bluuebunny/crossref_metadata_2025 huggingface dataset:
Raman microscopy study of synthetic cobalt blue spinels used in the field of art
Authors: Bouchard Michel , Gambardella Alessa
Published: March 2010

This study aims to provide a better understanding of the Raman spectra of cobalt‐based pigments in works of art. Systematic analyses of 21 industrial blue cobalt‐based pigments were carried out by using elemental energy dispersive spectroscopy and phase analyses by X‐ray diffraction (XRD) and Raman microspectroscopy, which led to the identification of 17 spinel Co‐based pigments. All the minerals contained in each pigment were characterised by all three techniques and subsequently attributed to diluents, extenders, mineralisers or unreacted reagents or to the main mineral phase, whether it was pure or contained doping or lattice modifier elements. In the particular case where doping elements were in low concentration in the host mineral lattice, their distinction by XRD from non‐doped spinel was impossible. On the contrary, Raman microspectroscopy turned out to be a perfect tool for detecting the presence of the doping agents in the spinel lattice. The determination of the elemental and mineralogical composition of the industrial blue cobalt‐based pigments commercially available for artists and studied in this survey represents a significant increase in the amount of analytical data available for this type of pigment as well as a valuable addition in the characterisation by Raman microspectroscopy of these compoundsin situ, on works of art. Copyright © 2010 John Wiley & Sons, Ltd.
Identification of copper carboxylates as degradation residues on an ancient manuscript
Authors: Aceto Maurizio , Agostino Angelo , Boccaleri Enrico , Crivello Fabrizio , Cerutti Garlanda Anna
Published: March 2010

Copper carboxylates were identified as degradation residues on the surface of a metallic pigment used in the illumination and in the text of a 9th century Italian manuscript containing theHomilies on the Gospelsof Gregory the Great, belonging to the Archive and Chapter Library of Vercelli (Italy). These compounds are responsible of the greenish aspect that several text lines and decorated initials have developed over time from their original golden texture, starting from more than a century as could be guessed from the early 20th century descriptions of the manuscript by art historians. Further, Raman investigations carried out on a particle recovered from the gutters between folios allowed (1) the identification with good accuracy of the nature of these compounds, confirmed by scanning electron microscopy‐energy dispersive X‐ray (SEM‐EDX) analysis, (2) proposing a hypothesis on their origin as due to the interaction of copper with carboxylic acids and (3) making suggestions on the proper restoration intervention; moreover, evidence was found for similar compounds in three 9th–10th century Italian manuscripts coming from Bobbio abbey. Besides, the presence of orpiment in ink composition was verified and compared with citations in some medieval texts. Copyright © 2010 John Wiley & Sons, Ltd.
Thermostable L‐arabinose isomerase from Bacillus stearothermophilus IAM 11001 for D‐tagatose production: gene cloning, purification and characterisation
Authors: Cheng Lifang , Mu Wanmeng , Jiang Bo
Published: March 2010

BACKGROUND: D‐Tagatose, as one of the rare sugars, has been found to be a natural and safe low‐calorie sweetener in food products and is classified as a GRAS substance. L‐Arabinose isomerase (L‐AI, EC 5.3.1.4), catalysing the isomerisations of L‐arabinose and D‐galactose to L‐ribulose and D‐tagatose respectively, is considered to be the most promising enzyme for the production of D‐tagatose.

RESULTS: The araA gene encoding an L‐AI from Bacillus stearothermophilus IAM 11001 was cloned, sequenced and overexpressed in Escherichia coli. The gene is composed of 1491 bp nucleotides and codes for a protein of 496 amino acid residues. The recombinant L‐AI was purified to electrophoretical homogeneity by affinity chromatography. The purified enzyme was optimally active at 65 °C and pH 7.5 and had an absolute requirement for the divalent metal ion Mn2+ for both catalytic activity and thermostability. The enzyme was relatively active and stable at acidic pH of 6. The bioconversion yield of D‐galactose to D‐tagatose by the purified L‐AI after 12 h at 65 °C reached 36%.

CONCLUSION: The purified L‐AI from B. stearothermophilus IAM 11001 was characterised and shown to be a good candidate for potential application in D‐tagatose production. Copyright © 2010 Society of Chemical Industry
Resilience and crime victimization
Authors: Dutton Mary Ann , Greene Rebecca
Published: March 2010

What do we know about resilience in crime victimization? In this article, the authors discuss resilience defined as protective factors (e.g., personality characteristics, biological characteristics, social and cultural factors, and community characteristics); as a process of adaptation (e.g., self‐enhancement, positive cognitive appraisals, coping styles, and spirituality), including an iterative perspective on resilience as a cascade of protective processes; and as positive outcomes (e.g., lack of symptoms) following exposure to adverse events. Within each of these definitional frameworks, they consider general conceptual issues pertaining to resilience and then the small body of research that has focused specifically on resilience and some type of crime victimization. Research and clinical implications are discussed.
Paired donor interchange to avoid ABO-incompatible living donor liver transplantation
Authors: Chan See Ching , Lo Chung Mau , Yong Boon Hun , Tsui Wilson J. C. , Ng Kelvin K. C. , Fan Sheung Tat
Published: March 2010

We report an emergency paired donor interchange living donor liver transplant performed on January 13, 2009. The 4 operations (2 liver transplants) were performed simultaneously. The aim was to avoid 2 ABO-incompatible liver transplants. One recipient in acute liver failure underwent transplantation in a high-urgency situation. The abdomen of the other recipient had severe adhesions from previous spontaneous bacterial peritonitis that rendered the recipient operation almost impossible. The ethical and logistical issues are discussed. Approaches adopted in anticipation of potential adverse outcomes are explained in view of the higher donor and recipient mortality and morbidity rates in comparison with kidney transplantation.
Velocity Sedimentation and Intrinsic Viscosity Analysis of Polystyrene Standards with a Wide Range of Molar Masses
Authors: Pavlov Georges M. , Perevyazko Igor , Schubert Ulrich S.
Published: March 2010

Analytical ultracentrifugation is one of the key methods among the molecular hydrodynamic methods of polymer science, biophysics, and colloid science. The aim of this work is to demonstrate the possibilities of a modern instrument, the Beckman XLI Analytical Ultracentrifuge, coupled with the now available software for the molecular characterization of synthetic polymers. For this purpose the classical system polystyrene in methyl ethylketone was investigated. The samples of low polydispersity index were studied in a 1 000‐fold interval of molar mass values. The exhaustive analysis of such hydrodynamic values as velocity sedimentation coefficient, frictional ratio, concentration Gralen coefficient, and intrinsic viscosity, was done. The values of partial specific volume, refractive index increment, and hydrodynamic invariants were also determined and discussed. The estimation of the statistical segment length (or persistent length) of polystyrene chains was made taking into account the intrachain excluded volume and draining effects (Gray–Bloomfield–Hearst theory). The obtained experimental data and results of its analysis allow the conclusion that the method of velocity sedimentation, coupled with the numerical solution of the Lamm equation, represents a powerful absolute characterization method for molar mass determination of flexible polymers of low polydispersity in relatively poor solvent.

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Glycopolymers of Various Architectures—More than Mimicking Nature
Authors: Voit Brigitte , Appelhans Dietmar
Published: March 2010

Carbohydrates have a highly important role in biological functions. The increasing understanding of their biological interactions has also triggered a strongly increased interest in the preparation of synthetic glycopolymers of various architectures and well‐defined structure which can mimic biological functions in a less complex environment. In the last few years synthetic approaches in polymer science have been refined and newly developed in order to achieve complex carbohydrate architectures and to make use of them in various areas like glycomics, biotechnology, biosensors, and medicine. Besides the use of especially controlled radical polymerization techniques, highly efficient polymer analogous reactions that can be carried out in aqueous media have been developed and applied to linear and dendritic macromolecules. Self assembly aspects and their effectiveness in biological functions have been assessed.

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Homogeneous Detection of Trypsin in Protein Mixtures Based on Fluorescence Resonance Energy Transfer between Anionic Conjugated Polymer and Fluorescent Probe
Authors: Zhu Qing , Zhan Ruoyu , Liu Bin
Published: March 2010

Herein we describe a novel and simple conjugated polymer‐fluorescent probe based platform for trypsin detection from protein mixtures in homogeneous solution. This platform takes advantage of specific interaction between the probe and the active site of trypsin and the electrostatic interaction between the polymer and the protein to mediate energy transfer between the polymer and the probe. This method does not require any separation steps, which should facilitate high‐throughput protease screening and drug discovery.

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The changing face of Parkinson's disease‐associated psychosis: A cross‐sectional study based on the new NINDS‐NIMH criteria
Authors: Fénelon Gilles , Soulas Thierry , Zenasni Franck , de Langavant Laurent Cleret
Published: March 2010

New criteria for Parkinson's disease‐associated psychosis (PDAP) were recently proposed by a NINDS‐NIMH working group. We assessed 116 consecutive unselected outpatients with PD for the existence of psychotic symptoms during the previous month, using a structured questionnaire covering the whole spectrum of PDAP symptoms. Hallucinations occurred in 42% of the patients (visual: 16%; nonvisual: 35%), delusions in 4%, and minor symptoms in 45% (sense of presence, visual illusions, or passage hallucinations). The prevalence of PDAP was 43% when the usual definition was used (hallucinations and/or delusions) and 60% when the NINDS‐NIHM criteria were used. Correlations between PDAP and patient characteristics varied with the definition of PDAP. These findings suggest that the epidemiology of PDAP should be re‐evaluated with the new criteria. Minor symptoms and nonvisual hallucinations are an important part of the PDAP spectrum, which has commonly been restricted to visual hallucinations and delusions. © 2010 Movement Disorder Society
The nondeclaration of nonmotor symptoms of Parkinson's disease to health care professionals: An international study using the nonmotor symptoms questionnaire
Authors: Chaudhuri K. Ray , Prieto‐Jurcynska Cristina , Naidu Yogini , Mitra Tanya , Frades‐Payo Belen , Tluk Susanne , Ruessmann Anne , Odin Per , Macphee Graeme , Stocchi Fabrizio , Ondo William , Sethi Kapil , Schapira Anthony H.V. , Castrillo Juan Carlos Martinez , Martinez‐Martin Pablo
Published: March 2010

The nonmotor symptoms (NMS) of Parkinson's disease (PD) are less well recognised and can be more troublesome to patients and carers than classical motor features. NMS are frequently missed during routine consultations and such under‐recognition may have implications on quality of care given that many NMS are treatable. To determine the proportion of patients not declaring NMS to healthcare professional (HCP) as assessed by self completion of the NMS questionnaire (NMSQuest), a validated, self‐completing questionnaire with 30 items. Multicentre international study. The data was collected from PD patients across all age groups and stages attending outpatient clinics in specialist and care of the elderly settings. 242 patients recruited and undeclared NMS ranged from 31.8% (diplopia) to 65.2% (delusions). The most frequently nondeclared symptoms were delusions, daytime sleepiness, intense and vivid dreams, and dizziness. In many, appropriate treatments for undeclared NMS were started only after these were recognised following completion of NMSQuest. NMS of PD are frequently undeclared at routine hospital consultation and may be related to the fact that patients often do not link these symptoms with PD or may be too embarrassed to discuss these. Use of NMSQuest allows patients to flag symptoms which may be otherwise undeclared and remain untreated when potential treatments exist. © 2010 Movement Disorder Society
Endoscopic characteristics and levodopa responsiveness of swallowing function in progressive supranuclear palsy
Authors: Warnecke Tobias , Oelenberg Stephan , Teismann Inga , Hamacher Christina , Lohmann Hubertus , Ringelstein Erich Bernd , Dziewas Rainer
Published: March 2010

Dysphagia is a frequent and early symptom in progressive supranuclear palsy (PSP) predisposing patients to aspiration pneumonia. Fiberoptic endoscopic evaluation of swallowing (FEES®) has emerged as a valuable apparative tool for objective evaluation of neurogenic dysphagia. This is the first study using FEES® to investigate the nature of swallowing impairment in PSP. Eighteen consecutive PSP patients (mean age 69.7 ± 9.0 years) were included. The salient findings of FEES® in PSP patients were compared with those of 15 patients with Parkinson's disease (PD). In 7 PSP patients, a standardized FEES® protocol was performed to explore levodopa (L‐dopa) responsiveness of dysphagia. Most frequent abnormalities detected by FEES® were bolus leakage, delayed swallowing reflex, and residues in valleculae and piriformes. Aspiration events with at least one food consistency occurred in nearly 30% of PSP patients. Significant pharyngeal saliva pooling was observed in 4 PSP patients. We found no difference of salient endoscopic findings between PSP and PD patients. Endoscopic dysphagia severity in PSP correlated positively with disease duration, clinical disability, and cognitive impairment. No correlation was found with dysarthria severity. In early PSP patients, swallowing dysfunction was solely characterized by liquid leakage with the risk of predeglutitive aspiration during the oral phase of swallowing. Two PSP patients showed relevant improvement of swallowing function after L‐dopa challenge. Chin tuck—maneuver, hard swallow, and modification of food consistency were identified as the most effective therapeutic interventions. In conclusion, FEES® assessment can deliver important findings for the diagnosis and refined therapy of dysphagia in PSP patients. © 2010 Movement Disorder Society
Teaching program for the movement disorder society‐sponsored revision of the Unified Parkinson's Disease Rating Scale: (MDS‐UPDRS)
Authors: Goetz Christopher G. , Stebbins Glenn T. , Chmura Teresa A. , Fahn Stanley , Poewe Werner , Tanner Caroline M.
Published: March 2010

To accompany the newly developed Movement Disorder Society revision of the Unified Parkinson's Disease Rating Scale (MDS‐UPDRS), we developed a teaching program. The DVD‐based program covers the four parts of the scale with visual and verbal instructions for uniform application. For the motor section (Part III), all items except rigidity are shown with an example of each rating option (0–4) as agreed upon by a panel of experts. The rate of agreement for the selected samples was always significant, with Kendall's coefficient of concordance W ranging between 0.99 and 0.72. The teaching program also provides a full patient examination with rating answers provided and four full MDS‐UPDRS cases for a Certificate Program exercise of Part III. This training program is in English, but as non‐English official translations of the MDS‐UPDRS are developed, the program can be potentially modified into different languages. © 2010 Movement Disorder Society
Decision making in de novo Parkinson's disease
Authors: Poletti Michele , Frosini Daniela , Lucetti Claudio , Dotto Paolo Del , Ceravolo Roberto , Bonuccelli Ubaldo
Published: March 2010

The aim is to study decision making in patients with de novo Parkinson's disease (PD). Recent studies reported that medicated patients with PD have poor performances compared with age‐matched healthy controls in decision making tasks, specially in the Iowa Gambling Task. Two principal causal hypotheses have been proposed to explain this phenomenon: the overdosing effects of dopaminergic therapy on the orbital frontostriatal circuit that is involved in reward processing, or an amygdala dysfunction, as suggested by similar Skin Conductance Responses of patients with PD and amygdala‐damaged patients while performing this task. The assessment of decision making with the Iowa Gambling Task was conducted in 30 nondemented and nondepressed patients with de novo PD and in 25 age‐matched healthy controls. No statistically significant difference emerged between performances of de novo PD patients and performances of healthy controls. De novo PD patients have performances in the Iowa Gambling Task similar to those of age‐matched healthy controls, suggesting that difficulties in decision making emerge, at least in de novo PD patients, by dopaminergic overstimulation of the orbital frontostriatal circuits. © 2010 Movement Disorder Society
The identification of Parkinson's disease subtypes using cluster analysis: A systematic review
Authors: van Rooden Stephanie M. , Heiser Willem J. , Kok Joost N. , Verbaan Dagmar , van Hilten Jacobus J. , Marinus Johan
Published: March 2010

The clinical variability between patients with Parkinson's disease (PD) may point at the existence of subtypes of the disease. Identification of subtypes is important, since a focus on homogeneous groups may enhance the chance of success of research on mechanisms of disease and may also lead to tailored treatment strategies. Cluster analysis (CA) is an objective method to classify patients into subtypes. We systematically reviewed the methodology and results of CA studies in PD to gain a better understanding of the robustness of identified subtypes. We found seven studies that fulfilled the inclusion criteria. Studies were limited by incomplete reporting and methodological limitations. Differences between studies rendered comparisons of the results difficult. However, it appeared that studies which applied a comparable design identified similar subtypes. The cluster profiles “old age‐at‐onset and rapid disease progression” and “young age‐at‐onset and slow disease progression” emerged from the majority of studies. Other cluster profiles were less consistent across studies. Future studies with a rigorous study design that is standardized with respect to the included variables, data processing, and CA technique may advance the knowledge on subtypes in PD.© 2010 Movement Disorder Society
Early survival of a compromised fasciocutaneous flap without pedicle revision: Monitoring with photoplethysmography
Authors: Chubb Daniel , Rozen Warren M. , Ashton Mark W.
Published: March 2010

While free flaps are reliant on their vascular pedicle for survival intraoperatively and for a variable period of time postoperatively, there have been reports of late pedicle compromise after which complete flap survival has ensued. Successful neovascularization and revascularization at the edges of a flap in such cases result in the flap becoming independent of its pedicle. We report a case in which free flap survival occurred following pedicle compromise before postoperative day seven. The use of preoperative computed tomographic angiography (CTA) assessment to map flap vasculature was able to demonstrate the intrinsic vascular anatomy of the flap, and both clinical assessment and photoplethysmography (PPG) assessment of cutaneous blood flow obtained during and after flap compromise were able to highlight the changes in flap perfusion. With complete flap survival despite the lack of pedicle revision, the roles for close monitoring with clinical assessment and PPG, and delaying debridement are discussed. © 2010 Wiley‐Liss, Inc. Microsurgery 30:462–465, 2010.
A Mediterranean diet rich in virgin olive oil may reverse the effects of the ‐174G/C IL6 gene variant on 3‐year body weight change
Authors: Razquin Cristina , Martinez J. Alfredo , Martinez‐Gonzalez Miguel A. , Fernández‐Crehuet Joaquin , Santos José Manuel , Marti Amelia
Published: March 2010

Only a few studies have analyzed the effects of the potential interaction between the ‐174G/C polymorphism of IL6 gene and the adherence to the Mediterranean diet (MD) on adiposity indexes. Our aim was to investigate the interplay between the ‐174G/C polymorphism of the IL6 gene and a Mediterranean‐style diet on body weight changes after 3 years of nutritional intervention in a high cardiovascular risk population. A total of 737 participants, aged 55–80 years were assigned to a low‐fat diet or to a Mediterranean‐style diet group with high intake of virgin olive oil (VOO) or nuts. Anthropometric measurements were taken at baseline and after 3‐year follow‐up. The ‐174G/C polymorphism of the IL6 gene was genotyped. Minor allele frequency (C) was 0.39. At baseline, the CC genotype was associated with higher measures of adiposity. After 3 years, a significant interaction (p=0.028) was found between the polymorphism (GG+GCversusCC) and the nutritional intervention: CC subjects following the MD+VOO had the lowest body weight gain. In conclusion, at baseline, CC subjects for the ‐174G/C polymorphism of IL6 had the highest body weight and BMI. However, after 3 years of nutritional intervention with MD+VOO, these subjects were predicted to have the greatest reduction in body weight.
Acylated manoyl oxide diterpenes of Stemodia trifoliata
Authors: da Silva Wildson Max B. , Silveira Edilberto R. , Pessoa Otilia Deusdênia L.
Published: March 2010

Two new labdane diterpenes, 6α‐malonyloxy‐ethyl ester manoyl oxide and bis‐6α‐dioxymanoylmalonate, together with the known 6α‐hydroxymanoyl oxide, 6α‐malonyloxymaloyl oxide and betulinic acid were isolated from leaves of Stemodia trifoliata. Their structures were elucidated by spectroscopic studies (IR and HR‐ESI‐MS), including an extensive NMR (COSY, HSQC, HMBC and NOESY) analysis. Copyright © 2010 John Wiley & Sons, Ltd.
Diverse functions of Hedgehog signaling in formation and physiology of steroidogenic organs
Authors: Huang Chen‐Che Jeff , Yao Humphrey Hung‐Chang
Published: March 2010

Adrenal, testis, and ovary are steroidogenic organs derived from a common primordium that consists of steroidogenic factor 1 (SF1)‐positive precursor cells. SF1 not only defines the steroidogenic lineages in these organs but also controls their differentiation. Recent evidence implicates the Hedgehog (Hh) signaling pathway as a downstream regulator of SF1 in the appearance of steroidogenic cells in these organs. The Hh signaling pathway serves as a common crosstalk component, yet has evolved diverse functions in the expansion and differentiation of the steroidogenic cells in a tissue‐specific manner. The purpose of this review is to compare and contrast the different roles of Hh signaling in these three organs during development. Mol. Reprod. Dev. 77: 489–496, 2010. © 2010 Wiley‐Liss, Inc.
Early detection of radiation therapy response in non‐Hodgkin's lymphoma xenografts byin vivo1H magnetic resonance spectroscopy and imaging
Authors: Lee Seung‐Cheol , Poptani Harish , Pickup Stephen , Jenkins W. Timothy , Kim Sungheon , Koch Cameron J. , Delikatny E. James , Glickson Jerry D.
Published: March 2010

The purpose of the study was to investigate the capability of1H MRS and MRI methods for detecting early response to radiation therapy in non‐Hodgkin's lymphoma (NHL). Studies were performed on the WSU‐DLCL2 xenograft model in nude mice of human diffuse large B‐cell lymphoma, the most common form of NHL. Radiation treatment was applied as a single 15 Gy dose to the tumor. Tumor lactate, lipids, total choline,T2and apparent diffusion coefficients (ADC) were measured before treatment and at 24 h and 72 h after radiation. A Hadamard‐encoded slice‐selective multiple quantum coherence spectroscopy sequence was used for detecting lactate (Lac) while a stimulated echo acquisition mode sequence was used for detection of total choline (tCho) and lipids.T2‐ and diffusion‐weighted imaging sequences were used for measuringT2and ADC. Within 24 h after radiation, significant changes were observed in the normalized integrated resonance intensities of Lac and the methylenes of lipids. Lac/H2O decreased by 38 ± 15% (p = 0.03), and lipid (1.3 ppm, CH2)/H2O increased by 57 ± 14% (p = 0.01). At 72 h after radiation, tCho/H2O decreased by 45 ± 14% (p = 0.01), and lipid (2.8 ppm, polyunsaturated fatty acid)/H2O increased by 970 ± 36% (p = 0.001). ADC increased by 14 ± 2% (p = 0.003), andT2did not change significantly. Tumor growth delay and regression were observed thereafter. This study enabled comparison of the relative sensitivities of various1H MRS and MRI indices to radiation and suggests that1H MRS/MRI measurements detect early responses to radiation that precede tumor volume changes. Copyright © 2010 John Wiley & Sons, Ltd.
Complete semi‐analytical treatment of weakly singular integrals on planar triangles via the direct evaluation method
Authors: Polimeridis Athanasios G. , Mosig Juan R.
Published: March 2010

A complete semi‐analytical treatment of the four‐dimensional (4‐D) weakly singular integrals over coincident, edge adjacent and vertex adjacent triangles, arising in the Galerkin discretization of mixed potential integral equation formulations, is presented. The overall analysis is based on the direct evaluation method, utilizing a series of coordinate transformations, together with a re‐ordering of the integrations, in order to reduce the dimensionality of the original 4‐D weakly singular integrals into, respectively, 1‐D, 2‐D and 3‐D numerical integrations of smooth functions. The analytically obtained final formulas can be computed by using typical library routines for Gauss quadrature readily available in the literature. A comparison of the proposed method with singularity subtraction, singularity cancellation and fully numerical methods, often used to tackle the multi‐dimensional singular integrals evaluation problem, is provided through several numerical examples, which clearly highlights the superior accuracy and efficiency of the direct evaluation scheme. Copyright © 2010 John Wiley & Sons, Ltd.
Coupling BEM/TBEM and MFS for the simulation of transient conduction heat transfer
Authors: Tadeu António , Simões Nuno , Simões Inês
Published: March 2010

The coupling between the boundary element method (BEM)/the traction boundary element method (TBEM) and the method of fundamental solutions (MFS) is proposed for the transient analysis of conduction heat transfer in the presence of inclusions, thereby overcoming the limitations posed by each method. The full domain is divided into sub‐domains, which are modeled using the BEM/TBEM and the MFS, and the coupling of the sub‐domains is achieved by imposing the required boundary conditions.

The accuracy of the proposed algorithms, using different combinations of BEM/TBEM and MFS formulations, is checked by comparing the resulting solutions against referenced solutions.

The applicability of the proposed methodology is shown by simulating the thermal behavior of a solid ring incorporating a crack or a thin inclusion in its wall. The crack is assumed to have null thickness and does not allow diffusion of energy; hence, the heat fluxes are null along its boundary. The thin inclusion is modeled as filled with thermal insulating material. Copyright © 2010 John Wiley & Sons, Ltd.
Inspection model and correlation functions to assist in the correction of qualitative defects of injected parts
Authors: Chaves Miryam L. , Vizán Antonio , Márquez Juan J. , Ríos José
Published: March 2010

To perform quality inspection in the injection process is a complex task due to high number of defects that could occur in an injected part and the high number of process parameters that could produce them. Injection defects, in particular qualitative ones, are not a clear reference to determine correct process parameter value setting to produce good quality parts. Research results show that the occurrence of each injection defect could be caused by specific parameters with values above or below an optimal one. Although this information is a guide for the defect correction, the effective correction of qualitative defects with parameter modifications is very complex. This is due to the problems that arise when transforming a qualitative defect into a quantitative inspection. This article shows an inspection model to assist the qualitative defect intensity classification using defect behavior tendency curves. These curves have been deduced from generic analytical relationships established between injection defects and injection process parameters. Conducted tests allow validating the approach and its initial effectiveness. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers
Investigation of a strategy for well controlled inducement of microcellular and nanocellular morphologies in polymers
Authors: Janani Hamed , Famili M.H.N.
Published: March 2010

This study is an effort to modify conventional batch processes to be able to produce polymeric foams with high cell density and small cell size, which cannot be reached by conventional batch foaming processes. This has been attained by controlling the foaming temperature and controlled stabilization of the cellular structure. The method was tested for both with and without addition of nanosized particles in polymeric matrix. The desired morphologies were obtained using a novel apparatus with the capability of instantaneous pressure drop and controlling stabilization of the foam structure. The design of the said apparatus was based on the idea that in a foaming process, nucleation is the predominant mechanism that determines the final foam structure. The produced foam products have uniform structures without any unfoamed skin. Results show that the control of the foaming temperature and the cell stabilization are the predominant factors in adjustment of the final foam morphology. A wide range of microcellular structures with cell densities between 107 and 1012 bubbles/cm3 and average cell sizes of 500 nm–20 μm were produced. Foaming of polystyrene‐nano‐silica nano‐composites with the same method showed that nanoparticles act as nucleating agent and increase the cell density in the final foam products compared with that of neat polystyrene. POLYM. ENG. SCI., 50:1558–1570, 2010. © 2010 Society of Plastics Engineers
Preparation and characterization of chitosan/α‐zirconium phosphate nanocomposite films
Authors: Wu Haixia , Liu Changhua , Chen Jianguang , Yang Yajuan , Chen Yun
Published: March 2010

Nano‐fillers play an important role in the final structure and properties of nanocomposites. The objective of the work presented here was to prepare nanocomposite films of chitosan/α‐zirconium phosphate using a casting process, with α‐zirconium phosphate (α‐ZrP) as nano‐filler and chitosan as matrix. The effects of α‐ZrP on the structure and properties of the nanocomposites were investigated. X‐ray diffraction patterns showed that α‐ZrP crystals were intercalated by n‐butylamine. The results from scanning electron microscopy and transmission electron microscopy indicated that α‐ZrP could be uniformly dispersed in the chitosan matrix when α‐ZrP loading in the composites was less than 2 wt%. A strong interaction between α‐ZrP and chitosan formed during the film‐forming process. Tensile testing showed that the tensile strength and elongation at break of nanocomposite films achieved maximum values of 61.6 MPa and 58.1%, respectively, when α‐ZrP loading was 2 wt%. The parameter B calculated from tensile yield stress according to the Pukanszky model was used to estimate the interfacial interaction between the chitosan matrix and α‐ZrP. Films with a loading of 2 wt% α‐ZrP had the highest B value (3.2), indicating the strongest interfacial interaction. The moisture uptake of the nanocomposites was reduced with addition of α‐ZrP. It can be concluded that α‐ZrP as nano‐filler in a chitosan matrix can enhance the mechanical properties of nanocomposites due to the strong interactions between α‐ZrP and chitosan. Copyright © 2010 Society of Chemical Industry
Core–shell particles designed for toughening poly(vinyl chloride)
Authors: Chen Ming , Zhou Chao , Liu Zhenguo , Cao Chunlei , Liu Zhe , Yang Haidong , Zhang Huixuan
Published: March 2010

A novel core–shell modifier (MOD) made up of polystyrene and poly(butyl acrylate) (PBA) grafted on a crosslinked styrene‐co‐butadiene core was synthesized by emulsion polymerization. This modifier was used for enhancing effectively the impact ductility of poly(vinyl chloride) (PVC) without losing its transparency. The effects of the MOD on the properties of PVC/MOD blends were explored. It was found that the butyl acrylate (BA) content of the MOD was an important factor affecting the properties of PVC/MOD blends. The Izod impact strength of these blends reached 1200 J m−1 when the MOD contained 40 wt% BA. The dispersion morphology of the MOD in the PVC matrix was investigated using transmission electron microscopy, with a uniform dispersion of the MOD with higher BA content being obtained. The toughening mechanism of PVC/MOD blends was also investigated. The presence of BA in the MOD enhanced the ductility of the PVC blends due to the increased amount of soft phase (PBA). The dispersion morphology indicated that the interfacial interaction between MOD particles and PVC matrix was improved due to the presence of PBA graft chain in the MOD. TEM of impact fracture samples showed that shear yielding of the PVC matrix and debonding of MOD particles were the major toughening mechanisms for the PVC/MOD blends. Copyright © 2010 Society of Chemical Industry
The dependence of morphology of solid polymer electrolyte membranes on transient salt type: effect of cation type
Authors: Esmaeili Majid , Madaeni Sayed S , Barzin Jalal
Published: March 2010

The structures of poly(N‐vinyl pyrrolidone) (PVP) and poly(ether sulfone) composite membranes were investigated with transient salt addition. The effects of type and concentration of AgNO3 and Cu(NO3)2 on membrane morphology were evaluated through attenuated total reflection Fourier transform infrared (ATR‐FTIR) spectroscopy, differential scanning calorimetry (DSC) and atomic force microscopy. Complex formation between carbonyl groups (on PVP chains) and Cu2+ or Ag+ decreases the strength of the carbonyl bond as evidenced through ATR‐FTIR spectroscopy. The results indicate that the copper salts create more powerful interactions than the silver salts in the polymer matrix. DSC experiments reveal that the glass transition temperature of polymeric films containing silver or copper cations is lower than that of the PVP reference film. Comparison of the thermograms of PVP + AgNO3 and PVP + Cu(NO3)2 shows that copper ions disrupt the polymer crystallinity more than silver ions. Therefore, DSC observations confirm the ATR‐FTIR results in the case of the strength of the complexes formed. A morphological analysis of membrane surfaces reveals the existence of electrostatic interactions in the polymeric membrane structure. This is a result of the addition of salt to the casting solution, wrinkling the polymer chains including the surface layer, and accordingly the surface of the facilitated transport membranes is rougher than the initial PVP membrane. Copyright © 2010 Society of Chemical Industry
Comparison of the performance of two affinity depletion spin filters for quantitative proteomics of CSF: Evaluation of sensitivity and reproducibility of CSF analysis using GeLC‐MS/MS and spectral counting
Authors: Fratantoni Silvina A. , Piersma Sander R. , Jimenez Connie R.
Published: March 2010

Purpose: For biomarker discovery in cerebrospinal fluid (CSF), removal of major serum proteins is advantageous as more CSF proteins including brain‐derived proteins can be identified. Our goal was to create a reproducible discovery workflow with acceptable throughput that can identify 500–1000 CSF proteins in small volumes of CSF.

Experimental design: In this study, we compared the performance of two multi‐affinity depletion methods in spin filter format: MARS Human 14 and Seppro‐IgY‐14. To this end, we analyzed depleted and bound CSF fractions isolated from 0.5 mL aliquots of the same CSF sample (n=3 per depletion method) by label‐free GeLC‐MS/MS‐based proteomics and normalized spectral counting.

Results: The whole CSF dataset contained 884 proteins identified at high confidence. Depletion spin filter performance was assessed in terms of sensitivity and reproducibility of the CSF analysis. MARS and IgY‐14 spin filters yielded comparable reproducibility of protein identification (71–74%) and quantification (CV 17–18%) but a significant difference in the total number of identified CSF proteins (767 and 703 proteins, respectively).

Conclusions and clinical relevance: The MARS filter compared to IgY‐14 filter provides a CSF analysis with enhanced proteome coverage. We anticipate that this enhanced sensitivity will facilitate biomarker discovery in early stages of cancer or neurological disease.
Crystal structures of truncated alphaA and alphaB crystallins reveal structural mechanisms of polydispersity important for eye lens function
Authors: Laganowsky Arthur , Benesch Justin L. P. , Landau Meytal , Ding Linlin , Sawaya Michael R. , Cascio Duilio , Huang Qingling , Robinson Carol V. , Horwitz Joseph , Eisenberg David
Published: March 2010

Small heat shock proteins alphaA and alphaB crystallin form highly polydisperse oligomers that frustrate protein aggregation, crystallization, and amyloid formation. Here, we present the crystal structures of truncated forms of bovine alphaA crystallin (AAC59–163) and human alphaB crystallin (ABC68–162), both containing the C‐terminal extension that functions in chaperone action and oligomeric assembly. In both structures, the C‐terminal extensions swap into neighboring molecules, creating runaway domain swaps. This interface, termed DS, enables crystallin polydispersity because the C‐terminal extension is palindromic and thereby allows the formation of equivalent residue interactions in both directions. That is, we observe that the extension binds in opposite directions at the DS interfaces of AAC59–163 and ABC68–162. A second dimeric interface, termed AP, also enables polydispersity by forming an antiparallel beta sheet with three distinct registration shifts. These two polymorphic interfaces enforce polydispersity of alpha crystallin. This evolved polydispersity suggests molecular mechanisms for chaperone action and for prevention of crystallization, both necessary for transparency of eye lenses.
Functional rules for lac repressor–operator associations and implications for protein–DNA interactions
Authors: Milk Leslie , Daber Robert , Lewis Mitchell
Published: March 2010

The Lac repressor has been used as a tool to understand protein–DNA recognition for many years. Recent experiments have demonstrated the ability of the Lac repressor to control gene expression in various eukaryotic systems, making the quest for an arsenal of protein–DNA binding partners desirable for potential therapeutic applications. Here, we present the results of the most exhaustive screen of Lac repressor‐DNA binding partners to date, resulting in the elucidation of functional rules for Lac–DNA binding. Even within the confines of a single protein–DNA scaffold, modes of binding of different protein–DNA partners are sufficiently diverse so as to prevent elucidation of generalized rules for recognition for a single protein, much less an entire protein family.
Similarities between Argonautes and the alpha‐sarcin‐like ribotoxins: Implications for microRNA action
Authors: Pichinuk Edward , Wreschner Daniel H.
Published: March 2010

We report structural, functional, and biochemical similarities between Argonautes, the effector proteins of RNA‐induced silencing complexes (RISCs), and alpha‐sarcin‐like ribotoxins. At the structural level, regions of similarity in the amino acid sequence are located in protein loops both in the ribotoxins and in the Argonautes. In ribotoxins, these protein loops confer specificity for a highly conserved segment of ribosomal RNA, the Sarcin‐Ricin‐Loop (SRL) that undergoes cleavage by the ribotoxin ribonuclease. This leads to suppression of translation. In addition to the structural similarity with ribotoxins, the Argonaute proteins (Ago) show both functional and biochemical parallels. Like the ribotoxins, the Agos exhibit ribonuclease activity and like the ribotoxins, translational suppression mediated by miRISC‐resident Ago is accompanied by intact polysomes. Furthermore, in both translationally suppressed systems, the puromycin reaction, reflecting correct translocation and peptidyl‐transferase activities, is unharmed. These findings support a mechanism for Ago‐miRISCs whereby regulated cleavage of ribosomal RNA leads to translational suppression.
Structural basis for the negative regulation of bacterial stress response by RseB
Authors: Kim Dong Young , Kwon Eunju , Choi JongKeun , Hwang Hye‐Yeon , Kim Kyeong Kyu
Published: March 2010

The σE‐dependent stress response in bacterial cells is initiated by the DegS‐ and RseP‐regulated intramembrane proteolysis of a membrane‐spanning antisigma factor, RseA. RseB binds to RseA and inhibits its sequential cleavage, thereby functioning as a negative modulator of this response. In the crystal structure of the periplasmic domain of RseA bound to RseB, the DegS cleavage site of RseA is unstructured, however, its P1 residue is buried in the hydrophobic pocket of RseB, which suggests that RseB binding blocks the access of DegS to the cleavage site.
Systemic action of novel neonicotinoid insecticide IPP‐10 and its effect on the feeding behaviour of Rhopalosiphum padi on wheat
Authors: Cui Li , Sun Lina , Shao Xusheng , Cao Yazhong , Yang Daibin , Li Zhong , Yuan Huizhu
Published: March 2010

BACKGROUND: IPP‐10 is a novel neonicotinoid insecticide recently developed in China and has good activity against sucking insects. Studies were carried out to investigate the activity of IPP‐10 against Rhopalosiphum padi L.

RESULTS: The results demonstrated that IPP‐10 had both contact and systemic activity, including acropetal and basipetal translocation in wheat vascular bundles. Starved R. padi were allowed to stay on wheat treated with a sublethal dose of IPP‐10. The results of studying their feeding behaviour from an electrical penetration graph (EPG) revealed a decrease in total time and bout duration of xylem and phloem ingestion, but the total time and bout duration of phloem salivation were significantly prolonged. The frequency (7.03 ± 0.49 Hz) of the xylem ingestion waveform produced by aphids on wheat treated with IPP‐10 was significantly lower than that of blank control aphids (8.20 ± 0.30 Hz). Consequently, aphids born on wheat treated with IPP‐10 were obviously lighter and less fecund than the control aphids.

CONCLUSION: These tests indicated that IPP‐10 had both contact and systemic activity, with sublethal effects resulting in reduction in R. padi feeding behaviour, growth rate and fecundity. Copyright © 2010 Society of Chemical Industry
The action of herbicides on fatty acid biosynthesis and elongation in barley and cucumber
Authors: Yang Xueying , Guschina Irina A , Hurst Samantha , Wood Sophie , Langford Mike , Hawkes Tim , Harwood John L
Published: March 2010

BACKGROUND: Herbicides that affect lipid metabolism have been used commercially for many years. Here, napropamide, diphenamid, dimethachlor and cafenstrole are compared; these have all been classified by the Herbicide Resistance Action Committee (HRAC) as K3 herbicides and inhibitors of cell division and/or synthesis of very‐long‐chain fatty acids (VLCFAs). In addition, spiro‐decanedione A and pinoxaden dione are compared as inhibitors of lipid synthesis through inhibition of acetyl‐CoA carboxylase (ACCase).

RESULTS: Whereas the chloracetamide dimethachlor and the carboxyamide cafenstrole potently inhibited VLCFA synthesis in both barley and cucumber, the acetamides napropamide and diphenamid which are also classified as K3 herbicides and likewise the unclassified herbicide cinmethylin did not. The graminicide pinoxaden dione inhibited de novo fatty acid synthesis in barley, but not in cucumber, and correspondingly inhibited the plastid form of maize ACCase much more than the cytosolic form (IC50 values of 0.1 and 17 µM). By contrast, spiro‐decanedione A exhibited herbicidal effects not only on grasses but also on broad leaves, strongly inhibited maize cytosolic ACCase and inhibited synthesis of VLCFAs in cucumber.

CONCLUSIONS: The acetamides napropamide and diphenamid, which do not inhibit VLCFA synthesis, should be classified separately from K3 herbicides that do. Pinoxaden dione and spiro‐decanedione A represent new classes of chemicals acting on plant lipid synthesis. Copyright © 2010 Society of Chemical Industry
First report of cyromazine resistance in a population of UK house fly (Musca domestica) associated with intensive livestock production
Authors: Bell Howard A , Robinson Katherine A , Weaver Robert J
Published: March 2010

BACKGROUND: House fly control in livestock‐rearing facilities is heavily reliant on the use of the larvicide cyromazine. While extensive use of this compound has led to the development of resistance in several countries, no elevated tolerance has so far been reported from the United Kingdom.

RESULTS: Tolerance to cyromazine in larvae derived from a field strain collected at an intensive pig unit was significantly elevated over that of insects taken from a susceptible laboratory strain. Resistance factors (RFs) of 2.9 and 2.4 were returned for assays initiated with eggs and neonate larvae respectively. The RF for field strain larvae exposed from neonate increased significantly to 3.9 and 5.6 following rounds of selection at 1.0 and then 1.5 mg kg−1 cyromazine.

CONCLUSION: Low‐level resistance to cyromazine in UK house flies is reported here for the first time. The geographic extent of this resistance is unknown but, if widespread, may lead to control failures in the future, and indicates that careful stewardship of this compound in the United Kingdom is now required. © Crown copyright 2010. Reproduced with permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd.