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Avesani, Diego, Michael Dumbser, Renato Vacondio, and Maurizio Righetti. "An alternative SPH formulation: ADER-WENO-SPH." Computer Methods in Applied Mechanics and Engineering 382 (August 2021): 113871. http://dx.doi.org/10.1016/j.cma.2021.113871.
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Chow, E., and J. J. Monaghan. "Ultrarelativistic SPH." Journal of Computational Physics 134, no. 2 (July 1997): 296–305. http://dx.doi.org/10.1006/jcph.1997.5708.
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Krautscheid, Ulrike, Somanath Dev, Harald Krautscheid, Partha P. Paul, Scott R. Wilson, and Thomas B. Rauchfuss. "N-Methylimidazole Mediated Chemistry of Transition Metal Phenylthiolates. The Isolation of the Perthiolate Salts [M(N-MeIm)6](S2Ph)2." Zeitschrift für Naturforschung B 48, no. 5 (May 1, 1993): 653–58. http://dx.doi.org/10.1515/znb-1993-0515.
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Salts of the composition [M(N-MeIm)6](SPh)2 (M = Mn, Ni; N-MeIm = N-methylimidazole) were prepared by dissolution of the metal powders with N-MeIm solutions of Ph2S2. X-ray crystallographic examination established that these salts indeed feature uncoordinated PhS-. The salts [M(N-McIm)6](SPh)2 (M = Mn, Ni) react with S8 to give [M(N-MeIm)6]S8 via the intermediacy of the perthiolate salts [M(N-MeIm)6](S2Ph)2.
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Frei, Anne C., YiHe Guo, Deron W. Jones, Kirkwood A. Pritchard, Karen A. Fagan, Neil Hogg, and Nancy J. Wandersee. "Vascular dysfunction in a murine model of severe hemolysis." Blood 112, no. 2 (July 15, 2008): 398–405. http://dx.doi.org/10.1182/blood-2007-12-126714.
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Abstract Spectrin is the backbone of the erythroid cytoskeleton; sph/sph mice have severe hereditary spherocytosis (HS) because of a mutation in the murine erythroid α-spectrin gene. sph/sph mice have a high incidence of thrombosis and infarction in multiple tissues, suggesting significant vascular dysfunction. In the current study, we provide evidence for both pulmonary and systemic vascular dysfunction in sph/sph mice. We found increased levels of soluble cell adhesion molecules in sph/sph mice, suggesting activation of the vascular endothelium. We hypothesized that plasma hemoglobin released by intravascular hemolysis initiates endothelial injury through nitric oxide (NO) scavenging and oxidative damage. Likewise, electron paramagnetic resonance spectroscopy showed that plasma hemoglobin is much greater in sph/sph mice. Moreover, plasma from sph/sph mice had significantly higher oxidative potential. Finally, xanthine oxidase, a potent superoxide generator, is decreased in subpopulations of liver hepatocytes and increased on liver endothelium in sph/sph mice. These results indicate that vasoregulation is abnormal, and NO-based vasoregulatory mechanisms particularly impaired, in sph/sph mice. Together, these data indicate that sph/sph mice with severe HS have increased plasma hemoglobin and NO scavenging capacity, likely contributing to aberrant vasoregulation and initiating oxidative damage.
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Olkowski, Brian F., and Angela M. Stolfi. "Safe Patient Handling Perceptions and Practices: A Survey of Acute Care Physical Therapists." Physical Therapy 94, no. 5 (May 1, 2014): 682–95. http://dx.doi.org/10.2522/ptj.20120539.
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BackgroundAcute care physical therapists are at risk for developing work-related musculoskeletal disorders (WMSDs) due to manual patient handling. Safe patient handling (SPH) reduces WMSDs caused by manual handling.ObjectiveThe purpose of this study was to describe the patient handling practices of acute care physical therapists and their perceptions regarding SPH. Additionally, this study determined whether an SPH program influences the patient handling practices and perceptions regarding SPH of acute care physical therapists.MethodsSubscribers to the electronic discussion board of American Physical Therapy Association's Acute Care Section were invited to complete a survey questionnaire.ResultsThe majority of respondents used SPH equipment and practices (91.1%), were confident using SPH equipment and practices (93.8%), agreed that evidence supports the use of SPH equipment and practices (87.0%), and reported the use of SPH equipment and practices is feasible (92.2%). Respondents at a facility with an SPH program were more likely to use SPH equipment and practices, have received training in the use of SPH equipment and practices, agree that the use of SPH equipment and practices is feasible, and feel confident using SPH equipment and practices.LimitationsThe study might not reflect the perceptions and practices of the population of acute care physical therapists.ConclusionAcute care physical therapists are trained to use SPH equipment and practices, use SPH equipment and practices, and have positive perceptions regarding SPH. Acute care physical therapists in a facility with an SPH program are more likely to use SPH equipment and practices, receive training in SPH equipment and practices, and have positive perceptions regarding SPH. Quasi-regulatory organizations should incorporate SPH programs into their evaluative standards.
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Hisano, Nobuo, Yutaka Yatomi, Kaneo Satoh, Shigeo Akimoto, Masako Mitsumata, Masayuki A. Fujino, and Yukio Ozaki. "Induction and Suppression of Endothelial Cell Apoptosis by Sphingolipids: A Possible In Vitro Model for Cell-Cell Interactions Between Platelets and Endothelial Cells." Blood 93, no. 12 (June 15, 1999): 4293–99. http://dx.doi.org/10.1182/blood.v93.12.4293.
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Abstract Because sphingosine (Sph) is actively incorporated into platelets and rapidly converted to sphingosine 1-phosphate (Sph-1-P), which is then released extracellularly, it is important to study the effects of Sph and Sph-1-P on endothelial cells from the viewpoint of platelet-endothelial cell interaction. In this study, we found that Sph, as well as ceramide, induces apoptosis in human umbilical vein endothelial cells (HUVECs). In contrast, Sph-1-P acts as a HUVEC survival factor; this bioactive lipid was shown to protect HUVECs from apoptosis induced by the withdrawal of growth factors and to stimulate HUVEC DNA synthesis. In metabolic studies, [3H]Sph, incorporated into HUVECs, was converted to [3H]Cer and further to [3H]sphingomyelin in a time-dependent manner, whereas [3H]Sph-1-P formation from [3H]Sph was weak and transient. These findings in HUVECs are very different from those of platelets, which possess a highly active Sph kinase but lack Sph-1-P lyase. As a result, platelets abundantly store Sph-1-P, whereas HUVECs contain much less Sph-1-P. Finally, HUVECs, in contrast to platelets, failed to release Sph-1-P extracellularly, indicating that HUVECs themselves are not able to supply the survival factor Sph-1-P, but receive it from activated platelets. Our results suggest that platelets may maintain the integrity of endothelial cells by incorporating Sph and releasing Sph-1-P.
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Hisano, Nobuo, Yutaka Yatomi, Kaneo Satoh, Shigeo Akimoto, Masako Mitsumata, Masayuki A. Fujino, and Yukio Ozaki. "Induction and Suppression of Endothelial Cell Apoptosis by Sphingolipids: A Possible In Vitro Model for Cell-Cell Interactions Between Platelets and Endothelial Cells." Blood 93, no. 12 (June 15, 1999): 4293–99. http://dx.doi.org/10.1182/blood.v93.12.4293.412k26_4293_4299.
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Because sphingosine (Sph) is actively incorporated into platelets and rapidly converted to sphingosine 1-phosphate (Sph-1-P), which is then released extracellularly, it is important to study the effects of Sph and Sph-1-P on endothelial cells from the viewpoint of platelet-endothelial cell interaction. In this study, we found that Sph, as well as ceramide, induces apoptosis in human umbilical vein endothelial cells (HUVECs). In contrast, Sph-1-P acts as a HUVEC survival factor; this bioactive lipid was shown to protect HUVECs from apoptosis induced by the withdrawal of growth factors and to stimulate HUVEC DNA synthesis. In metabolic studies, [3H]Sph, incorporated into HUVECs, was converted to [3H]Cer and further to [3H]sphingomyelin in a time-dependent manner, whereas [3H]Sph-1-P formation from [3H]Sph was weak and transient. These findings in HUVECs are very different from those of platelets, which possess a highly active Sph kinase but lack Sph-1-P lyase. As a result, platelets abundantly store Sph-1-P, whereas HUVECs contain much less Sph-1-P. Finally, HUVECs, in contrast to platelets, failed to release Sph-1-P extracellularly, indicating that HUVECs themselves are not able to supply the survival factor Sph-1-P, but receive it from activated platelets. Our results suggest that platelets may maintain the integrity of endothelial cells by incorporating Sph and releasing Sph-1-P.
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Wandersee, Nancy J., John C. Lee, Tamma M. Kaysser, Roderick T. Bronson, and Jane E. Barker. "Hematopoietic Cells From -Spectrin–Deficient Mice Are Sufficient to Induce Thrombotic Events in Hematopoietically Ablated Recipients." Blood 92, no. 12 (December 15, 1998): 4856–63. http://dx.doi.org/10.1182/blood.v92.12.4856.
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Abstract Thrombotic events are life-threatening complications of human hemolytic anemias such as paroxysmal nocturnal hemoglobinuria, sickle cell disease, and thalassemia. It is not clear whether these events are solely influenced by aberrant hematopoietic cells or also involve aberrant nonhematopoietic cells. Spherocytosis mutant (Spna1sph/Spna1sph; for simplicity referred to as sph/sph) mice develop a severe hemolytic anemia postnatally due to deficiencies in -spectrin in erythroid and other as yet incompletely defined nonerythroid tissues. Thrombotic lesions occur in all adult sph/sph mice, thus providing a hematopoietically stressed model in which to assess putative causes of thrombus formation. To determine whether hematopoietic cells fromsph/sph mice are sufficient to initiate thrombi, bone marrow from sph/sph or +/+ mice was transplanted into mice with no hemolytic anemia. One set of recipients was lethally irradiated; the other set was genetically stem cell deficient. All mice implanted withsph/sph marrow, but not +/+ marrow, developed severe anemia and histopathology typical of sph/sph mice. Histological analyses of marrow recipients showed that thrombi were present in the recipients of sph/sph marrow, but not +/+ marrow. The results indicate that the -spectrin–deficient hematopoietic cells of sph/sph mice are the primary causative agents of the thrombotic events.
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Wandersee, Nancy J., John C. Lee, Tamma M. Kaysser, Roderick T. Bronson, and Jane E. Barker. "Hematopoietic Cells From -Spectrin–Deficient Mice Are Sufficient to Induce Thrombotic Events in Hematopoietically Ablated Recipients." Blood 92, no. 12 (December 15, 1998): 4856–63. http://dx.doi.org/10.1182/blood.v92.12.4856.424k31_4856_4863.
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Thrombotic events are life-threatening complications of human hemolytic anemias such as paroxysmal nocturnal hemoglobinuria, sickle cell disease, and thalassemia. It is not clear whether these events are solely influenced by aberrant hematopoietic cells or also involve aberrant nonhematopoietic cells. Spherocytosis mutant (Spna1sph/Spna1sph; for simplicity referred to as sph/sph) mice develop a severe hemolytic anemia postnatally due to deficiencies in -spectrin in erythroid and other as yet incompletely defined nonerythroid tissues. Thrombotic lesions occur in all adult sph/sph mice, thus providing a hematopoietically stressed model in which to assess putative causes of thrombus formation. To determine whether hematopoietic cells fromsph/sph mice are sufficient to initiate thrombi, bone marrow from sph/sph or +/+ mice was transplanted into mice with no hemolytic anemia. One set of recipients was lethally irradiated; the other set was genetically stem cell deficient. All mice implanted withsph/sph marrow, but not +/+ marrow, developed severe anemia and histopathology typical of sph/sph mice. Histological analyses of marrow recipients showed that thrombi were present in the recipients of sph/sph marrow, but not +/+ marrow. The results indicate that the -spectrin–deficient hematopoietic cells of sph/sph mice are the primary causative agents of the thrombotic events.
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Schraufnagel, Anne C., Barb Piknova, Kirkwood A. Pritchard, Neil Hogg, and Nancy J. Wandersee. "Nitric Oxide Scavenging, Abnormal Vasoregulation and Oxidative Damage in sph/sph Mice with Severe Hereditary Spherocytosis: Possible Consequences of Red Blood Cell Hemolysis." Blood 106, no. 11 (November 16, 2005): 1660. http://dx.doi.org/10.1182/blood.v106.11.1660.1660.
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Abstract The membrane skeleton, a multiprotein complex located just beneath the plasma membrane, provides the red blood cell (RBC) with the mechanical strength and deformability required to withstand high shear forces generated in the microcapillaries. Spectrin, a tetramer composed of a- and b- subunits, is the backbone of the erythroid membrane skeleton. Previously, we have shown that sph/sph mice have severe hereditary spherocytosis (HS) due to a spontaneous single-base deletion in the murine erythroid a-spectrin gene, Spna1. HS mice have severe hemolytic anemia, compensatory reticulocytosis, altered RBC morphology and increased fragility. Vascular dysfunction in sph/sph mice likely plays an important role in the mechanism by which these mice develop a high incidence of cardiac thrombosis and stroke between 6 and 12 weeks of age. We hypothesize that serum free hemoglobin released from intravascular hemolysis of sph/sph RBCs and xanthine oxidase, released from ischemic tissues, impairs endothelial cell function by scavenging nitric oxide (NO) and increasing oxidative damage. To test this hypothesis, we used helium electroparamagnetic resonance (EPR), to quantify plasma free Hb and NO scavenging capacity in the plasma of the mice; immunohistochemistry to determine tissue and vascular levels of xanthine oxidase and 3-nitrotyrosine; and, facialis arteries to measure changes in acetylcholine, endothelium and eNOS-dependent vasodilation. By EPR we found that the plasma free Hb and NO scavenging capacity in the plasma of sph/sph mice is much greater than that of the normal +/+ mice. Immunohistochemistry (IHC) for XO and NTyr revealed XO staining was decreased in livers of sph/sph mice as compared to livers from normal +/+ mice. XO staining was increased in local patches on the endothelium of lungs isolated from sph/sph mice compared to lungs from +/+ mice. NTyr, a marker of peroxynitrite formation was also increased in a focal manner in lungs of sph/sph mice compared to lungs of +/+ mice. Acetylcholine-induced and eNOS-dependent vasodilation in sph/sph mice was significantly impaired compared to vasodilation in normal +/+ mice. Taken together these data suggest the hemoglobin removal system in sph/sph mice is saturated, leading to increased free Hb and nitric oxide scavenging. IHC studies reveal XO is released from liver in sph/sph mice and once released binds the endothelium of lung, quite distal from the original site of injury. Such changes likely contribute to marked increases in NTyr staining and impaired endothelium and eNOS-dependent vasodilation in facialis arteries isolated from sph/sph mice. Taken together, these data indicate that sph/sph mice with severe HS have increased plasma free Hb and NO scavenging capacity as well as increased release of xanthine oxidase and subsequent binding to vascular endothelial cells to locations that are distal the original site of injury. Such plasma and vascular changes in hemoglobin and oxidative enzymes likely play a critical role in the mechanisms contributing to aberrant vasoregulation and initiating the pathways of oxidative damage found in sph/sph mice.
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Dong, Ye, Wen Yan, and Yi-Qi Zhang. "Effects of Spray Drying and Freeze Drying on Physicochemical Properties, Antioxidant and ACE Inhibitory Activities of Bighead Carp (Aristichthys nobilis) Skin Hydrolysates." Foods 11, no. 14 (July 13, 2022): 2083. http://dx.doi.org/10.3390/foods11142083.
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The physicochemical, structural properties, antioxidant, and angiotensin I-converting enzyme (ACE) inhibitory activities of fish skin protein hydrolysate (SPH) that were freeze-dried (SPH-FD) and spray-dried (SPH-SD) were investigated. SPH-SD showed abundant volatile compounds, higher DPPH radical scavenging activity and ferrous iron chelating activity than SPH-FD, while the ABTS radical scavenging activity and ACE inhibitory activity were not influenced by the drying method. Amino acid compositions showed a higher proportion of proline and hydroxyproline residues in SPH-FD. The major molecular weights were both distributed below 1000 Da. SPH-SD had spherical structures, while SPH-FD had glass shard-like structures. The results indicated that the drying method could affect the physicochemical properties of hydrolysates, and SPH-SD showed potential prospects in developing functional fortified foods.
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Barrett, Bradford S., and Sultan Hameed. "Seasonal Variability in Precipitation in Central and Southern Chile: Modulation by the South Pacific High." Journal of Climate 30, no. 1 (January 2017): 55–69. http://dx.doi.org/10.1175/jcli-d-16-0019.1.
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Monthly precipitation in Chile (30°–55°S) was found to vary by intensity, latitude, and longitude of the South Pacific high (SPH). In austral winter, precipitation was higher when the SPH was weaker and when it was centered farther west. In austral spring, precipitation was higher when the SPH was weaker, similar to winter. However, spring precipitation was not found to be related to SPH longitude, and higher precipitation was found when the SPH was centered farther north. In austral summer, no relationship was found between precipitation and either SPH intensity or longitude, but positive correlations were found between precipitation and latitude of the SPH. In austral autumn, correlation patterns between precipitation and all three SPH metrics more closely resembled those seen in winter. The results of a multiple linear regression confirmed the importance of two SPH metrics (intensity and longitude) and the unimportance of a third SPH metric (latitude) in understanding variability in winter, summer, and autumn precipitation in central and southern Chile. In spring, regression results confirmed a relationship between precipitation and SPH intensity and latitude. Furthermore, the SPH intensity and longitude in winter combined to hindcast monthly precipitation with a better goodness of fit than five El Niño–Southern Oscillation metrics traditionally related to Chilean precipitation. Anomalies of lower-tropospheric circulation and vertical velocities were found to support the observed relationships between SPH and precipitation. Based on these results, a physical mechanism is proposed that employs the SPH as a metric to aid in understanding variability in precipitation in central and south-central Chile in all seasons.
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Năstăsescu, Vasile. "FEM or SPH ?" Journal of Engineering Sciences and Innovation 1, no. 1 (August 30, 2016): 34–48. http://dx.doi.org/10.56958/jesi.2016.1.1.34.
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This paper brings, in front of the reader, some aspects regarding the using of those numerical methods, perhaps most used, for analysis of the fluids and structures. Next to the FEM (Finite Element Method), new numerical methods appeared, among these, the methods named meshfree methods are nowadays most used. The SPH (Smoothed Particle Hydrodynamics) method belongs to this category of meshfree method, being the most used in different fields like astrophysical phenomena, fluid dynamics, structure dynamics and others. The paper put face to face some results obtained by FEM and SPH, so the reader can alone to appreciate which method is better in a given problem or other. For to facilitate analysis and to understand the results, the fundamentals of SPH method are presented. In contrast to FEM, the SPH method is less known and less used in Romania. This finding underlies the emergence of this article. The answer to the title question depends on every one and it is influenced by many factors. Finally, the author suggests an answer by a correction of the title question: FEM and SPH or FEM with SPH.
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Ihmsen, Markus, Jens Cornelis, Barbara Solenthaler, Christopher Horvath, and Matthias Teschner. "Implicit Incompressible SPH." IEEE Transactions on Visualization and Computer Graphics 20, no. 3 (March 2014): 426–35. http://dx.doi.org/10.1109/tvcg.2013.105.
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Monaghan, J. J. "SPH compressible turbulence." Monthly Notices of the Royal Astronomical Society 335, no. 3 (September 2002): 843–52. http://dx.doi.org/10.1046/j.1365-8711.2002.05678.x.
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Nimmala, Praneeth Reddy, and Amala Dass. "Au36(SPh)23Nanomolecules." Journal of the American Chemical Society 133, no. 24 (June 22, 2011): 9175–77. http://dx.doi.org/10.1021/ja201685f.
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Gray, J. P., J. J. Monaghan, and R. P. Swift. "SPH elastic dynamics." Computer Methods in Applied Mechanics and Engineering 190, no. 49-50 (October 2001): 6641–62. http://dx.doi.org/10.1016/s0045-7825(01)00254-7.
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Vyas, Dhairya R., Sharen J. Cummins, Murray Rudman, Paul W. Cleary, Gary W. Delaney, and Devang V. Khakhar. "Collisional SPH: A method to model frictional collisions with SPH." Applied Mathematical Modelling 94 (June 2021): 13–35. http://dx.doi.org/10.1016/j.apm.2021.01.005.
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Yatomi, Y., F. Ruan, S. Hakomori, and Y. Igarashi. "Sphingosine-1-phosphate: a platelet-activating sphingolipid released from agonist-stimulated human platelets." Blood 86, no. 1 (July 1, 1995): 193–202. http://dx.doi.org/10.1182/blood.v86.1.193.bloodjournal861193.
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Sphingosine-1-phosphate (Sph-1-P) is the initial product of catabolism of sphingosine by sphingosine kinase and is cleaved by Sph-1-P lyase to a fatty aldehyde and ethanolamine phosphate. This phosphorylated sphingoid base is not only an intermediary catabolite, but also a bioactive lipid with important functions, including stimulation of cell proliferation in Swiss 3T3 fibroblasts and inhibition of tumor cell motility. In the present study, we examined functional roles of Sph-1-P in human platelets. Sph-1-P induced platelet shape change and aggregation reactions, although it failed to elicit secretion. Sphingosine, ceramide, sphingomyelin, and N,N-dimethylsphingosine did not mimic the positive effects of Sph-1-P on platelets. Subthreshold concentrations of Sph-1-P and weak platelet agonists such as adenosine diphosphate (ADP) and epinephrine synergistically elicited aggregation, which may be important for efficient amplification of platelet activation. Sph-1-P induced intracellular Ca2+ mobilization and the dose-response for Ca2+ release correlated closely with the concentration required for induction of shape change. On addition of [3H]sphingosine to intact platelets, the label was rapidly converted to Sph-1-P, and subsequently to ceramide and sphingomyelin. Interestingly, the Sph-1-P formed was specifically released into medium on stimulation of platelets with physiologic agonists. The amount of Sph-1-P in platelets, as measured by its conversion into radiolabeled N-acetyl-Sph- 1-P, was 1.4 nmol/10(9) cells and was about four times higher than the mass of Sph present. When compared by mole percent Sph-1- P/phospholipid, the value for platelets is over 10 times higher than that for neutrophils. Our results suggest that Sph-1-P, rapidly converted from sphingosine, abundantly stored in platelets, and released on the cell activation, may play a physiologic role in thrombosis, hemostasis, and the natural wound-healing processes.
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Micek, Hannah M., Lauren Rosenstock, Yicheng Ma, Caitlin Hielsberg, Lauren Montemorano, Metti K. Gari, Suzanne M. Ponik, and Pamela K. Kreeger. "Model of collective detachment in high-grade serous ovarian cancer demonstrates that tumor spheroids produce ECM to support metastatic processes." APL Bioengineering 7, no. 1 (March 1, 2023): 016111. http://dx.doi.org/10.1063/5.0132254.
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High-grade serous ovarian cancer (HGSOC) metastasizes through transcoelomic spread, with both single cells and spheroids of tumor cells observed in patient ascites. These spheroids may form through single cells that detach and aggregate (Sph-SC) or through collective detachment (Sph-CD). We developed an in vitro model to generate and separate Sph-SC from Sph-CD to enable study of Sph-CD in disease progression. In vitro-generated Sph-CD and spheroids isolated from ascites were similar in size (mean diameter 51 vs 55 μm, p > 0.05) and incorporated multiple ECM proteins. Using the in vitro model, nascent protein labeling, and qRT-PCR, we determined that ECM was produced after detachment. As fibronectin plays a key role in many cell adhesion events, we confirmed that inhibiting RGD-based adhesion or fibronectin assembly reduced Sph-CD-mesothelial adhesion strength under shear stress. Our model will enable future studies to determine factors that favor formation of Sph-CD, as well as allow investigators to manipulate Sph-CD to better study their effects on HGSOC progression.
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Tremel, Wolfgang, Bernt Krebs, Klaus Greiwe, Wolfgang Simon, Hans-Oscar Stephan, and Gerald Henkel. "[Mn(SPh)3Cl]2-, [Mn(SPh)3Br]2-, [Mn(SePh)4]2-, [Mn(TePh)4]2-, and [Co4(SPh)6Cl4]2-: New Mixed Halide/Thiolate and Chalcogenolate Complexes of Manganese and Cobalt." Zeitschrift für Naturforschung B 47, no. 11 (November 1, 1992): 1580–92. http://dx.doi.org/10.1515/znb-1992-1112.
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The reactions of 1:1:1 molar ratio mixtures of NaSPh/MnCl2/Et4NBr and NaSPh/CoCl2/ Et4NCl in methanol afford the compounds [Et4N]4[Mn(SPh)3Br][Mn(SPh)3Cl] (1) and [Et4N]2[Co4(SPh)6Cl4] · MeCN (2), respectively, with the following crystal data: a = 14.408(5), b = 13.788(4), c = 17.984(5) Å, β = 90.16(2)°, space group P21/c and Ζ = 4 for 1, and a = 21.976(4), b = 13.081(2), c = 22.012(4) Å, β = 105.48(1)°, space group P 21/c for 2. The structures were refined to R values of 0.049 and 0.037, respectively. Crystals of 1 contain both of the paramagnetic (S = 5/2) mononuclear anions [Mn(SPh)3Br]2- (3 a) and [Mn(SPh)3Cl]2- (3b). The anions 3 a and 3 b are superimposed in an averaged unit cell and thus occupy crystallographically equivalent sites, the positions of the chlorine and bromine atoms being unresolved. The monohalide species are distributed statistically over 93% of the total anion positions. The remaining 7% are occupied by the dihalide species [Mn(SPh)2Br2]2- (4a) and [Mn(SPh)2BrCl]2- (4b) in equal amounts. In all these cases the metal atoms exhibit a distorted tetrahedral stereochemistry. In crystals of 2 [Co4(SPh)6Cl4]2- anions (5) are observed which feature a {Co4S6Cl4} core consisting of a distorted (D2d) Co4 tetrahedron inscribed in a moderately irregular S6 octahedron defined by bridging S atoms of an adamantane type cage. The four chlorine atoms each bind to different Co atoms and define an outer Cl4 tetrahedron, such that the overall symmetry of the {Co4S6Cl4} core comes close to Td. The results presented show that [M3(SPh)3Hal6]3- type species reported for M = Fe are not as readily formed for M = Mn and Co in methanolic solution, where other species are found instead. Physical properties such as solid state susceptibilities and 1H NMR spectra confirm the identity of 1 and 2. Reactions of 4:1:2 molar ratio mixtures of NaSePh/MnCl2/Et4NCl and NaTePh/MnCl2/Et4NCl in methanol lead to [Et4N]2[Mn(SePh)4] (6) and [Et4N]2[Mn(TePh)4] (7). Both compounds crystallize in the monoclinic space group P21/n with a = 16.162(4), b = 15.323(4), c = 16.949(4) Å, β = 91.28(2)°, Z = 4 for 6, and a = 16.367(6), b = 15.641(7), c = 17.220(7) Å, β = 92.00(3)°, Z = 4 for 7. Their structures were refined to R = 0.077 and 0.026, respectively. Four benzeneselenolate and benzenetellurolate ligands provide a slightly distorted tetrahedral coordination about the Mn(II) center for 6 and 7, respectively. The Mn–Se and Mn–Te distances average 2.567 and 2.742 Å, the Se– Mn– Se and Te–Mn–Te angles range from 99.1(1) to 124.2(1) and from 94.7(1) to 127.0(1)°, respectively.
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Danieli-Betto, Daniela, Elena Germinario, Alessandra Esposito, Aram Megighian, Menotti Midrio, Barbara Ravara, Ernesto Damiani, Luciano Dalla Libera, Roger A. Sabbadini, and Romeo Betto. "Sphingosine 1-phosphate protects mouse extensor digitorum longus skeletal muscle during fatigue." American Journal of Physiology-Cell Physiology 288, no. 6 (June 2005): C1367—C1373. http://dx.doi.org/10.1152/ajpcell.00246.2004.
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Sphingomyelin derivatives exert various second messenger actions in numerous tissues. Sphingosine (SPH) and sphingosine 1-phosphate (S1P) are two major sphingomyelin derivatives present at high levels in blood. The aim of the present work was to investigate whether S1P and SPH exert relevant actions in mouse skeletal muscle contractility and fatigue. Exogenous S1P and SPH administration caused a significant reduction of tension decline during fatigue of extensor digitorum longus muscle. Final tension after the fatiguing protocol was 40% higher than in untreated muscle. Interestingly, N, N-dimethylsphingosine, an inhibitor of SPH kinase (SK), abolished the effect of supplemented SPH but not that of S1P, suggesting that SPH acts through its conversion to S1P. Moreover, SPH was not effective in Ca2+-free solutions, in agreement with the hypothesis that SPH action is dependent on its conversion to S1P by the Ca2+-requiring enzyme SK. In contrast to SPH, S1P produced its positive effects on fatigue in Ca2+-free conditions, indicating that S1P action does not require Ca2+ entry and most likely is receptor mediated. The effects of S1P could be ascribed in part to its ability to prevent the reduction (−20 mV) of action potential amplitude caused by fatigue. In conclusion, these results indicate that extracellular S1P has protective effects during the development of muscle fatigue and that the extracellular conversion of SPH to S1P may represent a rheostat mechanism to protect skeletal muscle from possible cytotoxic actions of SPH.
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Dean, Philip A. W., and Jagadese J. Vittal. "Halogen and pseudohalogen substitution of some adamantanoid chalcogenate clusters [(μ-EPh)6(MEPh)4]2− using methylmercury and triphenyltin derivatives. A multinuclear nuclear magnetic resonance study." Canadian Journal of Chemistry 66, no. 9 (September 1, 1988): 2443–51. http://dx.doi.org/10.1139/v88-385.
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Multinuclear nmr (1H, 77Se, 111/113Cd, 119Sn, 199Hg, as appropriate) has been used to study Y−−EPh− exchange in Me2CO or MeCN between RnM′Y (RnM′ = Ph3Sn or MeHg; Y = Cl, Br, I, NCO, or NCS) and the adamantane-like anions [(μ-EPh)6(MEPh)4]2− (E = S, M = Zn, Cd, or Co; E = Se, M = Zn or Cd), as their tetraalkylammonium salts. Quantitative terminal substitution of the clusters occurs in most cases, giving [(μ-EPh)6(MEPh)4 − x(MY)x]2−(x = 1–4). However, reaction is incomplete for M = Cd, E = S or Se, RnM′Y = Ph3SnNCO or Ph3SnNCS and for M = Zn or Co, E = S, RnM′Y = MeHgI. Differences in the extents of reaction for Ph3SnY and MeHgY are consistent with the position of equilibrium in MeHgY:Ph3SnEPh mixtures.Group interchange provides a convenient alternative synthesis of the known halogen-substituted clusters [(μ-EPh)6(MY)4]2−(M = Zn or Cd, Y = Cl, Br, or I; M = Co, Y = Cl), and the first syntheses of [(μ-SPh)6(CoY)4]2− (Y = Br or I) and various pseudohalogen-substituted adamantanoid anions. The nuclei used for full direct nmr characterization of the new clusters in solution were: 77Se and 113Cd for [(μ-SePh)6(CdSePh)4 − x(CdY)x]2− (x = 1–4; Y = NCO or NCS); 77Se for [(μ-SePh)6(ZnSePh)4 − x(ZnY)x]2− (x = 1–4, Y = NCO or NCS); 113Cd for [(μ-SPh)6(CdSPh)4 − x(CdY)x]2−(x = 1–4; Y = NCO or NCS); 1H for [(μ-SPh)6(CoY)4]2− (Y = Br, I, NCO, or NCS). The first solution 1H nmr spectrum of [(μ-SPh)6(CoCl)4]2− is also reported.
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Groskopf, J. C., and D. I. Linzer. "Characterization of a delayed early serum response region." Molecular and Cellular Biology 14, no. 9 (September 1994): 6013–20. http://dx.doi.org/10.1128/mcb.14.9.6013-6020.1994.
Full textAbstract:
The proliferin (PLF) gene promoter provides a relatively simple model system for the study of growth-regulated gene expression in mouse cells. The promoter elements required for this serum-induced regulation have been identified and include an AP-1 site as well as an adjacent element comprised of three imperfect repeats that are similar in sequence to the simian virus 40 (SV40) Sph motif. Distinct protein complexes bound independently to the AP-1 and Sph elements, and both of these juxtaposed sites could be occupied simultaneously. Furthermore, serum stimulation of mouse fibroblasts resulted in similar increases in protein binding to the AP-1 and Sph elements. Consistent with this increase in AP-1 and Sph binding activity, the PLF AP-1 and Sph elements were independently able to confer serum responsiveness to a minimal promoter, and together these two elements acted synergistically in response to serum. Although several members of the AP-1 family were able to activate the PLF gene promoter in transient cotransfection experiments, the predominant AP-1 components interacting with the PLF gene promoter in serum-stimulated cells were Fra-1, JunB, and JunD. Analysis of the Sph element revealed that mutation of Sph repeats I or III abolished serum responsiveness of the PLF gene promoter, and mutation of Sph repeat III decreased protein binding to this element. Although the Sph element is similar in sequence to the SV40 element, the PLF Sph-binding factor is distinct from TEF-1, the factor that binds to the SV40 Sph motif.
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Igarashi, Y., and Y. Yatomi. "Sphingosine 1-phosphate is a blood constituent released from activated platelets, possibly playing a variety of physiological and pathophysiological roles." Acta Biochimica Polonica 45, no. 2 (June 30, 1998): 299–309. http://dx.doi.org/10.18388/abp.1998_4226.
Full textAbstract:
We have found that sphingosine 1-phosphate (Sph-1-P) acts as an autocrine stimulator of platelets, being abundantly stored in platelets and released extracellularly, and that its exogenous addition induces platelet activation (Yatomi et al., Blood 1995, 86, 193-202) through a specific receptor on the platelet surface (Yatomi et al., J. Biol. Chem. 1997, 272, 5291-5297). Very recently, we identified Sph-1-P as a normal constituent of human plasma and serum. Sph-1-P levels in plasma and serum were 191+/-79 and 484+/-82 pmol/ml (mean +/- S.D., n = 8), respectively. Platelets are most likely the source of Sph-1-P discharged during blood clotting, since they abundantly store Sph-1-P as compared with other blood cells, and release considerable amounts of stored Sph-1-P extracellularly upon stimulation. The Sph-1-P released from activated platelets may be involved in a variety of physiological processes, including thrombosis, atherosclerosis, and wound healing. Moreover, we often observed that Sph-1-P injection into mice (iv., 10 mg/kg) caused immediate rigor and death. This may be related to the recent observations from an other laboratory that nanomolar concentrations of Sph-1-P affected atrial myocyte K+ channel. These observations taken together strongly suggest pathophysiological roles of the released Sph-1-P in the blood. As one example, we found that Sph-1-P content in the plasma of platelet concentrates correlated with poor platelet increments after transfusion and with the occurrence of transfusion reactions in patients.
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Fan, Hongbing, Wenlin Yu, Wang Liao, and Jianping Wu. "Spent Hen Protein Hydrolysate with Good Gastrointestinal Stability and Permeability in Caco-2 Cells Shows Antihypertensive Activity in SHR." Foods 9, no. 10 (October 1, 2020): 1384. http://dx.doi.org/10.3390/foods9101384.
Full textAbstract:
Spent hens are a major byproduct of the egg industry but are rich in muscle proteins that can be enzymatically transformed into bioactive peptides. The present study aimed to develop a spent hen muscle protein hydrolysate (SPH) with antihypertensive activity. Spent hen muscle proteins were hydrolyzed by nine enzymes, either individually or in combination; 18 SPHs were assessed initially for their in vitro angiotensin-converting enzyme (ACE) inhibitory activity, and three SPHs, prepared by Protex 26L (SPH-26L), pepsin (SPH-P), and thermoase (SPH-T), showed promising activity and peptide yield. These three hydrolysates were further assessed for their angiotensin-converting enzyme 2 (ACE2) upregulating, antioxidant, and anti-inflammatory activities; only SPH-T upregulated ACE2 expression, while all three SPHs showed antioxidant and anti-inflammatory activities. During simulated gastrointestinal digestion, ACE2 upregulating, ACE inhibitory and antioxidant activities of SPH-T were not affected, but those of SPH-26L and SPH-P were reduced. ACE inhibitory activity of gastrointestinal-digested SPH-T was not affected after the permeability study in Caco-2 cells, while ACE2 upregulating, antioxidant and anti-inflammatory activities were improved; nine novel peptides with five–eight amino acid residues were identified from the Caco-2 permeate. Among these three hydrolysates, only SPH-T reduced blood pressure significantly when given orally at a daily dose of 1000 mg/kg body weight to spontaneously hypertensive rats. SPH-T can be developed into a promising functional food ingredient against hypertension, contributing to a more sustainable utilization for spent hens while generating extra revenue for the egg industry.
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Groskopf, J. C., and D. I. Linzer. "Characterization of a delayed early serum response region." Molecular and Cellular Biology 14, no. 9 (September 1994): 6013–20. http://dx.doi.org/10.1128/mcb.14.9.6013.
Full textAbstract:
The proliferin (PLF) gene promoter provides a relatively simple model system for the study of growth-regulated gene expression in mouse cells. The promoter elements required for this serum-induced regulation have been identified and include an AP-1 site as well as an adjacent element comprised of three imperfect repeats that are similar in sequence to the simian virus 40 (SV40) Sph motif. Distinct protein complexes bound independently to the AP-1 and Sph elements, and both of these juxtaposed sites could be occupied simultaneously. Furthermore, serum stimulation of mouse fibroblasts resulted in similar increases in protein binding to the AP-1 and Sph elements. Consistent with this increase in AP-1 and Sph binding activity, the PLF AP-1 and Sph elements were independently able to confer serum responsiveness to a minimal promoter, and together these two elements acted synergistically in response to serum. Although several members of the AP-1 family were able to activate the PLF gene promoter in transient cotransfection experiments, the predominant AP-1 components interacting with the PLF gene promoter in serum-stimulated cells were Fra-1, JunB, and JunD. Analysis of the Sph element revealed that mutation of Sph repeats I or III abolished serum responsiveness of the PLF gene promoter, and mutation of Sph repeat III decreased protein binding to this element. Although the Sph element is similar in sequence to the SV40 element, the PLF Sph-binding factor is distinct from TEF-1, the factor that binds to the SV40 Sph motif.
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Wandersee, Nancy J., Anne C. Frei, Sandra L. Holzhauer, J. Paul Scott, Kirkwood A. Pritchard, Karen A. Fagan, Neil Hogg, and Cheryl A. Hillery. "Vascular Dysfunction in Murine Models of Hemolytic Anemia." Blood 110, no. 11 (November 16, 2007): 846. http://dx.doi.org/10.1182/blood.v110.11.846.846.
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Abstract Pulmonary hypertension affects approximately 30% of young adults with sickle cell disease (SCD) and is a risk factor for early death. There is increasing evidence that intravascular hemolysis contributes to the pathophysiology of pulmonary hypertension in SCD as well as other hemolytic disorders. In this study, we compare measures of vascular dysfunction in Berkeley sickle cell mice (SCD mice) with a murine model of hereditary spherocytosis (sph/sph mice) that exhibit severe hemolytic anemia due to alpha spectrin deficiency, but without HbS-induced RBC sickling. We assessed right ventricular systolic pressure in vivo as a measure of pulmonary arterial function and endothelial-dependent vasodilation of facialis arteries ex vivo as a measure of systemic arterial function. Right ventricular systolic pressures and right ventricle to body weight ratios were increased to similar levels in both SCD and sph/sph mice as compared to control mice (p <0.025), consistent with pulmonary hypertension in both SCD and sph/sph mice. Acetylcholine-induced vasodilation of facialis arteries (a branch of the carotid artery) was severely impaired in both SCD and sph/sph mice compared to control mice (p<0.02). We also found increased plasma levels of soluble VCAM-1, E-selectin, and P-selectin in SCD and sph/sph mice compared to control mice (p<0.005 for all groups), providing further evidence for increased endothelial injury in both murine models. Interestingly, sVCAM-1 and E-selectin were more elevated in SCD mice compared to sph/sph mice (p<0.0001), suggesting hemolysis combined with HbS induces further endothelial injury. We hypothesized that plasma free hemoglobin released by intravascular hemolysis initiates endothelial impairment and injury due to scavenging of nitric oxide (NO) and generation of oxidative damage. Plasma methemoglobin levels were determined by helium electron paramagnetic resonance (EPR) spectroscopy before and after the addition of the NO donor molecule PROLI/NO. The difference between these two signals represents the total NO scavenging capacity of plasma. We found that both the plasma free Hb and NO scavenging capacity in plasma from SCD and sph/sph mice was much greater than that of healthy control mice (p<0.05). In addition, we developed an oxygen electrode assay to assess the oxidizing potential of plasma. The initiation of lipid peroxidation by oxidants present in the plasma results in the consumption of oxygen. We found that plasma from SCD and sph/sph mice has a significantly higher oxidizing potential than plasma from control mice (p<0.05). We obtained similar results (increased plasma free Hb, NO scavenging capacity, and oxidizing potential) comparing plasma from individuals with SCD to plasma from healthy control individuals. Consistent with the higher levels of hemolysis in the sph/sph mice, plasma free Hb, NO scavenging and oxidizing capacity were greater in sph/sph mice compared SCD mice (p<0.05). These results indicate that both pulmonary and systemic vascular function is impaired in these two different murine models of hemolysis, and suggest that nitric oxide-based vasoregulatory mechanisms are particularly affected. These data, combined with previous pathologic reports, suggest that while hemolysis importantly contributes to aberrant vasoregulation and initiating pathways of oxidative damage, sickle hemoglobin may uniquely provoke additional vascular and organ injury.
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Dorkoosh, F. "Preparation and NMR characterization of superporous hydrogels (SPH) and SPH composites." Polymer 41, no. 23 (November 2000): 8213–20. http://dx.doi.org/10.1016/s0032-3861(00)00200-7.
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Fadl-Elmola, Salman A. M., Cristian Moisescu Ciocan, and Ioana Popescu. "Application of Smooth Particle Hydrodynamics to Particular Flow Cases Solved by Saint-Venant Equations." Water 13, no. 12 (June 16, 2021): 1671. http://dx.doi.org/10.3390/w13121671.
Full textAbstract:
Smoothed particle hydrodynamics (SPH) is a Lagrangian mesh free particle method which has been developed and widely applied to different areas in engineering. Recently, the SPH method has also been used to solve the shallow water equations, resulting in (SPH-SWEs) formulations. With the significant developments made, SPH-SWEs provide an accurate computational tool for solving problems of wave propagation, flood inundation, and wet-dry interfaces. Capabilities of the SPH method to solve Saint-Venant equations have been tested using a SPH-SWE code to simulate different hydraulic test cases. Results were compared to other established and commercial hydraulic modelling packages that use Eulerian approaches. The test cases cover non-uniform steady state profiles, wave propagation, and flood inundation cases. The SPH-SWEs simulations provided results that compared well with other established and commercial hydraulic modeling packages. Nevertheless, SPH-SWEs simulations experienced some drawbacks such as loss of inflow water volume of up to 2%, for 2D flood propagation. Simulations were carried out using an open source solver, named SWE-SPHysics.
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KOUMANOV, Kamen S., Peter J. QUINN, Gilbert BÉRÉZIAT, and Claude WOLF. "Cholesterol relieves the inhibitory effect of sphingomyelin on type II secretory phospholipase A2." Biochemical Journal 336, no. 3 (December 15, 1998): 625–30. http://dx.doi.org/10.1042/bj3360625.
Full textAbstract:
Secretory type II phospholipase A2 (sPLA2) is inhibited by sphingomyelin (SPH); cholesterol either mixed with the model glycerophospholipid substrate or added to the assay medium as separated liposomes counteracts this inhibition efficiently. The inhibition of fatty acid release assayed by quantitative gas chromatography–MS is observed when SPH is added to erythrocyte membranes as the substrate instead of a readily hydrolysable phosphatidylethanolamine/phosphatidylserine model mixture. Hydrolysis of SPH by Staphylococcus aureus sphingomyelinase suppresses its inhibitory potency. The addition of cholesterol to SPH liposomes with a 1:1 stoichiometry relieves completely the inhibition of sPLA2 exerted by SPH. The mechanism of inhibition suggested by the binding assay is that sPLA2 binds with affinity to the SPH interface, after either phase segregation at the assay temperature or on the pure SPH liposomes added to the incubation medium. Cholesterol is shown to suppress the binding affinity of the enzyme for the SPH interface. A model for inhibition is suggested in which binding of the sphingosine moiety is competitive for sPLA2 (inhibition) or for cholesterol (release of the enzyme).
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Stephan, Hans-Oscar, Klaus Griesar, Wolfgang Haase, and Gerald Henkel. "[Mn(SPh)Cl3]2-, [Mn(SPh)3Cl]2-, [Mn2(SPh)6]2- und [Mn4(SPh)6Br4]2–: Synthese, Struktur und ausgewählte Eigenschaften einiger neuer Chalkogenolatkomplexe des zweiwertigen Mangans / [Mn(SPh)Cl3]2-, [Mn(SPh)3Cl]2-, [Mn2(SPh)6]2- und [Mn4(SPh)6Br4]2-: Synthesis, Structure and Selected Properties of Some New Chalkogenolate Complexes of Divalent Manganese." Zeitschrift für Naturforschung B 49, no. 12 (December 1, 1994): 1620–32. http://dx.doi.org/10.1515/znb-1994-1204.
Full textAbstract:
[Me4N]2[Mn(SPh)Cl3] (1) was obtained by reaction of MnCl2·4H2O with one equivalent of NaSPh from methanolic solutions in the presence of [Me4N]Cl. Under similar conditions the compound [Et4N]2[Mn(SPh)3Cl] (2) waso isolated using [Et4N]+ cations. Crystal data: 1: a = 9.425(3), b = 11.903(3)t c -19.073(4) Å, space group P 21cn, Z = 4; 2: a = 14.420(7), b = 13.834(8), c = 17.918(10) Å, β = 90.69(4)°, space group P21/c, Z = 4. The structures were refined to R = 0.0839 (1) and 0.0328 (2), respectively. Besides the dianion [Mn(SPh)3Cl]2- (6), crystals of 2 contain traces of [Mn(SPh)2Cl2]2- (7) distributed over 3.8% of the anion positions. The existence of [Mn(SPh)Cl3]2- (5), 6 and 7 under similar conditions is interpreted in terms of ligand exchange solution equilibria. Within these mononuclear anions, the central metal/sulfur/halide cores show distorted tetrahedral stereochemistries. The reaction of MnCl2 with NaSPh (molar ratio 1:3) in hot mixtures of acetonitrile and DMF leads to [Mn2(SPh)6]2- (8), which can be isolated as crystalline [Ph4P]2[Mn2(SPh)6] (3) with a = 13.383(2), b = 13.565(2), c = 20.438(4) Å, β = 106.41(1)°, space group P21/c, Z = 2. The final refinement converged to R = 0.0380. 8 consists of two edge-sharing MnS4 tetrahedra showing structural similarities with other tetrahedral complexes of the type [M2(SR)6]2-. According to magnetochemical studies, the manganese atoms are antiferromagnetically coupled with J=-18.6(2) cm-1. Reaction of 3:2:1 molar ratio mixtures of NaSPh/MnBr2/[Et4N]Br in hot acetonitrile leads to [Et4N]2[Mn4(SPh)6Br4] (4) which crystallizes with a = 14.109(3), b = 27.556(5), c = 16.194(4) Å, β = 95.35(2)°, space group P 21/n, Z=4. The structure was refined to R = 0.0583. This compound is also available by reaction of [Et4N]2[Mn(SPh)4] with MnBr2 in a molar ratio of 3:5. The anion [Mn4(SPh)6Br4]2- (9) contains a central {Mn4S6Br4} core which exhibits an adamantane-like structure: A Mn4 tetrahedron is inscribed into a S6 octahedron with the S atoms bridging the edges of the Mn4 tetrahedron. Terminally bonded Br atoms complete the tetrahedral coordination spheres of the manganese atoms and thus form an outer Br4 tetrahedron. As a result, the symmetry of the central core comes close to Td. The observed distortion is attributed to intramolecular repulsions of the organic residues. Selected properties of compounds 1-4 are reported.
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Moujtahid, A., J. Zorec, and A. M. Hubert. "Physical Properties of Circumstellar Envelopes in Be Stars Derived from their Long-term Spectrophotometric Variations." International Astronomical Union Colloquium 175 (2000): 510–13. http://dx.doi.org/10.1017/s0252921100056384.
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AbstractThe long-term visible spectrophotometric variations depicted by the following parameters: V the apparent visual magnitude; Φrb the gradient of the observed Paschen energy distribution and D the total Balmer discontinuity (BD) of 49 Be stars in different spectrophotometric phases (SPh-E: spectrophotometric phase where the second component of the BD is in emission; SPh-A: spectrophotometric phase where the second component of the BD is in absorption) were translated into CE physical parameters. These parameters are: R/R* the mean extent of the CE zone that produces the visible energy distribution; Tenv its mean temperature; τ the continuum opacity at λ0.56μm. The results obtained show that the triplet of parameters (V, Φrb, D) do not depend on the (R/R*, Tenv, τ) set of parameters in the same way if Be stars are in a SPh-E or in a SPh-A phase. Independently of the spectrophotometric phase, Tenv always decreases as a linear function of (R/R*)−1. In SPh-E it is (R/R*,)−1 ≤ 0.7, and in SPh-A it is (R/R*)−1 ≥ 0.7. All SPh behaviours can be summarized by the relation ∂Tenv/∂(R*/R) = ∂Tenv/∂τ × ∂τ/∂(R*/R) ≥ 0, which describes different spectrophotometric behaviours in both SPh-E and SPh-A phases.
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Athmani, Nora, Allaoui Amine, Nasri Moncef, and Boualga Ahmed. "Effects of short- and long-term treatments of sardine (Sardina pilchardus) protein hydrolysates on blood lipid concentrations and antioxidant status, in rats fed cholesterol-enriched diets." South Asian Journal of Experimental Biology 11, no. 6 (January 11, 2022): 733–45. http://dx.doi.org/10.38150/sajeb.11(6).p733-745.
Full textAbstract:
Hypercholesterolemia is a major risk factor of cardiovascular diseases (CVD). A limited number of experimental studies have shown that sardine protein hydrolysates (SPH) could be a very useful natural compound to prevent hy-percholesterolemia by both improving the lipoprotein profile and modula-ting oxidative stress. In the present study, the effect of short and long term treatments with SPH were examined on serum lipid contents, lipid peroxida-tion and antioxidant enzymes activities in rats fed cholesterol-enriched diet. At day 0, rats were divided into five groups. The group of day 0 was the stan-dard group, and the four remaining groups were divided into two parts of two groups each consuming for 14 or 28 days an hypercholesterolemic diet, and treated (HC-SPH) or not (HC) by gavage with SPH. Compared with day 0, serum TC contents were increased at day 14 and remained unchanged at day 28 in HC-SPH group. These values were decreased in HC-SPH versus HC. Liver and heart TBARS concentrations were increased at day 14 then diminished at day 28 in HC-SPH group. Liver and heart SOD and CAT activities were decrea-sed at short term then remained unchanged at long term in HC-SPH group. In addition, these activities were enhanced in HC-SPH versus HC. In conclusion, these results indicate the potential effects of short and long term treatments of SPH to improved cholesterolemia and reduced radical attack in rats fed high-cholesterol diets.
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Wandersee, Nancy J., John C. Lee, Susan A. Deveau, and Jane E. Barker. "Reduced incidence of thrombosis in mice with hereditary spherocytosis following neonatal treatment with normal hematopoietic cells." Blood 97, no. 12 (June 15, 2001): 3972–75. http://dx.doi.org/10.1182/blood.v97.12.3972.
Full textAbstract:
Thrombosis is a life-threatening complication of hemolytic anemia in humans. Cardiac thrombi are present in all adult α-spectrin–deficient (sph/sph) mice with severe hereditary spherocytosis, providing a model for events preceding thrombosis. The current study evaluated (1) the timing of thrombosis initiation and (2) the effect of postnatal transplantation of normal cells on life span and thrombotic incidence in adult mice. Thrombi are detected histologically following necropsy in untreatedsph/sph mice of various ages and are not observed until 6 weeks of age. Thrombotic incidence increases from 50% at 6 to 7 weeks of age to 100% at 9 weeks of age. As a potential therapy, nonablatedsph/sph neonates were transfused with either genetically marked normal peripheral blood (PB), bone marrow (BM), or both and assessed for donor cells and thrombosis. A single transfusion of PB, with or without BM, significantly increases the percentage ofsph/sph mice that survive to weaning (4 weeks of age). Replacement in all sph/sph recipients is limited to red blood cells (RBCs). RBCs derived from donor PB are lost within 5 weeks. PB plus BM prolongs high-level donor PB cell production better than BM alone. Thrombotic incidence is significantly reduced in allsph/sph mice treated with PB, BM, or both. Hence, the presence of normal blood cells in the peripheral circulation of neonatal and adult sph/sph mice rescues the former and abrogates the development of thrombosis in the latter.
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Li, Jing, Kenneth A. Satyshur, Lian-Wang Guo, and Arnold E. Ruoho. "Sphingoid Bases Regulate the Sigma-1 Receptor—Sphingosine and N,N’-Dimethylsphingosine Are Endogenous Agonists." International Journal of Molecular Sciences 24, no. 4 (February 4, 2023): 3103. http://dx.doi.org/10.3390/ijms24043103.
Full textAbstract:
Both bioactive sphingolipids and Sigma-1 receptor (S1R) chaperones occur ubiquitously in mammalian cell membranes. Endogenous compounds that regulate the S1R are important for controlling S1R responses to cellular stress. Herein, we interrogated the S1R in intact Retinal Pigment Epithelial cells (ARPE-19) with the bioactive sphingoid base, sphingosine (SPH), or the pain-provoking dimethylated SPH derivative, N,N-dimethylsphingosine (DMS). As informed by a modified native gel approach, the basal and antagonist (BD-1047)-stabilized S1R oligomers dissociated to protomeric forms in the presence of SPH or DMS (PRE-084 as control). We, thus, posited that SPH and DMS are endogenous S1R agonists. Consistently, in silico docking of SPH and DMS to the S1R protomer showed strong associations with Asp126 and Glu172 in the cupin beta barrel and extensive van der Waals interactions of the C18 alkyl chains with the binding site including residues in helices 4 and 5. Mean docking free energies were 8.73–8.93 kcal/mol for SPH and 8.56–8.15 kcal/mol for DMS, and calculated binding constants were ~40 nM for SPH and ~120 nM for DMS. We hypothesize that SPH, DMS, and similar sphingoid bases access the S1R beta barrel via a membrane bilayer pathway. We further propose that the enzymatic control of ceramide concentrations in intracellular membranes as the primary sources of SPH dictates availability of endogenous SPH and DMS to the S1R and the subsequent control of S1R activity within the same cell and/or in cellular environments.
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Lyu, Hong-Guan, Peng-Nan Sun, Xiao-Ting Huang, Shi-Yun Zhong, Yu-Xiang Peng, Tao Jiang, and Chun-Ning Ji. "A Review of SPH Techniques for Hydrodynamic Simulations of Ocean Energy Devices." Energies 15, no. 2 (January 11, 2022): 502. http://dx.doi.org/10.3390/en15020502.
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This article is dedicated to providing a detailed review concerning the SPH-based hydrodynamic simulations for ocean energy devices (OEDs). Attention is particularly focused on three topics that are tightly related to the concerning field, covering (1) SPH-based numerical fluid tanks, (2) multi-physics SPH techniques towards simulating OEDs, and finally (3) computational efficiency and capacity. In addition, the striking challenges of the SPH method with respect to simulating OEDs are elaborated, and the future prospects of the SPH method for the concerning topics are also provided.
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Maningo, Jose Martin Z., Ryan Rhay P. Vicerra, Laurence A. Gan Lim, Edwin Sybingco, Elmer P. Dadios, and Argel A. Bandala. "Smoothed Particle Hydrodynamics Approach to Aggregation of Quadrotor Unmanned Aerial Vehicle Swarm." Journal of Advanced Computational Intelligence and Intelligent Informatics 21, no. 2 (March 15, 2017): 181–88. http://dx.doi.org/10.20965/jaciii.2017.p0181.
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This paper uses a fluid mechanics approach to perform swarming aggregation on a quadrotor unmanned aerial vehicle (QUAV) swarm platform. This is done by adapting the Smoothed Particle Hydrodynamics (SPH) technique. An algorithm benchmarking is conducted to see how well SPH performs. Simulations of varying set-ups are experimented to compare different algorithms with SPH. The position error of SPH is 30% less than the benchmark algorithm when a target enclosure is introduce. SPH is implemented using Crazyflie quadrotor swarm. The aggregation behavior exhibited successfully in the said platform.
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Dogra, Shilpa. "Better Self-Perceived Health Is Associated With Lower Odds of Physical Inactivity in Older Adults With Chronic Disease." Journal of Aging and Physical Activity 19, no. 4 (October 2011): 322–35. http://dx.doi.org/10.1123/japa.19.4.322.
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Poor self-perceived health (SPH) is associated with lower levels of physical activity (PA) and the presence of chronic disease in older adults. The purpose of this study was to determine whether SPH is associated with PA levels in older adults with existing chronic disease and whether this differs by disease. Using logistic regressions on data from the Canadian Community Health Survey (N= 33,168) it was found that adjusted logistic regressions revealed that odds of physical inactivity were similar in those with good SPH who reported having respiratory, musculoskeletal, or other chronic disease compared with those with good SPH without these diseases. Those with good SPH who reported having cardiometabolic disease were at significantly greater risk of physical inactivity than those with good SPH without cardiometabolic disease. It is apparent from the current analysis that SPH plays an important role in PA levels of older adults with chronic disease and should be targeted in future interventions.
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Hu, Man, Guangyu Wang, Guirong Liu, and Qing Peng. "The Application of Godunov SPH in the Simulation of Energetic Materials." International Journal of Computational Methods 17, no. 07 (May 8, 2019): 1950028. http://dx.doi.org/10.1142/s0219876219500282.
Full textAbstract:
The numerical study of detonation of high explosives has been the interest of researchers over decades. Due to its special advantages in tracking free surface and dealing with large deformation, smoothed particle hydrodynamics (SPH) has been a powerful tool to investigate detonation phenomenon. SPH is a Lagrangian mesh-free method with extensive applications in fluid mechanics and solid mechanics. In the early development of SPH method, artificial viscosity is introduced to suppress unphysical fluctuation. However, the parameters of artificial viscosity often need to be tuned for some simulation, which can be quite time-consuming. Herein, a Riemann solver is integrated in traditional SPH algorithm to eliminate artificial viscosity, which is known as Godunov SPH. First, shock tube problem is studied using the Godunov SPH. The simulation result is compared with that obtained by traditional SPH with artificial viscosity, finite volume method (FVM) and experiment. Then, the Godunov SPH is implemented to investigate the detonation of 1D and 2D polymer-bonded explosive PBX 9501. Various factors that may influence simulation are studied, such as particle density and smoothing length. It is demonstrated that the proposed method is accurate and reliable for the study of detonation of high explosives.
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Yatomi, Yutaka, Tsukasa Ohmori, Ge Rile, Fuminori Kazama, Hirotaka Okamoto, Takamitsu Sano, Kaneo Satoh, et al. "Sphingosine 1-phosphate as a major bioactive lysophospholipid that is released from platelets and interacts with endothelial cells." Blood 96, no. 10 (November 15, 2000): 3431–38. http://dx.doi.org/10.1182/blood.v96.10.3431.
Full textAbstract:
Abstract The serum-borne lysophospholipid mediators sphingosine 1-phosphate (Sph-1-P) and lysophosphatidic acid (LPA) have been shown to be released from activated platelets and to act on endothelial cells. In this study, we employed the repeated lipid extraction (under alkaline and acidic conditions), capable of detecting Sph-1-P, LPA, and possibly structurally similar lysophospholipids, whereby a marked formation of [32P]Sph-1-P, but not [32P]LPA, was observed in [32P]orthophosphate-labeled platelets. Platelet Sph-1-P release, possibly mediated by protein kinase C, was greatly enhanced in the presence of albumin, which formed a complex with Sph-1-P. This finding suggests that platelet Sph-1-P may become accessible to depletion by albumin when its transbilayer movement (flipping) across the plasma membrane is enhanced by protein kinase C. Although human umbilical vein endothelial cells expressed receptors for both Sph-1-P and LPA, Sph-1-P acted much more potently than LPA on the cells in terms of intracellular Ca++ mobilization, cytoskeletal reorganization, and migration. The results suggest that Sph-1-P, rather than LPA, is a major bioactive lysophospholipid that is released from platelets and interacts with endothelial cells, under the conditions in which critical platelet-endothelial interactions (including thrombosis, angiogenesis, and atherosclerosis) occur. Furthermore, albumin-bound Sph-1-P may account for at least some of the serum biological activities on endothelial cells, which have been ascribed to the effects of albumin-bound LPA, based on the similarities between LPA and serum effects.
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Yatomi, Yutaka, Tsukasa Ohmori, Ge Rile, Fuminori Kazama, Hirotaka Okamoto, Takamitsu Sano, Kaneo Satoh, et al. "Sphingosine 1-phosphate as a major bioactive lysophospholipid that is released from platelets and interacts with endothelial cells." Blood 96, no. 10 (November 15, 2000): 3431–38. http://dx.doi.org/10.1182/blood.v96.10.3431.h8003431_3431_3438.
Full textAbstract:
The serum-borne lysophospholipid mediators sphingosine 1-phosphate (Sph-1-P) and lysophosphatidic acid (LPA) have been shown to be released from activated platelets and to act on endothelial cells. In this study, we employed the repeated lipid extraction (under alkaline and acidic conditions), capable of detecting Sph-1-P, LPA, and possibly structurally similar lysophospholipids, whereby a marked formation of [32P]Sph-1-P, but not [32P]LPA, was observed in [32P]orthophosphate-labeled platelets. Platelet Sph-1-P release, possibly mediated by protein kinase C, was greatly enhanced in the presence of albumin, which formed a complex with Sph-1-P. This finding suggests that platelet Sph-1-P may become accessible to depletion by albumin when its transbilayer movement (flipping) across the plasma membrane is enhanced by protein kinase C. Although human umbilical vein endothelial cells expressed receptors for both Sph-1-P and LPA, Sph-1-P acted much more potently than LPA on the cells in terms of intracellular Ca++ mobilization, cytoskeletal reorganization, and migration. The results suggest that Sph-1-P, rather than LPA, is a major bioactive lysophospholipid that is released from platelets and interacts with endothelial cells, under the conditions in which critical platelet-endothelial interactions (including thrombosis, angiogenesis, and atherosclerosis) occur. Furthermore, albumin-bound Sph-1-P may account for at least some of the serum biological activities on endothelial cells, which have been ascribed to the effects of albumin-bound LPA, based on the similarities between LPA and serum effects.
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He, Yi, Zhao Yao Zhou, Wen Jiong Cao, and De Zhi Yang. "Numerical Simulation of Solidification by SPH in Sand Cast Process." Advanced Materials Research 314-316 (August 2011): 614–19. http://dx.doi.org/10.4028/www.scientific.net/amr.314-316.614.
Full textAbstract:
In this paper, Smoothed Particle Hydrodynamics (SPH) was used for the prediction of heat conduction problems in sand cast process. The implementation of solidification modeling in a curved casting based on SPH has been described. The treatment of latent heat was introduced in SPH conduction problem by temperature compensation method, which demonstrated the role of latent heat has a great influence on the heat distribution in the casting. The temperature distribution calculated by SPH provided a great agreement with those computed through numerical software MSC.Marc, which validated the efficiency and precision of SPH simulation of heat transfer problems in sand cast process.
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Rambukwella, Milan, Le Chang, Anish Ravishanker, Alessandro Fortunelli, Mauro Stener, and Amala Dass. "Au36(SePh)24 nanomolecules: synthesis, optical spectroscopy and theoretical analysis." Physical Chemistry Chemical Physics 20, no. 19 (2018): 13255–62. http://dx.doi.org/10.1039/c8cp01564c.
Full textAbstract:
Here, we report the synthesis of selenophenol (HSePh) protected Au36(SePh)24 nanomolecules via a ligand-exchange reaction of 4-tert-butylbenzenethiol (HSPh-tBu) protected Au36(SPh-tBu)24 with selenophenol, and its spectroscopic and theoretical analysis.
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MEACCI, Elisabetta, Francesca CENCETTI, Chiara DONATI, Francesca NUTI, Laura BECCIOLINI, and Paola BRUNI. "Sphingosine kinase activity is required for sphingosine-mediated phospholipase D activation in C2C12 myoblasts." Biochemical Journal 381, no. 3 (July 27, 2004): 655–63. http://dx.doi.org/10.1042/bj20031636.
Full textAbstract:
Sphingosine (Sph) has been implicated as a modulator of membrane signal transduction systems and as a regulatory element of cardiac and skeletal muscle physiology, but little information is presently available on its precise mechanism of action. Recent studies have shown that sphingosine 1-phosphate (S1P), generated by the action of sphingosine kinase (SphK) on Sph, also possesses biological activity, acting as an intracellular messenger, as well as an extracellular ligand for specific membrane receptors. At present, however, it is not clear whether the biological effects elicited by Sph are attributable to its conversion into S1P. In the present study, we show that Sph significantly stimulated phospholipase D (PLD) activity in mouse C2C12 myoblasts via a previously unrecognized mechanism that requires the conversion of Sph into S1P and its subsequent action as extracellular ligand. Indeed, Sph-induced activation of PLD was inhibited by N,N-dimethyl-D-erythro-sphingosine (DMS), at concentrations capable of specifically inhibiting SphK. Moreover, the crucial role of SphK-derived S1P in the activation of PLD by Sph was confirmed by the observed potentiated effect of Sph in myoblasts where SphK1 was overexpressed, and the attenuated response in cells transfected with the dominant negative form of SphK1. Notably, the measurement of S1P formation in vivo by employing labelled ATP revealed that cell-associated SphK activity in the extracellular compartment largely contributed to the transformation of Sph into S1P, with the amount of SphK released into the medium being negligible. It will be important to establish whether the mechanism of action identified in the present study is implicated in the multiple biological effects elicited by Sph in muscle cells.
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Gu, Luo, Qiuyu Zhu, Xiaoyu Zou, and Ru Song. "Antibacterial Effect of Shrimp By-Products Hydrolysate on Specific Spoilage Organisms of Squid." Molecules 28, no. 10 (May 15, 2023): 4105. http://dx.doi.org/10.3390/molecules28104105.
Full textAbstract:
In order to further develop and utilize shrimp processing by-products, in this study, a novel antibacterial hydrolysate of shrimp by-products by pepsin hydrolysis (SPH) was prepared. The antibacterial effect of SPH on specific spoilage organisms of squid after end storage at room temperature (SE–SSOs) was investigated. SPH showed an antibacterial effect on the growth of SE–SSOs, with (23.4 ± 0.2) mm of inhibition zone diameter. The cell permeability of SE–SSOs was enhanced after SPH treatment for 12 h. Some bacteria were twisted and shrunk, while pits and pores formed and intracellular contents leaked under scanning electron microscopy observation. The flora diversity of SE–SSOs treated with SPH was determined by a 16S rDNA sequencing technique. Results showed that SE–SSOs were mainly composed of the phyla of Firmicutes and Proteobacteria, among which Paraclostridium (47.29%) and Enterobacter (38.35%) were dominant genera. SPH treatment resulted in a significant reduction in the relative abundance of the genus Paraclostridium and increased the abundance of Enterococcus. Linear discriminant analysis (LDA) of LEfSe conveyed that SPH treatment had a significant impact on altering the bacterial structure of SE–SSOs. The 16S PICRUSt of Cluster of Orthologous Group (COG) annotation revealed that SPH treatment for 12 h could significantly increase the function of transcription level [K], while SPH treatment for 24 h could downregulate post-translational modifications, protein turnover, and chaperone metabolism functions [O]. In conclusion, SPH has a proper antibacterial effect on SE–SSOs and can change the flora structure of SE–SSOs. These findings will provide a technical basis for the development of inhibitors of squid SSOs.
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Lee, Chi-Woo, Yeok Boo Chang, Chun Woong Park, Sung Hee Han, Hyung Joo Suh, and Yejin Ahn. "Protein Hydrolysate from Spirulina platensis Prevents Dexamethasone-Induced Muscle Atrophy via Akt/Foxo3 Signaling in C2C12 Myotubes." Marine Drugs 20, no. 6 (May 29, 2022): 365. http://dx.doi.org/10.3390/md20060365.
Full textAbstract:
Loss of muscle mass is the primary symptom of sarcopenia. Protein intake is recommended to prevent muscle mass loss, and Spirulina platensis, a microalga with high protein content, is a potential protein supplement. Here, we evaluated the differentiation ability of C2C12 cells and the inhibitory effect of Spirulina hydrolysates (SPH) prepared by Collupulin on dexamethasone (DEX)-treated C2C12 cells. SPH contained 578.27 mg/g protein and 92.30 mg/g branched-chain amino acids. SPH increased C2C12 myotube length and diameter, likely owing to increased MyoD1 and Myf5 expression. Inhibition of increased Atrogin-1, MuRF-1, and FoxO3 expression by SPH in DEX-treated C2C12 cells suppressed DEX-induced muscle atrophy. Moreover, SPH inhibited the DEX-induced increase in cytosolic p-Akt protein expression and suppressed the increase in nuclear FoxO3a protein expression, thereby suppressing the increase in the protein expression of the ubiquitin-proteasome-related factors Atrogin-1 and MuRF-1, which are involved in muscle atrophy. SPH suppressed DEX-induced muscle atrophy by activating the Akt/FoxO3a pathway. SPH promoted C2C12 myoblast differentiation into myotubes and inhibited DEX-induced myotube atrophy by suppressing Atrogin-1 and MuRF-1 expression and regulating the FoxO3a transcription factor. Collectively, SPH can be used as a functional food to inhibit muscle atrophy and promote muscle regeneration.
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Heffernan, Shauna, Pádraigín A. Harnedy-Rothwell, Snehal Gite, Jason Whooley, Linda Giblin, Richard J. Fitzgerald, and Nora M. O’Brien. "Blue Whiting Protein Hydrolysates Exhibit Antioxidant and Immunomodulatory Activities in Stimulated Murine RAW264.7 Cells." Applied Sciences 11, no. 20 (October 19, 2021): 9762. http://dx.doi.org/10.3390/app11209762.
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This study investigated the antioxidant and immunomodulatory potential of six blue whiting soluble protein hydrolysates (BWSPHs, BW-SPH-A to -F) and their simulated gastrointestinal digests (SGID, BW-SPH-A-GI to -F-GI) in murine RAW264.7 macrophages. Hydrolysate BW-SPH-A, both pre- and post-SGID, increased endogenous antioxidant glutathione (GSH) in tert-butylhydroperoxide (tBOOH)-treated cells and reduced reactive oxygen species (ROS) in H2O2-challenged RAW264.7 cells compared with treated controls in the absence of BWSPHs (p < 0.05). BW-SPH-A-GI also exhibited higher ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC) activities than the other BWSPHs tested (p < 0.05). All BWSPHs and SGID BWSPH samples induced immunostimulating effects in lipopolysaccharide (LPS)-activated RAW264.7 macrophages through the upregulation of NO production. BW-SPH-F-GI increased IL-6 and TNF-α levels compared with the LPS controls indicating the liberation of immunomodulatory peptide/amino acids during the SGID process. Therefore, BW-SPH-A and BW-SPH-F may have potential use against oxidative stress and immunosuppression-related diseases, respectively.
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Ghaffari, Mir Ali, and Shaoping Xiao. "Smoothed Particle Hydrodynamics with Stress Points and Centroid Voronoi Tessellation (CVT) Topology Optimization." International Journal of Computational Methods 13, no. 05 (August 31, 2016): 1650031. http://dx.doi.org/10.1142/s0219876216500316.
Full textAbstract:
Various formulations of smoothed particle hydrodynamics (SPH) have been presented by scientists to overcome inherent numerical difficulties including instabilities and inconsistencies. Low approximation accuracy could cause a result of particle inconsistency in SPH and other meshfree methods. In this study, centroid Voronoi tessellation (CVT) topology optimization is used for rearrangement of particles so that the inconsistency due to irregular particle arrangement can be corrected. Using CVT topology optimization method, the SPH particles, which are generated randomly inside a predetermined domain, are moved to the centroids, i.e., the center of mass of the corresponding Voronoi cells based on Lloyd’s algorithm. The volume associated with each particle is determined by its Voronoi cell. On the other hand, it has been shown that particle methods with stress point integration are more stable than the ones using nodal integration. Conventional SPH approximations only use SPH particles, and it results in the so-called tensile instability. In this paper, a new approach of using stress points is introduced to assist SPH approximations and stabilize the SPH methods.
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Jin, Xiaoming, Fangping Ma, Di Wang, and Zhengtao Zhu. "Simulation of Mouldboard Plough Soil Cutting Based on Smooth Particle Hydrodynamics Method and FEM–SPH Coupling Method." Agriculture 13, no. 9 (September 21, 2023): 1847. http://dx.doi.org/10.3390/agriculture13091847.
Full textAbstract:
In the field of agricultural machinery, various empirical field tests are performed to measure the tillage force for precision tillage. However, the field test performance is costly and time-consuming, and there are many constraints on weather and field soil conditions; the utilization of simulation studies is required to overcome these shortcomings. As a result, the SPH method and the coupled FEM-SPH method are used in this paper to investigate the mouldboard plough–soil interaction. In this paper, the finite element software LS-DYNA was used to build the SPH model and the FEM-SPH coupling model of soil cutting, as well as to investigate the change in cutting resistance during the soil cutting process. The simulation results are compared with those of the experiments, and the curves of the simulation and experiment are in good agreement, which verifies the reliability of the model. The validated simulation model was used to investigate the effects of the cutting speed, depth of cut, inclination angle, and lifting angle of the mouldboard plough on cutting resistance. The simulation studies show that the SPH model takes 5 h and 2 min to compute, while the FEM-SPH coupled model takes 38 min; obviously, the computational efficiency of the FEM-SPH coupled model is higher. The relative errors between the SPH model and the experiment are 2.17% and 3.65%, respectively. The relative errors between the FEM-SPH coupled model and the experiment are 5.96% and 10.67%, respectively. Obviously, the SPH model has a higher computational accuracy. The average cutting resistances predicted by the SPH model and the FEM-SPH coupled model, respectively, were 349.48 N and 306.25 N; these resistances are useful for precision tillage. The cutting resistance increases with the increase in cutting speed and is quadratic; the cutting resistance increases with the increase in cutting depth and is quadratic; the horizontal cutting resistance and the combined cutting resistance increase with the increase in inclination angle, while the vertical cutting resistance remains essentially constant with the increase in inclination angle; the horizontal cutting resistance and combined cutting resistance increase as the lifting angle increases, while the vertical cutting resistance decreases as the lifting angle increases.