Magnetic properties of the low-dimensional spin-1/2 magnet \alpha-Cu_2As_2O_7

In this work we study the interplay between the crystal structure and magnetism of the pyroarsenate \alpha-Cu_2As_2O_7 by means of magnetization, heat capacity, electron spin resonance and nuclear magnetic resonance measurements as well as density functional theory (DFT) calculations and quantum Monte Carlo (QMC) simulations. The data reveal that the magnetic Cu-O chains in the crystal structure represent a realization of a quasi-one dimensional (1D) coupled alternating spin-1/2 Heisenberg chain model with relevant pathways through non-magnetic AsO_4 tetrahedra. Owing to residual 3D interactions antiferromagnetic long range ordering at T_N\simeq10K takes place. Application of external magnetic field B along the magnetically easy axis induces the transition to a spin-flop phase at B_{SF}~1.7T (2K). The experimental data suggest that substantial quantum spin fluctuations take place at low magnetic fields in the ordered state. DFT calculations confirm the quasi-one-dimensional nature of the spin lattice, with the leading coupling J_1 within the structural dimers. QMC fits to the magnetic susceptibility evaluate J_1=164K, the weaker intrachain coupling J'_1/J_1 = 0.55, and the effective interchain coupling J_{ic1}/J_1 = 0.20.Comment: Accepted for publication in Physical Review

Comparative Preclinical Evaluation of the Safety, Antifungal Activity, and Pharmacokinetics of Sertaconazole Products for External Use

The high prevalence of fungal skin infections motivates expanding the range of sertaconazole products for external use.The aim of the study was a preclinical comparison of the safety, antifungal activity, and pharmacokinetics of Sertaverin® 2% medicated shampoo (VERTEX JSC, Russia) with those of Sertamicol® 2% solution for external use (Glenmark Pharmaceuticals Ltd, India) and Nizoral® 2% shampoo (Janssen Pharmaceuticals N.V., Belgium) approved in the Russian Federation.Materials and methods. In the toxicity study, the medicinal products were applied to the skin of male and female outbred rats at doses of 0.5 or 1.5 mL/animal for 28 days. The authors evaluated the pharmacokinetics of two sertaconazole formulations (shampoo and solution) following a single administration to adult male rats at the same dose. Nizoral® was not used in the pharmacokinetics study because it contains a different active substance, ketoconazole. The minimum inhibitory concentration (MIC) was determined using the serial microdilution method in a wide range of concentrations.Results. The medicinal products did not exhibit any significant toxic effects in laboratory animals after 28 days of repeated dermal application. Plasma sertaconazole concentrations were negligible. Sertaconazole was intensively distributed in the liver, which is a highly vascularised organ, and in the target organ (skin at the site of application). The relative bioavailability of sertaconazole from the shampoo relative to that from the solution for external use was approximately 30% in liver tissues and approximately 363% in skin tissues at the application site. Sertaverin® was comparable to sertaconazole in the active substance form in terms of inhibiting the growth of Malassezia furfur strains. The MICs calculated on the active substance basis were ≤16–64 μg/mL.Conclusions. With its synergistic dual mechanism of action, broad-spectrum antifungal activity, lipophilic properties, and low systemic absorption, Sertaverin® may provide a more effective and safe alternative to marketed medicinal products for scalp diseases

АНТИАГРЕГАНТНАЯ ТЕРАПИЯ В ПРОФИЛАКТИКЕ НАРУШЕНИЙ МОЗГОВОГО КРОВООБРАЩЕНИЯ

Currently the problem of preventing cerebrovascular disorders, in which antiplatelet therapy takes one of the leading places, remains relevant. The efficiency of the therapy depends on a large number of modifiable and non-modifiable factors. There are many methods to assess the severity of the response to antiplatelet therapy, but there is no common approach to the assessment of the results and their prognostic significance. Further studies of this issue are essential with the aim of individualization of antiplatelet therapy thereby increasing its efficiency and safety.В настоящее время сохраняется проблема профилактики нарушений мозгового кровообращения, в которой антиагрегант­ ная терапия занимает одно из ведущих мест. Эффективность данной терапии зависит от большого числа модифицируемых и не модифицируемых факторов. Существует множество методов оценки ответа на антиагрегантную терапию, но нет единого подхода к оценке получаемых результатов и их прогностической значимости. Необходимы дальнейшие исследования данного вопроса с целью индивидуализации антиагрегантной терапии и, тем самым, повышения ее эффективности и безопасности

Parasites of the genus Nosema, Crithidia and Lotmaria in the honeybee and bumblebee populations : a case study in India

The populations of honeybees and bumblebees have been decreasing around the world in the recent decades. A variety of pathogens and parasites, including  bacteria, fungi, protozoa, nematodes, mites and insects play signi ficant role in honeybee and bumblebee colonies loss. Pa rasites of the genus Nosema (Microsporidia: Nosematidae) and the genera Crithidia and Lotmaria (Kinetoplastida: Trypanosomatidae) have a significant negative impact on honeybee and bumblebee colonies. Recent  studies of nuclear DNA markers of these parasites allowed to describe new species and genetic variants. The aim of this study was to investigate the Microsporidia (Nosema spp.) and Trypanosomatidae (Crithidia spp. and Lotmaria  passim) prevalence and genetic diversity in honeybee and bumble bee populations of Indian territories that haven’t been studied before. In total 119 specimens of 4 honeybee and 5 bumblebee species were analyzed in this study. The prevalence of parasites in honeybee and bumblebee po pulations of the two Indian states (Jammu and Kashmir, Karnataka) were identified using PCR with primers specific for the ribosomal RNA genes cluster of Nosema, Crithidia and Lotmaria species. Co­infection by microsporidian and trypanosomatid parasites was detected in several honeybee and bumblebee specimens from Jammu and Kash mir state. Comparative analysis of ribosomal RNA genes sequences showed that honeybee samples from India studied were infected by N. bombi, N. ceranae and L. passim.  Bumblebee populations were infected by Nosema D, Crithidia bombi and Crithidia expoeki. No honeybee’s specimen with trypanosomatid infection was found in Karnataka state. For the first time N. bombi infection was detected in the honeybee population. The studies of distribution of microsporidia and trypanosomatid parasites among the honeybee and bumblebee populations all over the World were summarized and supplemented

Effect of emotional stress on cold structural and functional state dental pulp rats

In the experiment established the influence of emotional and cold stress not only on metabolic changes, but also structural changes in the dental pulp. It was shown that the dental pulp stress leads to disruption of intercellular interactions due to morphological characteristics and cell fusion proteins and peptides. Short-term stress exposure causes a reaction similar to the inflammation of the pulp and long leads to inhibition of calcium and phosphorus metabolism and apoptosis odontoblasts

CHANGES OF IMMUNE STATUS IN WOMEN WITH MISSED ABORTION

Abstract. The article presents data on some changes of immunological parameters in women with missed abortion. The indices of humoral and cellular immunity were studied in pregnant women at the terms of 4 to 15 weeks, as compared with a group of women with missed abortion within the same terms