Symmetries and modelling functions for diffusion processes

A constructive approach to theory of diffusion processes is proposed, which is based on application of both the symmetry analysis and method of modelling functions. An algorithm for construction of the modelling functions is suggested. This algorithm is based on the error functions expansion (ERFEX) of experimental concentration profiles. The high-accuracy analytical description of the profiles provided by ERFEX approximation allows a convenient extraction of the concentration dependence of diffusivity from experimental data and prediction of the diffusion process. Our analysis is exemplified by its employment to experimental results obtained for surface diffusion of lithium on the molybdenum (112) surface pre-covered with dysprosium. The ERFEX approximation can be directly extended to many other diffusion systems.Comment: 19 pages, 8 figure

Modern Conception of the Control over the Abundance of Carriers and Vectors of Plague in the Territory of the Russian Federation

Disinfestation and deratization remain the main ways of non-specific disease prophylaxis in natural plague foci. Modern strategies, tactics, methods and means of control over carriers and vectors of plague and associated infectious diseases are selected with due consideration to epidemiological potential of territories, epizootic activity of a foci, peculiarities of population ecology of animals that are of a medical significance, preservation of biodiversity in natural ecosystems, and the requirements for human and natural environments protection from pollutants

Пиролиз хлористого метила на катализаторе SAPO-34/Al2O3 в условиях стационарного слоя и в режиме псевдоожижения

The process of pyrolysis of methyl chloride with the use of a silicoaluminophosphate catalyst granulated with Al2O3, the content of which varied in a range of 40–60 weight %, is investigated. The synthesized catalyst SAPO-34/Al2O3 in a mass ratio 60:40 is performed in the form of tablets for work in a stationary bed, as well as in a microsphere for the fluidized bed. The basic physical and chemical properties of the tested catalysts are determined. Comparison of the behaviour of the synthesized catalysts in the process of methyl chloride pyrolysis in the stationary bed and the fluidized bed is carried out. The process of methyl chloride pyrolysis on the fluidized bed microsphere catalyst is investigated. Temperature was varied in a range of 425–450ºС, the feed rate (WHSV, equivalent to the mass of methyl chloride) was in the range of 0.8–4.8 h−1 , time on stream (TOS) was 2 h. The basic technological parameters of the process providing conversion of methyl chloride not below 70% and selectivity of ethylene formation not lower than 45% are determined.Исследован процесс пиролиза хлористого метила с использованием силикоалюмофосфатного катализатора, гранулированного с оксидом алюминия, содержание которого варьируется в диапазоне 40–60% мас. Синтезированный катализатор SAPO-34/Al2O3 в массовом соотношении 60:40 выполнен в виде таблеток для работы в стационарном слое, а также в микросферическом виде для режима псевдоожижения. Определены основные физико-химические свойства тестируемых катализаторов. Проведено сравнение поведения синтезированных катализаторов в процессе пиролиза хлористого метила в условиях стационарного слоя и псевдоожижения. Процесс ката- литического пиролиза хлористого метила исследован при Т=425–450ºС, скорости массовой нагрузки хлористого метила 0.8–4.8 ч-1 на микросферическом катализаторе в режиме псевдоожижения. Определены основные технологические параметры проведения процесса, обеспечивающие конверсию хлористого метила не ниже 70% и селективность образования этилена не ниже 45%

Role of Mosquitoes, <I>Culex</I> <I>pipiens</I> Complex, in West Nile Fever Virus Persistence in Urbanized Biocoenoses of Saratov

. In wiggler samples as well as in imago ones detected are WNF virus markers, which indicate the possibility of transovarial and trans-phase transmission of virus into mosquito populations, habitant in urbanized biocoenoses. It is substantiated that Culex pipiens female mosquitoes, which reproduce autogenically, provide for the persistence of the virus within the inter-epidemic period. Therewith there is a possibility of sustained, epidemically-active WNF micro-foci to be formed in the residential area landscapes, and this issue should be given proper consideration when performing assessment of the risks associated with urban population exposure to the infection

Conditions for Virus Circulation and Premises for Natural West Nile Fever Foci Formation in the Territory of the Saratov Region

Local climate change (rise of mean temperatures and amount of precipitation, prolongation of frost-free season) triggers further distribution, and increase in numbers of animals – carriers and vectors of West Nile fever virus in the territory of the Saratov region. Based on the results of ecological-epizootiological monitoring (2006–2012) traced out have been the species composition, abundance dynamics, and character of distribution of birds habitant in aquatic and anthropogenic complexes, mosquitoes and Ixodidae ticks. Investigated are possible causes of West Nile fever nosoarea expansion, related to ecology of migrating birds wintering in Africa. Persistent circulation of the virus in intra-zonal inundated biocoenosis facilitates formation of secondary natural foci of West Nile fever and factors into epidemic complications as regards this particularly dangerous vector-borne infection. On the basis of analytical data concerning hydrographic network density, fauna structure, population numbers of birds and mosquitoes – potential carriers and vectors of WNF, epizootiological and epidemiological surveillance, designed has been expectation-driven forecasting map chart which illustrates possibility of sustainable WNF foci formation in various territories of the Saratov region

Studies of Biofilm Formation in Non-Pigmented and Plasmid-Deprived Mutants of <I>Yersinia pestis</I> on Biotic Surfaces, <I>in vivo</I> and <I>in vitro</I> Conditions

In non-pigmented and plasmid-deprived mutants – isogenic variants of highly virulent Yersinia pestis 231 strain – studied is the mechanism of biofilm formation on biotic surfaces, both in vitro (on the laboratory model of nematode Caenorhabdiitis elegans) and in vivo (inside the alimentary tract of Nosopsyllus laeviceps flea). It is determined that spontaneous loss of ability to form biofilms and generate pigmented colonies in the mutants is probably caused not only by the deletion of the whole chromosome pigmentation fragment, but also by a point(single base) mutation in structural hms operon. It is demonstrated that the absence of pCad, pFra or pPst plasmids does not have an impact on the ability of plasmid-deprived mutants to form biofilm on the cuticle of nematode C. elegans

Impact of the Present-Day Climate Changes on the Natural Plague Foci Condition, Situated in the Territory of the Russian Federation and Other CIS Countries

Climate changes determine dynamics of epizootic activity of natural plague foci in the XX and XXI centuries. Obvious shift to continentality in the Northern hemisphere can put an end to inter-epizootic period in lowland steppe and semi-desert natural foci of the Pre-Caucasian region, North and North-West Caspian Sea regions. Presently observed conjoined development of inter-epizootic periods in natural plague foci with different biocoenotic structure in the territory of Pre-Caspian Lowland gives the grounds for assuming the presence of a common cause preconditioning parasitic system depression in the region. One of the key elements of this phenomenon is a change of status of little souslik – formerly the main plague carrier in the region. Subsequent to the climate change the key role of plague carrier is more often played by non-hibernating rodent species nowadays. Thus a significant increase in epizootic potential of steppe natural plague foci in the territory of Kazakhstan and Central Asia is prognosticated. With the further temperature fall during wintertime, snow cover height increase and glacial area extension epizootic activity of the mountain and high mountain foci must drop off significantly. Alongside with this updated data on plague agent ecology, predetermining possibility of its existence in the soil biota, confirm the key role of climactic factors in the plague enzootic outbreak

Studies of West Nile Virus Circulation in the Territory of the Saratov Region in 2010

Presented are the results of ecological and epizootiological surveillance of the territory of the Saratov region, which was carried out in autumn of 2010. The surveillance was aimed at detection of West Nile (WN) virus circulation and premises for WN Fever natural focus formation. It is demonstrated that in 2010 WN virus circulation took place in damp biotopes of the Saratov region territory, and that common species of small mammals were involved in it. Presented are the results of analysis of the WN virus role in the infectious pathology in the territory of the Saratov region

Factors affecting the results of analgesic therapy. Results of the Russian multicentre study of NOTE (NSAID: Open-label Trial of Efficacy)

Non-steroidal anti-inflammatory drugs (NSAIDs) are most popular medications for the treatment of pain in common musculoskeletal diseases such as osteoarthritis (OA) and non-specific low back pain (LBP). However, the factors affecting the effectiveness of these drugs have not been determined fully. Aim: to identify factors affecting the effectiveness of NSAIDs in patients with OA and LBP. Materials and methods. An observational study was conducted to evaluate the effectiveness of a 2-week course of NSAIDs in OA and LBP in real clinical practice. The study group consisted of 3604 patients with OA and LBP (60.6% women and 39.4% men, mean age 55.0±13.4 years). According to the study design, aceclofenac (Airtal) and other NSAIDs used in the ratio 1:1. The main criterion of effectiveness was the frequency of complete pain relief after 2 weeks of therapy. In addition, the decrease of pain and general health were determined on a 10-point numerical rating scale (NRS). We compared the frequency of complete pain relief in patients who had and did not have the studied factors. The value of the studied factors was determined using OR (95% CI). Results and discussion. Most patients received aceclofenac (54.9%), as well as diclofenac (2.0%), ketoprofen (1.9%), lornoxicam (2.2%), meloxicam (13.7%), naproxen (2.1%), nimesulide (5.8%), celecoxib (5.9%), ethicoxib (7.1%) and other NSAIDs (4.4%); 56.2% of patients received muscle relaxants, mainly tolperisone (74.7%), vitamin B (10.4%), and proton pump inhibitors (42.8%). Complete pain relief was achieved in 54.8% of patients. The pain decrease and general health improvement were (for NRS) 63.9±13.4% and 61.7±14.8%, respectively. The efficacy of aceclofenac was slightly higher than in the whole group: complete pain relief was in 59.9% of patients. Adverse events in aceclofenac use were observed in 2.3% of patients, other NSAIDs-from 2.4 to 14.1%. The frequency of complete pain relief was higher in men: OR 1,239 (95% CI 1.08-1.418; p=0.002), who had the first episode of pain - OR 3.341 (95% CI 2.873-3.875; p=0.000), a good" response " to NSAIDs in history - OR 1.656 (95% CI 1.385-1.980; p=0.000) and received NSAIDs in combination with muscle relaxants - OR 1.218 (95% CI 1.067-1.390; p=0.004). The effect of therapy is lower in patients 65 years and older-OR 0,378 (95% CI 0.324-0.442; p=0,000), with body mass index >30 kg/m² - OR 0.619 (95% CI 0.529-0.723; p=0.000), with severe pain (≥7 points NRS) - OR 0.662 (95% CI 0.580-0.756; p=0.002), with pain at rest, - OR 0.515 (95% CI 0.450-0,589; p=0.000), pain at night - OR 0.581 (95% CI 0.501-0.672; p=0.000) and the presence of stiffness - OR 0.501 (95% CI 0.438-0,573; p=0.000). Treatment results are significantly worse in the cases of combination of LBP and joint pain, as well as pain in the trochanter major and pes anserinus area (