Mass transfer kinetics and regressional‐desirability optimisation during osmotic dehydration of pumpkin,kiwi and pear

Mass transfer kinetics and optimisation of osmotic dehydration (OD) of fruits and vegetables with diverse structures were studied. Different concentrations of sucrose (20–60 °Brix) and process times (0–24 h) were used. Magee’s model was appropriate for predicting water loss (WL), while Azuara’s model fitted well solids gain (SG) data and represented more accurately the evolution of the complete process close to equilibrium. Polynomial equations for each kinetic variable [WL, SG and weight reduction (WR) – for pumpkin, kiwi and pear] using multiple linear regression were fitted for a selected range of experimental data (30–240 min, 20–60 °Brix). A complete solution algorithm for desirability function was coded in Matlab^® 7.2 (Mathworks, Natick, MA, USA) with the aim to optimise osmotic dehydration process in terms of WL, SG and WR; optimal conditions were found for each fruit. Besides, an optimal common zone was identified for OD corresponding to process time from 114 to 240 min and sucrose concentration from 54 to 60 °Brix.     

Polydiacetylene as a Biosensor: Fundamentals and Applications in the Food Industry

Biosensors offer the potential for real-time pathogen detection. Polydiacetylene (PDA) is an ideal choice for use as a sensor due to its unique optical properties. PDA molecules can form thin films or vesicles that change color from deep blue to red in response to different stimuli, like temperature, pH, and the presence of biological molecules. PDA films and vesicles have been proven to be promising devices for the detection of bacteria and bacterial toxins. Langmuir troughs (for films) and microcalorimetry (for vesicles) are among the many techniques used to characterize PDA films and vesicles. In order to enable more applications of PDA films, it is imperative to elucidate and gain a deeper understanding of the molecular interactions associated with their color change. In addition, it is necessary to transfer the PDA film onto a solid support like plastic in order to incorporate PDA biosensors into an intelligent packaging system. Through the use of such a system, consumers can monitor food quality, thereby preventing foodborne outbreaks. In this review, we discuss the formation of PDA films and vesicles, their characteristics, and their potential applications as biosensors. The possibility to incorporate PDA biosensors into an intelligent packaging system to be used in the food industry is also explored.     

Biomass to fuels: A water-free process for biodiesel production with phosphazene catalysts

Non-ionic triamino(imino)phosphoranes (phosphazenes) give excellent results as base catalysts for the water-free alcoholysis of vegetable fatty esters. Two phosphazene catalysts, with different intrinsic basicities, P₁-t-Bu and P₄-t-Bu, together with reaction parameters, such as temperature, alcohol/oil molar ratio, or catalyst concentration, have been studied. It was found that activity can be directly correlated to the basicity of the catalyst. Very high biodiesel yields (93–95% mol) were achieved under mild reaction conditions with methanol and ethanol. The catalyst can be recovered and recycled.     

Structure and Dynamics of Meprin β in Complex with a Hydroxamate-Based Inhibitor

The astacin protease Meprin β represents an emerging target for drug development due to its potential involvement in disorders such as acute and chronic kidney injury and fibrosis. Here, we elaborate on the structural basis of inhibition by a specific Meprin β inhibitor. Our analysis of the crystal structure suggests different binding modes of the inhibitor to the active site. This flexibility is caused, at least in part, by movement of the C-terminal region of the protease domain (CTD). The CTD movement narrows the active site cleft upon inhibitor binding. Compared with other astacin proteases, among these the highly homologous isoenzyme Meprin α, differences in the subsites account for the unique selectivity of the inhibitor. Although the inhibitor shows substantial flexibility in orientation within the active site, the structural data as well as binding analyses, including molecular dynamics simulations, support a contribution of electrostatic interactions, presumably by arginine residues, to binding and specificity. Collectively, the results presented here and previously support an induced fit and substantial movement of the CTD upon ligand binding and, possibly, during catalysis. To the best of our knowledge, we here present the first structure of a Meprin β holoenzyme containing a zinc ion and a specific inhibitor bound to the active site. The structural data will guide rational drug design and the discovery of highly potent Meprin inhibitors.     

Observed reductions in school bullying, nonbullying aggression, and destructive bystander behavior: A longitudinal evaluation.

This study was a longitudinal extension of a random control trial of the Steps to Respect antibullying program. Students in Grades 3–5 were surveyed (n = 624) and observed on the playground (n = 360). Growth curve models of intervention students showed 2-year declines in playground bullying, victimization, nonbullying aggression, destructive bystander, and argumentative behavior. Grade-equivalent contrasts indicated group differences in all problem behaviors. Problem behaviors in the control group increased or remained stable across grade. Intervention group students reported less difficulty responding assertively to bullying compared with control students. Within both groups, older students perceived themselves to be more aggressive and less frequently victimized than younger students. Methodological issues posed by inconsistencies between self-reported and observed behavior are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Optimized linker sequences for the expression of monomeric and dimeric bispecific single-chain diabodies

Bispecific single-chain diabodies (scDb) consist of the variableheavy and light chain domains of two antibodies connected bythree linkers. The structure of an scDb in the V_H–V_L orientationis V_HA–linkerA–V_LB–linkerM–V_HB–linkerB–V_LA,with linkers A and B routinely chosen to be 5–6 residuesand linker M 15–20 residues. Here, we applied displayof scDb on filamentous phage to analyse the composition of optimallinker sequences. The three linkers were randomized in lengthand sequence using degenerated triplets coding for only sixhydrophilic or aliphatic amino acids (Thr, Ser, Asp, Asn, Gly,Ala). Antigen-binding clones were then isolated by one to tworounds of selection on the two different antigens recognizedby the bispecific scDb. Using an scDb directed against carcinoembryonicantigen (CEA) and ß-galactosidase (Gal), we foundthat monomeric scDb had a preferred length of 15 or more aminoacid residues for the middle linker M and of 3–6 residuesfor the linkers A and B. No obvious bias towards a preferredlinker sequence was observed. Reduction of the middle linkerbelow 13 residues led to the formation of dimeric scDb, whichmost likely results from interchain pairing between all theV_H and V_L domains. Dimeric scDb were also formed by fragmentspossessing a long linker M and linkers A and B of 0 or 1 residue.We assume that these dimeric scDb are formed by intrachain pairingof the central variable domains and interchain pairing of theflanking variable domains. Thus, the latter molecules representa novel format of bispecific and tetravalent molecules. Thedescribed strategy allows for the isolation of both optimizedand minimal linker sequences for the assembly of monomeric ordimeric single-chain diabodies.     

Study on the interaction of diarylbutadiynes with free radicals: Interaction with propagating radicals of some vinyl monomers

In order to study the nature of interaction of arylbutadiynes with transient free radicals, polymerization and copolymerization of some vinyl monomers such as methyl methacrylate (MMA), styrene (ST), methacrylonitrile (MAN), vinylidene chloride (VCl₂), ethyl acrylate (EA) and acrylonitrile (AN), were carried out in the presence of diphenylbutadiyne (DPB), 4,4'-butadiynylene-N,N,N',N'-tetra-n-butyl-dibenzamide (BBA), and 4,4'-dibromodiphenylbutadiyne (BPB). MMA gave an intense ESR signal at the polymerization temperature when the polymerization system became viscous, and the number of radicals increased with polymerization time. Strong signals of polyEA and polyMAN radicals were also observed in the presence of DPB when the polymerization system became almost solid. This is a unique case where active transient propagating radicals such as that of polyEA can be detected at polymerization temperature. The rates of polymerization decreased by the presence of the diacetylenes, but the molecular weights did not change with the diacetylene concentrations. UV spectroscopy revealed that there was no diacetylene unit bonded to the obtained polymers, indicating that degradative chain transfer is not the case. The monomer reactivity ratios for MMA-ST and MMA-AN systems did not vary significantly in the presence of the diacetylenes, although some difference was observed. It seems that some arylbutadiynes interact with free radicals but do not form bonds. Received: 4 June 1999/Revised version: 29 September 1999/Accepted: 29 September 1999     

Can questionnaire reports correctly classify relationship distress and partner physical abuse?

Relationship adjustment (e.g., Dyadic Adjustment Scale; DAS) and physical aggression (e.g., Conflict Tactics Scale) measures are used both as screening tools and as the sole criterion for classification. This study created face valid diagnostic interviews for relationship distress and physical abuse, through which one could compare preliminarily the classification properties of questionnaire reports. The DAS (and a global measure of relationship satisfaction) had modest agreement with a structured diagnostic interview; both questionnaires tended to overdiagnose distress compared with the interview. Results for partner abuse reiterated the need to go beyond occurrence of aggression as the sole diagnostic criterion, because men's aggression was more likely than women's to rise to the level of "abuse" when diagnostic criteria (injury or substantial fear) were applied. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neuroprotective and Symptomatic Effects of Cannabidiol in an Animal Model of Parkinson’s Disease

Parkinson’s disease (PD) is a neurodegenerative disorder characterized by the loss of dopaminergic neurons in the Substantia Nigra pars compacta, leading to classical PD motor symptoms. Current therapies are purely symptomatic and do not modify disease progression. Cannabidiol (CBD), one of the main phytocannabinoids identified in Cannabis Sativa, which exhibits a large spectrum of therapeutic properties, including anti-inflammatory and antioxidant effects, suggesting its potential as disease-modifying agent for PD. The aim of this study was to evaluate the effects of chronic treatment with CBD (10 mg/kg, i.p.) on PD-associated neurodegenerative and neuroinflammatory processes, and motor deficits in the 6-hydroxydopamine model. Moreover, we investigated the potential mechanisms by which CBD exerted its effects in this model. CBD-treated animals showed a reduction of nigrostriatal degeneration accompanied by a damping of the neuroinflammatory response and an improvement of motor performance. In particular, CBD exhibits a preferential action on astrocytes and activates the astrocytic transient receptor potential vanilloid 1 (TRPV1), thus, enhancing the endogenous neuroprotective response of ciliary neurotrophic factor (CNTF). These results overall support the potential therapeutic utility of CBD in PD, as both neuroprotective and symptomatic agent.     

Development of a Novel Nanoarchitecture of the Robust Photosystem I from a Volcanic Microalga Cyanidioschyzon merolae on Single Layer Graphene for Improved Photocurrent Generation

Here, we report the development of a novel photoactive biomolecular nanoarchitecture based on the genetically engineered extremophilic photosystem I (PSI) biophotocatalyst interfaced with a single layer graphene via pyrene-nitrilotriacetic acid self-assembled monolayer (SAM). For the oriented and stable immobilization of the PSI biophotocatalyst, an His₆-tag was genetically engineered at the N-terminus of the stromal PsaD subunit of PSI, allowing for the preferential binding of this photoactive complex with its reducing side towards the graphene monolayer. This approach yielded a novel robust and ordered nanoarchitecture designed to generate an efficient direct electron transfer pathway between graphene, the metal redox center in the organic SAM and the photo-oxidized PSI biocatalyst. The nanosystem yielded an overall current output of 16.5 µA·cm⁻² for the nickel- and 17.3 µA·cm⁻² for the cobalt-based nanoassemblies, and was stable for at least 1 h of continuous standard illumination. The novel green nanosystem described in this work carries the high potential for future applications due to its robustness, highly ordered and simple architecture characterized by the high biophotocatalyst loading as well as simplicity of manufacturing.