48 research outputs found
Strangelet search at RHIC
Two position sensitive Shower Maximum Detector (SMDs) for Zero-Degree
Calorimeters (ZDCs) were installed by STAR before run 2004 at both upstream and
downstream from the interaction point along the beam axis where particles with
small rigidity are swept away by strong magnetic field. The ZDC-SMDs provides
information about neutral energy deposition as a function of transverse
position in ZDCs. We report the preliminary results of strangelet search from a
triggered data-set sampling 100 million Au+Au collisions at top RHIC energy.Comment: Strange Quark Matter 2004 conference proceedin
Strangelet Search in AuAu Collisions at 200 GeV
We have searched for strangelets in a triggered sample of 61 million central
(top 4%) Au+Au collisions at \sNN = 200 GeV near beam rapidities at the STAR
detector. We have sensitivity to metastable strangelets with lifetimes of order
, in contrast to limits over ten times longer in AGS studies and
longer still at the SPS. Upper limits of a few 10^{-6} to 10^{-7} per central
Au+Au collision are set for strangelets with mass GeV/c^{2}.Comment: As publishe
Metabolic regulation by p53
We are increasingly aware that cellular metabolism plays a vital role in diseases such as cancer, and that p53 is an important regulator of metabolic pathways. By transcriptional activation and other means, p53 is able to contribute to the regulation of glycolysis, oxidative phosphorylation, glutaminolysis, insulin sensitivity, nucleotide biosynthesis, mitochondrial integrity, fatty acid oxidation, antioxidant response, autophagy and mTOR signalling. The ability to positively and negatively regulate many of these pathways, combined with feedback signalling from these pathways to p53, demonstrates the reciprocal and flexible nature of the regulation, facilitating a diverse range of responses to metabolic stress. Intriguingly, metabolic stress triggers primarily an adaptive (rather than pro-apoptotic) p53 response, and p53 is emerging as an important regulator of metabolic homeostasis. A better understanding of how p53 coordinates metabolic adaptation will facilitate the identification of novel therapeutic targets and will also illuminate the wider role of p53 in human biology
Carboxypeptidase-M is regulated by lipids and CSFs in macrophages and dendritic cells and expressed selectively in tissue granulomas and foam cells
Granulomatous inflammations, characterized by the presence of activated macrophages (MAs) forming epithelioid cell (EPC) clusters, are usually easy to recognize. However, in ambiguous cases the use of a MA marker that expresses selectively in EPCs may be needed. Here, we report that carboxypeptidase-M (CPM), a MA-differentiation marker, is preferentially induced in EPCs of all granuloma types studied, but not in resting MAs. As CPM is not expressed constitutively in MAs, this allows utilization of CPM-immunohistochemistry in diagnostics of minute granuloma detection when dense non-granulomatous MAs are also present. Despite this rule, hardly any detectable CPM was found in advanced/active tubercle caseous disease, albeit in early tuberculosis granuloma, MAs still expressed CPM. Indeed, in vitro both the CPM-protein and -mRNA became downregulated when MAs were infected with live mycobacteria. In vitro, MA-CPM transcript is neither induced remarkably by interferon-γ, known to cause classical MA activation, nor by IL-4, an alternative MA activator. Instead, CPM is selectively expressed in lipid-laden MAs, including the foam cells of atherosclerotic plaques, xanthomatous lesions and lipid pneumonias. By using serum, rich in lipids, and low-density lipoprotein (LDL) or VLDL, CPM upregulation could be reproduced in vitro in monocyte-derived MAs both at transcriptional and protein levels, and the increase is repressed under lipid-depleted conditions. The microarray analyses support the notion that CPM induction correlates with a robust progressive increase in CPM gene expression during monocyte to MA maturation and dendritic cell (DC) differentiation mediated by granulocyte–MA-colony-stimulating factor+IL-4. M-CSF alone also induced CPM. These results collectively indicate that CPM upregulation in MAs is preferentially associated with increased lipid uptake, and exposure to CSF, features of EPCs, also. Therefore, CPM-immunohistochemistry is useful for granuloma and foam MA detections in tissue sections. Furthermore, the present data offer CPM for the first time to be a novel marker and cellular player in lipid uptake and/or metabolism of MAs by promoting foam cell formation
Cytokine and Chemokine Concentrations as Biomarkers of Feline Mycobacteriosis
Abstract Mycobacteriosis is an emerging zoonotic disease of domestic cats and timely, accurate diagnosis is currently challenging. To identify differential cytokine/chemokine concentrations in serum/plasma of cats, which could be diagnostic biomarkers of infection we analysed plasma/serum from 116 mycobacteria-infected cats, 16 healthy controls and six cats hospitalised for unrelated reasons was analysed using the Milliplex MAP Feline Cytokine Magnetic Bead multiplex assay. Three cytokines; sFAS, IL-13 and IL-4 were reduced while seven; GM-CSF, IL-2, PDGF-BB, IL-8, KC, RANTES and TNF-α were elevated in mycobacteria-infected cats compared to healthy controls. However, IL-8 and KC concentrations were not significantly different from cats hospitalised for other reasons. Elevations in TNF-α and PDGF-BB may have potential to identify M. bovis and M. microti infected cats specifically while GM-CSF, IL-2 and FLT3L were increased in MTBC infected cats. This study demonstrates potential use of feline tuberculosis as a spontaneously occurring model of this significant human disease. Cytokine profiling has clear diagnostic potential for mycobacteriosis of cats and could be used discriminate tuberculous from non-tuberculous disease to rapidly inform on zoonotic risk. Future work should focus on the in-field utility of these findings to establish diagnostic sensitivity and specificity of these markers
Gospodarka wodno-ściekowa w zamkniętym układzie chłodzenia elektrowni
The paper presents a mathematical model describing the changes in SO42- concentration in a closed system of cooling water in a professional power plant. The analyzed installation consists of condensers and cooling towers connected by a system of channels. The main mechanism of heat transfer in the cooling tower bases on partial evaporation of water, resulting in the increase of concentration of SO42- ions in the circulating liquid. The only mechanism to decrease concentration of undesirable chemicals in the circulating water is its periodic discharge to a wastewater treatment. According to the latest Polish Government Regulations (Regulation of the Ministry of Environment dated 18 November 2014) and the Directive of the European Parliament and of the Council (2010/75/EU of 24 November 2010 on industrial emissions) from the beginning of 2016 the new limits on the chemical components of a wastewater led to the natural tanks has been accepted, what forced planned and costeffective wastewater treatment in a professional power plants. Presented mathematical model has an analytical solution which allows not only to predict daily changes of SO42- concentration in circulating water but also to indicate asymptotic concentration of sulphate ions under given working parameters of the system and to calculate minimal volumetric flow rate of wastewater required to keep the SO42-concentration below legal value.W pracy przedstawiono model matematyczny stężenia jonów siarczanowych SO42-- opisujący zmianę w zamkniętym obiegu wody chłodzącej bloku energetycznego. Analizowana instalacja obejmuje: skraplacze bloków energetycznych oraz chłodnie kominowe połączone systemem kanałów ssących i kolektorów tłocznych. Głównym mechanizmem wymiany ciepła w chłodni jest częściowe odparowanie przepływającej przez nią wody, co powoduje jednak wzrost stężeń związków chemicznych w cyrkulującej cieczy i wymusza okresowy zrzut części wody do przyzakładowej oczyszczalni ścieków. Zgodnie z najnowszymi rozporządzeniami prawnymi: Rozporządzeniem Ministra Środowiska z dnia 18 listopada 2014 roku oraz dyrektywą Parlamentu Europejskiego i Rady 2010/75/UE z dnia 24 listopada 2010 r. w sprawie emisji przemysłowych, od początku roku 2016 obowiązują nowe limity dotyczące składu chemicznego ścieków technologicznych kierowanych do zbiorników naturalnych, które wymuszają planową i oszczędną gospodarkę wodnościekową elektrowni. Prezentowany model matematyczny posiada analityczne rozwiązanie pozwalające nie tylko przewidzieć dobowe zmiany stężeń siarczanów w cyrkulującej wodzie, ale również określić graniczne stężenie jonów siarczanowych dla bieżących parametrów pracy układu oraz wyznaczyć minimalny strumień odprowadzanych ścieków zapewniający spełnienie norm emisji ścieków przemysłowych
Mathematical model of sulphate ion concentration in a closed cooling system of a power plant
In commercial power plants, water is used in many processes and its physical and chemical properties
have a significant impact on the efficiency of energy and heat production as well as failure-free operation.
One of the largest consumers of water in a power unit is the cooling system consisting of condensers and
cooling towers. In cooling towers, the main mechanism for the decrease in temperature of the water is its
partial evaporation, which causes a gradual decrease in the amount of circulating water and, on the other
hand, a continuous increase in the concentration of chemical compounds in the closed system. Among
others, an uncontrolled increase in the sulphate ion concentration in cooling water may cause the corrosion
of the concrete parts of the hydraulic system as well as an increase in the deposition of calcium salts
on the surfaces of the heat exchangers, thereby worsening the heat exchange processes inside the condenser.
The daily demand for fresh water in power plants often reaches tens of thousands of cubic metres and
so the amount of wastewater released also has a significant influence on the environment. Therefore the
Polish Ministry of Environment and EU directives have introduced, from the beginning of 2016, new limits
on the physical and chemical parameters of wastewater released to natural reservoirs. Taking into
account the previous regulations, the authors present a mathematical model which allows the prediction
of the daily changes of the sulphate ion concentration in the circulating water in a condenser - cooling
tower closed cooling system and the calculation of the minimum wastewater flow rate fulfilling legal
restrictions
Modelowanie procesów SNCR uwzględnieniem efektu przesunięcia w zakresie CO
The paper deals with CFD simulation of SNCR technology with implemented CO temperature shift. The influence of CO on the SNCR process is described by empirical adjustment of kinetics parameters of chemical reactions. Results of CFD simulation were compared with results of experimental measurements. Although the proposed kinetics model of SNCR technology is simplified, it is able to describe reduction of NOx and other phenomena of SNCR with good precision. The model can be used to verify of injection levels and injection lances arrangement at design phase.Artykuł przedstawia wyniki symulacji procesów SNCR z wykorzystaniem obliczeń CFD z uwzględnieniem przesunięcia temperaturowego związanego z obecnością CO oraz parametrów kinetycznych przedstawionych w tekście reakcji chemicznych. Wpływ CO na proces SNCR opisuje empiryczna korekta parametrów kinetyki reakcji chemicznych. Wyniki symulacji CFD porównano z wynikami pomiarów eksperymentalnych. Chociaż proponowany kinetyczny model technologii SNCR jest uproszczony, to jest w stanie opisać redukcję NOx, z uwzględnieniem wielu parametrów technologii SNCR, z dobrą precyzją. Opisany model może być wykorzystany na etapie projektowania instalacji SNCR uwzględniając m.in. miejsca iniekcji i układ lanc