Conductivity, weak ferromagnetism and charge instability in α−MnS\alpha-MnS single crystal

The temperature dependence of resistivity, magnetization and electron-spin resonance of the $\alpha- MnS$ single crystal were measured in temperature range of $5 K < T < 550 K$. Magnetization hysteresis in applied magnetic field up to 0.7 T at $T=5 K, 77 K, 300 K$, irreversible temperature behavior of magnetization and resistivity were found . The obtained data were explained in terms of degenerate tight binding model using random phase approximation. The contribution of holes in $t_{2g}$ and $e_g$ bands of manganese ions to the conductivity, optical absorbtion spectra and charge instability in $\alpha -MnS$ were studied. Charge susceptibility maxima resulted from the competition of the on-site Coulomb interaction between the holes in different orbitals and small hybridization of sub-bands were calculated at $T=160 K, 250 K, 475 K$.Comment: 6 pages, 12 figure

Solid-state synthesis and characterization of ferromagnetic Mn5Ge3 nanoclusters in GeO/Mn thin films

Mn5Ge3 films are promising materials for spintronic applications due to their high spin polarization and a Curie temperature above room temperature. However, non-magnetic elements such as oxygen, carbon and nitrogen may unpredictably change the structural and magnetic properties of Mn5Ge3 films. Here, we use the solid-state reaction between Mn and GeO thin films to describe the synthesis and the structural and magnetic characterization of Mn5Ge3(Mn5Ge3Oy)-GeO2(GeOx) nanocomposite materials. Our results show that the synthesis of these nanocomposites starts at 180°С when the GeO decomposes into elemental germanium and oxygen and the resulting Ge atoms immediately migrate into the Mn layer to form ferromagnetic Mn5Ge3 nanoclusters. At the same time the oxygen atoms take part in the synthesis of GeOx and GeO2 oxides and also migrate into the Mn5Ge3 lattice to form Mn5Ge3Oy Nowotny nanoclusters. Magnetic analysis assumes the general nature of the Curie temperature increase in carbon-doped Mn5Ge3Cx and Mn5Ge3Oy films. Our findings prove that not only carbon, but oxygen may contribute to the increase of the saturation magnetization and Curie temperature of Mn5Ge3-based nanostructures

Effects of processing parameters on the morphology, structure, and magnetic properties of Cu1−xFexCr2Se4 nanoparticles synthesized with chemical methods

Cu1−xFexCr2Se4 nanoparticles with x = 0, 0.2, and 0.4 were synthesized via thermal decomposition of metal nitrate or chloride salts and selenium powder using different precursor compositions and processing details. Single crystalline nano-belts or nano-rods coexist in the synthesized powder samples with hexagon-shaped plates in dependence on the precursor composition. The belts gathered into conglomerates forming “hierarchical” particles. Visible magnetic circular dichroism (MCD) of Cu1−xFexCr2Se4 nanoparticles embedded into a transparent matrix was investigated for the first time. The similarity of the MCD spectra of all samples showed the similarity of the nanoparticles electronic structure independent of their morphology. Basing on the MCD spectral maxima characteristics, electron transitions from the ground to the excited states were identified with the help of the conventional band theory and the multi-electron approach

Study of morphology, magnetic properties, and visible magnetic circular dichroism of Ni nanoparticles synthesized in SiO2 by ion implantation

A systematic study of ensembles of nickel nanoparticles fabricated by Ni+-ion implantation at a dose of (0.5-1.0)×1017 ions/cm2 in a thin near-surface layer of an amorphous SiO2 matrix by means of transmission electron microscopy (TEM), dc magnetic measurements, and magneto-optical technique is presented. TEM characterization of Ni nanoparticles proves the formation of isolated spherical nickel nanoparticles with diameters from 2 to 16 nm. The crystal structure and lattice constant of the nanoparticles correspond to face-centered-cubic Ni. The larger size nanoparticles are shown to have core-shell structure, which is unusual for the implantation conditions used. The shell of these nanoparticles consists of Ni, while the core has supposedly the composition coinciding with the matrix, i.e., SiO2. The core-shell nanoparticles in the investigated sample coexist with ordinary pure Ni nanoparticles, which strongly affects the magnetic and especially magneto-optic properties of the samples. For all three doses, the nanoparticles are in the superparamagnetic state at room temperature passing to the "frozen" state at lower temperatures. However, only the sample implanted with the lowest dose demonstrates the classic superparamagnetic behavior according to the shape of the experimental magnetization temperature dependencies for the zero-field-cooled (ZFC) and field-cooled regimes. This shape deviation from that characteristic of the pure superparamagnetic ensembles is ascribed mainly to the particle core-shell structure. The Ni nanoparticles' anisotropy constant estimated with the help of ZFC curves appears to exceed the bulk Ni anisotropy second constant approximately by two orders of magnitude. Magnetic circular dichroism (MCD) is characterized by spectral dependence modified strongly as compared to the MCD spectra of a continuous Ni film. In the spectral range 1.1-4.2 eV, the MCD spectrum consists of two broad maxima of opposite sign with the characteristics depending on the implantation dose and the measurement temperature. The MCD spectra analysis allows one to show that the higher-energy maximum (at 3.34-3.48 eV depending on the dose) is related to the surface plasmon resonance (SPR) excitation in pure Ni nanoparticles, while the lower-energy maximum (at 2.19-2.73 eV depending on the dose) should be associated with the SPR excitation in core-shell nanoparticles. © 2013 American Physical Society

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

КЛИНИЧЕСКИЙ ОПЫТ ПРИМЕНЕНИЯ МЕДИКАМЕНТОЗНЫХ ПРЕПАРАТОВ ПРИ ПОДГОТОВКЕ К КОЛОНОСКОПИИ

Bowel preparation remains an important issue despite vast clinical experience in this field.Methods. 530 patients were included in retrospective analysis. 234 (44.2 %) patients in group 1 used sodium phosphate (SP) for bowel preparation, 176 (33.2 %) patients in group 2 used polyethylene glycol (PEG), 120 (22.6 %) patients used castor oil. Quality of bowel preparation was assessed according to following grading system: «good», «acceptable», «bad».Results. «Good», «acceptable», «bad» bowel preparation was observed in following number of patients: 160 (68.4 %), 46 (19.7 %) and 28 (12 %) patients who used SP, 38.6, 40.3 and 20.1 % who used PEG and 43.3, 20.8, 35.8 % who used castor oil. Results of «good» preparation were significantly better in patients who used SP comparing to other treatment groups.Conclusions. Better bowel preparation with SP was observed in our study, though results need to be validated in randomized trials.Выбор оптимальных методов подготовки пациентов к колоноскопии остается актуальной проблемой, несмотря на многолетний опыт в данной области.Методы. Ретроспективно проанализированы результаты подготовки к колоноскопии 530 пациентов, находящихся на стационарном лечении. Пациенты 1-й группы – 234 (44,2 %) больных – для подготовки к колоноскопии получали препарат фосфата натрия, во 2-й группе – 176 (33,2 %) человек  использовали полиэтиленгликоль (ПЭГ), 3-я группа – 120 (22,6 %) пациентов – применяли касторовое масло. Качество подготовки оценивали согласно степени визуализации стенки толстого кишечника на всем протяжении при каждом эндоскопическом исследовании и описывали как «отличную», «удовлетворительную» или «плохую».Результаты. У большей доли пациентов – 160 (68,4 %) человек, которые получали фосфат натрия, во всех сегментах толстой кишки подготовка была признана «отличной», у 46 (19,7 %) оценена как «удовлетворительная», у 28 (12 %) – как «плохая». Аналогичные показатели для ПЭГ составили 38,6; 40,3 и 20,1 % соответственно, для касторового масла – 43,3; 20,8; 35,8 %. Различия были достоверны по показателю «отличной» подготовки в пользу препарата фосфата натрия по сравнению с двумя другими исследуемыми препаратами.Выводы. Отмечено преимущество подготовки кишечника препаратом фосфата натрия, которое требуется подтвердить в рандомизированных исследованиях

Temperature- and field-induced transformation of the magnetic state in Co2.5Ge0.5BO5

A tetravalent-substituted cobalt ludwigite Co2.5Ge0.5BO5 has been synthesized using the flux method. The compound undergoes two magnetic transitions: a long-range antiferromagnetic transition at TN1 = 84 K and a metamagnetic one at TN2 = 36 K. The sample-oriented magnetization measurements revealed a fully compensated magnetic moment along the a- and c-axes and an uncompensated one along the b-axis leading to high uniaxial anisotropy. A field-induced enhancement of the ferromagnetic correlations at TN2 is observed in specific heat measurements. The DFT+GGA calculation predicts the spin configuration of (↑↓↓↑) as a ground state with a magnetic moment of 1.37 μB/f.u. The strong hybridization of Ge(4s, 4p) with O (2p) orbitals resulting from the high electronegativity of Ge4+ is assumed to cause an increase in the interlayer interaction, contributing to the long-range magnetic order. The effect of two super–superexchange pathways Co2+-O-B-O-Co2+ and Co2+-O-M4-O-Co2+ on the magnetic state is discussed.This work has been financed by the Russian Foundation for Basic Research (project no. 20-02-00559). The authors acknowledge financial support from the Spanish Agencia Estatal de Investigación, through projects MAT2017-83468-R (AEI/FEDER, UE) and PID2020-115159GB-I00/AEI/10.13039/501100011033, the Aragonese project RASMIA E12_20R (co-funded by Fondo Social Europeo), and of the European Union FEDER (ES).Peer reviewe

Upper and lower gastrointestinal tract disorders in patients with newly diagnosed acromegaly

Background: Increased growth hormone production in acromegaly results in enlargement of inner organs, their dysfunction and morphological abnormalities. Of special interest are patients with newly diagnosed acromegaly, because their gastrointestinal mucosa can be assessed without consideration of the influence of medications used for the treatment of the underlying disorder. Aim: To describe characteristic features of upper and lower gastrointestinal tract disorders in patient with treatment-naive acromegaly. Materials and methods: We examined 37 patients with newly diagnosed acromegaly, aged from 22 to 73 years (mean age, 49.9 ± 2.1 years). All patients underwent esophagogastroduodenoscopy with biopsy for identification of Helicobacter pylori, colonoscopy, morphological examination of biopsy samples taken from neoplasms of the upper gastrointestinal tract, as well as of the colon. The control group included 35 individuals without acromegaly who were ageand gender compatible with the patients of the main group. Results: Cardiac insufficiency was diagnosed in 23 patients with acromegaly and in 13 in the control group (p &lt; 0.05), simultaneous lesions of the stomach and duodenal bulb (erosions), in 7 and 2 patients, respectively (p &gt; 0.05), gastric polypoids, in 6 patients of the main group and in no patient from the control group (p &lt; 0.05). There were no significant differences between groups on esophagitis Savary Miller Grade 1 and 2 (grading, Grade 1 in 7 and 5 patients and Grade 2 in 3 and 2, respectively), as well as on contamination with Helicobacter pylori (19 patients in each of the groups). Colon abnormalities were found in patients with acromegaly more frequently than in the control group: dolichosigma, in 12 and 4 (p &lt; 0.05), colonic polyps, in 13 and 2, respectively (p &lt; 0.01). Diverticles were found in 9 with acromegaly and in 3 in the control group (p &gt; 0.05). At histological examination, hyperplastic gastric polyps were found only in patients with acromegaly (6 patients, p &lt; 0.05), colonic polyps in 8 patients from the main group and in 2 from the control one (p &gt; 0.05). Tubular adenomas were diagnosed only in patients with acromegaly, in 2 of them they were located in the stomach (p &gt; 0.05) and in 5, in the colon (p &lt; 0.05). Conclusion: Right from the diagnosis, patients with acromegaly should undergo an examination of upper and lower gastrointestinal tract, because of the high probability of various disorders under high production of the growth hormone