Ultrasound-assisted extraction of natural products

Ultrasound-assisted extraction (USAE) is an interesting process to obtain high valuable compounds and could contribute to the increase in the value of some food by-products when used as sources of natural compounds. The main benefits will be a more effective extraction, thus saving energy, and also the use of moderate temperatures, which is beneficial for heat-sensitive compounds. For a successful application of the USAE, it is necessary to consider the influence of several process variables, the main ones being the applied ultrasonic power, the frequency, the extraction temperature, the reactor characteristics, and the solvent-sample interaction. The highest extraction rate is usually achieved in the first few minutes, which is the most profitable period. To optimize the process, rate equations and unambiguous process characterization are needed, aspects that have often been lacking. © 2011 Springer Science+Business Media, LLC.The authors thank the Generalitat Valenciana for their financial support in project PROMETEO/2010/062 and the Caja de Ahorros del Mediterraneo for M.D. Esclapez's pre-doctoral grant.Esclapez Vicente, MD.; García Pérez, JV.; Mulet Pons, A.; Cárcel Carrión, JA.; Esclapez, MD. (2011). Ultrasound-assisted extraction of natural products. Food Engineering Reviews. 3(2):108-120. https://doi.org/10.1007/s12393-011-9036-6S10812032Abad Romero B, Bou-Maroun E, Reparet JM, Blanquet J, Cayot N (2010) Impact of lipid extraction on the dearomatisation of an Eisenia foetida protein powder. Food Chem 119:459–466Adewuyi YG (2001) Sonochemistry: environmental science and engineering applications. Ind Eng Chem Res 40:4681–4715Atchley AA, Crum LA (1988) Acoustic cavitation and bubble dynamics. 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An overview of tissue engineering approaches for management of spinal cord injuries

Severe spinal cord injury (SCI) leads to devastating neurological deficits and disabilities, which necessitates spending a great deal of health budget for psychological and healthcare problems of these patients and their relatives. This justifies the cost of research into the new modalities for treatment of spinal cord injuries, even in developing countries. Apart from surgical management and nerve grafting, several other approaches have been adopted for management of this condition including pharmacologic and gene therapy, cell therapy, and use of different cell-free or cell-seeded bioscaffolds. In current paper, the recent developments for therapeutic delivery of stem and non-stem cells to the site of injury, and application of cell-free and cell-seeded natural and synthetic scaffolds have been reviewed

Foam-Mat Freeze-Drying of Blueberry Juice by Using Trehalose-β-Lactoglobulin and Trehalose-Bovine Serum Albumin as Matrices

This study aimed to evaluate the effect of pure protein compounds and trehalose incorporated into blueberry juice for foam-mat freeze-drying on the foam and powder properties. Foam-mat freeze-drying (FMFD) of blueberry juice was tested at − 55 °C for 24 h. Matrices used were trehalose + β-lactoglobulin (T3BL1) and trehalose + bovine serum albumin (T3A1) and compared with maltodextrin + whey protein isolate (M3W1). Physicochemical properties of foam and powder, e.g., foam stability, foam density, moisture, rehydration time, color, particle morphology, total phenolic, and anthocyanins (total and individuals), were investigated. T3BL1 and T3A1 had more stable foam than M3W1. However, overrun of T3BL1 and T3A1 foamed were inferior to the M3W1 sample. The M3W1 sample recovered 79% powder (dry weight) and was superior to others. Rehydration time of powdered T3BL1 and T3A1, with bulk densities of 0.55–0.60 g cm−3, was the fastest (34–36 s). The blueberry powders of M3W1 showed more irregular particle size and shape, while the samples with trehalose and pure proteins generated particles of more uniform size with obvious pores. T3BL1 and T3A1 showed less redness (a*) values than the M3W1 product. All samples were considered pure red due to hue values < 90. M3W1 was superior in total phenolic content (TPC) and total monomeric anthocyanins (TMA) compared with both samples made with trehalose + β-lactoglobulin and trehalose+bovine serum albumin. Delphinidin-3-glucoside (Del3Gl) concentration was found to be higher in M3W1. Also, M3W1 had higher cyanidin-3-glucoside (Cyn3Gl) and malvidin-3-glucoside (Mal3Gl) concentration. M3W1 also prevented the degradation of these bioactive compounds better than the other FMFD samples. The use of pure proteins and trehalose as matrices in the FMFD process had little advantage compared with maltodextrin/whey protein isolate. Thus, maltodextrin/whey protein isolate seems an ideal matrix for the manufacture of FMFD blueberry

Development and Validation of a Risk Score for Chronic Kidney Disease in HIV Infection Using Prospective Cohort Data from the D:A:D Study

Ristola M. on työryhmien DAD Study Grp ; Royal Free Hosp Clin Cohort ; INSIGHT Study Grp ; SMART Study Grp ; ESPRIT Study Grp jäsen.Background Chronic kidney disease (CKD) is a major health issue for HIV-positive individuals, associated with increased morbidity and mortality. Development and implementation of a risk score model for CKD would allow comparison of the risks and benefits of adding potentially nephrotoxic antiretrovirals to a treatment regimen and would identify those at greatest risk of CKD. The aims of this study were to develop a simple, externally validated, and widely applicable long-term risk score model for CKD in HIV-positive individuals that can guide decision making in clinical practice. Methods and Findings A total of 17,954 HIV-positive individuals from the Data Collection on Adverse Events of Anti-HIV Drugs (D:A:D) study with >= 3 estimated glomerular filtration rate (eGFR) values after 1 January 2004 were included. Baseline was defined as the first eGFR > 60 ml/min/1.73 m2 after 1 January 2004; individuals with exposure to tenofovir, atazanavir, atazanavir/ritonavir, lopinavir/ritonavir, other boosted protease inhibitors before baseline were excluded. CKD was defined as confirmed (>3 mo apart) eGFR In the D:A:D study, 641 individuals developed CKD during 103,185 person-years of follow-up (PYFU; incidence 6.2/1,000 PYFU, 95% CI 5.7-6.7; median follow-up 6.1 y, range 0.3-9.1 y). Older age, intravenous drug use, hepatitis C coinfection, lower baseline eGFR, female gender, lower CD4 count nadir, hypertension, diabetes, and cardiovascular disease (CVD) predicted CKD. The adjusted incidence rate ratios of these nine categorical variables were scaled and summed to create the risk score. The median risk score at baseline was -2 (interquartile range -4 to 2). There was a 1: 393 chance of developing CKD in the next 5 y in the low risk group (risk score = 5, 505 events), respectively. Number needed to harm (NNTH) at 5 y when starting unboosted atazanavir or lopinavir/ritonavir among those with a low risk score was 1,702 (95% CI 1,166-3,367); NNTH was 202 (95% CI 159-278) and 21 (95% CI 19-23), respectively, for those with a medium and high risk score. NNTH was 739 (95% CI 506-1462), 88 (95% CI 69-121), and 9 (95% CI 8-10) for those with a low, medium, and high risk score, respectively, starting tenofovir, atazanavir/ritonavir, or another boosted protease inhibitor. The Royal Free Hospital Clinic Cohort included 2,548 individuals, of whom 94 individuals developed CKD (3.7%) during 18,376 PYFU (median follow-up 7.4 y, range 0.3-12.7 y). Of 2,013 individuals included from the SMART/ESPRIT control arms, 32 individuals developed CKD (1.6%) during 8,452 PYFU (median follow-up 4.1 y, range 0.6-8.1 y). External validation showed that the risk score predicted well in these cohorts. Limitations of this study included limited data on race and no information on proteinuria. Conclusions Both traditional and HIV-related risk factors were predictive of CKD. These factors were used to develop a risk score for CKD in HIV infection, externally validated, that has direct clinical relevance for patients and clinicians to weigh the benefits of certain antiretrovirals against the risk of CKD and to identify those at greatest risk of CKD.Peer reviewe

Learning to Play Board Games using Temporal Difference Methods

A promising approach to learn to play board games is to use reinforcement learning algorithms that can learn a game position evaluation function. In this paper we examine and compare three different methods for generating training games: (1) Learning by self-play, (2) Learning by playing against an expert program, and (3) Learning from viewing experts play against themselves. Although the third possibility generates highquality games from the start compared to initial random games generated by self-play, the drawback is that the learning program is never allowed to test moves which it prefers. We compared these three methods using temporal difference methods to learn the game of backgammon. For particular games such as draughts and chess, learning from a large database containing games played by human experts has as a large advantage that during the generation of (useful) training games, no expensive lookahead planning is necessary for move selection. Experimental results in this paper show how useful this method is for learning to play chess and draughts

Micellization and adsorption of phospholipids and soybean oil onto hydrophilic and hydrophobic surfaces in nonaqueous media

Micelle formation of phospholipids (PL) in bulk was investigated in nonaqueous media. Dye solubilization was used to determine the critical micelle concentration (CMC) of reverse micelles of phospholipids in a hexane-oil environment. The CMC, which represents the total PL monomer concentration in bulk, was also studied as a function of amount of water present in the system. The CMC was found to decrease with the addition of water. In addition, the sign of the surface charge of phospholipid micelles was determined in nonaqueous media using the phase analysis light scattering technique (PALS). Phospholipid reversed micelles appear to exhibit a negative charge even in nonaqueous media due possibly to a trace amount of water trapped inside the polar head center. These results are significant to the understanding of membrane separation processes since the main objective is to separate out micellar aggregates from hexane-oil mixtures. Two important factors which control the efficiency of membrane separations are: size exclusion and chemical interaction between membrane surfaces and bulk species. The micelle formation affects separation in a positive way since monomers are believed to pass through the membranes more easily than micelles. On the other hand adsorption of bulk species to membrane surfaces is frequently cited as the primary cause of fouling which results in pore plugging. Adsorption behavior of phospholipids and soybean oil onto acid (HF) treated silicon and polymer surfaces were analyzed by ex-situ FTIR/ATR and in-situ contact angle methods. In-situ contact angle measurements were found to be very efficient in detecting adsorbed oil and phospholipids on modified silicon and polymer surfaces. Results from this work reveal for the first time that hydrophobic surfaces ( > 50degrees) are more prone to phospholipid and soybean oil adsorption than hydrophilic surfaces in hexane-soybean oil media. (C) 2002 Elsevier Science B.V. All rights reserved