Articles de revues : « Sponge replication »

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Sutygina, Alina, Ulf Betke et Michael Scheffler. « Manufacturing of Open-Cell Aluminium Foams : Comparing the Sponge Replication Technique and Its Combination with the Freezing Method ». Materials 15, n^o 6 (15 mars 2022) : 2147. http://dx.doi.org/10.3390/ma15062147.

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The manufacturing of aluminium foams with a total porosity of 87% using the sponge replication method and a combination of the sponge replication and freezing technique is presented. Foams with different cell counts were prepared from polyurethane (PU) templates with a pore count per inch (ppi) of 10, 20 and 30; consolidation of the foams was performed in an argon atmosphere at 650 °C. The additional freezing steps resulted in lamellar pores in the foam struts. The formation of lamellar pores increased the specific surface area by a factor of 1.9 compared to foams prepared by the sponge replication method without freezing steps. The formation of additional lamellar pores improved the mechanical properties but reduced the thermal conductivity of the foams. Varying the pore cell sizes of the PU template showed that—compared to foams with dense struts—the highest increase (~7 times) in the specific surface area was observed in foams made from 10 ppi PU templates. The effect of the cell size on the mechanical and thermal properties of aluminium foams was also investigated.

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Hasmaliza, Mohamad, Musa Siti Naqiah et Ibrahim Norfadhilah. « Effect of the Sponge Used as the Template for the Production of Porous Cordierite ». Advanced Materials Research 858 (novembre 2013) : 56–59. http://dx.doi.org/10.4028/www.scientific.net/amr.858.56.

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Cordierite (2MgO.2Al2O3.5SiO2) is widely used in high temperature applications due to its high melting temperature and high resistance to thermal, chemical and corrosion shock. The use of various structure of cordierite especially porous structure became more popular where its properties can be tailored by controlling the open and closed porosity, cell size distribution and cell morphology. In this study, porous cordierite was synthesized using sol-gel method followed by replication of polymeric sponge method using three different types of polymeric sponge (Type A, B and C). Immersed sponge were then sintered at 1300°C to determine better sponge types to produce porous cordierite. Sponge was characterized using FTIR and porous sample produced were characterized using Scanning Electron Microscope (SEM) and density and porosity testing.

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Sutygina, Betke et Scheffler. « Open-Cell Aluminum Foams by the Sponge Replication Technique ». Materials 12, n^o 23 (21 novembre 2019) : 3840. http://dx.doi.org/10.3390/ma12233840.

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Open-cell aluminum foams were manufactured by a sponge replication technique having a total porosity of ~90%. The influence of the thermal processing conditions such as atmosphere and temperature on the cellular structure, phase composition porosity, thermal conductivity, and compressive strength of the foams was studied. It was found that the thermal processing of aluminum foams in Ar at temperatures up to 800 °C led to aluminum foams with a reduced strut porosity, a lower amount of aluminum oxide, a higher thermal conductivity, and a higher compression strength, compared to foams thermally processed in air. These results were explained by the lower amount of aluminum oxide after thermal processing of the foams.

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Li, J. P., J. R. Wijn, Clemens A. van Blitterswijk et K. de Groot. « Comparison of Porous Ti₆Al₄V Made by Sponge Replication and Directly 3D Fiber Deposition and Cancellous Bone ». Key Engineering Materials 330-332 (février 2007) : 999–1002. http://dx.doi.org/10.4028/www.scientific.net/kem.330-332.999.

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The present investigation gives a comparison of the structure and properties of porous Ti6Al4V made by sponge replication (Sponge Ti) and directly 3D fiber deposition (D3DF Ti) and cancellous bone. Although the macrostructure of these two materials differs, their microstructure seems to be similar. Both scaffolds reveal an open pore structure, while D3DF Ti shows a fairly regular open pore structure, sponge Ti6Al4V exhibit an irregular open pore structure similar to that of cancellous bone. The mechanisms resulting in mechanical properties like stiffness or strength are, accordingly, different. The compressive strength and E’ modulus of Ti6Al4V scaffold are higher than that of cancellous bone,. The permeability results show both Ti6Al4V scaffolds are quite comparable with cancellous bone.

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Soy, Ugur, et Adem Demir. « Fabrication and Optimization of Boron Carbide Foams by Polymeric Sponge Replication ». Emerging Materials Research 9, n^o 2 (1 juin 2020) : 1–8. http://dx.doi.org/10.1680/jemmr.20.00046.

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Soy, Ugur, et Adem Demir. « AlSi10Mg alloy infiltration into porous SiC structures manufactured by sponge replication ». Emerging Materials Research 9, n^o 3 (1 septembre 2020) : 868–76. http://dx.doi.org/10.1680/jemmr.20.00196.

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Chaari, Kamel. « Elaboration And Characterization Of Macroporous Bioceramics Using Polymeric Sponge Replication Method ». Advanced Materials Letters 11, n^o 11 (1 novembre 2020) : 20111578. http://dx.doi.org/10.5185/amlett.2020.111578.

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Sutygina, A., U. Betke, G. Hasemann et M. Scheffler. « Manufacturing of Open-Cell Metal Foams by the Sponge Replication Technique ». IOP Conference Series : Materials Science and Engineering 882 (29 août 2020) : 012022. http://dx.doi.org/10.1088/1757-899x/882/1/012022.

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Wang, Chunli, Hongjie Chen, Xiangdong Zhu, Zhanwen Xiao, Kai Zhang et Xingdong Zhang. « An improved polymeric sponge replication method for biomedical porous titanium scaffolds ». Materials Science and Engineering : C 70 (janvier 2017) : 1192–99. http://dx.doi.org/10.1016/j.msec.2016.03.037.

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Choudhary, Abhisek, Swadesh K. Pratihar, Ashish K. Agrawal et Shantanu K. Behera. « Macroporous SiOC Ceramics with Dense Struts by Positive Sponge Replication Technique ». Advanced Engineering Materials 20, n^o 3 (9 novembre 2017) : 1700586. http://dx.doi.org/10.1002/adem.201700586.

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Mehatlaf, Auday A., Saad B. H. Farid et Alaa A. Atiyah. « Fabrication and Investigation of Bioceramic Scaffolds by a Polymer Sponge Replication Technique ». IOP Conference Series : Materials Science and Engineering 1076, n^o 1 (1 février 2021) : 012080. http://dx.doi.org/10.1088/1757-899x/1076/1/012080.

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Vitale-Brovarone, Chiara, Francesco Baino, Germana Martinasso, Rosangela Canuto, Francesco Bassi et Enrica Verné. « Glass-Ceramic Scaffolds and Shock Waves Effect on Cells Migration ». Key Engineering Materials 361-363 (novembre 2007) : 233–36. http://dx.doi.org/10.4028/www.scientific.net/kem.361-363.233.

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Glass-ceramic scaffolds for bone grafting have been prepared using the sponge replication method and a highly bioactive silica based glass belonging to the system SiO2-P2O5- CaO-MgO-Na2O-K2O (CEL2). The parameters for the sponge impregnation were optimized in order to obtain a continuous coating of the polymeric skeleton which will lead, after the polymeric phase removal, to a resistant macroporous glass-ceramic template. A complete characterization was carried out on the obtained scaffold in order to assess its morphology and specifically its porosity and the degree of pores interconnection. A human osteoblasts cells line (MG-63) was cultured onto the scaffold and the effect of stimulation with shock waves on the cell ability of colonizing the scaffold was investigated.

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Mazali, Italo O., et Oswaldo L. Alves. « [NO TITLE AVAILABLE] ». Anais da Academia Brasileira de Ciências 77, n^o 1 (mars 2005) : 25–31. http://dx.doi.org/10.1590/s0001-37652005000100003.

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High fidelity calcium carbonate and hydroxyapatite (bio) inorganic replicas of the fibrous network of the dried fruit of Luffa cylindrica are described, utilizing a facile synthetic route. The loofa sponge is a highly complex macroscopic architectural template, an inexpensive and sustainable resource. In the context of the morphosynthesis, the capability of replication of the loofa sponge opens the possibility of the use of biodiversity in obtaining new materials. We would like to emphasize that the template proposed in this paper, makes possible the preparation of inorganic replicas with a very desirable size, on the centimeter scale. This fact is innovative with respect to inorganic replicas described in the literature, which predominate at the micrometric scale, limited to the original size of the template.

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Afriani, F., J. Evi., R. A. Rafsanjani, R. Amelia, M. Hudatwi et Y. Tiandho. « Synthesis of 3D-porous scaffold from cockle shells waste-based hydroxyapatite with addition silica from tin tailings ». IOP Conference Series : Earth and Environmental Science 926, n^o 1 (1 novembre 2021) : 012044. http://dx.doi.org/10.1088/1755-1315/926/1/012044.

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Abstract This study aims to synthesize a porous scaffold based on hydroxyapatite and silica using the polymer sponge replication method. In bone tissue engineering technology, the development of porous scaffolds is a topic that is intensively studied because it is expected to be a solution to various problems of conventional bone therapy. In addition to proposing a porous scaffold synthesis method, we also utilize natural waste-based materials such as cockle shells and tin tailings as raw materials in this research. Investigation through x-ray diffraction (XRD) pattern with the goodness of fit coefficient, X 2 = 0.09 shows that the coprecipitation method is effective for the synthesis of hydroxyapatite. Analysis of XRD pattern of tin tailings sand with a value of X 2 = 0.008 showed that the diffraction pattern was related to silica with space group P 41 21 2. The polymer sponge replication method with polyurethane template succeeded in obtaining scaffolds with macropores above 300 μm. Based on the diffraction pattern of the three porous scaffolds prepared with different percentages of HA, it is known that all porous scaffolds have peaks related to HA and silica. It indicates that the decomposition temperature of polymer does not provide sufficient energy for the HA and silica to transform or react chemically.

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Bovio, Elena, Laura Garzoli, Anna Poli, Anna Luganini, Pietro Villa, Rosario Musumeci, Grace P. McCormack et al. « Marine Fungi from the Sponge Grantia compressa : Biodiversity, Chemodiversity, and Biotechnological Potential ». Marine Drugs 17, n^o 4 (11 avril 2019) : 220. http://dx.doi.org/10.3390/md17040220.

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The emergence of antibiotic resistance and viruses with high epidemic potential made unexplored marine environments an appealing target source for new metabolites. Marine fungi represent one of the most suitable sources for the discovery of new compounds. Thus, the aim of this work was (i) to isolate and identify fungi associated with the Atlantic sponge Grantia compressa; (ii) to study the fungal metabolites by applying the OSMAC approach (one strain; many compounds); (iii) to test fungal compounds for their antimicrobial activities. Twenty-one fungal strains (17 taxa) were isolated from G. compressa. The OSMAC approach revealed an astonishing metabolic diversity in the marine fungus Eurotium chevalieri MUT 2316, from which 10 compounds were extracted, isolated, and characterized. All metabolites were tested against viruses and bacteria (reference and multidrug-resistant strains). Dihydroauroglaucin completely inhibited the replication of influenza A virus; as for herpes simplex virus 1, total inhibition of replication was observed for both physcion and neoechinulin D. Six out of 10 compounds were active against Gram-positive bacteria with isodihydroauroglaucin being the most promising compound (minimal inhibitory concentration (MIC) 4–64 µg/mL) with bactericidal activity. Overall, G. compressa proved to be an outstanding source of fungal diversity. Marine fungi were capable of producing different metabolites; in particular, the compounds isolated from E. chevalieri showed promising bioactivity against well-known and emerging pathogens.

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Pawlik, JR, RA Armstrong, S. Farrington, J. Reed, S. Rivero-Calle, H. Singh, BK Walker et J. White. « Comparison of recent survey techniques for estimating benthic cover on Caribbean mesophotic reefs ». Marine Ecology Progress Series 686 (24 mars 2022) : 201–11. http://dx.doi.org/10.3354/meps14018.

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Highly divergent estimates of benthic cover of sponges have been reported for Caribbean mesophotic reefs (90-100 m) based on quadrat point-intercept data collection using 2 methods: visual surveys conducted in situ by technical divers, and analyses of photographs taken by unmanned underwater vehicles (UUVs). The second method has been criticized for potential errors from image distortion caused by variable camera angle relative to the substratum, but without a broader comparison of both methods. We find that studies that have used the UUV-based method are advantageous for a number of reasons, most importantly: (1) access to the full mesophotic zone, (2) higher sample replication, and (3) reduced likelihood of sampling bias. For tech diving surveys conducted at 91 m, i.e. the deepest depth reported using this method but only mid-way through the mesophotic zone, studies have reported particularly high sponge cover (~80 vs. <10% for UUV-based surveys), which may be a consequence of low replication and targeted sampling influenced by very short working times under hazardous conditions. When evaluating benthic abundance metrics from photographs, issues associated with variable substratum angle are common to any topographically complex surface, particularly within a quadrat. Nevertheless, point-intercept estimates are not dependent on quadrat area and are not subject to error due to image distortion or surface complexity. Unlike visual census data from tech dives, UUV photographs can be validated by taxonomic experts and archived for re-analysis. Past tech diving surveys should be repeated using the UUV-based method with greater replication over the full range of the mesophotic zone in order to reconcile divergent estimates of benthic cover.

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Hasmaliza, Mohamad, M. Siti Naqiah, R. J. Shafinaz et Ibrahim Norfadhilah. « Production of Porous Cordierite through Sol-Gel Polymeric Sponge Method ». Advanced Materials Research 620 (décembre 2012) : 127–31. http://dx.doi.org/10.4028/www.scientific.net/amr.620.127.

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Cordierite (2MgO.2Al2O3.5SiO2) is widely used in high temperature applications due to its high melting temperature and high resistance to thermal shock, chemical and corrosion. In this study, porous cordierite was synthesized using sol-gel method followed by replication of polymeric sponge method. Three different sintering temperatures were studied (1200°C, 1300°C and 1400°C to determine the crucial temperatures meant for pure cordierite phase. The effect of different temperature on the pore size, density and porosity were also studied. Produced porous cordierite was then analyzed using X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM). XRD results showed that pure cordierite phase was obtained at 1300°C. SEM micrograph shows that with increasing sintering temperature, the pore size decreased and sample sintered at 1300°C has pore size ranging from 61-126μm.

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Sutygina, Alina, Ulf Betke et Michael Scheffler. « Open‐Cell Aluminum Foams by the Sponge Replication Technique : A Starting Powder Particle Study ». Advanced Engineering Materials 22, n^o 5 (11 février 2020) : 1901194. http://dx.doi.org/10.1002/adem.201901194.

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Rejab, Nik Akmar, Abdul Rashid Jamaludin, Norazharuddin Shah Abdullah et Zainal Arifin Ahmad. « Compressive Strength of Zirconia-Toughened Alumina (ZTA) Foam with CaCO<sub>3</sub> ; and CeO<sub>2 </sub>Addition via Polymeric Sponge Replication Technique ». Key Engineering Materials 908 (28 janvier 2022) : 234–39. http://dx.doi.org/10.4028/p-58yt68.

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The effects of CaCO3 and CeO2 additions on structural, microstructural and mechanical properties of zirconia-toughened alumina (ZTA) foams were investigated. The foams were fabricated via the sponge replication technique and sintered for 4 hours. The CaCO3 decomposition and elongated hibonite grains produced micropores. The compressive strength for both ZTA foams after adding CaCO3 and CeO2 was higher than the rest of the foams, respectively. The addition of CeO2 triggered larger yttria-stabilized zirconia (YSZ) grains, which significantly improved the compressive strength of ZTA.

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Min, Sang Ho, Hyeong Ho Jin, B. S. Jun, Ik Min Park, Hong Chae Park et Seog Young Yoon. « Effect of Reaction Conditions on Pore Configuration and Mechanical Property for Porous Hydroxyapatite Prepared by Polymer Sponge Method ». Key Engineering Materials 336-338 (avril 2007) : 1567–70. http://dx.doi.org/10.4028/www.scientific.net/kem.336-338.1567.

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Porous HAp scaffolds have been prepared by using the slurry including HAp and magnesia based on the replication of polymer sponge substrate. The influence of HAp and MgO content in slurry on the pore morphology and size, and density, porosity, and mechanical strength of porous HAp scaffolds was investigated. The obtained scaffolds with average pore sizes ranging 150 to 300 μm had open, relatively uniform, and interconnected porous structure regardless of HAp and MgO content. As the MgO content increased, the pore network frame of scaffolds became to be relatively stronger, even though the pore size was not much changed. The compressive strength of the scaffolds increased rapidly with the increase of MgO content at a fixed HAp content because of increasing the pore wall thickness and density of the scaffolds. As a result, the porosity, density, and compressive strength of the porous HAp scaffolds scaffolds prepared by the sponge method were significantly affected by the addition of MgO.

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Kim, Yeon Ung, Min Chul Kim, Kyoung Nam Kim, Kwang Mahn Kim, Seong Ho Choi, Chong Kwan Kim, Racquel Z. LeGeros et Yong Keun Lee. « Effect of Calcium Phosphate Glass on Compressive Strength of Macroporous Hydroxyapatite Scaffold ». Key Engineering Materials 284-286 (avril 2005) : 313–16. http://dx.doi.org/10.4028/www.scientific.net/kem.284-286.313.

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This study presents the manufacture of macroporous hydroxyapatite scaffolds with a small amount of calcium phosphate glass powder as sintering additives. Hydroxyapatite slurry was prepared by suspending the hydroxyapatite and glass powder in water. Polyurethane sponge was used to produce highly macroporous scaffolds. The rheological characteristic of the slurry was measured to identify the effect of adding calcium phosphate glass powder into hydroxyapatite slurry. Sintered scaffolds could be repeatedly coated to improve mechanical properties. Scaffolds prepared by single and double replication cycle process were characterized by density, porosity and compressive strength measurements by increasing amount of the calcium phosphate glass powder to the hydroxyapatite slurry, viscosity by increased more than same amount of pure hydroxyapatite, and the capillary force was similar to pure hydroxyapatite slurry. The compressive strength of the macroporous hydroxyxapatite scaffold containing the calcium phosphate glass powder showed higher value than that of pure hydroxyapatite at single replication cycle. SEM demonstrated that the microstructure of the scaffold became denser with the introduction of the calcium phosphate glass powder. The pore struts were thicker as replication cycle was increased.

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Kim, Dong-Kyoo, Min-Young Lee, Hyun Soo Lee, Dong Seok Lee, Jong-Ryul Lee, Burm-Jong Lee et Jee H. Jung. « Polyacetylenes from a marine sponge Petrosia sp. inhibit DNA replication at the level of initiation ». Cancer Letters 185, n^o 1 (novembre 2002) : 95–101. http://dx.doi.org/10.1016/s0304-3835(02)00233-1.

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Lohr, Jayme E., Feng Chen et Russell T. Hill. « Genomic Analysis of Bacteriophage ΦJL001 : Insights into Its Interaction with a Sponge-Associated Alpha-Proteobacterium ». Applied and Environmental Microbiology 71, n^o 3 (mars 2005) : 1598–609. http://dx.doi.org/10.1128/aem.71.3.1598-1609.2005.

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ABSTRACT Bacteriophage ΦJL001 infects a novel marine bacterium in the α subclass of the Proteobacteria isolated from the marine sponge Ircinia strobilina. ΦJL001 is a siphovirus and forms turbid plaques on its host. The genome sequence of ΦJL001 was determined in order to better understand the interaction between the marine phage and its sponge-associated host bacterium. The complete genome sequence of ΦJL001 comprised 63,469 bp with an overall G+C content of 62%. The genome has 91 predicted open reading frames (ORFs), and 17 ORFs have been assigned putative functions. ΦJL001 appears to be a temperate phage, and the integrase gene was identified in the genome. DNA hybridization analysis showed that the ΦJL001 genome does not integrate into the host chromosome under the conditions tested. DNA hybridization experiments therefore suggested that ΦJL001 has some pseudolysogenic characteristics. The genome of ΦJL001 contains many putative genes involved in phage DNA replication (e.g., helicase, DNA polymerase, and thymidylate synthase genes) and also contains a putative integrase gene associated with the lysogenic cycle. Phylogeny based on DNA polymerase gene sequences indicates that ΦJL001 is related to a group of siphoviruses that infect mycobacteria. Designation of ΦJL001 as a siphovirus is consistent with the morphology of the phage visualized by transmission electron microscopy. The unique marine phage-host system described here provides a model system for studying the role of phages in sponge microbial communities.

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Li, Jing, Peiying Teng, Fan Yang, Xia Ou, Jihong Zhang et Wei Chen. « Bioinformatics and Screening of a Circular RNA-microRNA-mRNA Regulatory Network Induced by Coxsackievirus Group B5 in Human Rhabdomyosarcoma Cells ». International Journal of Molecular Sciences 23, n^o 9 (22 avril 2022) : 4628. http://dx.doi.org/10.3390/ijms23094628.

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Hand, foot and mouth disease (HFMD) caused by Coxsackievirus Group B5 (CVB5) is one of the most common herpetic diseases in human infants and children. The pathogenesis of CVB5 remains unknown. Circular RNAs (CircRNAs), as novel noncoding RNAs, have been shown to play a key role in many pathogenic processes in different species; however, their functions during the process of CVB5 infection remain unclear. In the present study, we investigated the expression profiles of circRNAs using RNA sequencing technology in CVB5-infected and mock-infected human rhabdomyosarcoma cells (CVB5 virus that had been isolated from clinical specimens). In addition, several differentially expressed circRNAs were validated by RT-qPCR. Moreover, the innate immune responses related to circRNA-miRNA-mRNA interaction networks were constructed and verified. A total of 5461 circRNAs were identified at different genomic locations in CVB5 infections and controls, of which 235 were differentially expressed. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis demonstrated that the differentially expressed circRNAs were principally involved in specific signaling pathways related to ErbB, TNF, and innate immunity. We further predicted that novel_circ_0002006 might act as a molecular sponge for miR-152-3p through the IFN-I pathway to inhibit CVB5 replication, and that novel_circ_0001066 might act as a molecular sponge for miR-29b-3p via the NF-κB pathway and for the inhibition of CVB5 replication. These findings will help to elucidate the biological functions of circRNAs in the progression of CVB5-related HFMD and identify prospective biomarkers and therapeutic targets for this disease.

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Kahn, Amanda S., et Sally P. Leys. « The role of cell replacement in benthic–pelagic coupling by suspension feeders ». Royal Society Open Science 3, n^o 11 (novembre 2016) : 160484. http://dx.doi.org/10.1098/rsos.160484.

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Benthic–pelagic coupling through suspension feeders and their detrital pathways is integral to carbon transport in oceans. In food-poor ecosystems however, a novel mechanism of carbon recycling has been proposed that involves direct uptake of dissolved carbon by suspension feeders followed by shedding of cells as particulate carbon. We studied cell replacement rates in a range of cold-water sponge species to determine how universal this mechanism might be. We show that cell replacement rates of feeding epithelia in explants vary from 30 hours up to 7 days, and change during different seasons and life-history stages. We also found that feeding epithelia are not replaced through direct replication but instead arise from a population of stem cells that differentiate and integrate into epithelial tissues. Our results reveal a surprising amount of complexity in the control of cell processes in sponges, with cell turnover depending on environmental conditions and using stem cells as rate-limiting mechanisms. Our results also suggest that for species in cold water with high particulate organic matter, cell turnover is not the mechanism delivering carbon flux to surrounding communities.

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Baino, Francesco, Joaquim Minguella-Canela, Feza Korkusuz, Petek Korkusuz, Berna Kankılıç, María Montealegre, M. De los Santos-López et Chiara Vitale-Brovarone. « In Vitro Assessment of Bioactive Glass Coatings on Alumina/Zirconia Composite Implants for Potential Use in Prosthetic Applications ». International Journal of Molecular Sciences 20, n^o 3 (8 février 2019) : 722. http://dx.doi.org/10.3390/ijms20030722.

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Achieving the stable osteointegration of prosthetic implants is one of the great challenges of modern orthopedic surgery. The fixation of ceramic acetabular cups of hip joint prostheses is usually achieved using a metal shell provided with screws or pegs that penetrate into the host pelvic bone. The deposition of bioactive coatings on the implant surface to be put in contact with bone could be a valuable strategy to promote a more “physiological” osteointegration. In this work, bioactive glass porous coatings were manufactured on the top of alumina/zirconia composite implants by two different methods, i.e., sponge replication and laser cladding. The coated samples underwent immersion studies in Kokubo’s simulated body fluid (SBF) to assess in vitro bioactivity and were found to exhibit an excellent hydroxyapatite-forming ability, which is key to allow bonding to bone. Biological tests using mesenchymal stem and osteoblast-like cells revealed the good biocompatibility of both types of materials. Furthermore, a higher level of mineralization was induced by the sponge-replicated coatings at 10 days. Overall, these results are highly promising and encourage further research on these materials.

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Färber, Claudia, Jürgen Titschack, Christine Hanna Lydia Schönberg, Karsten Ehrig, Karin Boos, Daniel Baum, Bernhard Illerhaus et al. « Long-term macrobioerosion in the Mediterranean Sea assessed by micro-computed tomography ». Biogeosciences 13, n^o 11 (15 juin 2016) : 3461–74. http://dx.doi.org/10.5194/bg-13-3461-2016.

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Abstract. Biological erosion is a key process for the recycling of carbonate and the formation of calcareous sediments in the oceans. Experimental studies showed that bioerosion is subject to distinct temporal variability, but previous long-term studies were restricted to tropical waters. Here, we present results from a 14-year bioerosion experiment that was carried out along the rocky limestone coast of the island of Rhodes, Greece, in the Eastern Mediterranean Sea, in order to monitor the pace at which bioerosion affects carbonate substrate and the sequence of colonisation by bioeroding organisms. Internal macrobioerosion was visualised and quantified by micro-computed tomography and computer-algorithm-based segmentation procedures. Analysis of internal macrobioerosion traces revealed a dominance of bioeroding sponges producing eight types of characteristic Entobia cavity networks, which were matched to five different clionaid sponges by spicule identification in extracted tissue. The morphology of the entobians strongly varied depending on the species of the producing sponge, its ontogenetic stage, available space, and competition by other bioeroders. An early community developed during the first 5 years of exposure with initially very low macrobioerosion rates and was followed by an intermediate stage when sponges formed large and more diverse entobians and bioerosion rates increased. After 14 years, 30 % of the block volumes were occupied by boring sponges, yielding maximum bioerosion rates of 900 g m−2 yr−1. A high spatial variability in macrobioerosion prohibited clear conclusions about the onset of macrobioerosion equilibrium conditions. This highlights the necessity of even longer experimental exposures and higher replication at various factor levels in order to better understand and quantify temporal patterns of macrobioerosion in marine carbonate environments.

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Cheng, Yu, Weiwu Shi, Xudong Cui, Lei Sun, Yi Nan, Hong Yao, Jian Fan, LiYing Zhu et Lei Yu. « Long Noncoding RNA TFAP2A-AS1 Suppressed Hepatitis B Virus Replication by Modulating miR-933/HDAC11 ». Disease Markers 2022 (18 avril 2022) : 1–11. http://dx.doi.org/10.1155/2022/7733390.

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Objective. Studies have shown that long noncoding RNAs (lncRNAs) play crucial roles in multiple tumor types and regulate various biological processes. The present study tried to study lncRNA TFAP2A-AS1 in HBV infection hepatocellular carcinoma. Methods. The level of TFAP2A-AS1 and miR-933 in HCC cell and samples were detected by qRT-PCR assay. Luciferase reporter gene assay was carried out to study the mechanism of TFAP2A-AS1 and miR-933. Cell proliferation was measured by CCK-8 assay. HBV DNA replication was detected by RT-qPCR. Results. We firstly demonstrated that TFAP2A-AS1 was downregulated in HCC cell lines and HBV-infected HCC samples compared with nontumor tissues. However, miR-933 was upregulated in HCC cell lines and HBV-infected HCC samples compared with nontumor tissues, and miR-933 was negatively associated with the expression of TFAP2A-AS1 in HBV-correlated HCC samples. TFAP2A-AS1 and HDAC11 expression was decreased and miR-933 was upregulated in the HBV-infected cell HepG2.2.15. TFAP2A-AS1 acted as a sponge for miR-933 and HDAC11 was one direct target gene for miR-933. Overexpression of TFAP2A-AS1 suppressed cell growth, HBV DNA replication, HbeAg, and HbsAg expression, while knockdown of TFAP2A-AS1 enhanced cell proliferation, HBV DNA replication, HbeAg, and HbsAg expression in HepG2.2.15 cell. In addition, ectopic expression of miR-933 promoted cell growth, HBV DNA replication, HbeAg, and HbsAg expression in HepG2.2.15 cell. TFAP2A-AS1 suppressed HBV replication and infection through regulating HDAC11. Conclusion. These data demonstrated that TFAP2A-AS1 acted crucial roles in the modulation of HbeAg and HbsAg expression and HBV replication and may be one potential target for HBV infection treatment.

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Sadraie, Seyed Homayoon, Kaveh Roshanbinfar, Gholamreza Kaka et Jamal Hoseini. « Mechanical and Structural Study of Hydroxyapatite (HA) Scaffolds Produced by Gel Casting and Sponge Replication Methods ». Journal of Biomaterials and Tissue Engineering 4, n^o 7 (1 juillet 2014) : 562–66. http://dx.doi.org/10.1166/jbt.2014.1203.

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Jafari, Saeed, A. Ataie et Amin Nozari. « Effect of Sintering Aid on Synthesis and Magnetic Properties of Nanocrystalline BaFe₁₂O₁₉ Ceramic Foam ». Advanced Materials Research 622-623 (décembre 2012) : 980–84. http://dx.doi.org/10.4028/www.scientific.net/amr.622-623.980.

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BaFe12O19 ceramic foam was synthesized from the mixture of Fe2O3 and BaCO3 using polymeric sponge replication technique. Effect of 1, 1.5, 2, 2.5, and 3 wt.% of SiO2 addition on foam lattice shape and magnetic properties of foams were investigated. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), vibrating samplemagnetometer (VSM) and Brunauer–Emmett–Teller (BET) techniques.Addition of 3 wt.% SiO2 can completely maintain the foam lattice shape at lower calcination temperature of 1075 °C. It resulted in higher values of coercivity and saturation magnetization. Moreover, BET analysis of the foam sample with 3 wt.% SiO2 demonstrate a specific surface area of 0.3 m2g-1.

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Betke, Ulf, et Michael Scheffler. « Reticulated Open-Celled Zinc Oxide Ceramic Foams : Manufacturing, Microstructure, Mechanical, and Thermal Properties ». Advances in Materials Science and Engineering 2019 (2 mai 2019) : 1–10. http://dx.doi.org/10.1155/2019/6570180.

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Open-celled zinc oxide ceramic foams were prepared by the polymer sponge replication (Schwartzwalder) technique from aqueous ZnO dispersions with Sb2O3 and Bi2O3 as sintering additives, and mechanically stable ZnO foams with an average porosity of 93.6% were obtained. Their microstructure consists of ZnO grains with a Bi-containing grain boundary phase together with a Zn-Sb-O secondary phase with spinel structure. The obtained ZnO ceramic foams were characterized with respect to their morphology by computed tomography; in addition, the compressive strength and the thermal conductivity were determined, and the data were applied for modelling of the mechanical and thermal properties of the bulk ZnO strut material.

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Lianingsih, Fitri. « In silico analysis of Trisindoline 1 compound against Mpro SARS-CoV-2 as novel potential drugs candidate ». Sasambo Journal of Pharmacy 2, n^o 2 (30 septembre 2021) : 42–50. http://dx.doi.org/10.29303/sjp.v2i2.87.

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The novel coronavirus 2019 (SARS-CoV-2) is one of the viruses that can infect humans and cause high mortality worldwide. The protease (Mpro) is key SARS-CoV-2 an enzyme mediates the viral replication and the transcription. Mpro is currently used as the candidate for the SARS-CoV-2 vaccine because Mpro is one of the key enzymes in the viral life cycle that essential for interactions between the virus and host cell receptor during viral entry. The Mpro can be a target protein to design the novel drug of SARS-CoV-2. The drug design from natural products that are considered to have low toxicity is needed against the virus. The study aims to determines the potential pharmacology of Trisindoline 1 compound from the sponge Hyrtios altum against SARS-CoV-2 and to find the amino acid residues between interaction ligand-protein receptors. The methods of this study use the virtual screening of Auto Dock Vina and visualization the amino acid residue using Bio via Discovery Studio. The result of this study was the selected marine compound from Trisindoline 1 may have potential to developed as inhibitor of SARS-CoV-2.Keywords: In Silico, Mpro, Sars Cov 2, Trisindoline 1, Sponges

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Sari, Novi Yulanda, et Eka Tarwaca Susila Putra. « The Contribution of Calcium to Changes in Leaf Anatomical Character of Oil Palm Seedlings (Elaeis guineensis Jacq.) under Drought Stress ». Ilmu Pertanian (Agricultural Science) 4, n^o 1 (29 mai 2019) : 23. http://dx.doi.org/10.22146/ipas.42447.

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The research was purposed (1) to know the effects of drought stress on changes in leaf anatomical character of oil palm seedlings (2) to know the contribution of calcium in cell compactness and increase the structural strength of leaf tissue so that oil palm seedlings were more tolerant to drought stress. This experiment was laid out following a split plot design with three blocks as replication. Main plot consists of drought stress levels, that are field capacity (FTSW 1.00), moderate drought stress (FTSW 0.35) and severe drought stress (FTSW 0.15). The fraction of transpirable soil water (FTSW) is a method for evaluating gradually increasing drought stress based on the amount of water loss due to transpiration. Meanwhile, subplot consists of four doses of calcium (Ca), that are of 0.0 g/seedlings, 0.04 g/seedlings, 0.08 g/seedlings, and 0.12 g/seedlings. Calcium fertilizer used is calcium sulfate (CaSO4) pure analysis. Leaf anatomical character was observed including the epidermal length and epidermal width; hypodermal length and hypodermal width; palisade cell length and palisade cell width; sponge cell length and sponge cell width; mesophyll tissue thickness; xylem and phloem diameter. The results showed that moderate and severe drought stress reduced epidermal cell length, upper hypodermal cell width, mesophyll thickness, palisade width and phloem diameter of leaf vessels. The applications of calcium to the leaf of oil palm seedlings under drought stresses were able to increased in the sponge cell length at a Ca dosage of 0.04 g/seedlings; increased lower hypodermal width and diameter phloem at a Ca dosage of 0.04 g/seedlings; and increased diameter xylem of leaves vessel at a Ca dosage of 0.12 g/seedlings.

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Li, Jian, Dandan Chen, Lei Huang, Min Ni, Yu Zhao, Huizhou Fan et Xiaofeng Bao. « Antichlamydial Dimeric Indole Derivatives from Marine Actinomycete Rubrobacter radiotolerans ». Planta Medica 83, n^o 09 (17 janvier 2017) : 805–11. http://dx.doi.org/10.1055/s-0043-100382.

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AbstractChlamydiae are widely distributed pathogens of human populations, which can lead to serious reproductive and other health problems. In our search for novel antichlamydial metabolites from marine derived-microorganisms, one new (1) and two known (2, 3) dimeric indole derivatives were isolated from the sponge-derived actinomycete Rubrobacter radiotolerans. The chemical structures of these metabolites were elucidated by NMR spectroscopic data as well as CD calculations. All three metabolites suppressed chlamydial growth in a concentration-dependent manner. Among them, compound 1 exhibited the most effective antichlamydial activity with IC50 values of 46.6 ~ 96.4 µM in the production of infectious progeny. Compounds appeared to target the mid-stage of the chlamydial developmental cycle by interfering with reticular body replication, but not directly inactivating the infectious elementary body.

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Vitale-Brovarone, Chiara, Gabriela Ciapetti, Elisa Leonardi, Nicola Baldini, Oana Bretcanu, Enrica Verné et Francesco Baino. « Resorbable Glass–Ceramic Phosphate-based Scaffolds for Bone Tissue Engineering : Synthesis, Properties, and In vitro Effects on Human Marrow Stromal Cells ». Journal of Biomaterials Applications 26, n^o 4 (21 juin 2010) : 465–89. http://dx.doi.org/10.1177/0885328210372149.

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Highly porous bioresorbable glass–ceramic scaffolds were prepared via sponge replication method by using an open-cell polyurethane foam as a template and phosphate-based glass powders. The glass, belonging to the P2O5–SiO2–CaO–MgO–Na2O–K2O system, was synthesized by a melting–quenching route, ground, and sieved to obtain powders with a grain size of less than 30 μm. A slurry containing glass powders, polyvinyl alcohol, and water was prepared to coat the polymeric template. The removal of the polymer and the sintering of the glass powders were performed by a thermal treatment, in order to obtain an inorganic replica of the template structure. The structure and properties of the scaffold were investigated from structural, morphological, and mechanical viewpoints by means of X-ray diffraction, scanning electron microscopy, density measurements, image analysis, and compressive tests. The scaffolds exhibited a trabecular architecture that closely mimics the structure of a natural spongy bone. The solubility of the porous structures was assessed by soaking the samples in acellular simulated body fluid (SBF) and Tris–HCl for different time frames and then by assessing the scaffold weight loss. As far as the test in SBF is concerned, the nucleation of hydroxyapatite on the scaffold trabeculae demonstrates the bioactivity of the material. Biological tests were carried out using human bone marrow stromal cells to test the osteoconductivity of the material. The cells adhered to the scaffold struts and were metabolically active; it was found that cell differentiation over proliferation occurred. Therefore, the produced scaffolds, being biocompatible, bioactive, resorbable, and structurally similar to a spongy bone, can be proposed as interesting candidates for bone grafting.

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Ramlee, S. N. L., N. S. A. N. Sharifulden, H. Mohamad et S. N. F. M. Noor. « Sol-gel derived bioactive glass scaffolds incorporated with polyvinyl-alcohol and pluronic P123 polymers using sponge replication technique ». Materials Today : Proceedings 17 (2019) : 966–75. http://dx.doi.org/10.1016/j.matpr.2019.06.463.

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Jamaludin, Abdul Rashid, Shah Rizal Kasim, Ahmad Kamal Ismail, Mohd Zukifly Abdullah et Zainal Arifin Ahmad. « The effect of sago as binder in the fabrication of alumina foam through the polymeric sponge replication technique ». Journal of the European Ceramic Society 35, n^o 6 (juin 2015) : 1905–14. http://dx.doi.org/10.1016/j.jeurceramsoc.2014.12.005.

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Min, Sang Ho, Hyeong Ho Jin, Hoy Yul Park, Ik Min Park, Hong Chae Park et Seog Young Yoon. « Preparation of Porous Hydroxyapatite Scaffolds for Bone Tissue Engineering ». Materials Science Forum 510-511 (mars 2006) : 754–57. http://dx.doi.org/10.4028/www.scientific.net/msf.510-511.754.

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Porous hydroxyapatite (HAp) scaffolds were successfully prepared by using the HAp slurry based on the replication of polymer sponge substrate. The effect of HAp content in slurry on the pore morphology and size, and density, porosity, and mechanical strength of porous scaffolds was investigated. The scaffolds with average pore sizes ranging from 200 to 400 µm had an open, relatively uniform, and interconnected porous structure. As the HAp content increased, the porosity of scaffold decreased while the density increased. These phenomena were attributed to the fact that the pores became interconnected with more dense and thicker pore walls with increasing HAp content in slurry. The results suggest that the density, porosity, and compressive strength of the porous HAp scaffold were significantly affected by the content of the HAp powder in the slurry.

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Sopyan, I., C. M. Mardziah et Ramesh Singh. « Fabrication of Porous Ceramic Scaffolds via Polymeric Sponge Method Using Sol-Gel Derived Strontium Doped Hydroxyapatite ». Applied Mechanics and Materials 117-119 (octobre 2011) : 829–32. http://dx.doi.org/10.4028/www.scientific.net/amm.117-119.829.

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Recently, development of porous calcium phosphates ceramics has raised considerable interest. A porous structure promotes cell attachment, proliferation and provides pathways for biofluids. Therefore, a high porosity with interconnected pore structure generally favors tissue regeneration. In this work, replication of 0, 2, 5, 10 and 15% SrHA (strontium-doped hydroxyapatite) porous scaffolds via polymeric sponge method has been employed using the sol-gel derived SrHA powders. To prepare the porous samples, the synthesized SrHA powders were mixed with distilled water and dispersing agent followed by drying in the ambient air and specific sintering process. Morphological evaluation by FESEM measurement revealed that the SrHA scaffolds were characterized by macro-micro interconnected porosity, which replicates the morphology of the cancellous bone. Compression test on the porous scaffolds revealed that doping 10 mol% of strontium in HA has increased the compressive strength by a factor of two compared to the undoped HA with 1.81±0.26 MPa at 41% porosity.

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Ou, Shih-Fu, Yuan-Li Tsao, Wei-Chun Lin, Yi-Ting Wang, Liping Wang et Fang-Yu Fan. « Novel Epigallocatechin-3-Gallate (EGCG)-Loaded Mesoporous Bioglass Scaffolds for Bone Recruitment Applications ». Applied Sciences 11, n^o 1 (29 décembre 2020) : 243. http://dx.doi.org/10.3390/app11010243.

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Bioglass-based material has been widely used in the field of biomedical science. In this study, the proper concentration of epigallocatechin-3-gallate (EGCG) for a mesoporous bioglass (MBG) scaffold was determined based on the sponge replication method. The fabrication procedure performed using a foam exchange technique resulted in an interconnected network of pores scaffolds with no cracks. In the minimum bactericidal concentrations of the bacteria assessed, the antibacterial concentration of EGCG against E. coli (200 μg/mL) was higher than that against S. aureus (25 μg/mL). The MBG and EGCG-MBG scaffolds exhibited excellent apatite mineralization and drug release abilities (the highest cumulative drug release from the EGCG-MBG scaffold was 75.37%). Thus, a 200 μg/mL EGCG can prevent cell apoptosis and directly enhance cell proliferation. Hence, a low-dose EGCG-MBG scaffold is another option for bone recruitment material.

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Rosmiati, Rosmiati, Emma Suryati et Arifuddin Tompo. « USE OF SPONGE, Callyspongia basilana EXTRACT AS ADDITIVE MATERIAL ON TIGER SHRIMP CULTURE ». Indonesian Aquaculture Journal 5, n^o 1 (30 juin 2010) : 53. http://dx.doi.org/10.15578/iaj.5.1.2010.53-59.

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Blue shrimp disease is one of the main problems in tiger shrimp culture. It reduces shrimp quality which eventually will decrease its market price. Blue shrimp is caused by deficiency of nutrition and additive materials such as carotene and other nutrient which function as vitamin source for important metabolic processes and formation of color profile in shrimp and fish. The aims of this study were to study the application effect of carotenoid extract of sponge Callyspongia basilana, as an additive material on the ability of shrimp to get back to normal state after suffering blue shrimp disease and survival rate of shrimp and to find out the optimal concentration of sponge carotenoid extract to cure the diseased shrimp. This study was consisted of two steps namely; (1). Extraction of sponge carotenoid by maseration and fractionation using acetone and petroleum ether solvents and (2), the application of carotenoid extract on the diseased shrimp. The research was arranged in a complete randomized design with four experiments consisted of (A). Control (without carotenoid extract); (B),(C), and (D) carotetoid extract addition of 3 mg/L, 6 mg/L, and 9 mg/L respectively with three replication each. The test animal used were blue diseased tiger shrimp with the density of 15 ind./container having 7.5–9.5 cm in size and the average weight of 5.5–10.0 g. The study showed that Callyspongia basilana carotenoid extract was able to change blue diseased shrimp to be normal within six days at the concentration of 9 mg/L. The highest survival rate was found in the experiment D (93.3%). Meanwhile, the lowest was obtained by the control population (13.3%) and the other two treatments were 80.0%(C) and 73.3% (B). The average of water quality parameters such as temperature, dissolved oxygen, pH, salinity, nitrite, and ammonia were in the suitable range for the growth and survival rate of tiger shrimp.

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Olhero, Susana M. H., João M. P. Q. Delgado, José Maria F. Ferreira et C. Pinho. « Development of Porous Ceramics for Gas Burners ». Defect and Diffusion Forum 273-276 (février 2008) : 814–19. http://dx.doi.org/10.4028/www.scientific.net/ddf.273-276.814.

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The present work aims to develop porous ceramic plates based on cordierite, using the polymer foam replication method, to be used for gas burners. Ceramic foams were produced by coating polyurethane foams of different pore sizes with ceramic powders dispersed in aqueous slurries. The final porous structures were shown to depend on the structure of the original polymer sponge and on the details of the fabrication procedure. However, a suitable process control enabled to obtain a close relation between the final properties and the template polymer characteristics. The performance of the porous cordierite plates, with different pore size distributions, as medium burners was tested and compared by measuring the pressure drop in the burner against the air flow rate. It could be concluded that good performance is achieved with the higher porous materials due to its higher porosity fraction, and more suitable pore size range.

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Fang, Zhi Gang, Yu Xin Gao et Chun Fang. « Effect of Structure Modification on the Microwave Absorbing Performance of Carbon Foams ». Advanced Materials Research 197-198 (février 2011) : 536–39. http://dx.doi.org/10.4028/www.scientific.net/amr.197-198.536.

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Carbon foams were prepared by a polymer sponge replication process and their microwave absorbing properties were investigated. The electric conductivity of carbon foam has a direct effect on its microwave absorbing property, as the carbon foam with a medium electric conductivity of 0.46S/m has got a relatively excellent microwave absorbing property and demonstrated a characteristic of broadband absorption. Some structure modification has been made on carbon foams to fruther imrove their microwave absorbing performance. The result shows that making slots, especially gradient slots on the surface of carbon foams can greatly improve their microwave absorbing properties, while the reflection coefficients for a three-layered carbon foam structure exceeds -10dB with the combination effect of multilayer structure design and parameters gradient variatioin in the whole frequency range of 2.6-18GHz, which is usually to be considered as the practical application standard for microwave absorbing materials.

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Lhullier, Cintia, Eliane de Oliveira Tabalipa, Fernanda Nienkötter Sardá, Louis Sandjo, Naira Zanchett Schneider, João Carraro, Cláudia Oliveira Simões et Eloir Schenkel. « Clerodane Diterpenes from the Marine Sponge Raspailia bouryesnaultae Collected in South Brazil ». Marine Drugs 17, n^o 1 (16 janvier 2019) : 57. http://dx.doi.org/10.3390/md17010057.

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The marine sponge Raspailia bouryesnaultae, collected in South Brazil, was selected for detailed investigation considering the results of a screening that pointed to an in vitro antiproliferative effect against non-small cells of human lung cancer (A549) and anti-herpes activity against Herpes Simplex virus type 1 (KOS and 29R strains) of ethanolic extracts. The fractionation and chemical investigation of the sponge’s hexanic fraction led to the isolation and structural elucidation of six clerodane diterpenes. The main component was identified as the already-reported raspailol (1), isolated from a sponge of the same genus collected in New Zealand. The structure of a new diterpene (2) with a rearranged skeleton was established by high-resolution mass spectrometry (HRMS) and 1D and 2D Nuclear magnetic resonance spectroscopy (NMR) experiments, and named here as raspadiene. Furthermore, four diterpenes were elucidated as isomers of clerodane diterpenes previously obtained from plants, namely kerlinic acid (3), kerlinic acid methyl ester (4), annonene (5), and 6-hydroxyannonene (6). They differ in their stereochemistry, since these diterpenes are characterized by a trans ring fusion at the decalin moiety and the relative configuration of the two methyl groups at C-8 and C-9 in a cis relationship (type trans/cis). The Raspailia diterpenes have a cis ring fusion at the decalin moiety, and the two methyl groups at C-8 and C-9 are in a trans relationship (type cis/trans). The isolated compounds were evaluated for their potential antiproliferative effects on human cancer cell line A549, and it was observed that the diterpenes bearing a hydroxyl group at C-6 exhibited moderate cytotoxic activity, with 50% inhibitory concentration (IC50) values lower than 25 μM. The evaluation of the potential anti-herpes activity against Herpes Simplex Virus type 1 (HSV-1, KOS and 29R strains) showed that the more promising results were observed for the new compound 2, since it inhibited HSV-1 (KOS and 29R strains) replication by 83% and 74%, respectively.

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Waldstein, Kody, Stephanie van de Wall, Scott Anthony, John T. Harty et Steven M. Varga. « Alveolar macrophages act as an early viral sponge inducing long-lived functional enhancement ». Journal of Immunology 208, n^o 1_Supplement (1 mai 2022) : 126.05. http://dx.doi.org/10.4049/jimmunol.208.supp.126.05.

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Abstract Alveolar macrophages (AM) are one of the first immune cells to encounter pathogens in the lung. However, the role of AMs early after infection remains to be completely defined. To track virally infected cells, mice were infected with a panel of fluorescent reporter-expressing respiratory viruses. By 6 hr post-infection (p.i.), AM numbers significantly declined. The remaining AMs accounted for the majority of infected cells at early time points, surpassing the epithelium, but did not support significant viral replication. Strikingly, AMs represented over 80% of all respiratory syncytial virus (RSV)-infected cells which was confirmed by intravital microscopy and ImageStream flow cytometry. To track cells that survive infection, we utilized a novel cre recombinase-expressing RSV in a floxed-reporter mouse in which infected cells are indelibly marked. Cre-mediated reporter activation required direct infection, and reporter-positive AM numbers remained constant up to 30 days p.i., long after viral clearance. Reporter-positive and -negative AMs were isolated at 30 days p.i., and their functional capacity was assessed ex vivo. Both reporter-positive and -negative AMs exhibited increased basal levels of pro-inflammatory cytokines as compared to naïve AMs which was further increased upon heterologous infection. Reporter-positive AMs displayed an enhanced inflammatory response as compared to reporter-negative AMs from the same lung, indicating innate immunity can be further increased post-direct infection. Our results confirm that AMs play an essential role in limiting early viral access to the respiratory epithelium by serving as a reservoir for non-productive infection resulting in long-lived functional enhancement. Supported by grants from NIH (R01AI124093-01A1, T32AI007485) and fellowships from NASA (Iowa Space Grant Consortium) and the University of Iowa Graduate College.

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Betke, Ulf, Katja Schelm, Andreas Rodak et Michael Scheffler. « Cellular Nickel-Yttria/Zirconia (Ni–YSZ) Cermet Foams : Manufacturing, Microstructure and Properties ». Materials 13, n^o 11 (26 mai 2020) : 2437. http://dx.doi.org/10.3390/ma13112437.

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Open-celled ceramic composite foams were prepared from NiO and yttria-stabilized zirconia (YSZ) powders by the polymer sponge replication (Schwartzwalder) technique using the respective aqueous dispersions. Mechanically stable NiO–YSZ foams with an average porosity of 93 vol.% were obtained. After chemical reduction of the NiO phase with hydrogen, cellular Ni–YSZ cermet structures were obtained. They are characterized by an electric conductivity up to 19∙103 S∙m−1 which can be adjusted by both, the Ni volume fraction, and the sintering/reduction procedure. The NiO–YSZ ceramic foams, as well as the cellular Ni–YSZ cermets prepared therefrom, were characterized with respect to their microstructure by scanning electron microscopy, confocal Raman microscopy and X-ray diffraction with Rietveld analysis. In addition, the compressive strength, the electric conductivity and the thermal conductivity were determined. The collected data were then correlated to the sample microstructure and porosity and were also applied for modelling of the mechanical and electric properties of the bulk Ni–YSZ strut material.

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Muda, Rizamarhaiza, Hamimah Abdul Rahman, Mohd Azham Azmi, Sufizar Ahmad, Shahruddin Mahzan et Hariati Taib. « Fabrication of Silica (SiO₂) Foam from Rice Husk Ash (RHA) : Effects of Solid Loadings ». Solid State Phenomena 317 (mai 2021) : 109–15. http://dx.doi.org/10.4028/www.scientific.net/ssp.317.109.

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Silica (SiO2) foams have been widely applied in numerous fields, mainly filters and catalysts supports, due to their characteristics of high permeability, high porosity and specific surface area. In this study, foams of SiO2 from rice husk ash (RHA) was fabricated via polymeric sponge replication method. Polymeric foam initially was used as template and dipped into SiO2 slurry followed by drying and sintering to yield the replica of the original polymeric foam. Different solid loadings of SiO2 as-derived from RHA (20 to 35 wt. %) slurry and sintering temperature of 1150 °C were applied. Phase identification and chemical composition of the green and sintered foams were conducted using X-Ray Diffraction (XRD) and X-Ray Fluorescence (XRF). Morphological observations were performed using Scanning Electron Microscopy (SEM). Density and porosity of the SiO2 foams were characterized using Archimedes method. Compressive strengths of the foams were determined as per ASTM C773-88 (1999). XRD analyses confirmed that the SiO2 as derived from the RHA were of tridymite and cristobalite phases with as high as 93% purity, as confirmed by XRF analyses. The density of SiO2 foams fabricated was in the range of 0.614 to 0.989 g/cm3, whereas the porosity values was in the range of 70% to 82%%. Compressive strengths were found to increase from 0.05 to 0.30 MPa respectively, proportionate with the increased SiO2 solid loading. Excellent properties of the SiO2 foams definitely signifies that the polymeric replication method is indeed a promising technique for SiO2 as derived from RHA foam fabrication.

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Suparman, Nur Syazana, Khadijah Ahmad Alwi et Mohd Al Amin Muhamad Nor. « Preparation and Characterization of Hydrophobic Ceramic Foam ». Materials Science Forum 840 (janvier 2016) : 77–81. http://dx.doi.org/10.4028/www.scientific.net/msf.840.77.

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Ceramic foam are a class of high porosity materials that are used for various applications. In this study, foam ceramic porcelain powder was produced by using polymeric sponge replication method at different solid content ranging from 30 to 50 wt. %. Properties of ceramic foam was characterized for porosity and density. Ceramic foam then grafted with methyltriethoxysilane (MTMS) at different concentration ranging from 0 to 9.0% v/v to determine hydrophobic effect and oil absorption capacity. From the results, it was found that the density of ceramic foam increased while porosity was decreased with increasing solid contents. It is clearly seen that, MTMS grafting contribute to hydrophobic effect of ceramic foam which enable repelling of water. The amount of oil absorbed by ceramic was found increased by increasing concentration of MTMS for all solid contents. As conclusion, MTMS give significant effects on hyrdophobic ceramic foam and produce good absorption capacity. The lower solid content produced better oil absorption compared to higher solid content due to presence of higher porosity.

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Muda, Rizamarhaiza, M. Azham Azmi, Shahruddin Mahzan, Hatem Mostafa Elwalwal, Sufizar Ahmad et Hariati Taib. « Effect of SiO₂ Solid Loading and Sintering Temperatures on the Physical Properties of SiO₂-NiO Foam ». Key Engineering Materials 791 (novembre 2018) : 37–44. http://dx.doi.org/10.4028/www.scientific.net/kem.791.37.

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Porous ceramic is a type of material that has highly open and partially interconnected pores. It has a wide range of applications which include catalyst support, electrical conductivity, refractory insulation of furnaces, filtration, adsorption, and separation. There are many conventional methods for producing silica foam including direct forming, steam heating, freeze casting and the polymeric sponge method which is also known as the replication method. In this study, SiO2-NiO foam was fabricated using 25wt. %, 30wt % and 35wt.% of SiO2and 5wt.% of NiO under different sintering temperatures (850 °C and 1050 °C)viareplication method. The morphologies of SiO2-NiO foams were observed using Scanning Electron Microscopy (SEM) while the identification of the different phases of foam was analysed using X-Ray Diffraction (XRD). The XRD analysis indicated that there were only SiO2and NiO present and no additional phases were detected after sintering. The effects of sintering temperature (850 °C, 1050 °C) and SiO2solid loading on properties such as apparent porosity, bulk density and shrinkage were investigated. It was found that when the solid loading of SiO2and sintering temperature increased, the density of SiO2-NiO foams increased in the range of 0.6373 g/cm3to 0.8165 g/cm3. On the other hand, the porosity percentage obtained increased from 78.51 % to 81.63 %. The density and porosity analyses showed that the density of foam increases when the porosity of SiO2-NiO foam decreases. However, the shrinkage after sintering ranged between 3.5081cm to 6.9975 cm at 850C ̊ and 7.3618 cm to 8.3704 cm at 1050 °C respectively. Thus, this proves that SiO2-NiO foam can be successfully fabricated through the replication method.

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Mehatlaf, Auday A., Alaa A. Atiyah et Saad B. H. Farid. « An Experimental Study of Porous Hydroxyapatite Scaffold Bioactivity in Biomedical Applications ». Engineering and Technology Journal 39, n^o 6 (25 juin 2021) : 977–85. http://dx.doi.org/10.30684/etj.v39i6.2059.

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Résumé :

Hydroxyapatite is one of the most bioactive materials used in tissue engineering due to its excellent biocompatibility and chemical composition which is equivalent to the mineral element of bone. In this study, polymer sponge replication method was used to fabricate porous hydroxyapatite scaffolds. Pure phase of hydroxyapatite scaffolds and the chemical bonding were verified via Fourier Transform Infrared and X-ray diffraction. Emission scanning electron microscopy (F E S E M) examination showed that the proposed scaffold has high interconnected pores that were achieved just after sintering at temperatures 1350 ºC for 2 hours. The percentage porosity values were estimated to be between 75–78 percent. The bioactivity of porous scaffolds was also investigated. They were submerged in a slurry of simulated body fluid (S B F) for seven, fourteen, and twenty-one days, respectively. Both FESEM and XRD analysis have confirmed the bioactivity of the prepared porous hydroxyapatite scaffold through the formation of a dense layer of apatite on its surface. Based on the results, the porous hydroxyapatite scaffolds could be recommended as a critical option for bone defects as well as replacement applications.

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