A PCM-WATER HEAT EXCHANGER WITH POLYMERIC HOLLOW FIBRES FOR LATENT HEAT THERMAL ENERGY STORAGE: A PARAMETRIC STUDY OF DISCHARGING STAGE

The paper presents a theoretical parametric study into latent heat thermal energy storage (LHTES) employing polymeric hollow fibres embedded in a phase change material (PCM). The polymeric hollow fibres of five inner diameters between 0.5mm and 1.5mm are considered in the study. The effectiveness-NTU method is employed to calculate the thermal performance of a theoretical LHTES unit of the shell-and-tube design. The results indicate that the hollow fibres embedded in a PCM can mitigate the drawback of low thermal conductivity of phase change materials. For the same packing fraction, the total heat transfer rates between the heat transfer fluid and the PCM increase with the decreasing diameter of the hollow fibres. This increase in the heat transfer rate and thus the efficiency of the heat exchange to some extent compensate for the energy consumption of the pump that also increases with the decreasing fibre diameter

<i>Helicobacter</i> Species and Their Association with Gastric Pathology in a Cohort of Dogs with Chronic Gastrointestinal Signs

Prevalence of individual Helicobacter species, data evaluating their association with gastric pathology and comparison of accuracy of diagnostic techniques are limited. The aims of this study were to determine the prevalence of gastric Helicobacter species, their association with gastric pathology, and to compare diagnostic techniques. Gastric biopsies from 84 privately-owned dogs with chronic gastrointestinal signs were obtained endoscopically. Helicobacters were detected using PCR, cytology, urease test, and histopathology. PCR detected helicobacters in 71.4% of dogs. Helicobacter heilmannii sensu stricto (s.s.) was the predominant species. Mixed infection was detected in 40% of PCR positive dogs. Gastritis was diagnosed in 38.5% of Helicobacter positive and 47.4% of Helicobacter negative dogs. Mono-infection was associated with 2.4 times increased odds of having more severe inflammation compared to mixed infection. Erosions and ulcers were common endoscopic lesions. Cytology had sensitivity/specificity of 88.3/91.7%. Association between infection and lymphoid follicular hyperplasia was demonstrated

Data from: Disentangling evolutionary, environmental and morphological drivers of plant anatomical adaptations to drought and cold in Himalayan graminoids

Understanding what determine plants ability to survive drought and cold is crucial for predicting how plants may respond to ongoing climate change. Plant survival strategies are usually characterized by morphological and physiological adaptations, while their underlying anatomical settings are largely unknown. Woody angiosperms and herbaceous dicots have repeatedly evolved small water transporting conduits and large storage parenchyma tissues at colder or drier places to cope with freezing- and drought-induced damages. However, whether these adaptations are also valid for graminoids remains unclear. Here we show that stem anatomical variations in grasses, sedges and rushes dominating in western Himalayan grasslands are driven by elevation and soil moisture via control over aboveground plant stature and belowground clonal growth, while phylogenetic constraints have only a weak effect. Phylogenetic comparative analyses controlling for confounding factors showed that the elevation-related cooling controls the conductive system through reduced vessel diameter and extended assimilatory and storage tissues with more chlorenchyma and less sclerenchyma around vessels. The soil moisture deficit, on the other hand, determines stabilization structures by promoting short-rhizomatous turf graminoids with hollow stems, thicker epidermis and deep adventitious roots in dry steppes and semi-deserts. Saline wetlands and moist alpine pastures promote long-rhizomatous short-stature plants with lower need for mechanical support (absence of hollow stem) and exposure to high evaporative forcing (thinner epidermis). Observed trends of decreasing vessel sizes and lignification rate with elevation supports the existing knowledge that narrower vessels and extensive parenchyma assist plants to grow in cold environments by avoiding freezing-induced cavitation. Our results bring novel information on ecological drivers influencing the evolution of anatomical adaptations in high mountain graminoids. Distinct grassland types, covering elevations from 2650 to 6150 m, harbor unrelated species with different evolutionary histories that have converged towards similar anatomical structures

Transport of olomoucine II at concentrations of 100(A, B, C), 1 µM (D, E, F) and 10 µM (G, H, I) across monolayers of MDCKII-ABCG2 (A, D, G), MDCKII-ABCB1 (B, E, H) and MDCKII-par (C, F, I) cells.

<p>5 µM fumitremorgin C (FTC) was used as a specific ABCG2 inhibitor in MDCKII-ABCG2 cells. 1 µM LY335979 (LY) was employed as a specific ABCB1 and endogenous canine Abcb1 inhibitor in MDCKII-ABCB1 and MDCKII-par cells, respectively. Ratios of olomoucine II transport across cell monolayers (olomoucine II transport in basolateral to apical direction divided by transport in apical to basolateral direction) with or without inhibitor were calculated two hours after olomoucine II addition and statistically compared (see insets). Due to the generation of sulfated conjugate of olomoucine II, transport ratios were determined at 2 h interval to reduce the misrepresenting effect of the metabolite. In basolateral to apical transport direction, olomoucine II was added into the basolateral compartment and its concentrations were determined in the apical compartment. In the opposite transport direction, olomoucine II was applied into the apical compartment and its concentrations were analyzed in the basolateral compartment. ▴, basolateral to apical transport without inhibitor; ▾, apical to basolateral transport without inhibitor; ▵, basolateral to apical transport with inhibitor; ▿, apical to basolateral transport with inhibitor. Data are expressed as means ± SD of three independent experiments. *p<0.05; **p<0.01; ***p<0.001.</p

Mass spectra of an unknown peak eluted in the fifth minute of HPLC analysis of olomoucine II transport.

<p>(A) spectrum in positive mode, (B) MS² in positive mode, (C) negative mode, (D) MS² in negative mode. Based on the nominal mass shift (+80 Da) from parent compound and the collision spectra in negative as well as positive mode the compound was identified as a sulfated conjugate of olomoucine II.</p

Chemical structures of olomoucine II and purvalanol A.

<p>Chemical structures of olomoucine II and purvalanol A.</p

Chromatograms of samples from MDCKII-par cells six hours after olomoucine II addition.

<p>(A) olomoucine II was added into apical compartment while olomoucine II and its sulfated conjugate were analyzed in acceptor basolateral compartment, (B) olomoucine II was added into apical compartment while olomoucine II and its sulfated conjugate were analyzed in donor apical compartment, (C) olomoucine II was added into basolateral compartment while olomoucine II and its sulfated conjugate were analyzed in acceptor apical compartment, (D) olomoucine II was added into basolateral compartment while olomoucine II and its sulfated conjugate were analyzed in donor basolateral compartment. This analysis with end point samples was performed for all olomoucine II transport experiments.</p