Inverse problem methodology for thermal-physical properties estimation of frozen green beans

Frozen green beans (Phaseolus vulgaris, L.) thermal conductivity (k) and heat capacity (Cp) were determined experimentally by a one dimensional finite difference (transient method) and differential scanning calorimetry, respectively. Thermal properties were also estimated by the inverse problem methodology (IPM). Heat capacity and thermal conductivity behaviour with temperature were modelled by the Schwartzberg equations and linear relationship, respectively below and above the melting point. These equations were used inside a finite element model (FEM) to simulate green beans phase transition under thawing conditions. The sequential simplex method was used to minimise the error vector of the FEM inverse problem, to estimate thermal capacity and thermal conductivity. The accuracy of thermal-physical properties estimated by the two methodologies was compared with data from literature. The thermo-physical properties estimated by the IPM converged for physically meaningful values. Important conclusions were obtained about errors in model predictions. Furthermore, the IPM thermal properties increased the accuracy of simulations, especially during phase transition

Haricots verts congelés : modélisation de la diminution de l’intensité de la couleur et de la teneur en chlorophylle

Colour changes and chlorophyll degradation of frozen green beans (Phaseolus vulgaris, L., variety bencanta) were studied during 250 days of storage at 7, 15 and 30 C. Chlorophyll a and b losses and colour Hunter a and b coordinates and total colour difference (TCDH) changes were successfully described by first order and reversible first order models, respectively. The temperature effect was described by the Arrhenius law. Disagreement between the colour co-ordinates and chlorophyll content was obtained. Therefore, chlorophyll content is not a good colour index of frozen green beans. The results emphasise that colour is a more important parameter to assess frozen green beans visual quality. # 2002 Elsevier Science Ltd and IIR. All rights reserved

Green beans (Phaseolus vulgaris, L.) quality loss upon thawing

Frozen green beans (Phaseolus vulgaris, L.) thawing is one of the operations that compromises significantly quality. The present research aims at studying the effects of thawing, at environmental and refrigeration temperatures, on the quality profile of a frozen green beans package. Quality losses were computationally evaluated, using a simulation system based on object-oriented technologies. Simulations show that sensory parameters, such as flavour and colour, are more sensitive to thawing at environmental temperatures, than nutritional parameters, such as vitamin C and starch contents. The study demonstrates that green beans quality retention is also influenced by packaging materials, with different degrees of thermal insulation, and environmental conditions, such as temperature and surface heat convection coefficients. Important conclusions are discussed on shelf-life limiting quality parameters during thawing and temperature abuses, as well as on thawing green vegetables to maximise their quality profile. Results emphasise that the principle of high-temperature–short-times is not directly applicable to frozen green beans thawing. Furthermore, simulations lead to the conclusion that overall quality profile is maximised by thawing under refrigeration temperatures

Magnetic Resonance Image In The Diagnosis And Evaluation Of Extra-prostatic Extension And Involvement Of Seminal Vesicles Of Prostate Cancer: A Systematic Review Of Literature And Meta-analysis.

Systematic review of literature and meta-analysis to evaluate the results of magnetic resonance image 1.5T with endorectal coil in the diagnosis and evaluation of extra-prostatic extension and involvement of seminal vesicles of prostate cancer, compared to the histopathological results of the radical prostatectomy specimen. It was conducted a systematic review of literature and meta-analyses of all studies data published after 2008. In those studies, the patients with prostate cancer with indication to radical prostatectomy were submitted to magnetic resonance image (MRI) at pre-operatory period and the results were compared to those of histopathological studies after the surgery. The selected terms for research included prostate cancer, magnetic resonance, radical prostatectomy, and prostate cancer diagnosis, in the databases EMBASE, LILACS, PUBMED/MEDLINE and Cochrane Library. The data were collected using a specific qualitative instrument and the meta-analysis data were presented in the forest plot graphics, homogeneity test and sROC curves and funnel plot. A total of seven studies were included, with a total of 603 patients. Among these studies, six evaluated the value of MRI for the detection of prostate cancer, and the median sensitivity of meta-analysis was 0.6 and specificity 0.58, but with heterogeneity among the studies. Three studies evaluated extra-prostatic extension with a median sensitivity of 0.49, specificity 0.82 and heterogeneity only for sensitivity. Three studies evaluated invasion of seminal vesicles, with median sensitivity of 0.45 and specificity 0.96, with heterogeneity in both analysis. Magnetic resonance of 1.5T with endocoil showed low values of sensitivity and specificity for the diagnosis and staging of prostate cancer. The reviewed studies showed a significant heterogeneity among them. The best observed result was MRI specificity for invasion of seminal vesicles. More studies are necessary to evaluate new techniques and parameters before recommending the routine use of MRI in clinical practice.39215516

The effect of home storage conditions and packaging materials on the quality of frozen green beans

Home storage is the final step of the frozen foods distribution chain, and little is known on how it affects the products quality. The present research describes frozen green beans (Phaseolus vulgaris, L.) quality retention profile during the recommended ‘star marking’ system dates, at the storage temperatures of þ5,26, 212 and 218 8C (along 1, 4, 14 and 60 days, respectively). The quality profile was assessed by a simulation system. Simulations were set by a response surface methodology to access the effect of different packaging materials (thermal conductivities and thickness), surface heat transfer coefficient, and refrigerator dynamics (effect of refrigeration cycles at the different storage temperatures) on the average retentions of Ascorbic Acid, total vitamin C, colour and flavour. Green beans quality losses along frozen storage are significantly influenced by temperature, refrigerator dynamics and kinetic properties. Quality is also highly dependent on packaging materials thermal insulation (e.g. at temperatures above the melting point). Temperature cycles inside frozen chambers have a long term effect, and at the higher storage temperatures (e.g. T . 26 8C) are detrimental to frozen green beans quality after shorter periods

Novel pharmacological actions of Trequinsin Hydrochloride improve human sperm cell motility and function

Background and purposeAsthenozoospermia is a leading cause of male infertility, but the development of pharmaceuticals to improve sperm motility has been hindered by the lack of effective screening platforms and knowledge of suitable molecular targets. We have demonstrated that a high throughput screening (HTS) strategy in conjunction with established in vitro tests can identify and characterise the action of compounds that improve sperm motility. The study aimed to apply HTS to identify new compounds from a novel small molecule library that increase intracellular calcium, [Ca2+]I, promote human sperm cell motility and systemically determine the mechanism of action. Experimental approach A validated HTS fluorometric [Ca2+]i assay was used to screen an in-house library of compounds. Trequinsin hydrochloride (a phosphodiesterase 3 inhibitor) was selected for detailed molecular (plate reader assays, electrophysiology and cyclic nucleotide measurement) and functional (motility and acrosome reaction) testing in sperm from healthy volunteer donors and, where possible, patients.   Key resultsThe fluorometric analysis identified Trequinsin as an efficacious agonist of [Ca2+]i, although less potent than progesterone (P4). Functionally, Trequinsin significantly increased cell hyperactivation and penetration into viscous medium in all donor sperm samples and cell hyperactivation in 22/25 (88%) patient sperm samples. The Trequinsin-induced [Ca2+]i response was cross-desensitised consistently by prostaglandin E1 but not with P4. Whole-cell patch clamp electrophysiology confirmed that Trequinsin activates CatSper and partially inhibits potassium channel activity. Trequinsin also increases intracellular cGMP.   Conclusion and Implications Trequinsin exhibits a novel pharmacological profile in human sperm and may be a suitable lead compound for the development of new pharmaceuticals to improve patient sperm function and fertilisation potential

Multi giant graviton systems, SUSY breaking and CFT

In this article, we describe giant gravitons in AdS_5 x S^5 moving along generic trajectories in AdS_5. The giant graviton dynamics is solved by proving that the D3-brane effective action reduces to that of a massive point particle in AdS_5 and therefore the solutions are in one to one correspondence with timelike geodesics of AdS_5. All these configurations are related via isometries of the background, which induce target space symmetries in the world volume theory of the D-brane. Hence, all these configurations preserve the same amount of supersymmetry as the original giant graviton, i.e. half of the maximal supersymmetry. Multiparticle configurations of two or more giant gravitons are also considered. In particular, a binary system preserving one quarter of the supersymmetries is found, providing a non trivial time-dependent supersymmetric solution. A short study on the dual CFT description of all the above states is given, including a derivation of the exact induced isometry map in the CFT side of the correspondence.Comment: latex, 27+1 pages. v2: comment on mixing of states in section 4.3 added, reference added, typos corrected, final versio