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

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

Quality of life of patients with different forms of hemophilia on the example of Nizhny Novgorod region

It is important for public health to monitor and improve the health indicators of the population using the system of patient's quality of life (HRQoL) assessment regardless of the nosology of the disease. The use of HRQoL assessment provides health authorities with a tool for additional analysis of the performance of health services and for making decisions about funding priorities. The definition of HRQoL is one of the decisive factors in the calculation of QALYs because it measures the effectiveness of medical treatment in terms of how much it prolongs and/or improves patients' lives. The aim of the study is to determine the QALYs of hemophilia patients in Nizhny Novgorod region by means of electronic questionnaire using the SF-36 questionnaire. Methods. A validated SF-36 short form questionnaire was used in the study, which was distributed to adult patients with hemophilia A, B and Willebrand's disease of Nizhny Novgorod region together with a short form of informed voluntary consent. Twenty-eight people participated in the questionnaire. Calculation of general and final indicators of the HRQoL was carried out according to the instructions for processing data obtained with the SF-36 questionnaire. Results. The lowest score among all respondents was for GH "General Health Status" with a mean value of 61.00, and the highest score was for PF "Physical Functioning" with a mean value of 81.43. The study revealed that the majority of the surveyed patients were receiving Emicizumab (42.86 %). After comparing the ranges of values of the final indicators of physical (PH) and mental (MN') health in patients with different forms of hemophilia, the highest values of HRQoL indicators are observed in patients with hemophilia B, and the highest range of extreme values — in patients with hemophilia A. Conclusion. Patients with different forms of hemophilia are determined to have satisfactory values of HRQoL indicators, as all the results obtained in the course of the questionnaire are above the average value of the indicators. Mean HRQoL scores in patients receiving emicizumab are at a similar level compared to patients receiving other LPs, and fluctuations in HRQoL scores in these patients are less marked than in the other patients with hemophilia A

Economic analysis of the use of drugs for the treatment of hemophilia A, B and Willebrand's disease

Relevance. Therapy of hemophilia A, B and Willebrand's disease is carried out under the program of 14 VZN due to the use of federal budget funds. The use of funding is increasing in line with the growth of the total number of patients. In 2022,85.99 billion rubles were allocated, which corresponds to a 1.5‑fold increase in funding compared to 2018. The aim of the study was to conduct an economic analysis of the use of drugs for the therapy of hemophilia A, B and Willebrand's disease. Methods. The materials for the analysis were the dosing regimen of LPs selected on the basis of clinical recommendations, the availability of LPs in the 14 VZN program, and the prices for LPs from the State Register of maximum selling prices for VED drugs. Costs of on demand prophylaxis and treatment regimens for hemophilia A, B and Willebrand's disease according to clinical recommendations for each INN for all trade names (TN) were assessed. Results. For hemophilia A the number of submitted drugs by INN is 7;IN — 14; of them domestic drugs were submitted — 1. The minimum cost of LPs for prophylaxis is 2 584 764,00 rubles. Coit-DVI (Grifols Therapeutics LLC, USA), and the maximum cost is RUR 9,955,517.21. Advait (Takeda Manufacturing AG, Austria). Forhemophilia B, the number of represented PL — 2 INN; INN — 6; domestic drugs — 2. The minimum cost is RUR 1,559,376.00. Innonafactor (AO Generium, Russia), maximum — 3 079 319,88 rubles for a year course of prophylaxis LP Immunin (TakedaManufacturing, Austria). To stop bleeding in patients with inhibitor form use anti-inhibitor coagulant complex (Feiba, Austria), which is necessary on average 9100 units per 1 patient, and the average cost of application — 430 863,52 rubles or eptacog alpha(activated) (Coagil-VII, Russia) at multiple administration to the patient 6 times a day — maximum cost — 2 739 803,64 rubles or once a day — 293 550,35 rubles. Conclusion. In the structure of drug supply for patients with hemophilia, domestic drugs are represented by 5 names: Octofactor (JSC "Generium", Russia); Agemfil B (FGBU "NMIC Hematology" of the Ministry of Health of Russia, Russia) and Innonafactor (JSC "Generium", Russia); ArioSaven (LLC "PSK Pharma", Russia) and Coagil-VII (JSC "SG Biotech", Russia). There are no domestic drugs available for the therapy of Willebrand's disease

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

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

Mechanism of Disruption of the Amt-GlnK Complex by PII-Mediated Sensing of 2-Oxoglutarate

GlnK proteins regulate the active uptake of ammonium by Amt transport proteins by inserting their regulatory T-loops into the transport channels of the Amt trimer and physically blocking substrate passage. They sense the cellular nitrogen status through 2-oxoglutarate, and the energy level of the cell by binding both ATP and ADP with different affinities. The hyperthermophilic euryarchaeon Archaeoglobus fulgidus possesses three Amt proteins, each encoded in an operon with a GlnK ortholog. One of these proteins, GlnK2 was recently found to be incapable of binding 2-OG, and in order to understand the implications of this finding we conducted a detailed structural and functional analysis of a second GlnK protein from A. fulgidus, GlnK3. Contrary to Af-GlnK2 this protein was able to bind both ATP/2-OG and ADP to yield inactive and functional states, respectively. Due to the thermostable nature of the protein we could observe the exact positioning of the notoriously flexible T-loops and explain the binding behavior of GlnK proteins to their interaction partner, the Amt proteins. A thermodynamic analysis of these binding events using microcalorimetry evaluated by microstate modeling revealed significant differences in binding cooperativity compared to other characterized PII proteins, underlining the diversity and adaptability of this class of regulatory signaling proteins

Near-Edge X-ray Absorption Fine Structure Spectroscopy of Diamondoid Thiol Monolayers on Gold

Diamondoids, hydrocarbon molecules with cubic-diamond-cage structures, have unique properties with potential value for nanotechnology. The availability and ability to selectively functionalize this special class of nanodiamond materials opens new possibilities for surface-modification, for high-efficiency field emitters in molecular electronics, as seed crystals for diamond growth, or as robust mechanical coatings. The properties of self-assembled monolayers (SAMs) of diamondoids are thus of fundamental interest for a variety of emerging applications. This paper presents the effects of thiol substitution position and polymantane order on diamondoid SAMs on gold using near-edge X-ray absorption fine structure spectroscopy (NEXAFS) and X-ray photoelectron spectroscopy (XPS). A framework to determine both molecular tilt and twist through NEXAFS is presented and reveals highly ordered diamondoid SAMs, with the molecular orientation controlled by the thiol location. C 1s and S 2p binding energies are lower in adamantane thiol than alkane thiols on gold by 0.67 {+-} 0.05 eV and 0.16 {+-} 0.04 eV respectively. These binding energies vary with diamondoid monolayer structure and thiol substitution position, consistent with different amounts of steric strain and electronic interaction with the substrate. This work demonstrates control over the assembly, in particular the orientational and electronic structure, providing a flexible design of surface properties with this exciting new class of diamond clusters