Inferring the diurnal variability of OH radical concentrations over the Amazon from BVOC measurements.

The atmospheric oxidation of biogenic volatile organic compounds (BVOC) by OH radicals over tropical rainforests impacts local particle production and the lifetime of globally distributed chemically and radiatively active gases. For the pristine Amazon rainforest during the dry season, we empirically determined the diurnal OH radical variability at the forest-atmosphere interface region between 80 and 325 m from 07:00 to 15:00 LT using BVOC measurements. A dynamic time warping approach was applied showing that median averaged mixing times between 80 to 325 m decrease from 105 to 15 min over this time period. The inferred OH concentrations show evidence for an early morning OH peak (07:00-08:00 LT) and an OH maximum (14:00 LT) reaching 2.2 (0.2, 3.8) × 106 molecules cm-3 controlled by the coupling between BVOC emission fluxes, nocturnal NOx accumulation, convective turbulence, air chemistry and photolysis rates. The results were evaluated with a turbulence resolving transport (DALES), a regional scale (WRF-Chem) and a global (EMAC) atmospheric chemistry model.

Ubiquitous atmospheric production of organic acids mediated by cloud droplets.

Atmospheric acidity is increasingly determined by carbon dioxide and organic acids1-3. Among the latter, formic acid facilitates the nucleation of cloud droplets4 and contributes to the acidity of clouds and rainwater1,5. At present, chemistry-climate models greatly underestimate the atmospheric burden of formic acid, because key processes related to its sources and sinks remain poorly understood2,6-9. Here we present atmospheric chamber experiments that show that formaldehyde is efficiently converted to gaseous formic acid via a multiphase pathway that involves its hydrated form, methanediol. In warm cloud droplets, methanediol undergoes fast outgassing but slow dehydration. Using a chemistry-climate model, we estimate that the gas-phase oxidation of methanediol produces up to four times more formic acid than all other known chemical sources combined. Our findings reconcile model predictions and measurements of formic acid abundance. The additional formic acid burden increases atmospheric acidity by reducing the pH of clouds and rainwater by up to 0.3. The diol mechanism presented here probably applies to other aldehydes and may help to explain the high atmospheric levels of other organic acids that affect aerosol growth and cloud evolution.

[Conservative and surgical treatment of patients with resistant epilepsy].

AIM: To optimize drug treatment in early (6 months) and late (up to 3 years) stages of postoperative period and to study its efficacy. MATERIAL AND METHODS: There were selected 72 patients with resistant epilepsy and epileptic encephalopathy symptoms from 467 patients operated for epilepsy. RESULTS: By the end of a 3-year follow-up observation, we found the reduction in seizure frequency and seizure control in 66.3% of patients; regression of EEG paroxysmal activity in 56.8% and reduction in mental disorder symptoms (anxiety and depression) in 12.7%. CONCLUSION: The data obtained substantiate the necessity to optimize antiepileptic and pathogenetic drug treatment of patients with resistant epilepsy and encephalopathy symptoms during the 3-year postoperative period.

[Comparative analysis of natural and synthetic antimutagens as regulators of gene expression in human cells under exposure to ionizing radiation].

This paper studies the effect of plant peptides of thionine Ns-W2 extracted from seeds of fennel flower (Nigella sativa) and ß-purothionine from wheat germs (Triticum kiharae), as well as a synthetic antimutagen (crown-compound), on the expression of several genes involved in the.control of cellular homeostasis, processes of carcinogenesis, and radiation response in human rhabdomyosarcoma cells (RD cells), T-lymphoblastoid cell line Jurkat, and blood cells. All of these agents acted as antimutagens-anticarcinogens, reducing the expression of genes involved in carcinogenesis (genes of families MMP, TIMP, and IAP and G-protein genes) in a tumor cell. A pronounced reduction in the mRNA level of these genes was caused by thionine Ns-W2, and the least effect was demonstrated by ß-purothionine. Antimutagens had very little effect on the mRNA levels of the several studied genes in normal blood cells.

[Modern aspects of the rehabilitation of patients with epilepsy].

A conception of rehabilitation of epileptic patients, which corresponds to the realities of their life, has been elaborated on the basis of clinical data on 4348 epileptic patients with long-time follow-up period. An algorithm of treatment and rehabilitation programs based on medical-biopsychosocial approaches and studying of QOL was proposed and scientifically substantiated. The system of rehabilitation was tested in practice and its high efficacy was shown.

Organization of butadienyl dyes containing benzodithiacrown-ether or dimethoxybenzene in monolayers at the air/aqueous salt solution interface.

Two amphiphilic butadienyl dyes 1 and 2 form stable monolayers at the air/water interface in the presence of various salts. Dye 1 consists of the basic amphiphilic butadienyl chromophore. In dye 2, the dimethoxybenzene part of dye 1 is substituted by benzodithia-15-crown-5. The monolayers have been characterized by surface pressure-area and surface potential-area isotherms as well as Brewster angle microscopy and reflection spectroscopy. In contrast to dye 1, dye 2 interacts specifically with Hg(2+) and Ag(+) cations forming complexes. No complex formation was observed with alkali and earth alkali metal ions. The nature of the anion (Cl(-) or ClO(4)(-)) influences the monolayer behaviour of both dyes. At the air/water interface, besides monomers of the dyes, two types of associates are coexisting in the pure dye monolayers on aqueous salt solutions, attributed to dimers and aggregates, respectively. Their equilibria depend on the nature of both cations and anions in the subphase, as in the case of dye 2, or only anions, as in the case of dye 1. The dimers may be organized as head-to-tail dimers with the intermolecular distances 0.38 and 0.45nm for dye 1 and dye 2, respectively. According to the extended dipole model, we propose formation of aggregates in which the chromophores are parallel to each other with the same intermolecular distances as in the dimers, and the centers of their transition moments shifted by 0.95nm (dye 1) and 1.2nm (dye 2).

[The use of the antiepileptic drug trileptal in the clinical practice].

The data on therapeutical efficacy of the new antiepileptic drug trileptal (oxcarbazepine) and results of the own observations of 38 patients with partial epilepsy who received trileptal as mono- or polytherapy are presented. The high efficacy and good tolerability of the drug has been shown. The seizure control has been obtained in 84% of patients.

[The use of generic valparin xr in the treatment of epilepsy.].

Therapeutic efficacy of valparin xr, a new form of valproic acid (VPA) generic drugs, manufactured by "Torrent Pharmaceuticals Ltd", India, has been studied in 25 patients with epilepsy of different types and frequency of seizures. The therapeutic efficacy similar to that of an original VPA was determined in monotherapy strategy, being lower in polytherapy, but more effective than other antiepileptic treatment. As for original drugs, the best results were obtained for controlling myoclonic and polyclonic seizures. The percentage of side-effects did not exceed the same index for brand drugs. The substantial advantage of valparin xr is a lower price as compared to the original VPA.

Antimutagenic characteristics of new diazacrown compounds with N-carboxyalkyl substitutes.

Two new benzodiaza-15-crown-5 compounds containing two N-hydroxycarbonylmethyl or N-hydroxycarbonylpropyl substitutes were synthesized. The first of these compounds exhibited more pronounced protective effects towards human cells according to criteria of primary DNA injury and cell survival after exposure to gamma-radiation and CdCl2; by antimutagenic activity this compound was comparable to garlic extract. The antimutagenic effect of these compounds was realized not through the antioxidant mechanism.

[Topamax in the treatment of epilepsy].

To specify efficacy of topamax in different types of epileptic seizures and its influence on patient's quality of life (QL), the drug was assigned to 38 patients, aged 18-69 years, as mono- and polytherapy (in combination with other anticonvulsive medications). Topamax dosages ranged from 25-50 mg at a base-line to 600 mg. Treatment duration was 6-18 months. Positive effect of different extent was achieved in 95.7% patients. A seizures frequency decreased by 25% in 17.4% patients; by 50%--in 8.7%; by 75%--in 43.5%; a complete disappearance of seizures was detected in 30.4%. The results confirmed the earlier data received by the authors that topamax was most effective in generalized convulsive, partial and secondary generalized seizures. It exerts a less pronounced effect in myoclonic seizures and absences. After topamax treatment, a total QL index measured by WHO questionnaire increased by 5.2%. The drug is well tolerated and does not affect cognitive functions of the patients. It is concluded that currently topamax is one of the most effective antiepileptic medications.

[The use of valproates-generics in the treatment of epileptic patients].

Therapeutic efficacy, adverse effects, cost efficacy of Encorate chrono (generics of Depakine chrono) as well as impact on quality of life have been studied in 36 patients with symptomatic and idiopathic epilepsy and different types of seizures. For all parameters, Encorate-chrono was as effective as the original drug. It may be recommended for patients with epilepsy with generalized and partial seizures as an equal analogue of Depakine in case of its absence.

Monolayers of a novel ionoselective butadienyl dye.

The novel amphiphilic benzodithia-18-crown-6 butadienyl dye (1) forms relatively stable insoluble monolayers on distilled water (collapse pressure of 41 mN/m) and on aqueous subphases containing alkali metal or heavy metal salts (collapse pressures in the range of 27-38 mN/m, respectively). The dye 1 monolayer organization depends on chromophore association and interactions (especially complex formation) with heavy and alkali metal ions as deduced from surface pressure-area and surface potential-area isotherms as well as reflection spectra and Brewster angle microscopy observations. Dye 1 undergoes specific interactions with Hg(2+) and Ag(+), respectively (formation of different complexes). Nonspecific interactions have been observed with other salts, such as KClO(4) or Pb(ClO(4))(2). Further, dye 1 monolayers on 1 mM Hg(ClO(4))(2) solution undergo reversible photoisomerization, in contrast to monolayers on water and other aqueous salt subphases.