An experimental investigation on pool boiling heat transfer enhancement using Cu-Al2O3 nano-composite coating

Pool boiling heat transfer performances of Cu-Al₂O₃-coated copper surfaces have been studied experimentally for its potential use in heat transfer applications. In the present study, a two-step electrochemical deposition method is examined. This method provides an easy control on surface properties such as porosity and coating thickness. The deposition method is studied carefully and responsible surface morphology parameters are reported. After performing the pool boiling experiments on coated surfaces with DI water, the maximum critical heat flux of 1800 kW/m² and heat transfer coefficient of 193 kW/m² K, which are 68% and 260% higher than that of bare surface, respectively.     

Quantitative Analysis of Phytochemicals from Inula cappa Roots

JPC – Journal of Planar Chromatography – Modern TLC - Inula cappa (family Compositae) is used in the Ayurvedic medicinal system for the treatment of bronchitis, diabetes, fever,...     

Detection of blood flow through artery in the presence of steno-occlusive disease post liver transplantation by modeling for theatrical and detrimental environmental changes

This research intends to expand a mathematical model for studying the non-Newtonian surge of blood through a hepatic artery in the presence of steno occlusive disease post-liver transplantation. Power law liquid demonstrates the non- Newtonian character of blood. The hemodynamic conduit of the fluid is altered by the occurrence of arterial stenosis. In our study, the difficulty is resolved by applying diagnostic methods with the assistance of marginal circumstances and consequences. The outcomes are explained graphically for unusual cases for such stenosis. The study design is based on a tensorial form and converts its solution using numerical and analytical techniques. Our study outcome suitably demonstrates that the mathematical model used corroborates with the clinical scenario of the patient with hepatic disease.     

Cell‐Laden Hydrogels for Multikingdom 3D Printing

Living materials are created through the embedding of live, whole cells into a matrix that can house and sustain the viability of the encapsulated cells. Through the immobilization of these cells, their bioactivity can be harnessed for applications such as bioreactors for the production of high‐value chemicals. While the interest in living materials is growing, many existing materials lack robust structure and are difficult to pattern. Furthermore, many living materials employ only one type of microorganism, or microbial consortia with little control over the arrangement of the various cell types. In this work, a Pluronic F127‐based hydrogel system is characterized for the encapsulation of algae, yeast, and bacteria to create living materials. This hydrogel system is also demonstrated to be an excellent material for additive manufacturing in the form of direct write 3D‐printing to spatially arrange the cells within a single printed construct. These living materials allow for the development of incredibly complex, immobilized consortia, and the results detailed herein further enhance the understanding of how cells behave within living material matrices. The utilization of these materials allows for interesting applications of multikingdom microbial cultures in immobilized bioreactor or biosensing technologies.     

Two-Dimensional Supramolecular Polymerization of a Bis-Urea Macrocycle into a Brick-Like Hydrogen-Bonded Network

We report on a dendronized bis-urea macrocycle 1 self-assembling via a cooperative mechanism into two-dimensional (2D) nanosheets formed solely by alternated urea-urea hydrogen bonding interactions. The pure macrocycle self-assembles in bulk into one-dimensional liquid-crystalline columnar phases. In contrast, its self-assembly mode drastically changes in CHCl₃ or tetrachloroethane, leading to 2D hydrogen-bonded networks. Theoretical calculations, complemented by previously reported crystalline structures, indicate that the 2D assembly is formed by a brick-like hydrogen bonding pattern between bis-urea macrocycles. This assembly is promoted by the swelling of the trisdodecyloxyphenyl groups upon solvation, which frustrates, due to steric effects, the formation of the thermodynamically more stable columnar macrocycle stacks. This work proposes a new design strategy to access 2D supramolecular polymers by means of a single non-covalent interaction motif, which is of great interest for materials development.     

The complex role of the triphenylmethyl motif in anticancer compounds

Compounds incorporating the triphenylmethyl motif constitute an emerging family of potent anticancer agents. Although several small molecules containing this pharmacophore have now been identified, the mechanism of cell death induction for some of these compounds is unknown. In an effort to define their mechanism of action, and to distinguish subtypes within the group of compounds containing the triphenylmethyl moiety, we have created novel triphenylmethyl-containing small molecules and have evaluated them in a battery of biological assays. Here we show that several phosphonate and phosphonochloridates possessing the triphenylmethyl motif potently induce death of multiple cancer cell lines in culture. Further assays evaluating the ability to cause cell cycle arrest, inhibit tubulin polymerization, dissociate mitochondrial-bound hexokinase in cancer cells, and inhibit calcium-dependent potassium ion channels indicate that triphenylmethyl-containing compounds can be placed into at least four distinct categories, each with a different mechanism of action.     

Imparting nanoparticle function with size-controlled amphiphilic polymers

Herein we report our method of water solubilization and subsequent functionalization of a variety of nanoparticle systems with amphiphilic polymers containing build-in "chemical handles". We have used these polymers, which have narrow polydispersity indices, to impart water solubility and chemical sensitivity toward targeted species (here: pH). These material systems have high chemical conjugation efficiencies in aqueous conditions which may be used to create a variety of chemical and biological multifunctional materials.     

Quasi-static response and texture evolution of α- and γ-RDX: a comparative study

In this paper, we undertake a comparative study of the stress–strain response and slip activity of α- and γ-polymorph of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) under pressure loading using a rate-dependent single-crystal plasticity model. Texture evolution studies are performed to further understand the effects of the dominant slip systems. The simulations indicate that the difference in elastic moduli and lattice parameters for α- and γ-RDX lead to different elastic–plastic constitutive response in the two polymorphs. γ-RDX exhibits more plastic slip compared to α-RDX for loading on (1 1 1) plane and the two polymorphs have different sets of dominant slip systems. We observe that the high-pressure slip system (0 0 1)[0 1 0] that is determined using molecular dynamics simulations is the most dominant slip system for this orientation. Whereas, for loading on (2 1 0) plane, α-RDX has marginally higher plastic slip than γ-RDX, though the same slip system is dominant for both the polymorphs. The texture evolution for loading on (1 1 1) and (2 1 0) planes follow the path towards the most dominant slip systems for both the polymorphs. We predict that the larger plastic slip in γ-RDX for loading on (1 1 1) plane might play an important role in understanding the reduced sensitivity for shock loading on (1 1 1) plane, when compared to (2 1 0) for which γ-RDX has lesser plastic slip, and (1 0 0) which is purely elastic.     

Two [Fe(IV)=O Trp*] intermediates in M. tuberculosis catalase-peroxidase discriminated by multifrequency (9-285 GHz) EPR spectroscopy: reactivity toward isoniazid

We have characterized the intermediates formed in the peroxidase cycle of the multifunctional heme-containing enzyme KatG of M. tuberculosis. Selected Trp variants from the heme proximal (W321F) and distal (W107F and W91F) sides were analyzed together with the wild-type enzyme with regard to the reaction with peroxyacetic acid and hydrogen peroxide (in the catalase-inactive W107F). The 9 GHz EPR spectrum of the enzyme upon reaction with peroxyacetic acid showed the contribution of three protein-based radical species, two Trp* and a Tyr*, which could be discerned using a combined approach of multifrequency Electron Paramagnetic Resonance (EPR) spectroscopy with selective deuterium labeling of tryptophan and tyrosine residues and site-directed mutagenesis. Trp321, a residue in H-bonding interactions with the iron through Asp381 and the heme axial ligand His270, was identified as one of the radical sites. The 9 GHz EPR signal of the Trp321 radical species was consistent with an exchange-coupled species similar to the oxoferryl-Trp radical intermediate in cytochrome c peroxidase. On the basis of the possibility of distinguishing among the different radical intermediates of the peroxidase cycle in M. tuberculosis KatG (MtKatG), we used EPR spectroscopy to monitor the reactivity of the enzyme and its W321F variant with isoniazid, the front-line drug used in the treatment of tuberculosis. The EPR experiments on the W321F variant preincubated with isoniazid allowed us to detect the short-lived [Fe(IV)=O Por*+] intermediate. Our results showed that neither the [Fe(IV)=O Por*+] nor the [Fe(IV)=O Trp321*+] intermediates were the reactive species with isoniazid. Accordingly, the subsequent intermediate (most probably the other Trp*) is proposed to be the oxidizing species. Our findings demonstrate that the protein-based radicals formed as alternative intermediates to the [Fe(IV)=O Por*+] can play the role of cofactors for substrate oxidation in the peroxidase cyle of KatGs.