bluuebunny/crossref_metadata_2025 huggingface dataset:
Behavior of hippocampal stem/progenitor cells following grafting into the injured aged hippocampus
Authors: Shetty Ashok K. , Rao Muddanna S. , Hattiangady Bharathi
Published: July 2008

Multipotent neural stem/progenitor cells (NSCs) from the embryonic hippocampus are potentially useful as donor cells to repopulate the degenerated regions of the aged hippocampus after stroke, epilepsy, or Alzheimer's disease. However, the efficacy of the NSC grafting strategy for repairing the injured aged hippocampus is unknown. To address this issue, we expanded FGF‐2‐responsive NSCs from the hippocampus of embryonic day 14 green fluorescent protein–expressing transgenic mice as neurospheres in vitro and grafted them into the hippocampus of 24‐month‐old F344 rats 4 days after CA3 region injury. Engraftment, migration, and neuronal/glial differentiation of cells derived from NSCs were analyzed 1 month after grafting. Differentiation of neurospheres in culture dishes or after placement on organotypic hippocampal slice cultures demonstrated that these cells had the ability to generate considerable numbers of neurons, astrocytes, and oligodendrocytes. Following grafting into the injured aged hippocampus, cells derived from neurospheres survived and dispersed, but exhibited no directed migration into degenerated or intact hippocampal cell layers. Phenotypic analyses of graft‐derived cells revealed neuronal differentiation in 3%–5% of cells, astrocytic differentiation in 28% of cells, and oligodendrocytic differentiation in 6%–10% cells. The results demonstrate for the first time that NSCs derived from the fetal hippocampus survive and give rise to all three CNS phenotypes following transplantation into the injured aged hippocampus. However, grafted NSCs do not exhibit directed migration into lesioned areas or widespread neuronal differentiation, suggesting that direct grafting of primitive NSCs is not adequate for repair of the injured aged brain without priming the microenvironment. © 2008 Wiley‐Liss, Inc.
Development of active plastic crate and evaluation of phytopathogenic and pathogenic food spoilage micro‐organism inhibition
Authors: Pinto Michele da Silva , Ferreira Soares Nilda de Fátima , Filomeno Fontes Edimar Aparecida , Maia Geraldine Robson , Baffa Júnior José Carlos , Ramos Melo Nathália
Published: July 2008

BACKGROUND: The plastic crates used in fruit and vegetable shipping can be vehicles of disease dissemination among production fields, since there is a chance of phytopathogenic micro‐organism adhesion on the crate surfaces when in contact with soil, contaminated produce or handling. The aim of this study was to develop an active plastic crate incorporated with a triclosan‐based antimicrobial agent and to evaluate its efficiency of micro‐organism inhibition.

RESULTS: Staphylococcus aureus (a human pathogen), Clavibacter michiganensis ssp. michiganensis and Erwinia carotovora ssp. carotovora (phytopathogens) were the most sensitive micro‐organisms when in contact with samples of plastic crate incorporated with 30 g kg−1 of antimicrobial agent. They presented diameters of approximately 5.0, 3.5 and 3.5 cm respectively in the halo test. Mean specific growth rates decreased in samples with 30 g kg−1 of antimicrobial agent, compared with control samples, from 1.13 to 0 h−1 for S. aureus, from 1.26 to 0.47 h−1 for Escherichia coli and from 1.75 to 0.18 h−1 for Listeria monocytogenes. The antimicrobial agent did not influence the mechanical properties of the crates.

CONCLUSION: The active plastic crate has great potential to contribute to the safety of horticultural produce by restraining the proliferation of micro‐organisms among production fields. Copyright © 2008 Society of Chemical Industry
Performance evaluation for aged environmentally adapted lubricants in bronze‐steel sliding contacts
Authors: McCarthy D. M. C. , Glavatskih S. B. , Pach M. , Dmitriev A.
Published: July 2008

Environmentally adapted lubricants (EALs) are becoming of increasing interest to the industry as legislation demands the replacement of mineral oil lubricants. However, little or nothing is known about the influence of ageing on the performance of these fluids in mixed and boundary lubricated tribological contacts. In this study, samples of three fully formulated lubricating oils, both in their ‘unaged’ form and ‘aged’ by means of an oxidation process in the laboratory, were utilized in a detailed study whereby variations in relative lubrication performance were examined. Standard laboratory pin‐on‐disc equipment was utilized in order to allow comparisons to be made and the definition of conclusions for a sliding tin bronze on steel contact. This simulated the interaction between an oil‐lubricated bronze bushing and steel shaft as found in the vane adjustment mechanism of a Kaplan turbine. X‐ray photoelectron spectroscopy analysis was employed to assess the effect on surface layer structural chemistry. Results showed, for the specific application being investigated, that EALs continue to function well in terms of their friction and wear performance even at high acid numbers. Copyright © 2008 John Wiley & Sons, Ltd.
In hospital outcomes after pancreatectomies: An analysis of a national database from 1996 to 2004
Authors: Turaga Kiran , Kaushik Manas , Forse R. Armour , Sasson Aaron R.
Published: July 2008

Introduction

National complication rates following pancreatectomies have not been systematically reported.

Methods

We queried the national hospital discharge survey (NHDS) database to analyze risk factors associated with mortality and length of stay after pancreatectomies.

Results

An estimated 49,346 pancreatectomies were performed from 1996 to 2004. The national mortality rate is 9% with an average length of stay 15 days (Interquartile range 10–23) while the morbidity is 35%. Size of the hospital (<300 beds) (OR 2.76 (95% CI 1.14–6.70, P = 0.02)), post‐operative pulmonary edema (OR 2.80 (95% CI 1.28–6.12, P = 0.01)) and sepsis (OR 5.22 (95% CI 1.94–14.11, P = 0.001)) are associated with higher mortality. Patients in larger hospitals (>500 beds) (Rate ratio 0.87 (95% CI 0.83–0.91, P < 0.001)) had a shorter hospital stay. Temporal trends reveal a shorter hospital length of stay in 2004 (Rate ratio 0.86 (95% CI 0.78–0.94, P = 0.001)) as compared to 1996. The percentage of pancreatectomies performed at larger hospitals in 1996 (40%) and 2004 (41%) has remained constant.

Conclusion

The national mortality and morbidity rates after pancreaticoduodenectomy are 9% and 35%, respectively. Larger hospital size and absence of pulmonary edema and sepsis improves mortality. Larger hospitals have better outcomes although the trend for regionalization is not apparent. J. Surg. Oncol. 2008;98:156–160. © 2008 Wiley‐Liss, Inc.
A rationale for the targeted treatment of oligometastases with radiotherapy
Authors: MacDermed Dhara M. , Weichselbaum Ralph R. , Salama Joseph K.
Published: July 2008

An oligometastatic state has been proposed wherein patients with metastases limited in number and location may benefit from local therapy directed at all known sites of metastases. We describe here the clinical and biological basis for the oligometastatic state. We present evidence for a potentially curative approach to patients with oligometastases using stereotactic body radiotherapy (SBRT) and we review the literature for SBRT directed at specific metastatic sites in the lungs, liver and multiple organs. J. Surg. Oncol. 2008;98:202–206. © 2008 Wiley‐Liss, Inc.
The analysis of status and clinical implication of KIT and PDGFRA mutations in gastrointestinal stromal tumor (GIST)
Authors: Du Chun‐Yan , Shi Ying‐Qiang , Zhou Ye , Fu Hong , Zhao Guangfa
Published: July 2008

Background and objective

to analyze the frequency and spectrum of KIT and platelet‐derived growth factor receptor‐alpha (PDGFRA) gene in a large series of study and to explore the clinical implication of mutations in the gastrointestinal stromal tumors (GISTs) in China.

Method

A total of 141 GISTs were subject to mutation analysis of KIT (exons 9, 11, 13, and 17) and PDGFRA (exons 12 and 18) using PCR amplification and direct sequencing. Clinicopathologic characteristics were correlated to gene mutations.

Results

Of the 141 tumors studied, approximately 76.6% had KIT gene mutations, 2.8% had PDGFRA gene mutations and 20.6% had a wild‐type gene of KIT and PDGFRA. Among those with KIT gene mutations, 70.2% occurred in exon 11, 5.7% in exon 9, 0.7% in exon 13, and no mutation was detected in exons 17. The most frequent sites of mutation were in exon 11 and the mutations clustered in the classic “hot spot” at the 5′end of the exon mostly heterogeneous and the second “hot spot” were internal tandem duplications (ITD) at the 3′end of the exon. The overall mutation rate was significantly lower in GISTs originated from colorectum or extra‐gastrointestinal tract (χ2 = 6.728, P = 0.009; χ2 = 4.059, P = 0.044), however, mutation rate on exon 11 was significantly increased in gastric stromal tumor (χ2 = 5.713, P = 0.017; χ2 = 4.341, P = 0.037). There were no significant differences in terms of age, gender, tumor size, mitotic counts, grade of malignant potential and liver metastasis in patients with or without gene mutations.

Conclusion

KIT and PDGFRA gene were frequently found in patients with GISTs. Gene mutation rate varies in originated organ. J. Surg. Oncol. 2008;98:175–178. © 2008 Wiley‐Liss, Inc.
Upstaging benefits and accuracy of sentinel lymph node mapping in colorectal adenocarcinoma nodal staging
Authors: Quadros Claudio Almeida , Lopes Ademar , Araujo Iguaracyra , Fregnani Jose Humberto , Fahel Fernanda
Published: July 2008

Background and Objectives

Sentinel lymph node (SLN) mapping is an additional method for improving colorectal cancer nodal staging. The purpose of the study was to define the method's accuracy in nodal staging, its upstaging benefits and to identify the predictive factors for its failure.

Methods

Lymphatic mapping was performed using technetium‐99m‐phytate and patent blue in 52 consecutive colorectal adenocarcinoma patients. Enhanced pathological examination was carried out on SLNs with hematoxylin–eosin step‐sectioning and immunochemistry.

Results

The patients studied had an average tumor size of 6.5 cm; 85% had T3/T4 tumors; and rectal tumors represented 57.7% of the group. Overall SLN mapping accuracy was 79.5%, with sensitivity of 65.2% and 34.8% false negatives. Upstaging with SLN mapping was 23.1%. Colon tumors had an SLN identification rate of 90.9% and rectal tumors had 63.3% (P = 0.023). Multivariate statistical analysis identified lower rectal tumor (P = 0.009), neoadjuvant treatment (P = 0.029) and tumor size (P = 0.036) as independent risk factors for the inability to detect SLNs.

Conclusions

Upstaging benefits of SLN mapping should be considered in colon and mid‐ and upper rectal tumors. The method should be avoided in patients with lower rectal tumors, large tumors and having had neoadjuvant therapy. J. Surg. Oncol. 2008;98:324–330. © 2008 Wiley‐Liss, Inc.
Dynamic liquid phase nanoextraction coupled to GC/MS for rapid analysis of methoxyacetophenone and anisaldehye isomers in urine
Authors: Wu Hui‐Fen , Yen Jyh‐Hao
Published: July 2008

This study introduces a novel extraction technique in the nanoscale and challenges the limits of solvent extraction in the GC/MS using electronic ionization (EI) method for quantitative determination of six methoxyacetophenone (MAP) and anisaldehye (AAH) isomers in one drop of water and urine. This technique is termed as dynamic liquid phase nanoextraction (DLPNE). The optimum parameters for the DLPNE technique were: selection of solvent, toluene; sampling volume, 0.44 μL; dwell time, 2 s; number of sampling, 15; extraction time, 1.5 min; volume of extraction solvent, 60 nL; and no salt addition. The LODs for this technique were 5–20 ng/mL. The RSDs were in the range of 9.7–12.6% (n = 6). The linear dynamic range of the calibration curve of DLPNE is from 0.02 to 0.5 μg/mL with correlation coefficient (r2) >0.9705. The advantages of the DLPNE technique are rapidity, ease of operation, simple device, and extremely little solvent and sample consumption. This technique was also compared with the static liquid phase nanoextraction (SLPNE) while the SLPNE failed to detect any signal for the six isomers. We believe that this technique can be very useful for the detection of volatile organic compounds in environmental science from microscale of water or it can be applied to clinical or pharmaceutical application such as diagnosis of microamount of urine or blood samples by GC/MS.
Efficient enrichment of α,β‐unsaturated bovine insulins‐(C12)n using tweezing adsorptive bubble separation (TABS) with bovine serum albumin
Authors: Nicolai Andreas , Friess Albrecht , Parlar Harun
Published: July 2008

Alkyl‐substituted insulin molecules are depository preparations used in the treatment of diabetes. The isolation and purification of these active compounds is performed on the hand of several complicated separation steps. In this work, nonmodified and new synthesized α,β‐unsaturated bovine insulins‐(C12)n were selectively isolated from aqueous solution using tweezing adsorptive bubble separation (TABS) with BSA, which enabled reversible binding with the unpolar side chains of bovine insulin and its derivates. The bovine insulin/serum albumin complex could be efficiently transferred into the foam phase at pH 8 with an enrichment factor of 2.6 and a recovery of 89.7%. Experiments with alkylated α,β‐unsaturated bovine insulins‐(C12)n performed at pH 9 enriched even quantitatively the complex under equal experimental conditions, accompanied with an enrichment factor of 3.3. Additionally performed radio immunoassay tests revealed that the immunological activity of α,β‐unsaturated bovine insulins‐(C12)n remained unchanged after foaming.
Poisson's effects in electrical field flow fractionation
Authors: Biernacki Joseph J. , Mellacheruvu P. Manikya , Mahajan Satish M.
Published: July 2008

Recent and earlier models of electrical field flow fractionation (ELFFF) have assumed that the electric field within the fluid domain is governed by Laplace's equation. This assumption results in a linear potential and a spatially constant field across the channel and is generally true for very dilute systems and relatively high effective potentials. Experimental studies show, however, that the effective potential within the channel may be less than 1% of the applied potential; this is apparently due to double layer formation and charge buildup at the poles. In such cases, local analyte concentrations can, nonetheless, be orders of magnitude higher than the bulk mean and the local potential small, both of which can lead to a nonlinear spatial distribution of the field strength. In such cases Poisson's equation must be used rather than Laplace's equation. Steady‐state ELFFF simulations were performed using a Poisson's equation‐based model. The domain in which Laplace's equation is valid was identified and the effects of concentration and effective field strength on device performance were explored.
Analysis of yohimbine alkaloid from Pausinystalia yohimbe by non‐aqueous capillary electrophoresis and gas chromatography‐mass spectrometry
Authors: Chen Qinhua , Li Peng , Zhang Zhuo , Li Kaijun , Liu Jia , Li Qiang
Published: July 2008

In the present work, the qualitative and quantitative analysis of Pausinystalia yohimbe‐type alkaloids in the barks of Rubiaceae species is presented using different analytical approaches. Extracts of P. yohimbe were first examined by GC‐MS and the major alkaloids were identified. The quantitation of yohimbine was then accomplished by non‐aqueous CE (NACE) with diode array detection. This approach was selected in order to use a running buffer fully compatible with samples in organic solvent. In particular, a mixture of methanol containing ammonium acetate (20 mM) and glacial acetic acid was used as a BGE. The same analytical sample was subjected to GC‐MS and NACE analysis; the different selectivity displayed by these techniques allowed different separation profiles that can be useful in phytochemical characterization of the extracts. The linear calibration ranges were all 10–1000 μg/mL for yohimbine by GC‐MS and NACE analysis. The recovery of yohimbine was 91.2–94.0% with RSD 1.4–4.3%. The LOD for yohimbine were 0.6 μg/mL by GC‐MS and 1.0 μg/mL by NACE, respectively. The GC‐MS and NACE methods were successfully validated and applied to the quantitation of yohimbine.
Optimizing protein extraction from plant tissues for enhanced proteomics analysis
Authors: Wang Wei , Tai Fuju , Chen Shaoning
Published: July 2008

Plant tissues usually contain high levels of proteases and secondary metabolites that severely interfere with protein extraction, separation, and identification. Preparation of high‐quality protein samples from plant tissues for proteomic analysis represents a great challenge. This article briefly describes the critical points in protein separation, especially secondary metabolites in plant tissues, and removal strategy. It provides an updated overview of three total protein extraction methods and their applications in proteomic analysis of various recalcitrant tissues.
Porous polymer monoliths for extraction: Diverse applications and platforms
Authors: Potter Oscar G. , Hilder Emily F.
Published: July 2008

Polymer monoliths are becoming increasingly popular as sorbent materials, and, along with silica monoliths, they are sometimes touted as replacements for the particulate stationary phases used in HPLC. This critical and prospective review shows how polymer monoliths are in fact finding numerous extraction roles that do not resemble HPLC. They are showing great promise as extractors in a remarkable range of platforms, formats and hyphenated systems with functions ranging from chromatographic preconcentration to large‐scale preparative extraction. Monolith surface chemistry, morphology and the approaches to monolith synthesis are discussed with regards to these emerging roles.
Hyphenation in sample preparation: Advancement from the micro to the nano world
Authors: Ali Imran , Gupta Vinod.K. , Aboul‐Enein Hassan Y. , Hussain Afzal
Published: July 2008

Analysis at trace levels, an ideal area of application for hyphenated techniques, is steadily gaining importance. Many sample pre‐concentration and clean‐up methods have been hyphenated with core analytical techniques to accomplish the task of low level detection. The present article describes the state of the art of hyphenation of various techniques such as solid phase extraction, micro‐solid phase extraction, dialysis, and chromatographic modalities etc. with liquid chromatography, gas chromatography, capillary electrophoresis, and spectroscopic methods. Besides, attempts have been made to address the hyphenation approach in microfluidic devices.
Traditional Chinese medicine and separation science
Authors: Liu Shao , Yi Lun‐Zhao , Liang Yi‐Zeng
Published: July 2008

Traditional Chinese medicines (TCMs) are getting more and more popular nowadays in the whole world for improving health condition of human beings as well as preventing and healing diseases. TCM is a multi‐component system with components mostly unknown, and only a few compounds are responsible for the pharmaceutical and/or toxic effects. The large numbers of other components in the TCM make the screening and analysis of the bioactive components extremely difficult. So, separation and analysis of the desired chemical components in TCM are very important subjects for modernization research of TCM. Thus, many novel separation techniques with significant advantages over conventional methods were introduced and applied to separation and analysis of the chemical constituents in TCM. This review presents just a brief outline of the applications of different separation methods for the isolation and analysis of TCM constituents.
Use of polymer fiber stationary phases for liquid chromatography separations: Part I – physical and chemical rationale
Authors: Marcus R. Kenneth
Published: July 2008

The idea of using polymer fibers as stationary phases for LC is not a new one. There are in fact a number of good reasons for which they should be considered. To this point though, they have not produced sufficiently good performance to garner much commercial interest. Presented here are the physical and chemical rationale by which they should show enhanced performance relative to conventional stationary phases. Most notably, the mass transport and hydrodynamic characteristics suggest applications in areas of macromolecule and prep‐scale separations. Additionally, there exists an incredible wealth of polymer surface chemistries and potential derivatization pathways that greatly exceed what is practical on conventional silica supports. The potential for important impact suggests further research into polymer fiber phases.
Evaluation of protein, peptide, and amino acid retention on C5 hydride‐based stationary phases
Authors: Pesek Joseph J. , Matyska Maria T. , Venkat Jayasree Pindi
Published: July 2008

A pentyl (C5) stationary phase is synthesized on a hydride surface using both 100 and 300 Å silica particles. The aqueous normal phase properties of these new phases are evaluated using amino acids at high concentrations of ACN in the mobile phase containing 0.1% formic acid. The RP properties of the materials are tested by using peptides and proteins in order to evaluate the effect of pore size on retention. Comparisons of retention as well as efficiencies and peak symmetry with a C18 phase are used to determine the influence of the hydrophobic properties of the bonded material. An evaporative light scattering detector (ELSD) is used in all phases of the study and compared with UV detector for gradient elution of proteins.
Considerations on HILIC and polar organic solvent‐based separations: Use of cyclodextrin and macrocyclic glycopetide stationary phases
Authors: Wang Chunlei , Jiang Chunxia , Armstrong Daniel W.
Published: July 2008

There is a natural tendency in science to prefer straightforward, logical classification systems. The use of mobile phase–stationary phase combinations that do not fit neatly into the standard “normal phase” or “reversed‐phase” categories has been going on for over 50 years. The term “hydrophilic interaction chromatography” (HILIC) is sometimes being used as a general category for these “other” separations. In some cases, it may be appropriate and in others, not. Indeed the mechanistic constrains used to define the method seem to be varying with time. Given the name HILIC, it is assumed that water is not only present in the mobile phase, but also plays an essential role in the retention mechanism. However, there is residual water present in all organic solvents. Regardless, the number of reported separations in this alternative mode has increased tremendously in the last two decades. This is due to the advent of new stationary phases and an emphasis on polar, biologically important molecules. We discuss the relationships between HILIC and other chromatographic modes. We then examine two classes of stationary phases that have played a major role in these separations. These particular stationary phases can be used to provide appreciable mechanistic information as well.
Determination of volatile and non‐volatile products of milk fermentation processes using capillary zone electrophoresis and solid phase microextraction coupled to gas chromatography
Authors: Ligor Magdalena , Jarmalaviciene Reda , Szumski Michal , Maruška Audrius , Buszewski Boguslaw
Published: July 2008

The aim of the investigations was to develop analytical methods for the determination of selected volatile and non‐volatile organic compounds numbering among the final products of milk fermentation. The analyzed compounds were as follows: biacetyl and carboxylic acids (formic, acetic, citric, and lactic). The model yogurt was prepared under controlled conditions in our laboratory by addition of the selected bacteria (Lactobacillus bulgaricus and Streptococcus thermophilus) to the milk sample. The temperature, time, and stirring were controlled during the fermentation process. Factors considered in SPMPE–GC–FID method development included fiber exposure time, salt addition, temperature of extraction, and temperature of desorption. Various SPME fibers, for example with PDMS, CAR/PDMS, PA, and PDMS/DVB coatings, were tested to obtain the highest recovery of the investigated compounds extracted from yogurt samples. Based on these preliminary experiments, qualitative and quantitative analyses for the determination of biacetyl were performed by SPME–GC–FID. Moreover, a capillary zone electrophoresis method was developed for the determination of carboxylic acids in the yogurt samples. The buffer composition as well as deproteinization by acetonitrile were found to have a crucial effect on the analysis.
Separation of inorganic anions on a high capacity porous polymeric monolithic column and application to direct determination of anions in seawater
Authors: Evenhuis Christopher J. , Buchberger Wolfgang , Hilder Emily F. , Flook Kelly J. , Pohl Christopher A. , Nesterenko Pavel N. , Haddad Paul R.
Published: July 2008

A commercially available 4.6 mm id×50 mm polymethacrylate‐based monolithic strong anion exchange column (ProSwiftTM SAX‐1S) designed for the separation of proteins has been successfully used to separate small inorganic anions in the presence of a seawater sample matrix. Using a hydroxide eluent with suppressed conductivity detection the ion exchange capacity of this column declined over time; however, using KCl as the eluent, the column performance was stable with a capacity of 530 μequiv. for nitrate. The optimum conditions for the separation of iodate, bromate, nitrite, bromide and nitrate were assessed by constructing van Deemter plots using 1.00 and 0.100 M KCl. Efficiencies of up to 26 700 plates/m were recorded using 1.00 M KCl, at a flow rate of 0.20 mL/min but iodate was not baseline resolved from the void peak. By reducing the concentration of the eluent to 0.100 M, efficiencies of up to 39 900 plates/m could be obtained at 0.35 mL/min. By employing a linear gradient ranging from 0.05 to 1.00 M KCl the ions dissolved in distilled water or a salt water matrix could be baseline separated in less than 3 min at a flow rate of 2.50 mL/min.
Holiday users of the Internet — ease of use, functionality and novelty
Authors: Ryan Chris , Rao Ulhas
Published: July 2008

This study is based upon a sample of 517 international visitors to New Zealand. It suggests that Internet usage is based upon perceived usefulness and ease of system use. Of additional importance is user confidence about system security. Functional issues of purchasing seem to take priority over information search as users become more familiar with web pages. An additional finding is that entertainment needs are arguably better met by other Internet functions than those provided by destination web pages. Novelty on the Net is perhaps sought from specific sources, and not from the Net generally. Implications are discussed for both measurement and marketing. Copyright © 2008 John Wiley & Sons, Ltd.
Carbon stocks in Ethiopian soils in relation to land use and soil management
Authors: Girmay G. , Singh B. R. , Mitiku H. , Borresen T. , Lal R.
Published: July 2008

The effect of soil management and land use change are of interest to the sustainable land management for improving the environment and advancing food security in developing countries. Both anthropogenic changes and natural processes affect agriculture primarily by altering soil quality. This paper reviews and synthesizes the available literatures related to the influence of soil management and land use changes on soil carbon (C) stock in Ethiopia. The review shows that topsoil C stock declines approximately 0–63%, 0–23%, and 17–83% upon land use conversion from forest to crop land, to open grazing, and to plantation, respectively. An increase of 1–3% in soil C stock was observed within 10 years of converting open grazed land to protected enclosures. However, there was a little change in soil C stock below 20 cm depth.

There is a large potential of increasing SOC pool with adoption of land restorative measures. Total potential of soil C sequestration with the adoption of restoration measures ranges 0·066–2·2 Tg C y−1 on rain‐fed cropland and 4·2–10·5 Tg C y−1 on rangeland. Given large area and diverse ecological conditions in Ethiopia, research data available in published literature are rather scanty. Therefore, researchable priorities identified in this review are important. Copyright © 2008 John Wiley & Sons, Ltd.
Biomaterials and Biofunctionality in Layered Macromolecular Assemblies
Authors: Ariga Katsuhiko , Hill Jonathan P. , Ji Qingmin
Published: July 2008

Recent research in the field of LbL assembly is summarized and categorized as fabrication, sensing, drug release/delivery, and cell technology. Special emphasis is given to topics such as cell‐membrane‐mimic assembly, fabrication of free‐standing biomolecular structures including protein microtubes, detection of DNA adducts and reactive metabolites, DNA hybridization analysis, sensing of toxic and bio‐active chemicals, entrapment of proteins and DNA, biocomponent carriers with barcode encoding, release and delivery of DNA plasmids, multiagent delivery, smart defense capsules and oxidation‐resistant films, vector introduction to cells, patterned cell culturing and microfluidic microreactors, stem cell differentiation, cellular uptake and degradation, and control of cellular apoptosis.

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A software tool for lifetime prediction of thermal barrier coating systems
Authors: Busso E. P. , Evans H. E. , Wright L. , McCartney L. N. , Nunn J. , Osgerby S.
Published: July 2008

Thermal barrier coatings (TBCs) are widely used to extend the lifetime of key components within gas turbines, and so the ability to predict the lifetime of TBCs is a high priority for gas turbine users. A complete model of TBC failure requires characterisation of the coating system, identification of the main failure mechanisms, quantitative description of stress evolution in the key areas within the coating system and robust failure criteria for each failure mechanism. Thus lifetime prediction invariably requires a massive effort both in terms of determining the appropriate input parameters for the model and in computing the solution.

In order to reduce the need for extensive calculation, a software tool has been developed that interpolates the key stresses for each failure mechanism from a matrix of previously calculated values. The matrix of values is generated using a recently developed finite element (FE) model of TBC lifetime of an IN738/MCrAlY/EB‐PVD YSZ system. The stress distribution predicted by this model is dependent on exposure time and temperature as well as the morphology of the bond coat/ceramic interface and requires FE calculation for each specific set of conditions. The software tool interpolates the FE results with respect to time, temperature and a geometric parameter to predict key stresses that drive failure, and coating system lifetime.

This paper describes the principles behind the development of the algorithms implemented in the software tool. Validation of the approach is in progress through comparison of predictions with non‐destructive measurements on the coating system.
Waste incineration corrosion processes: Oxidation mechanisms by electrochemical impedance spectroscopy
Authors: Pérez F. J. , Hierro M. P. , Nieto J.
Published: July 2008

Molten chloride mixtures are formed in waste incineration plants during waste firing and energy production. These mixtures are responsible for degradation processes like hot corrosion. In order to evaluate the damage of molten salt mixtures in waste incineration environments, the alloys 625 and 617 were exposed beneath a molten KCl‐ZnCl2 mixture at 650 °C in air. The corrosion process was monitored by electrochemical impedance spectroscopy (EIS). An extensive microscopy analysis has been done in order to correlate the electrochemical results, and to establish an electrochemical mechanism for such high temperature corrosion processes.
Protective coatings for very high temperature reactor applications
Authors: Cabet C. , Thieblemont F. , Guerre C.
Published: July 2008

The future very high temperature reactors (VHTR) are nuclear systems that shall operate at a maximum temperature of about 950 °C. Primary circuit materials thus require good creep and corrosion resistance on very long time. Use of high‐strength alloys with protective coatings could significantly improve the service life of high temperature reactor components. However, coating systems are mainly designed for shorter term purposes, often under extremely aggressive atmospheres, that cannot be extrapolated to the VHTR environment. We present our first investigations on the environmental resistance of Alloy 800H coated with two different protective systems under VHTR representative conditions: NiAl(Pt)/EBPVD ZrO2(Y) and NiCrAl(Y)/CVD ZrO2(Y). Isothermal exposures were carried out up to 1000 h at 950 °C in impure helium. This specific atmosphere was shown to induce formation of a surface oxide scale together with carburisation of the bare Alloy 800H. After high temperature exposure to impure helium, the microstructure of the coated specimens has changed due to both thermal ageing and corrosion. Performances of the two coating systems are compared regarding the VHTR application.
Experimental analysis and computer‐based simulation of nitridation of Ni‐base alloys—the effect of a pre‐oxidation treatment
Authors: Trindade V. B. , Krupp U. , Gorr B. , Kaczorowski D. , Girardin G. , Christ H.‐J.
Published: July 2008

Nickel‐base superalloys are commonly used for high‐temperature applications in power‐generation industry, e.g., gas‐turbine blades or heat exchangers. They are designed to resist high creep loading and severe corrosion attack during operation. Nitridation is one of these corrosion processes, in particular when the alloys need to be exposed to a N2 atmosphere. Based on past assumptions, a dense oxide layer should be an efficient barrier against N2 ingress. But is this really the case? This work is focused on the nitridation behavior of commercial Ni‐base alloys and the influence of a pre‐oxidation treatment. To model the growth of the internal‐nitridation zone, the diffusion processes were solved using the numerical implicit finite‐difference method in combination with the subroutine ChemApp for thermodynamic calculations.
Influence of alloy compositions on the halogen effect in TiAl alloys
Authors: Masset P. J. , Neve S. , Zschau H.‐E. , Schütze M.
Published: July 2008

F‐implantation concentration profile simulations were carried out and the influence of the ion fluence, implantation energy as well as the alloy composition were investigated. For alloys with Al contents between 40 and 50 at% the conditions to get the halogen effect were assessed by thermodynamic calculations. According to the thermodynamic predictions the implantation parameters were kept constant in this composition range. The implanted alloys were exposed in laboratory air over 4000 h. With the implantation parameters used (20 keV and 1 × 1017 F/cm2), the halogen effect was found to be efficient over 4000 h. The oxide growth kinetic constants were measured and vary between 1.2 and 2.7 × 10−13 g2/cm4/s.
High‐temperature oxidation of Ti3Al0.7Si0.3C2 compound at 900 and 1000 °C in air
Authors: Lee D. B. , Nguyen T. D.
Published: July 2008

The compound, Ti3Al0.7Si0.3C2, was synthesized by hot pressing a powder mixture of TiCX (x = 0.6), Al and Si. Its oxidation at 900 and 1000 °C in air for up to 50 h resulted in the formation of rutile‐TiO2, α‐Al2O3 and amorphous SiO2. The oxide scales formed consisted of triple layers, viz, an outer TiO2 layer containing Al2O3 particles, an intermediate Al2O3 layer, and an inner mixed layer that was rich in TiO2, but deficient in Al2O3 and SiO2. During oxidation, Ti diffused outwards to form the outer TiO2 layer, and oxygen was transported inwards to form the inner mixed layer. At the same time, carbon was liberated from Ti3Al0.7Si0.3C2. Ti3Al0.7Si0.3C2 oxidized slower than the TiO2‐forming kinetics, but faster than the (α‐Al2O3 or SiO2)‐forming kinetics.
Poisson's Ratio of Monodomain Liquid Crystalline Elastomers
Authors: Ren Wanting , McMullan Philip J. , Griffin Anselm C.
Published: July 2008

Monodomains of smectic C liquid crystalline elastomers were prepared by controlled stretching of a polydomain thin film. Specimens were prepared from this film for stress–strain study. A Poisson's ratio of zero was found at small strains for uniaxial stretching perpendicular to the director. For uniaxial strain parallel to the director, Poisson's ratios of approximately 0.4–0.5 were found (by extrapolation) for very small strains. A modulus anisotropy of 8 was found for stretching parallel versus perpendicular to the director.

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On contraction and the modal fragment
Authors: Brünnler Kai , Probst Dieter , Studer Thomas
Published: July 2008

We observe that removing contraction from a standard sequent calculus for first‐order predicate logic preserves completeness for the modal fragment. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Bisimulations between generalized Veltman models and Veltman models
Authors: Vuković Mladen
Published: July 2008

Interpretability logic is an extension of provability logic. Veltman models and generalized Veltman models are two semantics for interpretability logic. We consider a connection between Veltman semantics and generalized Veltman semantics. We prove that for a complete image‐finite generalized Veltman modelW there is a Veltman model W ′ that is bisimular to W. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Positive Frege and its Scott‐style semantics
Authors: Libert Thierry
Published: July 2008

We show that the untyped λ ‐calculus can be extended with Frege's interpretation of propositional notions, provided we restrict β ‐conversion to positive expressions. The system of illative λ ‐calculus so obtained admits a natural Scott‐style semantics. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A note on the first‐order logic of complete BL‐chains
Authors: Hájek Petr , Montagna Franco
Published: July 2008

In [10] it is claimed that the set of predicate tautologies of all complete BL‐chains and the set of all standard tautologies (i. e., the set of predicate formulas valid in all standard BL‐algebras) coincide. As noticed in [11], this claim is wrong. In this paper we show that a complete BL‐chain B satisfies all standard BL‐tautologies iff for any transfinite sequence (ai: i ∈ I) of elements of B, the condition ∧i ∈ I (a2i ) = (∧i ∈ I ai)2 holds in B. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A model of adoption of digital multimedia broadcasting (DMB) service: Comparisons in Korea, Japan, and Germany
Authors: Kim Kyung Hoon , Ko Eunju , Takahashi Ikuo , Schellhase Ralf , Kim Myung Soo , Lee Chang Han
Published: July 2008

Recently launched in a limited number of countries, digital multimedia broadcasting (DMB) is a brand new mobile service that uses the most advanced IT technology. Analyzing data collected from Korea, Japan, and Germany, this study investigates the relationship between attitudes, and their antecedents, toward using a DMB service and the intention of using it. Results of the study indicate that permanent access, entertainment, and social interaction have a positive influence on attitudes toward using DMB, and that those attitudes positively influence consumers' intention to do so, as do self‐efficacy and consumer perceptions of DMB as an innovation. Some differences in consumer behavior toward DMB service were also found among the three countries. From these findings, practical implications are drawn. © 2008 Wiley Periodicals, Inc.
Comparing consumer responses to advertising and non‐advertising mobile communications
Authors: Nasco Suzanne Altobello , Bruner Gordon C.
Published: July 2008

With a variety of mobile content, such as weather, sports, and commercial ads, available for consumers to access on wireless devices, it is important to explore the effect of presentation modalities on consumers' ability to retain the information and on consumers' perception of the content. Three messages were presented on a mobile device to 116 respondents via six presentation modalities that combined text, audio, static pictures, and/or video. Strong content effects were found, such that weather information was perceived as most important, most involving, and most likely to influence future mobile usage. Modality effects influenced recall, with complementary modes (visual and audio) facilitating recall of the commercial ad, but hindered recall of weather information. Implications for marketers, content designers, and mobile service providers are discussed. © 2008 Wiley Periodicals, Inc.
Synthesis and Electrooptic Properties of Poly(2,6‐anthracenevinylene)s
Authors: Xu Jun , Fang Yujie , Ren Peihua , Zhang Haichang , Guo Erqian , Yang Wenjun
Published: July 2008

High molecular weight poly(9,10‐bis(p‐(2‐ethylhexyloxy)phenyl)‐2,6‐anthracenevinylene) (2,6‐PAV) was synthesized with 2,6‐dimethylanthraquinone as a key intermediate. The as‐synthesized polymer is readily soluble in common organic solvents and can be used for spin‐coating. The as‐synthesized polymer exhibits a broad absorption band ranging from 280 to 520 nm and a bluish green emission band with a peak at 500 nm. The polymer shows good thermal stability, and no distinct glass transition is observed. A simple device with the configuration ITO/PEDOT:PSS/2,6‐PAV/Ba/Al showed a turn‐on voltage of 4.8 V and a maximal brightness of 340 cd · m−2.

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Modeling Studies of the Phase Behavior of Monomer/Polymer/Disk Composites
Authors: Torrens Francisco , Gómez Clara M. , León Luis M. , Abad Concepción , Campos Agustín
Published: July 2008

The model developed by Balazs et al. to explain the phase behavior of polymer/clay composites is extended to monomer/polymer/clay composites, obtaining an expression for the free energy of a monomer/polymer/thin‐disk mixture. By minimizing the free energy and calculating the chemical potentials of the three system components, phase diagrams for the monomer/disk and monomer/polymer/disk mixtures are contructed. Through the evolution and comparison of these diagrams, the effects of nanodisk size, polymer molecular mass and interaction parameters (temperature) on mixture stability and attained morphology are then studied.

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Dynamics of Phase Separation in Polymer Blends Revisited: Morphology, Spinodal, Noise, and Nucleation
Authors: Fiałkowski Marcin , Hołyst Robert
Published: July 2008

The properties of the model B of mesoscopic dynamic with the Flory–Huggins free energy for the homopolymer blend are discussed. We focus on the rescaling of the spatial coordinates in the model and demonstrate that the commonly used rescaling of the spatial coordinates by the function vanishing at the spinodal leads to the unphysical pinning of the domains. The proper rescaling function for the spatial variables which avoids the unphysical pinning of the domain growth at the spinodal is proposed. We discuss in detail the evolution of morphological measures during separation in homopolymer blends and the problem of nucleation close to the spinodal.

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Phase diagrams beyond the critical point
Authors: Hoffmann H.‐J.
Published: July 2008

Following a path in the usual p‐T‐diagrams of one‐component systems via the supercritical region it seems that one can make a transition from the liquid to the gas phase (and in reverse) without traversing a phase boundary curve, whereas in the sub‐critical region one clearly has to pass a phase boundary curve. To solve this paradox situation, the phase diagrams of one‐component systems are analyzed with respect to the phase transition from the liquid to the gas state in the sub‐ and supercritical range. It is shown that the critical point is not an isolated point or an end point on the phase boundary curve between the gaseous and the liquid phase in a p‐T‐diagram. Instead, it marks on the boundary curve just the transition between the section of a first order phase transition in the sub‐critical range and the section of a second or higher order phase transition in the supercritical range. Thus, the present phase diagrams of one‐component systems are incomplete with respect to the phase boundary curve between liquid and gas in the supercritical region. The result is illustrated using the model of a van der Waals gas.
Cost‐efficient conversion coatings for corrosion protection prepared by the sol‐gel process
Authors: Lampke Th. , Darwich S. , Wielage B. , Steinhäuser S.
Published: July 2008

For several years, chromate compounds were used as effective and inexpensive corrosion inhibitors. Studies showed that these materials were toxic and carcinogenic. A subsequent ban on these materials has led to extensive research to develop effective alternative inhibitors. The sol‐gel method appeared as an effective technique forming protective silane layers from hydrolyzed tetraethylorthosilicate (TEOS) and glycidoxypropyltrimethoxy silane (GPTMS) in an aqueous sol–gel process. The final cross‐linking of the layer is realized by heat treatment to form thin, fully dense, protective films of silane on diverse metal surfaces.

Most sol‐gel layers use a considerable amount of solvent VOC (volatile organic compound) in order to achieve a dispersion of silane with water. However, in a wide range of industries, the high amount of VOC is the major hindrance for the application of silane layers.

This article shows a coating concept without VOC, which is cost‐efficient, effective for corrosion protection and applicable for metal surfaces. The corrosion protection effect is given by means of comprehensive impedance spectroscopy measurements.
Einsatz von Hartstoffbeschichtungen bei Spindellagern
Authors: Brecher C. , Spachtholz G. , Gerlach G.
Published: July 2008

Die Ansprüche an moderne Werkzeugmaschinen (WZM) steigen kontinuierlich mit den Forderungen der Produktion nach qualitativ hochwertigen und immer kürzeren Bearbeitungsprozessen. Insbesondere die Zunahme der Bearbeitungs‐ und Schnittgeschwindigkeiten der letzten Jahre führt zu einer höheren Belastung der Lagerung der Hauptspindel. Diese kennzeichnet als zentrale Komponente das Leistungsvermögen einer Werkzeugmaschine für die spanende Bearbeitung und ist maßgebend für die Zuverlässigkeit der Hauptspindel.

Die überwiegend eingesetzten Spindellagerungen sind wälzgelagert ausgeführt. Ein großer Anteil der in der Praxis auftretenden Spindelausfälle resultiert aus mangelnder bzw. unzureichender Schmierung der Lagerungen und somit aus den tribologischen Eigenschaften der Wälzpartner. Zur Reduzierung von Reibung und Verschleiß werden heutzutage sowohl unterschiedliche Werkstoffe und Beschichtungen für die Lagerkomponenten eingesetzt als auch verschiedene Additive den Schmierstoffen zugefügt.

Aktuelle Forschungen zielen darauf ab, Hartstoffschichten (a‐C:H:W) mit einer Metall‐Nanodotierung für den Wälzkontakt zu entwickeln, welche die Zuverlässigkeit der Lager erhöhen sollen.

In diesem Artikel wird daher die Erprobung von Lagern mit nanostrukturierten Schichtsystemen zur Reduktion der Reibung und somit der Wärmeeinbringung sowie des Verschleißes vorgestellt. Dazu werden die Schichtsysteme durch Voruntersuchungen für den Einsatz in Spindellagern geprüft. Basierend auf diesen Ergebnissen werden die Lagerringe von Standard‐Hybrid‐Spindellagern beschichtet und die Schichthaftung hinsichtlich Drehzahleignung, Dauerfestigkeit sowie Verschleißverhalten bei hoher Beschleunigung analysiert. Abschließend werden die Notlaufeigenschaften der Lagerkomponenten bei Mangelschmierung evaluiert, um das Einsatzfeld der Beschichtungen ermitteln zu können.