Increase In Osmotic Pressure Research Articles

Material Composition Characteristics of Aspergillus cristatus under High Salt Stress through LC-MS Metabolomics.

Aspergillus cristatus is a crucial edible fungus used in tea fermentation. In the industrial fermentation process, the fungus experiences a low to high osmotic pressure environment. To explore the law of material metabolism changes during osmotic pressure changes, NaCl was used here to construct different osmotic pressure environments. Liquid chromatography-mass spectrometry (LC-MS) combined with multivariate analysis was performed to analyze the distribution and composition of A. cristatus under different salt concentrations. At the same time, the in vitro antioxidant activity was evaluated. The LC-MS metabolomics analysis revealed significant differences between three A. cristatus mycelium samples grown on media with and without NaCl concentrations of 8% and 18%. The contents of gibberellin A3, A124, and prostaglandin A2 related to mycelial growth and those of arabitol and fructose-1,6-diphosphate related to osmotic pressure regulation were significantly reduced at high NaCl concentrations. The biosynthesis of energy-related pantothenol and pantothenic acid and antagonism-related fluvastatin, aflatoxin, and alternariol significantly increased at high NaCl concentrations. Several antioxidant capacities of A. cristatus mycelia were directly related to osmotic pressure and exhibited a significant downward trend with an increase in environmental osmotic pressure. The aforementioned results indicate that A. cristatus adapts to changes in salt concentration by adjusting their metabolite synthesis. At the same time, a unique set of strategies was developed to cope with high salt stress, including growth restriction, osmotic pressure balance, oxidative stress response, antioxidant defense, and survival competition.

Fluid Spontaneous Imbibition Under the Influence of Osmotic Pressure in Deep Coalbed Methane Reservoir in the Ordos Basin, China

Summary The flowback rate of a hydraulic fracturing fluid is related to coalbed methane (CBM) production in gas wells. The deep (>2000 m) CBM reservoir in the Ordos Basin has an extremely high salinity (>200 000 mg/L), which results in a very low flowback rate of fracturing fluid. The mechanism underlying the extremely low flowback rate of the fracturing fluid remains unclear. This study experimentally simulated two patterns of osmotic pressure variation that exist at a hydraulic fracturing site: the processes of injection of a low-salinity fracturing fluid into a high-salinity reservoir and a high-salinity fracturing fluid into a low-salinity reservoir. Low-field nuclear magnetic resonance (NMR) technology was used to monitor dynamic fluid migration and fluid distribution in the coals. Results showed that osmotic pressure is a driving force for spontaneous imbibition when the salinity of the fracturing fluid is lower than that of the reservoir water, and more fluid enters the coal as the osmotic pressure increases. This causes the displacement of the high-salinity fluid already present in the micropores by the low-salinity fracturing fluid. In high-salinity deep coal seams, both osmotic pressure and capillary forces cause the spontaneous imbibition of the fracturing fluid from fractures into pores, promoting CH4 desorption, alleviating the water-blocking effect, and enhancing the filtration loss of the fracturing fluid. In contrast, the injection of a high-salinity fluid into the reservoir with a low-salinity brine (LSB) creates an osmotic pressure difference that prevents fluid imbibition. In shallow, low-salinity coal seams, the injection of high-salinity fracturing fluids can result in high flowback rates. Therefore, these two injection schemes are significant for an understanding of the role of osmotic pressure in deep CBM extraction and serve as valuable guides for optimizing the selection of the fracturing fluid and improving its effective flowback.

Osmosis as nature’s method for establishing optical alignment

For eyes to maintain optimal focus, precise coordination is required between lens optics and retina position, a mechanism that in vertebrates is governed by genetics, visual feedback, and possibly intraocular pressure (IOP).1 While the underlying processes have been intensely studied in vertebrates, they remain elusive in arthropods,though visual feedback may be unimportant.2 How do arthropod eyes remain functional while undergoing substantial growth? Here, we test whether a common physiological process, osmoregulation,3 could regulate growth in the sophisticated camera-type eyes of the predatory larvae of Thermonectus marmoratus diving beetles. Upon molting, their eye tubes elongate in less than an hour, and osmotic pressure measurements reveal that this growth is preceded by a transient increase in hemolymph osmotic pressure. Histological evaluation of support cells that determine the lens-to-retina spacing reveals swelling rather than the addition of new cells. In addition, as expected, treating larvae with hyperosmotic media post-molt leads to far-sighted (hyperopic) eyes due to a failure of proper lengthening of the eye tube and results in impaired hunting success. This study suggests that osmoregulation could be of ubiquitous importance for properly focused eyes.

Isopropanol concentration by osmotically assisted reverse osmosis

Isopropanol (IPA) is a versatile solvent used in a wide range of industrial and consumer applications, and its disposal may pose high costs and environmental concerns. In this work, the osmotically assisted reverse osmosis (OARO) technology was employed to demonstrate the effective treatment and concentration of IPA wastewater. The effect of various operating parameters, including feed solution concentration, number of membrane modules, flow rate, and applied pressure, was systematically investigated. Both permeance and IPA rejection decreased with an increase in IPA concentration, due to increase of feed solution osmotic pressure and occurrence of membrane swelling. By adjusting the feed flow rate and applied pressure, we can effectively control the final IPA concentration. Specifically, lowering the feed flow rate will result in higher IPA concentration, and increasing the applied pressure will also lead to higher IPA concentration. Long-term operational stability was also investigated, and results showed that the OARO process could maintain stable operation over an extended period of 180 days. Lastly, real IPA wastewater sourced from an electronics devices factory was treated using the OARO system and the wastewater sample was concentrated for more than four times. The results of this work exhibit the great practical application potential of the OARO process for the concentration of IPA wastewater.

Co-activation of NMDAR and mGluRs controls protein nanoparticle-induced osmotic pressure in neurotoxic edema

BackgroundGlutamate stimuli and hyperactivation of its receptor are predominant determinants of ischemia-induced cytotoxic cerebral edema, which is closely associated with protein nanoparticle (PN)-induced increases in osmotic pressure. Herein, we investigated the electrochemical and mechanical mechanisms underlying the neuron swelling induced by PNs via the co-activation of N-methyl-D-aspartate receptor subunit (NMDAR) and excitatory metabotropic glutamate receptors (mGluRs). ResultsWe observed that co-activation of ionic glutamate receptor NMDAR and Group I metabotropic mGluRs promoted alteration of PN-induced membrane potential and increased intracellular osmosis, which was closely associated with calcium and voltage-dependent ion channels. In addition, activation of NMDAR-induced calmodulin (CaM) and mGluR downstream diacylglycerol (DAG)/protein kinase C α (PKCα) were observed to play crucial roles in cytotoxic hyperosmosis. The crosstalk between CaM and PKCα could upregulate the sensitivity and sustained opening of sulfonylurea receptor 1 (SUR1)-transient receptor potential cation channel subfamily M member 4 (TRPM4) and transmembrane protein 16 A (TMEM16A) channels, respectively, maintaining the massive Na+/Cl- influx, and the resultant neuron hyperosmosis and swelling. Intracellular PNs and Na+/Cl- influx were found to be as potential targets for cerebral edema treatment, using the neurocyte osmosis system and a cerebral ischemic rat model. ConclusionsThis study highlights PNs as a key factor in “electrochemistry-tension” signal transduction controlling Na+/Cl- ion channels and increased osmotic pressure in ischemia-induced cytotoxic edema. Moreover, enhanced sensitivity in both Na+ and Cl- ion channels also has a crucial role in cerebral edema.

Microplastics - Back to Reality: Impact of Pristine and Aged Microplastics in Soil on Earthworm Eisenia fetida under Environmentally Relevant Conditions.

Recently, studies have highlighted the potential danger for soil organisms posed by film-derived microplastics (MPs). However, the majority of those does not accurately reflect the field conditions and the degree of MP contamination that can be found in actual settings. To fill the gap between laboratory and field scenarios, the polyethylene (PE) plastic film was made into PE-MPs and aged. Toxicity and molecular mechanisms of pristine PE-MPs (PMPs) and aged PE-MPs (AMPs) with the concentration at 500 mg/kg of dry weight were determined after 14 days of exposure by measuring the oxidative stress, osmoregulation pressure, gut microbiota, and metabolic responses in earthworms under environmentally relevant conditions. Our research showed that, when compared to PMPs (13.13 ± 1.99 items/g), AMPs accumulated more (16.19 ± 8.47 items/g), caused more severe tissue lesions, and caused a higher increase of cell membrane osmotic pressure in earthworms' intestines. Furthermore, the proportion of probiotic bacteria Lactobacillus johnsonii in the gut bacterial communities was 24.26%, 23.26%, and 12.96%, while the proportion of pathogenic bacteria of the phylum Verrucomicrobia was 2.28%, 4.79%, and 10.39% in the control and PMP- and AMP-exposed earthworms, indicating that the decrease in number of probiotic bacteria and the increase in number of pathogenic bacteria were more pronounced in the gut of AMP- rather than PMP-exposed earthworms. Metabolomic analysis showed that AMP exposure reduced earthworm energy metabolites. Consequently, the constant need for energy may result in protein catabolism, which raises levels of some amino acids, disturbs normal cell homeostasis, causes changes of cell membrane osmolarity, and destroys the cell structure. Our studies showed that aged MPs, with the same characteristics as those found in the environment, have greater toxicity than pristine MPs. The results of this study broaden our understanding of the toxicological effects of MPs on soil organisms under environmentally relevant conditions.

Comparing polymer-surfactant complexes to polyelectrolytes

HypothesisUnderstanding the complex interactions between polymers and surfactants is required to optimise commercially relevant systems such as paint, toothpaste and detergent. Neutral polymers complex with surfactants, forming ‘pearl necklace’ structures that are often conceptualised as pseudo-polyelectrolytes. Here we pose two questions to test the limits of this analogy: Firstly, in the presence of salt, do these polymer-surfactant systems behave like polyelectrolytes? Secondly, do polymer-surfactant complexes resist geometric confinement like polyelectrolytes? ExperimentsWe test the limits of the pseudo-polyelectrolyte analogy through studying a poly(N-isopropylacrylamide) (PNIPAM) brush in the presence of sodium dodecylsulfate (SDS). Brushes are ideal for interrogating pseudo-polyelectrolytes, as neutral and polyelectrolyte brushes exhibit distinct and well understood behaviours. Spectroscopic ellipsometry, quartz crystal microbalance with dissipation monitoring (QCM-D), and neutron reflectometry (NR) were used to monitor the behaviour and structure of the PNIPAM-SDS system as a function of NaCl concentration. The ability of the PNIPAM-SDS complex to resist geometric confinement was probed with NR. FindingsAt a fixed SDS concentration below the zero-salt CMC, increasing NaCl concentration <100 mM promoted brush swelling due to an increase in osmotic pressure, not dissimilar to a weak polyelectrolyte. At these salt concentrations, the swelling of the brush could be described by a single parameter: the effective CMC. However, at high NaCl concentrations (e.g., 500 mM) no brush collapse was observed at all (non-zero) concentrations of SDS studied, contrary to what is seen for many polyelectrolytes. Study of the polymer-surfactant system under confinement revealed that the physical volume of surfactant dominates the structure of the strongly confined system, which further differentiates it from the polyelectrolyte case.

Deciphering Structural Determinants Distinguishing Active from Inactive Cell-Penetrating Peptides for Cytosolic mRNA Delivery.

The formation of noncovalent complexes by mixing of positively charged polymers with negatively charged oligonucleotides (ONs) is a widely explored concept in nanomedicine to achieve cellular delivery of ONs. Uptake of ON complexes occurs through endocytosis, which then requires release of ON from endosomes. As one type of polymer, cell-penetrating peptides (CPPs) are being used which are peptides of about 8-30 amino acids in length. However, only a few CPPs yield effective cytosolic ON delivery and activity. Several strategies have been devised to increase cellular uptake and enhance endosomal release, among which an increase of osmotic pressure through the so-called proton sponge effect, disruption of membrane integrity through membrane activity, and disulfide-mediated polymerization. Here, we address the relevance of these concepts for mRNA delivery by incorporating structural features into the human lactoferrin-derived CPP, which shows uptake but not delivery. The incorporation of histidines was explored to address osmotic pressure and structural motifs of the delivery-active CPP PepFect14 (PF14) to address membrane disturbance, and finally, the impact of polymerization was explored. Whereas oligomerization increased the stability of polyplexes against heparin-induced decomplexation, neither this approach nor the incorporation of histidine residues to promote a proton-sponge effect yielded activity. Also, the replacement of arginine residues with lysine or ornithine residues, as in PF14, was without effect, even though all polyplexes showed cellular uptake. Ultimately, sufficient activity could only be achieved by transferring amphipathic sequence motifs from PF14 into the hLF context with some benefit of oligomerization demonstrating overarching principles of delivery for CPPs, lipid nanoparticles, and other types of delivery polymers.

Влияние основных типов химизма степени засоления почв и техногенных грунтов на всхожесть семян фитомелиорантов

Abstract. The purpose and objectives of the study is to establish the levels of influence of chemistry and the degree of salinity on the onset of half (LD50) and full (LD99) death of seeds of alfalfa blue hybrid and yellow clover. To identify the degree of participation of each factor in the death of legume seeds using the correlation coefficient and determination. To conduct a comparative assessment of the salt resistance of the seeds of sweet clover and alfalfa. Methods. The main natural types of salinization characteristic of the forest-steppe zone of Western Siberia are selected as objects of study. The germination energy and germination of seeds were determined according to GOST 12038-84. Model variants of salt solutions for germination of seeds of sweet clover and alfalfa were created taking into account the proportions of the formation of the main types of salinization. The types of salinization are represented by sulfate-soda, sulfate-chloride (neutral), and gypsum chloride-sulfate salt. Scientific novelty. Drilling slurries stored in barns during the extraction of hydrocarbon raw materials correspond to similar salinization conditions. Artificial salinization of water-salt solutions with a given concentration made it possible to identify half (LD50) and complete death (LD99) of clover and alfalfa seeds at the appropriate level and chemistry of salinization. Comparison of neutral and sulfate-soda salinization showed that the presence of soda in the solution determines its toxicity by 86–87 %. The negative effect of neutral salinization appears to a greater extent due to an increase in osmotic pressure. The presence of gypsum in the nutrient saline solution reduced the toxicity to seeds of phytomeliorant crops by 1.9–2.5 times. Results. It has been established that under conditions of neutral and sulfate-soda salinization, plants experience an acute deficiency in calcium. The introduction of gypsum during chemical reclamation of salt pans and drilling slurries eliminates this deficiency. The establishment of indicators (LD50) allows you to adjust the seeding rate of phytomeliorants. The indicator (LD99) indicates the expediency of applying gypsum on salt pans and drilling slurries.

Behaviour of FITC-Labeled Polyallylamine in Polyelectrolyte Microcapsules.

There are many studies devoted to the application of polyelectrolyte microcapsules (PMC) in various fields; however, there are significantly fewer studies devoted to the study of the polyelectrolyte microcapsules themselves. The study examined the mutual arrangement of the polyelectrolytes in 13-layered PMC capsules composed of (PAH/PSS)6PAH. The research showed that different layers of the polyelectrolyte microcapsules dissociate equally, as in the case of 13-layered PMC capsules composed of (PAH/PSS)6PAH with a well-defined shell, and in the case of 7-layered PMC capsules composed of (PAH/PSS)3PAH, where the shell is absent. The study showed that polyallylamine layers labeled with FITC migrate to the periphery of the microcapsule regardless of the number of layers. This is due to an increase in osmotic pressure caused by the rapid flow of ions from the interior of the microcapsule into the surrounding solution. In addition, FITC-polyallylamine has a lower charge density and less interaction with polystyrene sulfonate in the structure of the microcapsule. Meanwhile, the hydrophilicity of FITC-polyallylamine does not change or decreases slightly. The results suggest that this effect promotes the migration of labeled polyallylamine to a more hydrophilic region of the microcapsule, towards its periphery.

Osmotic pressure induces translocation of aquaporin-8 by P38 and JNK MAPK signaling pathways in patients with functional constipation.

Aquaporins (AQPs) maintain fluid homeostasis in the colon. The role of colonic AQPs in the pathophysiology of functional constipation (FC) remains largely unknown. To explore variations in aquaporins and investigate their underlying mechanisms. Colonic biopsies were collected from patients with FC and healthy controls. The expression and localization of AQPs were evaluated using quantitative real-time polymerase chain reaction (qRT-PCR), western blot analysis, and immunofluorescence assays. Furthermore, osmotic pressure-induced cell model was used in vitro to investigate the potential relationship between AQP8 and osmotic pressure, and to reveal the underlying mechanisms. Upregulation of AQP3 and AQP8, and downregulation of AQP1, AQP7, AQP9, AQP10, and AQP11 were observed in the patients with functional constipation. Furthermore, cellular translocation of AQP8 from the cytoplasm to the plasma membrane was observed in patients with FC. Mechanistically, the increase in osmotic pressure could activate the Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK) signaling pathways, and subsequently promote the upregulation and translocation of AQP8. Upregulation of AQP8 and AQP3, and translocation of AQP8 were observed in colon biopsies from patients with FC. The p38 and JNK MAPK signaling pathways are involved in the regulation of osmotic pressure-induced AQP8 variation.

Germination of Microsporidian Spores: The Known and Unknown.

Microsporidia are a large group of mysterious obligate intracellular eukaryotic parasites. The microsporidian spore can survive in the absence of nutrients for years under harsh conditions and germinate within seconds under the stimulation of environmental changes like pH and ions. During germination, microsporidia experience an increase in intrasporal osmotic pressure, which leads to an influx of water into the spore, followed by swelling of the polaroplasts and posterior vacuole, which eventually fires the polar filament (PF). Infectious sporoplasm was transported through the extruded polar tube (PT) and delivered into the host cell. Despite much that has been learned about the germination of microsporidia, there are still several major questions that remain unanswered, including: (i) There is still a lack of knowledge about the signaling pathways involved in spore germination. (ii) The germination of spores is not well understood in terms of its specific energetics. (iii) Limited understanding of how spores germinate and how the nucleus and membranes are rearranged during germination. (iv) Only a few proteins in the invasion organelles have been identified; many more are likely undiscovered. This review summarizes the major resolved and unresolved issues concerning the process of microsporidian spore germination.

Impairment of endothelial Kir channels in response to elevated glucose is independent of changes in channel expression

Background and Objective. Obesity comprises a complex metabolic pathophysiology often associated with poor glycemic control. Our past studies detailed that impairment of inward rectifying potassium channels (Kir2.1) is a contributing factor to obesity-induced endothelial dysfunction, however, the major obesity-associated factors driving Kir2.1 impairment are unknown. As obesity is often associated with hyperglycemia, we aimed to determine the effect of elevated glucose on endothelial Kir2.1 channel function and expression in vitro. Method. We treated human adipose microvascular endothelial cells (HAMECs) with high glucose (200mg/dL), mannitol (200 mg/dL), or NaCl (300 mOsm/kg) for 72 hours. Control cells were maintained in standard media containing 100 mg/dL glucose. Following treatments, Kir currents were measured using whole-cell patch clamp electrophysiology and Kir2.1 expression was assessed using qPCR, Western immunoblotting, and immunocytochemistry (ICC). ICC was performed on nonpermeabilized HAMECs to detect membrane expression. Statistics: A Kruskal-Wallis one-way analysis of variance (p &lt; 0.05) followed by Dunn Sidak post hoc analysis (*) was used to determine significant differences. Result. HAMECs exposed to elevated glucose exhibited reduced Kir current compared to control. Surprisingly, mannitol induced similar decreases in Kir current. As mannitol originally served as the osmotic control, we next tested the effect of osmotic stress on endothelial Kir current by exposing cells to elevated NaCl, which had no effect. Furthermore, increased glucose or mannitol did not influence channel KCNJ2 gene or total Kir2.1 protein expression, however, preliminary experiments indicate that the membrane expression of Kir2.1 may be increased following exposure to elevated sugars. Discussion and Conclusions. Our findings indicate that glucose and mannitol reduce endothelial Kir currents without affecting channel expression, suggesting that functional impairment of the channels is induced by elevated sugars. This is further supported by preliminary studies that indicate that membrane Kir2.1 expression is increased in response to elevated sugars, suggesting that a possible compensatory trafficking mechanism fails to restore Kir2.1 channel function despite an increased membrane presence. As the observed decreases in Kir channel current are not mediated by an increase in osmotic pressure under these conditions, we aim to next test if damage to the glycocalyx, which is established to occur in obesity and renders endothelial Kir channels dysfunctional, occurs in the presence of elevated sugars. This study was supported by an Institutional Development Award (IDeA) from the National Institute of General Medical Sciences of the National Institutes of Health under award number 2P20GM113125 (Ibra Fancher). 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.

Evaluation of Different Reverse Osmosis Membranes for Textile Dyeing and Finishing Wastewater Reuse

Different commercial reverse osmosis (RO) membranes from Vontron and DuPont Filmtec were evaluated for textile dyeing and finishing wastewater (TDFW) reuse in China. All six tested RO membranes produced qualified permeate meeting TDFW reuse standards at a water recovery ratio (WRR) of 70% in single batch tests. The rapid decline of apparent specific flux at WRR over 50% was mainly ascribed to feed osmotic pressure increase caused by concentrating effects. Multiple batch tests using Vontron HOR and DuPont Filmtec BW RO membranes with comparable permeability and selectivity demonstrated the reproducibility and showed low fouling development. The occurrence of carbonate scaling on both RO membranes was identified by scanning electron microscopy and energy disperse spectroscopy. No obvious organic fouling was detected on both RO membranes by attenuated total reflectance Fourier transform infrared spectrometry. From the orthogonal tests, with an integrated RO membrane performance index (i.e., 25% rejection ratio of total organic carbon + 25% rejection ratio of conductivity + 50% flux ratio of final to initial) as a target, the optimal parameters were determined as WRR of 60%, cross-flow velocity (CFV) of 1.0 m/s, temperature (T) of 20 °C for both RO membranes, while trans-membrane pressures (TMP) of 2 and 4 MPa were optimal for Vontron HOR RO membrane and DuPont Filmtec BW RO membrane, respectively. Both RO membranes with the optimal parameters produced good permeate quality for TDFW reuse and kept a high flux ratio of final to initial, demonstrating the effectiveness of the orthogonal tests.

In situ visualization of water transport in cement mortar with an ultra-low w/b ratio under the coupling conditions of osmotic pressure, confining pressure, and temperature

The deep underground environment has complex geological conditions, which result in cement-based materials under the coupling conditions of high crustal stress, high pressure, and high temperature for the long-term. Thus, the mechanism of water transport is more complicated and often accelerates the deterioration of cement-based materials. In this study, the rules of water transport in mortar with an ultra-low w/b ratio under the coupling conditions of osmotic pressure, confining pressure, and temperature were systemically investigated based on a novel experimental device and low-field NMR technology. Experimental results showed that the saturation of the pore structure and penetration depth of mortar increased rapidly in the early stage (the first 10 min), and the water was mainly filled in nano-scale pores. Low-field NMR imaging technology could be applied to the visualization study of water transport in WPC mortar. With the increase of osmotic pressure and ambient temperature, the penetration rate of water in mortar was significantly increased, and the water was preferentially filled in nano-scale pores with pore sizes less than approximately 200 nm. The increase of confining pressure could improve the permeability of mortar to a certain extent due to the decrease in the penetration rate of water. For water transport in mortar with an ultra-low w/b ratio, the descending order of influence degree of different factors was osmotic pressure, confining pressure, and temperature.

Mechanisms of macular edema.

Macular edema is the pathological accumulation of fluid in the central retina. It is a complication of many retinal diseases, including diabetic retinopathy, retinal vascular occlusions and uveitis, among others. Macular edema causes decreased visual acuity and, when chronic or refractory, can cause severe and permanent visual impairment and blindness. In most instances, it develops due to dysregulation of the blood-retinal barrier which permits infiltration of the retinal tissue by proteins and other solutes that are normally retained in the blood. The increase in osmotic pressure in the tissue drives fluid accumulation. Current treatments include vascular endothelial growth factor blockers, corticosteroids, and non-steroidal anti-inflammatory drugs. These treatments target vasoactive and inflammatory mediators that cause disruption to the blood-retinal barrier. In this review, a clinical overview of macular edema is provided, mechanisms of disease are discussed, highlighting processes targeted by current treatments, and areas of opportunity for future research are identified.

Factors Regulating Fluid Restitution and Plasma Volume Reduction over the Course of Hemodialysis.

Over the course of hemodialysis, fluid and protein are restituted from the tissue compartment to the circulation compartment through the endothelia. Our previous model analysis on fluid and protein transport during hemodialysis is expanded to account for changes occurring in the tissue. The measured initial and end plasma protein concentration (PPC, Cp and Cp') for six hemodialysis studies are analyzed by this expanded model. The computation results indicate that the total driving pressure to restitute fluid from the tissue to the circulation ranges from 5.4 to 20.3 mmHg. The analysis identifies that the increase in plasma colloidal osmotic pressure (COP) contributes 78 ± 6% of the total driving pressure, the decrease in microvascular blood pressure 32 ± 4%, the increase in the COP of interstitial fluid -6 ± 3%, and the decrease in interstitial fluid pressure -5 ± 2%. Let this ratio (Cp' - Cp)/Cp' be termed the PPC increment. The six HDs can be divided into three groups which are to have these PPC increments 25.7%, 14.5 ± 2.6(SD)% and 8.3%. It is calculated that their correspondent filtration coefficients are 0.43, 1.29 ± 0.28 and 5.93 mL/min/mmHg and the relative reductions in plasma volume (RRPV) -22.1%, -13.1 ± 6% and -9.4%. The large variations in PPC increments and RRPV show the filtration coefficient is a key factor to regulate the hemodialysis process.

Surgical treatment of inflammatory periapical cyst: a clinical case report

Among the odontogenic cysts, there are radicular cysts or also called periapical cysts, are the most common odontogenic cyst. They develop at the apex of a tooth with pulp necrosis, which may be the consequence of dental caries or trauma. they are asymptomatic, grow slowly, and are discovered on routine radiographs. With the proliferation of the ERM and its activation, there is an increase in osmotic pressure, causing the cyst to expand, normally this ERM is not activated, so only granulation tissue develops at the apex of the affected tooth. Granulation tissue is called periapical granuloma and, as such, histologically lacks an epithelial lining. In the present study, a case of a 65-year-old female patient with an inflammatory periapical cyst in the region of the lower incisors is reported.

Combining macro and micro experiments to reveal the real-time evolution of permeability of shale

This research analyzed the real-time evolution of shale permeability using a combination of micro and macro experiments. The macro permeability experiment adopted the steady-state method and considered a particular stress path to study the influence of osmotic pressure, pore pressure, and confining pressure on the real-time evolution of permeability. The mechanism of the slippage effect on permeability evolution was studied using microscopic observations. The macro experiment results showed that: (1) permeability decreased as a concave power function with the increase of osmotic pressure; (2) permeability increased as a positive exponential function with an increase in mean pore pressure; (3) permeability decreased as a negative exponential function with an increase in confining pressure; (4) a multiple regression function was established to quantitatively describe the permeability evolution under the combined effect of the confining pressure and pore pressure. Furthermore, increasing the back pressure reduces the osmotic pressure and can effectively weaken the slippage effect, indicating that the back pressure has an essential effect on permeability evolution. The slip and transition flow, which account for a large proportion of all flow patterns, play a significant role in the slippage effect on permeability.

Effect of Cellulose Acetate (CA-398-10 NF/ EP) on Osmotically Controlled Drug Delivery System of Amitriptyline

Background: Amitriptyline hydrochloride is a Tricyclic Antidepressant (TCA) belonging to BCS class I exhibiting only 30-60% bioavailability and often coupled with poor patient compliance. The primary objective was to develop a formulation with commercial viability and to reduce dosing frequency in order to promote adherence of depressed patients to the treatment regime. The study also focused on reducing the dose of amitriptyline by controlling the release using osmotic technology; thereby reducing the side effects of amitriptyline. Methods: Controlled Porosity Osmotic Pump (CPOP) systems eliminate the need for expensive drilling processes and in turn are apt for industrial manufacturing systems where as other osmotic systems have practical limitations. Wet granulation technique was used for the formulation of CPOP tablets of amitriptyline as burst release was observed in directly compressed tablets. Screening of polymers, osmogen and weight gain were performed. Results: F6-D3 (3 % Di-butyl phthalate) with lactose as osmogen and HPMC K 35 M as polymer was optimized. The drug release from the optimized formulation was found to be independent of the effect of agitational intensity and pH. To confirm the osmotic release mechanism, the osmotic pressure of the dissolution medium was increased. The drug release decreased markedly due to an increase in osmotic pressure. Conclusion: Accelerated Stability studies were carried out in ICH certified stability chambers as per the specifications and were found to be stable. It was evident that osmotic pressure generated within the CPOP tablets along with the controlled formation of pores using Cellulose Acetate (CA-398-10 EP/ NP) was able to control the release of amitriptyline hydrochloride for 24 hours. Thus, the Oral Osmotic Drug Delivery system is a promising technology for product life-cycle strategies.