Ultrastructural aspects of acute pancreatitis induced by 2, 2'-azobis (2-amidinopropane) dihydrochloride (AAPH) in rats

Background. Pathophysiology of acute pancreatitis (AP) has not been clearly established, nevertheless accumulating evidence implicates highly reactive oxygen species (ROS) as important mediators of exocrine tissue damage.Methods. In this study, we used a water-soluble radical initiator, 2,2'-azobis-(2-amidinopropane) dihydrochloride (AAPH), to investigate consequences of oxidative stress insult to rats pancreas. Detailed ultrastructural characterization of exocrine pancreatic changes that involved a time course of AAPH (40 mg/1kg body weight) induction from 3 to 24 hours was performed. Results. Considerable damage to the mitochondria in acinar cells manifested by increased translucence of the matrix, partial destruction of cristae and formation of myelin figures were noted. At the same time, focal dilation, degranulation of rough endoplasmic reticulum (RER), and reduced number of zymogen granules was observed. The most prominent ultrastructural feature was accumulation of highly polymorphic cytoplasmic vacuoles in acinar cells. Different in size and shape double membrane-bound autophagosomes with sequestered organelles, autophagolisosomes, and also large, empty, single-membrane-bound vacuoles were observed within the cytoplasm. Conclusions. The results indicate that intensive but impaired autophagy mediates pathological accumulation of vacuoles in acinar cells. Rat model of acute pancreatitis induced by AAPH  is useful to investigate the early events of oxidative stress insult to pancreas

In Vitro Cultivation of 'Unculturable' Oral Bacteria, Facilitated by Community Culture and Media Supplementation with Siderophores

Over a third of oral bacteria are as-yet-uncultivated in-vitro. Siderophores have been previously shown to enable in-vitro growth of previously uncultivated bacteria. The objective of this study was to cultivate novel oral bacteria in siderophore-supplemented culture media. Various compounds with siderophore activity, including pyoverdines-Fe-complex, desferricoprogen and salicylic acid, were found to stimulate the growth of difficult-to-culture strains Prevotella sp. HOT-376 and Fretibacterium fastidiosum. Furthermore, pyrosequencing analysis demonstrated increased proportions of the as-yet-uncultivated phylotypes Dialister sp. HOT-119 and Megasphaera sp. HOT-123 on mixed culture plates supplemented with siderophores. Therefore a culture model was developed, which incorporated 15 μg siderophore (pyoverdines-Fe-complex or desferricoprogen) or 150 μl neat subgingival-plaque suspension into a central well on agar plates that were inoculated with heavily-diluted subgingival-plaque samples from subjects with periodontitis. Colonies showing satellitism were passaged onto fresh plates in co-culture with selected helper strains. Five novel strains, representatives of three previously-uncultivated taxa (Anaerolineae bacterium HOT-439, the first oral taxon from the Chloroflexi phylum to have been cultivated; Bacteroidetes bacterium HOT-365; and Peptostreptococcaceae bacterium HOT-091) were successfully isolated. All novel isolates required helper strains for growth, implying dependence on a biofilm lifestyle. Their characterisation will further our understanding of the human oral microbiome

The evaluation of the solar radiation impact on the nanoscoppic properties of the surface of the sheet moulder composite

Ocena wpływu promieniowania słonecznego na właściwości mechaniczne materiałów jest jednym z podstawowych badań środowiskowych, które przywoływane są w normach przedmiotowych dotyczących różnego typu urządzeń i elementów stosowanych w elektrotechnice. Rozwój wysokorozdzielczych technik diagnostycznych pozwala na dokonywanie bardziej szczegółowych niż dotychczas analiz wpływu czynników środowiskowych na właściwości mechaniczne powierzchni, co może być szczególnie cenne w przypadku prac nad tzw. nanomateriałami. W pracy zostaną przedstawione wyniki analiz wykonanych dla próbki kompozytu termoutwardzalnego – SMC (sheet moulder composite), przeprowadzonych z wykorzystaniem mikroskopii sił atomowych oraz mikrotomografii komputerowej, odniesione do wykonanych zgodnie z wymaganiami normy testów odporności na udarność. Uzyskane wyniki pozwalają stwierdzić przydatność wysokorozdzielczych technik diagnostycznych w badaniach wpływu promieniowania świetnego na powierzchnię materiału.The evaluation of the solar radiation influence on the mechanical properties of the material is one of the most popular investigation methods among various environmental tests, mentioned in standards related to various devices and components utilized in electrotechnics. The development of the high-resolution diagnostic methods allowed to perform much more detailed analysis of the influence of the environmental factors on the mechanical properties of the surface. Such tools can be particularly useful in case of the nanomaterials development. In this work we present the analysis of the solar radiation caused degradation of the SMC material - sheet moulder composite, investigated with atomic force microscopy and micro computer tomography. Obtained results were compared to the outcome of the measurements of the impact strength tests. The measurement data allow to confirm the usability of the high-resolution diagnostic methods in the determination of the influence of the solar radiation on the surface of the material

Automatic detection of flame resistance in the studies on the ARC dielectric

Badania odporności materiałów dielektrycznych na działanie łuku elektrycznego (prądów pełzających) zgodnie z normą PN-EN 60112:2003 są procesem długotrwałym, mogącym trwać kilka godzin. Zautomatyzowanie tego procesu na poziomie sterowania, umożliwia realizację badania bez konieczności bezpośredniego udziału obsługi w procesie badawczym. Jednak możliwość zapłonu materiału badanego stwarza zagrożenie dla aparatury badawczej oraz obsługi, co wymusza ciągły nadzór nad przebiegiem badania. Wymusza to więc pełne zaangażowanie personelu w czasochłonną weryfikację właściwości materiału. W niniejszej pracy zaprezentowane zostanie rozwiązanie bazujące na komputerowej, zaawansowanej analizie obrazu, pozwalające na automatyczne wykrycie obecności płomienia na powierzchni badanego materiału, podczas realizacji złożonego cyklu badawczego. Zautomatyzowanie procesu wykrywania płomienia pozwoliło znacząco ograniczyć koszty realizacji badań poprzez redukcję zaangażowanie pracowników. W pracy zaprezentowane zostaną podstawy działania algorytmów oraz wyniki weryfikacji skuteczności ich pracy.The determination of the Comparative Tracking Index (CTI) according to PN-EN 60112:2003 standard is a time-consuming process, which can last few hours. Automating of the test process in terms of conditions control, allows to perform the procedure without constant involvement of the personnel. There is however a risk of fire appearance on the sample, therefore the supervision of the time-consuming material’s properties verification procedure by the staff is necessary. In this work the solution basing on the advanced, computer image processing, allowing detection of the flame on the sample’s surface during the complex test procedure will be presented. Automated flame detection allowed to decrease the costs of the procedure as the reduction of the involvement of the personnel is possible. In the paper, the principles of the algorithms development and their performance verification will be presented

Dielectric Relaxations of Some Pyrrones

The properties of a series of new synthesized poly(imidazopyrolones) shortly named here as pyrrones, are presented. The pyrrones show excellent thermal properties as it was evaluated by thermogravimetric analysis and small weight loss below 300 °C. The electrical properties are highly affected by fiexibilizing groups X such as amide, ester or other between ladder segments. The frequency dependence of electrical permitivities and conductivity thermograms are presented The pyrrones containing ester groups, show significantly lower conductivities in comparison to those containing amide or other groups