110 research outputs found
Nonlinear nonlocal Douglas identity
We give Hardy-Stein and Douglas identities for nonlinear nonlocal
Sobolev-Bregman integral forms with unimodal L\'evy measures. We prove that the
corresponding Poisson integral defines an extension operator for the
Sobolev-Bregman spaces. We also show that the Poisson integrals are
quasiminimizers of the Sobolev-Bregman forms.Comment: 25 page
Synthesis and Catalytic Study of NiAg Bimetallic Core–Shell Nanoparticles
This publication presents the synthesis of core–shell nanoparticles, where the core was Ni, and the shell was a Ag–Ni nano alloy. The synthesis was based on the reduction of Ni and Ag ions with sodium borohydride in the presence of trisodium citrate as a stabilizer. In order to determine the phase composition of the obtained nanoparticles, an XRD study was performed, and in order to identify the oxidation states of the nanoparticle components, an XPS spectroscopic study was performed. The composition and shape of the particles were determined using the HR-TEM EDS test. The obtained nanoparticles had a size of 11 nm. The research on catalytic properties was carried out in the model methylene blue reduction system. The investigation of the catalytic activity of colloids was carried out with the use of UV–Vis spectrophotometry. The Ag–Ni alloy was about ten times more active than were pure silver nanoparticles of a similar size
Prevalence and control of cardiovascular risk factors in Poland : assumptions and objectives of the NATPOL 2011 Survey
Milk-Derived Carbon Quantum Dots: Study of Biological and Chemical Properties Provides Evidence of Toxicity
Carbon dots (CDs) are carbon-based zero-dimensional nanomaterials that can be prepared from a number of organic precursors. In this research, they are prepared using fat-free UHT cow milk through the hydrothermal method. FTIR analysis shows C=O and C-H bond presence, as well as nitrogen-based bond like C-N, C=N and –NH2 presence in CDs, while the absorption spectra show the absorption band at 280 ± 3 nm. Next, the Biuret test was performed, with the results showing no presence of unreacted proteins in CDs. It can be said that all proteins are converted in CDs. Photo luminance spectra shows the emission of CDs is 420 nm and a toxicity study of CDs was performed. The Presto Blue method was used to test the toxicity of CDs for murine hippocampal cells. CDs at a concentration of 4 mg/mL were hazardous independent of synthesis time, while the toxicity was higher for lower synthesis times of 1 and 2 h. When the concentration is reduced in 1 and 2 h synthesized CDs, the cytotoxic effect also decreases significantly, ensuring a survival rate of 60–80%. However, when the synthesis time of CDs is increased, the cytotoxic effect decreases to a lesser extent. The CDs with the highest synthesis time of 8 h do not show a cytotoxic effect above 60%. The cytotoxicity study shows that CDs may have a concentration and time–dependent cytotoxic effect, reducing the number of viable cells by 40%
Prevalence of lipid abnormalities in Poland. The NATPOL 2011 survey
Wstęp: Polska ciągle należy do krajów o wysokim ryzyku sercowo-naczyniowym. Zaburzenia lipidowe należą do głównych czynników ryzyka chorób sercowo-naczyniowych. Dotyczy to przede wszystkim stężenia cholesterolu całkowitego (TC) i cholesterolu frakcji liporotein o niskiej gęstości (LDL-C). Dlatego potrzebna jest okresowa ocena występowania dyslipidemii w populacji, by sprawdzić efektywność podejmowanych działań prewencyjnych i terapii.
Cel: Celem pracy było zbadanie średniego stężenia lipidów w surowicy krwi oraz ocena częstości występowania, wykrywania i kontroli zaburzeń lipidowych w dorosłej populacji Polski.
Metody: Badanie przeprowadzono w reprezentatywnej próbie 1168 mężczyzn (M) i 1245 kobiet (K) w wieku 18–79 lat. W surowicy krwi oznaÂczono stężenie TC, cholesterolu o wysokiej gÄ™stoÅ›ci (HDL-C) i triglicerydów (TG). KorzystajÄ…c z formuÅ‚y Friedewalda, wyliczono stężenie LDL-C.
Wyniki: Średnie stężenie TC u M wynosi 197,1 mg/dl (95% Cl 193,8–200,4), a u K 198,6 mg/dl (195,7–201,5), LDL-C odpowiednio: 123,6 mg/dl (120,9–126,2) i 123,7 mg/dl (121,4–126,1), HDL-C: 45,8 mg/dl (44,7–47,0) i 54,1 mg/dl (53,1–55,1), a TG: 140,9 mg/dl (133,0–148,8) i 104 mg/dl (99,8–108,2). Stężenie TC ≥ 190 mg/dl stwierdzono u 54,3% badanych. Odsetki są podobne dla M (54,3%) i K (54,4%). Biorąc pod uwagę również osoby leczące się z tego powodu, hipercholesterolemia (TC ≥ 190 mg/dl lub terapia statynami) występuje u 61,1% (58,2–63,9%) dorosłych Polaków, w tym u 60,8% M (56,4–65,1%) i 61,3% K (57,4–65,1%). Częstość występowania zwiększonego stężenia LDL-C (≥ 115 mg/dl) wśród wszystkich badanych wynosi 57,8% (M 58,3%; K 57,3%). Stężenie HDL-C < 40 mg/dl zanotowano u 35,2% M, a < 45 mg/dl — u 22,2% K. Hipertriglicerydemia (TG ≥ 150 mg/dl) występuje u 21,1% badanych (M 28,4%; K 14,0%). Nieprawidłowe stężenia TC i LDL-C najczęściej stwierdzano u pacjentów w wieku 40–59 lat. Wśród osób z hipercholesterolemią 58,7% (M 61,5%, K 56,0%) było nieświadomych jej obecności, 22,0% (M 21,0%, K 24,5%) wiedziało o tym, ale się nie leczyło, 8,1% (M 7,7%, K 8,5%) leczyło się, ale nieskutecznie i tylko 10,9% (M 10,7%, K 11,0%) leczyło się skutecznie (TC < 190 mg/dl). Jak wynika z porównań wyników badań NATPOL PLUS (2002) i NATPOL 2011, średnie stężenie TC w populacji zmniejszyło się. Jednak korzystne zmiany stężenia TC i LDL-C dotyczą osób po 60. rż.
Wnioski: Wśród dorosłych Polaków w wieku 18–79 lat aż 61% ma hipercholesterolemię. Niepokojące jest, że nieprawidłowe stężenia TC i LDL-C dotyczą szczególnie często osób w średnim wieku, a poprawa pod tym względem w latach 2002–2011 dotyczy pacjentów > 60. rż. Może to wskazywać i wynikać ze wzrostu przyjmowania statyn przez osoby w tym wieku. Prewencja zaburzeń lipidowych, ich wykrywanie i kontrola w Polsce wymagają radykalnej poprawy.Background: Poland represents a country of high cardiovascular (CV) risk. The association between lipid abnormalities and increased CV risk is well established. Therefore, it is important to monitor the prevalence and control of dyslipidaemia.
Aim: To evaluate serum lipids concentrations as well as the prevalence, awareness, and control of lipid abnormalities in a representative sample of adults in Poland.
Methods: In 2011, in a national cross-sectional survey blood samples were collected from 1168 males and 1245 females, aged 18–79 years, for measurement of total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), and triglycerides (TG) in blood serum. Low density lipoprotein cholesterol (LDL-C) was calculated using Friedewald’s formula.
Results: Mean serum TC concentration was 197.1 mg/dL (95% CI 193.8–200.4) in males (M) and 198.6 mg/dL (95% CI 195.7–201.5) in females (F). Levels of LDL-C were 123.6 mg/dL (120.9–126.2) and 123.7 mg/dL (121.4–126.1), HDL-C — 45.8 mg/dL (44.7–47.0) and 54.1 mg/dL (53.1–55.1), TG — 140.9 mg/dL (133.0–148.8) and 104.0 mg/dL (99.8–108.2) for males and females, respectively. TC ≥ 190 mg/dL was found in 54.3% subjects (M 54.3%; F 54.4%). After adding patients on lipid-lowering treatment, hypercholesterolaemia was present in 61.1% of adults (M 60.8%; F 61.3%). LDL-C ≥ 115 mg/dL was detected in 57.8% of all subjects (M 58.3%; F 57.3%), while HDL-C < 40 mg/dL in 35.2% of males and < 45 mg/dL in 22% of females TG ≥ 150 mg/dL was found in 21.1% of subjects (M 28.4%; F 14.0%). The highest prevalence of elevated TC and LDL-C levels was present in the age group of 40–59-year-olds. Of those with hypercholesterolaemia 58.7% (M 61.5%, F 56.0%) were not aware of the condition; 22.0% (M 21.0%, F 24.5%) were aware but were not being treated; 8.1% (M 7.7%, F 8.5%) were treated but with TC ≥ 190 mg/dL; and only 10.9% (M 10.7%, F 11.0%) were being treated with TC < 190 mg/dL.
Conclusions: The prevalence of dyslipidaemia in Poland continues to be high — over 60% of adults have hypercholesterolaemia, and control remains poor. The results of the NATPOL 2011 survey call for urgent preventive measures
Decline in mortality from coronary heart disease in Poland after socioeconomic transformation: modelling study
Objectives To examine how much of the observed rapid decrease in mortality from coronary heart disease in Poland after the political, social, and economic transformation in the early 1990s could be explained by the use of medical and surgical treatments and how much by changes in cardiovascular risk factors
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