bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of parameter‐adapted segmentation methods for fluorescence micrographs
Authors: Held Christian , Palmisano Ralf , Häberle Lothar , Hensel Michael , Wittenberg Thomas
Published: October 2011

Interpreting images from fluorescence microscopy is often a time‐consuming task with poor reproducibility. Various image processing routines that can help investigators evaluate the images are therefore useful. The critical aspect for a reliable automatic image analysis system is a robust segmentation algorithm that can perform accurate segmentation for different cell types. In this study, several image segmentation methods were therefore compared and evaluated in order to identify the most appropriate segmentation schemes that are usable with little new parameterization and robustly with different types of fluorescence‐stained cells for various biological and biomedical tasks. The study investigated, compared, and enhanced four different methods for segmentation of cultured epithelial cells. The maximum‐intensity linking (MIL) method, an improved MIL, a watershed method, and an improved watershed method based on morphological reconstruction were used. Three manually annotated datasets consisting of 261, 817, and 1,333 HeLa or L929 cells were used to compare the different algorithms. The comparisons and evaluations showed that the segmentation performance of methods based on the watershed transform was significantly superior to the performance of the MIL method. The results also indicate that using morphological opening by reconstruction can improve the segmentation of cells stained with a marker that exhibits the dotted surface of cells. © 2011 International Society for Advancement of Cytometry
Utility of Screen Printed Electrodes for in Vitro Metabolic Stability Assays: Application to Acetaminophen and its Thioconjugates
Authors: Kauffmann Jean‐Michel , Van Antwerpen Pierre , Sarakbi Ahmad , Feier Bogdan , Tarik Sidali , Aydogmus Zeynep
Published: October 2011

Screen printed electrodes (SPEs), in addition to their utility in the electrochemical quantification of compounds of pharmacological interest may be used (i) for studying the redox pattern of drug candidates by cyclic voltammetry, (ii) for electrochemical synthesis in microvolumes (microelectrosynthesis) at a selected applied potential with subsequent off‐line LC‐MS identification of the generated products, and (iii) for monitoring enzymatic reactions in microvolumes of samples. The resulting data are of valuable predictive value for in vitro metabolic stability assays. Acetaminophen (APAP) was used as relevant model drug compound to illustrate potential applications of SPEs in pharmaceutical research. The electrooxidation of APAP was studied, in the absence and presence of endogenous thiols, in microvolume sample by cyclic voltammetry and by microelectrolysis at a carbon based SPE (CSPE) and the generated products were identified off‐line by liquid chromatography coupled to mass spectrometry (LC‐MS).
A competent extraction method of plant proteins for 2‐D gel electrophoresis
Authors: Ashoub Ahmed , Berberich Thomas , Beckhaus Tobias , Brüggemann Wolfgang
Published: October 2011

The efficient extraction of high‐quality proteins is a key factor for a successful proteomic analysis approach. In the method suggested here, absolute ethanol containing 10 mM DTT was used to precipitate the proteins in plant tissue homogenates followed by their resuspension in a urea‐/thiourea‐ and NP‐40‐containing solution. Protein profiles were examined on pH 3–11 non‐linear IEF strips and SDS‐PAGE and compared with extracts using the established method of acetone‐10% TCA/0.07% 2‐mercaptoethanol precipitation (V. Méchin et al., Methods Mol. Biol. 2006, 355, 1–8). In addition to protein profile similarity for the two extracts, the acidic part of the acetone containing 10% TCA/0.07% 2‐mercaptoethanol extraction showed protein spots with high molecular weight in the range of 250–150 kDa, while the ethanol containing 10 mM DTT extracts indicated extra proteins spots at the basic part of the gels with molecular weights in the range of 25–15 kDa. The MALDI‐TOF‐MS of differential spots from acetone containing 10% TCA/0.07% 2‐mercaptoethanol precipitation method and absolute ethanol containing 10mM DTT indicated no similarity, ruling out the possibility that the two clusters shown represent identical proteins. The described method is easy in implementation, chemicals used are less toxic and proteins are easier to resuspend therefore presents an additional choice to implement towards finding the optimum method for extraction.
Electrophoretic isolation of saponin fractions from Saponinum album and their evaluation in synergistically enhancing the receptor‐specific cytotoxicity of targeted toxins
Authors: Thakur Mayank , Weng Alexander , Bachran Diana , Riese Sebastian B. , Böttger Stefan , Melzig Matthias F. , Fuchs Hendrik
Published: October 2011

Saponinum album (SA) is a commercial mixture of saponins isolated from Gypsophila species. In the previously published work, we reported that SA dramatically improves the inhibition of tumor growth by targeted toxins in mice in a synergistic way. Here we report a simplified electrophoretic method for the isolation of a highly effective fraction of SA with a relative electrophoretic mobility to the dye front (Rf) of 0.63 from the mixture. In total, four different fractions were separated at a preparative scale, and evaluated by ESI‐MS, HPLC and TLC analysis. Electrophoretic mobility and electrochemical properties of the different fractions of saponins from SA were set into relation to their ability to enhance the cytotoxicity of epidermal growth factor (EGF)‐based targeted toxins. We here treated HER‐14 cells, which are NIH‐3T3 Swiss mouse embryo cells transfected with the human EGF receptor. Untransfected NIH‐3T3 cells served as control. The major bulk of SA (72.3%) (Rf=0.78) migrated the farthest and was found to be significantly ineffective (p<0.05) in enhancing the cytotoxicity of the targeted toxin, while the second fraction (Rf=0.63) showed an enhancement of 9800‐fold. The third (Rf=0.56) had an enhancement factor of 3200, the fourth (Rf=0.08) was again significantly ineffective (p<0.05) in exhibiting any enhancement of cytotoxicity.
Anion separations with pressure‐assisted capillary electrophoresis using a sequential injection analysis manifold and contactless conductivity detection
Authors: Mai Thanh Duc , Hauser Peter C.
Published: October 2011

It is demonstrated that a hydrodynamic flow superimposed on the mobility of analyte anions can be used for the optimization of analysis time in capillary zone electrophoresis. It was also possible to use the approach for counter‐balancing the electroosmotic flow and this works as well as the use of surface modifiers. To avoid any band‐broadening due to the bulk flow narrow capillaries of 10 μm internal diameter were employed. This was enabled by the use of capacitively coupled contactless conductivity detection, which does not suffer from the downscaling, and detection down to between 1 and 20 μM for a range of inorganic and small organic anions was found feasible. Precisely controlled hydrodynamic flow was generated with a sequential injection manifold based on a syringe pump. Sample injection was carried out with a new design relying on a simple piece of capillary tubing to achieve the appropriate back‐pressure for the required split‐injection procedure.
Aqueous suspension methods of carbon-based nanomaterials and biological effects on model aquatic organisms
Authors: Gao Jie , Llaneza Veronica , Youn Sejin , Silvera-Batista Carlos A. , Ziegler Kirk J. , Bonzongo Jean-Claude J.
Published: October 2011

The preparation of aqueous suspensions of carbon-based nanomaterials (NMs) requires the use of dispersing agents to overcome their hydrophobic character. Although studies on the toxicity of NMs have focused primarily on linking the characteristics of particles to biological responses, the role of dispersing agents has been overlooked. This study assessed the biological effects of a number of commonly used dispersing agents on Pseudokirchneriella subcapitata and Ceriodaphnia dubia as model test organisms. The results show that for a given organism, NM toxicity can be mitigated by use of nontoxic surfactants, and that a multispecies approach is necessary to account for the sensitivity of different organisms. In addition to the intrinsic physicochemical properties of NMs, exposure studies should take into account the effects of used dispersing fluids. Environ. Toxicol. Chem. 2012;31:210–214. © 2011 SETAC
Impact of carbon nanotube morphology on phenanthrene adsorption
Authors: Apul Onur Guven , Shao Ting , Zhang Shujuan , Karanfil Tanju
Published: October 2011

The present study examined the roles of the specific surface area (SSA), diameter, and length of carbon nanotubes (CNT) on the adsorption of phenanthrene (PNT) by analyzing the adsorption isotherms obtained with several single-walled carbon nanotubes (SWNT) and multiwalled carbon nanotubes (MWNT). At low equilibrium concentrations (e.g., 1 ppb), MWNTs with larger outer diameters exhibited higher PNT adsorption capacity on an SSA basis than those with smaller diameters. With increasing equilibrium concentration, adsorption on an SSA basis became independent of MWNT diameter, and the total surface area controlled maximum adsorption capacity. A similar analysis for the adsorption of naphthalene, a planar molecule with one less benzene ring but 20 times higher solubility than PNT, showed no correlation with respect to MWNT outer diameter. The results indicated that the surface curvature of MWNT was more important on the adsorption of PNT than on the adsorption of naphthalene. Specific surface area normalized isotherms did not show a correlation between PNT adsorption and lengths of SWNTs and MWNTs. Characterization results indicated that the morphology of CNTs plays an important role on the SSA and pore volume. Data from the manufacturer may not always represent the characteristics of CNTs in a particular batch. Therefore, accurate characterization of CNTs is critical to systematically examine the behavior of CNTs, such as adsorption and transport, in environmental systems. Environ. Toxicol. Chem. 2012;31:73–78. © 2011 SETAC
Correlation between Different Hand Force Assessment Methods from an Epidemiological Study
Authors: Coelho Denis A. , Harris‐Adamson Carisa , Lima Tânia M. , Janowitz Ira , Rempel David M.
Published: October 2011

This article presents the outcome of correlation analyses of data results obtained from using different methods for objectively and subjectively assessing hand force from a prospective study of 450 blue‐collar workers from several companies and industries, followed for up to 3 years. The study collected detailed ergonomic exposure data at baseline and upper extremity health outcome data at baseline and every 4 months during the study. Ultimately, the study was intended to evaluate dose‐response relationships of specific upper extremity disorders with detailed physical and psychosocial exposure data at the workplace while controlling for important individual factors. This article presents the methods used to collect data, as well as the hand force results of the epidemiological study in aggregate correlated form, as a means of exploring the degree of independence between the variables considered. These insights are useful in identifying musculoskeletal disorder (MSD) causation and predicting MSD risk based on work exposures. An enhanced understanding of the independence of MSD causal factors is instrumental in establishing more accurate multivariable models of MSD causation that will play an important role in extrapolating from the understanding of mechanisms of causation to establishing effective recommendations and programs to prevent the occurrence of MSDs. © 2011 Wiley Periodicals, Inc.
Affecting osteoblastic responses with in vivo engineered potato pectin fragments
Authors: Kokkonen Hanna , Verhoef Renè , Kauppinen Kyösti , Muhonen Virpi , Jørgensen Bodil , Damager Iben , Schols Henk A. , Morra Marco , Ulvskov Peter , Tuukkanen Juha
Published: October 2011

Pectins, complex plant‐derived polysaccharides, are novel candidates for biomaterial nanocoatings. Pectic rhamnogalacturonan‐I regions (RG‐I) can be enzymatically treated to so‐called modified hairy regions (MHR). We surveyed the growth and differentiation of murine preosteoblastic MC3T3‐E1 cells on Petri dishes coated with RG‐Is from native or genetically engineered potato tubers. Uncoated tissue culture polystyrene (TCPS) and aminated (AMI) dishes served as controls. MHRPTR_GAL sample was depleted of galactose (9 mol % galactose; 23 mol % arabinose) and MHRPTR_ARA of arabinose (61 mol % galactose; 6 mol % arabinose). Wild‐type (modified hairy region from potato pectin (MHRP)_WT) fragment contained default amounts (58 mol % galactose; 13 mol % arabinose) of both sugars. Focal adhesions (FAs) indicating cellular attachment were quantified. Reverse transcriptase polymerase chain reaction (RT‐PCR) of alkaline phosphatase and osteocalcin genes indicating osteoblastic differentiation was performed along with staining the produced calcium with tetracycline as an indicator of osteoblastic differentiation. Osteoblasts proliferated on all the samples to some extent. The control surfaces performed better than any of the pectin samples, of which the MHRP_WT seemed to function best. FA length was greater on MHRPTR_GAL than on other pectin samples, otherwise the mutants did not significantly deviate. RT‐PCR results indicate that differences between the samples at the gene expression level might be even subtler. However, tetracycline‐stained calcium‐containing mineral was detected merely only on uncoated TCPS. These results indicate the possibility to affect bone cell growth with in vivo‐modified pectin fragments, consecutively providing information on the significance of certain monosaccharides on the biocompatibility of these polysaccharides. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.
Ultrastructural analysis of human bone marrow mesenchymal stem cells during in vitro osteogenesis and chondrogenesis
Authors: Teti Gabriella , Cavallo Carola , Grigolo Brunella , Giannini Sandro , Facchini Andrea , Mazzotti Antonio , Falconi Mirella
Published: October 2011

The main purpose of this article was to describe the morphology of mesenchymal stem cells (MSCs) differentiated in vitro towards osteogenic and chondrogenic lineages and to focus on the ultrastructural features associated with these processes. Human mononuclear cells (hMNC) were isolated, expanded, and analyzed for the expression of specific cell surface markers to demonstrate their stem cell characteristics. Human mononuclear cells were differentiated in vitro in an osteogenic and in a chondrogenic sense for 7, 14, 21, and 28 days. Subsequently, they were processed using electron microscopic analysis (FEISEM). Alizarin red and alcian blue staining were carried out to demonstrate the deposition of mineral salts and proteoglycans in the extracellular matrix. Undifferentiated MSCs showed a cell surface covered by filopodia and ondulopodia. During differentiation, the MSCs changed their shape from a round to a fibroblastic‐like shape. At the end of the differentiation, several filaments with a parallel orientation in the osteogenic samples as well as a network organization in the chondrogenic samples were detected in the extracellular spaces. This study demonstrated that there are morphological features associated with the undifferentiated and differentiated states of the MSCs, which could be utilized as new parameters for identifying and classifying these cells. Microsc. Res. Tech., 2012. © 2011 Wiley Periodicals, Inc.
Study of specific interaction between nucleotides and dye support by nuclear magnetic resonance
Authors: Cruz Carla , Boto Renato E. F. , Almeida Paulo , Queiroz João A.
Published: October 2011

The binding between four matrices (beaded cellulose, cellulose acetate, cellulose triacetate and Sepharose CL‐6B) and beaded cellulose derivatized with a thiacarbocyanine dye with 5′‐mononucleotides is investigated by Saturation Transfer Difference Nuclear Magnetic Resonance (STD–NMR) technique. This procedure intends to identify unspecific interactions between 5′‐mononucleotides and matrices commonly used in affinity chromatography systems and also clarify the contribution of a thiacarbocyanine dye immobilized onto cellulose beads in a biorecognition process. The differences between non‐derivatized and derivatized beaded cellulose evidence the contribution of thiacarbocyanine dye in the observed interaction. STD–NMR experiments show that Sepharose CL‐ 6B interact less with the 5′‐mononucleotides comparatively with beaded cellulose. Indeed, beaded cellulose shows nonspecific interactions with almost all 5′‐mononucleotides that compromises the specificity of the interaction between the thiacarbocyanine dye immobilized with the 5′‐mononucleotides. The cellulose matrices where the hydroxyl groups are replaced by acetate and triacetate groups do not exhibit binding response to the 5′‐ mononucleotides, whereas the thiacarbocyanine dye contribution is evidenced by the reinforcement of the interactions with the sugar moiety of 5′‐GMP and 5′‐UMP and with base of 5′‐AMP, 5′‐CMP and 5′‐TMP. This screening of the nucleotide atoms involved in the binding to the supports can be very useful in chromatography evaluations in which dye‐affinity chromatography supports may be used, such as purification of nucleic acids. Copyright © 2011 John Wiley & Sons, Ltd.
Polyamide recognition‐mass spectrometry for distinguishing hairpin DNA from coil DNA
Authors: Zheng Bo , Liu Yiquan , Yuan Gu
Published: October 2011

The discrimination between hairpin DNA and coil DNA has been well achieved through polyamides as probes by electrospray ionization (ESI) mass spectrometry. ESI mass spectra showed that polyamides bind to hairpin DNA with high selectivity, and almost no binding with coil DNA. In addition, the noncovalent interaction between polyamides and hairpin DNA was also studied; the results show that hairpin DNA with longer stem and polyamides with more heterocycles have higher binding affinity and stability in gas phase. Copyright © 2011 John Wiley & Sons, Ltd.
Structure and elasticity of desmin protofibrils explored with scanning force microscopy
Authors: Kiss Balázs , Röhlich Pál , Kellermayer Miklós S. Z.
Published: October 2011

Desmin filaments form the intermediate filament system of muscle cells where they play important role in maintaining mechanical integrity and elasticity. Although the importance of desmin elasticity and assembly–disassembly dynamics in cellular mechanics is being increasingly recognized, the molecular basis of neither desmin's elasticity nor its disassembly pathway is well understood. In the present work, we explored the topographical structure of purified and reconstituted desmin filaments by using scanning force microscopy. With the addition of divalent cation chelators ethyleneglycoltetraacetic acid or ethylenediaminetetraacetic acid, the filaments disassembled on a time scale of hours to days into stable, thin fibrillar components with variable (up to micrometer) length, smooth surface and uniform thickness, which are identified as protofibrils. Desmin protofibrils appear as elastic structures with a persistence length of 51.5 nm, and their Young's modulus (10.6 MPa) far exceeds that of the mature filament (3.7 MPa). Protofibrillar bundling within the desmin filament results in high longitudinal tensile strength at a large bending flexibility. The stability of protofibrils suggests that desmin may disassemble along a pathway quite distinct from its assembly. Copyright © 2011 John Wiley & Sons, Ltd.
Impaired regional left ventricular strain after repair of tetralogy of fallot
Authors: Ordovas Karen G. , Carlsson Marcus , Lease Katy E. , Foster Elyse , Meadows Alison K. , Martin Alastair J. , Hope Michael , Do Loi , Higgins Charles B. , Saeed Maythem
Published: October 2011

Purpose:

To test the potential of magnetic resonance imaging (MRI) in early detection of left ventricular (LV) dysfunction in patients with pulmonary regurgitation and normal LV ejection fraction after repair of tetralogy of Fallot.

Materials and Methods:

Patients (n = 18) with repaired tetralogy of Fallot and pulmonary regurgitation were prospectively recruited. Healthy volunteers (n = 10) were used as control. Tagging MR images were acquired at the base, mid, and apical LV levels for assessing segmental rotation and circumferential strain. Cine MR images and velocity‐encoded MR images were also acquired for assessment of biventricular volumes and biventricular function and pulmonary regurgitant fraction, respectively. Mean values were compared between groups using unpaired Student's t‐test.

Results:

Patients presented with preserved global LV function (LVEF of 59 ± 5%). A significant decrease in LV peak circumferential strain was seen in patients compared with normal volunteers at the basilar (−15.6 ± 4.5% vs. −17.6 ± 4.4%; P < 0.01) and apical (−14.4± 6.1% vs. −17.3± 5.1%, P < 0.01) slices. LV peak rotation was also delayed in patients compared with volunteers at the basilar (6.1 ± 2.6° vs. 4.2 ± 0.6°; P < 0.01) and mid (8.0 ± 1.7° vs. 4.9 ± 1.0°; P < 0.01) slices.

Conclusion:

MRI can detect early regional LV dysfunction in patients with preserved LVEF after repair of tetralogy of Fallot. MR may be a useful technique for guiding clinical decisions in these patients in order to prevent future global LV deterioration. J. Magn. Reson. Imaging 2012;35:79‐85. © 2011 Wiley Periodicals, Inc.
Characterization of adrenal lesions using chemical shift MRI: Comparison between 1.5 tesla and two echo time pair selection at 3.0 tesla MRI
Authors: Nakamura Shinichi , Namimoto Tomohiro , Morita Kosuke , Utsunomiya Daisuke , Oda Seitaro , Nakaura Takeshi , Hirai Toshinori , Yamashita Yasuyuki
Published: October 2011

Purpose:

To compare chemical shift MRI obtained at 1.5 Tesla (T) and two pairs of echo time (TE) in‐phase and opposed‐phase 3.0T MRI to assess their usefulness for the differentiation between adrenal adenomas and non‐adenomas.

Materials and Methods:

We evaluated 91 adrenal masses (75 adenomas, 16 non‐adenomas) in 85 patients. The MR imaging parameters were: T1‐dual‐gradient‐echo(GRE) [echo times (TEs) = 1.1/2.3 ms (first‐echo‐pair) or 3.5/4.6 ms (second‐echo‐pair)] at 3.0T, and T1‐dual‐GRE (TEs = 2.4/4.8 ms) at 1.5T. Scans were quantitatively assessed for the signal intensity (SI) index, calculated as [(SIin‐phase‐SIopposed‐phase)/(SIin‐phase)] × 100(%). To test for differences between adenomas and non‐adenomas, we performed quantitative analysis and analysis of variance.

Results:

For all images, the SI index differed significantly between adenomas and non‐adenomas. The sensitivity /specificity of SI index at the first‐echo‐pair of 3.0T was 100%/ 100%, that of 95.6%/ 100% at the second‐echo‐pair of 3.0T, and 91.7%/ 88.9% at 1.5T, respectively. At intra‐individual comparisons, the SI indices obtained with the second‐echo‐pair at 3.0T were significantly lower than on the first‐echo‐pair at 3.0T and 1.5T.

Conclusion:

Chemical shift MRI at 3.0T provides more accurate differentiation between adenomas and non‐adenomas than at 1.5T. The SI index of the first‐echo‐pair at 3.0T is the most reliable evaluation method for differentiating adrenal adenomas from non‐adenomas. J. Magn. Reson. Imaging 2012;35:95‐102. © 2011 Wiley Periodicals, Inc.
Comparison of 3 Tesla proton MR spectroscopy, MR perfusion and MR diffusion for distinguishing glioma recurrence from posttreatment effects
Authors: Fink James R. , Carr Robert B. , Matsusue Eiji , Iyer Ramesh S. , Rockhill Jason K. , Haynor David R. , Maravilla Kenneth R.
Published: October 2011

Purpose:

To compare 3 Tesla (3T) multi‐voxel and single‐voxel proton MR spectroscopy (MRS), dynamic susceptibility contrast perfusion MRI (DSC), and diffusion‐weighted MRI (DWI) for distinguishing recurrent glioma from postradiation injury.

Materials and Methods:

We reviewed all 3T MRS, DSC and DWI studies performed for suspicion of malignant glioma recurrence between October 2006 and December 2008. Maximum Cho/NAA and Cho/Cr peak‐area and peak‐height ratios were recorded for both multi‐voxel and single‐voxel MRS. Maximum cerebral blood volume (CBV) and minimum apparent diffusion coefficient (ADC) were normalized to white matter. Histopathology and clinical‐radiologic follow‐up served as reference standards. Receiver operating characteristic curves for each parameter were compared.

Results:

Forty lesions were classified as glioma recurrence (n = 30) or posttreatment effect (n = 10). Diagnostic performance was similar for CBV ratio (AUC = 0.917, P < 0.001), multi‐voxel Cho/Cr peak‐area (AUC = 0.913, P = 0.002), and multi‐voxel Cho/NAA peak‐height (AUC = 0.913, P = 0.002), while ADC ratio (AUC = 0.726, P = 0.035) did not appear to perform as well. Single‐voxel MRS parameters did not reliably distinguish tumor recurrence from posttreatment effects.

Conclusion:

A 3T DSC and multi‐voxel MRS Cho/Cr peak‐area and Cho/NAA peak‐height appear to outperform DWI for distinguishing glioma recurrence from posttreatment effects. Single‐voxel MRS parameters do not appear to distinguish glioma recurrence from posttreatment effects reliably, and therefore should not be used in place of multi‐voxel MRS. J. Magn. Reson. Imaging 2012;35:56‐63. © 2011 Wiley Periodicals, Inc.
The nature of black stains in Lascaux Cave, France, as revealed by surface‐enhanced Raman spectroscopy
Authors: Martin‐Sanchez Pedro M. , Sanchez‐Cortes Santiago , Lopez‐Tobar Eduardo , Jurado Valme , Bastian Fabiola , Alabouvette Claude , Saiz‐Jimenez Cesareo
Published: October 2011

We used surface‐enhanced Raman spectroscopy to investigate the chemical composition of the black stains threatening the rock‐art paintings of Lascaux Cave, Montignac, France. The stains are mainly composed of melanin from the fungus Ochroconis sp. and the faecal pellets of the collembolan Folsomia candida. Surface‐enhanced Raman spectroscopy is a useful technique for revealing the structure of unknown macromolecules in cultural heritage research. Copyright © 2011 John Wiley & Sons, Ltd.
Determination of benzoyl peroxide, as benzoic acid, in wheat flour by capillary electrophoresis compared with HPLC
Authors: Mu Guangfen , Liu Huitao , Gao Yuan , Luan Feng
Published: October 2011

BACKGROUND: In recent years, debate on the addition of benzoyl peroxide (BP) to wheat flour has increased in China. Medical studies have so far not confirmed that BP in wheat flour causes definite damage to the human body, but its main metabolite in the human body is benzoic acid. The addition of BP to wheat flour has been forbidden in China since 1 May 2011. It is therefore necessary to develop a suitable method to determine BP in wheat flour.

RESULTS: A simple method using capillary electrophoresis (CE) was developed for determination of BP in wheat flour. BP was determined as benzoic acid after preceding reduction by potassium iodide. Separation was completed in less than 7 min with a running buffer of 10 mmol L−1 sodium borate (pH 9.18), 4 s hydrodynamic injection, 25 kV separation voltage and UV detection at 228 nm. The method was validated in terms of linearity, sensitivity, detection limit, precision and accuracy. The detection limit was 0.29 µg mL−1. The method was successfully applied to the determination of BP in wheat flour samples, with recoveries between 96.1% and 102.6%.

CONCLUSION: The performance of the CE method was comparable, and the quantitative results were in good agreement with those using high‐performance liquid chromatography (HPLC). Meanwhile the proposed CE method has the advantages of better resolution, shorter analysis time and lower cost, and would be a good alternative to HPLC for routine monitoring of BP amount in wheat flour. Copyright © 2011 Society of Chemical Industry
Birch inner bark procyanidins can be resolved with enhanced sensitivity by hydrophilic interaction HPLC‐MS
Authors: Karonen Maarit , Liimatainen Jaana , Sinkkonen Jari
Published: October 2011

A complex mixture of procyanidin aglycones was isolated by Sephadex LH‐20 column chromatography from the silver birch inner bark, which is a polyphenol‐rich source of natural antioxidants. Procyanidins were studied by using hydrophilic interaction liquid chromatography combined with high‐resolution ESI‐TOF‐MS. A good chromatographic separation was achieved and procyanidins eluted according to their increasing degree of polymerization. Individual procyanidins were detected from dimers up to the degree of polymerization of 22 by their negative‐ion mass spectra. The results showed that hydrophilic interaction liquid chromatography can be successfully applied for the analysis of high‐molecular‐weight procyanidins with enhanced sensitivity in electrospray mass spectrometry.
Optimal execution strategy in the presence of permanent price impact and fixed transaction cost
Authors: Junca Mauricio
Published: October 2011

We study a single risky financial asset model subject to price impact and transaction cost over an infinite horizon. An investor needs to execute a long position in the asset, affecting the price of the asset and possibly incurring a fixed transaction cost. The objective is to maximize the discounted revenue obtained by this transaction. This problem is formulated first as an impulse control problem, and the value function is characterized using the viscosity solutions framework. We also analyze the case where there is no transaction cost and how this formulation relates with a singular control problem. A viscosity solution characterization is provided in this case as well. We also establish a connection between both formulations with zero fixed transaction cost. Numerical examples with different types of price impact conclude the discussion. Copyright © 2011 John Wiley & Sons, Ltd.
Crystallization of glass fiber‐reinforced poly(p‐phenylene sulfide) nanocomposites
Authors: Liang Ji‐Zhao
Published: October 2011

Ternary composites of glass fiber‐reinforced poly(p‐phenylene sulfide) (PPS/GF) filled with nanometric calcium carbonate (nano‐CaCO3) were prepared by means of a twin‐screw extruder. The nano‐CaCO3 surface was treated with stearate and treated with titanate, the composites being called SI composite system and SII composite system, respectively. The crystallization and heatproof properties of the PPS/GF/nano‐CaCO3 composites were measured using a differential scanning calorimeter, to investigate the influence of the nanometric filler content on the crystallinity. The results show that the variation of the starting crystallization temperature, crystallization temperature and crystallinity with an increase of the particle weigh fraction (ϕf) of SI composite system is different from that of SII composite system. When ϕf is less than 4 wt%, the crystallinity of the two composite systems increases and then decreases slightly with increasing ϕf. Moreover, the crystallization behavior and mechanisms are discussed. Copyright © 2011 Society of Chemical Industry
Evaluation of the efficacy of glyphosate plus urea phosphate in the greenhouse and the field
Authors: Li Pingliang , He Shun , Tang Tao , Qian Kun , Ni Hanwen , Cao Yongsong
Published: October 2011

BACKGROUND: Glyphosate is a non‐selective, foliar‐applied, systemic herbicide that kills weeds by inhibiting the synthesis of 5‐enolpyruvylshikimate‐3‐phosphate synthase. Urea phosphate (UPP), made by the reaction of urea with phosphoric acid, was applied as an adjuvant for glyphosate in this study. Experiments in the greenhouse and the field were conducted to determine the effects of UPP by comparing the efficacies of glyphosate plus UPP, glyphosate plus 1‐aminomethanamide dihydrogen tetraoxosulfate (AMADS) and Roundup.

RESULTS: The optimum concentration of UPP in glyphosate solution was 2.0% when UPP was used as an adjuvant. The ED50 values for glyphosate‐UPP were 291.7 and 462.4 g AI ha−1 in the greenhouse and the field respectively, while the values for Roundup were 448.2 and 519.6 g AI ha−1. The ED50 values at 2 weeks after treatment (WAT) and 3 WAT were lowered when UPP was used as an adjuvant in the greenhouse and field study, and the glyphosate + UPP was absorbed over a 2 week period. UPP may increase the efficacy by causing severe cuticle disruption or accelerating the initial herbicide absorption. The result also showed that UPP could reduce the binding behaviour of Ca2+ to glyphosate.

CONCLUSION: The application of UPP as an adjuvant could increase the efficacy of glyphosate and make it possible to achieve effective control of weeds with glyphosate at lower dose. Moreover, UPP showed less causticity to spraying tools and presented less of a health hazard. Therefore, UPP is accepted as being a new, effective and environmentally benign adjuvant for glyphosate. Copyright © 2011 Society of Chemical Industry
Dynamical X‐ray diffractometry of the defect structure of garnet crystals
Authors: Pylypiv V. M. , Vladimirova T. P. , Fodchuk I. M. , Ostafiychuk B. K. , Kyslovskyy Ye. M. , Molodkin V. B. , Olikhovskii S. I. , Reshetnyk O. V. , Skakunova O. S. , Lizunov V. V. , Garpul' O. Z.
Published: October 2011

The generalized statistical dynamical theory of X‐ray diffraction by imperfect single crystals is applied for the structural characterization of real single crystals with complex basis, namely, gadolinium gallium garnet (GGG) crystal Gd3Ga5O12. The developed theoretical approach takes into account the presence of various structural defects as well as provides the self‐consistent description of coherent and diffuse components of diffraction profiles from such crystals.

The characteristics of microdefects in the investigated GGG single crystal have been determined by analyzing the rocking curves measured for 444 and 888 reflections of CuKα1 radiation.
High‐order sliding mode control design based on adaptive terminal sliding mode
Authors: Tang W.Q. , Cai Y.L.
Published: October 2011

High‐order sliding mode control techniques are proposed for uncertain nonlinear SISO systems with bounded uncertainties based on two different terminal sliding mode approaches. The tracking error of the output converges to zero in finite time by designing a terminal sliding mode controller. In addition, the adaptive control method is employed to identify bounded uncertainties for eliminating the requirement of boundaries needed in the conventional design. The controllers are derived using Lyapunov theory, so the stability of the closed‐loop system is guaranteed. In the first technique, the developed procedure removes the reaching phase of sliding mode and realizes global robustness. The proposed algorithms ensure establishment of high‐order sliding mode. An illustrative example of a car control demonstrates effectiveness of the presented designs. Copyright © 2011 John Wiley & Sons, Ltd.
LANDSCAPE‐LEVEL MODEL TO PREDICT SPAWNING HABITAT FOR LOWER COLUMBIA RIVER FALL CHINOOK SALMON (ONCORHYNCHUS TSHAWYTSCHA)
Authors: Shallin Busch D. , Sheer Mindi , Burnett Kelly , McElhany Paul , Cooney Tom
Published: October 2011

We developed an intrinsic potential (IP) model to estimate the potential of streams to provide habitat for spawning fall Chinook salmon (Oncorhynchus tshawytscha) in the Lower Columbia River evolutionarily significant unit. This evolutionarily significant unit is a threatened species, and both fish abundance and distribution are reduced from historical levels. The IP model focuses on geomorphic conditions that lead to the development of a habitat that fish use and includes three geomorphic channel parameters: confinement, width and gradient. We found that the amount of potential habitat for each population does not correlate with current, depressed, total population abundance. However, reaches currently used by spawners have high IP, and IP model results correlate well with results from the complex Ecosystem Diagnosis and Treatment model. A disproportionately large amount of habitat with the best potential is currently inaccessible to fish because of anthropogenic barriers. Sensitivity analyses indicate that uncertainty in the relationship between channel width and habitat suitability has the largest influence on model results and that model form influences model results more for some populations than for others. Published in 2011 by John Wiley & Sons, Ltd.
Limitations of current definitions of miscarriage using mean gestational sac diameter and crown–rump length measurements: a multicenter observational study
Authors: Abdallah Y. , Daemen A. , Kirk E. , Pexsters A. , Naji O. , Stalder C. , Gould D. , Ahmed S. , Guha S. , Syed S. , Bottomley C. , Timmerman D. , Bourne T.
Published: October 2011

Objectives

There is significant variation in cut‐off values for mean gestational sac diameter (MSD) and embryo crown–rump length (CRL) used to define miscarriage, values suggested in the literature ranging from 13 to 25 mm for MSD and from 3 to 8 mm for CRL. We aimed to define the false‐positive rate (FPR) for the diagnosis of miscarriage associated with different CRL and MSD measurements with or without a yolk sac in a large study population of patients attending early pregnancy clinics. We also aimed to define cut‐off values for CRL and MSD that, on the basis of a single measurement, can definitively diagnose a miscarriage and so exclude possible inadvertent termination of pregnancy.

Methods

This was an observational cross‐sectional study. Data were collected prospectively according to a predefined protocol. Intrauterine pregnancy of uncertain viability (IPUV) was defined as an empty gestational sac or sac with a yolk sac but no embryo seen with MSD < 20 or < 30 mm or an embryo with an absent heartbeat and CRL < 6 mm or < 8 mm. We recruited to the study 1060 consecutive women with IPUV. The endpoint was presence or absence of a viable pregnancy at the time of first‐trimester screening ultrasonography between 11 and 14 weeks. The sensitivity, specificity, positive and negative predictive values were calculated for potential cut‐off values to define miscarriage from MSD 8 to 30 mm with or without a yolk sac and from CRL 3 to 8 mm.

Results

Of the 1060 women with a diagnosis of IPUV, 473 remained viable and 587 were non‐viable by the time of the 11–14‐week scan. In the absence of both embryo and yolk sac, the FPR for miscarriage was 4.4% when an MSD cut‐off of 16 mm was used and 0.5% for a cut‐off of 20 mm. There were no false‐positive test results for miscarriage when a cut‐off of MSD ≥ 21 mm was used. If a yolk sac was present but an embryo was not, the FPR for miscarriage was 2.6% for an MSD cut‐off of 16 mm and 0.4% for a cut‐off of 20 mm, with no false‐positive results when a cut‐off of MSD ≥ 21 mm was used. When an embryo was visible with an absent heartbeat, using a CRL cut‐off of 4 mm the FPR for miscarriage was 8.3%, and for a CRL cut‐off of 5 mm it was also 8.3%. There were no false‐positive results using a CRL cut‐off of ≥ 5.3 mm.

Conclusions

These data show that some current definitions used to diagnose miscarriage are potentially unsafe. Current national guidelines should be reviewed to avoid inadvertent termination of wanted pregnancies. An MSD cut‐off of > 25 mm and a CRL cut‐off of > 7 mm could be introduced to minimize the risk of a false‐positive diagnosis of miscarriage. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.
Unfolded protein response is not activated in the mucopolysaccharidoses but protein disulfide isomerase 5 is deregulated
Authors: Villani Guglielmo R. D. , Chierchia Armando , Di Napoli Daniele , Di Natale Paola
Published: October 2011

Mucopolysaccharidoses (MPSs) are lysosomal storage diseases (LSDs) caused by defects in lysosomal enzymes involved in the catabolism of glycosaminoglycans. The pathogenesis of these disorders is still not completely known, although inflammation and oxidative stress appear to be common mechanisms, as in all LSDs. Recently, it was hypothesized that endoplasmic reticulum (ER) stress followed by an unfolded protein response (UPR) could be another common pathogenetic mechanism in LSDs. The aim of the present study was to verify if the UPR was elicited in the mucopolysaccharidoses and if the mechanism was MPS type‐ and mutation‐dependent. To this end, we analyzed the UPR in vitro, in fibroblasts from patients with different types of mucopolysaccharidoses (MPS I, II, IIIA, IIIB, IVA) and in vivo, in the murine MPS IIIB model. In both cases we found no changes in mRNA levels of several UPR‐related genes, such as the spliced or unspliced form of Xbp‐1, Bip, Chop, Edem1, Edem2, Edem3. Therefore, we report here that the unfolded protein response of the ER is not triggered either in vitro or in vivo; accordingly, cytotoxicity assays indicated that affected fibroblasts are no more sensitive to apoptosis induction than normal cells. However, our results show that in most of the analyzed MPS fibroblasts the expression of a poorly known protein belonging to the family of the protein disulfide isomerases, namely Pdia5, is upregulated; here we discuss if its upregulation could be an early event of ER stress possibly related to the severity of the damage induced in the mutant proteins.
A scenario for finite-time singularity in the quasigeostrophic model
Authors: Scott Richard K.
Published: October 2011

A possible route to finite-time singularity in the quasigeostrophic system, via a cascade of filament instabilities of geometrically decreasing spatial and temporal scales, is investigated numerically using a high-resolution hybrid contour dynamical algorithm. A number of initial temperature distributions are considered, of varying degrees of continuity. In all cases, primary, secondary, and tertiary instabilities are apparent before the algorithm loses accuracy due to limitations of finite resolution. Filament instability is also shown to be potentially important in the closing saddle scenario investigated in many previous studies. The results do not provide a rigorous demonstration of finite-time singularity, but suggest avenues for further investigation.
The whey fermentation product malleable protein matrix decreases TAG concentrations in patients with the metabolic syndrome: a randomised placebo-controlled trial
Authors: Gouni-Berthold Ioanna , Schulte Dominik M. , Krone Wilhelm , Lapointe Jean-François , Lemieux Pierre , Predel Hans-Georg , Berthold Heiner K.
Published: October 2011

Animal and human studies suggest that a malleable protein matrix (MPM) from whey decreases plasma lipid concentrations and may positively influence other components of the metabolic syndrome such as glucose metabolism and blood pressure (BP). The primary objective of this double-blind, multi-centre trial was to investigate the effects of a low-fat yoghurt supplemented with whey MPM on fasting TAG concentrations in patients with the metabolic syndrome. A total of 197 patients were randomised to receive MPM or a matching placebo yoghurt identical in protein content (15 g/d). Patients were treated during 3 months with two daily servings of 150 g yoghurt each to compare changes from baseline in efficacy variables. MPM treatment resulted in a significantly larger reduction of TAG concentrations in comparison to placebo (relative change − 16 %, P = 0·004). The difference was even more pronounced in subjects with elevated fasting TAG ( ≥ 200 mg/dl) at baseline ( − 18 %, P = 0·005). The relative treatment difference in fasting plasma glucose was − 7·1 mg/dl (P = 0·089). This effect was also more pronounced in subjects with impaired fasting glucose at baseline ( − 11 mg/dl, P = 0·03). In patients with hypertension, the relative treatment difference in systolic BP reached − 5·9 mmHg (P = 0·054). The relative treatment difference in body weight was − 1·7 kg (P = 0·015). The most common adverse events were gastrointestinal in nature. Conclusions from the present study are that consumption of a low-fat yoghurt supplemented with whey MPM twice a day over 3 months significantly reduces fasting TAG concentrations in patients with the metabolic syndrome and improves multiple other cardiovascular risk factors.
Histidine and arginine are associated with inflammation and oxidative stress in obese women
Authors: Niu Yu-Cun , Feng Ren-Nan , Hou Yan , Li Kang , Kang Zhen , Wang Jian , Sun Chang-Hao , Li Ying
Published: October 2011

The aims of the present study were to examine the serum amino acid profiles in obese and non-obese women and investigate the relationships between the serum amino acids and inflammation and oxidative stress in a human case–control study. Serum amino acids, inflammatory biomarkers (C-reactive protein and IL-6) and oxidative biomarkers (superoxide dismutase, malondialdehyde and glutathione peroxidase) were measured and compared in 235 obese women and 217 non-obese controls. The relationships between serum amino acids and inflammatory and oxidative biomarkers were examined using multiple linear regression. Among the amino acids determined, serum histidine, arginine, threonine, glycine, lysine and serine were found to be significantly lower in obese women as compared to non-obese controls (P < 0·001). The difference was the greatest for histidine (P < 0·001). In obese women, both histidine and arginine were negatively associated with inflammation and oxidative stress. In non-obese controls, histidine was negatively associated with oxidative stress. The findings in this study indicate that the metabolism of amino acids is abnormal in obese women in whom histidine and arginine have close relationships with inflammation and oxidative stress.
Parental magma composition of the syntectonic Dawros Peridotite chromitites, NW Connemara, Ireland
Authors: HUNT E. , O'DRISCOLL B. , DALY J. S.
Published: October 2011

Chromium-spinels have been widely used as petrogenetic indicators to infer parent melt compositions and the tectonic setting of their formation. This study integrates petrographic, quantitative textural and geochemical analyses of Cr-spinel seams within the Dawros Peridotite, NW Connemara, Ireland to determine the composition of their parental magmas. Calculation of Cr no. (Cr/(Cr + Al)) (0.50–0.77) values and TiO2 (0.18–0.36 wt%) contents of the Cr-spinel seams, coupled with an estimation of the Al2O3 and TiO2 contents (~11.86 wt% and ~0.39 wt%, respectively) of their parental melts, indicates that they probably formed from boninitic melts sourced from a highly depleted mantle. This implies that the Cr-spinel seams formed in a supra-subduction zone undergoing high degrees of partial melting. The Cr-spinel data support tectonic models for the formation of the Dawros Peridotite (and Connemara Metagabbro-Gneiss Complex) during island arc collision, immediately prior to Grampian orogenesis at ~470 Ma. The occurrence of the Dawros chromitite seams at the approximate transition between the lower harzburgite sequence and the upper lherzolite sequence bears marked similarities to the positions of such seams in larger anorogenic layered mafic-ultramafic intrusions, and implies that the Dawros Peridotite behaved as an open-system magma chamber.