Structure and spatial distribution of Ge nanocrystals subjected to fast neutron irradiation

The influence of fast neutron irradiation on the structure and spatial distribution of Ge nanocrystals (NC) embedded in an amorphous SiO2 matrix has been studied. The investigation was conducted by means of laser Raman Scattering (RS), High Resolution Transmission Electron Microscopy (HR-TEM) and X-ray photoelectron spectroscopy (XPS). The irradiation of NC-Ge samples by a high dose of fast neutrons lead to a partial destruction of the nanocrystals. Full reconstruction of crystallinity was achieved after annealing the radiation damage at 800 deg. C, which resulted in full restoration of the RS spectrum. HR-TEM images show, however, that the spatial distributions of NC-Ge changed as a result of irradiation and annealing. A sharp decrease in NC distribution towards the SiO2 surface has been observed. This was accompanied by XPS detection of Ge oxides and elemental Ge within both the surface and subsurface region

Electronic correlation effects and the Coulomb gap at finite temperature

We have investigated the effect of the long-range Coulomb interaction on the one-particle excitation spectrum of n-type Germanium, using tunneling spectroscopy on mechanically controllable break junctions. The tunnel conductance was measured as a function of energy and temperature. At low temperatures, the spectra reveal a minimum at zero bias voltage due to the Coulomb gap. In the temperature range above 1 K the Coulomb gap is filled by thermal excitations. This behavior is reflected in the temperature dependence of the variable-range hopping resitivity measured on the same samples: Up to a few degrees Kelvin the Efros-Shkovskii ln$R \propto T^{-1/2}$ law is obeyed, whereas at higher temperatures deviations from this law are observed, indicating a cross-over to Mott's ln$R \propto T^{-1/4}$ law. The mechanism of this cross-over is different from that considered previously in the literature.Comment: 3 pages, 3 figure

About low field memory and negative magnetization in semiconductors and polymers

Ginzburg-Landau bulk magnetization of itinerant electrons can provide a negative effective field in the Weiss model by coupling to localized magnetic moments. The coupling enforces remnant magnetization, which can be negative or positive depending on the sample magnetic history. Stable magnetic susceptibility of coupled nonequilibrium subsystems with magnetization reversal is always positive. Gauss-scale fields could be expected for switching between negative and positive remnant moments in semiconductors with coupling at ambient temperatures. Negative magnetization in ultra-high conducting polymers is also discussed within the developed framework.Comment: 8 pages, no figure

Influence of trigonal warping on interference effects in bilayer graphene

Bilayer graphene (two coupled graphitic monolayers arranged according to Bernal stacking) is a two-dimensional gapless semiconductor with a peculiar electronic spectrum different from the Dirac spectrum in the monolayer material. In particular, the electronic Fermi line in each of its valleys has a strong p -> -p asymmetry due to trigonal warping, which suppresses the weak localization effect. We show that weak localization in bilayer graphene may be present only in devices with pronounced intervalley scattering, and we evaluate the corresponding magnetoresistance

Дослідження впливу маклеї серцевидної та біологічно активних добавок на вуглеводний обмін свиней

Pork production plays a significant role in meat balance of Ukraine. High productivity of pigs is accompanied with increased intensity of metabolic processes and intense functional activity of all organs and systems, which requires additional support. To grow a healthy livestock, it is necessary to use preparations and biologically active forage plant additives that help a body to realize productive qualities, fight against various pathogens, but do not harm the animal body and are safe in the production of meat products for human nutrition. The influence of phytobiotic of the cardiac macleaya (Macleáya cordáta R. Br.) has been investigated separately and in combination with vegetable additives (buckwheat, ground onion and buckwheat husks) as a source of flavonoids on the physiological state and carbohydrate metabolism of pigs. It has been determined that application of only macleaya supplements to the 30 and 60 days of studies leads to an increase in the number of erythrocytes by 16.7% and 23.2% (P < 0.05) and hemoglobin concentration by 30.7% and 37.9% (P < 0.01), as well as activation of anaerobic glycolysis, as evidenced by a significant increase in glucose concentration by 96.4–48.0% (P < 0.01), lactate by 71.4–55.2%, (P < 0.01) and activity of lactate dehydrogenase at 18.6–29.4% (P < 0.05) and reduction of pyruvate content by 34.0–13.4% (P < 0.01) and activity of alkaline phosphatase – by 66.2% and 76.8% (P < 0.01) in the corresponding terms of research. While using macleaya with green buckwheat, buckwheat and onion husks, the hematological parameters and parameters of carbohydrate metabolism were at the level of the control group, confirming the significant decrease in the concentration of glucose and lactate compared with the control and shift ratio lactate / pyruvate towards pyruvate. This fact suggests that bioflavonoids, which are part of plant additives, have not only antioxidant properties, but also serve as a correction and stabilizer of carbohydrate metabolism and mitigate the side hypoxic effects of alkaloids of phytobiotic of the macleaya cordata.Виробництво свинини відіграє значну роль в м’ясному балансі України. Висока продуктивність свиней супроводжується підвищеною інтенсивністю процесів обміну речовин і напруженою функціональною діяльністю всіх органів і систем, що потребує додаткової підтримки. Для вирощування здорового поголів’я необхідно застосовувати препарати та біологічно активні кормові рослинні добавки, які допомагають організму реалізувати продуктивні якості, боротися з різними хвороботворними агентами, але не наносять шкоди самому організму тварини і є безпечними у виробництві м’ясної продукції для харчування людини. Досліджено вплив фітобіотика маклеї серцевидної (Macleáya cordáta R. Br.) окремо і в комбінації з добавками рослинного походження (гречка посівна, мелене цибульне і гречане лушпиння) як джерело флавоноїдів на фізіологічний стан та вуглеводний обмін організму свиней. Встановлено, що застосування у раціоні тільки добавки маклеї на 30 і 60 добу досліджень призводить до збільшення кількості еритроцитів на 16,7% і 23,2% (P < 0,05) і концентрації гемоглобіну на 30,7% і 37,9% (P < 0,01) відповідно, а також активації анаеробного гліколізу, про що свідчить достовірне підвищення концентрації глюкози на 96,4–48,0% (P < 0,01), лактату на 71,4–55,2% (P < 0,01) і активності лактатдегідрогенази на 18,6–29,4% (P < 0,05) та зниження вмісту пірувату на 34,0–13,4% (P < 0,01) і активності лужної фосфатази – на 66,2% і 76,8% (P < 0,01) у відповідні терміни дослідження. За застосування разом з травою маклеї зеленої гречки, гречаного і цибульного лушпиння гематологічні показники і вуглеводний обмін були на рівні показників контрольної групи, що підтверджує достовірним зниженням концентрації глюкози і лактату порівняно з контролем та зміщення коефіцієнту лактат/пірувату в бік пірувату. Цей факт свідчить про те, що біофлавоноїди, які входять до складу рослинних добавок, мають не тільки антиоксидантні властивості, а й слугують коректором і стабілізатором вуглеводного обміну і пом’якшують побічний гіпоксичний вплив алкалоїдів фітобіотика маклеї серцевидної

Integrated solution for very high cardiovascular risk patients. Rationale and design of a pilot study

Coronary artery disease (CAD) is the most common cardiovascular disease and the leading cause of morbidity and mortality. Acute coronary syndrome (ACS) as an abrupt destabilization of CAD, multiplies the risk of cardiovascular events. To reduce the incidence of recurrent cardiovascular events, timely tackling potentially reversible risk factors such as hypertension and/or hyperglycemia is imperative. However, a solid basis for a secondary prevention lies in the treatment of dyslipidemia and begins in the first hours of hospital admission. Despite considerable evidence regarding the efficacy and safety of lipid-lowering therapy, averagely only one third of patients maintain control of lipids. The main challenges are low adherence, poor continuity of medical care, and the lack of an ambulatory routine follow-up. Telehealth solutions are believed to address these barriers and may be considered as an add-on to in-person patient care. Telemonitoring of vital and laboratory parameters, remote patient counseling can be introduced into routine care delivery. Telemedicine shows promise for fostering better clinical effect, and provides health-related quality of life improvement.It is planned to conduct a pilot observational study aimed to create and to test an integrated solution, i.e. telemonitoring and remote counseling in patients of very high cardiovascular risk with ACS followed by myocardial revascularization. The goal is to determine the clinical effectiveness, i.e achievement of target values of blood pressure, lipid profile and glycemia, and patient-centeredness of this approach

Integrated solution for patients of a very high cardiovascular risk. Final results

Secondary prevention should be actively implemented at all stages of treatment and rehabilitation of patients after acute coronary syndrome (ACS). The integration of remote monitoring of patients with the transfer of vital and laboratory data into clinical practice seems promising.Aim. To evaluate the clinical and patient-centered effectiveness of the original 12-month combined face-to-face and telecare program in patients with recent ACS.Material and methods. For the present analysis the data from 84 (out of 100) patients (median age, 56 (50;61) years, 70 males) was used. These patients had to have hypertension and/or type 2 diabetes and an ACS with percutaneous revascularization within 12 months. Their low-density lipoprotein cholesterol (LDL-C) had to be above 2,4 mmol/L. Telehealth program supplemented routine care. A program contained electronic self-control diaries for blood pressure (BP) and lipid profile, and teleconsulting service (text chat). Mandatory face-to-face visits were carried out at 3 and 12 months after the enrollment. The primary end point was ∆LDL-C. Additional clinical and patient-specific endpoints were evaluated.Results. At the 12-month visit, there was a significant decrease in LDL-C by 1,6 (-2,3;-0,9) mmol/L. Besides the initial LDL-C value, the decrease in LDL-C was associated with the proper adherence to keeping diaries of BP and lipid profile (β=0,7), and the number of text messages sent by the doctor in the 1st month after the enrollment (β=0,04). In more adherent patients, the ∆LDL-C was greater by 0,49 mmol/L (95% CI (-1,2; -0,1)) after adjustment for abovementioned covariates. In 35 patients (42%), target LDL-C was achieved, in 60 patients (71%) — a decrease ≥1 mmol/l. Other lipids also have changed for the better. Moreover, adherent patients were twice as likely to achieve the target LDL-C (OR 2,2; 95% CI (0,6; 3,8)) than non-adherent ones. A decrease in office systolic BP by 5,8 mm Hg was shown (p=0,03). The number of physician-to-patient messages exceeded those from patients to physician (median 143 and 111 per patient for 12 months, respectively). The quality of life has improved, but only in terms of emotions. Satisfaction with the program remained high at all timepoints of the study.Conclusion. Our study showed the effectiveness of the integrated care in ACS patients with the telehealth tool included. Commitment to BP self-monitoring, as well as active consultative support at the first stages of rehabilitation, contributes to additional dynamic control of lipid profile, timely correction of lipid-lowering therapy with the achievement of the target LDL-C level. Most of the patients did not experience any difficulties in using the program and are ready to recommend integrated approach to other peers

An integrated approach for very high cardiovascular risk patients. Intermediate results

The main objective of secondary prevention measures is to modify key risk factors such as hypertension (HTN) and dyslipidemia in patients with established cardiovascular diseases. Its proper implementation improves both short- and long-term outcomes. Telehealth technologies contributes to faster achievement of target levels and better control of key risk factors.Aim. To establish a comprehensive personalized follow-up framework for patients recovered from an acute coronary syndrome (ACS) that integrates telehealth software and to test its clinical and patient-centered efficacy.Material and methods. The three-month follow-up data of 50 patients (50% of planned enrollees; median age, 57 years [53; 61]; males, 84%) who suffered ACS with myocardial revascularization and low-density lipoprotein cholesterol (LDL-C) at least 2,5 mmol/L at admission. We introduced the simple and save telehealth software for home BP monitoring and lipid profiling. The basic demographic, clinical and laboratory characteristics of patients were described, as well as the changes lipid profile, office and home BP over this period was analyzed. The primary endpoint was a change in LDL-C after 3 months. In addition, we also focused on pharmacological therapy and its dynamics, as well as on remote counseling and patient’ experience with the mobile application.Results. Three months after inclusion, we have noted significant decrease of total cholesterol (-1,67 mmol/L, p<0,0001) and triglycerides (-0,48 mmol/L, p<0,0001). LDL-C changes were also significant (-1,49 mmol/L, adjusted for age, sex and lipid-lowering therapy; p<0,0001) and was associated only with the baseline LDL-C levels (R2=-0,521, p<0,0001). Thirty-nine (78%) patients achieved at least 1 mmol/L drop of LDL-C. Nine of them reached target LDL-C <1,4 mmol/L (and/or a decrease of 50% from baseline). Both high-density lipoprotein cholesterol (-0,48 mmol/l, p=0,348), office and home BP remained mostly unchanged. The proportion of patients with target office BP levels was almost the same (χ2=3,06, p=0,08). Patients who were recommended combined lipid-lowering therapy with cholesterol absorption inhibitor (ezetimibe) were more likely to achieve target LDL-C (χ2=10,95; p=0,003) than those with single agent (67% versus 17%, p=0,003). No differences were found in subgroups of patients in LDL-C reduction. In each patient an average of 15 remote consultations have been performed (from 1 to 54 per patient per 3 moths). Investigators have had to send reminders to 22 patients regarding the need for regular home BP monitoring. The majority of patients treated telehealth software as easy-to-use and user-friendly.Conclusion. According to the 3-month follow-up of patients after ACS who used the framework integrated with telemonitoring and remote counseling, a positive trend in reducing atherogenic lipid levels was demonstrated, but not in office BP. Only a fifth of patients reached the target LDL-C, but the vast majority had target BP. Despite the fact that the program is convenient to use, almost half of participants require additional reminders from physician on self-monitoring