Complications in connection with venous port systems: prevention and therapy

OBJECTIVE: To assess the effects of graded intramedullary reaming and nailing on the healing pattern of segmental diaphyseal fractures using male Wistar rats. STUDY DESIGN: In male Wistar rats we produced two standardized, partial osteotomies with an eight-millimeter intermediary fragment in the femoral diaphysis. The osteotomies were subsequently manually broken. In Group A, intramedullary reaming was performed to 1.6 millimeters, and the fracture was stabilized with a 1.6-millimeter steel pin. In Group B, the femoral canal was reamed to 2.0 millimeters, and a hollow steel tube of 2.0 millimeters was installed. The rats were allowed free movement. After four, eight, and twelve weeks, eight rats in each group were sacrificed and callus formation, biomechanical properties, and bone blood flow were evaluated. RESULTS: The callus area was relatively constant with time in Group B, whereas a reduction was observed in Group A at twelve weeks. The biomechanical properties increased throughout the experimental period in both groups, and no significant differences between the groups were detected in bending moment, bending rigidity, or fracture energy. Total bone blood flow was substantially increased at four weeks in both groups and decreased throughout the experimental period. In addition, blood flow of the segmental fractured area was substantially increased after four weeks and decreased gradually thereafter. The increases in blood flow tended to be largest in the moderately reamed group. CONCLUSION: This study indicates that the degree of reaming does not significantly affect the healing pattern measured as restoration of mechanical characteristics.     

Assessment of an “Energy Tower” potential in Australia using a mathematical model and GIS

“Energy Tower” is a technology for producing renewable and clean electricity by means of cooling hot and dry air, which is continuously supplied to arid lands. We assess the potential of an Energy Tower by incorporating topographic and meteorological parameters into a computational model, providing evaluations for the net power production and the electricity production cost. We formulate a highly simplified model for the Energy Tower’s flow, setup and process a spatial dataset of topographic and Meteorological upper air parameters. The model was applied to the Australian continent. A model simulation of one annual cycle enabled the ranking and selection of promising sites. The highest potential for energy towers is in the Port Hedland region, where favorable meteorological and topographic conditions would result in high average net power (≈370 ± 160 MW), potentially providing the electricity needs of 0.5 million people, for an economically competitive costs (3.5 ¢kWh).     

Storage technologies for wind power in the Columbia River Gorge

The transition from traditional energy sources to renewable has gained popularity and acceptance in recent years. This has been driven mainly by the current level of pollution, global warming, decommission of old nuclear power plants and the increasing cost of conventional energy sources. Nevertheless, one of the many steps to overcome is the seasonality or intermittency of renewable energy sources such as wind power. In recent years, new technologies have come up to address this problem, so the energy can be stored for future purposes. This paper analyses these energy storage alternatives for a specific case in the Columbia River Gorge for wind power. A hierarchical decision model is developed with criteria including political, social, environmental, technical and economical. The main conclusions highlight that the economical and technical criteria are among the most important ones for decision-makers.     

Determination of the overall migration from silicone baking moulds into simulants and food using 1H-NMR techniques

Different silicone baking moulds (37 samples) were characterized with respect to potential migrating substances using ¹H-NMR, RP-HPLC–UV/ELSD and GC techniques. In all cases cyclic organosiloxane oligomers with the formula [Si(CH₃)₂–O] _n were identified (n = 6 … 50). Additionally, linear, partly hydroxyl-terminated organosiloxanes HO–[Si(CH₃)₂–O] _n –H (n = 7 … 20) were found in 13 samples. No substances other than siloxanes could be detected, meaning the migrants mainly consist of organopolysiloxanes. Based on this knowledge, a ¹H-NMR quantification method for siloxanes was established for the analysis of both simulants and foodstuffs. Validation of the ¹H-NMR method gave suitable performance characteristics: limit of detection 8.7 mg kg^–1 oil, coefficient of variation 7.8% (at a level of 1.0 mg kg^–1 food). Migration studies were carried out with simulants (olive oil, isooctane, ethanol (95%), Tenax) as well as preparation of different cakes. From the 1st to 10th experiment, siloxane migration into cakes only slightly decreased, with a significant dependence on fat content. Migration never exceeded a level of 21 mg kg^–1 (3 mg dm^–2) and was, therefore, well below the overall migration limit of 60 mg kg^–1 (10 mg dm^–2). However, migration behaviour into simulants differed completely from these results.     

Type II Fuzzy Logic Based Cluster Head Selection for Wireless Sensor Network

Wireless Sensor Network (WSN) forms an essential part of IoT. It is embedded in the target environment to observe the physical parameters based on the type of application. Sensor nodes in WSN are constrained by different features such as memory, bandwidth, energy, and its processing capabilities. In WSN, data transmission process consumes the maximum amount of energy than sensing and processing of the sensors. So, diverse clustering and data aggregation techniques are designed to achieve excellent energy efficiency in WSN. In this view, the current research article presents a novel Type II Fuzzy Logic-based Cluster Head selection with Low Complexity Data Aggregation (T2FLCH-LCDA) technique for WSN. The presented model involves a two-stage process such as clustering and data aggregation. Initially, three input parameters such as residual energy, distance to Base Station (BS), and node centrality are used in T2FLCH technique for CH selection and cluster construction. Besides, the LCDA technique which follows Dictionary Based Encoding (DBE) process is used to perform the data aggregation at CHs. Finally, the aggregated data is transmitted to the BS where it achieves energy efficiency. The experimental validation of the T2FLCH-LCDA technique was executed under three different scenarios based on the position of BS. The experimental results revealed that the T2FLCH-LCDA technique achieved maximum energy efficiency, lifetime, Compression Ratio (CR), and power saving than the compared methods.     

Mass + retention time = structure: a strategy for the analysis of N-glycans by carbon LC-ESI-MS and its application to fibrin N-glycans

Analysis of the numerous possible, often isobaric structures of protein-bound oligosaccharides calls for a high-performance two-dimensional method that combines liquid chromatography's ability to separate isomers and mass spectrometry's ability to determine glycan composition. Here we investigate the usefulness of porous graphitic carbon columns coupled to ESI-MS for the separation of N-glycans with two or more sialic acids. Internal standards helped to rectify retention time fluctuations and thus allowed elution times to play an essential role in the structural assignment of peaks. For generation of a retention time library, standards representing the possible isomers of diantennary non-, mono-, and disialylated N-glycans, differing in the linkage of galactose and sialic acids as well as isobaric hybrid-type N-glycans, were produced using recombinant glycosyltransferases. Once the retention times library was established, isomers could be identified by LC-ESI-MS in the positive mode without additional MS/MS experiments. The method was applied for the detailed structural analysis of fibrin(ogen) N-glycans from various species (human, cow, pig, mouse, rat, cat, dog, Chinese hamster, horse, sheep, and chicken). All fibrins contained diantennary N-glycans. They differed in the occurrence of beta1,3-linked galactose, alpha2,3-linked sialic acids, and N-glycolylneuraminic acid, in the mono/diantennary glycan ratio, and in the O-acetylation of neuraminic acids. The separation system's potential for analyzing tri- and tetrasialylated N-glycans was demonstrated.