Physical properties of thermoelectric zinc antimonide using first-principles calculations

We report first principles calculations of the structural, electronic, elastic and vibrational properties of the semiconducting orthorhombic ZnSb compound. We study also the intrinsic point defects in order to eventually improve the thermoelectric properties of this already very promising thermoelectric material. Concerning the electronic properties, in addition to the band structure, we show that the Zn (Sb) crystallographically equivalent atoms are not exactly equivalent from the electronic point of view. Lattice dynamics, elastic and thermodynamic properties are found to be in good agreement with experiments and they confirm the non equivalency of the zinc and antimony atoms from the vibrational point of view. The calculated elastic properties show a relatively weak anisotropy and the hardest direction is the y direction. We observe the presence of low energy modes involving both Zn and Sb atoms at about 5-6 meV, similarly to what has been found in Zn4Sb3 and we suggest that the interactions of these modes with acoustic phonons could explain the relatively low thermal conductivity of ZnSb. Zinc vacancies are the most stable defects and this explains the intrinsic p-type conductivity of ZnSb.Comment: 33 pages, 8 figure

Complex-Radical Terpolymerization of Maleic Anhydride (Styrene), Allyl Propionate and Methyl Methacrylate

The radical terpolymerization reactions of the acceptor-donor-acceptor and donor-acceptor-donor systems, maleic anhydride (MA)-allyl propionate (AP)-methyl methacrylate (MMA) and styrene (St)-MMA-AP, had been studied. The terpolymerizations were carried out in methyl ethyl ketone at 60-75 °C in the presence of 2,2’-azoisobutyronitrile (ABIN) used as the initiator. Some kinetic parameters and copolymerization constants - for both, system were determined by dilatometric and Kelen-Tudos or Seiner-Lift methods. The obtained results are discussed in terms of the free monomer and complex chain growth models. It is shown that terpolymerization was carried out at a stage close to binary copolymerization of MA...AP complex with free MMA and St...MMA complex with AP in the both studied system, respectively. These systems are also used as model for interpretation of cyclocopolymerization mechanism in allyl methactylate-MA (or St) system. DTA and TGA analyses indicated the relatively high thermal stability of St-MMA-AP terpolymer. It is shown that this terpolymer decomposes through a one-step reaction at 310 °C, however MA-AP-MMA terpolymer decomposes through a multi-step reactions at 150, 260 and 310 °C

Concerning the issue of early diagnostics of low tannin content in faba bean seeds (<i>Vicia faba</i> L.)

Background. The use of faba bean (Vicia faba L.) as a feed and food plant is hindered by the presence of antinutritional substances and in particular phenolic compounds – tannins – in the seed coat. The existence of low-tannin or zero-tannin forms in the faba bean gene pool allows breeders to promote this trait. The aim of this work was to carry out biochemical validation of a known morphological marker of low tannin content and identify relationships of some phenotypic traits characterized by accumulation of phenolic compounds (tannins and anthocyanins) with their concentration for use as additional morphological markers of the low content of these antinutrients in bean seeds.Materials and methods. Associations of the presence/absence of anthocyanin in seedlings, pigmentation on petals, and dark extrafloral nectaries on stipules with the content of tannins and anthocyanins were analyzed in 10 faba bean accessions with different seed coat colors from the VIR collection. The plants were grown and evaluated in Leningrad Province in 2020–2021. Tannins in seeds were assessed using Leventhal’s method. Anthocyanins were analyzed in the green biomass of plants using a spectrophotometric method.Results and conclusion. Different combinations of the studied morphological features associated with the coloration of the studied organs were found. A high positive correlation between the levels of anthocyanins and tannins (r = 0.79) was identified as well as a direct connection of the high value of these traits with the presence of a dark extrafloral nectary on stipules and anthocyanin in seedlings. The absence of anthocyanin staining on seedlings and the absence of dark-colored extrafloral nectaries on stipules can serve as markers of low-tannin genotypes in the early stages of plant development. The light seed coat color that does not darken for a long time may also be the evidence of low tannin content

Pilot study of transcranial photobiomodulation of lymphatic clearance of beta-amyloid from the mouse brain: breakthrough strategies for non-pharmacologic therapy of Alzheimer's disease

In this pilot study, we analyzed effects of transcranial photobiomodulation (tPBM, 1267 nm, 32 J/cm2) on clearance of beta-amyloid (Aβ) from the mouse brain. The immunohistochemical and confocal data clearly demonstrate the significant reduction of deposition of Aβ plaques in mice after tPBM vs. untreated animals. The behavior tests showed that tPBM improved the cognitive, memory and neurological status of mice with Alzheimer’s disease (AD). Using of our original method based on optical coherence tomography (OCT) analysis of clearance of gold nanorods (GNRs) from the brain, we proposed possible mechanism underlying tPBM-stimulating effects on clearance of Aβ via the lymphatic system of the brain and the neck. These results open breakthrough strategies for a non-pharmacological therapy of Alzheimer’s disease and clearly demonstrate that tPBM might be a promising therapeutic target for preventing or delaying Alzheimer’s disease

Fatty Acid Binding Domain Mediated Conjugation of Ultrafine Magnetic Nanoparticles with Albumin Protein

A novel bioconjugate of stearic acid capped maghemite nanoparticle (γ-Fe2O3) with bovine serum albumin (BSA) was developed by taking recourse to the fatty acid binding property of the protein. From FT-IR study, it was found that conjugation took place covalently between the amine group of protein molecule and carboxyl group of stearic acid capped maghemite nanoparticle. TEM study further signified the morphology of the proposed nanobioconjuagte. The binding constant of nanoparticle with protein molecule was evaluated from the optical property studies. Also, magnetic measurement (M–H) showed retaining of magnetic property by significant values of saturation magnetization and other hysteretic parameters

Особенности получения биодизеля первого поколения в аппарате с вихревым слоем

The possibility of intensifying the process of transesterification of triglycerides of carboxylic acids of vegetable oils with alcohols C1-C3 in the presence of potassium hydroxide in an apparatus with a vortex sheet is shown. Analysis of the composition of mixtures of methyl esters of carboxylic acids of sunflower oil showed that the redistribution of hydrogen and the destructive transformation in the system take place along with the transesterification reactions. This results in the expenditure of octadecyl acid ether.Показана возможность интенсификации процесса переэтерификации триглицеридов карбоновых кислот растительных масел спиртами С1-С3 в присутствии гидроксида калия в аппарате с вихревым слоем. Анализ состава смесей метиловых эфиров карбоновых кислот подсолнечного масла показал, что наряду с переэтерификацией в системе протекают реакции перераспределения водорода и деструктивные превращения, приводящие к исчезновению в биодизеле метилового эфира октадеценовой кислоты

Состояние микрофлоры кишечника у госпитализированных детей с острыми кишечными инфекциями

The purpose of this study was to study the state of the intestinal microflora in young children who received inpatient treatment for acute intestinal infections. A study of the microflora in 183 children aged 0 months. up to 3 years of life. At the same time, 43 (23.5%) children received breast milk, 53 (29.0%) were artificially fed and 87 (47.5%) mixed-fed children. All children were examined by bacteriological method. Conditionally pathogenic flora among hospitalized patients was detected in 114 (62.3%), Candida was mainly detected in 67.5% of cases, in 57 patients (50.0%) in association with other opportunistic microorganisms — Candida + St. aureus — in 32 (28.1%), Candida + P. vulgaris — in 9 (7.9%), Candida + + P. vulgaris + St. aureus — in 12 (10.5%), Candida + St. aureus + Ps. aeroginosa — in 4 (3.5%). As a result of studying the composition of the intestinal microflora in patients hospitalized with intestinal infection, a decrease in the number of E. coli and B. bifidum was found, 43.7% and 63.4%, respectively.Целью данного исследования явилось изучение состояния микрофлоры кишечника у детей раннего возраста, получавших стационарное лечение по поводу острых кишечных инфекций. Проведено исследование состояния микрофлоры у 183 детей в возрасте от 0 мес. до 3 лет жизни. При этом 43 (23,5%) ребенка получали грудное молоко, 53 (29,0%) находились на искусственном и 87 (47,5%) детей на смешанном вскармливании. Все дети обследовались бактериологическим методом. Среди госпитализированных детей условно-патогенная флора была выявлена у 114 (62,3%) больных, в основном определялась Candida — в 67,5% случаях , у 57 больных (50,0%) — в ассоциации с другими условно-патогенными микроорганизмами — Candida + St. aureus — у 32 (28,1%), Candida + P. vulgaris — у 9 (7,9%), Candida + P. vulgaris + St. aureus — у 12 (10,5%), Candida + St. aureus + Ps. aeroginosa — у 4 (3,5%). В результате изучения состава микрофлоры кишечника у госпитализированных с кишечной инфекцией больных установлено снижение количества E. coli и B. bifidum, соответственно в 43,7% и 63,4% случаев

P2Y2 and P2Y6 receptor activation elicits intracellular calcium responses in human adipose-derived mesenchymal stromal cells

Adipose tissue contains self-renewing multipotent cells termed mesenchymal stromal cells. In situ, these cells serve to expand adipose tissue by adipogenesis, but their multipotency has gained interest for use in tissue regeneration. Little is known regarding the repertoire of receptors expressed by adipose-derived mesenchymal stromal cells (AD-MSCs). The purpose of this study was to undertake a comprehensive analysis of purinergic receptor expression. Mesenchymal stromal cells were isolated from human subcutaneous adipose tissue and confirmed by flow cytometry. The expression profile of purinergic receptors was determined by quantitative real-time PCR and immunocytochemistry. The molecular basis for adenine and uracil nucleotide-evoked intracellular calcium responses was determined using Fura-2 measurements. All the known subtypes of P2X and P2Y receptors, excluding P2X2, P2X3 and P2Y12 receptors, were detected at the mRNA and protein level. ATP, ADP and UTP elicited concentration-dependent calcium responses in mesenchymal cells (N = 7–9 donors), with a potency ranking ADP (EC50 1.3 ± 1.0 μM) > ATP (EC50 2.2 ± 1.1 μM) = UTP (3.2 ± 2.8 μM). Cells were unresponsive to UDP (< 30 μM) and UDP-glucose (< 30 μM). ATP responses were attenuated by selective P2Y2 receptor antagonism (AR-C118925XX; IC50 1.1 ± 0.8 μM, 73.0 ± 8.5% max inhibition; N = 7 donors), and UTP responses were abolished. ADP responses were attenuated by the selective P2Y6 receptor antagonist, MRS2587 (IC50 437 ± 133nM, 81.0 ± 8.4% max inhibition; N = 6 donors). These data demonstrate that adenine and uracil nucleotides elicit intracellular calcium responses in human AD-MSCs with a predominant role for P2Y2 and P2Y6 receptor activation. This study furthers understanding about how human adipose-derived mesenchymal stromal cells can respond to external signalling cues

Algorithm of physical diagnostics of dorsopathies of the cervical and thoracic spine

The article presents an algorithm tor the physical examination of patients suffering from degenerative-dystrophic diseases of the spine. Dorsopathies of the cervical and thoracic spine are manifested in a variety of different symptoms, and differential diagnosis comes with a wide range of diseases. Every physician involved in the rehabilitation of patients with this type of pathology should receive a systematic understanding of the physical diagnosis, which allows avoiding damage to the patient's health and obtaining the maximum effect in treatment.В статье представлен алгоритм физикального обследования пациентов, страдающих дегенеративно-дистрофическими заболеваниями позвоночника. Дорсопатии шейного и грудного отдела позвоночника проявляются множеством различных симптомов, а дифференциальная диагностика идет с широким спектром заболеваний. Каждый врач, занимающийся реабилитацией больных с данным видом патологии, должен получить системное представление о физикальной диагностики, позволяющее избежать нанесения вреда здоровью пациента и получить максимальный эффект в лечении

РОЛЬ ОППОРТУНИСТИЧЕСКИХ ИНФЕКЦИЙ В ВОЗНИКНОВЕНИИ ОСЛОЖНЕНИЙ У ДЕТЕЙ

The article highlights problems in the diagnosis of opportunistic infections (OI), shows the frequency of detection of acute infections in children with immunodeficiency and without marked disturbances in the immune system. The mothers and their ailing children were surveyed, The children were diagnosed with immune neutropenia. High presence of opportunistic infection pathogens was revealed both in mothers and in children. 4,5% of cases proved the mother to be the source of infection. The article discusses the role of causative agents of OI in the etiology of obstructive bronchitis and prolonged subfebrility in children. В статье освещены вопросы диагностики оппортунистических инфекций (ОИ), показана частота выявления острых форм инфекции у детей с иммунодефицитом и без выраженных нарушений в иммунной системе. Проведены наблюдения за парами мать — ребенок, где ребенок болен иммунной нейтропенией и была показана высокая инфицированность как матерей, так и детей возбудителями ОИ. В 4,5% случаев была доказана роль матери как источника инфекции. Определена роль возбудителей ОИ в этиологии обструктивных бронхитов и длительных субфебрилитетов у детей.