Quick design of truncated pin fins of hyperbolic profile for heat-sink applications by using shortened power series

A heat sink normally consists of a substrate on which a bundle of pin fins made of a highly conducting metal like aluminum or copper is attached. Its performance can be qualified by the space they occupy in relation to the thermal resistance they provide, which requires the solution of the quasi one-dimensional heat conduction equation in the geometry of interest. This technical brief reports exact and approximate analytical procedures for the truncated pin fin of hyperbolic profile. The exact solution involves rather intricate Bessel functions, whereas the approximation is based on easily computable power series. Compared to the exact figures, simple, truncated power series having between five and eight terms yield results of excellent quality for practical combinations of the two controlling parameters: the thermal length mL and the coordinate ratio W. Results are presented for the two variables of interest in thermal design: the fin tip temperature (a local quantity) and the fin thermal efficiency (a global quality ratio).     

Capillary electrophoresis-mass spectrometry as a powerful tool in biomarker discovery and clinical diagnosis: an update of recent developments

Proteome analysis has emerged as a powerful technology to decipher biological processes. One of the main goals is to discover biomarkers for diseases from tissues and body fluids. However, the complexity and wide dynamic range of protein expression present an enormous challenge to separation technologies and mass spectrometry (MS). In this review, we examine the limitations of proteomics, and aim towards the definition of the current key prerequisites. We focus on capillary electrophoresis coupled to mass spectrometry (CE-MS), because this technique continues to show great promise. We discuss CE-MS from an application point of view, and evaluate its merits and vices for biomarker discovery and clinical applications. Finally, we present several examples on the use of CE-MS to determine urinary biomarkers and implications for disease diagnosis, prognosis, and therapy evaluation.     

Effect of finishing diet on consumer acceptability of Uruguayan beef in the European market

Eighty Hereford steers were used to evaluate the effect of finishing diet [A: pasture, B: pasture plus concentrate (0.6% live weight), C: pasture plus concentrate (1.2% live weight), D: concentrate] on consumer acceptability of Uruguayan beef in France (FR), United Kingdom (UK), Spain (ES) and Germany (DE). Consumers (200 per country) evaluated overall, tenderness and flavour acceptability of beef (8 point scale: 1 ‘dislike extremely’, 8 ‘like extremely’). FR and UK rated lower acceptability scores for beef from D compared with A, B, and C. ES showed similar results for tenderness, but flavour scores did not differ between A and D. German consumers preferred beef from B and C. Overall, low levels of supplementation on pasture produced beef with the highest consumer acceptability followed by beef from pasture-fed animals. Feeding cattle with concentrate only may not be necessary to satisfy the EU market resulting in more profitable production systems for Uruguayan producers.     

Content and distribution of vicine,convicine and <Emphasis Type="SmallCaps">l</Emphasis>-DOPA during germination and seedling growth of two <Emphasis Type="Italic">Vicia faba</Emphasis> L. varieties

This work examined the content and distribution of the pyrimidine glucosides vicine and convicine, and the nonproteic amino acid l-DOPA in cotyledons and embryo axes along the germination and seedling growth of Vicia faba L. vars. Alameda and Brocal. The behaviour of these compounds was similar in both varieties. Vicine and convicine, implicated in favism disease, slowly declined in cotyledons. In embryo axis, vicine levels were sharply reduced and convicine amount was slightly increased as assay progressed. Total pyrimidine glucosides remained unchanged in the whole plant during the study. l-DOPA only appeared in the embryo axis of V. faba seeds and the highest content was observed in Brocal variety at 6 DAI (days after imbibition). The information provided in this study could be valuable for a possible role of embryo axis, rich in l-DOPA, for the treatment of Parkinson’s disease and also as a choice ingredient for functional foods or as nutraceutical.     

Follicular development in European ground squirrels (Spermophilus citellus) in different phases of the annual cycle

In seasonally breeding mammals, in particular hibernators, reproduction underlies severe energetic and temporal constraints to enable the allocation of sufficient body fat reserves before winter. Thus, the timing of conception in spring can be crucial in terms of reproductive success. This study investigates follicular development in European ground squirrels (Spermophilus citellus) in three phases of the annual cycle: at vernal emergence, after weaning the offspring and shortly before hibernation. The animals were kept in outdoor enclosures within the natural habitat of the species. They were captured in weekly intervals, weighed and reproductive status was determined. Unilateral ovariectomy was scheduled such that the three periods were sampled. Numbers and diameters of tertiary follicles (TF) and corpora lutea (CL) in each ovary were determined, and plasma oestradiol and progesterone levels were analysed. The highest numbers of TF, including Graafian follicles, were found in ovaries at vernal emergence. During post-lactation, the number of TF was lower and active CL appeared in the investigated ovaries. Shortly before hibernation, active CL were present, but luteolysis had started in some individuals. Both oestradiol and progesterone secretion peaked after the termination of lactation and decreased before hibernation. The results demonstrate a second oestrus cycle in European ground squirrels after weaning, including an active luteal phase. This non-reproductive oestrus cycle with its endocrine output is an intriguing phenomenon. It may positively affect both prehibernatory fattening and reproduction in the subsequent season.     

A Retro-biosynthesis-Based Route to Generate Pinene-Derived Polyesters

Significantly increased production of biobased polymers is a prerequisite to replace petroleum-based materials towards reaching a circular bioeconomy. However, many renewable building blocks from wood and other plant material are not directly amenable for polymerization, due to their inert backbones and/or lack of functional group compatibility with the desired polymerization type. Based on a retro-biosynthetic analysis of polyesters, a chemoenzymatic route from (−)-α-pinene towards a verbanone-based lactone, which is further used in ring-opening polymerization, is presented. Generated pinene-derived polyesters showed elevated degradation and glass transition temperatures, compared with poly(ϵ-decalactone), which lacks a ring structure in its backbone. Semirational enzyme engineering of the cyclohexanone monooxygenase from Acinetobacter calcoaceticus enabled the biosynthesis of the key lactone intermediate for the targeted polyester. As a proof of principle, one enzyme variant identified from screening in a microtiter plate was used in biocatalytic upscaling, which afforded the bicyclic lactone in 39 % conversion in shake flask scale reactions.