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In vivo assessment of structural changes of the urethra in lower urinary tract disease using cross-polarization optical coherence tomography

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Journal of Innovative Optical Health Sciences 2020年第6期3卷 55-70页

作者： Elena B.Kiseleva Alexander A.Moiseev Anton S.Kuyarov Muhammat A.Molvi grigory v.gelikonov Anna v.Maslennikova Olga S.Streltsova Privolzhsky Research Medical University 10/1 Minin and Pozharsky Square 603005 Nizhny NovgorodRussia Institute of Applied Physics Russian Academy of Sciences Ulyanova Street 46603950Nizhny NovgorodRussia

The paper presents the results of a study of the female urethra in cases of urethral pain syndrome(UPS)and inflammatory diseases of the lower urinary tract using cross-polarization optical coherence tomography(CP OCT).Urethral wall structure was studied in 86 patients;233 CP OCT images were collected.A comparative qualitative analysis of three groups of CP OCT images—"norm","Inflammation"and"UPS"—identified that despite the absence of a clear inflammatory factor in the patient's examination,the urethral tissues in UPS were in an altered *** changes in the urethral wall with UPS and in cases of inflammation were *** a point scale,three experts independently performed visual scoring of the CP OCT *** parameters:epithelial contrast,cavities and the minimum signal depth in the co-channel were *** was found that,individually,the parameters correlate only weakly with the *** under the receiver operating characteristic(ROC)curve was from 0.51 to *** joint use of a number of visual signs has a greater diagnostic value than the use of the criteria *** under the ROC curve using the developed cumulative criterion reached up to *** study could form the basis of a scoring system for assessing the state of the urethral tract using CP OCT images in real *** CP OCT method provides information on the state of urethral tissues that cannot be obtained with traditional cystoscopy.

关键词： Cross-polarization optical coherence tomography urethral pain syndrome connective tissue visual analysis of images automatic classification of images

Practical obstacles and their mitigation strategies in compressional optical coherence elastography of biological tissues

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Journal of Innovative Optical Health Sciences 2017年第6期10卷 51-63页

作者： vladimir Y.Zaitsev Alexandr L.Matveyev Lev A.Matveev Ekaterina v.Gubarkova Alexandr A.Sovetsky Marina A.Sirotkina grigory v.gelikonov Elena v.Zagaynova Natalia D.Gladkova Alex vitkin Institute of Applied Physics Russian Academy of Sciences Ulyanova Street 46 Nizhny Novgorod 603950 Russia Nizhny Novgorod State Medical Academy 10/1 Minina Square Nizhny Novgorod 603005 Russia University of Toronto and University Health Network 610 University Avenue Toronto ON M5G 2M9Canada

In this paper,we point out some practical obstacles arising in realization of compressional optical coherence elastography(OCE)that have not attracted sufficient attention ***-cally,we discuss(i)complications in quantification of the Young modulus of tissues related to partial adhesion between the OCE probe and soft intervening reference layer sensor,(i)distorting influence of tisue suface curvature/corrugation on the subsurface strain distri-bution mapping,(ii)ways of signal-to-noise mtio(SNR)enhancement in OCE strain mapping when periodic averaging is not realized,and(iv)potentially significant infuence of tissue elastic nonlinearity on quantification of its *** pnactical approaches to mitigate the effects of these complications are also described.

关键词： Optical coherence elastography optical coherence tomography phase-resolved methods strain mapping stiffness characterization

Medium chromatic dispersion spectral-domain optical calculation and correction in coherence tomography

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Frontiers of Optoelectronics 2017年第3期10卷 323-328页

作者： vasily A. MATKIvSKY Alexander A. MOISEEv Sergey Yu. KSENOFONTOv Irina v. KASATKINA grigory v. gelikonov Dmitry v. SHABANOv Pavel A. SHILYAGIN valentine M. gelikonov Institute of Applied Physics Russian Academy of Sciences Nizhny Novgorod 603950 Russia

A method for determining and correcting distortions in spectral-domain optical coherence tomography images caused by medium dispersion was developed. The method is based on analysis of the phase distribution of the interference signal recorded by an optical coherence tomography device using an iterative approach to find and compensate for the effect of a medium＇s chromatic dispersion on point-spread function broadening in optical coherence tomography. This enables compensation of the impact of medium dispersion to an accuracy of a fraction of a radian （units of percent） while avoiding additional measurements and solution of the optimization problem. The robustness of the method was demonstrated experimentally using model and biological objects.

关键词： optical coherence tomography (OCT) dispersion image resolution restoration

Assessment on facile Diels-Alder approach of α-pyrone and terpenoquinone for the expedient synthesis of various natural scaffolds

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Natural Products and Bioprospecting 2022年第1期12卷 137-157页

作者： Aluru Rammohan Albert F.Khasanov Dmitry S.Kopchuk Duvvuru Gunasekar grigory v.Zyryanov Oleg N.Chupakhin Ural Federal University 19 Mira St.Ekaterinburg 620002Russian Federation Natural Products Division Department of ChemistrySri Venkateswara UniversityTirupati 517502India Ural Division of the Russian Academy of Sciences I.Ya.Postovsky Institute of Organic Synthesis22 S.Kovalevskoy St.Ekaterinburg 620219Russian Federation

The development of highly facile synthetic procedures for the expedient synthesis of complex natural molecules is always in *** this aspect,the Diels-Alder reaction(DAR)has a versatile approach to the synthesis of complex natural compounds and highly regio-/stereoselcetive heterocyclic ***,α-pyrone and terpeno-quinone are two versatile key intermediates that are prevalent in various bioactive natural compounds for instance,(±)-crinine,(±)-joubertinamine,(±)-pancratistatin,(−)-cyclozonarone,and 8-ephipuupehedione,***,the current review summarizes the Diels-Alder reaction application ofα-pyrone and terpenoquinone to the construc-tive synthesis of various natural products over the past two decades(2001-2021).Equally,it serves as a stencil for the invention and development of new synthetic strategies for high-complex molecular structured natural and heterocy-clic molecules.

关键词： α-Pyrone Diels-Alder reaction(DAR) Marine natural compounds Terpenoquinone Total synthesis

Giant non-linear susceptibility of hydrogenic donors in silicon and germanium

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Light(Science & Applications) 2019年第1期8卷 624-630页

作者： Nguyen H.Le grigory v.Lanskii Gabriel Aeppli Benedict N.Murdin Advanced Technology Institute and SEPNet University of SurreyGuildford GU27XHUK Institute of Monitoring of Climatic and Ecological Systems SB RAS 10/3 Academical Ave.Tomsk 634055Russia Laboratory for Solid State Physics ETH ZurichZurich CH-8093Switzerland Institut de Physique EPF LausanneLausanne CH-1015Switzerland Paul Scherrer Institut VilligenPSI CH-5232Switzerland

Implicit summation is a technique for the conversion of sums over intermediate states in multiphoton absorption and the high-order susceptibility in hydrogen into simple ***,we derive the equivalent technique for hydrogenic impurities in multi-valley *** the absorption has useful applications,it is primarily a loss process;conversely,the non-linear susceptibility is a crucial parameter for active photonic *** Si:P,we predict the hyperpolarizability ranges from χ^((3))/n_(3D)=2.9 to 580×10^(−38 )m^(5)/v^(2) depending on the frequency,even while avoiding *** samples of a reasonable density,n3D,and thickness,L,to produce thirdharmonic generation at 9 THz,a frequency that is difficult to produce with existing solid-state sources,we predict that χ^((3)) should exceed that of bulk InSb and χ^((3))L should exceed that of graphene and resonantly enhanced quantum wells.

关键词： susceptibility hydrogenic absorption

Pendulum-type laser strainmeter

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Earthquake Science 2015年第4期28卷 311-317页

作者： grigory Ivanovich Dolgikh v.I.Il'ichev Pacific Oceanological Institute of the Far Eastern Branch Russian Academy of Sciences

Constructive disposition principles of the basic optical units of Michelson interferometers are used in making one-coordinate laser strainmeters of unequal-arm type. The fundamental advantages of pendulurn-type laser ... 详细信息

关键词： Amplitude-frequency characteristic Classical-type laser strainmeter Elastic wave Infrasound Pendulum-type laser strainmeter

A Finite Difference Scheme on a Priori Adapted Meshes for a Singularly Perturbed Parabolic Convection-Diffusion Equation

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Numerical Mathematics(Theory,Methods and Applications) 2008年第2期1卷 214-234页

作者： grigory I.Shishkin Institute of Mathematics and Mechanics Ural Branch of Russian Academy of Sciences

A boundary value problem is considered for a singularly perturbed parabolic convection-diffusion equation;we construct a finite difference scheme on a priori (se-quentially) adapted meshes and study its *** scheme on a priori adapted meshes is constructed using a majorant function for the singular component of the discrete solution,which allows us to find a priori a subdomain where the computed solution requires a further *** subdomain is defined by the perturbation parameterε,the step-size of a uniform mesh in x,and also by the required accuracy of the discrete solution and the prescribed number of refinement iterations K for im- proving the *** solve the discrete problems aimed at the improvement of the solution,we use uniform meshes on the *** error of the numerical so- lution depends weakly on the parameterε.The scheme converges almostε-uniformly, precisely,under the condition N^(-1)=o(ε~v),where N denotes the number of nodes in the spatial mesh,and the value v=v(K) can be chosen arbitrarily small for suitable K.

关键词：有限微分奇异扰动对流扩散问题收敛性

An efficient synthetic approach towards new 5,5'-diaryl-2,2'-bipyridine-based fluorophores

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Chinese Chemical Letters 2017年第5期28卷 1099-1103页

作者： Alexey P.Krinochkin Dmitry S.Kopchuk Nikolay v.Chepchugov grigory A.Kim Igor S.Kovalev Matiur Rahman grigory v.Zyryanov Adinath Majee vladimir L.Rusinov Oleg N.Chupakhin Ural Federal University Yekaterinburg 620002Russian Federation Postovsky Institute of Organic Synthesis of RAS(Ural Division) Yekaterinhurg 620990Russian Federation Department of Chemistry Visva-Bharati(A Central University)Santiniketan 731235India

An efficient approach has been developed for the synthesis of 5,5＇-diaryl-2,2＇-bipyridines via their 1,2,4-triazine *** notable advantages of the present method are：The possibility of varying the aromatic substituents in the positions 5 and 5＇ of bipyridine core and the possibility for obtaining 2,2＇-bipyridines bearing a fused cyclopentene core to increase the solubility in organic *** 5,5＇-diaryl-2,2＇-bipyridines exhibited an intense emission in a range of ca.422-521 nm in acetonitrile solution;depending on the nature of the aromatic substituents and the presence of annulated cyclopentene *** from that,the significant bathochromic shifts of the both absorption and emission maxima were observed in comparison with a number of previously described similar *** some cases the significant increasing of the fluorescence quantum yields took place.

关键词： 2 2'-Bipyridines 1 2 4-Triazines Aza-Diels-Alder reaction Fluorescence

Assessing workability of greased bearings after long-term storage

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Friction 2019年第5期7卷 489-496页

作者： Michael vARENBERG Yuri KLIGERMAN grigory HALPERIN Saad NAKAD Haytam KASEM George W.Woodruff School of Mechanical Engineering Georgia Institute of TechnologyAtlantaGA30332USA Department of Mechanical Engineering Technion-Israel Institute of TechnologyHaifa32000Israel Department of Mechanical Engineering Azrieli College of EngineeringJerusalem9103501Israel

Here, we developed a technique to assess the workability of sealed-for-life greased rolling bearings after a long-term storage. In this framework, we devised a model of equivalent transition between the conditions of natural ageing under daily and seasonally fluctuating temperature, and the conditions of accelerated thermal ageing at a constant high temperature. The tested bearings were thermally aged, and then their steady state friction and outer ring temperature were examined in a custom high-speed spindle. These results were compared to the performance of a reference new bearing tested under the same loading conditions. Our findings suggest that long-term storage can significantly degrade the performance of sealed-for-life greased rolling bearings. However, a proper running-in can substantially deter the ageing-driven degradation of the bearings.

关键词： grease lubrication ball bearings thermal ageing lubricant degradation