16 research outputs found
Optimization of human tracking systems in virtual reality based on a neural network approach
The problem of determining the optimal number and location of tracking points on the human body to ensure the
necessary accuracy of reconstruction of kinematic parameters of human movements in virtual space is considered.
Optimization of the human tracking system in virtual reality has been performed to reduce the amount of transmitted
information, computational load and cost of motion capture systems by reducing the number of physical sensors. The
task of optimizing the number and location of tracking points on the human body necessary for the reconstruction of a
virtual body model from a limited set of input points using numerical approximation of the regression function is set.
An algorithm has been developed for collecting a large amount of data from a human body model in a virtual scene and
from a motion capture suit in the real world. The smallest number of human body tracking points and their location were
obtained using the proposed algorithm. Various neural network topologies have been trained and tested to approximate
the regression relationship between a vector of tracking points limited in size (from 3 to 13) and a vector of 18 virtual
points used for the complete reconstruction of the human body model. The necessary accuracy of reconstruction of
kinematic parameters of human movements is provided at 5 and 7 input points. The proposed approach made it possible
to use 5 or 7 physical sensors to build a model of the human body and restore the kinetic parameters of its movements
in virtual reality. The approach can be applied to solving inverse kinematics problems in order to reduce the number
of physical sensors placed on the surface of the object under study, to simplify the processing and transmission of
information. By combining data from both the motion capture suit and the virtual avatar, the process of collecting
information has been significantly accelerated, the volume of the training sample has been expanded and various patterns
of user body movements have been modeled
PROTECTIVE ACTIVITY OF NOVEL BENZIMIDAZOLE DERIVATIVES AT EXPERIMENTAL INFLUENZA INFECTION
Influenza is an acute respiratory viral infection, which represents an important health problem. Every year, influenza causes epidemics and pandemics, leading to increase in morbidity and mortality in all regions of the globe. Due to the segmental organization of the genome and low accuracy of its replication, the influenza virus is capable of escaping the host’s immune response (antigenic drift), as well as the selection of drug-resistant variants. This calls for constant monitoring of the sensitivity of viral isolates to antiviral drugs and the development of new etiotropic antiviral agents that have alternative targets and mechanisms of activity. The purpose of this study was to characterize the new aminobenzimidazole derivatives as protective agents in lethal influenza infection in white mice. The efficacy of the compounds was assessed by their ability to reduce specific mortality of animals in the course of lethal influenza pneumonia caused by the influenza A/Puerto Rico/8/34 (H1N1) irus, increase the life duration of animals, and normalize the morphological structure of lung tissue comparing to the placebo group. For all the compounds studied, a decrease in the specific mortality of animals (from 20 to 60%) has been shown. The reference drug (oseltamivir phosphate) reduced the mortality of mice by 80%. The benzimidazole derivative 2519 demonstrated the highest indices of protective activity, its use reduced the mortality of animals by 60% and increased their mean day of death by 1.6 days in comparison with the control group. Morphological analysis showed that the activity of derivative 2519 was manifested in the normalization of the morphological structure of lung tissue in the course of influenza pneumonia. On day 5 after infection, the cells of the bronchial epithelium looked intact, in contrast to destroyed cells with numerous viral inclusions in control animals. The foci of inflammation themselves occupied a smaller area compared to the control. At the same time, there was no correlation between the previously obtained data on the virus-inhibiting effect of these compounds in vitro and the data obtained in animals. This suggests that despite the presence of direct antiviral activity detected previously in in vitro experiments, the protective properties of the studied aminobenzimidazoles on animals are caused, in addition to the etiotropic effect, by other pathogenetic factors. In conclusion, amino derivatives of benzimidazole should be considered as compounds that are promising for further development and introduction as an anti-influenza agents
Preparation and synthesis a new chemotherapeutic drug of silver nanoparticle-chitosan composite; Chemical characterization and analysis of their antioxidant, cytotoxicity, and anti-acute myeloid leukemia effects in comparison to Daunorubicin in a leukemic mouse model
Nanoparticles usually have better outcomes than the bulk samples of the same element because they possess a higher specificity level than the larger particles. This is also true for silver nanoparticles, and little amount of these materials has high remedial effects. Silver nanoparticles are used as a therapeutic tool for the treatment of several diseases such as cancer. In this study, silver nanoparticles using chitosan (AgNPs-chitosan composite) are reported for the first time to exert a dietary therapeutic potential compared to Daunorubicin in an animal model of acute myeloid leukemia. The synthesized AgNPs-chitosan composite was characterized using different techniques including ultraviolet-visible spectroscopy, fourier-transform infrared spectroscopy, energy dispersive X-ray spectrometry, scanning electron microscopy, and transmission electron microscopy. FTIR findings suggested antioxidant compounds in the nanoparticles were the sources of reducing power, reducing silver ions to AgNPs. SEM and TEM images exhibited a uniform spherical morphology and average diameters of 30 nm for the nanoparticles. Then, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging test was done to evaluate the antioxidant potentials of Daunorubicin, AgNO3, chitosan, and AgNPs-chitosan composite. DPPH test revealed similar antioxidant potentials for Daunorubicin and AgNPs-chitosan composite. For the analyzing of cytotoxicity effects of Daunorubicin, AgNO3, chitosan, and AgNPs, 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromidefor (MTT) assay was used on HUVEC, 32D-FLT3-ITD, and Murine C1498 cell lines. AgNPs-chitosan composite similar to Daunorubicin had low cell viability dose-dependently against 32D-FLT3-ITD and Murine C1498 cell lines without any cytotoxicity on HUVEC cell line. In vivo design, induction of acute myeloid leukemia was done by 7,12-Dimethylbenzaanthracene in 50 mice. Then, the animals were randomly divided into six subgroups, including control, untreated, Daunorubicin, AgNO3, chitosan, and AgNPs-chitosan composite. Similar to Daunorubicin, AgNPs-chitosan composite significantly (P <= .01) decreased the weight of the body, the pro-inflammatory cytokines, and the total white blood cells, blast, neutrophil, monocyte, eosinophil, and basophil counts and increased the anti-inflammatory cytokines and the lymphocyte, platelet, and red blood cell parameters as compared to the untreated mice. These results show that the inclusion of chitosan improves the therapeutic properties of AgNPs-chitosan composite, which led to a significant enhancement in the antioxidant, cytotoxicity, and anti-acute myeloid leukemia activities of the nanoparticles. It appears that AgNPs-chitosan composite can be used as a chemotherapeutic drug for the treatment of acute myeloid leukemia in the clinical trial