160 research outputs found
Catalytic cracking performance of alkaline-treated zeolite Beta in the terms of acid sites properties and their accessibility
The zeolite Beta is considered as a promising additive for FCC catalyst in diesel oil production. In this article, it is shown that hierarchical zeolite Beta obtained by an optimized desilication procedure increases diesel and propylene yields during gas oil cracking reaction. The alkaline treatment of zeolite Beta (Si/Al = 22) by desilication with NaOH and NaOH&TBAOH was investigated. The catalytic performance improvement of desilicated zeolite Beta has been rationalized by deep characterization of the samples including X-ray diffraction, low-temperature adsorption of nitrogen, solid-state 29Si MAS NMR and IR studies of acidity. Finally, the catalytic performance of the zeolites Beta was evaluated in the cracking of n-decane, 1,3,5-tri-iso-propylbenzene, and vacuum gas oil. It was found that desilication with NaOH&TBAOH ensures the more uniform intracrystalline mesoporosity with the formation of narrower mesopores, while preserving full crystallinity resulting in catalysts with the most appropriated acidity and then with better catalytic performance.Also, M.C.I.L., J.M.T. and F.R. thank financial support from the Spanish Ministry of Economy and Competitiveness through the Severo Ochoa program (SEV-2012-0267) as well as operating grants Consolider Ingenio Multicat (CSD-2009-00050) and MAT-2012-3856-0O2-01.Tarach, K.; Gora-Marek, K.; Tekla, J.; Brylewska, K.; Datka, J.; Mlekodaj, K.; Makowski, W.... (2014). Catalytic cracking performance of alkaline-treated zeolite Beta in the terms of acid sites properties and their accessibility. Journal of Catalysis. 312:46-57. https://doi.org/10.1016/j.jcat.2014.01.009S465731
Investigation of x-ray emission from high-current discharges of the PF type
The invited paper reports on measurements of soft x-rays emitted from hot plasmas produced in a modernised
PF-1000U facility. The discharges were performed at the D2-filling with or without a Ne-admixture, under the initial
pressure of 0.9 or 1.5 Torr and at the initial charging voltage equal to 16 or 18 kV. Time-integrated x-ray images
were recorded with a pinhole camera situated side-on, at an angle of 75º to the z-axis. Differences in the pinch
column structure were observed. Time-resolved measurements were performed with four PIN diodes located behind
filtered pinholes. Two couples of PIN diodes (with Be-filters of 7 and 10 μm in thickness) observed 30 mm-diam.
regions which had centres at a distance of 30 and 60 mm form the electrode outlets. From the recorded timeresolved
x-ray signals the electron temperatures (Te) were calculated. For the pure D2-discharges the estimated Te
values ranged from 75 to 250 eV depending on the discharge conditions. For discharges with a Ne-admixture Te values were higher and reached about 800 eV.Описаны измерения мягкого рентгеновского излучения горячей плазмы, генерируемой в модернизированной
установке ПФ-1000U. Разряд происходит в вакуумной камере при напуске дейтерия D2 с добавкой Ne и без, начальное
давление составляло 0,9 и 1,5 Торр, а рабочее напряжение 16…18 кВ. С помощью камеры обскура, расположенной
под углом 75º относительно оси z, зарегистрированы рентгеновские снимки с временным разрешением. Наблюдается
разница в структуре пинча. Измерения с временным разрешением проводились с помощью четырёх диодов,
расположенных за отверстием с фильтром. Две пары диодов (с бериллиевым фильтром толщиной 7 и 10 мкм)
передавали изображение из зон радиусом 30 мм, центры которых находятся на расстоянии 30 и 60 мм от среза
электродов. Анализ сигналов рентгеновского излучения с временным разрешением позволил оценить электронную
температуру (Те). Для разрядов с чистым дейтерием величина электронной температуры варьируется от 75 до 250 эВ в
зависимости от условий разряда. Для разрядов с добавкой неона температура была выше и достигала 800 эВ.Описані вимірювання м’якого рентгенівського випромінювання гарячої плазми, що генерується в
модернізованому пристрої ПФ-1000U. Розряд відбувається у вакуумній камері при напуску дейтерію D2 з домішкою
Ne та без нього, початковий тиск складав 0,9 та 1,5 Торр, а робоча напруга 16…18 кВ. Рентгенівські знімки з
часовим розділенням зареєстровані за допомогою камери обскура, яка знаходилась під кутом 750
відносно осі z.
Спостерігається різниця в структурі пінча. Вимірювання з часовим розділенням проводились за допомогою чотирьох
діодів, що розташовані за отвором із фільтром. Дві пари діодів (з берилієвим фільтром 7 та 10 мкм) передавали
зображення із зон радіусом 30 мм в плазмі, центри діодів розташовано на відстані 30 та 60 мм від електродів. Аналіз
сигналів рентгенівського випромінювання з часовим розділенням дозволив оцінити електронну температуру (Те).
Для розрядів с чистим дейтерієм величина електронної температури змінюється від 75 до 250 еВ в залежності від
умов розряду. Для розрядів з домішкою неону температура сягає 800 еВ
Role of N-acetylcysteine in the management of COPD
The importance of the underlying local and systemic oxidative stress and inflammation in chronic obstructive pulmonary disease (COPD) has long been established. In view of the lack of therapy that might inhibit the progress of the disease, there is an urgent need for a successful therapeutic approach that, through affecting the pathological processes, will influence the subsequent issues in COPD management such as lung function, airway clearance, dyspnoea, exacerbation, and quality of life. N-acetylcysteine (NAC) is a mucolytic and antioxidant drug that may also influence several inflammatory pathways. It provides the sulfhydryl groups and acts both as a precursor of reduced glutathione and as a direct reactive oxygen species (ROS) scavenger, hence regulating the redox status in the cells. The changed redox status may, in turn, influence the inflammation-controlling pathways. Moreover, as a mucolytic drug, it may, by means of decreasing viscosity of the sputum, clean the bronchi leading to a decrease in dyspnoea and improved lung function. Nevertheless, as successful as it is in the in vitro studies and in vivo studies with high dosage, its actions at the dosages used in COPD management are debatable. It seems to influence exacerbation rate and limit the number of hospitalization days, however, with little or no influence on the lung function parameters. Despite these considerations and in view of the present lack of effective therapies to inhibit disease progression in COPD, NAC and its derivatives with their multiple molecular modes of action remain promising medication once doses and route of administration are optimized
Is FLT3 internal tandem duplication an unfavorable risk factor for high risk children with acute myeloid leukemia? : Polish experience
According to the AML-BFM 2004 Interim, a treatment protocol used in Poland since 2005, presence of FLT3
internal tandem duplication (FLT3/ITD) qualifies a patient with acute myeloid leukemia (AML) to a high-risk group (HRG).
The present study was aimed to identify the prevalence of FLT3/ITD in children with AML in Poland and to evaluate its
prognostic significance in the HRG patients.
Out of 291 children with de novo AML treated in 14 Polish centers between January 2006 and December 2012, samples
from 174 patients were available for FLT3/ITD analysis. Among study patients 108 children (61.7%) were qualified to
HRG. Genomic DNA samples from bone marrow were tested for identification of FLT3/ITD mutation by PCR
amplification of exon 14 and 15 of FLT3 gene. Clinical features and treatment outcome in patients with and without
FLT3/ITD were analyzed in the study.
The FLT3/ITD was found in 14 (12.9%) of 108 HRG children. There were no significant differences between children with
and without FLT3/ITD in age and FAB distribution. The white blood cells count in peripheral blood at diagnosis was
significantly higher (p <0.01) in the children with FLT3/ITD. Over 5-year overall survival rate for FLT3/ITD positive
children was worse (42.4%) comparing to FLT3/ITD negative children (58.9%), but the statistical difference was not
significant. However, over 5-year survivals free from treatment failures were similar.
The FLT3/ITD rate (12.9%) observed in the study corresponded to the published data. There was no significant impact of
FLT3/ITD mutation on survival rates, although further studies are needed on this subject
Simultaneous Sample Preparation Method for Determination of 3-Monochloropropane-1,2-Diol and Polycyclic Aromatic Hydrocarbons in Different Foodstuffs
A prospective survey in European Society of Cardiology member countries of atrial fibrillation management: baseline results of EURO bservational Research Programme Atrial Fibrillation (EORP-AF) Pilot General Registry
Aims: Given the advances in atrial fibrillation (AF) management and the availability of new European Society of Cardiology (ESC) guidelines, there is a need for the systematic collection of contemporary data regarding the management and treatment of AF in ESC member countries. Methods and results: We conducted a registry of consecutive in- and outpatients with AF presenting to cardiologists in nine participating ESC countries. All patients with an ECG-documented diagnosis of AF confirmed in the year prior to enrolment were eligible. We enroled a total of 3119 patients from February 2012 to March 2013, with full data on clinical subtype available for 3049 patients (40.4% female; mean age 68.8 years). Common comorbidities were hypertension, coronary disease, and heart failure. Lone AF was present in only 3.9% (122 patients). Asymptomatic AF was common, particularly among those with permanent AF. Amiodarone was the most common antiarrhythmic agent used (~20%), while beta-blockers and digoxin were the most used rate control drugs. Oral anticoagulants (OACs) were used in 80% overall, most often vitamin K antagonists (71.6%), with novel OACs being used in 8.4%. Other antithrombotics (mostly antiplatelet therapy, especially aspirin) were still used in one-third of the patients, and no antithrombotic treatment in only 4.8%. Oral anticoagulants were used in 56.4% of CHA 2DS2-VASc = 0, with 26.3% having no antithrombotic therapy. A high HAS-BLED score was not used to exclude OAC use, but there was a trend towards more aspirin use in the presence of a high HAS-BLED score. Conclusion: The EURObservational Research Programme Atrial Fibrillation (EORP-AF) Pilot Registry has provided systematic collection of contemporary data regarding the management and treatment of AF by cardiologists in ESC member countries. Oral anticoagulant use has increased, but novel OAC use was still low. Compliance with the treatment guidelines for patients with the lowest and higher stroke risk scores remains suboptimal. © The Author 2013
Phase Behavior of Aqueous Na-K-Mg-Ca-CI-NO3 Mixtures: Isopiestic Measurements and Thermodynamic Modeling
A comprehensive model has been established for calculating thermodynamic properties of multicomponent aqueous systems containing the Na{sup +}, K{sup +}, Mg{sup 2+}, Ca{sup 2+}, Cl{sup -}, and NO{sub 3}{sup -} ions. The thermodynamic framework is based on a previously developed model for mixed-solvent electrolyte solutions. The framework has been designed to reproduce the properties of salt solutions at temperatures ranging from the freezing point to 300 C and concentrations ranging from infinite dilution to the fused salt limit. The model has been parameterized using a combination of an extensive literature database and new isopiestic measurements for thirteen salt mixtures at 140 C. The measurements have been performed using Oak Ridge National Laboratory's (ORNL) previously designed gravimetric isopiestic apparatus, which makes it possible to detect solid phase precipitation. Water activities are reported for mixtures with a fixed ratio of salts as a function of the total apparent salt mole fraction. The isopiestic measurements reported here simultaneously reflect two fundamental properties of the system, i.e., the activity of water as a function of solution concentration and the occurrence of solid-liquid transitions. The thermodynamic model accurately reproduces the new isopiestic data as well as literature data for binary, ternary and higher-order subsystems. Because of its high accuracy in calculating vapor-liquid and solid-liquid equilibria, the model is suitable for studying deliquescence behavior of multicomponent salt systems
Chronic intravenous administration of V1 arginine vasopressin agonist results in sustained hypertension
Antybiotykooporność drobnoustrojów w kontekście aktualnego raportu Światowej Organizacji Zdrowia (WHO)
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