bluuebunny/crossref_metadata_2025 huggingface dataset:
Sustainable Composites: Glass Reinforced Plastic Waste Filled Concrete
Authors: Osmani Mohamed , Pappu Asokan
Published: September 2011

At present, glass reinforced plastics (GRP) waste recycling worldwide is very limited due to its intrinsic thermoset properties, lack of characterization results, and nonavailability of viable recycling and recovery routes. GRP waste produced by the polymer composite manufacturing process in the United Kingdom has a low recycling rate because of a number of factors, namely, lack of information on its characterization and knowledge on potential recycling options. At present, most of the GRP waste is sent to landfill. However, current and impending waste management legislation have put more pressure on the industry to address the options available for dealing with GRP waste in a more sustainable and resource‐efficient manner. Hence, efforts were made to characterize GRP waste and explore the possibilities to assess its recycling potential in concrete composites. These are summarized in this article. Detailed characterization studies of GRP waste were carried out, and a comprehensive testing program was conducted to identify the potential use of GRP waste as an admixture and as a partial substitute for fine aggregate at different proportions in concrete composite. The findings of this work pave the way for further composite waste recycling in construction products for use in various applications.
Bonded Repair of Composite Aircraft Structures
Authors: Baker Alan
Published: September 2011

The trend in extensive use of composites, especially carbon/epoxy, in commercial and military aircraft structures, including highly loaded primary structure, is driving the requirement for cost‐effective and efficient repair techniques. Repair patches may be attached to the parent structure by adhesive bonding or mechanical fastening. This article focuses on adhesively bonded repairs and discusses the various key issues, including types of damage, repair criteria and requirements, simple design procedures, choice of materials, moisture problems, and repair implementation.
Carbon/Carbon Composites
Authors: Luo Ruiying , Zhang Jincao , Li Jinsong , Zhang Yunfeng , Zhang Jiangsong , Su Chenhan
Published: September 2011

Carbon/carbon (C/C) composites as high temperature structural materials have been widely used in aeronautics and astronautics because of their remarkable mechanical, thermophysical, and tribological properties. For the deep investigation of carbon deposition mechanism, newly developed approaches of fast densification of C/C composites have been indicated, such as thermal gradient chemical vapor infiltration (TCVI), pressure gradient chemical vapor infiltration (PCVI), electrified CVI (ECVI), and chemical liquid‐vaporized infiltration (CLVI). Multilayer coating system provides a new way for the long‐term antioxidation of C/C composites. Carbon nanotubes and nanofibers, forming the bridge between carbon fibers of micrometer size, could also further enhance the mechanical properties of composite materials. Bonded repair of C/C composite structure is used to extend the life of wear or underdesigned components and joins different components at a reasonable cost. All these studies promote the research and development of advanced C/C composites.
Composite Joining
Authors: Liu Dahsin
Published: September 2011

This article addresses issues involved in composite joining. Mechanical fastening and adhesive bonding are of primary interest because of their common applications. In each joining technique, the discussions include geometry, material, design, testing, and analysis. Other joining techniques are only briefly mentioned for reference purpose.
Curing Agent
Authors: Frigione Mariaenrica , Maffezzoli Alfonso
Published: September 2011

Reactive compounds in thermosetting matrices of composite materials are monomers or oligomers characterized by a functionality that ranges from a minimum of two up to six or more, in order to produce a cross‐linked network. The generic term of resin is usually referred either to the monomer present in the larger amount either to the mix containing the main monomer and all other reactive components, that is, curing agents, catalysts, and initiators. The same base monomer can thus be used to produce cross‐linked polymers characterized by properties strongly different depending on the curing agents.

In this section, the curing agents involved in and strictly necessary to the curing reactions, are only considered. In very basic terms, curing agents are divided in two classes depending on the role they play in the curing reactions. In step reactions curing agents participate to form the cross‐linked network being present in a significant amount and are often referred as hardeners. In radical chain reactions the initiator, producing the first radical promoting the initiation step, is present in a very limited amount in the reactive mixture (a few percent by weight). The discussion will be essentially limited to epoxy resin and partly to polyester and vinylester resins.
Design with Composites: Material Uncertainty in Designing Composites Component
Authors: Conceição António Carlos
Published: September 2011

The propagation of material uncertainty of the structural response of composites using two different approaches: a first‐order local method and a global sensitivity analysis supported by a variance‐based method, is studied. The importance measures of input parameters on the structural response based on numerical results are established and discussed as functions of the anisotropy of composite materials. The effects of uncertainty propagation on the response of composite structures under nonlinear geometric behavior are analyzed, especially the effects of uncertainty of material properties on the response of stiffened shell composite structures supporting buckling loads.

The reliability assessment of composite structures is presented, and difficulties of structural reliability definition are identified. The most probable failure point (MPP) search in composite structures introduces new uncertainty factors associated with multiple failure points influencing the structural reliability system. The reliability index is very sensitive to the uncertainty in mean values of the mechanical properties of composites. The analyzed case studies demonstrate that knowledge of uncertainty propagation and reliability analysis are two important challenges toward more realistic modeling of failure in the design of composites.
Epoxy Resins: Fluorine Systems
Authors: Park Soo‐Jin , Jin Fan‐Long
Published: September 2011

Commercially available epoxy resins are extensively used as coatings, electronic materials, and adhesives; they find use in structural applications owing to their outstanding mechanical and electrical properties, including those of adhesion, chemical resistance, and minimal shrinkage after curing. Currently, several types of fluorine‐containing epoxy resins have been developed and are being evaluated for practical uses. In this article, we present in‐depth information on epoxy resins and fluorine systems including contemporary processing technologies of epoxy composites and recent advances in epoxy composite materials. Finally, we introduce new areas of application of epoxy resins in detail, such as in the biomedical, electronic, and other fields.
Fatigue and Fracture of Rubbers
Authors: Bathias Claude , Dong Shanyan
Published: September 2011

This article is a review of what was done in our laboratory by several PhD students (Lu Chuming, K. Legorju, and S. Dong) in order to have a better understanding and prediction of the mechanical behavior and of the damage of elastomeric matrix used for rubber composites. Both monotonic and cyclic loadings are of interest.
Honeycomb
Authors: Othman Abdul Rahim
Published: September 2011

Honeycomb has been widely used as a core material in sandwich structure. It possesses distinctive characteristics compared to other solid or cellular cores. The preference in selecting the type of honeycomb is based on the material types, cell diameters, and densities as well as the cost.

In this contribution, the reader will be first provided with a general type of honeycomb material and its classification. In addition, different types of manufacturing process of the honeycomb structure will also made available in this article. Emphases on the details of mechanical properties and test methods are presented to the reader for further reference in establishing the right type of honeycomb. The final section provides the brief overview on new developments in the honeycomb core technologies.
Laminates: Developments in the Multiscale Analysis of Multifunctional Nanocomposite Materials
Authors: Reddy J. N. , Unnikrishnan V.
Published: September 2011

Analysis of multiscale nanocomposite materials continues to evolve with new developments in several fronts. Most of the recent advances include theoretical developments in improving the accuracy and efficiency of multiple physics‐based mathematical and computational models, and also generation of new defect‐free nanomaterial systems for large‐scale applications. In this article, the authors discuss some of the recent developments on multiscale mechanical and thermal analysis of nanotube and nanocomposite systems. This article also examines the effect of interfacial thermal characteristics on the overall effective thermal properties of a composite system, using a multiscale computational strategy involving atomistic simulations coupled with mesoscale thermal analysis models. Apart from the various computational models described in this article, several relevant works from literature are also cited to enhance the developed theoretical models discussed in this article.
Polymer‐Embedded Metal and Metal Sulfide Clusters
Authors: Carotenuto Gianfranco , Giannini Cinzia , Siliqi Dritan , Nicolais Luigi
Published: September 2011

Transition metal alkane‐thiolates [i.e., organic salts with formula Me(SR)x, where R is a linear aliphatic hydrocarbon group, −CnH2n+1] undergo a thermolysis reaction at moderately low temperatures (close to 200°C), which produces metal atoms or metal sulfide species and an organic by‐product, disulfide (RSSR) or thioether (RSR) molecules, respectively. Alkane‐thiolates are nonpolar chemical species that may dissolve in most techno‐polymers and the resulting solid solutions can be annealed to generate polymer‐embedded metal or metal sulfide clusters. Here, the preparation of silver and gold clusters embedded into amorphous polystyrene by thermolysis of a dodecyl‐thiolate precursor is described in detail. However, this chemical approach is quite general and a large variety of polymer‐embedded metals or metal sulfides can be similarly prepared.
Prepreg Manufacturing
Authors: Seferis James C. , Velisaris Chris N. , Drakonakis Vasileios M.
Published: September 2011

Continuous carbon fiber impregnation by polymeric systems, either thermoplastic or thermosets, has been practiced for almost 50 years. The process defined as prepreg may be viewed as a viscoelastic unit operation in a classic chemical engineering sense, where the elastic fibers are impregnated with viscous polymers. However, to lead to a final solid laminate, the resulting product form requires further processing by the application of heat and pressure. This feedback on product quality and process specification cannot be easily accomplished on‐line and in real‐time, thus restricting in the application of quality principles to the prepreg process. By defining a series of dimensionless numbers, the prepregging process can be described on the basis of fundamental engineering principles and thus can reach beyond required limitations. This was the case for the development of double pass impregnation with thermosetting resins that gave rise to a layered structure exceeding in toughening most thermoplastic systems as well.
Processing and Performance of Braided Composites
Authors: Carey Jason P. , Ayranci Cagri
Published: September 2011

Textile braiding and composites production have been carried out throughout human history. In this article we focus on a review of two‐ and three‐dimensional braiding processing and mechanical performance, discuss available predictive modeling techniques, and discuss the advantages and disadvantages of braiding as it relates to other similar manufacturing methods; in contrast to the earlier version of this article, we also emphasize the importance of two‐dimensional braiding. The article concludes by discussing possible future research directions.
Putting Anion–π Interactions Into Perspective
Authors: Frontera Antonio , Gamez Patrick , Mascal Mark , Mooibroek Tiddo J. , Reedijk Jan
Published: September 2011

Supramolecular chemistry is a field of scientific exploration that probes the relationship between molecular structure and function. It is the chemistry of the noncovalent bond, which forms the basis of highly specific recognition, transport, and regulation events that actuate biological processes. The classic design principles of supramolecular chemistry include strong, directional interactions like hydrogen bonding, halogen bonding, and cation–π complexation, as well as less directional forces like ion pairing, π–π, solvophobic, and van der Waals potentials. In recent years, the anion–π interaction (an attractive force between an electron‐deficient aromatic π system and an anion) has been recognized as a hitherto unexplored noncovalent bond, the nature of which has been interpreted through both experimental and theoretical investigations. The design of selective anion receptors and channels based on this interaction represent important advances in the field of supramolecular chemistry. The objectives of this Review are 1) to discuss current thinking on the nature of this interaction, 2) to survey key experimental work in which anion–π bonding is demonstrated, and 3) to provide insights into the directional nature of anion–π contact in X‐ray crystal structures.
Tissue‐specific biomass recalcitrance in corn stover pretreated with liquid hot‐water: SEM imaging (part 2)
Authors: Zeng Meijuan , Ximenes Eduardo , Ladisch Michael R. , Mosier Nathan S. , Vermerris Wilfred , Huang Chia‐Ping , Sherman Debra M.
Published: September 2011

In the first part of our work, we combined compositional analysis, pretreatment and enzyme hydrolysis for fractionated pith, rind, and leaf tissues from a hybrid stay‐green corn, in order to identify the role of structural characteristics on enzyme hydrolysis of cell walls. Hydrolysis experiments coupled with chemical analysis of the different fractions of corn stover showed significant differences in cell wall structure before and after liquid hot water pretreatment. The extent of enzyme hydrolysis followed the sequence rind < leaves < pith with 90% conversion of cellulose to glucose in 24 h in the best cases. Since similar lignin contents remained after liquid hot water pretreatment of leaves, rind, and pith, our results indicated that the amount of lignin alone is not sufficient to explain the different enzymatic hydrolysis characteristics of the fractions. While the role of structural characteristics on enzyme hydrolysis of cell walls is measured as described in part I, the SEM images presented in this part II of our work show that sugar yields from enzymatic hydrolysis of corn fractions correlate with changes in plant cell wall structure both before and after liquid hot water pretreatment. Biotechnol. Bioeng. 2012; 109:398–404. © 2011 Wiley Periodicals, Inc.
Risk of recurrence after surgery for chronic radiation enteritis
Authors: Lefevre J H , Amiot A , Joly F , Bretagnol F , Panis Y
Published: September 2011

Background

Approximately one-third of patients with chronic radiation enteritis (CRE) require surgery, which is associated with a high morbidity rate and a high risk of reoperation. The aim of this study was to report outcome after surgery for CRE.

Methods

Patients with CRE who underwent operation with extensive small bowel resection between 1980 and 2009 were included in the study. Postoperative morbidity and mortality, reoperation for recurrent enteritis and risk factors for reoperation were analysed.

Results

Of 107 patients (94 women; 87·8 per cent) with CRE included in the study, the main indication for surgery was symptomatic stricture (82 patients; 76·6 per cent). Forty-nine ileocaecal resections (45·8 per cent) were performed. Overall and surgical morbidity rates were 74·8 per cent (80 patients) and 28·0 per cent (30) respectively. Fourteen patients (13·1 per cent) underwent reoperation for complications. Reoperation rates for CRE at 1 and 3 years of follow-up were 37 and 54 per cent respectively. Risk factors for reoperation for recurrent enteritis were: emergency surgery (odds ratio (OR) 2·72, 95 per cent confidence interval 1·57 to 4·86), anastomotic leakage (OR 2·53, 1·54 to 4·42) and male sex (OR 3·57, 1·82 to 7·29). The only protective factor for reoperation was ileocaecal resection during the first surgical procedure (OR 4·48, 2·52 to 8·31).

Conclusion

Ileocaecal resection was the only factor that protected against reoperation for recurrent CRE, demonstrating the importance of resecting all damaged tissue in these patients. These results suggest that there is little place for intestinal bypass surgery or adhesiolysis.
Evidence-based management of postoperative pain in adults undergoing open inguinal hernia surgery
Authors: Joshi G P , Rawal N , Kehlet H
Published: September 2011

Background

Open inguinal hernia repair is associated with moderate postoperative pain, but optimal analgesia remains controversial. The aim of this systematic review was to evaluate the available literature on the management of pain after open hernia surgery.

Methods

Randomized studies, in English, published between January 1966 and March 2009, assessing analgesic and anaesthetic interventions in adult open hernia surgery, and reporting pain scores, were retrieved from the Embase and MEDLINE databases. In addition to published evidence, clinical practice was taken into account to ensure that the recommendations had clinical validity.

Results

Of the 334 randomized studies identified, 79 were included. Quantitative analysis suggested that regional anaesthesia was superior to general anaesthesia for reducing postoperative pain. Spinal anaesthesia was associated with a higher incidence of urinary retention and increased time to home-readiness compared with regional anaesthesia.

Conclusion

Field block with, or without wound infiltration, either as a sole anaesthetic/analgesic technique or as an adjunct to general anaesthesia, is recommended to reduce postoperative pain. Continuous local anaesthetic infusion of a surgical wound provides a longer duration of analgesia. Conventional non-steroidal anti-inflammatory drugs or cyclo-oxygenase 2-selective inhibitors in combination with paracetamol, administered in time to provide sufficient analgesia in the early recovery phase, are optimal. In addition, weak opioids are recommended for moderate pain, and strong opioids for severe pain, on request.
Late results of endoscopic thoracic sympathectomy for hyperhidrosis and facial blushing
Authors: Smidfelt K , Drott C
Published: September 2011

Background

The purpose of this study was to clarify the long-term effects, side-effects and overall satisfaction rates of endoscopic thoracic sympathectomy (ETS) used in the treatment of hyperhidrosis and facial blushing.

Methods

Some 3015 patients had bilateral ETS from 1989 to 1998. A questionnaire follow-up was used. Some of the patients had participated in a previous follow-up study, and the answers in both surveys were compared.

Results

A total of 1700 patients responded (56·4 per cent); mean(s.d.) follow-up was 14·6(2·4) years. The best result was achieved for palmar hyperhidrosis (95·6 per cent) compared with axillary hyperhidrosis (68·9 per cent), facial hyperhidrosis (83 per cent) and facial blushing (72·8 per cent) (P < 0·001). Compensatory sweating, the main side-effect, was present in 80·0 per cent. Some 6·5 per cent were dissatisfied and 13·5 per cent regretted having the procedure. Patients with palmar hyperhidrosis were more satisfied (86·6 per cent) than those with axillary hyperhidrosis (66·0 per cent), facial hyperhidrosis (74 per cent) or facial blushing (73·5 per cent) (P < 0·001). Women were more satisfied than men (85·4 versus 71·4 per cent; P < 0·001). The procedure regret rate rose from 7·8 per cent in the first survey to 13·5 per cent in the present one.

Conclusion

ETS had an excellent and lasting effect on palmar hyperhidrosis. The effect on facial and axillary hyperhidrosis and facial blushing was less rewarding. The procedure regret rate increased over time.
First-year results of a national abdominal aortic aneurysm screening programme in a single centre
Authors: Conway A M , Malkawi A H , Hinchliffe R J , Holt P J , Murray S , Thompson M M , Loftus I M
Published: September 2011

Background

The UK Multicentre Aneurysm Screening Study (MASS) demonstrated reduced mortality from screening for abdominal aortic aneurysm (AAA). As a result, the National Health Service AAA Screening Programme was introduced in England. This study reports the results from an early-implementation screening centre.

Methods

Men aged 65 years were invited to attend an ultrasound assessment. Data were analysed for 15 months from the onset of the screening programme.

Results

A total of 6091 men aged 65 years were invited between April 2009 and June 2010, of whom 2037 (33·4 per cent) failed to attend. There were 162 self-referrals (median age 71·3 years) so that 4216 men were screened. Of those scanned, 4146 (98·3 per cent) had an aortic diameter of less than 3·0 cm, 65 (1·5 per cent) had an aneurysm measuring 3·0–5·4 cm, and five (0·1 per cent) had an aneurysm with a diameter of 5·5 cm and above. The presence of an aneurysm was more common in those who self-referred than in the invited group (P < 0·001). All 70 screen-detected aneurysms were found in white men.

Conclusion

The prevalence of AAA was lower than expected. This reflects the younger age of this cohort compared with those in published large multicentre studies and the diverse ethnic background of the local population. Copyright © 2011 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.
White matter maturation of normal human fetal brain. An in vivo diffusion tensor tractography study
Authors: Zanin Emilie , Ranjeva Jean‐Philippe , Confort‐Gouny Sylviane , Guye Maxime , Denis Daniele , Cozzone Patrick J. , Girard Nadine
Published: September 2011

We demonstrate for the first time the ability to determine in vivo and in utero the transitions between the main stages of white matter (WM) maturation in normal human fetuses using magnetic resonance diffusion tensor imaging (DTI) tractography. Biophysical characteristics of water motion are used as an indirect probe to evaluate progression of the tissue matrix organization in cortico‐spinal tracts (CSTs), optic radiations (OR), and corpus callosum (CC) in 17 normal human fetuses explored between 23 and 38 weeks of gestation (GW) and selected strictly on minimal motion artifacts. Nonlinear polynomial (third order) curve fittings of normalized longitudinal and radial water diffusivities (Z‐scores) as a function of age identify three different phases of maturation with specific dynamics for each WM bundle type. These phases may correspond to distinct cellular events such as axonal organization, myelination gliosis, and myelination, previously reported by other groups on post‐mortem fetuses using immunostaining methods. According to the DTI parameter dynamics, we suggest that myelination (phase 3) appears early in the CSTs, followed by the OR and by the CC, respectively. DTI tractography provides access to a better understanding of fetal WM maturation.
Substance Use and Violent Behavior in Women with Antisocial Personality Disorder
Authors: Lewis Catherine F.
Published: September 2011

The purpose of this study was to examine the relationship between substance abuse and dependence and violent behavior in a sample of incarcerated women with antisocial personality disorder (ASPD). Among male populations, substance dependence is associated with aggression and criminal behavior. Individuals with ASPD have more severe substance dependence, including higher symptom counts, earlier age of onset, and more frequent co‐morbidity. Incarcerated women have a high prevalence of ASPD and substance dependence, but there has been little detailed work regarding addiction severity. Similarly, work on association of substance abuse and dependence with specific violent behaviors has been limited. This study examined a group of 41 mid‐sentence female felons with a diagnosis of ASPD to determine associations with substance abuse and dependence. Data were gathered through administration of the Semi‐Structured Assessment of the Genetics of Alcoholism II (SSAGA II). Substance dependence was highly prevalent (i.e., alcohol dependence, 56.1%; opiate dependence, 48.8%; cocaine dependence, 61.0%). While specific diagnoses were not associated with violent behavior and offending, symptom severity (i.e., age of onset, symptom count, co‐morbidity) was associated with violent behavior in women dependent on opiates, alcohol, and cocaine. Arrest for an assault 1 was associated with alcohol dependence and opiate dependence. These data suggest that measurement of symptom severity and co‐morbidity is important in assessing violent behavior in incarcerated women with ASPD. These findings are potentially important in examining non‐incarcerated, substance‐dependent women. Copyright © 2011 John Wiley & Sons, Ltd.
Women Accused of Sex Offenses: A Gender‐Based Comparison
Authors: West Sara G. , Friedman Susan Hatters , Kim Ki Dan
Published: September 2011

Sexual offenses committed by women are likely underestimated and under‐reported. This exploratory study compares and contrasts women accused of sexual offenses and their male counterparts. Data were retrospectively compiled on all alleged female and age‐matched male sex offenders who were referred for psychiatric evaluation to a large Midwestern city's court psychiatric clinic over a six‐year period. Data were abstracted regarding their crimes, charges, demographics, social history, medical history, legal history, violence history, substance use, sexual history, psychiatric history and their victims. Like the men, women were most frequently referred for sexual predator classification evaluations. Ages ranged from 19 to 62 years, and the majority had children. Most had prior arrests. One‐third had a past history of psychiatric hospitalization, and most were given a non‐paraphilic psychiatric diagnosis. The majority of the women reported past histories of sexual or physical victimization. While there were many similarities between female and male sex offenders in this psychiatric sample, women more frequently had victims of both genders. Copyright © 2011 John Wiley & Sons, Ltd.
Neural networks applied in chemistry. I. Determination of the optimal topology of multilayer perceptron neural networks
Authors: Curteanu Silvia , Cartwright Hugh
Published: September 2011

Artificial neural networks (ANNs) are comparatively straightforward to understand and use in the analysis of scientific data. However, this relative transparency may encourage their use in an uncritical, and therefore possibly unproductive, fashion. The geometry of a network is among the most crucial factors in the successful deployment of network tools; in this review, we cover methods that can be used to determine optimum or near‐optimum geometries. These methods of determining neural network architecture include the following: (i)trial and error, in which architectures chosen semirandomly are tested and modified by the user; (ii)empirical or statistical methods, in which an ANN's internal parameters are adjusted based on the model's performance; (iii)hybrid methods, such as fuzzy inference; (iv)constructive and/or pruning algorithms, that add and/or remove neurons or weights from an initial architecture, respectively, based on a predefined link between architecture and ANN performance; (v)evolutionary strategies, which search the topology space using genetic operators to vary the neural network parameters. Several case studies illustrate the development of neural network models for applications in chemistry and chemical engineering. Copyright © 2011 John Wiley & Sons, Ltd.
On the Diels–Alder Approach to Solely Biomass‐Derived Polyethylene Terephthalate (PET): Conversion of 2,5‐Dimethylfuran and Acrolein into p‐Xylene
Authors: Shiramizu Mika , Toste F. Dean
Published: September 2011

Polyethylene terephthalate (PET) is a polymeric material with high global demand. Conventionally, PET is produced from fossil‐fuel‐based materials. Herein, we explored the feasibility of a sustainable method for PET production by using solely bio‐renewable resources. Specifically, 2,5‐dimethylfuran (derived from lignocellulosic biomass through 5‐(hydroxymethyl)furfural) and acrolein (produced from glycerol, a side product of biodiesel production) were converted into the key intermediate p‐xylene (a precursor of terephthalic acid). This synthesis consists of a sequential Diels–Alder reaction, oxidation, dehydration, and decarboxylation. In particular, the pivotal first step, the Diels–Alder reaction, was studied in detail to provide useful kinetic and thermodynamic data. Although it was found that this reaction requires low temperature to proceed efficiently, which presents a limitation on economic feasibility on an industrial scale, the concept was realized and bio‐derived p‐xylene was obtained in 34 % overall yield over four steps.
Transformation of the Information Technology Function in Organizations: A Case Study in the Manufacturing Sector
Authors: Guillemette Manon G. , Paré Guy
Published: September 2011

The main goal of this study is to better understand the nature of transformations of the Information Technology (IT) function in organizations. A conceptual framework combining a typology of the IT function and key elements of the theory of punctuated equilibrium was developed and applied in a case study of a manufacturing company. Our results suggest that IT functions are transformed in response to various pressures that push it toward change. However, these pressures need to be channelled through a catalyst consisting of three independent elements: (a) the vision of the enterprise concerning the potential value of IT tools, (b) the degree of Chief Information Officer's participation in strategic decision making, and (c) the level of IT knowledge among members of the executive team. Finally, our results challenge the notion that all IT functions tend towards the same optimal profile over time. Copyright © 2011 ASAC. Published by John Wiley & Sons, Ltd.
Thermodynamic assessment of the Cu‐Mg‐Si system in its copper‐rich region
Authors: Miettinen J. , Vassilev G.
Published: September 2011

A thermodynamic assessment of the ternary Cu‐Mg‐Si system was made in its copper‐rich region in relation with the development of a thermodynamic database for Cu‐Mg alloys. The adjustable parameters of the binary end‐systems (Cu‐Mg, Cu‐Si and Mg‐Si) were taken from the literature and those of the Cu‐Mg‐Si system were optimized using experimental thermodynamic and topological data. For the sake of simplicity, the solution phases were described with the substitutional solution model and the intermetallic compounds were treated as plain semi‐stoichiometric phases ((A,B)pCq‐type). The assessment developed is applicable for magnesium contents up to 20 wt% (i.e. magnesium mole fractions ≈0.4) and silicon contents up to 16 wt% (i.e. silicon mole fractions ≈0.3). (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Experimental and first‐principle investigation of Cu‐doped ZnO ferromagnetic powders
Authors: Zheng J. H. , Song J. L. , Li X. J. , Jiang Q. , Lian J. S.
Published: September 2011

Zn1‐xCux O powders were synthesized by using sol‐gel method. Electronic band structure and ferromagnetic properties of Zn1‐xCux O powders were studied experimentally and theoretically. The simulations are based upon the Perdew‐Burke‐Ernzerhof form of generalized gradient approximation within the density functional theory. Zn1‐xCux O shows dilute ferromagnetism, as a saturated magnetization of 0.9×10‐3emu/g was observed for Zn0.95Cu0.05O powders. The strong p ‐d hybridization between Cu and its four neighbouring O atoms is responsible for the ferromagnetism. Comparing with ZnO whose Fermi level locates at the valence band maximum, the Fermi level of the Zn1‐xCux O shifts upward into the valence band and hence the Zn1‐xCux O system exhibits theoretically a p ‐type metallic semiconducting property. The Zn1‐xCux O system may be a potential candidate in spintronics. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The Electrochemical Reduction of Carbon Dioxide to Formate/Formic Acid: Engineering and Economic Feasibility
Authors: Agarwal Arun S. , Zhai Yumei , Hill Davion , Sridhar Narasi
Published: September 2011

The engineering and economic feasibility of large‐scale electrochemical reduction of carbon dioxide to formate salts and formic acid is the focus of this Full Paper. In our study we investigated the long‐term performance of tin and other proprietary catalysts in the reduction of carbon dioxide to formate/formic acid at a gas/solid/liquid interface, using a flow‐through reactor. The overall economics and energy consumption of the process are evaluated through a value chain analysis. The sensitivity of the net present value of the process to various process parameters is examined.
Design and Synthesis of Near‐Infrared Emissive Lanthanide Complexes Based on Macrocyclic Ligands
Authors: Zhu Xunjin , Wong Wai‐Kwok , Wong Wai‐Yeung , Yang Xiaoping
Published: September 2011

This review firstly summarizes our recent work on the preparation and photophysical properties of cationic or neutral lanthanide(III) monoporphyrinate complexes, as well as some bridging dinuclear complexes, in which the porphyrinate anion can sensitize the NIR emission of NdIII, YbIII and ErIII ions by serving as an antenna that absorbs visible light and transfers the energy to the excited state of the lanthanide(III) ion, followed by relaxation through the NIR emission. Next, several d–f heterobimetallic diporphyrin complexes, in which a transition metal (M = Zn, Pd, and Pt) porphyrinate moiety serves as a donor by transferring its energy to the Yb3+ ion and enhances the NIR emission, are described. In addition, the synthesis and photophysical properties of some GdIII porphyrinate complexes and monophthalocyaninato lanthanide complexes are also described in this contribution. Apart from the above compounds, we also discuss the construction of multidecker multimetallic lanthanide Schiff base assemblies, which demonstrate that these varieties of salen‐type Schiff base ligands can stabilize LnIII centers and provide the antenna for lanthanide luminescence. By taking advantage of the absorption and emission properties of transition‐metal Schiff base complexes, multinuclear and polynuclear ZnII–LnIII Schiff base complexes have also been constructed with improved luminescence properties.
Cross‐Metathesis Reactions of Homoallyl Methyl Malonates with Sterically Hindered Allylic Esters
Authors: Barile Fabio , Bassetti Mauro , D'Annibale Andrea , Gerometta Renzo , Palazzi Michele
Published: September 2011

The methyl malonate esters of 3‐buten‐1‐ol and 2‐methyl‐3‐buten‐1‐ol can be coupled efficiently to different methallylic esters in the presence of the second‐generation Grubbs catalyst to yield trisubstituted olefins by the cross‐metathesis reaction. Product selectivity and yields depend on the relative amounts of reagents and to a minor extent on the methallylic ester functional group. Alkyl substituents at either the allylic or the geminal positions significantly affect the product yields and the E/Z stereoselectivity.
Tetra‐tert‐butyltetraoxa[8]circulene and Its Unusual Aggregation Behaviour
Authors: Brock‐Nannestad Theis , Nielsen Christian B. , Schau‐Magnussen Magnus , Hammershøj Peter , Reenberg Theis K. , Petersen Asger B. , Trpcevski Denis , Pittelkow Michael
Published: September 2011

We describe the first example of the synthesis of a tetraoxa[8]circulene with only four substituents by means of BF3·OEt2 mediated tetramerisation of tert‐butyl‐1,4‐benzoquinone. Two of the four regioisomers of tetra‐tert‐butyltetraoxa[8]circulene have been isolated and characterised by single‐crystal X‐ray analysis. It was found that the tetra‐tert‐butyltetraoxa[8]circulenes aggregate in solution through a cooperative polymerisation mechanism despite functionalisation with bulky tert‐butyl substituents.
MicroRNA profiling differentiates colorectal cancer according to KRAS status
Authors: Mosakhani Neda , Sarhadi Virinder Kaur , Borze Ioana , Karjalainen‐Lindsberg Marja‐Liisa , Sundström Jari , Ristamäki Raija , Österlund Pia , Knuutila Sakari
Published: September 2011

Recent studies have shown the important role of microRNAs (miRNAs) in a variety of biological processes, and in its ability to distinguish tumors according to their prognostic and predictive properties. To identify miRNA signatures associated with colorectal carcinoma (CRC) and with KRAS status, we studied, using Agilent's miRNA microarrays, miRNA expression in primary tumors from 55 metastatic CRC patients, including 15 with mutant and 40 with wild‐type KRAS. Comparing these with normal colon tissue, we identified 49 miRNAs—including 19 novel miRNAs—significantly deregulated in tumor tissue. The presence of the KRAS mutation was associated with up‐regulation of miR‐127‐3p, miR‐92a, and miR‐486‐3p and down‐regulation of miR‐378. Increased expression of miR‐127‐3p and miR‐92a in KRAS mutant tumors was significantly confirmed by quantitative reverse transcriptase polymerase chain reaction (qRT‐PCR) (P < 0.05). We identified some predicted target genes of differentially expressed miRNAs between mutated and wild‐type KRAS, such as RSG3 and TOB1, which are involved in apoptosis and proliferation. Target prediction and pathway analysis suggest a possible role for deregulated miRNAs in nicotinamide adenine dinucleotide phosphate (NADPH) regeneration and G protein‐coupled receptor signaling pathways. © 2011 Wiley Periodicals, Inc.
The role of the left posterior parietal lobule in top‐down modulation on space‐based attention: A transcranial magnetic stimulation study
Authors: Du Xiaoming , Chen Lin , Zhou Ke
Published: September 2011

Converging evidence from neuroimaging as well as lesion and transcranial magnetic stimulation (TMS) studies has been obtained for the involvement of right ventral posterior parietal cortex (PPC) in exogenous orienting. However, the contribution of dorsal PPC to attentional orienting, particularly endogenous orienting, is still under debate. In an informative peripheral cueing paradigm, in which the exogenous and endogenous orienting can be studied in relative isolation within a single task, we applied TMS over sub‐regions of dorsal PPC to explore their possible distinct involvement in exogenous and endogenous processes. We found that disruption of the left posterior intraparietal sulcus (pIPS) weakened the attentional effects of endogenous orienting, but did not affect exogenous processes. In addition, TMS applied over the right superior parietal lobule (SPL) resulted in an overall increase in reaction times. The present study provides the causal evidence that the left pIPS plays a crucial role in voluntary orienting of visual attention, while right SPL is involved in the processing of arousal and/or vigilance. Hum Brain Mapp 33:2477–2486, 2012. © 2011 Wiley Periodicals, Inc.
Water condition control of in situ soil water repellency: an observational study from a hillslope in a Japanese humid‐temperate forest
Authors: Kajiura Masako , Etori Yoshie , Tange Takeshi
Published: September 2011

To evaluate the relationship between the moisture conditions and the water repellency of soil surfaces in situ, we periodically conducted field surveys for more than a year in a humid‐temperate forest in Japan. Measurements were made in four plots with varying soil physicochemical properties and under different topographic conditions across a hillslope. Each plot contained permanent quadrats with measurement points in a grid pattern. At each point, we measured the volumetric water content at 0‐ to 5‐cm depths and the water repellency at soil surfaces approximately twice a month. The repeated measurements enabled us to estimate the critical water content (CWC) below which soils repelled water at each point. We defined the representative CWC (RCWC) of a plot as the median of all CWCs in a plot and estimated the representative critical water potential (RCWP) on the basis of the RCWC using the water retention curve. The RCWC values differed among plots, but the corresponding RCWP values were similar (pF = 3.5–3.9). The relationship of the areal fraction showing water repellency against soil water potentials was similar across plots, but the relationship differed among plots against the soil moisture content. These results suggest that soil water potential is more indicative of the spatial occurrence of water repellency than moisture content on a hillslope where soil physicochemical properties vary. Plots located on ridge crests frequently exhibited lower water potentials and showed a higher areal fraction of water repellency, implying a greater chance of generating surface runoff by rainfall events. Copyright © 2011 John Wiley & Sons, Ltd.
Hypoxia‐induced upregulation of pigment epithelium‐derived factor by retinal glial (Müller) cells
Authors: Yang Xiu Mei , Yafai Yousef , Wiedemann Peter , Kuhrt Heidrun , Wang Yu‐Sheng , Reichenbach Andreas , Eichler Wolfram
Published: September 2011

Neuronal degeneration and aberrant neovascularization are common problems of ischemic retinopathies. Pigment epithelium‐derived factor (PEDF), a neuroprotective protein and an inhibitor of angiogenesis, is produced by retinal glial (Müller) cells and can counterbalance elevated levels of vascular endothelial growth factor (VEGF), the expression of which is regulated primarily by hypoxia‐inducible factor (HIF)‐1. In an approach to mimic transient ischemia in vitro, primary Müller cells were cultured under transient and strong hypoxia (0.2% O2), followed by reoxygenation at 2.5% O2, and molecular mechanisms that might contribute to changes in the intraretinal PEDF level were determined. Hypoxic conditions caused an increasing expression of HIF‐1α and led to upregulation of both PEDF and VEGF. Treatment of the cells with synthetic HIF‐1α blockers or neutralization of VEGF binding to VEGF receptors (VEGFR‐1 and‐2) suppressed hypoxia‐induced PEDF upregulation. Furthermore, the presence of CoCl2 (a hypoxia mimetic) induced an accumulation of elevated HIF‐1α protein in the nucleus and an upregulation of PEDF expression in Müller cells. Increasing PEDF expression was attenuated when HIF‐1α levels were suppressed using HIF‐1α small interfering RNA (siRNA). On the other hand, siRNA‐mediated depletion of PEDF facilitated HIF‐1α upregulation caused by CoCl2 and resulted in increasing VEGF mRNA and protein levels. These results demonstrate that VEGF and PEDF may be unidirectionally regulated in hypoxia through HIF‐1α activation, with upregulation of PEDF, which may occur in a VEGF‐dependent manner. However, endogenously produced PEDF seems to be an inherent control element of HIF‐1α expression in Müller cells, indicating an important feedback mechanism for limiting upregulation of VEGF. © 2011 Wiley Periodicals, Inc.
Sex‐dependent and differential responses to acute restraint stress of corticotropin‐releasing factor–producing neurons in the rat paraventricular nucleus, central amygdala, and bed nucleus of the stria terminalis
Authors: Sterrenburg Linda , Gaszner Balázs , Boerrigter Jeroen , Santbergen Lennart , Bramini Mattia , Roubos Eric W. , Peeters Bernard W.M.M. , Kozicz Tamás
Published: September 2011

Male and female rodents respond differently to acute stress. We tested our hypothesis that this sex difference is based on differences in stress sensitivity of forebrain areas, by determining possible effects of a single acute psychogenic stressor (1‐hr restraint stress) on neuronal gene expression (c‐Fos and FosB immunoreactivities), storage of corticotropin‐releasing factor (CRF) immunoreactivity, and CRF production (CRF mRNA in situ hybridization) as well as the expression of genes associated with epigenetic processes (quantitative RT‐PCR) in the rat paraventricular nucleus (PVN), the oval and fusiform subdivisions of the bed nucleus of the stria terminalis (BSTov and BSTfu, respectively), and the central amygdala (CeA), in both males and females. Compared with females, male rats responded to the stressor with a stronger rise in corticosterone titer and a stronger increase in neuronal contents of c‐Fos, CRF mRNA, and CREB‐binding protein mRNA in the PVN. In the BSTov, females but not males showed an increase in c‐Fos, whereas the CRF mRNA content was increased in males only. In the BSTfu, males and females showed similar stress‐induced increases in c‐Fos and FosB, whereas in the CeA, both sexes revealed similar increases in c‐Fos and in CRF mRNA. We conclude that male and female rats differ in their reactivity to acute stress with respect to possibly epigenetically mediated (particularly in the PVN) neuronal gene expression and neuropeptide dynamics (PVN and BSTov) and that this difference may contribute to the sex dependence of the animal's physiological and behavioral responses to an acute stressor. © 2011 Wiley Periodicals, Inc.
A surface plasmon resonance sensor on a compact disk‐type microfluidic device
Authors: Hemmi Akihide , Usui Takashi , Moto Akihiro , Tobita Tatsuya , Soh Nobuaki , Nakano Koji , Zeng Hulie , Uchiyama Katsumi , Imato Toshihiko , Nakajima Hizuru
Published: September 2011

A surface plasmon resonance (SPR) sensor on a compact disk (CD)‐type microfluidic device was developed to miniaturize the elements of a complete analytical system, pump and valves. The CD‐type microfluidic device was fabricated by attaching a polydimethylsiloxane disk plate that contained microchannels and reservoirs to a flat polycarbonate disk plate that contained grating films with a thin layer of Au. The optical system of the SPR sensor and the theory for its operation are based on the principle of a grating coupled‐type SPR. The sample and reagent solutions in the reservoirs on the CD‐type microfluidic device were sequentially introduced into the detection chamber by centrifugal force generated by the rotation of the microfluidic device. The variation of resonance wavelength was dependent on the refractive index of the sample solution. This CD‐type SPR sensor was successfully used in an immunoassay of immunoglobulin A (IgA). The anti‐IgA, blocking reagent, sample and washing solution in the reservoirs were sequentially introduced into the detection chamber by changing the frequency of rotation of the microfluidic device. IgA in the sample solution was adsorbed to the anti‐IgA immobilized on the Au thin layer in the detection chamber and was then detected by the SPR sensor.