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Journal articles on the topic 'Active Granular Systems'
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1
Miao, Guoqing, Kai Huang, Yi Yun, and Rongjue Wei. "Active thermal convection in vibrofluidized granular systems." European Physical Journal B 40, no. 3 (September 2004): 301–4. http://dx.doi.org/10.1140/epjb/e2004-00277-7.
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Morse, Peter K., Sudeshna Roy, Elisabeth Agoritsas, Ethan Stanifer, Eric I. Corwin, and M. Lisa Manning. "A direct link between active matter and sheared granular systems." Proceedings of the National Academy of Sciences 118, no. 18 (April 30, 2021): e2019909118. http://dx.doi.org/10.1073/pnas.2019909118.
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The similarity in mechanical properties of dense active matter and sheared amorphous solids has been noted in recent years without a rigorous examination of the underlying mechanism. We develop a mean-field model that predicts that their critical behavior—as measured by their avalanche statistics—should be equivalent in infinite dimensions up to a rescaling factor that depends on the correlation length of the applied field. We test these predictions in two dimensions using a numerical protocol, termed “athermal quasistatic random displacement,” and find that these mean-field predictions are surprisingly accurate in low dimensions. We identify a general class of perturbations that smoothly interpolates between the uncorrelated localized forces that occur in the high-persistence limit of dense active matter and system-spanning correlated displacements that occur under applied shear. These results suggest a universal framework for predicting flow, deformation, and failure in active and sheared disordered materials.
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Williams, K. J., S. J. Tait, and R. M. Ashley. "In-sewer sedimentation associated with active flow control." Water Science and Technology 60, no. 1 (July 1, 2009): 55–63. http://dx.doi.org/10.2166/wst.2009.286.
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Active flow control using automated gates and weirs aims to utilise available dispersed storage within sewer systems to alleviate the severity and frequency of localised flooding incidents. Whilst a previous study has demonstrated its potential, a key operational concern before implementation was sedimentation. An experimental programme was designed to investigate the sediment deposition created when using a flow control device. Tests were also undertaken to examine the potential for rapid gate opening to flush away any resulting deposits. In catchments dominated by fine material in suspension, the use of an active flow control device can result in a uniformly thick deposit upstream of the gate. Rapid gate opening results in deposited material eroding in large sections starting at the gate and moving in an upstream direction. Granular sediment forms a series of discrete bedforms which are fairly uniform regardless of the flow conditions and a larger deposit further upstream. The potential for flushing granular deposits is limited and modification of the operation of the gate has shown little potential for increasing the effectiveness. Therefore, active flow control using a single downstream gate may only be suitable in systems with fine material moving in suspension during dry weather flow and not where there is significant granular sediment.
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Bérut, Antoine, Hugo Chauvet, Valérie Legué, Bruno Moulia, Olivier Pouliquen, and Yoël Forterre. "Gravisensors in plant cells behave like an active granular liquid." Proceedings of the National Academy of Sciences 115, no. 20 (April 30, 2018): 5123–28. http://dx.doi.org/10.1073/pnas.1801895115.
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Plants are able to sense and respond to minute tilt from the vertical direction of the gravity, which is key to maintain their upright posture during development. However, gravisensing in plants relies on a peculiar sensor made of microsize starch-filled grains (statoliths) that sediment and form tiny granular piles at the bottom of the cell. How such a sensor can detect inclination is unclear, as granular materials like sand are known to display flow threshold and finite avalanche angle due to friction and interparticle jamming. Here, we address this issue by combining direct visualization of statolith avalanches in plant cells and experiments in biomimetic cells made of microfluidic cavities filled with a suspension of heavy Brownian particles. We show that, despite their granular nature, statoliths move and respond to the weakest angle, as a liquid clinometer would do. Comparison between the biological and biomimetic systems reveals that this liquid-like behavior comes from the cell activity, which agitates statoliths with an apparent temperature one order of magnitude larger than actual temperature. Our results shed light on the key role of active fluctuations of statoliths for explaining the remarkable sensitivity of plants to inclination. Our study also provides support to a recent scenario of gravity perception in plants, by bridging the active granular rheology of statoliths at the microscopic level to the macroscopic gravitropic response of the plant.
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Schreiber, Marvin M., Michael V. Hickman, and Gordon D. Vail. "Efficacy of Starch-Encapsulated Formulations of Atrazine Containing Two or Three Herbicides in Same Granule." Weed Technology 8, no. 1 (March 1994): 105–13. http://dx.doi.org/10.1017/s0890037x00039282.
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Field experiments were conducted in 1990, 1991, and 1992 to evaluate and compare the efficacy of commercial herbicide formulations with starch encapsulated granules that contain one, two, or three herbicides. Atrazine in combination with alachlor or metolachlor composed the two-component granules and the addition of dicamba to both composed the three-component granules. All starch-encapsulated formulations were produced by twin screw extrusion technology and evaluated in two granule sizes, 1.4 to 0.5-mm (14 to 20 mesh) and 0.85 to 0.43-mm (20 to 40 mesh). Active ingredient rates applied were selected for the existing soil conditions and combination granules contained active ingredients proportional to premixed commercial formulations available or suggested for tank mixes. Evaluations were performed under conventional, chisel, and no-tillage systems. PRE and PPI applications of starch encapsulated two-component (atrazine-alachlor) in 1990 controlled giant foxtail (except at the low rate with large granule size), redroot pigweed, and common lambsquarters excellently but control of velvetleaf was fair to poor. Smaller-sized granules were generally more effective for controlling weeds than the larger-sized granules. In 1991, starch-encapsulated two-component (atrazine-metolachlor) granules applied both PRE and PPI in conventional, chisel, and no-till systems gave results similar to 1990 with the small granules more effective on velvetleaf. The addition of dicamba in the granule to form three-component starch-encapsulated granules in 1992 resulted in control of velvetleaf, ivyleaf morningglory, and jimsonweed statistically equal to commercial formulations except in one case of no-till corn. In our experiments, herbicide formulations (granular vs. commercial) had no significant effect on corn yield in 28 out of 31 treatments. These data indicate that if the experimental three-component starch-encapsulated formulations of corn herbicides used in these studies were optimized they could become as efficacious as commercial formulations presently on the market. This is the first report of research containing data on two- and three-component starch-encapsulated granular formulations.
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Li, Shengkai, Bahnisikha Dutta, Sarah Cannon, Joshua J. Daymude, Ram Avinery, Enes Aydin, Andréa W. Richa, Daniel I. Goldman, and Dana Randall. "Programming active cohesive granular matter with mechanically induced phase changes." Science Advances 7, no. 17 (April 2021): eabe8494. http://dx.doi.org/10.1126/sciadv.abe8494.
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At the macroscale, controlling robotic swarms typically uses substantial memory, processing power, and coordination unavailable at the microscale, e.g., for colloidal robots, which could be useful for fighting disease, fabricating intelligent textiles, and designing nanocomputers. To develop principles that can leverage physical interactions and thus be used across scales, we take a two-pronged approach: a theoretical abstraction of self-organizing particle systems and an experimental robot system of active cohesive granular matter that intentionally lacks digital electronic computation and communication, using minimal (or no) sensing and control. As predicted by theory, as interparticle attraction increases, the collective transitions from dispersed to a compact phase. When aggregated, the collective can transport non-robot “impurities,” thus performing an emergent task driven by the physics underlying the transition. These results reveal a fruitful interplay between algorithm design and active matter robophysics that can result in principles for programming collectives without the need for complex algorithms or capabilities.
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Khomenko, Andrei P., Sergey K. Kargapoltsev, and Andrey V. Eliseev. "Development of Approaches to Creation of Active Vibration Control System in Problems of the Dynamics for Granular Media." MATEC Web of Conferences 148 (2018): 11004. http://dx.doi.org/10.1051/matecconf/201814811004.
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The article deals with the development of mathematical models and evaluation criteria of the vibration field in the dynamic interactions of the elements of the vibrational technological machines for the processes of vibrational strengthening of long-length parts with help of a steel balls working medium. The study forms a theoretical understanding of the modes of motions of material particles in interaction with a vibrating surface of the working body of the vibration machine. The generalized approach to the assessment of the dynamic quality of the work of vibrating machines in multiple modes of tossing, when the period of free flight of particles is a multiple of the period of the surface oscillations of the working body, is developed in the article. For the correction of vibration field of the working body, the characteristics of dynamic interactions of granular elements of the medium are taken into account using original sensors. The sensors that can detect different particularities of interaction of the granular medium elements at different points of the working body are proposed to evaluate the deviation from a homogeneous and one-dimensional mode of vibration field. Specially developed sensors are able to register interactions between a single granule, a system of granules in filamentous structures, and multipoint interactions of the elements in a close-spaced cylindrical structure. The system of regularization of the structure of vibration fields based on the introduction of motion translation devices is proposed using the multi-point sensor locations on the working body. The article refers to analytical approaches of the theory of vibration displacements. For the experimental data assessment, the methods of statistical analysis are applied. It is shown that the peculiar features of the motion of granular medium registered by the sensors can be used to build active control systems of field vibration.
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Nadeina, Ksenia A., Sergey V. Budukva, Yuliya V. Vatutina, Polina P. Mukhacheva, Evgeniy Yu Gerasimov, Vera P. Pakharukova, Oleg V. Klimov, and Aleksandr S. Noskov. "Unsupported Ni—Mo—W Hydrotreating Catalyst: Influence of the Atomic Ratio of Active Metals on the HDS and HDN Activity." Catalysts 12, no. 12 (December 19, 2022): 1671. http://dx.doi.org/10.3390/catal12121671.
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Hydrotreating is one of the largest processes used in a refinery to improve the quality of oil products. The great demand of the present is to develop more active catalysts which could improve the energy efficiency of the process when it is necessary for heavier feedstock to be processed. Unsupported catalysts could solve this problem, because they contain the greatest amount of sulfide active sites, which significantly increase catalysts’ activity. Unfortunately, most of the information on the preparation and properties of unsupported catalysts is devoted to powder systems, while industrial plants require granular catalysts. Therefore, the present work describes a method for the preparation of granular Ni—Mo—W unsupported hydrotreating catalysts and studies the influence of the Ni/Mo/W atomic ratio on their properties. Catalysts have been prepared by plasticizing Ni—Mo—W precursor with aluminum hydroxide followed by granulation and drying stages. Ni—Mo—W precursor and granular catalysts were studied by X-ray diffraction (XRD), nitrogen adsorption–desorption method, high-resolution transmission electron microscopy (HRTEM), and thermal analysis. Granular catalysts were sulfided through a liquid-phase sulfidation procedure and tested in hydrotreating of straight-run vacuum gasoil. It was shown that the Ni/Mo/W atomic ratio influenced the formation and composition of active compounds and had almost no influence on the textural properties of catalysts. The best hydrodesulfurization (HDS) activity was obtained for the catalyst with Ni/Mo/W ratio—1/0.15/0.85, while hydrodenitrogenation (HDN) activity of the catalysts is very similar.
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Duan, Hai Xia, and Jia Hui Qu. "Study on Synergetic Catalytic Ozonation of Nitrobenzene in Nebulizing Systems." Advanced Materials Research 243-249 (May 2011): 5304–7. http://dx.doi.org/10.4028/www.scientific.net/amr.243-249.5304.
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The removal effect of nitrobenzene (NB) in water by VUV/O3/GAC synergetic catalyzing method in a nebulizing system was studied. In addition, the effects of the droplet size, the nebulization height, O3 flux, free radical scavengers and active carbon usage frequencies on the degradation of NB were investigated. In this study, a spray nozzle that could produce 10-micrometer droplets were adopted, a UV lamp that emitted 185nm VUV light was used as the light source and a layer of 0.5cm granular active carbon was laid at the bottom of the experimental apparatus. The results showed that, in the apparatus, when the NB concentration in deionized water was 200mg/L, the nebulization height was 1.3m, O3 flux was 150mg/L, the removal rate of NB reached 95.3%. Supercarbonate acted as a catalyst in the system.
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Ismail, S. B., P. Gonzalez, D. Jeison, and J. B. van Lier. "Effects of high salinity wastewater on methanogenic sludge bed systems." Water Science and Technology 58, no. 10 (November 1, 2008): 1963–70. http://dx.doi.org/10.2166/wst.2008.528.
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The attainable loading potentials of anaerobic sludge bed systems are strongly dependent on the growth of granular biomass with a particular wastewater. Experiments were conducted to determine the effects of high salinity wastewater on the biological and physical properties of methanogenic sludge. Sodium concentration of 5 g/L and 15 g/L were added to the influent of upflow anaerobic sludge bed (UASB) systems. After 100 days of operation, the methanogenic activity, extracellular polymeric substances (EPS), and granular strength were analyzed. The results show a high removal of organic matter but with accumulating propionate concentrations in the effluents. Meanwhile, wash-out of active methanogenic biomass in the effluent of the reactors was observed, likely as a results of the high Na+ concentrations. The rinsed biomass was characterized by a considerable specific methanogenic activity (SMA) on acetate, propionate and hydrogen as the substrates. On the other hand, results show that the SMA evolution was not affected by high salt concentrations. Also the amount and composition of extracellular polymeric substances (EPS) were similar in all sludges. However, results clearly show a sharp drop in the granule strength as a results of high Na+ concentration.
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Galanov, Sergey, Olga I. Sidorova, and Vera A. Batyreva. "Nickel-Containing Systems in Reaction of Partial Oxidation of Hydrocarbons." Key Engineering Materials 670 (October 2015): 33–38. http://dx.doi.org/10.4028/www.scientific.net/kem.670.33.
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Nickel dispersion, which provides total catalytically active metal surface, is significant for partial catalytic oxidation of natural gas to obtain high purpose products yield and productivity in syngas. The interaction of reaction medium under high reaction temperatures during 20-25 hours promotes the increase of total square of active Ni component for block catalysts obtained with self-propagating high-temperature synthesis, which allows achieving productivity in syngas 7.1·103cm3(syngas)/cm3(catalyst)·hour. It is observed that for catalyst systems obtained with precipitation, chemical composition of oxide phase influences the particles size of metal nickel. For granular catalysts obtained through precipitation after 25-hour exploitation, average particle size (according to CSR) metal nickel is 3-4.5 times smaller than Ni in catalysts obtained with self-propagating high-temperature synthesis. This allows achieving productivity in syngas 8.1·103cm3/сm3·hour, when there is average temperature decrease over the catalytic layer by ~100°С in comparison with blocks acquired through self-propagating high-temperature synthesis.
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Shen, Jinhua, Zhi Xu, Jianping Li, and Haisheng Ji. "Granular-scale Magnetic Flux Emergence and its Associated Features in an Emerging Active Region." Astrophysical Journal 925, no. 1 (January 1, 2022): 46. http://dx.doi.org/10.3847/1538-4357/ac37c3.
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Abstract Using the high-resolution photosphere and chromosphere observations made by the 1 m New Vacuum Solar Telescope, we studied the granular-scale magnetic flux emergence occurring in emerging active region NOAA 12579. Supplementary observations are also provided by the spacecraft Solar Dynamics Observatory. The studied granular-scale flux emergence took place at two different locations. One is completely embedded in the unipolar region of the following sunspots (Case 1), while another is located at the central part in the active region (Case 2). We find that both cases initially emerge from a dark patch like a wide intergranular lane, but showing the different subsequent features. In Case 1, the emerging granule grows in an elongated feature and reaches its maximum size of almost of 5″ × 3″, with an elongated speed of about 2–3 km s−1. An eruption (i.e., surge) with bright footpoints is observed after the emerging granule reaches its maximum scale. There is a time delay of more than 10 minutes between the appearance of the abnormal granule and the Hα surge. Furthermore, its footpoints are clearly rooted at the intergranular lane. We propose that the eruptive surge could be triggered by the reconnection between the emerging magnetic flux and the preexisting ambient field, leading to the localized heating and bidirectional flows. In Case 2, the granular cell emerging is simultaneously associated with bright points with opposite magnetic polarity, showing the separating motion between them and a bunch of newly formed arch filament systems. We infer that the bright points are due to the strong-field magnetic concentration in the dark intergranular lanes rather than the instantaneous Ellerman bombs.
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Mitsuda, Takashi, and Otsuka Shinsaku. "Active Bending Mechanism Employing Granular Jamming and Vacuum-Controlled Adaptable Gripper." IEEE Robotics and Automation Letters 6, no. 2 (April 2021): 3041–48. http://dx.doi.org/10.1109/lra.2021.3058914.
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Driessen, Willie, and Tim Hendrickx. "Two Decades of Experience with the Granular Sludge-Based ANAMMOX® Process Treating Municipal and Industrial Effluents." Processes 9, no. 7 (July 13, 2021): 1207. http://dx.doi.org/10.3390/pr9071207.
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This paper is a review of 20 years of full-scale experience with the granular sludge-based ANAMMOX process. The ANAMMOX process is a biological deammonification process for energy-efficient removal of ammoniacal nitrogen, which has been successfully applied on dewatering reject liquors from biosolids sludge digesters (e.g., mesophilic anaerobic digestions, codigestion, thermal sludge hydrolysis process (THP)) and nutrient-rich anaerobically treated industrial effluents (e.g., fermentation industry, food industry). The ANAMMOX process is a continuously operated biological process using granular biomass. The highly active concentrated granular biomass allows for compact reactor systems and a fast start-up. Long term operations of various case studies show stable process performance of full-scale reactors treating municipal and industrial effluents, achieving ammoniacal nitrogen (NH4-N) removal in excess of 90% at low and high loading rates up to 2.5 kgNH4-N/(m3·d). Some special aspects (e.g., micro-nutrients, inhibition, alkalinity consumption) of treating various wastewaters are discussed in detail. The ANAMMOX process is demonstrated to be resilient in handling process upsets and off-spec wastewater composition.
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Gardan, Julien. "Method for characterization and enhancement of 3D printing by binder jetting applied to the textures quality." Assembly Automation 37, no. 2 (April 3, 2017): 162–69. http://dx.doi.org/10.1108/aa-01-2016-007.
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Purpose This paper aims to present a technical approach to evaluate the quality of textures obtained by an inkjet during binder jetting in 3D printing on a powder bed through contours detection to improve the quality of the surface printed according to the result of the assembly between the inkjet and a granular product. Design/methodology/approach The manufacturing process is based on the use of computer-aided design and a 3D printer via binder jetting. Image processing measures the edge deviation of a texture on the granular surface with the possibility of implementing a correction in an active assembly through a “design for manufacturing” (DFM) approach. Example application is presented through first tests. Findings This approach observes a shape alteration of the printed image on a 3D printed product, and the work used the image processing method to improve the model according to the DFM approach. Originality/value This paper introduces a solution for improving the texture quality on 3D printed products realized via binder jetting. The DFM approach proposes an active assembly by compensating the print errors in upstream of a product life cycle.
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Hamiruddin, Nur Ain, and Nik Azimatolakma Awang. "The Relationship Between the Biokinetic Parameters of an Aerobic Granular Sludge System and the Applied Operating Conditions." Civil and Environmental Engineering Reports 31, no. 1 (March 1, 2021): 161–71. http://dx.doi.org/10.2478/ceer-2021-0011.
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Abstract Biokinetic parameters help to describe the rate of substrate utilization and biomass production or growth by microbial action, which is important to the design process and performance optimization of wastewater treatment. Although studies of the biokinetic parameters of aerobic granular sludge (AGS) systems have been increasing lately, the significance for each value in terms of maximum specific growth rate (μmax), substrate concentration at one-half of the maximum specific growth rate (KS), and cell yield (Y) in relation to the applied operating conditions are rarely discussed. Therefore, this study investigates the relationship and significance between the above-stated biokinetic parameters with organic loading rate (OLR) and reactor height/diameter (H/D) ratio from five different batches of AGS treated sewage, using the independent t-test. The biokinetic parameters are summarized as biomass production (Y and μmax ) and relied upon the relative increase in the OLR and reactor H/D ratios. Additionally, aerobic granules developed in reactors with a high H/D ratio have a shorter setup time and are more active in contrast with low H/D ratio reactors.
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Bär, Markus, Robert Großmann, Sebastian Heidenreich, and Fernando Peruani. "Self-Propelled Rods: Insights and Perspectives for Active Matter." Annual Review of Condensed Matter Physics 11, no. 1 (March 10, 2020): 441–66. http://dx.doi.org/10.1146/annurev-conmatphys-031119-050611.
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A wide range of experimental systems including gliding, swarming and swimming bacteria, in vitro motility assays, and shaken granular media are commonly described as self-propelled rods. Large ensembles of those entities display a large variety of self-organized, collective phenomena, including the formation of moving polar clusters, polar and nematic dynamic bands, mobility-induced phase separation, topological defects, and mesoscale turbulence, among others. Here, we give a brief survey of experimental observations and review the theoretical description of self-propelled rods. Our focus is on the emergent pattern formation of ensembles of dry self-propelled rods governed by short-ranged, contact mediated interactions and their wet counterparts that are also subject to long-ranged hydrodynamic flows. Altogether, self-propelled rods provide an overarching theme covering many aspects of active matter containing well-explored limiting cases. Their collective behavior not only bridges the well-studied regimes of polar self-propelled particles and active nematics, and includes active phase separation, but also reveals a rich variety of new patterns.
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Mandal, Rituparno, and Peter Sollich. "Shear-induced orientational ordering in an active glass former." Proceedings of the National Academy of Sciences 118, no. 39 (September 22, 2021): e2101964118. http://dx.doi.org/10.1073/pnas.2101964118.
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Dense assemblies of self-propelled particles that can form solid-like states also known as active or living glasses are abundant around us, covering a broad range of length scales and timescales: from the cytoplasm to tissues, from bacterial biofilms to vehicular traffic jams, and from Janus colloids to animal herds. Being structurally disordered as well as strongly out of equilibrium, these systems show fascinating dynamical and mechanical properties. Using extensive molecular dynamics simulation and a number of distinct dynamical and mechanical order parameters, we differentiate three dynamical steady states in a sheared model active glassy system: 1) a disordered state, 2) a propulsion-induced ordered state, and 3) a shear-induced ordered state. We supplement these observations with an analytical theory based on an effective single-particle Fokker–Planck description to rationalize the existence of the shear-induced orientational ordering behavior in an active glassy system without explicit aligning interactions of, for example, Vicsek type. This ordering phenomenon occurs in the large persistence time limit and is made possible only by the applied steady shear. Using a Fokker–Planck description with parameters that can be measured independently, we make testable predictions for the joint distribution of single-particle position and orientation. These predictions match well with the joint distribution measured from direct numerical simulation. Our results are of relevance for experiments exploring the rheological response of dense active colloids and jammed active granular matter systems.
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Fang, Luning, Ruochun Zhang, Colin Vanden Heuvel, Radu Serban, and Dan Negrut. "Chrono::GPU: An Open-Source Simulation Package for Granular Dynamics Using the Discrete Element Method." Processes 9, no. 10 (October 13, 2021): 1813. http://dx.doi.org/10.3390/pr9101813.
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We report on an open-source, publicly available C++ software module called Chrono::GPU, which uses the Discrete Element Method (DEM) to simulate large granular systems on Graphics Processing Unit (GPU) cards. The solver supports the integration of granular material with geometries defined by triangle meshes, as well as co-simulation with the multi-physics simulation engine Chrono. Chrono::GPU adopts a smooth contact formulation and implements various common contact force models, such as the Hertzian model for normal force and the Mindlin friction force model, which takes into account the history of tangential displacement, rolling frictional torques, and cohesion. We report on the code structure and highlight its use of mixed data types for reducing the memory footprint and increasing simulation speed. We discuss several validation tests (wave propagation, rotating drum, direct shear test, crater test) that compare the simulation results against experimental data or results reported in the literature. In another benchmark test, we demonstrate linear scaling with a problem size up to the GPU memory capacity; specifically, for systems with 130 million DEM elements. The simulation infrastructure is demonstrated in conjunction with simulations of the NASA Curiosity rover, which is currently active on Mars.
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Pasenko, Olexander, Liliya Frolova, and Ihnat Shunkin. "Characteristics of diatomite-alginate-Fe3O4 composite as a phosphate adsorbent." Bulletin of the National Technical University «KhPI» Series: New solutions in modern technologies, no. 3(9) (October 18, 2021): 61–65. http://dx.doi.org/10.20998/2413-4295.2021.03.09.
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Technological approaches to the use of diatomaceous earth as a raw material for the creation of composite adsorbents for wastewater treatment from phosphate ions are analysed. It is shown that the developed surface of diatomite can be used to create a granular adsorbent, and iron (III) oxides (magnetite, goethite, lepidocrocite, ferrihydrite, hematite and goethite) are environmentally safe, cheap, economically feasible modifiers. Emphasis is placed on the possibility of obtaining magnetic granules due to the formation of magnetite. The use of the deposition method for the formation of the applied granular adsorbent is proposed.
The influence of diatomite concentration on the static strength of granules was established. It is determined that the diameter of the nozzle is also an important factor. The selected technical solutions are aimed at solving the problems of granule hardening and ensuring high adsorption activity. Experimental studies of the synthesis and granulation of the composite adsorbent alginate - diatomaceous earth - magnetite have shown that an increase in the content of diatomaceous earth leads to a natural increase in the size of the granules. When increasing the diameter of the nozzle from 1.5 mm to 3.5 mm, for example, the size of the granules 1.5-4.0 (dc = 1.5 mm), 2.0-5.0 mm (dc = 3.0 mm) and 2.5-5.0 mm (dc = 3.5 mm). The diatomaceous earth content of more than 20% does not allow to carry out high-quality granulation on the experimental installation due to the increase in the viscosity of the suspension. The relationship between the size of gel granules and dried. The process of application of the active magnetic phase of the adsorbent is investigated. The dependence of the quality of the granulation process on the solid phase content is established. The measured static strength of the adsorbent granules is in the range of 17 - 25 kPa. It is established that the composite adsorbent with the applied layer of magnetite has magnetic properties. The adsorption of PO43- anions from aqueous solutions was studied. For the adsorbent alginate - diatomite and alginate - diatomite - Fe3O4 - the adsorption capacity is 4 and 9 mg PO43- / g, respectively. The obtained composite adsorbents have a set of functional properties that are promising for use in modern water purification and purification systems.
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Sutton, P. M., and P. N. Mishra. "Activated carbon based biological fluidized beds for contaminated water and wastewater treatment: a state-of-the-art review." Water Science and Technology 29, no. 10-11 (October 1, 1994): 309–17. http://dx.doi.org/10.2166/wst.1994.0774.
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The ability of the biological fluidized bed (BFB) process configuration to intensify biological reaction rates through accumulation of high concentrations of active biomass has brought attention to the technology for the past twenty years. Over 80 commercial, media based BFB reactors have been installed in North America and Europe. Currently there is much interest in systems in which granular activated carbon (GAC) is used as the fluidizing media for treatment of contaminated waters and wastewaters. This paper provides a historical review of the development of the technology together with information on design and commercial application of the technology in North America.
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Muñoz-Palazon, Barbara, Aurora Rosa-Masegosa, Miguel Hurtado-Martinez, Alejandro Rodriguez-Sanchez, Alexander Link, Ramiro Vilchez-Vargas, Alejandro Gonzalez-Martinez, and Jesus Gonzalez Lopez. "Total and Metabolically Active Microbial Community of Aerobic Granular Sludge Systems Operated in Sequential Batch Reactors: Effect of Pharmaceutical Compounds." Toxics 9, no. 5 (April 23, 2021): 93. http://dx.doi.org/10.3390/toxics9050093.
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Two aerobic granular sludge (AGS) sequential batch reactors were operated at a mild (15 °C) temperature for 180 days. One of those bioreactors was exposed to a mixture of diclofenac, naproxen, trimethoprim, and carbamazepine. The AGS system, operating under pressure from emerging contaminants, showed a decrease in COD, BOD5, and TN removal capacity, mainly observed during the first 100 days, in comparison with the removal ratios detected in the control bioreactor. After an acclimatisation period, the removal reached high-quality effluent for COD and TN, close to 95% and 90%, respectively. In the steady-state period, trimethoprim and diclofenac were successfully removed with values around 50%, while carbamazepine and naproxen were more recalcitrant. The dominant bacterial OTUs were affected by the presence of a mixture of pharmaceutical compounds, under which the dominant phylotypes changed to OTUs classified among the Pseudomonas, Gemmobacter, and Comamonadaceae. The RT-qPCR and qPCR results showed the deep effects of pharmaceutical compounds on the number of copies of target genes. Statistical analyses allowed for linking the total and active microbial communities with the physico-chemical performance, describing the effects of pharmaceutical compounds in pollution degradation, as well as the successful adaptation of the system to treat wastewater in the presence of toxic compounds.
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Rivero Pacho, Angeles M., Robert E. Critoph, and Steven J. Metcalf. "Study of Thermal Conductivity and Geometry Wall Contact Resistance Effect of Granular Active Carbon for Refrigeration and Heat Pumping Systems." Heat Transfer Engineering 37, no. 7-8 (November 16, 2015): 720–28. http://dx.doi.org/10.1080/01457632.2015.1067094.
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Melicher, Darya, Anlun Xu, Valerie Zhao, Alex Potanin, and Jonathan Aldrich. "Bounded Abstract Effects." ACM Transactions on Programming Languages and Systems 44, no. 1 (March 31, 2022): 1–48. http://dx.doi.org/10.1145/3492427.
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Effect systems have been a subject of active research for nearly four decades, with the most notable practical example being checked exceptions in programming languages such as Java. While many exception systems support abstraction, aggregation, and hierarchy (e.g., via class declaration and subclassing mechanisms), it is rare to see such expressive power in more generic effect systems. We designed an effect system around the idea of protecting system resources and incorporated our effect system into the Wyvern programming language. Similar to type members, a Wyvern object can have effect members that can abstract lower-level effects, allow for aggregation, and have both lower and upper bounds, providing for a granular effect hierarchy. We argue that Wyvern’s effects capture the right balance of expressiveness and power from the programming language design perspective. We present a full formalization of our effect-system design, showing that it allows reasoning about authority and attenuation. Our approach is evaluated through a security-related case study.
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Lakshmanan, S. K., and A. Koenig. "Towards a generic operational amplifier with dynamic reconfiguration capability." Advances in Radio Science 4 (September 6, 2006): 259–62. http://dx.doi.org/10.5194/ars-4-259-2006.
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Abstract. Analog and analog-digital mixed signal electronics needed for sensor systems are indispensable components which tend to drifts from the normal phase of operation due to the impact of manufacturing conditions and environmental influences like etching, aging etc. Precise design methodology, trimming / calibration are essential to restore functionality of the system. Recent block level granular approaches using Field Programmable Analog Array and the more recent approaches from evolutionary electronics providing transistor level granularity using Field Programmable Transistor Arrays offers considerable extensions. In our work, we started on a new medium granular level approach called Field Programmable medium-granular Mixed-signal Array (FPMA) providing basic building blocks of heterogeneous array of active and passive devices to configure established circuit structures which are adaptive, biologically inspired and dynamically re-configurable. Our design objective is to create components of clear compatibility to that of the industrial standards having predictable behavior along with the incorporation of existing design knowledge. The cells can be used in as a single instance or multiple instances. Further, we will focus on a generic dynamic reconfigurable amplifier cell with flexible topology and dimension called Generic Operational Amplifier (GOPA). The incentive of our work comes from recent development in the field of measurement and instrumentation. The digital programming of analog devices is carried out using range of algorithms from simple to evolutionary. Physical realization of the basic cells is carried out in 0.35 μm CMOS technology.
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Bogdanovich, M. V., V. N. Dudikov, K. V. Lepchenkov, V. A. Loiko, Yu M. Popov, A. G. Ryabtsev, G. I. Ryabtsev, P. V. Shpak, and M. A. Shchemelev. "Specific features of radiation flux formation in diode-pumped lasers and amplifiers with active elements made of Nd : YAG ceramics." Quantum Electronics 52, no. 5 (May 1, 2022): 449–53. http://dx.doi.org/10.1070/qel18041.
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Abstract The spatial, temporal, and spectral characteristics of the output radiation of diode-pumped laser systems and optical amplifiers with active elements made of Nd : YAG ceramics are studied. It is shown that the divergence of radiation in the subthreshold regime has the form of concentric nested cones emerging from the active element (AE) faces at angles of 2 – 4°. A model explaining the experimentally observed phenomenon is proposed based on the mechanism of scattering of the generated beam from the granular structure of the optical ceramics. Analysis of the divergence pattern makes it possible to estimate the grain size and the optical quality of ceramics. The output beam divergence in the lasing regime is determined mainly by the cavity parameters and does not exceed several milliradians. The scattering events in this case serve as sources of additional optical losses. Luminescence enhancement and parasitic oscillations in the AE volume restrict the possibility of using Nd : YAG ceramics for fabricating AEs of high-power optical amplifiers.
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Azari, M., A. V. Le, M. Lübken, and M. Denecke. "Model-based analysis of microbial consortia and microbial products in an anammox biofilm reactor." Water Science and Technology 77, no. 7 (February 23, 2018): 1951–59. http://dx.doi.org/10.2166/wst.2018.081.
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Abstract A mathematical model for a granular biofilm reactor for leachate treatment was validated by long-term measured data to investigate the mechanisms and drivers influencing biological nitrogen removal and microbial consortia dynamics. The proposed model, based on Activated Sludge Model (ASM1), included anaerobic ammonium oxidation (anammox), nitrifying and heterotrophic denitrifying bacteria which can attach and grow on granular activated carbon (GAC) particles. Two kinetic descriptions for the model were proposed: with and without soluble microbial products (SMP) and extracellular polymeric substance (EPS). The model accuracy was checked using recorded total inorganic nitrogen concentrations in the effluent and estimated relative abundance of active bacteria using quantitative fluorescence in-situ hybridization (qFISH). Results suggested that the model with EPS kinetics fits better for the relative abundance of anammox bacteria and nitrifying bacteria compared to the model without EPS. The model with EPS and SMP confirms that the growth and existence of heterotrophs in anammox biofilm systems slightly increased due to including the kinetics of SMP production in the model. During the one-year simulation period, the fractions of autotrophs and EPS in the biomass were almost stable but the fraction of heterotrophs decreased which is correlated with the reduction in nitrogen surface loading on the biofilm.
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Yukhymenko, Mykola, Ruslan Ostroha, and Jozef Bocko. "Design of a shelf pneumatic classifier for separating a polydisperse mixture of granulated superphosphate." Eastern-European Journal of Enterprise Technologies 6, no. 1 (120) (December 30, 2022): 33–42. http://dx.doi.org/10.15587/1729-4061.2022.267037.
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The object of this study is a polydisperse mixture of granular superphosphate. It is emphasized that existing technologies of granulation and processing of granules lead to the formation of dusty fractions of small particles. The content of small fractions in the finished product should be minimal and, in connection with this problem, the task is to remove small particles from the mixture. The purpose of the current experimental study is to classify a polydisperse mixture of granular superphosphate in a pneumatic classifier. The device includes an inclined perforated shelf with an unloading space between its end and the wall of the apparatus. It has been experimentally revealed that the maximum efficiency of extraction into the entrainment of small particles is achieved with a width of the discharge space equal to 0.5 of the length of the cross-sectional side of the apparatus; the degree of perforation of the shelf is 5 %; the angle of inclination of the shelf is 25–30°; the speed of the gas flow in the free section of the apparatus is 3.7 m/s. It is shown that the degree of extraction into the entrainment of a small fraction less than 1 mm in size reaches 70–75 %, the content of the small fraction in the carry-over is 96–98 %, and the large fraction is less than 5 %. By processing experimental data, an empirical equation was built that makes it possible to determine the concentration of particles in the gas stream for individual fractions of the material. It is shown that due to the implementation of an active aerodynamic weighing mode, the shelf pneumatic classifier works at specific loads for air flow rate less than the typical designs of fluidized bed separators. It is noted that the effective operation of the shelf pneumatic classifier in the production of granular mineral fertilizers is ensured at a productivity of no more than 10–12 t/h. With greater productivity, there is a need to install several devices in the technological line
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Ushakova, S. A., V. N. Shikhov, Е. S. Shklavtsova, S. V. Trifonov, O. V. Anishchenko, and А. А. Tikhomirov. "EFFECT OF LIGHT INTENSITY ON CENOSIS OF WHEAT CULTIVATED ON SOLUTIONS WITH THE USE OF LIQUID PRODUCTS OF HUMAN EXOMETABOLITES MINERALIZATION IN CONTEXT OF CLOSED ECO-SYSTEMS." Aerospace and Environmental Medicine 55, no. 5 (2021): 76–84. http://dx.doi.org/10.21687/0233-528x-2021-55-5-76-84.
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Goal of the investigation was to assess an impact of photosynthetically active radiation (RAR) intensity on crops growing hydroponically on solutions containing human exometabolites mineralized by hydrogen peroxide activated by alternating current. Object was wheat Triticum aestivum L. (strain 232, Lysovsky selection) bred for cultivation in bio-technical life support systems. Nutrient substrate was granular zirconium silencer of 0.8 cm in diameter. Till day 25 (initial booting) the crop grew under RAR intensity of 650 and 950 µmol/m2s. Well-being of the vegetating wheat was assessed by the following criteria: СО2, wheat cenosis gas-exchange, photosynthesis, nutrient uptake, plant biomass and mineral composition. High RAR intensity did not cause damage to the photosynthetic system but activated photosynthesis and increased dry biomass in 1.7 times. Besides, levels of macroelements in biomass increased significantly (Ca – more than 3 times, Mg – 2.7 times, Na – 2.3 times, S – doubled).
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Zelenikhin, P. V., A. G. Galeeva, R. R. Islamova, O. N. Lopatin, R. S. Yarullin, and O. N. Ilinskaya. "Hybrid Organomineral Carriers for Therapeutic Proteins." Russian Journal of Bioorganic Chemistry 49, no. 2 (April 2023): 298–305. http://dx.doi.org/10.1134/s1068162023020231.
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Abstract— Drug delivery systems are developed to provide a necessary concentration and prolonged effect of the active substance in the organism. Orally administered protein preparations require a protection from the proteolysis in the gastrointestinal tract. Biocompatible hydrophilic polysaccharides in the composition of the matrix are especially promising, since they do not irritate the intestine and are gradually cleaved by specific glycosidases, releasing a therapeutic agent. The introduction of an insoluble porous mineral matrix into the composition of the carrier allows us to increase the concentration of the therapeutic agent in the matrix without a significant increase in the volume of the drug tablet form. In this work, a new original organomineral carrier was created based on heat-treated crushed clinoptilolite zeolite in combination with natural polysaccharides of red algae (agar–agar, agarose, and carrageenan). Granular and finely dispersed clinoptilolites in the composition of the matrix are loaded with a promising therapeutic agent (Bacillus pumilus ribonuclease (binase)), which shows a selective cytotoxicity to tumor cells. It was established that both granular and finely dispersed zeolites in a complex with polysaccharides retain the protein better as compared with pure zeolites and provide a gradual complete release of the enzyme in 18 h; at the same time, binase retains a catalytic activity and causes apoptosis in up to 23.8% of the population of HuTu80 human duodenal adenocarcinoma cells. Data obtained substantiate the prospects of designing dosage forms based on the studied organomineral carriers.
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Mincu, Mariana, Maria Iuliana Marcus, Mihaela Andreea Mitiu, and Natalia Simona Raischi. "Increasing the Efficiency of Pollutants Removal from Municipal Wastewater Using Biological Filters." Revista de Chimie 69, no. 12 (January 15, 2019): 3553–56. http://dx.doi.org/10.37358/rc.18.12.6790.
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Biological filters are wastewater treatment systems that contain a granular filling material, which form an active biological film that contribute to the biooxidation of impurities from the wastewater. Recent research in the field aimed to improve the classical treatment facilities with aerobic fixed film by using inexpensive and easily accessible materials as filterable loading. Experiments have been carried out on biological filters loaded with volcanic tuff, with a diameter between 20-100 mm, supplied with municipal wastewater from primary settling. The biological filtration efficiency has been etablished throughout the continuous functioning of the experimental installation by physico-chemical water analysis. The analyzed indicators have been the ones stipulated by the legislation in force, namely: pH, chemical oxygen demand (COD), biochemical oxygen demand (BOD5), total suspended matter (TS), total nitrogen (TN), total phosphorus (TP), etc. The analysed wastewater samples have been average samples. The treatment efficiency have been calculated in various hypotheses, depending on the: installation capacity, hydraulic loading, organic loading.
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Yan, Bingxi. "Actuators for Implantable Devices: A Broad View." Micromachines 13, no. 10 (October 17, 2022): 1756. http://dx.doi.org/10.3390/mi13101756.
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The choice of actuators dictates how an implantable biomedical device moves. Specifically, the concept of implantable robots consists of the three pillars: actuators, sensors, and powering. Robotic devices that require active motion are driven by a biocompatible actuator. Depending on the actuating mechanism, different types of actuators vary remarkably in strain/stress output, frequency, power consumption, and durability. Most reviews to date focus on specific type of actuating mechanism (electric, photonic, electrothermal, etc.) for biomedical applications. With a rapidly expanding library of novel actuators, however, the granular boundaries between subcategories turns the selection of actuators a laborious task, which can be particularly time-consuming to those unfamiliar with actuation. To offer a broad view, this study (1) showcases the recent advances in various types of actuating technologies that can be potentially implemented in vivo, (2) outlines technical advantages and the limitations of each type, and (3) provides use-specific suggestions on actuator choice for applications such as drug delivery, cardiovascular, and endoscopy implants.
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Yamada, Takeshi, Kae Kikuchi, Toshihiro Yamauchi, Koji Shiraishi, Tsukasa Ito, Satoshi Okabe, Akira Hiraishi, et al. "Ecophysiology of Uncultured Filamentous Anaerobes Belonging to the Phylum KSB3 That Cause Bulking in Methanogenic Granular Sludge." Applied and Environmental Microbiology 77, no. 6 (January 21, 2011): 2081–87. http://dx.doi.org/10.1128/aem.02475-10.
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ABSTRACTA filamentous bulking of a methanogenic granular sludge caused by uncultured filamentous bacteria of the candidate phylum KSB3 in an upflow anaerobic sludge blanket (UASB) system has been reported. To characterize the physiological traits of the filaments, a polyphasic approach consisting of rRNA-based activity monitoring of the KSB3 filaments using the RNase H method and substrate uptake profiling using microautoradiography combined with fluorescencein situhybridization (MAR-FISH) was conducted. On the basis of rRNA-based activity, the monitoring of a full-scale UASB reactor operated continuously revealed that KSB3 cells became active and predominant (up to 54% of the total 16S rRNA) in the sludge when the carbohydrate loading to the system increased. Batch experiments with a short incubation of the sludge with maltose, glucose, fructose, and maltotriose at relatively low concentrations (approximately 0.1 mM) in the presence of yeast extract also showed an increase in KSB3 rRNA levels under anaerobic conditions. MAR-FISH confirmed that the KSB3 cells took up radioisotopic carbons from [14C]maltose and [14C]glucose under the same incubation conditions in the batch experiments. These results suggest that one of the important ecophysiological characteristics of KSB3 cells in the sludge is carbohydrate degradation in wastewater and that high carbohydrate loadings may trigger an outbreak of KSB3 bacteria, causing sludge bulking in UASB systems.
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Suárez, Irina, and Stefan Schulte-Merker. "Cells with Many Talents: Lymphatic Endothelial Cells in the Brain Meninges." Cells 10, no. 4 (April 2, 2021): 799. http://dx.doi.org/10.3390/cells10040799.
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The lymphatic system serves key functions in maintaining fluid homeostasis, the uptake of dietary fats in the small intestine, and the trafficking of immune cells. Almost all vascularized peripheral tissues and organs contain lymphatic vessels. The brain parenchyma, however, is considered immune privileged and devoid of lymphatic structures. This contrasts with the notion that the brain is metabolically extremely active, produces large amounts of waste and metabolites that need to be cleared, and is especially sensitive to edema formation. Recently, meningeal lymphatic vessels in mammals and zebrafish have been (re-)discovered, but how they contribute to fluid drainage is still not fully understood. Here, we discuss these meningeal vessel systems as well as a newly described cell population in the zebrafish and mouse meninges. These cells, termed brain lymphatic endothelial cells/Fluorescent Granular Perithelial cells/meningeal mural lymphatic endothelial cells in fish, and Leptomeningeal Lymphatic Endothelial Cells in mice, exhibit remarkable features. They have a typical lymphatic endothelial gene expression signature but do not form vessels and rather constitute a meshwork of single cells, covering the brain surface.
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Takahashi, Tetsuya, and Christopher Batty. "FrictionalMonolith." ACM Transactions on Graphics 40, no. 6 (December 2021): 1–20. http://dx.doi.org/10.1145/3478513.3480539.
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We propose FrictionalMonolith , a monolithic pressure-friction-contact solver for more accurately, robustly, and efficiently simulating two-way interactions of rigid bodies with continuum granular materials or inviscid liquids. By carefully formulating the components of such systems within a single unified minimization problem, our solver can simultaneously handle unilateral incompressibility and implicit integration of friction for the interior of the continuum, frictional contact resolution among the rigid bodies, and mutual force exchanges between the continuum and rigid bodies. Our monolithic approach eliminates various problematic artifacts in existing weakly coupled approaches, including loss of volume in the continuum material, artificial drift and slip of the continuum at solid boundaries, interpenetrations of rigid bodies, and simulation instabilities. To efficiently handle this challenging monolithic minimization problem, we present a customized solver for the resulting quadratically constrained quadratic program that combines elements of staggered projections, augmented Lagrangian methods, inexact projected Newton, and active-set methods. We demonstrate the critical importance of a unified treatment and the effectiveness of our proposed solver in a range of practical scenarios.
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Murashevych, Bohdan, Dmitry Girenko, Mykola Toropin, Iryna Koshova, Vadym Kovalenko, Oleg Lebed, Vasyl Chuiko, Valerii Kotok, and Dmytro Stepanskyi. "New multifunctional bromine-active polymers: synthesis, properties, and antimicrobial activity." Eastern-European Journal of Enterprise Technologies 2, no. 6 (122) (April 30, 2023): 32–42. http://dx.doi.org/10.15587/1729-4061.2023.278000.
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The increase in the frequency and scale of epidemics of infectious diseases gives extreme urgency to the development of new technologies for antiseptic and disinfectant treatment of various media, as well as materials/reagents for their implementation. Antimicrobial polymer materials of various chemical structures, including those containing halogen-active functional groups, are promising in this regard. This work is devoted to the synthesis and investigation of the properties of granular and fibrous polymer materials with immobilized N-bromosulfonamide groups of different structure. It is shown that copolymers of styrene with divinylbenzene and polypropylene can be used as a carrier polymer. A technique has been developed that allows obtaining polymers with a content of up to 23 % of immobilized active bromine. The compliance of the synthesized materials with the declared structure has been proven by IR spectroscopy and a complex of chemical methods. A decrease in the strength of the obtained polymers compared to the original carriers has been observed, especially in the case of fibers. The stability of the synthesized polymers during storage is lower that of the previously described chlorine-active analogs. For the quantitative determination of active bromine in the target materials, a technique based on its rapid diffusion from the polymer into the taurine solution has been developed. Microbiological research has shown that the synthesized polymers have a pronounced antimicrobial activity, which is higher than that of immobilized N-chlorosulfonamides and is manifested even in the presence of a significant organic load. The set of investigated characteristics of synthesized polymers with immobilized N-bromosulfonamide groups suggests the prospect of their use as components of antiseptic dressing materials, antimicrobial filters, devices for obtaining antiseptic solutions, and other medical products
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Alishavandi, Mahdi, Mahdi Mohammadmirzaei, Mahnam Ebadi, and Amir Hossein Kokabi. "Microstructural and mechanical evaluations of SAW by manufactured granular basic bonded Cr, Mo, and Cr–Mo active fluxes on ST37 low carbon steel." International Journal of Advanced Manufacturing Technology 119, no. 9-10 (January 20, 2022): 6335–47. http://dx.doi.org/10.1007/s00170-021-08238-1.
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Fults, D. W., A. C. Towle, J. M. Lauder, and P. F. Maness. "pp60c-src in the developing cerebellum." Molecular and Cellular Biology 5, no. 1 (January 1985): 27–32. http://dx.doi.org/10.1128/mcb.5.1.27-32.1985.
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pp60c-src was localized in the cerebellum of developing chicken embryos by immunoperoxidase staining with antisera raised against bacterially expressed pp60v-src. Immunoreactivity (IR) appeared in the cerebellum of the chicken embryos at the time of neuronal differentiation. pp60c-src IR was detected in regions of the developing cerebellum where processes of developing neurons and glia are located. In the early embryo (stage 17), pp60c-src IR was localized in the marginal zone of the cerebellar plate. By stage 40, pp60c-src IR was localized in the process-rich molecular layer of the cerebellum and between the cells of the developing internal granular layer. Cell bodies of cerebellar neurons did not show pp60c-src IR at any stage of development. Mitotically active neuroepithelial cells of the metencephalon did not express pp60c-src before the onset of differentiation in the early embryo, nor did proliferating cells of the external granular layer express pp60c-src at later stages. Although it is not possible to ascertain whether pp60c-src is localized in developing neurons or glia at the light microscope level, the time of its appearance and pattern of distribution in the molecular layer is suggestive of a localization within the developing neuronal processes which compose the bulk of this layer. Biochemical analyses of pp60c-src in the developing cerebellum by the immune complex protein kinase activity and sensitivity of the kinase to inhibition by P1,P4-di(adenosine-5')tetraphosphate confirmed that the expression of pp60c-src coincided with the time of neuronal differentiation. We conclude from these results that in the central nervous systems, pp60c-src may be more important in an aspect of cell differentiation or a mature neuronal function than in the proliferation of neuronal or glial precursors.
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Fults, D. W., A. C. Towle, J. M. Lauder, and P. F. Maness. "pp60c-src in the developing cerebellum." Molecular and Cellular Biology 5, no. 1 (January 1985): 27–32. http://dx.doi.org/10.1128/mcb.5.1.27.
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pp60c-src was localized in the cerebellum of developing chicken embryos by immunoperoxidase staining with antisera raised against bacterially expressed pp60v-src. Immunoreactivity (IR) appeared in the cerebellum of the chicken embryos at the time of neuronal differentiation. pp60c-src IR was detected in regions of the developing cerebellum where processes of developing neurons and glia are located. In the early embryo (stage 17), pp60c-src IR was localized in the marginal zone of the cerebellar plate. By stage 40, pp60c-src IR was localized in the process-rich molecular layer of the cerebellum and between the cells of the developing internal granular layer. Cell bodies of cerebellar neurons did not show pp60c-src IR at any stage of development. Mitotically active neuroepithelial cells of the metencephalon did not express pp60c-src before the onset of differentiation in the early embryo, nor did proliferating cells of the external granular layer express pp60c-src at later stages. Although it is not possible to ascertain whether pp60c-src is localized in developing neurons or glia at the light microscope level, the time of its appearance and pattern of distribution in the molecular layer is suggestive of a localization within the developing neuronal processes which compose the bulk of this layer. Biochemical analyses of pp60c-src in the developing cerebellum by the immune complex protein kinase activity and sensitivity of the kinase to inhibition by P1,P4-di(adenosine-5')tetraphosphate confirmed that the expression of pp60c-src coincided with the time of neuronal differentiation. We conclude from these results that in the central nervous systems, pp60c-src may be more important in an aspect of cell differentiation or a mature neuronal function than in the proliferation of neuronal or glial precursors.
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Moulia, Bruno, Renaud Bastien, Hugo Chauvet-Thiry, and Nathalie Leblanc-Fournier. "Posture control in land plants: growth, position sensing, proprioception, balance, and elasticity." Journal of Experimental Botany 70, no. 14 (July 1, 2019): 3467–94. http://dx.doi.org/10.1093/jxb/erz278.
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Abstract The colonization of the atmosphere by land plants was a major evolutionary step. The mechanisms that allow for vertical growth through air and the establishment and control of a stable erect habit are just starting to be understood. A key mechanism was found to be continuous posture control to counterbalance the mechanical and developmental challenges of maintaining a growing upright structure. An interdisciplinary systems biology approach was invaluable in understanding the underlying principles and in designing pertinent experiments. Since this discovery previously held views of gravitropic perception had to be reexamined and this has led to the description of proprioception in plants. In this review, we take a purposefully pedagogical approach to present the dynamics involved from the cellular to whole-plant level. We show how the textbook model of how plants sense gravitational force has been replaced by a model of position sensing, a clinometer mechanism that involves both passive avalanches and active motion of statoliths, granular starch-filled plastids, in statocytes. Moreover, there is a transmission of information between statocytes and other specialized cells that sense the degree of organ curvature and reset asymmetric growth to straighten and realign the structure. We give an overview of how plants have used the interplay of active posture control and elastic sagging to generate a whole range of spatial displays during their life cycles. Finally, a position-integrating mechanism has been discovered that prevents directional plant growth from being disrupted by wind-induced oscillations.
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Giuffrida, E., M. Mangia, V. Figini, E. Carli, A. Colombo, M. Mendolaro, A. Lavagna, et al. "P256 The practical use of an eHealth platform for inflammatory bowel disease patients: the validation of the IBD Tool web-based tele-monitoring system." Journal of Crohn's and Colitis 16, Supplement_1 (January 1, 2022): i297—i298. http://dx.doi.org/10.1093/ecco-jcc/jjab232.383.
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Abstract Background Tele-monitoring and eHealth tools are useful to monitor disease burden and activity in inflammatory bowel disease (IBD). We developed a web-based tele-monitoring platform (IBD Tool), in order to monitor granularly disease activity and impact on patients’ lives. Aim of this abstract is to report preliminary data on IBD Tool effectiveness. Methods Consecutive IBD patients were offered the access to the tele-monitoring platform (IBD Tool) as a part of an ongoing investigator-initiated observational study, overall 677 patients were enrolled between February and November 2021. Validated questionnaires administered on the platform captured disease activity [Harvey Bradshaw Index (HBI), Simple Clinical Colitis Activity Index (SCCAI), Monitor IBD At Home Questionnaire for Crohn’s disease (CD) or for ulcerative colitis (UC): MIAH-CD or MIAH-UC] and disease burden and quality of life. Patients were randomized 1:1 to standard of care (only activity questionnaires required every 3-months) and telemedicine (activity questionnaires required monthly, remaining questionnaires every 3-months). Results Out of 678 patients enrolled, 585 (87%) are active on the platform and filled overall 14,297 questionnaires during an average follow-up of 9.8 months, the mean number of questionnaires filled/patient was 24.9. Characteristics of the patient enrolled in the study are presented in Table 1. Table 1. Characteristics of patients enrolled on the IBD Tool tele-monitoring platform and questionnaires filled Among the 320 cases with 2 or more observations in the IBD Tool platform, it was possible to analyse disease activity variation (summarized as constant, amelioration, or worsening) according to SCCAI or HBI changes ±2 points, results are detailed in Table 2. Table 2. Charateristics of patients constant, ameliorating or worsening in time. Conclusion Patients’ persistence in the tele-monitoring system is adequate; the systems offer granular and precise multidimensional evaluation of IBD patients.
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ZHUMADILOVA, Zhanar O., Vladimir P. SELYAEV, Ruslan E. NURLYBAEV, Yelzhan S. ORYNBEKOV, and Indira B. SANGULOVA. "STUDY OF ENERGY-SAVING LIQUID THERMAL INSULATING COATINGS BASED ON LOCAL FINELY DISPERSED SYSTEMS." Periódico Tchê Química 17, no. 37 (March 20, 2021): 189–203. http://dx.doi.org/10.52571/ptq.v18.n37.2021.13_zhanar_pgs_189_203.pdf.
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Introduction: In recent years, in building materials science, there has been a tendency for the active introduction of hollow microspheres of various types for modifying the properties of building materials. Hollow microspheres are most widely used in the production of liquid thermal insulating coatings, which reduce heat loss, protect structures from corrosion and overheating, prevent condensation formation, reduce operating costs and increase the time between repairs. Aim: Assessment of the influence of the structural characteristics of granular systems on the properties of thermal insulating materials. Methods: It is proposed to determine and evaluate the structural characteristics of filler powders by the method of small-angle X-ray scattering. The most important feature of this method is analyzing the internal structure of disordered systems - particles, pore space, interfaces between heterogeneities of heterogeneous substances. When assessing thermal conductivity and thermal resistance, the stationary heat flux method was used following GOST 30290–94. The essence of the method is to create a stationary heat flux passing through a flat sample of a certain thickness and directed perpendicular to the front (largest) faces of the sample, measuring the density of this heat flux, the temperature of the opposite front faces and the thickness of the sample. Results and Discussion: The paper discusses the results of experimental studies that make it possible to create liquid thermal insulation coatings (LTIC) based on polymer binders, fine mineral powders, and a complex of modifying additives. Experimental studies of the structure and properties of heat-insulating coatings based on filled polymer binders confirm their superiority over foreign analogs. Conclusions: It has been established that during the production of LTIC, their heat-shielding properties can be regulated by changing: pressure, the viscosity of the molecular weight of the gas; porosity of macrostructure and clusters; the thermal conductivity of the solid and gas phase of the system; the coefficient of accommodation; coordination number; primary particle size; fractal dimension characterizing the topological features of the structure of particles, aggregates, globules, clusters and their tendency to dissipate the energy of gas molecules.
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Mendhe, Dinesh, Stephanie Bergren, and XinQi Dong. "A Novel Survey Platform in the Age of COVID-19 to Increase Accuracy and Adoptability While Reducing Selection Bias." Innovation in Aging 4, Supplement_1 (December 1, 2020): 931–32. http://dx.doi.org/10.1093/geroni/igaa057.3415.
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Abstract Given the ongoing COVID-19 pandemic, secure and distanced data collection platforms are critical for reaching vulnerable populations. Commonly used electronic data collection systems lack a myriad of critical features, including a modern technology stack, new data encryption and security standards, study workflows, and reporting algorithms. Moreover, these systems do not have multilingual mapping functionalities of survey and consent forms. All of these components ultimately increase selection bias while simultaneously reducing the security and quality of the response data. In order to directly address the aforementioned issues, we have developed a multilingual and highly secure data management platform. Our application is built using stable, tested, and modular programming frameworks and design patterns targeted at accommodating intricately complex structures of polyglot mapping, large volume of data, encryption and granular user authorization. The statistical accuracy along with the multilingual mapping are the core highlights of this system. The multilingual function of this platform has the ability to eliminate selection biases while creating a well-balanced cross-section of society. Modern survey design workflows and validation checks ultimately prevent data loss and help reduce data collection errors. The platform design was initiated in April 1, 2020 and has been pilot tested for use in multilingual populations. The currently active application version of the system is capable of supporting in-person and telephone interviews, emailing survey links to every registered participant, building family tree architecture, and online consent management. This platform also has built-in report functionality. Additional features are being explored to improve study coordination and monitoring.
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Steinmetz, P. R. "Cellular organization of urinary acidification." American Journal of Physiology-Renal Physiology 251, no. 2 (August 1, 1986): F173—F187. http://dx.doi.org/10.1152/ajprenal.1986.251.2.f173.
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The turtle bladder contains transport systems for active sodium absorption, electrogenic proton secretion, and bicarbonate secretion (coupled to chloride absorption) that are functionally separate and occur in specialized epithelial cells. Maneuvers that alter the intracellular acid-base state, such as changes in PCO2, cause marked changes in the apical membrane area of alpha-type carbonic anhydrase (CA) cells by addition or retrieval of membrane vesicles but have no effect on the granular cells that transport sodium. The apical cell membrane of alpha-CA cells contains characteristic rod-shaped intramembrane particles (RSP) by freeze fracture and is coated on its cytoplasmic side with studs. A subpopulation of CA cells (beta-type), which is characterized by apical microvilli, fails to exhibit an apical response to CO2 stimulation and does not reveal RSPs or studs at its apical membranes; instead, these elements can be demonstrated at the basolateral membrane. The reversal in the polarity of these elements as well as physiological evidence suggest that beta-type cells are responsible for bicarbonate secretion. Structure-function studies of CO2 stimulation of H+ secretion by alpha-CA cells indicate that the secretion rate (JH) correlates with apical membrane area and numbers of RSPs. The view that RSPs represent arrays of transmembrane channels and that studs represent catalytic units of H+ pumps is supported by quantitative considerations but remains to be proven. Urinary acidification is regulated not only by changes in the number of H+ pumps but also by the intrinsic properties of the H+ pump itself. For a given pump population, JH is closely controlled by the delta microH across the active transport pathway.
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Epling-Burnette, P. K., Lubomir Sokol, Lynn Moscinski, Magda Elkabani, Fanqi Bai, Michelle Blaskovich, JianXiang Zou, Jeffrey S. Painter, Said Sebti, and Thomas P. Loughran. "First Clinical Report of Tipifarnib for the Treatment of T-Large Granular Lymphocyte (LGL) Leukemia." Blood 110, no. 11 (November 16, 2007): 3132. http://dx.doi.org/10.1182/blood.v110.11.3132.3132.
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Abstract INTRODUCTION: Lymphoproliferative diseases of large granular lymphocytes (LGL leukemia) are clinical syndromes associated with increased circulating CD3+CD8+CD57+ T-LGL s. Chronic neutropenia, anemia, and arthritis are clinical manifestations mediated by autoimmune reactivity of this lymphocyte population. Previously, we found evidence that extracellular-regulated kinase (ERK) and Ras were constitutively active in the patient’s LGLs. Ablation of Ras activity by a dominant-negative form of Ras and pharmacologic inhibition with farnesyltransferase inhibitors FTI2153 and R115777 (tipifarnib, Zarnestra®, Johnson & Johnson) resulted in ERK inhibition and enhanced apoptosis of the leukemic LGLs. A multicenter phase 2 clinical trial using tipifarnib was initiated with a two-stage design. Here we provide the first report of the efficacy and safety of tipifarnib in patients with LGL leukemia. METHODS: Patients were to be treated in the first stage with four cycles of therapy at a dose of 300 mg twice daily for 21 days out of a 28- day intermittent cycle. Key patient entry criteria were neutrophil counts < 500 cells/μl, transfusion-dependent anemia, and clonal CD3+/CD57+ T-cells greater than 350 cells/μl in the peripheral blood. WBC, ALC, hemoglobin, platelet counts, and ANC were determined. Bone marrow biopsies were performed on all patients prior to therapy and then repeated when worsening cytopenias occurred. Tipifarnib was stopped when bone marrow cellularity was reduced by 50% compared to baseline. Bone marrow colony formation assessed using14-day CFU-GM and BFU-E assays in methycellulose (Stem Cell Separation Systems, Vancouver BC). Growth factor support with G-CSF was allowed during the 7 days off when ANCs were < 500 cells/μl. RESULTS: Five males and two females (mean 57 years old) received tipifarnib. Four patients failed to complete the study due to toxicity. Three patients were removed from study due to grade 3–4 bone marrow toxicity and/or infections requiring hospitalization and a tipifarnib-unrelated death occurred in one patient. Three patients completed four cycles and were evaluated for response with a dose reduction for bone marrow toxicity required in one of these evaluable patients. Leukemic LGL cells from the three evaluable patients displayed a dose-dependent increase in apoptosis in vitro and treatment was associated with reduced ALCs in two cases. None of the patients met the pre-determined criteria for response. However, one patient, shown to be growth factor unresponsive prior to therapy, had an increase in ANC from 0 at baseline to 8,600 cells/μl while receiving G-CSF on week 16. The number of bone marrow colonies also increased in this patient after therapy. All bone marrow biopsies, which were required in five cases, showed significantly improved erythroid or myeloid differentiation. CONCLUSIONS: Improvements in bone marrow differentiation suggest that tipifarnib may prove beneficial for the treatment of LGL leukemia if a safe dose and schedule is established and the treatment prolonged to allow for bone marrow recovery.
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Verbanck, M. "Field Investigations on Sediment Occurrence and Behaviour in Brussels Combined Sewers." Water Science and Technology 25, no. 8 (April 1, 1992): 71–82. http://dx.doi.org/10.2166/wst.1992.0181.
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Although sewer sediments are now widely recognized as a major source of misfunction of urban drainage systems (for both hydraulic and environmental considerations), it is still too infrequent that priority of research activities in this area is given to field studies. The measuring campaigns conducted since 1986 in the drainage system of Brussels-North have been focused on sedimentation processes in the major sewer lines. There is an obvious distinction to be made between solids constituting the sediment bed of a man-entry sewer, which are relevant for its hydraulic capacity, and the ones contributing to the pollutional impact of CSOs upon receiving waters. The material which is removed several times a year from the main trunk sewer of Brussels is coarse, granular and has a low environmental impact, notably because of its limited mobility. This appears to be due to a very efficient granulometric grading, as a result firstly of the retention of the coarsest solids in highly selective gully-pot inlets, and secondly of an elutriation process removing from the sediment bed all fine organic-rich particles during daily peak flows. There is evidence to show that the build-up of the sediment bed in these large-sized sewers is driven by a bed-load process (active even during dry spells), while the solid material responsible for the detrimental effects of CSOs (which is much finer) is primarily transported through wash-load and suspended-load.
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Siamidi, Angeliki, Aikaterini Dedeloudi, and Marilena Vlachou. "Probing the Release of Bupropion and Naltrexone Hydrochloride Salts from Biopolymeric Matrices of Diverse Chemical Structures." Polymers 13, no. 9 (April 30, 2021): 1456. http://dx.doi.org/10.3390/polym13091456.
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In the last decades, the notion of including excipients in the formulations, as inert substances aiding production processes, has changed and they are recently viewed as multifunctional discrete entities. It is now well documented that excipients serve several roles, spreading from the stabilization and modified release, to providing biocompatible properties and targeting moieties. The aim of this study was to develop matrix-based oral drug delivery systems of bupropion hydrochloride (BUP·HCl) and naltrexone hydrochloride (NTX·HCl), suitable for releasing these active substances in a modified manner, providing a stable level of drug release, which is simultaneously therapeutically effective and non-toxic, thus reducing side effects, after a single dose administration, throughout the gastrointestinal tract. The new formulations, employing hydroxypropylmethycellulose (HPMC K15M) (a cellulosic polymer, which, generally hydrates to form a gelatinous layer that is critical to prevent wetting and rapid drug release from the matrices), poly(methacylic acid-co-ethyl acrylate) 1:1 (Eudragit® L100-55: effective for site specific drug delivery in intestine), poly(ethylene oxide) (PEO) (7 × 106: a high molecular weight polymer, water-soluble, in micro-granular powder form), as the rate controlling polymers, were chosen to lead to a “soothing out” release pattern of these drugs, at 0 ≤ t ≤ 120 min. Moreover, the release of the two drugs from the ulvan-based tablets, was found to follow the desired profile, throughout the entire course of the dissolution experiments.
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Vasilenko, Violetta, Irina Arkadeva, Vera Bogdanovskaya, George Sudarev, Sergei Kalenov, Marco Vocciante, and Eleonora Koltsova. "Glucose-Oxygen Biofuel Cell with Biotic and Abiotic Catalysts: Experimental Research and Mathematical Modeling." Energies 13, no. 21 (October 28, 2020): 5630. http://dx.doi.org/10.3390/en13215630.
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The demand for alternative sources of clean, sustainable, and renewable energy has been a focus of research around the world for the past few decades. Microbial/enzymatic biofuel cells are one of the popular technologies for generating electricity from organic substrates. Currently, one of the promising fuel options is based on glucose due to its multiple advantages: high energy intensity, environmental friendliness, low cost, etc. The effectiveness of biofuel cells is largely determined by the activity of biocatalytic systems applied to accelerate electrode reactions. For this work with aerobic granular sludge as a basis, a nitrogen-fixing community of microorganisms has been selected. The microorganisms were immobilized on a carbon material (graphite foam, carbon nanotubes). The bioanode was developed from a selected biological material. A membraneless biofuel cell glucose/oxygen, with abiotic metal catalysts and biocatalysts based on a microorganism community and enzymes, has been developed. Using methods of laboratory electrochemical studies and mathematical modeling, the physicochemical phenomena and processes occurring in the cell has been studied. The mathematical model includes equations for the kinetics of electrochemical reactions and the growth of microbiological population, the material balance of the components, and charge balance. The results of calculations of the distribution of component concentrations over the thickness of the active layer and over time are presented. The data obtained from the model calculations correspond to the experimental ones. Optimization for fuel concentration has been carried out.
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Langley, P. A., and D. A. Carlson. "Laboratory evaluation of bisazir as a practical chemosterilant for the control of tsetse, Glossina spp. (Diptera: Glossinidae)." Bulletin of Entomological Research 76, no. 4 (December 1986): 583–92. http://dx.doi.org/10.1017/s0007485300015091.
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AbstractThe sensitivity of males and females of Glossina morsitans morsitans Westwood to the vapour phase of bisazir was tested in the laboratory in a moving air stream at temperatures ranging from 12 to 20°C. Similar tests were conducted in still air in closed systems. Bisazir was used in its granular form or absorbed onto silicone rubber or cellulose fibre surfaces from solution in dichloromethane. As a crystalline solid, it lost only 5% of its weight in a moving air stream over 12 days. However, even in relatively still air, bisazir absorbed onto cellulose fibre discs lost 70% of its weight at 20°C and 80% at 30°C in 24 days. Estimations of the amounts of bisazir present on a surface by weight difference were higher than those estimated by gas chromatographic analysis. Hence, in addition to being volatile, bisazir must be regarded as somewhat unstable. Nevertheless, sufficient active ingredient remained over a long enough period for it to be considered as a practical means of sterilizing tsetse in the field. Females were found more sensitive to bisazir than males, but exposure times required to produce total sterility in both sexes did not affect survival. Exposure times of only a few minutes were sufficient to induce a significant reduction in female fecundity or male fertility at 30–35°C, temperatures which might be expected under field conditions in a device to sterilize automatically tsetse attracted to traps in the field. The degree of sterility induced was permanent, and at these short exposure times the temperature had no effect on female fecundity.
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Coden, Mackenzie E., Matthew T. Walker, Brian M. Jeong, Andrew R. Connelly, Reina Nagasaka, and Sergejs Berdnikovs. "Beyond Il-5: Metabolic Reprogramming and Stromal Support Are Prerequisite for Generation and Survival of Long-Lived Eosinophil." Cells 10, no. 4 (April 6, 2021): 815. http://dx.doi.org/10.3390/cells10040815.
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Eosinophils play surprisingly diverse roles in health and disease. Accordingly, we have now begun to appreciate the scope of the functional and phenotypic heterogeneity and plasticity of these cells. Along with tissue-recruited subsets during inflammation, there are tissue resident eosinophil phenotypes with potentially longer life spans and less dependency on IL-5 for survival. Current models to study murine eosinophils ex vivo rely on IL-5-sustained expansion of eosinophils from bone marrow hematopoietic progenitors. Although it does generate eosinophils (bmEos) in high purity, such systems are short-lived (14 days on average) and depend on IL-5. In this report, we present a novel method of differentiating large numbers of pure bone marrow-derived eosinophils with a long-lived phenotype (llEos) (40 days on average) that require IL-5 for initial differentiation, but not for subsequent survival. We identified two key factors in the development of llEos: metabolic adaptation and reprogramming induced by suppressed nutrient intake during active differentiation (from Day 7 of culture), and interaction with IL-5-primed stromal cells for the remainder of the protocol. This regimen results in a higher yield and viability of mature eosinophils. Phenotypically, llEos develop as Siglec-F(+)Ly6G(+) cells transitioning to Siglec-F(+) only, and exhibit typical eosinophil features with red eosin granular staining, as well as the ability to chemotax to eotaxin Ccl11 and process fibrinogen. This culture system requires less reagent input and allows us to study eosinophils long-term, which is a significant improvement over IL-5-driven differentiation protocols. Moreover, it provides important insights into factors governing eosinophil plasticity and the ability to assume long-lived IL-5-independent phenotypes.