608 research outputs found
Comparison of solar activity proxies: eigen vectors versus averaged sunspot numbers
We attempt to establish links between a summary curve, or modulus summary
curve, MSC, of the solar background magnetic field (SBMF) derived from
Principal Component Analysis, with the averaged sunspot numbers (SSN). The
comparison of MSC with the whole set of SSN reveals rather close correspondence
of cycle timings, duration and maxima times for the cycles 12- 24, 6,7 and
-4,-3. Although, in 1720-1760 and 1830-1860 there are discrepancies in maximum
amplitudes of the cycles, durations and shifts of the maximum times between MSC
and SSN curves. The MSC curve reveals pretty regular cycles with double maxima
(cycles 1-4), triple maximum amplitude distributions for cycles 0 and 1 and for
cycles -1 and -2 just before Maunder minimum. The MSC cycles in 1700-1750
reveal smaller maximal magnitudes in cycles -3 to 0 and in cycle 1-4 than the
amplitudes of SSN, while cycles -2 to 0 have reversed maxima with minima with
SSN. Close fitting of MSC or Bayesian models to the sunspot curve distorts the
occurrences of either Maunder Minimum or/and modern grand solar minimum
(2020-2053). These discrepancies can be caused by poor observations and by
difference in solar magnetic fields responsible for these proxies. The dynamo
simulations of toroidal and poloidal magnetic field in the grand solar cycle
(GSC) from 1650 until 2050 demonstrate the clear differences between their
amplitude variations during the GSC. The use of eigen vectors of SBMF can
provide additional information to that derived from SSN that can be useful for
understanding solar activity.Comment: 23 pages, 9 figur
Phenotypes of Non-Alcoholic Fatty Liver Disease in Different Regions of the Russian Federation, Diagnostic and Therapeutic Approach in Clinical Practice
Аim: to present data on the prevalence of various phenotypes of non-alcoholic fatty liver disease (NAFLD), the features of its diagnosis and treatment in various regions of the Russian Federation following a meeting of chief gastroenterologists.Key points. Non-alcoholic fatty liver disease (NAFLD) holds the leading position among non-infectious liver diseases in the Russian Federation, its prevalence is 37.3 % and does not tend to decrease.To get information on various aspects of NAFLD diagnosis and treatment, opinion of 18 chief external regional gastroenterologists and leading specialists in the field of liver diseases was studied by analyzing the responses to questions specially formulated for them. Information on the situation in the Ural, Privolzhsky, Southern, Central and Northwestern Federal Districts was obtained. Regional statistics on the prevalence of NAFLD and its certain phenotypes (steatosis, steatohepatitis, cirrhosis), diagnostic instruments and treatment approaches which are used in clinical practice, as well as on the most common associated conditions was presented.Conclusions. The collected information allows to improve both administrative and treatment and diagnostic-related activities in managing patients suffering from this disease
Phenotypes of Non-Alcoholic Fatty Liver Disease in Different Regions of the Russian Federation, Diagnostic and Therapeutic Approach in Clinical Practice
Aim: to present data on the prevalence of various phenotypes of non-alcoholic fatty liver disease (NAFLD), the features of its diagnosis and treatment in various regions of the Russian Federation following a meeting of chief gastroenterologists.Key points. Non-alcoholic fatty liver disease (NAFLD) holds the leading position among non-infectious liver diseases in the Russian Federation, its prevalence is 37.3 % and does not tend to decrease.To get information on various aspects of NAFLD diagnosis and treatment, opinion of 18 chief external regional gastroenterologists and leading specialists in the field of liver diseases was studied by analyzing the responses to questions specially formulated for them. Information on the situation in the Ural, Privolzhsky, Southern, Central and North-western Federal Districts was obtained. Regional statistics on the prevalence of NAFLD and its certain phenotypes (steatosis, steatohepatitis, cirrhosis), diagnostic instruments and treatment approaches which are used in clinical practice, as well as on the most common associated conditions was presented.Conclusions. The collected information allows to improve both administrative and treatment and diagnostic-related activities in managing patients suffering from this disease
X-ray photoelectron study of electron density distribution in palladium(II) β-diketonate complexes
SPECTRAL RESPONSE IN LASER SYNTHESIZED WxMo(1-x)S2 ALLOYS
We report the spectral response of 2D WxMo1-xS2 alloys based photoconductors fabricated by direct laser synthesis of single source precursors. A comparative study for the main figure of merits of these devices is presented
Clinical Recommendations of the Russian Scientific Liver Society and Russian Gastroenterological Association on Diagnosis and Treatment of Liver Fibrosis, Cirrhosis and Their Complications
Aim. Current clinical recommendations are intended to supply gastroenterologists, physicians and general practitioners with modern methods for the diagnosis and treatment of liver cirrhosis and fibrosis.Key points. Liver fibrosis develops with connective tissue accumulation in liver in the outcome of various chronic diseases, including alcohol misuse, viral hepatitises, autoimmune and more rare hereditary liver diseases. Liver cirrhosis is the final stage of most chronic diffuse liver diseases. The recommendations present current opinions on pathogenesis of liver fibrosis and cirrhosis, principles of diagnosis, treatment and prevention of their main complications: hepatic encephalopathy, oesophageal and gastric variceal bleeding, acute kidney injury/hepatorenal syndrome, infectious complications (i.a. spontaneous bacterial peritonitis), hyponatraemia, pulmonary complications, etc.Conclusion. Timely diagnosis and adequate therapy in cirrhosis can prevent life-threatening complications and improve the patients’ prognosis and quality of life
Primary Terminal Haemochromatosis in a 50 Year-Old Patient
Aim. A clinical description of end-stage hereditary haemochromatosis manifested with chronic alcohol abuse.Key points. A 50-yo patient referred with marked general weakness as a major complaint. The patient had a history of long-term alcohol consumption at toxic doses, putative cirrhosis, paroxysmal atrial fibrillation, type 2 diabetes mellitus. The patient's severity on admission was conditioned by marked hypotension. Further examination aimed at excluding occult gastrointestinal bleeding, adrenal insufficiency, decompensated heart failure. Bronze skin and icteric sclerae were positive. Blood tests revealed severe macrocytic hyperchromic anaemia, thrombocytopae-nia, hyperbilirubinaemia, hypoalbuminaemia, hypocoagulation, elevated transaminases, hyponatraemia, elevated creatinine (CKD DPI 63 mL/min), severe hyperferritinaemia. Faecal occult blood test and EGDS for bleeding were negative. Abdominal ultrasound exposed signs of liver cirrhosis and portal hypertension (ascites, splenomegaly). Echocardiographic evidence of dilated cardiomyopathy of all chambers, a reduced 24% ejection fraction at absent acute myocardial infarction. Primary haemochromatosis was suspected upon high ferritin, transferrin iron saturation and multiple organ dysfunction. Genotyping revealed the HFE 845G > A variant diagnostic of haemochromatosis type 1. Clinical diagnosis: Primary disease: haemochromatosis (homozygous variant HFE 845G > A (A/A)): liver cirrhosis, Child-Pugh class C. Portal hypertension: splenomegaly, ascites. Dilated cardiomyopathy. Diabetes mellitus. Complications: multiple organ dysfunction (SOFA 16). Liver failure: jaundice, hypoalbuminaemia, hypocoagulation. Cardiac rhythm and conduction disorder: paroxysmal atrial fibrillation. Acute cardiac failure with underlying CHF IIb, NYHA class 3. Acute renal failure (anuria) with underlying CKD stage 3 (CKD DPI 63 mL/min). Moderate macrocytic hyperchromic anaemia. Acute and chronic adrenal failure. Despite a cardiovascular and renal failure compensation therapy and albumin transfusion, the patient died. Autopsy revealed a marked organ infiltration with haemosiderin (heart, stomach, liver, pancreas, lungs, kidneys, adrenal glands).Conclusion. The case describes a classical clinical manifestation of haemochromatosis: bronze skin hyperpigmentation, liver cirrhosis, diabetes mellitus, cardiomyopathy, adrenal insufficiency. Terminal haemochromatosis, severe cardiac and renal failure decompensation precluded phlebotomy and chelation therapy. A lethal outcome was conditioned by multiple organ dysfunction with underlying massive haemosiderin deposition in most organs
Electrospun magnetic composite poly-3-hydroxybutyrate/magnetite scaffolds for biomedical applications: composition, structure, magnetic properties, and biological performance
Magnetically responsive composite polymer scaffolds have good potential for a variety of biomedical applications. In this work, electrospun composite scaffolds made of polyhydroxybutyrate (PHB) and magnetite (Fe3O4) particles (MPs) were studied before and after degradation in either PBS or a lipase solution. MPs of different sizes with high saturation magnetization were synthesized by the coprecipitation method followed by coating with citric acid (CA). Nanosized MPs were prone to magnetite-maghemite phase transformation during scaffold fabrication, as revealed by Raman spectroscopy; however, for CA-functionalized nanoparticles, the main phase was found to be magnetite, with some traces of maghemite. Submicron MPs were resistant to the magnetite-maghemite phase transformation. MPs did not significantly affect the morphology and diameter of PHB fibers. The scaffolds containing CA-coated MPs lost 0.3 or 0.2% of mass in the lipase solution and PBS, respectively, whereas scaffolds doped with unmodified MPs showed no mass changes after 1 month of incubation in either medium. In all electrospun scaffolds, no alterations of the fiber morphology were observed. Possible mechanisms of the crystalline-lamellar-structure changes in hybrid PHB/Fe3O4 scaffolds during hydrolytic and enzymatic degradation are proposed. It was revealed that particle size and particle surface functionalization affect the mechanical properties of the hybrid scaffolds. The addition of unmodified MPs increased scaffolds' ultimate strength but reduced elongation at break after the biodegradation, whereas simultaneous increases in both parameters were observed for composite scaffolds doped with CA-coated MPs. The highest saturation magnetization-higher than that published in the literature-was registered for composite PHB scaffolds doped with submicron MPs. All PHB scaffolds proved to be biocompatible, and the ones doped with nanosized MPs yielded faster proliferation of rat mesenchymal stem cells. In addition, all electrospun scaffolds were able to support angiogenesis in vivo at 30 days after implantation in Wistar rats
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