its matching implements has now become very difficult in India because of availability of variety of tractor models ranging from 10 to 45 kW. To overcome the problem of matching of tractor-implement system, an expert system modelling approach leading to decision support system (DSS) was adopted to make the step wise decision. The application of DSS was demonstrated in the paper to select either an implement to match the tractor or to select a tractor to match the implement under different soil and operating conditions. The DSS leading to computer software developed in Visual Basic™ programming provided the intuitive user interfaces by linking databases such as specifications of tractors and implements, tractor performance data, soil and operating conditions, to support the decision on selection of tractor-implement system. The programme calculates working width of implement based on input data for the most critical field operation and helps in selection of a suitable implement having width nearer to the calculated value among the commercially available implements. The software calculates the required drawbar power of the tractor based on draft and working speed of the selected implement. Finally, the PTO power requirement of a tractor is calculated by the software. Based on calculated PTO power, the software suggests available makes and models of tractor/machinery from the compiled data bank. The developed DSS was tested with a case study to demonstrate the flexibility of the software. The DSS can be used effectively in selection of a tractor or an implement of particular size from various makes and models of commercially available tractors and implements.     

Orthogonal Ubiquitin Transfer through Engineered E1-E2 Cascades for Protein Ubiquitination

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Highlights? Orthogonal ubiquitin (UB) transfer pathway to synthesize specific UB-E2 conjugates ? Phage display to engineer UB-E1 and UB-E2 interactions ? Engineered xUB-xE1 and xE1-xE2 pairs with no cross-reactivities with native enzymes     

Electrokinetics over hydrophobic surfaces

Segregation of phases in the vicinity of hydrophobic surfaces may turn out to be immensely consequential towards altering the coupling of electrostatics and hydrodynamics over interfacial scales. Here, we review the fundamental advances towards bringing out the various facets of electrokinetic transport over hydrophobic interfaces. We lay significant emphasis on the developments in understanding the slippery electrohydrodynamics over such interfaces, by appealing to the considerations across various spatio‐temporal scales as unveiled by molecular dynamics as well as mesoscopic modelling paradigms (such as phase field and lattice Boltzmann). We envisage that despite significant advancements being achieved towards relating the macroscopic slip‐length with the underlying molecular or mesoscopic phenomena, future efforts could be directed towards developing more robust statistically based models that may connect rarefied gas dynamics in the segregated phase with bulk electrokinetic transport and possible giant augmentations in the consequent fluid flow.     

Enhanced optical and field emission properties of CTAB-assisted hydrothermal grown ZnO nanorods

We have developed a simple N-cetyl-N,N,N-trimethyl ammonium bromide (CTAB)-assisted hydrothermal route for the production of ZnO one-dimensional (1D) nanostructures on zinc foil at reaction temperature of 160 °C. With the increase of CTAB concentration, the one-dimensional structures change from microrod to a mixture of nano- and microrod and finally to nanorods. X-ray diffraction studies confirmed the proper phase formation of the grown nanostructures. The room temperature photoluminescence spectra showed that ZnO nanostructures prepared with increased CTAB concentration exhibited enhanced band edge UV emission and also blue shift of the emission peak. All the samples show no defect related green emission. Field emission property of the 1D structures has been investigated in detail. By tuning the CTAB concentration, the field emission property was optimized. The nanorods synthesized with high CTAB showed turn-on and threshold fields of 3.2 and 5 V/μm, respectively, which are comparable to the values for vapour phase synthesized high field emitting ZnO nanostructures.     

Quinone-modified polymers as electron transfer relay systems in amperometric glucose sensors

A polysiloxane and an acrylonitrile–ethylene copolymer with covalently attached p-hydroquinone/benzoquinone moieties were prepared and tested as electron transfer relay systems in amperometric glucose biosensors. Using experiments involving cyclic voltammetry and stationary potential measurements, it was shown that the polysiloxane relay system can efficiently mediate electron transfer from reduced glucose oxidase to a conventional carbon-paste electrode. Sensors containing this polymeric relay system and glucose oxidase respond rapidly to low (<0.1 mm) glucose concentrations, with steady state current responses achieved in less than 1 min. The acrylonitrile–ethylene copolymer was found to be less efficient than the polysiloxane system at mediating the electron transfer from reduced glucose oxidase to the electrode. The dependence of the sensor response on the nature of the polymer backbone is discussed.