Wood cell wall mimicking for composite films of spruce nanofibrillated cellulose with spruce galactoglucomannan and arabinoglucuronoxylan

Two hemicelluloses (HCs), galactoglucomannan (GGM) and arabinoglucuronoxylan (AGX), and nanofibrillated cellulose (NFC) were isolated from spruce wood and used for the preparation of composite films containing high amounts of cellulose, i.e. 85 and 80 wt% of NFC, respectively. The films were prepared in two ways: (i) by the pre-sorption of HCs on NFC and (ii) by the mixing of components in the usual way. Pre-sorption was applied in an attempt to mimic the carbohydrate biosynthesis pattern during wood cell wall development, where HCs were deposited on the cellulose fibrils prior to lignification taking place. It was assumed that pre-sorption would result in a better film-forming as well as stronger and denser composite films. The mechanical, thermal, structural, moisture sorption and oxygen barrier characteristics of such composite films were tested in order to examine whether the performance of composite films prepared by pre-sorption was better, when compared to the performance of composite films prepared by mixing. The performance of composite films was also tested with respect to the HCs used. All the films showed quite similar barrier and mechanical properties. In general, stiff, strong and quite ductile films were produced. The moisture sorption of the films was comparably low. The oxygen barrier properties of the films were in the range of commercially used poly ethylene vinyl alcohol films. However, the pre-sorption procedure for the preparation of composite films resulted in no additional improvement in the performance of the films compared to the corresponding composite films that had been prepared using the mixing process. Almost certainly, the applied mixing process led to an optimal mixing of components for the film performance achieved. The GGM contributed to a somewhat better film performance than the AGX did. Indications were observed for stronger interactions between the GGM and NFC than that for the AGX and NFC.     

Quantitative Insight into the Design of Compounds Recognized by the L‐Type Amino Acid Transporter 1 (LAT1)

L ‐Type amino acid transporter 1 (LAT1) is a transmembrane protein expressed abundantly at the blood–brain barrier (BBB), where it ensures the transport of hydrophobic acids from the blood to the brain. Due to its unique substrate specificity and high expression at the BBB, LAT1 is an intriguing target for carrier‐mediated transport of drugs into the brain. In this study, a comparative molecular field analysis (CoMFA) model with considerable statistical quality (Q²=0.53, R²=0.75, Q² SE=0.77, R² SE=0.57) and good external predictivity (CCC=0.91) was generated. The model was used to guide the synthesis of eight new prodrugs whose affinity for LAT1 was tested by using an in situ rat brain perfusion technique. This resulted in the creation of a novel LAT1 prodrug with L ‐tryptophan as the promoiety; it also provided a better understanding of the molecular features of LAT1‐targeted high‐affinity prodrugs, as well as their promoiety and parent drug. The results obtained will be beneficial in the rational design of novel LAT1‐binding prodrugs and other compounds that bind to LAT1.     

Distribution of monomeric,dimeric and polymeric products of stigmasterol during thermo‐oxidation

When plant sterols are oxidized at moderate temperatures (≤100 °C), products mainly derive from hydroperoxides, but at temperatures close to 200 °C, thermal reactions such as dehydration and condensation become important. Although sterols are often subjected to frying conditions, very little is known of their thermal reactions. In this study, stigmasterol was thermo‐oxidized at 180 °C, and the formation of dimers and polymers and the amounts of monomers were measured by high‐performance size‐exclusion chromatography. The products were further characterized by polarity using solid‐phase extraction fractionation. During heating, the amounts of monomers decreased at a steady rate, and those of dimers and polymers increased. After 3 h of heating, 21% of the material existed in higher‐molecular‐weight products. The amount of polar monomers increased especially during the first hour, demonstrating the formation of oxides and their further reactions, while that of mid‐polar monomers decreased constantly, indicating losses of stigmasterol. Polar dimers contributed to approximately 60% of the dimers, and polar polymers to approximately 78% of the polymers, which suggests that in most higher‐molecular‐weight products at least one of the sterol moieties was oxidized. This study showed that a significant proportion of thermo‐oxidation products are not polar monomeric oxides which are commonly analyzed as oxidation products.     

Prenatal expectations in transition to parenthood: Former infertility and family dynamic considerations.

Prenatal expectations are important for the future parent–child relationship. The authors examined how maternal and paternal prenatal expectations of the relationship with the child predicted 1st-year parenting stress and whether these expectations were violated over the transition to parenthood. They further examined how former infertility affected these associations. The participants were 745 Finnish couples, 367 having undergone a successful assisted reproductive treatment and 378 conceiving spontaneously. Couples completed a questionnaire of family representations during pregnancy and when the child was 2 and 12 months old and Abidin’s Parenting Stress Index at 2 and 12 months postpartum. The hypothesis of moderately high expectations predicting the lowest level of parenting stress was substantiated only concerning paternal expectations of own autonomy with the child. Generally, however, negative expectations of own and spouse’s relationship with the child were linearly associated with higher parenting stress. Postnatal representations were more positive or equal to expectations, except for negative violation occurring in maternal expectation of the father–child relationship, especially among normative mothers. The results are discussed in relation to family dynamic considerations and special features of formerly infertile couples. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Crosslinking with ammonium zirconium carbonate improves the formation and properties of spruce galactoglucomannan films

Spruce (Picea abies) O-acetyl-galactoglucomannans (GGMs), low-value by-products from the forestry industry were upgraded to sustainable film-forming materials by crosslinking with ammonium zirconium carbonate (AZC). The purpose of crosslinking was to enhance the film formation, reduce the need of polyol plasticizers, and decrease the sensitivity of the film properties to moisture. Tensile testing showed that AZC-crosslinked GGM can be used to prepare strong and stiff films, with tensile strength up to 52 MPa and Young’s modulus of 4.7 GPa. Dynamic mechanical analysis, performed as a function of relative humidity (RH), showed that AZC-crosslinked GGM films retained their stiffness at higher RH than the reference films without AZC. Water vapor sorption and permeability analyses were done to further study the effect of moisture on the film properties, and those showed that the effect of sorbitol as a plasticizer depended greatly on RH. The oxygen permeability of the AZC-crosslinked GGM films was in the range of 4–11 [cm³ μm/(m² day kPa)]. GGM films could offer a bio-based and biodegradable alternative to existing synthetic oxygen barrier materials, on the condition that they are protected from the effects of moisture, e.g., by hydrophobic laminated layers.     

Inoculum pretreatment differentially affects the active microbial community performing mesophilic and thermophilic dark fermentation of xylose

The influence of different inoculum pretreatments (pH and temperature shocks) on mesophilic (37 °C) and thermophilic (55 °C) dark fermentative H₂ production from xylose (50 mM) and, for the first time, on the composition of the active microbial community was evaluated. At 37 °C, an acidic shock (pH 3, 24 h) resulted in the highest yield of 0.8 mol H₂ mol^?1 xylose. The H₂ and butyrate yield correlated with the relative abundance of Clostridiaceae in the mesophilic active microbial community, whereas Lactobacillaceae were the most abundant non-hydrogenic competitors according to RNA-based analysis. At 55 °C, Clostridium and Thermoanaerobacterium were linked to H₂ production, but only an alkaline shock (pH 10, 24 h) repressed lactate production, resulting in the highest yield of 1.2 mol H₂ mol^?1 xylose. This study showed that pretreatments differentially affect the structure and productivity of the active mesophilic and thermophilic microbial community developed from an inoculum.     

What institutional kitchens require of packages

A theme interview study technique was used to investigate the requirements of institutional kitchens on packages. The interviewees included experts in the food and packaging industries as well as workers in staff restaurants and school dining rooms. Packages containing milk, juice, vegetables and convenience food products were studied. This study shows that the packages did not always function in a satisfactory way. The biggest problem seemed to be the weight of the package and the opening mechanism. The workers are mainly female and therefore 20 kg is too heavy for lifting. It is also important that the package can be disposed of easily. A good package is easy to open and reclose. Reclosing, in particular, proved to be problematic. It is important that the package can be reclosed properly. A problem with packages filled with convenience food is that they are often too full and the food boils over hen heated.     

Virtual Screening of Small Drug‐Like Compounds Stimulating the Enzymatic Activity of Kallikrein‐Related Peptidase 3 (KLK3)

Kallikrein‐related peptidase 3 (KLK3) is a prostatic serine protease shown to possess antiangiogenic properties which are exerted via its proteolytic activity. The antiangiogenic effect indicates that KLK3 may slow down the growth of prostate cancer; this makes it an interesting target for new therapies for prostate cancer. In this work, new drug‐like compounds were discovered that stimulate the proteolytic activity of KLK3. The compounds were identified using 2D similarity search and 3D pharmacophore‐based virtual screening, and their ability to stimulate KLK3 was verified by enzymatic activity assays. The effect of the molecules alone was modest, but in synergy with a cyclic peptide the most potent molecule was found to stimulate KLK3 activity significantly: up to 351 % of the activity of KLK3. This demonstrates that small drug‐like compounds can be beneficial tools in studying the antiangiogenic properties of KLK3.