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result(s) for
"Dispersing"
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Enhancement of Bottle Gourd Oil Activity via Optimized Self-Dispersing Lipid Formulations (SDLFs) to Mitigate Isoproterenol-Evoked Cardiac Toxicity in Rats via Modulating BNP, MMP2, and miRNA-21 and miRNA-23a Genes’ Expression
2023
Bottle gourd (BG) oil (family Cucurbitaceae) has several pharmacological activities including a reduction of the hazard of cardiovascular and atherosclerosis conditions. This work aimed to develop and optimize self-dispersing lipid formulations (SDLFs) of BG oil by applying a full 32 factorial design. The formulation variables (oil concentration and surfactant mixture ratio) showed an obvious impact on the characters of the prepared BG-SDLFs including droplet size (DS), polydispersity index (PDI), emulsification time (ET), and transmission percentage (Tr%). The optimum BG-SDLF composed of 30% oil and Tween 80/Cremophor® RH40 (1:1) showed good emulsification characteristics and a better drug release profile compared with BG oil. In vivo study in isoproterenol-injected rats showed that BG oil and the optimized BG-SDLF improved cardiac function, by elevating the miRNA-23a gene expression level and decreasing miRNA-21 gene expression. They also caused the inhibition of the plasma B-type natriuretic peptide (BNP), N-terminal proatrial natriuretic peptide (NT-pro-BNP), cystatin c, galectin-3, lipoprotein-associated phospholipase A2 (Lp-PLA2), matrix metallopeptidase 2 (MMP2), cardiac troponin I (cTnI), and cardiac troponin T (cTnT). Our study demonstrated that BG oil and the optimized BG-SDLF provided a cardioprotection against isoproterenol-induced cardiac toxicity with better results in groups treated with the optimized BG-SDLF.
Journal Article
Functional characterization of neuropeptides that act as ligands for both calcitonin-type and pigment-dispersing factor-type receptors in a deuterostome
2025
The calcitonin (CT) family of related peptides exerts diverse physiological effects in mammals via two G-protein-coupled receptors: CTR and the CTR-like receptor CLR. Phylogenetic analysis of CT-type signaling has revealed the presence of CT-type peptides and CTR/CLR-type proteins in both deuterostome and protostome invertebrates. Furthermore, experimental studies have demonstrated that in the protostome Drosophila melanogaster, the CT-like peptide DH 31 can act as a ligand for a CTR/CLR-type receptor and a pigment-dispersing factor (PDF) receptor. Here, we investigated the signaling mechanisms and functions of CT-type neuropeptides in a deuterostome invertebrate, the sea cucumber Apostichopus japonicus (phylum Echinodermata). In A. japonicus, a single gene encodes two CT-type peptides (AjCT1 and AjCT2), and both peptides act as ligands for a CTR/CLR-type receptor (AjCTR) and two PDF-type receptors (AjPDFR1, AjPDFR2), but with differential activation of downstream cAMP/PKA, Gαq/Ca 2+ /PKC, and ERK1/2 signaling pathways. AjCT1/AjCT2-encoding transcripts were detected in the central nervous system and a variety of organ systems, and neuropeptide expression was visualized immunohistochemically using an antiserum to a starfish CT-type peptide (ArCT). In vitro pharmacological experiments demonstrated that AjCT1 and/or AjCT2 cause dose-dependent relaxation of longitudinal muscle and intestine preparations. Furthermore, in vivo pharmacological experiments, combined with gain- and loss-of-function experiments, revealed a potential physiological role for AjCT2/AjPDFR2 signaling in promoting feeding and growth in A. japonicus . To our knowledge, this is the first study to obtain evidence that CT-type peptides can act as ligands for both CTR/CLR-type and PDF-type receptors in a deuterostome. Moreover, it provides the first evidence for appetite-stimulating and growth-promoting effects of CT-type neuropeptides in bilaterians. Given the economic importance of A. japonicus as a foodstuff, the discovery of CT-type peptides as potential regulators of feeding and growth in this species may offer novel strategies for aquaculture applications.
Journal Article
Neuropeptidergic Signaling in the American Lobster Homarus americanus: New Insights from High-Throughput Nucleotide Sequencing
by
Stanhope, Meredith E.
,
Pascual, Micah G.
,
Schulz, David J.
in
American lobster
,
Amino Acid Sequence
,
Animal models
2015
Peptides are the largest and most diverse class of molecules used for neurochemical communication, playing key roles in the control of essentially all aspects of physiology and behavior. The American lobster, Homarus americanus, is a crustacean of commercial and biomedical importance; lobster growth and reproduction are under neuropeptidergic control, and portions of the lobster nervous system serve as models for understanding the general principles underlying rhythmic motor behavior (including peptidergic neuromodulation). While a number of neuropeptides have been identified from H. americanus, and the effects of some have been investigated at the cellular/systems levels, little is currently known about the molecular components of neuropeptidergic signaling in the lobster. Here, a H. americanus neural transcriptome was generated and mined for sequences encoding putative peptide precursors and receptors; 35 precursor- and 41 receptor-encoding transcripts were identified. We predicted 194 distinct neuropeptides from the deduced precursor proteins, including members of the adipokinetic hormone-corazonin-like peptide, allatostatin A, allatostatin C, bursicon, CCHamide, corazonin, crustacean cardioactive peptide, crustacean hyperglycemic hormone (CHH), CHH precursor-related peptide, diuretic hormone 31, diuretic hormone 44, eclosion hormone, FLRFamide, GSEFLamide, insulin-like peptide, intocin, leucokinin, myosuppressin, neuroparsin, neuropeptide F, orcokinin, pigment dispersing hormone, proctolin, pyrokinin, SIFamide, sulfakinin and tachykinin-related peptide families. While some of the predicted peptides are known H. americanus isoforms, most are novel identifications, more than doubling the extant lobster neuropeptidome. The deduced receptor proteins are the first descriptions of H. americanus neuropeptide receptors, and include ones for most of the peptide groups mentioned earlier, as well as those for ecdysis-triggering hormone, red pigment concentrating hormone and short neuropeptide F. Multiple receptors were identified for most peptide families. These data represent the most complete description of the molecular underpinnings of peptidergic signaling in H. americanus, and will serve as a foundation for future gene-based studies of neuropeptidergic control in the lobster.
Journal Article
Reinforcement of Cement Nanocomposites through Optimization of Mixing Ratio between Carbon Nanotube and Polymer Dispersing Agent
2024
Carbon nanotubes (CNTs), known for their exceptional mechanical, thermal, and electrical properties, are being explored as cement nanofillers in the construction field. However, due to the limited water dispersion of CNTs, polymer dispersing agents like polycarboxylate ether (PCE) and sulfonated naphthalene formaldehyde (SNF) are essential for uniform dispersion. In a previous study, PCE and SNF, common cement superplasticizers, effectively dispersed CNTs in cement nanocomposites. However, uncertainties remained regarding the extent to which all dispersing agents interacted efficiently with CNTs. Therefore, this research quantitatively assessed CNT interaction with dispersing agents through dispersion and centrifugation. Approximately 37% of PCE and 50% of SNF persisted compared to CNT after centrifugation. The resulting cement nanocomposites, with optimized mixing ratios, exhibited enhanced compressive strength of about 14% for CNT/PCE (78.13 MPa) and 12.3% for CNT/SNF (76.97 MPa) compared to plain cement (68.52 MPa). XRD results linked strength reinforcement to increased cement hydrate from optimized CNT dispersion. FE-SEM analysis revealed that CNTs were positioned within the pores of the cement. These optimized cement nanocomposites hold promise for improved safety in the construction industry.
Journal Article
Research and Analysis on Dispersing Performance of Nano-TiO2 Powder in Water
2016
Due to the characteristics such as fine grain, large surface area, high surface free energy and serious insufficient of atomic coordinate, nanoTiO2 is easy to conglobated in solution and further affect its application seriously. The agglomerate mechanism of nanoTiO2 in solution was studied and the reason of agglomeration was analyzed. Experiments were conducted to research the influence law on dispersing stability of nanoTiO2 powder in water by factors of dispersant type, dispersant content and dispersing process of ultrasonic dispersing and high-speed stirring. The dispersing stability of nanoTiO2 powder in water is evaluated by combining gravity deposition method with electronic microscopy analysis. According to the research, dispersant type and dispersant mixing amount have great influence on the dispersing property of nanoTiO2 powder, and the inorganic dispersant sodium tripolyphosphate achieved better dispersing effect. Furthermore, ultrasonic dispersing and high-speed stirring can improve the dispersing stability of nanoTiO2 powder and after high-speed stirring at first and then ultrasonic dispersing, the dispersing effect of nanoTiO2 powder is much better.
Journal Article
Using dispersants after oil spills: impacts on the composition and activity of microbial communities
by
Paul, John H.
,
Kleindienst, Sara
,
Joye, Samantha B.
in
631/326/171
,
631/326/171/1878
,
631/326/1762
2015
Chemical dispersants are routinely applied during oil spills in marine ecosystems, yet little is known about how they affect microbial communities. Here, Joye and colleagues explore how dispersants affect the composition and activity of microbial communities and discuss crucial knowledge gaps that should guide future research efforts.
Dispersants are globally and routinely applied as an emergency response to oil spills in marine ecosystems with the goal of chemically enhancing the dissolution of oil into water, which is assumed to stimulate microbially mediated oil biodegradation. However, little is known about how dispersants affect the composition of microbial communities or their biodegradation activities. The published findings are controversial, probably owing to variations in laboratory methods, the selected model organisms and the chemistry of different dispersant–oil mixtures. Here, we argue that an in-depth assessment of the impacts of dispersants on microorganisms is needed to evaluate the planning and use of dispersants during future responses to oil spills.
Journal Article
Respiratory, Dermal, and Eye Irritation Symptoms Associated with CorexitTM EC9527A/EC9500A following the Deepwater Horizon Oil Spill: Findings from the GuLF STUDY
by
Engel, Lawrence S
,
McGowan, Craig J
,
Stenzel, Mark R
in
Dispersing agents
,
Environmental health
,
Health aspects
2017
BACKGROUND: The large quantities of chemical oil dispersants used in the oil spill response and cleanup (OSRC) work following the Deepwater Horizon disaster provide an opportunity to study associations between dispersant exposure (Corexit[TM] EC9500A or EC9527A) and human health. OBJECTIVES: Our objectives were to examine associations between potential exposure to the dispersants and adverse respiratory, dermal, and eye irritation symptoms. METHODS: Using data from detailed Gulf Long-term Follow-up (GuLF) Study enrollment interviews, we determined potential exposure to either dispersant from participant-reported tasks during the OSRC work. Between 27,659 and 29,468 participants provided information on respiratory, dermal, and eye irritation health. We estimated prevalence ratios (PRs) to measure associations with symptoms reported during the OSRC work and at study enrollment, adjusting for potential confounders including airborne total hydrocarbons exposure, use of cleaning chemicals, and participant demographics. RESULTS: Potential exposure to either of the dispersants was significantly associated with all health outcomes at the time of the OSRC, with the strongest association for burning in the nose, throat, or lungs [adjusted PR (aPR) = 1.61 (95% CI: 1.42, 1.82)], tightness in chest [aPR= 1.58 (95% CI: 1.37, 1.81)], and burning eyes [aPR = 1.48 (95% CI: 1.35, 1.64). Weaker, but still significant, associations were found between dispersant exposure and symptoms present at enrollment. CONCLUSIONS: Potential exposure to Corexit[TM] EC9527A or EC9500A was associated with a range of health symptoms at the time of the OSRC, as well as at the time of study enrollment, 1-3 y after the spill.
Journal Article
Influence of Dispersing Method on the Quality of Nano-Admixtures Homogenization in Cement Matrix
by
Łukowski, Paweł
,
Horszczaruk, Elżbieta
,
Seul, Cyprian
in
Admixtures
,
Carbon
,
Cement hydration
2020
In recent years, a nano-modification of the cement composites allowed to develop a number of new materials. The use of even small amount of nano-admixture makes possible not only to improve the physico-mechanical properties of the cement materials, but also to obtain the composite with high usability, optimised for the given application. The basic problem of nano-modification of the cement composites remains the effectiveness of dispersing the nanomaterials inside the cement matrix. This paper deals with the effect of the type and size of the nanoparticles on the tendency to their agglomeration in the cement matrix. The main techniques and methods of dispersing the nanomaterials are presented. It has been demonstrated, on the basis of the results of testing of three nanomodifiers of 0D type (nano-SiO2, nano-Fe3O4 and nano-Pb3O4), how the structure and properties of the nanomaterial affect the behaviour of the particles when dissolving in the mixing water and applying a superplasticiser. The nanoparticles had similar size of about 100 nm but different physico-chemical properties. The methods of dispersing covered the use of high-speed mechanical stirring and ultrasonication. The influence of the method of nano-modifier dispersing on the mechanical performance of the cement composite has been presented on the basis of the results of testing the cement mortars modified with 3% admixture of nano-SiO2.
Journal Article
Effect of Silica Fume as a Waste Material for Sustainable Environment on the Stabilization and Dynamic Behavior of Dispersive Soil
2021
The use of dispersive soils, which are common in many parts of the world, in engineering applications such as water structures, earthen dams and road embankments is possible with their improvement. Recently, the effects of different chemicals on the stabilization of dispersive soils have been investigated. The use of waste materials in stabilization is preferred both because of the more sustainable environment and the economic advantages it provides. The use of silica fume (SF) as a waste material in different engineering applications provides an important advantage in environmentally and economically sustainable ways. Many studies have been carried out regarding silica fume, especially in the construction industry. Although SF is used in many industries, there is no study about its potential impact on the stabilization and dynamic properties of dispersive soils. In this study, first, Atterberg limits and standard Proctor compaction tests were performed on the mixtures prepared by adding different SF percentages (0, 5, 10, 15, 20, 25 and 30%). Afterward, pinhole tests and resonant column tests were performed to determine dispersibility and dynamic properties on the samples prepared by compaction characteristics for each SF percentage reached. In general, it was determined that SF contributed to a change in soil class, and improvement in dispersibility and dynamic properties of the soil sample, depending on SF content; positive effects of SF were observed in terms of shallow soil improvement.
Journal Article
The effect of amorphous Si3N4 nanoparticles and magnetized distilled water on the mechanical properties and infrared transmittance of α-Al2O3
by
Loghman-Estarki, Mohammad Reza
,
Vafaei, Reza
,
Eshaghi, Akbar
in
639/166
,
639/301
,
Amorphous Si3N4 nanoparticles
2025
This study resolves the inherent trade-off between fracture toughness and mid-infrared transparency in α-Al
2
O
3
ceramics. A novel shear-stress thin-layer process with magnetic-field-assisted dispersion achieves uniform distribution of 0.1 wt% amorphous Si
3
N
4
nanoparticles and MgO/La
2
O
3
sintering aids using 2 wt% DL dispersant at pH 10. Post-annealing at 1200 °C enhances fracture toughness by 126% (3.4 ± 0.2 to 7.68 ± 0.3 MPa m
1/2
) while reducing hardness from 23.6 ± 0.8 GPa to 12.6 ± 0.5 GPa, confirming improved ductility. XRD analysis verifies compressive residual stress (− 1.60 ± 0.08 GPa) and lattice strain (− 0.49 ± 0.05%). FESEM/EDS reveals grain refinement from 402 ± 18 nm to 124 ± 6 nm with homogeneity index exceeding 0.93. These microstructural modifications enable 85.3 ± 0.5% mid-infrared transmittance between 3 and 6 μm, surpassing conventional transparent alumina by 41%. This approach establishes a scalable method for designing multifunctional ceramics with simultaneous mechanical resilience and optical performance.
Journal Article