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Academic literature on the topic 'Nanopores artificiels'

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Published: 25 May 2024

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Journal articles on the topic "Nanopores artificiels"

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Molcrette, Bastien, Léa Chazot-Franguiadakis, Thomas Auger, and Fabien Montel. "Quelques éléments de physique autour des nanopores biologiques." Reflets de la physique, no. 75 (April 2023): 18–23. http://dx.doi.org/10.1051/refdp/202375018.

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Les nanopores biologiques sont d’étonnantes machines moléculaires. Ils remplissent une grande variété de fonctions, allant du tri des biomolécules à la transmission des signaux dans nos neurones et au repliement des protéines nouvellement produites. Le membre le plus surprenant de ce club est le pore nucléaire. Il régule le flux de molécules entre le noyau et l’intérieur de la cellule. Ses performances, mesurées par son efficacité énergétique, sa directionnalité ou sa sélectivité, n’ont pas d’équivalent dans les systèmes artificiels. Nous verrons que la compréhension de son fonctionnement permet d’appréhender des phénomènes physiques nouveaux et d’imaginer des systèmes de filtration sélectifs, ainsi que des pompes moléculaires.
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Tsukanov, Alexey A., and Evgeny V. Shilko. "Computer-Aided Design of Boron Nitride-Based Membranes with Armchair and Zigzag Nanopores for Efficient Water Desalination." Materials 13, no. 22 (November 20, 2020): 5256. http://dx.doi.org/10.3390/ma13225256.

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Recent studies have shown that the use of membranes based on artificial nanoporous materials can be effective for desalination and decontamination of water, separation of ions and gases as well as for solutions to other related problems. Before the expensive stages of synthesis and experimental testing, the search of the optimal dimensions and geometry of nanopores for the water desalination membranes can be done using computer-aided design. In the present study, we propose and examine the assumption that rectangular nanopores with a high aspect ratio would demonstrate excellent properties in terms of water permeation rate and ion rejection. Using the non-equilibrium molecular dynamic simulations, the properties of promising hexagonal boron nitride (h-BN) membranes with rectangular nanopores were predicted. It has been found that not only the nanopore width but also its design (“armchair” or “zigzag”) determines the permeability and ion selectivity of the h-BN-based membrane. The results show that membranes with a zigzag-like design of nanopores of ~6.5 Å width and the armchair-like nanopores of ~7.5 Å width possess better efficiency compared with other considered geometries. Moreover, the estimated efficiency of these membranes is higher than that of any commercial membranes and many other previously studied single-layer model membranes with other designs of the nanopores.
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Willems, Kherim, Veerle Van Meervelt, Carsten Wloka, and Giovanni Maglia. "Single-molecule nanopore enzymology." Philosophical Transactions of the Royal Society B: Biological Sciences 372, no. 1726 (June 19, 2017): 20160230. http://dx.doi.org/10.1098/rstb.2016.0230.

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Biological nanopores are a class of membrane proteins that open nanoscale water conduits in biological membranes. When they are reconstituted in artificial membranes and a bias voltage is applied across the membrane, the ionic current passing through individual nanopores can be used to monitor chemical reactions, to recognize individual molecules and, of most interest, to sequence DNA. In addition, a more recent nanopore application is the analysis of single proteins and enzymes. Monitoring enzymatic reactions with nanopores, i.e. nanopore enzymology, has the unique advantage that it allows long-timescale observations of native proteins at the single-molecule level. Here, we describe the approaches and challenges in nanopore enzymology. This article is part of the themed issue ‘Membrane pores: from structure and assembly, to medicine and technology’.
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Ivanov, Yuri D., Alexander N. Ableev, Ivan D. Shumov, Irina A. Ivanova, Nikita V. Vaulin, Denis V. Lebedev, Anton S. Bukatin, Ivan S. Mukhin, and Alexander I. Archakov. "Registration of Functioning of a Single Horseradish Peroxidase Macromolecule with a Solid-State Nanopore." International Journal of Molecular Sciences 24, no. 21 (October 27, 2023): 15636. http://dx.doi.org/10.3390/ijms242115636.

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Currently, nanopore-based technology for the determination of the functional activity of single enzyme molecules continues its development. The use of natural nanopores for studying single enzyme molecules is known. At that, the approach utilizing artificial solid-state nanopores is also promising but still understudied. Herein, we demonstrate the use of a nanotechnology-based approach for the investigation of the enzymatic activity of a single molecule of horseradish peroxidase with a solid-state nanopore. The artificial 5 nm solid-state nanopore has been formed in a 40 nm thick silicon nitride structure. A single molecule of HRP has been entrapped into the nanopore. The activity of the horseradish peroxidase (HRP) enzyme molecule inserted in the nanopore has been monitored by recording the time dependence of the ion current through the nanopore in the course of the reaction of 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) oxidation reaction. We have found that in the process of ABTS oxidation in the presence of 2.5 mM hydrogen peroxide, individual HRP enzyme molecules are able to retain activity for approximately 700 s before a decrease in the ion current through the nanopore, which can be explained by structural changes of the enzyme.
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Acar, Elif Turker, Steven F. Buchsbaum, Cody Combs, Francesco Fornasiero, and Zuzanna S. Siwy. "Biomimetic potassium-selective nanopores." Science Advances 5, no. 2 (February 2019): eaav2568. http://dx.doi.org/10.1126/sciadv.aav2568.

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Reproducing the exquisite ion selectivity displayed by biological ion channels in artificial nanopore systems has proven to be one of the most challenging tasks undertaken by the nanopore community, yet a successful achievement of this goal offers immense technological potential. Here, we show a strategy to design solid-state nanopores that selectively transport potassium ions and show negligible conductance for sodium ions. The nanopores contain walls decorated with 4′-aminobenzo-18-crown-6 ether and single-stranded DNA (ssDNA) molecules located at one pore entrance. The ionic selectivity stems from facilitated transport of potassium ions in the pore region containing crown ether, while the highly charged ssDNA plays the role of a cation filter. Achieving potassium selectivity in solid-state nanopores opens new avenues toward advanced separation processes, more efficient biosensing technologies, and novel biomimetic nanopore systems.
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Mao, Haowei, Qun Ma, Hongquan Xu, Lei Xu, Qiujiao Du, Pengcheng Gao, and Fan Xia. "Exploring the contribution of charged species at the outer surface to the ion current signal of nanopores: a theoretical study." Analyst 146, no. 16 (2021): 5089–94. http://dx.doi.org/10.1039/d1an00826a.

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Nanopores attached to charged species realize the artificial regulation of ion transport by the electrostatic effect in nanoconfines, produce a sensitive ion current signal and play a critical role in nanopore-based analyses.
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Shimizu, Keisuke, Batsaikhan Mijiddorj, Masataka Usami, Ikuro Mizoguchi, Shuhei Yoshida, Shiori Akayama, Yoshio Hamada, et al. "De novo design of a nanopore for single-molecule detection that incorporates a β-hairpin peptide." Nature Nanotechnology 17, no. 1 (November 22, 2021): 67–75. http://dx.doi.org/10.1038/s41565-021-01008-w.

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AbstractThe amino-acid sequence of a protein encodes information on its three-dimensional structure and specific functionality. De novo design has emerged as a method to manipulate the primary structure for the development of artificial proteins and peptides with desired functionality. This paper describes the de novo design of a pore-forming peptide, named SV28, that has a β-hairpin structure and assembles to form a stable nanopore in a bilayer lipid membrane. This large synthetic nanopore is an entirely artificial device for practical applications. The peptide forms multidispersely sized nanopore structures ranging from 1.7 to 6.3 nm in diameter and can detect DNAs. To form a monodispersely sized nanopore, we redesigned the SV28 by introducing a glycine-kink mutation. The resulting redesigned peptide forms a monodisperse pore with a diameter of 1.7 nm leading to detection of a single polypeptide chain. Such de novo design of a β-hairpin peptide has the potential to create artificial nanopores, which can be size adjusted to a target molecule.
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Fürjes, Péter. "Controlled Focused Ion Beam Milling of Composite Solid State Nanopore Arrays for Molecule Sensing." Micromachines 10, no. 11 (November 13, 2019): 774. http://dx.doi.org/10.3390/mi10110774.

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Various nanoscale fabrication techniques are elaborated to form artificial nanoporous/nanochannel membranes to be applied for biosensing: one of the most prevalent is the micro-electromechanical systems (MEMS) compatible focused ion beam (FIB) milling. This technique can be easily adopted in micro- and nanomachining process sequences to develop composite multi-pore structures, although its precision and reproducibility are key points in the case of these thick multi-layered membranes. This work is to demonstrate a comprehensive characterisation of FIB milling to improve the reliability of the fabrication of solid state nanopore arrays with precisely predetermined pore geometries for a targeted molecule type to be recognised. The statistical geometric features of the fabricated nanopores were recorded as the function of the process parameters, and the resulting geometries were analysed in detail by high resolution scanning electron microscope (SEM), transmission electron microscope (TEM) and ion scanning microscopy. Continuous function of the pore diameter evolution rate was derived from the experimental results in the case of different material structures, and compared to former dissentient estimations. The additional metal layer was deposited onto the backside of the membrane and grounded during the ion milling to prevent the electrical charging of dielectric layers. The study proved that the conformity of the pore geometry and the reliability of their fabrication could be improved significantly. The applicability of the developed nanopore arrays for molecule detection was also considered by characterising the pore diameter dependent sensitivity of the membrane impedance modulation based measurement method.
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Kong, Hai Yan, Ji Huan He, Rou Xi Chen, and Liang Wang. "Highly Selective Adsorption of Plants' Leaves on Nanoparticles." Journal of Nano Research 22 (May 2013): 71–84. http://dx.doi.org/10.4028/www.scientific.net/jnanor.22.71.

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Adsorption of fine particles in air by a leaf is studied experimentally. It is found that each leaf can absorb only a kind of particles with almost same size, and it also exhibits high selectivity over other particles. The SEM study reveals that the size of nanopore on the epidermis is a main factor of the highly selective adsorption; the smaller nanopores can absorb larger nanoparticles in air. The morphology of a lotus leaf, which is waterproof and dustproof, has, on the other hand, many short nanofibrils instead of nanopores. It is concluded that the nanoscale geometrical structure of a surface affects its attraction/repulsion property. The experiment also shows that one square millimeter surface with nanopores in diameter of 18 nm can absorb 2 million nanoparticles of about 200 nm in diameter from air in 24 hours. A better understanding of the adsorption/repulsion mechanism could help the further design of bio-mimetic waterproof/dustproof artificial materials and artificial porous materials/fabrics/nonwovens for adsorption of nanoparticles in air.
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Agapova, O. I., A. E. Efimov, M. M. Moisenovich, V. G. Bogush, and I. I. Agapov. "COMPARATIVE ANALYSIS OF THREE-DIMENSIONAL NANOSTRUCTURE OF POROUS BIOCOMPATIBLE SCAFFOLDS MADE OF RECOMBINANT SPIDROIN AND SILK FIBROIN FOR REGENERATIVE MEDICINE." Russian Journal of Transplantology and Artificial Organs 17, no. 2 (May 26, 2015): 37–44. http://dx.doi.org/10.15825/1995-1191-2015-2-37-44.

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Aim.To perform a comparison of three-dimensional nanostructure of porous biocompatible scaffolds made of fibroinBombix moriand recombinant spidroin rS1/9.Materials and methods.Three-dimensional porous scaffolds were produced by salt leaching technique. The comparison of biological characteristics of the scaffolds shows that adhesion and proliferation of mouse fibroblastsin vitroon these two types of scaffolds do not differ significantly. Comparative experimentsin vivoshow that regeneration of bone tissue of rats is faster with implantation of recombinant spidroin scaffolds. Three-dimensional nanostructure of scaffolds and interconnectivity of nanopores were studied with scanning probe nanotomography (SPNT) to explain higher regenerative activity of spidroin-based scaffolds.Results.Significant differences were detected in the integral density and volume of pores: the integral density of nanopores detected on 2D AFM images is 46 μm–2 and calculated volume porosity is 24% in rS1/9-based scaffolds; in fibroin-based three-dimensional structures density of nanopores and calculated volume porosity were 2.4 μm–2 and 0.5%, respectively. Three-dimensional reconstruction system of nanopores and clusters of interconnected nanopores in rS1/9-based scaffolds showed that volume fraction of pores interconnected in percolation clusters is 35.3% of the total pore volume or 8.4% of the total scaffold volume.Conclusion.Scanning probe nanotomography method allows obtaining unique information about topology of micro – and nanopore systems of artificial biostructures. High regenerative activity of rS1/9-based scaffolds can be explained by higher nanoporosity of the scaffolds.
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Dissertations / Theses on the topic "Nanopores artificiels"

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Morin, Alan. "Nanopores artificiels pour la bio-analyse et la nanomédecine." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLE012/document.

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Les nanopores sont des ouvertures de taille nanométrique sur une membrane étanche isolante qui permettent de réaliser le suivi des objets qui les traversent. Il existe dans la nature des nanopores facilement reproductible en laboratoire comme l'alpha-hémolysine mais qui présente l'inconvénient d'avoir une durée de vie limitée ainsi qu'une fragilité importante (difficulté à les utiliser dans des dispositifs nomades). En s'intéressant aux nanopores solides nous cherchons à étudier une alternative plus stable dans le temps et donnant des résultats d'une plus grande reproductibilité. Les nanopores que nous utilisons sont obtenus par perçage par FIB (Focused Ion Beam) au LPN sur divers supports. Les membranes de silicium commerciales ont une épaisseur typique comprise entre 10 et 300 nm et servent à l'origine comme support d'observation de composé en microscopie électronique à transmission. Leur usage en est détourné ici afin de percer des nanopores uniques au sein d'une fenêtre de 100 x 100 μm en moyenne. Les nanopores peuvent alors être mesuré par TEM ou MEB afin d'estimer la taille du pore lors de la fabrication afin de calibrer les doses nécessaires au perçage des pores
Nanopores are nanometric holes on insulating membranes that allow the tracking of objects going through. Natural nanopores exist and are easily reproducible in laboratory conditions (alpha-hemolysine) but they are not compatible with a mobile device due to their fragility and to their reduced lifetime. Investigating solid-state nanopores allows us to approach a more stable alternative with a higher degree of reproductibility. Our nanopores are obtained by FIB drilling at LPN on various supporting membranes. The aim of this thesis is to investigate the use of SiN as a membrane to detect viruses
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Cressiot, Benjamin. "Transport de protéines natives, partiellement et complètement dépliées à travers des nanopores protéiques et artificiels." Thesis, Evry-Val d'Essonne, 2012. http://www.theses.fr/2012EVRY0016.

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Nous étudions le transport de protéines natives, partiellement ou complètement dépliées à travers des nanopores protéiques ou solides à l’échelle de la molécule unique en utilisant une détection électrique. Le système modèle que nous avons choisi est la protéine MalE sauvage ou mutante, en particulier la protéine MalE 219 qui se déplie à de plus faibles concentrations d’agent dénaturant que la protéine sauvage. Nous montrons que la translocation de protéines partiellement dépliées à travers un canal protéique, l’hémolysine du staphylocoque doré, dépend des conformations individuelles que nous pouvons distinguer. Les molécules dépliées passent rapidement dans les nanopores. Nous mesurons directement leur fraction en fonction de la concentration en agent dénaturant. La technique est très sensible aux mutations affectant le repliement.. Nous avons également étudié le transport de protéines à travers des nanopores solides dans différents cas. Nous comparons d’abord le transport de protéines natives et de protéines complètement dépliées à travers un nanopore de grand diamètre puis nous étudions la translocation de protéines dépliées à travers un nanopore étroit de diamètre inférieur à la taille de la protéine. Nous observons différents régimes de translocation quand nous varions le champ électrique appliqué que nous interprétons à l’aide d’un modèle théorique simple
We study the transport of native, partially or completely unfolded proteins through protein or solid-state nanopores at the single molecule level using an electrical detection. The model system that we use is the wild-type MalE or mutant protein, in particular MalE219, which unfolds at lower concentration of denaturing agent than the wild type. We show that the translocation of partially unfolded proteins through the Hemolysin protein channel, a toxin from Staphylococcus aureus, depends on of individual conformations that we can distinguish. The unfolded proteins pass rapidly through the nanopores. We directly measure their proportion as a function of the concentration of denaturing agent. The technique is very sensitive to the mutations affecting the folding properties. We also study the transport of proteins through solid-state nanopores in different situations. We first compare the transport of native and fully unfolded proteins through a nanopore of large diameter. We then study the tranlocation of unfolded proteins through a narrow pore, whose diameter is smaller than the protein size. We observe different regimes of translocation by varying the applied electric field, which we interpret using a simple theoretical model
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Auger, Thomas. "Translocation de biopolymères à travers des pores naturels ou artificiels." Thesis, Sorbonne Paris Cité, 2016. http://www.theses.fr/2016USPCC128/document.

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La translocation de biopolymères à travers un nanopore intervient dans de nombreux processus biologiques et technologiques, comme le transport nucléocytoplasmique dans le pore nucléaire des cellules eucaryotes, la sécrétion de protéines, le séquençage rapide de l’ADN ou l’électrophorèse capillaire.Nous proposons une technique optique en molécule unique originale pour l’étude de la translocation de biopolymères à travers un nanopore basée sur l’effet Zero-Mode Waveguide. Nous nous sommes intéressés au passage d’ADN double-brin de plusieurs tailles, d’ADN simple-brin et d’ARN, entraînés par un flux à travers une membrane nanoporeuse track-etched. Nous montrons qu’il existe un flux critique régissant le passage des biopolymères indépendant du rayon des pores ainsi que de la taille des biopolymères et de leur nature, conformément aux prédictions théoriques de Brochard et de Gennes.Le pore nucléaire est un nanopore biologique responsable du transport sélectif entre le noyau et lecytoplasme des cellules. Nous avons étudié l’influence de la concentration en importinBeta1 – une protéine nécessaire au transport nucléocytoplasmique – sur l’organisation du canal central du pore nucléaire deXenopus laevis en mesurant la diffusion de molécules de Dextran fluorescentes à travers celui-ci. Nous observons une ouverture du canal central à basse concentration suivi d’un rétrécissement de celui-ci à plus forte concentration. Cette évolution du rayon du canal central avec la concentration en importin Beta1est conforme aux modèles en champ moyen de Opferman et coll. et de Ando et coll. et aux observations expérimentales sur des systèmes reconstitués in vitro de Lim et coll. et Zahn et coll
The translocation of biopolymers through a nanopore is a feature common to many biological andtechnological processes such as the nucleocytoplasmic transport through the nuclear pore complex(NPC), protein secretion, fast DNA sequencing or capillary electrophoresis.We have developed an original single molecule optical detection technique for the study of biopolymerstranslocation through a nanopore based on the Zero-Mode Waveguide effect. We studied thepassage of double stranded DNA of different sizes, of single stranded DNA and of double-stranded RNAdriven by a flux through track-etched nanoporous membranes. We demonstrate that translocation isgoverned by a critical flux independent of both biopolymer size and nature and of the pore radius inagreement with the theoretical predictions of Brochard and de Gennes.The NPC is a biological nanopore responsible for the selective transport between cytoplasm andnucleus in cells. We studied the influence of importinBeta1 concentration – a protein involved in the nucleocytoplasmictransport – on the structure of the central channel of the NPC of Xenopus laevis byassessing the diffusion of fluorescently labeled Dextran molecules through the NPC. We observe anopening of the central channel at low concentration followed by a shrinking at higher concentrationin importinBeta1 in agreement with mean-field models from Opferman et al. and Ando et al. and withexperiments on biomimetic in vitro systems from Lim et al. and Zahn et al
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Boccalon, Mariangela. "Design and synthesis of artificial porphyrin nanopores." Doctoral thesis, Università degli studi di Trieste, 2012. http://hdl.handle.net/10077/7735.

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2010/2011
The regulation of transmembrane ion transport is a fundamental aspect of bioinspired chemistry which may find relevant applications in different fields ranging from pharmaceutics to sensing. In this contest the ability to form stable and well organized structures able to produce large and well defined pore in the membrane appears really promising. Several examples of such systems are present in the literature, usually formed in self-assembling processes mediated by hydrogen bonding, charge repulsion, and ion pairing. Coordination chemistry, however, has appeared only occasionally in design strategies for synthetic ion channels and pores. Recently Kobuke reported synthetic nanopores based on covalent adduct of porphyrins having six carboxylic acid groups directed up and down; the formation of hydrogen bonds between two monomers promotes their stacking and the formation of a nanopore able to span the lipid bilayer. The covalent approach for this type of macromolecules is synthetically laborious and the developments are therefore limited. In this context, the self-assembly approach, in which the macromolecules are generated by self-assembly of small and more synthetically accessible building blocks, is an attractive way to achieve the aim. In this field trans-porphyrin provides a linear substitution pattern that can be used for the construction of porphyrin-based architectures with a well-defined structure by metal mediated self-assembly. We have started a research project aimed to design synthetic metal-organic nanopores derived from the self-assembling of porphyrin ligands with proper metal fragments. In our first approach we have used trans-dipyridylporphyrins (linear difunctional ligands) which, upon binding with metal fragments such as Re(I) or Pd(II) (cis-coordinant metal fragments) may form supramolecular boxes (4+4 type). Subsequently, the porphyrins have been functionalized with groups able to give hydrogen bonds after appropriate modification, such as esters. A second part of the work was focused on the study of the ionophoric activity of the prepared compounds. Activity studies have been conducted on porphyrins and molecular squares using liposomes as models of biological membranes. Porphyrins and molecular squares without groups able to give hydrogen bonding do not show ionophoric activity. This behavior was expected because the dimension of these systems does not allow to span completely the lipid bilayer and there are not weak interactions that promote the self-assembly of the monomers. On the contrary, excellent ionophoric activity was observed with the molecular square bearing carboxylic acid. Thus, presence of hydrogen bonding groups that enable the formation of tubular, probably dimeric, structure are essential for forming the transmembrane nanopore. Ionophoric activity can be inhibited by using polyamino-dendrimers and this ability is function of their dimension. Parallel to the development of supramolecular porphyrins based nanopores, in the course of my PhD period, I studied also the ionophoric activity of cyclic phosphate-linked oligosaccharide analogues (CyPLOS) and guanosine-based amphiphiles in collaboration with prof.ssa Daniela Montesarchio, Department of Organic Chemistry and Biochemistry, University “Federico II” of Napoli.
XXIV Ciclo
1984
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Perret, Emilie. "Nez artificiel à transduction optique à base de matériaux sol-gel nanoporeux." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAS056/document.

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Ces travaux de thèse ont pour but l'élaboration de matrices poreuses sol-gel pour une applications de détections des composés organiques microbiens, ce-ci a des fins d'identifications bactériennes.Les travaux se sont articulés autour des la synthèse et l'optimisation du matériaux d'une part puis de l'analyse des composés organiques volatiles (COV) microbiens d'autre part. Cette analyse a été envisagé selon deux voies. La première était une approche globale des profils olfactifs microbiens. La seconde était une approche ciblée des COV cibles d’importance majeur.La synthèse du matériau a été mené par voie sol-gel, les études caractéristiques ont été effectué par manométrie d'azote et diffraction des rayons X aux petits angles.La détection microbienne, via notre matériaux sol-gel, s'effectue par transduction optique. Les spectrométries d'Absorbance ou de Fluorescence ont été envisagées en mode directe (sans molécules sondes) ou en mode indirect (avec molécules sondes)
989/5000The purpose of this thesis is to develop sol-gel porous matrices for microbial detection of microbial organic compounds for bacterial identification.The work revolved around the synthesis and optimization of materials on the one hand and then the analysis of volatile organic compounds (VOCs) on the other hand. This analysis was considered in two ways. The first was a global approach to microbial olfactory profiles. The second was a targeted approach to target VOCs of major importance.The synthesis of the material was carried out by sol-gel, the characteristic studies were carried out by nitrogen manometry and X-ray diffraction at small angles.Microbial detection, via our sol-gel material, is carried out by optical transduction. The Absorbance or Fluorescence spectrometries were considered in direct mode (without probe molecules) or in indirect mode (with probe molecules)
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Chau, Michael, Hsinchun Chen, Jailun Qin, Yilu Zhou, Wai-Ki Sung, Mark Chen, Yi Qin, Daniel M. McDonald, and Ann M. Lally. "NanoPort: A Web Portal for Nanoscale Science and Technology." ACM/IEEE-CS, 2002. http://hdl.handle.net/10150/105926.

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Artificial Intelligence Lab, Department of MIS, University of Arizona
Areas related to nanotechnology, or nanoscale science and engineering (NSSE), have experienced tremendous growth over the past few years. While there are a large variety of useful resources available on the Web, such information are usually distributed and difficult to locate, resulting in the problem of information overload. To address the problem, we developed the NanoPort system, an integrated Web portal aiming to provide a one-stop shopping service to satisfy the information needs of researchers and practitioners in the field of NSSE [1]. We believe that the approaches taken also can be applied to other domains.
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Bernhard, Max [Verfasser], Gerhard [Akademischer Betreuer] Thiel, and Bodo [Akademischer Betreuer] Laube. "Binding Proteins and Receptor Binding Domains as Sensor Elements for Biological and Artificial Nanopores / Max Bernhard ; Gerhard Thiel, Bodo Laube." Darmstadt : Universitäts- und Landesbibliothek, 2021. http://d-nb.info/1236344782/34.

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Hemmig, Elisa Alina. "DNA origami structures for artificial light-harvesting and optical voltage sensing." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/274005.

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In the past decade, DNA origami self-assembly has been widely applied for creating customised nanostructures with base-pair precision. In this technique, the unique chemical addressability of DNA can be harnessed to create programmable architectures, using components ranging from dye or protein molecules to metallic nanoparticles. In this thesis, we apply DNA nanotechnology for developing novel light-harvesting and optical voltage sensing nano-devices. We use the programmable positioning of dye molecules on a DNA origami plate as a mimic of a light-harvesting antenna complex required for photosynthesis. Such a structure allows us to systematically analyse optimal design concepts using different dye arrangements. Complementary to this, we use the resistive-pulse sensing technique in a range of electrolytes to characterise the mechanical responses of DNA origami structures to the electric field applied. Based on this knowledge, we assemble voltage responsive DNA origami structures labelled with a FRET pair. These undergo controlled structural changes upon application of an electric field that can be detected through a change in FRET efficiency. Such a DNA-based device could ultimately be used as a sensitive voltage sensor for live-cell imaging of transmembrane potentials.
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Corkery, Robert, and robert corkery@anu edu au. "Artificial biomineralisation and metallic soaps." The Australian National University. Research School of Physical Sciences and Engineering, 1998. http://thesis.anu.edu.au./public/adt-ANU20080124.190014.

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In this thesis, geometry is used as a basis for conducting experiments aimed at growing and arranging inorganic minerals on curved interfaces. Mineralisation is directed using crystalline and liquid-crystalline metallic soaps and surfactant/water systems as templates.¶ A review of the history, syntheses, structure and liquid crystallinity of metallic soaps and other amphiphiles is presented as a foundation to understanding the interfacial architectures in mesostructured template systems in general.¶ In this study, a range of metallic soaps of varying chain length and cation type are synthesised and characterised to find potentially useful templates for mineral growth. These include alkaline-earth, transition metal, heavy metal and lanthanide soaps. These are systematically characterised using a variety of analytical techniques, including chemical analyses, x-ray diffraction (XRD) infrared spectroscopy (IR) and differential scanning calorimetry (DSC). Their molecular and crystal structures are studied using transmission electron microscopy (TEM), cryo-TEM, electron diffraction (ED), electron paramagnetic spin resonance (EPR), absorption spectroscopy (UV-VIS), high resolution laser spectroscopy, atomic force microscopy (AFM), nuclear magnetic resonance spectroscopy, scanning electron microscopy (SEM), electron dispersive x-ray analysis (EDXA), thermal gravimetric analysis (TGA) and magnetic measurements. Models for the molecular and crystal structures of metallic soaps are proposed. The soaps are predominantly lamellar crystalline or liquid crystalline lamellar rotor phases with tilted and/or untilted molecular constituents. These display evidence of varying degrees of headgroup organisation, including superstructuring and polymerisation. A single crystal structure is presented for a complex of pyridine with cobalt soap. Simple models for their structure are discussed in terms of their swelling properties in water and oils. Experiments are also presented to demonstrate the sorbent properties of aluminium soaps on oil spills.¶ The thermotropic liquid crystallinity of alkaline earth, transition metal, heavy metal and lanthanide soaps is investigated in detail. This is done to assess their suitability as templates, and to document their novel thermotropic behaviour, particularly the relatively unknown lanthanide soaps. Liquid crystalline behaviours are studied using high-temperature XRD (HTXRD), hot-stage optical microscopy and DSC. Models for a liquid crystalline phase progression from crystals to anisotropic liquids are discussed in terms of theories of self-assembly and interfacial curvature. The terminology required for this is drawn from various nomenclature systems for amphiphilic crystals and liquid crystals. General agreement with previous studies is reported for known soaps, while liquid crystallinity is demonstrated in the lanthanide and some non-lanthanide soaps for the first time. A general phase progression of crystalline lamellar through liquid crystalline lamellar to non-lamellar liquid crystalline is discussed in terms of models concerned with the molecular and crystal structures of the soaps and their phase transitions via headgroup and chain re-arrangements.¶ Experiments aimed at guiding growth of metal sulfides using metallic soaps as templates are described, and a model for this growth is discussed. Metal sulfides have been successfully grown by reacting crystalline and liquid crystalline transition metal and heavy metal soaps with H2S gas at room temperature and at elevated temperature. These have been characterised using XRD, TEM, ED and IR. Sulfide growth is demonstrated to be restricted and guided by the reacting soap template architecture. Zinc, cadmium, indium and lead soaps formed confined nanoparticles within the matrix of their reacting soap template. In contrast, curved and flat sheet-like structures, some resembling sponges were found in the products of sulfided iron, cobalt, nickel, copper, tin and bismuth soaps. A model to explain this behaviour is developed in terms of the crystal and liquid crystal structures of the soaps and the crystal structures of the metal sulfide particles.¶ Liquid crystalline iron soaps have been subjected to controlled thermal degradation yielding magnetic iron oxide nanoparticles. Some XRD and TEM evidence has been found for formation of magnetic mesostructures in heat-treated iron soaps. Models for the molecular and liquid crystalline structure of iron soaps, their thermotropic phase progression and eventual conversion to these magnetic products are discussed. Systematic syntheses of mesoporous silicates from sheeted clays are discussed.¶The templates that have been used are cationic surfactants and small, organic molecular salts. Experiments are reported where a cooperative self-assembly of surfactant/water/kanemite plus or minus salt and oils yields 'folded sheet materials' (FSM'S). Templating of kanemite has also been achieved using cobalt cage surfactants. A theoretical prediction of the specific surface areas and specific volumes of homologous sets of FSM's gave excellent agreement with measured values. The geometry and topology of the mesostructures are discussed. A theoretical model is also discussed regarding the curvature found in the sheets of natural clays , and results of templating clays and silica using metallic soaps are presented. Experiments and a model for low temperature nucleation and growth of microporous silicalite-1 are described in terms of silica templating by water clathrates.¶ Finally, the problem of finding minimal surface descriptions of crystal networks is addressed. Combinatoric methods are used to disprove the existence of possible embeddings of type I and II clathrate networks in non-self intersecting periodic minimal surfaces. The crystal network of the clathrate silicate, melanophlogite is successfully embedded in the WI-10 self-intersecting surface. Details of a previously unreported, genus-25 periodic surface with symmetry Im3m are discussed.
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Bernhard, Max. "Binding Proteins and Receptor Binding Domains as Sensor Elements for Biological and Artificial Nanopores." Phd thesis, 2021. https://tuprints.ulb.tu-darmstadt.de/18587/1/Dissertation_Max_Bernhard_2021.pdf.

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Miniaturized electrical biosensors have become a promising tool for monitoring and analyzing biologically relevant substances by converting a biological signal into an electric current. Despite great progress in the analysis of macromolecules, the detection of small molecules that are of particular interest for medical and environmental analytics still remains a challenge. Here, the functional connection of a sensing element to an electrical switch is a bottleneck in biosensor design. Bacterial substrate binding proteins (SBPs) and ligand gated ion channels (LGICs) evolved over billions of years to recognize a variety of biologically relevant molecules with high selectivity and sensitivity. While SBPs are involved in the uptake of substances across bacterial cell membranes, LGICs mediate neuronal excitation in the central nervous system of vertebrates. The ancient binding modules of these two protein families share a conserved clamshell-like structure and entrap the ligand in their inter-lobe cleft by inducing a large conformational transition between the open- and closed- cleft states in a venus flytrap-like mechanism. In this work, i) the underlying mechanisms of ligand recognition and functional adaptability of LGICs and SBPs are investigated and exploited to ii) couple SBPs as sensor domains to biological and solid-state nanopores to build new types of electrical biosensors for the specific detection of biologically relevant small molecules. Despite their intrinsic capability to convert a chemical signal into an electrical signal, LGICs are only now gradually being used for biosensor design since core aspects in the mechanistic understanding of ligand recognition, modulation and activation in different receptor subtypes are poorly understood. Here we investigated the structural impact and mechanism(s) of full and partial agonism in glycine receptors (GlyRs) in its native lipid environment and the modulatory role of the amino terminal domain (NTD) in GluN1/GluN3 NMDA receptor auto-inhibition after glycine binding to the low affinity GluN1 subunit. We show that the full agonist glycine and the partial agonist taurine induce different conformational transitions of the α1 GlyR. In addition, we show that the expression system dependent variability of agonist affinity in HEK293 cells and Xenopus oocytes is not mediated by an altered conformational change. Furthermore, we report that the GluN3A NTD has a major role in GluN1/GluN3A receptor regulation by reducing the efficacy of glycine-depended receptor activation by agonist-evoked auto-inhibition. This effect is possibly mediated by the subunit interface and the NTD-LBD linkers of the GluN3A NTD. These insights into the conformational changes and structural adaptability have been further exploited to use bacterial SBPs and SBDs from LGICs as a molecule detector when connected to an electrical switch by coupling the ectoine binding protein EhuB to the channel pore of the ionotropic glutamate receptor GluR0 to design receptor-based biosensor and by coupling the phosphonate binding protein PhnD inside a single track-etched solid-state nanopore that combines the high affinity and selectivity of SBPs with the robustness of artificial nanopores. These new classes of electrical biosensors are characterized by a high ligand-affinity and specificity with concentration-dependent changes in the (nanopore) current after Ligand binding. The results in this work provide an excellent foundation for the use of SBPs and LGICs as sensor domains to developme new classes of electric biosensors with high specificity and affinity for detection of biologically relevant small molecules. Moreover, our approaches and insights into ligand recognition and modulation enhance the repertoire of biophysical methods and may deepen the understanding of the functions of LGICs at the molecular, synaptic and systemic level.
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Book chapters on the topic "Nanopores artificiels"

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Konnanath, Bharatan, Prasanna Sattigeri, Trupthi Mathew, Andreas Spanias, Shalini Prasad, Michael Goryll, Trevor Thornton, and Peter Knee. "Acquiring and Classifying Signals from Nanopores and Ion-Channels." In Artificial Neural Networks – ICANN 2009, 265–74. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-642-04277-5_27.

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Noy, Aleksandr, and Meni Wanunu. "Nanofluidic Transport and Sensing in Biological and Artificial Nanopores." In An Introduction to Single Molecule Biophysics, 197–228. Boca Raton : Taylor & Francis, 2017. | Series: Foundations of biochemistry and biophysics: CRC Press, 2017. http://dx.doi.org/10.1201/b22505-6.

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Antony, Rajini P. "Synthesis Aspects of Nanoporous and Quasi-One-Dimensional Thin Film Architecture Photoelectrodes for Artificial Photosynthesis." In Handbook on Synthesis Strategies for Advanced Materials, 277–323. Singapore: Springer Singapore, 2022. http://dx.doi.org/10.1007/978-981-16-1803-1_8.

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Actis, Paolo, Boaz Vilozny, and Nader Pourm. "Immunoassays Using Artificial Nanopores." In Advances in Immunoassay Technology. InTech, 2012. http://dx.doi.org/10.5772/34489.

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BALME, S., M. LEPOITEVIN, M. BECHELANY, and J. M. JANOT. "HYBRID BIOLOGICAL/ARTIFICIAL NANOPORE." In Physics, Chemistry and Applications of Nanostructures, 454–56. WORLD SCIENTIFIC, 2015. http://dx.doi.org/10.1142/9789814696524_0112.

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Agrawal, Shreni, Richa Das, Shivangee Solanki, Simran Choudhury, Indrani Bhattacharya, Pradeep Kumar, Amit kumar Singh, Sunil Kumar Mishra, and Kavindra Nath Tiwari. "An Introduction to Nanopriming for Sustainable Agriculture." In Nanopriming Approach to Sustainable Agriculture, 1–19. IGI Global, 2023. http://dx.doi.org/10.4018/978-1-6684-7232-3.ch001.

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Plant seeds are of paramount importance in the agricultural sector as well as plant life cycle, and are being severely threatened by environmental changes such as biotic and abiotic stress, resource deficiency, climate fluctuation, etc. Cue, nano-priming, a nascent yet innovative approach to seed technology, combining versatility of nanoparticles and engineered nanomaterials with ‘seed-priming' to induce adaptive physiological changes, thus, improving seed quality and crop yield. This study reported mechanisms by which nano-priming synchronizes seed germination, breaks seed dormancy, boosts seed vigor, increases tolerance to periodic stress conditions, assists phyto-microbiota to thrive under environmental uncertainties, creates nanopores in shoots along with upregulation of aquaporin genes for better water uptake, and other reported changes at molecular, biochemical level. Withal, this study offers insight on the future of nano-priming when blended with cutting-edge technologies like cold plasma, artificial intelligence, and digital analysis to revolutionize the agrarian sector.
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Yang, Y., L. Belfares, F. Larachi, B. P. A. Grandjean, and A. Sayari. "Silica-CTAB-Water Phase Diagram at 150 °C: Predicting Phase Structure by Artificial Neural Network." In Nanoporous Materials II, Proceedings of the 2nd Conference on Access in Nanoporous Materials, 871–78. Elsevier, 2000. http://dx.doi.org/10.1016/s0167-2991(00)80295-5.

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Conference papers on the topic "Nanopores artificiels"

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Saharia, Jugal, Y. M. Nuwan D. Y. Bandara, and Lokesh Saharan. "Molybdenum Disulfide Solid-State Nanopores for Single-Molecule Biosensing." In ASME 2023 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2023. http://dx.doi.org/10.1115/imece2023-116801.

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Abstract Solid-state nanopore (SSN) is a propitious class of sensors delivering single-molecule level readouts with advantages such as high-throughput and label-free detection. While biological nanopores have shown great promise as a tool for fast and low-cost DNA/RNA sequencing, their artificial counterparts — SSNs — are yet to achieve the base-to-base signal resolution required for such high-precision genomic applications. Silicon nitride is the ubiquitous membrane material for SSNs and even the thinnest silicon nitride membranes are still a few nm thick (housing several bases at a given time), thus, unable to achieve single base resolution. In recent years, 2D materials such as graphene, hexagonal boron nitride (h-BN), and molybdenum disulfide (MoS2) have gained considerable traction as suitable membrane materials for sequencing applications. 2D materials can range from a single layer to a few atomic layers of thickness. The main advantage of 2D materials over relatively thick silicon nitride membranes is their ability to achieve high spatial resolution. They are also accompanied by superior mechanical strength and favorable optical and electronic properties compared to silicon nitride. Among the 2D materials, MoS2 has emerged as a promising option with several advantages over graphene and h-BN. Here, we review the application and potential of MoS2 as SSN membrane material for DNA and protein sensing in addition to the mechanical properties of MoS2 membranes, fabrication methods of MoS2 layers, and the process of MoS2 transfer on silicon substrates. We have also critically reviewed various theoretical and experimental studies that have reported using MoS2 nanopores for single molecule studies. While the overall number of MoS2 nanopore devices reported is low, the results obtained promise greater application of such devices for single molecule sensing.
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Machado, Dijanah Cota. "NANOPOROS PROTEICOS E ARTIFICIAIS NO SENSORIAMENTO ESTOCÁSTICO." In Encontro Anual da Biofísica 2017. São Paulo: Editora Blucher, 2017. http://dx.doi.org/10.5151/biofisica2017-039.

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Zhang, Cuiping, Jianbo Wang, Donghui Zhang, Donghui Feng, Xiaoqi Li, and Jiaxu Shen. "Metasurface Holographic Imaging Based on Three-Nanopores." In 2023 IEEE 3rd International Conference on Software Engineering and Artificial Intelligence (SEAI). IEEE, 2023. http://dx.doi.org/10.1109/seai59139.2023.10217500.

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Roy, Shuvo, Anna Dubnisheva, Abigail Eldridge, Aaron J. Fleischman, Kenneth G. Goldman, H. David Humes, Andrew L. Zydney, and William H. Fissell. "Silicon nanopore membrane technology for an implantable artificial kidney." In TRANSDUCERS 2009 - 2009 International Solid-State Sensors, Actuators and Microsystems Conference. IEEE, 2009. http://dx.doi.org/10.1109/sensor.2009.5285603.

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Chui, B. W., P. Taheri-Tehrani, N. Wright, J. Ly, and S. Roy. "ROBUST "RIBBED" NANOPOROUS MEMBRANES FOR IMPLANTABLE BIO-ARTIFICIAL KIDNEYS." In 2018 Solid-State, Actuators, and Microsystems Workshop. San Diego: Transducer Research Foundation, 2018. http://dx.doi.org/10.31438/trf.hh2018.28.

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Shoji, Kan, and Shogo Ikarashi. "Probe-Type Artificial Cell Membranes Formed with Nanopore-Modified Gold Needles." In 2022 IEEE International Conference on Cyborg and Bionic Systems (CBS). IEEE, 2023. http://dx.doi.org/10.1109/cbs55922.2023.10115352.

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Yasuga, Hiroki, Ryuji Kawano, Masahiro Takinoue, Yutaro Tsuji, Toshihisa Osaki, Koki Kamiya, Norihisa Miki, and Shoji Takeuchi. "Logic gate using artificial cell-membrane: NAND operation by transmembrane DNA via a biological nanopore." In 2013 IEEE 26th International Conference on Micro Electro Mechanical Systems (MEMS). IEEE, 2013. http://dx.doi.org/10.1109/memsys.2013.6474417.

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Mustafa, Kamarul 'Asyikin, Jumril Yunas, Azrul Azlan Hamzah, and Burhanuddin Yeop Majlis. "Application of BOE and KOH+IPA for fabrication of smooth nanopore membrane surface for artificial kidney." In 2017 IEEE Regional Symposium on Micro- and Nanoelectronics (RSM). IEEE, 2017. http://dx.doi.org/10.1109/rsm.2017.8069130.

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Chiu, Justin N. W., Rahmatollah Khodabandeh, and Richard Furberg. "Advanced Thermosyphon Cooling With Nanoporous Structured Mini Channel Evaporators." In ASME 2009 Second International Conference on Micro/Nanoscale Heat and Mass Transfer. ASMEDC, 2009. http://dx.doi.org/10.1115/mnhmt2009-18251.

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Attention has been given to enhance boiling surfaces in order to decrease the temperature difference and to increase heat transfer coefficient. Structured surfaces may provide both surface enlargement and artificial nucleation sites, thus ameliorate the heat transfer coefficient. The goal of the present experimental work is to analyze the influence on heat transfer coefficient (HTC) of enhanced surface structures coated on mini channel heat exchanger working in a closed loop thermosyphon system. Experimental tests were carried out with three types of surface enhanced mini channel evaporators: smooth surface, threaded structure and nanoporous coating. The evaporators are single channel half circularly shaped, adapted for filming purpose, measuring 30mm in length and 3mm in diameter. Surface areas of channels are 1.41cm2. Experiments were conducted in refrigerant 134a at 4.87bar (reduced pressure pr = 0.12) and at heat fluxes ranging from 0.7W/cm2 to 63.8W/cm2. A high speed video camera was used for visualization of the two-phase flow in the evaporator channel. It is shown that threaded surface provides the highest heat transfer coefficient (HTC) from no load to heat flux of 7.1W/cm2, the nanoporous structure shows the highest performance between 7.1W/cm2 and 49.6W/cm2, and the smooth surface channel exhibits the best HTC from 49.6W/cm2 and higher. In this paper, the influences of heat flux and surface structures on HTC are discussed, and the impact of refrigerant flow regimes on heat transfer performance is also highlighted.
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Iarossi, Marzia, Daniel Darvill, Jian-An Huang, Aliaksandr Hubarevich, Yingqi Zhao, and F. De Angelis. "Plasmonic nanopore array to detect translocating DNA and proteins at single molecule level by Raman Spectroscopy." In 2023 Seventeenth International Congress on Artificial Materials for Novel Wave Phenomena (Metamaterials). IEEE, 2023. http://dx.doi.org/10.1109/metamaterials58257.2023.10289343.

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