Monday, 20 March 2017

A Study of the Effect of Pyrites and Rhizobium Inoculation on Chlorophyll and Sugar Content in Black Gram under Sodicity Stress Condition


Calcareous soils have resulted in precipitation of CaCO3 from water of some rivers which contain high amount of CaH(CO3)2. The tropical aridity creates reaction resulting in accumulation of salts. Most of the waterof uplands is lost due to runoff and transpiration reducing effective leaching. Precipitation of calcium increases sodium concentration which is further augmented by high RSC of the available water resources. Salinity is the major yield reducing factor in legume cultivation as legumes are salt sensitive crop, especially in the seedling stages where they are most susceptible to damage due to water stress and ion-imbalance.

Black Gram

In saline soils, many environmental factors such as soil pH, water deficiency and nutrient deficiency are reported in Ref.that the seedling stage suffers most damage due to ion-imbalance and thus, other physiological processes are negatively affected during the growth of theplant especially photosynthesis. Ref.reported that during long term exposure to salinity, plants experience premature senescence of adult leaves and root nodules which reduce the net photosynthetic area available to support continued growth of the plant. Thus, bio-synthesis of sugar and nitrogen fixation are negatively affected.

Monday, 13 March 2017

Quality Evaluation of Diclofenac Formulations Manufactured in DR Congo



Diclofenac sodium, the first phenylacetic acid derivative developed as an anti-inflammatory agent, is an inhibitor of cyclooxygenase extensively used for its analgesic, antipyretic and antiinflammatory activities. It is a potentnon-steroidal anti-inflammatory drug, extensively used for the treatment ofactive rheumatoid arthritis and osteoarthritis, ankylosing spondylitis, non-articular rheumatism and sport injuries. DS is one of the most consumed drugs by the population in DR Congo. 

Diclofenac FormulationsThe literature reports few studies on the effect of humidity and temperature on the stability of DS.The purpose of this study was to evaluate thequality of three generics of 50 mg DS tablets manufactured in DR Congo in comparison to the original formulation Voltarène® from Novartis Pharma. Drug content and drug release were determined at the time of their collection and at 3 and 6 months during their storage under the accelerated-aging conditions of temperature and relative humidity (RH) recommended by the WHO for climatic zone IVB (40°C/75% RH)

Friday, 20 January 2017

Combination of ESI and MALDI-MS Imaging Enhances Analysis on Brain Gangliosides



Recent advances in matrix-assisted laser desorption ionization (MALDI) mass spectrometry imaging (MSI) have led to the direct analysis of tissue slices. The major advantage of MSI is its capability of simultaneously localizing and identifying a parent molecule and its metabolites without any labeling or any prior knowledge. MSI has been extensively employed to detect the differentiated pattern of lipids in various organs in different diseases, such as brains in Alzheimer’s disease. Poor reproducibility of MALDIMSI analysis due to the heterogeneity of the matrix-analyte crystals, hindersits use on quantitative analysis. In addition, discontinuous ion flow due to quickly consumption of the samples under laser irradiation on specific site affects its ability in qualitative analysis. Although electrospray ionization mass spectrometry (ESI-MS) cannot directly be used for imaging, ESI tandem mass spectrometry (LC/ESI-MS/MS) can separate and distinguish gangliosides.

Combination of ESI and MALDI-MS Imaging

Zhang et al. have presented a promising workflow for qualitative, semi-quantitative and in situ analysis of gangliosides by combiningthe MALDI MSI and ESI-MS. Following obtaining the brain from the mice, fresh-frozen murine brain sections were prepared and coated with matrix for subsequent MALDI MSI analysis.

Wednesday, 18 January 2017

Potentiometric and pHmetric Studies of Paracetamol



Paracetamol (acetaminophen) is one of the most popular analgesic and antipyretic drugs. Paracetamol is available in different dosage forms: tablet, capsules, drops, elixirs, suspensions and suppositories. Dosage forms of paracetamol and its combinations with other drugs have been listed in various pharmacopoeias. The combination of paracetamol with dipyrone is used asan antipyretic, analgesic and anti-inflammatory drug. Numerous methods have been reported for the analysis of paracetamol and its combinations in pharmaceuticals or in biological fluids. Paracetamol has been determined in combination with other drugs using titrimetry, voltammetry, fluorimetry, colorimetry, UV-spectrophotometry, quantitative thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC) and gas chromatography (GC) in pharmaceutical preparations. 

Potentiometric and pHmetric Studies of Paracetamol

Effect of electrophilic and electrodotic groups on the potentiometric titration of amides and other weak bases was studied. Electrodotic groups enhance the potentiometric end point and electrophilicgroups depress it, sometimes to the extent that the compound is not titratable. A combination of chloroform and acetic anhydride is a useful alternative medium for the titration of weak bases. A potentiometric method for determination of p-acetamidophenol was reported.

Wednesday, 4 January 2017

Excitonic Quasimolecules in Nano Systems of Semiconductor and Dielectric Quantum Dots



The idea of superatom was fruitful for the development of nanophysics Superatom (quasiatomic nanoheterostructures) consists of a spherical quantum dot (QD) with radius a, the volume of that contains the semiconductor (or dielectric) material. QD is surrounded by dielectric(semiconductor) matrix. A hole is localized in the volume of QD, and the electron is localized over a spherical interface (QD-matrix). In this nanosystem the lowest electronic level is in matrix, and the lowest hole level is within volume of QD. A large shift of the valence band (700 meV) generates the localization of holes in the volume of QD. A significant shift of the conduction band (about 400 meV) is a potential barrier for electrons. 

 Dielectric Quantum Dots

The electrons moving in the matrix and do not penetrate in the volume of QD. Theenergy of the Coulomb interaction of electron with hole and the energy of thepolarization interaction of electron with interface (QDmatrix) form a potential well, in which the electron is localized over the surface of quantum dot. The certain orbitals, localized surrounding quantum dot correspond to electrons in superatom . During investigation of the optical characteristics of nanosystems with CdS, ZnSe, Al2O3 and Ge quantum dots in experimental papersit was found that the electron can be localized above the surface of the QD while the hole here moves in the volume of the QD. In Ref.