bluuebunny/crossref_metadata_2025 huggingface dataset:
Photo‐induced graft copolymerization of acrylonitrile onto sodium salt of partially carboxymethylated guar gum
Authors: Trivedi J. H. , Thaker Mehul D. , Trivedi Harikrishna C.
Published: September 2014

Photo‐induced graft copolymerization of acrylonitrile (AN) onto sodium salt of partially carboxymethylated guar gum (Na‐PCMGG,
= 0.291) was carried out in an aqueous medium using ceric ammonium nitrate (CAN) as photo‐initiator to synthesize a novel graft copolymer, Na‐PCMGG‐g‐PAN, which may find potential application as a superabsorbent hydrogel. Studying the influence of concentrations of photo‐initiator (CAN), nitric acid, monomer (AN) as well as reaction time, temperature, and amount of substrate on the grafting yields, the reaction conditions for optimum grafting were evaluated. Maximum values of the grafting yields achieved were %G = 285.77 and %GE = 70.76 at optimized conditions. The proposed kinetic scheme could explain very well the experimental results. The influence of different kind of acids on the grafting yields was also studied. Grafting process was confirmed with the help of FTIR, thermal (TGA/DSC), and SEM techniques. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41371.
In Silico Study Combining Docking and QSAR Methods on a Series of Matrix Metalloproteinase 13 Inhibitors
Authors: Xi Lili , Li Shuyan , Yao Xiaojun , Wei Yuhui , Li Jiazhong , Liu Huanxiang , Wu Xin'an
Published: September 2014

Matrix metalloproteinase 13 (MMP‐13) plays an important role in the degradation of articular cartilage and has been considered as an attractive target for the treatment of osteoarthritis; hence, the development of efficient inhibitors of MMP‐13 has become a hot study field. Taking a series of carboxylic acid‐based MMP‐13 inhibitors as research object, this work utilized an extended QSAR method to analyze the structure–activity relationships. We focused on two important topics in QSAR: bioactive conformation and descriptors. Firstly, molecular docking was carried out to dock all molecules into the MMP‐13 active site in order to obtain the bioactive conformation. Secondly, based on the docked complex, descriptors characterizing receptor–ligand interactions and the ligand structure were calculated. Thirdly, a genetic algorithm (GA) and multiple linear regression (MLR) were employed to select important descriptors related to inhibitory activities, simultaneously, to build the predictive model. The built model gave satisfactory results with highly accurate fitting and strong external predictive abilities for chemicals not used in model development. Furthermore, the selected descriptors were explored to elucidate important factors influencing the inhibition activities. This study demonstrates that the selection strategy of the docking‐guided bioactive conformation is rational and useful in predicting MMP‐13 inhibitor activities, and receptor–ligand complex descriptors have an advantage over directly reflecting receptor–ligand interactions.
Mechanistic modeling of biodiesel production using a liquid lipase formulation
Authors: Price Jason , Hofmann Björn , Silva Vanessa T. L. , Nordblad Mathias , Woodley John M. , Huusom Jakob K.
Published: September 2014

In this article, a kinetic model for the enzymatic transesterification of rapeseed oil with methanol using Callera™ Trans L (a liquid formulation of a modified Thermomyces lanuginosus lipase) was developed from first principles. We base the model formulation on a Ping‐Pong Bi‐Bi mechanism. Methanol inhibition, along with the interfacial and bulk concentrations of the enzyme was also modeled. The model was developed to describe the effect of different oil compositions, as well as different water, enzyme, and methanol concentrations, which are relevant conditions needed for process evaluation, with respect to the industrial production of biodiesel. The developed kinetic model, coupled with a mass balance of the system, was fitted to and validated on experimental results for the fed‐batch transesterification of rapeseed oil. The confidence intervals of the parameter estimates, along with the identifiability of the model parameters were presented. The predictive capability of the model was tested for a case using 0.5% (wt. Enzyme/wt. Oil), 0.5% (wt. Water /wt. Oil) and feeding 1.5 times the stoichiometric amount of methanol in total over 24 h. For this case, an optimized methanol feeding profile that constrains the amount of methanol in the reactor was computed and the predictions experimentally validated. Monte‐Carlo simulations were then used to characterize the effect of the parameter uncertainty on the model outputs, giving a biodiesel yield, based on the mass of oil, of 90.8 ± 0.55 mass %. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 30:1277–1290, 2014
Synthesis of poly(3‐hydroxybutyrate‐co‐4‐hydroxybutyrate)/chitosan/silver nanocomposite material with enhanced antimicrobial activity
Authors: Rennukka M. , Sipaut C. S. , Amirul A. A.
Published: September 2014

This work aims to shed light in the fabrication of poly(3‐hydroxybutyrate‐co‐44%‐4‐hydroxybutyrate)[P(3HB‐co‐44%4HB)]/chitosan‐based silver nanocomposite material using different contents of silver nanoparticle (SNP); 1–9 wt%. Two approaches were applied in the fabrication; namely solvent casting and chemical crosslinking via glutaraldehyde (GA). A detailed characterization was conducted in order to yield information regarding the nanocomposite material. X‐ray diffraction analysis exhibited the nature of the three components that exist in the nanocomposite films: P(3HB‐co‐4HB), chitosan, and SNP. In term of mechanical properties, tensile strength, and elongation at break were significantly improved up to 125% and 22%, respectively with the impregnation of the SNP. The melting temperature of the nanocomposite materials was increased whereas their thermal stability was slightly changed. Scanning electron microscopy images revealed that incorporation of 9 wt% of SNP caused agglomeration but the surface roughness of the material was significantly improved with the loading.Staphylococcus aureusandEscherichia coliwere completely inhibited by the nanocomposite films with 7 and 9 wt% of SNP, respectively. On the other hand, degradation of the nanocomposite materials outweighed the degradation of the pure copolymer. These bioactive and biodegradable materials stand a good chance to serve the vast need of biomedical applications namely management and care of wound as wound dressing. © 2014 American Institute of Chemical EngineersBiotechnol. Prog., 30:1469–1479, 2014
Quantitative Determination of Cellular Farnesyltransferase Activity: Towards Defining the Minimum Substrate Reactivity for Biologically Relevant Protein Farnesylation
Authors: Flynn Susan C. , Lindgren Danielle E. , Hougland James L.
Published: September 2014

Prenylation is a post‐translational modification wherein an isoprenoid group is attached to a protein substrate by a protein prenyltransferase. Hundreds of peptide sequences are in vitro substrates for protein farnesyltransferase (FTase), but it remains unknown which of these sequences can successfully compete for in vivo prenylation. Translating in vitro studies to predict in vivo protein farnesylation requires determining the minimum reactivity needed for modification by FTase within the cell. Towards this goal, we developed a reporter protein series spanning several orders of magnitude in FTase reactivity as a calibrated sensor for endogenous FTase activity. Our approach provides a minimally invasive method to monitor changes in cellular FTase activity in response to environmental or genetic factors. Determining the reactivity “threshold” for in vivo prenylation will help define the prenylated proteome and identify prenylation‐dependent pathways for therapeutic targeting.
Ruthenium‐Catalyzed N‐Alkylation for the Synthesis of 2‐N‐Pyridylmethyl Benzonitriles and an Exploration of Its Synthetic Utility
Authors: Chen Mengmeng , Zhang Min , Xie Feng , Wang Xiaoting , Jiang Huanfeng
Published: September 2014

The N‐alkylation of 2‐aminobenzonitriles with pyridyl methanols as the alkylating reagents has been demonstrated by using an easily available Ru3(CO)12/Binap/tBuOK [Binap=2,2′‐bis(diphenylphosphino)‐1,1′‐binaphthyl] catalyst system. The synthetic protocol can be used to synthesize various 2‐N‐pyridylmethyl benzonitriles in moderate to good isolated yields. Through an exploration of its synthetic utility, we have demonstrated a novel straightforward synthesis of biologically interesting 2,3‐diaryl‐1,2,3,4‐tetrahydrobenzo[e][1,4]diazepin‐5‐ones, which provides an important basis for the discovery of new bioactive compounds.
Photoelectrochemical Properties of LaFeO3 Nanoparticles
Authors: Celorrio Verónica , Bradley Kieren , Weber Oliver J. , Hall Simon R. , Fermín David J.
Published: September 2014

The photoelectrochemical properties of LaFeO3 nanoparticles are discussed for the first time. Highly phase‐pure LaFeO3 particles prepared by a novel ionic‐liquid‐based method are characterized by a (60±14) nm mean size and a band gap of (2.56±0.07) eV. Thin films deposited by screen printing exhibit photocurrent responses associated with hydrogen generation at potential up to 1 V more positive than the formal hydrogen potential. Analysis of the photocurrent responses as a function of photon flux and potential bias suggest that the hole‐collection efficiency at the back contact is in competition with interfacial water oxidation.
Synthesis and Analysis of the Conformational Preferences of 5‐Aminomethyloxazolidine‐2,4‐dione Scaffolds: First Examples of β2‐ and β2, 2‐Homo‐Freidinger Lactam Analogues
Authors: Greco Arianna , Tani Sara , De Marco Rossella , Gentilucci Luca
Published: September 2014

Constrained peptidomimetic scaffolds are of considerable interest for the design of therapeutically useful analogues of bioactive peptides. We present the single‐step cyclization of (S)‐ or (R)‐α‐hydroxy‐β2‐ or α‐substituted‐α‐hydroxy‐β2, 2‐amino acids already incorporated within oligopeptides to 5‐aminomethyl‐oxazolidine‐2,4‐dione (Amo) rings. These scaffolds can be regarded as unprecedented β2‐ or β2, 2‐homo‐Freidinger lactam analogues, and can be equipped with a proteinogenic side chain at each residue. In a biomimetic environment, Amo rings act as inducers of extended, semi‐bent or folded geometries, depending on the relative stereochemistry and the presence of α‐substituents.
Effect of p53 activity on the sensitivity of human glioblastoma cells to PARP‐1 inhibitor in combination with topoisomerase i inhibitor or radiation
Authors: Sabbatino Francesco , Fusciello Celeste , Somma Domenico , Pacelli Roberto , Poudel Ravin , Pepin David , Leonardi Antonio , Carlomagno Chiara , Della Vittoria Scarpati Giuseppina , Ferrone Soldano , Pepe Stefano
Published: September 2014

Poly (ADP‐Ribose) polymerase‐1 (PARP‐1) is involved in the DNA repairing system by sensing and signaling the presence of DNA damage. Inhibition of PARP‐1 is tested in combination with DNA damaging agents such as topoisomerase I inhibitors or ionizing radiations (RT) for the treatment of glioblastoma (GBM). Disruption of p53, widely prevalent in GBMs, plays a major role in DNA repairing system. The current study investigates whether p53 activity has an effect on the sensitivity of human GBM cells to PARP‐1 inhibitors in combination with topoisomerase I inhibitor topotecan (TPT) and/or RT. Human GBM cell lines carrying a different functional status of p53 were treated with PARP‐1 inhibitor NU1025, in combination with TPT and/or RT. Cytotoxic effects were examined by analyzing the antiproliferative activity, the cell cycle perturbations, and the DNA damage induced by combined treatments. PARP inhibition enhanced the antiproliferative activity, the cell cycle perturbations and the DNA damage induced by both TPT or RT in GBM cells. These effects were influenced by the p53 activity: cells carrying an active p53 were more sensitive to the combination of PARP inhibitor and RT, while cells carrying an inactive p53 displayed a higher sensitivity to the combination of PARP inhibitor and TPT. Our study suggests that p53 activity influences the differential sensitivity of GBM cells to combined treatments of TPT, RT, and PARP inhibitors. © 2014 International Society for Advancement of Cytometry
Analgesic interaction between ondansetron and acetaminophen after tonsillectomy in children: The Paratron randomized, controlled trial
Authors: Ramirez L. , Cros J. , Marin B. , Boulogne P. , Bergeron A. , de Lafont G.E. , Renon‐Carron F. , de Vinzelles M‐A. , Guigonis V. , Nathan N. , Beaulieu P.
Published: September 2014

Background

The mechanism of action of acetaminophen remains unclear. One hypothesis involves an interaction with the serotoninergic system. Antagonists to serotonin (5‐HT)3 receptors (setrons) have antiemetic properties. Therefore, co‐administration of acetaminophen and a setron could lead to a decrease or a loss of acetaminophen analgesic effects. The aim of this study was to demonstrate such an interaction.

Methods

Paratron is a prospective, randomized, controlled, double‐blind, parallel group trial. All children aged 2–7 years (n = 69) scheduled for a tonsillectomy ± adenoidectomy received intraoperative acetaminophen with ondansetron or droperidol. Pain scores [Children's Hospital of Eastern Ontario Pain Scale (CHEOPS)], morphine consumption and the incidence of post‐operative nausea and vomiting (PONV) were measured for 24 h following surgery.

Results

Pain scores were not different at all times between the groups but median morphine consumption (μg) in recovery was 322.5 [interquartile range (IQR) 0.0–500.0] and 0 (IQR 0‐0) in the ondansetron (n = 35) and droperidol (n = 34) groups, respectively (p = 0.004). The percentages of patients who received morphine titration were 57.1% and 20.6% in the ondansetron and droperidol groups, respectively (p = 0.008). No significant difference was found for PONV.

Conclusions

An interaction between acetaminophen and ondansetron is suggested, with children receiving three times more morphine during pain titration in the recovery room. More studies are necessary to evaluate whether this finding is clinically relevant enough to preclude the simultaneous perioperative administration of both drugs in the future.
Induction of macrophage cell‐cycle arrest and apoptosis by humic acid
Authors: Yang Hsin‐Ling , Huang Pei‐Jane , Chen Ssu‐Ching , Cho Hsin‐Ju , Kumar K. J. Senthil , Lu Fung‐Jou , Chen Chih‐Sheng , Chang Chia‐Ting , Hseu You‐Cheng
Published: September 2014

Humic acid (HA) in well water is associated with Blackfoot disease and various cancers. Previously, we reported that acute humic acid exposure (25–200 µg/mL for 24 hr) induces inflammation in RAW264.7 macrophages. In this study, we observed that prolonged (72 hr) HA exposure (25–200 µg/mL) induces cell‐cycle arrest and apoptosis in cultured RAW264.7 cells. We also observed that exposing macrophages to HA arrests cells in the G2/M phase of the cell cycle by reducing cyclin A/B1, Cdc2, and Cdc25C levels. Treating macrophages with HA triggers a sequence of events characteristic of apoptotic cell death including loss of cell viability, morphological changes, internucleosomal DNA fragmentation, sub‐G1 accumulation. Molecular markers of apoptosis associated with mitochondrial dysfunction were similarly observed, including cytochrome c release, caspase‐3 or caspase‐9 activation, and Bcl‐2/Bax dysregulation. In addition to the mitochondrial pathway, HA‐induced apoptosis may also be mediated through the death receptor and ER stress pathways, as evidence by induction of Fas, caspase‐8, caspase‐4, and caspase‐12 activity. HA also upregulates p53 expression and causes DNA damage as assessed by the comet assay. These findings yield new insight into the mechanisms by which HA exposure may trigger atherosclerosis through modulation of the macrophage‐mediated immune system. Environ. Mol. Mutagen. 55:741–750, 2014. © 2014 Wiley Periodicals, Inc.
The Validity of Scores from the GRE® revised General Test for Forecasting Performance in Business Schools: Phase One
Authors: Young John W. , Klieger David , Bochenek Jennifer , Li Chen , Cline Fred
Published: September 2014

Scores from the GRE® revised General Test provide important information regarding the verbal and quantitative reasoning abilities and analytical writing skills of applicants to graduate programs. The validity and utility of these scores depend upon the degree to which the scores predict success in graduate and business school in specific contexts. To assess the predictive validity of the GRE test for graduate business programs, we collaborated with a number of universities and obtained data from each university's admissions office and registrar. We focused specifically on part‐time and full‐time students in master's of business administration (MBA) degree programs. Given the nested structure of the data, we used a 2‐level (representing students and institutions) hierarchical linear model (HLM) to estimate regression models with first‐semester MBA grade point average (GPA) or cumulative MBA GPA as the dependent variable and GRE scores and undergraduate GPA (UGPA) as independent variables. For predicting cumulative MBA GPA, the pseudo R‐squared (R2) value was .04 using UGPA, cohort year, and program type as the only predictors; this value increased substantially to .19 with the addition of GRE scores. The HLM results show that both GRE‐Quantitative and GRE‐Verbal scores were statistically significant predictors of both first‐semester MBA GPA and cumulative MBA GPA.
Dramatic fate of a young coronary heart disease patient rescued with specific lipoprotein(a) apheresis
Authors: Safarova Maya S. , Ezhov Marat V. , Afanasieva Olga I. , Konovalov Gennady A. , Pokrovsky Sergei N.
Published: September 2014

Lipoprotein(a) [Lp(a)] is acknowledged to be an independent atherothrombotic risk factor. Although genetic studies have highlighted the causal relationship between coronary disease and Lp(a), it is uncertain which strategies maximize the therapeutic benefit of patients with high Lp(a) levels. We report the challenging case of a young coronary heart disease (CHD) patient who underwent 10 percutaneous coronary interventions due to repeated acute coronary syndromes (2006–2009) despite an optimally controlled, traditional risk‐factor profile. For the first time, we performed specific Lp(a) immunoadsorption in the presence of very low levels of low‐density lipoprotein cholesterol (LDL‐C) while the patient was on a high‐dose statin regimen. There have been no previous reports of patients with high Lp(a) levels who achieved LDL‐C goals when treated with an isolated Lp(a)‐lowering method. Despite the very high risk of cardiovascular death, targeting Lp(a) resulted in dramatic improvement of the patient's clinical condition. Thus, we suggest that specific Lp(a) apheresis should be considered an effective new treatment strategy for patients with progressive CHD who have reached LDL‐C goals but harbor elevated Lp(a) levels. J. Clin. Apheresis 30:193–195, 2015. © 2014 Wiley Periodicals, Inc.
A critique on neuroscientific methodologies in organizational behavior and management studies
Authors: Lindebaum Dirk , Jordan Peter J.
Published: September 2014

Organizational neuroscience continues to flourish in organizational behavior and management studies as indicated by the growing number of publications. However, with a few exceptions, substantive critiques of organizational neuroscience are conspicuous by their absence. In this point–counterpoint article, we aim to redress this imbalance. We do so by asking two significant yet neglected questions: (i) how strong is the science behind this domain, and (ii) why are we doing this type of research (the so what? question)? Our analysis shows that the science behind organizational neuroscience is far less rigorous than currently advocated (due to low statistical power of some neuroimaging studies plus an inability to locate mental phenomena precisely in the brain). In terms of the so what? question, we encourage researchers to move away from general statements and become more specific about the phenomena they research. We contend that the practical implications of this research, as well as inferences of the link to behavioral changes, are currently overstated. We also underscore the importance for these studies to become contextually sensitive in order for the researchers to capture important events in the workplace. Finally, we offer some suggestions for future research. Copyright © 2014 John Wiley & Sons, Ltd.
Ethics and genomic medicine, how to navigate decisions in surgical oncology
Authors: Devon Karen M. , Lerner‐Ellis Jordan P. , Ganai Sabha , Angelos Peter
Published: September 2014

Using genetic information to make medical decisions and tailor treatments to individuals will likely provide major benefits and become an important part of health care. Surgical oncologists must ethically apply scientific genetic information in a complex and evolving environment to the benefit of their patients. In this review we address ethical issues associated with: indications for genetic testing, informed consent for testing and therapy, confidentiality, targeted therapy, prophylactic surgery, and genetic testing in children. J. Surg. Oncol. 2015 111:18–23. © 2014 Wiley Periodicals, Inc.
Migrant Labour in Rural Tourism: Continuity and Change
Authors: Piso Annemarie
Published: September 2014

This paper considers the impact of the recession on the availability of migrant labour in the Yorkshire Dales and reassesses how the practice of employing migrant workers, previously explored by the author, has influenced current sources of recruitment. Findings suggest constantly evolving and altering patterns of migration not only shaped by economic and spatial factors but also socially constructed by the interactions of employers and migrants. In particular, results indicate how subjective experiences and judgements made around the use of social networks can recreate as well as transform the specific use of migrant labour in each establishment. Copyright © 2014 John Wiley & Sons, Ltd.
‘Quasi‐Mixture’ Descriptors for QSPR Analysis of Molecular Macroscopic Properties. The Critical Properties of Organic Compounds
Authors: Mokshyna E. , Nedostup V. I. , Polishchuk P. G. , Kuzmin V. E.
Published: September 2014

Rational approach towards the QSAR/QSPR modeling requires the descriptors to be computationally efficient, yet physically and chemically meaningful. On the basis of existing simplex representation of molecular structure (SiRMS) the novel ‘quasi‐mixture’ descriptors were developed in order to accomplish the goal of characterization molecules on 2D level (i.e. without explicit generation of 3D structure and exhaustive conformational search) with account for potential intermolecular interactions. The critical properties of organic compounds were chosen as target properties for the estimation of descriptors’ efficacy because of their well‐known physical nature, rigorously estimated experimental errors and large quantity of experimental data. Among described properties are critical temperature, pressure and volume. Obtained models have high statistical characteristics, therefore showing the efficacy of suggested ‘quasi‐mixture’ approach. Moreover, ‘quasi‐mixture’ approach, as a branch of the SiRMS, allows to interpret results in terms of simple basic molecular properties. The obtained picture of influences corresponds to the accepted theoretical views.
Pharmacophore Modeling, Ensemble Docking, Virtual Screening, and Biological Evaluation on Glycogen Synthase Kinase‐3β
Authors: Fu Gang , Sivaprakasam Prasanna , Dale Olivia R. , Manly Susan P. , Cutler Stephen J. , Doerksen Robert J.
Published: September 2014

Glycogen synthase kinase‐3 (GSK‐3) is a multifunctional serine/threonine protein kinase which is engaged in a variety of signaling pathways, regulating a wide range of cellular processes. GSK‐3β, also known as tau protein kinase I (TPK‐I), is one of the most important kinases implicated in the hyperphosphorylation of tau that leads to neurodegenerative diseases. Hence, GSK‐3β has emerged as an important therapeutic target. To identify compounds that are structurally novel and diverse compared to previously reported ATP‐competitive GSK‐3β inhibitors, we performed virtual screening by implementing a mixed ligand/structure‐based approach, which included pharmacophore modeling, diversity analysis, and ensemble docking. The sensitivities of different docking protocols to induced‐fit effects were explored. An enrichment study was employed to verify the robustness of ensemble docking, using 13 X‐ray structures of GSK‐3β, compared to individual docking in terms of retrieving active compounds from a decoy dataset. A total of 24 structurally diverse compounds obtained from the virtual screening underwent biological validation. The bioassay results showed that 15 out of the 24 hit compounds are indeed GSK‐3β inhibitors, and among them, one compound exhibiting sub‐micromolar inhibitory activity is a reasonable starting point for further optimization.
CORPORATE TAX CUTS AND FOREIGN DIRECT INVESTMENT
Authors: Baccini Leonardo , Li Quan , Mirkina Irina
Published: September 2014

Accurate policy evaluation is central to optimal policymaking, but difficult to achieve. Most often, analysts have to work with observational data and cannot directly observe the counterfactual of a policy to assess its effect accurately. In this paper, we craft a quasi‐experimental design and apply two relatively new methods—the difference‐in‐differences estimation and the synthetic controls method—to the policy debate on whether corporate tax cuts increase foreign direct investment (FDI). The taxation–FDI relationship has attracted wide attention because of mixed findings. We exploit a quasi‐experimental design for Russian regions, which were granted autonomy to reduce corporate profit tax in 2003, enabling them to simultaneously experiment with different tax policies. We estimate both the average and local treatment effects of two types of tax cuts on FDI inflows. We find that, on average, relative to the absence of tax cuts, nondiscriminatory tax cuts on direct investment profit increase FDI, but discriminatory tax cuts on selected government‐sanctioned investment projects do not. Yet for both types of tax cuts, local treatment effects vary dramatically from region to region. Our research has important implications for the design of tax policy and fiscal incentive, and the assessment of fiscal policy reforms.
Klein, schnell, hell
Authors: Engel Michael , Hennrich Frank , Krupke Ralph
Published: September 2014

Kohlenstoff‐Nanoröhren haben einzigartige elektrische und optische Eigenschaften. Besonders das schnelle Fließen der Ladungen prädestiniert sie für völlig neue Hochfrequenz‐Feldeffekt‐Transistoren. Diese könnten zum Beispiel die Telekommunikation erheblich beschleunigen. Auch als Lichtemitter mit präzise einstellbaren Eigenschaften sind Kohlenstoff‐Nanoröhren interessant. Ein Hindernis für technische Anwendungen waren bislang unselektive Syntheseverfahren, bei denen verschiedenste Typen von Nanoröhren zugleich entstehen. Neue, hoch selektive Sortierverfahren könnten diese Hürde überwinden.
Gravitationslinsen erhellen das Dunkel
Authors: Bartelmann Matthias
Published: September 2014

Dem kosmologischen Standardmodell zufolge besteht bei weitem die meiste Materie im Universum aus einer unbekannten, dunklen Substanz. Wie ist diese Dunkle Materie verteilt? Im Rahmen des internationalen Projekts “Clash” werden 25 massereiche Galaxienhaufen so genau wie nie zuvor beobachtet, um ihren inneren Aufbau möglichst präzise zu entschlüsseln. Die bisherigen Ergebnisse bestätigen das Bild der kalten Dunklen Materie, wonach die Ruheenergie der Teilchen wesentlich größer ist als ihre thermisch bedingte Bewegungsenergie.
Eine Lösung für das Heliumproblem
Authors: Good Jeremy
Published: September 2014

Pulsröhren‐ oder Gifford‐McMahon‐Kühler sind mit Stirling‐Motoren verwandt. Mit ihnen lassen sich heute extrem niedrige Temperaturen bis 1 K erreichen. Als kryogenfreie Systeme kommen sie mit einer kleinen Menge Helium als Arbeitsgas aus. Damit reduzieren sie den Verbrauch von flüssigem und gasförmigem Helium in Forschungs‐ und Laboranwendungen dramatisch. Sie ermöglichen neue Anwendungen und sind dabei im Betrieb viel kostengünstiger als herkömmliche Kühlverfahren. Je kostbarer und knapper Helium wird, desto wichtiger werden solche alternativen Kühltechnologien für Labore, die supraleitende Magnete einsetzen. Das gilt für die Physik ebenso wie die Chemie, Materialforschung, Pharmaforschung und Medizintechnik.
Strahlenoptik mit Ray Optics
Authors: Wilhelm Thomas , Aydinlik Hüseyin , Kuhn Jochen
Published: September 2014

Mit der kostenfreien Android‐App Ray Optics lassen sich schnell und unkompliziert Abbildungen an Spiegeln und Linsen simulieren. Dabei bietet die App verschiedene Einstellmöglichkeiten und eignet sich beispielsweise zur Bestimmung des Ortes eines reellen oder virtuellen Bildes bei einer Linse, einer Linsenkombination oder einem Spiegel.
Lichtstrahlen und Kettenbrüche
Authors: Loos Andreas
Published: September 2014

Er ist ein Autodidakt: Seine Familie, verarmte Hugenotten, können kaum mehr als den elementaren Schulbesuch bezahlen. So beginnt er mit zwölf Jahren zu arbeiten, als Gehilfe seines Vaters, eines Schneiders. Später verdient er als Buchhalter, Sekretär und Lehrer sein Brot. Gleichzeitig verschlingt er neugierig jedes Buch, das ihm zwischen die Finger kommt und beginnt auch mit eigenen physikalischen Experimenten, vor allem zur Optik.
Detection of morphine‐3‐sulfate and morphine‐6‐sulfate in human urine and plasma, and formation in liver cytosol
Authors: Andersson Maria , Björkhem‐Bergman Linda , Ekström Lena , Bergqvist Lena , Lagercrantz Hugo , Rane Anders , Beck Olof
Published: September 2014

Morphine is still the mainstay in treatment of severe pain and is metabolized in the liver mainly by glucuronidation, partly to the pharmacologically active morphine‐6‐glucuronide (M6G). The sulfation pathway has attracted much less attention but may also form active metabolites. The aim of the present study was to study two sulfate metabolites of morphine in humans. Urine and plasma from newborns, adult heroin addicts, and terminal cancer patients was analyzed for the presence of morphine‐3‐sulfate (M3S) and morphine‐6‐sulfate (M6S) by a new liquid chromatography – tandem mass spectrometry (LC‐MS/MS) method. In addition, morphine sulfation was studied in vitro in human liver cytosol preparations. M3S was present in urine and plasma from all study groups although at lower concentrations than morphine‐3‐glucuronide (M3G). The plasma M3S/M3G ratio was 30 times higher in newborns than in adults indicating that the relative sulfation is more important at early stage of life. M6S was measurable in only one plasma sample from a newborn patient, and in one of the urine sample from the drug testing group. The incubation of morphine with liver cytosol extracts resulted in approximately equal rate of formation of both M3S and M6S. In conclusion, sulfation of morphine is catalyzed in human liver but this minor metabolic pathway probably lacks clinical significance. The M6S metabolite is formed at a low rate, making it undetectable in most individuals.
Development of a ‘patient information leaflet’ for use following assessment of patients with reported or suspected paracetamol overdose in the UK
Authors: Potter Thomas , Chan Wui Ling , Archer John R. H. , Barrett Jessica , Dargan Paul I. , Wood David M.
Published: September 2014

The aim of this study was to design an information leaflet for patients with paracetamol overdose based on Medicines and Healthcare products Regulatory Agency guidance and to assess its readability. A two‐sided one page information leaflet was designed for patients being discharged from hospital after a paracetamol overdose. Patients presenting with an acute paracetamol overdose, irrespective of whether they were treated or not, were recruited to read the leaflet and then answer a brief structured questionnaire based on the leaflet. The readability of the information leaflet was assessed using the Flesch reading ease score. Thirty patients (15 male, 12 female, 3 not recorded; mean age 38 ± 13.0 years) were recruited, wherein 100% of patients reported the language used was understandable, 96.6% knew which symptoms would require urgent medical review after discharge and 100% of patients knew the liver was affected by paracetamol. The Flesch reading ease score was 67.6 (out of a maximum of 100), equivalent to a UK reading age of 10–11years old. Our information leaflet for all patients being discharged after paracetamol overdose was well received by patients, provided them with the required knowledge and had an appropriate reading age based on UK literacy rates. We would recommend that this leaflet could be used as a template on a national level, localized to individual hospitals, to improve patient knowledge of paracetamol toxicity, and facilitate early medical review in the event of deterioration following discharge from the hospital.
Selective IAP inhibition results in sensitization of unstimulated but not CD40‐stimulated chronic lymphocytic leukaemia cells to TRAIL‐induced apoptosis
Authors: Zhuang Jianguo , Laing Naomi , Oates Melanie , Lin Ke , Johnson Gillian , Pettitt Andrew R.
Published: September 2014

Despite recent advances in therapy, chronic lymphocytic leukaemia (CLL) remains incurable and new treatment strategies are therefore urgently required. Inhibitor of apoptosis proteins (IAPs) are over‐expressed in CLL, suggesting both a role in disease pathogenesis and the potential for therapeutic targeting. To explore these questions, we evaluated the effects on primary CLL cells of AZD5582, a novel potent and selective inhibitor of IAPs. AZD5582 at nanomolar concentrations induced extensive degradation of cIAP‐1 and cIAP‐2, but minimally of X chromosome‐linked IAP (XIAP). However, these effects of AZD5582 produced little or no direct cytotoxicity, nor did they sensitize CLL cells to p53‐dependent killing by fludarabine or p53‐independent killing by dexamethasone. In contrast, AZD5582 significantly enhanced apoptosis induced by the death receptor (DR) agonist tumour necrosis factor‐related apoptosis‐inducing ligand (TRAIL). Importantly, killing by TRAIL plus AZD5582 was independent of adverse prognostic features including TP53 deletion which is strongly associated with chemoresistance in CLL. Coculture experiments involving transfected mouse fibroblasts expressing human CD40L (CD154) to mimic the effect of T cells at sites of tissue involvement showed that CD40 stimulation almost completely prevented the killing of CLL cells by TRAIL plus AZD5582 despite up‐regulating TRAIL receptors 1 and 2. In conclusion, our findings confirm the rate‐limiting, upstream involvement of IAPs in the extrinsic but not intrinsic apoptotic pathway of CLL cells and suggest that drug combinations that simultaneously activate DRs and inhibit IAPs may have therapeutic potential in patients with CLL who have failed T‐cell‐depleting chemotherapy.
Return to Afghanistan: Migration as Reinforcement of Socio‐Economic Stratification
Authors: van Houte Marieke , Siegel Melissa , Davids Tine
Published: September 2014

This paper explores a new avenue of the hierarchisation of mobility amongst voluntary and involuntary return migrants to Afghanistan. We introduce the concept of multidimensional and multi‐local embeddedness as an analytical approach to the multi‐sited experience of migration, which merges transnationalism and integration into one analytical framework. Drawing on an in‐depth case study that focuses on the life histories of 35 Afghan returnees from European countries, we argue that socio‐economic differences that existed prior to migration are reinforced by the migration experience, which results in strongly differentiated patterns of multidimensional embeddedness and transnational mobility. These patterns reinforce previously existing socio‐economic stratification and restrict expectations of return migration and development. Copyright © 2014 John Wiley & Sons, Ltd.
Microwave extraction–isotope ratio infrared spectroscopy (ME‐IRIS): a novel technique for rapid extraction and in‐line analysis of δ18O and δ2H values of water in plants, soils and insects
Authors: Munksgaard Niels C. , Cheesman Alexander W. , Wurster Chris M. , Cernusak Lucas A. , Bird Michael I.
Published: September 2014

RATIONALE

Traditionally, stable isotope analysis of plant and soil water has been a technically challenging, labour‐intensive and time‐consuming process. Here we describe a rapid single‐step technique which combines Microwave Extraction with Isotope Ratio Infrared Spectroscopy (ME‐IRIS).

METHODS

Plant, soil and insect water is extracted into a dry air stream by microwave irradiation within a sealed vessel. The water vapor thus produced is carried to a cooled condensation chamber, which controls the water vapor concentration and flow rate to the spectrometer. Integration of the isotope signals over the whole analytical cycle provides quantitative δ18O and δ2H values for the initial liquid water contained in the sample. Calibration is carried out by the analysis of water standards using the same apparatus. Analysis of leaf and soil water by cryogenic vacuum distillation and IRMS was used to validate the ME‐IRIS data.

RESULTS

Comparison with data obtained by cryogenic distillation and IRMS shows that the new technique provides accurate water isotope data for leaves from a range of field‐grown tropical plant species. However, two exotic nursery plants were found to suffer from spectral interferences from co‐extracted organic compounds. The precision for extracted leaf, stem, soil and insect water was typically better than ±0.3 ‰ for δ18O and ±2 ‰ for δ2H values, and better than ±0.1 ‰ for δ18O and ±1 ‰ for δ2H values when analyzing water standards. The effects of sample size, microwave power and duration and sample‐to‐sample memory on isotope values were assessed.

CONCLUSIONS

ME‐IRIS provides rapid and low‐cost extraction and analysis of δ18O and δ2H values in plant, soil and insect water (≈10–15 min for samples yielding ≈ 0.3 mL of water). The technique can accommodate whole leaves of many plant species. Copyright © 2014 John Wiley & Sons, Ltd.
Influence of hydrophobicity on positive‐ and negative‐ion yields of peptides in electrospray ionization mass spectrometry
Authors: Osaka Issey , Takayama Mitsuo
Published: September 2014

RATIONALE

The influence of hydrophobicity originating from an amino acid phenylalanine (Phe) residue on the ion yields of peptides has been empirically evaluated using positive‐ and negative‐ion electrospray ionization (ESI) mass spectrometry. The enhancement effect of hydrophobicity was compared with that of the presence of basic and acidic residues of peptides.

METHODS

In order to empirically understand the ion yields in soft ionization methods, we have divided the total ionization process into ionization efficiency of analyte molecules and the rate of desorption or vaporization of molecules. The ion yields of protonated and deprotonated molecules of peptides were evaluated.

RESULTS

The presence of a Phe residue resulted in an increase in the ion yields of both the analyte ions [M + nH]n+ and [M–nH]n–. The relationship between the ion yields and hydrophobicities of peptides was evaluated using the partition coefficient measured by thin‐layer chromatography (PACTLC). A peptide containing a Phe residue at its C‐terminus gave a higher ion yield than when it was at the N‐terminus.

CONCLUSIONS

The ion yields of peptides increased with increasing hydrophobicity both in positive‐ and negative‐ion ESI. The enhancement effect of hydrophobicity on the ion yields was higher than that of basicity and acidity of the peptides in ESI. Copyright © 2014 John Wiley & Sons, Ltd.
Accurate mass searching of individual lipid species candidates from high‐resolution mass spectra for shotgun lipidomics
Authors: Wang Miao , Huang Yingying , Han Xianlin
Published: September 2014

RATIONALE

With the increased mass accuracy and resolution in commercialized mass spectrometers, new developments on shotgun lipidomics could be expected with increased speed, dynamic range, and coverage over lipid species and classes. However, we found that the major issue by using high mass accuracy/resolution instruments to search lipid species is the partial overlap between the two‐13C‐atom‐containing isotopologue of a species M (i.e., M+2 isotopologue) and the ion of a species with one less double bond than M (assigned here as L). This partial overlap alone could cause a mass shift of the species L to the lower mass end up to 12 ppm around m/z 750 as well as significant peak broadening.

METHODS

We developed an approach for accurate mass searching by exploring one of the major features of shotgun lipidomics data that lipid species of a class are present in ion clusters where neighboring masses from different species differ by one or a few double bonds. In the approach, a mass‐searching window of 18 ppm (from –15 to 3 ppm) was first searched for an entire group of species of a lipid class. Then accurate mass searching of the plus one 13C isotopologue of individual species was used to eliminate the potential false positive.

RESULTS

The approach was extensively validated through comparing with the species determined by the multi‐dimensional MS‐based shotgun lipidomics platform. The newly developed strategy of accurate mass searching enables the overlapped L species to be identified and the corresponding peak intensities to be acquired.

CONCLUSIONS

We believe that this novel approach could substantially broaden the applications of high mass accurate/resolution mass spectrometry for shotgun lipidomics. Copyright © 2014 John Wiley & Sons, Ltd.
QoS provisioning by power control for video communication via satellite links
Authors: Ma Ting , Lee Yee Hui , Winkler Stefan , Ma Maode
Published: September 2014

Video transmissions over satellite links are sensitive to signal fades because of rain, especially in the tropics. We performed a video‐streaming experiment over a satellite link for 24 days distributed over 1 year to investigate the effects of rain fade. Based on the measurements, models for the relationships between rainfall rate, power level, packet loss, and video quality are proposed. Furthermore, for both uplink and downlink channel, an adaptive closed loop power control algorithm, with a Proportional–Integral–Derivative controller is designed. This is used for the mitigation of the rain‐induced attenuation in order to guarantee a certain level of Quality of Service and Quality of Experience. Simulation results show the effectiveness of the proposed power control solution and its ability to sustain video quality levels in spite of rain fades. Copyright © 2014 John Wiley & Sons, Ltd.
Practical key‐dependent message chosen‐ciphertext security based on decisional composite residuosity and quadratic residuosity assumptions
Authors: Chang Jinyong , Xue Rui
Published: September 2014

An encryption scheme is key‐dependent message chosen plaintext attack (KDM‐CPA) secure if it is secure even against an attacker who has access to encryptions of messages that depend on the secret key. Such situations naturally occur in some scenarios such as formal calculus, hard‐disk encryption, or multi‐party protocols. However, up to now, there are not many schemes that achieve KDM‐CPA security, let alone KDM chosen ciphertext attack (KDM‐CCA) security. The constructions proposed by Camenisch, Chandran, and Shoup (Eurocrypt 2009), and Hofheinz (Eurocrypt 2013) are the only two general constructions that can be proved to be KDM‐CCA secure in the standard model. Besides, Qin, Liu, and Huang (ACISP 2013) also presented another concrete implementation. In particular, they showed how to obtain KDM‐CCA security from the classic Cramer–Shoup cryptosystem (based on the decisional Diffie–Hellman assumption) w.r.t. a new ensemble of functions (we call QLH ensemble). Since the Cramer–Shoup scheme has short ciphertext size and higher computational efficiency, they obtain practical KDM‐CCA security w.r.t. a reasonably large ensemble.

In this paper, we study the KDM‐CCA security of other cryptosystems proposed by Cramer and Shoup (Eurocrypt 2002). In particular, we prove that the schemes, based on decisional composite residuosity (DCR) and quadratic residuosity (QR) assumptions, respectively, also achieve KDM‐CCA security w.r.t. the QLH ensemble. On the one hand, because the DCR‐based and QR‐based schemes of Cramer et al. are fairly practical, we also obtain practical KDM‐CCA security based on DCR and QR assumptions, respectively. On the other hand, compared with the result of Qin et al., we need not tailor the original schemes of Cramer et al. because themselves have natural “compatibility” for the message space and the secret key space. Copyright © 2014 John Wiley & Sons, Ltd.
Optimization of Midrex Direct Reduced Iron Use in Ore‐Based Steelmaking
Authors: Huitu Kaisa , Helle Mikko , Helle Hannu , Kekkonen Marko , Saxén Henrik
Published: September 2014

Iron and steel industry contributes by more than 5% to the global anthropogenic CO2 emissions, so new ways to reduce the emissions in this industrial sector must be found. In order to facilitate a transition to more sustainable production concepts, economic factors must be considered. The potential of using direct reduced iron from the Midrex process, based on shaft furnace technology, as a partial substitute of pellets in a blast furnace was studied in the paper. Mathematical models of the different operations in a steel plant, including the shaft furnace, form the basis of the model of the system, which was optimized by non‐linear programming with respect to costs. The main objective was to analyze the prerequisites for an economically feasible operation of a steel plant integrated with a direct reduction plant under different raw material prices and varying costs of CO2 emission allowances. The results illustrate the conditions under which it would be beneficiary in a steel plant to integrate the shaft furnace in the operations. The implications of the integration on the overall CO2 emissions of the plant are also discussed.
Experimental Study on the Refining Desulfurization Slag Made from the Reduced Red Mud
Authors: Kai Dong , Long Wu , Wenjuan Liu , Rong Zhu
Published: September 2014

Red mud is unmanageable industrial waste produced from aluminum industry, which is difficult to be disposed and recycled with traditional method. In this paper, refining desulfurization slag was made from the reduced red mud, and the desulfurization abilities of the slag and the recovery rates of the metal Fe are studied. With thermodynamic simulation, orthogonal experiments, and verification experiment, it is found that binary basicity has significant effect on LS and ηs, while the effects of Al2O3 concentration in slag and the quantity of the reduced red mud are not obvious. The optimal combination with the best desulfurization ability can be derived as A3B2C2, which means the binary basicity of the optimal slag is 7, the concentration of Al2O3 is 30%, and the wt% of the residue is 15%, which means the reduced red mud quantity is 132.92 g. At the same time, the recovery rate of Fe element increases with the quantity of the reduced red mud, and the recovery rate of metal Fe in optimal combination slag is 87.84%. The separation of the metal Fe from the reduced red mud is satisfactory. The refining desulfurization slag manufacturing is a feasible method on the disposal and recycling of the red mud.