Morphological aspects of the traumatic chronic subdural hematoma capsule: SEM studies.

The morphology of the outer and inner membranes of traumatic chronic subdural hematomas (CSDHs) surgically removed from eight patients was investigated by scanning electron microscopy (SEM). Hematomas were divided into three groups based on time that had passed from the initiation of trauma to surgery. Structure of the CSDHs showed gradual morphological changes of the developing hematoma capsule. They initially included angiogenic and aseptic inflammatory reactions followed by progressive involvement of fibroblasts-proliferating and producing collagen fibrils. Numerous capillaries suggesting formation of new blood vessels were observed mainly in young hematomas removed between 15 and 21 days after trauma. In "older" hematomas (40 days after trauma), more numerous capillaries and thin-walled sinusoids were accompanied by patent, larger diameter blood vessels. Within the fibrotic outer membrane of the "oldest" hematoma capsules (60 or more days after trauma), especially in the area over the hematoma cavity, blood vessels were frequently occluded by clots. The results suggest dynamic changes in cellular and vascular organization of traumatic CSDH capsules paralleling the progression in hematoma age.     

Pretreatment procedures for characterization of arsenic and selenium species in complex samples utilizing coupled techniques with mass spectrometric detection

Research interest in analyzing arsenic and selenium is dictated by their species-dependent behavior in the environment and in living organisms. Different analytical methodologies for known species in relatively simple chemical systems are well established, yet the analysis of complex samples is still a challenge. Owing to the complex matrix and low concentrations of target species that may be chemically labile, suitable pretreatment of the sample becomes a critical step in any speciation procedure. In this paper, the pretreatment procedures used for arsenic and selenium speciation are reviewed with the emphasis on the link between the analytical protocol applied and the biologically-significant information provided by the results obtained. In the first approach, the aim of pretreatment is to convert the original sample into a form that can be analyzed by a coupled (hyphenated) technique, preventing possible losses and/or species interconversion. Common techniques include different leaching and extraction modes, enzymatic hydrolysis, species volatilization, and so on, with or without species preconcentration. On the other hand, if the speciation analysis is performed for elucidation of elemental pathways and specific functions in a living system, more conscious pretreatment and/or fractionation is needed. The macroscopic separation of organs and tissues, isolation of certain types of cells, cell disruption and separation of sub-cellular fractions, as well as isolation of a specific biomolecules become important. Furthermore, to understand molecular mechanisms, the identification of intermediate—often highly instable—metabolites is necessary. Real life applications are reviewed in this work for aquatic samples, soils and sediments, plants, yeast, and urine.     

Convergence of approximations vs. regularity of solutions for convex,control-constrained optimal-control problems

A method of estimating the rate of convergence of approximation to convex, control-constrained optimal-control problems is proposed. In the method, conditions of optimality involving projections on the set of admissible control are exploited. General results are illustrated by examples of Galerkin-type approximations to optimal-control problems for parabolic systems.     

Indirect extraction-spectrophotometric determination of 2-(thiocyanomethylthiol)benzothiazole in chrome tanning liquors after its breakdown to 2-mercaptobenzothiazole

The simple extraction-spectrophotometric procedure is proposed in this work for the determination of 2-(thiocyanomethylthiol)benzothiazole (TCMTB) in chrome tanning liquors after its breakdown to 2-mercaptobenzothiazole (MBT). The sample (50mul) was 4-fold diluted with deionized water and the conversion of TCMTB to MBT was obtained with cysteine (400 mul, 0.1 moll(-1)) in alkaline conditions (pH 10). After acidification to pH 2.5 (100 mul phosphoric acid, 2 moll(-1)), the extraction was carried out with 800 mul of ethyl acetate, containing 0.2% of beta-mercaptoethanol and absorbance was measured at 324 nm with the cut-off filter 295 nm. To avoid possible errors due to MBT presence in the sample, this same sample was taken for blank, but the reagents were added in form of one acid solution (omitting the conversion step). The calibration range was 10-120 mugml(-1) of TCMTB with the regression coefficient 0.9999, the quantitation limit was 2.80 mugml(-1) and the within day precision was 3.34 and 0.20%, respectively, for 10 and for 100 mugml(-1) of TCMTB. The results obtained in the analysis of the three industrial liquor samples by the proposed procedure were in a good agreement with the results obtained using liquid chromatography method.     

Synchronisation and Chaos in a Parametrically and Self-Excited System with Two Degrees of Freedom

Vibration analysis of a non-linear parametrically andself-excited system of two degrees of freedom was carried out. The modelcontains two van der Pol oscillators coupled by a linear spring with a aperiodically changing stiffness of the Mathieu type. By means of amultiple-scales method, the existence and stability of periodicsolutions close to the main parametric resonances have beeninvestigated. Bifurcations of the system and regions of chaoticsolutions have been found. The possibility of the appearance ofhyperchaos has also been discussed and an example of such solution hasbeen shown.     

Optimization of the Isolation of Some Taxoids from Yew Tissues

JPC – Journal of Planar Chromatography – Modern TLC - A new TLC procedure has been developed for the purification, separation, and isolation of paclitaxel and cephalomannine from yew...     

Set-Valued Means

Set-Valued and Variational Analysis - The notion of set-valued means is introduced. Set-valued counterparts of the arithmetic, quasi-arithmetic and Lagrangian means are investigated and various...     

Investigation effect of benzotriazole on the corrosion of brass-MM55 alloy in artificial seawater by dynamic EIS

The electrochemical behavior of brass-MM55 alloy was studied in artificial seawater with benzotriazole by using a novel method called dynamic electrochemical impedance spectroscopy (DEIS). This method gives possibility to investigate the protection of metals in corrosive medium by using inhibitors in galvanostatic conditions for a long time. Instantaneous impedance spectra for brass-MM55 were recorded for 10 h in artificial seawater for different concentration of benzotriazole. It was found that a few hours were not enough for the accurate calculation of corrosion inhibition. Also with this method it is possible to figure out how the charge transfer resistance (R _ct) changes by the time. Usefulness of the DEIS technique in the investigation of non-stationary phenomena has been proved in the field of inhibitor research. All studies clearly show that benzotriazole inhibits the corrosion of brass-MM55 alloy in artificial seawater solution and the value of inhibition efficiency increases with increasing concentration of benzotriazole.     

Some new results on integration for multifunction

It has been proven in Di Piazza and Musia? (Set Valued Anal 13:167–179, 2005, Vector measures, integration and related topics, Birkhauser Verlag, Basel, vol 201, pp 171–182, 2010) that each Henstock–Kurzweil–Pettis integrable multifunction with weakly compact values can be represented as a sum of one of its selections and a Pettis integrable multifunction. We prove here that if the initial multifunction is also Bochner measurable and has absolutely continuous variational measure of its integral, then it is a sum of a strongly measurable selection and of a variationally Henstock integrable multifunction that is also Birkhoff integrable (Theorem 3.4). Moreover, in case of strongly measurable (multi)functions, a characterization of the Birkhoff integrability is given using a kind of Birkhoff strong property.     

Effective methods for preparation and characterization of HNO‐adducts of heme proteins

Driven by the documented effectiveness of cryoradiolysis coupled with resonance Raman spectroscopy for the preparation and structural characterization of unstable peroxo and hydroperoxo intermediates of catalytic and oxidative enzymes, similar strategies have now been applied to prepare and study the still relatively unexplored chemistry of nitrosyl hydride (HNO) adducts of heme proteins and their derivatives. Previously, such HNO derivatives of heme proteins were prepared by chemical addition of reducing agents or by direct addition of an HNO donor. Here, for the first time, we report effective cryoradiolytic preparation of Fe–N(H)O species of myoglobin and their structural characterization by resonance Raman spectroscopy. Our results are in excellent agreement with those previously reported for chemically prepared derivatives and with computational results. Furthermore, the present study provides new data for the deuterated analogue; i.e. bearing a nitrosyl deuteride (DNO) fragment. Copyright © 2012 John Wiley & Sons, Ltd.