Sodium Bis 2-ethylhexyl Sulfosuccinate Research Articles

Effect of various surfactants on stability and thermophysical properties of nanofluids

The effect of Fe3O4 nanoparticles and carbon nanotubes (CNTs) on the viscosity of a nanofluid is experimentally investigated from 278 to 313 K by changing the nanoparticle volume fraction. These nanoparticles were put into distilled water with various surfactants, i.e., Colace (docusate sodium), trisodium citrate dihydrate (TSC), polyvinyl pyrrolidone, cetyl trimethylammonium bromide, tetramethylammonium hydroxide (TMAH), acacia senegal (GA), sodium dodecyl benzene sulfonate, sodium dodecyl sulfate (SDS), and sodium laurylsulfonate (SLS). Based on the present measurements, new empirical formulas are proposed for Fe3O4–water, CNT–water and Fe3O4–CNT–water nanofluids to provide accurate predictions for the nanofluid viscosity. Based on the viscosity testing, stabilities and thermal conductivities of Fe3O4–TMAH, Fe3O4–Colace, Fe3O4–TSC, CNT–SDS, CNT–GA, Fe3O4–CNT–SLS, and Fe3O4–CNT–TSC nanofluids with a volume concentration of 0.5% are investigated in the present research. Results indicate that better stability, smaller viscosity, and higher thermal conductivity are obtained, when the surfactants TMAH, SDS, and SLS are added into the Fe3O4–water, CNT–water, and the Fe3O4–CNT–water nanofluid, respectively. The CNT–water and Fe3O4–CNT–water nanofluids exhibit a shear-thinning behavior, whereas a linear rheological behavior can be observed by water-based Colace–Fe3O4, TMAH–Fe3O4, and TSC–Fe3O4 nanofluids.

Ethanol enhanced anionic surfactant solubility in CO2 and CO2 foam stability: MD simulation and experimental investigations

CO2 foam has been widely scrutinized as a potential candidate in enhanced oil recovery while reducing CO2 emissions through geo-sequestration due to the high-efficiency CO2 mobility control ability. However, its application has been retarded partially because of the limited solubility of commercial and environmentally friendly surfactants in supercritical CO2. In this work, the challenge of limited solubility of surfactant sodium bis(2-ethylhexyl) sulfosuccinate (AOT) in CO2 is overcome by using ethanol as a co-solvent. The presented MD simulation reveals the underlying mechanism of the ethanol increased solubility of AOT in CO2 and the subsequently water-CO2 interfacial properties favorable for a stable CO2 foam. Experimental observation is in good accordance with the MD simulation that foamability and foam stability both significantly increase with ethanol as co-solvent, and their dependence on ethanol content. With ethanol as co-solvent to assist the dissolution of AOT in CO2, the CO2 foam has a high stiffness and the foam film has a high dilational modulus under high pressure of 15 MPa, which explain the stable CO2 foam. Experiments also show that ethanol helps the foam regeneration, making the practical oil field application of the presented system even more promising.

Mass transport of SDS and AOT solutions during a rapid surface expansion: Relaxation of surface tension

Abstract Surface tension (ST) relaxations are influential in industrial processes that are characterized by substantial surface deformations. Despite this, the dynamics of surfactant adsorption onto a dilating surface is still unclear. Recently, the ST relaxation of a non-ionic surfactant (TX-100) was reported (Lin et al. (2017) [17]), but little is known about the behavior of ionic surfactants. In this study, the relaxations of ST and surface dilational rates (λ) of ionic aerosol-OT (AOT) and sodium dodecyl sulfate (SDS) solutions were investigated by monitoring a continuously expanding bubble using a pendant bubble tensiometer. The data showed that during the rapid bubble expansion, ST of AOT solutions increased with time, while that of SDS changed negligibly. This implied that the mass transfer rate of AOT molecules from bulk to the bubble surface during expansion (at λ

Effect of Polar Solvents on Surfactant Membranes

We have studied how a surfactant (Aerosol OT or AOT) self-assembles in different polar (Water, Ethylene glycol, Formamide, N, N-Dimethylformamide) and non-polar (Isooctane) solvents. AOT is a widely used surfactant in biological and industrial applications. The lamellar phase of the AOT/water system is often used as a model of lipidic membrane. We investigated two surfactant volume fractions (0.2 and 0.6) with visual inspection, SAXS, rheology and electrical conductivity experiments. The results indicate that AOT self-assembles differently depending on solvent type and concentration. SAXS experiments show that the AOT/water systems display lamellar phases. In the other cases, only formamide displays a lamellar phase for φ = 0.6. The other solvents (and formamide at φ= 0.2) promote the self-assembly of AOT in other microstructures. In these cases, the SAXS spectra display correlation peaks consistent with a disordered array of cylindrical aggregates. The visual inspection, rheology and electrical conductivity results are consistent with the deduced self-assembled structures. We explain most of our results in terms of surfactant packing models and solvent properties.

Potential Application of Dioctyl Sodium Sulfosuccinate Salt (DOSS)–Saponin Binary Dispersant in Oil Spill Remediation: Synergistic Interaction Between DOSS and Saponin

The interfacial activity of dispersants can be enhanced by combining two or more surfactants to formulate the dispersant. This paper examines the effects of Bio-Saponin (BS), a phytogenic surfactant on the interfacial activity of synthetic dioctyl sulfosuccinate sodium salt (DOSS) usually adopted as a suitable surface-active agent in dispersants used in dealing with large-scale oil spills. The o/w emulsion created with the binary DOSS-BS was very stable and recorded the least average droplet size compared with that of DOSS only and BS only. Lower surface and interfacial tension values were also obtained from the DOSS-BS binary formulation. The dispersion effectiveness was also higher compared with that of DOSS and BS. However, they were dependent on the salinity and type of crude oil. These observations were attributed to the moderation of the interaction between the anionic head group of DOSS by the polysaccharide hydrophilic group of BS. The results revealed the potential application of DOSS-BS binary dispersant in oil spill remediation and in other processes that would require an effective emulsifier.

Relaxation of Physicochemical Processes during the Chemical Synthesis of Silver Nanoparticles in Reverse Micellar Solutions

The kinetics of optical properties is studied experimentally on an OT Aerosol (dioctyl sulfosuccinate sodium salt)/isooctane/Qr (quercetin)/Ag+) reverse micellar system (RMS) during the chemical synthesis of Ag nanoparticles. The kinetic light optical absorption data acquired for an RMS at a wavelength λ = 432 nm with a chronometric resolution of 0.14 and 1 s are used to calculate the boundaries of the stages of Ag NP formation (at a confidence factor of at least 0.99). The determination of relaxation times (almost-periods) in an RMS allows evaluation of the kinetics parameters at certain stages of the chemical synthesis of NP metals.

Gold Nanotriangles with Crumble Topping and their Influence on Catalysis and Surface-Enhanced Raman Spectroscopy.

By adding hyaluronic acid (HA) to dioctyl sodium sulfosuccinate (AOT)-stabilized gold nanotriangles (AuNTs) with an average thickness of 7.5±1 nm and an edge length of about 175±17 nm, the AOT bilayer is replaced by a polymeric HA-layer leading to biocompatible nanoplatelets. The subsequent reduction process of tetrachloroauric acid in the HA-shell surrounding the AuNTs leads to the formation of spherical gold nanoparticles on the platelet surface. With increasing tetrachloroauric acid concentration, the decoration with gold nanoparticles can be tuned. SAXS measurements reveal an increase of the platelet thickness up to around 14.5 nm, twice the initial value of bare AuNTs. HRTEM micrographs show welding phenomena between densely packed particles on the platelet surface, leading to a crumble formation while preserving the original crystal structure. Crumbles crystallized on top of the platelets enhance the Raman signal by a factor of around 20, and intensify the plasmon-driven dimerization of 4-nitrothiophenol (4-NTP) to 4,4'-dimercaptoazobenzene in a yield of up to 50 %. The resulting crumbled nanotriangles, with a biopolymer shell and the absorption maximum in the second window for in vivo imaging, are promising candidates for biomedical sensing.

Horseradish peroxidase-catalyzed oxidative polymerization of aniline in bicontinuous microemulsion stabilized by AOT/SDS

A bicontinuous microemulsion system consisting of sodium bis(2-ethylhexyl) sulfosuccinate (AOT), sodium dodecylsulfate (SDS), an aqueous solution (a 0.1 M disodium hydrogenphosphate/citric acid buffer solution of pH = 4.3), and decane was investigated in detail for applications as reaction medium for the horseradish peroxidase (HRP)/hydrogen peroxide-mediated synthesis of the conductive form of polyaniline (PANI). To formulate the optimal single-phase microemulsion with the phase inversion temperature being close to room temperature, the T-γ fishlike phase diagram of the AOT/SDS-buffer-decane pseudoternary system was determined. The effects of the surfactant concentration (γ), the oil-to-water ratio (α) and the temperature (T) on the conductivity of the resulting PANI and the underlying mechanism were investigated using UV–vis-NIR, ESR and small-angle X-ray scattering (SAXS) techniques. Results show that the bicontinuous microemulsion plays a template role in the PANI biosynthesis, and the PANI conductivity also depends on the activity and stability of the solubilized HRP, which are determined by the microdomain size of the microemulsions and the reaction temperature. As far as γ is concerned, it is found that as γ increases, the microdomain size of the bicontinuous microemulsion as well as the activity of the solubilized HRP decreases significantly, leading to a great decrease of the PANI conductivity. Compared with γ, the change of α has small effect on the PANI conductivity. As the α-dependent microdomain size changes little with increasing α, the small change of the PANI conductivity should be ascribed mainly to the HRP activity. For T, over the range of 20 °C–35 °C, it has a slight effect on the microdomain size of the bicontinuous microemulsion, but it has a marked effect on the enzymatic properties of HRP. As the temperature increases, the activity of HRP increases, but its thermal stability decreases greatly. Therefore, the thermal stability of HRP is the major factor causing that the PANI conductivity decreases significantly with increasing T. The present work deepens the understanding of the template effect of anionic surfactant aggregates in the biosynthesis of conducting PANI. To the best of our knowledge, this work is the first study of the use of bicontinuous microemulsions as reaction media for the enzymatic synthesis of a conducting polymer.

Role of wetting agents and disintegrants in development of danazol nanocrystalline tablets.

Poor wetting and/or particle aggregation are the shortcomings of the dried nanocrystalline suspensions, which subsequently might hinder the superior dissolution performance of the nano-crystalline suspensions. The objective of this study was to evaluate the effect of wetting agents and disintegrants on the dissolution performance of dried nanocrystals of an active pharmaceutical ingredient (API) with poor wetting property. Danazol, a BCS Class II compound with high LogP and low polar surface area, was chosen as a model compound for this study. Danazol nanocrystalline suspension was prepared by wet-media milling and converted into powder via spray granulation either with mannitol or microcrystalline cellulose as carriers at a drug: carrier ratio of 1:9 w/w. Danazol nanocrystalline suspension showed a superior dissolution performance compared to an un-milled danazol suspension. Dried danazol nanocrystals suffered from poor wetting leading to hindered dissolution performance i.e.~40% and~15% drug dissolution within 15min for the mannitol and microcrystalline cellulose-based granules, respectively. Addition of a lipophilic surfactant (i.e. docusate sodium) at a surfactant: drug ratio of 0.015: 1 w/w during granulation helped in retaining the superior drug dissolution rates i.e. more than 80% drug dissolution within 15min for mannitol-based granules by enhancing the wettability of dried danazol nanocrystals when compared to a hydrophilic surfactant (i.e. poloxamer 188) or disintegrant (i.e. sodium starch glycolate or croscarmellose sodium). The fast-dissolving mannitol-based granules containing danazol nanocrystals and docusate sodium were compressed into a tablet dosage form. The tablets containing danazol nanocrystals with docusate sodium showed a superior dissolution performance compared to a tablet containing un-milled danazol with docusate sodium.

Tangled silver nanoparticles embedded polythiophene-functionalized multiwalled carbon nanotube nanocomposites with remarkable electrical and thermal properties

Tangled silver nanoparticles embedded layered polythiophene-functionalized multiwalled carbon nanotube ternary nanocomposite (PTCNT-COOH 300 Ag) has been prepared by ascorbic acid reduction of silver nitrate solution in presence of aqueous dispersion of polythiophene-functionalized multiwalled carbon nanotube (PTCNT-COOH) binary nanocomposites. Binary polythiophene–functionalized multiwalled carbon nanotube nanocomposites have been prepared by in-situ chemical oxidative polymerization of thiophene monomer stabilized by sodium bis(2-ethylhexyl) sulfosuccinate (AOT) micelles in presence of functionalized multiwalled carbon nanotubes (MWCNT-COOH) using ferric chloride (FeCl3) as an oxidizing agent in chloroform solvent. The structural formation and composition of binary and ternary nanocomposites have been confirmed by fourier transform infrared spectroscopy, fourier transform Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and wide angle X-ray diffraction studies. Scanning electron microscopy (SEM) studies have revealed the nanofibrous morphology in binary nanocomposites (PTCNT-COOHs), whereas in ternary nanocomposite (PTCNT-COOH 300 Ag), silver nanoparticles were densely embedded as nanoparticles over nanofibrous structure. Transmission electron microscopic (TEM) images have provided the evidence regarding silver nanoparticles that existed in a tangled state over the nanofibrous structure. Stable dispersion of binary nanocomposites (PTCNT-COOHs) in water, ethanol and chloroform enabled us to record the UV–visible absorption spectra which have shown two peaks at 260 nm and 360 nm corresponding to π-π* transition from aromatic rings and π-polaron absorption of polythiophene respectively. On the other hand, ternary nanocomposite have shown surface plasmon resonance as broad peak tailing to 550 nm. The electrical conductivity of nanocomposites PTCNT-COOH 100 (binary nanocomposite), PTCNT-COOH 200 (binary nanocomposite), PTCNT-COOH 300 (binary nanocomposite), pristine MWCNT, functionalized MWCNT-COOH, MWCNT-COOH Ag (binary nanocomposite) and PTCNT-COOH 300 Ag (ternary nanocomposite) were 4.42 × 10−2, 5.30 × 10−1, 1.64, 8.66, 2.80, 12.40 and 80.76 S/cm respectively. The enhanced electrical conductivity of ternary nanocomposite was due to the effective charge transport through polythiophene layer which act as conductive bridge between multiwalled carbon nanotube and silver nanoparticles. Thermogravimetric analysis have revealed that high thermal stability of ternary silver nanocomposite of PTCNT-COOH 300 Ag up to 620 °C for 10% weight loss. Silver nanoparticles embedded ternary nanocomposite in basic medium shows least leaching effect, therefore it could be potentially useful in catalytical applications.

Self-Assembly of Reverse Micelles to Engineer PEDOT Nanoribbons, Nanotubes, Nanorods and their High Capacitance Performances

Poly(3,4-ethylenedioxythiophene) (PEDOT) nanoribbons, nanotubes, nanorods were fabricated in a reverse microemulsion system by adjusting the ratio of sodium bis (2-ethylhexyl) sulfosuccinate (AOT) and FeCl3 aqueous solution. The morphologies and structures of nanostructured PEDOT were characterized by SEM, TEM, FTIR, XRD, and XPS. The PEDOT nanoribbons, nanotubes and nanorods can be obtained, when the volume ratio of FeCl3 aqueous solution to AOT hexane (Va/Vh) was between 2.0 × 10–2 and 3.0 × 10–2. As-obtained PEDOT nanotubes showed a high specific capacitance of 171.5 F g−1 at 0.4 A g−1, which was greater than the nanoribbons (134 F g−1) and nanorods (145.7 F g−1), respectively. Additionally, the PEDOT nanotubes exhibited excellent stability with a retention rate of 105% after 5000 cycles. This indicates that the as-prepared PEDOT nanotubes have potential applications in high capacity supercapacitors.

Complexation of Pluronic L62 (EO6)-(PO34)-(EO6)/aerosol-OT (sodium bis(2-ethylhexyl)sulfosuccinate) in aqueous solutions investigated by small angle neutron scattering.

We investigate the phase behaviours of Pluronic L62 in aqueous solution in the presence of aerosol-OT (AOT) molecules by small angle neutron scattering (SANS). The presence of AOT significantly changes the micellization phenomenon of L62 micelles in aqueous solution, including their critical micelle temperature (CMT), global size, and asphericity. The origin of these observations is attributed to the complexation between the neutral L62 surfactants and the ionic AOT molecules, which additionally provides charge to the mixed micelles: we analyse the data and extract meaningful information using the Ornstein-Zernike integral formalism. As a result, we observe that the co-micellization of L62 and AOT is very stable across a wide temperature range.

Bacterial motility enhances adhesion to oil droplets.

Adhesion of bacteria to liquid-liquid interfaces can play a role in the biodegradation of dispersed hydrocarbons and in biochemical and bioprocess engineering. Whereas thermodynamic factors underpinning adhesion are well studied, the role of bacterial activity on adhesion is less explored. Here, we show that bacterial motility enhances adhesion to surfactant-decorated oil droplets dispersed in artificial sea water. Motile Halomonas titanicae adhered to hexadecane droplets stabilized with dioctyl sodium sulfosuccinate (DOSS) more rapidly and at greater surface densities compared to nonmotile H. titanicae, whose flagellar motion was arrested through addition of a proton uncoupler. Increasing the concentration of DOSS reduced the surface density of both motile and nonmotile bacteria as a result of the reduced interfacial tension.

Synthesis of Pd−Rh Bimetallic Nanoparticles with Different Morphologies in Reverse Micelles and Characterization of Their Catalytic Properties

Synthesis of bimetallic nanoparticles (NPs) of the transition metals Rh and Pd in H2O/AOT/isooctane (where AOT is dioctyl sodium sulfosuccinate) reverse-micelle solutions (RMSs) in the presence of molecular oxygen and quercetin, a flavonoid, is described. The methods for NP synthesis used here enable us to prepare alloyed-type Rh−Pd NPs and core/shell Pd/Rh and Rh/Pd NPs with the metal molar ratio of 1 : 1. With both Rh3+ and Pd2+ ions present in an RMS simultaneously, palladium ions are reduced first, and the formed Pd NPs have an inhibitive effect on reduction of rhodium ions. The stability of a mixture of Rh and Pd NPs in RMSs is investigated, and the mixture of NPs with a mean diameter of ~2.7 nm is found to be stable for at least 25 days. Pd and Rh NP-based catalysts are prepared by absorption of the synthesized NPs on γ-Al2O3, and their catalytic activity is tested in the monomolecular hydrogen isotope exchange reaction. A synergetic effect, manifested as an enhanced catalytic activity, is observed for the catalyst prepared by adsorption of the mixture of Rh and Pd NPs on γ-Al2O3.

Electrochemical synthesis and characterizations of new nanocomposite electrodeposition on Co67Cr29W4 alloy substrate

In this study, galvanostatic electrodeposition techniques were employed for the achieved of new composite polymer: polypyrrole - sodium dioctyl sulfosuccinate/poly N-ethylaniline (PPY-AOT/PNEA) coatings on the Co67Cr29W4 alloy electrode surface. The PPYAOT/PNEA coating has been synthesized on the Co67Cr29W4 alloy electrode by galvanostatic deposition from aqueous solutions 0.1 M NEA, 0.1M PY, 0.01 M AOT and 0.5 M H2SO4 solution at various current densities (1mA/cm2 , 2mA/cm2 and 8mA/cm2 ) in different molar ratio. The sodium dioctyl sulfosuccinate (AOT) as a dopant ion used in electropolymerization process be able to a significant influence on the electrochemical activity of the composite polymer. The polymeric composite coatings were characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM) techniques. The results denoted that the electroactive behaviors of the composite polymer mainly depend on the molar ratio of monomers, the applied density current and times of electrodeposition. It has been established that the cobalt based alloy substrate had a meaningful influence on the electrochemical activity of the polypyrrole and poly(N-ethylaniline) composite films and that as in the existence of polymeric film, anodization of these modified electrodes obtained in constitution of an oxides complex film and polymeric layers together. All of the composite films were a very promising electrode material for application in supercapacitor, corrosion protection coatings or sensor employments.

High antimicrobial photodynamic activity of photosensitizer encapsulated dual-functional metallocatanionic vesicles against drug-resistant bacteria S. aureus.

Developments in the field of photodynamic therapy (PDT) are being made by investigating appropriate photosensitizers (PSs) and enhancing the penetration effect of light by developing new nano-carriers. So, to boost the PDT effect, in the present work, new metallocatanionic vesicles were fabricated by a convenient, efficient, green and inexpensive method to encapsulate PSs and evaluate their antimicrobial PDT against the drug-resistant bacterium Staphylococcus aureus. They were prepared from a combination of a double-chained copper-based cationic metallosurfactant (CuCPCII) and an anionic surfactant sodium bis(2-ethylhexyl)sulfosuccinate (Aerosol OT or AOT). The surface charge, structure and ability to encapsulate oppositely charged photosensitizers are some crucial factors that need to be controlled for their effective utilization in PDT. In this approach, two of the fractions, one each from a cationic rich and anionic rich side, were selected to encapsulate cationic (methylene blue; MB) and anionic (rose bengal (RB)) PSs after characterization by SAXS, AFM, FESEM, DLS, and zeta-potential, and conductivity measurements. Afterwards, PDT was performed on S. aureus (a multidrug-resistant bacterium) by the colony forming unit (CFU) method using PS encapsulated metallocatanionic vesicles that demonstrated high bactericidal activity by using visible light (532 nm) and facilitated the generation of singlet oxygen. The singlet oxygen generation capability of both the PSs was enhanced under irradiation when encapsulated in metallocatanionic vesicles because the presence of metal accelerated the intersystem crossing of triplet oxygen to singlet oxygen. Furthermore, these studies reveal that the metallocatanionic vesicles have dual functionality i.e. encapsulate PSs and even show dark toxicity against S. aureus. To study the killing of S. aureus, bacterial DNA was extracted and its interactions and conformational changes in the presence of metallocatanionic vesicles were analyzed via., UV-Visible, and circular dichroism (CD) spectroscopy. Comet assay (single-cell gel-electrophoresis) demonstrated the DNA damage after PDT treatment in an individual cell. The bacterial DNA damage was more with the metallosurfactant rich 70 : 30 fraction than with the 30 : 70 fraction, in combination with RB under irradiation. This work provides a new metal hybrid smart material that possesses dual functionality and is prepared by an easy, economical and feasible procedure which resulted in enhanced PDT against a drug-resistant bacterium, thus, providing an alternative for antibacterial therapy.

Response surface optimization of the forward extraction of jacalin from jackfruit seeds using AOT/isooctane reverse micellar system

Jacalin is the major protein contained in the crude extract of jackfruit (Artocarpus heterophyllus) seed that specifically recognizes and binds reversibly to galactose. Conventionally, purification of jacalin is carried out using the tedious and costly chromatographic techniques. In this study, extraction of jacalin from jackfruit seed crude extract were done using the sodium bis(2-ethylhexyl) sulfosuccinate (AOT)-based reverse micellar system. Reverse micellar extraction is an attractive alternative for downstream processing of various proteins. A successful reverse micellar extraction consists of two basic steps: forward and backward extraction. Forward extraction transfers a target protein from an aqueous solution into the reverse micellar solution, while backward extraction releases the protein from the reverse micelles structure into a new aqueous solution. The effects of the aqueous phase pH, NaCl concentration and AOT concentration on the forward extraction efficiency (FEE) are investigated using the response surface methodology (Box-Behnken Design). The main effects and interactions of the parameters are analyzed through the 3D surface plots. The optimum conditions for forward extraction were determined as follows: aqueous phase pH 4.58, 125 mM NaCl and 40 mM AOT. Under the optimal conditions, the FEE reached 88.04±1.30%, closer to 87.99% predicted by the model. The results indicated that AOT/isooctane reverse micelle system is effective in extracting jacalin from the jackfruit seed crude extract and verified the practicability of the BBD model for optimizing the main parameters in the forward extraction of jacalin.

Can the rectal size of prostate patients at MRI be used as a predictor of rectal size at CT for patients referred for radiotherapy planning?

Keywords: Prostate cancer, computed tomography, magnetic resonance Introduction: To audit the dynamic interrelationship between rectal distension at diagnosis magnetic resonance (MRI) scan with the computed tomography (CT) radiotherapy planning scan; to determine the effect of rectal movement on the position of the prostatic gland. This review will examine the efficacy of rectal preparation. At present rectal distension at RT CT planning scan is assessed on control slices using GSTT protocol prior to having a full CT scan. If this is outside tolerance a repeat CT scan appointment whereby the patient is given an enema. If rectal size can be predicted prior to the CT planning scan, bowl preparation can be pre-empted to ensure efficiencies in the patient pathway. Method: A retrospective audit looking at the MRI diagnostic scans and radiotherapy CT planning scans of 141 patients with adenocarcinoma of the prostate between May to August 2019. To find out if rectal size at MRI serves as an indicator of rectal size at planning RT CT. Dependent on the outcome of the retrospective study, a prospective study will then be undertaken to assess if an intervention prior to RT CT scan such as a prescription of Docusate Sodium enema help resolve the issue of rectal size at planning. Results: Results pending. Conclusions & Discussion: The outcome should inform clinical practice, benefit patients and clinicians and provision of service. The audit may result in reduction of rebooking patients for repeat CT scan and cease the delay of treatment processes. Numerical

Получение стабилизированных наночастиц серебра и изучение их антимикробной и цитотоксической активности в отношении клеток гепатомы человека линии HepG2

Синтезированы наночастицы серебра с использованием для их восстановления и стабилизации арабиногалактана и диоктилсульфосукцината натрия. Средний гидродинамический размер наночастиц, определенный по данным фотонной корреляционной спектроскопии, составлял 30 нм, дзета-потенциал –34.04 ± 1.54 мВ. По данным метода электронной дифракции серебро в образце золя находится в металлической форме. Препарат наночастиц серебра проявлял антибактериальную активность в отношении условно-патогенных грамотрицательных (Escherichia coli) и грамположительных (Bacillus subtilis и B. coagulans) бактерий. Наночастицы серебра также обладали антифунгальной активностью в отношении штаммов фитопатогенных грибов рода Fusarium sporotrichioides и F. solani. Проведено исследование цитотоксической активности наночастиц серебра в отношении клеток гепатомы печени человека линии HepG2. Продемонстрировано ингибирующее действие наночастиц серебра в отношении метаболической активности и жизнеспособности опухолевых клеток. Средние относительные значения EC50 для наночастиц серебра составляли 1.5 ± 0.4 и 41.2 ± 3.9 мкг/мл. Препарат стабилизированных наночастиц серебра может найти применение в медицине в качестве потенциального антимикробного и противоопухолевого средства, а также в сельском хозяйстве в качестве средства подавления роста фитопатогенных грибов.

Non-Equilibrium Mass Exchange in AOT Reverse Micelles.

Reverse micelles (RMs) composed of water and sodium bis(2-ethylhexyl)sulfosuccinate (AOT) in isooctane have a remarkably narrow size distribution around a mean value determined by the water loading ratio of the system. It has been proposed that RMs establish this equilibrium size distribution either by the diffusion of individual components through the isooctane phase or by cycles of fusion and fission. To examine these mechanisms, a 24 μs all-atom molecular dynamics simulation of a system containing one small RM and one large RM was performed. Results show that the net movement of water from the small RM to the large RM occurred in a direction that made the small RM smaller and the large RM larger-according to water loading ratios that would have been appropriate for their size. Changes in AOT number that would bring the water loading ratio of each RM closer to that of the overall system only occurred via cycles of RM fusion and fission. These behaviors are most likely driven by the electrostatics of sodium AOT and the dielectric effects of water.