bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamic mRNA and miRNA profiling of CHO‐K1 suspension cell cultures
Authors: Bort Juan A. Hernández , Hackl Matthias , Höflmayer Helga , Jadhav Vaibhav , Harreither Eva , Kumar Niraj , Ernst Wolfgang , Grillari Johannes , Borth Nicole
Published: June 2011

In spite of the importance of Chinese hamster ovary (CHO) cells for recombinant protein production, very little is known about the molecular and gene regulatory mechanisms that control cellular phenotypes such as enhanced growth under serum‐free conditions or high productivity. Most microarray analyses to this purpose are performed with samples taken during the exponential growth phase. However, the cellular transcriptome is dynamic, changing in response to external and internal stimuli and thus reflecting the current functional capacity of cells as well as their ability to adapt to a changing environment. Therefore, during batch or fed‐batch cultivations it can be expected that the transcription pattern of genes will change and that such changes may give indications on the cellular state in terms of viability, growth, and productivity. In the current study we monitored the change in expression patterns of mRNAs and microRNAs (miRNA) during lag, exponential, and stationary phases in CHO‐K1 suspension cell cultures. In total, over 1400 mRNAs and more than 100 miRNAs were differentially regulated (p<0.05) relative to the batch culture at the starting point. Functional clustering revealed groups of genes with similar expression patterns, which were subjected to functional pathway analysis. In addition, as miRNAs generally act as negative post‐transcriptional regulators of mRNAs, we looked for changes in their expression that were inverse to those of their predicted target mRNAs.
Flow Channel Boundaries in Silos
Authors: Yang Y. , Rotter M. , Ooi J. , Wang Y.
Published: June 2011

The critical slip planes at the silo filling state are compared with the flow channel boundary during silo discharge for semi‐mass flows. The static critical slip planes are determined by using the dynamic programming method based on the stress field of granular solids stored in silos at the filling state. The flow channel boundary is estimated through the finite element analysis of the silo discharge. The results indicate that the critical slip line lies above the flow channel boundary. This characteristic can be attributed to the changeover of major principal stress directions of granular solids from the silo filling to the silo discharge. The analysis demonstrates that the silo wall friction tends to lift up the critical slip plane and flow boundary. A simple correlation is developed between the positions of critical slip planes and flow boundaries and is experimentally verified.
Preparation, Structure, and Ethylene (Co)Polymerization Behavior of Group IV Metal Complexes with an [OSSO]‐Carborane Ligand
Authors: Hu Ping , Wang Jian‐Qiang , Wang Fosong , Jin Guo‐Xin
Published: June 2011

The synthesis of Group IV metal complexes that contain a tetradentate dianionic [OSSO]‐carborane ligand [(HOC6H2tBu2‐4,6)2(CH2)2S2C2(B10H10)] (1 a) is described. Reactions of TiCl4 and Ti(OiPr)4 with the [OSSO]‐type ligand 1 a afford six‐coordinated titanium complex [Ti(OC6H2tBu2‐4,6)2(CH2)2S2C2(B10H10)Cl2] (2 a) and four‐coordinated titanium complex [Ti(OC6H2tBu2‐4,6)2(CH2)2S2C2(B10H10)(OiPr)2] (2 b), respectively. ZrCl4 and HfCl4 were treated with 1 a to give six‐coordinated zirconium complex [Zr(OC6H2tBu2‐4,6)2(CH2)2S2C2(B10H10)Cl2(thf)2] (2 c) and six‐coordinated hafnium complex [Hf(OC6H2tBu2‐4,6)2(CH2)2S2C2(B10H10)Cl2] (2 d). All the complexes were fully characterized by IR, NMR spectroscopy, and elemental analysis. In addition, X‐ray structure analyses were performed on complexes 2 a and 2 b and reveal the expected different coordination geometry due to steric hindrance effects. Extended X‐ray absorption fine structure (EXAFS) spectroscopy was performed on complexes 2 c and 2 d to describe the coordination chemistry of this ligand around Zr and Hf. Six‐coordinated titanium complex 2 a showed good activity toward ethylene polymerization as well as toward copolymerization of ethylene with 1‐hexene in the presence of methylaluminoxane (MAO) as cocatalyst (up to 1060 kg [mol (Ti)]−1 h−1 in the case of 10 atm of ethylene pressure).
Synthesis and enantiopreferential DNA‐binding profile of late 3d transition metal R‐ and S‐enantiomeric complexes derived from N,N‐bis‐(1‐benzyl‐2‐ethoxyethane): Validation of R‐enantiomer of copper(II) complex as a human topoisomerase II inhibitor
Authors: Arjmand Farukh , Sharma Girish Chandra , Muddassir Mohd. , Tabassum Sartaj
Published: June 2011

To evaluate the biological preference of chiral drug candidates for molecular target DNA, new potential metal‐based chemotherapeutic agents 1, 1a, 1b, 2, 2a, 2b, 3, 3a, 3b of late 3d transition metals Ni(II), Cu(II), and Zn(II), respectively, derived from (R)‐ and (S)‐2‐amino‐2‐phenylethanol with CH2CH2 linker were synthesized and thoroughly characterized. Interaction studies of 1, 1a, 1b, 2, 2a, 2b, 3, 3a, 3b with calf thymus DNA in Tris buffer were studied by electronic absorption titrations, luminescence titrations, cyclic voltammetry, and circular dichroism. The results reveal that the extent of DNA binding of R‐enantiomer of copper 1a was highest in comparison to rest of the complexes via electrostatic interaction mode. The nuclease activity of 1a, 1b with supercoiled pBR322 DNA was further examined by gel electrophoresis, which reveals that complex 1a exhibits a remarkable DNA cleavage activity (concentration dependent) with pBR322DNA, and the cleavage activity of both enantiomers of complex 1 was significantly enhanced in the presence of activators. The activating efficiency follows the order Asc > H2O2 > MPA for 1a, and reverse order was observed for 1b, because of the differences in enantioselectivity and conformation. Further, it was observed that cleavage reaction involves singlet oxygen species and superoxide radicals via oxidative cleavage mechanism. In addition, complex 1a exhibits significant inhibitory effects on the topoisomerase II (topo II) activity at a very low concentration ∼24 μM, which suggest that complex 1a is indeed catalytic inhibitor or (poison) of human topo II. Chirality 2011 © 2011 Wiley‐Liss, Inc.
Criteria for Assessing Safety Inspections
Authors: Hauptmanns Ulrich
Published: June 2011

Es werden Methoden zur Abschätzung des Gefahrenpotenzials unterschiedlicher technischer Anlagen vorgestellt, die einen Vergleich ohne detaillierte anlagentechnische Untersuchung erlauben. Grundlage sind dabei die in den Anlagen vorhandenen Energieinhalte. Sofern Energien mit unterschiedlichen Wirkmechanismen, z. B. Druckwelle und Wärmestrahlung, zu vergleichen sind, wird die Probit‐Methode herangezogen. Zudem wird die erwartete Eintrittshäufigkeit in das Kalkül einbezogen. Dieser Ansatz wird bereits in einigen Nachbarländern verwendet und in Deutschland in Zukunft an Bedeutung gewinnen. Im Falle von Aufzügen wird das Räuber‐Beute Modell zur Beurteilung der zeitlichen Unfallverläufe herangezogen. Der Einfluss von Fehlern bei Prüfvorgängen und Instandhaltung wird durch Vergleich mit der SIL‐Klassifizierung verdeutlicht.
Die Firma Leopold Cassella & Co.
Authors: Vollmann Hansjörg W.
Published: June 2011

Aus der in der Frankfurter Judengasse entstandenen Handelsfirma Leopold Cassella entstand durch das geschickte Zusammenwirken des Familienverbandes Cassella‐Gans‐Weinberg ein international tätiges Unternehmen für den Vertrieb von Naturfarbstoffen. Nach der Entdeckung der ersten synthetischen Farbstoffe gründeten die Eigentümer 1870 eine Farbenfabrik, die durch Auswertung und Anwendung der Naphthalinchemie bis zur Jahrhundertwende 1900 zur größten und profitabelsten Azofarbenfabrik der Welt aufstieg. Nach dem Zusammenschluss der deutschen Chemieindustrie zur IG‐Farbenindustrie AG 1925 wurde die Leopold Cassella & Co. GmbH bis zur Arisierung durch die Nationalsozialisten – unter denen die jüdischen Eigentümerfamilien erheblich zu leiden hatten – 1938 als rechtlich selbständiges Unternehmen in diesem Verbund geführt. Aus der Zerschlagung der IG‐Farbenindustrie nach dem Zweiten Weltkrieg ging Cassella als eigenständige Aktiengesellschaft hervor, die 1970 mehrheitlich von der Hoechst AG übernommen und 1995 – kurz vor der Auflösung der Mutterfirma – eingegliedert wurde. Nach einem kurzen Zwischenspiel als Mitglied der schweizer Firma Clariant wird das Unternehmen von Privatinvestoren als AllessaChemie GmbH weitergeführt und feiert am 1. Juli 2011 sein 10jähriges Bestehen.
Impact of race on biochemical disease recurrence after prostate brachytherapy
Authors: Yamoah Kosj , Stone Nelson , Stock Richard
Published: June 2011

BACKGROUND:

Understanding racial differences in disease presentation and response to therapy is necessary for the effective treatment and control of prostate cancer. In this study, the authors examined the influence of race on biochemical disease‐free survival (BDFS) among men who received prostate brachytherapy.

METHODS:

In total, 2301 men were identified who had a minimum follow‐up of 24 months and had received low‐dose‐rate brachytherapy for prostate cancer at the Mount Sinai Medical Center from June 1990 to October 2008. Patient factors, with specific emphasis on patient race, were analyzed with respect to freedom from biochemical failure (FFbF). Kaplan‐Meier analyses, life‐tables, and log‐rank tests were used to identify variables that were predictive of 10‐year FFbF.

RESULTS:

In this series, a total of 2268 patients included 81% Caucasians, 12% African Americans, 6% Hispanics, and 1% Asians. The 10‐year actuarial FFbF rate was 70% for AA men and 84% for all others (P = .002). Between Caucasian men and AA men, the 10‐year FFbF rate was 83% versus 70%, respectively (P = .001).There was no significant difference in 10‐year FFbF between Caucasian men and Hispanic men (83% vs 86%, respectively; P = .6). The 10‐year FFbF rate for Hispanic men and AA men was 86% versus 70%, respectively (P = .062). A greater percentage of AA men presented with higher prostate‐specific antigen levels (PSA) (>10 ng/mL; 44% vs 21%; P < .001) and, thus, with higher risk disease (24% vs 15%; P < .001) compared with Caucasian men. Among the men with low‐risk disease, the 10‐year FFbF rate was 90% for Caucasian men and 76% for AA men (P = .041). The 10‐year BDFS rate for patients who received brachytherapy alone was 86% for Caucasian men and 61% for AA men (P = .001); however, this difference was not observed when brachytherapy was combined with androgen‐deprivation therapy(ADT) with or without supplemental external‐beam radiotherapy (EBRT). Multivariate analysis revealed that PSA (P = .024), Gleason score (P < .001), the biologic effective dose (P < .001), EBRT (P = .002), ADT (P = .03), and AA race (P = .037) were significant predictors of 10‐year FFbF. No significant differences was observed in overall survival, cause‐specific survival, or distant metastasis‐free survival between racial groups.

CONCLUSIONS:

AA race appeared to be an independent negative predictor of BDFS after prostate brachytherapy, and this result may highlight the need for more aggressive therapy in this patient population. Cancer 2011;. © 2011 American Cancer Society.
Do radiation use disparities influence survival in patients with advanced breast cancer?
Authors: Martinez Steve R. , Tseng Warren H. , Canter Robert J. , Chen Allen M. , Chen Steven L. , Bold Richard J.
Published: June 2011

BACKGROUND:

The authors previously identified racial/ethnic disparities in the use of radiation therapy (RT) in patients with advanced breast cancer (BC). They hypothesized that disparities in the use of RT were associated with survival differences favoring white patients.

METHODS:

The authors used the Surveillance, Epidemiology, and End Results database to identify white, black, Hispanic, and Asian patients with BC associated with ≥10 metastatic lymph nodes diagnosed between 1988 and 2005. Multivariate analyses of overall survival (OS) and disease‐specific survival (DSS) assessed age, sex, race, tumor size, histology, estrogen receptor status, progesterone receptor status, RT, and type of surgery. The authors further stratified for use of RT and type of surgery. Risk of mortality was reported as hazard ratios (HRs) with 95% confidence intervals (CIs).

RESULTS:

Of 15,895 patients with advanced BC, 12,653 met entry criteria. On multivariate analysis, RT was associated with a decreased risk of all‐cause (HR, 0.78; 95% CI 0.74‐0.83; P < .001) and disease‐specific (HR, 0.81; 95% CI, 0.76‐0.86; P < .001) mortality; black race was associated with an increased risk of all‐cause (HR, 1.54; 95% CI, 1.42‐1.68; P < .001) and disease‐specific (HR, 1.53; 95% CI, 1.39‐1.68; P < .001) mortality. After stratifying by type of surgery and use of RT, blacks demonstrated poorer survival than their white counterparts, regardless of surgery type or receipt of RT.

CONCLUSIONS:

Only black patients had poorer OS and DSS relative to whites. When stratified by type of surgery and use of RT, blacks continued to demonstrate poorer survival. This survival disparity is unlikely to be because of lack of RT. Cancer 2012;. © 2011 American Cancer Society.
Human papillomavirus vaccine uptake among 9‐ to 17‐year‐old girls
Authors: Wong Charlene A. , Berkowitz Zahava , Dorell Christina G. , Anhang Price Rebecca , Lee Jennifer , Saraiya Mona
Published: June 2011

BACKGROUND:

Since 2006, the human papillomavirus (HPV) vaccine has been routinely recommended for preadolescent and adolescent girls in the United States. Depending on uptake patterns, HPV vaccine could reduce existing disparities in cervical cancer.

METHODS:

HPV vaccination status and reasons for not vaccinating were assessed using data from the 2008 National Health Interview Survey. Households with a girl aged 9‐17 years were included (N = 2205). Sociodemographic factors and health behaviors associated with vaccine uptake were assessed using multivariate logistic regression.

RESULTS:

Overall, 2.8% of 9‐ to 10‐year‐olds, 14.7% of 11‐ to 12‐year‐olds, and 25.4% of 13‐ to 17‐year‐olds received at least 1 dose of HPV vaccine; 5.5% of 11‐ to 12‐year‐olds and 10.7% of 13‐ to 17‐year‐olds received all 3 doses. Factors associated with higher uptake in multivariate analysis included less than high school parental education, well‐child check and influenza shot in the past year, and parental familiarity with HPV vaccine. Parents' primary reasons for not vaccinating were beliefs that their daughters did not need vaccination, that their daughters were not sexually active, or had insufficient vaccine knowledge. More parents with private insurance (58.0%) than public (39.8%) or no insurance (39.5%) would pay $360‐$500 to vaccinate their daughters.

CONCLUSIONS:

Less than one quarter of girls aged 9‐17 years had initiated HPV vaccination by the end of 2008. Efforts to increase HPV uptake should focus on girls in the target age group, encourage providers to educate parents, and promote access to reduced‐cost vaccines. Cancer 2011;. © 2011 American Cancer Society.
Pseudo‐time‐coupled nonlinear models for biomolecular surface representation and solvation analysis
Authors: Zhao Shan
Published: June 2011

This paper presents an improved mathematical model for biomolecular surface representation and solvation analysis. Based on the Eulerian formulation, the polar and nonpolar contributions to the solvation process can be equally accounted for via a unified free energy functional. Using the variational analysis, two nonlinear partial differential equations, that is, one Poisson–Boltzmann (PB) type equation for electrostatic potential and one geometric flow type equation defining the solute–solvent interface, can be derived. To achieve a more efficient and stable coupling, we propose a time‐dependent PB equation by introducing a pseudo‐time. The system of nonlinear partial differential equations can then be coupled via the standard time integration. Furthermore, the numerical treatment of nonlinear terms becomes easier in the present model. Based on a hypersurface function, the biomolecular surface is represented as a smooth interface. However, for the nonlinear PB equation, such a smooth interface may cause unphysical blowup because of the existence of nonvanishing values within the solute domain. A filtering process is proposed to circumvent this problem. Example solvation analysis of various compounds and proteins was carried out to validate the proposed model. The contributions of electrostatic interactions to the protein–protein binding affinity are studied for selected protein complexes. Copyright © 2011 John Wiley & Sons, Ltd.
In Situ X‐Ray Spectromicroscopy Investigation of the Material Stability of SOFC Metal Interconnects in Operating Electrochemical Cells
Authors: Bozzini Benedetto , Tondo Elisabetta , Prasciolu Mauro , Amati Matteo , Abyaneh Majid Kazemian , Gregoratti Luca , Kiskinova Maya
Published: June 2011

The present in situ study of electrochemically induced processes occurring in Cr/Ni bilayers in contact with a YSZ electrolyte aims at a molecular‐level understanding of the fundamental aspects related to the durability of metallic interconnects in solid oxide fuel cells (SOFCs). The results demonstrate the potential of scanning photoelectron microspectroscopy and imaging to follow in situ the evolution of the chemical states and lateral distributions of the constituent elements (Ni, Cr, Zr, and Y) as a function of applied cathodic potential in a cell working at 650 °C in 10−6 mbar O2 ambient conditions. The most interesting findings are the temperature‐induced and potential‐dependent diffusion of Ni and Cr, and the oxidation–reduction processes resulting in specific morphology–composition changes in the Ni, Cr, and YSZ areas.
Forward light scatter is a simple measure of T‐cell activation and proliferation but is not universally suited for doublet discrimination
Authors: Böhmer Ralph M. , Bandala‐Sanchez Esther , Harrison Leonard C.
Published: June 2011

Following activation by antigen, T cells enter the cell cycle in stages that can be defined with flow cytometric markers. We show that these markers include the increase of forward light scatter width (FSC‐W) signal and the ratio of FSC area/peak. This change in light scatter precedes the first cell division and may reflect blast transformation. We show that the FSC‐W parameter can be used, alone or in combination with other activation markers, to monitor the relative and absolute numbers of T cells responding to a proliferative stimulus. In contrast to dye dilution assays, the FSC‐W method does not allow discrimination between consecutive cell divisions, but it has several advantages and could complement the dye dilution assay. Our findings also show that the routine elimination of doublets based on FSC signals may exclude proliferating T cells from the analysis. © 2011 International Society for Advancement of Cytometry
International Neuropathy Workshop of 2009: Introduction to the final reports
Authors: Boulton Andrew J. M. , Valensi Paul , Tesfaye Solomon
Published: June 2011

Neuropathies are amongst the most common of the long‐term complications of diabetes, affecting up to 50% of patients. Their clinical features vary immensely and patients may present with a wide spectrum of specialties, from neurology to urology, for example, or from cardiology to podiatry. Neuropathies are typically characterized by a progressive loss of nerve fibres which may affect both of the principal divisions of the peripheral nervous system. The epidemiology and natural history of the diabetic neuropathies remain poorly defined.

The International Consensus Workshop in Toronto in 2009 arose from the fact that at the moment there are no clear, universally accepted guidelines regarding the definition of diabetic neuropathies. This has resulted in a massive variation in how neuropathy is diagnosed in different centres and countries. A preliminary summary report of the Toronto meeting was published in 2010. The series of papers published in this issue of Diabetes/Metabolism Research and Reviews are the detailed reports that came from each sub‐group of this Consensus panel. These reviews cover the problems with definitions and classification of neuropathy, the management of painful neuropathy and then the sub‐group of small fibre neuropathies. There are also 3 papers on the autonomic neuropathies, covering cardiovascular autonomic neuropathies, as well as other areas of the autonomic neuropathies including gastrointestinal, urogenital and pseudomotor neuropathies. This series of papers will give the reader detailed information on the diverse aspects of diabetic neuropathies, their measurement and management, and will also assist in the selection of appropriate measures of both autonomic and somatic nerve function in clinical trials. This is clearly work in progress as diagnostic criteria for diabetic neuropathies are likely to evolve with developments in the field. Copyright © 2011 John Wiley & Sons, Ltd.
Propellers and Planes: Phosphorescent PtII σ‐Acetylides from Polyaromatic Ligands
Authors: Nolan Deanne , Gil Belén , Murphy Frances A. , Draper Sylvia M.
Published: June 2011

This article details the preparation, photophysical and electrochemical investigation of four novel polyaromatic square‐planar platinum(II) bis(acetylide) complexes, incorporating either a planar hexa‐peri‐hexabenzocoronene (L2) or its uncyclised ethynyl‐hexaphenylbenzene precursor (L1). Complexes in both cis and trans geometries (cis‐[Pt(L)2(dppe)] [C1, C2; dppe = 1,2‐bis(diphenylphosphanyl)ethane] and trans‐[Pt(L)2(PPh3)2] (T1, T2) were successfully prepared and fully characterised. The low‐energy bands of the UV/Vis absorption spectra for the uncyclised family (L1, C1, T1) and for the cyclised family (L2, C2, T2) exhibit a redshift in the order trans > cis > ligand, indicating enhanced π‐conjugation along the molecular axis in trans configuration. Each PtII complex is dual luminescent and possesses a high‐energy ligand‐centred fluorescence and a lower energy emission with significant phosphorescent character facilitated by the high spin‐orbit coupling of the heavy platinum metal centre. Notably, cis‐ and trans‐L2 complexes exhibit remarkably long lifetimes in degassed CH2Cl2 at room temperature (trans: 30.9 μs; cis: 18.3 μs) for sharp phosphorescence at λ = 578 nm.
2‐ and 3‐Monohalogenated BODIPY Dyes and Their Functionalized Analogues: Synthesis and Spectroscopy
Authors: Leen Volker , Leemans Tom , Boens Noël , Dehaen Wim
Published: June 2011

Starting from appropriately halogenated acylpyrroles, a wide range of reactive 4,4‐difluoro‐4‐bora‐3a,4a‐diaza‐s‐indacene (BODIPY) derivatives can be obtained. The fluorescent dyes display excellent reactivity in nucleophilic aromatic substitution, transition‐metal‐catalyzed cross‐coupling and copper‐catalyzed cycloaddition to azides (click chemistry). The spectral properties of the starting and final difluoroboron dipyrromethenes are discussed as a function of their structure.
Catalytic Enantioselective Oxidation of Bulky Alkyl Aryl Thioethers with H2O2 over Titanium–Salan Catalysts
Authors: Bryliakov Konstantin P. , Talsi Evgenii P.
Published: June 2011

A simple and efficient catalytic procedure for the oxidation of bulky (preferably aryl benzyl substituted) thioethers with hydrogen peroxide in good to high yields and enantioselectivities (up to 98.5 % ee) is reported. The high optical yields are achieved in a tandem stereoconvergent enantioselective oxidation and kinetic resolution process. A reasonable balance between the sulfoxide yield and enantioselectivity could be found by varying the concentration and temperature. An improved synthesis of the titanium–salan catalysts for the preparation of a more stereoselective catalyst is reported.
Synthesis and Antibody Binding of Highly Fluorinated Amphiphilic MUC1 Glycopeptide Antigens
Authors: Platen Tobias , Schüler Timo , Tremel Wolfgang , Hoffmann‐Röder Anja
Published: June 2011

The analysis of humoral immune responses is of great importance for basic and clinical research. Mapping the structural requirements of epitope recognition with modified tumor‐associated carbohydrate antigens allows both the development of biomarkers and the design of synthetic anticancer vaccines. For this purpose, double‐tailed hydrocarbon/fluorocarbon membrane anchors have been prepared and conjugated to a TN dipeptide. Furthermore, a novel hydrophobized MUC1 tandem repeat glycopeptide antigen was fully assembled on a solid support and its specific binding to different mouse anti‐MUC1 antibodies was demonstrated through ELISA, QCM, and SPR measurements. Such functional fluorous MUC1 antigens are of great interest for specific glycan (micro‐)array formats and allow a detailed analyses of serum antibodies obtained from immunization studies. In addition, the intriguing characteristics of fluorous surfactants, for example, their strong self‐association tendency, might stimulate the use of novel fluorous‐tagged antigen conjugates in the development of multivalent micellar glycopeptide vaccines.
Calcium‐Selective Electrodes for Measurements in the Presence of Anionic Surfactants
Authors: Ivanova Natalia M. , Bart Tatiana Ya. , Grekovich Alexander L. , Mikhelson Konstantin N.
Published: June 2011

Calcium selective electrodes with various membrane formulations were studied in solutions containing CaCl2 and sodium dodecylsulfate (NaDS). It is shown that electrodes based on neutral ionophores ETH 1001 and ETH 129 cannot be used as Ca2+ ion sensors in these solutions because of strong anion interference from DS− anion. Among other formulations, that based on calcium bis(tetramethylbutylphenyl)phosphate in tri(2‐ethylhexyl)phosphate appear the most promising. The interpretation of the ISE response in solutions under study relied on a novel approach which considers three forms of calcium: Ca2+ free ions, Ca in Ca(DS)2 precipitate, and Ca2+ bound by the DS− micelles. Data needed for the respective calculations were obtained by DS− selective electrode based on tetradecylammonium, and Na+ selective glass electrode.
Immunosensing Microchip Using Fast and Selective Preparation of an Iridium Oxide Nanoparticle‐Based Pseudoreference Electrode
Authors: Aziz Md. Abdul , Kim Byung‐Kwon , Kim Minjung , Yang Sang‐Youn , Lee Hyun‐Woo , Han Sang Woo , Kim Yeong Il , Jon Sangyong , Yang Haesik
Published: June 2011

Iridium oxide (IrOx) electrodes have been used as pseudoreference electrodes operating in buffered solutions, but their preparation requires a time‐consuming procedure. Here we report a simple, fast, and selective preparation of an IrOx pseudoreference electrode based on the deposition of presynthesized IrOx nanoparticles. The reference electrode is applied to an immunosensing microchip consisting of a patterned poly(dimethylsiloxane) plate and an indium–tin oxide‐micropatterned glass. The sequence of microfabrication is optimized to accomplish better performance. The microchip is operated by capillary‐driven microfluidic controls and used for detecting a target mouse IgG. The measured detection limit in the microchip is ca. 10 pg/mL.
CE‐electrochemiluminescence with ionic liquid for the facile separation and determination of diester‐diterpenoid aconitum alkaloids in traditional Chinese herbal medicine
Authors: Bao Yi , Yang Fan , Yang Xiurong
Published: June 2011

A CE‐electrochemiluminescence(CE‐ECL) detection system, CE/tris(2,2′‐bipyridyl) ruthenium(II)ECL with ionic liquid, was established for the determination of diester‐diterpenoid aconitum alkaloids (aconitine (AC), mesaconitine (MA) and hypaconitine (HA)) in traditional Chinese herbal medicine. Running buffer containing 25 mM borax‐20 mM 1‐ethyl‐3‐methylimidazolium tetrafluoroborate at pH 9.15 was used, which resulted in significant changes in separation and obvious enhancement in ECL intensity for AC, MA and HA with similar structures. End‐column detection was achieved in 50 mM phosphate buffer with 5 mM ${\rm{Ru}}({\rm{bpy}})_3^{2 + }$ (pH 9.15) at applied detection voltage of 1.20 V when the distance between the Pt working electrode and outlet of capillary (50 cm×25 μm id) was set at 150 μm. One single quantitative analysis of three alkaloids was achieved at a separation voltage of 15 kV within 10 min. Moreover, two extraction processes (ethanol extraction and ethyl ether extraction after basification) were investigated. The result showed that ethanol extraction process has higher extraction efficiency than ethyl ether extraction process. Under the optimized conditions, the detection limits of AC, MA and HA were 5.62×10−8, 2.78×10−8 and 3.50×10−9 mol/L (S/N=3), respectively. The method was successfully applied to determine the amounts of AC, MA and HA in the aconitum herbal samples.
Moment approach to the polydispersed particle size distribution of dust‐loaded fibers due to convective diffusion
Authors: Jung Chang H. , Park Hyun Seol , Kim Yong P.
Published: June 2011

In this study, convective diffusional collection efficiency of polydispersed particles on a dust‐loaded fiber filter is estimated. The change in the polydispersed particle size distribution on dust‐loaded fibers due to convective diffusion was studied. A log‐normal size distribution was assumed and the moment approach was applied. Consequently, the effect of dust loading on polydispersed particle size distribution could be obtained.

In the convective diffusional region, the geometric mean diameter increases and the geometric standard deviation decreases as filtration times goes. The collection efficiency increases further for a large polydispersed interception parameter for clean filters and this tendency is enhanced when dust loading is present. The geometric mean diameter increases further for a large polydispersed interception parameter. This study presents simplified methods for examining filter performance under dust‐loaded conditions. The obtained results enhance our understanding of the change in the collection efficiency of polydispersed particle when particles are deposited on a fiber. © 2011 American Institute of Chemical Engineers Environ Prog, 2011
Sorption of acetochlor, S-metolachlor, and atrazine in surface and subsurface soil horizons of Argentina
Authors: Bedmar Francisco , Daniel Peter E , Costa José L , Giménez Daniel
Published: June 2011

Understanding herbicide sorption within soil profiles is the first step to predicting their behavior and leaching potential. Laboratory studies were conducted to determine the influence of surface and subsurface soil properties on acetochlor, atrazine, and S-metolachlor sorption. Soil samples were taken from horizons A, B, and C of two loamy soils of the humid pampas of Argentina under no-till management; horizon A was divided into two layers, A0 (0–5 cm) and A1 (5 cm to the full thickness of an A horizon). Sorption isotherms were determined from each sampled horizon using the batch equilibrium method and seven concentrations (0, 0.1, 0.5, 2.0, 5.0, 10.0, and 20.0 mg L−1). Sorption affinity of herbicides was approximated by the Freundlich equation. The sorption strength Kf (mg1 − 1/n kg−1 L1/n) over the soils and horizons studied followed the order S-metolachlor (16.51–29.19) > atrazine (4.85–12.34) ≥ acetochlor (5.17–11.97), which was closely related to the hydrophobicity of herbicides expressed as octanol–water partition coefficient (KOW). The Kf values of the three herbicides were positively correlated with soil organic carbon, with a significance of p < 0.01. Values of Kf for the three herbicides decreased with depth in the two soils, indicating greater sorption onto surficial soil horizons and possibly a delayed transport toward subsurface soils and subsequent pollution of groundwater. Environ. Toxicol. Chem. 2011;30:1990–1996. © 2011 SETAC
Common problems in delay‐based congestion control algorithms: a gallery of solutions
Authors: Rodríguez‐Pérez M. , Herrería‐Alonso S. , Fernández‐Veiga M. , López‐García C.
Published: June 2011

Although delay‐based congestion control protocols such as FAST Transmission Control Protocol (TCP) promise to deliver better performance than traditional TCP Reno, they have not yet been widely incorporated to the Internet. Several factors have contributed to their lack of deployment. Probably, the main contributing factor is that they are not able to compete fairly against loss‐based congestion control protocols. In fact, the transmission rate in equilibrium of delay‐based approaches is always less than their fair share when they share the network with traditional TCP Reno derivatives that employ packet losses as their congestion signal. There are also other performance impairments caused by the sensitivity to errors in the measurement of the congestion signal (queuing delay) that reduce the efficiency and the intra‐protocol fairness of the algorithms. In this paper, we report, analyse and discuss some recent proposals in the literature to improve the dynamic behaviour of delay‐based congestion control algorithms, FAST in particular. The coexistence of sources reacting differently to congestion, the identification of congestion appearance in the reverse path and the persistent congestion problem are the issues specifically addressed. Copyright © 2011 John Wiley & Sons, Ltd.
NI/NI‐YSZ Current Collector/Anode Dual Layer Hollow Fibers for Micro‐Tubular Solid Oxide Fuel Cells
Authors: Kanawka K. , Othman M. H. D. , Droushiotis N. , Wu Z. , Kelsall G. , Li K.
Published: June 2011

A co‐extrusion technique was employed to fabricate a novel dual layer NiO/NiO‐YSZ hollow fiber (HF) precursor which was then co‐sintered at 1,400 °C and reduced at 700 °C to form, respectively, a meshed porous inner Ni current collector and outer Ni‐YSZ anode layers for SOFC applications. The inner thin and highly porous “mesh‐like” pure Ni layer of approximately 50 μm in thickness functions as a current collector in micro‐tubular solid oxide fuel cell (SOFC), aiming at highly efficient current collection with low fuel diffusion resistance, while the thicker outer Ni‐YSZ layer of 260 μm acts as an anode, providing also major mechanical strength to the dual‐layer HF. Achieved morphology consisted of short finger‐like voids originating from the inner lumen of the HF, and a sponge‐like structure filling most of the Ni‐YSZ anode layer, which is considered to be suitable macrostructure for anode SOFC system. The electrical conductivity of the meshed porous inner Ni layer is measured to be 77.5 × 105 S m–1. This result is significantly higher than previous reported results on single layer Ni‐YSZ HFs, which performs not only as a catalyst for the oxidation reaction, but also as a current collector. These results highlight the advantages of this novel dual‐layer HF design as a new and highly efficient way of collecting current from the lumen of micro‐tubular SOFC.
Humidity Related Low Temperature Conductivity Hysteresis of Ce1–xZrxO2 (0 ≤ x ≤ 1) Ceramics. Structural Disorder Relationship
Authors: Jimenez R. , Bucheli W. , Varez A. , Sanz J.
Published: June 2011

Ion‐electron mixed conductivity of the Ce1–xZrxO2 (0 < x < 1) series, prepared by solid‐state reaction, has been measured as a function of temperature, pO2 and pH2O relative pressures. The structural analysis of this series shows the formation of monoclinic, tetragonal, and cubic phases as the Ce content increases. The temperature used in samples preparation, 1,923 K, favors at intermediate compositions the homogeneous Ce and Zr mixing in the metastable tetragonal t′ phase. The variation of conductivity with the relative oxygen pressure indicates that electronic contribution increases, becoming preponderant, as the Ce‐content increases. The modifications in conductivity observed in Ce‐rich samples have been ascribed to the enhancement of the electronic contribution at the grain‐boundary of ceramics. The differences observed at low temperatures in electronic dc‐conductivity of Ce‐rich samples during heating and cooling treatments, have been ascribed to the incorporation of water as hydroxide defects at the grain boundary and interior of the particles. The surface hydroxylation is maximal in samples with improved OSC capacity, decreasing drastically in samples heated at 740 K. Finally, the potential application of prepared materials in intermediate temperature solid oxide fuel cells (SOFC) is discussed.
The impact of a pro‐rata algorithm on liquidity: Evidence from the NYSE LIFFE
Authors: Lepone Andrew , Yang Jin Young
Published: June 2011

This study investigates the impact of introducing a pure pro‐rata algorithm on the liquidity of the market for Euribor futures contracts on NYSE LIFFE. Results indicate that the Euribor market experiences deterioration in liquidity: (1) both best and total depth fall and (2) quoted spreads widen after the structural change. Results also reveal that the Euribor market becomes more active after the event; both trading volume and trade frequency increase substantially after the event. Finally, after the transition, liquidity demanders are more likely to submit smaller market orders. The reduction in depth and increase in quoted spreads suggest that liquidity demanders incur higher trade execution costs after the transition. In contrast, the transition is beneficial for the exchange since trading volume is higher under the new regime. © 2011 Wiley Periodicals, Inc. Jrl Fut Mark 32:660–682, 2012
New design of a VirtualGlove for grasping applications
Authors: Wang Hyuk , Jeon Moongu , Lee Yong‐Gu
Published: June 2011

Virtual gloves have received much attention in the field of virtual reality and computer simulations. They are considered to be essential tools for implementing any sort of hand‐based experiences in virtual environments. For applications with simpler motions, the accuracy of finger‐bending amount returned by these virtual gloves is not of primary interest. For grasping applications, however, inaccuracy in the bending amount results in unrealistic scenarios having discrepancies in the contact geometry for the hand and the object. In this study, we improve the measurements of bending amount by placing the bend sensors on the palm of the hand, where the objects are touched directly. Supporting evaluative data and design details are also discussed. © 2010 Wiley Periodicals, Inc.
Increasing short‐term output in assembly work
Authors: Looze Michiel P. de , Bosch T. , van Rhijn J. W.
Published: June 2011

Maximization of flexibility is one of the major challenges in assembly line design. This article addresses the question of how to temporarily (in times of peak demand) increase the output of a line, which is already optimized to attain the “normal” output rate. Instead of a costly reconfiguration of the line creating extra workstations for more operators, we applied an approach of keeping the line intact, adding two extra operators, and applying a scheme wherein the operators took their breaks alternately. For two different alternating break schemes, we compared the productivity rates, the physical load on operators, and the operators' experiences to those of the traditional situation. The new approach resulted in an increase in line output of 12–16%, depending on which alternating break scheme was applied. On the operator level, we observed no differences in productivity among conditions, despite the differences in total pause time per operator. Simultaneously, physical loads on the neck and shoulders, expressed by level of discomfort, were found to be significantly lower in one of the new alternating break schemes. A majority of the operators rated this alternating break scheme as “pleasant” (90%), but wanted the scheme to be applied only during the periods of peak demand because of social aspects (80%). In conclusion, an increase in volume flexibility can be achieved by adding two extra workers and applying an alternating work/rest scheme without a costly reconfiguration of the line. © 2010 Wiley Periodicals, Inc.
Using college students' self‐reported learning outcomes in scholarly research
Authors: Pike Gary R.
Published: June 2011

Construct validity provides a framework for evaluating the adequacy and appropriateness of using students' self‐reports of learning outcomes in scholarly research. Evidence from a recent study concerning the relationships between academic environments and self‐reported learning outcomes, based on Holland's person‐environment fit theory, provides evidence of the appropriateness of using these self‐report data in scholarly research.
The validity of student engagement survey questions: Can we accurately measure academic challenge?
Authors: Porter Stephen R. , Rumann Corey , Pontius Jason
Published: June 2011

This chapter examines the validity of several questions about academic challenge taken from the National Survey of Student Engagement. We compare student self‐reports about the number of books assigned to the same number derived from course syllabi, finding little relationship between the two measures.
Reconciling (seemingly) discrepant findings: Implications for practice and future research
Authors: Bowman Nicholas A. , Herzog Serge
Published: June 2011

This concluding chapter synthesizes the empirical chapters and suggests implications for practice and future research.
The Golden Gate Leech Helobdella californica (Hirudinea: Glossiphoniidae): Occurrence and DNA‐Based Taxonomy of a Species Restricted to San Francisco
Authors: Kutschera U.
Published: June 2011

Leeches of the genus Helobdella are small brooding annelids that inhabit lakes and streams on every continent, notably in South America. The type species, H. stagnalis L. 1758, occurs in Europe and North America. Here I provide novel observations on the occurrence, morphology, and parental care patterns of the related H. californica, a taxon described in 1988, based on specimens collected in Stow Lake, Golden Gate Park, San Francisco. In 2007, the original H. californica population no longer existed, possibly due to eutrophication of this popular “duck pond”. However, in other, cleaner lakes of the Golden Gate Park dense, stable populations of H. californica were discovered. Between 2007 and 2010 adult individuals were investigated in the laboratory with respect to their pigment patterns and feeding behaviour. The leeches suck the red, haemoglobin‐rich haemolymph from insect larvae (Chironomus sp.) and other small aquatic invertebrates and feed their young attached to their ventral surface. A typical feeding episode is described and documented. In addition, a neighbour‐joining analysis was performed based on a newly acquired DNA sequence of part of the mitochondrial gene cytochrome c oxidase subunit I (CO‐I) for H. californica, combined with other, related leech species. These molecular data corroborate that the “Golden Gate leech” is a separate species and not a colour variant of H. stagnalis. Since, over the past 25 years, H. californica has only been found in the freshwater ecosystems of the Golden Gate Park, it is concluded that this rare leech is a species restricted to San Francisco. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Phosphorus Enrichment Affects Immobilization but not Litter Decomposition or Exoenzymatic Activities in a Pampean Stream
Authors: Ferreiro Nicolás Andrés , Giorgi Adonis , Leggieri Leonardo , Feijoó Claudia , Vilches Carolina
Published: June 2011

The effect of phosphorous enrichment on decomposition rate, exoenzymatic activities (β‐glucosidase, cellobiohydrolase and alkaline phosphatase), and macroinvertebrate abundance in Typha latifolia leaves were assessed in a 2nd order Pampean stream (Central Argentina). Phosphorous was added to a downstream reach while another reach located upstream was kept intact and, once significant differences in phosphorus concentration in water were attained, leaf bags were attached to each reach bottom. T. latifolia leaves lost 77% of their initial weight along 154 days and decomposition rates were not significantly different between reaches. Besides, neither exoenzymatic activities nor macroinvertebrate abundances differed between reaches. However, an increment in leaf phosphorus content, attributed to immobilization by decomposer microorganisms, was detected in the enriched reach. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fungal and Bacterial Colonization of Submerged Leaf Litter in a Mediterranean Stream
Authors: Artigas Joan , Gaudes Ainhoa , Munoz Isabel , Romani Anna M. , Sabater Sergi
Published: June 2011

Microbial colonization dynamics of fungi and bacteria were analyzed in an intermittent Mediterranean forested stream using two different leaf substrata (Platanus acerifolia and Populus nigra). Results showed that fungal and bacterial biomass accumulation was stimulated on both leaves due to a flooding episode that increased dissolved inorganic nitrogen (DIN) and dissolved oxygen (DO) availability in the stream water. Leaf mass loss coincided with the parallel increase in microbial biomass and extracellular enzymatic activities after the flood event. Differences in litter quality favoured bacterial biomass accumulation and β‐glucosidase and cellobiohydrolase enzymatic activities in the soft Populus species. Microbial heterotrophs colonization of submerged leaf litter and organic matter use in Mediterranean‐type streams are modulated by environmental conditions, especially the hydrological variability. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of processing on silk‐based biomaterials: Reproducibility and biocompatibility
Authors: Wray Lindsay S. , Hu Xiao , Gallego Jabier , Georgakoudi Irene , Omenetto Fiorenzo G. , Schmidt Daniel , Kaplan David L.
Published: June 2011

Silk fibroin has been successfully used as a biomaterial for tissue regeneration. To prepare silk fibroin biomaterials for human implantation a series of processing steps are required to purify the protein. Degumming to remove inflammatory sericin is a crucial step related to biocompatibility and variability in the material. Detailed characterization of silk fibroin degumming is reported. The degumming conditions significantly affected cell viability on the silk fibroin material and the ability to form three‐dimensional porous scaffolds from the silk fibroin, but did not affect macrophage activation or β‐sheet content in the materials formed. Methods are also provided to determine the content of residual sericin in silk fibroin solutions and to assess changes in silk fibroin molecular weight. Amino acid composition analysis was used to detect sericin residuals in silk solutions with a detection limit between 1.0 and 10% wt/wt, while fluorescence spectroscopy was used to reproducibly distinguish between silk samples with different molecular weights. Both methods are simple and require minimal sample volume, providing useful quality control tools for silk fibroin preparation processes. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.