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

Categoricity Spectra for Rigid Structures

© 2016 by University of Notre Dame. For a computable structure M, the categoricity spectrum is the set of all Turing degrees capable of computing isomorphisms among arbitrary computable copies of M. If the spectrum has a least degree, this degree is called the degree of categoricity of M. In this paper we investigate spectra of categoricity for computable rigid structures. In particular, we give examples of rigid structures without degrees of categoricity

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

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

Phosphate-modified CpG oligonucleotides induce in vitro maturation of human myeloid dendritic cells

Myeloid dendritic cells (DCs) play an important role in the immune response; therefore, the search for compounds that can effectively activate DCs is a needful goal. This study was aimed to investigate the effect of synthetic CpG oligodeoxynucleotides (CpG-ODN) on the maturation and allostimulatory activity of myeloid DCs in comparison with other PAMP and DAMP molecules. For the research, we synthesized known CpG-ODN class C (SD-101 and D-SL03) containing thiophosphate internucleotide groups, and their original phosphate-modified analogues (SD-101M and D-SL03M) with mesylphosphoramide internucleotide groups (M = μ-modification). The effects of CpG-ODN and other activators were evaluated on DCs generated from blood monocytes in the presence of GM-CSF and IFN-α (IFN-DC) or IL-4 (IL4-DC). Evaluation of the intracellular TLR-9 expression showed that both types of DCs (IFN-DC and IL4-DC) contained on average 52 and 80 % of TLR-9-positive cells, respectively. The CpG-ODNs studied enhanced the allostimulatory activity of IFN-DCs, and the effect of μ-modified CpG-ODNs was higher than that of CpG-ODNs with thiophosphate groups. The stimulating effect of CpG-ODN at a dose of 1.0 μg/ml was comparable (for D-SL03, D-SL03M, SD-101) with or exceeded (for SD-101M) the effect of LPS at a dose of 10 μg/ml. At the same time, IFN-DCs were characterized by greater sensitivity to the action of CpG-ODNs than IL4-DCs. The enhancement of DC allostimulatory activity in the presence of CpG-ODNs was associated with the induction of final DC maturation, which was confirmed by a significant decrease in the number of CD14+DC, an increase in mature CD83+DC and a trend towards an increase in CD86+DC. Interestingly, the characteristic ability of LPS to enhance the expression of the co-stimulatory molecule OX40L on DCs was revealed only for the μ-analogue SD-101M. In addition, CpG-ODNs (SD-101 and SD-101M) had a stimulatory effect on IFN-γ production comparable to the action of LPS. The data obtained indicate a stimulating effect of CpG-ODN on the maturation and allostimulatory activity of human myeloid DCs, which is more pronounced for μ-modified analogs

Измерение разности назальных потенциалов — новый, информативный тест для диагностики муковисцидоза

An attempt was undertaken to evaluate peculiarities of biophysical phenotype of the basic cystic fibrosis (CF) defect in 21 cystic fibrosis patients from 5 to 41 years old. CF patients have demonstrated markedly more negative potential difference (NPD) across nasal epithelium than 15 patients of non-CF control group. The mean NPD of C F patients was 44.7±2.2 mV (range -32.5 to -68.9 mV), in the control group it was 17.2±1.8 mV. The method of the nasal PD measuring is acceptable and rapidly performed and may provide an additional tool for CF diagnosing.Была предпринята попытка оценить особенности биофизического фенотипа основного дефекта муковисцидоза у 21 больного в возрасте от 5 лет до 41 года. У лиц, страдающих муковисцидозом, были получены более выраженные отрицательные величины разности назальных потенциалов (nasal Potential Difference — NPD), чем у больных, страдающих хроническими неспецифическими заболеваниями легких (ХНЗЛ) контрольной группы. Средние значения NPD в группе больных муковисцидозом составили -44,7±2,2 мВ (от-32,5 мВ до -68,9 мВ), в контрольной группе -17,2±1,8 мВ (от-6,8 мВ до -30,2 мВ). Метод измерения NPD является легко и быстро выполнимым, может быть рекомендован в качестве дополнительного теста для диагностики муковисцидоза

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

The use of nonsteroidal anti-inflammatory drugs for the treatment of facial pain in practice

Studies have shown that the drug ibuprofen is effective for the relief of pain in the facial area, allowing the continuation of dental treatment. Clinical experience has shown that 87% of patients were satisfied with the result of pain relief.Проведенные исследования показали, что препарат ибупрофен является эффектив-ными для купирования болевого синдрома в лицевой области, что позволяет дальнейшее проведение стоматологического лечения. Клинический опыт показал, что 87% пациентов были удовлетворены результатом снятия болевого синдрома

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