Dark-field spectroscopy of plasmon resonance in metal nanoislands: effect of shape and light polarization

Abstract We present the experimental dark-field scattering studies and the simulation of plasmonic properties of isolated silver nanoislands. The nanoislands were fabricated on a soda- lime glass substrate using silver-sodium ion exchange, subsequent thermal poling and annealing of the processed glass substrate in hydrogen. The morphology of the nanoislands was characterized with atomic force microscopy and scanning electron microscopy; the dimensions were 100-180 nm in base and 80-160 nm in height. We measured and modeled dark-field scattering spectra of the silver hemiellipsoidal nanoparticles differing in size and shape. The SPR position varied from 450 nm to 730 nm depending on the particle shape and dimensions. Both experiments and simulation showed a red shift of the SPR for bigger nanoislands of the same shape. Losing the axial symmetry in nanoislands resulted in the resonance splitting, while their elongation led to an increase in the scattering of p-polarized light

MODELING OF INERTIA MOMENTS FORMATION FOR ELECTROSTATIC GYROSCOPE ROTORS

Subject of Research.The paper proposes principles, conditions and technical solutions of the creation process for moments of inertia of spherical rotors based on the mass redistribution of functional coatings formed on the rotor surface. We study the formation technology of the required values and the ratio of the axial and equatorial moments of inertia of the spherical rotor that is a main constructive element of electrostatic gyro. Traditional forming methods of the moments of inertia of solid spherical rotors are based on embedding reinforcing elements made of materials with higher density than the substrate in the body of the rotor. It can be realized by pressing the wire segments or by diffusion welding of the rotor assembly units. In this case the rotor consists of several components, and reinforcing elements, embedded in the body of the rotor create inhomogeneities and anisotropy of the assembly properties. This fact reduces the accuracy and negatively affects the dynamics of the rotor in the suspension. Existing methods also have limitations in terms of the possibility of nonmetallic material application for production of the rotor. Method. We propose an alternative method for formation of rotor moment of inertia based on the mass redistribution of thin-film functional coatings formed on rotor surface. It can be used for metals and nonmetallic materials. Mathematical models for realization of the proposed method are presented. Main Results. The developed mathematical models determine the dependence of moments of inertia on the geometric parameters of rotor elements and reveal significant factors controlling the process of formation of moments of inertia. Technical solutions for different rotor configurations are considered. A rotor can be realized as an ellipsoid of rotation, a ball with removed material in the shape of a spherical belt and a ball with an equatorial groove, with the following spherical-shape recovery during coating deposition. Practical Relevance. We present comparative analysis of the application efficiency for considered configurations and practical data, received from the production of rotors made of various materials.The mathematical models are developed that determine the variation ranges of the rotor geometric parameters and expand the technological capabilities of the formation process for moments of inertia through the use of various alternative versions of the manufacture of rotors

Affine extension of noncrystallographic Coxeter groups and quasicrystals

Unique affine extensions H^{\aff}_2, H^{\aff}_3 and H^{\aff}_4 are determined for the noncrystallographic Coxeter groups $H_2$, $H_3$ and $H_4$. They are used for the construction of new mathematical models for quasicrystal fragments with 10-fold symmetry. The case of H^{\aff}_2 corresponding to planar point sets is discussed in detail. In contrast to the cut-and-project scheme we obtain by construction finite point sets, which grow with a model specific growth parameter.Comment: (27 pages, to appear in J. Phys. A

FEATURES OF DIAGNOSTIC AND THERAPEUTIC TACTICS FOR BLUNT ABDOMINAL TRAUMA WITH DAMAGE TO THE PANCREAS

Abstract. Injuries of pancreas in the closed abdominal trauma remain the one of most challenging issues in diagnosis and choice of optimal therapy.Objectives. To analyze clinical results of the improved diagnostic and treatment tactics in patients with blunt abdominal trauma and damage to the pancreas.Material and methods. We report the results of treatment for 141 patients with pancreatic trauma treated from 1991 to 2015 at City Hospital No. 3 and City Hospital No. 40. All patients were divided into 2 groups. These groups were formed according to the time factor. The groups were comparable in age, gender, and pancreatic trauma severity. The study group consisted of 59 patients, treated in 2004-2015, and the comparison group consisted of 82 patients (1991–2003). The advanced diagnostic and treatment algorithm for the study group included modern instrumental diagnostic methods, such as ultrasound, computed tomography, diagnostic laparoscopy and improved surgical tactics to lower indications for omental plug, omentobursostomy, suturing capsule of pancreas and cholecystostomy.Results. This algorithm reduced the duration gap between hospitalization and surgery averagely from 10.7 to 4.0 hours, and the modified treatment tactics decreased the incidence of septic complications from 15.8% to 6.8%, and the mortality from 27.6% to 16.9%.Conclusion. As a rule, methods of radiodiagnosis detect only indirect signs of pancreatic injury in blunt abdominal trauma. It is advisable to perform omental plugging only as medical tactics of «damage control»

ОСОБЕННОСТИ ЛЕЧЕБНО-ДИАГНОСТИЧЕСКОЙ ТАКТИКИ ПРИ ЗАКРЫТОЙ ТРАВМЕ ЖИВОТА С ПОВРЕЖДЕНИЕМ ПОДЖЕЛУДОЧНОЙ ЖЕЛЕЗЫ

Abstract. Injuries of pancreas in the closed abdominal trauma remain the one of most challenging issues in diagnosis and choice of optimal therapy.Objectives. To analyze clinical results of the improved diagnostic and treatment tactics in patients with blunt abdominal trauma and damage to the pancreas.Material and methods. We report the results of treatment for 141 patients with pancreatic trauma treated from 1991 to 2015 at City Hospital No. 3 and City Hospital No. 40. All patients were divided into 2 groups. These groups were formed according to the time factor. The groups were comparable in age, gender, and pancreatic trauma severity. The study group consisted of 59 patients, treated in 2004-2015, and the comparison group consisted of 82 patients (1991–2003). The advanced diagnostic and treatment algorithm for the study group included modern instrumental diagnostic methods, such as ultrasound, computed tomography, diagnostic laparoscopy and improved surgical tactics to lower indications for omental plug, omentobursostomy, suturing capsule of pancreas and cholecystostomy.Results. This algorithm reduced the duration gap between hospitalization and surgery averagely from 10.7 to 4.0 hours, and the modified treatment tactics decreased the incidence of septic complications from 15.8% to 6.8%, and the mortality from 27.6% to 16.9%.Conclusion. As a rule, methods of radiodiagnosis detect only indirect signs of pancreatic injury in blunt abdominal trauma. It is advisable to perform omental plugging only as medical tactics of «damage control».Резюме. Травматические повреждения поджелудочной железы (ПЖ) при закрытой травме живота по трудности диагностики и выбора оптимальной лечебной тактики остаются одними из самых сложных среди травм органов брюшной полости.Цель. Анализ клинических результатов усовершенствованной лечебно-диагностической тактики у пострадавших с закрытой травмой живота с повреждением ПЖ.Материал и методы. Представлены результаты лечения 141 пострадавшего с закрытой травмой ПЖ, находившихся на лечении в городских больницах № 3 и № 40 города Санкт-Петербурга с 1991 по 2015 г. Все пациенты были разделены на 2 группы. Группы сформированы по временному фактору и были сопоставимы по половому и возрастному признакам, а также по тяжести повреждений ПЖ. Группу исследования составили 59 пострадавших, пролеченных в период с 2004 по 2015 г., группу срав- нения — 82 пациента (1991–2003 гг.). В основной группе в диагностический алгоритм были включены современные инструментальные методы диагностики, такие как ультразвуковое исследование, компьютерная томография, диагностическая лапароскопия, а также усовершенствована хирургическая тактика — сокращены показания к тампонированию, оментобурсостомии, отказ от ушивания капсулы железы, холецистостомии.Результаты. Использование данного диагностического алгоритма уменьшило время, проходящее от момента госпитализации до оказания пострадавшему оперативного пособия в среднем с 10,7 до 4,0 ч, а усовершенствование лечебной тактики снизило частоту гнойно-септических осложнений с 15,8 до 6,8%, а также общую летальность с 27,6 до 16,9%.Заключение. Методы лучевой диагностики как правило позволяют выявить лишь косвенные признаки повреждения ПЖ при закрытой травме живота. С целью уменьшения риска развития гнойно-септических осложнений целесообразно ограничить использование тампонирования сальниковой сумки лишь рамками лечебной тактики «damage control»

Identification of Novel Candidate Markers of Type 2 Diabetes and Obesity in Russia by Exome Sequencing with a Limited Sample Size

Type 2 diabetes (T2D) and obesity are common chronic disorders with multifactorial etiology. In our study, we performed an exome sequencing analysis of 110 patients of Russian ethnicity together with a multi-perspective approach based on biologically meaningful filtering criteria to detect novel candidate variants and loci for T2D and obesity. We have identified several known single nucleotide polymorphisms (SNPs) as markers for obesity (rs11960429), T2D (rs9379084, rs1126930), and body mass index (BMI) (rs11553746, rs1956549 and rs7195386) (p < 0.05). We show that a method based on scoring of case-specific variants together with selection of protein-altering variants can allow for the interrogation of novel and known candidate markers of T2D and obesity in small samples. Using this method, we identified rs328 in LPL (p = 0.023), rs11863726 in HBQ1 (p = 8 × 10−5), rs112984085 in VAV3 (p = 4.8 × 10−4) for T2D and obesity, rs6271 in DBH (p = 0.043), rs62618693 in QSER1 (p = 0.021), rs61758785 in RAD51B (p = 1.7 × 10−4), rs34042554 in PCDHA1 (p = 1 × 10−4), and rs144183813 in PLEKHA5 (p = 1.7 × 10−4) for obesity; and rs9379084 in RREB1 (p = 0.042), rs2233984 in C6orf15 (p = 0.030), rs61737764 in ITGB6 (p = 0.035), rs17801742 in COL2A1 (p = 8.5 × 10−5), and rs685523 in ADAMTS13 (p = 1 × 10−6) for T2D as important susceptibility loci in Russian population. Our results demonstrate the effectiveness of whole exome sequencing (WES) technologies for searching for novel markers of multifactorial diseases in cohorts of limited size in poorly studied populations

ПРОГНОСТИЧЕСКИЕ БИОМАРКЕРЫ НЕОПЛАЗИИ ЖЕЛУДОЧНО-КИШЕЧНОГО ТРАКТА

In the era of personalized treatment, oncologists are striving to tailor medical treatment to the characteristics of the individual patient, emphasizing the importance of a continuous search for accurate biomarkers. Prognostic biomarkers reflect the intricate underlying biology that enables cancer to progress. Intratumoral heterogeneity includes genetic, epigenetic and functional heterogeneity. Genetic intratumoral heterogeneity is a consequence of clonal evolution and a cause of disease progression. During the oncogenesis process, genetic aberrations accumulate continuously, result of this process is that tumors are genetically heterogeneous, with a plurality of coexisting clones that vary over time. Herewith specific mutations are associated with particular stages of tumor development, correlates with specific histopathological disease stages. Many patients with colorectal cancer have disease recurrence after resection of the tumor despite adjuvant therapy, while some patients don’t have a relapse despite the absence of treatment. Identifying reliable predictors of outcome after resection is a universal problem. So the reassessment of the current criteria and better prognostic and predictive biomarkers for the selection of patients who might benefit from adjuvant chemotherapy are urgently needed. A prognostic biomarker reflects the natural history of the tumor and provides information on the likely outcome and prognosis, independent of a specific treatment. Predictive biomarkers indicate the sensitivity or resistance of the tumor to a given treatment. Some markers can be both prognostic and predictive. Gene mutations and epigenetic aberrations that modify the intracellular signaling pathways may be important factors in oncogenesis. In this context, oncogenes, genes – tumor suppressors and small non-coding RNA have attracted attention as potential biomarkers and regulators of oncogenesis and evaluate in clinical trials.В эпоху персонализированного лечения онкологи стремятся адаптировать лечение к особенностям конкретного пациента, подчеркивая важность непрерывного поиска точных биомаркеров. Прогностические биомаркеры отражают сложную биологию, которая позволяет раковой опухоли прогрессировать. Внутриопухолевая гетерогенность включает в себя генетическую, эпигенетическую и функциональную. Генетическая внутриопухолевая гетерогенность является следствием клональной эволюции и причиной прогрессирования заболевания. В процессе онкогенеза постоянно накапливаются генетические аберрации, в результате чего раковые опухоли становятся генетически гетерогенными, с множеством сосуществующих клонов, меняющихся с течением времени. При этом специфические мутации ассоциированы с определенными стадиями развития опухоли, которые коррелируют с соответствующими гистопатологическими стадиями заболевания. Многие пациенты с колоректальным раком после резекции опухоли имеют рецидив заболевания, несмотря на проведение адъювантной терапии, в то время как у некоторых пациентов не происходит рецидива, несмотря на отсутствие лечения. Выявление надежных предикторов исхода после резекции остается важной проблемой, поэтому срочно необходимы переоценка существующих критериев и поиск новых прогностических и предиктивных биомаркеров для отбора пациентов, которые могли бы получить пользу от адъювантной химиотерапии. Прогностический биомаркер отражает естественную историю развития опухоли и предоставляет информацию о вероятном исходе и прогнозе независимо от специфического лечения. Предиктивные биомаркеры указывают на чувствительность или резистентность опухоли к определенному лечению. Некоторые биомаркеры могут быть одновременно прогностическими и предиктивными. Генные мутации и эпигенетические аберрации, изменяющие внутриклеточные сигнальные пути, могут быть важными факторами онкогенеза. В этом контексте онкогены, гены-супрессоры опухолей и малые некодирующие молекулы РНК привлекают внимание в качестве потенциальных регуляторов и биомаркеров онкогенеза и оцениваются в клинических исследованиях

Cyclotomic Gaudin models, Miura opers and flag varieties

Let g be a semisimple Lie algebra over C. Let ν∈Autg be a diagram automorphism whose order divides T∈Z≥1. We define cyclotomic g-opers over the Riemann sphere P1 as gauge equivalence classes of g-valued connections of a certain form, equivariant under actions of the cyclic group Z/TZ on g and P1. It reduces to the usual notion of g-opers when T=1. We also extend the notion of Miura g-opers to the cyclotomic setting. To any cyclotomic Miura g-oper ∇ we associate a corresponding cyclotomic g-oper. Let ∇ have residue at the origin given by a ν-invariant rational dominant coweight λˇ0 and be monodromy-free on a cover of P1. We prove that the subset of all cyclotomic Miura g-opers associated with the same cyclotomic g-oper as ∇ is isomorphic to the ϑ-invariant subset of the full flag variety of the adjoint group G of g, where the automorphism ϑ depends on ν, T and λˇ0. The big cell of the latter is isomorphic to Nϑ, the ϑ-invariant subgroup of the unipotent subgroup N⊂G, which we identify with those cyclotomic Miura g-opers whose residue at the origin is the same as that of ∇. In particular, the cyclotomic generation procedure recently introduced in [arXiv:1505.07582] is interpreted as taking ∇ to other cyclotomic Miura g-opers corresponding to elements of Nϑ associated with simple root generators. We motivate the introduction of cyclotomic g-opers by formulating two conjectures which relate them to the cyclotomic Gaudin model of [arXiv:1409.6937]