Acculturation, Familism, Parental Monitoring, and Knowledge as Predictors of Marijuana and Inhalant Use in Adolescents.

The authors investigated relationships between marijuana and inhalant use and several cultural and demographic factors in Anglo American and Hispanic American adolescents (N=1,094). Outcome measures assessed lifetime and 30-day marijuana and inhalant use. Predictors and covariates used in logistic regression analyses were region, grade, gender, knowledge, acculturation, familism, and parental monitoring. Hispanic Americans exhibited higher usage across all measures. In this group, high acculturation was associated with low marijuana, but high inhalant, use. Across all participants, positive family relations and parental monitoring were strongly associated with attenuated marijuana use hut only among those most knowledgeable about drugs. Familism and monitoring were not associated with diminished usage among the less knowledgeable. For inhalants, monitoring combined with high knowledge or high familism was associated with diminished usage. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A histological study on polyactive® for the prevention of peridural adhesions after spinal surgery: an experimental study in dogs with a 3 months follow-up

In the present study the potential of Polyactive^® bilayer sheets in the prevention of scar tissue formation after spinal surgery was investigated. Eight adult beagle dogs underwent 3 laminectomies at three levels (L2, L4 and L6). According to a randomized implantation schedule a Polyactive^® sheet or autogenous fat graft was placed in the defect. The third site served as a control without implant. After 4 or 12 weeks (4 dogs per period) the dogs were sacrificed and histological sections were prepared. The Polyactive^® treated defects showed partial closure by newly formed bone. The Polyactive^® was encapsuled by a thin fibrous tissue layer. Ventral to the defect, dense fibrous tissue was present which was separated from the dura by the Polyactive^® sheet in all cases. In some cases fibrous tissue was present between the implant capsule and the dura. In the fat graft group there were no signs of closure of the defect but most sites showed fibrous tissue at the edges of the graft, which was in 4 sites continous with the dura mater. Fibrosis and degeneration of the fat grafts were seen. All control defects showed partial closure by newly formed bone, and ventral to the defect extensive fibrous tissue, which was in 50% continous with the dura mater. Other sections showed loose connective tissue in contact with the dura mater. It is concluded that Polyactive^® has a potential as a mechanical barrier in the prevention of adhesions between the dorsal spinal muscles and the dura mater.     

13C solid-state NMR of gramicidin A in a lipid membrane

The natural-abundance 13C NMR spectrum of gramicidin A in a lipid membrane was acquired under magic-angle spinning conditions. With fast sample spinning (15 kHz) at approximately 65 degrees C the peaks from several of the aliphatic, beta-, alpha-, aromatic, and carbonyl carbons in the peptide could be resolved. The resolution in the 13C spectrum was superior that observed with 1H NMR under similar conditions. The 13C linewidths were in the range 30-100 Hz, except for the alpha- and beta-carbons, the widths of which were approximately 350 Hz. The beta-sheet-like local structure of gramicidin A was observed as an upfield shift of the gramicidin alpha and carbonyl resonances. Under slow sample spinning (500 Hz), the intensity of the spinning sidebands from 13C in the backbone carbonyls was used to determine the residual chemical shift tensor. As expected, the elements of the residual chemical shift tensor were consistent with the single-stranded, right-handed beta6.3 helix structure proposed for gramicidin A in lipid membranes.     

Copper(I)-Dioxygen Adducts and Copper Enzyme Mechanisms

Primary copper(I)-dioxygen (O₂) adducts, cupric-superoxide complexes, have been proposed intermediates in copper-containing dioxygen-activating monooxygenase and oxidase enzymes. Here, mechanisms of C−H activation by reactive copper-(di)oxygen intermediates are discussed, with an emphasis on cupric-superoxide species. Over the past 25 years, many synthetically derived cupric-superoxide model complexes have been reported. Due to the thermal instability of these intermediates, early studies focused on increasing their stability and obtaining physical characterization. More recently, in an effort to gain insight into the possible substrate oxidation step in some copper monooxygenases, several cupric-superoxide complexes have been used as surrogates to probe substrate scope and reaction mechanisms. These cupric superoxides are capable of oxidizing substrates containing weak O−H and C−H bonds. Mechanistic studies for some enzymes and model systems have supported an initial hydrogen-atom abstraction via the cupric-superoxide complex as the first step of substrate oxidation.     

The effect of enzyme systems and processing on the hydrolysis of peanut (Arachis hypogaea L.) protein

In vitro protein digestion studies were carried out on raw and roasted peanut flour as the starting material in the production of peanut protein hydrolysate. Peanut flour was hydrolyzed with alcalase and alternately in a sequential digestion with pepsin-pancreatin, both for up to 24 h. The degree of hydrolysis (DH) at different times of hydrolysis was determined using the trinitrobenzenesulfonic acid (TNBS) method. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was used to indicate destruction of native protein units in the enzymatic digests.Hydrolysis with alcalase was very rapid for the first 6 h after which a plateau was reached, whereas that with pepsin–pancreatin was more gradual reaching a plateau after 12 h of hydrolysis. Raw peanut hydrolyzed with alcalase and pepsin–pancreatin had 23% and 21% DH after 24 h respectively, whilst roasted peanut hydrolyzed with alcalase had 21% DH, with the pepsin–pancreatin hydrolysate recording the highest value of 25% after 24 h of hydrolysis.SDS-PAGE results showed that raw peanut samples behaved differently from the roasted samples; increasing hydrolysis time reduced larger peanut protein subunits, with only peptides of <20 kDa visible after hydrolysis for raw peanut, and virtually no distinct visible bands for the roasted peanut after 3 h of hydrolysis.     

The Effect of Annealing on the Charge‐Carrier Dynamics in a Polymer/Polymer Bulk Heterojunction for Photovoltaic Applications

The effect of annealing blends of poly(2‐methoxy‐5‐(3′,7′‐dimethyloctyloxy)‐1,4‐phenylenevinylene) (MDMO‐PPV) and a poly(cyanoether phenylenevinylene) (PCNEPV) on the photoconductivity is studied. Charge carriers are generated by pulsed‐laser excitation and their mobility and decay kinetics are monitored using time‐resolved microwave conductivity (TRMC) measurements. Photoexcitation leads to the formation of an exciton, which can undergo charge separation at an interface between the electron‐donating MDMO‐PPV and the electron‐accepting PCNEPV. The electrons and holes formed in this way must escape from each other to contribute to the photoconductivity. The photoconductivity of the blends is found to increase by almost two orders of magnitude upon thermal annealing for three hours at 100 °C. This increase is attributed to the occurrence of phase separation in the polymer/polymer film, resulting in PCNEPV‐rich parts. The formation of PCNEPV‐rich parts allows the electron to diffuse away from the interface, which favors escape from geminate recombination, leading to a higher photoconductivity.     

Evaluation of Adh1 alleles and transgenic soybean seeds using Scorpion PCR and HRM analysis

The identification of both approved and non-approved genetically modified organisms (GMOs) is an integral part of GMO biosafety legislation in many countries. One aspect that may affect PCR-based detection of a GMO lies within the analysis of its genetic stability, as sequence alterations or DNA instabilities may impede quantification by PCR. Genetic stability can be analyzed using various methods, yet many of these methods have distinct disadvantages, including low sensitivity. In this study, high resolution melting (HRM) analysis and real-time PCR with Scorpion primers were used as a method to analyze the 3′ end of RR soybeans (RR 40-3-2) in a large number of samples (n = 1,034). No evidence for the occurrence of mutation events was found, implying that the nucleotide sequence of this region is unlikely to be unstable and is well suited as a target for the quantification of RR soybeans. Additionally, and as a preparative work for an optimization of the method, a 174 bp region of the first intron of the Adh1 gene was analyzed in several varieties of maize with different GMO events using the same approach. The results show that 2 alleles are present. In further experiments, the different alleles were cloned into plasmids to generate homozygous plasmids from heterozygous templates in order to generate for a more precise analysis. The overall methodological aim of these studies was to compare HRM analysis with Scorpion primer PCR. Both methods were capable of differentiating between the 2 homozygous and heterozygous alleles. For a better discrimination, however, we conclude that it is most reliable to consider the results of both methods. This dual approach is assumed to be an effective tool as an accurate, high-throughput means of the screening of GMOs for potential genetic instabilities that may interfere with the detection and identification of specific GM events.