bluuebunny/crossref_metadata_2025 huggingface dataset:
A biophysical model of the male urethra: Comparing viscoelastic properties of polyvinyl alcohol urethras to male pig urethras
Authors: Idzenga Tim , Pel Johan J.M. , Mastrigt Ron van
Published: June 2006

Aims

We aim at developing a non‐invasive method for grading and diagnosing urinary bladder outlet obstruction, based on noise recording with a perineal contact microphone during voiding. We found that the noise production during voiding depends amongst others on the viscoelastic properties of the urethral wall. To further test our method, we need a realistic biophysical model of the male urethra.

Methods

We made various model urethras with different viscoelastic properties from a 10% aqueous solution of polyvinyl alcohol cryogel. We measured the viscoelastic properties of each model and compared them to those of the male pig urethra. The male pig urethra was used, as it is physiologically comparable to the human male urethra. The viscoelastic properties of both model and pig urethras were measured by applying strain to the urethral wall in a stepwise manner and recording the pressure response. We fitted the step‐response of a mechanical model to this pressure response and derived the viscoelastic properties from the coefficients of this response.

Results

A uniform model urethra that was freeze‐thawed three times, with a Y‐shaped flow channel was found to best represent the male pig urethra.

Conclusions

We consider the three times freeze‐thawed model urethra with a Y‐shaped flow channel the best model of the human male urethra. And we therefore use this model urethra for studying the relation between noise recording during urine flow and the degree of bladder outlet obstruction. Neurourol. Urodynam. © 2006 Wiley‐Liss, Inc.
Focus on the Belkin Pre‐N Wireless Router
Authors: Held Gilbert
Published: June 2006

The latest evolution of wireless LAN products recognizes the old adage that ‘two is better than one,’ resulting in the development of the IEEE 802.11n specification, better known as multiple‐input/multiple‐output (MIMO). Although ratification of the IEEE 802.11n specification isn't expected until the later part of 2006, several vendors over the past year introduced hardware products that double the throughput of current 802.11 g products owing to the ability of such hardware to transmit via multiple antennas and radios. One such product is the Belkin Pre‐N wireless router, which is the focus of this issue's column
Improvements for some condition number estimates for preconditioned system in p‐FEM
Authors: Beuchler Sven , Braess Dietrich
Published: June 2006

In this paper, we consider domain decomposition preconditioners for a system of linear algebraic equations arising from the p‐version of the FEM. We analyse several multi‐level preconditioners for the Dirichlet problems in the sub‐domains in two and three dimensions. It is proved that the condition number of the preconditioned system is bounded by a constant independent of the polynomial degree. Relations between the p‐version of the FEM and the h‐version are helpful in the interpretations of the results. Copyright © 2006 John Wiley & Sons, Ltd.
Cerebral metastasis and other central nervous system complications of pleuropulmonary blastoma
Authors: Priest John R. , Magnuson Jeffrey , Williams Gretchen M. , Abromowitch Minnie , Byrd Rebecca , Sprinz Philippa , Finkelstein Marsha , Moertel Christopher L. , Ashley Hill D.
Published: June 2006

Background

Pleuropulmonary blastoma (PPB) is a rare tumor of pleura and lung in young children. Central nervous system (CNS) complications, particularly cerebral parenchymal metastases, occur in aggressive forms of PPB: Types II and III PPB. This article evaluates cerebral and meningeal metastases, cerebrovascular events (CVA) caused by tumor emboli, spinal cord complications, and intracranial second malignancies in PPB.

Procedure

International PPB Registry and literature cases were evaluated for CNS events. Cerebral metastasis patients were evaluated for gender, side of origin of PPB, PPB Type, interval from diagnosis to metastasis, status of chest disease, treatment, and outcome. Standard statistical methods were used to calculate the cumulative probability of cerebral metastasis and survival following metastasis.

Results

Thirty‐nine cases of cerebral metastasis were identified in 5/53 Registry Type II cases, 15/44 Registry Type III cases, and 19/143 literature Type II/III cases. Metastases occurred 1–60, median 11.5 months after diagnosis. Chest disease was controlled in 50% of children at time of metastasis. The cumulative probability of cerebral metastasis by 5 years from diagnosis was 11% for Type II patients (95%CI (confidence interval): 2–20%) and 54% for Type III patients (95%CI: 31–76%). Seven children survive cerebral metastasis. Other CNS complications were post‐operative CVA (five cases), spinal cord invasion or compression (six), leptomeningeal disease (three), and second intracranial malignancies (two).

Conclusions

Cerebral metastasis is more frequent in PPB than in other childhood sarcomas. Clinicians should screen for this complication. Diverse other CNS complications are less common and require careful diagnosis. Pediatr Blood Cancer 2007;49:266–273. © 2006 Wiley‐Liss, Inc.
A combination of atypical antipsychotics and diabetic ketoacidosis
Authors: Macfarlane DP , Fisher Miles
Published: June 2006

Atypical antipsychotic agents are increasingly used in the management of schizophrenia and other psychiatric conditions due to their efficacy and reduced incidence of extrapyramidal side effects. Large observational studies suggest that the risk of developing diabetes attributable to atypical antipsychotic treatment is relatively small. However, several case reports describe new onset diabetes or diabetic ketoacidosis (DKA) developing shortly following the introduction of atypical antipsychotic monotherapy. We report a case of new onset diabetes presenting as DKA, coinciding with the introduction of a second atypical antipsychotic agent, suggesting that the effect might possibly be additive. Copyright © 2006 John Wiley & Sons, Ltd.
A young person's perspective of type 1 diabetes: development of an innovative DVD
Authors: Cheyette C
Published: June 2006

In recognition of a lack of suitable and age specific educational material for young people with type 1 diabetes it was decided to develop a new resource for the local area. The author decided on using the multimedia format of a DVD due to its ability to portray images and real life situations. A patient focus group approach was used to establish the main areas to be incorporated within the DVD which, to name a few, included diagnosis, school/college, alcohol, injections and drug use. The same patients then agreed, along with their families, to discuss these areas on camera using a non‐scripted approach.

The DVD has been positively evaluated by 21 health care professionals undergoing the Warwick Diabetes Care course. In all, 81% rated it as excellent and 19% as good with no negative feedback. Patient feedback was also sought from 12 patients who had transferred from the paediatric service. This was done in the form of verbal feedback. Patients commented on the DVD showing what living with diabetes is like for ‘ real people’ with the main theme being that ‘ diabetes is just another part of life’.

The DVD started out as a small local project but it has since become possible to have 1000 copies produced and these are now available free of charge to all diabetes centres in the UK. Further evaluation of the impact of the DVD for patients and health care professionals is planned. Copyright © 2006 John Wiley & Sons, Ltd.
ABCD guidelines for the management of hyperglycaemic emergencies in adults
Authors: Savage MW , Kilvert A
Published: June 2006

Diabetic emergencies are traditionally treated by the acute medical admitting team or the Accident and Emergency Department staff. Most will see these on a regular basis, as they are common and both type 1 and type 2 disease are increasing in prevalence. Diabetic emergencies are usually easily treated and the patients discharged. However, it is vital not to become complacent as these disorders can lead to death. It is particularly important to follow local guidance and to involve the Diabetes Team after each episode. We outline the basic management steps in the common diabetic hyperglycaemic emergencies and hope to give an insight to the non‐expert. A proforma for the management of diabetic hyperglycaemic emergencies can be down‐loaded from the Association of British Clinical Diabetologists (ABCD) website at: http://www.diabetologists.org.uk/ABCD_DKA_Chart.pdf. ABCD proposes this chart as an example only and is not responsible for its use; that lies with the treating doctor. Copyright © 2006 John Wiley & Sons, Ltd.
Reports of hyperkalemia after publication of RALES—a pharmacovigilance study
Authors: Hauben Manfred , Reich Lester , Gerrits Charles M.
Published: June 2006

Purpose

A population‐based study and anecdotal reports have indicated that the publication of the Randomized Aldactone Evaluation Study (RALES) was associated with not merely a broader use of spironolactone in the treatment of heart failure, but also with a coinciding sharp increase in hyperkalemia‐associated morbidity/mortality in patients also being treated with ACE‐inhibitors. Data mining algorithms (DMAs) are being applied to spontaneous reporting system (SRS) databases in hopes of obtaining early warnings/additional insights into post‐licensure safety data. We applied two DMAs (i.e. multi‐item gamma Poisson shrinker [MGPS] and proportional reporting ratios [PRRs]) to spontaneous reporting system (SRS) data to determine if these DMAs could have provided an earlier indication of a possible hyperkalemia safety issue.

Methods

MGPS and PRRs were retrospectively applied to US FDA‐AERS, an SRS database. Year‐by‐year analysis and analysis of increasing cumulative time intervals were performed on cases in which both spironolactone and hyperkalemia and possibly related cardiac events had been reported.

Results

Neither of the DMAs initially provided a compelling signal of disproportionate reporting (SDR) for hyperkalemia after publication of RALES. However, using events consistent with clinical sequelae of hyperkalemia (e.g,. sudden death), SDRs were identified with PRRs.

Conclusions

The quality and usefulness of data mining analysis is highly situation dependent and may vary with the knowledge and experience of the drug safety reviewer. Our analysis suggests that contemporary DMAs may have significant limitations in detecting increased frequency of labeled events in real‐life prospective pharmacovigilance. There is a paucity of research in this area and we recommend further research for new approaches to detecting increased frequency of labeled events. Copyright © 2006 John Wiley & Sons, Ltd.
Atom transfer radical polymerization of methyl methacrylate induced by an initiator derived from an ionic liquid
Authors: Gong Shengmin , Ma Hongyang , Wan Xinhua
Published: June 2006

An ionic liquid, 1‐(2‐bromoisobutyryloxyethyl)‐3‐methylimidazolium hexafluorophosphate, was synthesized to act as the initiator of the atom transfer radical polymerization of methyl methacrylate (MMA). By a combination with CuBr and pentamethyldiethylenetriamine, the ionic liquid initiated the free radical polymerization of MMA to proceed in a controlled way over a wide temperature range of 0 to 60 °C. The number‐average molecular weight of the poly(methyl methacrylate) (PMMA) increased with monomer conversion and the polydispersity was relatively narrow. End‐group analysis by proton NMR indicated the presence of the initiator fragments at the ends of the polymer main chain. Lowering the reaction temperature had the result of increasing the content of rr triads. The glass transition temperature was higher for PMMA obtained at lower temperature than at higher temperature. The solubility of the PMMA in methanol increased with the incorporation of imidazolium groups in the polymer. Copyright © 2006 Society of Chemical Industry
Vapor‐based polymer coatings for potential biomedical applications
Authors: Lahann Joerg
Published: June 2006

Over the last decade, biology and biotechnology have witnessed an extraordinary development spanning genomics, proteomics, and metabolics. This progress was so rapid and definite that it not only changed the face of modern biology, but indeed altered the way day‐to‐day business is done in biology and related fields. This scientific advancement came with a need for concurrent technological advances. In this context, the ability to interface sophisticated devices with relevant biological microenvironments has emerged as a critical challenge. Already, novel biomaterials are on the horizon that promise to fulfill the rigid criteria of being both biocompatible under the conditions of a versatile range of biological applications and compatible with the increasing demands for miniaturization, integration, and throughput of future device architectures. As currently employed solvent‐based polymer coatings are increasingly reaching their limits, a range of unconventional materials, such as vapor‐based polymer coatings, are discussed as attractive alternatives. One of the main features of vapor‐based polyreactions is their versatility in synthesizing both simple and complex polymers with relative ease and at generally low temperatures. The advantages of the chemical vapor deposition (CVD) technique also include control of the composition and architecture of the resulting materials, high accuracy, solvent‐free environments, excellent adhesion, and the ability to accommodate custom‐tailored surface modifications. For further illustration, selected examples of polymer‐based surface engineering approaches using vapor‐based polyreactions are discussed in this review. For instance, reactive coating technology uses CVD polymerization to deposit a wide range of chemically functionalized polymer coatings on various substrate materials. Its simplicity in providing chemically reactive groups and its applicability to three‐dimensional geometries (e.g. for microfluidics) enables exact tailoring of surface properties and the preparation of biologically relevant microenvironments. CVD‐based reactive coatings are compatible with soft lithographic processes allowing for patterning of proteins, DNA, cytokines, and mammalian cells. Copyright © 2006 Society of Chemical Industry
Consolidation of thin‐film photovoltaic technology: the coming decade of opportunity
Authors: Green Martin A.
Published: June 2006

The previous decade, particularly its latter half, has been an exhilarating period for photovoltaics. Companies have entered a new era of profitability with photovoltaic company stocks now some of the most eagerly sought. The challenge for the next decade is for the industry to take advantage of the increased resources made available by the recent boom to position photovoltaics for an onslaught into wholesale electricity markets. It is argued that only the best of the thin‐film technologies are likely to be able to lead such a charge. Criteria for the success of thin‐film technology in the long term are discussed. Copyright © 2006 John Wiley & Sons, Ltd.
A vision for crystalline silicon photovoltaics
Authors: Swanson Richard M.
Published: June 2006

This paper discusses the driving forces behind the continued strength of crystalline silicon technology. The history of silicon technology development is reviewed, and projections made as where to silicon technology is likely to go in the following 10 years. Next the barriers that have inhibited the emergence of competing technologies are discussed, along with the steps that need to be taken to surmount those barriers. Copyright © 2006 John Wiley & Sons, Ltd.
The advent of mesoscopic injection solar cells
Authors: Grätzel Michael
Published: June 2006

Mesoscopic injection solar cells operate in an entirely different fashion than conventional solar p‐n junction devices. Mimicking the principles that natural photosynthesis has used successfully over the last 3·5 billion years in solar energy conversion, they achieve the separation of light harvesting and charge carrier transport. The semiconductors used in conventional cells assume both functions simultaneously imposing stringent demands on purity and entailing high material and production costs. The prototype of this new PV family is the dye‐sensitized solar cell (DSC). The DSC has made phenomenal progress since its discovery was announced in the scientific literature only 14 years ago.1 Conversion efficiencies of 11·3% and excellent stability have been reached rendering it a credible alternative to conventional p‐n junction photovoltaic devices. The industrial development is advancing rapidly. Several enterprises currently produce modules and flexible cells on a pilot scale and commercial manufacturing of the DSC has recently been announced. It is asserted that this type of cell is a viable contender for large‐scale future solar energy conversion systems on the bases of cost, efficiency, stability and availability, as well as environmental compatibility. Copyright © 2006 John Wiley & Sons, Ltd.
Solar cell efficiency tables (version 28)
Authors: Green Martin A. , Emery Keith , King David L. , Hishikawa Yoshihiro , Warta Wilhelm
Published: June 2006

Consolidated tables showing an extensive listing of the highest independently confirmed efficiencies for solar cells and modules are presented. Guidelines for inclusion of results into these tables are outlined and new entries since January, 2006 are reviewed. Copyright © 2006 John Wiley & Sons, Ltd.
Protein changes between dormant and dormancy‐broken seeds of Prunus campanulata Maxim
Authors: Lee Chung‐Shu , Chien Ching‐Te , Lin Chao‐Hsiung , Chiu Yi‐Ying , Yang Yuh‐Shyong
Published: June 2006

Seed dormancy is regulated by complex networks in order to optimize the timing of germination. However, the biochemical basis of the regulation of seed dormancy is still poorly understood. Many temperate timber species, which are of ecological and/or economic interest, are deeply dormant in seeds, such as Prunus campanulata. Freshly harvested seeds require warm plus cold stratification to break dormancy before they can begin to germinate. According to the results of germination, both warm and cold stratifications are the critical influences for breaking seed dormancy. Significant variations in seed proteins were observed by 2‐DE before and after the breaking of seed dormancy. Among the 320, 455, and 491 reproducibly detected spots on the cotyledons, embryos, and testae, respectively, 71 dramatic changes in abundances were observed following warm and/or cold stratification. Among these protein spots, dehydrin, prunin 1 precursor, prunin 2 precursor, and prunin 2 were identified by MS and sequence comparison. The implications of protein changes in relation to the breaking of seed dormancy and germination are discussed. This is the first report of a proteomic analysis of dormancy breaking in woody plant seeds.
Protein Equalizer™ Technology : The quest for a “democratic proteome”
Authors: Righetti Pier Giorgio , Boschetti Egisto , Lomas Lee , Citterio Attilio
Published: June 2006

No proteome can be considered “democratic”, but rather “oligarchic”, since a few proteins dominate the landscape and often obliterate the signal of the rare ones. This is the reason why most scientists lament that, in proteome analysis, the same set of abundant proteins is seen again and again. A host of pre‐fractionation techniques have been described, but all of them, one way or another, are besieged by problems, in that they are based on a “depletion principle”, i.e. getting rid of the unwanted species. Yet “democracy” calls not for killing the enemy, but for giving “equal rights” to all people. One way to achieve that would be the use of “Protein Equalizer Technology” for reducing protein concentration differences. This comprises a diverse library of combinatorial ligands coupled to spherical porous beads. When these beads come into contact with complex proteomes (e.g. human urine and serum, egg white, and any cell lysate, for that matter) of widely differing protein composition and relative abundances, they are able to “equalize” the protein population, by sharply reducing the concentration of the most abundant components, while simultaneously enhancing the concentration of the most dilute species. It is felt that this novel method could offer a strong step forward in bringing the “unseen proteome” (due to either low abundance and/or presence of interference) within the detection capabilities of current proteomics detection methods. Examples are given of equalization of human urine and serum samples, resulting in the discovery of a host of proteins never reported before. Additionally, these beads can be used to remove host cell proteins from purified recombinant proteins or protein purified from natural sources that are intended for human consumption. These proteins typically reach purities of the order of 98%: higher purities often become prohibitively expensive. Yet, if incubated with “equalizer beads”, these last impurities can be effectively removed at a small cost and with minute losses of the main, valuable product.
Mass spectrometric analysis of formalin‐fixed paraffin‐embedded tissue: Unlocking the proteome within
Authors: Hood Brian L. , Conrads Thomas P. , Veenstra Timothy D.
Published: June 2006

The predominance of tissues stored worldwide in hospitals and clinical laboratories exist in formalin‐fixed paraffin‐embedded (FFPE) blocks that are generated by simple and well‐established protocols. Although generation of FFPE tissues has facilitated their characterization by such techniques as histopathology, they have proven refractory to biomarker discovery investigations using state‐of‐the‐art MS‐based proteomic methodologies. Very recently new methods have been developed that enable proteins extracted from FFPE tissues to be analyzed by MS. This review will highlight and discuss those efforts that have led to this exciting recent progress. Although these developments are quite new, the ability to conduct MS‐based proteomic analyses of FFPE tissues opens heretofore intractable clinical samples for discovery‐based biomarker research.
A high efficiency cloning and expression system for proteomic analysis
Authors: Ding Xuan Z. , Paulsen Ian T. , Bhattacharjee Apurba K. , Nikolich Mikeljon P. , Myers Gary , Hoover David L.
Published: June 2006

The recent description of the complete genomes of the two most pathogenic species of Brucella opens the way for genome‐based analysis of the antigenicity of their proteins. In the present report, we describe a bench‐level high‐efficiency cloning and expression system (HECES) that allow expression of large numbers of Brucella proteins based on genomic sequence information. Purified proteins are produced with high efficiency in a microarray format conducive to analysis of their sero‐reactivity against serum from immunized animals. This method is applicable at either small or large scale of protein processing. While it does not require robotics, the format is amenable to robotic implementation for all aspects of the process and subsequent analysis of protein characteristics. This method will allow selection of new reagents for diagnosis of brucellosis and development of vaccine against Brucella, an important zoonotic disease and biothreat agent.
Preparation and properties of polyhedral oligosilsequioxane tethered aromatic polyamide nanocomposites through Michael addition between maleimide‐containing polyamides and an amino‐functionalized polyhedral oligosilsequioxane
Authors: Liu Ying‐Ling , Lee Hui‐Chen
Published: June 2006

Polyhedral oligosilsequioxane (POSS) tethered aromatic polyamide nanocomposites with various POSS fractions were prepared through Michael addition between maleimide‐containing polyamides and amino‐functionalized POSS. The chemical structures of the polyamide–POSS nanocomposites were characterized with Fourier transform infrared and 1H NMR. The polyamide–POSS nanocomposites exhibited good homogeneity in scanning electron microscopy and transmission electron microscopy observations. POSS modification increased the storage modulus and Young's modulus of the polyamides, slightly decreased their glass‐transition temperatures from 312 to 305 °C, and significantly lowered their dielectric constants from 4.45 to 3.35. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4632–4643, 2006
Synthesis, rheology, and morphology of nylon‐11/layered silicate nanocomposite
Authors: Zhang Xikui , Yang Guisheng , Lin Jiaping
Published: June 2006

Exfoliated nylon‐11/layered silicate nanocomposites were prepared via in situ polymerization by dispersing organoclay in 11‐aminoundecanoic acid monomer. The original clay was modified by a novel method with 11‐aminoundecanoic acid. In situ Fourier transform infrared spectroscopy results show that stronger hydrogen bonds exist between nylon‐11 and organoclay than that of between nylon‐11 and original clay. The linear dynamic viscoelasticity of organoclay nanocomposites was investigated. Before taking rheological measurements, the exfoliated and intercalating structures and the thermal properties were characterized using X‐ray diffraction, transmission electron microscopy, differential scanning calorimetry, and thermogravimetric analysis. The results show that the clay was uniformly distributed in nylon‐11 matrix during in situ polymerization of clay with 4 wt % or less. The presence of clay in nylon‐11 matrix increased the crystallization temperature and the thermal stability of nanocomposites prepared. Rheological properties such as storage modulus, loss modulus, and relative viscosity have close relationship with the dispersion favorably compatible with the organically modified clay. Comparing with neat nylon‐11, the nanocomposites show much higher dynamic modulus and stronger shear thinning behavior. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2161–2172, 2006
In situ FT‐Raman spectroscopic study of the conformational changes occurring in isotactic polypropylene during its melting and crystallization processes
Authors: Khafagy Rasha M.
Published: June 2006

The conformational changes occurring in isotactic polypropylene during the melting and crystallization processes have been carefully investigated using FT‐Raman spectroscopy at temperatures below, at, and above the polymer melting point. Results confirmed the retention of some crystallinity up to +210 °C, which is 50 °C above the melting point. It was found that, at temperatures just above the melting point (1–10 °C), there is still some short range order of at least 12 monomer units long in certain regions of the melt. At 10 °C above the melting point, the short range order drops below 12 monomer units resulting in the disappearance of the Raman band at 841 cm–1. Vice versa, the experimental measurements show that the iPP melt system is stable when the persistence length of helical sequences is less than 12 monomer units. As soon as the helix length exceeds 12 units, the 31 helix conformation extends quickly and then crystallization occurs. These results are discussed in terms of Imai's microphase separation theory and it agreed very well with it. Also, from our observations for correlation splitting, Raman bands related to conformational states were identified. This analysis indicates the existence of three different conformational states at 808, 830, and 841 cm–1. The 808 cm–1 band was assigned to helical chains within crystals (representing crystalline phase). The 841 cm–1 band was shown to be composed of a band at 841 cm–1, assigned to shorter chains in helical conformation with isomeric defects (representing the isomeric defect phase), and a broader band at 830 cm–1 assigned to chains in nonhelical conformation (representing the melt‐like amorphous phase). This indicates the detection of a three‐phase structure in iPP, where a third phase could be due to the presence of defect regions within the crystalline region, or due to the presence of an amorphous–crystal interphase. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2173–2182, 2006
Synthesis, Characterization and Optical Property of Novel Conjugated Polynitrile
Authors: Zhao Xiong‐Yan , Wang Ming‐Zhu , Xiao Ji‐Jun , Wang Zhi
Published: June 2006

Summary: A novel conjugated polynitrile, plasma‐polymerized 1‐isoquinolinecarbonitrile (PPIQCN) was prepared by plasma polymerization for the first time. The structure and surface compositions of the deposited PPIQCN thin films were investigated by Fourier Transform Infrared (FTIR), UV‐Visible absorption and X‐ray Photoelectron Spectroscopy (XPS). The results show that extensively conjugated CN double bonds were formed in PPIQCN films during the plasma polymerization of 1‐isoquinolinecarbonitrile. An obvious red shift of more than 120 nm in the maximum absorption wavelength (λmax) for PPIQCN films as compared with the monomer absorption spectrum was observed. To check the possibility of applying the PPIQCN films as optical devices, photoluminescence (PL) measurements were also carried out and a maximum PL emission intensity was observed at about 458 nm.

Photoluminescence spectrum of the PPIQCN18 thin film.

magnified image

Photoluminescence spectrum of the PPIQCN18 thin film.
Mercury Porosimetry: A General (Practical) Overview
Authors: Giesche Herbert
Published: June 2006

The paper describes general concepts of mercury porosimetry measurements and provides an overview on the current status of pore‐network analysis tools. Practical aspects of the technique are described as well as emphasizing the need for testing of model pore structures and the status on pore network modeling software.
Non Intrusive Mercury Porosimetry: Pyrolysis of Resorcinol‐Formaldehyde Xerogels
Authors: Job Nathalie , Pirard René , Pirard Jean‐Paul , Alié Christelle
Published: June 2006

When submitted to mercury porosimetry, some materials are penetrated by mercury whereas others, among the most porous, are densified by the isostatic pressure. Notably, this is the case for materials whose structure is made of particles aggregated into filament‐like clusters that are interconnected in a 3‐D array. Indeed, that kind of material undergoes a volume variation due to hierarchical pore collapse. In the case of intrusion, the mercury porosimetry data are classically analyzed by the Washburn equation. In the case of hierarchical pore collapse, data can be correctly analyzed by the collapse model equation. Using an equation that does not correspond to the mechanism leads to large errors in the pore size distribution. Thus, an accurate data analysis requires prior determination of the mechanism leading to the volume variation recorded as a function of the pressure. The present work particularly examines the complex and unusual behavior of partially pyrolyzed resorcinol‐formaldehyde gels when submitted to mercury porosimetry. The unusual behavior encountered complicates the mechanism identification and, therefore, the equation selection. However, the major part of the volume distribution as a function of the pore size can be determined with a good accuracy.
Using Nano‐Cast Model Porous Media and Integrated Gas Sorption to Improve Fundamental Understanding and Data Interpretation in Mercury Porosimetry
Authors: Rigby Sean P. , Evbuomwan Irene O. , Watt‐Smith Matthew J. , Edler Karen , Fletcher Robin S.
Published: June 2006

The mechanisms of entrapment, and the nanoscopic spatial distribution, of the residual mercury within nano‐cast and amorphous porous media (pore sizes ~1–100 nm) following high‐pressure penetration have been studied. It has been shown that, even at the nano‐scale, one of the same two principle mechanisms that have been observed previously in mercury porosimetry experiments on macroscopic glass pore models also occur within a given amorphous, nanoporous solid. Using percolation theory to interpret novel, integrated gas sorption experiments, entrapment was shown to arise, either because of the presence of sufficiently narrow pore necks interspersed between larger voids, or due to non‐random, longer‐range structural heterogeneity. The threshold "snap‐off" ratio parameter for the entrapment process has also been directly measured but found to be considerably smaller than seen previously for macroporous materials. The techniques employed here enable information not previously available for nanoporous systems to be determined, and therefore to be incorporated into simulations of mercury porosimetry on those materials.
Application of Mercury Porosimetry to Predict the Porosity and Strength of Ceramic Catalyst Supports
Authors: Yates Malcolm
Published: June 2006

Ceramic based monolithic supports are used in many catalytic reactions, especially in environmental remediation to avoid pressure drop limitations that may arise in the treatment of large effluent gas volumes. In these systems, the active phases or their precursors can be incorporated into the paste prior to kneading, extrusion and calcination, in order to achieve a uniform deposition throughout the final structure. However, these types of incorporated monolithic catalysts can suffer from diffusion limitations that necessitate the inclusion of temporary agents, which when removed by thermal treatments, generate a higher porosity. This results in an increase in the interconnectivity of the pore structure of the final material. However, an upper limit is reached since an increased porosity negatively affects the mechanical strength of these ceramic materials. In this paper, the mechanical strength and porosity of ceramic catalyst supports are related to the primary particle size of the raw materials, initial composition and final heat treatment temperature.
Multi‐template approach to modeling engineered disulfide bonds
Authors: Pellequer Jean‐Luc , Chen Shu‐wen W.
Published: June 2006

The key issue for disulfide bond engineering is to select the most appropriate location in the protein. By surveying the structure of experimentally engineered disulfide bonds, we found about half of them that have geometry incompatible with any native disulfide bond geometry. To improve the current prediction methods that tend to apply either ideal geometrical or energetical criteria to single three‐dimensional structures, we have combined a novel computational protocol with the usage of multiple protein structures to take into account protein backbone flexibility. The multiple structures can be selected from either independently determined crystal structures for identical proteins, models of nuclear magnetic resonance experiments, or crystal structures of homology‐related proteins. We have validated our approach by comparing the predictions with known disulfide bonds. The accuracy of prediction for native disulfide bonds reaches 99.6%. In a more stringent test on the reported engineered disulfide bonds, we have obtained a success rate of 93%. Our protocol also determines the oxido‐reduction state of a predicted disulfide bond and the corresponding mutational cost. From the energy ranking, the user can easily choose top predicted sites for mutagenesis experiments. Our method provides information about local stability of the engineered disulfide bond surroundings. Proteins 2006. © 2006 Wiley‐Liss, Inc.
The effect of Echinacea purpurea, Astragalus membranaceus and Glycyrrhiza glabra on CD69 expression and immune cell activation in humans
Authors: Brush Julie , Mendenhall Elissa , Guggenheim Alena , Chan Tracy , Connelly Erin , Soumyanath Amala , Buresh Randal , Barrett Richard , Zwickey Heather
Published: June 2006

The increasing use of medicinal herbs among the general public has piqued the need for scientific‐based research to determine the mechanism of action of herbs administered orally in human subjects. The ability of three herbs, Echinacea purpurea, Astragalus membranaceus and Glycyrrhiza glabra, to activate immune cells in human subjects was assessed in this pilot study. The effect of these herbs when ingested for 7 days was measured both when administered singly, and in combination, using flow cytometry. The primary cell activation marker measured was CD69. The results demonstrate that Echinacea, Astragalus and Glycyrrhiza herbal tinctures stimulated immune cells as quantified by CD69 expression on CD4 and CD8 T cells. This activation took place within 24 h of ingestion, and continued for at least 7 days. In addition, these three herbs had an additive effect on CD69 expression when used in combination. Copyright © 2006 John Wiley & Sons, Ltd.
Excitation of the a1Πg and B3Πg electronic states of the nitrogen molecule by electron impact
Authors: Da Costa R. F. , Lima M. A. P.
Published: June 2006

Ab initio calculations were performed for the excitations of the a1Πg and B3Πg electronic states of the N2 molecule by impact of low‐energy electrons. The scattering amplitudes were obtained by means of the Schwinger multichannel method within the scope of the minimal orbital basis for the single configuration interactions (MOB‐SCI) approach. Through the use of the MOB‐SCI strategy, we have investigated the coupling effects among ground state, first singlet, and first triplet excited states of the Πg symmetry. Integral and differential cross sections are shown for impact energies from near threshold up to 30 eV. Present results are compared with SMC two‐state calculations and also with available theoretical and experimental data. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Electronic structure study of the reaction C2H → C2H + H2
Authors: Costa Fabio
Published: June 2006

The photoionization of ethylene (C2H4) and the behavior of the molecular ion (C2H) in its diverse electronic states have been subject of numerous experimental and theoretical studies. The first ethylene cation fragments from the dissociative process; i.e., acetylene cation (C2H) and vinyl cation (C2H), appear on the second ionization band. The papers in literature, though enlightening, leave behind some unclarified points and doubts about the C2H → C2H + H2 dissociative process. As for example: whether some energetic barriers exist or not along the steps followed. Hence, the main goal of this paper is to carry out a systematic research on the C2H → C2H + H2 dissociative process using quality electronic structure calculations to determine the least energy pertinent pathway and to characterize the stationary points along this pathway. Geometry optimization and vibrational frequencies calculations were carried out at the B3LYP, MP2 and CCSD (T) using the 6‐311G(d,p) basis set. To establish the stationary points connectivity in the transitional states, characterized as the first order saddle point, intrinsic reaction coordinate (IRC) calculations were performed. In order to obtain more accurate electronic energies, single point calculations were performed at the CCSD(T)/6‐311++G(3d,2p) theoretical level in the CCSD(T)/6‐311G(d,p) optimized geometries. All energies were corrected for zero point energy (ZPE) contributions, calculated at the CCSD)(T)/6‐311G(d,p) level. Calculated AE at high theoretical level, CCSD(T)/6‐311++G(3df,2p)//CCSD(T)/6‐311 G(d,p), presents an excellent concurrence with the experimental values. More accurate barrier energies are established using CCSD(T)/6‐311++G(3df,2p)//CCSD(T)/6‐311G(d,p) level. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Falciform Ligament in the Management of the Residual Cavity for Liver Hydatidosis: New Surgical Technique
Authors: Ozmen M. Mahir , Coskun Faruk , Ziraman Ipek
Published: June 2006

Introduction

Hydatid disease is a common condition worldwide and continues to be a significant societal problem in many countries of all continents. Alhough other treatment options are also available, surgery remains the cornerstone of therapy for hepatic hydatid disease. Omentoplasty seems to be an efficient technique for managing the residual cavity, but it has some shortcomings and might be difficult in secondary cases. Therefore we describe a new technique using the falciform ligament as a flap instead of omentum for managing the residual cavity, as it is more anatomic and a better option for liver cysts.

Methods

From April 2004 to October 2005, a total of 20 patients (11 women) with a median age of 43 years (range 23–66 years) underwent partial cystectomy‐falciformoplasty for hydatid liver disease. The falciform ligament was prepared as a flap in all patients during the initial step of the operation and, after partial cystectomy and evacuation of the cystic components, the flap was inserted into the cystic cavity and fixed with sutures. A single drain was inserted into the subhepatic area.

Results

Cysts were located in the right lobe of the liver in 14 patients and mean diameter of the cyst was 10 cm (range 7–25 cm). The mean duration of the operation was 40 minutes (range 35–69 minutes), and the mean postoperative hospital stay was 4 days (range 3–7 days). None of the patients had any major complications. Only two patients had persistent drainage for 7 days, which stopped spontaneously. The median follow‐up was 9 months (range 2–19 months). Patients underwent duplex ultrasonography (US) to check the viability of the flap and the residual cavity at 1 week, 1 month, and 3 months postoperatively. US did not reveal any collection, the cavities were fully collapsed, and blood flow to the falciform ligaments was seen to be viable.

Conclusions

Using the falciform ligament as a flap for management of the residual cavity is an easy, safe, effective new technique with few complications. It might be a good choice in patients with hydatid liver disease.
Bollons Seamount and early New Zealand–Antarctic seafloor spreading
Authors: Davy Bryan
Published: June 2006

Magnetic anomaly, swath bathymetry and gravity data from the southern Chatham Rise to Bollons Seamount region reveal a history of Cretaceous seafloor spreading in the mouth of the Bounty Trough starting at ∼85 Ma followed by spreading ridge jumps back to the Marie Byrd Land Margin at 83.7 and 78.5 Ma. The latter ridge jump accompanied the rifting of the Bollons Seamount from the Marie Byrd Land margin. Interpreted magnetic anomalies indicate a pattern of highly asymmetric spreading prior to 78 Ma that varied in bias along the margin on a ∼100 km length scale. Crustal thickening within the ∼50 km Bollons Gap linking the Bollons Seamount to the Campbell Plateau is interpreted to be due to excess volcanism associated with the initial rifting–seafloor spreading process and possible thinned continental crust. The elevated 200 km long segment of Antipodes Fracture Zone southeast of Bollons Seamount has been exposed to varying styles of ridge end volcanism and possible normal compression associated with the development during chron 32n.2n of a triple junction at its southeastern limit marking the Bellingshausen‐Marie Byrd Land plate boundary.
Corotating solar wind streams and recurrent geomagnetic activity: A review
Authors: Tsurutani Bruce T. , Gonzalez Walter D. , Gonzalez Alicia L. C. , Guarnieri Fernando L. , Gopalswamy Nat , Grande Manuel , Kamide Yohsuke , Kasahara Yoshiya , Lu Gang , Mann Ian , McPherron Robert , Soraas Finn , Vasyliunas Vytenis
Published: June 2006

Solar wind fast streams emanating from solar coronal holes cause recurrent, moderate intensity geomagnetic activity at Earth. Intense magnetic field regions called Corotating Interaction Regions or CIRs are created by the interaction of fast streams with upstream slow streams. Because of the highly oscillatory nature of the GSM magnetic field z component within CIRs, the resultant magnetic storms are typically only weak to moderate in intensity. CIR‐generated magnetic storm main phases of intensity Dst < −100 nT (major storms) are rare. The elongated storm “recovery” phases which are characterized by continuous AE activity that can last for up to 27 days (a solar rotation) are caused by nonlinear Alfven waves within the high streams proper. Magnetic reconnection associated with the southward (GSM) components of the Alfvén waves is the solar wind energy transfer mechanism. The acceleration of relativistic electrons occurs during these magnetic storm “recovery” phases. The magnetic reconnection associated with the Alfvén waves cause continuous, shallow injections of plasma sheet plasma into the magnetosphere. The asymmetric plasma is unstable to wave (chorus and other modes) growth, a feature central to many theories of electron acceleration. It is noted that the continuous AE activity is not a series of substorm expansion phases. Arguments are also presented why these AE activity intervals are not convection bays. The auroras during these continuous AE activity intervals are less intense than substorm auroras and are global (both dayside and nightside) in nature. Owing to the continuous nature of this activity, it is possible that there is greater average energy input into the magnetosphere/ionosphere system during far declining phases of the solar cycle compared with those during solar maximum. The discontinuities and magnetic decreases (MDs) associated with interplanetary Alfven waves may be important for geomagnetic activity. In conclusion, it will be shown that geomagnetic storms associated with high‐speed streams/CIRs will have the same initial, main, and “recovery” phases as those associated with ICME‐related magnetic storms but that the interplanetary causes are considerably different.
Thermal equation of state of Fe3S and implications for sulfur in Earth's core
Authors: Seagle Christopher T. , Campbell Andrew J. , Heinz Dion L. , Shen Guoyin , Prakapenka Vitali B.
Published: June 2006

Iron (Fe) and coexisting Fe3S were studied simultaneously using synchrotron X‐ray diffraction and a laser‐heated diamond anvil cell (DAC). The thermal equation of state (EOS) of Fe3S was investigated up to pressures of 80 GPa and temperatures of 2500 K. Fitting a third‐order Birch‐Murnaghan EOS to the room temperature data yielded bulk modulus K0 = 156(7) GPa (values in parentheses are standard deviation) and pressure derivative K′0 = 3.8(3) calibrated against NaCl in the B2 structure. The room temperature data were also calibrated against the EOS of hcp‐Fe for comparison and aid in the determination of the thermal pressure contribution of Fe3S. This fit yielded bulk modulus K0 = 113(9) GPa and pressure derivative K′0 = 5.2(6). The thermal pressure contribution of Fe3S was assumed to be of the form ΔPthermal = αKTΔT, where αKT is constant. The best fit to the data yielded αKT = 0.011(2) GPa K−1. Iron and Fe3S coexisted in the high‐pressure, high‐temperature experiments, and a density relationship between Fe and Fe3S was found to be linear and independent of temperature. Extrapolation of the data to the core‐mantle boundary (CMB), using an assumed temperature of 3500 K at the CMB, a 2% volume change associated with melting, and applying a small adjustment to account for the nickel content of the core indicates that 14.7(11) wt % sulfur is adequate to resolve the density deficit of the outer core.