481 research outputs found
Luminescent properties of Bi-doped polycrystalline KAlCl4
We observed an intensive near-infrared luminescence in Bi-doped KAlCl4
polycrystalline material. Luminescence dependence on the excitation wavelength
and temperature of the sample was studied. Our experimental results allow
asserting that the luminescence peaked near 1 um belongs solely to Bi+ ion
which isomorphically substitutes potassium in the crystal. It was also
demonstrated that Bi+ luminescence features strongly depend on the local ion
surroundings
EFFECTS OF AMLODIPIN AND METOPROLOL ON AUTONOMIC SYSTEM IN EMOTIONAL AND COLD TESTS IN HYPERTENSIVE PATIENTS WITH DIFFERENT PSYCHOLOGICAL PROFILE
Aim. To asses effects of amlodipin and metoprolol on autonomic system in emotional and cold tests in hypertensive patients with different psychological profile (PP) Material and methods. 61 patients with arterial hypertension of II grade were observed. Therapy with amlodipin or metoprolol was prescribed and allowed to reach target blood pressure (BP) level in all the patients. Patients were divided into 2 groups: 1-st one – patients with normal PP, 2-nd group – patients with subclinical depression. Patients were examined before and 30 days after therapy. Examination included ambulatory BP monitoring, assessment of autonomic status by variational intervalometry and spectral analysis of heart rate variability (HRV) in cold and emotional tests. Depression and anxiety levels were determined with Bek’s and HADS scales. Results. Treatment with amlodipin and metoprolol can result in improvement, worsening or unchanging of PP. In hypertensive patients with subclinical depression improving their PP resulted in autonomic reaction change: sympathetic activity increases and reaction on stress becomes more adequate. If subclinical depression occurred in hypertensive patients because of amlodipin and metoprolol therapy, sympathetic system stress-reaction decreased and parasympathetic influence increased. Conclusion. The study results show necessity of psychometric examination of hypertensive patients in order to reveal subclinical depression and anxiety
Analysis of medical and social factors affecting the formation and course of co-infection HIV, tuberculosis and viral hepatitis
Currently, HIV infection is characterized by emergence of its severe and comorbid forms. Mid-1990 HIV epidemics was expanded due to injection drug users who brought viral hepatitis C to the cohort. Along with developing immunosuppression, opportunistic and AIDS-defining diseases, including tuberculosis emerged. Various combinations of coinfections (HIV infection+tuberculosis±viral hepatitis) affect clinical manifestations and clinical score, reduce the therapeutic efficacy and worsen disease prognosis.Objective: to study an impact medical and social factors on course of TB-co-infection associated with immunosuppression related to HIV infection and viral hepatitis.Materials and methods. Comorbid cases (HIV infection, tuberculosis and chronic hepatitis) dominated by verified TB-infection (n = 137) were analyzed.Results. It was shown that socially maladapted young people with previous experience of intravenous drug and alcohol abuse dominated among subjects with co-infections, half of which were held in penal institutions. More-over, the mean CD4 lymphocyte level in generalized tuberculosis was significantly lower than in patients with significantly reaching 164±21.5 cells. In addition, lung-specific lesions were observed in 73.4% of patients with generalized tuberculosis that developed by initial targeting of the lymphoid system followed by affecting other organs, mainly the central nervous system, urinary system and abdominal organs. Introduction of antiretroviral drugs to anti-TB therapy reduced mortality rate by 8 times. Viral hepatitis was the most common concomitant disease found in co-infected patients, with dominating viral hepatitis C both as a mono-infection (86.8%) as well as in combination with viral hepatitis B (9.43%). In addition, co-morbid viral hepatitis resulted in progression of TB infection affected due to intra-thoracic lymph nodes being involved in tuberculosis process as well as development of opportunistic diseases due to a markedly decreased CD4 cell count. Analysis of potentially aggravating risk factors for developing hepatotoxicity (viral hepatitis, combined treatment with anti-TB and anti-retroviral drugs) did not reveal their any additional negative impact on hepatic functions. Thus, use of a combination therapy with anti-TB and anti-retroviral drugs in co-infected patients was shown to be safe and not accompanied by a high rate of hepatotoxic reactions
Non-alcoholic fatty liver disease as a risk factor for anemia of chronic inflammation (experimental research)
The aim of the study. In recent years, non-alcoholic fatty liver disease (NAFLD) has been considered a hepatic manifestation of the metabolic syndrome. The main consequence of NAFLD is chronic hepatic inflammation, which leads to dyslipidemia, inflammation, increased oxidative stress, and endothelial dysfunction. Immune activation in response to interaction with agents of a metabolic nature induces the release of pro-inflammatory cytokines in the liver, which subsequently cause iron сhomeostasis disorder. This leads to a frequent association of NAFLD with anemia of various etiology. In this regard, we considered it important to assess the severity of the systemic inflammatory response in NAFLD in the experiment in order to -diagnose anemia of chronic inflammation.Materials and methods. The study was carried out on 26 male Wistar rats, which were divided into control and experimental groups. In animals of the experimental group, NAFLD was modeled according to the generally accepted method. In order to assess metabolic disorders, we determined the main biochemical parameters, a complete blood count with the calculation of erythrocyte indices, the concentration of the main pro-inflammatory cytokines – interleukin (IL) 1, IL-6. Results. In laboratory rats with NAFLD, a statistically significant increase of intrahepatic enzymes in blood serum was found. The state of the erythrocyte lineage of hematopoiesis in the experimental group progressively worsened and caused the development of anemic syndrome. Synchronously, a statistically significant increase in serum levels of IL-1, IL-6 was recorded, which confirms the correlation of NAFLD with anemia of chronic inflammation.Conclusions. A high concentration of IL-1, IL-6 cytokines in NAFLD inhibits iron absorption in the duodenum, leads to the activation of macrophages, blocking the release of iron processed from aging erythrocytes into plasma. Further study of the mechanisms of anemia in NAFLD provides important therapeutic targets in the treatment of both NAFLD and its comorbidities
Easy-plane to easy-axis anisotropy switching in a Co(ii) single-ion magnet triggered by the diamagnetic lattice
Single ion magnets SIMs with large magnetic anisotropy are promising candidates for realization of single molecule based magnetic memory and qubits. Creation of materials with magnetically uncoupled spatially separated SIMs requires dilution in a diamagnetic matrix. Herein, we report that progressive dilution of paramagnetic Co II by diamagnetic Zn II in the SIM [CoxZn 1 amp; 8722;x piv 2 2 NH2 Py 2], x 1 0 beyond a threshold of 50 reveals an abrupt structural change, where the distorted tetrahedral Zn coordination structure is superimposed on the remaining Co ions, which were initially in a distorted octahedral environment. Dilution induced structure modification switches the magnetic anisotropy from easy plane D 36.7 cm amp; 8722;1 to easy axis type D amp; 8722;23.9 cm amp; 8722;1 , accompanied by a fivefold increase of the magnetic relaxation time at 2 K. Changes of the static and dynamic magnetic properties are monitored by electron paramagnetic resonance spectroscopy and AC susceptibility measurements. Complementary quantum chemical ab initio calculations quantify the influence of structural changes on the electronic structure and the magnetic anisotropy. Thus, magnetic dilution hits two goals at once, the creation of isolated magnetic centres and an improvement of their SIM propertie
Основные направления совершенствования технологической подготовки морских инженеров
The paper contains a training structure for ship-builders which is accepted at higher educational institutions of Russian Federation. A special attention is paid to the necessity of a continuous training (in computers, machine drawing, mathematics, languages, technologies) during the whole educational process. In order to improve the educational process quality it is recommended to integrate enterprises’ resources (personnel and production) into it. The paper reveals fields of cooperation, some joint projects in tile sphere of shipbuilding to be realized in the Republic of Belarus.Приводится структура подготовки специалистов по судостроению, принятая в вузах РФ. Обращается внимание на необходимость непрерывной подготовки (компьютерной, математической, по машинной графике, языковой, технологической) в ходе учебного процесса. Для повышения качества учебного процесса рекомендуется интегрировать ресурсы предприятий (кадровые и производственные). Приводятся области сотрудничества, совместные проекты в сфере судостроения для реализации в Республике Беларусь
FTIR study of thermally induced magnetostructural transitions in breathing crystals
© 2015 American Chemical Society. "Breathing crystals" based on copper(II) hexafluoroacetylacetonates and pyrazolyl-substituted nitronyl nitroxides comprise the exchange-coupled clusters within the polymeric chains. Owing to an interplay of exchange interaction between copper(II) and nitroxide spins and Jahn-Teller nature of copper(II) complex, the breathing crystals demonstrate thermally and light-induced magnetostructural transitions in many aspects similar to the classical spin crossover. Herewith, we report the first application of variable temperature (VT) far/mid Fourier transform infrared (FTIR) spectroscopy and mid FTIR microscopy to breathing crystals. This VT-FTIR study was aimed toward clarification of the transitions mechanism previously debated on the basis of superconducting quantum interference device, X-ray diffraction, and electron paramagnetic resonance data. VT-FTIR showed the onset of new vibrational bands during phase transitions occurring at the expense of several existing ones, whose intensity was significantly reduced. The most pronounced spectral changes were assigned to corresponding vibrational modes using quantum chemical calculations. A clear-cut correlation was found between temperature-dependent effective magnetic moment of studied compounds and the observed VT-FTIR spectra. Importantly, VT-FTIR confirmed coexistence of two types of copper(II)-nitroxide clusters during gradual magnetostructural transition. Such clusters correspond to weakly coupled and strongly coupled spin states, whose relative contribution depends on temperature. The pronounced difference in the VT-FTIR spectra of two states in breathing crystals is a fingerprint of magnetostructural transition, and understanding of these characteristics achieved by us will be useful for future studies of breathing crystals as well as their diamagnetic analogues
EPIDEMIOLOGY OF PRIMARY HIP ARTHROPLASTY: REPORT FROM REGISTER OF VREDEN RUSSIAN RESEARCH INSTITUTE OF TRAUMATOLOGY AND ORTHOPEDICS
The paper presents data analysis of the Hip Arthroplasty Register of Vreden Russian Research Institute of Traumatology and Orthopedics, namely information on 37373 primary THA performed at the Vreden Institute and at several other orthopedic centers and 1200 hip replacements at other hospitals of St. Petersburg.There were 1.5 times more women in the studied cohort than men. A significant predominance of women with dysplastic osteoarthritis (72.4%) and rheumatoid arthritis (82.1%) was reported. A male predominance was noted in patients with secondary osteoarthritis (53.1%), post-traumatic changes of hip (61.0%) and osteonecrosis of the femoral head (68.6 %). The mean age of patients was 58.0±12.9 years (95% CI from 57.9 to 58.1, median 59 years). Age data of the study revealed that patients were 10-12 years younger than reported in the national arthroplasty registers of other countries.Total hip arthroplasty was performed in the absolute majority of patients – 37295 cases (99,8%). Uncemented implants were used in 59.3% of cases, hybrid – in 29.6%, cemented – in 10.2%, reverse-hybrid – in 0.9% of all patients. The most common bearing used was metal on crosslink polyethylene, which was applied in 50.1% of all cases of arthroplasty. The type of fixation of the implant, and the use of different bearings varied in different age groups. The paper presents not only the absolute numbers of the data, but also demonstrated the dynamics of the changes in time starting from 2007.The present epidemiological study does not claim the absolute completeness of the presented data, but contains the analysis of the large number of cases, comparable with follow-ups of patients in some national registers of certain European countries. The authors analyzed about 10% of all cases of hip replacements performed on the territory of the Russian Federation in ten-year period
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