One approach to factorization of positive integers

Factorization of positive integers into primes is a hard computational task. Its complexity lies in the base of the most popular method of cryptography, the RSA method. In this paper we propose a new technique in a factorization procedure which combines ideas of the Number Field Sieve (NFS) and the Quadratic Sieve (QS) in a special manner. © Allerton Press, Inc., 2011

Susceptibility of various cell lines to the <i>Chikungunya virus</i> and method selection for commercial-scale production of viral material

An increase in cases of chikungunya fever is reported in the Caribbean, Central and South America, and Southeast Asia. As there is no specific treatment for this disease and the only available treatment is symptomatic, it is very relevant to develop vaccines against chikungunya fever. To develop an inactivated whole-virion vaccine against the disease, it is important to choose a susceptible cell culture that both provides high virus yields and is used for vaccine production.The aim of the study was to evaluate the susceptibility of multiple cell lines to Chikungunya virus infection and to select the monolayer culture method with the highest virus accumulation and yield.Materials and methods. The study used the CHIKV_Nic strain of the Chikungunya virus and cell lines C6/36 (for virus titration), CEF, MRC-5, Vero, and 4647. While choosing the culture method, the authors used culture flasks, a cell factory, and roller bottles. The authors determined the susceptibility of the cell lines to viral infection by the degree of accumulation of the infectious agent in the culture fluid. The results of virus titration were calculated on day 5 on the basis of a pronounced viral cytopathic effect.Results. The Vero and 4647 cell lines demonstrated the highest susceptibility to infection and virus concentrations in the culture fluid. The СEF and MRC-5 cell lines accumulated the virus at lower concentrations. The maximum virus titres (7.10–7.75 log10 TCID50/mL) were observed in the culture fluid 48 h after infection. The optimal multiplicity of infection (MOI) ranged between 0.001 and 0.0001 MOI/cell. At 0.0001 MOI/cell, the virus accumulated in the Vero cells cultured in roller bottles on day 2, with the maximum virus titre being 8.6±0.2 log10 TCID50/mL.Conclusions. Vero cells meet the safety and stability requirements set for the production of chikungunya vaccines. The study determined the minimum MOI of the Chikungunya virus for cell culture. The roller bottle culture method provides the highest cell culture yield and the highest titre of the virus in the culture fluid

Towards effective COVID\u201119 vaccines: Updates, perspectives and challenges (Review)

In the current context of the pandemic triggered by SARS-COV-2, the immunization of the population through vaccination is recognized as a public health priority. In the case of SARS\u2011COV\u20112, the genetic sequencing was done quickly, in one month. Since then, worldwide research has focused on obtaining a vaccine. This has a major economic impact because new technological platforms and advanced genetic engineering procedures are required to obtain a COVID\u201119 vaccine. The most difficult scientific challenge for this future vaccine obtained in the laboratory is the proof of clinical safety and efficacy. The biggest challenge of manufacturing is the construction and validation of production platforms capable of making the vaccine on a large scale

Development of Biocompatible Glass Substrate With Surface Nanotopography

The work was performed according to the Russian Government Program of Competitive Growth of Kazan Federal University and funded by the Russian Presidential grant MК-4498.2018.

Чувствительность клеточных линий к вирусу Чикунгунья и подбор метода наработки вирусного материала в промышленных объемах

An increase in cases of chikungunya fever is reported in the Caribbean, Central and South America, and Southeast Asia. As there is no specific treatment for this disease and the only available treatment is symptomatic, it is very relevant to develop vaccines against chikungunya fever. To develop an inactivated whole-virion vaccine against the disease, it is important to choose a susceptible cell culture that both provides high virus yields and is used for vaccine production.The aim of the study was to evaluate the susceptibility of multiple cell lines to Chikungunya virus infection and to select the monolayer culture method with the highest virus accumulation and yield.Materials and methods. The study used the CHIKV_Nic strain of the Chikungunya virus and cell lines C6/36 (for virus titration), CEF, MRC-5, Vero, and 4647. While choosing the culture method, the authors used culture flasks, a cell factory, and roller bottles. The authors determined the susceptibility of the cell lines to viral infection by the degree of accumulation of the infectious agent in the culture fluid. The results of virus titration were calculated on day 5 on the basis of a pronounced viral cytopathic effect.Results. The Vero and 4647 cell lines demonstrated the highest susceptibility to infection and virus concentrations in the culture fluid. The СEF and MRC-5 cell lines accumulated the virus at lower concentrations. The maximum virus titres (7.10–7.75 log10 TCID50/mL) were observed in the culture fluid 48 h after infection. The optimal multiplicity of infection (MOI) ranged between 0.001 and 0.0001 MOI/cell. At 0.0001 MOI/cell, the virus accumulated in the Vero cells cultured in roller bottles on day 2, with the maximum virus titre being 8.6±0.2 log10 TCID50/mL.Conclusions. Vero cells meet the safety and stability requirements set for the production of chikungunya vaccines. The study determined the minimum MOI of the Chikungunya virus for cell culture. The roller bottle culture method provides the highest cell culture yield and the highest titre of the virus in the culture fluid.Рост случаев заболевания лихорадкой Чикунгунья регистрируется в странах Карибского бассейна, Центральной и Южной Америки и Юго-Восточной Азии. Специфического лечения против этого заболевания нет, лечение проводится симптоматическое, что делает разработку вакцин против лихорадки Чикунгунья весьма актуальной. Для разработки инактивированной цельновирионной вакцины против лихорадки Чикунгунья важен выбор чувствительной культуры клеток, которая обеспечивает высокую продукцию вируса, а также используется в производстве вакцинных препаратов.Цель работы: изучение чувствительности различных линий клеток к заражению вирусом Чикунгунья и подбор метода культивирования клеток для максимального накопления и сбора вируса с монослоя.Материалы и методы: в работе использовали вирус Чикунгунья штамм CHIKV_Nic, линии клеток ФЭК, MRC-5, Vero и 4647; титрование проводили на клетках линии С6/36. При подборе метода культивирования использовали культуральный флакон, клеточную фабрику, роллерную бутыль. Чувствительность клеточных линий к репродукции вируса выявляли по степени накопления инфекционного агента в культуральной жидкости (КЖ). Результат титрования учитывали на 5 сут по выраженному цитопатическому действию вируса.Результаты: наибольшую чувствительность к заражению и максимальное накопление вируса в КЖ продемонстрировали клеточные линии 4647 и Vero. Клетки линий ФЭК и MRC-5 накапливали вирус в меньших концентрациях. Максимальные титры накопления вируса в КЖ клеточной линии Vero (7,10–7,75 lg ТЦД50/мл) отмечались через 48 ч с момента заражения; оптимальной является множественность заражения (MOI) в диапазоне 0,001– 0,0001 MOI/кл. При множественности заражения 0,0001 MOI/кл накопление вируса в клетках линии Vero при роллерном культивировании происходит на 2 сут с максимальным титром вируса 8,6±0,2 lg ТЦД50/мл.Выводы: линия клеток Vero соответствует требованиям стабильности и безопасности при производстве вакцины против лихорадки Чикунгунья. Определена минимальная множественность заражения культуры клеток вирусом Чикунгунья. Применение роллерного метода позволяет получить наиболее высокий выход клеточной культуры и, соответственно, наиболее высокое значение титра вируса в КЖ

Fluorescence and cytotoxicity of cadmium sulfide quantum dots stabilized on clay nanotubes

© 2018 by the authors. Licensee MDPI, Basel, Switzerland. Quantum dots (QD) are widely used for cellular labeling due to enhanced brightness, resistance to photobleaching, and multicolor light emissions. CdS and CdxZn1−xS nanoparticles with sizes of 6–8 nm were synthesized via a ligand assisted technique inside and outside of 50 nm diameter halloysite clay nanotubes (QD were immobilized on the tube’s surface). The halloysite– QD composites were tested by labeling human skin fibroblasts and prostate cancer cells. In human cell cultures, halloysite–QD systems were internalized by living cells, and demonstrated intense and stable fluorescence combined with pronounced nanotube light scattering. The best signal stability was observed for QD that were synthesized externally on the amino-grafted halloysite. The best cell viability was observed for CdxZn1−xS QD immobilized onto the azine-grafted halloysite. The possibility to use QD clay nanotube core-shell nanoarchitectures for the intracellular labeling was demonstrated. A pronounced scattering and fluorescence by halloysite–QD systems allows for their promising usage as markers for biomedical applications

Search for squarks and gluinos in events with isolated leptons, jets and missing transverse momentum at s√=8 TeV with the ATLAS detector

The results of a search for supersymmetry in final states containing at least one isolated lepton (electron or muon), jets and large missing transverse momentum with the ATLAS detector at the Large Hadron Collider are reported. The search is based on proton-proton collision data at a centre-of-mass energy s√=8 TeV collected in 2012, corresponding to an integrated luminosity of 20 fb−1. No significant excess above the Standard Model expectation is observed. Limits are set on supersymmetric particle masses for various supersymmetric models. Depending on the model, the search excludes gluino masses up to 1.32 TeV and squark masses up to 840 GeV. Limits are also set on the parameters of a minimal universal extra dimension model, excluding a compactification radius of 1/R c = 950 GeV for a cut-off scale times radius (ΛR c) of approximately 30

Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal

Evidence for the Higgs-boson Yukawa coupling to tau leptons with the ATLAS detector

Results of a search for H → τ τ decays are presented, based on the full set of proton-proton collision data recorded by the ATLAS experiment at the LHC during 2011 and 2012. The data correspond to integrated luminosities of 4.5 fb−1 and 20.3 fb−1 at centre-of-mass energies of √s = 7 TeV and √s = 8 TeV respectively. All combinations of leptonic (τ → `νν¯ with ` = e, µ) and hadronic (τ → hadrons ν) tau decays are considered. An excess of events over the expected background from other Standard Model processes is found with an observed (expected) significance of 4.5 (3.4) standard deviations. This excess provides evidence for the direct coupling of the recently discovered Higgs boson to fermions. The measured signal strength, normalised to the Standard Model expectation, of µ = 1.43 +0.43 −0.37 is consistent with the predicted Yukawa coupling strength in the Standard Model

Measurements of fiducial and differential cross sections for Higgs boson production in the diphoton decay channel at s√=8 TeV with ATLAS

Measurements of fiducial and differential cross sections are presented for Higgs boson production in proton-proton collisions at a centre-of-mass energy of s√=8 TeV. The analysis is performed in the H → γγ decay channel using 20.3 fb−1 of data recorded by the ATLAS experiment at the CERN Large Hadron Collider. The signal is extracted using a fit to the diphoton invariant mass spectrum assuming that the width of the resonance is much smaller than the experimental resolution. The signal yields are corrected for the effects of detector inefficiency and resolution. The pp → H → γγ fiducial cross section is measured to be 43.2 ±9.4(stat.) − 2.9 + 3.2 (syst.) ±1.2(lumi)fb for a Higgs boson of mass 125.4GeV decaying to two isolated photons that have transverse momentum greater than 35% and 25% of the diphoton invariant mass and each with absolute pseudorapidity less than 2.37. Four additional fiducial cross sections and two cross-section limits are presented in phase space regions that test the theoretical modelling of different Higgs boson production mechanisms, or are sensitive to physics beyond the Standard Model. Differential cross sections are also presented, as a function of variables related to the diphoton kinematics and the jet activity produced in the Higgs boson events. The observed spectra are statistically limited but broadly in line with the theoretical expectations