Soil contamination by diesel fuel destabilizes the soil microbial pools: Insights from permafrost soil incubations.

Arctic contamination by diesel fuel (DF) is of great concern because of the uncertain feedback of permafrost carbon (C) and soil microbiota to DF in the context of climate change in high latitudes. We conducted a laboratory incubation experiment with a gradient of DF addition ratios to examine the responses of the soil microbiota of the typical permafrost soils in the tundra ecosystems of the Norilsk region (Siberia). The study revealed initial heterogeneity in the microbial activity of the studied soils (Histic Gleyic Cryosols (CR-hi,gl), Turbic Cryosols (CR-tu), Turbic Spodic Folic Cryosols (CR-tu,sd,fo), Gleyic Fluvisols (FL-gl)).

Identifying Performance Descriptors in CO Hydrogenation over Iron-Based Catalysts Promoted with Alkali Metals.

Alkali metal promoters have been widely employed for preparation of heterogeneous catalysts used in many industrially important reactions. However, the fundamentals of their effects are usually difficult to access. Herein, we unravel mechanistic and kinetic aspects of the role of alkali metals in CO hydrogenation over Fe-based catalysts through state-of-the-art characterization techniques, spatially resolved steady-state and transient kinetic analyses.

Reproductive disorders in male rats induced by high-fructose consumption from juvenile age to puberty.

There is compelling evidence that a hypercaloric, high-fructose diet can cause metabolic syndrome (MetS) and a whole range of other metabolic changes. In the context of androgen deficiency, MetS in boys merits special attention, but the effects of fructose-rich diet in youth on future male reproductive function are still poorly evidenced. The aim of this study was to address this issue and analyse the effects of high-fructose intake starting from weaning to puberty (postnatal day 23 up to 83) on the reproductive function of male rats.

Structural aspects of displacive transformations: what can optical microscopy contribute? Dehydration of Sm(CO)·10HO as a case study.

For martensitic transformations the macroscopic crystal strain is directly related to the corresponding structural rearrangement at the microscopic level. optical microscopy observations of the interface migration and the change in crystal shape during a displacive single crystal to single crystal transformation can contribute significantly to understanding the mechanism of the process at the atomic scale. This is illustrated for the dehydration of samarium oxalate decahydrate in a study combining optical microscopy and single-crystal X-ray diffraction.

Repeated administration of ethambutol in therapeutic dose causes testes alteration and spermatogenesis disruption in Wistar rats.

Ethambutol (EMB) is conventionally used to treat tuberculosis and atypical Mycobacterium infections in combination with other antimycobacterial drugs. Eventually, EMB testicular toxicity has not been explored extensively yet. The aim of the study is to evaluate testicular toxicity of EMB.

Effect of 5-Fluorouracil on Thymidine Phosphorylase Activity in Model Experiment.

Variations in thymidine phosphorylase activity in rat liver were studied in 1, 3, 6, 12, and 24 h after intraperitoneal bolus injection of 5-fluorouracil. Enzyme activity was measured by HPLC. A 2-fold decrease in enzyme activity was observed 3 h after 5-fluorouracil administration and persisted for 12 h.

Isoenergetic Polymorphism: The Puzzle of Tolazamide as a Case Study.

In the present case study of tolazamide we illustrate how many seemingly contradictory results that have been obtained from experimental observations and theoretical calculations can finally start forming a consistent picture: a "puzzle put together". For many years, tolazamide was considered to have no polymorphs. This made this drug substance unique among the large family of sulfonylureas, which was known to be significantly more prone to polymorphism than many other organic compounds.

Chronic alcoholism-mediated metabolic disorders in albino rat testes.

There is good evidence for impairment of spermatogenesis and reductions in sperm counts and testosterone levels in chronic alcoholics. The mechanisms for these effects have not yet been studied in detail. The consequences of chronic alcohol consumption on the structure and/or metabolism of testis cell macromolecules require to be intensively investigated.

Induction of CYP2E1 in testes of isoniazid-treated rats as possible cause of testicular disorders.

Isoniazid is reported to be the most reliable and cost-effective remedy for tuberculosis treatment and prophylaxis among first line anti-tuberculosis drugs. Conventionally, the most common and best studied adverse effect of isoniazid is hepatotoxicity, but as for testicular toxicity the problem has not yet explored extensively. The aim of the study was to identify in vivo influence of isoniazid on induction of testicular cytochrome Р-450 2Е1 (CYP2E1) mRNA expression and enzymatic activity, testes DNA fragmentation, serum total testosterone level, and spermatogenesis indices.

Correlation between spermatogenesis disorders and rat testes CYP2E1 mRNA contents under experimental alcoholism or type I diabetes.

Purpose: The aim of the study was to investigate the correlation between spermatogenesis disorders and CYP2E1 mRNA contents in testes of rats with experimental alcoholism or type I diabetes.

Material/methods: Two pathological states characterized by CYP2E1 induction were simulated on Wistar male rats: experimental alcoholism and type I diabetes. As controls for each state, equal number of animals (of the same age and weight) were used.

Oxygen release technique as a method for the determination of "δ-pO2-T" diagrams for MIEC oxides.

A new approach to the determination of oxygen nonstoichiometry (δ) of MIEC oxides as a continuous function of pO2 at high temperatures was developed. The description of the model allowing one to distinguish the contribution of oxygen released from the samples to the partial pressure of oxygen at the outlet of the continuous-flow fixed-bed reactor after the stepwise change of the oxygen partial pressure of inlet gas from 0.2 to 10(-5) atm and to calculate the dependence of δ on pO2 is presented.

Optothermophysical properties of demineralized human dental enamel determined using photothermally generated diffuse photon density and thermal-wave fields.

Noninvasive dental diagnostics is a growing discipline since it has been established that early detection and quantification of tooth mineral loss can reverse caries lesions in their incipient state. A theoretical coupled diffuse photon density and thermal-wave model was developed and applied to photothermal radiometric frequency responses, fitted to experimental data using a multiparameter simplex downhill minimization algorithm for the extraction of optothermophysical properties from artificially demineralized human enamel. The aim of this study was to evaluate the reliability and robustness of the advanced fitting algorithm.

Dynamic photophysical processes in laser-irradiated human cortical skull bone measured by means of modulated diffuse luminescence.

The technique of modulated luminescence of bones was developed experimentally and theoretically and was subsequently used to interpret measurements performed on the cortical layer of human skull bones. The photophysical theory is based on the optical excitation and decay rate equations of the fluorescent endogenous chromophore and on the molecular interaction parameter with the photon field density in the matrix of the bone. An effective mean relaxation lifetime, tau(M), of skull cortical bone was derived theoretically and was found to depend on the endogenous chromophore decay lifetime, tau(2), in the upper energy state, on the generated luminescence field density through its dependence on the incident photon field density and on the thickness of the bone.

Robust multiparameter method of evaluating the optical and thermal properties of a layered tissue structure using photothermal radiometry.

The thermal and optical properties of multilayered dental tissue structure, the result of the surface-grown prismless layer on enamel, were evaluated simultaneously using multiparameter fits of photothermal radiometry frequency responses. The photothermal field generated in a tooth sample with near-infrared laser excitation was described using a coupled diffuse-photon-density and thermal wave model. The optical (absorption and scattering) coefficients and thermal parameters (spectrally averaged infrared emissivity, thermal diffusivity and conductivity) of each layer, as well as the thickness of the upper prismless enamel layer, were fitted using a multiparameter simplex downhill minimization algorithm.

In vitro detection and quantification of enamel and root caries using infrared photothermal radiometry and modulated luminescence.

Artificially created demineralized and remineralized carious lesions on the root and enamel of human teeth were examined by photothermal radiometry (PTR) and modulated luminescence (LUM). Fourteen extracted human teeth were used and a lesion was created on a 1 mmx4 mm rectangular window, spanning root to enamel, using a lactic acid-based acidified gel to demineralize the tooth surface. The lesion was then exposed to a remineralization solution.

Optimally accurate thermal-wave cavity photopyroelectric measurements of pressure-dependent thermophysical properties of air: theory and experiments.

An experimental technique for the measurement of thermal properties of air at low pressures using a photopyroelectric (PPE) thermal-wave cavity (TWC) was developed. In addition, two theoretical approaches, a conventional one-dimensional thermal-wave model and a three-dimensional theory based on the Hankel integral, were applied to interpret the thermal-wave field in the thermal-wave cavity. The importance of radiation heat transfer mechanisms in a TWC was also investigated.

Epigenetic changes in the rat livers induced by pyrazinamide treatment.

Drug-induced liver injury, including drug-induced hepatotoxicity during the treatment of tuberculosis infection, is a major health problem with increasingly significant challenges to modern hepatology. Therefore, the assessment and monitoring of the hepatotoxicity of antituberculosis drugs for prevention of liver injury are great concerns during disease treatment. The recently emerged data showing the ability of toxicants, including pharmaceutical agents, to alter cellular epigenetic status, open a unique opportunity for early detection of drug hepatotoxicity.

Detection of interproximal demineralized lesions on human teeth in vitro using frequency-domain infrared photothermal radiometry and modulated luminescence.

Frequency-domain photothermal radiometry (FD-PTR or PTR) is used to detect mechanical holes and demineralized enamel in the interproximal contact area of extracted human teeth. Thirty-four teeth are used in a series of experiments. Preliminary tests to detect mechanical holes created by dental burs and 37% phosphoric acid etching for 20 s on the interproximal contact points show distinct differences in the signal.

[Disorders of the bioenergetics and microcirculation in the gastric mucosa in peptic ulcer with concomitant involvement of the hepatobiliary system].

Unlabelled: The histological structure, distribution of neutral glycoseaminoglycanes, the content of glycogen in the cells, activity of succinate dehydrogenase, cytochromoxidase, magnesium-dependent ATP-ase, alkaline phosphatase, lactate dehydrogenase were studied in the biopsies of the gastric mucosa removed from the anterior third of the anterior part of its body in 104 patients.

Results: essential decrease of the enzymes of oxidative phosphorylation, increased reaction to lactate dehydrogenase, inhibition of enzymes controlling the microcirculation in the gastric mucosa in ulcer disease. These changes deteriorate in elderly patients as well as concomitant diseases of the hepatobiliary system.

[Degree of lipid peroxidation and vitamin E level during the treatment of peptic ulcer].

The study of 468 ulcer patients treated by laser irradiation plus choline blocking agents with adjuvant alpha-tocopherol antioxidants (alpha-tocopherol acetate, wild rose and sea-buckthorn oils) provided evidence in favour of the antioxidants addition. Combination of hyperbaric oxygenation (5-6 sessions) or riboxin with choline blocking agents made antioxidants unnecessary. Biochemical findings (vitamin E and malonic dialdehyde concentrations), electron microscopic, ++histo-enzyme and amino acids studies supported the clinical evidence.

[Histological characteristics of the reactions of cerebral neuroglia in laboratory animals].

Literature data and the authors' results, concerning structural and functional peculiarities of all varieties of the cerebral neuroglia under effect of a cranial-cerebral trauma, neurotropic chemical products and oxygen insufficiency have been considered. Ideas that neuroglial reactions under the conditions mentioned are proved to be constant and in dependence of certain peculiarities of each case are either progressive or regressive. The reaction degree is mainly proportional to the disturbance power.

[A complex unit EKGS3T-01 for ECG recording and processing with preserving the syndromal findings].

Functional and technical parameters of the microprocessor diagnostic complex are being considered herein. It allows one to combine the automatic ECG data analysis and the possibility of the active participation in the processing of the cardiological information.