bluuebunny/crossref_metadata_2025 huggingface dataset:
The Order of Service: The Practical Management of Customer Interaction
Authors: Brown Barry
Published: March 2010

This paper discusses a pervasive yet neglected form of social interaction, that between service staff and customers. Observational and video data from two different shop settings are used to explore three aspects of service interactions. First, queues are discussed, a mundane yet massively prevalent device for managing when and how customers are served. Queues depend on customers ability to ‘work the queue’, to be able to see who is queuing and their place in the queue. This rests not only on the recognition of queuing behaviour, but also its production by those queuing. Second, artefacts in shop settings have not only a material role, but are resources used in interaction. The shop counter is both a surface to place goods, and a shared interactional space between customer and staff where the placement of goods has meaning for the interaction. Third, staff and customers manage their interactions using rhetorical devices, such as using three part list display can be used to show the validity of advice being given. From these observations we draw two conclusions: Behaviour in service settings has a strong moral component in that divergences from correct behaviour (such as queue skipping) are quickly sanctioned. This morality is from those in the setting, rather than an analyst's judgement, suggesting that the morality of economic markets can be studied as an endogenous feature of those markets. Second, customer service relies upon a prevalent yet powerful ‘ordinary vision’ - the skills of seeing, but also producing, the predictable actions that make up the order of service.
Sustainability and Modernity in the European Union: A Frame Theory Approach to Policy-Making
Authors: Triandafyllidou A. , Fotiou A.
Published: March 2010

Frame analysis has been often used by scholars studying New Social Movements to analyze their discourses and their ability to mobilise people. This paper refers to the application of ‘frame analysis’ to a different context, namely to discourses of both social movements and institutional actors in the context of public policy-making. More particularly, the study is concerned with the discourses of social actors who participate in the making of EU environmental policy. The advantages and limitations of frame analysis as a method for analysing discourse in an institutional context are discussed. Two case-studies are used to highlight the pros and cons of the method. First, the competing discourses of environmental organisations, business associations, and EU officials with regard to environmental sustainability and the Fifth Action Programme are examined. The second case study addresses the issue of Trans-European Transport Networks (TEN-Ts) and examines different types of framing of sustainable mobility developed by policy actors. Conclusions are drawn with regard to the contribution of frame theory in the analysis of policy-making processes.
SemiParametric Analysis of Competing Risks Data
Authors: Sundaram Rajeshwari , Balakrishnan N.K.
Published: March 2010

Competing risks data are typically encountered in biomedical/epidemiological studies. Examples of such data can be found in studying labor in women as labor can be either spontaneous or due to medical intervention (example: delivery by cesarean) or due to membrane rupture leading to labor. Typically in competing risks framework, each individual is exposed to K distinct types of risks and the eventual failure can be attributed to precisely one of the risks. As is usual in survival data, these competing risks data are further subjected to censoring. Two quantities of considerable interest include, the cause‐specific hazard and the corresponding cumulative incidence function for a specific cause. In this article, we will review various modeling approaches for assessing the effects of covariates through modeling cause‐specific hazard. We will also discuss various approaches for constructing confidence intervals as well as confidence bands for the cause‐specific cumulative incidence function of subjects with given values of the covariates.
Sample Size Determination for Clinical Trials
Authors: Tang Man‐Lai
Published: March 2010

In this article, we will present some useful sample size formulas that guarantee to achieve a pre‐specified power level of a test at a chosen nominal level or control a pre‐specified confidence width of a confidence interval estimator at a chosen coverage level (wherever available) for some popular topics in general clinical trials. Topics include: (a) one‐sample problem for mean and proportion; (b) two‐sample problem for comparing means and proportions; (c) multiple‐sample problem for comparing means and proportions; (d) multiple‐arm dose response trials for trend; (e) multiple regression analysis; and (f) multiple logistic regression analysis.
In Situ Damage Detection With Acoustic Emission Analysis During Cyclic Loading of Wire Reinforced EN AW‐6082
Authors: Weidenmann Kay André , Kerscher Eberhard , Merzkirch Matthias
Published: March 2010

In the field of lightweight construction, hybrid structures such as reinforced metal matrix composites are highly qualified materials. The direct composite extrusion process allows for continuous manufacturing of wire reinforced aluminum matrix profiles. The aim is to increase the stiffness and specific strength in a way that the composite material shows better mechanical properties than the single matrix material. To determine and locate damage evolution during cyclic loading of spring steel reinforced EN AW‐6082 matrix the acoustic emission analysis is used. Furthermore it allows for getting more information about the damage mechanisms during fatigue of the matrix and the final failure of the reinforcing element. The current work also includes the determination of damage evolution using strain measuring methods.
Conductive Nanostructures of MMX Chains
Authors: Guijarro Alejandro , Castillo Oscar , Welte Lorena , Calzolari Arrigo , Miguel Pablo J. Sanz , Gómez‐García Carlos J. , Olea David , di Felice Rosa , Gómez‐Herrero Julio , Zamora Felix
Published: March 2010

Crystals of [Pt2(n‐pentylCS2)4I] show a transition from semiconductor to metallic with the increase of the temperature (conductivity is 0.3–1.4 S · cm−1 at room temperature) and a second metallic–metallic transition at 330 K, inferred by electrical conductivity measurements. X‐ray diffraction studies carried out at different temperatures (100, 298, and 350 K) confirm the presence of three different phases. The valence‐ordering of these phases is analyzed using structural, magnetic, and electrical data. Density functional theory calculations allow a further analysis of the band structure derived for each phase. Nanostructures adsorbed on an insulating surface show electrical conductivity. These results suggest that MMX‐polymer‐based nanowires could be suitable for device applications.
Aligned, Ultralong Single‐Walled Carbon Nanotubes: From Synthesis, Sorting, to Electronic Devices
Authors: Liu Zhongfan , Jiao Liying , Yao Yagang , Xian Xiaojun , Zhang Jin
Published: March 2010

Aligned, ultralong single‐walled carbon nanotubes (SWNTs) represent attractive building blocks for nanoelectronics. The structural uniformity along their tube axis and well‐ordered two‐dimensional architectures on wafer surfaces may provide a straightforward platform for fabricating high‐performance SWNT‐based integrated circuits. On the way towards future nanoelectronic devices, many challenges for such a specific system also exist. This Review summarizes the recent advances in the synthesis, identification and sorting, transfer printing and manipulation, device fabrication and integration of aligned, ultralong SWNTs in detail together with discussion on their major challenges and opportunities for their practical application.
A Gaussian quadrature method for solving batch crystallization models
Authors: Qamar Shamsul , Mukhtar Safyan , Ali Qasim , Seidel‐Morgenstern Andreas
Published: March 2010

The quadrature method of moments (QMOM) has been recently introduced for solving population balance models. In this article, an alternative approach of QMOM is proposed for solving batch crystallization models describing crystals nucleation, size‐dependent growth, aggregation, breakage, and dissolution of small nuclei below certain critical size. In this technique, orthogonal polynomials, obtained from the lower order moments, are used to find the quadrature abscissas (points) and weights. Several test problems with different combinations of processes are considered in this manuscript. The numerical results are compared with analytical solutions and with the finite‐volume scheme results. Excellent agreements were observed on the moment calculations in all test cases. © 2010 American Institute of Chemical Engineers AIChE J, 2011
Calculation of multiplicity of steady states in a catalyst pellet by homotopic continuation method
Authors: Giunta Pablo , Amadeo Norma , Laborde Miguel , Bergamini María
Published: March 2010

Many exothermic reactions, such as the oxidation of CO in a catalyst pellet may present multiplicity of steady states. Experimental results suggest this behavior in a copper ceria catalyst, and this in turn would indicate that the kinetics should be nonmonotonic with respect to reactants' compositions. The model for the reaction is described by a two‐point boundary value problem that is hard to solve with direct methods, even when seeking a single solution. The aim of this work is to implement a homotopic method to find all the steady states of this kind of problems. The search for solutions is driven by a pseudo arclength continuation. Homotopic curves that passes through all possible solutions are obtained. Also, a study of the dependence of the initial point upon the curve is performed. © 2010 American Institute of Chemical Engineers AIChE J,2011
Heat exposure in the Canadian workplace
Authors: Jay Ollie , Kenny Glen P.
Published: March 2010

Exposure to excessive heat is a physical hazard that threatens Canadian workers. As patterns of global climate change suggest an increased frequency of heat waves, the potential impact of these extreme climate events on the health and well‐being of the Canadian workforce is a new and growing challenge. Increasingly, industries rely on available technology and information to ensure the safety of their workers. Current Canadian labor codes in all provinces employ the guidelines recommended by the American Conference of Governmental Industrial Hygienists (ACGIH) that are Threshold Limit Values (TLVs) based upon Wet Bulb Globe Temperature (WBGT). The TLVs are set so that core body temperature of the workers supposedly does not exceed 38.0°C. Legislation in most Canadian provinces also requires employers to install engineering and administrative controls to reduce the heat stress risk of their working environment should it exceed the levels permissible under the WBGT system. There are however severe limitations using the WGBT system because it only directly evaluates the environmental parameters and merely incorporates personal factors such as clothing insulation and metabolic heat production through simple correction factors for broadly generalized groups. An improved awareness of the strengths and limitations of TLVs and the WGBT index can minimize preventable measurement errors and improve their utilization in workplaces. Work is on‐going, particularly in the European Union to develop an improved individualized heat stress risk assessment tool. More work is required to improve the predictive capacity of these indices. Am. J. Ind. Med. 53:842–853, 2010. © 2010 Wiley‐Liss, Inc.
Cancer morbidity among Danish male urban bus drivers: A historical cohort study
Authors: Petersen Anne , Hansen Johnni , Olsen Jørgen H. , Netterstrøm Bo
Published: March 2010

Objective

To investigate whether urban bus drivers are at increased risk for cancer.

Methods

Urban bus drivers in a cohort established in 1978 in the three largest cities of Denmark were followed‐up in the Danish Cancer Registry until the end of 2003, and relative risks for cancers were estimated.

Results

Of 2,037 men included 70% reported in 1978 that they smoked. The standardized incidence ratio (SIR) for cancer in comparison with that of other male residents of the three cities was 1.09 [1.0–1.2]. The excess was due mainly to increased risks for cancers of the bladder (SIR, 1.6; 1.2–2.0) and lung (1.2; 1.0–1.4). In an analysis with internal comparisons and adjustment for smoking, we found no significant associations between duration of employment and increased risks for cancers at these two sites.

Conclusions

In this long‐term follow‐up study we found little evidence of a causal association between employment as an urban bus driver in Denmark and subsequent cancer. Am. J. Ind. Med. 53:757–761, 2010. © 2010 Wiley‐Liss, Inc.
Perception, experience, and response to genetic discrimination in Huntington disease: The international RESPOND‐HD study
Authors: Erwin Cheryl , Williams Janet K. , Juhl Andrew R. , Mengeling Michelle , Mills James A. , Bombard Yvonne , Hayden Michael R. , Quaid Kimberly , Shoulson Ira , Taylor Sandra , Paulsen Jane S. ,   the I‐RESPOND‐HD Investigators of the Huntington Study Group
Published: March 2010

Genetic discrimination—defined as the denial of rights, privileges, or opportunities or other adverse treatment based solely on genetic information (including family history)—is an important concern to patients, healthcare professionals, lawmakers, and family members at risk for carrying a deleterious gene. Data from the United States, Canada, and Australia were collected from 433 individuals at risk for Huntington disease (HD) who have tested either positive or negative for the gene that causes HD and family members of affected individuals who have a 50% risk for developing the disorder but remain untested. Across all three countries, a total of 46.2% of respondents report genetic discrimination or stigma based on either their family history of HD or genetic testing for the HD gene mutation. We report on the overall incidence of discrimination and stigma in the domains of insurance (25.9%), employment (6.5%), relationships (32.9%), and other transactions (4.6%) in the United States, Canada, and Australia combined. The incidence of self‐reported discrimination is less than the overall worry about the risk of discrimination, which is more prevalent in each domain. Despite a relatively low rate of perceived genetic discrimination in the areas of health insurance and employment, compared to the perception of discrimination and stigma in personal relationships, the cumulative burden of genetic discrimination across all domains of experience represents a challenge to those at risk for HD. The effect of this cumulative burden on daily life decisions remains unknown. © 2010 Wiley‐Liss, Inc.
Attenuation of pain and inflammation in adjuvant‐induced arthritis by the proteasome inhibitor MG132
Authors: Ahmed Aisha S. , Li Jian , Ahmed Mahmood , Hua Long , Yakovleva Tatiana , Ossipov Michael H. , Bakalkin Georgy , Stark André
Published: March 2010

Objective

In rheumatoid arthritis (RA), pain and joint destruction are initiated and propagated by the production of proinflammatory mediators. Synthesis of these mediators is regulated by the transcription factor NF‐κB, which is controlled by the ubiquitin proteasome system (UPS). The present study explored the effects of the proteasome inhibitor MG132 on inflammation, pain, joint destruction, and expression of sensory neuropeptides as markers of neuronal response in a rat model of arthritis.

Methods

Arthritis was induced in rats by injection of heat‐killed Mycobacterium butyricum. Arthritis severity was scored, and nociception was evaluated by mechanical pressure applied to the hind paw. Joint destruction was assessed by radiologic and histologic analyses. NF‐κB DNA‐binding activity was analyzed by electromobility shift assay, and changes in the expression of the p50 NF‐κB subunit and the proinflammatory neuropeptides substance P (SP) and calcitonin gene‐related peptide (CGRP) were detected by immunohistochemistry.

Results

Arthritic rats treated with MG132 demonstrated a marked reduction in inflammation, pain, and joint destruction. The elevated DNA‐binding activity of the NF‐κB/p50 homodimer and p50, as well as the neuronal expression of SP and CGRP, observed in the ankle joints of arthritic rats were normalized after treatment with MG132.

Conclusion

In arthritic rats, inhibition of proteasome reduced the severity of arthritis and reversed the pain behavior associated with joint inflammation. These effects may be mediated through the inhibition of NF‐κB activation and may possibly involve the peripheral nervous system. New generations of nontoxic proteasome inhibitors may represent a novel pharmacotherapy for RA.
Reward processing in autism
Authors: Scott‐Van Zeeland Ashley A. , Dapretto Mirella , Ghahremani Dara G. , Poldrack Russell A. , Bookheimer Susan Y.
Published: March 2010

The social motivation hypothesis of autism posits that infants with autism do not experience social stimuli as rewarding, thereby leading to a cascade of potentially negative consequences for later development. While possible downstream effects of this hypothesis such as altered face and voice processing have been examined, there has not been a direct investigation of social reward processing in autism. Here we use functional magnetic resonance imaging to examine social and monetary rewarded implicit learning in children with and without autism spectrum disorders (ASD). Sixteen males with ASD and sixteen age‐ and IQ‐matched typically developing (TD) males were scanned while performing two versions of a rewarded implicit learning task. In addition to examining responses to reward, we investigated the neural circuitry supporting rewarded learning and the relationship between these factors and social development. We found diminished neural responses to both social and monetary rewards in ASD, with a pronounced reduction in response to social rewards (SR). Children with ASD also demonstrated a further deficit in frontostriatal response during social, but not monetary, rewarded learning. Moreover, we show a relationship between ventral striatum activity and social reciprocity in TD children. Together, these data support the hypothesis that children with ASD have diminished neural responses to SR, and that this deficit relates to social learning impairments.
Effects of Ginkgo biloba extract on the embryo‐fetal development in Wistar rats
Authors: Fernandes Eduardo Siqueira , Pinto Rafael Moraes , de Paula Reis João Evangelista , de Oliveira Guerra Martha , Peters Vera Maria
Published: March 2010

BACKGROUND: Ginkgo biloba extract (GBE) is an herbal medicine used for treating neurodegenerative diseases, cerebrovascular insufficiency, peripheral arterial occlusive disease, and also vestibular disturbance. Some components of GBE have presented estrogenic effects and, in a previous study, high dosages of GBE caused intra‐uterine growth retardation in fetuses of Wistar rats treated during the fetogenesis period. METHODS: Pregnant Wistar rats were treated, through gavage, with different dosages of aqueous GBE (3.5, 7.0, and 14.0 mg/Kg/day), during the tubal transit and implantation period. Rats were killed on the 15th day of pregnancy and the following parameters were evaluated: clinical symptoms of maternal toxicity; maternal body weight; feed and water intake; maternal liver, kidney, and ovary weights; number of corpora lutea; implants per group ratio; pre‐ and post‐implantation loss per group ratio; live fetuses mean; dead fetuses percentage; fetus and placenta weight per offspring ratio; and fetal external malformation. RESULTS: No significant alteration was found for both the maternal and embryonic parameters evaluated. CONCLUSIONS: The GBE treatment in pregnant Wistar rats, during the tubal transit and implantation period, caused no toxic effect on the maternal organism and did not induce embryonic death, growth retardation, and/or fetal malformations. Birth Defects Res (Part B) 89:133–138, 2010. © 2010 Wiley‐Liss, Inc.
Prenatal developmental toxicity of decabromodiphenyl ethane in the rat and rabbit
Authors: Hardy Marcia L. , Mercieca Michael D. , Rodwell Dean E. , Stedeford Todd
Published: March 2010

BACKGROUND: The potential embryotoxic and teratogenic effects of decabromodiphenyl ethane (DBDPEthane; CASRN 84852–53–9) were evaluated in prenatal developmental studies using rats and rabbits and performed in accordance with international guidelines and Good Laboratory Practice standards. Preliminary dose‐range‐finding studies were conducted, which indicated doses up to 1,250 mg/kg‐day were well tolerated by both rats and rabbits. METHODS: For the developmental studies, animals were administered DBDPEthane via gavage at dosage levels of 0, 125, 400, or 1,250 mg/kg‐day from gestation day (GD) 6 through 15 for rats and GDs 6 through 18 for rabbits. All female rats and rabbits were sacrificed on GD 20 or GD 29, respectively, and subjected to cesarean section. Fetuses were individually weighed, sexed, and examined for external, visceral and skeletal abnormalities. RESULTS: No treatment‐related mortality, abortions, or clinical signs of toxicity were observed during the study. Body weights, body weight gain, and food consumption were not affected by treatment. No significant internal abnormalities were observed in either species on necropsy. Cesarean section parameters were comparable between control and treated groups. No treatment‐induced malformations or developmental variations occurred. CONCLUSIONS: Based on these results, no evidence of maternal toxicity, developmental toxicity, or teratogenicity was observed in rats or rabbits treated with DBDPEthane at dosage levels up to 1,250 mg/kg‐day. Birth Defects Res (Part B) 89:139–146, 2010. © 2010 Wiley‐Liss, Inc.
Antihypertensive medication use during pregnancy and the risk of major congenital malformations or small‐for‐gestational‐age newborns
Authors: Nakhai‐Pour H. R. , Rey E. , Bérard A.
Published: March 2010

BACKGROUND: In spite of the widespread use of antihypertensives during pregnancy, data on their risks and benefits for the newborn are limited. We investigated the risk of major congenital malformations or small‐for‐gestational‐age newborns (SGA) in relation to gestational use of antihypertensives. METHODS: Within the Quebec Pregnancy Registry, we conducted two case‐control studies. First, cases were defined as major congenital malformations diagnosed during the first year of life and controls were selected from the same cohort; index date was date of delivery. Gestational exposure was defined as filling a prescription for an antihypertensive during the 1st trimester of pregnancy. Next, cases (SGA) were defined as newborns with a birth weight <10th percentile for that gestational age and gender; controls were the newborns with a birth weight ≥10 percentile. Gestational exposure was defined as filling a prescription for an antihypertensive during the 2nd or 3rd trimester. Multivariate logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (95% CI). RESULTS: We found that overall antihypertensives use during the 2nd or 3rd trimesters of pregnancy was associated with a higher risk of SGA (OR 1.53, 95% CI 1.17–1.99). Moreover, selective β‐blocker (OR 6.00, 95% CI 1.06–33.87), α β blocker (OR 2.26, 95% CI 1.04–4.88), or centrally‐acting adrenergic agents use (OR 1.70, 95% CI 1.00–2.89) was associated with a higher risk of SGA compared to non‐use. CONCLUSION: Gestational use of antihypertensives, especially β‐blocker, α β blocker, or centrally‐acting adrenergic agents, may increase the risk of SGA. Birth Defects Res (Part B) 89:147–154, 2010. © 2010 Wiley‐Liss, Inc.
Bayesian Semiparametric Frailty Selection in Multivariate Event Time Data
Authors: Cai Bo
Published: March 2010

Biomedical studies often collect multivariate event time data from multiple clusters (either subjects or groups) within each of which event times for individuals are correlated and the correlation may vary in different classes. In such survival analyses, heterogeneity among clusters for shared and specific classes can be accommodated by incorporating parametric frailty terms into the model. In this article, we propose a Bayesian approach to relax the parametric distribution assumption for shared and specific‐class frailties by using a Dirichlet process prior while also allowing for the uncertainty of heterogeneity for different classes. Multiple cluster‐specific frailty selections rely on variable selection‐type mixture priors by applying mixtures of point masses at zero and inverse gamma distributions to the variance of log frailties. This selection allows frailties with zero variance to effectively drop out of the model. A reparameterization of log‐frailty terms is performed to reduce the potential bias of fixed effects due to variation of the random distribution and dependence among the parameters resulting in easy interpretation and faster Markov chain Monte Carlo convergence. Simulated data examples and an application to a lung cancer clinical trial are used for illustration.
Human laryngeal ganglia contain both sympathetic and parasympathetic cell types
Authors: Ibanez Marta , Valderrama‐Canales Francisco J. , Maranillo Eva , Vazquez Teresa , Pascual‐Font Arán , McHanwell Stephen , Sanudo Jose
Published: March 2010

The presence of ganglia associated with the laryngeal nerves is well documented. In man, these ganglia have been less well studied than in other species and, in particular, the cell types within these ganglia are less well characterized. Using a panel of antibodies to a variety of markers found in the paraganglion cells of other species, we were able to show the existence of at least two populations of cells within human laryngeal paraganglia. One population contained chromogranin and tyrosine hydroxylase representing a neurosecretory population possibly secreting dopamine. A second population of choline acetyltransferase positive cells would appear to have a putative parasympathetic function. Further work is needed to characterize these cell populations more fully before it will be possible to assign functions to these cell types but our results are consistent with the postulated functions of these ganglia as chemoreceptors, neurosecretory cells, and regulators of laryngeal mucus secretion. Clin. Anat. 23:673–682, 2010. © 2010 Wiley‐Liss, Inc.
Disability and participation: It's about us but still without us!
Authors: Radermacher Harriet , Sonn Christopher , Keys Christopher , Duckett Paul
Published: March 2010

Participation is often espoused as a strategy to promote inclusion, social justice and equality. Exactly how to facilitate participation in practice is often not explicated, nor are the challenges or issues highlighted. By drawing on interview data, the first aim of this paper is to identify the key barriers to participation in an organizational planning activity as experienced by 12 disabled and non‐disabled staff and board members in a small community‐based disability advocacy organization. The second aim is to draw upon Jim Ife's principles of participation to further analyse the factors that hinder and enable participation in organizations. Reported barriers to participation were categorized at individual, interpersonal and organizational levels of analysis, and included a lack of skills and competence, interpersonal conflicts, poor resourcing and ad hoc processes. The importance of understanding the dynamic interplay of individual and structural factors, valuing different forms of participation and having participatory structures and processes embedded in organizational settings are all highlighted. This study illustrates that, even in an organization that is specifically attuned to meeting the needs of disabled people, there is still considerable exclusion and institutional discrimination. Strategies to promote participation within an organizational context may include providing sufficient time for reflection and support, and opportunities for board members to learn how to take part in constructive planning activities and to develop their strengths. Copyright © 2010 John Wiley & Sons, Ltd.
Solution‐Phase Racemization in the Presence of an Enantiopure Solid Phase
Authors: Viedma Cristobal , Verkuijl Bastiaan J. V. , Ortiz José E. , de Torres Trinidad , Kellogg Richard M. , Blackmond Donna G.
Published: March 2010

Solution‐phase racemization drives the evolution of single chirality in the solid phase by the “chiral amnesia” process first described by Viedma. The current investigations lay the basis for a better understanding of the mechanism of the solid‐phase deracemization by uncoupling the chemical rate processes associated with the interconversion of enantiomers in the solution phase from the physical processes associated with solution–solid phase transfer via dissolution and reaccretion of molecules onto crystals. In addition, the enantiomer concentration profiles presented in this work, together with an analytical treatment of the racemization process in the presence of excess enantiopure solid, unequivocally reconfirm the validity of the Meyerhoffer double solubility rule for systems under solution racemization conditions.
Molecular Structure of Amyloid Fibrils Formed by Residues 127 to 147 of the Human Prion Protein
Authors: Lin Ni‐Shian , Chao John Ching‐Hao , Cheng Hsin‐Mei , Chou Fang‐Chieh , Chang Chi‐Fon , Chen Yun‐Ru , Chang Yu‐Jen , Huang Shing‐Jong , Chan Jerry C. C.
Published: March 2010

Amyloid fibrils are filamentous and insoluble forms of peptides or proteins. Proline has long been considered to be incompatible with the cross‐β structural motif of amyloid fibrils. On the basis of solid‐state NMR spectroscopy data, we present a structural model of an in‐register parallel β sheet for the amyloid fibrils formed from a human prion protein fragment, huPrP127–47. We have developed a simple solid‐state NMR spectroscopy technique to identify solvent‐protected backbone amide protons in a H/D exchange experiment without disaggregating the amyloid fibrils, from which we find that proline residue P137 does not disrupt the β‐sheet structure from G127 to G142. We suggest that the resultant kink at P137 generates a twist between adjacent peptide strands to maintain hydrogen bonding in the β‐sheet regions flanking the P137 residue. Although proline can be well integrated into the cross‐β structure of amyloid fibrils, the kink formed at the position of the proline residue will considerably weaken the hydrogen bonding between the neighboring strands, especially when the mutation site is near the central region of a β sheet.
Structural Analysis of a Helical Peptide Unfolding Pathway
Authors: Diana Donatella , Ziaco Barbara , Scarabelli Guido , Pedone Carlo , Colombo Giorgio , D'Andrea Luca D. , Fattorusso Roberto
Published: March 2010

The analysis of the folding mechanism in peptides adopting well‐defined secondary structure is fundamental to understand protein folding. Herein, we describe the thermal unfolding of a 15‐mer vascular endothelial growth factor mimicking α‐helical peptide (QKL10A) through the combination of spectroscopic and computational analyses. In particular, on the basis of the temperature dependencies of QKL10A Hα chemical shifts we show that the first phase of the thermal helix unfolding, ending at around 320 K, involves mainly the terminal regions. A second phase of the transition, ending at around 333 K, comprises the central helical region of the peptide. The determination of high‐resolution QKL10A conformational preferences in water at 313 K allowed us to identify, at atomic resolution, one intermediate of the folding–unfolding pathway. Molecular dynamics simulations corroborate experimental observations detecting a stable central helical turn, which represents the most probable site for the helix nucleation in the folding direction. The data presented herein allows us to draw a folding–unfolding picture for the small peptide QKL10A compatible with the nucleation–propagation model. This study, besides contributing to the basic field of peptide helix folding, is useful to gain an insight into the design of stable helical peptides, which could find applications as molecular scaffolds to target protein–protein interactions.
Compositional Analysis and Adsorption Performance of Surfactants Used for Combined Chemical Flooding
Authors: Kang Wanli , Zhang Hongyan , Meng Lingwei , Liu Shuren
Published: March 2010

Adsorption of surfactants on reservoir sands in a combined chemical flooding process was investigated using a microcosmic method in order to reveal the effects of surfactant composition on their adsorption. Alkylbenzenesulfonate types of surfactant have been used in this study. The experimental results indicate that surfactant adsorption on the sands heavily depends on its lipophilicity, and the adsorption quantity increases with increasing the lipophilic chain length of the surfactant. It was found that the saturated adsorption could be reached when the concentration of the surfactant was near the critical micelle concentration (CMC). For oilfield applications, the molecular ion peak of the alkylbenzene‐sulfonate type surfactants should concentrate at around C18.
DFT Study of N2O Activation with La+, Hf+, Ta+ and W+ in the Gas Phase
Authors: Zhang Jianhui , Wang Yongcheng , Leng Yanli , Li Fengxian
Published: March 2010

The spin‐forbidden reaction N2O(X1Δ)+M+→N2 (X1Σ+g)+MO+(M+=La+, Hf+, Ta+, W+) was discussed using density functional theory. The reaction mechanism between M+ transition metal ions and N2O is an insertion‐elimination one. All products are formed in exothermic processes. The potential energy curve crossings, which dramatically affect reaction mechanisms, were discussed in detail. In comparison with the previous work, an essential conclusion could be drawn that the reaction N2O(X1Δ)+CO(1Δ+)→N2(X1Σ+g)+CO2(1Σ+g) catalyzed by M+ was endothermic by 358.89 kJ·mol−1 which is in accord with the experiment finding.
3,4,9,10‐Perylenetetracarboxylic Acid Derivatives, Their Spectral Behavior and Their Chemical Interaction with Hydrated Iron Oxide Nanopar
Authors: El‐Sayed Yusif S. , El‐Daly Samy A.
Published: March 2010

The photophysical properties such as electronic absorption, excitation and emission spectra as well as molar absorptivity and fluorescence quantum yield of N,N‐bis(pyrimidenyl)‐3,4,9,10‐perylenetetracarboxylic diimide (PmPBD), N,N‐bis(pyridenyl)‐3,4,9,10‐perylenetetracarboxylic diimide (PyPBD) and N,N‐bis(4‐methylpyridenyl)‐3,4,9,10‐perylenetetracarboxylic diimide (MPyPBD) have been measured in different solvents. Both electronic absorption and fluorescence spectra are not sensitive to medium polarity, while the fluorescence quantum yield ((f) is solvent dependent. Perylene derivatives under investigation undergo molecular aggregation to dimmer or larger aggregates in water. Dye solution in dimethylformmaide (DMF) gives laser emission at 565 nm upon pumping with 337.1 nm nitrogen laser pulse. The excitation energy transfer from 7‐dimethylamino‐4‐methylcoumarine (DMC) to PmPBD has been studied to improve the laser emission of PmPBD. The value of energy transfer rate constant (kET) and critical transfer distance (R0) indicate a F?rster type energy transfer mechanism. There is a large interaction between the perylene compounds under investigation and the hydrated nanoparticles in the excited state therefore the fluorescence quenching rate constant of these derivatives by hydrated iron oxide nanoparticles has a large value.
Preparation of Ammonium Cerium Phosphate via Low‐heating Solid State Reaction and Its Catalysis for Benzyl Acetate Synthesis
Authors: Liao Sen , Chen Zhipeng , Liu Gang , Tian Xiaozhen , Wang Tianshun , Wu Wenwei
Published: March 2010

Ammonium cerium phosphate was prepared with (NH4)3PO4·3H2O and Ce(SO4)2·4H2O as raw materials and PEG‐400 as surfactant via a solid state reaction at low‐heating temperature. The characterization result of XRD indicates that the molecular formula of the product was (NH4)2Ce(PO4)2·H2O. The synthesis of benzyl acetate was carried out with H2SO4/ammonium cerium phosphate as catalyst, and uniform experimental design as well as data mining technology was applied to the experiments, in which the effect of the reaction time, the molar ratio of acid to alcohol and the amount of catalyst on the conversion yield of acetic acid were studied. When benzalcohol was 0.10 mol, under the optimal reaction conditions, i.e. reaction time of 174 min, 2.02 of molar ratio of acid to alcohol and 0.5 g of catalyst, the esterification rate of acetic acid was 97.9%. The ammonium cerium phosphate had potential for industry application since it not only was feasible and simple in synthesis technics, but also had good catalysis activity for the synthesis of benzyl acetate.
Three Component Reaction: An Efficient Synthesis of 3,4‐Dihydropyrimidin‐2(1H)‐ones and Thiones Using Heterogeneous Catalyst
Authors: Kamble Vinod Tribhuvannathji , Muley Dnyanoba Baburao , Atkore Sandeep Tukaram , Dakore Sharad Digambarrao
Published: March 2010

Fluoroboric acid supported on silica gel (HBF4‐SiO2) catalyzes efficiently the three component condensation of an aldehyde, a 1,3‐dicarbonyl compound and urea or thiourea to afford the corresponding 3,4‐dihydropyrimidin‐ 2(1H)‐ones and thiones in high yields. The ambient conditions, fast reaction rates, and excellent product yields are the important characteristics of this reaction.
Non‐isothermal Decomposition Kinetics, Specific Heat Capacity and Adiabatic Time‐to‐explosion of a High Energy Material: 4,6‐Bis(5‐amino‐3‐nitro‐1,2,4‐triazol‐1‐yl)‐5‐nitropyrimidine
Authors: Zhang Laying , Heng Shuyun , Jia Siyuan , Xu Kangzhen , Zhang Gao , Yi Jianhua , Wang Bozhou , Zhao Fengqi
Published: March 2010

The thermal behavior of 4,6‐bis‐(5‐amino‐3‐nitro‐1,2,4‐triazol‐1‐yl)‐5‐nitropyrimidine (BANTNP) was studied under a non‐isothermal condition by DSC, PDSC and TG/DTG methods. The kinetic parameters (Ea and A) of the exothermic decomposition reaction are 304.52 kJ·mol−1 and 1024.47 s−1 at 0.1 MPa, 272.52 kJ·mol−1 and 1021.76 s−1 at 5.0 MPa, respectively. The kinetic equation at 0.1 MPa can be expressed as:
dα/dT=1025.3(1−α)3/4exp(−3.8044×104/T)/β
The critical temperature of thermal explosion is 588.28 K. The specific heat capacity of BANTNP was determined with a Micro‐DSC method, and the standard molar specific heat capacity is 397.54 J·mol−1·K−1 at 298.15 K. The adiabatic time‐to‐explosion of BANTNP was calculated to be 11.75 s.
Enhancement of Electrochemical Capacitance of Carbon Nanotubes by Polythionine Modification
Authors: Xu Ying , Zhang Xiaoyan , Wang Yanzhi , He Pingang , Fang Yuzhi
Published: March 2010

Thionine molecules have been electropolymerized onto different types of carbon nanotubes (CNT) using a cyclic voltammetry scanning technology, including multi‐walled carbon nanotubes, single‐walled carbon nanotubes and aligned carbon nanotubes. Results indicate that such prepared nanocomposites have combined the intrinsic faradic capacitance of polythionine with the double layer capacitance of polythionine‐CNT, and thus the polythionine modification obviously enhanced the CNT capacitance. Especially the carboxyl group modified multi‐walled carbon nanotubes, which have made their nanotube tips opened, allowed much more electropolymerization cycles and then obtained a most significant increment in capacitance than the other three ones.
First Reaction of a Chiral Gly‐Ni(II) Complex in Water
Authors: Liu Guannan , Zhou Yu , Ding Xiao , Wang Jiang , Jiang Hualiang , Liu Hong
Published: March 2010

The amination of a chiral Ni(II) complex as a model reaction was studied to develop a highly practical, efficient, and stereospecific approach for Ni(II) complex reactions in an aqueous phase. A convenient and clean water‐mediated reaction of the Ni(II) complex has been reached, and a broad spectrum of substrates could participate in the process effectively to produce desired products in good yields and excellent diastereoselectivities. Significantly, it is the first report of chiral gly‐Ni(II) complex reaction in aqueous media.
Stereoselective Cycloaddition of N‐Acyliminium Ions with α,β‐Unsaturated Ketones and Esters
Authors: Qiao Lingfeng , Zhou Yuehua , Zhang Wei
Published: March 2010

The [4+2] reactions of N‐acyliminium ions, produced from 2‐aryl‐3‐hydroxy‐2,3‐dihydroisoindol‐1‐ones or 5‐hydroxy‐1‐phenyl‐2,5‐dihydro/2,3,4,5‐tetrahydropyrrol‐2‐ones in the presence of BF3OEt2, with α,β‐unsaturated ketones or esters were examined, and the dependence of these reactions on the substituents at double bonds was clarified. For β‐aryl substituted α,β‐unsaturated ketones and esters such as 4‐aryl‐3‐buten‐2‐ones, chalcones and methyl cinnamate, the [4+2] reactions could proceed smoothly at room temperature to afford 6‐acyl‐5,6,6a,11‐tetrahydroisoindolo[2,1‐a]quinolin‐11‐ones and 4‐acyl‐1,3a,4,5‐tetrahydropyrrolo[1,2‐a]quinolin‐ 1‐ones or 4‐acyl‐1,2,3,3a,4,5‐hexahydropyrrolo[1,2‐a]quinolin‐1‐ones in moderate to high yields; while for simple α,β‐unsaturated ketones and esters such as methyl crotonate and ethyl 3‐methylbut‐2‐enoate, except mesityloxide, the [4+2] reactions were difficult to proceed. The cycloaddition reactions were highly stereoselective, and only one stereoisomer was produced in each reaction.
Rhombic Polyaniline Microsheets Constituted of Nanoparticles: Synthesis and Application to the Detection of Dopamine
Authors: Wang Xiuhua , Shao Mingwang , Liu Li , Shao Guang
Published: March 2010

Rhombic polyaniline microsheets constituted of nanoparticles with the average diameter of 130 nm were synthesized and characterized by SEM, XRD and FTIR spectroscopy. A glassy carbon electrode modified with such rhombic polyaniline microsheets was fabricated and employed to detect dopamine via cyclic voltammetry, which displayed excellent electrochemical stability and sensitivity compared with the bare electrode. A linear relationship between the concentrations of dopamine and its oxidation peak currents was obtained. The proposed method was simple and economical in terms of the electrochemical method and apparatus.
Technetium‐99m‐sestamibi Redistribution after Exercise Stress Test Identified by a Novel Cardiac Gamma Camera: Two Case Reports
Authors: Sheikine Yuri , Berman Daniel S. , Di Carli Marcelo F.
Published: March 2010

Single photon emission computer tomography (SPECT) myocardial perfusion imaging (MPI) employing technetium‐99m (Tc‐99m)‐based imaging tracers is the mainstay of nuclear cardiology for the detection of myocardial ischemia. Current guidelines for same day rest/stress Tc‐99m‐sestamibi SPECT MPI recommend image acquisition 15–60 minutes after the stress testing. A novel sensitive SPECT imaging technique, D‐SPECT, allows fast acquisition of images and captures rapid changes in radiotracer distribution. Here we report 2 cases of SPECT MPI in patients with angiographically confirmed coronary artery disease (CAD) where Tc‐99m‐sestamibi exhibited marked redistribution between early (6–8 min) and late (60–70 min) post‐stress imaging leading to an underestimation of the extent and severity of ischemia on late images. These observations suggest that early imaging maybe more sensitive for CAD detection. Fast SPECT imaging techniques, such as D‐SPECT, will facilitate similar studies in the future as they will allow fast image acquisition at several time points after the stress test. Copyright © 2010 Wiley Periodicals, Inc.
Multimode phonon structure of Be‐containing II ‐ VI mixed crystals determined by IR spectroscopic ellipsometry
Authors: Wronkowska A. A. , Wronkowski A. , Skowroński Ł. , Firszt F.
Published: March 2010

Spectroscopic ellipsometry in the infrared spectral range 250‐5000 cm‐1 is used for analysis of the dielectric response of Zn1‐x‐yBexMgySe and Zn1‐x‐yBexMnySe crystals grown by a high‐pressure Bridgman method. Ellipsometric spectra display features in the spectral range 390‐500 cm‐1 associated with BeSe‐type phonon modes. In the optical spectra of Zn1‐x‐yBexMgySe crystals both BeSe‐type and MgSe‐type lattice absorption bands are detected. The MgSe‐like modes are located at approximately 300 cm‐1. The complex dielectric functions can be reproduced using a model with two or three and one or two classical damped oscillators corresponding to the BeSe‐like and the MgSe‐like transverse‐optical phonon modes, respectively. The frequencies of longitudinal‐optical phonons have been derived from the dielectric loss functions. A red‐shift of the BeSe‐like phonons frequencies with a mean rate 0.42 cm‐1 (0.50 cm‐1) per mole percent of Mg (Mn) incorporated to the alloy has been found for examined concentration range x, y ≤ 0.25. A noticeable damping the intensities of BeSe‐type modes with increasing fraction of Mg and Mn dopant is observed in comparison to the strengths of BeSe‐type modes in Zn1‐xBexSe crystals. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Explanations of the optical absorption and ESR spectrum for tetragonal Ni+ centers in CuAlS2:Ni+ crystals
Authors: Wu Ying , Wang Li‐Juan J. , Liu Guo‐Yue
Published: March 2010

In this paper, the optical absorption and electron spin resonance (ESR) spectrum of Ni+‐doped CuAlS2 crystals have been studied by using a double spin‐orbit (SO) coupling approximation model, where the effects due to the SO coupling of the central metal 3d1 ion and those of ligands are included. From this model, the formulas of the ESR g factors g‖, g⊥ and hyperfine structure constants A‖, A⊥ for 3d1 ions in the tetragonal MX4 clusters are constructed. The optical absorption and ESR parameters for Cu+ sites of CuAlS2 have been calculated. The results obtained show that Ni+ ions substitute for Cu+ ions sites. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Physics Programme for Initial Operation of Wendelstein 7‐X
Authors: Bosch H.‐S. , Dinklage A. , Klinger T. , Wolf R. , Wendelstein 7‐X Team
Published: March 2010

It is the mission of the Wendelstein 7‐X (W7‐X) stellarator to demonstrate the reactor potential of the optimized stellarator line. Therefore W7‐X has to demonstrate high‐power, steady‐state operation. After completion of its construction and commissioning of the device, a first operational phase is planned to investigate basic stellarator properties and to prepare later steady‐state operation of Wendelstein 7‐X. The physics programme for this initial operation period has been developed recently to comply with the physics goals of W7‐X and will be discussed in this paper (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Rapid onset metastatic pulmonary calcifications in end‐stage renal disease
Authors: Tendulkar Ketki , Lazenby Audrey J. , Groggel Gerald C.
Published: March 2010

Metastatic calcification occurs in patients on long‐term dialysis. Electrolyte imbalances in these individuals can result in calcium deposition into otherwise normal tissues. In this article, we present the unusual case of a patient who progressed to end‐stage renal disease soon after a liver transplant and developed extensive pulmonary metastatic calcifications within a few months of starting dialysis. A 56‐year‐old female underwent an orthotopic liver transplant for end‐stage liver disease secondary to hepatitis C; her immunosuppression included tacrolimus and prednisone. She developed acute kidney injury in the immediate post‐operative period, which progressed to end‐stage renal disease. Her serum calcium and phosphorus levels were within normal limits. Within a few months, a CT scan of her chest showed progressive development of metastatic pulmonary calcification. A CT‐guided right lung biopsy showed extensive calcification in the alveolar and blood vessel walls with fibroblastic plugs in the alveolar spaces. To our knowledge, this is the first report of metastatic pulmonary calcification developing rapidly after initiation of hemodialysis. Immunosuppressive therapy may have played a role in the development of metastatic calcification.