Surface modification of Angora rabbit fibers using dielectric barrier discharge

Dielectric barrier discharge (DBD) of Helium and Helium + air modify the surface of Angora rabbit fibers. DBD treatment carried out at different power densities, changes the morphology and chemical composition of the surface of Angora fiber. Scanning electron microscopy (SEM) results reveal that the DBD treatment eliminates fibrosity from the fiber surface. X-ray photoelectron spectroscopy and Fourier transform infrared spectrometer (FTIR) spectrum confirm the increase in oxygen bonding at the surface. These changes reduce shedding of the fibers and improve dye-uptake property. However, even after 10 min of plasma exposure the thermal insulation (heat keeping ratio) of Angora fibers nearly remain unchanged. It has been noticed that DBD treatment (10 min) reduces whiteness of the fiber.     

Review on asymmetric synthetic methodologies for chiral isoquinuclidines; 2008 to date

Isoquinuclidines constitute the central structural nucleus of numerous biologically active natural products, for example, iboga alkaloids such as ibogamine and catharanthine as well as non-indole-containing alkaloids such as the dioscorine and the cannivonines. Furthermore, in medicinal and pharmaceutical chemistry, the isoquinuclidine core is commonly employed as a rigid azabicyclic scaffold, thus providing significant precursors in the synthesis of numerous valuable alkaloids. Summarizing well-organized approaches to access the chiral isoquinuclidine structural centerpiece signifies a significant endeavor not only for developing biologically active natural products but also enhancing biological researches that can lead to possible drug discovery. Over time, the values and methodologies for the asymmetric synthesis of chiral isoquinuclidines are increasing; hence to advance asymmetric synthesis, this review combines and discusses the pros and cons of each synthesis techniques from 2008. This review should be helpful for promoting further developments of asymmetric synthetic methodologies and for medicinal chemistry.     

Structural changes in tin oxide thin film with laser exposure

The effects of laser irradiation on the surface, structure and optical properties of SnO thin films deposited on glass substrates using electron beam evaporation, are investigated. The thin film samples are irradiated using fundamental beam at 1064 nm from Q-switched Nd:YAG pulsed laser with different power densities. Structural morphology of the film is investigated using XRD patterns and AFM image. Both XRD pattern and AFM image show increase in grain size of the film with increasing laser power density. Other optical phenomena, photoluminescence emission, transmission, refractive index determination and optical band gaps calculations are also carried out at various laser power densities. Results from all these investigations reveal expansion in grain size of the crystalline SnO thin film with increasing laser power density.     

Luminol-Based Chemiluminescent Signals: Clinical and Non-clinical Application and Future Uses

Chemiluminescence (CL) is an important method for quantification and analysis of various macromolecules. A wide range of CL agents such as luminol, hydrogen peroxide, fluorescein, dioxetanes and derivatives of oxalate, and acridinium dyes are used according to their biological specificity and utility. This review describes the application of luminol chemiluminescence (LCL) in forensic, biomedical, and clinical sciences. LCL is a very useful detection method due to its selectivity, simplicity, low cost, and high sensitivity. LCL has a dynamic range of applications, including quantification and detection of macro and micromolecules such as proteins, carbohydrates, DNA, and RNA. Luminol-based methods are used in environmental monitoring as biosensors, in the pharmaceutical industry for cellular localization and as biological tracers, and in reporter gene-based assays and several other immunoassays. Here, we also provide information about different compounds that may enhance or inhibit the LCL along with the effect of pH and concentration on LCL. This review covers most of the significant information related to the applications of luminol in different fields.     

Impact of Metal Ions in Porphyrin‐Based Applied Materials for Visible‐Light Photocatalysis: Key Information from Ultrafast Electronic Spectroscopy

Protoporphyrin IX‐zinc oxide (PP‐ZnO) nanohybrids have been synthesized for applications in photocatalytic devices. High‐resolution transmission electron microscopy (HRTEM), X‐ray diffraction (XRD), and steady‐state infrared, absorption, and emission spectroscopies have been used to analyze the structural details and optical properties of these nanohybrids. Time‐resolved fluorescence and transient absorption techniques have been applied to study the ultrafast dynamic events that are key to photocatalytic activities. The photocatalytic efficiency under visible‐light irradiation in the presence of naturally abundant iron(III) and copper(II) ions has been found to be significantly retarded in the former case, but enhanced in the latter case. More importantly, femtosecond (fs) transient absorption data have clearly demonstrated that the residence of photoexcited electrons from the sensitizer PP in the centrally located iron moiety hinders ground‐state bleach recovery of the sensitizer, affecting the overall photocatalytic rate of the nanohybrid. The presence of copper(II) ions, on the other hand, offers additional stability against photobleaching and eventually enhances the efficiency of photocatalysis. In addition, we have also explored the role of UV light in the efficiency of photocatalysis and have rationalized our observations from femtosecond‐ to picosecond‐resolved studies.     

Measurement of sodium ion concentration in undiluted urine with cation-selective polymeric membrane electrodes after the removal of interfering compounds

The measurement of sodium ion concentration in urine can provide diagnostic information and guide therapy. Unfortunately, neutral-carrier-based ion-selective electrodes show a large positive drift and loss in selectivity in undiluted urine. The extraction of electrically neutral lipids from the urine into the sensing membrane was suggested as the main source of the drift, loss of selectivity and the consequent incorrect concentration readings.In this work, (i) solvent-solvent extraction, (ii) membrane-immobilized solvent extraction and (iii) solid phase extraction were used to remove interfering compounds from urine samples. The “cleaned” urine samples were subsequently analyzed using a calixarene (sodium ionophore X)-based, solid-contact, sodium-selective electrode in a flow-through manifold. The solid-contact sodium sensors had excellent stability in cleaned urine and an acceptable bias compared to commercial clinical analyzers.     

Use of quadrupole time of flight mass spectrometry for the characterization of transformation products of the antibiotic sulfamethazine upon photocatalysis with Pd‐doped ceria‐ZnO nanocomposite

The photocatalytic degradation of the antibiotic sulfamethazine under excitation at 365 nm of Pd‐doped ceria‐ZnO nanocomposite, titanium dioxide and iron(III) aqua complex was deeply studied from the analytical point of view. It reveals the formation of nine degradation products that were detected in their protonated forms using LC/electrospray ionization quadrupole time‐of‐flight MS in the positive mode. Their formation involves the hydroxyl radical, and their concentrations increased with irradiation time. Collision‐induced dissociation tandem mass spectrometry associated with the accurate mass measurements was efficiently used for the elucidation of their chemical structures. None of these identified degradation products has been already reported in the literature. Three by‐products result from the hydroxylation at the pyrimidine moiety as well as at the aromatic part, two of them arise from the scission of the pyrimidine group, and finally, three of them come from the scission of the sulfamide bridge. This points the evidence of studying the fate of these degradation products if their toxicity is demonstrated because they are clearly the result of the reaction of hydroxyl radical with the antibiotic sulfamethazine. Copyright © 2015 John Wiley & Sons, Ltd.