Computer-aided calculation of accident costs

Accurate data about accident costs motivate top managers to improve safety in production. The problem has been, however, to specify costs reliably and easily. This article presents the computer-aided module for calculating accident costs in the TATU-Safety Information System developed by the Finnish Institute of Occupational Health. The module computes the direct costs and company-controlled total costs of accidents. The calculation is based on the accident consequence tree (ACT) method. The software provides information about accident costs to motivate accident prevention. The authors explain the system design of the software and its use in cost calculation. © 1997 John Wiley & Sons, Inc.     

Mast Cells and Basophils in the Defense against Ectoparasites: Efficient Degradation of Parasite Anticoagulants by the Connective Tissue Mast Cell Chymases

Ticks, lice, flees, mosquitos, leeches and vampire bats need to prevent the host’s blood coagulation during their feeding process. This is primarily achieved by injecting potent anticoagulant proteins. Basophils frequently accumulate at the site of tick feeding. However, this occurs only after the second encounter with the parasite involving an adaptive immune response and IgE. To study the potential role of basophils and mast cells in the defense against ticks and other ectoparasites, we produced anticoagulant proteins from three blood-feeding animals; tick, mosquito, and leech. We tested these anticoagulant proteins for their sensitivity to inactivation by a panel of hematopoietic serine proteases. The majority of the connective tissue mast cell proteases tested, originating from humans, dogs, rats, hamsters, and opossums, efficiently cleaved these anticoagulant proteins. Interestingly, the mucosal mast cell proteases that contain closely similar cleavage specificity, had little effect on these anticoagulant proteins. Ticks have been shown to produce serpins, serine protease inhibitors, upon a blood meal that efficiently inhibit the human mast cell chymase and cathepsin G, indicating that ticks have developed a strategy to inactivate these proteases. We show here that one of these tick serpins (IRS-2) shows broad activity against the majority of the mast cell chymotryptic enzymes and the neutrophil proteases from human to opossum. However, it had no effect on the mast cell tryptases or the basophil specific protease mMCP-8. The production of anticoagulants, proteases and anti-proteases by the parasite and the host presents a fascinating example of an arms race between the blood-feeding animals and the mammalian immune system with an apparent and potent role of the connective tissue mast cell chymases in the host defense.     

Topology optimization in Bernoulli free boundary problems

In this work we consider the topology optimization of systems governed by the external Bernoulli free boundary problem arising, for example, from the mathematical modelling of electro-chemical machining. In this work we combine, for the first time, the so-called pseudo-solid approach to the solution of governing free boundary problems and the level set method, which is used to define the design domain. Previous studies of the problem showed a tendency towards topological changes in the design, which can now automatically take place thanks to level set parametrization. The scalar function used in the level set method is parametrized using radial basis functions, converting the problem into a parametric optimization problem, which is solved using a gradient-based method.     

Near-infrared spectroscopy for cocrystal screening. A comparative study with Raman spectroscopy

Near-infrared (NIR) spectroscopy is a well-established technique for solid-state analysis, providing fast, noninvasive measurements. The use of NIR spectroscopy for polymorph screening and the associated advantages have recently been demonstrated. The objective of this work was to evaluate the analytical potential of NIR spectroscopy for cocrystal screening using Raman spectroscopy as a comparative method. Indomethacin was used as the parent molecule, while saccharin and l-aspartic acid were chosen as guest molecules. Molar ratios of 1:1 for each system were subjected to two types of preparative methods. In the case of saccharin, liquid-assisted cogrinding as well as cocrystallization from solution resulted in a stable 1:1 cocrystalline phase termed IND-SAC cocrystal. For l-aspartic acid, the solution-based method resulted in a polymorphic transition of indomethacin into the metastable alpha form retained in a physical mixture with the guest molecule, while liquid-assisted cogrinding did not induce any changes in the crystal lattice. The good chemical peak selectivity of Raman spectroscopy allowed a straightforward interpretation of sample data by analyzing peak positions and comparing to those of pure references. In addition, Raman spectroscopy provided additional information on the crystal structure of the IND-SAC cocrystal. The broad spectral line shapes of NIR spectra make visual interpretation of the spectra difficult, and consequently, multivariate modeling by principal component analysis (PCA) was applied. Successful use of NIR/PCA was possible only through the inclusion of a set of reference mixtures of parent and guest molecules representing possible solid-state outcomes from the cocrystal screening. The practical hurdle related to the need for reference mixtures seems to restrict the applicability of NIR spectroscopy in cocrystal screening.     

A lumped-parameter transducer model for piezoelectric and ferroelectret polymers

We have developed a model to describe the sensor operation of piezoelectric and ferroelectret polymer materials. The lumped-parameter model for the sensors describes the interaction between a mechanical motion and an electrical signal. The differences in material properties are considered in the model, and especially, the effects of dynamic and static forces and temperature to the electrical output signals provided by the sensors constructed from the materials are discussed.     

System- and circuit-level optimization of PLL designs for DVB-T/H receivers

This article proposes a framework for the optimization of voltage-controlled oscillator (VCO) designs in frequency synthesizers for digital video broadcasting ?C terrestrial/handheld (DVB-T/H) receivers. Linear time-invariant phase-domain model of a charge-pump phase-locked loop (PLL) is devised and includes both flicker (1/f) and thermal noise contributions from the loop oscillators. By modeling the entire receiver, it is shown that there are combinations of flicker and thermal noise contributions that result in a constant sum of inter-carrier interference (ICI) and adjacent channel interference, and constant symbol error rate as well. Consequently, optimization of the VCO phase noise spectrum is defined while maintaining the standard-specified symbol-error rate. Link-level performance evaluation is carried out to validate the stipulated trade-off. The effect of ICI mitigation schemes is discussed. Circuit-level VCO design approaches utilizing the derived trade-off are finally presented. The proposed optimization procedure is generic and is also applicable to other systems based on Orthogonal Frequency-Division Multiplexing.     

Targeting Efficiency and Biodistribution of Zoledronate Conjugated Docetaxel Loaded Pegylated PBCA Nanoparticles for Bone Metastasis

In an attempt to improve tumor localization of docetaxel (DTX)‐loaded nanoparticles (NPs), zoledronic acid (ZOL) is used as a ligand to target bone metastasis. DTX‐loaded ZOL‐conjugated polyethylene glycol (PEG)ylated polybutyl cyanoacrylate (PBCA) NPs are prepared using an anionic polymerization technique. PBCA‐PEG‐ZOL NPs are subjected to cytotoxic assay in both BO2 and MCF‐7 cell lines. Cell cycle arrest and apoptosis induced by the PBCA‐PEG‐ZOL NPs are studied. Quantitative cellular uptake, NP uptake route characterization, confocal microscopy and IPP/ApppI levels are performed. PBCA‐PEG‐ZOL NPs show an enhanced cytotoxic effect in both BO2 as well as MCF‐7 cell lines due to higher uptake following ZOL‐mediated endocytosis. The molecular basis of apoptosis reveals the involvement of a cytoplasmic protein in activating the programmed cell death pathway. Route characterization studies reveal that PBCA‐PEG‐ZOL NPs uptake is not completely blocked even by using both inhibitors (genistein and phenyl arsinoxide) simultaneously, conferring that uptake is not entirely based upon clathrin or caveolae. PBCA‐PEG‐ZOL NPs showed 7 and 5.3 times increase in IPP and ApppI production, in comparison to ZOL treatment, and 138 times higher than the control group in MCF‐7 cell line. In BO2 cell line, after treatment with NPs, IPP was 5.35 times higher than ZOL solution. No ApppI in BO2 cell line after treatment with NPs and ZOL solution was found. NP distribution in tumor infected bone is also significantly high in comparison to the normal bone at any time point. It is concluded that ZOL‐conjugated NPs provide an efficient and targeted delivery of DTX, with synergistic effects. Thus, these NPs present a promising treatment in the near future, by actively targeting metastatic tumor.     

Identification of adequate neurally adjusted ventilatory assist (NAVA) during systematic increases in the NAVA level

Neurally adjusted ventilatory assist (NAVA) delivers airway pressure (P(aw)) in proportion to the electrical activity of the diaphragm (EAdi) using an adjustable proportionality constant (NAVA level, cm·H(2)O/μV). During systematic increases in the NAVA level, feedback-controlled down-regulation of the EAdi results in a characteristic two-phased response in P(aw) and tidal volume (Vt). The transition from the 1st to the 2nd response phase allows identification of adequate unloading of the respiratory muscles with NAVA (NAVA(AL)). We aimed to develop and validate a mathematical algorithm to identify NAVA(AL). P(aw), Vt, and EAdi were recorded while systematically increasing the NAVA level in 19 adult patients. In a multistep approach, inspiratory P(aw) peaks were first identified by dividing the EAdi into inspiratory portions using Gaussian mixture modeling. Two polynomials were then fitted onto the curves of both P(aw) peaks and Vt. The beginning of the P(aw) and Vt plateaus, and thus NAVA(AL), was identified at the minimum of squared polynomial derivative and polynomial fitting errors. A graphical user interface was developed in the Matlab computing environment. Median NAVA(AL) visually estimated by 18 independent physicians was 2.7 (range 0.4 to 5.8) cm·H(2)O/μV and identified by our model was 2.6 (range 0.6 to 5.0) cm·H(2)O/μV. NAVA(AL) identified by our model was below the range of visually estimated NAVA(AL) in two instances and was above in one instance. We conclude that our model identifies NAVA(AL) in most instances with acceptable accuracy for application in clinical routine and research.     

Thermoset lactic acid‐based resin as a matrix for flax fibers

Thermoset composites were produced from flax fibers and a novel lactic acid (LA)‐based thermoset resin. This resin is based on methacrylated, star‐shaped oligomers of LA. The main purpose of this work was to evaluate whether this resin can be used to produce structural composites from flax fibers. Composites were prepared by spray impregnation followed by compression molding at elevated temperature. The tests showed that composites can be produced with as much as 70 wt% fiber. The composites were evaluated by tensile testing, flexural testing, charpy impact test, dynamic mechanical thermal analysis (DMTA), and low‐vacuum scanning electron microscopy. The ageing properties in high humid conditions were evaluated, the Young's modulus ranged from 3 GPa to 9 GPa in the best case. This work shows that structural composites can be produced from renewable material. It is clear from the results that these composites have properties that make them suitable for furniture, panels, or automotive parts. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011