38 research outputs found
Otkrivanje i dijagnoza kvarova u velikim solarnim toplinskim sustavima
A four-step concept for fault detection and fault diagnosis for solar thermal systems has been developed in the framework of the ongoing research activities at Kassel University. This concept is able to combine different general approaches for fault detection and fault diagnosis in one structure. Additionally it introduces a systematic categorization of information and a more precise terminology by distinguishing between element sensor values, measured values, features and symptoms.Koncept u četiri koraka za otkrivanje i dijagnozu kvarova (FDD) u velikim solarnim toplinskim sustavima je razvijen u okviru tekućih istraživačkih aktivnosti na Sveučilištu Kassel. Ovaj koncept kombinira različite opće pristupe za otkrivanje i dijagnozu kvarova u jednoj strukturi. Osim toga, uvodi se sustavna kategorizacija podataka i preciznija terminologija prema razlikovanju između veličina dobivenih iz osjetnika, mjerenih veličina, svojstava i simptoma za pojedine elemente sustava
Histopathological changes in the skin and gut mucus layers of rainbow trout (Oncorhynchus mykiss) challenged with Ichthyophthirius multifiliis inactivated by gamma rays and formalin
Ichthyophthirius multifiliis, a protozoan parasite, is a significant problem for fish farmers and Aquarium fish worldwide. This study aimed to evaluate the immunization of rainbow trout with gamma-irradiated, formalin inactive, and live theronts of I. multifiliis. In this study, fish were exposed to gamma-irradiated, formalin-inactivated, and live I. multifiliis theronts. Then, the histopathological changes in the mucous layers of the skin and intestines were studied after 7 and 14 days of exposure. Although no significant morphological changes were observed in the skin and intestines of the treated fish, the number of skin goblet cells increased significantly in fish treated with formalin-inactivated, gamma-inactivated, and live trophonts on 7 and 14 days. Compared to the negative control group, an increase in epidermal thickness on the skin was observed in fish challenged with formalin-inactivated, gamma-inactivated, and live trophonts. The numbers of mucous cells/total enterocytes in the intestinal epithelium of fish exposed to gamma-irradiated, formalin-inactivated, and trophonts live were higher than in non-infected fish. Moreover, a significant increase was found in the mucous cell numbers of the pyloric fold in treated fish with gamma-irradiated and formalin inactive trophonts at the first and second weeks. The results showed that the gamma-irradiated trophonts and formalin inactive trophonts could be safe for use in rainbow trout against I. multifiliis
Thymoquinone, the main constituent of nigella sativa, could impact on adenosine a2 receptors in ovalbumin-sensitized guinea pigs
mir-451a-5p Modulates Breast Cancer Cell Apoptosis, Migration, and Chemosensitivity to Carboplatin through the PTEN Pathway
Background: MicroRNAs (miRNAs) can play essential roles in the modulation of cancer cell growth, survival, and resistance to chemotherapy. Thus, we hypothesized that restoration of miR-451a-5p (a tumor suppressor) might affect sensitivity to chemotherapeutics in breast cancer cells. Methods: For this purpose, malignant breast cancer cells (MDA-MB-231) were transfected with miR-451a-5p mimic and exposed with carboplatin. Then, the apoptotic rate was evaluated by flow cytometry and DAPI staining (apoptosis), q-RT-PCR (expression levels of caspase-3, caspase-8, MMP9, ROCK, vimentin, c-Myc genes). Moreover, the proliferation and migration of cancer cells were assessed by MTT (cell viability) and wound healing assay. The western blot assay was used for protein expression of PTEN, AKT, and P-AKT. Results: Our findings demonstrated that a combination of miR-451a-5p restoration with carboplatin administration could additionally induce apoptosis, repress the proliferation and migration, and also increase PTEN protein expression with no significant alteration on the AKT/P-AKT protein expressions in the breast cancer cells. The present data was analyzed using GraphPad Prism 6 software by non-parametric one-way ANOVA and t-test. Conclusion: In conclusion, it seems that overexpression of miR-451a can enhance the chemosensitivity of breast cancer cells to carboplatin therapy. Thus, it may shed new light on miR-451a management of breast cancer chemoresistance and may be a beneficial strategy for future cancer therapy. However, further studies, particularly in other signaling pathways, should be required
ERGEBNISSE DER UNTERSUCHUNG VON HB-AL BEI 94 PATIENTEN MIT NIERENINSUFFIZIENZ
We have qua nt i t a l ed Hb- Al ~n 125 patients . 74 pa t ient s had chronic Renal Failure . 20 of them had Diabetes wi th Renal Fai lure , 21 Diabetics and 10 patients were evaluat ed as control. We have divided the patients with Renal Failure i n 3 groups according to t heir serum c reatin i ne . Hb-Al in a ll groups "as not correlated wi th serum creat i ne. Hb-Al in Diabetic gr oup was highe r than Diabetic patients with Renal Failure . This group a lso had mor e HbA1 than t he gr oup with Renal ~ailure a nd no Diabetes ,and control group . , Hb-Al was correlated with Blood suger i n all pa t i e nt s s o we can u se"nal Failure the me a sureme nt of Hb-Al i n pati ents with Renunder Dial ys i s with gl ucose solution fo r evalua t i o n of sugar meta boli s m. &nbsp
Solarthermische Kollektorfassaden - Systematische Bewertung des primärenergetischen Ertragspotentials bei hybrider Nutzung der Wärmeträgerfluide Luft und Solarflüssigkeit sowie Entwicklung einer Simulationssoftware zur energetischen Planung von solaraktiven Gebäudefassaden
In solarthermischen Anlagen kommen heute vorwiegend Luft oder eine frostgeschützte Flüssigkeit als Energietransportmittel zum Einsatz. Verschiedene Bestrebungen bestehen gegenwärtig darin, diese Wärmeträgerfluide gleichzeitig zu verwenden, um so eine Effektivitätssteigerung zu erzielen.
In dieser Arbeit wird diese Fragestellung in Zusammenhang mit einer solarthermischen Kollektorfassade aufgegriffen. Unter Berücksichtigung diverser Einflussfaktoren wird das primärenergetische Potential durch den Einsatz und die Kombination der Wärmeträgermedien Luft und Flüssigkeit sehr detailliert untersucht.
Insbesondere werden mechanische Strömungsleistungen, unter Einbeziehung reibungsbedingter Verluste oder thermische Auftriebskräfte betrachtet. Daneben werden der prozessdynamische elektrische Wirkungsgrad der Strömungsarbeitsmaschinen und Wärmepumpen in die Untersuchungen eingebunden.
Für die Durchführung der Arbeit werden zunächst zahlreiche detaillierte physikalische und mathematische Modelle entwickelt, profund validiert und in ein vom Autor entwickeltes Simulationsprogramm implementiert. Darüber hinaus liefern experimentelle Untersuchungen Erkenntnisse, die zur Validierung der entwickelten Modelle genutzt werden.
Die durchgeführten Studien zeigen, dass aus energetischer Sicht beide Wärmeträgermedien ihre spezifischen Vor- und Nachteile aufweisen. Dabei sind die erforderlichen Systemtemperaturen, die Transparenz der Sekundärfassade und die notwendige mechanische Strömungsleistung als Einflussgrößen hervorzuheben. Insbesondere diese Faktoren können, in abhängig von ihrem Betrag, den primärenergetischen Vorteil von einem Wärmeträgermedium zum anderen verschieben.
Allerdings zeigen die Erkenntnisse dieser Arbeit, dass eine fortwährende kombinierte Nutzung beider Fluide Luft und Flüssigkeit in der untersuchten Fassadenkonstruktion die primärenergetische Bilanz nicht wesentlichen positiv beeinflusst.
Gemäß dem weiteren Ziel der Arbeit entsteht ein neuartiges serverbasiertes Computerwerkzeug zur Simulation solaraktiver Gebäudefassaden, das mit spezifischen Weiterentwicklungen, künftig ein hilfreiches, einfach zu bedienendes und ansprechendes Werkzeug für Planer und andere Interessenten zu sein vermag. Individuelle architektonische Entwürfe der Gebäudefassade ließen sich hinsichtlich der solarthermischen Nutzung durch die Eingabe weniger Parameter der Sekundärfassade, dem Standort und einiger Gebäudedaten einfach quantifizieren und vergleichen.
Neben der Beantwortung der zentralen Forschungsfrage und der Entwicklung des Planungswerkzeugs, verschafft sich die Arbeit Zutritt zu weiteren Forschungs- und Entwicklungsfeldern:
Es wird ein neuartiger virtueller Kollektortest entwickelt. Dieser Test identifiziert und beschreibt das energetische Verhalten der untersuchten solarthermischen Gebäudefassade. Dadurch werden unterschiedliche Kollektorfassaden anhand weniger Parameter schon im Rahmen des Planungsprozesses vergleichbar gemacht.
Ein darüber hinaus entwickeltes Verfahren ermöglicht es für Untersuchungen von solarthermischen Anlagen, die geringe Dynamik der Wetterdaten der Testreferenzjahre des Deutschen Wetterdienstes DWD zu erhöhen. Dabei wird unter Berücksichtigung des Bewölkungsgrades über eine arithmetische oder stochastische Methode die so- lare Bestrahlungsstärke variiert.
Weiterhin wird eine Regelungsstrategie für den Betrieb der Kollektorfassade entwickelt und in durchgeführte Simulation implementiert. Diese gibt die Temperartureinschaltbedingungen unter der Verwendung des Matched Flow – Prinzips vor und stellt fortwährend eine primärenergetische Bilanz auf. Sobald sich diese negativ entwickelt, werden die elektrischen Leistungen der Strömungsarbeitsmaschinen reduziert oder diese ausgeschaltet.
Die gewonnenen Erkenntnisse und entstandenen Werkzeuge dieser Arbeit sind hinsichtlich der energetischen Planung von aktiven Gebäudefassaden von Bedeutung. Ebenso sind sie Ausgangspunkt für Weiterentwicklungen, wie zum Beispiel die Übertragung der Regelungsstrategie auf reale Anlagen oder der Ausbau des Simulationsprogramms für weitere individuelle Anforderungen
Developing a Rabbit Model of Neointimal Stenosis and Atherosclerotic Fibrous Plaque Rupture
Background: A precise understanding of the mechanism of human neointimal stenoses and atherosclerotic fibrous plaques, which give rise to thromboses in vital arteries, requires a suitable animal model that would mimic the same characteristics well. We developed a rabbit model of neointimal stenosis and fibrotic plaque rupture in the carotid artery to visualize the lesion progress and to characterize the lesion types according to the American Heart Association classification. Methods: Twenty-eight healthy male New Zealand white rabbits were randomly divided into two groups: The rabbits in group A (n = 14) consumed a standard chow diet, and those in group B (n = 14) were injured via perivascular cold injury using liquid nitrogen at the right common carotid artery before being fed a high cholesterol diet (1.5%) for eight weeks. Plasma lipid evaluation was performed before the sacrificing of the rabbits. At the end of every week, at least 1 rabbit from group B was sacrificed for an analysis of lesion histopathology and calculation of the area ratios of the intima to media. Results: The plasma lipid level in group B was significantly higher than that in group A (p value < 0.05). The histopathological results revealed atherosclerosis characteristics such as endothelial layer destruction, fatty streaks and lipid-containing macrophages (foam cells) formation in the intima and media layers, extracellular lipid collections, smooth muscle cells proliferation and migration, neointima formation, intima thickening and deformation, fibrotic plaque formation, and finally plaque rupture. Statistical analysis revealed a significant increase in the intima-to-media ratio at the end of the eighth week (6.41 ± 0.27, p value < 0.05). Conclusion: We successfully developed a rabbit model of neointimal stenosis and atherosclerotic fibrous connective tissue plaque rupture, which is not only quickly and easily reproducible and inexpensive but also without mortality. The merits of our model render the evaluation of neointimal stenoses and fibrotic plaques and their treatment strategies more feasible in humans
The effect of single dose of thymoquinone, the main constituents of Nigella sativa, in guinea pig model of asthma
Introduction: In previous studies, the relaxant and antihistaminic effects of thymoquinone, the main constituents of Nigella sativa,
have been demonstrated on guinea pig tracheal chains. In the present
study, the prophylactic effect of (IP) single dose of thymoquinone on
tracheal responsiveness and lung inflammation of guinea pig model of
asthma was examined.
Methods: Thirty guinea pigs were
randomly divided to 3 groups; control (C), sensitized (S) and pretreated
group with (TQ); 3 mg/kg, IP (S+TQ). Tracheal responsiveness to
methacholine and ovalbumin (OA), total and differential cell count in
bronchoalveolar lavage, lung pathological changes and blood Interleukin
4(IL-4) and Interferon gamma (IFNγ) level in three groups were measured.Results: Increased tracheal
responsiveness to methacholine and OA, lung lavage fluid white blood
cell (WBC) and eosinophil count, IL-4 and IFN-γ levels and pathological
changes were seen in sensitized group in comparison to control group
(p<0.001 to p<0.05). Decreased tracheal responsiveness to
methacholine and OA, pathological changes and bronchoalveolar
lavage eosinophil were observed in S+TQ group compared to S group
(p<0.001 to p<0.05). However, tracheal responsiveness to
methacholine and OA, contractility, bronchoalveolar lavage WBC
and eosinophil and most of pathological changes in S+TQ group were
significantly higher than those in controls (p<0.01 to p<0.05). Conclusion: These results showed the preventive effect of single dose of thymoquinone on guinea pig model of asthma
The Protective Effect of Artemisia spicigera Ethanolic Extract against Cryptosporidium parvum Infection in Immunosuppressed Mice
Background: A specific treatment has not yet developed for cryptosporidiosis, and some of the used drugs had side effects in immunodeficient patients. The goal of an appropriate remedy is to remove symptoms and improve immune responses in hosts. The current study was designed to evaluate the therapeutic efficacy of Artemisia spicigera ethanolic extract in experimentally infected immunosuppressed mice.
Methods: Thirty six NMRI mice, 4-6 wk old, were randomly divided into six equal groups. C1: uninfected, treated control; C2: infected, untreated control; T1, T2, T3, and P: infected, treated with 0.2, 2, and 20 mg/ml extract, and 5mg/ml paromomycin, respectively. Mice were experimentally infected by oral administration of 104 oocysts/animal of Cryptosporidium parvum and treated orally for eight days per 12h, starting 12h before experimental infection. The presence of oocyst shedding, weight gain/loss, and the histopathology of ileum sections were examined.
Results: Results revealed that oocyst shedding was significantly (P<0.05) reduced in treatment groups. There was no significant difference between the mean of weight gain/loss in the infected control and treated groups. Histopathological analysis of ileum sections further supported the parasitological findings.
Conclusion: Artemisia spicigera had acceptable efficacy as a therapeutic agent for cryptosporidiosis