Load Estimation of Moving Passenger Cars Using Inductive-Loop Technology.

Due to their lack of driving controllability, overweight vehicles are a big threat to road safety. The proposed method for a moving passenger car load estimation is capable of detecting an overweight vehicle, and thus it finds its application in road safety improvement. The weight of a car's load entering or leaving a considered zone, e.g., industrial facility, a state, etc., is also of concern in many applications, e.g., surveillance. Dedicated vehicle weight-in-motion measurement systems generally use expensive load sensors that also require deep intervention in the road while being installed and also are calibrated only for heavy trucks. In this paper, a vehicle magnetic profile (VMP) is used for defining a load parameter proportional to the passenger vehicle load. The usefulness of the proposed load parameter is experimentally demonstrated in field tests. The sensitivity of the VMP to the load change results from the fact that the higher load decreases the vehicle clearance value which in turn increases the VMP. It is also shown that a slim inductive-loop sensors allows the building of a load estimation system, with a maximum error around 30 kg, which allows approximate determination of the number of passengers in the car. The presented proof of concept extends the functionality of inductive loops, already installed in the road, for acquiring other traffic parameters, e.g., moving vehicle axle-to-axle distance measurement, to road safety and surveillance related applications.

Do Epidural Catheter Size and Flow Rate Affect Bolus Injection Pressure in Different Programmed Intermittent Epidural Bolus Regimens? An In Vitro Study.

BACKGROUND: The optimal programmed intermittent epidural bolus regimen for labor analgesia remains unknown. Some studies indicate that better drug spread in the epidural space results from greater injection pressure; however, there is a lack of data regarding the maximum pressure generated by epidural bolus injection using different catheters and flow rates. METHODS: We evaluated the flow and pressure characteristics of 11 commonly used epidural catheters combined with 3 different infusion pumps that deliver epidural infusions according to the programmed intermittent epidural bolus regimen. Pressure changes were measured over time at flow rates of 100, 250, and 400 mL·hour and with a bolus volume of 10 mL. To account for repeated measures, linear mixed models were used. Features were selected with a backward stepwise procedure continued until only statistically significant variables were left in the model. RESULTS: We performed 660 measurements. The mean maximal pressure generated during bolus injection ranged from 86 to 863 mm Hg for different flow rates and catheter designs. The interaction between flow rate and catheter gauge resulted in 1.31, 1.65, and 2.00 mm Hg of pressure increase for 18G, 19G, and 20G catheters, respectively, per 1 mL·hour of increased flow rate (P< .001). Analyses including wire-reinforced catheters revealed a 1.16, 1.76, and 2.36 mm Hg pressure increase for 18G, 19G, and 20G catheters, respectively, per 1 mL·hour of increased flow rate (P< .001). In some cases, it triggered the occlusion pump alarm. CONCLUSIONS: Significant differences were observed in the in vitro maximum pressure value among the various catheter and flow rate combinations with a higher pressure value for wire-reinforced catheters used in the study. The optimal flow rate and epidural catheter combination may allow for delivery of the bolus with high flow rate without triggering the occlusion alarm.

Regularization and grouping -omics data by GCA method: A transcriptomic case.

The paper presents the application of Grade Correspondence Analysis (GCA) and Grade Correspondence Cluster Analysis (GCCA) for ordering and grouping -omics datasets, using transcriptomic data as an example. Based on gene expression data describing 256 patients with Multiple Myeloma it was shown that the GCA method could be used to find regularities in the analyzed collections and to create characteristic gene expression profiles for individual groups of patients. GCA iteratively permutes rows and columns to maximize the tau-Kendall or rho-Spearman coefficients, which makes it possible to arrange rows and columns in such a way that the most similar ones remain in each other's neighbourhood. In this way, the GCA algorithm highlights regularities in the data matrix. The ranked data can then be grouped using the GCCA method, and after that aggregated in clusters, providing a representation that is easier to analyze-especially in the case of large sets of gene expression profiles. Regularization of transcriptomic data, which is presented in this manuscript, has enabled division of the data set into column clusters (representing genes) and row clusters (representing patients). Subsequently, rows were aggregated (based on medians) to visualise the gene expression profiles for patients with Multiple Myeloma in each collection. The presented analysis became the starting point for characterisation of differentiated genes and biochemical processes in which they are involved. GCA analysis may provide an alternative analytical method to support differentiation and analysis of gene expression profiles characterising individual groups of patients.

Silver ions as em marker of congo red ligation sites in amyloids and amyloid-like aggregates.

Congo red (CR) is a known selective amyloid ligand. The focus of our work is identification (by EM imaging) of dye binding sites and their distribution in amyloids and amyloid-like aggregates formed in vitro. In order to produce the required contrast, CR has been indirectly combined with metal via including Titan yellow (TY) by intercalation which exhibits a relatively strong affinity for silver ions. The resulting combined ligand retains its ability to bind to proteins (which it owes to CR) and can easily be detected in EM studies thanks to TY. We have found, however, that in protein aggregates where unfolding is stabilized by aggregation and therefore is irreversible, TY alone may serve as both, the ligand and the metal carrier. The formation of ordered structures in amyloids was studied using IgG light chains with amyloidogenic properties, converted into amyloids by shaking. The resulting EM images were subjected to interpretation on the basis of the authors' earlier research on the CR/light chain complexation process. Our results indicate that dimeric light chains, which are the subject of our study, produce amyloids or amyloid-like complexes with chain-like properties and strong helicalization tendencies. Cursory analysis suggests that the edge polypeptide loops belonging to unstable light chains form intermolecular bridges which promote creation of loose gel deposits, or are otherwise engaged in the swapping processes leading to higher structural ordering.

The use of supramolecular structures as protein ligands.

Congo red dye as well as other eagerly self-assembling organic molecules which form rod-like or ribbon-like supramolecular structures in water solutions, appears to represent a new class of protein ligands with possible wide-ranging medical applications. Such molecules associate with proteins as integral clusters and preferentially penetrate into areas of low molecular stability. Abnormal, partly unfolded proteins are the main binding target for such ligands, while well packed molecules are generally inaccessible. Of particular interest is the observation that local susceptibility for binding supramolecular ligands may be promoted in some proteins as a consequence of function-derived structural changes, and that such complexation may alter the activity profile of target proteins. Examples are presented in this paper.

Influence of the electric field on supramolecular structure and properties of amyloid-specific reagent Congo red.

Among specific amyloid ligands, Congo red and its analogues are often considered potential therapeutic compounds. However, the results of the studies so far have not been univocal because the properties of this dye, derived mostly from its supramolecular nature, are still poorly understood. The supramolecular structure of Congo red, formed by π-π stacking of dye molecules, is susceptible to the influence of the electric field, which may significantly facilitate electron delocalization. Consequently, the electric field may generate altered physico-chemical properties of the dye. Enhanced electron delocalization, induced by the electric field, alters the total charge of Congo red, making the dye more acidic (negatively charged). This is a consequence of withdrawing electrons from polar substituents of aromatic rings-sulfonic and amino groups-thus increasing their tendency to dissociate protons. The electric field-induced charge alteration observed in electrophoresis depends on dye concentration. This concentration-dependent charge alteration effect disappears when the supramolecular structure disintegrates in DMSO. Dipoles formed from supramolecular fibrillar species in the electric field become ordered in the solution, introducing the modified arrangement to liquid crystalline phase. Experimental results and theoretical studies provide evidence confirming predictions that the supramolecular character of Congo red is the main reason for its specific properties and reactivity.

A tabular approach to the sequence-to-structure relation in proteins (tetrapeptide representation) for de novo protein design.

BACKGROUND: Experimental observations classify the protein-folding process as a multi-step event. The backbone conformation has been experimentally recognized as responsible for the early-stage structural forms of a polypeptide. The sequence-to-structure and structure-to-sequence relation is critical for predicting protein structure. A contingency table representing this relation for tetrapeptides in their early-stage is presented. Their correlation seems to be essential in protein-folding simulation. MATERIAL/METHODS: The polypeptide chains of all the proteins in the Protein Data Bank were transformed into their early-stage structural forms. The tetrapeptide was selected as the structural unit. Tetrapetide sequences and structures were expressed by letter codes. The transformation of a contingency table of any size (here: 160,000x2401) to a 2x2 table performed for each non-zero cell of the original table allowed calculation of the rho-coefficient measuring the strength of the relation. RESULTS: High values of the rho-coefficient extracted sequences of strong structural determinability and structures of high sequence selectivity. The web-site program to calculate the rho-coefficient ranking list was constructed to enable applying this method to any problem of contingency table analysis. CONCLUSIONS: The results revealed sequence-to-structure (and vice versa) correlation in early-stage folding. Surprisingly, the irregular structural forms of loops and bends appeared to be highly determined. Comparison of these results with another method based on information entropy revealed high accordance. The method oriented on interpretation of a large contingency table seems very useful especially for large-scale microarray analysis, a very popular technique in the post-genomic era.

Tandemly repeated trinucleotides - comparative analysis.

Characteristics of 64 possible tandem trinucleotide repeats (TSSR) from Homo sapiens (hs), Mus musculus (mm) and Rattus norvegicus (rn) genomes are presented. Comparative analysis of TSSR frequency depending on their repetitiveness and similarity of the TSSR length distributions is shown. Comparative analysis of TSSR sequence motifs and association between type of motif and its length (n) using rho-coefficient method (quantitatively measuring the association between variables in contingency tables) is presented. These analyses were carried out in the context of neurodegenerative diseases based on trinucleotide tandems. The length of these tandems and their relation to other TSSR is estimated. It was found that the higher repetitiveness (n) the lower frequency of trinucleotides tandems. Differences between genomes under consideration, especially in longer than n=9 TSSR were discussed. A significantly higher frequency off A- and T-rich tandems is observed in the human genome (as well as in human mRNA). This observation also applies to mm and rn, although lower abundant in proportion to human genomes was found. The origin of elongation (or shortening) of TSSR seems to be neither frequency nor length dependent. The results of TSSR analysis presented in this work suggest that neurodegenerative disease-related microsatellites do not differ versus the other except the lower frequency versus the other TSSR. CAG occurs with relatively high frequency in human mRNA, although there are other TSSR with higher frequency that do not cause comparable disease disorders. It suggests that the mechanism of TSSR instability is not the only origin of neurodegenerative diseases.