Changes In Tension Research Articles

Acute oxygen sensing by vascular smooth muscle cells.

An adequate supply of oxygen (O2) is essential for most life forms on earth, making the delivery of appropriate levels of O2 to tissues a fundamental physiological challenge. When O2 levels in the alveoli and/or blood are low, compensatory adaptive reflexes are produced that increase the uptake of O2 and its distribution to tissues within a few seconds. This paper analyzes the most important acute vasomotor responses to lack of O2 (hypoxia): hypoxic pulmonary vasoconstriction (HPV) and hypoxic vasodilation (HVD). HPV affects distal pulmonary (resistance) arteries, with its homeostatic role being to divert blood to well ventilated alveoli to thereby optimize the ventilation/perfusion ratio. HVD is produced in most systemic arteries, in particular in the skeletal muscle, coronary, and cerebral circulations, to increase blood supply to poorly oxygenated tissues. Although vasomotor responses to hypoxia are modulated by endothelial factors and autonomic innervation, it is well established that arterial smooth muscle cells contain an acute O2 sensing system capable of detecting changes in O2 tension and to signal membrane ion channels, which in turn regulate cytosolic Ca2+ levels and myocyte contraction. Here, we summarize current knowledge on the nature of O2 sensing and signaling systems underlying acute vasomotor responses to hypoxia. We also discuss similarities and differences existing in O2 sensors and effectors in the various arterial territories.

Experimental and computational investigation into hydrodynamic and heat transfer characteristics of subcooled flow boiling on the International Space Station

This study is part of a long-term initiative to investigate flow boiling of n-perfluorohexane (n-PFH) under microgravity on the International Space Station (ISS). Investigated are data received from the ISS during 2022 using the Flow Boiling and Condensation Experiment (FBCE) (actual name of experimental payload). FBCE is designed to accommodate one of two test modules, one for flow boiling and another for condensation. Data for the present study are acquired using FBCE's Flow Boiling Module (FBM), which features a rectangular channel of 5.0-mm height, 2.5-mm width, and 114.6-mm heated length. Examined are results for three different mass velocities of 199.9, 799.9, and 2399.9 kg/m2.s, and heat fluxes corresponding to approximately 20, 40, and 60% of critical heat flux (CHF). Detailed development of the interfacial behavior is captured by high-speed video through the channel's transparent sidewalls. In the Computational Fluid Dynamics (CFD) model, numerical solver is constructed in ANSYS-Fluent wherein the multiphase model is combined with appropriate models for turbulence, surface tension, and interfacial phase change. Also incorporated are momentum source terms governing bubble shear-lift, bubble drag, and bubble dispersion. Accuracy of the CFD predictions is assessed by comparison against both the heat transfer data and video-captured interfacial behavior. Very good agreement is achieved against measured axial profile of heated wall temperatures and further validated by accurately capturing such interfacial features as bubble formation, detachment, coalescence, and downstream wavy vapor layer development. Additionally, the CFD simulations enable prediction of other transport parameters vitally important to understanding evolution of the boiling flow but not possible from experiment, such as cross-sectional profiles of void fraction, fluid velocity, and mixture temperature.

Composite wheat-amaranth flour baking properties and bread freshness

The study has reviled the benefits of amaranth groat flour application into wheat bread making towards enhancing the technological efficiency and the quality of the bread, prolonging the freshness of the product without artificial improvers involved in the formulations. Paying attention to textural characteristics of the wheat-amaranth bread during its shelf-life, amaranth groat flour as a derived product of amaranth grain processing presented a positive impact on the change of textural properties of the bread crumb during wheat-amaranth bread shelf-life. The effect of ranging 5–30% substitution of common wheat high-grade flour by the amaranth flour derived from partially defatted amaranth grain was investigated and the complex organoleptic quality of the bread made of the composite flour reached the highest level at 15% of the amaranth flour in the formulation. The technological parameters of bread making such as the duration of proofing, shape stability, specific volume, crumb porosity, baking and drying losses, when wheat high-grade flour was partially replaced by the amaranth grain-derived milling product showed better performance for the bread enriched by the amaranth flour at higher substitution level approving the wider application of the pseudocereal flour in the food industry. The freshness of the bread made of the composite flour is related to the textural characteristics of the crumb which tend to change drastically due to styling. The amaranth groat flour application into the wheat bread formulation led to changes in compressive force and tension of the crumb, the stress value at relative strain ε = 25%, the elastic modulus, and the statical elastic hysteresis index. The resulting application of the amaranth groat flour into bread formulation allowed to ensure a 2-2.5-fold increase in the freshness of wheat bread with a 15% amaranth groat flour content when providing higher comprehensive quality of the product.

DEVELOPMENT OF A COMPUTER MODULE FOR KINEMATIC AND DYNAMIC ANALYSIS OF IMPORTANT MECHANISMS OF LIGHT INDUSTRIAL MACHINES, PROGRAMS FOR ASSESSING THE TENSION OF TECHNOLOGICAL PROCESSES

The development of a computer module for kinematic and dynamic analysis of the lever mechanisms of light industry machines allows determining the parameters that are used in the program to assess the intensity of technological processes of the light and textile industry when determining the change in the relative tension of the thread in the filling zones of the technological equipment. Kinematic and dynamic analysis of flat mechanisms plays a significant role in the design of new mechanisms and modernization of existing ones. The results obtained during these studies can be used to calculate the strength of individual links, their inertial characteristics, optimization of structural parameters of mechanisms, and minimization of consumed energy. A sharp increase in tension leads to a violation of the normal course of the technological process of thread processing. The imperfection of the structural elements of the feed system, thread tensioning devices and thread guides on knitting, textile and sewing machines will not allow thread processing with a sudden increase in input tension. The development of new schemes of the thread feeding system requires an operational assessment of the value of the tension in front of the working zone. To do this, it is effective to use specially developed programs for performing a computational experiment. The tension of the thread increases when moving through the refueling zones of the thread feeding system on the technological equipment. This increase is due to the interaction of the thread with the guides and tension devices. The maximum tension value will be in front of the working area. The development of special computer programs for determining the tension in the working area allows you to determine the necessary technological parameters, make adjustments to both the structure itself and the components of the thread feeding system to obtain the minimum necessary tension in the working area. The objective function in the problem is the minimum necessary tension, which is the minimum sum of the angles covered by the thread of guide surfaces that have a cylindrical, elliptical shape, discrete segments of a straight line. The use of a computer program allows you to determine tensions and changes in relative tension in the filling zones of light and textile industry machines, which allows you to optimize the shape of the thread supply line even at the stage of designing the technological process. The development of application packages of computer programs allows to reduce the time for the design of technological processes in the light and textile industry as much as possible. This is due to the modernization of the thread filling line on the technological equipment, which allows to minimize thread tension in the working area. Minimization of tension is ensured by optimization of the shape of the thread filling line, in which the total angle of coverage of the guides will be minimal. Computer determination of kinematic and dynamic parameters of flat mechanisms allows to determine the parameters used in determining the intensity of technological processes.

“Neural Tension Among Hemiplegic Subjects”- A Cross-Sectional Study

AIM: This study was performed with the aim to know if there will be any change in the neural tension of the peripheral nerves following hemiplegia. The study analyzed the status of neural tension in radial, median, ulnar nerves following stroke METHODOLOGY: 30 individuals in post-stroke condition were selected based on inclusion and exclusion criteria. Detailed procedure was explained in the subject’s words and those who are interested; informed consent was obtained from all the participants. Complete neurological assessment was done. The subject was positioned in a supine position at lateral end of the couch in a diagonal manner. Upper limb tension testing 2 and 3 was tested on both the upper limbs of the subject. The positive and negative test results of the ULTT will be analyzed for the three major nerve of upper limb. RESULT: There were seven subjects positive with neural tension in upper limb out of thirty samples taken. There were 4 subjects with positive ULTT2a, 2 subjects with ULTT2b and 3 patients with ULTT3 positive. CONCLUSION: From this study, we conclude that neural tension is not a regular phenomenon in stroke hence it can be generalized as a treatment protocol for all the stroke subjects. This study also concludes that median nerve and ulnar nerve are the mostly affected in subjects tested positive for neural tension. Keywords: Neural Tension, Hemiplegia, Stroke.

Design and Simulation of Hydraulic Winch Tension Control for Trawler

The trawler winch is a main winching tool in the fishing operation of trawler. The disturbing influence of various factors such as sea wind and waves, change in the size of the catch and the turning of the fishing vessel during the operation of the trawler will cause unbalanced force on the wire rope of the two winches, which will easily cause the deformation and damage of the fishing net facilities and directly affect the improvement of the fishing yield and increase the harvest. In order to compensate for the change of the tension of the winch tractor during the operation of the trawler, the change of the load tension caused by the wave, or the rotation direction of the fishing vessel, and to ensure the good shape of the net opening, an electro-hydraulic control technology was used to design an automatic trawler tension controller. The tension control method of the trawler is investigated. The tension sensor is used as the input information of the electrical signal of the trawler's left and right trawler, which is measured indirectly and transmitted to the controller for logical operation, and the output torque of the hydraulic motor is changed by controlling the pilot overflow, which drives the trawler winch to adjust the tension of the left and right trawler to achieve the dynamic balance of the control system. In order to solve the problem of the tension of the trawl and the influence of the length change on the trawl, we designed an intelligent control system combining PLC control system and hydraulic system and used AMEsim hydraulic simulation software system to model and simulate it, the results show that without PLC control the torque of hydraulic motor 1 is 2387.7NM, the torque of hydraulic motor 9 is 2148.64NM the difference is 239.06 NM uneven force on both sides of the trailing platform, after adding PLC adjustment torque is obviously controlled torque to maintain about 2300NM, within a certain range to play a reliable adjustment effect.

COMMD5 is involved in the mechanisms of hypotension after parathyroidectomy in patients receiving hemodialysis

BackgroundSecondary hyperparathyroidism (SHPT) is a common complication of end-stage renal disease. Parathyroidectomy (PTx) is often employed for treatment of severe SHPT. However, PTx may cause hypotension via unknown mechanisms. COMM domain-containing protein 5 (COMMD5) in the parathyroid glands has been linked to blood pressure regulation of spontaneously hypertensive rats. ObjectiveTo explore the relationship between COMMD5 levels and reduced BP after PTx in patients receiving hemodialysis (HD). Methods and results(1) The study cohort included 31 patients receiving HD who underwent PTx. Serum COMMD5 levels were higher post-PTx vs. pre-PTx. (2) Sprague-Dawley rats (n = 22) were assigned to a 5/6 nephrectomy group or sham surgery group, vascular rings of the thoracic aorta from rats with CKD were incubated with COMMD5, and changes in vascular tension were compared. COMMD5 inhibited vasoconstriction of vascular rings with intact endothelium, but had no effect on vascular rings without the endothelium. (3) Human umbilical vein endothelial cells were stimulated with COMMD5 or small interfering RNA (siRNA). The expression levels of atrial natriuretic peptide (ANP) and endothelial nitric oxide synthase (eNOS) were up-regulated and down-regulated, respectively. ConclusionsSerum COMMD5 levels were increased after PTx in SHPT patients. COMMD5 promoted high expression of ANP and eNOS in endothelial cells, leading to vasodilation and resulting in hypotension.

Spatial organization of lysosomal exocytosis relies on membrane tension gradients

Lysosomal exocytosis is involved in many key cellular processes but its spatiotemporal regulation is poorly known. Using total internal reflection fluorescence microscopy (TIRFM) and spatial statistics, we observed that lysosomal exocytosis is not random at the adhesive part of the plasma membrane of RPE1 cells but clustered at different scales. Although the rate of exocytosis is regulated by the actin cytoskeleton, neither interfering with actin or microtubule dynamics by drug treatments alters its spatial organization. Exocytosis events partially co-appear at focal adhesions (FAs) and their clustering is reduced upon removal of FAs. Changes in membrane tension following a hypo-osmotic shock or treatment with methyl-β-cyclodextrin were found to increase clustering. To investigate the link between FAs and membrane tension, cells were cultured on adhesive ring-shaped micropatterns, which allow to control the spatial organization of FAs. By using a combination of TIRFM and fluorescence lifetime imaging microscopy (FLIM), we revealed the existence of a radial gradient in membrane tension. By changing the diameter of micropatterned substrates, we further showed that this gradient as well as the extent of exocytosis clustering can be controlled. Together, our data indicate that the spatial clustering of lysosomal exocytosis relies on membrane tension patterning controlled by the spatial organization of FAs.

Assessment of facial surface tension after CGF Harmony treatment – preliminary report

Introduction. The aim of the study was to evaluate the usefulness of the Clinical Direct Transmission System device and photographic medical documentation to assess the improvement in the skin of the face and hands before and after a one‑time CGF Harmony treatment.Material and methods. The study, after signing a voluntary informed consent, was attended by 3 patients of the Facial Aesthetics Clinic of the University Center of Dentistry and Specialist Medicine of the limited liability company. in Poznan. Once, in accordance with the procedure, a complex of stem cells and growth factors (CGF Harmony – in liquid and gel form) was administered to the area of the facial skin and the gel skin to the area of the dorsal surface of the hands. The observation period was 12 months, from the moment of the procedure, including control tests at several stages: before the procedure, immediately after administration, and approximately 6 and 12 months after the application.Results. The study showed no statistically significant differences in the surface tension of facial expressive muscles with a single application of CGF Harmony for most of the measurements.Conclusions. The analyzis of the photographic documentation and the subjective assessment of the patients, showed that the treatment turned out to be beneficial in terms of improving the quality of the facial skin and exceptionally beneficial in the area of the skin of the hands, which requires confirmation in further studies with a larger study group. There were no statistically significant changes in the facial expression muscles surface tension after the CGF Harmony procedure.

In Vivo Imaging of Lipid Droplets and Oxygen Status in Hepatic Tissues of Nonalcoholic Fatty Liver Model Mice Using a Lipophilic Ir(III) Complex

Nonalcoholic fatty liver disease (NAFLD) is becoming common worldwide. In pathophysiological studies of NAFLD, an in vivo optical probe that enables visualization of lipid droplets (LDs) and imaging of oxygen status in hepatic tissues simultaneously would be very useful. Here, we present the phosphorescent Ir(III) complex BTP ((btp)2Ir(acac) (btp = benzothienylpyridine, acac = acetylacetone)) as the first probe that meets this requirement. BTP was efficiently taken up into cultured 3T3-L1 adipocytes and selectively accumulated into LDs. Quantifying oxygen levels in LDs based on the phosphorescence lifetime of BTP allowed us to track changes in cellular oxygen tension after treatment with metabolic stimulants. Phosphorescence lifetime imaging microscopy combined with intravenously administered BTP in mice enabled specific visualization of LDs in hepatic lobules and simultaneous imaging of the oxygen gradient that decreased from the portal vein (PV) to the central vein (CV). NAFL model mice were created by feeding a high-fat diet (HFD) to mice for 3 or 7 days. The mice fed an HFD showed a marked increase in the amount and size of LDs in hepatocytes compared with those fed a normal diet, leading to abnormal microvascular structures. In addition, HFD-fed mice also exhibited reduced oxygen tension in areas other than the CV. Multicolor imaging with the LD-accumulated oxygen probe BTP and vasculature-staining FITC-lectin suggested that structural distortions of the sinusoidal microvasculature caused by enlarged LDs were associated with partial hypoxia in NAFL.

Effect of Ambient Temperature on Current Collection Quality in Pantograph–Catenary Interaction

This paper investigates the effect of the ambient temperature change on the dynamic interaction between pantograph and catenary (PAC). Thermal expansion/contraction of the components of the overhead contact system (OCS) is considered. Simulation results show that the thermal stress has a much greater influence on the longitudinal positioning of the contact wire than on the horizontal and vertical positioning. When ambient temperature reduces to [Formula: see text] from design temperature of [Formula: see text]C, the maximum longitudinal displacement of the positioner can reach as high as 301 mm, while the maximum horizontal and vertical displacement of the positioner is within 4[Formula: see text]mm. The change of ambient temperature results in the uneven tension distribution of the contact wire, especially near the central anchor. With the increase in temperature, the tension of contact wire decreases; vice versa, with the decrease in temperature, the tension of contact wire increases. For nine-span OCS, the tension change caused by ambient temperature change shall not exceed 2%. The variation of ambient temperature also leads to the deterioration of current collection quality. It is shown that a decreasing ambient temperature results in more significant changes in contact force, close to 5%. An increasing ambient temperature environment leads to a higher uplift of pantograph, close to 30%.

LEMONADE: Lego-like membrane tension analyzer based on self-assembled DNA elastic networks.

Membrane tension regulates and is affected by many cellular processes, including cell motility and membrane trafficking. However, the role of membrane tension in such processes is poorly understood because of difficulties in measuring dynamic membrane tension changes in live cells. Current approaches for membrane tension measurements can be broadly divided into two categories. In the first, fluorescence-based signals from small molecular probes that insert into cellular membranes are used. These allow convenient mapping of the signals throughout the cell membrane, but probe local membrane properties which are not always easy to relate to membrane tension. In addition, they are prone to artefacts due to membrane heterogenicities. The second type of approach relies on pulling a thin membrane tether from the cell surface. The restoring force acting on the tether is related to membrane tension and can be measured using optical tweezers. However, this approach requires specialized equipment and tension is measured at a single location. To overcome these challenges, we are developing a novel approach based on the self-assembly of an elastic network on the cell surface we call LEMONADE (Lego-like membrane tensionanalyzer based on self-assembled DNA elastic networks). The new membrane tension sensor relies on membrane-anchored Lego-like DNA nanostructures that are linked by elastic connectors with a FRET pair modification. Cell membrane area changes will result in transient FRET signals which can be detected throughout the cell surface using standard live fluorescence microscopy. We will report our progress in the design, assembly, and calibration of LEMONADE.

Phenylephrine-Induced Contraction in Guinea Pig Thoracic Aorta Is Triggered by Stimulation of α1L-Adrenoceptors Functionally Coupled with Store-Operated Ca2+ Channels and Voltage-Dependent Ca2+ Channels.

We examined whether the α1L-adrenoceptor (AR), which shows low affinity (pA2 < 9) for prazosin (an α1-AR antagonist) and high affinity (pA2 ≈ 10) for tamsulosin/silodosin (α1A-AR antagonists), is involved in phenylephrine-induced contractions in the guinea pig (GP) thoracic aorta (TA). Intracellular signaling induced by α1L-AR activation was also examined by focusing on Ca2+ influx pathways. Tension changes of endothelium-denuded TAs were isometrically recorded and mRNA encoding α-ARs/Ca2+ channels and their related molecules were measured using RT-quantitative PCR. Phenylephrine-induced contractions were competitively inhibited by prazosin/tamsulosin, and their pA2 value were calculated to be 8.53/9.74, respectively. These contractions were also inhibited by silodosin concentration-dependently. However, the inhibition was not competitive fashion with the apparent pA2 value being 9.48. In contrast, phenylephrine-induced contractions were not substantially suppressed by L-765314 (an α1B-AR antagonist), BMY 7378 (an α1D-AR antagonist), yohimbine, and idazoxan (α2-AR antagonists). Phenylephrine-induced contractions were markedly inhibited by YM-254890 (a Gq protein inhibitor) or removal of extracellular Ca2+, and partially inhibited by verapamil (a voltage-dependent Ca2+ channel (VDCC) inhibitor). The residual contractions in the presence of verapamil were slightly inhibited by LOE 908 (a receptor-operated Ca2+ channel (ROCC) inhibitor) and strongly inhibited by SKF-96365 (a store-operated Ca2+ channel (SOCC) and ROCC inhibitor). Among the mRNA encoding α-ARs/SOCC-related molecules, α1A-AR (Adra1a)/Orai3, Orai1, and Stim2 were abundant in this tissue. In conclusion, phenylephrine-induced contractions in the GP TA can be triggered by stimulation of Gq protein-coupled α1L-AR, followed by activation of SOCCs and VDCCs.

Determining the roles of membrane tension in breast cancer cell migration

Within the past two years, breast cancer has exceeded lung cancer as the most frequently diagnosed cancer, ranking first for incidence and mortality in most of the world. Cancer reaches its deadliest stage when metastatic spread of cells occurs from tumor sites. Cell metastasis relies, in part, on 1) endocytic membrane trafficking and 2) the formation of adhesive contacts with the extracellular matrix. These processes are regulated by mechanical tension on the cell membrane, which varies spatially within migrating cells. While tension gradients assist in maintaining polarity of the cell during migration, recently it has been shown that these gradients create an asymmetry in endocytic dynamics across the plasma membrane, termed as polarized membrane trafficking. Our preliminary data have shown that changes in membrane tension additionally result in the heterogeneous expression of two distinct adhesive structures during proliferation and nondirectional migration of breast cancer cells. Although membrane tension, endocytosis, adhesion, and cell migration have been extensively studied individually, it is unknown how these processes are collectively regulated by breast cancer cells to metastasize. We thus aim to develop experimental and analytical approaches that will allow us to monitor polarized membrane trafficking, the formation of adhesive structures, and membrane tension in several migrating breast epithelial cell lines. This involves using a microfluidic platform that simultaneously allows the leading and trailing edge of a cell to be separately treated during migration and enables the application of inputs native to the cellular microenvironment. Examination of the various regulatory pathways on the cell membrane that contribute to breast cancer metastasis will significantly impact the development of therapeutic targets in breast cancer drug discovery.

Mechanosensitive (de)regulation of exosome production in tumors.

Cells release membrane-bound nanovesicles (extracellular vesicles) as efficient modes for cell-to-cell communication. Exosomes are nanovesicles produced through the endocytic pathway (involving inwards budding of the endosomal membrane to form multivesicular endosomes, MVEs) and secreted via exocytosis. Tumor-derived exosomes (TEXs) have been implicated in cancer progression and metastasis, with studies showing their role in promoting tumor cell invasion, immune evasion, and pre-metastatic niches. Tumors also leverage dysregulated extracellular matrix (ECM) remodeling mechanisms to create a conducive microenvironment. One such essential mechanical alteration is the stiffening of ECM, which enhances oncogenic signaling pathways leading to tumor progression. Recent experiments have demonstrated ECM stiffness-dependent exosome secretion in various cancer cell lines with higher exosome release on stiff matrix. To capture this mechanobiology-based regulatory axis hijacked by tumors, we suggest a two-pronged mechanosensitive modulation of TEXs. First, using a mesoscale membrane model evolved with Monte Carlo techniques based on the Helfrich Hamiltonian, we show that stiff ECM modulates exosome formation through its effect on cortical tension. Our results suggest an ultrasensitive response of vesicle nucleation induced by curvature-inducing proteins to changes in cortical tension. Second, experimental collaborators have observed Akt-dependent activation of Rabin8 (Guanine Exchange Factor (GEF) of Rab8) along with increased Rab8-mediated exosome secretion on a stiff matrix for transformed cell lines. We capture this mechanosensitive signaling pathway, involved in directing MVE transport to the cellular membrane for exosome release, using an ODE model. Exosome secretion can then be quantified as the combination of formation and trafficking of MVEs. These coarse-grain predictions agree with the experimentally observed change in exosome amount as the matrix stiffens.

Logical-probabilistic model of the reliability of means for preparing and distributing fodder

Countries with a developed agricultural sector of the economy use modern advances in industry and computer technology in precision animal husbandry. At the current stage of animal husbandry development, both in global practice and in Ukraine, for the preparation of fodder mixtures, means for preparation and distribution of fodder are becoming more and more widespread, which combine the operations of loading, grinding, mixing, transportation and dosed distribution of fodder mixtures. The purpose of the presented article is to assess and ensure the reliability of the operation of the means for preparing and distributing fodder due to the logic-probabilistic modeling of failures of the feed mixture unloading mechanism as a subsystem of the "Man-Machine-Environment" technical system. The results of theoretical and experimental research are a continuation of previous work and are aimed at increasing the efficiency of use and ensuring the reliability of machines and equipment for animal husbandry. The obtained results of theoretical and experimental studies of reliability based on logical-probabilistic modeling of means for preparing and distributing feed as complex technical systems depending on the influence of the components "man-operator", "machine", "environment". The shortest paths of failures and the minimum cross-sections of their prevention for the research objects were analyzed. In order to prevent the failure of the human-operator component of the system, it is necessary to provide sufficient qualification of the personnel, foresee the possible occurrence of errors and ensure their timely elimination. In order to prevent failures of the feed mixture unloading mechanism, it is necessary to timely control and adjust the condition of parts during operation and when restoring performance. It has been established that the probability of failure of the mechanism will be less important, provided that the probability of elimination of failures due to insufficient qualification of the operator and failure of drive parts is 0.2. An increase in the probability of failure of the operator under the condition of insufficient qualification from 0.5 to 0.9 will lead to an increase in the probability of failure as a result of a change in the conveyor tension and the impossibility of adjusting the conveyor tension, and at 0.9 the probability of failure of the mechanism will be 0.046. The practical significance of the results lies in the possibility of investigating the probability of failure of the feed mixture unloading mechanism based on the reliability of the components of the means for preparing and distributing feed, including the hydraulic cylinder, drive parts, and conveyor belts

Demolded hollow high aspect-ratio parylene-C micropillars for real-time mechanosensing applications

Cells generate mechanical forces to maintain normal cellular function or play a role in developing pathological processes. The mechanical force called the traction force can be estimated from the pillar deflection using a polymeric micropillar array. Here, we develop a transparent membrane of hollow cone-shape high aspect ratio (AR) parylene-C micropillars by the molding method. The membrane of the pillar array is exposed after the etching of the silicon mold and the residual silicon serves as the cultivation chamber. The AR and spring constant (k) of micropillars are estimated to AR ≈ 10 and k ≈ 0.349 N·m−1. The spring constant of developing micropillars is 3.5-times decreased compared to cylindrical, non-hollow pillars. This slightly tune the elastic properties of micropillars. The array is further shown as the mechanosensor detecting the change of cellular tension during hyperosmotic stress. The traction force of cancerous PC-3 cells is estimated from pillar deflections by image analysis. Additionally, the cell volume and surface area are measured using a digital holographic microscope (DHM). The results show that the molding technique can be used to develop high AR parylene-C micropillars and that this array can serve as the mechanosensor of cellular processes.

A dual organelle-targeting mechanosensitive probe.

Cells are responsive to the mechanical environment, but the methods to detect simultaneously how different organelles react in mechanobiological processes remain largely unexplored. We herein report a dual organelle-targeting fluorescent probe, (E)-1-[3-(diethoxyphosphoryl)propyl]-4-[4-(diethylamino)styryl]pyridin-1-ium bromide (ASP-PE), for mechanical mapping in live cells. ASP-PE is aggregation-induced emission active and is sensitive to the local mechanical environment. It targets the plasma membrane (PM) and intracellular mitochondria in cells by its phosphonate moiety and pyridinium. In this work, through ASP-PE staining, changes of membrane tension in the PM and mitochondria in response to varied osmotic pressure and substrate stiffness are visualized using fluorescence lifetime imaging microscopy. The mechanobiological importance of actin filaments and microtubules in the PM and mitochondria is also investigated using this probe. Computational simulations are applied to study the sensing mechanism of the probe. This study introduces a unique tool for mapping the membrane tension in the PM and mitochondria together, providing us great opportunities to study organelle's interactions in mechanobiology.

Zinc- and Copper-Doped Mesoporous Borate Bioactive Glasses: Promising Additives for Potential Use in Skin Wound Healing Applications.

In this study, zinc (Zn)- and copper (Cu)-doped 13-93B3 borate mesoporous bioactive glasses (MBGs) were successfully synthesized using nitrate precursors in the presence of Pluronic P123. We benefited from computational approaches for predicting and confirming the experimental findings. The changes in the dynamic surface tension (SFT) of simulated body fluid (SBF) were investigated using the Du Noüy ring method to shed light on the mineralization process of hydroxyapatite (HAp) on the glass surface. The obtained MBGs were in a glassy state before incubation in SBF. The formation of an apatite-like layer on the SBF-incubated borate glasses was investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The incorporation of Zn and Cu into the basic composition of 13-93B3 glass led to changes in the glass transition temperature (Tg) (773 to 556 °C), particle size (373 to 64 nm), zeta potential (-12 to -26 mV), and specific surface area (SBET) (54 to 123 m2/g). Based on the K-means algorithm and chi-square automatic interaction detection (CHAID) tree, we found that the SFT of SBF is an important factor for the prediction and confirmation of the HAp mineralization process on the glasses. Furthermore, we proposed a simple calculation, based on SFT variation, to quantify the bioactivity of MBGs. The doped and dopant-free borate MBGs could enhance the proliferation of mouse fibroblast L929 cells at a concentration of 0.5 mg/mL. These glasses also induced very low hemolysis (&lt;5%), confirming good compatibility with red blood cells. The results of the antibacterial test revealed that all the samples could significantly decrease the viability of Pseudomonas aeruginosa. In summary, we showed that Cu-/Zn-doped borate MBGs can be fabricated using a cost-effective method and also show promise for wound healing/skin tissue engineering applications, as especially supported by the cell test with fibroblasts, good compatibility with blood, and antibacterial properties.

Study on volume change of droplet

In infusion therapy, flow rate errors are caused by changes in the droplet volume dripped from drip chamber. The purpose of this study is to determine the change in droplet volume when surface tension, viscosity, density, and flow rate are varied. The droplet mass in a continuous drip is precisely measured and the droplet volume and standard deviation are determined for each 100 drops. At drip nozzle A, the rate of change in droplet volume was -44.78% at the change in surface tension, -12.14% at the change in viscosity, -5.70% at the change in density, and 8.14% at the change in flow rate. The volume change rate when double the surface tension, viscosity, and density were changed was 43.18% at the change in surface tension, -2.87% at the change in viscosity, and -16.10% at the change in density. The volume change rate affected by the viscosity change was slight. An experimental equation was tried to calculate the droplet volume of each condition. Since a change in surface tension causes a significant change in droplet volume, infusion therapy used drugs with significantly different surface tensions needs to pay attention to flow rate errors. It is recommended that the surface tension of drugs used for infusion is written on the package insert.