Structure‐Guided Design of Thiazolidine Derivatives as Mycobacterium tuberculosis Pantothenate Synthetase Inhibitors

The pantothenate biosynthetic pathway is essential for the persistent growth and virulence of Mycobacterium tuberculosis (Mtb) and one of the enzymes in the pathway, pantothenate synthetase (PS, EC: 6.3.2.1), encoded by the panC gene, has become an appropriate target for new therapeutics to treat tuberculosis. Herein, we report nanomolar thiazolidine inhibitors of Mtb PS developed by a rational inhibitor design approach. The thiazolidine compounds were discovered by using energy‐based pharmacophore modelling and subsequent in vitro screening, which resulted in compounds with a half maximal inhibitory concentration (IC₅₀) value of (1.12±0.12) μM . These compounds were subsequently optimised by a combination of modelling and synthetic chemistry. Hit expansion of the lead by chemical synthesis led to an improved inhibitor with an IC₅₀ value of 350 nM and an Mtb minimum inhibitory concentration (MIC) of 1.55 μM . Some of these compounds also showed good activity against dormant Mtb cells.     

Synthesis and characterization of hybrid graphene nanocoolant for heat transfer dissipation in microchannel heat sinks

An attempt is made to examine the effect of hybrid nanocoolant in microchannel heat sink for computer cooling.Two-hybrid coolants with graphene as one of the prime components are synthesized and images of the particles are shown using scanning electron microscopy(SEM) and transmission electron microscopy(TEM). Heat transfer properties like thermal conductivity of the hybrid fluid, specific heat, density, and viscosity are evaluated experimentally and theoretically. The heat transfer characteristics are also studied in heat sink channels of micro level in the processors of personal computers. The parameters like internal heat transfer coefficient, thermal resistances and base temperature representing the processor temperature are examined for the applied heater power of 325 W. The coolant dilution was varied in the range of 0.05 vol%, 0.075 vol% and 0.1 vol% and the base temperature is noted. The recorded lowest base temperature is 310.01 K for the concentration of 0.1 vol%graphene-iron oxide(GFO) system for 0.5 mm fin spacing for the graphene-iron oxide hybrid coolant and for graphene oxide–iron oxide(GOFO) hybrid coolant it is 311.24 K for the same operating conditions.     

Linear and networked polymers formed by the near simultaneous occurrence of etherification and esterification under mild reaction conditions

Despite the large difference in their nucleophilicity, phenoxide and carboxylate anions take part nearly simultaneously in the aliphatic nucleophilic substitution reaction with 1,4‐dibromo‐2‐butene. This leads to the formation of ether (? O? ) and ester (? COO? ) linkages simultaneously under mild reaction conditions when hydroxyl benzoic acids are employed as nucleophiles. The process yields a new class of polymer broadly classified as unsaturated poly(ether ester) which are potentially functionalizable. This methodology has also been extended for preparing networked polymers by making use of 3,5‐dihydroxybenzoic acid as A₃ type monomer. Copyright © 2011 Society of Chemical Industry     

Effect of co-digestion agricultural-industrial residues: various slurry temperatures

The main objective of this study is to investigate the effect of co-digestion using industrial-agro waste and operating temperature of digester slurry to enhance the biogas and methane yield. The anaerobic digestion process is carried out by using a floating dome type bio-digester with the capacity of 1?m³. The co-digestion of press mud and rice straw with the ratio of 1:1, slurry temperature mesophilic range of (30–40°C) and thermophilic raange of (41–55°C) is used in this study. The maximum generation of daily biogas and weekly methane yield obtained were about 190?L/day and 55% in the case of the thermophilic condition. The lowest generation of daily biogas and weekly methane yield obtained were about 130?L/day and 33% in the case of mesophilic condition. The 10 percentage of cow dung is used as an inoculum of the digester and 30 days of hydro retention time for both the temperature ranges. The methane and biogas yield is at its peak and there was a faster hydro retention time in thermophilic range temperature at 52°C.     

Exploration of artificial neural network [ANN] to predict the electrochemical characteristics of lithium-ion cells

CoO anode, as an alternate to the carbonaceous anodes of lithium-ion cells has been prepared and investigated for electrochemical charge-discharge characteristics for about 50 cycles. Artificial neural networks (ANNs), which are useful in estimating battery performance, has been deployed for the first time to forecast and to verify the charge-discharge behavior of lithium-ion cells containing CoO anode for a total of 50 cycles. In this novel approach, ANN that has one input layer with one neuron corresponding to one input variable, viz., cycles [charge-discharge cycles] and a hidden layer consisting of three neurons to produce their outputs to the output layer through a sigmoid function has been selected for the present investigation. The output layer consists of two neurons, representing the charge and discharge capacity, whose activation function is also the sigmoid transfer function. In this ever first attempt to exploit ANN as an effective theoretical tool to understand the charge-discharge characteristics of lithium-ion cells, an excellent agreement between the calculated and observed capacity values was found with CoO anodes with the best fit values corresponding to an error factor of <1%, which is the highlight of the present study.     

Stability of Lactobacillus reuteri in Different Types of Microcapsules

This study was designed to find the most suitable method and wall material for microencapsulation of the probiotic bacterium Lactobacillus reuteri to maintain cell viability during gastric challenge. Five L. reuteri strains were individually encapsulated using alginate, alginate plus starch, K‐carrageenan with locust bean gum, or xanthan with gellan by extrusion or phase separation (emulsion). The morphology of the microcapsules was studied using phase contrast and cryo‐scanning electron microscopy (cryo‐SEM). The resistance of these microcapsules and the viability of contained L. reuteri to simulated gastric juice were studied. The shape and size of the microcapsules produced varied with the preparation method and type of wall material. Extruded microcapsules were larger and more uniformly shaped. Survival of microencapsulated L. reuteri was significantly better than that of planktonic cells and varied with the strain, method of microencapsulation, and wall material used. In general, microencapsulation using alginate and alginate with starch by both extrusion and phase separation were found to provide bacteria significantly greater protection (P < 0.05) against simulated gastric juice.     

Polysulfobetaine bearing tertiary amide between counterions and its applications

Modified sulfobetaine bearing tertiary amide spacer between the counterions is synthesized and polymerized by reversible addition–fragmentation chain transfer polymerization technique. The tertiary amide spacer influences various characteristics of the zwitterionic polymer. The modified polyzwitterion, PZI, forms coacervates in deionized water. The coacervates are thoroughly characterized by scanning electron microscopy, transmission electron microscopy, and transmittance studies. The ability to form coacervate complexes with functional ingredients has been demonstrated by encapsulating renewable resource actives like ferulic acid. The coacervate complexes have been studied by optical microscopy, transmission electron microscopy, and automated sunscreen sun protection factor analyzer. Synergism is noticed in the coacervate complex. Because of its ability to form self‐coacervates, this novel addition to the zwitterionic family is potentially useful for encapsulating many functional ingredients through coacervate complex formation. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46178.     

Copper molybdenum sulfide: A novel pseudocapacitive electrode material for electrochemical energy storage device

The ever-growing demand for energy storage devices necessitates the development of novel energy storage materials with high performance. In this work, copper molybdenum sulfide (Cu₂MoS₄) nanostructures were prepared via a one-pot hydrothermal method and examined as an advanced electrode material for supercapacitor. Physico-chemical characterizations such as X-ray diffraction, laser Raman, field emission scanning electron microscope with elemental mapping, and X-ray photoelectron spectroscopy analyses revealed the formation of I-phase Cu₂MoS₄. Electrochemical analysis using cyclic voltammetry (CV), charge-discharge (CD) and electrochemical impedance spectroscopy (EIS) showed the pseudocapacitive nature of charge-storage via ion intercalation/de-intercalation occurring in the Cu₂MoS₄ electrode. The Cu₂MoS₄ electrode delivered a specific capacitance of 127 F g^?1 obtained from the CD measured using a constant current density of 1.5 mA cm^?2. Further, Cu₂MoS₄ symmetric supercapacitor (SSC) device delivered a specific capacitance of 28.25 F g^?1 at a current density of 0.25 mA cm^?2 with excellent rate capability. The device acquired high energy and power density of 3.92 Wh kg^?1 and 1250 W kg^?1, respectively. The Nyquist and Bode analysis further confirmed the pseudocapacitive nature of Cu₂MoS₄ electrodes. The experimental results indicate the potential application of Cu₂MoS₄ nanostructures as a novel electrode material for energy storage devices.