Development and functional significance of the pulmonary surfactant system

Relevance. Prevention of the development of postoperative acute respiratory distress syndrome during operations on the descending thoracic aorta increases the effectiveness of therapy. The study of damage to the surfactant complex during ischemia and reperfusion of the lungs is relevant, since it involves the prophylactic use of the surfactant preparation during operations on the descending part of the thoracic aorta, which are characterized by a high risk of postoperative acute respiratory distress syndrome. Objective: to increase the effectiveness of pharmacological and respiratory therapy of acute respiratory distress syndrome, as well as to identify the role of the surfactant system of the lungs in the onset of inflammation against the background of tuberculosis and the development of regeneration mechanisms that affect the course and outcome of the disease. Materials and Methods. The study involved 24 people, including 14 volunteer patients with a diagnosed respiratory disease in an acute course (while the whole group received the drug from the study as an additional therapy). The sample of 14 people was formed solely due to the compliance of these patients with the criteria that were established before the start of the study of the drug, which had postoperative acute respiratory distress syndrome of various origins in their diagnosis. Results and Discussion. For a comprehensive laboratory determination, an algorithm was used that corresponded to the state standard to identify postoperative acute respiratory distress syndrome. For each participant in the experiments, it was proposed to develop a plan of treatment procedures, taking into account individualization and standardization. Conclusion. Some of the resulting data are collected with respect to the surfactant pulmonary system, which is presented in a compactor model format. A number of basic components are reflected here, which are classified according to cellular and non-cellular factors. At the same time, the surfactant substance helps to reduce the pronounced swelling, which can significantly reduce the process of sticking of the alveolar structures during inhalation. All this added up to the normal system of gas metabolism in the lung structures, including the control of the mucociliary system, which acts as a natural stimulator of the function of alveolar macrophages.

The effect of hypoxia on the surfactant system of the lungs

The study was conducted on mongrel male rats 120-180 g. Physical activity was performed by swimming for 40 minutes for 3 consecutive days. After three days, the development of insufficiency of the surfactant respiratory system was established, which will be characterized by moderate destruction of alveolocytes, violation of the entire aerogematic barrier as a whole, edema of alveolocytes, and, of course, POL. Key words: surfactant system of the lungs, physical activity, lipid peroxidation, respiratory organs.

Development of polymer emulsions stabilized with anionic polyelectrolytes

The colloidal-chemical principles of the formation of reversibly reversible microemulsions based on compositions of anionic polysaccharides, higher fatty acids, and nonionic polyoxyethylated surfactants have been investigated. The structural formula of the interpolymer complex in the “polyelectrolyte - surfactant” system was proposed, and the molar ratios of the components were determined. The effectiveness of the developed polymer emulsions as drilling fluids for the construction of oil wells is shown.

Synthesis, Structural Characterisation and Self Assembly of Nanoparticles

<p>This thesis is concerned with the synthesis, structural characterisation and self assembly of various nanocrystalline materials. These materials include gold, lead sulfide and lead selenide with substantial focus given to the noble metal palladium. The aim of this research was to obtain size and shape control over nanoparticles formed from solution phase synthesis for various applications. This was realised with chemical techniques using organic surfactants as growth controlling agents. The morphology, composition, internal crystal structure and applicable properties of the as synthesised nanoparticles were fully investigated to give a complete characterisation. Characterisation was carried out using a number of techniques including Super and High Resolution Transmission Electron Microscopy (SHREM, HREM), Synchrotron Powder X-Ray Diffraction (XRD), Selected Area Electron Diffraction (SAED) and Energy Dispersive X-Ray Spectroscopy (EDS). The first chapter in this thesis focuses on the synthesis and self assembly of monodisperse gold nanoparticles into nanoparticle superlattices (NPSLs), an exciting new type of material. The nanoparticles were prepared using a well known chemical method at room temperature. They were then arranged into NPSLs by a simple evaporation technique. Intermediate structures to the SLs were isolated which gave an insight into their formation. This showed that the NPs first self assembled into an energetically unfavourable bilayer before forming the most thermodynamically preferred three dimensional structure. This behaviour was due to the presence of organic capping ligands. The second chapter is concerned with the synthesis and characterisation of lead chalcogenide nanoparticles (lead sulfide and lead selenide). These are semiconductor materials which can provide a photocurrent when illuminated with infra-red radiation which makes them ideal candidates for solar cell technology. The nanoparticles were synthesised using a bench top solvothermal method. By varying the nature of the surfactant system, the precursor and the reaction time and temperature a wide range of nanoparticles with different sizes and shapes were prepared. A type of lead sulfide nanoparticles was then chosen for capping ligand exchange experiments. The new method developed here provides a facile route to water soluble lead chalcogenide nanoparticles and a means to more easily extract a photocurrent when used in solar cell applications. The remainder of this thesis is focussed on the synthesis and structural characterisation of palladium nanoparticles. Palladium is a very important catalytic metal therefore control over its size and shape on the nanoscale is of primary concern. In the third chapter of this thesis various types of palladium nanoparticles were produced using solution phase techniques in a pressure reaction vessel. By varying the nature of the surfactant system, the precursor and the reaction pressure, temperature and time the size and shape of the resulting nanoparticles could be controlled. These included spherical and worm-like nanoparticles as well as novel pod-like and highly branched palladium nanostructures. These complex shapes were the first evidence of this kind of morphology for palladium and provide a new and exciting material for catalytic applications. The final chapter in this thesis features a full structural characterisation and growth mechanism for the novel, complex palladium nanostructures along with an investigation into their catalytic and hydrogen absorption properties. The structural characterisation of a palladium tripod provides the first direct evidence of complex growth from a symmetrical nanoparticle core possessing the face centred cubic crystal structure. The growth of the highly branched palladium nanostructures is then tracked in real time. It is shown that the growth involves the formation of nuclei followed by tripod intermediates and finally highly branched nanostructures. By varying the nature of the surfactant system the kinetics of the reaction and hence the morphology of the resulting nanostructures can be controlled. A full growth mechanism is therefore proposed. The catalytic activity of the highly branched palladium nanostructures towards a simple organic transformation reaction is investigated. Finally, the hydrogen absorption and desorption properties of the highly branched nanostructures is explored. The results presented here regarding palladium nanoparticles are applicable to other industrially important noble metals such as gold, silver and platinum. A final conclusion chapter is then presented along with ideas for future research.</p>

Cost-Effective Chemical EOR for Heterogenous Carbonate Reservoirs Using a Ketone-Surfactant System

The complexity, high cost, and potential environmental concerns of chemical enhanced oil recovery (EOR) methods have diminished their field applications considerably. However, considering the significant incremental oil recoveries that can be obtained from these methods encourage researchers to explore ways to reduce both complexity, cost, and environmental concerns of such systems. This is especially important in carbonate formations, where after waterflooding, much of the oil remains trapped in complex reservoir pores—especially if the reservoir contains an interconnected fracture network of flow channels within the bulk rock matrix. In this paper, we present an experimental assessment of several simple chemical EOR waterflooding systems comprising of small concentrations of a low cost, low molecular weight ketone and a non-ionic surfactant in association with low-salinity brine. The experiments were conducted in carbonate cores from a Permian Basin San Andres Formation. Four different oil displacement scenarios were investigated using San Andres carbonate cores from the Central Vacuum Field in New Mexico. This included 1) low-salinity brine, 2) low-salinity brine with a surfactant, 3) low-salinity brine with a ketone, and 4) low-salinity brine with a combined ketone-surfactant system. Static imbibition experiments were conducted using a spontaneous imbibition apparatus in addition to the use of a high-speed centrifuge to saturate the cores to irreducible brine saturation. Adding a 1% concentration of 3-pentanone and a 1% non-ionic surfactant to a low-salinity brine yielded oil recoveries of 44% from the 3-pentanone system, compared to 11.4% from low-salinity brine only. The oil recovery is enhanced by a single mechanism or synergy of several mechanisms that includes interfacial tension (IFT) reduction by surfactant, capillary imbibition, favorable wettability alteration by ketone, and osmotic low-salinity brine imbibition. The IFT decreased to 1.79 mN/m upon addition of non-ionic surfactant to low-salinity brine, and it reduced to 2.96 mN/m in a mixture of 3-pentanone and non-ionic surfactant in low-salinity brine. Furthermore, ketone improved the core wettability by reducing the contact angle to 43.9° from 50.7° in the low-salinity brine experiment. In addition, the low-salinity brine systems caused mineral dissolution, which created an alkali environment confirmed by an increase in the brine pH. We believe the increase in pH increased the hydrophilic character of the pores; thus, increasing oil recovery.