Optical control of electron spin coherence in CdTe/(Cd,Mg)Te quantum wells

Optical control of the spin coherence of quantum well electrons by short laser pulses with circular or linear polarization is studied experimentally and theoretically. For that purpose the coherent electron spin dynamics in a n-doped CdTe/(Cd,Mg)Te quantum well structure was measured by time-resolved pump-probe Kerr rotation, using resonant excitation of the negatively charged exciton (trion) state. The amplitude and phase shifts of the electron spin beat signal in an external magnetic field, that are induced by laser control pulses, depend on the pump-control delay and polarization of the control relative to the pump pulse. Additive and non-additive contributions to pump-induced signal due to the control are isolated experimentally. These contributions can be well described in the framework of a two-level model for the optical excitation of the resident electron to the trion.Comment: 15 pages, 18 figure

Spin dynamics of electrons and holes in InGaAs/GaAs quantum wells at milliKelvin temperatures

The carrier spin dynamics in a n-doped (In,Ga)As/GaAs quantum well has been studied by time-resolved Faraday rotation and ellipticity techniques in the temperature range down to 430 milliKelvin. These techniques give data with very different spectral dependencies, from which nonetheless consistent information on the spin dynamics can be obtained, in agreement with theoretical predictions. The mechanisms of long-lived spin coherence generation are discussed for the cases of trion and exciton resonant excitation. We demonstrate that carrier localization leads to a saturation of spin relaxation times at 45 ns for electrons below 4.5 K and at 2 ns for holes below 2.3 K. The underlying spin relaxation mechanisms are discussed.Comment: 8 pages, 8 figure

EVALUATION OF FCR THERAPY EFFICACY IN PATIENTS WITH CHRONIC LYMPHOCYTIC LEUKEMIA BASED ON IMMUNOGENETIC CRITERIA

A number of studies have shown that distinct common variants of the genes controlling immune/inflammatory response may affect efficiency of chronic lymphocytic leukemia (CLL) treatment. In a recently published paper, we reported polymorphic variants of some immune response genes in CLL patients to be associated with different rates of disease progression. Correlations between the distribution of gene modification profiles in indolent and agressive forms of CLL have been established. The present study describes results of pharmacogenetic studies aimed for identifying associations between the immune response genes polymorphism, and efficacy of FCR treatment regimen in CLL patients. 19 polymorphic loci of 14 immune response genes were studied in 33 patients with CLL who received FCR therapy. The TLR2, TLR3, TLR4, TLR6, TLR9, IL-1β, IL-2, IL-4, IL-6, IL-10, IL-17A, CD14, TNFα, FCGR2A genotypes were determined by polymerase chain reaction with allele-specific primers. CLL patients were divided into several groups depending on the terms of response to FCR treatment, i.e., achieving partial/complete remission after two, four, six courses of treatment, and those who did not respond to the therapy. Statistically significant differences in the distribution of haplotype frequencies were detected for the following genes: IL-1β (C-3953T, p = 0.02-0.009); IL-10 (C-819T, p = 0.04); IL-10 (G-1082A, p = 0.04-0.002-0.006), FCGR2A (His166Arg, p = 0.006); TLR4 (Thr399Ile, p = 0.02); TLR6 (Ser249Pro, p = 0.04); TLR9 (A2848G, p = 0.04-0.007); CD14 (C-159T, p = 0.03). When testing the significance hypothesis by multiple comparisons, the difference for the detected events was confirmed only for IL-10 gene (G-1082A, p < 0.01; χ2 = 20,082). The results show a relationship between the allelic status of the IL-10-1082 gene and the timing of response to FCR therapy, as well as predict a group of patients with primary-resistant CLL before treatment. The role of the relationship between IL-10 gene polymorphism and IL-10 production is discussed in connection with occurrence risk and clinical course of mature B-cell lymphoid malignancies. IL-10 is thought to be a growth factor for normal and transformed human B-lymphocytes, it controls a balance between cellular and humoral immune responses while exerting a pronounced immunosuppressive activity, along with ability to stimulate tumor cell proliferation. A rationale for conducting pharmacogenomic studies in CLL is provided, in order to predict efficiency of a specific drug or their combination in a distinct patient, thus representing chances to detect a factor which may influence success of the therapy since its earlier stage

Coherent spin relaxation in molecular magnets

Numerical modelling of coherent spin relaxation in nanomagnets, formed by magnetic molecules of high spins, is accomplished. Such a coherent spin dynamics can be realized in the presence of a resonant electric circuit coupled to the magnet. Computer simulations for a system of a large number of interacting spins is an efficient tool for studying the microscopic properties of such systems. Coherent spin relaxation is an ultrafast process, with the relaxation time that can be an order shorter than the transverse spin dephasing time. The influence of different system parameters on the relaxation process is analysed. The role of the sample geometry on the spin relaxation is investigated.Comment: Latex file, 22 pages, 7 figure

Effectiveness of pantoprazole for the treatment of erosive and ulcerative gastroduodenal lesions in patients taking dual antiplatelet therapy after emergency PCI

The effectiveness of proton pump inhibitors (PPIs) in patients with erosive and ulcerative lesions of the upper gastrointestinal tract (GIT), receiving dual antiplatelet therapy, is poorly evaluated. Aim. To determine the efficacy of PPIs in treatment of erosive and ulcerative lesions of stomach and duodenum in patients receiving dual antiplatelet therapy with aspirin and clopidogrel after urgent percutaneous coronary intervention (PCI) related to acute coronary syndromes (ACS). Methods. The study included 42 patients, whom urgent PCI related to ACS was performed. Duodenal and gastric erosive and ulcer lesions were found with gastroduodenoscopy in all of patients. Biopsy of antrum mucosae were evaluated to detect Helicobacter pilory (Hp). Repeated gastroduodenoscopy was provided through a month. Patients received dual antiplatelet therapy with aspirin and clopidogrel, and pantoprazole 40 mg per day for prevention of erosive-ulcer complications. Results. By gastroduodenoscopy 10-14 days after ACS erosive gastritis or duodenitis was identified in 38 (90,5%) patients, gastric ulcer - in 4 (9.5%) patients. Hp infection was detected in 62% of cases (26 patients). Abdominal pain and/or dyspeptic syndromes were noted in 18 (42,9%) patients. After one month clinical signs of abdominal and dyspeptic syndromes were eliminated in all of patients. There were no bleeding from the upper GIT. Complete epithelization of gastric and duodenal lesions was achieved in 22 (52.4%) patients. A significant inverse correlation was found between endoscopic criteria of effectiveness and Hp infection (r = - 0,36, p = 0.021), endoscopic criteria of effectiveness and smoking (r = - 0,5, p = 0.002). Conclusion. The short course of pantoprazole for treatment of erosive and ulcerative gastric and duodenal lesions in patients taking dual antiplatelet therapy after ACS and urgent PCI is effective only in half of cases. Smoking cessation and eradication therapy in the presence of Hp infection can enhance the efficacy of treatment.Эффективность ингибиторов протонной помпы (ИПП) у пациентов с зрозивно-язвенными поражениями верхних отделов желудочно-кишечного тракта (ЖКТ), принимающих двойную антитромбоцитарную терапию, изучена недостаточно. Цель. Оценка эффективности применения пантопразола при лечении эрозивно-язвенных поражений желудка и ДПК у пациентов, получающих двойную антитромбоцитарную терапию аспирином и клопидогрелем после проведения неотложных чрескожных коронарных вмешательств (ЧКВ) в связи с острыми коронарными синдромами (ОКС). Материалы и методы. Обследованы 42 пациента, которым в связи с ОКС проведено неотложное ЧКВ. У всех пациентов при фиброгастродуоденоскопии (ФГДС) выявлены эрозивно-язвенные поражения желудка и ДПК. Биоптаты слизистой антрального отдела желудка исследовались для выявления Helicobacter pilory (Нр). Повторная ФГДС проводилась через один месяц. Пациентам назначали двойную антитромбоцитарную терапию аспирином и клопидогрелем, а для профилактики эрозивно-язвенных осложнений - пантопразол 40 мг в сутки. Результаты. При проведении ФГДС через 10-14 дней после ОКС у 38 (90,5%) пациентов выявлен эрозивный гастрит или дуоденит, у 4 (9,5%) пациентов - язва желудка. Нр инфекция выявлена в 62% случаев (26 пациентов). Абдоминальный болевой и/или диспепсический синдромы отмечены у 18 (42,9%) больных. Через один месяц клинические проявления абдоминального болевого и диспепсического синдромов устранены у всех пациентов. Кровотечений из верхних отделов ЖКТ не отмечено. Полная эпителизация поражений желудка и ДПК достигнута у 22 (52,4%) пациентов. Выявлена достоверная обратная корреляция между эндоскопическим критерием эффективности и Нр инфекцией (г = - 0,36, р = 0,021), эндоскопическим критерием эффективности и курением (г = - 0,5, р = 0,002). Заключение. Короткий курс терапии пантопразолом при лечении эрозивно-язвенных поражений желудка и ДПК у пациентов, принимающих двойную антитромбоцитарную терапию после перенесенного ОКС и неотложного ЧКВ, эффективен лишь в половине случаев. Отказ от курения и проведение эрадикационной терапии при наличии Нр-инфекции могут способствовать повышению эффективности лечения

Comparative morphological characteristics of the uteroplacental area in abnormal placentation

The aim. To carry out a comparative morphological characteristic of the uteroplacental area with abnormal placentation – pl. accreta, pl. increta, pl. percreta. Materials and methods. The study included 47 patients with atypical placentation; the comparison group included 10 healthy pregnant women with uterine scar after a previous caesarean section. A histological study of uteroplacental area samples was performed with hematoxylin and eosin, methylene blue staining. An immunohistochemical study with primary antibodies to cytokeratin 7 (CK7), Hif2a, vascular endothelial growth factor, α-SMA was carried out. The differences between the compared values were considered to be statistically significant at p < 0.05. The results of the study. Pl. accreta was determined in 12 (25.5 %), pl. increta – in 30 (63.9 %), pl. percreta – in 5 (10.6 %) patients. In all patients of the main group, the decidua was completely or partially absent in the area of abnormal placentation or was replaced by an uneven layer of fetal fibrinoid. Cases when placental villi unevenly penetrated into the thickness of myometrium in the form of “tongues” or “coves” bordered by fetal fibrinoid and often located intermuscularly were defined as pl. increta (n = 26). Cases with the placental villi ingrowth to the serous membrane were considered as pl.  percreta (n  =  5). In cases with deep variants of  ingrowth (pl. increta and pl. percreta) (n = 31), the villi were visualized in the lumen of the vessels and the thinning of the lower uterine segment with the presence of stretched muscle bundles was revealed. Aseptic necrosis of  the myometrium was  found: in 2 (16.7 %) of 12 women with pl. accreta, in 26 (86.7 %) of 30 women with pl. increta and in 5 (100 %) women with pl. percreta. There were no areas of necrosis in the myometrium of the women of comparison group. Conclusion. The appearance and increase of myometrial necrosis zones in response to an increase in the depth of placental villus ingrowth were detected. Myometrial necrosis zones could be the cause of activation of angiogenic factors and an important stimulus for the development of abnormal vascularization in placenta accreta spectrum

Влияние комплекса хитозан-ß-циклодекстрин с левофлоксацином на микрофлору ран и толстого кишечника осетра

The authors in the article presented the results of determining the effectiveness of using the chitosan-ß-cyclodextrin complex with levofloxacin in the healing of mechanical wounds of valuable commercial fish sturgeons and their feeding. The experiment was conducted based on the “Progressive biotechnologies in aquaculture” research laboratory of the Saratov State University of Genetics, Biotechnology and Engineering. N.I. Vavilov. The microflora of incised wounds and the large intestine of sturgeon fingerlings under the influence of fluoroquinolone, represented by levofloxacin based on cyclodextrin, included in the shell of high-molecular chitosan, was studied. The studied microbiological indicators were chosen to determine that changes in the total number of microorganisms show the nature of the course of the inflammatory/pathological process, which contributes to the development of microorganisms (including opportunistic pathogens) and lactic acid bacteria in the intestine. Therefore, they are essential physiological indicators of the formation of “ intestinal immunity. It was found that the use of cyclodextrin with levofloxacin in the treatment of incised wounds in sturgeons leads to a significant decrease in the total microbial number (TMC) on their surface (by 10 thousand times compared to the group without treatment). It has been shown that using cyclodextrin with levofloxacin in feeding sturgeons reduces the total microbial number in the large intestine. This complex is characterised by good solubility and bioavailability for fish. The future study results can be used in aquaculture to treat mechanical injuries received during transportation and sorting in the rearing process in fish.Представлены результаты определения эффективности применения комплекса хитозан-ß-циклодекстрин с левофлоксацином в заживлении механических ран ценных промысловых рыб – осетров и их кормлении. Эксперимент проводили на базе научно-исследовательской лаборатории «Прогрессивные биотехнологии в аквакультуре» Саратовского государственного университета генетики, биотехнологии и инженерии им. Н.И. Вавилова. Исследовалась микрофлора резаных ран и толстого кишечника сеголетков осетров под действием фторхинолона, представленного левофлоксацином на основе циклодекстрина, включенного в оболочку высокомолекулярного хитозана. Исследуемые микробиологические показатели были выбраны для определения на том основании, что изменения общего количества микроорганизмов показывают характер течения воспалительного/патологического процесса, способствующего развитию микроорганизмов (в т.ч. условно-патогенных) и молочнокислых бактерий в кишечнике, поэтому являются важными физиологическими показателями формирования «кишечного иммунитета». Было обнаружено, что применение при лечении резаных ран у осетров циклодекстрина с левофлоксацином приводит к значительному уменьшению общего микробного числа (ОМЧ) на их поверхности (в 10 тыс. раз по сравнению с группой без лечения). Показано, что использование в кормлении осетров циклодекстрина с левофлоксацином также снижает общее микробное число в толстом кишечнике. Данный комплекс характеризуется хорошей растворимостью и биодоступностью для рыб. Результаты исследования в перспективе могут найти применение в аквакультуре при лечении механических травм, полученных при перевозке и сортировке в процессе выращивания, у рыб

Influence of addictions on stomatologic health and progress of students of higher education institutions

The work purpose - to study interrelation between the frequency of distribution of addictions and a state of health of students of higher education institutions. Examination of 365 students of stomatologic faculty of the Perm state medical university at the age of 21-26 years, and also 44 students of chemical faculty of the Perm state scientific research university at the age of 20-22 years is conducted. In the I gr. supervision special attention was paid on a condition of the mucous membrane of an oral cavity (MMOC) and the red border of lips (RBL) of the smoking students, and in the II gr. - on progress level depending on the frequency of distribution of addictions (smoking, alcohol intake). The obtained data confirm need of dispensary supervision over students, since their 1 st course in HIGHER EDUCATION INSTITUTION, and teachers should carry out an individual approach when carrying out teaching and educational work.Цель работы - изучить взаимосвязь между частотой распространения вредных привычек и состоянием здоровья студентов вузов. Проведено обследование 365 студентов стоматологического факультета Пермского государственного медицинского университета в возрасте 21-26 лет, а также 44 студентов химического факультета Пермского государственного научного исследовательского университета в возрасте 20-22 лет. В l-й гр. наблюдений особое внимание обращали на состояние слизистой оболочки полости рта (СОПР) и красной каймы губ (ККГ) курящих студентов, а во II-й гр. - на уровень успеваемости в зависимости от частоты распространения вредных привычек (курение, употребление алкоголя). Полученные данные свидетельствуют о необходимости диспансерного наблюдения за студентами, начиная с 1-го курса обучения их в ВУЗе, а преподавателям следует осуществлять индивидуальный подход при проведении учебно-воспитательной работы

Monochromatic electron photoemission from diamondoid monolayers

We found monochromatic electron photoemission from large-area self-assembled monolayers of a functionalized diamondoid, [121]tetramantane-6-thiol. Photoelectron spectra of the diamondoid monolayers exhibited a peak at the low-kinetic energy threshold; up to 68percent of all emitted electrons were emitted within this single energy peak. The intensity of the emission peak is indicative of diamondoids being negative electron affinity materials. With an energy distribution width of less than 0.5 electron volts, this source of monochromatic electrons may find application in technologies such as electron microscopy, electron beam lithography, and field-emission flatpanel displays