EVALUATION METHOD FOR PARASITIC EFFECTS OF THE ELECTRO-OPTICAL MODULATOR IN A FIBER OPTIC GYROSCOPE

Subject of Research.The paper proposes an original method for studying the parasitic effects in the electro-optic modulator of the fiber optic gyroscope. Proposed method is based on the usage of a special waveform phase modulation signal. Method. The essence of the proposed method lies in modification of serrodyne modulation signal, thereby providing a periodic displacement of the phase difference signal to the maximum of the interference curve. In this case, the intensity level reflects the influence of parasitic effects with the degree of manifestation being determined by the sequence of voltage control signals applied to the modulator. Enumeration of combinations of control signals and the corresponding intensity levels gives the possibility to observe an empirical dependence of the parasitic effects and use it later for compensation. Main Results. The efficiency of the proposed method is demonstrated by the program model of the fiber optic gyroscope. The results of the method application on a production sample of the device were obtained. Comparison with the results of direct estimate of the parasitic intensity modulation effect testifies to the effectiveness of the proposed method. Practical Relevance. The method can be used as a diagnostic tool to quantify the influence of parasitic effects in the electro-optic modulator of the fiber optic gyroscope as well as for their subsequent compensation

The problem of mismatches between CT scan and DXA results

Background. It is reported that radiodensity measured in Hounsfield units becomes more and more popular in bone property assessment, however also mismatch with DXA results is observed.Purpose. The aim of this study is to evaluate the relationships between the results of DXA and CT with a focus on explanations for observed discrepancies.Material and Methods. This is a cross-sectional study; forty patients were enrolled, all patients underwent DXA and CT. A bone mineral density BMD (g/cm2) was calculated for each vertebra of a lumbar spine (L1-L4 inclusive), neck, upper neck, shaft, Wards triangle and trochanter of hip. Bone radiodensity in HU was taken from each vertebral body in the sagittal, axial and coronal planes. A total vertebra body radiodensity including cortical bone and radiodensity of only cancellous bone were calculated. To assess a potential impact on DXA and CT data agreement a mean radiodensity and square of the right and left vertebral pedicles and facet joints were measured for each vertebra.Results. A strong correlation between BMD measured using DXA and CT data was estimated with a multiply r accounting for 0.84169, p < 0.0001, however the most contributing parameters were those calculated for facet joints. It has been detected that both radiodensity of only a cancellous bone and total have a weak correlation with matching BMD measurements of a proximal femur.Conclusion. The results of DXA could be strongly influenced by hypertrophic changes of facet joints. Both CT and DXA measurements taken from a lumbar spine may have a mismatch with figures taken from hip

CENTRAL WAVELENGTH ADJUSTMENT OF LIGHT EMITTING SOURCE IN INTERFEROMETRIC SENSORS BASED ON FIBER-OPTIC BRAGG GRATINGS

The paper is focused on the investigation of fiber-optic interferometric sensor based on the array of fiber Bragg gratings. Reflection spectra displacement mechanism of the fiber Bragg gratings under the external temperature effects and the static pressure is described. The experiment has shown that reflection spectra displacement of Bragg gratings reduces the visibility of the interference pattern. A method of center wavelength adjustment is proposed for the optical radiation source in accord ance with the current Bragg gratings reflection spectra based on the impulse relative modulation of control signal for the Peltier element controller. The semiconductor vertical-cavity surface-emitting laser controlled by a pump driver is used as a light source. The method is implemented by the Peltier element controller regulating and stabilizing the light source temperature, and a programmable logic-integrated circuit monitoring the Peltier element controller. The experiment has proved that the proposed method rendered possible to regulate the light source temperature at a pitch of 0.05 K and adjust the optical radiation source center wavelength at a pitch of 0.05 nm. Experimental results have revealed that the central wavelength of the radiation adjustment at a pitch of 0.005 nm gives the possibility for the capacity of the array consisting of four opticalfiber sensors based on the fiber Bragg gratings. They are formed in one optical fiber under the Bragg grating temperature change from 0° C to 300° C and by the optical fiber mechanical stretching by the force up to 2 N

Assessing the product quality of meat processing companies and costs on quality improvement

Within the context of new economic conditions, the issues of quality become a priority that allows gaining competitive advantages, on the one hand, and satisfy the ever-growing needs of consumers, on the other hand. Meat processors carry out the multilevel quality control both of their products and of the processes: the quality issues are of particular importance for such companies; that is why they were chosen as the object of researc

HABreports: Online Early Warning of Harmful Algal and Biotoxin Risk for the Scottish Shellfish and Finfish Aquaculture Industries

We present an on-line early warning system that is operational in Scottish coastal waters to minimize the risk to humans and aquaculture businesses in terms of the human health and economic impacts of harmful algal blooms (HABs) and their associated biotoxins. The system includes both map and time-series based visualization tools. A “traffic light” index approach is used to highlight locations at elevated HAB/biotoxin risk. High resolution mathematical modelling of cell advection, in combination with satellite remote sensing, provides early warning of HABs that advect from offshore waters to the coast. Expert interpretation of HAB, biotoxin and environmental data in light of recent and historical trends is used to provide, on a weekly basis, a forecast of the risk from HABs and their biotoxins to allow mitigation measures to be put in place by aquaculture businesses, should a HAB event be imminent

Восстановление ограниченных дефектов суставного хряща с помощью клеточно-инженерных конструкций

Aim: to develop a three-dimensional composite cell-engineered constructs (CEC) for restoration of limited defects of the cartilage in experiment.Materials and methods. To create a cell-engineered constructs (CEC), were used collagenic carriers: «Chondro Gide» impermeable bilayer membrane and «Osteoplast» permeable matrix. A comparative study of their cytotoxic and adhesion properties was made in vitro. Chondroplastic potential of prepared CECs based on collagenous matrices with allogeneic mesenchymal stem cells (MSC) of the rabbit bone marrow grown on their surface was assessed in vivo. A cylindrical defect of the cartilage of the medial femoral condyle 3.3 mm in diameter at a depth of 1.5 mm was formed on both rabbit feet. Laboratory animals were divided into 3 groups: control group; Experiment 1 group with Chondro Gide used as the MSC carrier within CEC; Experiment 2 group using Osteoplast matrix. Upon experiment completion, a morphometric and histomorphologic research of tissue specimens was made. For statistical evaluation of the results a defect region recovery factor (RF) was offered and used. Results. After a 6-month observation period the control group showed partial recovery of the defect region with the recovery factor (RF) of 0.62 ± 0.06. The RF in Experiment 1 group equalled to 0.79 ± 0.07, Experiment 2 group revealed RF at the level of 0.88 ± 0.02. Statistical analysis of the research results shows that the use of CEC used in Experiment 2 group reduces a relative risk of therapeutic failures by 92.9%, and absolute risk – by 43.3% as compared to Experiment 1 group. Histomorphologic research data are indicative of a hyaline cartilage formation in the central defect zone, which is partially close to the intact cartilage to the maximum with zonality marked.Conclusion. Results of the research of the developed three-dimension cell-engineered constructs consisting of mesenchymal stem cells of the bone marrow grown on the Osteoplast permeable collagenic matrix show the formation of a cartilaginous hyaline tissue with a high level of structural organization in the area of its implantation. The thickness of a newly formed cartilage is insignifi cantly less than that of the preceding cartilaginous tissue, thus facilitating a dynamic distribution of the axial load on the articular surface, and as a whole this holds out hope for good long-term results. Therefore, based on the data obtained, we consider it reasonable to perform next investigation phases of the offered cell-engineered constructs for chondroplasty of limited cartilage defects. Цель. Разработать трехмерную комбинированную клеточно-инженерную конструкцию (КИК) для восстановления ограниченных повреждений суставного хряща в эксперименте. Материалы и методы. Для создания клеточно-инженерной конструкции (КИК) использованы коллагеновые носители: двухслойная непроницаемая мембрана «Chondro Gide» и проницаемая матрица «Остеопласт», проводилось сравнительное исследование их цитотоксических, адгезивных свойств in vitro. Хондропластический потенциал подготовленных КИК на основе коллагеновых матриц с выращенными на их поверхности аллогенными мезенхимальными стволовыми клетки (МСК) костного мозга кролика оценивался in vivo. Кроликам на обеих лапах был сформирован цилиндрический дефект суставного хряща внутреннего мыщелка бедренной кости диаметром 3,3 мм на глубину 1,5 мм. При этом лабораторные животные были разделены на 3 группы: контрольная; группа «Опыт 1», в которой в качестве носителя для МСК в составе КИК использовался «Chondro Gide»; группа «Опыт 2», где была применена матрица «Остеопласт». По завершении эксперимента проводились морфометрическое и гистоморфологическое исследование образцов тканей. Для статистической оценки результатов был предложен и использован коэффициент восстановления области дефекта (КВ).Результаты. Через 6 месяцев наблюдений в контрольной группе отмечено частичное восстановление области дефекта, коэффициент восстановления (КВ) составил 0,62 ± 0,06. В группе «Опыт 1» КВ был равным 0,79 ± 0,07, в группе «Опыт 2» КВ находился на уровне 0,88 ± 0,02. Статистическая оценка результатов исследования показывает, что применение КИК, используемой в группе «Опыт 2», позволяет снизить относительный риск наступления неблагоприятных исходов лечения на 92,9%, абсолютный риск – на 43,3% по сравнению с группой «Опыт 1». Данные гистоморфологического исследования свидетельствуют о формировании в центральной зоне дефекта гиалинового хряща, местами максимально приближенного к интактному хрящу с обозначением зональности.Заключение. Результаты исследования разработанной трехмерной клеточно-инженерной конструкции, состоящей из мезенхимальных стволовых клеток костного мозга, выращенных на проницаемой коллагеновой матрице «Остеопласт», демонстрируют формирование в области ее имплантации хрящевой гиалиновой ткани с высокой степенью структурной организации. Вновь образованный хрящ лишь незначительно уступает по толщине предсуществующей хрящевой ткани, что способствует динамическому распределению осевой нагрузки по суставной поверхности и в совокупности позволяет надеяться на хорошие долгосрочные результаты. Таким образом, на основании полученных данных считаем обоснованным проведение следующих этапов исследования предложенной клеточно-инженерной конструкции для хондропластики ограниченных дефектов суставного хряща.

Matrix Metalloproteinase Gene Delivery for Liver Fibrosis

The resolution of advanced liver fibrosis has been recently recognized to be possible, if the causative stimuli are successfully removed. However, whether complete resolution from cirrhosis, the end stage of liver fibrosis, can be achieved is still questionable. Delivery of interstitial collagenases, such as matrix metalloproteinase (MMP)-1, in the liver could be an attractive strategy to treat advanced hepatic fibrosis from the view point that the imbalance between too few interstitial collagenases and too many of their inhibitors is the main obstacle to the resolution from fibrosis. Remodeling of hepatic extracellular matrix by delivered interstitial collagenases also facilitates the disappearance of activated hepatic stellate cells, the main matrix-producing cells in the liver, and promotes the proliferation of hepatocytes. This review will focus on the impact of the gene delivery of MMPs for the treatment of advanced liver fibrosis while discussing other current therapeutic strategies for liver fibrosis, and on the need for the development of a safe and effective delivery system of MMPs