bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of Ash in Animal Feed: AOAC Official Method 942.05 Revisited
Authors: Thiex Nancy , Novotny Lawrence , Crawford Andy
Published: October 2012

AOAc Official MethodSM 942.05, Ash in Animal Feed, has been applied in feed laboratories since its publication in the Official Methods of Analysis in 1942. it is a routine test with renewed interest due to the incorporation of “ash values” into modern equations for the estimation of energy content of dairy feed, beef feed, and pet food. As with other empirical methods, results obtained are a function of the test conditions. For this method, the critical conditions are the ignition time, ignition temperature, and any other furnace or weighing conditions. complete ignition can be observed by the absence of black color (due to residual carbonaceous material) in the ash residue. to investigate performance of AOAc 942.05, 15 samples were chosen to be representative of a wide range of feed materials. these materials were tested at the conditions of AOAc 942.05 (ignition at 600°c for 2 h) and similar or more rigorous conditions. the additional conditions investigated included: 600°c for 4 h; 600°c for 2 h, cool, and ignite 2 additional h; 600°c for 2 h, cool, wet, dry, and ignite 2 additional h; 550°c for 6 h; 550°c for 3 h, cool, and ignite 3 additional h; and 550°c for 3 h, cool, wet, dry, ignite 3 additional h. results for all other conditions investigated were found to be significantly different from the current AOAc Method 942.05. All ignition conditions were significantly different from each other except two: 550°c for 3 h, cool, ignite 3 additional h; and 550°c for 3 h, cool, wet, dry, and ignite 3 additional h. recommendations for modification to AOAc Official Method 942.05 are suggested based on statistical analysis of the data and a review of the literature.
Microwave-Assisted Extraction and Quantitative LC/ID-MS Measurement of Total Choline and Free Carnitine in Food Standard Reference Materials
Authors: Phillips Melissa M , Sander Lane C
Published: October 2012

The Stakeholder Panel on Infant Formula and Adult Nutritionals of AOAC INTERNATIONAL has declared both choline and carnitine to be priority nutrients in infant formulas, and ongoing efforts exist to develop or improve Official Methods of AnalysisSM for these nutrients. As a result, matrix-based certified reference materials are needed with assigned values for these compounds. In this work, traditional acid and enzymatic hydrolysis procedures were compared to microwave-assisted acid hydrolysis, and conditions optimized to provide complete sample hydrolysis and recovery of total choline from four food standard reference materials (SRMs): whole milk powder, whole egg powder, infant formula, and soy flour. The extracts were analyzed using LC on a mixed-mode column (simultaneous RP and ion exchange) with isotope dilution-MS detection to achieve simultaneous quantification of total choline and free carnitine. Total choline has been determined in these four food matrixes with excellent precision (0.65 to 2.60%) and accuracy, as confirmed by use of SRM 1849 Infant/Adult Nutritional Formula as a control material. Free carnitine has been determined in two of these food matrixes with excellent precision (0.69 to 2.19%) and accuracy, as confirmed by use of SRM 1849 Infant/Adult Nutritional Formula as a control material. Limitations in simultaneous determination of total choline and free carnitine resulted from extreme differences in concentration of the two components in egg powder and soy flour (at least three orders of magnitude). Samples required dilution to prevent poor LC peak shape, which caused decreased precision in the determination of low concentrations of free carnitine. Despite this limitation, the described method yields results comparable to current AOAC Official Method 999.14 Choline in Infant Formula, with a decrease of more than 2 h in sample preparation time.
Evaluation of the VITEK 2 Gram Positive (GP) Microbial Identification Test Card: Collaborative Study
Authors: Crowley Erin , Bird Patrick , Fisher Kiel , Goetz Katherine , Boyle Megan , Benzinger, Jr M Joseph , Juenger Marc , Agin James , Goins David , Johnson Ronald L
Published: October 2012

A collaborative study was conducted to evaluate the performance of the VITEK® 2 Gram Positive (GP) identification card for use with the VITEK 2 automated microbial identification system. The GP test card is used in the identification of selected Gram positive organisms, including Listeria and Staphylococcus species. The VITEK 2 GP card is based on 43 biochemical tests measuring carbon source utilization, inhibition and resistance, and enzymatic activities. A total of 20 laboratories representing government, industry, and private testing laboratories throughout the United States participated. In this study, 720 Gram-positive inclusivity isolates were analyzed by the GP Identification method. Of the 720 well-characterized isolates, 714 were identified correctly, zero were misidentified, zero were unidentified, and six were not characterized as a Gram-positive organism by the VITEK 2 GP method. Additionally, 120 strains exclusive of Gram-positive organisms were screened by Gram stain. A total of 106 isolates were correctly excluded. Fourteen organisms were incorrectly characterized by Gram stain procedures, thus resulting in improper analysis and misidentification by VITEK GP. The VITEK 2 GP identification method is an acceptable automated method for the rapid identification of selected Gram-positive bacteria.
Analytical Methodology for the Determination of Organochlorine Pesticides in Vegetation
Authors: Beceiro-González Elisa , González-Castro María J , Muniategui-Lorenzo Soledad , López-Mahía Purificación , Prada-Rodríguez Darío
Published: October 2012

Due to the extensive use of organochlorine pesticides (OCPs) for agricultural purposes and their high persistence and low biodegradability, they have become an important group of contaminants. Detection and quantification of pesticide residues in food, particularly fruits and vegetables, is of growing concern for producers, consumers, and governments. The most widely used pretreatment for the extraction of pesticides in plants is based on solvent extraction liquid-solid extraction (LSE). LSE can be carried out using Soxhlet, shake-flask, homogenization, sonication, and, more recently, microwave-assisted extraction, pressurized liquid extraction, and supercritical fluid extraction. Furthermore, new analytical procedures using the extraction with sorbents, such as solid-phase micro-extraction, stir bar sorptive extraction, and matrix solid-phase dispersion, have also been used. On the other hand, a wide range of cleanup methods (liquid–liquid extraction, solid-phase extraction, gel permeation chromatography, and dispersive solid-phase extraction; and chromatographic techniques with electron capture detector and mass spectrometry detector; and HPLC with a ultraviolet detector are reported in the literature. This article reviews the applicability, advantages, and disadvantages of various sample preparation techniques (traditional and new techniques) for the analysis of OCPs in different plants and plant materials. It covers more than 15 years of published methods in which pesticide residues have been determined in a wide range of vegetation samples (fruits, horticultural samples, medicinal plants, tree leaves, etc.) by the use of chromatographic techniques after various sample preparation steps. A great number of applications in different plant material are provided. To the best of the authors' knowledge, previously published reviews have not covered as wide and exhaustive range of vegetation matrixes as presented here. A summary of pesticide levels cited in the literature is included.
The Role of Proteins in Biosilicification
Authors: Otzen Daniel
Published: October 2012

Although the use of silicon dioxide (silica) as a constituent of living organisms is mainly restricted to diatoms and sponges, the ways in which this process is controlled by nature continue to inspire and fascinate. Both diatoms and sponges carry out biosilificiation using an organic matrix but they adopt very different strategies. Diatoms use small and heavily modified peptides called silaffins, where the most characteristic feature is a modulation of charge by attaching long chain polyamines (LCPAs) to lysine groups. Free LCPAs can also cooperate with silaffins. Sponges use the enzyme silicatein which is homologous to the cysteine protease cathepsin. Both classes of proteins form higher-order structures which act both as structural templates and mechanistic catalysts for the polycondensation reaction. In both cases, additional proteins are continuously being discovered which modulate the process further. This paper concentrates on the role of these proteins in the biosilification process as well as in various applications, highlighting areas where focus on specific protein properties may provide further insight. The field of biosilification is a crossroads of different disciplines, where insight into the energetics and mechanisms of molecular self-assembly combine with fundamental biology, complex multicomponent colloidal systems, and an impressive array of potential technological applications.
Intégration internationale et concurrence effective : quelques apports de la théorie de l’oligopole
Authors: Gaussens Olivier , Lecostey Sophie , Simon Geoffray
Published: October 2012

L’objectif de ce papier est de présenter une sélection de contributions théoriques étudiant l’effet de l’intégration internationale des marchés sur la concurrence effective. L’analyse est menée en termes d’équilibre partiel. Elle mêle concurrence oligopolistique et intégration imparfaite et met l’accent sur les comportements stratégiques des firmes permettant ainsi de ne pas réduire le champ décisionnel des firmes au simple ajustement de leurs volumes de production ou de leurs prix. En cela, cette littérature relève d’une « économie industrielle de l’intégration internationale ». Le principal résultat auquel aboutissent les contributions présentées est qu’un accroissement de l’intégration internationale n’entraîne pas nécessairement un renforcement de la concurrence et, en corollaire, qu’une intégration plus poussée des marchés doit s’appuyer sur une politique de la concurrence renforcée et/ou une politique industrielle adaptée.
Competencies of Local Officials on Land Governance: Basis for Empowerment
Authors: Gatus Jose P.
Published: October 2012

Cagayan de Oro City, Philippines “Empower the Local Government for Local Autonomy”, an aspiration of the government for a strong republic, so upon the enactment of RA-7160 – The Local Government Code of the Philippines in 1991, the DENR devolved its Cadastral Survey Program to the LGU. In 2009 the DENR took back the Cadastral survey because it was a failure. Among the cause that was determined was that the LGUs were not equipped or empowered, hence, this study. The study aims to determine the competency levels of the Village Officials in the administration and management of the land resources in selected urbanizing Villages in Cagayan de Oro City. The findings will be used as basis in coming up with the kind of intervention in empowering them on land governance. Basic laws on land administration and management were made part of the Survey Questionnaire to determine the extent of their knowledge and understanding on those laws. Hypothetical problems and situations were included to ascertain their knowledge and skills in sett ling land disputes with legal basis. Findings showed that majorities are college graduates but their level of competencies on land governance is very poor, hence, the recommendation for them to undergo trainings on land governance.   Keywords – assessment, competencies, empowerment, land governance, knowledge, understanding, skills, legal basis.
Development of Competitiveness of Farm Commodity at Selayar Regency South Sulawesi Province
Authors: Sufri Mukhlis
Published: October 2012

The development of competitiveness at Selayar Regency South Sulawesi Province of Indonesia hinges on the identification of superior and high potential farm commodities through experimental methods. The study established the trend of economic structures and non-base factors. The descriptive method of research was used involving primary and secondary data analyzed through Domestic Resources Cost analysis approach. Results showed that the sector basis identified is < Q >1 which has superior commodity of corn, shrimp, seaweed, crops, nutmeg, walnuts, melinjo and cashew nuts. The study concludes that these farm commodities have good prospects for the needs of the domestic and export orientation. There is a need to create economic structures toward investments in Selayar district. Keywords - farm commodities, high potential commodities, economic structures, non-base factors.
Smallholder Dairy Farmers’ Group Development in Bhutan: Strengthening Rural Communities through Group Mobilization
Authors: Sonam Thubten , Martwanna Niwat
Published: October 2012

This paper describes the mobilization processes of Smallholder Dairy Farmers’ Groups (SDFG) and its relevance to the process of community development in an integrated crop livestock forestry farming system in Bhutan. The group approach aims to ensure effective delivery of dairy services for strengthening collective self-help capacity, promoting self-reliance, group cooperation and solidarity of poor rural farmers through collective action. Data for the study were generated through focused group interviews and workshop organized among the relevant stakeholders involved in formation and development of dairy farmers’ groups. The study found that the group mobilization processes demanded new competencies in managing the different stages of group formation and development processes with professional support backed by new knowledge and skills. While the government encourages and supports the mobilization of dairy groups, the process of forming a group is still difficult due to a wide range of technical, socio-cultural, organizational, and physical challenges. However, despite the challenges and difficulties, SDFGs are slowly contributing to the enhancement of smallholder dairy farmers’ skills, achievement of economies-of-scale and improving their bargaining power. The SDFGs are helping to build trust among members, instill positive changes in attitude and commitment to achieve group’s success motivated by accrued financial benefits and easy access to other services. The formation and development of dairy groups needs to be supported by well-trained competent group mobilizers who are able to manage and facilitate group processes effectively.   Keywords - service delivery, collective action, smallholder dairy farmers’ group, mobilization and integrated crop-livestock-forestry farming systems.
Viable Solutions in Addressing Climate Changes thru Private (BCCFI) –Public (LGU) Partnerships in the Province of Bataan: A Case Study
Authors: Baylon Angelica M.
Published: October 2012

This paper articulates the partnership between the private sector represented by the Bataan Coastal Care Foundation Inc (BCCFI) and the public sector represented by the various local government units (LGUs) in the Province of Bataan. The partnership was initiated based on common objectives of these two (BCCFI and LGUs) likeminded institutions to build better coastal governance, increase awareness , promote community participation in coastal management and explore ways for dynamic and sustainable public-private partnerships in addressing climate changes . Since February 2000, BCCFI has actively led in partnering with its various stakeholders in the province‘s 11 municipalities and lone city to implement the Bataan Integrated Coastal Management Program (BICMP) with focus on the 87 coastal villages. As manifested in the socio-economic investment survey form that was accomplished by, among and between the BCCFI members in close collaboration with the local government units. Through varied approaches and entry points, BCCFI, serve as catalyst in protecting the environment in Bataan either individually or collectively, within their respective spheres of influence and capabilities. This is a case point that could be explored as one of the strategies and actions for ASIAN networking on coastal resource management in addressing climate changes.   Keywords - Addressing Climate Changes, private- public partnerships, environmental protection, coastal resource management, Biodiversity Programs
Detection of Carbamates and Organophosphorus Pesticides and Residues in Selected Vegetables in Northern Philippines
Authors: Delima Precila C.
Published: October 2012

Acute pesticide poisoning is a serious public health problem in developing countries like the Philippines. Pesticides like organophosphates (OP) and carbamates are the most widely used pesticides in the world. The presence of these pesticides and their residues from two vegetable provincial producers: La Trinidad, Benguet and Bambang, Nueva Vizcaya in Northern Philippines were determined using the Colorimetric Spot Technique. The source (Factor A) and the type (Factor B ) of vegetables were examined using the Randomized Complete Block Design (RCBD) in Factorial with three replications to allocate treatments. Results showed that the source and type of vegetables were not statistically significant on the amount of pesticide residue. Source and vegetable combination interaction had no statistical significance on the amount of pesticide residue. However, cabbage (T1) was found to have the highest amount of organophosphate pesticide residue followed by Chinese pechay (T2) and cauliflower (T3). In terms of location or vegetable source, both Benguet (S1) and Nueva Vizcaya (S2 ) showed the presence of pesticide residue. String beans, Baguio Beans and tomatoes registered positive with the Carbamate Detection Kit. The study concludes that none of the treatments analyzed exceeds the safe level of toxic substances as to source and type. Keywords - carbamates, organophosphates, colorimetric spot technique, cruciferae, pesticide , residue
Ultrathin Sticker‐Type ZnO Thin Film Transistors Formed by Transfer Printing via Topological Confinement of Water‐Soluble Sacrificial Polymer in Dimple Structure
Authors: Kim Suk Ho , Yoon Jongwon , Yun Su Ok , Hwang Youngkyu , Jang Hun Soo , Ko Heung Cho
Published: October 2012

To create ultrathin sticker‐type electronic devices that can be attached to unconventional substrates, it is highly desirable to develop printable membrane‐type electronics on a handling substrate and then transfer the printing to a target surface. A facile method is presented for high‐efficiency transfer printing by controlling the interfacial adhesion between a handling substrate and an ultrathin substrate in a systematic manner under mild conditions. A water‐soluble sacrificial polymer layer is employed on a dimpled handling substrate, which enables the topological confinement of the polymer residue inside and near the dimples during the etching and drying processes to reduce the interfacial adhesion gently, creating a high yield of transfer printing in a deterministic manner. As an example of an electronic device that was created using this method, a highly flexible sticker‐type ZnO thin film transistor was successfully developed with a thickness of 13 μm including a printable ultrathin substrate, which can be attached to various substrates, such as paper, plastic, and stickers.
Bioactive Glass Foam Scaffolds are Remodelled by Osteoclasts and Support the Formation of Mineralized Matrix and Vascular Networks In Vitro
Authors: Midha Swati , van den Bergh Wouter , Kim Taek B. , Lee Peter D. , Jones Julian R. , Mitchell Christopher A.
Published: October 2012

Remodelling of scaffolds and new bone formation is critical for effective bone regeneration. Herein is reported the first demonstration of resorption pits due to osteoclast activity on the surface of sol–gel bioactive glass foam scaffolds. Bioactive glass foam scaffolds are known to have osteogenic potential and suitable pore networks for bone regeneration. Degradation of the scaffolds is known to be initially solution mediated, but for effective bone regeneration, remodelling of the scaffold by osteoclasts and vascularisation of the scaffold is necessary. The culture of C7 macrophages on a bioactive glass scaffold induces the cells to differentiate into (TRAP+ve) osteoclasts. They then form distinctive resorption pits within 3 weeks, while MC3T3‐E1 pre‐osteoblasts deposit mineralized osteoid on their surfaces in co‐culture. The scaffolds are of the 70S30C (70 mol% SiO2, 30 mol% CaO) composition, with modal pore and interconnect diameters of 373 μm and 172 μm respectively (quantified by X‐ray micro‐tomography and 3D image analysis). The release of soluble silica and calcium ions from 70S30C scaffolds induces an increase in osteoblast numbers as determined via the MTT assay. Scaffolds also support growth of endothelial cells on their surface and tube formation (characteristic of functional microvasculature) following 4 days in culture. This data supports the hypothesis that 70S30C bioactive glass scaffolds promote the differentiation of the 3 main cell types involved in vascularized bone regeneration.
Molecular genetics research in ADHD: Ethical considerations concerning patients' benefit and resource allocation
Authors: Rothenberger Lillian Geza
Published: October 2012

Immense resource allocations have led to great data output in genetic research. Concerning ADHD resources spent on genetic research are less than those spent on clinical research. But there are successful efforts made to increase support for molecular genetics research in ADHD. Concerning genetics no evidence based conclusive results have significant impact on prevention, diagnosis or treatment yet. With regard to ethical aspects like the patients' benefit and limited resources the question arises if it is indicated to think about a new balance of resource allocation between molecular genetics and non‐genetics research in ADHD. An ethical reflection was performed focusing on recent genetic studies and reviews based on a selective literature search. There are plausible reasons why genetic research results in ADHD are somehow disappointing for clinical practice so far. Researchers try to overcome these gaps systematically, without knowing what the potential future benefits for the patients might be. Non‐genetic diagnostic/therapeutic research may lead to clinically relevant findings within a shorter period of time. On the other hand, non‐genetic research in ADHD may be nurtured by genetic approaches. But, with the latter there exist significant risks of harm like stigmatization and concerns regarding data protection. Isolated speeding up resources of genetic research in ADHD seems questionable from an ethical point of view. There is a need to find a new balance of resource allocation between genetic and non‐genetic research in ADHD, probably by integrating genetics more systematically into clinical research. A transdisciplinary debate is recommended. © 2012 Wiley Periodicals, Inc.
Synthesis of UV‐curable hyperbranched polyurethane (meth)acrylate oligomers via thiol‐ene “click” chemistry
Authors: Han Wensong , Lin Baoping , Yang Hong , Zhang Xueqin
Published: October 2012

First, the second‐generation hyperbranched poly(amine‐ester) (G2‐OH) was successfully prepared by thiol‐ene “click” chemistry. Subsequently, a series of photosensitive hyperbranched oligomers (G2‐ORs) were synthesized by facile modifications of the G2‐OH with acryloyl chloride, methacryloyl chloride, IPDI‐HEA, and IPDI‐HEMA, respectively. The structures of hyperbranched oligomers were characterized by element analysis, FT‐IR, 1H NMR, GPC and viscosity measurement. It was shown that these synthesized oligomers have narrow molecular weight distribution and low intrinsic viscosity at 30°C. UV–vis spectra results showed that the G2‐ORs had sharp absorption bands at around 202 nm. The results of photosensitivities measurement indicated that the G2‐Macr shows the highest photosensitive than other hyperbranched oligomers in the absence of photoinitiator. In addition, these UV‐cured photosensitive G2‐ORs had good thermal properties. The solubilities of the synthesized hyperbranched oligomers were also examined. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Surface and bulk analysis of bleaching soybean fabric in the presence of protein hydrolysate
Authors: Vynias D. , Owens H. , Carr C. M.
Published: October 2012

The effect of oxidative and oxidative‐reductive bleaching on the colorimetric, topographical, and mechanical properties of soybean fabric has been investigated by yellowness index, abrasion resistance, tensile strength, Kawabata evaluation system for fabrics, scanning electron microscopy, X‐ray photoelectron spectroscopy, and time of flight secondary ion mass spectrometry in order to examine both the bulk and surface properties. Surface changes to the soybean fiber due to bleaching treatments have been evaluated and the protective effect of protein hydrolysates assessed. Improved tensile strength, flat abrasion performance, and handle maintenance of the soybean fabric was demonstrated with the incorporation of Byco C in both bleaching treatments. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Preparation and characterization of thermally stable phosphonium organoclays and their use in poly(ethylene terephthalate) nanocomposites
Authors: Abdallah Wissam , Yilmazer Ulku
Published: October 2012

Purification of montmorillonite rich bentonite followed by surface modification using organic salts was performed. The bentonite was purified by sedimentation and then surface modified by ion exchange using alkyl‐ and aryl‐based phosphonium salts. The thermal stability, morphology, melt flow, and mechanical properties of the poly(ethylene terephthalate) (PET) nanocomposites prepared with these organoclays were studied with and without using a reactive elastomeric compatibilizer. TEM results showed that the alkyl based organoclay exhibited better dispersion and thus, higher tensile strength and elongation at break in the PET/organoclay/elastomer ternary nanocomposites than the aryl‐based organoclay did. The notched Charpy impact strength of PET increased from 2.9 to 4.7 kJ m−2 and 3.4 kJ m−2 for alkyl and aryl phosphonium organoclay‐based ternary nanocomposites, respectively. Upon compounding PET with alkyl and aryl phosphonium organoclays, the onset decomposition temperature of PET increased from 413°C to 420°C and 424°C, respectively. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Synthesis of defined polyhedral oligosilsesquioxane‐containing diblock and triblock methacrylate copolymers by atom transfer radical polymerization
Authors: Janata Miroslav , Sikora Antonín , Látalová Petra , Čadová Eva , Raus Vladimír , Matějka Libor , Vlček Petr
Published: October 2012

Defined diblock and triblock copolymers composed of methyl methacrylate‐co‐glycidyl methacrylate block and 3‐{3,5,7,9,11,13,15‐hepta(2‐methylpropyl)‐pentacyclo[9.5.1.13,9.15,15.17,13]‐octasiloxan‐1‐yl}propyl methacrylate block(s), i.e., P(MMA‐co‐GMA)‐b‐PiBuPOSSMA and PiBuPOSSMA‐b‐P(MMA‐co‐GMA)‐b‐PiBuPOSSMA, were synthesized by atom transfer radical polymerization (ATRP). First, monofunctional and bifunctional P(MMA‐co‐GMA) copolymers were synthesized by ATRP. Subsequently, these copolymers were successfully used as macroinitiators for ATRP of POSS‐containing methacrylate monomer. The process showed high initiation efficiency of macroinitiators and led to products with low dispersity. The synthesized block copolymers were characterized by size exclusion chromatography, 1H‐NMR spectroscopy and their glass transition temperatures were determined by differential scanning calorimetry. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Polypropylene/date stone flour composites: Effects of filler contents and EBAGMA compatibilizer on morphology, thermal, and mechanical properties
Authors: Hamma Amel , Kaci Mustapha , Pegoretti Alessandro
Published: October 2012

This work aims to study the effects of date stone flour (DSF) on morphology, thermal, and mechanical properties of polypropylene (PP) composites in the absence and presence of ethylene‐butyl acrylate‐glycidyl methacrylate (EBAGMA) used as the compatibilizer. DSF was added to the PP matrix at loading rates of 10, 20, 30, and 40 wt %, while the amount of compatibilizer was fixed to the half of the filler content. The study showed through scanning electron microscopy analysis that EBAGMA compatibilizer improved the dispersion and the wettability of DSF in the PP matrix. Thermogravimetric analysis (TGA) indicated a slight decrease in the decomposition temperature at onset (Tonset) for all composite materials compared to PP matrix, whereas the thermal degradation rate was slower. Differential scanning calorimetry (DSC) data revealed that the melting temperature of PP in the composite materials remained almost unchanged. The nucleating effect of DSF was however reduced by the compatibilizer. Furthermore, the incorporation of DSF resulted in the increase of stiffness of the PP composites accompanied by a significant decrease in both the stress and strain at break. The addition of EBAGMA to PP/DSF composites improved significantly the ductility due to the elastomeric effect of EBAGMA. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
A dynamically distributed reactor model for identifying the flow fields in industrial loop propylene polymerization reactors
Authors: Yang Xiong‐Fa , Zheng Tao , Che Li‐Ming , Luo Zheng‐Hong
Published: October 2012

The use of distributed parameter model is becoming a common approach for simulating liquid–solid flow in loop polymerization reactors. However, there are still several issues with it. One of them is the absence of modeling of distributed pressure, as no thermodynamic state‐equation is incorporated into the model. In this work, inner pressure of the reactor was associated with temperature using a thermodynamic state‐equation for high‐pressure liquid. The thermodynamic state‐equation was solved together with a dynamically distributed reactor model based on the mass, energy, and momentum conservation as well as polymerization kinetics to predict the dynamic trajectories of component concentration, temperature, pressure, and bulk mass velocity in the reactor. Industrial steady‐state data were used for model validation. The application of the model was demonstrated by simulating the effect of recycle ratio on the above distributed reactor parameters. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Recombinant hHscFv–RC‐RNase protein derived from transgenic tobacco acts as a bifunctional molecular complex against hepatocellular carcinoma
Authors: Cui Lijie , Peng Huizhen , Zhang Ran , Chen Yuhui , Zhao Lingxia , Tang Kexuan
Published: October 2012

Hepatocellular carcinoma (HCC) is a common clinical primary malignant tumor; however, efficient drugs for the treatment of HCC are still lacking at the present time. To develop a new approach for liver cancer therapy, we designed a chimeric gene (his‐HR) encoding a single‐chain variable fragment of human HAb25 (hHscFv) fused to a cytotoxic ribonuclease from Rana catesbeiana (RC‐RNase) and expressed the corresponding fusion protein in transgenic tobacco (Nicotiana tabacum). Eleven positive transgenic plant lines were identified from 204 regenerated tobacco plants by PCR and Southern blot analysis, and the immunocompetence of the recombinant his‐HR protein was confirmed by Western blotting. The expression levels of his‐HR protein ranged from 0.75 to 1.99 µg/g in the fresh tobacco leaves. To characterize the bifunction of the expressed his‐HR protein in tobacco, binding specificity and cell toxicity to several cell lines were examined by the indirect immunocytochemical streptavidin–biotin complex method and 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl‐2H‐tetrazolium bromide assay. Data indicated that the his‐HR protein had stronger specific binding affinity to HepG2 (human liver HCC cell line) than to the other tumor cell lines and normal liver cell line, and the capacity to kill the HCC cell lines SMMC7721 and HepG2 with an half maximal inhibiting concentration of 2.0 and 2.4 nM, respectively. The results suggest that recombinant bifunctional his‐HR protein derived from transgenic plants may provide a novel strategy to treat HCC in the future.
Role of NF‐κB activation in matrix metalloproteinase 9, vascular endothelial growth factor and interleukin 8 expression and secretion in human breast cancer cells
Authors: Li Caijuan , Guo Sufen , Shi Tiemei
Published: October 2012

The aims of this study were to assess the effects and potential mechanisms of parthenolide on the expression of vascular endothelial growth factor (VEGF), interleukin 8 (IL‐8) and matrix metalloproteinase 9 (MMP‐9) in human breast cancer cell line MDA‐MB‐231. After incubation with different concentrations of parthenolide for 24 h, MDA‐MB‐231 cells were collected, and the expressions of VEGF, IL‐8 and MMP‐9 were measured by real‐time PCR and Western blot. The secretions of VEGF, IL‐8 and MMP‐9 in culture supernatant of MDA‐MB‐231 cells were then measured with ELISA assays. The NF‐κB DNA‐binding activity of breast cancer cells treated with parthenolide was analyzed using electrophoretic mobility assays. The real‐time PCR and Western blot data showed that the expressions of VEGF, IL‐8 and MMP‐9 were significantly inhibited by parthenolide at both transcription level and protein level in MDA‐MB‐231 cells. ELISA results also confirmed these effects at a secretion level. The electrophoretic mobility assay results demonstrated that parthenolide can inhibit NF‐κB DNA‐binding activity of the breast cancer cells. Hence, the expression of VEGF, IL‐8 and MMP‐9 may be suppressed by parthenolide through the inhibition of NF‐κB DNA‐binding activity in MDA‐MB‐231 cells. Copyright © 2012 John Wiley & Sons, Ltd.
Inhibition of autophagy enhances apoptosis induced by the PI3K/AKT/mTor inhibitor NVP‐BEZ235 in renal cell carcinoma cells
Authors: Li Hongyan , Jin Xuefei , Zhang Zhuo , Xing Yuanyuan , Kong Xiangbo
Published: October 2012

The PI3K/AKT/mTOR pathway plays a key role in the development of the hypervascular tumor renal cell carcinoma (RCC). NVP‐BEZ235 (NVP), a novel dual PI3K/mTOR inhibitor, showed great antitumor benefit and provided a treatment strategy in RCC. In this study, we test the effect of NVP on survival rate, apoptosis and autophagy in the RCC cell line, 786‐0. We also explore the hypothesis that NVP, in combination with autophagy inhibitors, leads to apoptosis enhancement in 786‐0 cells. The results showed that the PI3K/AKT/mTOR pathway proteins p‐AKT and p‐P70S6K were highly expressed in RCC tissue. We also showed that NVP inhibited cell growth and induced apoptosis and autophagy in RCC cells. The combination treatment of NVP with autophagy inhibitors enhanced the effect of NVP on suppressing 786‐0 growth and induction of apoptosis. This study proposes a novel treatment paradigm where combining PI3K/AKT/mTOR pathway inhibitors and autophagy inhibitors lead to enhanced RCC cell apoptosis. Copyright © 2012 John Wiley & Sons, Ltd.
Solvent‐ and Light‐Controlled Unidirectional Transit of a Nonsymmetric Molecular Axle Through a Nonsymmetric Molecular Wheel
Authors: Arduini Arturo , Bussolati Rocco , Credi Alberto , Monaco Simone , Secchi Andrea , Silvi Serena , Venturi Margherita
Published: October 2012

The development of a pseudorotaxane motif capable of performing unidirectional threading and dethreading processes under control of external stimuli is particularly important for the construction of processive linear motors based on rotaxanes and, at least in principle, it discloses the possibility to access to rotary motors based on catenanes. Here, we report a strategy to obtain the solvent‐controlled unidirectional transit of a molecular axle through a molecular wheel. It is based on the use of appropriately designed molecular components, the essential feature of which is their non‐symmetric structure. Specifically they are an axle containing a central electron‐acceptor 4,4′‐bipyridinium core functionalized with a hexanol chain at one side, and a stilbene unit connected through a C6 chain at the other side, and a heteroditopic tris(phenylureido)‐calix[6]arene wheel. In apolar solvents the axle threads into the wheel from its upper rim and with the end carrying the OH group, giving an oriented pseudorotaxane structure. After a stoppering reaction, which replaces the small hydroxy group with a bulky diphenylacetyl moiety, and replacement of the apolar solvent with a polar one, dethreading occurs through the slippage of the stilbene unit from the lower rim of the wheel, that is, in the same direction of the threading process. The essential role played by the stilbene unit to achieve the unidirectional transit of the axle through the wheel, and to tune the dethreading rate by light is also demonstrated.
Light‐Driven Coordination‐Induced Spin‐State Switching: Rational Design of Photodissociable Ligands
Authors: Thies Steffen , Sell Hanno , Bornholdt Claudia , Schütt Christian , Köhler Felix , Tuczek Felix , Herges Rainer
Published: October 2012

The bistability of spin states (e.g., spin crossover) in bulk materials is well investigated and understood. We recently extended spin‐state switching to isolated molecules at room temperature (light‐driven coordination‐induced spin‐state switching, or LD‐CISSS). Whereas bistability and hysteresis in conventional spin‐crossover materials are caused by cooperative effects in the crystal lattice, spin switching in LD‐CISSS is achieved by reversibly changing the coordination number of a metal complex by means of a photochromic ligand that binds in one configuration but dissociates in the other form. We present mathematical proof that the maximum efficiency in property switching by such a photodissociable ligand (PDL) is only dependent on the ratio of the association constants of both configurations. Rational design by using DFT calculations was applied to develop a photoswitchable ligand with a high switching efficiency. The starting point was a nickel–porphyrin as the transition‐metal complex and 3‐phenylazopyridine as the photodissociable ligand. Calculations and experiments were performed in two iterative steps to find a substitution pattern at the phenylazopyridine ligand that provided optimum performance. Following this strategy, we synthesized an improved photodissociable ligand that binds to the Ni–porphyrin with an association constant that is 5.36 times higher in its trans form than in the cis form. The switching efficiency between the diamagnetic and paramagnetic state is efficient as well (72 % paramagnetic Ni–porphyrin after irradiation at 365 nm, 32 % paramagnetic species after irradiation at 440 nm). Potential applications arise from the fact that the LD‐CISSS approach for the first time allows reversible switching of the magnetic susceptibility of a homogeneous solution. Photoswitchable contrast agents for magnetic resonance imaging and light‐controlled magnetic levitation are conceivable applications.
Template‐Free Fabrication of Bi2O3 and (BiO)2CO3 Nanotubes and Their Application in Water Treatment
Authors: Qin Fan , Li Guangfang , Wang Runming , Wu Jiliang , Sun Hongzhe , Chen Rong
Published: October 2012

Uniform bismuth oxide (Bi2O3) and bismuth subcarbonate ((BiO)2CO3) nanotubes were successfully synthesized by a facile solvothermal method without the need for any surfactants or templates. The synergistic effect of ethylene glycol (EG) and urea played a critical role in the formation of the tubular nanostructures. These Bi2O3 and (BiO)2CO3 nanotubes exhibited excellent CrVI‐removal capacity. Bi2O3 nanotubes, with a maximum CrVI‐removal capacity of 79 mg g−1, possessed high removal ability in a wide range of pH values (3–11). Moreover, Bi2O3 and (BiO)2CO3 nanotubes also displayed highly efficient photocatalytic activity for the degradation of RhB under visible‐light irradiation. This work not only demonstrates a new and facile route for the fabrication of Bi2O3 and (BiO)2CO3 nanotubes, but also provides new promising adsorbents for the removal of heavy‐metal ions and potential photocatalysts for environmental remediation.
Synthesis and Promising Properties of a New Family of High‐Nitrogen Compounds: Polyazido‐ and Polyamino‐Substituted N,N′‐Azo‐1,2,4‐triazoles
Authors: Qi Cai , Li Sheng‐Hua , Li Yu‐Chuan , Wang Yuan , Zhao Xiu‐Xiu , Pang Si‐Ping
Published: October 2012

A new family of high‐nitrogen compounds, that is, polyazido‐ and polyamino‐substituted N,N′‐azo‐1,2,4‐triazoles, were synthesized in a safe and convenient manner and fully characterized. The structures of 3,3′,5,5′‐tetra(azido)‐4,4′‐azo‐1,2,4‐triazole (15) and 3,3′,5,5′‐tetra(amino)‐4,4′‐azo‐1,2,4‐triazole (23) were also confirmed by X‐ray diffraction. Differential scanning calorimetry (DSC) was performed to determine their thermal stability. Their heats of formation and density, which were calculated by using Gaussian 03, were used to determine the detonation performances of the related compounds (EXPLO 5.05). The heats of formation of the polyazido compounds were also derived by using an additive method. Compound 15 has the highest heat of formation (6933 kJ kg−1) reported so far for energetic compounds and a detonation performance that is comparable to that of octahydro‐1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocine (HMX), while compound 23 has a decomposition temperature of up to 290 °C.
Synthesis and Immunological Evaluation of Self‐Assembling and Self‐Adjuvanting Tricomponent Glycopeptide Cancer‐Vaccine Candidates
Authors: Wilkinson Brendan L. , Day Stephanie , Chapman Robert , Perrier Sébastien , Apostolopoulos Vasso , Payne Richard J.
Published: October 2012

Self‐adjuvanting tricomponent vaccines were prepared and assessed for their self‐assembly and immunological activity in mouse models. The vaccines each consisted of a peptide or glycopeptide antigen that corresponds to a complete copy of the variable‐number tandem repeat (VNTR) of the tumor‐associated mucin 1 (MUC1) glycoprotein, the universal T‐cell helper peptide epitope PADRE, and the immunoadjuvant Pam3CysSer. The vaccines were shown to spontaneously self‐assemble in water to form isotropic particles varying in size from 17 to 25 nm and elicited robust humoral responses in murine models without the addition of an external adjuvant. The serum antibodies could recognize tumor‐associated MUC1 epitopes on the surface of MCF7 breast‐cancer cells and B16 melanoma cells, which overexpress this tumor‐associated glycoprotein.
Cationic Complexes of Hydrogen with Helium
Authors: Bartl Peter , Leidlmair Christian , Denifl Stephan , Scheier Paul , Echt Olof
Published: October 2012

High‐resolution mass spectra of helium nanodroplets doped with hydrogen or deuterium reveal that copious amounts of helium can be bound to H+, H2+, H3+, and larger hydrogen‐cluster ions. All conceivable HenHx+ stoichiometries are identified if their mass is below the limit of ≈120 u set by the resolution of the spectrometer. Anomalies in the ion yields of HenHx+ for x=1, 2, or 3, and n≤30 reveal particularly stable cluster ions. Our results for HenH1+ are consistent with conclusions drawn from previous experimental and theoretical studies which were limited to smaller cluster ions. The HenH3+ series exhibits a pronounced anomaly at n=12 which was outside the reliable range of earlier experiments. Contrary to findings reported for other diatomic dopant molecules, the monomer ion (i.e. H2+) retains helium with much greater efficiency than hydrogen‐cluster ions.
Photoionization of Yb(NH3)n Complexes
Authors: Guttridge Matthew J. , Don Sadna H. , Ellis Andrew M.
Published: October 2012

The ionization energies of complexes between a rare‐earth metal (Yb) and ammonia were measured for the first time. Using photoionization mass spectrometry under molecular‐beam conditions, the adiabatic ionization energies of Yb(NH3)n were determined for n=1–10. Ab initio calculations were also carried out in support of this work and were found to be in excellent agreement with experiment. The combined findings from theory and experiment are consistent with formation of “interior” complexes in which the Yb atom is embedded within a shell of NH3 molecules, rather than sitting on the surface of an (NH3)n cluster. The calculations also suggest that Yb can accommodate up to eight NH3 molecules in its first solvation shell before steric repulsion makes occupancy of the second solvation shell more favourable energetically. The experimental ionization data are consistent with this prediction, as demonstrated by below‐trend adiabatic ionization energies for the n=9 and 10 complexes. The ionization energies of Yb(NH3)n complexes closely follow those for complexes of alkali metal atoms with NH3, which suggests that a valence electron will eventually detach from the Yb atom to form a solvated electron in Yb(NH3)n when n is sufficiently large.
Nuclear energy conversion with stacks of graphene nanocapacitors
Authors: Shinn Eric , Hübler Alfred , Lyon Dave , Perdekamp Matthias Grosse , Bezryadin Alexey , Belkin Andrey
Published: October 2012

The efficiency of conventional techniques used to harvest energy in nuclear reactors lies around 35%. This limit exists, because the nuclear energy is converted to electrical energy via heat engines. We study an alternative approach where the kinetic energy of nuclear reaction products is directly converted into electric energy in a stack of charged capacitors with a gap size of 500 nm and graphene electrodes. Graphene is expected to be chemically and mechanically stable in high‐radiation environments, because its tensile strength of 130 GPa is very large, about 100 times larger than most metals. The dielectric strength of such nanocapacitors exceeds 1 GV/m, because avalanching is suppressed at small gap sizes. In a 1 GV/m electric field charged nuclear reaction products, such as 5.6 MeV alpha particles, come to rest in of a stack with 5000 nanocapacitors. We show that during the deceleration process more than 90% of kinetic energy of charged nuclear reaction products is converted to electric energy and stored as electric energy in the stack. Each stack is 2.5‐mm thick and produces a high‐voltage DC current. A device with a 1‐Ci241Am source is expected to generate 22 mW of electric power.
Optimizing the Deposition of Hydrogen Evolution Sites on Suspended Semiconductor Particles using On‐Line Photocatalytic Reforming of Aqueous Methanol Solutions
Authors: Busser G. Wilma , Mei Bastian , Muhler Martin
Published: October 2012

The deposition of hydrogen evolution sites on photocatalysts is a crucial step in the multistep process of synthesizing a catalyst that is active for overall photocatalytic water splitting. An alternative approach to conventional photodeposition was developed, applying the photocatalytic reforming of aqueous methanol solutions to deposit metal particles on semiconductor materials such as Ga2O3 and (Ga0.6Zn0.4)(N0.6O0.4). The method allows optimizing the loading of the co‐catalysts based on the stepwise addition of their precursors and the continuous online monitoring of the evolved hydrogen. Moreover, a synergetic effect between different co‐catalysts can be directly established.
Further improvement of a certificateless signature scheme without pairing
Authors: Gong Peng , Li Ping
Published: October 2012

Recently, He et al. proposed an efficient certificateless signature (CLS) scheme without pairings and demonstrated their scheme to be provably secure in the random oracle model. Unfortunately, Tian and Huang and Tsai et al. pointed out that the scheme cannot withstand a Type II adversary's attack. Tsai et al. also proposed an improved scheme to enhance security. However, the schemes of He et al. and Tsai et al. are not real CLS schemes because the user's public key is used to generate its partial private key. Besides, He et al. and Tsai et al. just demonstrated that their schemes are secure against the normal adversary in the random oracle model. In this paper, we propose a real CLS scheme and demonstrate that our scheme is secure against the super adversary. Security analysis and performance analysis show that our scheme could enhance security and increase computational cost slightly. Copyright © 2012 John Wiley & Sons, Ltd.