16 research outputs found
Skeletons of Glass Sponges as a Substrate for Creating Functional Composite Organosilicon Materials
The article describes a method of creating a three-dimensional organosilicon composite material based on the glass sponge spicules through a combination of soft etching and controlled mechanical action, non-destroying spicules. When in an alkaline medium, the material of the spicules' outer concentric layers is dissolved and silica passes into solution. After 20 to 30 days in alkaline medium, the silica is in excess and precipitates on organic components, forming a network of 300-500-nm thick organosilicon trabeculae, by which the spicules are fused into a single structure. The resulting composite material contains a mineral component of silica and an organic component. The results indicate that the natural organosilicon material can be reformed as a result of self-assembly into three-dimensional or flat structures
Omecamtiv mecarbil in chronic heart failure with reduced ejection fraction, GALACTICâHF: baseline characteristics and comparison with contemporary clinical trials
Aims:
The safety and efficacy of the novel selective cardiac myosin activator, omecamtiv mecarbil, in patients with heart failure with reduced ejection fraction (HFrEF) is tested in the Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure (GALACTICâHF) trial. Here we describe the baseline characteristics of participants in GALACTICâHF and how these compare with other contemporary trials.
Methods and Results:
Adults with established HFrEF, New York Heart Association functional class (NYHA)ââ„âII, EF â€35%, elevated natriuretic peptides and either current hospitalization for HF or history of hospitalization/ emergency department visit for HF within a year were randomized to either placebo or omecamtiv mecarbil (pharmacokineticâguided dosing: 25, 37.5 or 50âmg bid). 8256 patients [male (79%), nonâwhite (22%), mean age 65âyears] were enrolled with a mean EF 27%, ischemic etiology in 54%, NYHA II 53% and III/IV 47%, and median NTâproBNP 1971âpg/mL. HF therapies at baseline were among the most effectively employed in contemporary HF trials. GALACTICâHF randomized patients representative of recent HF registries and trials with substantial numbers of patients also having characteristics understudied in previous trials including more from North America (n = 1386), enrolled as inpatients (n = 2084), systolic blood pressureâ<â100âmmHg (n = 1127), estimated glomerular filtration rate <â30âmL/min/1.73 m2 (n = 528), and treated with sacubitrilâvalsartan at baseline (n = 1594).
Conclusions:
GALACTICâHF enrolled a wellâtreated, highârisk population from both inpatient and outpatient settings, which will provide a definitive evaluation of the efficacy and safety of this novel therapy, as well as informing its potential future implementation
Enhanced optomechanical interaction in the unbalanced interferometer
Quantum optomechanical systems enable the study of fundamental questions on
quantum nature of massive objects. For that a strong coupling between light and
mechanical motion is required, which presents a challenge for massive objects.
In particular large interferometric sensors with low frequency oscillators are
difficult to bring into quantum regime. Here we propose a modification of the
Michelson-Sagnac interferometer, which allows to boost the optomechanical
coupling strength. This is done by unbalancing the central beam-splitter of the
interferometer, allowing to balance two types of optomechanical coupling
present in the system: dissipative and dispersive. We analyse two different
configurations, when the optomechanical cavity is formed by the mirror for the
laser pump field (power-recycling), and by the mirror for the signal field
(signal-recycling). We show that the imbalance of the beam splitter allows to
dramatically increase the optical cooling of the test mass motion. We also
formulate the conditions for observing quantum radiation-pressure noise and
ponderomotive squeezing. Our configuration can serve as the basis for more
complex modifications of the interferometer that would utilize the enhanced
coupling strength. This will allow to efficiently reach quantum state of large
test masses, opening the way to studying fundamental aspects of quantum
mechanics and experimental search for quantum gravity.Comment: 12 pages, 6 figure
Modelling an Optimal Capital Srtucture of the Telecommunication Company
The article is devoted to the development and approbation of a methodological approach to the modelling of an optimal structure of a joint stock company. The optimal capital structure is defined by the authors as a combination of debt and equity, which maximizes the overall value of the company. The article contains the main conclusions received from different economic researches on the optimization of a capital structure. The authors invented a model of the optimal capital structure that may be used by the joint stock companies in emerging markets with greater risk due to political instability, domestic infrastructure problems, currency volatility and limited equity opportunities. This model is supplemented with corrective indicators of financial risks
Assessment of Electrospun Pellethane-Based Scaffolds for Vascular Tissue Engineering
We examined the physicochemical properties and the biocompatibility and hemocompatibility of electrospun 3D matrices produced using polyurethane Pellethane 2363-80A (Pel-80A) blends Pel-80A with gelatin or/and bivalirudin. Two layers of vascular grafts of 1.8 mm in diameter were manufactured and studied for hemocompatibility ex vivo and functioning in the infrarenal position of Wistar rat abdominal aorta in vivo (n = 18). Expanded polytetrafluoroethylene (ePTFE) vascular grafts of similar diameter were implanted as a control (n = 18). Scaffolds produced from Pel-80A with Gel showed high stiffness with a long proportional limit and limited influence of wetting on mechanical characteristics. The electrospun matrices with gelatin have moderate capacity to support cell adhesion and proliferation (~30â47%), whereas vascular grafts with bivalirudin in the inner layer have good hemocompatibility ex vivo. The introduction of bivalirudin into grafts inhibited platelet adhesion and does not lead to a change hemolysis and D-dimers concentration. Study in vivo indicates the advantages of Pel-80A grafts over ePTFE in terms of graft occlusion, calcification level, and blood velocity after 6 months of implantation. The thickness of neointima in Pel-80Aâbased grafts stabilizes after three months (41.84 ± 20.21 ”m) and does not increase until six months, demonstrating potential for long-term functioning without stenosis and as a suitable candidate for subsequent preclinical studies in large animals
Utilization and recycling of municipal solid waste in a subarctic zone
Municipal solid waste (MSW) collection and disposal is one of the major problems of urban environment in most countries worldwide today. The problem of utilization of solid waste in the Northern Europe on the Kola Peninsula was raised in this article, where the ground arrangement in a subarctic zone is very special and the weather conditions are severe. The paper main goal is to verify long-term impact of the Mezhdurechie municipal landfill on the atmosphere in Kola Peninsula. The paper also aims to establish the holding actions for recycling and utilization of worn-out tires for mentioned municipal landfill. The ground concentrations of pollutants from the operational sources were presented. The proposed recycling development in this paper has a positive impact on the ecoindustry and ensures environmental safety and municipal economy