48 research outputs found
Retrospective trial of long acting analogues detemir and degludec usage in children and adolescents to overcome glucose variability caused by dawn phenomenon and reverse dawn phenomenon
Backgraund: Children with type 1 diabetes mellitus (T1DM) need more insulin late in the evening (reverse dawn phenomenon (RDP)), and adolescents need more insulin yearly in the morning (dawn phenomenon (DP)); these cause blood glucose variability. Modern long acting insulin analogues allow to achieve satisfactory glycemic control.Aims: To study the characteristics of insulin therapy in children and adolescents with T1DM using insulin analogues detemir and degludec to overcome blood glucose variability caused by DP and RDP in different age periods.Materials and methods: We analyzed medical documents of 200 patients using detemir, admitted to pediatric endocrinology department in 2013–2019, at mean age 9.0 years (5.4; 13.0), with T1DM for 1.3 years (0.5; 3.0); and medical documents of 50 patients switched to degludec in 2018–2019 at mean age 12.0 years (10.5; 14.5) with T1DM for 3.0 years (1.5; 6.0). Before degludec they were on intensive insulin therapy with glargine (22), detemir (26), or insulin pump (2); 16 patients (32%) presented with clinical characteristics of DP, and 5 (10%) — RDP.Results: 67 children of 108 (62%) aged 1–9 years had redistribution of detemir doses to daytime; 58 adolescents of 92 (63%) aged 10–17 лет — to nighttime. Patients switched to degludec demonstrated decrease in HbA1с from 8.7% (7.8; 9.9) to 8.0% (7.4; 9.0) (р<0.001); fasting blood glucose from 9.8 mmol/l (7.4; 11.7) to 7.7 mmol/l (6.4; 8.6) (р<0.001); within-day variability from 35.2% (31.6; 40.9) to 23.5% (19.7; 28.6) (р<0.001); daily insulin dose from 0.98 U/kg/day (0.82; 1.14) to 0.87 U/kg/day (0.75; 1.07) (р=0.002). Sub-groups of patients with DP and RDP demonstrated decrease in fasting blood glucose (from 11.5 mmol/l (9.8; 13.8) to 7.5 mmol/l (6.6; 9.1) (р<0.001)), and late evening blood glucose (from 11.0 mmol/l (10.2; 11.2) to 8.0 mmol/l (6.7; 9.5) (р= 0.03)) correspondently. Achieved levels of glycemic control did not differ between sub-groups of patients initially using glargine or detemir.Conclusions: Compensation of T1DM may be complicated due to DP and RDP. Switching to degludec allowed to achieve better glycemic control and lowering of blood glucose variability caused by DP and DRP
The Electronic Structure, Thermoelectric, and Optical Properties of Heusler Alloys Mn2MeAl (Me = Ti, V, Cr)
Abstract: The results of calculations of the electronic structure, thermoelectric characteristics, and experimental study of the thermoelectric, electrical, and optical properties of Mn2MeAl Heusler alloys (Me = Ti, V, Cr) are presented. The agreement between theory and experiment in the sign of the Seebeck coefficient is shown. The obtained pattern of the band spectrum allows us to qualitatively explain the peculiarities of the temperature dependences of the electrical resistance and the permittivity dispersion. © 2023, The Author(s).Ural Branch, Russian Academy of Sciences, UB RAS; Russian Science Foundation, RSF: 22-22-20109This study was supported by a grant from the Russian Science Foundation (project no. 22-22-20109, https://rscf.ru/project/22-22-20109/ , Institute of Metal Physics, Ural Branch, Russian Academy of Sciences)
Electrical and optical properties of a PtSn 4 single crystal
A topological semimetal PtSn4 single crystal was grown by method of crystallization from a solution in a melt. Then the electrical resistivity and galvanomagnetic properties (magnetoresistivity and the Hall effect) were studied in the temperature range from 4.2 to 80 K and in magnetic fields up to 100 kOe. The optical measurements were carried out at room temperature. The residual resistivity is shown to be low enough and amount to ∼ 0.5 μOhm•cm. The temperature dependence of the electrical resistivity has a metallic type, increasing monotonically with temperature. A sufficiently large magnetoresistance of 750% is observed. The majority carriers are supposed to be holes with a concentration of ∼ 6.8•10 21 cm -3 and mobility of ∼ 1950 cm 2 /Vs at T = 4.2 K as a result of the Hall effect studies. The optical properties of PtSn 4 have features characteristic of "bad" metals. © 2019 Published under licence by IOP Publishing Ltd.This work was partly supported by the state assignment of Russia (theme “Spin” No. АААА-А18-18020290104-2 and theme “Electron” No. АААА-А18-118020190098-5), by the RFBR (project No.17-52-52008) and by the Government of the Russian Federation (state contract No. 02.A03.21.0006)
Electronic Structure and Charge Dynamics of Huesler Alloy Fe2TiSn Probed by Infrared and Optical Spectroscopy
We report on the electrodynamics of a Heusler alloy Fe2TiSn probed over four
decades in energy: from the far infrared to the ultraviolet. Our results do not
support the suggestion of Kondo-lattice behavior inferred from specific heat
measurements. Instead, we find a conventional Drude-like response of free
carriers, with two additional absorption bands centered at around 0.1 and 0.87
eV. The latter feature can be interpreted as excitations across a pseudogap, in
accord with band structure calculations.Comment: 3 pages, 4 figure
Novel GLIS3 mutation in patient with neonatal diabetes mellitus and congenital hypothyroidism (NDH-syndrome)
Mutations in the GLIS3 gene encoding the GLIS3 transcription factor are cause of a rare syndromic form of neonatal diabetes mellitus (NDM) with congenital hypothyroidism. Additional features include congenital glaucoma, hepatic fibrosis, polycystic kidneys, developmental delay and other anomalies. This disease in foreign literature is called NDH-syndrome (Neonatal diabetes and Hypothyroidism syndrome).We present the description of a patient with this syndrome with novel homozygous GLIS3 mutation.Our patient is a female, who was born with a weight of 1680 gr, length of 44 cm to consanguineous parents. She developed diabetes on 2 day after birth, requiring continuous intravenous insulin. On day 5 of life hypothyroidism was identified. Thyroid anatomy was normal on ultrasound scan. NDH syndrome was suspected.Genetic analysis revealed a novel homozygous mutation c.1836delT, p.Ser612ArgfsTer33 in exon 5 in GLIS3 gene.To date, the patient is followed up for 4 years in total. Currently, growth retardation, psychomotor and speech development persist. Carbohydrate metabolism and thyroid profile has been subcompensated against the background of replacement therapy. No other components of the syndrome have been identified.In this report, we have demonstrated the features of the neonatal diabetes mellitus in a patient with a defect in the GLIS3 gene. Early genetic verification of the diagnosis contributes to the timely starting of personalized therapy, can improve the quality of life of such patients, and, given the nature of inheritance, is necessary for medical genetic counseling of the family
Effect of quenching on the electrical and optical properties of MoTe2
The effect of quenching on the electrical resistivity and optical properties of MoTe2 compound was studied. Significant changes were detected in the behaviour and value of the electrical resistivity, indicating an increase in the metallic (conductive) properties of the compound, which is in good agreement with the data of optical measurements. © 2019 Published under licence by IOP Publishing Ltd.Government Council on Grants, Russian Federation: 211Russian Foundation for Basic Research, RFBR: 17-52-52008Ministry of Education and Science of the Russian Federation, Minobrnauka: АААА-А18-118020190098-5The research was carried out within the state assignment of the Ministry of Education and Science of the Russian Federation (theme “Spin”, No. АААА-А18-118020290104-2, and theme “Electron”, No. АААА-А18-118020190098-5), supported in part by RFBR (Project No. 17-52-52008) and the Government of Russian Federation (Decree No. 211, Contract No. 02.A03.21.0006)
Electronic properties of WTe2 and MoTe2 single crystals
WTe2 and MoTe2 single crystals were grown, and their electrical resistivity in the temperature range from 80 K to 300 K, optical properties at room temperature in the spectral range of 0.17-5.0 eV were studied as well as theoretical calculations of the electronic structure were performed. It is shown that the temperature dependence of the electrical resistivity of orthorhombic WTe2 has a metallic type with resistivity value of (0.5-1) mOhmcm, while hexagonal MoTe2 has a semiconductor one and resistivity value (0.5-1) Ohmcm, which is three orders of magnitude larger than the resistivity of WTe2. Optical properties indicated that there is no contribution from free carriers in the entire spectral range studied. The calculated densities of the electronic states of MoTe2 and WTe2 showed the presence of a bunch of the molybdenum and tungsten electronic states in a wide energy interval with strong admixing of tellurium states. In the WTe2 compound, the larger number of the electronic states is located near the Fermi energy, characterizing a more metallic state in this compound as compared to MoTe2. © Published under licence by IOP Publishing Ltd.Government Council on Grants, Russian Federation: 02, 211Russian Foundation for Basic Research, RFBR: 17-52-52008Ministry of Education and Science of the Russian Federation, Minobrnauka: АААА-А18-118020190098-5The research was carried out within the state assignment of Ministry of Education and Science of the Russian Federation (theme “Spin” No. АААА-А18-118020290104-2 and theme “Electron” No. АААА-А18-118020190098-5), supported in part by RFBR (Project No. 17-52-52008) and the Government of Russian Federation (Decree No. 211, Contract No. 02.A03.21.0006)
Clinical, hormonal and molecular-genetic characteristics of monogenic diabetes mellitus associated with the mutations in the <i>INS</i> gene
Background: Currently more than 50 mutations of the INS gene are known to affect the various stages of insulin biosynthesis in the beta cells of the pancreas. However only individual cases of diabetes mellitus (DM) associated with heterozygous mutations in the coding region of the INS gene were reported in Russian Federation. We report a group of patients with a clinical manifestation of DM caused by mutations in both coding and non-coding regions of the INS gene. The patients with a mutation in the intron of the INS gene are reported for the first time in Russian FederationMaterials and methods: 60 patients with an isolated course of neonatal DM (NDM), 52 patients with a manifestation of DM at the age of 7–12 months and the absence of the main autoimmune markers of type 1 DM, 650 patients with the MODY phenotype were included in the study. NGS technology was used for molecular genetic research. Author’s panel of primers (Custom DNA Panel) was used for multiplex PCR and sequencing using Ion Ampliseq™ technology. The author’s panel “Diabetes Mellitus” included 28 genes (13 candidate genes of MODY and other genes associated with DM).Results: 13 heterozygous mutations were identified in 16 probands and 9 relatives. The majority of mutations were detected in patients with PNDM (18.75%) and in patients with an onset of DM at the age of 7–12 months (9.6%). Mutations in the INS gene were detected in 2 patients (0.3%) in the group with the MODY phenotype. Mutations in the INS gene were not detected in patients with transient NDM (TNDM). Analysis of clinical data in patients with PND and onset of diabetes at the age of 7–12 months did not show significant differences in the course of the disease. The clinical characteristics of the cases of MODY10 and diabetes caused by a mutation in the intron of the INS gene are reported in details.Conclusion: The role of INS gene mutations in NDM, MODY, and DM with an onset at the age of 7–12 months was analyzed in a large group of patients. The clinical characteristics of DM due to a mutation in the intron of the INS gene are reported for the first time in the Russian Federation
A review of the optical properties of alloys and intermetallics for plasmonics
Alternative materials are required to enhance the efficacy of plasmonic
devices. We discuss the optical properties of a number of alloys, doped metals,
intermetallics, silicides, metallic glasses and high pressure materials. We
conclude that due to the probability of low frequency interband transitions,
materials with partially occupied d-states perform poorly as plasmonic
materials, ruling out many alloys, intermetallics and silicides as viable. The
increased probability of electron-electron and electron-phonon scattering rules
out many doped and glassy metals.Comment: 26 pages, 10 figures, 3 table
Effective modelling of the Seebeck coefficient of Fe2VAl
Previous first-principles calculations have failed to reproduce many of the key thermoelectric features of Fe2VAl, e.g. the maximum values of the Seebeck coefficientSand its asymmetry with respect to the chemical potential. Also, previous theoretical predictions suggested that the pseudo band gap of Fe2VAl switches from indirect to direct upon doping. In this work, we report first-principles calculations that correctly reproduce the experimentally measured thermoelectric properties of Fe2VAl. This is achieved by adding a larger HubbardUterm to V atoms than to Fe atoms and including a scissors operator afterwards. As a result, bulk Fe2VAl is modelled as a gapless semiconductor with maximumSvalues of 76 and -158 μV/K forp- andn-type, respectively, which agree well with the experimental measurements