Enzymic interesterification of fats: Factors influencing the choice of support for immobilized lipase

Three grades of diatomaceous earth (Celite 560, Filtercel and Hyflo Supercel) and a controlled-pore silica have been examined for their suitability as support materials for lipase (triacyglycerol acylhydrolase, EC 3.1.1.3) catalysing the interesterification of fats. The controlled-pore silica gave a preparation with a low activity. Although all three Celites gave preparations with similar lipolytic activities, Hyflo Supercel gave the highest interesterification activity. The distribution of enzyme protein in Hyflo Supercel was examined by transmission electron microscopy.     

Exploiting cell-mediated contraction and adhesion to structure tissues in vitro

Progress in tissue engineering is now impacting beyond the field of regenerative medicine. Engineered tissues are now used as tools to evaluate the toxicity of compounds or even to enable the modelling of disease. While many of the materials that are used to facilitate tissue growth are designed to enable cell attachment, many researchers consider that the contraction and modification of these matrices by attached cells is not desirable and take measures to prevent this from occurring. Where substantial alignment of the molecules within tissues, however, is a feature of structure the process of contraction can be exploited to guide new matrix deposition. In this paper, we will demonstrate how we have used the cell contraction process to generate tissues with high levels of organization. The tissues that have been grown in the laboratory have been characterized using a suite of analytical techniques to demonstrate significant levels of matrix organization and mechanical behaviour analogous to natural tissues. This paper provides an overview of research that has been undertaken to determine how tissues have been grown in vitro with structuring from the molecular, right through to the macroscopic level.     

Influence of resin cement thickness and temperature variation on mechanical behavior of dental ceramic fragment restoration

To evaluate the stress behavior of ceramic fragment restoration, varying the thickness of the cement layer and intraoral temperature variation. A solid model of a upper lateral incisor was obtained and a defect at enamel distal/incisal edge was restored with a ceramic fragment. Based on this initial model, 4 different models (M) were built: M1 – absence of cement layer (CL) (0?μm of thickness); M2 – CL with an uniform thickness of 50?μm; M3 – CL with 50?μm at the margin of ceramics and 100?μm in the inner area far from margins; M4 – CL with 50?μm at the margin of ceramics and 200?μm in the inner area far from margins. The environment temperature changed from 5?°C to 50?°C in 4 increments. The finite element analysis was performed. Increase the cement layer thickness generated higher stress levels on ceramic surface in all temperatures, as well as on cement interface. In general hot temperature was the worst scenario for ceramic fragments integrity, since tensile and compressive stress were more intense. The maximum principal stress on ceramic fragment was found 90?MPa for M4 at 50?°C, followed for M3 (87?Mpa). For CL, the peak of stress was found for M3 at 5?°C (47?MPa). Is it possible to conclude that thick resin cement layer contribute to higher stress concentration on ceramic fragment, and extremely hot temperatures increase the risk of structural failure, since both ceramic and \cl are exposed to higher compressive and tensile stresses.     

Detecting fraudulent whiplash claims by support vector machines

A new method is proposed for detecting fraudulent whiplash claims based on measurements of movement control of the neck. The method is noninvasive and inexpensive. The subjects track a slowly moving object on a computer screen with their head. The deviation between the measured and actual trajectory is quantified and used as input to an ensemble of support vector machine classifiers. The ensemble was trained on a group of 34 subjects with chronic whiplash disorder together with a group of 31 healthy subjects instructed to feign whiplash injury. The sensitivity of the proposed method was 86%, the specificity 84% and the area under curve (AUC) was 0.86. This suggests that the method can be of practical use for evaluating the validity of whiplash claims.     

Ergonomics for surgeons – prototype of an external surgeon support system reduces muscular activity and fatigue

BackgroundSince the unergonomic postures cannot be changed during a surgery, it seems reasonable to externally support the surgeon's posture in order to relieve the musculature. To evaluate this matter, we conducted a pilot study to investigate if a prototype of an external surgeon support system (S3) relieves the musculature in an objectively measurable manner.MethodsSimultaneous surface electromyography (EMG) was used alongside a combination of a laser Doppler flowmeter and a tissue spectrometer to record back and leg muscles during a simulated surgical situation.FindingsWith S3, muscle activity was significantly lower (p < 0.05) and also fatigue decreased when compared to without S3. Muscle blood flow and oxygenation were relatively close to baseline with S3, but increased without S3.InterpretationAn ergonomic S3 is a possible approach to reduce muscle activity and fatigue and may therefore prevent chronic back pain amongst surgeons in the long term.     

hCKSAAP_UbSite: Improved prediction of human ubiquitination sites by exploiting amino acid pattern and properties

As one of the most common post-translational modifications, ubiquitination regulates the quantity and function of a variety of proteins. Experimental and clinical investigations have also suggested the crucial roles of ubiquitination in several human diseases. The complicated sequence context of human ubiquitination sites revealed by proteomic studies highlights the need of developing effective computational strategies to predict human ubiquitination sites. Here we report the establishment of a novel human-specific ubiquitination site predictor through the integration of multiple complementary classifiers. Firstly, a Support Vector Machine (SVM) classier was constructed based on the composition of k-spaced amino acid pairs (CKSAAP) encoding, which has been utilized in our previous yeast ubiquitination site predictor. To further exploit the pattern and properties of the ubiquitination sites and their flanking residues, three additional SVM classifiers were constructed using the binary amino acid encoding, the AAindex physicochemical property encoding and the protein aggregation propensity encoding, respectively. Through an integration that relied on logistic regression, the resulting predictor termed hCKSAAP_UbSite achieved an area under ROC curve (AUC) of 0.770 in 5-fold cross-validation test on a class-balanced training dataset. When tested on a class-balanced independent testing dataset that contains 3419 ubiquitination sites, hCKSAAP_UbSite has also achieved a robust performance with an AUC of 0.757. Specifically, it has consistently performed better than the predictor using the CKSAAP encoding alone and two other publicly available predictors which are not human-specific. Given its promising performance in our large-scale datasets, hCKSAAP_UbSite has been made publicly available at our server (http://protein.cau.edu.cn/cksaap_ubsite/).     

Speech signal analysis of alzheimer’s diseases in farsi using auditory model system

In recent years, extensive studies have been conducted on the diagnosis of Alzheimer''s disease (AD) using the non-invasive speech signal recognition method. In this study, Farsi speech signals were analyzed using the auditory model system (AMS) in order to recognize AD. For this purpose, after the pre-processing of the speech signals and utilizing AMS, 4D outputs as function of time, frequency, rate, and scale range were obtained. The AMS outcomes were averaged in term of time to analyze the rate-frequency-scale for both groups, Alzheimer''s and healthy control subjects. Thereafter, the maximum of spectral and temporal modulation and frequency were extracted to classify by the support vector machine (SVM). The SVM achieves higher promising recognition accuracy with compare to prevalent approaches in the field of speech processing. The acceptable results demonstrate the applicability of the proposed algorithm in non-invasive and low-cost recognizing Alzheimer''s only using the few extracted features of the speech signal.     

TLD characteristic of glass,feldspathic and lithium disilicate ceramics

Thermoluminescence (TL) emission of dental ceramics could be potentially used for retrospective dosimetry purposes as this allows a quick and reliable dose assessment in case of nuclear accident or bad use of a nuclear attack. This paper reports on the chemical and luminescence characterization of glass, feldspathic and lithium disilicate glass ceramic (LS₂). Swedish and Turkish dental ceramics supplied by Vivadent Ivoclar considering: (i) the dose response in the range 10 Gy to 6.9 kGy which displays a linear dose?response at low dose values up to 36 Gy (glass and feldspathic ceramics) and shows sublinear behavior from 12 Gy to 6 kGy (lithium disilicate glass ceramics), (ii) a reproducibility of the TL signal in which the area under the glow curve increased about 25% after 10 cycles for glass and lithium disilicate ceramics and increased about 30% after seven cycles for feldspathic ceramics, (iii) stability of the luminescence emission with the elapsed time and (iv) effect of the heating rate. Glass, lithium disilicate and feldspathic ceramics display a complex UV‐blue glow emission that can be respectively fitted to five and four groups of components assuming first‐order kinetics behavior.     

Separation and analysis of charged isomers of monoclonal immunoglobulin G by ceramic hydroxyapatite chromatography

Analysis of monoclonal antibody (MAb) heterogeneity caused by posttranslational modifications is important for pharmaceutical quality assurance of antibody drugs. In this study, by employing small ceramic hydroxyapatite (HAp) particles that were self-manufactured to have a 2.5-µm diameter, we attempted to separate and analyze MAb isomers. The MAb without N-linked oligosaccharides could be separated by 2.5-µm HAp chromatography as well as MAb with N-linked oligosaccharides. Hence, a variety of N-linked oligosaccharides do not appear to be involved in the separation mechanism of HAp chromatography. However, there is a difference in retention time between MAb with and without N-linked oligosaccharides, meaning that the presence of N-glycan could influence the retention time of HAp chromatography. Subsequently, the MAb fractions separated by 2.5-µm HAp chromatography were analyzed by isoelectric focusing, and seven isomers of the MAb having different isoelectric points (pI) were identified. The MAb isomers were eluted in order of lower pI isomers with sodium phosphate buffer, and enzyme-linked immunosorbent assay indicated the immunoreactivity of the fraction including the lowest pI isomers to be remarkably reduced. This study yielded details of the separation behavior of HAp chromatography owing to 2.5-µm HAp particles.     

Answering six questions in extracting children��s mismatch negativity through combining wavelet decomposition and independent component analysis

This study combines wavelet decomposition and independent component analysis (ICA) to extract mismatch negativity (MMN) from electroencephalography (EEG) recordings. As MMN is a small event-related potential (ERP), a systematic ICA based approach is designed, exploiting MMN’s temporal, frequency and spatial information. Moreover, this study answers which type of EEG recordings is more appropriate for ICA to extract MMN, what kind of the preprocessing is beneficial for ICA decomposition, which algorithm of ICA can be chosen to decompose EEG recordings under the selected type, how to determine the desired independent component extracted by ICA, how to improve the accuracy of the back projection of the selected independent component in the electrode field, and what can be finally obtained with the application of ICA. Results showed that the proposed method extracted MMN with better properties than those estimated by difference wave only using temporal information or ICA only using spatial information. The better properties mean that the deviant with larger magnitude of deviance to repeated stimuli in the oddball paradigm can elicit MMN with larger peak amplitude and shorter latency. As other ERPs also have the similar information exploited here, the proposed method can be used to study other ERPs.