177 research outputs found
Impact of transfusion of blood components on the recipient immune system
Transfusions of blood provide essential therapeutic measures in a number of pathological conditions. However, when carrying out blood component therapy, it is important to consider probability of post-transfusion complications. Most of them are immune-mediated side effects. The unfavorable consequences of blood transfusions can manifest at long-range time periods, and pathogenesis of these phenomena may be associated not only with the presence of alloantibodies. They may be caused by alloimmunization to HLA antigens, leukocyte factors, including cytokines, products of leukocyte degranulation, as well as storage-related erythrocyte damage («storage lesion»), immunomodulatory properties of extracellular vesicles or microparticles derived from blood components, and other factors. Despite significant number of publications on this issue, a lot of unresolved issues still remain, concerning transfusion-related effects of blood components on the immune system of recipients. The review article provides the results of current studies in this area. We present and discuss the results of current studies and the features of transfusion-mediated immunomodulation (TRIM) revealed over recent years, when transfusing different blood components. The role of plasma factors, microparticles, platelets and erythrocytes, HLA sensitization and microchimerism in the development of TRIM is highlighted, the data on occurrence and clinical features of TRIM in perioperative period are presented. A separate section of the review provides information about recent clinical studies, devoted to the issues of TRIM in different clinical cohorts, including newborns, patients with malignant neoplasms, immunocompromised patients after heart and vascular surgery. The data on TRIM incidence in the patients with exhausted immune system due to previous disease or treatment, severe comorbidity, extensive surgical thoracic/abdominal intervention and artificial circulation are also in scope. As based on the studies performed, the role of distinct measures, e.g., washing of erythrocyte concentrates, leukodepletion, and gamma irradiation are discussed in view of potential TRIM prevention. The results of published research do not allow us to draw definite conclusions about the effects of blood component transfusion on the immune system of recipients with respect to differences between the studied groups of patients, characteristics of the studied disorders and clinical situations, diversity of hemocomponents, as well as varying standards of transfusion therapy adopted in different countries. However, the systematic literature review may provide some guidance in transfusion-mediated immune modulation
Hybrid silicon nanostructures with conductive ligands and their microscopic conductivities
Silicon nanoparticles (SiNPs) functionalized with conjugated molecules promise a potential pathway to generate a new category of thermoelectric materials. While the thermoelectric performance of materials based on phenyl-acetylene capped SiNPs has been proven, their low conductivity is still a problem for their general application. A muon study of phenyl-acetylene capped SiNPs has been recently carried out using the HiFi spectrometer at the Rutherford Appleton Laboratory, measuring the ALC spectra as a function of temperature. The results show a reduction in the measured line width of the resonance above room temperature, suggesting an activated behaviour for this system. This study shows that the muon study could be a powerful method to investigate microscopic conductivity of hybrid thermoelectric materials
Analysis of the Dynamics of Tick-Borne Encephalitis Incidence and the Number of People who Appealed to Medical Organizations about Tick Bites in the European North of Russia
In recent decades, a significant increase in the incidence of tick-borne viral encephalitis (TBVE) and the number of people attacked by ticks has been recorded in the European North of Russia.The aim of the study was to analyze the dynamics of the TBVE incidence and the number of people who appealed to medical organizations regarding tick bites in the European North of Russia.Materials and methods. We used the Form No. 2 “Information on infectious and parasitic diseases”, the results of operational seasonal monitoring of TBVE, presented by the Rospotrebnadzor Administrations of the respective territories for our study. Statistical data processing was performed using the Microsoft Excel program. Display of the results on the map was carried out in the geographic information system ESRI ArcMap.Results and discussion. Combined analysis of the data on the number of cases and TBVE incidence, the number of people who appealed to medical organizations about tick bites and the number of people seeking advice about tick bites per 100 thousand population for the Arkhangelsk Region, the Republics of Karelia and Komi and their municipal districts has been performed. The mean values and gradients of the number of cases, incidence (2010–2020), the number of people who appealed to medical organizations regarding tick bites, and the number of people seeking treatment for tick bites per 100 000 population (2002–2020) have been calculated; maps of average values and gradients constructed. The incidence and the number of cases remain at the high level, exceeding the national average, but have been declining in the last decade. The number of people who appealed to medical organizations and the appealability of the population about tick bites per 100 000 of the population remain at a consistently high level and show no downward trend. The incidence and appealability of the population due to tick bites per 100 thousand of the population is spreading in a northerly direction, covering new territories in the Arctic zone. The main driving force behind the observed epidemic situation in the European North of Russia is the natural processes of climate change
Thermoelectric properties of tetrathiotetracene iodide crystals: modeling and experiment
A more complete physical model for nanostructured crystals of tetrathiotetracene-iodide that takes into account the interaction of carriers with the neighboring one-dimensional (1D) conductive chains and also the scattering on impurities and defects is presented. For simplicity, the 2D approximation is applied. It is shown that this model describes very well the temperature dependencies of electrical conductivity in the temperature interval between 180 and 300 K, and of the Seebeck coefficient between 50 and 300 K, the highest temperature for which the measurements were reported. For lower temperatures, it is necessary to also consider the fluctuations of dielectric phase that appear before the metal–dielectric transition. It is found that the predictions made in the 1D approximation are valid only if the crystal purity is not very high, and the electrical conductivity is limited up to ∼3.5×106Ω−1m−1 and the thermoelectric figure of merit up to ZT∼4
The entangled triplet pair state in acene and heteroacene materials
Entanglement of states is one of the most surprising and counter-intuitive consequences of quantum mechanics, with potent applications in cryptography and computing. In organic materials, one particularly significant manifestation is the spin-entangled triplet-pair state, which mediates the spin-conserving fission of one spin-0 singlet exciton into two spin-1 triplet excitons. Despite long theoretical and experimental exploration, the nature of the triplet-pair state and inter-triplet interactions have proved elusive. Here we use a range of organic semiconductors that undergo singlet exciton fission to reveal the photophysical properties of entangled triplet-pair states. We find that the triplet pair is bound with respect to free triplets with an energy that is largely material independent (∼30 meV). During its lifetime, the component triplets behave cooperatively as a singlet and emit light through a Herzberg–Teller-type mechanism, resulting in vibronically structured photoluminescence. In photovoltaic blends, charge transfer can occur from the bound triplet pairs with >100% photon-to-charge conversion efficiency.The authors thank the G8 Research Councils Initiative on Multilateral Research Funding (EPSRC EP/K025651; US National Science Foundation CMM1-1255494; Japanese Society for the Promotion of Science), JC thanks the University of Sheffield for a VC fellowship. AJM and SLB thank EPSRC (EP/M01083X and EP/M025330). The work in Mons is supported by BELSPO through the PAI P6/27 Functional Supramolecular Systems project and by the Belgian National Fund for Scientific Research FNRS/F.R.S. DB is a Research Director of FNRS
Insights from computational modeling in inflammation and acute rejection in limb transplantation
Acute skin rejection in vascularized composite allotransplantation (VCA) is the major obstacle for wider adoption in clinical practice. This study utilized computational modeling to identify biomarkers for diagnosis and targets for treatment of skin rejection. Protein levels of 14 inflammatory mediators in skin and muscle biopsies from syngeneic grafts [n = 10], allogeneic transplants without immunosuppression [n = 10] and allografts treated with tacrolimus [n = 10] were assessed by multiplexed analysis technology. Hierarchical Clustering Analysis, Principal Component Analysis, Random Forest Classification and Multinomial Logistic Regression models were used to segregate experimental groups. Based on Random Forest Classification, Multinomial Logistic Regression and Hierarchical Clustering Analysis models, IL-4, TNF-α and IL-12p70 were the best predictors of skin rejection and identified rejection well in advance of histopathological alterations. TNF-α and IL-12p70 were the best predictors of muscle rejection and also preceded histopathological alterations. Principal Component Analysis identified IL-1α, IL-18, IL-1β, and IL-4 as principal drivers of transplant rejection. Thus, inflammatory patterns associated with rejection are specific for the individual tissue and may be superior for early detection and targeted treatment of rejection. © 2014 Wolfram et al
Electrode Materials, Thermal Annealing Sequences, and Lateral/Vertical Phase Separation of Polymer Solar Cells from Multiscale Molecular Simulations
The nanomorphologies of the bulk heterojunction (BHJ) layer of polymer solar cells are extremely sensitive to the electrode materials and thermal annealing conditions. In this work, the correlations of electrode materials, thermal annealing sequences, and resultant BHJ nanomorphological details of P3HT:PCBM BHJ polymer solar cell are studied by a series of large-scale, coarse-grained (CG) molecular simulations of system comprised of PEDOT:PSS/P3HT:PCBM/Al layers. Simulations are performed for various configurations of electrode materials as well as processing temperature. The complex CG molecular data are characterized using a novel extension of our graph-based framework to quantify morphology and establish a link between morphology and processing conditions. Our analysis indicates that vertical phase segregation of P3HT:PCBM blend strongly depends on the electrode material and thermal annealing schedule. A thin P3HT-rich film is formed on the top, regardless of bottom electrode material, when the BHJ layer is exposed to the free surface during thermal annealing. In addition, preferential segregation of P3HT chains and PCBM molecules toward PEDOT:PSS and Al electrodes, respectively, is observed. Detailed morphology analysis indicated that, surprisingly, vertical phase segregation does not affect the connectivity of donor/acceptor domains with respective electrodes. However, the formation of P3HT/PCBM depletion zones next to the P3HT/PCBM-rich zones can be a potential bottleneck for electron/hole transport due to increase in transport pathway length. Analysis in terms of fraction of intra- and interchain charge transports revealed that processing schedule affects the average vertical orientation of polymer chains, which may be crucial for enhanced charge transport, nongeminate recombination, and charge collection. The present study establishes a more detailed link between processing and morphology by combining multiscale molecular simulation framework with an extensive morphology feature analysis, providing a quantitative means for process optimization
ПИЛОТНЫЙ ПРОЕКТ «РАЗВИТИЕ СИСТЕМЫ МЕДИЦИНСКОЙ РЕАБИЛИТАЦИИ В РОССИЙСКОЙ ФЕДЕРАЦИИ». ПРОТОКОЛ ВТОРОЙ ФАЗЫ
The Pilot project «Development of medical rehabilitation system in Russian Federation» is the large Russian project which is intended to transform system of rehabilitation care for patients with stroke, heart attack, and after total hip arthroplasty. The present article is the second one in the series of publications of the Project’s protocol. The publication shows the criteria of translation from 1 to 2 stages of rehabilitation and from 2 to 3 stages for all three profiles of the project. Working peculiarities of the second phase of the project are prescribed which realizes the new model of rehabilitation with assessment according to the ICF, determination of rehabilitation diagnosis, work in multidistsiplinary team and the introduction of a new speciality – ergotherapy. Пилотный проект «Развитие системы медицинской реабилитации в Российской федерации» – большой всероссийский проект, призванный преобразовать систему оказания реабилитационной помощи больным с инсультом, инфарктом и после эндопротезирования тазобедренного сустава. Данная статья является второй в серии публикаций протокола Проекта. В данной публикации приведены критерии перевода с 1-го на 2-й этапы реабилитации и со 2-го на 3-й по всем трем профилям проекта. Прописаны особенности работы во 2-й фазе проекта, где реализована новая модель реабилитации с оценкой по МКФ, установкой реабилитационного диагноза, работой в мультидисциплинарной команде и введением новой специальности – эрготерапии
Electrode Materials, Thermal Annealing Sequences, and Lateral/Vertical Phase Separation of Polymer Solar Cells from Multiscale Molecular Simulations
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