New trends of nanofluids to combat Staphylococcus aureus in clinical isolates

Journal of Thermal Analysis and Calorimetry - Methicillin-resistant Staphylococcus aureus (MRSA), multi-drug-resistant (MDR) Staphylococcus aureus and sensitive Staphylococcus aureus were selected...     

Influence of temperature dependent viscosity on peristaltic transport of a Newtonian fluid: Application of an endoscope

The effects of variable temperature dependent viscosity on peristaltic flow of Newtonian fluid in an annulus has been investigated with long wave length approximations. A regular perturbation method has been used to obtain explicit form for the velocity, temperature and relation between flow rate and pressure gradient. The expression for the pressure rise, friction force, velocity and temperature were plotted for different values of variable viscosity parameter β, radius ratio, amplitude ratio ?, heat absorption parameter β₁, and force convection parameter G_r. It is found that the pressure rise decrease as the viscosity parameter β increases and increases as the radius ratio as ? increases and β decreases.     

Phenolic constituents from Perovskia atriplicifolia

Perovskoate, an isorinic acid derivative (1) and perovskoside, the catechol derivative (2) have been isolated from the ethyl acetate soluble fraction of the whole plant of Perovskia atriplicifolia and assigned the structure 3(7-hydroxyphenyl)-2-hydroxy propanoic acid; (R)-form, 2-O-(6',7'-dihydroxy-E-cinnamoyl) (1) and 2-methoxy-4-(undecyl-4'-O-beta-D-glucopyranosyl) phenol (2). In addition, caffeic acid (3) and ferulic acid (4) have been reported for the first time from this species. The structures of these compounds were assigned on the basis of 1D and 2D NMR techniques. The compound 1 showed significant inhibitory activity against lipoxygenase and weak to moderate activity against cholinesterases.     

Aluminium phthalocyanine chloride thin films for temperature sensing

This study presents the fabrication and temperature sensing properties of sensors based on aluminium phthalocyanine chloride(AlPcCl)thin films.To fabricate the sensors,50-nm-thick electrodes with 50-μm gaps between them are deposited on glass substrates.AlPcCl thin films with thickness of 50–100 nm are deposited in the gap between electrodes by thermal evaporation.The resistance of the sensors decreases with increasing thickness and the annealing at 100℃ results in an increase in the initial resistance of sensors up to 24%.The sensing mechanism is based on the change in resistance with temperature.For temperature varying from 25℃ to 80℃,the change in resistance is up to 60%.Simulation is carried out and results obtained coincide with experimental data with an error of±1%.     

SERS- and Electrochemically Active 3D Plasmonic Liquid Marbles for Molecular-Level Spectroelectrochemical Investigation of Microliter Reactions

Liquid marbles are emergent microreactors owing to their isolated environment and the flexibility of materials used. Plasmonic liquid marbles (PLMs) are demonstrated as the smallest spectroelectrochemical microliter-scale reactor for concurrent spectro- and electrochemical analyses. The three-dimensional Ag shell of PLMs are exploited as a bifunctional surface-enhanced Raman scattering (SERS) platform and working electrode for redox process modulation. The combination of SERS and electrochemistry (EC) capabilities enables in situ molecular read-out of transient electrochemical species, and elucidate the potential-dependent and multi-step reaction dynamics. The 3D configuration of our PLM-based EC-SERS system exhibits 2-fold and 10-fold superior electrochemical and SERS performance than conventional 2D platforms. The rich molecular-level electrochemical insights and excellent EC-SERS capabilities offered by our 3D spectroelectrochemical system are pertinent in charge transfer processes.     

Impedimetric sensing of humidity and temperature using CeO2–Co3O4 nanoparticles in polymer hosts

Humidity and temperature sensors were fabricated from a nanocomposite consisting of CeO₂-Co₃O₄ hybrid nanoparticle-silicone adhesive and CeO₂-Co₃O₄ hybrid nanoparticle-polymer adhesive, respectively, to fix the material on a glass supported copper electrode. The impedance of the sensor decreases by a factor of 960 at a working frequency of 100 Hz, and by a factor of 800 at 1 kHz, on increasing relative humidity (RH) from 30 to 90 %. In parallel, the capacitances increase by factors of 567 and 355, respectively, under the same experimental conditions. The effect of temperature in the range from 25 to 70 °C on impedance (again at 100 Hz and 1 kHz) was also studied and found to decrease with increasing temperature. On going from 25 to 70 °C, the impedance measured at 100 Hz and 1 kHz decreases 2.22 and 1.58 times, respectively, in surface type sensors, while in sandwich type sensors this decrease is 3.0 and 2.08 times. The calculated average sensitivity to temperature is −1.02 and −0.8 % °C⁻¹ for the surface type and −1.5 and −1.2 % °C⁻¹ for the sandwich type sensors at frequencies of 100 Hz and 1 kHz, respectively.

A highly sensitive sensor with dual functionality for humidity and temperature has been fabricated by using CeO₂-codoped Co₃O₄ nanoparticles with silicone and polymer adhesive.

     

Interaction of the Amphiphilic Drug Amitriptyline Hydrochloride with Gemini and Conventional Surfactants: A Physicochemical Approach

Pyrene fluorescence measurements were carried out on various binary mixtures of the antidepressant amphiphilic drug amitriptyline hydrochloride (AMT) with conventional (TTAB and CTAB) and gemini surfactants (14-4-14 and 16-4-16). In all cases mixed micellar aggregates were formed and the mixed critical micelle concentration (cmc) of various mixtures was computed from the I ₁/I ₃ versus total surfactant concentration plots. In the region where mixed micelles are formed, the interaction of the amphiphlic drug and four surfactants showed synergistic behavior. The results were analyzed using an interaction parameter, β, which characterize the interaction in the mixed micelle and is introduced by a regular solution theory. The β values are negative in all binary mixtures, and their magnitudes increase with increasing hydrophobicity of the amphiphile. The micellar mole fraction of AMT in the mixed micelle (x ₁) and in the ideal sate (x _ideal) were evaluated and their values (x ₁ > x _ideal) suggest that the contribution of the AMT component is greater in binary mixtures as compared to that in the ideal state. Activity coefficients (f ₁ and f ₂) and excess Gibbs energy (G _ex) were also calculated. The values of micelle aggregation numbers (N _agg) and various other parameters like the Stern–Volmer constant (K _sv), micropolarity and dielectric constant of mixed systems have also been evaluated from the ratios of respective peak intensities (I ₁/I ₃ or I ₀/I ₁).     

Investigation of Micellar and Phase Separation Phenomenon of the Amphiphilic Drug Amitriptyline Hydrochloride with Cationic Hydrotropes

Micellization and phase separation of the amphiphilic drug amitriptyline hydrochloride (AMT) in the absence and presence of cationic hydrotropes (aniline hydrochloride, para-toluidine hydrochloride, and ortho-toluidine hydrochloride) have been investigated in the present study. The experimental critical micelle concentration (cmc) values are lower than cmc ^id values (cmc ^id is the cmc value at ideal mixing state), indicating attractive interactions between the two components (drug and hydrotrope) in mixed micelles. The bulk behaviors were investigated using the different theoretical models of Clint, Rubingh, Motomura, and Rodenas for comparison of the results of different binary combinations of the drug and hydrotropes. Synergistic interactions were confirmed in all binary combinations at all temperatures, which increase with increasing concentration of hydrotropes. Activity coefficients (f ₁ and f ₂) were found to be consistently less than unity indicating nonideality in the systems. At a fixed drug concentration (50 mmol·dm^?3) and pH (6.7), the hydrotropes showed a continuous increase in the cloud point. Thermodynamic parameters were also evaluated and discussed in detail.     

Acetone sensor based on solvothermally prepared ZnO doped with Co3O4 nanorods

This paper describes a reliable and sensitive method for sensing dissolved acetone using doped nanomaterials. Large-scale synthesis of ZnO nanorods (NRs) doped with Co₃O₄ was accomplished by a solvothermal method at low temperature. The doped NRs were characterized in terms of their morphological, structural, and optical properties by using field-emission scanning electron microscopy coupled with energy-dispersive system, UV-Vis., Fourier transform IR, X-ray diffraction, and Xray photoelectron spectroscopy. The calcinated (at 400 °C) doped NRs are shown to be an attractive semiconductor nanomaterial for detecting acetone in aqueous solution using silver electrodes. The sensor exhibits excellent sensitivity, stability and reproducibility. The calibration plot is linear over a large concentration range (66.8 μM to 0.133 mM), displays high sensitivity (~3.58 μA cm^?2 mM^?1) and a low detection limit (~14.7?±?0.2 μM; at SNR of 3).