The multiple quantum NMR dynamics in systems of equivalent spins with the dipolar ordered initial state

The multiple quantum (MQ) NMR dynamics in the system of equivalent spins with the dipolar ordered initial state is considered. The high symmetry of the MQ Hamiltonian is used in order to develop the analytical and numerical methods for an investigation of the MQ NMR dynamics in the systems consisting of hundreds of spins from "the first principles". We obtain the dependence of the intensities of the MQ NMR coherences on their orders (profiles of the MQ NMR coherences) for the systems of $200 - 600$ spins. It is shown that these profiles may be well approximated by the exponential distribution functions. We also compare the MQ NMR dynamics in the systems of equivalent spins having two different initial states, namely the dipolar ordered state and the thermal equilibrium state in the strong external magnetic field.Comment: 11 pages 4 figure

Luminescence evidence for bulk and surface excitons in free xenon clusters

Cathodoluminescence spectra of free xenon clusters produced by condensation of xenon-argon gas mixtures in supersonic jets expanding into vacuum were studied. By varying initial experimental parameters, including xenon concentration, we could obtain clusters with a xenon core (300-3500 atoms) covered by an argon outer shell as well as shell-free xenon clusters (about 1500 atoms). The cluster size and temperature (about 40 K for both cases) were measured electronographically. Luminescence bands evidencing the existence of bulk and surface excitons were detected for shell-free xenon clusters. The emission from bulk excitons in small clusters is supposed to be due to processes of their multiple elastic reflections from the xenon-vacuum interface. A presence of an argon shell causes extinction of the excitonic bands. In addition, some new bands were found which have no analogs for bulk xenon cryosamples.Comment: The final modified version will be published in Phys. Rev. A 76 (2007

INFLUENCE OF HERBICIDES QUALITY ROYAL ROOTS AND SUGAR BEET SEEDS PROCESSING OF CROPS QUEEN

Research on the effect of herbicides against dicotyledonous weeds Betanal Extra and against grass weeds Centurion on uterine beet growth and development is widely used on sugar beet.No significant difference according to the rules and types of herbicides as ChS component and pollinators and polyspermous for fractional composition of roots was found. The basic amount of ChS component of uterine plants was 150 g from 66 to 72%, polyspermous pollinators - from 46 to 72%, which can be planted by existing planting machines. In the meantime, as on the control such roots by the components were 66 and 42% respectively. However, negative influence of these herbicides on seed biometric indicators, which uterine plants were treated with, wasn’t set. Significant violations of ploidy of uterine beet plant components were determined. Uterine sugar beet treatment with maximum dose of herbicides is recommended for sugar beet sowings, the number of diploids is decreased by 51.3–54.2%, while the number of miksploids is increased in 3,9–4,1 times in comparison with the control. The least chromosomal device change is undergone by the uterine plants processing of Betanal Expert herbicide in norm 1 l/ha. Seed analysis showed that even with such significant violations of ploidy of uterine sugar beet plant components, there is no significant influence of herbicides on seed quality, especially for its purity. Using Extra Betanal herbicide as completely norm and as half of the norm, from the recommended rate and Centurion herbicide half norm from the recommended has not led to germination and purity of seed decreasing. Germination of seed was 66–72% (66% in control), purity - 96,1–97,6% in control 96.6% (LSD05 = 2.6%)

Study of the Forces Acting on the Animal in the Installation for Fixing with Veterinary Treatments

The study of the forces acting on the animal in the installation for fixing with veterinary treatments. The most time consuming processes in service animals are zootechnical and veterinary treatment of sheep. During the year, it is necessary to carry out more than ten such treatments of each animal, which requires a lot of labor. Almost all animal treatments such as feed to the operator’s workplace and their fixation in a convenient position for him requires significant physical effort of the operator. Therefore, today the technologies and technical means should be created to reduce labor costs for various treatments. The relevance of the problem is due to the lack of theoretical foundations and experimental data for the creation of technological equipment for fixing sheep in zootechnical and veterinary treatments. The purpose of the study is the theoretical and experimental justification of the installation for fixing sheep in zootechnical and veterinary treatments with the justification of the existing efforts on the animal, excluding injury. Developed installation and presented a scheme with two of the conveyor belts forming the grooved shape When designing the installation, the main focus was on the justification of structural elements and modes of operation from the viewpoint of eliminating the possibility of injury to the animal. The experimental studies have confirmed the correctness of the obtained analytical dependences. The obtained results will enable designers to create equipment for the fixation of sheep at the zootechnical and veterinary treatments, precluding injury to the animal and reducing labor costs

Multiple-Quantum Spin Dynamics of Entanglement

Dynamics of entanglement is investigated on the basis of exactly solvable models of multiple-quantum (MQ) NMR spin dynamics. It is shown that the time evolution of MQ coherences of systems of coupled nuclear spins in solids is directly connected with dynamics of the quantum entanglement. We studied analytically dynamics of entangled states for two- and three-spin systems coupled by the dipole-dipole interaction. In this case dynamics of the quantum entanglement is uniquely determined by the time evolution of MQ coherences of the second order. The real part of the density matrix describing MQ dynamics in solids is responsible for MQ coherences of the zeroth order while its imaginary part is responsible for the second order. Thus, one can conclude that dynamics of the entanglement is connected with transitions from the real part of the density matrix to the imaginary one and vice versa. A pure state which generalizes the GHZ and W states is found. Different measures of the entanglement of this state are analyzed for three-partite systems.Comment: 11 pages, 4 figure

Direct observation of free excitons in luminescence spectra of xenon clusters

Luminescence of surface and free bulk excitons is detected in xenon for the first time for substrate-free rare-gas clusters. Xenon clusters were produced by the method of gas condensation in a supersonic jet emitted into vacuum. Optical study was accompanied by electron diffraction measurements to determine the structure of clusters.Comment: The more complete version of the paper is to be published in 'Low Temperature Physics' (2007

NMR multiple quantum coherences in quasi-one-dimensional spin systems: Comparison with ideal spin-chain dynamics

The 19F spins in a crystal of fluorapatite have often been used to experimentally approximate a one-dimensional spin system. Under suitable multi-pulse control, the nuclear spin dynamics may be modeled to first approximation by a double-quantum one-dimensional Hamiltonian, which is analytically solvable for nearest-neighbor couplings. Here, we use solid-state nuclear magnetic resonance techniques to investigate the multiple quantum coherence dynamics of fluorapatite, with an emphasis on understanding the region of validity for such a simplified picture. Using experimental, numerical, and analytical methods, we explore the effects of long-range intra-chain couplings, cross-chain couplings, as well as couplings to a spin environment, all of which tend to damp the oscillations of the multiple quantum coherence signal at sufficiently long times. Our analysis characterizes the extent to which fluorapatite can faithfully simulate a one-dimensional quantum wire.Comment: 14 pages, 11 eps color figure

Функциональное состояние кардиореспираторной системы после ортотопической трансплантации сердца с длительной холодовой ишемией трансплантата

Objective: to assess the functional state of the cardiorespiratory system in the long term after orthotopic heart transplantation (HT) with prolonged cold ischemia time. Materials and methods. The results of 60 orthotopic HTs performed at Meshalkin National Medical Research Center were analyzed. A comparison was made of the immediate and long-term outcomes of HTs in the group with cold ischemia time lasting for less than 240 minutes and in those with farther distance between donor and recipient sites with cold ischemia time of 240 minutes or more. In the long-term follow-up after HT, all patients underwent cardiopulmonary exercise testing, body plethysmography, assessment of the diffusing capacity of the lungs, and quality of life assessment. Results. Prolonged cold ischemia showed a negative effect on the early postoperative period – decreased myocardial contractility on postoperative day 1 and longer duration of inotropic support. At the same time, the survival rate and incidence of graft rejection reactions in the early and late post-HT periods in the studied groups did not differ significantly. Peak oxygen consumption in the general group in the long term after HT was 17 (14.7–21.0) mL/kg/min, VE/ VCO2 slope was 30 (29–36) at 100 (90–120) W threshold load power. All the parameters of pulmonary function tests did not differ significantly depending on cold ischemia duration. Quality of life also did not show significant differences depending on the duration of graft ischemia in terms of both physical and psycho-emotional health components of the SF-36 questionnaire. Conclusion. Long-term cold ischemia of the graft did not show any negative impact on the functional state of the cardiorespiratory system and quality of life in the long term after HT. The studied group of recipients was characterized by high efficiency of pulmonary ventilation and gas exchange, as well as high tolerance to physical activity in the long-term post-HT period.Цель. Оценка функционального состояния кардиореспираторной системы в отдаленные сроки после ортотопической трансплантации сердца (ТС) с длительной холодовой ишемией трансплантата. Материалы и методы. Проанализированы результаты 60 ортотопических ТС, выполненных в ФГБУ «НМИЦ им. акад. Е.Н. Мешалкина» Минздрава России. Проведено сравнение непосредственных и отдаленных результатов ТС в группах с холодовой ишемией трансплантата менее 240 минут и при дистанционном изъятии с холодовой ишемией 240 минут и более. В отдаленные сроки после ТС всем пациентам проведено кардиопульмональное нагрузочное тестирование, бодиплетизмография, оценка диффузионной способности легких, оценка качества жизни. Результаты. Длительная холодовая ишемия донорского сердца показала негативное влияние на ранний послеоперационный период ТС в виде снижения сократительной способности миокарда в первые сутки после операции и увеличения длительности инотропной поддержки. При этом выживаемость и частота развития реакций отторжения трансплантата в ранние и отдаленные сроки после ТС в изучаемых группах значимо не различалась. Пиковое потребление кислорода в отдаленные сроки после ТС в общей группе составило 17 (14,7–21,0) мл/мин/кг, VE/VCO2 slope – 30 (29–36) при пороговой мощности нагрузки 100 (90–120) Вт. Все параметры легочных функциональных тестов не имели значимых отличий в зависимости от длительности холодовой ишемии. Качество жизни также не показало значимых различий в зависимости от длительности ишемии трансплантата как по физическому, так и психоэмоциональному компонентам здоровья опросника SF-36. Заключение. Длительная холодовая ишемия трансплантата не показала отрицательного влияния на функциональное состояние кардиореспираторной системы и качество жизни в отдаленные сроки после ТС. Изучаемая группа реципиентов характеризовалась высокой эффективностью легочной вентиляции и газообмена, а также высокой толерантностью к физическим нагрузкам в отдаленные сроки после ТС

Modern approaches to production of safe and effective genetically modified rabies vaccines for animals

Rabies is a dangerous zoonoticdisease that affects the central nervous system, causes encephalomyelitis and paralyses and Is almost invariably fatal. The disease causes significant economic losses associated with the death of animals, outbreak consequences, strict restrictions on domestic and international trade in livestock products, preventive and quarantine measures, laboratory tests. The World Organization for Animal Health recommends vaccination to control rabies. Taking into account that there is a lack of affordable high-quality vaccines to globally prevent and control the disease, stable, attenuated production strains of rabies virus with broad cross-activity against various variants of the pathogen shall be considered as ideal candidates to produce high-quality, safe and effective vaccines. Currently, someapproachesareappliedtoreducethevirusvirulenceandimprovesafetyof rabies vaccines. Reverse genetics is very popular now. It provides new approaches to study functions of a specific gene by analyzing phenotypic effects after direct manipulations with nucleotide sequences. The methods of reverse genetics have revolutionized molecular biology and have become apowerful tool to study genetics of RNA viruses. These methods are widely used to study rabies virus. The use of reverse genetics has made it possible to modify rabies virus production strains for manufacture of modern genetically modified rabies vaccines that induce a persistent and long-term immunity. The review briefly covers general approaches to development of viral vectors with the purpose to create genetically modified rabies vaccines