Sheet-forming abiotic hetero foldamers

Abiotic hetero oligomers, adopting a well-defined extended self-assembled sheet-like structure, derived from conformationally constrained aliphatic and aromatic amino acid residues repeating at regular intervals are reported.     

Dissipation pattern and dietary risk assessment of some commonly used insecticides on tomato (Solanum lycopersicum L.)

Pesticide residue in food commodities is a serious concern in relation to consumer safety and also the most significant barrier in the trade of food commodities. The dissipation pattern of four insecticides, namely novaluron, λ-cyhalothrin, imidacloprid, and fenazaquin, was evaluated on tomato fruits and cropped soil. The residues were extracted using the QuEChERS analytical method and quantized using a gas chromatograph with electron capture detector, gas chromatograph mass spectrometer, and high-performance liquid chromatography with photo diode array detector. The analytical method was validated using parameters like recovery, linearity, accuracy, matrix effect, and specificity, with limit of detection and limit of quantitation established to be 0.01 and 0.05 mg/kg, respectively, for all the pesticides. The average initial deposits (samples collected after 2 h of application) at the recommended dose of novaluron, λ-cyhalothrin, imidacloprid, and fenazaquin were 0.593, 0.293, 0.227, and 0.431 mg/kg on tomato fruits, respectively, and were below the limit of quantification in soil. The pre-harvest interval of 17, 8, 1, and 13 days was suggested for novaluron, λ-cyhalothrin, imidacloprid, and fenazaquin on tomato, respectively. Risk assessment studies revealed that all pesticides under study are safe and do not pose any threat to humans as theoretical maximum dietary intake is less than the maximum permissible intake and acceptable daily intake.     

Computational modeling of novel InN/Al0.30In0.70N multilayer nano-heterostructure

Most of the low dimension heterostructures that have been modeled and simulated to determine various important quantum mechanical parameters are based on GaN/AlGaN and GaAs/AlGaAs. The heterostructures of newly invented material (InN/AlInN), however, have not been well studied. In this paper, novel multilayer nano-heterostructure InN/Al_0.30In_0.70N of length 288 nm have been modeled and studied to compute the energy band profile within the frame work of eight band k.p method, which graphs the energy of conduction and valence band edges versus position, and potential distribution throughout the modeled and one dimensionally simulated nano-heterostructure. In addition, electron–hole densities along with space charge densities have also been calculated for 30% Al concentration. The novelty of the nano-heterostructure due to unusual properties of InN studied by FP-LAPW and LCAO methods is also discussed. The results obtained in this paper will be applicable to the newly invented nano-opto-electronic devices.     

Glucose Responsive Hydrogel Networks Based on Protein Recognition

Stimuli‐responsive materials capable of manifesting physical changes in response to environmental signals are valuable tools for use in a variety of biomedical applications. Herein we describe one such smart glucose‐responsive hydrogel material prepared by immobilizing the glucose/galactose binding protein within an acrylamide hydrogel network. This hydrogel demonstrates a quantitative “accordion”‐like dynamic response in the presence of glucose. We further show the feasibility of employing this responsive smart material as a gating agent for controlled drug delivery, thus, demonstrating that these hydrogels may eventually lead to the development of implantable drug delivery systems for diabetes management applications.

     

Anthozoa red fluorescent protein in biosensing

The identification and cloning of a red fluorescent protein (DsRed) obtained from Anthozoa corals has provided an alternative to commonly used green fluorescent proteins (GFPs) in bioanalytical and biomedical research. DsRed in tandem with GFPs has enhanced the feasibility of multicolor labeling studies. Properties of DsRed, for example high photostability, red-shifted fluorescence emission, and stability to pH changes have proven valuable in its use as a fluorescent tag in cell-biology applications. DsRed has some limitations, however. Its slow folding and tendency to form tetramers have been a hurdle. Several different mutational studies have been performed on DsRed to overcome these problems. In this paper, applications of DsRed in biosensing, specifically in FRET/BRET assays, whole-cell assays, and in biosensors, is discussed. In the future, construction of DsRed mutants with unique characteristics will further expand its applications in bioanalysis.     

Nonlinear analysis of traffic jams in an anisotropic continuum model

This paper presents our study of the nonlinear stability of a new anisotropic continuum traffic flow model in which the dimensionless parameter or anisotropic factor controls the non-isotropic character and diffusive influence.In order to establish traffic flow stability criterion or to know the critical parameters that lead,on one hand,to a stable response to perturbations or disturbances or,on the other hand,to an unstable response and therefore to a possible congestion,a nonlinear stability criterion is derived by using a wavefront expansion technique.The stability criterion is illustrated by numerical results using the finite difference method for two different values of anisotropic parameter.It is also been observed that the newly derived stability results are consistent with previously reported results obtained using approximate linearisation methods.Moreover,the stability criterion derived in this paper can provide more refined information from the perspective of the capability to reproduce nonlinear traffic flow behaviors observed in real traffic than previously established methodologies.     

All Solid State Chromium(III) Selective Potentiometric Sensor Based on 2‐(1‐(2‐((3‐(2‐Hydroxyphenyl)‐1H‐pyrozol‐1‐yl)methyl)benzyl)‐1H‐pyrazol‐3‐yl)phenol

Highly selective all solid state electrochemical sensor based on a synthesized compound i.e. 2‐(1‐(2‐((3‐(2‐hydroxyphenyl)‐1H‐pyrozol‐1‐yl)methyl)benzyl)‐1H‐pyrazol‐3‐yl)phenol (I) as an ionophore has been prepared and investigated for the selective quantification of chromium(III) ions. The effect of various plasticizers, viz. dibutyl phosphonate (DBP), dibutyl(butyl) phosphonate (DBBP), nitrophenyl octyl ether (NPOE), tris‐(2‐ethylhexyl)phosphonate (TEP), tri‐butyl phosphonate (TBP), dioctyl phthalate (DOP), dioctyl sebacate (DOS), benzyl acetate (BA) and acetophenone (AP) along with anion excluders NaTPB (sodium tetraphenyl borate) and KClTPB (potassium(tetrakis‐4‐chlorophenyl)borate was also studied. The optimum composition of the best performing membrane contained (I):KClTPB:NPOE:PVC in the ratio 15 : 3 : 40 : 42 w/w. The sensor exhibited near Nernstian slope of 20.1±0.2 mV/decade of activity in the working concentration range of 1.2×10^?7–1.0×10^?1 M, and in a pH range of 3.8–4.5. The sensor exhibited a fast response time of 10 s and could be used for about 5 months without any considerable divergence in potentials. The proposed sensor showed very good selectivity over most of the common cations including Na⁺, Li⁺, K⁺, Cu²⁺, Sr²⁺, Ni²⁺, Co²⁺, Ba²⁺, Hg²⁺, Pb²⁺, Zn²⁺, Cs⁺, Mg²⁺, Cd²⁺, Al³⁺, Fe³⁺and La³⁺. The activity of Cr(III) ions was successfully determined in the industrial waste samples by using this sensor.     

Kinetics and mechanism of oxidation of l-ascorbic acid by peroxomonosulphate in acid perchlorate medium. Role of copper (II) as a trace metal-ion catalyst

The kinetics of oxidation of l-ascorbic acid by peroxomonosulphate (PMS) in presence and absence of Cu(II) catalyst has been studied. The stoichiometry of the reaction is represented by the following:

H₂A + HSO₅⁻ → A + HSO₄⁻ + H₂O     

A novel technique for the fabrication of laboratory scale model functionally graded materials

In this work, the authors describe the design, fabrication and testing of model functionally graded materials (FGMs). The inhomogeneous property variations were generated by altering material properties through selective ultraviolet (UV) irradiation. Poly(ethylene co-carbon monoxide) (ECO) was chosen to make the FGMs because of its rapid degradation under UV light. Irradiated ECO becomes stiffer, stronger and more brittle with increasing irradiation time. Through a series of tension tests, the authors characterized the mechanical behavior of the specific ECO used as a function of UV exposure time. Furthermore, by controlling exposure time, specimens with continuously and discretely varying mechanical properties were produced. The resulting graded materials exhibited a Young's modulus that varied from about 160 MPa to 250 MPa and a strain to failure that varied from about 900 percent to 10 percent over the width in a 150 mm wide specimen. Microhardness measurements were used to determine the differences between discretely and continuously varying mechanical properties.