bluuebunny/crossref_metadata_2025 huggingface dataset:
Folate‐Conjugated Polymer Micelles with pH‐Triggered Drug Release Properties
Authors: Zhao Haizheng , Duong Hoang Hanh Phuoc , Yung Lin Yue Lanry
Published: May 2010

Folate has been applied as a targeting moiety for various anticancer drug‐delivery agents to avoid non‐specific attack of normal tissues as well as to increase cellular uptake at the target tumor cells. Polymer micelles made of poly[(D,L‐lactide)‐co‐glycolide)]‐poly(ethylene glycol)‐folate (PLGA‐PEG‐FOL) was fabricated as a tumor targeting carrier for encapsulating the anticancer drug doxorubicin. To accelerate the drug release in the endosome after folate‐mediated cellular uptake, pH‐sensitive poly(β‐amino ester)‐PEG‐FOL (PAE‐PEG‐FOL) was added together with PLGA‐PEG‐FOL to form mixed micelles. The results showed that the drug release can be triggered at different pH due to the ionization of PAE. The IC50 of PLGA‐PEG‐FOL micelles is 0.46 × 10−6 M. With 20% PAE in the mixed micelles (20:80 mixed micelles), the IC50 decreases to 0.34 × 10−6 M, which is comparable to that of pure PAE‐PEG‐FOL micelles at pH 7.4. As a result of the pH sensitivity, the PAE‐PEG‐FOL micelles are not stable at pH 6.5 or lower, and the drug may be released from the micelles into the extracellular environment before uptake by the cells. The 20:80 mixed micelles are relatively stable at this condition. As a result, the micelles retain more drug in the micelles for a higher degree of cellular uptake by folate receptor‐mediated endocytosis, and exhibit higher cytotoxicity.

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Characterization of lupin major allergens (Lupinus albus L.)
Authors: Guillamón Eva , Rodríguez Julia , Burbano Carmen , Muzquiz Mercedes , Pedrosa Mercedes M. , Cabanillas Beatriz , Crespo Jesús F. , Sancho Ana I. , Mills E. N. Clare , Cuadrado Carmen
Published: May 2010

White lupin is considered to be a rich source of protein with a notable content of lysine and is being increasingly used in bakery, confectionery, snacks and pastry products due to its multifunctional properties, in addition to its potential hypocholesterolemic and hypoglycemic properties. However, lupin seed flour has been reported as a causative agent of allergic reactions, especially in patients with allergy to peanut since the risk of immunological cross‐reactivity between lupin and peanut is higher than with other legumes. Previously, we had identified two proteins as major lupin allergens (34.5 and 20 kDa) as determined by IgE immunoblotting using sera of 23 patients with lupin‐specific IgE. The aim of this study was to purify and characterize the two major lupin allergens. The results using in vitro IgE‐binding studies and MS analysis have shown that the 34.5 kDa allergen (Lup‐1) is a conglutin β (vicilin‐like protein) while the 20 kDa allergen (Lup‐2) corresponds to the conglutin α fraction (legumin‐like protein). The high level of amino acid sequence homology of Lup‐1 and Lup‐2 with the major allergens of some legumes explains the IgE cross‐reactivity and clinical cross‐reactivity of lupin and other legumes.
Tea polyphenols inhibit IL‐6 production in tumor necrosis factor superfamily 14‐stimulated human gingival fibroblasts
Authors: Hosokawa Yoshitaka , Hosokawa Ikuko , Ozaki Kazumi , Nakanishi Tadashi , Nakae Hideaki , Matsuo Takashi
Published: May 2010

IL‐6 is well recognized to be a potent bone resorptive agent and thus in the development of periodontal disease. Epigallocatechin gallate (EGCG) and epicatechin gallate (ECG), the major catechins in green tea, and theaflavin‐3,3′‐digallate (TFDG), polyphenol in black tea, have multiple beneficial effects, but the effects of catechins and theaflavins on IL‐6 production in human gingival fibroblasts (HGFs) are not known. In this study, we investigated the mechanisms by which EGCG, ECG, and TFDG inhibit tumor necrosis factor superfamily 14 (TNFSF14)‐induced IL‐6 production in HGFs. We detected TNFSF14 mRNA expression in human diseased periodontal tissues. TNFSF14 increased IL‐6 production in HGFs in a concentration‐dependent manner. EGCG, ECG, and TFDG prevented TNFSF14‐mediated IL‐6 production in HGFs. EGCG, ECG, and TFDG prevented TNFSF14‐induced extracellular signal‐regulated kinase (ERK), c‐Jun N‐terminal kinase (JNK), and nuclear factor‐κB activation in HGFs. Inhibitors of ERK, JNK, and nuclear factor‐κB decreased TNFSF14‐induced IL‐6 production. In addition, EGCG, ECG, and TFDG attenuated TNFSF14 receptor expression on HGFs. These data provide a novel mechanism through which the green tea and black tea polyphenols could be used to provide direct benefits in periodontal disease.
Synthesis of HIPS using an A2B2 Star‐Type Graft Copolymer (PB‐g‐PS)
Authors: de Anda Carlos , Morales Graciela , Acuña Pablo , Sosa Jose , Knoeppel Dave , Mays Jimmy
Published: May 2010

The properties of HIPS are largely related to the morphology of the disperse rubber particles developed during polymerization. Since the graft copolymer PB‐g‐PS formed in situ has the role of a compatibilizer between the disperse rubber particles and the continuous PS phase, through the control of the molecular characteristics of the grafting species, the rubber particles' morphology and distribution can be controlled. Several HIPS were synthesized by radical polymerization using a mixture of polybutadiene and model graft copolymers, PB‐g‐PS, and the final materials were characterized physicochemically and morphologically. Different ratios of PB/graft copolymer were used in order to study the effects on the molecular characteristics and morphology of the HIPS obtained.

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Rapid B1+ mapping using a preconditioning RF pulse with TurboFLASH readout
Authors: Chung Sohae , Kim Daniel , Breton Elodie , Axel Leon
Published: May 2010

In MRI, the transmit radiofrequency field (B) inhomogeneity can lead to signal intensity variations and quantitative measurement errors. By independently mapping the local B variation, the radiofrequency‐related signal variations can be corrected for. In this study, we present a new fast B mapping method using a slice‐selective preconditioning radiofrequency pulse. Immediately after applying a slice‐selective preconditioning pulse, a turbo fast low‐angle‐shot imaging sequence with centric k‐space reordering is performed to capture the residual longitudinal magnetization left behind by the slice‐selective preconditioning pulse due to B variation. Compared to the reference double‐angle method, this method is considerably faster. Specifically, the total scan time for the double‐angle method is equal to the product of 2 (number of images), the number of phase‐encoding lines, and approximately 5T1, whereas the slice‐selective preconditioning method takes approximately 5T1. This method was validated in vitro and in vivo with a 3‐T whole‐body MRI system. The combined brain and pelvis B measurements showed excellent agreement and strong correlation with those by the double‐angle method (mean difference = 0.025; upper and lower 95% limits of agreement were −0.07 and 0.12; R = 0.93; P < 0.001). This fast B mapping method can be used for a variety of applications, including body imaging where fast imaging is desirable. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Health‐related quality of life in children with sickle cell disease: A report from the Comprehensive Sickle Cell Centers Clinical Trial Consortium
Authors: Dampier Carlton , Lieff Susan , LeBeau Petra , Rhee Seungshin , McMurray Marsha , Rogers Zora , Smith‐Whitley Kim , Wang Winfred
Published: May 2010

Background

Pediatric health‐related quality of life (HRQOL) questionnaires have been validated in children with sickle cell disease (SCD), but small sample sizes in these studies have limited clinical comparisons. We used the baseline clinical data from the Collaborative Data (C‐Data) Project of the Comprehensive Sickle Cell Centers (CSCC) Clinical Trial Consortium to perform a detailed, descriptive study of HRQOL using the PedsQL™ version 4.0 generic core and fatigue scales.

Methods

Retrospective clinical data were obtained via medical record abstraction. Staff‐administered health history, psychosocial, and health behavior interviews were completed by a parent or guardian. PedsQL™ forms were completed separately by the child and a parent/guardian.

Results

The study enrolled 1,772 subjects (53% boys) with a mean age of 9.6 years (SD 4.7). SS or Sβ0 thalassemia occurred in 68% and 32% had SC or Sβ+ thalassemia. The occurrences of pain, priapism, avascular necrosis of hips/shoulders (AVN), or asthma were the most common complications/conditions reported. Multiple regression models controlling for hemoglobinopathies, gender, and age suggested that parent reports of physical functioning and sleep/rest fatigue declined in response to pain or AVN, while school functioning scales declined in response to pain or asthma. Sickle pain, and to a lesser extent asthma, negatively influenced child reports on almost all functioning and fatigue scales.

Conclusions

While longitudinal studies will be necessary to determine sensitivity to change, the current study suggests the potential utility of several PedsQL™ HRQOL scales as patient‐reported outcome measures for observational or interventional treatment studies of children and adolescents with SCD. Pediatr Blood Cancer. 2010;55:485–494. © 2010 Wiley‐Liss, Inc.
Synchronous occurrence of metastatic Wilms tumor and ganglioneuroma
Authors: Moran Cassandra , Greiner Robert J. , Mardam‐Bey Sami W. , Hollingsworth Caroline L. , Kulbacki Evan , Wechsler Daniel S.
Published: May 2010

We describe a 4‐year‐old female patient with a persistent paraspinal mass following chemotherapy for Wilms tumor. A discordant response to chemotherapy prompted biopsy of the persistent mass, which revealed a ganglioneuroma. This report highlights the synchronous occurrence of different tumors in the same patient, and suggests that repeat biopsies should be considered when contiguous tumor masses do not respond as expected. Pediatr Blood Cancer. 2010;55:562–565. © 2010 Wiley‐Liss, Inc.
Chloride intracellular channel 1 identified using proteomic analysis plays an important role in the radiosensitivity of HEp‐2 cells via reactive oxygen species production
Authors: Kim Jae‐Sung , Chang Jong Wook , Yun Hong Shik , Yang Kyung Mi , Hong Eun‐Hee , Kim Dong Hyun , Um Hong‐Duck , Lee Kee‐Ho , Lee Su‐Jae , Hwang Sang‐Gu
Published: May 2010

The nature of the molecules underlying the radioresistance phenotype of laryngeal cancer cells remains to be established. We initially generated radioresistant laryngeal cancer cell lines from human HEp‐2 cells with fractionated radiation. These RR‐HEp‐2 cells and isolated clones displayed more radioresistant and anti‐apoptotic phenotypes than parental HEp‐2 cells after radiation. Characteristics of RR‐Hep‐2 cell lines were confirmed by upregulation of radioresistance‐related genes, such as epidermal growth factor receptor, Hsp90, and Bcl‐xl. Subsequently, we examined proteome changes between HEp‐2 and RR‐HEp‐2 cells and identified 16 proteins showing significantly altered expression levels. Interestingly, protein expression of chloride intracellular channel 1 (CLIC1) was markedly suppressed in RR‐HEp‐2 cells, compared with non‐irradiated control cells. Suppression of CLIC1 with an indanyloxyacetic acid‐94 or small interfering RNA led to radioresistance in HEp‐2 cells by suppressing the radiation‐induced cellular ROS level. However, ectopic overexpression of CLIC1 induced radiosensitivity in RR‐HEp‐2 cells via induction of ROS level after radiation, suggesting that the protein acts as a positive regulator of ROS production. Our results collectively indicate that suppression of CLIC1 contributes to acquisition of the radioresistance phenotype of laryngeal cancer cells via inhibition of ROS production, implying that this protein is an important candidate molecule for radiotherapy in radioresistant laryngeal cancer cells.
Blowing Hot and Cold on Project Management
Authors: Bredillet Christophe N.
Published: May 2010

The purpose of this article is to suggest a possible “meta” approach of the project management field—the unit of analysis—respectful of the various perspectives in existence, while providing an integrative ontological and epistemological framework. In order to do so, I first suggest what could be perceived as being the state of the field and its main constituting “school of thoughts.” Then I open the debate on what could be the ontological and epistemological perspectives enabling us to better take into account the diversity we face in considering the richness of the field. Based on these developments, I propose to address project management as a complex integrative knowledge field, which eventually will lead us to consider “modeling—developing specific convention—to do ingeniously” as acting and learning mode in the management of projects.
Opening the “Black Box” of Collective Competence in Extreme Projects: Lessons from the French Special Forces
Authors: Melkonian Tessa , Picq Thierry
Published: May 2010

Developing teams capable of completing projects in extreme situations is becoming a major challenge for a growing number of organizations. The notion of collective competence is increasingly being seen as a vital precondition for the success of project teams, particularly in extreme environments. However, we still know little about the ingredients of this collective competence. To partially fill this gap, we make use of the insights offered by the very particular world of the French Special Forces, which have been operating successfully for several decades in extreme environments. Based on an in-depth qualitative study of their project-based mode of operations, we detail the six main ingredients of the collective competence that underpins the activities of commando units in the field and insist upon the criticality of the pre- and postmission phases during which this collective competence is actively reinforced.
Psychological distress among family carers of oesophageal cancer survivors: the role of illness cognitions and coping
Authors: Dempster Martin , McCorry Noleen K. , Brennan Emma , Donnelly Michael , Murray Liam J. , Johnston Brian T.
Published: May 2010

Objective: The research aimed to determine the extent to which illness cognitions and coping explain psychological distress (fear of cancer recurrence, anxiety and depression symptoms) among family carers of survivors of oesophageal cancer.

Methods: Carers of patients registered with the Oesophageal Patients' Association in the UK were mailed a questionnaire booklet containing questions about medical and demographic variables, the Illness Perception Questionnaire‐Revised, the Cancer Coping Questionnaire, the Concerns about Recurrence Scale and the Hospital Anxiety and Depression Scale.

Results: Complete responses were received from 382 family carers (75% male; mean (SD) age=62 (10.91) years). Regression models indicated that the variables measured could explain between 35 and 49% of the variance in psychological distress among carers. Illness cognitions (particularly perceptions of the cause of, consequences of and personal control over oesophageal cancer and the carer's understanding of the condition) explained the majority of this variance. Positive focus coping strategies were also found to be important in explaining psychological distress.

Conclusion: The results of this study are consistent with previous research demonstrating that illness cognitions are significant correlates of adaptive outcomes, thereby suggesting that cognition‐based interventions could potentially be effective in minimizing emotional distress among family carers of oesophageal cancer survivors. Copyright © 2010 John Wiley & Sons, Ltd.
Functionalization of Nonwoven Pet Fabrics by Water/O2 Plasma for Biomolecule Mediated Cell Cultivation
Authors: Sasmazel Hilal Turkoglu , Manolache Sorin , Gümüşderelioğlu Menemşe
Published: May 2010

The main target of this study was to obtain COOH functionalities on the surface of 3D, nonwoven polyethylene terephthalate fabrics (NWPFs) by using low pressure water/O2 plasma assisted treatment. The plasma treatments were performed in a cylindrical, capacitively coupled RF‐plasma‐reactor and then following steps were performed: in situ (oxalyl chloride vapors) gas/solid reaction to convert OH functionalities into COCl groups; and hydrolysis under open laboratory conditions using air moisture for finalCOOH functionalities. COOH and OH functionalities on the surfaces were detected quantitatively by fluorescent labeling techniques. The COOH‐functionalized samples were biologically activated with insulin or heparin molecules by using spacer polyoxyethylene bis‐amine (PEO). Successful immobilization was checked qualitatively using electron spectroscopy for chemical analysis (ESCA). The average amount of immobilized insulin and heparin onto NWPF surfaces were determined as 146.09 and 4.81 nmol · cm−2, respectively. Our results showed that water/O2 plasma assisted treatment worked very well for functionalization and biofunctionalization of 3D NWPF disks comparing with wet‐chemistry methods. Cell culture experiments indicated that functionalization of NWPF disks and/or nanotopographies on the disk surfaces were effective on adhesion and proliferation of L929 mouse fibroblasts.

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Crystal structure of Bacillus subtilis SPP1 phage gp22 shares fold similarity with a domain of lactococcal phage p2 RBP
Authors: Veesler David , Blangy Stéphanie , Spinelli Silvia , Tavares Paulo , Campanacci Valérie , Cambillau Christian
Published: May 2010

SPP1 is a siphophage infecting the gram‐positive bacterium Bacillus subtilis. It is constituted by an icosahedric head and a long non‐contractile tail formed by gene products (gp) 17–21. A group of 5 small genes (gp 22–24.1) follows in the genome those coding for the main tail components. However, the belonging of the corresponding gp to the tail or to other parts of the phage is not documented. Among these, gp22 lacks sequence identity to any known protein. We report here the gp22 structure solved by X‐ray crystallography at 2.35 Å resolution. We found that gp22 is a monomer in solution and possesses a significant structural similarity with lactococcal phage p2 ORF 18 N‐terminal “shoulder” domain.
Near‐UV LEDs for integrated InO‐based ozone sensors
Authors: Wang Ch. Y. , Cimalla V. , Kunzer M. , Passow T. , Pletschen W. , Kappeler O. , Wagner J. , Ambacher O.
Published: May 2010

The paper reports on the integration of resistive gas sensors from indium oxide nanoparticles with near‐ultraviolet light emitting diodes (LEDs) for miniaturized and highly sensitive ozone sensing. For the integrated sensor an LED with an optical power as low as 250 μW is sufficient. An optimum operational window of the LED wavelength is determined to be between 380–420 nm. Furthermore, two operational modes of the used LED (pulse and continuous modes) have been compared and it is found that the pulse mode is more suitable for real applications. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
MOVPE growth of high optical quality InGaPN layers on GaAs (001) substrates
Authors: Kaewket Dares , Sanorpim Sakuntam , Tungasmita Sukkaneste , Katayama Ryuji , Onabe Kentaro
Published: May 2010

Highly luminescent In0.528Ga0.472P1‐yNy layers (y =0–0.027) were grown on GaAs (001) substrates by metalorganic vapor phase epitaxy. The dependence of photoluminescence (PL) properties on the N content in In0.528Ga0.472P1‐yNy layers was investigated. Near‐band edge emissions were obviously observed up to room temperature. With increasing temperature, the PL peak energy exhibits an inverted S‐shape, which explained by the strong localization of carriers at low‐temperatures, while the band‐to‐band transition becomes dominant at higher temperatures. With incorporation of N into In0.528Ga0.472P, the bandgap at 10 K is red‐shifted as large as 110 meV for the highest N‐containing layer (y =0.027), indicating a large bandgap bowing. Further, the temperature dependence of the bandgap energy becomes significantly weak with increasing N content. Our results suggest that the density of states around the band edge of In0.528Ga0.472P1‐yNy is modified from that of In0.528Ga0.472P due to the localized states possibly induced by the presence of N. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Very low sheet resistance AlInN/GaN HEMT grown on 100 mm Si(111) by MOVPE
Authors: Cheng Kai , Degroote S. , Leys M. , Medjdoub F. , Derluyn J. , Sijmus B. , Germain M. , Borghs G.
Published: May 2010

This paper presents results on the properties of AlInN/GaN high electron mobility transistors (HEMT) grown on 100 mm Si(111) substrates by metal organic vapour phase epitaxy (MOVPE). To the best of our knowledge this is the first demonstration of AlInN/GaN HEMT with a very low sheet resistance of 179 ± 3.9 Ω/□ on large size Si substrates. The electron density of the two dimensional electron gas (2DEG) is as high as 3.1×1013/cm2, while the electron mobility is around 1000 cm2/Vs. The very low sheet resistance of AlInN/GaN HEMT results in a high current density of 1.3 A/mm in device operation with a gate length of 1.5 μm. The current density of the AlInN/GaN HEMT is twice as high as our standard AlGaN/GaN HEMT with the same geometry, which shows a great potential for high power switching applications. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High‐performance GaN/InGaN heterojunction bipolar transistors using a direct‐growth approach
Authors: Lee Yi‐Che , Kim Hee‐Jin , Zhang Yun , Choi Suk , Dupuis Russell D. , Ryou Jae‐Hyun , Shen Shyh‐Chiang
Published: May 2010

We report high performance npn GaN/InGaN double heterojunction bipolar transistors (DHBTs) that was directly grown on sapphire substrates with high common‐emitter current gain (>40) at collector current density (JC) > 5 kA/cm2. A study on the emitter sizing effect shows that the perimeter‐dependent recombination current density changes from 1.5×10‐6 to 6.1×10‐4 A/cm as JC increases from 5 A/cm2 to 100 A/cm2. The fabricated multi‐fingered DHBTs show similar surface recombination current density and a current gain of > 23 at JC > 100 A/cm2 is also achieved (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
AlGaN‐based 330 nm resonant‐cavity‐enhanced p–i–n junction ultraviolet photodetectors using AlN/AlGaN distributed Bragg reflectors
Authors: Xie Zili , Liu Bin , Nie Chao , Jiang Ruolian , Ji Xiaoli , Zhao Hong , Han Ping , Xiu Xiangqian , Zhang Rong , Zheng Youdou , Gong Haimei
Published: May 2010

AlGaN‐based resonant‐cavity‐enhanced (RCE) p‐i‐n junction photodetectors (PDs) operating at the wavelength of 330 nm are fabricated by metal organic chemical vapor deposition (MOCVD). The growth and characterization of AlN/Al0.3Ga0.7N distributed Bragg reflectors(DBRs) are investigated firstly. It is shown that with increasing the pairs of the bi‐layers, the reflectance of AlN/AlGaN DBR is elevated, but the stop band width is depressed. For grown RCE PDs structure, a 20.5‐pair AlN/Al0.3Ga0.7N DBR is selected as the back mirror and 3‐pair AlN/Al0.3Ga0.7N DBR as the front one to form an optical micro‐cavity. A p‐GaN/i‐GaN/n‐Al0.3Ga0.7N junction structure is used as active layers within the cavity. The optical absorption of the RCE PD structure is approximately 59.8% determined by reflectance measurement. Selectively enhanced by the cavity effect, a response peak of 0.128 A/W at 330 nm with external quantum efficiency of 48% is obtained under zero bias. The peak wavelength shifted 15 nm with the incident angle of light increasing from 0° to 60°, which suggests that the detection wavelength can be tuned by controlling the angle of incoming light (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Resonating valence‐bond mechanism for the superconductivity in K3C60
Authors: Bastos Cristiano C. , Costa Marconi B. S. , Pavão Antonio C.
Published: May 2010

Density functional theory calculations in different cluster models, the largest one K38(C60)23 with 1,418 atoms, combined with the resonating valence‐bond theory show that superconductivity in K3C60 involves interaction of C60 with K+, K0, and K− in octahedral interstices as well as immobilization of negative charges on positive tetrahedral K atoms. We found that the orbitals involved in the highest occupied molecular orbital–lowest unoccupied molecular orbital gap are mainly from C60 and octahedral potassium atoms. We suggest that a K3C60 superconductor improvement can be achieved through potassium atom vacancy in octahedral sites. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
Resilient decentralized stabilization of interconnected time‐delay systems with polytopic uncertainties
Authors: Mahmoud Magdi S. , Almutairi Naif B.
Published: May 2010

Decentralized delay‐dependent local stability and resilient feedback stabilization methods are developed for a class of linear interconnected continuous‐time systems. The subsystems are time‐delay plants which are subjected to convex‐bounded parametric uncertainties and additive feedback gain perturbations while allowing time‐varying delays to occur within the local subsystems and across the interconnections. The delay‐dependent local stability conditions are established at the subsystem level through the construction of appropriate Lyapunov–Krasovskii functional. We characterize decentralized linear matrix inequalities (LMIs)‐based delay‐dependent stability conditions by deploying an injection procedure such that every local subsystem is delay‐dependent robustly asymptotically stable with an γ‐level ℒ︁2‐gain. Resilient decentralized state‐feedback stabilization schemes are designed, which takes into account additive gain perturbations such that the family of closed‐loop feedback subsystems enjoys the delay‐dependent asymptotic stability with a prescribed γ‐level ℒ︁2‐gain for each subsystem. The decentralized feedback gains are determined by convex optimization over LMIs. All the developed results are tested on representative examples. Copyright © 2010 John Wiley & Sons, Ltd.
Factors affecting stranding of juvenile salmonids by wakes from ship passage in the Lower Columbia River
Authors: Pearson W. H. , Skalski J. R.
Published: May 2010

The effects of deep‐draft vessel traffic in confined riverine channels on shorelines and fish are of widespread concern. In the Pacific Northwest of the United States, wakes and subsequent beach run‐up from ships transiting the Lower Columbia River have been observed to strand juvenile salmon and other fish. As part of a before‐and‐after study to assess stranding effects that may be associated with channel deepening, we measured 19 variables from observations of 126 vessel passages at three low‐slope beaches and used multiple logistic regression to discern the significant factors influencing the frequency of stranding. Subyearling Chinook salmon were 82% of the fish stranded over all sites and seasons. Given a low‐slope beach, stranding frequencies for juvenile salmon were significantly related to river location, salmon density in the shallows, a proxy for ship kinetic energy, tidal height and two interactions. The beach types selected for our study do not include all the beach types along the Lower Columbia River so that the stranding probabilities described here cannot be extrapolated river‐wide. A more sophisticated modelling effort, informed by additional field data, is needed to assess salmon losses by stranding for the entire lower river. Such modelling needs to include river‐scale factors such as beach type, berms, proximity to navigation channel, and perhaps, proximity to tributaries that act as sources of outmigrating juvenile salmon. At both river and beach scales, no one factor produces stranding; rather interactions among several conditions produce a stranding event and give stranding its episodic nature. Published in 2010 by John Wiley & Sons, Ltd.
An in situ temperature‐programmed XPS study of the surface chemical reactions of thiophene with Ag/titania
Authors: Samokhvalov Alexander , Duin Eduardus C. , Nair Sachin , Tatarchuk Bruce J.
Published: May 2010

The Ag/titania sorbent for the ultradeep desulfurization of liquid fuels was characterized by electron spin resonance and was found to contain nearly the stoichiometric titania, without significant concentration of Ti3+ or the reactive oxygen species. The surface chemical reactions of thiophene adsorbed on the Ag/titania were studied by temperature‐programmed XPS from 25 to 525 °C upon in situ thermal annealing in high vacuum and in situ oxidation by oxygen gas. The titania support is not chemically reactive under those conditions. Silver oxide in the Ag/titania sorbent is converted to Ag2 S without formation of the transient surface sulfates or sulfites and is further oxidized by molecular oxygen. Copyright © 2010 John Wiley & Sons, Ltd.
Grafting of polyethylene glycols onto nanometer silica surface by 1,4‐phenylene diisocyanate
Authors: Zhang Wentao , Lee Hong‐Ro
Published: May 2010

In this paper, polyethylene glycol (PEG) molecules have been grafted onto the surface of nanometer silica in toluene by using 1,4‐phenylene diisocyanate (PPDI) as a coupling agent, and dibutyltion dilaurate (DBTDL) as a catalyst. This process was executed by using a one‐step procedure involving a first reaction of PPDI with silica and a subsequent reaction of isocyanate‐bound silica with PEG. The PEG‐grafted silica has been characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and SEM analyses. The effects of reaction time, temperature and molar ratio of reactant on the effectiveness of the surface grafting were also investigated. Optimum grafting conditions of PEG were obtained at the temperature of 80 °C for 8 h. Maximum grafting of PEG molecules ratio was 22.6%, and maximum overall grafting ratio was 35%, as determined by TGA. Copyright © 2010 John Wiley & Sons, Ltd.
Surface studies of diamond‐like carbon films grown by plasma‐enhanced chemical vapor deposition
Authors: Maheswaran R. , Sivaraman R. , Mahapatra O. , Rao P. C. , Gopalakrishnan C. , Thiruvadigal D. J.
Published: May 2010

The influence of plasma pressure on the surface morphology of diamond‐like carbon (DLC) films, synthesized by plasma enhanced chemical vapour deposition (PECVD) has been investigated. The DLC films have been grown at different methane–argon ratios. The grain size and the surface roughness have been studied as a function of plasma pressure. The morphology and surface roughness of the films have been inspected by atomic force microscopy. The film surface has also been characterized by Raman spectroscopy to study the hybridization of carbon in the film so as to evaluate its carbon composition. The results confirm that the film grown at low argon pressure has more uniform distribution on the substrate. The Raman spectrum indicates that increase in plasma pressure leads to a proportional increase in the amount of sp3 hybridized carbon in the grown film. Copyright © 2010 John Wiley & Sons, Ltd.
Probing chemical homogeneity within single cluster impact sites
Authors: Pinnick Veronica , Verkhoturov Stanislav V. , Kaledin Leonid , Schweikert Emile A.
Published: May 2010

We have recently reported a nanoprobe technique based on time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS) capable of obtaining molecular information from individual nanoobjects. The technique is based on event‐by‐event bombardment/detection, where information from individual objects is obtained via coincidental secondary ion emission from single projectile impacts. Here, we demonstrate that the event‐by‐event mode is sensitive to the chemical and/or physical separation of molecular species. As a test case, two nanoobject samples with the same chemical composition were prepared with different morphologies. Both consisted of polystyrene spheres deposited onto nanoalumina whiskers, but their structures differed. One sample contained 30 nm spheres intact, and the other produced nanoflake structures. Bombardment with Au4004+ at 136 keV total impact energy demonstrates that conventional mass spectra do not reflect differences between the morphologies, whereas the coincidental mass spectra show significant differences in coemission of aluminum‐based and carbon‐based secondary ions. Copyright © 2010 John Wiley & Sons, Ltd.
Failure analysis of fine Cu patterning by shave‐off profiling
Authors: Nojima M. , Fujii M. , Kakuhara Y. , Tsuchiya H. , Kameyama A. , Yokogawa S. , Owari M. , Nihei Y.
Published: May 2010

We focused on failure within fine copper patterning on a semiconductor chip. Three grades of samples were prepared; hard CMP treatment, soft CMP treatment and standard, and compared the differences by shave‐off profiling. The shave‐off profiles of CMP treatment revealed a saw‐toothed structure, and the shave‐off profile of a standard chip was revealed as a periodic triangular wave. The difference can be explained by the existence of residue on the CMP process. Copyright © 2010 John Wiley & Sons, Ltd.
Sputtering soft materials with molecular projectiles: a microscopic view
Authors: Delcorte A. , Garrison B. J. , Hamraoui K.
Published: May 2010

The sputtering of bulk organic samples by molecular projectiles is modeled using molecular dynamics simulations. A coarse‐grained representation of entangled polyethylene oligomers (1.4 kDa) is used as a model of an amorphous soft material. In this study, a variety of projectiles are compared, including C60, coronene and a series of polystyrene molecular cluster (0.6–110 kDa). The polystyrene clusters bridge the gap between the polyatomic ions (SF5, C60) used in secondary ion mass spectrometry (SIMS) and the large organic microdroplets generated, e.g. in desorption electrospray ionization. In addition, they allow us to explore a wide range of energies/nucleon (0.1–18 eV/nucleon) with projectiles of similar nature and the same total kinetic energy (10 keV). Two regions of sputtering can be distinguished. Above 1 eV/nucleon (smaller projectiles), the sputtering yield depends only on the total projectile energy and not on the projectile nuclearity. Below 1 eV/nucleon (larger projectiles), yields are influenced by both the projectile energy and their nuclearity. Larger projectiles also eject fewer fragments and induce significantly less damage in the sample. A region of intact molecular emission, without induced fragmentation, exists in the < 1 eV/nucleon range. For large clusters, an energy of < 1 eV/nucleon still provides a sputtered mass from the target that is larger than 10 kDa. This region of molecular emission with minimal fragmentation, also attainable with large gas clusters, offers new analytical perspectives. Copyright © 2010 John Wiley & Sons, Ltd.
ToF‐SIMS characterization of the lipid layer on the hair surface. I: the damage caused by chemical treatments and UV radiation
Authors: Habe Taichi , Tanji Noriyuki , Inoue Shigeto , Okamoto Masayuki , Tokunaga Shinichi , Tanamachi Hiroto
Published: May 2010

In this study, we investigated how the lipids bound to the outermost surface of human hair are affected by chemical treatments such as hair bleach and ultraviolet (UV) radiation using time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS). Many lipid components are bound covalently via a thioester or ester linkage on the outermost surface of hair. We studied how these components are changed by chemical treatment. It was found that the fatty acids covalently bound via a thioester linkage are removed more easily than those with an ester linkage. Eighty percent of the 18‐MEA (18‐methyleicosanoic acid), which is a major component of lipids, was removed in a single bleach treatment, and most had vanished entirely after three treatments. We also investigated the influence of UV radiation and found that the amount of 18‐MEA decreased with the radiation time. More than 90% of the 18‐MEA was removed by UV radiation with corresponding exposure of three summer months. Copyright © 2010 John Wiley & Sons, Ltd.
ToF‐SIMS imaging and depth profiling of HeLa cells treated with bromodeoxyuridine
Authors: Brison Jeremy , Benoit Danielle S. W. , Muramoto Shin , Robinson Michael , Stayton Patrick S. , Castner David G.
Published: May 2010

Time‐of‐flight (ToF) SIMS 2D images and molecular depth profiles of human HeLa cells treated with bromodeoxyuridine (BrdU) were acquired in the dual beam mode (Bi3+ analysis beam, C60+ etching beam). Several preparation protocols were investigated and were compared to a simple wash‐and‐dry method. The feasibility of using C60 to clean the samples prior to imaging with Bi was also investigated quantitatively by calibrating full depth profiles of the cells using atomic force microscopy. BrdU was used as a marker for the cell nucleus, facilitating identification and localization of subcellular features during depth profiling. Results show that C60 can be used to remove the surface contamination and to access different layers within the cells for 2D imaging. For a 1 nA, 10 keV C60+ beam incident at 45° and rastered over a 500 × 500 µm2 area, ∼1 nm of biological material was sputtered every second. Our results show that HeLa cells were completely removed after etching with 1.3 × 1015 C60+ ions per cm2, giving an average etching rate of 3.9 nm for every 1013 C60 per cm2 at 10 keV and 45° incidence. Copyright © 2010 John Wiley & Sons, Ltd.
Study of charge effect during Cs+ sputtering of polystyrene in the pre‐equilibrium regime
Authors: Wahoud F. , Mouhib T. , Audinot J.‐N. , Delcorte A. , Migeon H.‐N.
Published: May 2010

This study investigates the effect of the insulating nature of polystyrene thin films on the SIMS signal during Cs+ sputtering. A threshold primary fluence φth (∼3 × 1014 cm−2 for a 150 nm film) marks the transition between different behaviours for charge accumulation/neutralization and their effects on the detected SIMS signal. For Cs+ fluences lower than φth, the voltage difference between the surface and the conductive substrate increases linearly with the film thickness. This voltage difference is due to the accumulation of positive charge on the film surface, which causes a breakdown in the SIMS signal. At fluence φth, the accumulated charge density induces in the polystyrene film a high electric field permitting to reach the dielectric breakdown voltage, i.e. the minimum voltage that causes a portion of an insulator to become electrically conductive. In this paper, we will suppose that the positive charge, previously accumulated on the surface, could be then neutralized through the conductive regions, which are created in the insulating film. Copyright © 2010 John Wiley & Sons, Ltd.
Optimizing C60 incidence angle for polymer depth profiling by ToF‐SIMS
Authors: Iida Shin‐ichi , Miyayama Takuya , Sanada Noriaki , Suzuki Mineharu , Fisher Gregory L. , Bryan Scott R.
Published: May 2010

The introduction of C60+ as a sputter ion beam for ToF‐SIMS has made it possible to acquire molecular depth profiles on a wide variety of polymers. However, previous studies have indicated that certain classes of polymers undergo sputter‐induced damage when bombarded with C60+ that prevents obtaining stable molecular secondary ion signals as a function of depth. A number of different analytical parameters have been previously explored in attempts to improve depth profiling of these polymer classes. In this study, the effect of C60+ incident angle on the ability to depth profile polycarbonate (PC) and polystyrene (PS) was investigated at angles from 48° to 76° with respect to the sample normal. This study indicates that the highest sputtering angle provided the best conditions for molecular depth profiling. Copyright © 2010 John Wiley & Sons, Ltd.
Depth profiling of anodic tantalum oxide films with gold cluster ions
Authors: Poerschke David , Wucher Andreas
Published: May 2010

In order to investigate the merits of cluster bombardment for inorganic sputter depth profiling, thin (50‐nm) anodic Ta2O5 films were analyzed by ToF‐SNMS using 25 keV Aun+ projectile ions. The same focused primary ion beam was employed both for sputter erosion and (static) data acquisition. Sputtered neutral particles were postionized by means of single photon ionization using a 157 nm F2 excimer laser. The results show that, for the amorphous films investigated here, the transition from mono‐ to polyatomic projectiles does not lead to a significant improvement of the apparent depth resolution. Copyright © 2010 John Wiley & Sons, Ltd.
SKP as a tool to study the physicochemical interaction at buried metal–coating interfaces
Authors: Wielant Jan , Posner Ralf , Hausbrand René , Grundmeier Guido , Terryn Herman
Published: May 2010

The scanning Kelvin probe (SKP) was used as a tool to receive information about the interfacial interaction strength between coatings and oxide surfaces. Potential shifts induced by the application of two polymer films (polyurethane and epoxy‐amide) on differently treated steel substrates were measured as a function of the physicochemical condition of the oxide surface (hydroxyl fraction and surface energy). The results showed that, in the case of strong interfacial acid‐base interactions, a direct correlation exists between the Volta potential drop and the adhesion strength of the coating. This phenomenon indicated that the interface dipoles formed by oxide‐coating acid‐base interactions were reflected in the SKP potential shifts and that these dipoles could be detected, even when they were covered by a thick coating. Copyright © 2010 John Wiley & Sons, Ltd.
Work‐related dimensions and job stress: the moderating effect of coping strategies
Authors: Wickramasinghe Vathsala
Published: May 2010

The aim of this paper is to examine the moderating effect of coping strategies on the relationship between work‐related dimensions (i.e. work routinization, role clarity, relationships with others and promotional opportunity) and job stress. For the study, a convenience sample of 385 white‐collar employees, full‐time employed in various types of private sector organizations, belong to different industries and ranked at different levels within the organizations responded. The factor analysis led to identify four broad coping strategies that individuals use, namely, individual positive coping, workplace initiatives, workplace informal support and individual destructive coping. It was found that both individual positive coping and workplace initiatives moderate the relationship between ‘relationships with others’ and job stress. However, none of the coping strategies have moderated the relationship between job stress and the other three work‐related dimensions. Copyright © 2010 John Wiley & Sons, Ltd.
Irritant‐drinking behaviour can be modified by gravity‐stress loaded in developing but not in adult rats
Authors: Kimoto Mari , Zeredo Jorge L , Toda Kazuo
Published: May 2010

It is generally accepted that taste and taste‐related trigeminal chemical sensation bring up emotions that are essential for animal living and for a good quality of life, and that stress may modify sensory systems related to emotionality. The purpose of this study was to clarify (1) the effects of stress on taste and trigeminal irritant sensations, (2) effects of stress at a developing stage on these sensations. Male Wistar albino rats received 1G, 2G or 3G stimulation. Hyper‐gravity was applied with a centrifugal apparatus. The two‐bottle preference test was performed to measure chemical sensation. Adult rats received 1G (control), 2G (moderate) or 3G (strong) gravity loading every 10  min/day during 32 days. Developing rats received 3G gravity loading every 10  min/day during 45 days and were compared with 1G controls. As test solutions, taste solutions (sucrose, saccharin, citric acid, NaCl, monosodium glutamate, quinine and caffeine) and a trigeminal irritant solution (capsaicin) were used. In developing rats, but not in adult rats, hyper‐gravity stimulation increased the intake volume of sucrose, saccharin, NaCl, quinine and capsaicin, and the preference ratio for quinine, caffeine and capsaicin. It is suggested that the life stage where stress is loaded is critical for determining changes in emotionality as well as in emotion‐related sensory systems. Copyright © 2010 John Wiley & Sons, Ltd.
Exposure to psychosocial risks at work in prisons: does contact with inmates matter? A pilot study among prison workers in Spain
Authors: Ghaddar Ali , Ronda Elena , Nolasco Andreu , Álvares Nahum , Mateo Inmaculada
Published: May 2010

Research has lately increased its focus on work conditions as predictors of stress among prison workers but only few studies have focused on how the exposure of workers to psychosocial risks vary according to their occupational groups and their contact with inmates. Work psychosocial risks (demands, control and social support) were assessed using the Spanish version of the Copenhagen Psychosocial Questionnaire among 164 Spanish prison workers (43 per cent of those surveyed). Regression analysis was used to explore how psychosocial hazards and their combinations (outcome variables) vary according to occupational groups. Results suggest that psychosocial risks were highest among guards that have more contact with inmates. Implications of the findings for policy making and practice application are discussed. Copyright © 2010 John Wiley & Sons, Ltd.
Frequency and cause of disagreements in imaging diagnosis in children with ventriculomegaly diagnosed prenatally
Authors: Senapati G. M. , Levine D. , SMITH C. , Estroff J. A. , Barnewolt C. E. , Robertson R. L. , Poussaint T. Y. , Mehta T. S. , Werdich X. Q. , Pier D. , Feldman H. A. , Robson C. D.
Published: May 2010

Objectives

To assess the frequency and cause of variability in diagnosis on cranial sonography and magnetic resonance imaging (MRI) in children referred following prenatal diagnosis of ventriculomegaly.

Methods

Between 19 September 2003 and 16 March 2007, 119 infants with ultrasound and/or MRI studies performed within 13 months (median, 6 days) after birth, following prenatal referral for ventriculomegaly, were studied prospectively. There were 97 infants with ultrasound results and 53 with MRI, including 31 with both. Three sonologists and three pediatric neuroradiologists interpreted the postnatal ultrasound and MRI findings, blinded to prenatal diagnosis, and a final consensus diagnosis or group of diagnoses was obtained. Ventricular sizes as well as types of and reasons for any disagreement in diagnosis were recorded. Disagreements on a per patient basis were categorized as being major when they crossed diagnostic categories and had the potential to change patient counseling. Postnatal and prenatal diagnoses were compared.

Results

There was prospective agreement on 42/97 (43%) ultrasound and on 9/53 (17%) MRI readings. Prospective consensus was more likely when the number of central nervous system (CNS) anomalies was lower (P < 0.001 and P = 0.002 for ultrasound and MRI, respectively). In 24/55 (44%) ultrasound and 11/44 (25%) MRI examinations with disagreement in diagnosis, there was disagreement concerning the presence of ventriculomegaly. In 22/97 (23%) ultrasound studies and 22/53 (42%) MRI studies the disagreements were potentially important. Reasons for discrepancies in the reporting of major findings included errors of observation as well as modality differences in depiction of abnormalities. In comparing prenatal with postnatal diagnoses, there were 11/97 (11%) ultrasound and 27/53 (51%) MRI examinations with newly detected major findings, the most common being migrational abnormalities, callosal dysgenesis/destruction and interval development of hemorrhage.

Conclusion

Variability in postnatal CNS diagnosis is common after a prenatal diagnosis of ventriculomegaly. This is due in part to a lack of standardization in the definition of postnatal ventriculomegaly. Copyright © 2010 ISUOG. Published by John Wiley & Sons, Ltd.