Evaluation of heat seal quality of aseptic food containers by ultrasonic and optical microscopic imaging

A rapid and simple method for determination of mono- and diglycerides in milk and milk products is described. The emulsifiers were extracted from the samples with organic solvents. Soxhlet extraction and supercritical fluid extraction were compared. To avoid interference of the co-extracted triglycerides with mono- and diglycerides during the GC run, triglycerides were separated by solid phase extraction. Then the emulsifiers were silylated and determined by GC-FID. Optimising GC parameters, the contents of mono- and diglycerides could be determined in the same run within 20 min. Mono- and diglycerides were gathered in two separate groups and quantified with betulin as internal standard. Commercial samples were analysed for the presence of mono- and diglycerides. The recovery rates of monoglycerides were about 98% for skim milk and 99% for dessert. Spiked diglycerides were found with 101% in skim milk and 94% in dessert. The limit of determination was 0.001% for mono- and 0.006% for diglycerides.     

Design and simulation of a solar-hydrogen system for different situations

In recent years, hybrid photovoltaic–fuel cell energy systems have been popular as energy production systems for different applications. A typical solar-hydrogen system can be modeled the electricity supplied by PV panels is used to meet the demand directly to the maximum extent possible. If there is any surplus PV power over demand, and capacity left in the tank for accommodating additional hydrogen, this surplus power is supplied to the electrolyser to produce hydrogen for storage. When the output of the PV array is not sufficient to supply the demand, the fuel cell draws on hydrogen from storage and produces electricity to meet the supply deficit.     

Equilibrium studies for trimethoprim adsorption on montmorillonite KSF

In this study, the adsorption of trimethoprim (TMP) on montmorillonite KSF was studied under different conditions (pH, ionic strength, temperature). The results indicate that a pH value of 5.04 is optimum value for the adsorption of TMP on KSF. The adsorption kinetics was interpreted using pseudo-first-order kinetic model, pseudo-second-order kinetic model and intraparticle diffusion model. The pseudo-second-order model provides the best correlation with the experimental data of KSF adsorption. The adsorption data could be fitted with Freundlich, Langmuir and Dubinin-Radushkevich equation to find the characteristic parameters of each model. It was found that linear form of Langmuir isotherm seems to produce a better model than linear form of Freundlich equation. From the Langmuir and Freundlich equation, the adsorption capacity values raised as the solution temperature decreased. From DR isotherm, it was also determined that the type of adsorption can be considered as ion-exchange mechanism. Determination of the thermodynamic parameters DeltaH(0), DeltaS(0) and DeltaG(0) showed that adsorption was spontaneous and exothermic in nature. It was also added that adsorption of TMP by KSF may involve physical adsorption.     

Executive functions, information sampling, and decision making in narcolepsy with cataplexy.

Objective: Narcolepsy with cataplexy (NC) affects neurotransmitter systems regulating emotions and cognitive functions. This study aimed to assess executive functions, information sampling, reward processing, and decision making in NC. Method: Twenty-one NC patients and 58 healthy participants performed an extensive neuropsychological test battery. Results: NC patients scored as controls in executive function tasks assessing set shifting, reversal learning, working memory, and planning. Group differences appeared in a task measuring information sampling and reward sensitivity. NC patients gathered less information, tolerated a higher level of uncertainty, and were less influenced by reward contingencies than controls. NC patients also showed reduced learning in decision making and had significantly lower scores than controls in the fifth block of the IOWA gambling task. No correlations were found with measures of sleepiness. Conclusions: NC patients may achieve high performance in several neuropsychological domains, including executive functions. Specific differences between NC patients and controls highlight the importance of the hypocretin system in reward processing and decision making and are in line with previous neuroimaging and neurophysiological studies. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Revelation effect: Effort or priming does not create the sense of familiarity.

The revelation effect is the tendency to give higher proportions of positive responses to recognition test items that are distorted. Two plausible explanations of this response bias were tested. The 1st 3 experiments showed that the sense of familiarity leading to the revelation effect is not created because of the extra time or effort spent on the distorted items. The magnitude of the effect was neither correlated with the time taken to reveal the distorted items nor influenced by the Ss' efforts in revealing such items. The next 4 experiments showed that the sense of familiarity is not created because of priming of target words during the act of revealing. High-frequency words (presumed to be more highly associated to other words) and categorically or orthographically similar words did not elicit greater revelation effects than those elicited with low-frequency words and categorically or orthographically dissimilar words. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Anatomical studies of DNA fragmentation in rat brain after systemic kainate administration

Rats treated systemically with kainate develop stereotyped epileptic seizures involving mainly limbic structures that may last for hours. This model of limbic status epilepticus has been widely studied using classical neuropathological techniques. We used in situ nick translation histochemistry to examine patterns of DNA fragmentation in this model. We found a stereotyped and reproducible pattern of neuronal populations that demonstrate evidence of DNA fragmentation from 24 h to one week after kainate treatment. Neither blockade of new protein synthesis nor blockade of the N-methyl-D-aspartate-type glutamate receptors significantly altered this response. Moreover, we saw no evidence of the regular internucleosomal cleavage of DNA that produces a characteristic laddered appearance of 180-200 bp DNA fragments after gel electrophoresis in samples obtained from microdissected affected regions. These studies suggest that DNA fragmentation after systemic kainate-induced seizures is not the result of programmed cell death. This assay may be useful for quantitative testing of both neuroprotective agents and mechanistic hypotheses.     

Tuning pH sensitivities of zinc phthalocyanines in ionic liquid modified matrices

Phthalocyanine dyes are clinically important bright fluorophores with many desirable properties. Their absorption and emission maxima in near infrared region make them proper tool for optical probing of biologically relevant materials and optical-chemical-sensing purposes. In this work we have shown that pH sensitivities of the phthalocyanines can be manipulated as desired. This property makes the Pcs very proper photosensitizers for photodynamic therapy applications. In this work pH sensitivities of alpha (α) and beta (β) tetra-substituted zinc phthalocyanines (ZnPcs) were studied spectroscopically in ethyl cellulose and PVC matrices. In experiments designed to manipulate pH, lipophilic room temperature ionic liquids (RTILs) were added into the test environment. The RTIL-modified thin films provided higher relative fluorescence intensity changes upon exposure to proton with respect to the RTIL-free ones. By this way, acidity constants of the ZnPcs could be tuned to the desired region of interest. The ZnPcs, exhibited good reproducibility and reversibility upon protonation. The RTILs also enhanced short and long term stabilities of the Pc-dyes. There was no significant drift in their proton sensitivities even after 10 assays and after being stored in a buffer condition for over six months.     

Improving Performance Prediction on Education Data with Noise and Class Imbalance

This paper proposes to apply machine learning techniques to predict students’ performance on two real-world educational data-sets. The first data-set is used to predict the response of students with autism while they learn a specific task, whereas the second one is used to predict students’ failure at a secondary school. The two data-sets suffer from two major problems that can negatively impact the ability of classification models to predict the correct label; class imbalance and class noise. A series of experiments have been carried out to improve the quality of training data, and hence improve prediction results. In this paper, we propose two noise filter methods to eliminate the noisy instances from the majority class located inside the borderline area. Our methods combine the over-sampling SMOTE technique with the thresholding technique to balance the training data and choose the best boundary between classes. Then we apply a noise detection approach to identify the noisy instances. We have used the two data-sets to assess the efficacy of class-imbalance approaches as well as both proposed methods. Results for different classifiers show that, the AUC scores significantly improved when the two proposed methods combined with existing class-imbalance techniques.     

Volatile Compounds and Sensory Properties in Various Melons,Which were Chosen from Different Species and Different Locations,Grown in Turkey

Gas chromatography coupled to mass spectrometry using a static head space technique was applied to analyze the volatile aromatic compounds of various melons collected from different locations in Turkey. Some physicochemical and sensory analyses were also made. A total of 33 volatile compounds were identified. Differences in the physicochemical and sensory properties of various Turkish melon samples were observed. The multivariate analyses by the volatile compounds separated the three varieties into groups successfully. The most abundant volatile compounds as mean value in all melon varieties were ethyl acetate (22.10%), acetaldehyde (13.65%), and ethanol (23.25%). The results showed that Cantaloupe melons were more preferred by panelists, which had relatively high levels of esters being responsible for strong fruit flavor, like melon, as well as high total soluble solid content and low titratable acidity compared with Inodorus and Simama.