Articles de revues : « Permeable bead »

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Heade, Joanne, Robert Kent, Sinead B. Bleiel et David J. Brayden. « Entrapment of Hydrophilic and Hydrophobic Molecules in Beads Prepared from Isolated Denatured Whey Protein ». Pharmaceutics 13, n^o 7 (1 juillet 2021) : 1001. http://dx.doi.org/10.3390/pharmaceutics13071001.

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The oral route of administration is by far the most convenient route, especially in the treatment of chronic conditions. However, many therapeutics present formulation difficulties which make them unsuitable for oral delivery. Recently, we synthesized a denatured whey protein isolate (dWPI) bead entrapped with insulin. Our present goal was to assess the suitability of this delivery system to the delivery of other potential molecules, both hydrophilic and hydrophobic. Beads of 1.2–1.5 mm in diameter were entrapped with four payloads representing a range of solubilities. The water-soluble payloads were sodium fluorescein (SF) and FITC dextran 4000 Da (FD4), while the hydrophobic ones were Fast Green and curcumin. Encapsulation efficiency (EE) was 73%, 84%, 70%, and 83% for SF, FD4, Fast Green, and curcumin-loaded beads, respectively. The corresponding loading capacity for each bead was 0.07%, 1.1%, 0.75%, and 1.1%, respectively. Each payload produced different release profiles in simulated gastric fluid (SGF) and simulated intestinal fluids (SIF). SF released steadily in both SGF and SIF. FD4 and curcumin release was not substantial in any buffers, while Fast Green release was low in SGF and high in SIF. The differences in release behaviour were likely due to the varying properties of the payloads. The effect of proteolysis on beads suggested that enzymatic degradation of the whey bead may promote payload release. The beads swelled rapidly in SGF compared to SIF, which likely contributed to the release from the beads, which was largely governed by solvent diffusion and polymer relaxation. Our results offer a systematic examination of the behaviour of hydrophilic and hydrophobic payloads in a dWPI delivery system. These beads may be further designed to orally deliver poorly permeable macromolecules and poorly soluble small molecules of pharmaceutical interest.

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Chowdhury, Shakhawat, Imran Rahman Chowdhury, Fayzul Kabir, Mohammad Abu Jafar Mazumder, Md Hasan Zahir et Khalid Alhooshani. « Alginate-based biotechnology : a review on the arsenic removal technologies and future possibilities ». Journal of Water Supply : Research and Technology-Aqua 68, n^o 6 (15 juillet 2019) : 369–89. http://dx.doi.org/10.2166/aqua.2019.005.

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Abstract The alginate-based adsorption technologies have emerged as potential methods for arsenic removal from drinking water. The adsorbents (iron oxide, hydroxide, nano zero valent iron (nZVI), industrial waste, minerals, magnetite, goethite, zirconium oxide, etc.) are impregnated into alginate beads to produce the media. The biocompatibility, rough surface with large area, and amorphous and high water permeable bead structure improve arsenic adsorption efficiency while the regeneration process is simpler than the conventional adsorbents. In recent years, studies have reported laboratory-scale applications of alginate beads, encapsulated and impregnated with adsorbents, for arsenic removal from drinking water. The arsenic removal efficiencies were reported to be over 95% with a wide range of concentrations (10–1,000 parts per billion) and pH (3.0–7.5). However, commercial- and/or mass-scale applications have not been reported yet, due possibly to overall cost, complexity, reusability, and arsenic waste-laden sludge management. In this paper, research achievement on arsenic removal using alginate-based adsorbents has been reviewed. The review was performed in context to alginate bead development, adsorbent encapsulation and impregnation, application, performance, and regeneration. The advantages and limitations of the methods were analyzed and the scopes of future research were identified for mass scale domestic and industrial applications.

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Chung, Jin, et Zhang Zhibing. « Mechanical characterization of calcium pectinate hydrogel for controlled drug delivery ». Chemical Industry 57, n^o 12 (2003) : 611–16. http://dx.doi.org/10.2298/hemind0312611c.

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Calcium pectinate beads, a paniculate hydrogel system, is an attractive drug carrier for oral delivery. In this study, a poorly water-soluble model drug indomethacin was incorporated into calcium pectinate beads made of different pectin concentrations, which were produced by an extrusion method. The effect of pectin concentration on bead size, circularity, swelling behavior, and mechanical properties, as well as in vitro drug release profile was investigated. The mechanical properties of calcium pectinate beads were determined by a micromanipulation technique. The drug release profile was measured using a standard British Pharmacopoeia method. It was found that the beads made of higher pectin concentration in general had a less permeable matrix structure and greater mechanical rigidity, although they swelled more after hydration. However, such an effect was not significant when the pectin concentration was increased to above 8%. Micromanipulation measurements showed that there was significant relaxation of the force being imposed on single hydrated beads when they were held, but this phenomenon did not occur on dry beads, which means that the force relaxation was dominated by liquid loss from the beads. The rate of the force relaxation was determined, and has been related to the release rate of the model drug entrapped in the calcium pectinate beads.

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Xin, Bao-Ping, Chih-Hung Wu, Cheng-Han Wu et Chi-Wen Lin. « Bioaugmented remediation of high concentration BTEX-contaminated groundwater by permeable reactive barrier with immobilized bead ». Journal of Hazardous Materials 244-245 (janvier 2013) : 765–72. http://dx.doi.org/10.1016/j.jhazmat.2012.11.007.

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Sperry, David C., Steven J. Thomas et Evelyn Lobo. « Dissolution Modeling of Bead Formulations and Predictions of Bioequivalence for a Highly Soluble, Highly Permeable Drug ». Molecular Pharmaceutics 7, n^o 5 (4 octobre 2010) : 1450–57. http://dx.doi.org/10.1021/mp100118t.

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Glogauer, M., P. Arora, G. Yao, I. Sokholov, J. Ferrier et C. A. McCulloch. « Calcium ions and tyrosine phosphorylation interact coordinately with actin to regulate cytoprotective responses to stretching ». Journal of Cell Science 110, n^o 1 (1 janvier 1997) : 11–21. http://dx.doi.org/10.1242/jcs.110.1.11.

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The actin-dependent sensory and response elements of stromal cells that are involved in mechanical signal transduction are poorly understood. To study mechanotransduction we have described previously a collagen-magnetic bead model in which application of well-defined forces to integrins induces an immediate (< 1 second) calcium influx. In this report we used the model to determine the role of calcium ions and tyrosine-phosphorylation in the regulation of force-mediated actin assembly and the resulting change in membrane rigidity. Collagen-beads were bound to cells through the focal adhesion-associated proteins talin, vinculin, alpha 2-integrin and beta-actin, indicating that force application was mediated through cytoskeletal elements. When force (2 N/m2) was applied to collagen beads, confocal microscopy showed a marked vertical extension of the cell which was counteracted by an actin-mediated retraction. Immunoblotting showed that force application induced F-actin accumulation at the bead-membrane complex but vinculin, talin and alpha 2-integrin remained unchanged. Atomic force microscopy showed that membrane rigidity increased 6-fold in the vicinity of beads which had been exposed to force. Force also induced tyrosine phosphorylation of several cytoplasmic proteins including paxillin. The force-induced actin accumulation was blocked in cells loaded with BAPTA/AM or in cells preincubated with genistein, an inhibitor of tyrosine phosphorylation. Repeated force application progressively inhibited the amplitude of force-induced calcium ion flux. As force-induced actin reorganization was dependent on calcium and tyrosine phosphorylation, and as progressive increases of filamentous actin in the submembrane cortex were correlated with increased membrane rigidity and dampened calcium influx, we suggest that cortical actin regulates stretch-activated cation permeable channel activity and provides a desensitization mechanism for cells exposed to repeated long-term mechanical stimuli. The actin response may be cytoprotective since it counteracts the initial force-mediated membrane extension and potentially strengthens cytoskeletal integrity at force-transfer points.

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Arora, P. D., M. W. C. Chan, R. A. Anderson, P. A. Janmey et C. A. McCulloch. « Separate Functions of Gelsolin Mediate Sequential Steps of Collagen Phagocytosis ». Molecular Biology of the Cell 16, n^o 11 (novembre 2005) : 5175–90. http://dx.doi.org/10.1091/mbc.e05-07-0648.

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Collagen phagocytosis is a critical mediator of extracellular matrix remodeling. Whereas the binding step of collagen phagocytosis is facilitated by Ca2+-dependent, gelsolin-mediated severing of actin filaments, the regulation of the collagen internalization step is not defined. We determined here whether phosphatidylinositol-4,5-bisphosphate [PI(4,5)P2] regulation of gelsolin is required for collagen internalization. In gelsolin null fibroblasts transfected with gelsolin severing mutants, actin severing and collagen binding were strongly impaired but internalization and actin monomer addition at collagen bead sites were much less affected. PI(4,5)P2 accumulated around collagen during internalization and was associated with gelsolin. Cell-permeable peptides mimicking the PI(4,5)P2 binding site of gelsolin blocked actin monomer addition, the association of gelsolin with actin at phagosomes, and collagen internalization but did not affect collagen binding. Collagen beads induced recruitment of type 1 γ phosphatidylinositol phosphate kinase (PIPK1γ661) to internalization sites. Dominant negative constructs and RNA interference demonstrated a requirement for catalytically active PIPK1γ661 for collagen internalization. We conclude that separate functions of gelsolin mediate sequential stages of collagen phagocytosis: Ca2+-dependent actin severing facilitates collagen binding, whereas PI(4,5)P2-dependent regulation of gelsolin promotes the actin assembly required for internalization of collagen fibrils.

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Glogauer, M., J. Ferrier et C. A. McCulloch. « Magnetic fields applied to collagen-coated ferric oxide beads induce stretch-activated Ca2+ flux in fibroblasts ». American Journal of Physiology-Cell Physiology 269, n^o 5 (1 novembre 1995) : C1093—C1104. http://dx.doi.org/10.1152/ajpcell.1995.269.5.c1093.

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The ability to apply controlled forces to the cell membrane may enable elucidation of the mechanisms and pathways involved in signal transduction in response to applied physical stimuli. We have developed a magnetic particle-electromagnet model that allows the application of controlled forces to the plasma membrane of substrate-attached fibroblasts. The system allows applied forces to be controlled by the magnitude of the magnetic field and by the surface area of cell membrane covered with collagen-coated ferric beads. Analysis by single-cell ratio fluorimetry of fura 2-loaded cells demonstrated large calcium transients (50-300 nM) in response to the magnetic force applications. Experiments using either the stretch-activated channel blocker gadolinium chloride or ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid to eliminate external calcium ions, or addition of extracellular manganese ions, indicated that there was a calcium influx through putative stretch-activated channels. The probability of a calcium influx in single cells was increased by higher surface bead loading and the degree of cell spreading. Depolymerization of actin filaments by cytochalasin D increased the amplitude of calcium response twofold. The regulation of calcium flux by filamentous actin content and by cell spreading indicates a possible modulatory role for the cytoskeleton in channel sensitivity. Magnetic force application to beads on single cells provides a controlled model to study mechanisms and heterogeneity in physical force stimulation of cation-permeable channels.

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Schroeder, Mark A., Julie Ritchey, Brian K. Dieckgraefe et John F. DiPersio. « Pegylated Murine GM-CSF Increases Myeloid Derived Suppressor Cells In Vivo ». Blood 118, n^o 21 (18 novembre 2011) : 2967. http://dx.doi.org/10.1182/blood.v118.21.2967.2967.

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Abstract Abstract 2967 Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of cells initially identified in tumor bearing mice that have potent immunosuppressive capabilities. Recent evidence suggests that graft-versus-host disease (GvHD) can be abrogated by ex vivo expanded, bone marrow derived, MDSCs generated in the presence of GM-CSF, G-CSF and IL-13 (Highfill et al. Blood 2010 116 :5738). It remains to be shown whether phenotypic MDSCs identified in non-tumor bearing mice are capable of immune suppression. In addition, the mechanism by which an immature myeloid cell becomes a functional MDSC remains unknown. We hypothesized that pegylated murine GM-CSF (peg-mGM) may be protective from acute GvHD in MHC mismatched murine models by increasing regulatory T-cells (Treg) and MDSCs. Previously, we reported that peg-mGM increased circulating and splenic Tregs by 2–3 fold and they were functional in mixed leukocyte reactions (MLRs). We have also reported on the in vivo potential of mobilized splenocytes to abrogate murine GvHD. B6D2F1 mice receiving C57/Bl6 GM treated splenocytes had improved survival and less weight loss compared to G-CSF and PBS controls (3 independent experiments, n=15-19/group, GM vs. G p = 0.0005, GM vs. PBS p = 0.0005, G vs. PBS p = 0.5 (Log rank test)). In an attempt to identify cellular mediators of the reduced incidence of GvHD we investigated the impact of peg-mGM on putative MDSCs. We have observed an ∼8 fold increase in putative monocytic MDSCs (monoMDSCs) (CD11b+Ly6C+Ly6G-) and an ∼18 fold increase in putative granulocytic MDSCs (granMDSCs) (CD11b+Ly6C+Ly6G+) in the spleens and blood of mice mobilized with peg-mGM. To investigate the function of MDSCs we performed bead stimulated tritiated thymidine and CFSE based proliferation assays. We observed that granMDSCs and monoMDSCs isolated from spleens of mice treated with peg-mGM have potent suppressive function on bead stimulated T-cell proliferation exceeding that of na•ve Tregs at equal suppressor :Tcell ratios (Fold suppression of CD4+ T-cells: granMDSCs = 4.5, monoMDSCs = 2.3, Tregs = 1.08. Fold suppression of CD8+ T-cells: granMDSCs = 2.26, monoMDSCs = 1.4, Tregs = 1.05). To investigate mechanism we performed a transwell experiment using bead stimulated T-cells separated from MDSCs by a permeable membrane. Sorted monoMDSCs and granMDSCs were not suppressive in this assay suggesting the dependence on contact for inhibition of T-cell proliferation. In addition, we observed that in bead stimulated proliferation assays wells containing putative MDSCs had more dispersed beads suggesting possible sequestration of beads by the suppressor cells. To determine if all subsets were suppressive in an alternative non-bead based proliferation assay we coated plates with CD3/CD28 antibodies. Only the putative monoMDSCs were suppressive in this assay. We observed that suppression of bead stimulated T-cells was abrogated by adding an arginase-1 inhibitor, nor-NOHA, to cultures containing putative monoMDSCs. When attempting to validate these results in a MLR using MHC mismatched antigen-presenting cell (APC) stimulation, the suppressive effect was decreased or lost suggesting that the magnitude of stimulation by APC, bead or antibodies may affect activation and function of MDSCs; or, a critical factor produced in bead and antibody stimulated T-cell proliferation assays is lacking in the APC setting. We are currently functionally characterizing the monoMDSCs generated by treatment with peg-mGM and investigating potential secondary factors critical to the development of MDSCs such as IL-13 and IFN-gamma. In addition, future studies will evaluate the in vivo function of monoMDSCs generated by peg-mGM mobilization on GvHD and GVL outcomes. In summary, treatment with peg-mGM results in enrichment in functional MDSCs in the spleens of non-tumor bearing mice. The mechanism by which immature myeloid cells generated by peg-mGM become MDSCs is under investigation but appears to be contact dependent. This work is currently being translated in a clinical trial investigating the combination of GM-CSF and plerixafor for the mobilization of peripheral blood stem cells for allogeneic stem cell transplantation from matched sibling donors. Correlative studies to characterize stem cell subsets and evaluate the content of Tregs and MDSCs in the blood and apheresis product are ongoing. Disclosures: No relevant conflicts of interest to declare.

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Tóthová, Jana, Katarína Paulovičová et Vladimír Lisý. « Viscosity Measurements of Dilute Poly(2-ethyl-2-oxazoline) Aqueous Solutions Near Theta Temperature Analyzed within the Joint Rouse-Zimm Model ». International Journal of Polymer Science 2015 (2015) : 1–7. http://dx.doi.org/10.1155/2015/690136.

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The steady-state shear viscosity of low-concentrated Poly(2-ethyl-2-oxazoline) (PEOX) aqueous solutions is measured near the presumed theta temperature using the falling ball viscometry technique. The experimental data are analyzed within the model that joins the Rouse and Zimm bead-spring theories of the polymer dynamics at the theta condition, which means that the polymer coils are considered to be partially permeable to the solvent. The polymer characteristics thus depend on the draining parameterhthat is related to the strength of the hydrodynamic interaction between the polymer segments. The Huggins coefficient was found to be 0.418 at the temperature 20°C, as predicted by the theory. This value corresponds toh= 2.92, contrary to the usual assumption of the infiniteh. This result indicates that the theta temperature for the PEOX water solutions is 20°C rather than 25°C in the previous studies. The experimental intrinsic viscosity is well described coming from the Arrhenius equation for the shear viscosity.

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McNiven, Ian J. « Beyond bridge and barrier : Reconceptualising Torres Strait as a co-constructed border zone in ethnographic object distributions between Queensland and New Guinea ». Queensland Archaeological Research 25 (3 juin 2022) : 25–46. http://dx.doi.org/10.25120/qar.25.2022.3885.

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For over 200 years, Western scholarship has presented Torres Strait variously as a bridge and barrier to cultural influences between mainland New Guinea and Australia. An alternative approach is to see Torres Strait as neither a bridge (permeable boundary) nor a barrier (impervious boundary) but as a socially and culturally co-constructed border zone. Central to this new approach is conceptualisation of the Coral Sea Cultural Interaction Sphere (CSCIS) that centres on a series of ethnographically-known, canoe-based, long-distance maritime exchange networks that linked communities and information on objects over a distance of 2000 km along the south coast of Papua New Guinea and the northeast coast of Australia. The CSCIS emphasises Indigenous agency and the shared/selective uptake of objects and ideas by potential recipient communities across Torres Strait and their New Guinea neighbours to the north and mainland Australian neighbours to the south. Object distribution maps created using data derived from anthropological texts and museum online catalogues reveal continuities and discontinuities in the distribution of selected objects across the study area. These maps illustrate three forms of object uptake: (1) shared uptake of double-outrigger canoes and bamboo smoking pipes between New Guinea, Torres Strait and Australia; (2) selective uptake of dog-tooth necklaces and cone shell armbands between New Guinea and Torres Strait and not Australia; and (3) selective uptake of nautilus bead headbands and shell-handled spearthrowers between Australia and Torres Strait and not New Guinea. Archaeological evidence for temporal changes in the geographical spread of pottery indicates that the CSCIS was historically dynamic, with numerous reconfigurations over the past 3000 years. Enhanced understanding of the CSCIS requires the addition of contemporary Indigenous perspectives.

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Davis, Craig C., Melissa Mazur et Paul Szabolcs. « IL-7 along with Optimized CD3/CD28 Artificial APC Beads Promotes Ex Vivo Expansion of Cord Blood T Cells towards Adoptive Immunotherapy. » Blood 110, n^o 11 (16 novembre 2007) : 2992. http://dx.doi.org/10.1182/blood.v110.11.2992.2992.

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Abstract Background: Viral infections are the leading cause of non-relapse mortality after unrelated umbilical cord blood transplants (UCBT). Post-transplant lymphopenia, lack of established antiviral memory, and lack of cytotoxic function among infused UCB lymphocytes are jointly responsible for ineffective immunity. We have previously demonstrated ex vivo T cell expansion and maturation starting from a very small fraction (<5%) of the graft that could be employed post transplant as donor leukocyte infusion (DLI). Naïve UCB T cells proliferate when stimulated with IL-2 + CD3/CD28 co-stimulatory beads that function as artificial antigen presenting cells (APCs). However, high rate of apoptosis (>10%) has hindered T cell expansion. We hypothesized that the presence of cytokines essential for T cell homeostasis, in particular IL-7 may aid expansion and survival, beads with different densities of CD3/CD28 antibodies may impact UCB T cell expansion. Research Design: From frozen/thawed specimens we tested 2 different sources of CD3/CD28 artificial beads (historical control beads vs ClinExVivo®, (Invitrogen Corporation), ± IL-7. Methods: Thawed UCB samples were centrifuged over Ficoll gradient. T cells were positively selected with EasySep®, (StemCell Technologies) and were incubated in gas permeable bags with CD3/CD28 beads in 5% serum replete media + 100u/ml IL-2 ± 10ng/ml of IL7. Media & cytokines were replenished to maintain a concentration of ∼0.75 ×106 cells/ ml. Automated cell count, trypan blue viability assessed overall cell growth and viability at each feeding . ‘Lyse no wash’ FACS staining with Trucount® beads quantified viable CD3+ T cells. 4-color FACS was employed to characterize the evolution of surface and intracellular immunophenotype. Cytotoxicity profile of the day 0 and D12-14 progeny was tested by Europium release assay (Delfia® assay) against a Burkitt’s lymphoma cell line (IM9). Two-tailed paired Student t-tests analyzed the impact of the experimental variables. Results: At the end of 12–14 day expansion periods, analyzing all cytokine conditions, we could demonstrate an average of 43-fold viable CD3+ T cell expansion using control APC beads (n=8), while T cells on ClinExVivo® beads expanded on average 94-fold (p=0.11, n=11). Addition of IL7 to the culture media afforded significantly better expansion with the control bead condition (mean 43 vs 26 fold, p=0.02). IL7 also enhanced T cell expansion with ClinExVivo® beads (mean 147 fold vs 49 fold, though statistically NS). There were significantly more viable T cells generated with ClinExVivo® beads when all timepoints were analyzed, irrespective of the absence (p=0.017) or presence (p=0.05) of IL7. We also analyzed the mechanism how IL7 may potentiate overall T cell expansion. T cells entering cell cycle was enhanced (though not significantly) as demonstrated with intracellular Ki-67 staining (65% T cells in cycle with IL7 versus 52% without, p=0.2). IL7’s overall salutary effect on total expansion may be best explained by simultaneously reduced T cell apoptosis as quantified by activated ic Caspase-3 detection (9.3% versus 7.6% without vs with IL7, respectively, p=0.08) regardless of the source of beads. Granzyme A, B, perforin expression was enhanced comparably, while cytotoxicity was absent against IM9 cells regardless of ± IL-7. Conclusions: These results demonstrate significant expansion of UCB T cell that is further improved by utilizing ClinExVivo® clinical grade APC beads and IL7. These results pave the way to donor-derived UCB T cell expansion suitable for DLI to boost immunity.

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Shapiro, F., TJ Yao, G. Raptis, L. Reich, L. Norton et MA Moore. « Optimization of conditions for ex vivo expansion of CD34+ cells from patients with stage IV breast cancer ». Blood 84, n^o 10 (15 novembre 1994) : 3567–74. http://dx.doi.org/10.1182/blood.v84.10.3567.3567.

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Abstract Multiple cycles of high-dose chemotherapy can be hematologically supported by repeated administration of peripheral blood progenitors obtained after mobilization using cytokine alone or in combination with chemotherapy. We have explored the quality of such cells and their potential to undergo ex vivo expansion. Twenty-five leukapheresis samples from 19 patients who had received extensive prior chemotherapy for stage IV breast cancer were subjected to CD34+ cell selection using immunoaffinity columns of immunomagnetic bead separation. Cells were cultured in suspension in the presence of c-kit ligand, interleukin-3, interleukin-6, erythropoietin, and granulocyte colony-stimulating factor. Ten experiments were performed using weekly exchange of media and cytokines (Delta assay). Median myeloid and erythroid progenitors expanded 15-fold at 7 days (range, 7 to 43), 40-fold at 14 days (range, 18 to 470), 46-fold at 21 days (range, 0 to 118), and 21-fold at 28 days (range, 0 to 61). In a system using gas-permeable bags without exchange of media or cytokine, median progenitors expanded 13-fold at 7 days (range, 7 to 36), 14-fold at 10 days (range, 4 to 61), 14-fold at 12 days (range, 3 to 46), and 10-fold at 14 days (range, 1 to 35). Progenitor expansion less than 10-fold occurred in 8% of experiments at day 7, in 17% at day 10, in 43% at day 12, and in 50% at day 14. When autologous plasma, autologous plasma processed (removal of cryoprecipitate, centrifugation, then filtration), or human serum were substituted for 20% fetal calf serum, the ratio of progenitor expansion at 7 days relative to 20% fetal calf serum for 10% human serum, 20% human serum, and 1% autologous plasma processed was 1.01 (range, 0.62 to 1.33), 0.88 (range, 0.61 to 1.20), and 0.96 (range, 0.55 to 1.64), respectively. These findings support the feasibility of ex vivo expansion in a system free of nonhuman proteins of CD34(+)-derived progenitors obtained from the peripheral blood of patients who have received prior chemotherapy.

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Shapiro, F., TJ Yao, G. Raptis, L. Reich, L. Norton et MA Moore. « Optimization of conditions for ex vivo expansion of CD34+ cells from patients with stage IV breast cancer ». Blood 84, n^o 10 (15 novembre 1994) : 3567–74. http://dx.doi.org/10.1182/blood.v84.10.3567.bloodjournal84103567.

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Multiple cycles of high-dose chemotherapy can be hematologically supported by repeated administration of peripheral blood progenitors obtained after mobilization using cytokine alone or in combination with chemotherapy. We have explored the quality of such cells and their potential to undergo ex vivo expansion. Twenty-five leukapheresis samples from 19 patients who had received extensive prior chemotherapy for stage IV breast cancer were subjected to CD34+ cell selection using immunoaffinity columns of immunomagnetic bead separation. Cells were cultured in suspension in the presence of c-kit ligand, interleukin-3, interleukin-6, erythropoietin, and granulocyte colony-stimulating factor. Ten experiments were performed using weekly exchange of media and cytokines (Delta assay). Median myeloid and erythroid progenitors expanded 15-fold at 7 days (range, 7 to 43), 40-fold at 14 days (range, 18 to 470), 46-fold at 21 days (range, 0 to 118), and 21-fold at 28 days (range, 0 to 61). In a system using gas-permeable bags without exchange of media or cytokine, median progenitors expanded 13-fold at 7 days (range, 7 to 36), 14-fold at 10 days (range, 4 to 61), 14-fold at 12 days (range, 3 to 46), and 10-fold at 14 days (range, 1 to 35). Progenitor expansion less than 10-fold occurred in 8% of experiments at day 7, in 17% at day 10, in 43% at day 12, and in 50% at day 14. When autologous plasma, autologous plasma processed (removal of cryoprecipitate, centrifugation, then filtration), or human serum were substituted for 20% fetal calf serum, the ratio of progenitor expansion at 7 days relative to 20% fetal calf serum for 10% human serum, 20% human serum, and 1% autologous plasma processed was 1.01 (range, 0.62 to 1.33), 0.88 (range, 0.61 to 1.20), and 0.96 (range, 0.55 to 1.64), respectively. These findings support the feasibility of ex vivo expansion in a system free of nonhuman proteins of CD34(+)-derived progenitors obtained from the peripheral blood of patients who have received prior chemotherapy.

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Naydenov, N., T. H. N. Le, S. Lechuga Villarauz, M. Elias, G. West, D. Czarnecki, T. Plesec, A. Ivanov et F. Rieder. « OP38 Modulation of the septin cytoskeleton ameliorates intestinal fibrogenesis ». Journal of Crohn's and Colitis 17, Supplement_1 (30 janvier 2023) : i54—i55. http://dx.doi.org/10.1093/ecco-jcc/jjac190.0038.

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Abstract Background Fibrosis-induced intestinal strictures leading to obstruction are a common and serious complication of Crohn’s disease (CD) with currently no available specific anti-fibrotic therapies. Cytoskeletal dynamics in mesenchymal cells are associated with organ fibrogenesis. Septin filaments are a novel cytoskeletal element, but the functional role of septins in regulating intestinal inflammation and fibrosis remain unknown. We examined the involvement of the septin cytoskeleton in modulating fibrogenic signaling in intestinal fibrogenesis in vitro and in vivo. Methods Expression of different septins in human intestinal resection tissues, primary human intestinal myofibroblasts (HIMF) and immortalized colonic myofibroblast (CCD 18co cells) were examined by real-time PCR and immunoblotting. Functional inhibition of the septin cytoskeleton was achieved using siRNA for septin 7 and the cell-permeable small molecule forchlorfenuron (FCF). Migration and proliferation of HIMF were examined by wound healing and thymidine incorporation assays, respectively. Levels of secreted cytokines were measured using cytometric bead array. Roles of septins in the development intestinal fibrosis in vivo was studied using a chronic DSS colitis model in mice with administration of FCF or vehicle. Results All septin genes were expressed in intestinal tissues with a predominant expression of septin 7. Pro-fibrotic transforming growth factor-β1 (TGFβ1) triggered HIMF activation manifested by the increased production of ECM proteins such as fibronectin and collagen 1 and enhanced expression of the myofibroblast markers α-smooth muscle actin, L-caldesmon and tropomyosin. Septin 7 knockdown resulted in loss of other septin proteins thereby disrupting the entire septin cytoskeleton. Either pharmacological, or genetic disruption of the septin cytoskeleton reversed the effect of TGFβ1 by attenuating production of ECM proteins and reducing expression of myofibroblast markers. Interestingly, these effects were only found on protein level and were not due to changes in gene expression, suggesting inhibition of their expression at a post-transcriptional level. Moreover, pharmacological or genetic disruptions of the septin cytoskeleton resulted in reduced migration, and attenuated cytokine secretion by activated myofibroblasts. FCF administration did not affect intestinal inflammation, but decreased the fibrosis score during chronic DSS colitis in mice. Conclusion Our data highlights the septin cytoskeleton as a novel regulator of intestinal myofibroblast activation and function. This for the first time implicates the cytoskeleton as an active participant in intestinal fibrosis and as a potential novel target for the development of anti-fibrotic therapies in IBD patients.

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Kelley, Todd W., et Olga Efimova. « The Antioxidant n-Acetylcysteine Blocks Direct Regulatory T Cell Mediated Suppression of CD4+ Effector T Cells In Vitro ». Blood 116, n^o 21 (19 novembre 2010) : 2765. http://dx.doi.org/10.1182/blood.v116.21.2765.2765.

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Abstract Abstract 2765 Background: CD4+CD25+FOXP3+ regulatory T cells (Tregs) employ a range of suppressive strategies including factors that are cytotoxic to target CD4+CD25−FOXP3− effector T cells (Teff) such as perforin and granzyme B and those that suppress proliferation, differentiation and/or cytokine production including TGF-beta1, IL-10 and CTLA-4. The relative contribution of each of these mechanisms to Treg function is unclear but from the available data their importance appears context specific. Because T cells are very sensitive to the redox state of the microenvironment, and display a pattern of impaired activation under conditions of oxidative stress, we investigated the potential contribution of an oxidant dependent suppressive pathway on direct Treg mediated suppression of Teff in vitro using the antioxidant n-acetylcysteine (NAC) to block reactive oxidants. Methods: Tregs and Teff were derived from the spleens of 2–4 month old C57BL/6 mice maintained in pathogen free conditions. T cell subsets were isolated using magnetic bead based techniques. Purity was assessed by flow cytometry. For suppression assays, Tregs were co-cultured with CFSE-labeled Teff at the indicated ratios and stimulated with anti-CD3/CD28 coated beads for 3 days. Proliferation was measured by flow cytometric evaluation of CFSE dilutional staining. Suppression was calculated by comparing proliferation of Teff cultured alone to those co-cultured with Tregs (% suppression= 1 − Tregs:Teff/Teff alone). In other experiments, CFSE-labeled Teff were cultured alone in the indicated conditions with TGF-beta +/− NAC and proliferation was assessed by CFSE staining. Intracellular reactive oxygen species (ROS) were measured by flow cytometry using the redox sensitive cell permeable indicator dye 5-(and-6)-chloromethyl-2',7'-dichlorodihydrofluorescein diacetate, acetyl ester (DCFDA). Results: The presence of NAC prevented Treg suppression of Teff in a dose dependent fashion at Treg:Teff ratios of 1:2, 1:1 and 2:1 (see figure). Suppression was significantly decreased at 0.1mM NAC (p<0.05 at 1:1; p<0.01 at 2:1) and essentially absent at 1mM NAC. Proliferation of Teff was markedly higher in the setting of 1mM NAC compared to conditions without NAC, even during co-culture with Tregs at a 2:1 ratio of Tregs:Teff. Treg suppression of Teff proliferation was dependent on TGF-beta as neutralizing antibodies reversed the effect (p<0.001). The presence of NAC was sufficient to overcome the suppressive effects of exogenous TGF-beta on CD3/CD28 stimulated Teff proliferation. Treatment of CD3/CD28 stimulated Teff with TGFbeta resulted in a significant dose dependent increase in the levels of intracellular ROS (p<0.0001 at 10ng/mL TGF-beta) that inversely correlated with the degree of proliferation. Conclusion: NAC blocks Treg mediated TGF-beta dependent suppression in vitro. This suggests that TGF-beta may function to suppress proliferation of Teff via a ROS dependent mechanism and raises the possibility that targeted delivery of antioxidants may have clinical utility for modulating the effects of Tregs in vivo. Disclosures: No relevant conflicts of interest to declare.

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Liu, Philip L. F., Matthew H. Davis et Sean Downing. « Wave-induced boundary layer flows above and in a permeable bed ». Journal of Fluid Mechanics 325 (25 octobre 1996) : 195–218. http://dx.doi.org/10.1017/s0022112096008087.

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In this paper, the oscillatory and steady streaming velocities over a permeable bed are studied both theoretically and experimentally. Three different sizes of glass beads are used to construct permeable beds in laboratory experiments: the diameters of the glass beads are 0.5 mm, 1.5 mm, and 3.0 mm, respectively. Several experiments are performed using different wave parameters. A one-component laser-doppler velocimeter (LDV) is used to measure the horizontal velocity component inside the Stokes boundary layer above the solid and permeable surfaces. It is observed that neither oscillatory nor steady velocity components vanish on the permeable surface. The ‘slip velocities’ increase with increasing permeability. Based on the laminar flow assumption and the order of magnitude of the parameters used in the experiments, a perturbation theory is developed for the oscillatory velocity and the steady wave-induced streaming in the boundary layers above and inside the permeable bed. The theory confirms many experimental observations. The theory also provides the damping rate and the phase changes caused by the permeable bed.

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Mihara, Hirotaka, Mai Kugawa, Kanae Sayo, Fumiya Tao, Marie Shinohara, Masaki Nishikawa, Yasuyuki Sakai, Takeshi Akama et Nobuhiko Kojima. « Improved Oxygen Supply to Multicellular Spheroids Using A Gas-permeable Plate and Embedded Hydrogel Beads ». Cells 8, n^o 6 (31 mai 2019) : 525. http://dx.doi.org/10.3390/cells8060525.

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Culture systems for three-dimensional tissues, such as multicellular spheroids, are indispensable for high-throughput screening of primary or patient-derived xenograft (PDX)-expanded cancer tissues. Oxygen supply to the center of such spheroids is particularly critical for maintaining cellular functions as well as avoiding the development of a necrotic core. In this study, we evaluated two methods to enhance oxygen supply: (1) using a culture plate with a gas-permeable polydimethylsiloxane (PDMS) membrane on the bottom, and; (2) embedding hydrogel beads in the spheroids. Culturing spheroids on PDMS increased cell growth and affected glucose/lactate metabolism and CYP3A4 mRNA expression and subsequent enzyme activity. The spheroids, comprised of 5000 Hep G2 cells and 5000 20 µm-diameter hydrogel beads, did not develop a necrotic core for nine days when cultured on a gas-permeable sheet. In contrast, central necrosis in spheroids lacking hydrogel beads was observed after day 3 of culture, even when using PDMS. These results indicate that the combination of gas-permeable culture equipment and embedded hydrogel beads improves culture 3D spheroids produced from primary or PDX-expanded tumor cells.

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Yang, Jinmeng, Zhenzhong Shen, Jing Zhang, Xiaomin Teng, Wenbing Zhang et Jie Dai. « Experimental and numerical investigation of flow over a spillway bend with different combinations of permeable spur dikes ». Water Supply 22, n^o 2 (30 septembre 2021) : 1557–74. http://dx.doi.org/10.2166/ws.2021.335.

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Abstract In this paper, the effects of different combinations of permeable spur dikes installed in the bend section of spillway on flow characteristics and energy dissipation rate were experimentally and numerically investigated. The results indicate that the permeable spur dikes installed in the spillway bend appreciably contributes to the improvement on the water surface uniformity, and the water surface uniformity can reach 90.13% with three permeable spur dikes installed in the bend. The permeable spur dike can lead to different degrees of decrease in the time-averaged longitudinal velocity in each zone of spillway bend. Different from previous study, no circulation zone is formed upstream and downstream of permeable spur dike due to the presence of permeable holes, and the flow upstream of permeable spur dikes could be divided into three distinctly different flow modes according to dye tracing. The presence of permeable spur dikes causes the concentration of TKE zone at concave bank of the spillway bend, except for TKE zone immediately next to the bottom plate. The TKE first increases and then decreases with the increase in the vertical distance from the bottom plate of the spillway bend, exhibiting a typical parabolic distribution. The energy dissipation rate in the spillway bend with permeable spur dike was calculated using a modified integral method, and the dissipation rate can reach as high as 21.08% with three spur dikes installed in the bend.

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Sisinggih, D., S. Wahyuni, Adenan Rasyid, M. F. Maruf et G. Halik. « The numerical investigation of turbulence and scour interaction around the permeable groynes at the channel bend ». IOP Conference Series : Earth and Environmental Science 1311, n^o 1 (1 mars 2024) : 012007. http://dx.doi.org/10.1088/1755-1315/1311/1/012007.

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Abstract Turbulence, particularly Reynolds Stress, plays a significant role in the flow field surrounding groynes, causing local scour. A limited number of studies have comprehensively analyzed the flow and turbulence structures encompassing a series of groynes in channel bends. This study numerically investigated the interplay between turbulence, sediment deposition, and scouring in a sharp channel bend with permeable groynes. The results show that the inner bank maintained high velocity, while permeable groynes decreased longitudinal velocity near the outer bank. Implementing permeable groynes structures reduced bottom velocity and increased flow separation. Turbulent kinetic energy distribution across the bend, particularly streamwise, influenced scour development more than vertical motion.

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Peng, Yong, et Xin Liu. « Application of Variable Frequency Speed Control to Beam Pumping Units Based on Mechanical Properties in Mechanical Controlling Engineering ». Advanced Materials Research 648 (janvier 2013) : 365–69. http://dx.doi.org/10.4028/www.scientific.net/amr.648.365.

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According to the present production conditions of the beam pumping unit and the features of low permeable oil field, in order to meet the need of low permeable oil field, a successful approach was invited to change the stroke frequency of beam pumping unit by comparing. By analyzing the past and present ways of adjusting stroke frequency, a new technology by adopting variable frequency speed control technology is introduced for adjusting stroke frequency, and its principle is simply described. Through the simulation of inverter and vvvf system based on Matlab software, it’s obvious that inverter could output better three-phase voltage and current diagrams, vvvf speed control system could output relative stable speed and torque in a certain range with robust abilities to overcome fluctuation.

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Yang, Jinmeng, Jing Zhang, Qinghua Zhang, Xiaomin Teng, Wei Chen et Xuemei Li. « Experimental research on the maximum backwater height in front of a permeable spur dike in the bend of a spillway chute ». Water Supply 19, n^o 6 (9 avril 2019) : 1841–50. http://dx.doi.org/10.2166/ws.2019.061.

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Abstract Hydraulic experiments on installing a permeable spur dike at three positions (1/4, 1/2, and 3/4) on the concave bank of the bend of a spillway chute with three angles (45°, 60° and 75°) were carried out for studying the backwater condition in front of the permeable spur dike. Results show that the maximum backwater height occurs at the cross-section where the permeable spur dike meets the concave bank of the bend. A formula for the maximum backwater height was derived by the employment of the principle of momentum conservation, and the formula indicates that the height is influenced by the geometric parameters of the permeable spur dike and the bend, the layout of the spur dike in the bend, and the inflow discharge. Based on experimental data, a regression analysis was implemented on the water depth coefficient in the formula. Furthermore, the maximum backwater height can be obtained through the water depth at the concave bank of the end of bend when the parameters and installing pattern of the permeable spur dike are determined.

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Kowata, Shugo, Tatsuo Oyake, Shigeki Ito, Kazunori Murai et Yoji Ishida. « The Role of Actin Nucleating Factors, Arp3 and mDia1, During Proplatelet Formation of Megakaryocytes. » Blood 114, n^o 22 (20 novembre 2009) : 1472. http://dx.doi.org/10.1182/blood.v114.22.1472.1472.

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Abstract Abstract 1472 Poster Board I-495 Platelets are generated from the proplatelets of mature megakaryocyte (MK) in bone marrow (BM). Proplatelet formation (PPF) requires profound changes in the cytoskeletal elements including microtubules and actin fibers. The bending and branching of proplatelet shafts are mediated by actin dynamics (Italiano JE Jr, J Cell Biol, 1999) in the process of PPF. Recent reports showed that Rho and its effecter ROCK, inhibit PPF (Chang Y. et al, Blood, 2007) and that the Wiskott-Aldrich syndrome protein (N-WASP) and its effector Arp2/3 complex, the actin nucleating factor, are essential in PPF (Schulze H. et al Blood, 2006). The contribution of another actin nucleating factor, mammalian diaphanous-related forming (mDia1), which is the other downstream effector of Rho, however, has not been reported in the process of PPF. In this study, we investigated the role of these factors and free barbed ends of actin filaments during PPF using the immunofluorescence method and inhibitory assay with specific inhibitors. Materials and methods. Inhibitory assay: Primary mature MKs, isolated by albumin density gradient method, were cultured in IMDM supplemented with 1% Insulin-Transferin-Selenium (ITS) with the specific signal inhibitor of each signal pathway, including Rho, Rho kinase (ROCK), Rac1 or N-WASP. After incubation at 37°C in 5%CO2 and 20%O2 for 16 hrs, MKs were fixed with 4% paraformaldehyde and then counted the ratio of MKs with PPF. Immunofluorescence method: Isolated MKs were cultured in the same condition, described above, fixed with 4% paraformaldehyde and incubated with the following primary antibodies: anti-mDia1 antibody, anti-Arp3 antibody for 1 hr. After washing, MKs were stained with fluolescence conjugated-antibody against the primary antibody. The free barbed end assay: To allow the visualization of actin nucleation sites, it was performed as described previously (Symons and Mitchison, J Cell Biol, 1991). Fluorescence in MKs was observed under a Zeiss LSM meta confocal microscopy. Results and Discussions. Inhibitory assay: The ratio of MKs with PPF increased significantly at low concentration of cell permeable C3 transferase, the specific inhibitor of Rho, (5 ug/ml)(38.4±7.2%, Control 20.3±8.8%, p<0.05) but decreased significantly at high concentration (data not shown). These data indicated that only ROCK might be inactivated at 5 ug/ml but both ROCK and mDia1 might be inactivated at high concentration. The ratio of MKs with PPF increased in the presence of Y27632, a specific inhibitor of ROCK (10 uM: 51.1±10.2%, Control 20.3±8.8%, p<0.05). However, inhibitor of Rac1 or N-WASP signaling decreased the ratio of MKs with PPF compared to the controls (NSC23766: 50 uM: 8.0±5.2%. Wiskostatin: 50uM: 4±3.4% vs control 18.3±6.8%, p<0.05). These data indicated that Arp2/3 was an important role in PPF, because Rac-1 and N-WASP were located at the upperstream of Arp2/3. Immunofluorescence method & free barbed end assay: Isolated MKs without PPF were round and smooth on their surface, and had a thin F-actin layer under the surface area. Free barbed end (FBE) signals were clearly observed along the plasma membrane and co-localized with mDia1 signals (Figure 1), not with Arp3 signal (data not shown). Thesedata indicated the presence of dynamic equilibrium of actin filaments, regulated by Rho/mDia1 signal, around the plasma membrane of MKs. Considering the previous reports in which Rho/Rock/myosin light chain/myosin IIA pathway was reported to restrain PPF and inhibit releasing premature platelets until the appropriate time, myosin IIA might utilize the actin filaments which was produced via Rho/mDia1 signal. In proplatelets, FBE were accumulated in the roots of proplatelet shaft, bifurcation sites, thin filopodias, and beads (Figure 2). These data indicated that actin filaments, produced at FBE, might have important roles in leading of microtubules at the roots and bifrucation sites and beads formation. mDia1 and Arp3 signals were localized at these sites. The differences of localization between mDia1 and Arp3 signals were that only mDia1 signals were accumulated at thin filopodias around the shaft and bead (data not shown). In conclusion, actin dynamics, which is controlled by the actin nucleating factor Arp3 and mDia1 play important roles in PPF of MKs. Disclosures: No relevant conflicts of interest to declare.

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Saka, Hiroyasu, Hiroyuki Iwata et Daisuke Kawaguchi. « Thermal stability of laser-induced modified volumes in Si as studied by in situ and ex situ heating experiments ». Microscopy 67, n^o 2 (21 février 2018) : 112–20. http://dx.doi.org/10.1093/jmicro/dfy008.

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Abstract Radiation of a permeable laser beam into Si induces considerable modification of structures. Thermal stability of the laser-induced modified volumes (LIMV’s) was studied comprehensively by means of in situ and ex situ heating experiments using transmission electron microscopy. The behavior in the tail region of a LIMV can be understood by dislocation theory, while that of a void formed at the very focus of a laser beam cannot be understood easily.

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Hedayati, Reza, Naeim Ghavidelnia, Mojtaba Sadighi et Mahdi Bodaghi. « Improving the Accuracy of Analytical Relationships for Mechanical Properties of Permeable Metamaterials ». Applied Sciences 11, n^o 3 (2 février 2021) : 1332. http://dx.doi.org/10.3390/app11031332.

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Permeable porous implants must satisfy several physical and biological requirements in order to be promising materials for orthopaedic application: they should have the proper levels of stiffness, permeability, and fatigue resistance approximately matching the corresponding levels in bone tissues. This can be achieved using designer materials, which exhibit exotic properties, commonly known as metamaterials. In recent years, several experimental, numerical, and analytical studies have been carried out on the influence of unit cell micro-architecture on the mechanical and physical properties of metamaterials. Even though experimental and numerical approaches can study and predict the behaviour of different micro-structures effectively, they lack the ease and quickness provided by analytical relationships in predicting the answer. Although it is well known that Timoshenko beam theory is much more accurate in predicting the deformation of a beam (and as a result lattice structures), many of the already-existing relationships in the literature have been derived based on Euler–Bernoulli beam theory. The question that arises here is whether or not there exists a convenient way to convert the already-existing analytical relationships based on Euler–Bernoulli theory to relationships based on Timoshenko beam theory without the need to rewrite all the derivations from the start point. In this paper, this question is addressed and answered, and a handy and easy-to-use approach is presented. This technique is applied to six unit cell types (body-centred cubic (BCC), hexagonal packing, rhombicuboctahedron, diamond, truncated cube, and truncated octahedron) for which Euler–Bernoulli analytical relationships already exist in the literature while Timoshenko theory-based relationships could not be found. The results of this study demonstrated that converting analytical relationships based on Euler–Bernoulli to equivalent Timoshenko ones can decrease the difference between the analytical and numerical values for one order of magnitude, which is a significant improvement in accuracy of the analytical formulas. The methodology presented in this study is not only beneficial for improving the already-existing analytical relationships, but it also facilitates derivation of accurate analytical relationships for other, yet unexplored, unit cell types.

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Iwata, Hiroyuki, Daisuke Kawaguchi et Hiroyasu Saka. « Crystal structures of high-pressure phases formed in Si by laser irradiation ». Microscopy 67, n^o 1 (6 janvier 2018) : 30–36. http://dx.doi.org/10.1093/jmicro/dfx128.

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Abstract Internal modification induced in Si by a permeable pulse laser was investigated by transmission electron microscopy. A laser induced modified volume (LIMV) was a cylindrical rod along the track of a laser beam with the head at the focus of the laser beam. In the LIMV, beside voids, dislocations, micro-cracks and what had been supposed to be an unidentified high-pressure phase (hpp) of Si were observed in LIMV. The so-called ‘hpp’ was identified mostly as diamond Si.

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Moerniati, Sri, Agustine Susilowati et Aspiyanto Aspiyanto. « UTILIZATION OF MEMBRANE MICROFILTRATION IN PREPARATION OF HYDROLYZED VEGETABLE PROTEIN FROM FERMENTED RED BEAN (Phaseolus vulgaris L.) EXTRACT AS FORTIFICATION AGENT ». Indonesian Journal of Chemistry 9, n^o 2 (22 juin 2010) : 332–38. http://dx.doi.org/10.22146/ijc.21552.

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Preparation of Hydrolyzed Vegetable Protein (HVP) as savory flavor from fermented red bean broth through stirred membrane cell using micro filtration membrane with pore size of 0.45 µm was performed to get fortified agent utilized in preparation of beans sauce. The objective of this work was to study an effect of pressure and kind of red bean broth extract on content of total protein, soluble protein and dry solid in the retentate and permeate as hydrolyzed vegetable protein used for fortified agent of red bean sauces. Preparation process of hydrolyzed vegetable protein was done using fixed rotary speed of 400 rpm, pressure of 20, 25 and 30 psi at room temperature. To investigate the effect of pressure on this separation, the feed were red bean broth extract fermented for 6, 8, 10 and 12 weeks, respectively. Fermentation process were conducted using salt fermentation with inoculum of Rhizopus-C1, salt and red bean ratios of 30:10:60%. The analysis of flux and contents of total protein, dissolved protein and dry solid in the retentate and permeate was carried out, and the result of experiment showed that interaction of Red bean broth extract with 6, 8, 10 and 12 weeks of fermentation and operation condition of microfiltration membrane separation tends to affect on flux and content of total protein, dissolved protein and dry solid in retentate and permeate. Red bean broth extract for 6 weeks fermentation resulted higher protein content in permeate as hydrolyzed vegetable protein than in retentate. Permeate at pressure of 25 psi gives flux value of 0.0217 mL/cm2.minute and contents of total protein of 1.31 %, dissolved protein of 6.9 mg/g, and dry solid of 2.6%, while retentate as hydrolyzed vegetable protein or fortified agent indicate contents of total protein of 1.52%, dissolved protein of 4.15 mg/g, and dry solid of 3.64%. It was found that micro filtration process was able to increase dissolved protein content of about 3 times. Keywords: Microfiltration, membrane, Hydrolyzed Vegetable Protein (HVP), fermented red bean (Phaseolus vulgaris L.).

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Fedotova, Karolina, Valeriy R. Grabovetsky, Sergey A. Novikov et Evgeniy L. Akopov. « New opportunities for the use of miniscleral contact lenses ». Ophthalmology journal 12, n^o 2 (12 juin 2019) : 81–84. http://dx.doi.org/10.17816/ov2019281-84.

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This case report demonstrates a new possibility of using rigid gas permeable miniscleral contact lenses as a device for performing Nd:YAG laser capsulotomy in patients with corneal irregularity. A correctly formed optical surface with a lens on the eye eliminates optical errors of the distorted cornea, and can be a useful tool for the optimization of aiming laser beam directing and focusing.

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Jakubowski, Andrzej, et Renata Crasto. « The Structure Analytical Research of Porous Permeable Wire Material ». Management Systems in Production Engineering 22, n^o 2 (1 juin 2016) : 81–88. http://dx.doi.org/10.2478/mspe-02-02-2016.

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Abstract The details of making technology of porous permeable material with use of wire are allowed to carry out the analytical research of structure and structural characteristics of wire winding body. Its permit for prognostication the final properties of material, that is produced by the following deformation treatment (diameter reduction). Due to the regular organized arrangement of wire, the coil of winding body is considered as a multispan continuous beam, but a contact of coils - as interaction of two cylinders. Possibility of exactly calculation of the contacts between coils is allowed to go over the single fragment displacements into deformation of whole winding body. During research of deformation processes in regards of winding body geometry and used wire mechanical properties, the structural characteristics of porous permeable wire material are expected. The optimal number of winding layers, eliminating the distortion of organized final structure, is established. The material pressure-compactness relation is obtained in order to control the technological conditions of winding and drafting for guarantee the product required properties.

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Paranjpe, R. S., et H. G. Elrod. « Stability of chains of permeable spherical beads in an applied magnetic field ». Journal of Applied Physics 60, n^o 1 (juillet 1986) : 418–22. http://dx.doi.org/10.1063/1.337666.

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Kojima, Michio, Hiroyuki Narahara, Yoshiyuki Nakao, Hirofumi Fukumaru, Hiroshi Koresawa, Hiroshi Suzuki et Satoshi Abe. « Permeability Characteristics and Applications of Plastic Injection Molding Fabricated by Metal Laser Sintering Combined with High Speed Milling ». International Journal of Automation Technology 2, n^o 3 (5 mai 2008) : 175–81. http://dx.doi.org/10.20965/ijat.2008.p0175.

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This paper describes the results of fundamental experiments conducted by injection mold with permeability fabricated by Metal Laser Sintering Combined with High Speed Milling. Metal Laser Sintering Combined with High Speed Milling is attracting attention as a new mold fabrication approach. This machining method combines the metallic powder layer fabrication method with high-speed cutting. Since this process does not have the problem of tool L/D in usual cutting, it provides outstanding shape machining performance of deep ribs etc. Moreover, with this processing method, sintered density can be controlled by changing the exposure conditions of the laser beam, and gas permeable structures can also be manufactured. This fabrication method does not require the mold to be divided. From these features, this method is expected to offer such advantages as quick delivery of molds and low manufacturing costs. However, little is known about the application of laser sintered metallic molds which have gas permeability structure to plastic injection molding, and the practical use of these molds is not easy. The aim of this research was therefore to investigate the gas permeable structures realized by laser sintered metallic mold in plastic injection molding The results confirmed that permeable injection molds are effective for influencing residue air in products.

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Kim, Jung Min, et Young-Mi Kang. « Optical Fluorescence Imaging of Native Proteins Using a Fluorescent Probe with a Cell-Membrane-Permeable Carboxyl Group ». International Journal of Molecular Sciences 23, n^o 10 (23 mai 2022) : 5841. http://dx.doi.org/10.3390/ijms23105841.

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Although various methods for selective protein tagging have been established, their ap plications are limited by the low fluorescent tagging efficiency of specific terminal regions of the native proteins of interest (NPIs). In this study, the highly sensitive fluorescence imaging of single NPIs was demonstrated using a eukaryotic translation mechanism involving a free carboxyl group of a cell-permeable fluorescent dye. In living cells, the carboxyl group of cell-permeable fluorescent dyes reacted with the lysine residues of acceptor peptides (AP or AVI-Tag). Genetically encoded recognition demonstrated that the efficiency of fluorescence labeling was nearly 100%. Nickel-nitrilotriacetic acid (Ni-NTA) beads bound efficiently to a single NPI for detection in a cell without purification. Our labeling approach satisfied the necessary conditions for measuring fluorescently labeled NPI using universal carboxyl fluorescent dyes. This approach is expected to be useful for resolving complex biological/ecological issues and robust single-molecule analyses of dynamic processes, in addition to applications in ultra-sensitive NPIs detection using nanotechnology.

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Luo, Yishan, Ken McDonald et John W. Hanrahan. « Trafficking of immature ΔF508-CFTR to the plasma membrane and its detection by biotinylation ». Biochemical Journal 419, n^o 1 (13 mars 2009) : 211–21. http://dx.doi.org/10.1042/bj20081869.

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Recent studies suggest that immature, core-glycosylated ΔF508-CFTR [the predominant mutant form of the CFTR (cystic fibrosis transmembrane conductance regulator)] can reach the plasma membrane under some conditions. In the present study we investigated this possibility since it has implications for understanding how therapeutics rescue the trafficking of mutant CFTR and perhaps other misfolded proteins. Core-glycosylated CFTR was labelled and pulled down on streptavidin beads after exposure to sulfo-NHS-SS-biotin [biotin attached to a reactive NHS (N-hydroxysuccinimide) ester with a disulfide spacer; molecular mass=606.7 Da]; however, intracellular proteins were also detected in the precipitates. When the R domain of CFTR was expressed in the cytosol of BHK (baby-hamster kidney) cells as a soluble polypeptide it was also labelled after surface biotinylation and pulled down on streptavidin beads. Intracellular biotinylation was reduced when cells were treated with sulfo-NHS-LC-biotin (biotin attached to a reactive NHS ester with an aminocaproic acid spacer) or sulfo-NHS-PEO12-biotin [biotin attached to a reactive NHS ester with a poly(ethylene glycol) spacer], but the reduction could be explained by the lower reactivity of these reagents. The R domain was detected on Western blots after loading <0.25% of the pulldown sample (∼0.01% of total lysate protein), a fraction that could be ascribed to cells that were permeable to ethidium homodimer-1 (molecular mass=856.8 Da) and propidium iodide (molecular mass=668.6 Da). When BHK cells were incubated at 29 °C to rescue ΔF508-CFTR trafficking, and then biotinylated and sorted to remove permeable cells, labelling of core-glycosylated ΔF508-CFTR was no longer detected although a weak signal was still observed using CFBE (cystic fibrosis bronchial epithelial) cells. These results suggest that there is weak surface expression of immature ΔF508-CFTR on airway epithelial cells and demonstrate the need to remove permeable cells when studying CFTR glycoforms by surface biotinylation.

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Neill, Christopher, Michael T. Coe, Shelby H. Riskin, Alex V. Krusche, Helmut Elsenbeer, Marcia N. Macedo, Richard McHorney et al. « Watershed responses to Amazon soya bean cropland expansion and intensification ». Philosophical Transactions of the Royal Society B : Biological Sciences 368, n^o 1619 (5 juin 2013) : 20120425. http://dx.doi.org/10.1098/rstb.2012.0425.

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The expansion and intensification of soya bean agriculture in southeastern Amazonia can alter watershed hydrology and biogeochemistry by changing the land cover, water balance and nutrient inputs. Several new insights on the responses of watershed hydrology and biogeochemistry to deforestation in Mato Grosso have emerged from recent intensive field campaigns in this region. Because of reduced evapotranspiration, total water export increases threefold to fourfold in soya bean watersheds compared with forest. However, the deep and highly permeable soils on the broad plateaus on which much of the soya bean cultivation has expanded buffer small soya bean watersheds against increased stormflows. Concentrations of nitrate and phosphate do not differ between forest or soya bean watersheds because fixation of phosphorus fertilizer by iron and aluminium oxides and anion exchange of nitrate in deep soils restrict nutrient movement. Despite resistance to biogeochemical change, streams in soya bean watersheds have higher temperatures caused by impoundments and reduction of bordering riparian forest. In larger rivers, increased water flow, current velocities and sediment flux following deforestation can reshape stream morphology, suggesting that cumulative impacts of deforestation in small watersheds will occur at larger scales.

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Hwang, Sungju, Yooju Lee et Jin Yong Park. « The Role of Humic Acid, PP Beads, and pH with Water Backwashing in a Hybrid Water Treatment of Multichannel Alumina Microfiltration and PP Beads ». Membranes 10, n^o 1 (25 décembre 2019) : 3. http://dx.doi.org/10.3390/membranes10010003.

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Photooxidation oxidizes most organic compounds by mineralizing them to small inorganic molecules. In this study, the effects of dissolved organic matter (DOM), pH, and polypropylene (PP) beads concentration on membrane fouling were investigated in a hybrid water treatment process consisting of seven-channel alumina microfiltration (pore size 1.0 μm) and pure PP beads water backwashing with UV irradiation for photooxidation. The synthetic feed was prepared with humic acid and kaolin and flowed inside the microfiltration (MF) membrane. The permeate contacted the PP beads fluidized in the gap of the membrane and module with outside UV irradiation. Membrane fouling resistance (Rf) increased dramatically with an increase in the concentration of humic acid (HA) from 6 mg/L to 8 mg/L. The treatment efficiency of DOM increased dramatically, from 14.3% to 49.7%, with an increase in the concentration of HA. The Rf decreased with an increase of PP beads concentration. However, maximum permeate volume (VT) was acquired at 5 g/L of PP beads. The maximal treatment efficiency of DOM was 51.3% at 40 g/L of PP beads. The Rf increased with an increase in the pH of feed, and the maximum VT was acquired at a pH of 5. The maximal treatment efficiency of DOM was 52.5% at pH 9.

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Ciriminna, Diego, Giovanni Battista Ferreri, Leonardo Valerio Noto et Clara Celauro. « Numerical Comparison of the Hydrological Response of Different Permeable Pavements in Urban Area ». Sustainability 14, n^o 9 (9 mai 2022) : 5704. http://dx.doi.org/10.3390/su14095704.

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Floods are becoming more frequent, especially in urban environments where most of the surface is waterproofed. Permeable pavement (PP) can be applied as low impact development (LID) systems for runoff mitigation in urban areas. Their effectiveness can be assessed, case by case, by numerical simulations. In this study, the effectiveness of mitigating runoff of different permeable pavements has been evaluated. In particular, porous asphalt (PA), pervious concrete (PC), permeable interlocking concrete pavement (PICP) and grid pavement (GP) have been investigated using EPA Storm Water Management Model (SWMM) software. To this aim, a car parking area located in the University Campus of Palermo (Italy) has been taken as a case study, considering several scenarios, each having a different percentage and planimetric layout of a PP type combined with an impermeable pavement. All the scenarios were tested assuming four synthetic rainfall events, referring to return periods of 5, 10, 50 and 100 years, and a real high return period event that occurred in Palermo in 2020. The results showed that amongst the different PPs considered, only the PA, bounded at the bottom by an impermeable layer, was practically ineffective. The other three PPs, proved to be effective in a noticeable way and furthermore for each scenario studied, they proved to bear almost the same mitigated runoff. The results proved appreciable differences in runoff as a function of the location of the PP over the study area.

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Janajreh, Isam. « CFD Analysis of Wind Loads on Permeable Low-Rise Structures ». Applied Mechanics and Materials 152-154 (janvier 2012) : 1814–20. http://dx.doi.org/10.4028/www.scientific.net/amm.152-154.1814.

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Current screen enclosure building codes are based on the experimental wind tunnel studies and, to a smaller extent, full scale open terrain studies conducted at Virginia Tech and Clemson University. There are still widespread wind damages to pool and patio enclosures during wind storms. Experimental studies based on simulation comparison of wind load on a low-rise structure in general, continue to show large discrepancies based on NIST data. Accounting for the many parameters which are essential to achieve an accurate simulation through experimentation is daunting. Reynolds number, spectrum density, large and small turbulent scales, viscous shear layer, and flow intermittency are a few of those parameters. Numerical simulation (CFD) provides an attractive parametric study and offers a richer, higher resolution data output. In this work, flow around a screen enclosure embedded within the atmospheric boundary layer is investigated numerically. The flow is governed by Navier-Stokes equations with a momentum sink that follows Darcy equations and incorporating the eddy viscosity k-ε turbulent closure model. The pressure drop that is computed provides the basis of evaluating wind load on the screen structure. The evaluated load is compared to the Florida Building Code ASCE7 provision and is used to conduct structural analysis on common baseline enclosures to assess their reliability. The structure is analyzed using Bernoulli-Euler beam elements having cross sections according to the code and subjected to forces and moments with 6 (3displacements and 3 rotational) degrees of freedom.

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Mazumder, Mohammad A. Jafar. « Bio-Encapsulation for the Immune-Protection of Therapeutic Cells ». Advanced Materials Research 810 (septembre 2013) : 1–39. http://dx.doi.org/10.4028/www.scientific.net/amr.810.1.

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The design of new technologies for treatment of human disorders is a complex and difficult task. The aim of this article is to explore state of art discussion of various techniques and materials involve in cell encapsulations. Encapsulation of cells within semi-permeable polymer shells or beads is a potentially powerful tool, and has long been explored as a promising approach for the treatment of several human diseases such as lysosomal storage disease (LSD), neurological disorders, Parkinsons disease, dwarfism, hemophilia, cancer and diabetes using immune-isolation gene therapy.

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Liu, Xiu Li, Lin Zhao, She Jiang Liu et Cheng Yang Cui. « Remediation of Groundwater Contaminated by BTEX Using a Biological Barrier ». Advanced Materials Research 178 (décembre 2010) : 254–59. http://dx.doi.org/10.4028/www.scientific.net/amr.178.254.

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In this study, a biological permeable reactive barrier system was designed to evaluate the remediation effectiveness of BTEX-contaminated groundwater. The biological barrier using immobilized bio-beads encapsulated with calcium alginate and activated carbon fiber as microbial carrier is able to biodegrade BTEX entering the barrier system. A laboratory-scale experiment using one continuous up-flow stainless steel column was then performed to evaluate the feasibility of this designed system. The second column was filled with bio-beads immobilizing BTEX-degrading microbial consortium. Simulated BTEX-contaminated groundwater, in which dissolved oxygen (DO) content was saturated, was pumped into this system at a flow rate of 0.07ml/min. Samples from the column were analyzed for BTEX and effluent DO. Results showed that BTEX could be well removed in this biological barrier.

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Aspiyanto, Aspiyanto, Agustine Susilowati, Puspa Dewi Lotulung, Hakiki Melanie et Yati Maryati. « Potency of Stirred Microfiltration Cell in Separation of Fermented Beans as Protein Isolate for Natural Source of Folic Acid ». Indonesian Journal of Chemistry 19, n^o 1 (29 janvier 2019) : 9. http://dx.doi.org/10.22146/ijc.25164.

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Protein isolate from soy bean (Glycine soja L.) tempeh, mung bean (Phaseolus radiatus L.) tempeh and kidney bean (Phaseolus vulgaris L.) tempeh are natural source of folic acid with main role in brain smartness. 0.15 µm microfiltration (MF) membrane fitted in dead-end stirred microfiltration cell (SMFC) was able to separate protein isolate from three (3) kinds of tempeh at stirrer rotation speed 400 rpm, room temperature and pressure 40 psia for 30 minutes. The result of experimental work showed that SMFC had potential use in separation of protein isolate affected by kinds of bean and membrane performance on isolate composition in retentate and permeate. SMFC was able to retain better protein isolate in retentate than that passing across permeate. Retentate of protein isolate from soy bean tempeh, mung bean tempeh and kidney bean tempeh had subsequently compositions of folic acid 362.07, 254.07 and 506.07 µg/mL, total solids 5.56, 4.08 and 1.82 %, N-Amino 4.34, 3.36 and 0.56 mg/mL, and dissolved protein 0.79, 0.34 and 0.72 mg/mL. In this process condition, SMFC was able to increase folic acid in protein isolate retentate of soy tempeh of 0.59 times, mung bean tempeh of 1.1 times and kydney bean tempeh of 1.42 times before purification process in retentate. Based on both SMFC performance and efficiency, all the best purification optimization were obtained kidney beans tempeh. Identification of monomer of kidney bean tempeh protein isolate gave monomers of folic acid, glutamic acid and folic acid fractionation with molecular weight of 443.5797, 148.1643 and 221.2132 Da. and relative intensity of 1.28, 50.11 and 7.05 %, respectively.

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Banthia, Nemkumar, Jean-Francois Trottier, Denis Beaupre et David Wood. « Properties of steel fiber reinforced shotcrete ». Canadian Journal of Civil Engineering 21, n^o 4 (1 août 1994) : 564–75. http://dx.doi.org/10.1139/l94-058.

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Five commercially available steel fibers with different geometries were investigated both in dry-mix and in wet-mix shotcretes. In the dry process, bulk-bin bags with dry premixes were used. In the wet process, ingredients were wet-mixed centrally in a batching plant and then transported to the shooting site in ready-mix trucks. Mixes were shot on wooden forms and the rebound characteristics of the fibers and other ingredients were determined. Once hardened, shotcrete panels were sawed and cored to obtain beam specimens for flexural toughness tests and cylinders for compression tests. Hardened shotcrete specimens were also tested for boiled absorption and permeable voids. The boiled absorption and permeable voids data indicated that an adequately dense in-place shotcrete was obtained for both processes. The rebound of fibers in the dry process was found to be much higher than that in the wet process. Both compressive and flexural strengths were found to be improved because of the addition of fibers. Fibers also led to a significant enhancement in the toughness of shotcrete. Key words: shotcrete, wet mix, dry mix, steel fibers, rebound, toughness.

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Rostam-Afschar, Davud. « Inklusive Beschäftigungspolitik : Fakten, Herausforderungen und neue Ideen zur Regulierung von Berufen ». Zeitschrift für Wirtschaftspolitik 69, n^o 2 (25 septembre 2020) : 129–39. http://dx.doi.org/10.1515/zfwp-2020-2034.

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AbstractOccupational licensing aims to restrict access for providing products and services to only those who promise a minimal level of quality by imposing time and cost-intensive barriers. This can be reasonable to verify personal experience, but bear substantial costs, which need to be justified with proven quality improvements. A series of studies shows that occupational licensing reduces self-employment and overall employment, may lead through limiting geographical and social mobility to higher wages, inequality, and unfair market entry. A more efficient and inclusive guarantee of quality could be achieved with focused, permeable, and independently verifiable occupational licensing.

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Cao, Hui, Chen Ye, Xu-Feng Yan, Xing-Nian Liu et Xie-Kang Wang. « Experimental investigation of turbulent flows through a boulder array placed on a permeable bed ». Water Supply 20, n^o 4 (18 mars 2020) : 1281–93. http://dx.doi.org/10.2166/ws.2020.046.

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Abstract Glass beads were used to model permeable beds and boulders (simulated by plastic spherical balls) placed on the centre section of the bed. Flume experiments were conducted to investigate the hydrodynamics through a boulder array over impermeable and permeable beds (i.e. IMPB and PB). For background reference, hydrodynamics investigation was made over smooth beds (SB) with the boulder array. Through measuring the instantaneous velocity field, the major flow characteristics such as mean flow velocity, turbulence intensity, turbulent kinetic energy (TKE) and instantaneous Reynolds stresses (through quadrant analysis) were presented. The results show that the increase in bed permeability through decreasing the exposure height of boulders has little impact on the magnitude of streamwise velocity, but tends to decrease the near-bed velocity gradient, thus affecting the bed shear-stress. For turbulence, similar to the previous studies, the bed permeability is identified to enable a downward shift of the peak of turbulence intensity. The TKE budget analysis shows that bed permeability tends to inhibit the transport and diffusion processes of TKE generation. Finally, the quadrant analysis of turbulence structure clearly shows that the ejections (Q2) and sweeps (Q4) with and without the boulder array are dominated by turbulence structure of different scales.

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Schmitz-Hertzberg, Sebastian-Tim, Rick Liese, Carsten Terjung et Frank F. Bier. « Towards a Smart Encapsulation System for Small-Sized Electronic Devices : A New Approach ». International Journal of Polymer Science 2014 (2014) : 1–12. http://dx.doi.org/10.1155/2014/713603.

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Miniaturized analytical chip devices like biosensors nowadays provide assistance in highly diverse fields of application such as point-of-care diagnostics and industrial bioprocess engineering. However, upon contact with fluids, the sensor requires a protective shell for its electrical components that simultaneously offers controlled access for the target analytes to the measuring units. We therefore developed a capsule that comprises a permeable and a sealed compartment consisting of variable polymers such as biocompatible and biodegradable polylactic acid (PLA) for medical applications or more economical polyvinyl chloride (PVC) and polystyrene (PS) polymers for bioengineering applications. Production of the sealed capsule compartments was performed by heat pressing of polymer pellets placed in individually designable molds. Controlled permeability of the opposite compartments was achieved by inclusion of NaCl inside the polymer matrix during heat pressing, followed by its subsequent release in aqueous solution. Correlating diffusion rates through the so made permeable capsule compartments were quantified for preselected model analytes: glucose, peroxidase, and polystyrene beads of three different diameters (1.4 μm, 4.2 μm, and 20.0 μm). In summary, the presented capsule system turned out to provide sufficient shelter for small-sized electronic devices and gives insight into its potential permeability for defined substances of analytical interest.

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Abe, Satoshi, Seiichi Uemoto et Masanori Morimoto. « Advantages of Injection Mold with Hybrid Process of Metal Powder Bed Fusion and Subtractive Process ». International Journal of Automation Technology 17, n^o 4 (5 juillet 2023) : 388–97. http://dx.doi.org/10.20965/ijat.2023.p0388.

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This paper focuses on the hybrid process combining metal additive manufacturing (AM) and subtractive processing developed for application to injection molds. The basic concept is a combination of laser powder bed fusion of metal powder and subtractive processing. This process is characterized by alternating buildup and milling processes. Even the inner surface of deep grooves, which conventionally required electrical discharge machining, can be machined with small-diameter tools with a short flute length. Therefore, molds with complex shapes that previously required electrical discharge machining can be manufactured in a single process. Moreover, a dimensional accuracy and surface roughness of levels equal to those achieved by machining with the machining center can be ensured. In the hybrid process, it is necessary to minimize the surplus solidified area (which is the area milled by the small-diameter tool). Therefore, the formation mechanism of the surplus solidified region is verified. It is shown that the power distribution of the laser beam significantly affects the size (width and depth) and density distribution of the excessively solidified region. In addition, the effective value of metal AM mold is introduced. The 3D cooling circuit improves the efficiency of the injection molding process. If the temperature balance between the cavity side and core side is achieved, the distortion of the molded product would be suppressed. If the cooling effect is promoted, the molding cycle would be shortened substantially. Second, the effect of the gas vent function by a permeable structure is explained through actual examples. The effect of the gas vent function by the permeable structure is explained. It is indicated that stable molding can be achieved. In addition, the appearance defects of molded products can be reduced when the air inside the cavity is exhausted sufficiently from the mold through the permeable structure.

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Li, Bai, Yu-Ying Li, Hua-Mao Wu, Fang-Fang Zhang, Chun-Jie Li, Xue-Xian Li, Hans Lambers et Long Li. « Root exudates drive interspecific facilitation by enhancing nodulation and N2 fixation ». Proceedings of the National Academy of Sciences 113, n^o 23 (23 mai 2016) : 6496–501. http://dx.doi.org/10.1073/pnas.1523580113.

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Plant diversity in experimental systems often enhances ecosystem productivity, but the mechanisms causing this overyielding are only partly understood. Intercropping faba beans (Vicia faba L.) and maize (Zea mays L.) result in overyielding and also, enhanced nodulation by faba beans. By using permeable and impermeable root barriers in a 2-y field experiment, we show that root–root interactions between faba bean and maize significantly increase both nodulation and symbiotic N2 fixation in intercropped faba bean. Furthermore, root exudates from maize promote faba bean nodulation, whereas root exudates from wheat and barley do not. Thus, a decline of soil nitrate concentrations caused by intercropped cereals is not the sole mechanism for maize promoting faba bean nodulation. Intercropped maize also caused a twofold increase in exudation of flavonoids (signaling compounds for rhizobia) in the systems. Roots of faba bean treated with maize root exudates exhibited an immediate 11-fold increase in the expression of chalcone–flavanone isomerase (involved in flavonoid synthesis) gene together with a significantly increased expression of genes mediating nodulation and auxin response. After 35 d, faba beans treated with maize root exudate continued to show up-regulation of key nodulation genes, such as early nodulin 93 (ENOD93), and promoted nitrogen fixation. Our results reveal a mechanism for how intercropped maize promotes nitrogen fixation of faba bean, where maize root exudates promote flavonoid synthesis in faba bean, increase nodulation, and stimulate nitrogen fixation after enhanced gene expression. These results indicate facilitative root–root interactions and provide a mechanism for a positive relationship between species diversity and ecosystem productivity.

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Krajangpan, Sita, Juan J. Elorza Bermudez, Achintya N. Bezbaruah, Bret J. Chisholm et Eakalak Khan. « Nitrate removal by entrapped zero-valent iron nanoparticles in calcium alginate ». Water Science and Technology 58, n^o 11 (1 décembre 2008) : 2215–22. http://dx.doi.org/10.2166/wst.2008.925.

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Zero-valent iron nanoparticles (nZVI) were successfully entrapped in calcium alginate beads. The potential use of this technique in environmental remediation using nitrate as a model contaminant was investigated. Kinetics of nitrate degradation using bare nZVI (∼35 nm dia) and entrapped nZVI were compared. Calcium alginate beads show promise as the entrapment medium for nZVI for possible use in permeable reactive barriers for groundwater remediation. Based on scanning electron microscopy images it can be inferred that the alginate gel cluster acts as a bridge that binds the nZVI particles together. Kinetic experiments with 100, 60, and 20 mg NO3−-N L−1 indicate that 50–73% nitrate-N removal was achieved with entrapped nZVI as compared to 55–73% with bare nZVI over a 2 h period. The controls ran simultaneously show little or no NO3−-N removal. Statistical analysis indicates that there was no significant difference between the reaction rates of bare and entrapped nZVI. The authors have shown for the first time that nZVI can be effectively entrapped in Ca-alginate beads and no significant decrease in the reactivity of nZVI toward the model contaminant (nitrate here) was observed after the entrapment.

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Gill, Patrick. « Role Reversals and Permeable Bodies in the Modern Robinsonade : From Postcolonialism to Ecocriticism ». Nordic Journal of English Studies 23, n^o 1 (10 avril 2024) : 181–95. http://dx.doi.org/10.35360/njes.2024.23320.

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This essay argues that the particular lens of Bakhtinian body theory as developed for the Robinsonade by Rebecca Weaver-Hightower will help to shed light on a process observable over the past fifty years, in which colonial and postcolonial authors first embraced and then quickly abandoned the technique of role reversal in drafting their castaway stories. Enamoured of its comedic potential, Adrian Mitchell wrote Man Friday (1973). Derek Walcott was somewhat more circumspect in his Pantomime (1978), based on the realisation that role reversal demands the ascription of univocal roles and identities, something he did not see in evidence in the creolised world of the Caribbean. Later colonial and postcolonial writers such as J. M. Coetzee and Patrick Chamoiseau were then at pains to avoid questions of identity altogether, making epistemology and discourse their preferred topics. By the beginning of the twenty-first century, however, the clichéd identities formerly applied to Indigenous peoples (physical strength, close connection to nature) could be brought to bear on the idea of nature itself, thus making animal Robinsonades such as Life of Pi (2001) and The Red Turtle (2016) tremendous successes that could forgo the messiness of human affairs and simply champion the everlasting superiority of nature over civilisation as an expression of contemporary environmental preoccupations.

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Aspiyanto, Agustine Susilowati, Hakiki Melanie et Yati Maryati. « The Performance of Nanofiltration Membrane in Concentrating Folic Acid from Fermented Mungbean (Phaseolus radiatus L.) by Rhizopus oligosporus Strain-C₁ and Rhizopus sp. for Recovery Efficiency of Natural Folic Acid ». E3S Web of Conferences 503 (2024) : 07003. http://dx.doi.org/10.1051/e3sconf/202450307003.

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This research was conducted to evaluate the performance of the nanofiltration (NF) membrane in concentrating permeate obtained from the ultrafiltration (UF) membrane of fermented mung bean. The procedure was performed to determine both the best flux and efficiency of recovering folic acid from the multi-filtration process. Feed A and Feed B were used as ultrafiltered permeate of fermented mung bean (Phaseolus radiatus L.) obtained using Rhizopus oligosporus strain-C1 and Rhizopus sp., respectively. These feeds were subjected to the NF membrane installed in crossflow filtration (CFF) module system at room temperature, flow rate ~7.5 L/min. and transmembrane pressure (TMP) of 10 bar for 0, 15, 30, 45, 60, 75 and 90 minutes. The results showed that based on the optimum flux, the best performance of the NF membrane for Feed A and B was achieved at 15 and 15 min, with permeate flux of 32.22 and 20.44 L/m2.h., respectively. Retentate A and B contained folic acid concentrations of 308.51 and 297.53 μg/mL, as well as total solids of 1.39% and 2.20%. Meanwhile, permeate A and B yielded folic acid concentrations of 106.88 and 63.77 μg/mL, with total solids of 0.22 and 0.32%. Under the NF process conditions, retentate A and B showed observed rejection (Robs) rates of folic acid at 65.35 and 78.56%, as well as total solids of 84.34 and 85.36%, respectively. There was also a 9.75 and 3.10% increase in folic acid with a 4.18% and 17.31% rise in total solids compared to the initial condition at 0 minutes. Molecular weight analysis of folic acid in permeate A and B after 15 min. and 15 min. of processing were dominated by monomer with a MW of 442.17 Da. Meanwhile, mass spectra of feed B for a processing time of 15 min. were dominated by monomers with MW of 442.19 and 442.47 Da, both with a relative intensity of 100%.

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Rosencher, E., G. Glastre, G. Vincent, G. Vareille et F. Arnaud D'avitaya. « Si/CoSi2/Si permeable base transistor obtained by silicon molecular beam epitaxy over a CoSi2 grating ». Electronics Letters 22, n^o 13 (1986) : 699. http://dx.doi.org/10.1049/el:19860478.

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