8 research outputs found
Acoustoelectric properties of graphene under the influence of saw and external electric field
The effect of SAW on the electrical properties of the few-layer (2-3 layers) graphene is
studied. Under the influence of SAW the appearence of acoustoelectric current IAEC in graphene is observed. The sign and magnitude of the induced IAEC in graphene conditioned by magnitude and direction of the electromagnetic fields induced by SAW and an external electric field. When the direction of SAW and Vbias is the same IAEC amplified, when at the opposite direction - IAEC are reduced in result of the interaction of these fields with each other. As a result of the measurement of the induced acoustoelectric (IAEC) current in graphene under the influence of a surface acoustic wave (SAW) the fluctuation nature of acoustoelectric current in the area of electrical neutrality is established at low voltages of an external bias (Vbias) applied on a graphene. The fluctuation character of the IAEC is manifested in all cases of measurements depending on the action of SAW and Vbias near the point of electrical neutrality. Chaotic fluctuation potential of graphene in the area of electrical neutrality is enhanced by the action of SAW that allows observing it in real conditions of the experiment at room temperature in air. The magnitude of IAEC depends on the power of SAW, while there is a parabolic dependence of the induced IAEC on the amplification current of SAW power (ISAW). The parabolic dependence of IAEC on ISAW explained by specific relaxation of acoustic phonons of the piezocrystallical substrate, which is dominant in the process of electronphonon scattering in graphene and acoustoelectric current induction in it. For large magnitudes of Vbias strict linear dependence of the IAEC on Vbias is observed. Large Vbias effectively suppress the appearance of the fluctuation potential of electrons and holes. The ability to control the magnitude and direction of IAEC induced in graphene by SAW is of practical importance
ZnO Nanorods: Synthesis by Catalyst-Free CVD and Thermal Growth from Salt Composites and Application to Nanodevices
Standards of specialized diabetes care. Edited by Dedov I.I., Shestakova M.V., Mayorov A.Yu. 9th edition
Dear Colleagues! We are glad to present the 9th Edition (revised) of Standards of Diabetes Care. These evidence-based guidelines were designed to standardize and facilitate diabetes care in all regions of the Russian Federation. The Standards are updated on the regular basis to incorporate new data and relevant recommendations from national and international clinical societies, including World Health Organization Guidelines (WHO, 2011, 2013), International Diabetes Federation (IDF, 2011, 2012, 2013), American Diabetes Association (ADA, 2018, 2019), American Association of Clinical Endocrinologists (AACE, 2019), International Society for Pediatric and Adolescent Diabetes (ISPAD, 2014, 2018) and Russian Association of Endocrinologists (RAE, 2011, 2012, 2015). Current edition of the “Standards” also integrates results of completed randomized clinical trials (ADVANCE, ACCORD, VADT, UKPDS, SAVOR, TECOS, LEADER, EXAMINE, ELIXA, SUSTAIN, DEVOTE, EMPA-REG OUTCOME, CANVAS, DECLARE, CARMELINA, REWIND, etc.), as well as findings from the national studies of diabetes mellitus (DM), conducted in close partnership with a number of Russian hospitals. Latest data indicates that prevalence of DM in the world increased during the last decade more than two-fold, reaching some 463 million patients by the end of 2019. According to the current estimation by the International Diabetes Federation, 578 million patients will be suffering from diabetes mellitus by by 2030 and 700 million by 2045. Like many other countries, Russian Federation experiences a sharp rise in the prevalence of DM. According to Russian Federal Diabetes Register, there are at least 4 584 575 patients with DM in this country by the end of 2018 (3,1% of population) with 92% (4 238 503) – Type 2 DM, 6% (256 202) – Type 1 DM and 2% (89 870) – other types of DM, including 8 006 women with gestational DM. However, these results underestimates real quantity of patients, because they consider only registered cases. Results of Russian epidemiological study (NATION) con- firmed that only 54% of Type 2 DM are diagnosed. So real number of patients with DM in Russia is 9 million patients (about 6% of population). This is a great long-term problem, because a lot of patients are not diagnosed, so they don’t receive any treatment ant have high risk of vascular complications. Severe consequences of the global pandemics of DM include its vascular complications: nephropathy, retinopathy, coronary, cerebral, coronary and peripheral vascular disease. These conditions are responsible for the majority of cases of diabetes-related disability and death. In сurrent edition of the “Standards”: New goals of glycemic control for the elderly, based on the presence of functional dependence, as well as for pregnant women, children and adolescents, are given. Added a snippet that describes the continuous glucose monitoring. Only low-density lipoprotein cholesterol level is used as a target for lipid metabolism. Proposes more stringent target levels of blood pressure. It also features updated guidelines on stratification of treatment in newly diagnosed Type 2 diabetes: the excess of the initial level of HbA1c over the target level was used as a criterion. In the recommendations for the personalization of the choice of antidiabetic agents, it is taken into account that in certain clinical situations (the presence of atherosclerotic cardiovascular diseases and their risk factors, chronic heart failure, chronic kidney disease, obesity, the risk of hypoglycemia) certain classes of hypoglycemic agents (or individual drugs) have proven advantages. Recommendations for psychosocial support are added. The position of metabolic surgery as a method of treatment of DM with morbid obesity is updated. Recommendations for diagnostic and treatment of hypogonadism syndrome in men with DM are added. For the first time, evidence levels of confidence and credibility levels of recommendations for diagnostic, therapeutic, rehabilitative and preventive interventions based on a systematic review of the literature are given in accordance with the recommendations of the Center for Healthcare Quality Assessment and Control of the Ministry of Health of the Russian Federation. This text represents a consensus by the absolute majority of national experts, achieved through a number of fruitful discus- sions held at national meetings and forums. These guidelines are intended for endocrinologists, primary care physicians and other medical professionals involved in the treatment of DM. On behalf of the Working Grou
Standards of specialized diabetes care. Edited by Dedov I.I., Shestakova M.V., Mayorov A.Yu. 10th edition
Dear Colleagues!We are glad to present the 10th Edition (revised) of the Standards of Specialized Diabetes Care. These evidence-based guidelines were designed to standardize and facilitate diabetes care in all regions of the Russian Federation.The Standards are updated on the regular basis to incorporate new data and relevant recommendations from national and international clinical societies, including World Health Organization Guidelines (WHO, 2011, 2013), International Diabetes Federation (IDF, 2011, 2012, 2013), European Association for the Study of Diabetes (EASD 2018, 2019), American Diabetes Association (ADA, 2018, 2019, 2021), American Association of Clinical Endocrinologists (AACE, 2020, 2021), International Society for Pediatric and Adolescent Diabetes (ISPAD, 2018) and Russian Association of Endocrinologists (RAE, 2019). Current edition of the “Standards” also integrates results of completed randomized clinical trials (ADVANCE, ACCORD, VADT, UKPDS, SAVOR, TECOS, LEADER, EXAMINE, ELIXA, SUSTAIN, DEVOTE, EMPA-REG OUTCOME, CANVAS, DECLARE, CARMELINA, REWIND, CREDENCE, CAROLINA, DAPA-CKD, DAPA-HF, EMPEROR-Reduced trial, VERIFY, VERTIS CV, PIONEER, etc.), as well as findings from the national studies of diabetes mellitus (DM), conducted in close partnership with a number of Russian hospitals.Latest data indicates that prevalence of DM in the world increased during the last decade more than two-fold, reaching some 537 million patients by the end of 2021. According to the current estimation by the International Diabetes Federation, 643 million patients will be suffering from DM by 2030 and 784 million by 2045.Like many other countries, Russian Federation experiences a sharp rise in the prevalence of DM. According to Russian Federal Diabetes Register, there are at least 4 871 863 patients with DM in this country on 01.01.2021 (3,34% of population) with 92,3% (4 498 826)–Type 2 DM, 5,6% (271 468)–Type 1 DM and 2,1% (101 569)–other types of DM, including 9 729 women with gestational DM. However, these results underestimates real quantity of patients, because they consider only registered cases. Results of Russian epidemiological study (NATION) confirmed that only 54% of Type 2 DM are diagnosed. So real number of patients with DM in Russia is 10 million patients (about 7% of population). This is a great long-term problem, because a lot of patients are not diagnosed, so they don’t receive any treatment and have high risk of vascular complications.Severe consequences of the global pandemic of DM include its vascular complications: nephropathy, retinopathy, coronary, cerebral and peripheral vascular disease. These conditions are responsible for the majority of cases of diabetes-related disability and death.In сurrent edition of the “Standards”:New goals of glycemic control for continuous glucose monitoring (time in range, below range and above range, glucose variability) are given.It also features updated guidelines on stratification of treatment in newly diagnosed Type 2 diabetes.In the recommendations for the personalization of the choice of antidiabetic agents, it is taken into account that in certain clinical situations (the presence of atherosclerotic cardiovascular diseases and their risk factors, chronic heart failure, chronic kidney disease, obesity, the risk of hypoglycemia) certain classes of hypoglycemic agents (or individual drugs) have proven advantages.Indications for the use of antidiabetic agents in chronic kidney disease are expanded.Information about insulin pump therapy is added.Recommendations on vaccination are added.An algorithm for replacing some insulin preparations with others is given.This text represents a consensus by the absolute majority of national experts, achieved through a number of fruitful discussions held at national meetings and forums. These guidelines are intended for endocrinologists, primary care physicians, pediatricians and other medical professionals involved in the treatment of DM.Compared with previous edition of the Standards of Specialized Diabetes Care edited by Dedov I.I., Shestakova M.V., Mayorov A.Yu., 10th edition, Moscow, 2021 (signed for printing on 10.09.2021) a number of changes have been made.On behalf of the Working Grou
Acoustoelectric properties of graphene under the influence of saw and external electric field
The effect of SAW on the electrical properties of the few-layer (2-3 layers) graphene is
studied. Under the influence of SAW the appearence of acoustoelectric current IAEC in graphene is observed. The sign and magnitude of the induced IAEC in graphene conditioned by magnitude and direction of the electromagnetic fields induced by SAW and an external electric field. When the direction of SAW and Vbias is the same IAEC amplified, when at the opposite direction - IAEC are reduced in result of the interaction of these fields with each other. As a result of the measurement of the induced acoustoelectric (IAEC) current in graphene under the influence of a surface acoustic wave (SAW) the fluctuation nature of acoustoelectric current in the area of electrical neutrality is established at low voltages of an external bias (Vbias) applied on a graphene. The fluctuation character of the IAEC is manifested in all cases of measurements depending on the action of SAW and Vbias near the point of electrical neutrality. Chaotic fluctuation potential of graphene in the area of electrical neutrality is enhanced by the action of SAW that allows observing it in real conditions of the experiment at room temperature in air. The magnitude of IAEC depends on the power of SAW, while there is a parabolic dependence of the induced IAEC on the amplification current of SAW power (ISAW). The parabolic dependence of IAEC on ISAW explained by specific relaxation of acoustic phonons of the piezocrystallical substrate, which is dominant in the process of electronphonon scattering in graphene and acoustoelectric current induction in it. For large magnitudes of Vbias strict linear dependence of the IAEC on Vbias is observed. Large Vbias effectively suppress the appearance of the fluctuation potential of electrons and holes. The ability to control the magnitude and direction of IAEC induced in graphene by SAW is of practical importance
Raman Study of the Diamond to Graphite Transition Induced by the Single Femtosecond Laser Pulse on the (111) Face
The use of the ultrafast pulse is the current trend in laser processing many materials, including diamonds. Recently, the orientation of the irradiated crystal face was shown to play a crucial role in the diamond to graphite transition process. Here, we develop this approach and explore the nanostructure of the sp2 phase, and the structural perfection of the graphite produced. The single pulse of the third harmonic of a Ti:sapphire laser (100 fs, 266 nm) was used to study the process of producing highly oriented graphite (HOG) layers on the (111) surface of a diamond monocrystal. The laser fluence dependence on ablated crater depth was analyzed, and three different regimes of laser-induced diamond graphitization are discussed, namely: nonablative graphitization, customary ablative graphitization, and bulk graphitization. The structure of the graphitized material was investigated by confocal Raman spectroscopy. A clear correlation was found between laser ablation regimes and sp2 phase structure. The main types of structural defects that disrupt the HOG formation both at low and high laser fluencies were determined by Raman spectroscopy. The patterns revealed give optimal laser fluence for the production of perfect graphite spots on the diamond surface