Synthesis of High-Purity Silica Nanoparticles by Sol-Gel Method

Colloidal silica (silica sol) nanoparticles were synthesized by ammonia- and hydrochloric acid-catalyzed hydrolysis of tetraethoxysilane with subsequent condensation and polymerization. Silica particles with the size of 12‒160 nm were obtained at different temperatures and ratios of the initial reactants and studied by means of TEM, AFM, IR spectroscopy and zeta-potential measurements. The reaction conditions providing the minimum particle size in the final product of the most complete hydrolysis were determined. At pH above 8.5, an increase in the SiO2 content of the sol to 23 wt.% did not change the particle size. At a low (~ 1.8 wt.%) SiO2 content of the sol, a wide variation in pH also did not exert a significant effect on the particle size. Stability of the silica sols synthesized in an alkaline medium was enhanced by the replacement of alcohol with water during evaporation at pH 8.5‒9.5. The possibility to produce silica sols with the required characteristics (particle size, pH, stability, purity, and SiO2 content in an aqueous or alcohol medium) makes them applicable in various industries

The dependence of cylindrical resonator natural frequencies on the fluid density

The article examines the dependence of cylindrical resonator natural frequencies (sensitive element) on the density (mass) of different fluids flowing through it. The cylindrical resonators are being widely applied in automatic control systems of technological processes as oscillating transducer density meter. The article presents the experimental results that prove the dependence of natural frequencies and vibration amplitude on the fluid density

Synthesis of Nanoscale TiO2 and Study of the Effect of Their Crystal Structure on Single Cell Response

To study the effect of nanoscale titanium dioxide (TiO2) on cell responses, we synthesized four modifications of the TiO2 (amorphous, anatase, brookite, and rutile) capable of keeping their physicochemical characteristics in a cell culture medium. The modifications of nanoscale TiO2 were obtained by hydrolysis of TiCl4 and Ti(i-OC3H7)4 (TIP) upon variation of the synthesis conditions; their textural, morphological, structural, and dispersion characteristics were examined by a set of physicochemical methods: XRD, BET, SAXS, DLS, AFM, SEM, and HR-TEM. The effect of synthesis conditions (nature of precursor, pH, temperature, and addition of a complexing agent) on the structural-dispersion properties of TiO2 nanoparticles was studied. The hydrolysis methods providing the preparation of amorphous, anatase, brookite, and rutile modifications of TiO2 nanoparticles 3–5 nm in size were selected. Examination of different forms of TiO2 nanoparticles interaction with MDCK cells by transmission electron microscopy of ultrathin sections revealed different cell responses after treatment with different crystalline modifications and amorphous form of TiO2. The obtained results allowed us to conclude that direct contact of the nanoparticles with cell plasma membrane is the primary and critical step of their interaction and defines a subsequent response of the cell

Peripheral vascular lesions with the development of hand and foot skin necrosis in a patient with COVID-19: a case report

In the presented case report, 36-year-old female patient, who was hospitalized in the rheumatology department, developed thrombotic microangiopathy and sepsis-related coronavirus disease 2019 (COVID-19). In the department, hereditary thrombophilia was revealed: heterozygous polymorphism in the coagulation factor 5 gene (Factor V Leiden). Livedo reticularis. It is known that in October 2020, the patient had COVID-19 with bilateral pneumonitis on chest computed tomography. On examination, dry gangrene of 1, 2, 4, 5 fingers of the right hand, 2 finger of the left hand, as well as 2, 3, 4, 5 fingers of the right and left feet were diagnosed. Necrosis of the nasal tip. Surgery was performed with amputation of the affected fingers and distal feet with autodermoplasty

Investigation of the Sorption Properties of Ore Materials for the Removal of Sulfur Dioxide from Exhaust Flue Gases of Power Plants

The prospects of using a natural material – ferromanganese nodules (FMN) from the Gulf of Finland – as the SO2 adsorbent are discussed. The starting material was studied as pellets and powder using X-ray fluorescence spectroscopy, XRD, BET, and mechanical strength analysis; dependences of physicochemical parameters of the material on heat treatment at 100-1000 ºC were found. FMN samples were tested in the process of SO2 sorption. The sorptive capacity of FMN samples for SO2 was found to increase with humidity of adsorbents; FMN samples with a humidity above 40% were shown to be promising for the removal of sulfur dioxide from gase

Evaluation of Synthetic Conditions for H3PO4 Chemically Activated Rice Husk and Preparation of Honeycomb Monoliths

Activated carbons in this work were prepared from rice husk by phosphoric acid activation followed by alkaline desilication. Pseudo-random selection of 16 rice husk samples was subjected to carbonization at the following conditions: 0.5 to 2 h of activation time, 300-600 ºС and Н3РО4/precursor (wt/wt) impregnation ratio of 0.5 to 2. Concentration of NaOH desilication solution varied from 0.5 to 2M. It was found that out of the four factors impregnation ratio is clearly the strongest and at the impregnation ratio of 2 for 1 h at 500 °C N2 BET-surface area reaches 1690 m2/g (SBET (Ar)=2492 m2/g) while pore volume becomes 1.95 cm3/g. Elemental analysis showed highest carbon content for this sample (87.96%). All samples have insignificant amount of Si and traces of metals, but considerable amount of phosphorus. Blocks of honeycomb structure prepared from Ca-montmorillonite and desilicated carbonized rice husk (impregnation ratio is 1.5, 1 h at 600 ºC) have BET-surface area obtained by thermal desorption of argon up to 856 m2/g

Convultions assosiated with chemotherapy in a child with acute lymphoblastic leukemia. Clinical case

The aim of this study – to describe and analyse a clinical case of seizures during chemotherapy in a child with acute lymphoblastic leukemia.Цель исследования – описание и анализ клинического случая возникновения судорог на фоне проведения химиотерапии у ребёнка с острым лимфобластным лейкозом

Влияние дистресса на неоангиогенез у больных раком яичников

Background. Previous pre-clinical and clinical trials showed that distress experienced by cancer patients can activate the sympathetic nervous system, resulting in the elevation of the level of catecholamines in tumor tissue. catecholamines activate tumor neoangiogenesis via binding to the adrenergic receptors of tumor cells and cells of tumor microenvironment. Vascular endothelial growth factor a(VEgF a) plays a key role in tumor neoangiogenesis.Objective. To evaluate the correlation between serum VEgF alevel and distress in ovarian cancer patients.Material and methods. The prospective cross-sectional study included 100 patients with stage i–iV ovarian cancer. the median age of the patients was 56 ± 9,56 years. Enzym-linked immunosorbent assay was used for the assessment of serum VEgF alevel. distress thermometer (validated self-reported questionnaire) was used for distress diagnosis.Results. The median serum VEgF alevel was 325.77 pg/ml. aclinically significant distress was diagnosed in 54 % of patients. We found the correlation between the serum VEgF alevel and distress level in ovarian cancer patients (spearman’s rho=0.33; 95 % ci, 0.11–0.52; р< 0.004). We also found the correlation between the serum VEgR alevel and disease stage (rho=0.30; 95 % ci0.02–0.53; p<0.05). However, there was no correlation between distress and disease stage. the regression analysis method revealed that distress was an independent factor of serum VEgF aelevation in ovarian cancer patients (p<0.05).Conclusion. Assessment and early diagnosis of cancer-related distress was shown to be important for the appropriate management of ovarian cancer.Введение. По данным экспериментальных и клинических исследований, дистресс, испытываемый онкологическими пациентами, активирует симпатическую нервную систему, в результате чего повышается уровень катехоламинов в опухолевой ткани. Катехоламины, связываясь с адренорецептора-ми опухолевых клеток и клеток опухолевого микроокружения, активируют процессы неоангиогенеза опухоли. Ключевую роль в процессе неоангиогенеза опухоли играет фактор роста эндотелия сосудов семейства А (VEgF a).Цель исследования – оценить взаимосвязь уровня сывороточного VEgF aс дистрессом у больных раком яичников.Материал и методы. Проведено проспективное исследование «поперечного среза», в которое включено 100 пациенток с морфологически верифицированным раком яичников i–iV стадии, медиана возраста – 56 ± 9,56 года. Определение уровня VEgF aв сыворотке крови пациенток проводили методом иммуноферментного анализа. Для выявления дистресса применяли «Скрининговый опросник дистресса».Результаты. Медиана показателя сывороточного VEgF aу больных раком яичников составила 325,77 пг/мл. Клинически значимый дистресс был диагностирован у 54 % пациенток. Показатель сывороточного VEgF aстатистически значимо коррелировал с дистрес-сом (коэффициент ранговой корреляции Спирмена rho=0,33; 95 % ДИ=0,11–0,52, p<0,004) и стадией заболевания (rho=0,30; 95 % ДИ=0,02–0,53, p<0,05). При этом не было выявлено корреляции между дистрессом и стадией опухолевого процесса. Методом регрессионного анализа было установлено, что дистресс является независимым фактором, повышающим VEgF aв сыворотке крови больных раком яичников.Заключение. Проведенное исследование свидетельствует о важности диагностики и коррекции дистресса у больных раком яичников, так как данное состояние через стимуляцию процессов неоангиогенеза может влиять на прогрессирование опухолевого процесса

The stages of microbial colonization of a child's body in the first year of life (review)

The article presents a review of domestic and foreign literature on the main stages of microbial colonization of a child's body in the first year of life. The species composition of the microbiota of the child's body in different systems is presented. The factors affecting the formation of the child's microflora are analyzed.В статье представлен обзор отечественной и зарубежной литературы по основным этапам микробной колонизации организма ребёнка первого года жизни. Представлен видовой состав микробиоты организма ребёнка в разных системах. Проанализированы факторы, влияющие на формирование микрофлоры ребёнка

Eribulin-trastuzumab combination in HER2-positive metastatic breast cancer: updated results from a Russian observational study

Introduction. The standard of 1st line treatment of HER2+ metastatic breast cancer (mBC) is double blockade with trastuzumab and pertuzumab + taxane, 2nd line – Trastuzumab-emtazine. There are no standards for further treatment, as well as the optimal drug sequence. Expansion of the arsenal of therapeutic possibilities and the use of new combinations will certainly improve the results of treatment of this category of patients and increase their life expectancy.Aim. We sought to describe treatment patterns of  eribulin  and clinical outcomes of  metastatic HER2-positive breast cancer treated with eribulin  plus trastuzumab combination in  academic institutions and community oncology practices across the Russian Federation.Materials and methods. Patients treated with eribulin anytime between Jan, 2014 and Sep, 2019 with a diagnosis of MBC were identified by 23 providers from Russia. Providers retrospectively reviewed the health records and abstracted selected data points into an electronic case report form for each eligible patient.Results. 100 HER2-positive pts received eribulin in combination with trastuzumab. Median age was 55 (31–80) yrs and ECOG status 0–3. 67% pts had visceral metastases. Eribulin was administered as 1st and 2nd line to 23 (23%) pts, 3rd line to 31 (31%) pts, 4th line and later to 46 (46%). Median number of cycles was 5 (2–27). ORR was 12%, SD – 72%, SD > 6 months – 23%, PD – 16%. Clinical efficacy rate achieved in 35%. Median PFS was 5.07 months (95% CI 4.021–6.119). According to the ER-status the response to eribulin and trastuzumab was different. ORR was 18.8%, SD 72.9% in pts with ER-positive MBC (n = 48) and 5.8% and 71.2% respectively in ER-negative MBC (n = 52). Median PFS was 6.97 months (95% CI 3.924–10.016) in pts with ER-positive MBC and 4.67 months (95% CI 3.841–5.499) in ER-negative MBC (р = 0.3). The combination was well tolerated: dose reductions were required in 12% pts, withdrawal due to toxicity in 4% pts. The most common type of toxicity was hematological with neutropenia Gr III-IV in 14 (14%) pts. Peripheral neuropathy Gr III was observed in 5 (5%) pts. No cardiotoxicity was detected.Conclusions. This is the real-life data of clinical outcomes for patients receiving eribulin plus trastuzumab for HER2-positive MBC throughout the Russian Federation. Our experience with eribulin plus trastuzumab demonstrates that this combination may be a potential effective treatment option for HER-2 positive MBC patients