Changes In Tension Research Articles

A thermodynamic framework for bulk–surface partitioning in finite-volume mixed organic–inorganic aerosol particles and cloud droplets

Abstract. Atmospheric aerosol particles and their interactions with clouds are among the largest sources of uncertainty in global climate modeling. Aerosol particles in the ultrafine size range with diameters less than 100 nm have very high surface-area-to-volume ratios, with a substantial fraction of molecules occupying the air–droplet interface. The partitioning of surface-active species between the interior bulk of a droplet and the interface with the surrounding air plays a large role in the physicochemical properties of a particle and in the activation of ultrafine particles, especially those of less than 50 nm diameter, into cloud droplets. In this work, a novel and thermodynamically rigorous treatment of bulk–surface equilibrium partitioning is developed through the use of a framework based on the Aerosol Inorganic–Organic Mixtures Functional groups Activity Coefficients (AIOMFAC) model in combination with a finite-depth Guggenheim interface region on spherical, finite-volume droplets. We outline our numerical implementation of the resulting modified Butler equation, including accounting for challenging extreme cases when certain compounds have very limited solubility in either the surface or the bulk phase. This model, which uses a single, physically constrained interface thickness parameter, is capable of predicting the size-dependent surface tension of complex multicomponent solutions containing organic and inorganic species. We explore the impacts of coupled surface tension changes and changes in bulk–surface partitioning coefficients for aerosol particles ranging in diameters from several micrometers to as small as 10 nm and across atmospherically relevant relative humidity ranges. The treatment of bulk–surface equilibrium leads to deviations from classical cloud droplet activation behavior as modeled by simplified treatments of the Köhler equation that do not account for bulk–surface partitioning. The treatments for bulk–surface partitioning laid out in this work, when applied to the Köhler equation, are in agreement with measured critical supersaturations of a range of different systems. However, we also find that challenges remain in accurately modeling the growth behavior of certain systems containing small dicarboxylic acids, especially in a predictive manner. Furthermore, it was determined that the thickness of the interfacial phase is a sensitive parameter in this treatment; however, constraining it to a meaningful range allows for predictive modeling of aerosol particle activation into cloud droplets, including cases with consideration of co-condensation of semivolatile organics.

Inhibition of asphaltene deposition by Al2O3 nanoparticles during CO2 injection

Carbon dioxide flooding is of interest due to its high oil-sweep efficiency for enhanced oil recovery and contribution to the reduction of greenhouse gas emissions. However, when CO2 is injected into deep geological strata, asphaltene may precipitate. In this work, the effect of Al2O3 nanoparticles on the deposition of asphaltene was examined by assessing the variations of bond number and interfacial tension at different pressures and a temperature of 60 °C. The asphaltene onset point and intensity were characterized using the bond number, which proved a better indicator of changes in oil droplet shape and interfacial tension with gravity. Synthesized mixtures of toluene and n-heptane that contained two different kinds of asphaltenes were used as M and D oil samples. A 0.06 mass% addition of Al2O3 nanoparticles, which worked best for reduction of interfacial tension, was also applied at various pressures. Addition of nanoparticles to the oils prevented asphaltene precipitation in both synthetic samples by altering the slope of the plot of interfacial tension with pressure by 49.7% for the M sample and 9.0% for the D sample. The Al2O3 nanoparticles were found to be more effective at inhibiting asphaltene precipitation for the M oil sample due to its lower H/C ratio and higher nitrogen content.

Feedback Control of Electrospray with and without an External Liquid Pump Using the Spray Current and the Apex Angle of a Taylor Cone for ESI-MS.

An electrospray operated in the steady cone-jet mode is highly stable but the operating state can shift to pulsation or multijet modes owing to changes in flow rate, surface tension, and electrostatic variables. Here, a simple feedback control system was developed using the spray current and the apex angle of a Taylor cone to determine the error signal for correcting the emitter voltage. The system was applied to lock the cone-jet mode operation against external perturbations. For a pump-driven electrospray at a regulated flow rate, the apex angle of the Taylor cone decreased with increasing voltage. In contrast, for a voltage-driven electrospray with low flow resistance, the angle was found to increase with the emitter voltage. A simple algorithm based on iterative learning control was formulated and implemented using a personal computer to automatically correct the emitter voltage in response to the error signal. For voltage-driven electrospray ionization (ESI), the feedback control of the spray current can also be used to regulate the flow rate to an arbitrary value or pattern. Electrospray ionization-mass spectrometry (ESI-MS) with feedback control was demonstrated to produce ion signal acquisition with long-term stability that was insusceptible to the emulated external disturbances.

Effects of static magnetic field on the surface tension of surfactant solutions

AbstractThe magnetic field (MF) effects resulting from water or solution treatments are still of significant interest. However, a relatively small number of papers have been published dealing with the pure surfactant solutions alone. On the other hand, surfactants are applied in many industrial processes as well as in everyday life and are also present in different waste waters. Therefore, it seemed interesting to investigate whether some effects would appear after the MF treatment of pure aqueous surfactant solutions. In the earlier published papers after MF action the changes in water evaporation rate and the surface tension were found for both the cationic dodecyltrimethylammonium bromide (DTAB) and anionic sodium dodecyl sulfate (SDS) solutions. The gradient MF originated from three connected ring magnets inside which the solutions were placed. The objective of this paper is to study whether using the same magnets but in a different position the effects of the MF are observed. The given surfactant solution in a closed vessel was placed in an uniform MF when the magnets were in the “lying” position. The investigated solutions on the magnet surface remained for 24 h. In this paper, despite SDS and DTAB also the cationic hexadecyltrimethylammonium bromide (CTAB) and nonionic Triton X‐100 solutions were applied. It appeared that in the uniform MF the surface tension of cationic and anionic surfactant solutions changes. However, larger changes were observed in the gradient MF. Generally, the changes of surface tension depend on the surfactant kind and its concentration. Stronger MF influence was found for the cationic surfactant and almost no changes were observed for nonionic Triton X‐100.

Ultrasound Shear Wave Elastography Quantitatively Assesses Tension Changes of Supraspinous/Interspinous Ligament Complex Under Varied Loads.

Although interspinous and supraspinous ligaments of the lumbar spine are thought to contribute to spinal stability, little is known about their dynamic biomechanics. We demonstrate that shear wave elastography (SWE) offers a novel technique to noninvasively and quantitatively evaluate posterior spinous ligament complex functional loading and stiffness in different physiologic positions. We performed SWE and measured the length of the interspinous/supraspinous ligament complex in cadaveric torsos (N = 5), isolated ligaments (N = 10), and healthy volunteers (N = 9) to obtain length and shear wave velocity measurements. For cadavers and volunteers, SWE was utilized in 2 lumbar positions: lumbar spine flexion and extension. In addition, SWE was performed on isolated ligaments undergoing uniaxial tension to correlate shear wave velocities with experienced load. Average shear wave velocity in cadaveric supraspinous/interspinous ligament complexes increased for lumbar levels (23%-43%) and most thoracic levels (0%-50%). This corresponded to an average increase in interspinous distance from extension to flexion for the lumbar spine (19%-63%) and thoracic spine (3%-8%). Volunteer spines also demonstrated an average increase in shear wave velocity from extension to flexion for both the lumbar spine (195% at L2-L3 to 200% at L4-L5) and thoracic spine (31% at T10-T11). There was an average increase in interspinous distance from extension to flexion for the lumbar spine (93% at L2-L3 to 127% at L4-L5) and thoracic spine (11% at T10-T11). In isolated ligaments, there was a positive correlation between applied tensile load and average shear wave velocity. This study creates a foundation to apply SWE as a noninvasive tool for assessing the mechanical stiffness of posterior ligamentous structures and has potential applications in augmenting or evaluating these ligaments in patients with spine pathology. The interspinous and supraspinous ligaments are critical soft tissue supports of the posterior lumbar spine. Disruption of these structures is thought to have a negative impact on spinal stability in trauma and spine deformities.

Synthesis of Ag-modified ZnO/MWCNT nanoparticles and their application as a catalyst in the degradation of methylene blue

Ag-ZnO/MWCNT composites were obtained by microwave-assisted, varying-charge synthesis of multiwalled carbon nanotubes (MWCNT). The structural, morphological and optical properties were characterized by: XRD, SEM, TEM, Physisorption of N2 and UVVis. The incorporation of Ag ions and MWNTC caused changes in the structure tension and in the average crystallite size of ZnO. The micrographs revealed that ZnO agglomerates were distributed on the MWNTC and that Ag particles were deposited on the surface of the heterostructure, thus the energy gap decreased. The percentages of degradation of methylene blue were 98 and 75% under ultraviolet and visible radiation, respectively, in the Ag-ZnO/CNT composites.

Diurnal changes in apoplast bypass flow of water and ions in salt-stressed wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.).

The aim of the present study was to quantify the contribution of apoplastic bypass flow to the uptake of water and salt across the root cylinder of wheat and barley during day and night. Plants were grown on hydroponics until they were 14-17d old and then analysed over a single day (16h) or night (8h) period while being exposed to different concentrations of NaCl (50, 100, 150 and 200 mM NaCl). Exposure to salt started just before the experiment (short-term stress) or had started 6d before (longer-term stress). Bypass flow was quantified using the apoplastic tracer dye 8-hydroxy-1,3,6-pyrenesulphonic acid (PTS). The percent contribution of bypass flow to root water uptake increased in response to salt stress and during the night and amounted to up to 4.4%. Bypass flow across the root cylinder of Na+ and Cl- made up 2-12% of the net delivery of these ions to the shoot; this percentage changed little (wheat) or decreased (barley) during the night. Changes in the contribution of bypass flow to the net uptake of water, Na+ and Cl- in response to salt stress and day/night are the combined result of changes in xylem tension, the contribution of alternative cell-to-cell flow path and the requirement to generate xylem osmotic pressure. This article is protected by copyright. All rights reserved.

Impacting Factors of Changes in Dynamic Viscosity and Interfacial Tension of Wood Xylem Sap

The growth of trees is inseparable from the water transpiration in the xylem. To explore the mechanism of sap rising in the xylem, the monthly variation of the dynamic viscosity and interfacial tension of the xylem sap of different tree species and their impacting factors were analyzed. In this experiment, the dynamic viscosity and interfacial tension of the xylem sap of poplar and metasequoia were measured within one year, as well as the sap velocity of poplar. Gas chromatography–mass spectrometry and atomic absorption spectroscopy were used to detect the organic components and inorganic cations of the xylem sap of poplar and metasequoia. By analyzing the influence of organic components and the inorganic cation concentration of xylem sap on the dynamic viscosity and interfacial tension of xylem sap, this study revealed that the dynamic viscosity and the interfacial tension of poplar and metasequoia samples in different months changed in basically the same manner. However, the dynamic viscosity and the interfacial tension of the metasequoia samples were generally higher than those of the poplar samples. The dynamic viscosity of the xylem sap had an obvious exponential relationship with temperature, while the interfacial tension of the xylem sap had an inconspicuous linear relationship with temperature. In addition, disparate xylem structures of the broad-leaved tree poplar and the coniferous tree metasequoia led to different concentrations of organic components and inorganic cations in their xylem sap, which made a difference in the dynamic viscosity and interfacial tension between poplar and metasequoia samples.

A novel and noninvasive approach to study the shear rheology of complex fluid interfaces

Surfactants at gas-liquid and liquid-liquid interfaces have profound effects on interfacial stresses that strongly influence flow in bulk phases in contact with the interface. These effects include changes in interfacial tension and the development of extra stresses that arise when the interface is deformed. Surfactants are important in nature, biological function, and numerous technologies. Understanding interfacial rheology is critical to the development of improved surfactants for these important applications. Here, we propose a novel and noninvasive technique for the investigation of interfacial rheological behavior in shear deformations. In recent years, several techniques for such measurements have been developed and utilized to study a wide range of surfactant systems. However, existing techniques may inherently be invasive making it difficult to isolate the intrinsic interfacial rheological behavior from disturbances to the interface caused by the measurement itself. The proposed technique is indirect in that it does not require the introduction of a probe to deform the interface making it noninvasive. The viability of the technique is demonstrated through comprehensive fluid dynamics modeling of the flow involving a gas-liquid interface with different rheological behaviors.

Модернизация системы обеспечения устойчивости железнодорожного крана КЖ-971 и оценка её эффективности

The weight of the load hanging on the boom of a railroad hydraulic crane KZH-971 creates a load moment that bends the crane slewing ring. To partially balance the load moment, a stationary counterweight is installed on the crane, rigidly fixed on a slewing platform. With an increase in the boom departure, the unbalanced part of the load moment and tensions in the slewing ring increases. In this article, to ensure a constant value of the unbalanced part of the load moment and reduce bending tensions, it is proposed to install a counterweight on the railroad crane with a telescoping system and the ability to rotate about the vertical axis for a work in cramped conditions. A strength analysis of the slewing ring for the change in maximum tensions from the use of a movable counterweight was carried out. An adaptive control system for the position of a movable counterweight has been modeled, with the help of which it will be possible to develop a device for convenient control from the crane operator’s cabin in the future. The advantages of using a movable counter-weight with the possibility of rotation relative the vertical axis are shown when performing loading and repair work in cramped conditions. The results of the strength analysis of the slewing ring with the location of loads in the main working positions are summarized.

Surface plasmon resonance imaging for analyzing the local variation of evaporation flux of multiple binary mixture droplets

This study investigates the local variation of concentration and selective evaporation flux affected by the droplet-to-droplet distance during the evaporation of multiple-binary mixture droplets (M-BMDs). Surface plasmon resonance imaging (SPRi) is used to measure the local liquid concentration of the binary mixture droplets and to analyze the spatial distributions of liquid concentration with the estimated local changes of surface tension during evaporation. In addition, we conduct three-dimensional numerical simulations to predict the ethanol vapor distributions and the local ethanol evaporation flux for single- and multiple-binary mixture droplets. It was found that the total evaporation time of M-BMDs is delayed due to vapor accumulation in the region adjacent to the neighboring droplets for M-BMDs, which significantly reduces the local evaporation flux. Also, the local liquid concentration of M-BMDs was found to vary, showing a lower ethanol concentration far away from the adjacent region due to vapor shielding and selective evaporation. Moreover, the scaled lifetime, which is the ratio of evaporation time between multiple droplets and a single droplet, shows good agreement with the previously reported experiments and theoretical models.

Silicon electrodeposition from the KF-KCl-K<sub>2</sub>SiF<sub>6</sub> and KF-KCl-KI-K<sub>2</sub>SiF<sub>6</sub> melts

Silicon and silicon-based materials find extensive applications in metallurgy, microelectronics, and other emerging industries. The field of use of synthesized silicon varies based on its morphology and purity. This study employs voltammetry, galvanostatic electrolysis, and scanning electron microscopy to examine the impact of KI surfactant (in mol %) to 66.5KF–33.3KCl–0.23K2SiF6 melt at 750°C on the electrowinning kinetics of silicon ions and the morphology of silicon deposits formed on a glassy carbon electrode. The findings demonstrate that the addition of potassium iodide to the KF–KCl–K2SiF6 melt at a concentration of 2 mol % induces changes in interfacial tension at the boundary between the glassy carbon, melt, and atmosphere. Consequently, the wetting of the glassy carbon with the melt decreases, leading to a reduction in the actual working surface area and, consequently, a decrease in cathode current while maintaining current density. Taking into account this effect and employing an algebraic estimation of the influence of the melt meniscus shape, it is postulated that the addition of KI does not significantly affect the kinetics of the cathode process. Nevertheless, the impact of KI addition on the morphology of electrodeposited silicon is mentioned. During the electrolysis of the KF–KCl–K2SiF6 melt, fibrous silicon deposits with arbitrary shapes are formed on the glassy carbon electrode, whereas the addition of 2 and 4 mol % of potassium iodide to the melt leads to the agglomeration and smoothing of silicon deposits under the same electrolysis conditions (cathode current density: 0.02 A/cm2, electrolysis duration: 2 h). The obtained results indicate the potential to manipulate the morphology of electrodeposited silicon for specific applications in various fields.

Adopted Coping Strategies among Professionals in Stress Management- A Questionnaire Based Survey

Background: Stress may affects professionals’ health and their professional performance. In present era of globalization where competition, novelty and change is a contributing factor in stress development and stimuli for tension, anxiety anger and behavioral changes ultimately lead to health problems. Coping strategies are then adopted to manage these stresses. Aim: To uncover the level of stress, the major responses in regards to the imposed stress and ultimately to inquire the adopted strategies to cope with stressful situation in professionalism. Methods: Thismulticenter crossestional survey was conducted among 257 participants of different level professions of different institute and departments of Grand Asian University (formerly Islam medical & dental college) from June – August 2021 and at Jinnah Sindh medical University (JSMU) from Feb – April 2022. Stress causes and major responses were accessed by well-structured preexisting validated questionnaires (consent taken by mail). Sociodemograpic variables were taken using self-generated questionnaire comprising question about age, sex, education level, financial status, job level and marital status. Aim: To access the adopted coping strategies by the professional in stress management in their professional tasks Results:Major respondents of study (58.2%) were female followed by male (41.8%) , 82% with age group 20 -35 years old, 38.7% were married, 47.7% from joint family system, 52.3% were graduated, 83.2% with less than 100,000 PKR income per month. The major cause of stress was No recreational activity (32%), Frequent travelling (36.3%), Working on holidays (14.5%), Complications from children (22.7%) and for disorganization or misfiring of system (23.8%).Major responses to stress including unable to recall things (34.4%), Unable to express their feeling with their social circle (30.1%), unable to focus on their job related tasks (24.2%). abdominal pain (23.8%), usually feel stressed (23.8%) and get disappointed (19.5%). Practical implication: Although the findings of coping strategies in this study is emotional based coping which is considered the weak one and these findings reveals that stress among professionals is not much addressed which potentially placed hindrances in outcomes thus the organizational policy makers are suggested to make these consideration for better outcome and potential benefits of the professionals and organization to excel outcome and reduce health hazards. Conclusion: This research revealed that professionals were actively involved in emotional focused coping strategies and typically indicates adoptive coping mechanisms. Keywords: Stress, coping, strategies, job level, social support, health problems

Robust Adaptive Backstepping Motion Control of Underwater Cable-Driven Parallel Mechanism Using Improved Linear Model Predictive Control

This paper proposes a novel motion-tracking control methodology for an underwater cable-driven parallel mechanism (CDPM) that achieves calculation of dynamic tension constraint values, tension planning, parameter linearization, and motion tracking. The control objective is divided into three sub-objectives: motion tracking, horizontal displacement suppression, and cable-tension restriction. A linear model predictive control (LMPC) method is designed to plan cable tensions for motion-tracking and displacement suppression. The robust adaptive backstepping controller converts cable tension into winch speed based on the joint-space method and command filtering. Moreover, the X−swapping method is used to linearize and identify the time−varying nonlinear parameters. An essential prerequisite for restricting cable tension is to obtain cable-tension constraint values. A novel dynamic minimum tension control (DMTC) method, based on the equivalent control concept, is proposed for this aim. The DMTC can adaptively obtain the lower cable-tension threshold through the platform posture and motion status, anchor distribution position, and cable integrity status. Compared to traditional fixed tension constraint values, DMTC can more effectively cope with sudden changes in cable tension than fixed tension constraints. Finally, several simulations are carried out to verify the effectiveness and robustness of the proposed approach.

Preliminary experience of an international orthopaedic registry: The ESSKA Paediatric Anterior Cruciate Ligament Initiative (PAMI) registry

To evaluate the effect of preconditioning according to intraoperative workflow on initial tension and elongation behavior for femoral adjustable loop devices (ALDs) and closed loop devices (CLDs) in suspensory anterior cruciate ligament reconstruction (ACLR) with tibial screw fixation in a biomechanical in vitro study.Three ACLR groups with tibial screw fixation were biomechanically tested in a full-construct setup using porcine tibias. Groups (n = 8 per group) varied by femoral fixation method and consisted of a CLD (group 3) and ALD fixation with (group 2) and without simulated intraoperative preconditioning (group 1). The change in tension after screw insertion and the displacement to restore the initial loading situation were measured. Grafts underwent dynamic cycling (1,000 cycles at 0.75 Hz) using both a position and a force control mode.Data are presented as mean [standard deviation]. Placement of an interference screw induced a graft tension loss of 62% (49.4 [0.4] N vs 19.0 [10.0] N, P < .001) by introducing a laxity of 0.53 [0.26] mm. Intraoperative preconditioning led to a higher initial load level (228.3 [19.8] N) compared with unconditioned ALD (156.1 [25.5] N, P < .001) and CLD groups (156.6 [12.8] N, P < .001) with less force decrease over position-controlled cyclic loading. Furthermore, initial (−0.22 [0.16] mm) and dynamic elongation (0.88 [0.23] mm) were reduced compared with the unconditioned ALD (0.65 [0.35] mm, P < .001; and 1.56 [0.19] mm, P < .001) and CLD groups (0.16 [0.26] mm, P < .001; and 1.64 [0.24] mm, P < .001).ACLR with femoral ALD fixation and intraoperative preconditioning allows for restoration of time-zero screw-imparted slack and leads to significantly reduced cyclic elongation in accordance with native ACL function. Both ALD and CLD control groups behaved similarly, with total elongation less than 3 mm including time-zero slack.Although the clinical relevance of time-zero graft tension loss is uncertain, the use of an ALD in concert with tibial screw fixation may be favorable to allow for tension optimization.

Optimal control of the belt conveyor as part of the technological process of ore mass transportation by controlling the belt tension

Optimum control of the conveyor in the transport flow due to the change of the belt tension is proposed in order to reduce the costs of transporting goods by increasing the life of the belt and reducing energy consumption costs. It is suggested to use tape tension control to eliminate the accidental slippage of the tape on the drum and its excessive abrasion during the transportation of the ore mass. To implement the control method being developed, it is necessary to use a mathe-matical model with distributed parameters, on the basis of which an optimal control model will be formed using the control principles considered in the work. Control of this kind of objects is determined by the technological need to compen-sate for the slippage of the belt on the drive drum of the conveyor, which is based on the process of transmission of motion using friction, and is implemented by changing the thermal field on the arc of the girth by changing the tension of the conveyor belt or the speed of rotation of the drum. Thus, from the point of view of the theory of control of systems with distributed pa-rameters, in the process of controlling the thermal field of the drive drum and belt, the controlled coordinate is the temperature or its distribution on the girth arc. As a result of a change in the circumferential force on the drive drum, the pressure of the tape on the lining of the drum changes, which leads to a change in the value of the heat flow both in terms of amplitude and spatial distribution (the value of the working sliding arc changes, i.e. the area of elastic interaction), which is compensated by con-trolling the tension ribbons

Mechanics of leukemic T-cell.

Cell mechanics is a factor that determines cell growth, migration, proliferation, or differentiation, as well as trafficking inside the cytoplasm and organization of organelles. Knowledge about cell mechanics is critical to gaining insight into these biological processes. Here, we used atomic force microscopy to examine the elasticity, an important parameter of cell mechanics, of non-adherent Jurkat leukemic T-cells in both interphase and mitotic phases. We found that the elasticity of an individual cell does not significantly change at interphase. When a cell starts to divide, its elasticity increases in the transition from metaphase to telophase during normal division while the cell is stiffened right after it enters mitosis during abnormal division. At the end of the division, the cell elasticity gradually returned to the value of the mother cell. These changes may originate from the changes in cell surface tension during modulating actomyosin at the cleavage furrow, redistributing cell organelles, and constricting the contractile ring to sever mother cell to form daughters. The difference in elasticity patterns suggests that there is a discrepancy in the redistribution of the cell organelles during normal and abnormal division.

Essential oil of Sicilian Prangos ferulacea (L.) Lindl. and its major component, β−ocimen, affect contractility in rat small and large intestine

Ethnopharmacological relevancePrangos ferulacea (L.) Lindl is an Apiaceae plant, widely used in traditional medicine. Recently, chemical composition and biological activities of its essential oil (Prangroil) have been reported, but there are no studies on possible effects on intestinal contractility. Aims of the studyWe investigated the effects of essential oil Sicilian Prangoil on the contractility of rat small (duodenum) and large (colon) intestine and the related action mechanism. Materials and methodsResponses to Prangoil and to its major component β−ocimen in intestinal segments were assessed in vitro as changes in isometric tension. ResultsPrangoil, induced in duodenum, depending upon doses, contraction and/or muscular relaxation. Instead, in colon Prangoil only reduced the phasic contractions and induced muscular relaxation. β−ocimen, in both segments, produced only reduction of the spontaneous contractions without affecting basal tone. Prangoil contractile effects were abolished by ω-conotoxin, neural N-type Ca2+ channels blocker, atropine, muscarinic receptor antagonist, neostigmine, acetylcholinesterase (AChE) inhibitor, suggesting that Prangoil-induced contraction would be the result of an increase in neuronal cholinergic activity. Prangoil and β−ocimen inhibitory effects were unaffected by ω−conotoxin, L-NAME, blocker of the NO synthase, ODQ, soluble guanylate cyclase inhibitor, excluding involvement of neurotransmitter release or NO synthesis in the inhibitory effects. Potassium channel blocker did not affect Prangoil or β-ocimen inhibitory responses. Prangoil or β-ocimen inhibited the Ca2+ and high-KCl solution -induced contractions and the Carbachol-induced contractions in calcium free solution. ConclusionPrangoil affects the contractility of small and large intestine in rat, with regional differences, via potentiation of neural cholinergic activity, blockade of L-type voltage-gated calcium channel and reduction of Ca2+ release from the intracellular store. The Prangroil main components, β−ocimen, contributes to the inhibitory effects.

Synthesis and Enhanced Oil Recovery Potential of the Bio-Nano-Oil Displacement System.

Nanoparticles (NPs) have attracted great attention in the tertiary oil recovery process due to their unique properties. As an economical and efficient green synthesis method, biosynthesized nanoparticles have the advantages of low toxicity, fast preparation, and high yield. In this study, with the theme of biotechnology, for the first time, the bio-nanoparticles reduced by iron-reducing bacteria were compounded with the biosurfactant produced by Bacillus to form a stable bio-nano flooding system, revealing the oil flooding mechanism and enhanced oil recovery (EOR) potential of the bio-nano flooding system. The interfacial properties of the bio-nano-oil displacement system were studied by interfacial tension and wettability change experiments. The enhanced oil recovery potential of the bio-nano-oil displacement agent was measured by microscopic oil displacement experiments and core flooding experiments. The bio-nano-oil displacement system with different nanoparticle concentrations can form a stable dispersion system. The oil-water interfacial tension and contact angle decreased with the increase in concentration of the bio-nano flooding system, which also has a high salt tolerance. Microscopic oil displacement experiments proved the efficient oil displacement of the bio-nano-oil displacement system and revealed its main oil displacement mechanism. The effects of concentration and temperature on the recovery of the nano-biological flooding system were investigated by core displacement experiments. The results showed that the recovery rate increased from 4.53 to 15.26% with the increase of the concentration of the system. The optimum experimental temperature was 60 °C, and the maximum recovery rate was 15.63%.

Understanding the role of ZO-1 in cell phenotype and gene expression through myosin inhibition

Zonula occludens-1 (ZO-1) is a tight junction protein contributing to junctional formation as well as mediating interactions with junctional proteins and the actomyosin cytoskeleton. To investigate the role of ZO-1, Madin-Darby canine kidney (MDCK) II knockout cells lacking ZO-1 were created utilizing a CRISPR gene editing platform. These ZO-1 KO cells display characteristic phenotypic changes including actin accumulation and junction linearization. We evaluated membrane tension and found ZO-1 loss leads to increased membrane tension and nuclear density. We hypothesized that due changes in cytoskeletal organization and membrane tension the ZO-1 KO cells would spread less following plating. It is suspected that phenotypic changes related to actin accumulation may be the result of myosin dysregulation in the absence of ZO-1. ZO-1 KO cells that are exposed to blebbistatin, a myosin II inhibitor, resemble wild type cells in cell height and junction linearization. RNAseq and qRT-PCR were used to investigate gene expression changes related to ZO-1 loss to further interrogate ZO-1’s role in regulating membrane tension. This study highlights and expands our understanding of how ZO-1 regulates the mechanical properties of epithelial cells. Trinity University, Mach Research Fellowship This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.