87 research outputs found
Bacterial Cellulose/Alginate Nanocomposite for Antimicrobial Wound Dressing
Development of novel wound dressing has attracted more and more attentions in recent years. Bacterial cellulose is a biopolymer of great potentials, which features a distinctive three-dimensional structure consisting of an ultrafine network of cellulos nanofibers. In the present study, nanocomposite bacterial cellulose films modified in situ by the addition of alginate during the static cultivation of Gluconacetobacter sucrofermentans B-11267 were produced and then enriching the polymer with an antimicrobial agent tetracycline hydrochloride. The structure of bacterial cellulose and nanocomposite was analyzed by AFM and FTIR. The FTIR spectra displayed the specified interaction between the hydroxyl group of cellulose and the carboxyl group of alginate. The produced bacterial cellulose and nanocomposite were analyzed to determine tensile modulus. The antibacterial activity of nanocomposites were investigated by disk diffusion method. The resulting nanocomposite have high antibiotic activity against Staphylococcus aureus and can be used in medicine as a wound dressing.
Keywords: bacterial cellulose, Gluconacetobacter sucrofermentans, alginate, nanocomposite, antibacterial activity, wound dressin
The balance of elements in the system “Luvic Chernozems – agricultural plants” on the Plavsk upland (Tula region of Russia)
To assess the transfer of macro (K, P, S, Mg, Ca, as well as Si, Na, Fe, Al, Mn and Ti) and microelements (Zn, Ba, Cu, Sr, Mo, as well as As, Zr, Pb, Co, Ni, V and Cr) from Luvic Chernozems (Aric, Loamic, Pachic) into agricultural plants, we studied the inventories of chemical elements in three agrocenoses (wheat, soybean, Galega orientalis Lam. and Bromopsis inermis Leyss grass mixtures) from the Plavsk upland (Tula Region). This territory is subjected to intensive industrial and agricultural impacts: it is 40 km away from the town of Shchekino with a nitrogen fertilizer plant and a thermal power plant, 60 km away from Tula with large metallurgical enterprises, 70 km away from the town of Novomoskovsk with several chemical enterprises and state district power plant. In soils, the total content of elements was determined by the X-ray fluorescence spectrometry. The elemental composition of plants after autoclave decomposition with a mixture of concentrated nitric acid and hydrogen peroxide and the content of the bioavailable fraction (extracted by an ammonium acetate buffer with pH 4.8) of elements in soil were estimated by the atomic emission spectrometry with inductively coupled plasma. In topsoil (a 10-cm layer), maximal inventories are typical for total Si (40 ± 4 kg/m2), Al (7.0 ± 0.8 kg/m2) and Fe (3.4 ± 0.3 kg/m2) and for bioavailable Ca (570 ± 48 g/m2), Mg (43 ± 4 g/m2), K (22 ± 6 g/m2). In plants, the main inventories (g/m2) of K, P, S, Mg, Si, Mn, Zn, Ba, Cu, Mo occur in the above ground phytomass. The most effectively plants assimilate bioavailable fractions of K, P, Ti, Mo, As, Zr, V. Based on the resource method for soil quality assessment, the studied Chernozems are characterized by a low level of Ni contamination, a moderate supply of bioavailable K with a lack of bioavailable P
Using Chernobyl-derived 137Cs to document recent sediment deposition rates on the River Plava floodplain (Central European Russia)
Floodplain sedimentation is one of the most dynamic geomorphic processes within plain and lowland landscapes. There is generally a good understanding of longer term floodplain evolution, but quantitative information on overbank deposition rates for recent shorter timescales is lacking. This paper describes the application of Chernobyl-derived 137Cs to quantify floodplain aggradation rates for the River Plava (a small river draining a severely contaminated part of the upland region of Central European Russia), based on detailed sampling of four representative floodplain study sites. Two approaches have been employed for estimating post-Chernobyl (1986-2009) floodplain accumulation rates. The first was based simply on locating the Chernobyl fallout-associated 137Cs peak in overbank sediment sections. The second involved quantification of the increase in the total 137Cs inventory at individual sampling points associated with the post-Chernobyl deposition of contaminated suspended sediment. It has been shown that considerable local-scale variability of overbank deposition rates exists, with aggradation rates on the low level floodplain (6±1.2-14±2.8 mm year-1) exceeding by 1.5-3 times the values for the middle level floodplain (2±0.4-9±1.8 mm year-1) and by 3-6 times the values for the upper level floodplain (1±0.2-5±1.0 mm year-1) floodplain levels. Combining these estimates with information on the areas occupied by different floodplain levels within the 54 km long valley section, derived from detailed geomorphic surveys of the selected reaches, it has been estimated that about 9700±1950 t of sediment have been stored on floodplain during the 1986-2009 period. The role of floodplain storage in the overall basin sediment budget and conveyance losses within the main channel system have been evaluated. © 2012 John Wiley & Sons, Ltd
Peculiarities of immunological manifestations in patients with rheumatoid arthritis in the presence of chronic infection with <i>Helicobacter pylori</i> variant encoding cytotoxin-associated gene A
The study aimed to evaluate the association between cyclic citrullinated peptide antibody seropositivity and chronic Helicobacter pylori (H. pylori) infection in patients with rheumatoid arthritis (RA). We examined 92 women with moderate RA activity. Serum antibodies to cyclic citrullinated peptide (antiCCP), antibodies to H. pylori (anti-H. pylori-IgG), and total antibodies to H. pylori CagA antigen (antiCagA) were determined by enzyme immunoassay; the presence of anti-CagA-IgG positivity was confirmed by immunoblot. 68.5% of RA patients were positive for anti-H. pylori-IgG, and 44.4% of patients in this group were positive for anti-CagA-IgG. All the study participants were divided into three groups: I – H. pylori seronegative (H. pylori- ); II – H. pylori positive, CagA negative (H. pylori+/CagA- ); III – H. pylori positive and CagA positive (CagA+). The anti-CCP values in RA patients with CagA+ (group III) were significantly higher not only in comparison with patients seronegative for H. pylori (p < 0.001), but also in comparison with patients from group II (H. pylori+/CagA- ) (p = 0.041). A study of the influence of the RA activity, the presence of RF and H. pylori on anti-CCP content demonstrated a small proportion of anti-CCP variability (R2 = 0.09), with a high contribution of H. pylori (beta = 0.25). The addition of the CagA(+) index (beta = 0.503) to the presented model allowed us to describe the variability of anti-CCP in almost 30% of cases (R2 = 0.29). In the group of RA patients with anti-CCP values exceeding the established threshold value of 20 U/mL (normal index), there was an increase in the proportion of patients infected with H. pylori (p < 0.001), but not the proportion of CagA-positive patients (p = 0.06). When the threshold level was increased to 60 U/mL (three times the upper limit of normal) in patients with significantly high anti-CCP, the association with positivity for CagA became significant (p = 0.005). CagA is highly immunogenic and is capable of inducing an inflammatory response in the host that goes beyond the effect of H. pylori itself. Additional experimental studies are needed to investigate possible clinical and laboratory associations that may influence the treatment tactics of CagA+ patients with RA who are seropositive for anti-citrullinated antibodies, as well as to evaluate the possible effects of therapeutic intervention aimed at the eradication of H. pylori in this group
Kostroma cattle breed in the new century: the state and the prospects (review)
The article reflects the current state and the prospects of the Kostroma cattle breed development. The creation and improvement of the breed anticipated the formation and further breed development in the domestic and world zoo technical science. In recent years, the number of Kostroma cattle breed has been unreasonably reducing despite its economic valuable traits. At the same time in the Kostroma region there are prospects for preserving the valuable gene pool of one of the best domestic dairy and meat cattle breeds. As a result of directed selection and breeding work with the use of Brown Swiss bulls, a stud milk breed "Karavaevsky KK-1" has been developed. At present cow-champions of the Kostroma breed give up to 12,000 kg of milk per lactation. The milk of the Kostroma breed cows has a high content of protein and fat. The animals of Kostroma breed have good meat qualities, high resistance to a number of diseases, strong ungulate horn, easy adaptability to intensive technologies, good fertility and high productive longevity. To save the Kostroma breed it is important to put on 8-10 bulls of 8 planned lines and related groups for the validation and accumulation of sperm every year. The restoration of previously created lines with high genetic potential should be foreseen. It is necessary to identify and actively use the stud bulls bred in their own breeding farms; to conduct a linear assessment of bulls and daughter heifers by body type for more competent selection. In addition to the generally accepted forms and methods of selection, it is necessary to continue immunogenetic control of the authenticity of the origin of breeding animals and introduce modern methods of DNA technology to assess the breeding and productive qualities of cattle, which will reveal valuable genetic complexes in the best breeding animals and thus 1.5-2 times accelerate the selection processes.Conflict of interest: the authors stated that there was no conflict of interest
Influence of liposome forms of rhenium-platinum anti-tumor system on the proliferative activity of cancer cells
Уперше показано антипроліферативну активність реній-платинової системи на клітинах раку крові людини СЕМ-Т4. Найефективнішими виявилися експерименти, де використовувались обидва компоненти системи. Показано також перевагу ліпосомних форм порівняно з розчинами препаратів та переважний апоптотичний механізм загибелі клітин під дією системи.Впервые показана антипролиферативная активность рений-платиновой системы на клетках рака крови человека СЕМ-Т4. Наиболее эффективными оказались эксперименты, где использовались оба компонента системы. Показано также преимущество липосомных форм в сравнении с растворами препаратов и преимущественный апоптотический механизм гибели клеток под действием системы.First the antiproliferative activity of the antitumor system rhenium-platinum on the human blood cancer cells СЕМ-Т4 was shown. Experimental administration of both components of the system showed the most effectiveness. The advantages of liposomic forms in comparison with preparations solutions and dominating apoptotic mechanism of the cancer cells death under the treatment by the system were shown
Internal scheme of the body assessment in an experiment with environmental uncertainty
The aim of the work was to analyze the influence of various environmental factors forming environmental uncertainty on the nature of the transformation of the "internal scheme of the body". Materials and methods. For the study, a group of healthy volunteers (n = 90) was selected. The results in this paper are median, 75 and 25 percentiles (Me [UQ / LQ]). The study was conducted in several stages. At the first stage, the criteria for excluding potential participants from the experiment were formed. At the second stage of the study, a video analysis of the main anatomical orientations of the pelvic region in static and dynamic samples was conducted for all participants. Conclusion. In the course of the study, specific patterns of spatial deviations of biomechanical blocks of the pelvic region were established, triggered by changes in the qualitative and quantitative parameters of the external environment. So, in conditions of static equilibrium, coordination is activated with involvement of the anterior and posterior half-rings of the pelvis (frontal biomechanical blocks); in conditions of dynamic equilibrium, diagonal biomechanical blocks of the pelvic region are activated; in conditions of deprivation of visual afferentation, the compensatory reactions of the lateral semirings of the pelvic region (lateral biomechanical blocks) are formed
A new estimation of the recent tropospheric molecular hydrogen budget using atmospheric observations and variational inversion
This paper presents an analysis of the recent tropospheric molecular hydrogen (H2) budget with a particular focus on soil uptake and European surface emissions. A variational inversion scheme is combined with observations from the RAMCES and EUROHYDROS atmospheric networks, which include continuous measurements performed between mid-2006 and mid-2009. Net H2 surface flux, then deposition velocity and surface emissions and finally, deposition velocity, biomass burning, anthropogenic and N2 fixation-related emissions were simultaneously inverted in several scenarios. These scenarios have focused on the sensibility of the soil uptake value to different spatio-temporal distributions. The range of variations of these diverse inversion sets generate an estimate of the uncertainty for each term of the H2 budget. The net H2 flux per region (High Northern Hemisphere, Tropics and High Southern Hemisphere) varies between −8 and +8 Tg yr−1. The best inversion in terms of fit to the observations combines updated prior surface emissions and a soil deposition velocity map that is based on bottom-up and top-down estimations. Our estimate of global H2 soil uptake is −59±9 Tg yr−1. Forty per cent of this uptake is located in the High Northern Hemisphere and 55% is located in the Tropics. In terms of surface emissions, seasonality is mainly driven by biomass burning emissions. The inferred European anthropogenic emissions are consistent with independent H2 emissions estimated using a H2/CO mass ratio of 0.034 and CO emissions within the range of their respective uncertainties. Additional constraints, such as isotopic measurements would be needed to infer a more robust partition of H2 sources and sinks
Epileptic Focus in Drug-Resistant Epilepsy: Structure, Organization, and Pathophysiology
The chapter focuses on how different cutting-edge techniques can be used to study electrophysiological, pathomorphological, and biochemical changes in the “epileptic focus” area of the cerebral cortex and white matter to see how epileptic seizures become drug-resistant and how it affects the other regions of the brain. The authors highlight the significance of neuroinflammation and apoptosis in the epilepsy pathogenesis providing EEG characteristics and describing structural changes in the cortex and white matter under such conditions as focal cortical dysplasia and epileptic leukoencephalopathy. Particular focus is given to structural and functional changes in the hippocampus and the role of hippocampal sclerosis in epilepsy. Key conceptions regarding the epileptic focus formation are outlined
Печеночная недостаточность при механическом холестазе паразитарного генеза
In Tomsk zonal hepatologic center 358 patients with obstructive parasitogenic jaundice have been operated (alveococcosis-based — 43, echinococcosis-based — 17, opisthorchosis-based — 298). Clinical presentations of hepatic failure before the surgery have been observed at 30,7% of patients, more often — under long and intensive cholestasis. Postsurgical hepatic failure has developed at 23,1%. Intraportal medicine infusions play an important role in prophylaxis and treatment of hepatic failure along with timely and optimal surgery. Infusions permit to decrease the hepatic failure progress probability from 60,6 to 30,5%, probability of suppurative complications from 10,3 to 3,1% and postsurgical lethality from 38,2 to 9,5%.В Томском зональном гепатологическом центре оперировано по поводу механической желтухи паразитарного генеза 358 человек (на почве альвеококкоза — 43, эхинококкоза — 17, описторхоза — 298). Клинические проявления печеночной недостаточности до операции наблюдались у 30,7% пациентов, чаще при длительном и интенсивном холестазе. Послеоперационная недостаточность печени развилась у 23,2%. В профилактике и лечении печеночной недостаточности наряду со своевременностью и оптимальностью оперативного вмешательства важную роль играют внутрипортальные инфузии лекарственных средств, позволяющие снизить вероятность прогрессирования недостаточности печени с 60,6 до 30,5%, развития гнойных осложнений с 10,3 до 3,1%, уменьшить послеоперационную летальность с 38,2 до 9,5%
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