TOBB ETU GCRIS Database
Not a member yet
9778 research outputs found
Sort by
Observation of Wγγ Triboson Production in Proton-Proton Collisions at S=13 Tev With the Atlas Detector
No full textThis letter reports the observation of W(ℓν)γγ production in proton-proton collisions. This measurement uses the full Run 2 sample of events recorded at a center-of-mass energy of s=13 TeV by the ATLAS detector at the LHC, corresponding to an integrated luminosity of 140 fb−1. Events with a leptonically-decaying W boson and at least two photons are considered. The background-only hypothesis is rejected with an observed and expected significance of 5.6 standard deviations. The inclusive fiducial production cross section of W(eν)γγ and W(μν)γγ events is measured to be σfid=13.8±1.1(stat)+2.1−2.0(syst)±0.1(lumi) fb, in agreement with the Standard Model prediction. © 2023 The Author(s)IN2P3-CNRS; CC-IN2P3; 2014-2021; SCI/013; U.S. Department of Energy, USDOE; Alexander von Humboldt-Stiftung, AvH; Alabama Space Grant Consortium, ASGC; Brookhaven National Laboratory, BNL; Karlsruhe Institute of Technology, KIT; H2020 Marie Skłodowska-Curie Actions, MSCA; Multiple Sclerosis Scientific Research Foundation, MSSRF; CERN; Göran Gustafssons Stiftelser; Natural Sciences and Engineering Research Council of Canada, NSERC; National Research Council Canada, NRC; Canada Foundation for Innovation, CFI; Science and Technology Facilities Council, STFC; Leverhulme Trust; European Research Council, ERC; European Cooperation in Science and Technology, COST; Australian Research Council, ARC; National Stroke Foundation, NSF; Neurosurgical Research Foundation, NRF; Helmholtz-Gemeinschaft, HGF; Minerva Foundation; Deutsche Forschungsgemeinschaft, DFG; Agence Nationale de la Recherche, ANR; Japan Society for the Promotion of Science, JSPS; Ministry of Education, Culture, Sports, Science and Technology, MEXT; Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung, SNF; Danmarks Grundforskningsfond, DNRF; Fundação de Amparo à Pesquisa do Estado de São Paulo, FAPESP; National Natural Science Foundation of China, NSFC; Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT; Fundação para a Ciência e a Tecnologia, FCT; Bundesministerium für Bildung und Forschung, BMBF; Chinese Academy of Sciences, CAS; Austrian Science Fund, FWF; Generalitat de Catalunya; Ministry of Science and Technology of the People's Republic of China, MOST; Agencia Nacional de Promoción Científica y Tecnológica, ANPCyT; Nederlandse Organisatie voor Wetenschappelijk Onderzoek, NWO; Bundesministerium für Wissenschaft, Forschung und Wirtschaft, BMWFW; Conselho Nacional de Desenvolvimento Científico e Tecnológico, CNPq; Nella and Leon Benoziyo Center for Neurological Diseases, Weizmann Institute of Science; Israel Science Foundation, ISF; Instituto Nazionale di Fisica Nucleare, INFN; Narodowe Centrum Nauki, NCN; Javna Agencija za Raziskovalno Dejavnost RS, ARRS; Ministarstvo Prosvete, Nauke i Tehnološkog Razvoja, MPNTR; Ministerio de Ciencia e Innovación, MICINN; Centre National pour la Recherche Scientifique et Technique, CNRST; Staatssekretariat für Bildung, Forschung und Innovation, SBFI; Horizon 2020; British Columbia Knowledge Development Fund, BCKDF: 21/SCI/017; European Regional Development Fund, ERDF; Defence Science Institute, DSI; Narodowa Agencja Wymiany Akademickiej, NAWA; Institutul de Fizică Atomică, IFA; Agencia Nacional de Investigación y Desarrollo, ANID; Royal Society of South Australia, RSSA; Irish Rugby Football Union, IRF
Exploring the Potential of Artificial Intelligence Tools in Enhancing the Performance of an Inline Pipe Turbine
No full textIn this study, investigations were conducted using computational fluid dynamics (CFD) to assess the applicability of a Francis-type water turbine within a pipe. The objective of the study is to determine the feasibility of implementing a turbine within a pipe and enhance its performance values within the operating range. The turbine within the pipe occupies significantly less space in hydroelectric power plants since a spiral casing is not used to distribute the flow to stationary vanes. Consequently, production and assembly costs can be reduced. Hence, there is a broad scope for application, particularly in small and medium-scale hydroelectric power plants. According to the results, the efficiency value increases on average by approximately 1.5% compared to conventional design, and it operates with higher efficiencies over a wider flow rate range. In the second part of the study, machine learning was employed for the efficiency prediction of an inline-type turbine. An appropriate Artificial Neural Network (ANN) architecture was initially obtained, with the Bayesian Regularization training algorithm proving to be the best approach for this type of problem. When the suitable ANN architecture was utilized, the prediction was found to be in good agreement with CFD, with an root mean squared error value of 0.194. An R2 value of 0.99631 was achieved with the appropriate ANN architecture.Turkish Ministry of DevelopmentThe authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by the Turkish Ministry of Development
Choroidal Vascularity Index and Choroidal Thickness Assessment in Vitiligo
No full textBackground: To evaluate structural changes in the choroid by measuring choroidal thickness and vascularity index using optical coherence tomography in patients with vitiligo and comparing them to healthy subjects. Methods: This study included 168 participants: 84 with vitiligo (30 females, 54 males) and 84 controls (36 females, 48 males). Choroidal thickness and vascularity index were measured using the enhanced depth imaging mode in spectral-domain optical coherence tomography. The choroidal thickness was measured at the following five points; subfoveal (SF), 500 mu m (NCT1) and 1000 mu m (NCT2) nasal to the fovea; and 500 mu m (TCT1) and 1000 mu m (TCT2) temporal to the fovea. The choroidal vascularity index was calculated using the ImageJ software. Results: SF (p 0.001), NCT1 (p 0.001), NCT2 (p = 0.021), TCT1 (p = 0.001), and TCT2 (p 0.006) choroidal thicknesses were significantly smaller in the vitiligo group than in the control group. Total choroidal (p 0.001) and stromal (p 0.001) areas were significantly smaller in the vitiligo group than in the control group. Choroidal vascularity indices were significantly higher in the vitiligo group than in the control group (p 0.001). However, luminal areas did not differ significantly between groups (p = 0.935). Conclusion: Patients with vitiligo should be regularly monitored for choroidal alterations and, if necessary, referred to an ophthalmologist
Ankara Apartmanları: Architectural Representation & Reproduction In Social Media
No full textBu çalışma, Türkiye 20. yüzyıl modern mimarlığının önemli bir unsuru olan Ankara Apartmanları kavramını, tarihsel, kültürel ve sosyal boyutlarıyla birlikte dijital temsilleri üzerinden incelemektedir. Çalışma, mimari analizleri sosyal medya içeriklerinin eleştirel bir incelemesiyle birleştirerek Ankara Apartmanları kavramını hem fiziksel hem de kavramsal bir varlık olarak tanımlamayı ve genişletmeyi amaçlamaktadır. Araştırma, Ankara Apartmanları'nın fiziksel ve dijital temsillerini incelemek amacıyla tarihsel bağlam analizini ve sosyal medya içeriklerinin derinlemesine incelenmesini birleştiren kapsamlı bir yöntemsel çerçeve benimsemektedir. Tarihsel analiz, Türkiye'nin modernleşme sürecinde Ankara'daki apartman yapılaşmasının gelişimine dair içgörüler sunarken, sosyal medya analizi bu yapıların özellikle Instagram gibi platformlarda nasıl temsil edildiğini ve yeniden yorumlandığını incelemektedir. Bulgular, Ankara Apartmanları'nın yalnızca Türkiye'nin kentsel dönüşümünün fiziksel belirteçleri olarak değil, aynı zamanda mimari ayrıntılarının vurgulandığı, paylaşıldığı ve sıklıkla yeniden bağlamlandırıldığı dijital söylemin özneleri olarak da hizmet ettiğini ortaya koyuyor. Araştırma ayrıca kullanıcı etkileşim dinamiklerini ve bu dinamiklerin mimari anlatıların şekillenmesindeki rolünü anlamak için Instagram hesaplarını tematik gruplara ayırmaktadır. Temsildeki estetik unsurlar ve tarihsel bağlam gibi belirgin temaların öne çıkarıldığı kalıplar belirlenmiştir. Bu analizler, sosyal medyanın mimari temsili demokratikleştirmedeki rolünü vurgulamakta ve Ankara'nın mimari mirasıyla yeni etkileşim biçimlerini teşvik etmektedir. Bu araştırma, Ankara Apartmanları kavramının fiziksel ve dijital temsilleri arasındaki kesişimi anlamak için kapsamlı bir çerçeve sunmaktadır. Tarihsel mimari ile dijital medya arasındaki ilişkiyi ele alarak, kentsel kültürel belleğin korunması ve yeniden yorumlanmasına yönelik tartışmalara katkıda bulunmaktadır. Bulgular, dijital platformların mimarlık söylemini ve toplumsal katılımı nasıl etkilediğine dair eleştirel bir bakış sunmaktadır. Anahtar Kelimeler: Ankara Apartmanları, Mimari Temsil, Sosyal Medya, Dijital Mimari, Kentsel Bellek, Cumhuriyet Dönemi, Apartman Yapısı, Instagram, Mimari Üretim, Dijitalleşme, Görsel AnlatılarThis study investigates the concept of Ankara Apartmanları, a significant element of Turkey's mid-20th-century modernist architecture, focusing on its historical, cultural, and social dimensions alongside its digital representations. By integrating architectural analysis with a critical examination of social media content, the study seeks to define and expand the understanding of Ankara Apartmanları as a physical and conceptual entity. The research adopts a comprehensive methodological framework, integrating historical context analysis with an in-depth examination of social media content to explore the representation and evolution of Ankara Apartmanları in both physical and digital realms. Historical analysis provides insights into the development of Ankara's apartment buildings during Turkey's modernization process. In contrast, social media analysis examines how these buildings are represented and reinterpreted on platforms, particularly Instagram. The findings reveal that Ankara Apartmanları serve not only as physical markers of Turkey's urban transformation but also as subjects of digital discourse, where their architectural details are highlighted, shared, and often recontextualized. The study further categorizes Instagram accounts into thematic groups to understand the dynamics of user interactions and their role in shaping architectural narratives. It identifies patterns in the representation of Ankara Apartmanları, including the emphasis on specific aesthetic elements and historical contexts, which contribute to their contemporary cultural significance. These analyses underscore the role of social media in democratizing architectural representation and fostering new forms of engagement with Ankara's architectural heritage. This research offers a comprehensive framework for understanding the intersection of physical and digital representations of Ankara Apartmanları. By addressing the interplay between historical architecture and digital media, the study contributes to ongoing discussions on the preservation and reinterpretation of urban cultural memory in the digital age. The findings provide a critical perspective on how digital platforms influence public perception and participation in architectural discourse. Keywords: Ankara Apartmanları, Architectural Representation, Social Media, Digital Architecture, Urban Memory, Republican Era, Apartment Building, Instagram, Architectural Production, Digitalization, Visual Narrative
Synthesis and Characterization of Homogeneously Dispersed Graphene–copper Heterostructures With Enhanced Thermal Properties
No full textGraphene-reinforced copper composites have gained significant attention due to their exceptional properties and potential applications across various industries. This study presents a novel approach to synthesize 3D graphene–copper heterostructures using a plasma-enhanced chemical vapor deposition (PECVD) technique. The method involves encapsulating Cu powders with graphitic layers through PECVD at a low temperature of 400 °C to prevent copper powder agglomeration during the process, ensuring uniform graphene coating across the entire copper surface. Microstructural characterization of the resulting 3D graphene–copper heterostructures confirms successful encapsulation, with graphitic coating thicknesses ranging from 5–15 nm. The unique graphene-encapsulated Cu powder structure facilitates pressureless sintering, yielding consolidated composites with exceptional structural integrity. Metallographic analysis of the consolidated samples revealed a uniformly distributed multilayer graphitic network within the graphene–copper (G/Cu) composite structure. The presence of graphene between copper grains is found to inhibit copper grain growth, leading to smaller copper grains compared to graphene-free copper monoliths. Furthermore, the G/Cu composite had significantly reduced pore size and ensuant higher density when compared to the sample prepared without graphene encapsulation. Graphene’s lubricating effect is presumed to enhance the freedom of rotation for copper grains during sintering and cause increased densification. The thermal diffusivity of the graphene–copper heterostructure is measured as 1.38 cm2/s using thermal flash technique, representing an approximate 40% improvement compared to graphene-free copper. This enhancement in thermal conductivity is attributed to the presence of strongly bonded graphene layers between copper grains and additional thermal transport originating from graphitic interface. Thermal diffusivity was decreased monotonically with increasing temperature at temperature range 20–200 °C indicating prevalent phonon contribution. In the context of technological implications, successful synthesis of 3D graphene–copper heterostructures using scalable plasma-enhanced chemical vapor deposition (PECVD) technique establishes a foundation for the development of advanced materials with tailored properties and multifunctional applications, particularly those requiring lightweight characteristics, high transport properties (thermal or electrical), and exceptional mechanical strength. © 2023, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.Türkiye Bilimsel ve Teknolojik Araştırma Kurumu, TÜBİTAK: 118F49
A Fabrication Method for Memristors With Graphene Top Electrodes and Their Characterization
No full textIn recent years, there has been extensive research on the memristor, a non-volatile memory device that demonstrates effective emulation of biological synapses. The implementation of graphene as a top electrode in memristive switching systems presents an intriguing alterna- tive to conventional materials such as Platinum. Graphene, as a carbon-derived material, pos- sesses a remarkable area- to-volume ratio, biocompatibility, adsorption capabilities, and high electrical conductivity and thereby offers a promising avenue for the fabrication of biosen- sors with superior characteristics. This study reports a novel fabrication method of utilizing graphene as a top electrode in memristive devices. Characterization results of micrometric devices as well as larger memristive devices are also discussed. Larger devices show promising results to be used as memristive sensors. Microstructures have been fabricated successfully through developing a process flow and patterning graphene using photolithography and lift- off. E-beam evaporation and sputtering were used for depositing bottom metal electrodes and active layer respectively. Graphene was produced using the chemical vapor deposition (CVD) method and subsequently transferred using the fishing technique. Ultimately Pt/ TiO2/TiOx/Graphene memristive devices were fabricated
Fabrication of Anodic and Atomic Layer Deposition-Alumina Coated Titanium Implants for Effective Osteointegration Applications
No full textBiomimicking the chemical, mechanical, and topographical properties of bone on an implant model is crucial to obtain rapid and effective osteointegration, especially for the large-area fractures of the skeletal system. Titanium-based biomaterials are more frequently preferred in clinical use in such cases and coating these materials with oxide layers having chemical/nanotopographic properties to enhance osteointegration and implantation success rates has been studied for a long time. The objective of this study is to examine the high and rapid mineralization potential of anodized aluminum oxide (AAO) coated and atomic layer deposition (ALD)-alumina coated titanium substrates on large deformation areas with difficult spontaneous healing. AAO-coated titanium (AAO@Ti) substrates were fabricated via anodization technique in different electrolytes and their osteogenic potential was analyzed by comparing them to the bare titanium surface as a control. In order to investigate the effect of the ionic characters gained by the surfaces through anodization, the oxidized nanotopographic substrates were additionally coated with an ultrathin alumina layer via ALD (ALD@AAO@Ti), which is a sensitive and conformal coating vapor deposition technique. Besides, a bare titanium sample was also coated with pure alumina by ALD (ALD@Ti) to investigate the effect of nanoscale surface morphology. XPS analysis after ALD coating showed that the ionic character of each surface fabricated by anodization was successfully suppressed. In vitro studies demonstrated that, among the substrates investigated, the mineralization capacity of MG-63 osteosarcoma cells were highest when incubated on ALD-treated and bare AAO@Ti samples that were anodized in phosphoric acid (H3PO4_AAO@Ti and ALD@H3PO4_AAO@Ti). Mineralization on these substrates also increased consistently beginning from day 2 to day 21. Moreover, immunocytochemistry for osteopontin (OPN) demonstrated the highest expression for ALD@H3PO4_AAO@Ti, followed by the H3PO4_AAO@Ti sample. Consequently, it was observed that, although ALD treatment improves cellular characteristics on all samples, effective mineralization requires more than a simple ALD coating or the presence of a nanostructured topography. Overall, ALD@H3PO4_AAO@Ti substrates can be considered as an implant alternative with its enhanced osteogenic differentiation potential and rapid mineralization capacity.This study was funded by The Scientific and Technological Research Council of Turkey (TUBITAK, project number: 217 M643) and Sheikh Saleh Abdullah Kamel doctoral fellowship program.The Scientific and Technological Research Council of Turkey [217 M643]; Scientific and Technological Research Council of Turkey (TUBITAK
Yenilenebilir Enerji Güvenliği Bağlamında Kritik Mineral Tedariki: Devletlerin Ticaret Politikalarının Değerlendirilmesinde Çin Vakası
No full textBu tez, yenilenebilir ve temiz enerji teknolojilerine geçiş sürecinin önemli bir unsuru olan kritik mineral tedarikine yönelik ticaret politikalarını analiz etmektedir. Tezde, Uluslararası Politik Ekonomi (UPE) literatüründeki tartışmalara dayanarak, takip eden araştırma sorusu için devletlerin ticaret politikalarının tek bir kuramsal çerçeve ile bütüncül biçimde anlaşılamayacağı iddia edilmektedir: Enerji dönüşümü sürecinde yenilenebilir enerji arz güvenliğini sağlama doğrultusunda devletler nasıl bir ticaret politikası izlemektedir? Bu bağlamda, Ekonomi Diplomasisi ve Enerji Güvenliği literatüründeki yaklaşımlar sentezlenerek oluşturulan eklektik analitik çerçeve, UPE zemininde seçilen Çin vakasına uygulanmıştır. Çin'in güneş paneli, rüzgâr türbini ve elektrikli araç bataryası üretimi için ihtiyaç duyduğu bakır, kobalt, lityum, nadir toprak elementleri ve nikel minerallerini en yüksek miktarda tedarik ettiği ülkeler belirlenmiştir. Eklektik çerçeve doğrultusunda bu minerallerin tedarikine yönelik ticaret politikaları hem merkezi politikalar hem de ülke bazındaki politikalar açısından 2010-2021 yılları arasında analiz edilmiştir. Analiz yöntemi içerik analizidir. Tezin temel bulgusu, kritik minerallerin tedarikinde Realist, Liberal ve İnşacı kuramlarla açıklanan ve çeşitli amaçlar ve araçlarla karakterize edilen politikaların bir arada kullanıldığıdır. Dolayısıyla, kritik minerallerin tedarikinde UPE açısından ticaret politikasından ziyade ticaret politikalarının varlığı söz konusudur.This thesis analyses trade policies towards the supply of critical minerals as an essential element of the transition to renewable and clean energy technologies. The thesis, based on discussions in the International Political Economy (IPE) argues that states' trade policies cannot be understood holistically with a single theory for the following research question: What kind of trade policy do states pursue towards ensuring renewable energy supply security in the energy transition process? In this context, an eclectic analytical framework synthesising approaches from the Economic Diplomacy and Energy Security literatures is applied to the case of China, chosen based on IPE. The countries that supply the highest amounts of cobalt, copper, lithium, nickel, and rare earth elements that China needs to produce solar panels, wind turbines, and electric vehicle batteries have been identified. In alignment with the eclectic framework, trade policies for the supply of these minerals were analysed in terms of both central policies and country-specific policies between 2010 and 2021. The method of analysis employed is content analysis. The primary finding of the thesis is that a combination of policies, which can be explained by Realist, Liberal, and Constructivist theories and characterised by various aims and means, are used in the supply of critical minerals. Consequently, the supply of critical minerals involves a combination of trade policies rather than a single trade policy based on IPE
Studies of New Higgs Boson Interactions Through Nonresonant Hh Production in the B(b)over-Barγγ Final State in Pp Collisions at √s=13 Tev With the Atlas Detector
No full textA search for nonresonant Higgs boson pair production in the b (b) over bar gamma gamma final state is performed using 140 fb(-1) of proton-proton collisions at a centre-of-mass energy of 13 TeV recorded by the ATLAS detector at the CERN Large Hadron Collider. This analysis supersedes and expands upon the previous nonresonant ATLAS results in this final state based on the same data sample. The analysis strategy is optimised to probe anomalous values not only of the Higgs (H) boson self-coupling modifier kappa(lambda) but also of the quartic HHVV (V = W, Z) coupling modifier kappa(2V). No significant excess above the expected background from Standard Model processes is observed. An observed upper limit mu(HH) 4.0 is set at 95% confidence level on the Higgs boson pair production cross-section normalised to its Standard Model prediction. The 95% confidence intervals for the coupling modifiers are -1.4 kappa(lambda) 6.9 and -0.5 kappa(2V) 2.7, assuming all other Higgs boson couplings except the one under study are fixed to the Standard Model predictions. The results are interpreted in the Standard Model effective field theory and Higgs effective field theory frameworks in terms of constraints on the couplings of anomalous Higgs boson (self-)interactions.ANPCyT, Argentina; YerPhI, Armenia; ARC, Australia; BMWFW, Austria; FWF, Austria; ANAS, Azerbaijan; SSTC, Belarus; CNPq, Brazil; FAPESP, Brazil; NSERC, Canada; NRC, Canada; CFI, Canada; CERN; ANID, Chile; CAS, China; MOST, China; NSFC, China; Minciencias, Colombia; MEYS CR, Czech Republic; DNRF, Denmark; DNSRC, Denmark; IN2P3-CNRS, France; CEA-DRF/IRFU, France; SRNSFG, Georgia; BMBF, Germany; HGF, Germany; MPG, Germany; GSRI, Greece; RGC, China; Hong Kong SAR, China; ISF, Israel; Benoziyo Center, Israel; INFN, Italy; MEXT, Japan; JSPS, Japan; CNRST, Morocco; NWO, Netherlands; RCN, Norway; MEiN, Poland; FCT, Portugal; MNE/IFA, Romania; JINR; MES of Russia; NRC KI, Russian Federation; MESTD, Serbia; MSSR, Slovakia; ARRS, Slovenia; MIZS, Slovenia; DSI/NRF, South Africa; MICINN, Spain; SRC, Sweden; Wallenberg Foundation, Sweden; SERI, Switzerland; SNSF, Switzerland; Canton of Bern, Switzerland; Canton of Geneva, Switzerland; MOST, Taiwan; TENMAK, Turkiye; STFC, United Kingdom; DOE, United States of America; NSF, United States of America; BCKDF, Canada; CANARIE, Canada; Compute Canada, Canada; CRC, Canada; COST, European Union; ERC, European Union; ERDF, European Union; Horizon 2020, European Union; Marie Sklodowska-Curie Actions, European Union; Investissements d'Avenir Labex, France; Investissements d'Avenir Idex, France; ANR, France; DFG, Germany; AvH Foundation, Germany; Herakleitos programme - EU-ESF, Greece; Thales programme - EU-ESF, Greece; Aristeia programme - EU-ESF, Greece; Greek NSRF, Greece; BSF-NSF, Israel; GIF, Israel; Norwegian Financial Mechanism 2014-2021, Norway; NCN, Poland; NAWA, Poland; La Caixa Banking Foundation, Spain; CERCA Programme Generalitat de Catalunya, Spain; PROMETEO Programme Generalitat Valenciana, Spain; GenT Programme Generalitat Valenciana, Spain; Goran Gustafssons Stiftelse, Sweden; Royal Society, United Kingdom; Leverhulme Trust, United Kingdom; PRIMUS, Czech Republic [21/SCI/017]; UNCE, Czech Republic [SCI/013]We thank CERN for the very successful operation of the LHC, as well as the support staff from our institutions without whom ATLAS could not be operated efficiently. We acknowledge the support of ANPCyT, Argentina; YerPhI, Armenia; ARC, Australia; BMWFW and FWF, Austria; ANAS, Azerbaijan; CNPq and FAPESP, Brazil; NSERC, NRC and CFI, Canada; CERN; ANID, Chile; CAS, MOST and NSFC, China; Minciencias, Colombia; MEYS CR, Czech Republic; DNRF and DNSRC, Denmark; IN2P3-CNRS and CEA-DRF/IRFU, France; SRNSFG, Georgia; BMBF, HGF and MPG, Germany; GSRI, Greece; RGC and Hong Kong SAR, China; ISF and Benoziyo Center, Israel; INFN, Italy; MEXT and JSPS, Japan; CNRST, Morocco; NWO, Netherlands; RCN, Norway; MEiN, Poland; FCT, Portugal; MNE/IFA, Romania; MESTD, Serbia; MSSR, Slovakia; ARRS and MIZS, Slovenia; DSI/NRF, South Africa; MICINN, Spain; SRC and Wallenberg Foundation, Sweden; SERI, SNSF and Cantons of Bern and Geneva, Switzerland; MOST, Taiwan; TENMAK, Turkiye; STFC, United Kingdom; DOE and NSF, United States of America. In addition, individual groups and members have received support from BCKDF, CANARIE, Compute Canada and CRC, Canada; PRIMUS 21/SCI/017 and UNCE SCI/013, Czech Republic; COST, ERC, ERDF, Horizon 2020, ICSC-NextGenerationEU and Marie Skodowska-Curie Actions, European Union; Investissements d'Avenir Labex, Investissements d'Avenir Idex and ANR, France; DFG and AvH Foundation, Germany; Herakleitos, Thales and Aristeia programmes co-financed by EU-ESF and the Greek NSRF, Greece; BSF-NSF and MINERVA, Israel; Norwegian Financial Mechanism 2014-2021, Norway; NCN and NAWA, Poland; La Caixa Banking Foundation, CERCA Programme Generalitat de Catalunya and PROMETEO and GenT Programmes Generalitat Valenciana, Spain; Goran Gustafssons Stiftelse, Sweden; The Royal Society and Leverhulme Trust, United Kingdom. The crucial computing support from all WLCG partners is acknowledged gratefully, in particular from CERN, the ATLAS Tier-1 facilities at TRIUMF (Canada), NDGF (Denmark, Norway, Sweden), CC-IN2P3 (France), KIT/GridKA (Germany), INFN-CNAF (Italy), NL-T1 (Netherlands), PIC (Spain), ASGC (Taiwan), RAL (U.K.) and BNL (U.S.A.), the Tier-2 facilities worldwide and large non-WLCG resource providers. Major contributors of computing resources are listed in ref
Identifying SARS-CoV-2 Variants Using Single-Molecule Conductance Measurements
No full textThe global COVID-19 pandemic has highlighted the need for rapid, reliable, and efficient detection of biological agents and the necessity of tracking changes in genetic material as new SARS-CoV-2 variants emerge. Here, we demonstrate that RNA-based, single-molecule conductance experiments can be used to identify specific variants of SARS-CoV-2. To this end, we (i) select target sequences of interest for specific variants, (ii) utilize single-molecule break junction measurements to obtain conductance histograms for each sequence and its potential mutations, and (iii) employ the XGBoost machine learning classifier to rapidly identify the presence of target molecules in solution with a limited number of conductance traces. This approach allows high-specificity and high-sensitivity detection of RNA target sequences less than 20 base pairs in length by utilizing a complementary DNA probe capable of binding to the specific target. We use this approach to directly detect SARS-CoV-2 variants of concerns B.1.1.7 (Alpha), B.1.351 (Beta), B.1.617.2 (Delta), and B.1.1.529 (Omicron) and further demonstrate that the specific sequence conductance is sensitive to nucleotide mismatches, thus broadening the identification capabilities of the system. Thus, our experimental methodology detects specific SARS-CoV-2 variants, as well as recognizes the emergence of new variants as they arise.J.H. acknowledges funding support from the National Science Foundation Future Manufacturing Program, NSF-2036865/2328217 and the Keck Foundation. M.P.A. acknowledges NSF Semisyn bio grant number 2027165 and Future of Manufacturing grant number 2036865. The authors also acknowledge using TUBITAK ULAKBIM, High Performance and Grid Computing Center (TRUBA resources).National Science Foundation Future Manufacturing Program [NSF-2036865/2328217]; Keck Foundation; NSF Semisyn bio [2027165]; Future of Manufacturing [2036865