Solvatochromic Behaviour of Rifampicin in Diluted Solutions

The solvent influence on the maxima of UV-Vis electronic absorption spectra of rifampicin diluted solutions was studied by Bakshiev's Antibacterial agents included in the tuberculosis treatment programs can be divided in broad spectrum compounds and narrow ones. Rifampicin is included in the broad spectrum antibiotics according to the above classification; is a semi-synthetic compound derived from the rifamycin B family, produced by strains of Nocardia (Streptomyces) mediterranei which focused not only the microbiologist attention, but also the interest of several multidisciplinary research groups. Rifampicin solubility and stability varies according to pH due to its amphoteric nature regarding the rifampicin conformers structural and energetic parameters Aiming to provide a mathematical insight in the spectral behaviour in the UV-Vis range of solvated compounds in diluted solution, by taking into account the solvent influence on the absorption transition energies, various theoretical models of real liquids were proposed The mathematical approach developed by Bakhshiev [12] expressed the solvent influence on the electronic absorption band (EAB) maximum, when passing from vapour to solution, by graphical approach of the dependence on the solvent macroscopic parameters of the difference of the wave numbers (Δν) in solution (ν) and in vapour state (ν), so that for the solute-solvent universal interactions (dispersive, orientation, inductive) the relation (1) results: (1

THE EFFECT OF MAGNETIC LIQUIDS IN SOME TREE SEEDLINGS

The seedlings of two tree species, the black poplar hybrid (Populus canadiensis Moench.) and the pedunculate oak (Quercus robur L.), among the most important for the temperate region, were treated with various concentrations of oil-ferrofluid based on natural hydrocarbons. The experiment has revealed the ferrofluid influence on the assimilatory pigments as well as on the nucleic acids (spectral measurements) in young plantlets aged of 3 months. It was found that the levels of assimilatory pigments are generally diminished though the ratio chlorophyll a/chlorophyll b is generally enhanced for ferrofluid samples suggesting the seedlings sensitivity to the chemical and magnetic stimuli consistent with the ferrofuid addition. The LHC II system (Light Harvesting Complex II) sensitivity to external factors might be associated with the ferrofluid influence on the young seedlings photosynthesis

ADRENALINE EFFECT ON THE ACTIVITY OF CARDIAC CELLS

The increased content of adrenaline in emotionally stressed people is known as a major source of heart beat acceleration. Using the electrocardiographic recordings (ECG) the influence of the adrenaline on the electric activity of heart muscle cells has been indirectly investigated. Physiologically normal and emotional loaded voluntary human subjects have been studied. Computationally tests based on the Hurst exponent and the capacity dimension have been used to get numerical data able to make the difference between the two physiological situations. While Hurts exponent led to similar values in both situations the capacity dimension has provided higher values for correspondingly higher adrenaline content indicating higher complexity in the electric activity of emotional subjects hear

A preliminary study on ultra high frequency electromagnetic fields effect on black locust chlorophylls

Chlorophylls were quantitatively studied in the leaves of black locust (Robinia pseudoacacia L.) seedlings exposed to electromagnetic fields of high frequency. Exposure system was designed and built up to make possible simultaneous exposure of seedling lots (3 months old) to low power density electromagnetic fields corresponding to a frequency of 400 MHz. After three weeks of daily exposures (1, 2, 3 and 8 hours), chlorophyll levels were measured using adequate spectral device. Statistical analysis of experimental results was performed by means of t-test to identify significant modifications induced by electromagnetic treatment in exposed samples in comparison to the control. Chlorophyll-a as well as chlorophyll-b level was found to decrease except the exposure time of two hours, where a considerable enhancement was noticed. It was revealed that the ratio of the two main types of chlorophyll was decreasing logarithmically to the increase of daily exposure time

Atomic force microscopy in the study of ferrofluids

Comparative study on the ferrophase dimensional distribution within a water ferrofluid was carried out by applying the atomic force microscopy (AFM) scanning and the transmission electron microscopy (TEM). The ferrophase has a magnetite core prepared by chemical co-precipitation and a double layer coating of citric acid. The diameter histograms revealed the main peak at about 9 nm which is concordant with a high degree of stability of the ferrofluid

Газовая плазма для стерилизации поверхностей

University Grigore T. Popa, Faculty of Pharmacy, Iasi, Romania, University Ion Ionescu dela Brad, Biophysics Department, Iasi, Romania, University Alexandru Ioan Cuza, Faculty of Physics, Iasi, Romania, Conferința științifico-practică cu participare internațională Centrul de Sănătate Publică din municipiul Chișinău – 70 de ani la straja sănătăţii 23 octombrie 2014Interacţiunea plasmei gazoase cu culturi bacteriene a fost studiată ca aplicaţie practică a plasmei reci la sterilizarea obiectelor mici pentru utilizare medicală. Zonele de inhibiţie a creşterii microbiene au fost măsurate în jurul spotului de impact cu jetul de plasmă pentru un jet de 3.5 cm lungime şi pentru unul de 2.5 cm, pentru acelaşi timp de expunere de 50 secunde. Efectul evident de distrugere a bacteriilor recomandă această metodă pentru sterilizarea unor ustensile medicale ce sunt sensibile la temperatură sau la reactivi chimici, ea fi ind de asemenea susţinută de relativa accesibilitate şi costurile mici.Взаимодействие газообразной плазмы с культурами бактерий было исследовано с точки зрения практического применения холодной плазмы для стерилизации малых предметов медицинского пользования. Зоны подавления микробного роста были измерены вокруг места воздействия струй плазмы для струи с длиной 3,5 см, а также с длиной 2,5 см при одинаковом времени воздействия равной 35 сек. Благодаря очевидному эффекту уничтожения бактерий, этот метод рекомендуется использовать для стерилизации некоторых медицинских принадлежностей, чувствительных к температуре или химическим реактивам, метод будучи удобным также благодаря относительной доступности и малой стоимости

Fluorescent bacteria for colloidal iron biosensors

This research was focused on the possibility of iron sensing by means of bacterial cultures. The effect of ferric and ferrous ions on Pseudomonas aeruginosa, which has the ability to uptake the environmental iron in the form of complex iron compositions named siderophores, characterized by luminescent features, was studied. The different sensitivity to the iron from oxide compounds in comparison to the iron from chlorides and sulfate was emphasized by means of fluorescence measurements. It could be stated that Pseudomonas aeruginosa, from human body specimens could be the biological component of an iron biosensor for ferrofluid traces reminiscent after the administration for medical purposes

Theoretical modeling and experimental study of sodium oleate properties for wastewater cleaning with magnetic nanoparticles stabilized with oleate

We present some preliminary results regarding possible reducing of environment phenol contamination with nanotechnology involving. Magnetic nanoparticles stabilized in water dispersion with oleate were prepared for experimental testing of their interaction with wastewater samples containing phenol residues from industrial and sanitation sources. Magnetite with moderate level of cobalt doping was synthesized by co-precipitation method in the form of nanoparticles; further their surface was modified by the reaction with sodium oleate solution. Quantum chemical simulation of oleate structure recommended it for the interaction with water dipolar molecules as well as with metal cations at the nanocores surface. Transmission Electron Microscopy confirmed fine granulation of the prepared sample meaning significant total surface of nanoparticle sample. Phenol loaded water model was let to interact with magnetic nanoparticles in various reaction conditions. Phenol absorbance in the main spectral band showed the concentration diminution following magnetic nanoparticle action in the presence of ultraviolet radiation and hydrogen peroxide supply. Further experiments are planned for the better optimization of the phenol concentration decreasing in the large volumes of wastewater with adequate nanostructures, able to develop efficient interaction mechanisms with pollutant molecules

Cytogenetic and Biochemical Responses of Wheat Seeds to Proton Irradiation at the Bragg Peak

The present study aimed to evaluate the morphological, cytogenetic and biochemical changes in wheat seedlings as affected by seed exposure to a proton beam at the Bragg peak. The average energy of the proton beam was of 171 MeV at the entrance into the irradiator room while at the point of sample irradiation the beam energy was of 150 MeV, with the average value of the Linear Energy Transfer of 0.539 keV/μm and the dose rate of 0.55 Gy/min, the radiation doses being of the order of tens of Gy. Cytogenetic investigation has revealed the remarkable diminution of the mitotic index as linear dose-response curve as well as the spectacular linear increase of the aberration index. Analyzing some biometric parameters, it was found that neither dry matter nor water content of wheat seedlings was influenced by proton beam exposure. Studying the biochemical parameters related to the antioxidant defense system, we found that the irradiation caused the slight increasing tendency of peroxidase activity as well as the decreasing trend in the activity of superoxidedismutase in the seedlings grown from the irradiated seeds. The level of malonedialdehyde (MDA) and total polyphenols showed an increasing tendency in all seedling variants corresponding to irradiated seeds, compared to the control. We conclude that the irradiation clearly induced dose-response curves at the level of cytogenetic parameters together with relatively slight variation tendency of some biochemical parameters related to the antioxidant defense system while imperceptible changes could be noticed in the biometric parameters