bluuebunny/crossref_metadata_2025 huggingface dataset:
Inhibition of angiotensin I‐converting enzyme and lipid peroxidation by fermented rapeseed and flaxseed meal
Authors: Pihlanto Anne , Johansson Tessa , Mäkinen Sari
Published: June 2012

This study investigates the inhibition of angiotensin I‐converting enzyme (ACE) and lipid peroxidation of fermented rapeseed and flaxseed meals. Rapeseed and flaxseed meals were fermented with Lactobacillus helveticus, Lactococcus lactis ssp. lactis, Bacillus subtilis, and Kluyveromyces marxianus monocultures at 37°C or 30°C for 48 h. The ACE‐inhibition potencies increased by 20–37% during fermentation with L. helveticus and B. subtilis, whereas fermentation with other strains did not produce a significant change in ACE inhibition. The lowest IC50 value of 0.36 mg/mL was found with flaxseed fermented by L. helveticus. The same strains were also able to produce compounds that inhibited lipid peroxidation. The results showed that L. helveticus and B. subtilis degraded effectively rapeseed and flaxseed proteins as the amount of low molecular weight compounds increased during fermentation. ACE inhibition was found in low molecular weight (300–500 Da) fractions. In fermented rapeseed, the inhibition of lipid peroxidation was found in 1200–1300 Da fractions and fermented flaxseed showed inhibition in several fractions, first around 1300 Da and at lower molecular weight fractions 300–500 Da. The results demonstrated that fermentation with L. helveticus or B. subtilis produce compounds that may have beneficial effect on cardiovascular health.
Isolation and characterization of a manganese‐oxidizing bacterium from a biofiltration system for the treatment of borehole water in KwaZulu‐Natal (South Africa)
Authors: Beukes Lorika S. , Schmidt Stefan
Published: June 2012

Using minimal salts medium containing vitamins and pyruvate (MSVP) plus added manganese sulfate, a manganese (II) oxidizing bacterial strain was isolated from water samples of a biofiltration system treating borehole water in KwaZulu‐Natal, South Africa. The nonmotile Gram‐negative and oxidase‐negative isolate was subsequently characterized microbiologically. Based on its morphological and physiological characteristics and on the analysis of its 16S rRNA gene sequence, the isolate was assigned to the genus Acinetobacter. Growth of the isolated strain in MSVP with added manganese sulfate gave rise to a drop in pH and a concomitant increase in oxidation–reduction potential, which was absent in controls, thus indicating manganese oxidation. The ability of Acinetobacter sp. strain LB1 to oxidize Mn (II) was further verified using the leucoberbelin blue dye assay as well as by energy dispersive X‐ray analysis of crystals formed in the medium. In addition, a biofilm assay indicated that this isolate can attach to solid surfaces such as a biofilter matrix, thus confirming its potential for biotechnological applications in the area of water purification.
Advanced photobioreactor LED illumination system: Scale‐down approach to study microalgal growth kinetics
Authors: Jacobi Anna , Steinweg Christian , Sastre Rosa Rosello , Posten Clemens
Published: June 2012

A newly designed and constructed LED illumination device for commercial cylindrical bioreactors is presented for application in microalgal cultivations and investigation of growth kinetics. An ideally illuminated volume is achieved by focusing the light toward the center of the reactor and thereby compensating the mutual shading of the cells. The relevant biomass concentration for homogeneous illumination depending on reactor radius was determined by light distribution measurements for Chlamydomonas to 0.2 g/L (equal 0.435 optical density at 750 nm). It is shown that cultivation experiments with the newly designed illumination device operated in batch mode can be successfully applied for determination of growth rates and photo conversion efficiencies. The exact knowledge of physiological reactions of specific strain(s) and the estimation of relevant parameters for scale‐up can be used for construction of economic pilot plant photobioreactors. The determination of light‐dependent kinetics of growth and product formation is the first necessary step to achieve this. A wide variety of different parameters can be examined like the effect of different illumination conditions (light intensity, frequency of day/night cycles, flashing light, light color…) and thereby for each single application specific, relevant, and interesting parameters will be examined.
Predicted toxicity of the biofuel candidate 2,5‐dimethylfuran in environmental and biological systems
Authors: Phuong Jimmy , Kim Simon , Thomas Reuben , Zhang Luoping
Published: June 2012

Although not mutagenic by Ames test, 2,5‐dimethylfuran (DMF), a leading biofuel candidate, was found to induce chromosomal damage in cultured murine cells, suggesting that it may be genotoxic. We sought to prioritize the environmental and biological impacts of using DMF as a combustible biofuel. First, we assessed DMF and its combustion intermediates for potential persistence, bioaccumulation, and aquatic toxicity (PBT) using PBT profiler. Our findings predict DMF to have moderate‐level aquatic toxicity; however, a greater subset of the combustion intermediates is predicted to have moderate‐ and high‐level aquatic toxicity with bioaccumulation and persistence concerns. Second, we assessed the biological impact of DMF by testing for statistically significant chemical–disease associations. No direct associations for DMF were found; however, indirect associations were identified from two structurally similar analogs. Curated associations between furfuryl alcohol to kidney neoplasm and adenoma, and significant inferred associations between furan to lung neoplasm, drug‐induced liver injury, and experimentally induced liver cirrhosis were found, based on 21 furan–gene interactions. Nine of 49 DMF combustion intermediates analyzed, including benzene and 1,3‐butadiene, were found to have associations with 26 tumors and systemic diseases. Although inadequate for a stand‐alone risk assessment, our data suggest that DMF combustion intermediates pose a much broader range of hazards than DMF itself, and that both should be further investigated. Environ. Mol. Mutagen. 2012. © 2012 Wiley Periodicals, Inc.
A Study of Chemical Modifications of a Nafion Membrane by Incorporation of Different Room Temperature Ionic Liquids
Authors: Martínez de Yuso M. V. , Neves L. A. , Coelhoso I. M. , Crespo J. G. , Benavente J. , Rodríguez‐Castellón E.
Published: June 2012

Surface and bulk chemical changes in a Nafion membrane as a result of room temperature ionic liquids (RTILs) incorporation were determined by X‐ray photoelectron spectroscopy (XPS) and elemental analysis, respectively. RTILs with different physicochemical properties were selected. Two imidazolium based RTIL‐cations (1‐octyl‐3‐methylimidazolium and 1‐butyl‐3‐methylimidazolium) were used to detect the effect of cation size on membrane modification, while the effect of the RTIL hydrophilic/hydrophobic character was also considered by choosing different anions. Angle resolved XPS measurements (ARXPS) were carried out varying the angle of analysis between 15° and 75° to get elemental information on the Nafion/RTIL‐modified membranes interactions for a deepness of around 10 nm. Moreover, changes in the RTIL‐modified membranes associated to thermal effect were also considered by analyzing the samples after their heating at 120 °C for 24 h. Agreement between both chemical techniques, bulk and destructive elemental analysis and surface and non‐destructive XPS, were obtained.
Ergonomics in Design Processes: The Journey from Ergonomist toward workspace designer
Authors: Seim Rikke , Broberg Ole , Andersen Vibeke
Published: June 2012

The aim of this article is to study the learning processes that take place in an interactive research project, which involved university researchers as well as ergonomic practitioners. The project simultaneously developed and tested a new framework—designated Workspace Design—for intervention in workplace design processes in companies. The basic idea in Workspace Design was that ergonomists should take a new role and apply new participatory methods when involved as consultants. The course of the project was evaluated by the application of social learning theory. The goal was to find out if and why the ergonomic practitioners had learned to practice the new concept by themselves. The results confirm that learning to some extent took place with help from two different mechanisms: learning by interacting and learning by practicing. Three factors are of crucial importance to the successful transfer of a new framework to ergonomic practitioners: 1) the practitioners must take part in developing and testing the framework and the subsequent interpretation of results, 2) they must have the opportunity to practice the framework in the daily consultancy setting and then reflect on their experiences, and 3) their consultancy organization must be committed to adopt the new framework. © 2012 Wiley Periodicals, Inc.
The human side of service engineering
Authors: Freund Louis E. , Spohrer James C.
Published: June 2012

Service engineering is concerned with applying engineering methods to make and scale diverse types of service systems, which range from transportation and finance to health care and government. What makes modern service engineering uniquely challenging is the need not only to consider the technical side of these system designs but also to focus on how these systems engage, relate to, and are perceived to contribute to the self‐actualization goals of their all‐too‐human “cocreators of value.” Service systems must have a wide‐ranging “human side.” In this article, we propose a framework to scope and better define the human side of modern service systems. We then explore how to impact the cocreation of value in modern service systems, characterized by their digital, interconnected, dynamic, and human‐intensive nature. In conclusion, we relate the other articles in this special issue to this modern service system framework, as well as suggesting future research directions. © 2012 Wiley Periodicals, Inc.
The point of transition on the dose‐effect curve as a reference point in the evaluation of in vitro toxicity data
Authors: Sand Salomon , Ringblom Joakim , Håkansson Helen , Öberg Mattias
Published: June 2012

Dose‐effect evaluation is an increasingly important step of health risk assessment. The foreseen increase of in vitro methods argues for the development and evaluation of a clearly defined reference points for dose‐effect modelling of in vitro data. In the present study, the traditional use of a concentration corresponding to 10% or 50% of the maximal effect (EC10 or EC50) is compared with a strategy, under which, a reference point (Benchmark dose, BMDT) is calculated that represents the dose where the slope of the dose‐effect curve changes the most (per unit log‐dose) in the low dose region. To illustrate the importance of the reference point, dose‐effect data on CYP1A1 enzyme activity for 30 polychlorinated biphenyl (PCB) congeners were evaluated in order to calculate relative potencies, in relation to 2,3,7,8‐TCDD, with confidence intervals (CIs). The present study shows that the interpretation of the results as potency and rank orders potentially depends on the choice and definition of the reference point (BMDT, EC10 or EC50). This is important as potency ranking may be used as a method for screening and prioritization, in research, in policy development or in pharmaceutical development. The use of the BMDT implies a focus on the change of structure in the parameter's dose–response rather than a particular percentage change in the response in such a parameter. In conclusion, the BMDT may be used as an alternative base for evaluation of dose‐effect relationships in vitro. It offers an objective geometrical definition of a reference point in the low‐dose region of the dose‐effect curve. Copyright © 2012 John Wiley & Sons, Ltd.
Efficient compression of molecular dynamics trajectory files
Authors: Marais Patrick , Kenwood Julian , Smith Keegan Carruthers , Kuttel Michelle M. , Gain James
Published: June 2012

We investigate whether specific properties of molecular dynamics trajectory files can be exploited to achieve effective file compression. We explore two classes of lossy, quantized compression scheme: “interframe” predictors, which exploit temporal coherence between successive frames in a simulation, and more complex “intraframe” schemes, which compress each frame independently. Our interframe predictors are fast, memory‐efficient and well suited to on‐the‐fly compression of massive simulation data sets, and significantly outperform the benchmark BZip2 application. Our schemes are configurable: atomic positional accuracy can be sacrificed to achieve greater compression. For high fidelity compression, our linear interframe predictor gives the best results at very little computational cost: at moderate levels of approximation (12‐bit quantization, maximum error ≈ 10−2 Å), we can compress a 1–2 fs trajectory file to 5–8% of its original size. For 200 fs time steps—typically used in fine grained water diffusion experiments—we can compress files to ∼25% of their input size, still substantially better than BZip2. While compression performance degrades with high levels of quantization, the simulation error is typically much greater than the associated approximation error in such cases. © 2012 Wiley Periodicals, Inc.
Lithium Storage Behavior of Graphene Nanosheets‐based Materials
Authors: Kuo Shin‐Liang , Liu Wei‐Ren , Wu Hung‐Chun
Published: June 2012

Reduced graphene materials were prepared by different reducing approaches of graphite oxide, including chemical reduction and thermal reduction. In this study, the characteristics of reduced graphene and the lithium storage behavior of graphene‐based anodes were investigated by SEM, BET, TPD, FTIR as well as C/D tests and Raman measurements. The electrochemical behaviors of reduced graphene materials were sensitive to reduction process, of which the capacity varying from 717 to 230 mAh/g. The enhanced capacity should not be predominantly attributed to exceptional high surface area and enlarged d‐spacing, but rather more possible for existence of functional groups along with structure defects.
Cine cerebrospinal fluid imaging in multiple sclerosis
Authors: Magnano Christopher , Schirda Claudiu , Weinstock‐Guttman Bianca , Wack David S. , Lindzen Eric , Hojnacki David , Bergsland Niels , Kennedy Cheryl , Belov Pavel , Dwyer Michael G. , Poloni Guy U. , Beggs Clive B. , Zivadinov Robert
Published: June 2012

Purpose:

To investigate cerebrospinal fluid (CSF) dynamics in the aqueduct of Sylvius in multiple sclerosis (MS) patients and healthy controls (HC) using cine phase contrast imaging.

Materials and Methods:

In all, 67 MS patients (48 relapsing‐remitting [RR] and 19 secondary‐progressive [SP]), nine patients with clinically isolated syndrome (CIS), and 35 age‐ and sex‐matched HC were examined. CSF flow and velocity measures were quantified using a semiautomated method and compared with clinical and magnetic resonance imaging (MRI) disease outcomes.

Results:

Significantly decreased CSF net flow was detected in MS patients compared to HC (−3.7 vs. −7.1 μL/beat,P= 0.005). There was a trend for increased net positive flow between SP, RR, and CIS patients. Altered CSF flow and velocity measures were associated with more severe T1 and T2 lesion volumes, lateral and fourth ventricular volumes, and third ventricular width in MS and CIS patients (P< 0.01 for all). In CIS patients, conversion to clinically definite MS in the following year was related to decreased CSF net flow (P= 0.007). There was a trend between increased annual relapse rate and altered CSF flow/velocity measures in RRMS patients (P< 0.05).

Conclusion:

CSF flow dynamics are altered in MS patients. More severe clinical and MRI outcomes in RRMS and CIS patients relate to altered CSF flow and velocity measures. J. Magn. Reson. Imaging 2012;36:825–834. © 2012 Wiley Periodicals, Inc.
A case of paraspinal arteriovenous fistula in the lumbar spinal body assessed with time resolved three‐dimensional phase contrast MRI
Authors: Iwakura Takashi , Takehara Yasuo , Yamashita Shuhei , Nasu Hatsuko , Unno Naoki , Nishiyama Motohiro , Yamamoto Naoto , Isoda Haruo , Alley Marcus , Konno Hiroyuki , Sakahara Harumi
Published: June 2012

A 93‐year‐old female with a paraspinal arteriovenous fistula (AVF) occurred within the lumbar spinal vertebral body was assessed with time resolved three‐dimensional (3D) phase‐contrast MRI (4D‐Flow) on 1.5 Tesla MR scanner (GE Healthcare). The 3D vector field, streamlines, and pathlines analyses demonstrated uni‐directional flow from the aorta to the large vascular cavity in the lumbar vertebral body by means of the lumbar artery as well as dilated paravertebral veins as drainers, which confirmed AVF, not aortic pseudoaneurysm. The 4D‐Flow also showed an added value in planned endovascular surgery concerning localization of the precise shunting point and the shunting volume quantification. J. Magn. Reson. Imaging 2012;36:1231–1233. © 2012 Wiley Periodicals, Inc.
Using a 2D multibreath‐hold susceptibility‐weighted imaging to visualize intratumoral hemorrhage of hepatocellular carcinoma at 3T MRI: Correlation with pathology
Authors: Li Ruo‐kun , Zeng Meng‐su , Rao Sheng‐xiang , Qiang Jin‐wei , Dai Yong‐ming , Ji Yuan , Chen Cai‐zhong , Renate Jerecic
Published: June 2012

Purpose:

To assess the value of 2D multibreath‐hold susceptibility‐weighted imaging (SWI) for visualizing intratumoral hemorrhage of hepatocellular carcinoma (HCC) and correlate with pathological results.

Materials and Methods:

Fifty‐eight patients with 65 HCCs underwent T1‐, T2‐, T2*‐weighted imaging and SWI. The ability to detect intratumoral hemorrhage for each imaging technique was evaluated. A radiologic‐pathological correlation was performed.

Results:

The area under the receiver operator characteristic (ROC) curve (Az value) for SWI (Az = 0.941) was significantly greater than that for T1WI (Az = 0.748) and T2WI (Az = 0.700) (P = 0.000). When compared with T2*, SWI had slightly higher sensitivity and equal specificity, but the Az value was not significantly different (P = 0.768). The total number of hemorrhages detected by SWI was greatest by factors of 13.3, 6.7, and 2.2 compared to T1WI, T2WI, and T2*, respectively. SWI detected more microbleeds (585 in 25 HCCs) than T1WI (13 in 5 HCCs), T2WI (66 in 11 HCCs), and T2* (238 in 21 HCCs).

Conclusion:

SWI can accurately visualize internal hemorrhages and provide valuable information regarding the internal architecture of HCC. J. Magn. Reson. Imaging 2012;36:900–906. © 2012 Wiley Periodicals, Inc.
Proactive socialization behavior in China: The mediating role of perceived insider status and the moderating role of supervisors' traditionality
Authors: Wang Jie , Kim Tae‐Yeol
Published: June 2012

This paper identified the dimensions of proactive socialization behavior among Chinese employees. We examined the mediating effects of perceived insider status on the relationships between proactive socialization behavior and socialization outcomes, and the moderating effect of supervisors' traditionality on the relationship between proactive socialization behavior and perceived insider status. Results from 280 newcomer–supervisor pairs supported the hypotheses that proactive socialization behavior was positively associated with task performance and social integration through perceived insider status. In addition, supervisors' traditionality significantly influenced the indirect relationships that proactive socialization behavior had with task performance and social integration via perceived insider status, such that the relationships became weaker as supervisors' traditionality increased. Copyright © 2013 John Wiley & Sons, Ltd.
Portable Raman study on the conservation state of four CorTen steel‐based sculptures by Eduardo Chillida impacted by urban atmospheres
Authors: Aramendia J. , Gomez‐Nubla L. , Castro K. , Martinez‐Arkarazo I. , Vega D. , Sanz López de Heredia A. , García Ibáñez de Opakua A. , Madariaga J. M.
Published: June 2012

Weathering steel, and particularly CorTen steel, is a very used material for modern artworks exhibited outdoors. One of the characteristic that makes this material so attractive to artists is the property to develop a protective rust layer composed by iron oxides which preserves its metallic core from atmospheric corrosion. This study was conducted to evaluate the conservation state of four CorTen sculptures by Eduardo Chillida, located in different places of Bilbao city (north of Spain) and affected by different factors (environmental among others) by using Raman spectroscopy. Measurements were performed in situ with a handheld Raman spectrometer mounted on a tripod with x–y–z axes motorization at the micron level. The most common oxyhydroxides detected were lepidocrocite (γ‐FeO(OH)), goethite (α‐FeO(OH)), hematite ( ‐Fe2O3) and magnetite (Fe3O4), being goethite the most stable phase. All the iron oxyhydroxides were identified in all of the studied sculptures but their relative amounts were different for each sculpture. The consequences of the marine aerosols exposure in the steel surface were also studied, detecting limonite (FeO(OH)·nH2O) and akaganeite (β‐FeO(OH)). The results confirmed that the evolution of the rust layer present on the analyzed weathering steels is different, depending both on the exposure and the particular type of the steel. Copyright © 2012 John Wiley & Sons, Ltd.
The application of pseudo template molecularly imprinted polymer to the solid‐phase extraction of cyromazine and its metabolic melamine from egg and milk
Authors: Wang Xianhua , Fang Qiuxue , Liu Shipeng , Chen Lei
Published: June 2012

The combination of molecularly imprinted polymer with high performance liquid chromatography has been developed to determine cyromazine and its metabolic melamine in some samples. However, the potential risk of template leakage used in molecularly imprinted polymer is a major disadvantage. To solve this problem, 2‐(4,6‐diamino‐1,3,5‐triazin‐2‐ylamino) ethanethiol disulfide, a molecule that shares the similar imprinting sites with cyromazine and melamine, was selected as pseudo template to prepare molecularly imprinted polymer. Methacrylic acid, ethylene glycol dimethyl acrylate and toluene were selected as functional monomer, crosslinker and porogen, respectively. The molecular recognition property and binding capability of cyromazine and melamine were evaluated by adsorption test and Scatchard analysis. The results showed that the molecularly imprinted polymer based on pseudo template had more excellent affinity and selectivity for cyromazine and melamine. The resulting molecularly imprinted polymer was used as a solid‐phase extraction material to enrich cyromazine and melamine in egg and milk samples for high performance liquid chromatography analysis. The solid‐phase extraction process was carefully optimized. It was found that when different concentration of cyromazine and melamine standards were spiked into samples, satisfactory recovery rate of cyromazine and melamine were obtained as 85.6–98.8% with relative standard deviation <5.5%.
Assessment of β‐lactams retention in hydrophilic interaction chromatography applying Box–Behnken Design
Authors: Jovanović Marko , Rakić Tijana , Jančić‐Stojanović Biljana , Malenović Anđelija , Ivanović Darko , Medenica Mirjana
Published: June 2012

In this paper, the retention prediction models for mixture of β‐lactam antibiotics analyzed by hydrophilic interaction chromatography (HILIC) are presented. The aim of the study was to investigate the retention behavior of some organic acids and amphoteric compounds including cephalosporins (cefotaxime, cefalexin, cefaclor, cefuroxime, and cefuroxime axetil) and penicillins (ampicillin and amoxicillin). Retention of substances with acidic functional group in HILIC is considered to be interesting since the majority of publications in literature are related to basic compounds. In the beginning of the study, classical silica columns were chosen for the retention analysis. Then, preliminary study was done and factors with the most significant influence on the retention factors were selected. These factors with the impact on the retention factors were investigated employing Box–Behnken design as a tool. On the basis of the obtained results the mathematical models were created and tested using ANOVA test and finally verified. This approach enables the presentation of chromatographic retention in many ways (three‐dimensional (3‐D) graphs and simple two‐dimensional graphical presentations). All of these gave the possibility to predict the chromatographic retention under different conditions. Furthermore, regarding the structure of the analyzed compounds, the potential retention mechanisms in HILIC were suggested.
Ultrasound‐assisted emulsification microextraction for the determination of ephedrines in human urine by capillary electrophoresis with direct injection. Comparison with dispersive liquid–liquid microextraction
Authors: Alshana Usama , Göğer Nilgün G. , Ertaş Nusret
Published: June 2012

Ultrasound‐assisted emulsification microextraction and dispersive liquid–liquid microextraction were compared for extraction of ephedrine, norephedrine, and pseudoephedrine from human urine samples prior to their determination by capillary electrophoresis. Formation of a microemulsion of the organic extract with an aqueous solution (at pH 3.2) containing 10% methanol facilitated the direct injection of the final extract into the capillary. Influential parameters affecting extraction efficiency were systematically studied and optimized. In order to enhance the sensitivity further, field‐amplified sample injection was applied. Under optimum extraction and stacking conditions, enrichment factors of up to 140 and 1750 as compared to conventional capillary zone electrophoresis were obtained resulting in limits of detection of 12–33 μg/L and 1.0–2.8 μg/L with dispersive liquid–liquid microextraction and ultrasound‐assisted emulsification microextraction when combined with field‐amplified sample injection. Calibration graphs showed good linearity for urine samples by both methods with coefficients of determination higher than 0.9973 and percent relative standard deviations of the analyses in the range of 3.4–8.2% for (n = 5). The results showed that the use of ultrasound to assist microextraction provided higher extraction efficiencies than disperser solvents, regarding the hydrophilic nature of the investigated analytes.
Uptake of Well‐Defined, Highly Glycosylated, Pentafluorostyrene‐Based Polymers and Nanoparticles by Human Hepatocellular Carcinoma Cells
Authors: Babiuch Krzysztof , Pretzel David , Tolstik Tatiana , Vollrath Antje , Stanca Sarmiza , Foertsch Franziska , Becer C. Remzi , Gottschaldt Michael , Biskup Christoph , Schubert Ulrich S.
Published: June 2012

Chain length, size, composition, surface charge, and other properties of polymeric materials affect their recognition and uptake by cells and must be optimized to deliver polymers selectively to their target. However, it is often not possible to precisely modify selected properties without changing other parameters. To overcome these difficulties, well‐defined poly(pentafluorostyrene)‐based polymers are prepared that can be grafted via thiol/para‐fluorine “click” reaction with 1‐thio‐β‐D‐glucose and 1‐thio‐β‐D‐galactose. Fluorescence microscopy and flow cytometry show that nanoparticles are taken up by HepG2 cells to a higher degree than the respective water‐soluble polymers, and that internalization of both galactosylated homo‐ and nanoprecipitated block copolymers is enhanced.

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Multifunctional Polypeptide–PEO Nanoreactors via the Hydrophobic Switch
Authors: Wu Yuzhou , Wang Tao , Ng David Y. W. , Weil Tanja
Published: June 2012

We prepare various protein‐derived amphiphilic polymers. By modifying the polypeptide backbone with a few (5–8) hydrophilic or lipophilic substituents, we are able to switch the hydrophobicity of the polymer and control the formation of stable nano‐sized micelles. In the hydrophobic interior of these micelles, ethynyl groups are introduced to provide a nanoreactor environment for click reactions with lipophilic cargo molecules, such as 3‐azidocoumarin, a hydrophobic fluorophore, and the anti‐cancer drug doxorubicin. These protein‐derived amphiphilic polymers reported herein offer a promising potential to design a delivery platform for biomedical applications.
A Novel Fibrous Material Created by Self‐Rolling of a Patterned Polymer Thin Film
Authors: Luchnikov V. A. , Saito Y. , Tzanis L.
Published: June 2012

A new kind of a fibrous material is produced by controlled self‐rolling of patterned thin poly(4‐vinyl)pyridine films in acidic water. Self‐rolling is induced by unequal swelling of the top and the bottom layers of the films in the solvent. Rolling starts from parallel scratches in the film and results in twin‐scroll fibers. The fibers are stabilized by staining with CuCl2 salt and freeze‐dried. The output of the fiber material production is of the order of 1 cm3 from approximately 50 cm2 of the patterned polymer film. The approach opens new broad opportunities for creation of smart fibrous materials via loading the fibers with functional micro‐ and nanoparticles.
Thermoresponsive Copolymers of Ethylene Oxide and N,N‐Diethyl Glycidyl Amine: Polyether Polyelectrolytes and PEGylated Gold Nanoparticle Formation
Authors: Reuss Valerie S. , Werre Mathias , Frey Holger
Published: June 2012

The synthesis of diblock as well as gradient copolymers of N,N‐diethyl glycidyl amine (DEGA) with ethylene oxide (EO) via anionic ring‐opening polymerization is presented. The polymers exhibit low polydispersities (≤1.13) and molecular weights in the range of 3300–10 200 g mol−1. In PEG‐co‐PDEGA copolymers, incorporation of 4%–29% DEGA results in tailorable cloud point temperatures in aqueous solution and melting points depending on DEGA content. mPEG‐b‐PDEGA block copolymers can be quaternized to generate cationic double‐hydrophilic polyelectrolyte copolymers with polyether backbone. Furthermore, mPEG‐b‐PDEGA has been used as dual reducing and capping agent for gold nanoparticle synthesis.
Building a legacy of volunteers through servant leadership: A cause‐related sporting event
Authors: Linda Parris Denise , Welty Peachey Jon
Published: June 2012

This study explores the leadership style of the founder of a cause‐related sporting event and investigates the effects of this style on motivating volunteers. The National Kidney Foundation Surf Festival, established more than twenty‐five years ago to benefit people with kidney disease, was selected as an extreme case because of the event's longevity and success. Data were collected through semi‐structured personal interviews, document analysis, and personal observation. Results indicated that the founder is a servant leader. Three key themes of servant leadership, and its influence on volunteer motivation, emerged from the data: generating a shared vision dedicated to helping others, building a caring and loving community, and creating the freedom and resources for followers to become servants themselves. Our findings also indicated that the spiritual and moral tenets of servant leadership are applicable to secular nonprofit organizations.
Motor performance and functional exercise capacity in survivors of pediatric acute lymphoblastic leukemia
Authors: Hartman Annelies , Hop Wim , Takken Tim , Pieters Rob , van den Heuvel‐Eibrink Marry
Published: June 2012

Background

Impaired motor performance and reduced maximum exercise capacity during and after treatment of acute lymphoblastic leukemia (ALL) has been shown. However, no longitudinal study monitoring motor performance after cessation of treatment has been published. Whether sub‐maximal exercise capacity is reduced is unknown.

Procedure

Motor performance of pediatric ALL survivors, treated with Dutch Childhood Oncology Group ALL‐9 protocol was measured with the movement‐ABC at stop treatment and ≥5 years later. At follow‐up functional exercise capacity was also investigated using the 6‐minute walk test (6MWT). Heart rate and oxygen saturation were measured with a portable pulse oximeter before and after the 6MWT.

Results

Nineteen boys and 15 girls, median age 12.3 years (range: 9.0–18.7), median time since completion of chemotherapy 5.2 years (5.0–7.1), participated. Mean height/age and weight/age were within the norm, whereas mean BMI/age was significantly increased (mean SDS 0.38, SEM 0.17, P = 0.04). Motor performance had improved significantly (P = 0.001). In contrast, functional exercise capacity at follow‐up was significantly impaired (mean SDS −2.05, SEM 0.13, P < 0.001).

Conclusions

At ≥5 years after completion of ALL treatment motor performance had improved significantly, but functional exercise capacity was significantly impaired. The exact underlying cause of this late effect needs further study. Pediatr Blood Cancer 2013; 60: 494–499. © 2012 Wiley Periodicals, Inc.
Proteomic analysis of salicylic acid‐induced resistance to Magnaporthe oryzae in susceptible and resistant rice
Authors: Li Yunfeng , Zhang Zhihui , Nie Yanfang , Zhang Lianhui , Wang Zhenzhong
Published: June 2012

To probe salicylic acid (SA)‐induced sequential events at translational level and factors associated with SA response, we conducted virulence assays and proteomic profiling analysis on rice resistant and susceptible cultivars against Magnaporthe oryzae at various time points after SA treatment. The results showed that SA significantly enhanced rice resistance against M. oryzae. Proteomic analysis of SA‐treated leaves unveiled 36 differentially expressed proteins implicated in various functions, including defense, antioxidative enzymes, and signal transduction. Majority of these proteins were induced except three antioxidative enzymes, which were negatively regulated by SA. Consistent with the above findings, SA increased the level of reactive oxygen species (ROS) with resistant cultivar C101LAC showing faster response to SA and producing higher level of ROS than susceptible cultivar CO39. Furthermore, we showed that nucleoside diphosphate kinase 1, which is implicated in regulation of ROS production, was strongly induced in C101LAC but not in CO39. Taken together, the findings suggest that resistant rice cultivar might possess a more sensitive SA signaling system or effective pathway than susceptible cultivar. In addition, our results indicate that SA also coordinates other cellular activities such as photosynthesis and metabolism to facilitate defense response and recovery, highlighting the complexity of SA‐induced resistance mechanisms.
Self‐assembly of p‐tert‐butyl thiacalix[4]arenes and metal cations into nanoscale three‐dimensional particles
Authors: Stoikov Ivan I. , Yushkova Elena A. , Bukharaev Anastas A. , Biziaev Dmitry A. , Selivanovskaya Svetlana Yu. , Chursina Mariya A. , Antipin Igor S. , Konovalov Alexander I. , Zharov Ilya
Published: June 2012

The shape of supramolecular aggregates based on stereoisomers of p‐tert‐butyl thiacalix[4]arenes functionalized with secondary, tertiary amide and hydrazide groups at the lower rim in cone, partial cone and 1,3‐alternate conformations with several metal cations were investigated by atomic force microscopy. The examined p‐tert‐butyl thiacalix[4]arenes form host–guest complexes; dimers, spherics ellipsoids and elongated nanoscale particles depending on the conformation of macrocycles, the nature of the binding centers and the nature of the metal cation. Only associates formed by p‐tert‐butyl thiacalix[4]arenes with morpholide groups at the lower rim in cone conformation with silver cations exhibited a higher antimicrobial activity. Copyright © 2012 John Wiley & Sons, Ltd.
The counselees' self‐reported request for psychological help in genetic counseling for hereditary breast/ovarian cancer: not only psychopathology matters
Authors: Vos Joël , van Asperen Christi J. , Oosterwijk Jan C. , Menko Fred H. , Collee Margriet J. , Garcia Encarna Gomez , Tibben Aad
Published: June 2012

Background

Several studies have shown that counselees do not experience psychopathological levels of distress after DNA test result disclosure. However, it has not systematically been studied whether the absence of psychopathology also means that counselees do not want to receive help. Their self‐reported request for help may be related not only with psychopathology/distress but also with other psychological needs (e.g., surgery decisions), genetics‐specific needs (e.g., feeling vulnerable/stigmatized), and existential concerns (e.g., meaning in life).

Methods

Questionnaires were filled in by Dutch cancer patients, before and after disclosure of BRCA1/2 test results for hereditary breast/ovarian cancer: pathogenic mutation results (n = 30), uninformative results (n = 202), or unclassified variants (n = 16). Newly developed questions measured request for help, psychopathology was estimated with factor analyses on distress/psychopathology instruments, and several validated questionnaires measured other needs/concerns.

Results

One‐third of all counselees who reported a request for psychological help had actually received help. The level of psychopathology correlated between 0.34 and 0.44 with this self‐reported need‐for‐help. Other needs, genetics‐specific distress, and existential concerns correlated strongly/moderately with the counselees' self‐reported need‐for‐help. Examples of other needs were intention to undergo surgery, inaccuracy of their interpretation, the impact of cancer, and family communication difficulties. Genetics‐specific distress was for instance feeling vulnerable to develop cancer, stigma, and lack of mastery. Existential concerns were, among others, lack of purpose in life, low self‐acceptance, and an unfulfilled wish for certainty.

Conclusions

The request for help is related to multiple factors. Referral to psychosocial professionals may be improved by not only discussing psychopathology during genetic‐counseling sessions but also by other needs and existential concerns. Questions about other needs and existential issues may be added to psychological screening instruments. Copyright © 2012 John Wiley & Sons, Ltd.
Dabigatran (Pradaxa) for stroke prevention in atrial fibrillation
Authors: Chaplin Steve , Lip Gregory
Published: June 2012

Dabigatran (Pradaxa) is a new oral anticoagulant licensed for the prevention of stroke in patients with atrial fibrillation and a risk factor for stroke. In our New products review, Steve Chaplin presents the data relating to its efficacy and adverse events compared with warfarin, and Professor Gregory Lip considers its potential role in therapy.
Constructing a Crisis: the Role of Immigration Detention in Malta
Authors: Mainwaring Cetta
Published: June 2012

Malta remains the only country in the European Union that maintains an 18‐month, mandatory detention policy for all irregular migrants upon arrival. This paper examines the role that detention has played in the Maltese government's response to the flows of irregular immigration to the island in the 21st century. It argues that detention is symbolic of the crisis narrative that the Maltese government has constructed as a response to these immigration flows in order to gain more practical and financial support from the European Union. The detention policy also serves to reinforce this interpretation of irregular immigration. Such a portrayal, combined with the use of detention as a deterrent, produces detrimental consequences for the migrant population, as well as the wider Maltese society. The paper draws on over 50 interviews, conducted by the author, with government officials, non‐governmental organisations, and migrants and refugees on the island. Copyright © 2012 John Wiley & Sons, Ltd.
Complete Partite subgraphs in dense hypergraphs
Authors: Rödl Vojtěch , Schacht Mathias
Published: June 2012

For a given r ‐uniform hypergraph
${\cal F}$
we study the largest blow‐up of ${\cal F}$
which can be guaranteed in every large r ‐uniform hypergraph with many copies of ${\cal F}$. For graphs this problem was addressed by Nikiforov, who proved that every n ‐vertex graph that contains Ω(nℓ) copies of the complete graph Kℓ must contain a complete ℓ ‐partite graph with Ω(log n) vertices in each class. We give another proof of Nikiforov's result, make very small progress towards that problem for hypergraphs, and consider a Ramsey‐type problem related to a conjecture of Erdős and Hajnal.© 2012 Wiley Periodicals, Inc. Random Struct. Alg., 2012
Order‐restricted inference for multivariate longitudinal data with applications to the natural history of hearing loss
Authors: Rosen Sophia , Davidov Ori
Published: June 2012

Multivariate outcomes are often measured longitudinally. For example, in hearing loss studies, hearing thresholds for each subject are measured repeatedly over time at several frequencies. Thus, each patient is associated with a multivariate longitudinal outcome. The multivariate mixed‐effects model is a useful tool for the analysis of such data. There are situations in which the parameters of the model are subject to some restrictions or constraints. For example, it is known that hearing thresholds, at every frequency, increase with age. Moreover, this age‐related threshold elevation is monotone in frequency, that is, the higher the frequency, the higher, on average, is the rate of threshold elevation. This means that there is a natural ordering among the different frequencies in the rate of hearing loss. In practice, this amounts to imposing a set of constraints on the different frequencies’ regression coefficients modeling the mean effect of time and age at entry to the study on hearing thresholds. The aforementioned constraints should be accounted for in the analysis. The result is a multivariate longitudinal model with restricted parameters. We propose estimation and testing procedures for such models. We show that ignoring the constraints may lead to misleading inferences regarding the direction and the magnitude of various effects. Moreover, simulations show that incorporating the constraints substantially improves the mean squared error of the estimates and the power of the tests. We used this methodology to analyze a real hearing loss study. Copyright © 2012 John Wiley & Sons, Ltd.
Mirtrons, an emerging class of atypical miRNA
Authors: Curtis Helen J. , Sibley Christopher R. , Wood Matthew J. A.
Published: June 2012

Post‐transcriptional gene silencing (PTGS) via RNA interference (RNAi) is a vital gene regulatory mechanism for fine‐tuning gene expression. RNAi effectors termed microRNAs (miRNAs) are implicated in various aspects of animal development and normal physiological function, while dysregulation has been linked to several pathologies. Several atypical miRNA biogenesis pathways have been identified, yet in most cases the reasons for their emergence remain unclear. One of these atypical pathways is the mirtron pathway, where short introns are excised by splicing to generate intermediates of the RNAi pathway, with no cleavage by the microprocessor. Closely related pathways involving tailed‐mirtron and simtron biogenesis have also been described. There is extensive evidence that mirtrons function as miRNAs, and while some are evolutionarily conserved across similar species, others appear to have emerged relatively recently. In addition, through exploitation of the potent and sequence‐specific silencing capabilities of RNAi, synthetic mirtrons may have potential for overcoming certain therapeutic challenges. WIREs RNA 2012 doi: 10.1002/wrna.1122

This article is categorized under:

Regulatory RNAs/RNAi/Riboswitches > Biogenesis of Effector Small RNAs
Exploring probabilistic bisimulations, part I
Authors: Hennessy Matthew
Published: June 2012

We take a fresh look at strong probabilistic bisimulations for processes which exhibit both non-deterministic and probabilistic behaviour. We suggest that it is natural to interpret such processes as distributions over states in a probabilistic labelled transition system, a pLTS; this enables us to adapt the standard notion of contextual equivalence to this setting. We then prove that a novel form of bisimulation equivalence between distributions are both sound and complete with respect to this contextual equivalence. We also show that a very simple extension to HML, Hennessy–Milner Logic, provides finite explanations for inequivalences between distributions. Finally we show that our bisimulations between distributions in a pLTS are simply an alternative characterisation of a standard notion of probabilistic bisimulation equivalence, defined between states in a pLTS.
In praise of algebra
Authors: Hoare Tony , van Staden Stephan
Published: June 2012

We survey the well-known algebraic laws of sequential programming, and extend them with some less familiar laws for concurrent programming. We give an algebraic definition of the Hoare triple, and algebraic proofs of all the relevant laws for concurrent separation logic. We give the provable concurrency laws for Milner transitions, for the Back/Morgan refinement calculus, and for Dijkstra’s weakest preconditions. We end with a section in praise of algebra, of which Carroll Morgan is such a master.
The effects of CO2 and nutrient enrichment on photosynthesis and growth of Poa annua in two consecutive generations
Authors: Bezemer T. Martijn , Jones T. Hefin
Published: June 2012

We studied short‐ and long‐term growth responses of Poa annua L. (Gramineae) at ambient and elevated (ambient +200 μmol mol−1) atmospheric CO2. In experiment 1 we compared plant growth during the early, vegetative and final, reproductive growth phases. Plant growth in elevated CO2 was significantly enhanced during the early phase, but this was reversed in the reproductive phase. Seed mass and percentage germination were significantly reduced in elevated CO2. Experiment 2 tested for the impact of transgenerational and nutrient effects on the response of Poa annua to elevated CO2. Plants were grown at ambient and elevated CO2 for one or two consecutive generations at three soil nutrient levels. Leaf photosynthesis was significantly higher at elevated CO2, but was also affected by both soil nutrient status and plant generation. Plants grown at elevated CO2 and under conditions of low nutrient availability showed photosynthetic acclimation after 12 weeks of growth but not after 6 weeks. First‐generation growth remained unaffected by elevated CO2, while second‐generation plants produced significantly more tillers and flowers when grown in elevated CO2 compared to ambient conditions. This effect was strongest at low nutrient availability. Average above‐ and belowground biomass after 12 weeks of growth was enhanced in elevated CO2 during both generations, but more so during plant generation 2. This study demonstrates the importance of temporal/maternal effects in plant responses to elevated CO2.
Microarray Analysis of Ageing-Related Signatures and Their Expression in Tumors Based on a Computational Biology Approach
Authors: Wang Xiaosheng
Published: June 2012

Ageing and cancer have been associated with genetic and genomic changes. The identification of common signatures between ageing and cancer can reveal shared molecular mechanisms underlying them. In this study, we collected ageing-related gene signatures from ten published studies involved in six different human tissues and an online resource. We found that most of these gene signatures were tissue-specific and a few were related to multiple tissues. We performed a genome-wide examination of the expression of these signatures in various human tumor types, and found that a large proportion of these signatures were universally differentially expressed among normal vs. tumor phenotypes. Functional analyses of the highly-overlapping genes between ageing and cancer using DAVID tools have identified important functional categories and pathways linking ageing with cancer. The convergent and divergent mechanisms between ageing and cancer are discussed. This study provides insights into the biology of ageing and cancer, suggesting the possibility of potential interventions aimed at postponing ageing and preventing cancer.