bluuebunny/crossref_metadata_2025 huggingface dataset:
Simulations of Hydroxyapatite Nanocrystals for HRTEM Images Calculations
Authors: Ospina C. A. , Terra J. , Ramirez Antonio Jose , Ellis D.E. , Rossi Antonella M.
Published: October 2011

Hydroxyapatite (HA, Ca10(PO4)6(OH)2) is one of the most important biomaterials used in bone regeneration therapies due to their chemical properties are very similar to the inorganic phase found in bone tissues. The direct observation of the ultrastructure of HA is very important in the comprehension of their nucleation and interactions with the molecules involved in bone formation. High-resolution Transmission Electron Microscopy (HRTEM) is a currently technique used for this task. However, the interpretation of the images is not straightforward and needs the use of softwares dedicated to high-resolution images simulations. This work presents the applicability of MEGACELL software in the analysis of HRTEM images of HA nanoparticles. MEGACELL is the most newly software, developed to construct nanocrystals models for HRTEM multislice simulations. The output files generated by MEGACELL are raw data format (.xyz), containing all the atomic positions, as well as input files compatible with JEMS (Java Electron Microscopy Software) format files. High-resolution images were acquired using a JEM 3010 URP microscope, with a LaB6 thermionic electron gun operating at 300 kV, with a point-to-point resolution of 0.17 nm and a CCD Gatan 794SC multiscan digital camera, attached to the DigitalMicrographTM software for recording and image processing. Electron microscopy samples were prepared by dropping HA powder on copper TEM grids. HRTEM experimental images of HA particles, orientated along different zone axes, were interpreted applying the MEGACELL software to construct HA nanocrystal models and the multislice method to simulated them. MEGACELL improves the extraction of the ultrastructural features and facilitates a better interpretation of the phase-contrast images.
Nano-Bioceramics Production from Razor Shell
Authors: Agathopoulos Simeon , Ozyegin L.S. , Ahmad Z. , Gunduz O. , Kayali E.S. , Meydanoglu Onur , Oktar F.N.
Published: October 2011

The regeneration potential of human bone is limited in the cases of repairing large bone defects, such as those associated with comminuted fractures or bone tumor resection. In most cases, autogenous and allogenic bones are used as bone grafts. However, the amount of both of them is severely limited. Nowadays, natural biomaterials are in question, like corals, cuttlefish, and various nacre species, or hydroxyapatite (HA) made from egg shells. The present work aims at preparing inexpensive nano-sized HA and whitlockite particles from various raw materials of natural-biological origin. Razor shells (ensis ensis) were collected from beaches of Thessaloniki in Greece. Each sample was reduced to particle size <100 µm and DTA/TG was employed to determine their exact CaCO3 content. The suspended raw powders were put on a hotplate. The temperature was set to 80°C for 15 min. Then, equivalent amount of H3PO4 was added, drop by drop, into the solution. Different Ca/P ratios were tried. The reaction was ultrasonically assisted and continued for 8h. Then, to evaporate the liquid part, the mixture was put into an incubator at 100°C for 24 h and the resulting dried sediment was collected. The morphology of the produced powders was examined by SEM and revealed nano-sized particles. X-ray diffraction analysis indicated various Ca-phosphate phases, i.e. monetite and calcium phosphate hydrate. Thus, razor shells could be an alternative source for calcium phosphate ceramics production. In this study, long nacre shells were converted to various bioceramic structures with simple ultrasonic method without using hydrothermal method, which is carried out in a close vessel heated in a furnace and could cause accident if the vessel is worn. Chemical ultrasonic method is very safe and reliable method for bioceramic production from aragonite structures.
Sea Snail: An Alternative Source for Nano-Bioceramic Production
Authors: Ozyegin L.S. , Sima Felix , Ristoscu Carmen , Kiyici Ismail Akin , Mihailescu Ion N. , Meydanoglu Onur , Agathopoulos Simeon , Oktar F.N.
Published: October 2011

The production of nano-calcium phosphate, such as HA (hydroxyapatite), materials from synthetic chemicals could sometimes lead to a costly and tedious work. Sea creatures could be an alternative way to produce very fine and even nano-structured calcium phosphate materials. Nacres vastly consist of rich calcium carbonate and/or aragonite mater. With simple conversion methods, like hotplate stirring, various bioceramic structures could be produced suitable for thin film coatings with various methods, like pulsed laser deposition (MAPLE). This study is part of a bigger project which eventually and ultimately aims to produce nano-phases of calcium phosphate biocompatible bioceramics, which can be used for biomedical coatings. In this particular study, we focus at transforming chemically, using hotplate stirring method, local sea snail shells rapana thomasiana. Cleaned sea snail samples were provided from local markets in Istanbul. The shells were smashed down, ball-milled and the powder was sieved (<100 µm powder particles). Differential thermal analysis (DTA/TG) was employed to evaluate the exact CaCO3 content of the shells. According to these results, the required volume of H3PO4 was added in order to set the molar ratio of Ca/P (during hotplate stirring) either 10/6 or 3/2 (these ratios correspond to HA and TCP, respectively). SEM and X-ray diffraction analyses were conducted. The SEM observations showed brick-like particles were formed with sizes <5 µm. From the X-ray diffraction analysis, predominantly monetite, which can be considered as a precursor of HA and TCP, was detected. The results of this study showed that to produce HA and other bioceramic phases, hot-plate stirring method is a reliable, fast, rapid and economic method when compared to other tedious HA production methods. Moreover, sea snail shells are very good candidate materials to produce fine powders with hotplate stirring method for various tissue engineering applications.
Hydroxyapatite/Biopolymers Composite Scaffolds for Bone Tissue Engineering
Authors: Fook A.C.B.M. , Fideles Thiago Bizerra , Barbosa R.C. , Furtado G.T.F.S. , Sampaio G.Y.H. , Fook Marcus Vinícius Lia
Published: October 2011

The application of a hybrid composite consisting of biopolymer and calcium phosphate, similar morphology and properties of natural bone, may be a way to solve the problem of the fragility of ceramics without reducing its mechanical properties, retaining the properties of biocompatibility and high bioactivity. This work aims at the preparation and characterization of three-dimensional scaffolds composite HA / biopolymers (chitosan and gelatin). The freeze-drying technique was employed in this study to obtain these frameworks and partial results showed the effectiveness of this method. This involved the study of structural, chemical and morphological frameworks, in order to direct the research suggested the application. The X Ray Diffraction (XRD) and infrared spectroscopy and Fourier transform (FTIR) results confirmed the formation of hydroxyapatite (HA) phase and the presence of characteristic bands of HA and biopolymers in all compositions. The microstructure of the scaffolds study conducted by Scanning Electron Microscopy (SEM) revealed the formation of longitudinally oriented microchannels with interconnected pores. In all compositions the porous scaffolds showed varying sizes and mostly larger than 100μm, and is therefore considered materials with potential for application in bone tissue engineering.
Stability of the Magnesium Carbonate Apatite/Anionic Collagen Scaffolds: Effect of the Cross-Link Concentration
Authors: Sader Marcia S. , Alves Gutemberg , LeGeros Racquel Z. , de Almeida Soares Gloria Dulce
Published: October 2011

Natural bone constitutes of an inorganic phase (a biological nanoapatite) and an organic phase (mostly type I collagen). The challenge is to develop a material that can regenerate lost bone tissue with degradation and resorption kinetics compatible with the new bone formation. The aim of this study was to prepare self-organized magnesium and carbonate substituted apatite/collagen scaffolds, cross-linked with glutaraldehyde (GA). Bovine tendon was submitted to alkaline treatment resulting in a negatively charged collagen surface. The scaffolds were prepared by precipitation: simultaneous dropwise addition of solution containing calcium (Ca) and magnesium (Mg) ions and collagen into a buffered solution containing carbonate and phosphate ions in reaction vessel maintained at 37 °C, pH=8. The reaction products were cross-linked with 0.125 and 0.25% (v/v) glutaraldehyde (GA) solution and freeze-dried. The samples were characterized by Fourier-transformed infrared spectroscopy (FTIR). In vitro cytotoxicity (based on three parameters assays) and scaffolds degradation in culture medium and osteoblastic cells culture were performed in the cross-linked materials. No cytotoxic effects were observed. The cross-linked samples with the lower GA concentration showed a lower stability when placed in contact with culture medium. Human osteoblasts attached on the scaffolds surface cross-linked with 0.25% GA, forming a continuous layer after 14 days of incubation. These results showed potential application of the designed scaffolds for bone tissue engineering.
Physical Properties and Biological Performance of Bioactive Glasses and Glass-Ceramics Tested In Vitro
Authors: Simon Viorica , Lucacel R. Ciceo , Titorencu I. , Jinga V.
Published: October 2011

Lime phosphosilicate and soda lime phosphosilicate glasses prepared by sol-gel method were precursors of bioactive glass-ceramics. The structure of the samples and the distribution of the [SiO4] units was investigated by X-ray diffraction and infrared spectroscopy. Human osteosarcoma cell line (MG63) was used for the in vitro cellular response. DNA staining (Hoechst 33258) assay was performed for assessing samples colonization.
Experimental Investigations for Rapid Moulding Solution of Plastics Using Polyjet Printing
Authors: Singh Rupinder , Singh Varinderjit
Published: October 2011

Rapid prototyping (RP) has been in evidence for the past twenty years and is being widely used in diverse areas, from the building of aesthetic and functional prototypes to the production of tools and moulds for technological prototypes. The purpose of the present study is to experimentally investigate the rapid moulding (RM) solutions for plastic components using polyjet printing (PP) technique. Starting from the identification of component/benchmark, prototypes with three different type of plastic material were produced, at different orientation and support material. Measurements on the coordinate measuring machine helped in calculating the dimensional tolerances of the plastic components produced. Some important mechanical properties were also compared to verify the suitability of the components. The study highlighted the best orientation, support material quantity and type of plastic material for the selected component from dimensional accuracy and economic point of view as RM solution for plastic components. This process ensures rapid production of pre-series technological prototypes and proof of concept at less production cost and time.
Surface Modification of High Carbon High Chromium, EN31 and Hot Die Steel Using Powder Mixed EDM Process
Authors: Bhattacharya Anirban , Batish Ajay , Singh Gurpreet
Published: October 2011

This paper investigates the effect of electric discharge machining (EDM) process parameters and powder mixed in dielectric on surface properties of three die steel work materials; namely High Carbon High Chromium (HCHCr), EN 31 and Hot Die Steel (HDS). The mechanism of material deposition from the suspended powder and/or tool electrode is reported. Current emerged as the most significant factor affecting the microhardness along with powder mixed in the dielectric and electrode material. Amongst the two electrode materials, copper-tungsten along with tungsten powder had the best microhardness. Selected samples were analyzed for X-ray Diffraction (XRD) followed by microstructure analysis using a Scanning Electron Microscope (SEM). The results showed significant material transfer from the electrode as well as powder either in free form or in compound form. It was concluded that surface modification of die steels can be done by incorporating simple modifications in the EDM set-up resulting in higher microhardness and superior wear resistance of the machined surface.
Natural variability and anthropogenic effects in a Central Mediterranean core
Authors: Alessio S. , Vivaldo G. , Taricco C. , Ghil M.
Published: October 2011

Abstract. We evaluate the contribution of natural variability to the modern decrease in foraminiferal δ18O by relying on a 2200-years-long, high-resolution record of oxygen isotopic ratio from a Central Mediterranean sediment core. Pre-industrial values are used to train and test two sets of algorithms that are able to forecast the natural variability in δ18O over the last 150 yr. These algorithms are based on autoregressive models and neural networks, respectively; they are applied separately to each of the δ18O series' significant variability components, rather than to the complete series. The separate components are extracted by singular-spectrum analysis and have narrow-band spectral content, which reduces the forecast error. By comparing the sum of the predicted components to the actual values during the Industrial Era, we deduce that the natural contribution to the modern δ18O variation decreased gradually, until it reached roughly 40% as early as the end of the 1970s.
Prevalence of and Some Factors Relating with Unwanted Pregnancy, in Ahwaz City, Iran, 2010
Authors: Najafian M. , Karami K. B. , Cheraghi M. , Mohammad Jafari R.
Published: October 2011

Weaimedto find the prevalence and some factors relating with unwanted pregnancy.Methods. It was a cross-sectional study on 400 randomly pregnant women, who were referring to different health centers in Ahwaz city during 2010. Data was conducted based on questionnaire, and all the analysis was performed using SPSS (version 17) statistical analysis software.Results. The prevalence of unwanted pregnancy was 26%. The percentage of unwanted pregnancy in ages more than 35 years was approximately three times more than the intended pregnancy. There were significant relationship between unwanted pregnancy and some variables such as age, number of pregnancy, number of childbirth, education status, economic status, husband's occupation, and the relationship with the spouse and contraceptive methods ().Conclusion. The prevalence of unwanted pregnancy was high. To prevent unwanted pregnancy using consultation services before planning to be pregnancy, it is necessary to identify the factors relating with unwanted pregnancy.
Minimal or No Residual Prostatic Adenocarcinoma on Radical Prostatectomy: A 5-Year Experience With “Vanishing Carcinoma Phenomenon”
Authors: Kosarac Ognjen , Zhai Qihui “Jim” , Shen Steven , Takei Hidehiro , Ro Jae Y. , Ayala Alberto G.
Published: October 2011

Context.—“Vanishing carcinoma phenomenon” (VC) has been defined as the finding of minute or no cancer on radical prostatectomy specimens after a positive biopsy.

Objective.—To discuss our experience with VC and to recommend guidelines for its detection.

Design.—One thousand seven hundred forty-one radical prostatectomy specimens (2004–2009) processed by whole-mount section procedure yielded 21 (1.2%) cases with VC and 6 (0.34%) cases with minimal carcinoma (≤2 mm) in the radical prostatectomy specimen. To find the eluding carcinoma in VC cases or more carcinoma in minimal carcinoma cases, the following was done: 3 levels of all the paraffin blocks were obtained; if negative, the paraffin blocks were melted, the tissue was flipped, and 3 levels were prepared. The tumor bank frozen tissue was also processed for routine examination.

Results.—Three deeper levels in the radical prostatectomy specimen of 21 VC cases failed to show malignancy; however, the flipping and recutting of the tissue yielded a focus of carcinoma (1–5 mm) in 16 of 21 cases and in 3 of 16 cases in the saved frozen tissue. In 1 of the 6 cases with minimal carcinoma, subsequent recuts of the flipped tissue displayed carcinoma (2 foci of tumor, <1 mm each).

Conclusions.—In VC we recommend: embed and process any remaining prostatic tissue including any saved fresh-frozen tissue; obtain 3 levels of each paraffin block; if results are negative, melt and flip the tissue and obtain 3 more levels. Following the above guidelines, a hidden carcinoma may be detected in the majority of the cases of VC.
Assuring Quality in Point-of-Care Testing: Evolution of Technologies, Informatics, and Program Management
Authors: Lewandrowski Kent , Gregory Kimberly , Macmillan Donna
Published: October 2011

Context.—Managing the quality of point-of-care testing (POCT) is a continuing challenge. Advances in testing technologies and the development of specialized informatics for POCT have greatly improved the ability of hospitals to manage their POCT program.

Objectives.—To present the evolving role of technology improvement, informatics, and program management as the key developments to ensure the quality of POCT.

Data Sources.—This presentation is based on a review of the literature and on our experiences with POCT at the Massachusetts General Hospital (Boston).

Conclusions.—Federal and state regulations, along with accreditation standards developed by the College of American Pathologists and The Joint Commission, have established guidelines for the performance of POCT and have provided a strong incentive to improve the quality of testing. Many instruments for POCT have incorporated advanced design features to prevent analytic and operator errors. This, along with the development of connectivity standards and specialized data management software, has enabled remote review of test data and electronic flow of information to hospital information systems. However, documentation of manually performed, visually read tests remains problematic and some POCT devices do not have adequate safeguards to prevent significant errors. In the past 2 decades the structure of a successful POCT management program has been defined, emphasizing the role of POCT managers working in conjunction with a pathology-based medical director. The critical skill set of POCT managers has also been identified. The POCT manager is now recognized as a true specialist in laboratory medicine.
The Sense of Community in French Caribbean Fiction
Authors: Britton Celia
Published: October 2011

This book analyses the theme of community in seven French Caribbean novels in relation to the work of the French philosopher Jean-Luc Nancy. The islands complex history means that community is a central and problematic issue in their literature, and underlies a range of other questions such as political agency, individual and collective subjectivity, attitudes towards the past and the future, and even literary form itself. Britton examines Jacques Roumains Gouverneurs de la rosée, Edouard Glissants Le Quatrième Siècle, Simone Schwarz-Barts Pluie et vent sur Télumée Miracle, Vincent Placolys Leau-de-mort guildive, Patrick Chamoiseaus Texaco, Daniel Maximins LIle et une nuit and Maryse Condés Desirada.
Thresholds of Meaning
Authors: Duffy Jean
Published: October 2011

Thresholds of Meaning examines contemporary French narrative and explores two related issues: the centrality within recent French fiction and autofiction of the themes of passage, ritual and liminality; the thematic continuity which links this work with its literary ancestors of the 1960s and 1970s. Through the close analysis of novels and récits by Pierre Bergounioux, François Bon, Marie Darrieussecq, Hélène Lenoir, Laurent Mauvignier and Jean Rouaud, Duffy demonstrates the ways in which contemporary narrative, while capitalising on the formal lessons of the nouveau roman and drawing upon a shared repertoire of motifs and themes, engages with the complex processes by which meaning is produced in the referential world and, in particular, with the rituals and codes that social man brings into play in order to negotiate the various stages of the human life-cycle. By the application of theoretical concepts and models derived from anthropology and from visual studies, the study situates itself at the intersection of the developing field of literature and anthropology studies and research into word and image.
Niedermolekulare Verbindungen aus Spinnen als chemische Sensoren
Authors: Olsen Christian A. , Kristensen Anders S. , Strømgaard Kristian
Published: October 2011

Spinnen sind für viele Ökosysteme wichtig, und als Hauptfeinde von Insekten verfügen sie über eine Fülle von niedermolekularen Naturstoffen mit faszinierenden biologischen Wirkungen. Die Isolierung und die biologische Charakterisierung dieser Verbindungen sind wohlbekannt, aber erst kürzlich wurden sie als Leitstrukturen für die Entwicklung, Synthese und biologische Untersuchung synthetischer Analoga verwendet. Weit weniger erforscht sind hingegen Verbindungen, die der Kommunikation von Spinnen dienen. Vor kurzem wurden jedoch auf dem Gebiet der Pheromone und Allomone aus Spinnen neue Erkenntnisse erhalten, die wir hier zusammenfassen und mit früheren Ergebnissen in Zusammenhang bringen. Abschließend geben wir einen Ausblick auf künftige Untersuchungen an dieser Art von Verbindungen.
Small Molecules from Spiders Used as Chemical Probes
Authors: Olsen Christian A. , Kristensen Anders S. , Strømgaard Kristian
Published: October 2011

Spiders are important species in ecological systems and as major predators of insects they are endowed with a plethora of low‐molecular‐weight natural products having intriguing biological activities. The isolation and biological characterization of these entities are well established, however, only very recently have these compounds been used as templates for the design, synthesis, and biological evaluation of synthetic analogues. In contrast, the investigation of compounds responsible for chemical communication between spiders is far less developed, but recently new light has been shed onto the area of pheromones and allomones from spiders. Herein, we recapitulate these recent results, put them into perspective with previous findings, and provide an outlook for future studies of these chemotypes.
An Improved Sliding‐Mode Repetitive Learning Control Scheme Using Wavelet Transform
Authors: Lu Yu‐Sheng , Wu Bing‐Xuan , Lien Shu‐Fen
Published: October 2011

This paper presents an enhanced sliding‐mode repetitive learning control (SMRLC) scheme using the wavelet transform. Distinct from previous wavelet transform‐based repetitive control schemes, the proposed SMRLC learns from a switching signal that is equivalent to the compensation error of the SMRLC, thereby speeding up the learning process. The wavelet analysis is employed to decompose the switching signal, capture its low‐frequency components effectively, and synthesize a de‐noised, high‐scale signal for the learning process. Experimental study on a directly driven Hoekens straight‐line mechanism is conducted, and the proposed wavelet transform‐based SMRLC is experimentally compared with a Fourier series‐based SMRLC.

Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Einsatz eines mobilen NMR‐Sensors als zerstörungsfreies Messsystem in der Bauwerkserhaltung
Authors: Keil Allessandra , Orlowsky Jeanette , Raupach Michael
Published: October 2011

Das Potential der NMR‐MOUSE® als mobiles zerstörungsfreies Messsystem im Bereich der Bauwerkserhaltung wird anhand zweier Beispiele erläutert. Das erste Beispiel behandelt den Feuchtetransport in Feinbetonen während im zweiten die Bestimmung der Schichtdicken ausgewählter Oberflächenschutzsysteme dargestellt wird.

Mit dem angewendeten Messsystem wurden aussagekräftige Feuchteprofile für Feinbetone bis in eine Messtiefe von 5 mm mit einer Ortsauflösung von 250 µm erstellt. Der zeitliche Verlauf der kapillaren Wasseraufnahme unterschiedlicher Feinbetone kann anhand dieser Feuchteprofile differenziert betrachtet und darüber der Einfluss von Polymerzugaben zum Bindemittel beurteilt werden.

Anhand von Tiefenprofilen wurden die Schichtdicken eines Modellsystems und zweier OS 11a‐Beschichtungen zerstörungsfrei mit hoher Auflösung ermittelt. Die Messungen zeigen, dass Schichtdicken von ca. 50 bis 200 µm bei entsprechend gleichmäßigem Auftrag mit einer Standardabweichung von aufgerundet 5 µm bestimmbar sind.

Application of a mobile NMR sensor as a non‐destructive measurement system in the field of maintenance. The potential to use the NMR‐MOUSE® as non‐destructive analytical tool in building maintenance is demonstrated on two examples. The first one covers moisture transport through fine grained concrete matrices, whereas in the second one the NMR‐MOUSE is used to determine the layer thickness of selected coating systems for concrete protection.

In using this NMR technique, significant moisture profiles have been determined in fine grained concrete matrices with a maximum measuring depth of 5 mm and a depth‐resolution of 250 µm. The NMR technique also allows observing the time depended progress of capillary water uptake and evaluating the effects of polymer modifications of the concrete matrix.

Furthermore, the layer thickness of one model coating system and two OS 11a‐coating systems were determined on the basis of depth profiles. The results show, that layer thickness between 50 and 200 µm can be determined with a standard deviation of about 5 µm.
Die Überprüfung von Spannbetonkonstruktionen auf Unversehrtheit der Spannglieder
Authors: Hillemeier Bernd , Walther Andrei
Published: October 2011

Brückenbauwerke sind einer ständig steigenden Verkehrslast ausgesetzt. Die Altersstruktur, die Belastungssituation und der Zustand der Brücken sind verschieden. Mehr als 20000 Brücken in Deutschland bestehen aus Spannbeton, deren Stabilität wesentlich von der Unversehrtheit der Spannbewehrung abhängt. Korrosionsschäden an der Spannbewehrung sind von der Oberfläche her nicht sichtbar. An der Technischen Universität Berlin wurde ein mobiles Magnetmesssystem entwickelt, das speziell für Brücken den Zustand der Spanndrähte analysiert. Dazu müssen weder Brückenbereiche geöffnet noch der Fahrbahnbelag entfernt werden. In den letzten zehn Jahren wurden bisher mehr als 14 Spannbetonbrücken, fünf davon in den USA/Kanada, untersucht. Das Verfahren wurde an der Lehigh Universität in Bethlehem (USA) im Zuge einer weltweiten Vergleichsuntersuchung 2009 und 2010 als besonders qualifiziert evaluiert.

The inspection of prestressed concrete structures to the integrity of the tendons. Bridges are exposed to an ever‐increasing traffic load. The age structure, the stress situation and the condition of the bridges are different. More than 20000 bridges in Germany are made of prestressed concrete, whose stability depends essentially on the integrity of the tension reinforcement. Corrosion damages to the tension reinforcement are not visible from the surface. At the Technical University of Berlin, a mobile magnetic measurement system has been developed specifically for bridges. It analyzes the state of the tension wires. This system areas not require any removal of the bridge pavement. In the past ten years 14 prestressed concrete bridges have been studied, five of them in the USA/Canada. The process was evaluated at Lehigh University in Bethlehem (USA), as part of a worldwide comparative study in 2009 and 2010.
Quantitation of glucosamine sulfate in plasma by HPLC‐MS/MS after administration of powder for oral solution formulation
Authors: César Isabela Costa , Byrro Ricardo Martins Duarte , de Santana e Silva Cardoso Fabiana Fernandes , Mundim Iram Moreira , de Souza Teixeira Leonardo , Rezende Kênnia Rocha , da Silva Enikson Pontes , Gomes Sandro Antônio , de Sousa Vilmar Alves , Bonfim Ricardo Rodrigues , Pianetti Gerson Antônio
Published: October 2011

A rapid method for the quantification of glucosamine in human plasma using high‐performance liquid chromatography coupled to tandem mass spectrometry was developed and validated. The sample preparation includes a simple deproteinization step, using d‐[1‐13C] glucosamine hydrochloride as an internal standard. Chromatographic separation was performed on an ACE Ciano column using isocratic elution with acetonitrile and aqueous 2 mm ammonium acetate containing 0.025% formic acid (80:20). Selected reaction monitoring was performed using the transitions m/z 180.1 → m/z 72.1 and m/z 181.0 → m/z 74.6 to quantify glucosamine and internal standard, respectively. The method was validated and proved to be linear, accurate and precise over the range 50–5000 ng/mL of glucosamine. Recovery rates higher than 90% were obtained for both glucosamine and internal standard. No matrix effect was detected in the samples. The validated method was successfully applied to a pharmacokinetic study after oral administration of a powder for oral solution formulation containing glucosamine sulfate. Copyright © 2011 John Wiley & Sons, Ltd.
ChemInform Abstract: The Design of Orally Bioavailable 2,5‐Diketopiperazine Oxytocin Antagonists: From Concept to Clinical Candidate for Premature Labor
Authors: Borthwick Alan D. , Liddle John
Published: October 2011

Review: 45 refs.
ChemInform Abstract: Asymmetric Catalysis with Helical Polymers
Authors: Megens Rik P. , Roelfes Gerard
Published: October 2011

Review: 58 refs.
ChemInform Abstract: Interactions and Incompatibilities of Pharmaceutical Excipients with Active Pharmaceutical Ingredients
Authors: Bharate Sonali S. , Bharate Sandip B. , Bajaj Amrita N.
Published: October 2011

Review: 130 refs.
In‐Depth Study of Mass Transfer in Nanoporous Materials by Micro‐Imaging
Authors: Hibbe Florian , van Baten Jasper M. , Krishna Rajamani , Chmelik Christian , Weitkamp Jens , Kärger Jörg
Published: October 2011

The first application of interference microscopy to monitoring mass transfer in nanoporous materials dates back to late 1970s when Caro and colleagues reported results of investigations of water uptake by LTA type zeolites. It was, however, not before the beginning of the new millennium that the developments in both the measuring technique and computational power have enabled the recording of transient guest profiles during molecular uptake and release under well‐defined conditions, leading to the establishment of a novel access to diffusion studies, now referred to as micro‐imaging. In the present contribution, the thus accessible novel type of information is illustrated by an in‐depth analysis of the uptake kinetics of methanol in an all‐silica ferrierite. In particular, two remarkable experimental findings are reported, which may be tracked back to their microstructural and/or microdynamic origin, namely a pronounced asymmetry in the transient concentration profiles and a slowing down of guest uptake with increasing temperature.
Detection of malondialdehyde in vivo using microdialysis sampling with CE‐fluorescence
Authors: Cooley Justin Carl , Lunte Craig Edward
Published: October 2011

Oxidative damage is a naturally occurring process where reactive oxygen species (ROS) attack and disrupt normal cellular function; however, these effects become elevated during a stress event, such as ischemia/reperfusion or seizure. One result of oxidative stress is lipid peroxidation, where ROS attack free unsaturated fatty acids forming lipid hydorperoxides, which then break down to form secondary products acrolein, 4‐hydroxynonenal, and malondialdehyde (MDA) resulting in irreversible membrane damage and ultimately cell death. Described here is a CE‐fluorescence method for the determination of MDA in conjunction with in vivo microdialysis sampling. MDA was derivatized with thiobarbituric acid under acidic conditions for 20 minutes and injected directly into the capillary without any pretreatment. This method provided a limit of detection of 25 nM (S/N=3) and a linear range of 25–2400 nM (1.8–174 ng/mL). This method was used to quantify MDA in rat heart, muscle, liver, and brain dialysate.
Native Chemical Ligation Combined with Desulfurization and Deselenization: A General Strategy for Chemical Protein Synthesis
Authors: Dawson Philip E.
Published: October 2011

Of the many approaches proposed to generalize the native chemical ligation approach for protein synthesis, the simple procedure of global desulfurization of peptide thiols has become the most widely adopted. In this review, the development of the native ligation–desulfurization strategy is described, focusing on the conversion of Cys to Ala following ligation at N‐terminal Cys residues. Subsequent variations on this theme have broadened the scope to other natural amino acids including Phe, Leu, Val, and Lys, and even non‐native peptide linkages such as isopeptide bonds on lysine side chains. Using insights from both selenocysteine–peptide side reactions and radical initiated desulfurization procedures, a new method for the selective deselenization of peptides containing both selenocysteine and cysteine residues has been developed. Together, these approaches represent a robust and flexible methodology for the synthesis of complex polypeptides without the use of protecting groups.
New application of optical agent to image angiogenesis in hindlimb ischemia
Authors: Tekabe Yared , Klose Alex , Nizami Saqib , Luma Joane , Lee Francis Y. , Johnson Lynne
Published: October 2011

Optical agents targeting αvβ3 are potential tools to image the angiogenic response to limb ischemia. The left (L) femoral artery was ligated in 17 mice and sham surgery performed on the contralateral right (R) hindlimb. Seven days later, IntegriSense (2 nmol) was injected into 11 mice and 6 were probe controls. Six hours later, mice underwent optical imaging. Ratios of photon flux in the L/R limbs were calculated. Tissue was stained for αv, CD31, and lectin. The signal was increased in the ischemic limbs compared to contralateral legs and ratio of photon flux in L/R limb averaged 2.37. Control probe showed no hindlimb signal. IntegriSense colocalized with CD 31 by dual fluorescent staining. Ratios for L/R hindlimbs correlated with quantitative lectin staining (r = 0.88, p = 0.003). Optical imaging can identify and quantify angiogenic response to hindlimb ischemia. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Defined benefit plan headache: Rule changes boost volatility of pension cash flow
Authors: Campbell John L. , Schwartz Jr. William C.
Published: October 2011

Recent legislative changes dramatically increase the annual mandatory minimum pension contributions for firms sponsoring defined benefit pension plans. And the rules have also increased the volatility of firm cash flows.

In recent years, many firms have made excess contributions to their pension plans—only to see those efforts erased when equity prices dramatically dropped. Companies were chagrined to again find their pension plans significantly underfunded.

An unintended consequence of the new legislation is that managing defined benefit plans is now more difficult than ever.

So what is the best strategy now?

The authors of this article provide specific guidance to CEOs, CFOs, and treasurers‐to help them decide how best to respond to the new funding regulations. © 2011 Wiley Periodicals, Inc.
Phosphatidylserine externalization and membrane blebbing are involved in the nonclassical export of FGF1
Authors: Kirov Aleksandr , Al‐Hashimi Huda , Solomon Phil , Mazur Courtney , Thorpe Philip E. , Sims Peter J. , Tarantini Francesca , Kumar Thallapuranam K. Suresh , Prudovsky Igor
Published: October 2011

The mechanisms of nonclassical export of signal peptide‐less proteins remain insufficiently understood. Here, we demonstrate that stress‐induced unconventional export of FGF1, a potent and ubiquitously expressed mitogenic and proangiogenic protein, is associated with and dependent on the formation of membrane blebs and localized cell surface exposure of phosphatidylserine (PS). In addition, we found that the differentiation of promonocytic cells results in massive FGF1 release, which also correlates with membrane blebbing and exposure of PS. These findings indicate that the externalization of acidic phospholipids could be used as a pharmacological target to regulate the availability of FGF1 in the organism. J. Cell. Biochem. 113: 956–966, 2012. © 2011 Wiley Periodicals, Inc.
MicroRNA‐21 represses human cystathionine gamma‐lyase expression by targeting at specificity protein‐1 in smooth muscle cells
Authors: Yang Guangdong , Pei Yanxi , Cao Qiuhui , Wang Rui
Published: October 2011

Cystathionine gamma‐lyase (CSE) is the major H2S‐generating enzyme in vascular smooth muscle cells (SMCs). CSE/H2S system contributes to the maintenance of SMC phenotype, and transcript factor specificity protein‐1 (SP1) is a critical regulator of CSE expression during SMC differentiation. The involvements of microRNA‐21 (miR‐21) in cardiovascular pathophysiology have been known, however miR‐21 regulation of CSE and SP1 as well as SMC phenotype are uncertain. Using quantitative real‐time PCR, we demonstrated that the expression of miR‐21 was upregulated in dedifferentiated human aorta SMCs (HASMCs) and injured mouse carotid arteries. To determine the potential roles of miR‐21 in SP1‐mediated CSE gene expression and SMC phenotypic change, we showed that miR‐21 expression was upregulated by miR‐21 precursor. Interestingly, miR‐21 overexpression significantly repressed the protein expressions of both CSE and SP1, inhibited H2S production, stimulated SMC proliferation, and reduced SMC differentiation marker gene expression, respectively. The mRNA expression of CSE but not SP1 was inhibited by miR‐21 precursor. Blockage of SP1 binding by mithramycin or inhibition of CSE activity by DL‐propargylglycine did not change miR‐21 expression. We further demonstrated that miR‐21 repressed SP1 protein expression by directly targeting at SP1 3′ untranslational regions, which in turn downregulated CSE mRNA expression and stimulated SMC proliferation. Take together, these results suggest that miR‐21 participates in CSE/H2S‐mediated‐SMC differentiation by targeting SP1. J. Cell. Physiol. 227: 3192–3200, 2012. © 2011 Wiley Periodicals, Inc.
MRI and “Tenderness Guided” transvaginal ultrasonography in the diagnosis of recto‐sigmoid endometriosis
Authors: Saba Luca , Guerriero Stefano , Sulcis Rosa , Pilloni Monica , Ajossa Silvia , Melis Gianbenedetto , Mallarini Giorgio
Published: October 2011

Purpose:

To compare the diagnostic accuracy of MRI and “tenderness‐guided” transvaginal ultrasonography (tg‐TVUS) in the identification of recto‐sigmoid endometriosis.

Materials and Methods:

Institutional Review Board approval for this study was obtained, and written informed consent was given by all patients. This study is compliant with the STARD (Standards for Reporting of Diagnostic Accuracy) method. Fifty‐nine patients (mean age, 33 years; range, 21–44 years) with clinical suspicion of deep pelvic endometriosis were prospectively enrolled. They underwent tg‐TVUS and MRI before surgery. The characteristics of the MRI signal were analyzed. Mapping of recto‐sigmoid endometriosis was performed and tg‐TVUS and MR imaging results were compared with surgical and pathological findings. Sensitivity, specificity, and the positive and negative likelihood ratio (LR+ and LR−) were calculated. Inter‐technique concordance was assessed using the Cohen statistic, and receiver operating characteristic (ROC) curves were obtained. Logistic regression analysis was performed.

Results:

The prevalence of recto‐sigmoid endometriosis was 51%. The specificity, sensitivity, and LR+ and LR− were 90%, 73%, 7.089 and 0.297, respectively, for MRI and 86%, 73%, 5.317 and 0.309, respectively, for tg‐TVUS. The presence of a high T1 signal spot was an excellent specific finding (100%) but was associated with a low sensitivity (30%). Inter‐technique concordance using the Cohen statistic indicated a kappa value of 0.658 (± 0.098 SD). According to the logistic regression equation obtained, the use of both tg‐TVUS and MRI allows optimal diagnostic performance.

Conclusion:

MRI and tg‐TVUS show similar results in the identification of recto‐sigmoid endometriosis. The Cohen kappa value suggests that these methods may have complementary roles in the identification of recto‐sigmoid endometriosis, depending on the site affected. J. Magn. Reson. Imaging 2012;352‐360. © 2011 Wiley Periodicals, Inc.
mGluR5 is involved in proliferation of rat neural progenitor cells exposed to hypoxia with activation of mitogen‐activated protein kinase signaling pathway
Authors: Zhao Lingyu , Jiao Qian , Chen Xinlin , Yang Pengbo , Zhao Bingqiao , Zheng Ping , Liu Yong
Published: October 2011

Hypoxia/ischemia induces proliferation of neural progenitor cells (NPCs) in rodent and human brain; however, the mechanisms remain unknown. We investigated the effects of metabotropic glutamate receptor 5 (mGluR5) on NPC proliferation under hypoxia, the expression of cyclin D1, and the activation of the mitogen‐activated protein kinases (MAPKs) signaling pathway in cell culture. The results showed that hypoxia induced mGluR5 expression on NPCs in vitro. Under hypoxia, the mGluR5 agonists DHPG and CHPG significantly increased NPC proliferation in cell activity, diameter of neurospheres, bromodeoxyuridine (BrdU) incorporation and cell division, and expression of cyclin D1, with decreasing cell death. The mGluR5 siRNA and antagonist MPEP decreased the NPC proliferation and expression of cyclin D1, with increasing cell death. Phosphorylated JNK and ERK increased with the proliferation of NPCs after DHPG and CHPG treatment under hypoxia, while p‐p38 level decreased. These results demonstrate that the expression of mGluR5 was upregulated during the proliferation of rat NPCs stimulated by hypoxia in vitro. The activation of the ERK and JNK signaling pathway and the expression of cyclin D1 were increased in this process. These finding suggest the involvement of mGluR5 in rat NPC proliferation and provide a target molecule in neural repair after ischemia/hypoxia injury of CNS. © 2011 Wiley Periodicals, Inc. © 2011 Wiley Periodicals, Inc.
On Becoming a Person (1961) Carl Rogers' celebrated classic in memoriam
Authors: Morgan John H.
Published: October 2011

By Carl R. Rogers

Boston, MA: Houghton Mifflin, 1961. ISBN 0‐395‐75531‐X 422 pages

Reviewed by John H. Morgan, PhD, DSc, PsyD
Investigation of stress and structural damage in H and He implanted Ge using micro‐Raman mapping technique on bevelled samples
Authors: Wasyluk J. , Rainey P. V. , Perova T. S. , Mitchell S. J. N. , McNeill D. W. , Gamble H. S. , Armstrong B. M. , Hurley R.
Published: October 2011

The results on structural damage in germanium wafers caused by hydrogen and helium implants of typical doses used in Smart Cut™ Technology (1–6 × 1016 atoms/cm2) are investigated using Raman mapping and spreading resistance profiling techniques. Raman line‐mapping measurements were performed up to the depth of ~400 nm into a Ge substrate (well beyond the limit of visible light penetration depth) using a bevelling technique. From analysis of the Ge–Ge Raman peak it was found that implantation of H and He introduced a different type of stress, tensile and compressive, respectively and significant structural damage with maximum at the projected range. The obtained data shows that hydrogen incorporation in Ge can act as an acceptor. This is undesirable when the hydrogen ion‐cut technology is applied to high resistivity Ge. The crystalline structure after implantation is completely recovered when annealed at 600 °C for both types of implants. Spreading resistance profiling results reveal that 4−8x1015 acceptors/cm3 remain after 600 °C, and these are thought to be because of vacancy related defect clusters. Copyright © 2011 John Wiley & Sons, Ltd.
Surface‐enhanced Raman scattering spectroscopy for potential noninvasive nasopharyngeal cancer detection
Authors: Lin Juqiang , Chen Rong , Feng Shangyuan , Pan Jianji , Li Buhong , Chen Guannan , Lin Shaojun , Li Chao , Sun Li‐qing , Huang Zufang , Zeng Haishan
Published: October 2011

Combining membrane electrophoresis with surface‐enhanced Raman scattering (SERS) spectroscopy, the serum proteins were first purified and then mixed with silver nanoparticles to perform SERS spectral analysis. Therefore, the spectral signatures were enhanced to high‐fidelity SERS signatures because of the purification procedure of the first step. We used the method to analyze blood plasma samples from nasopharyngeal cancer patients (n = 43) and healthy volunteers (n = 33) for cancer detection. Principle component analysis of the SERS spectra revealed that the data points for the cancer group and the normal group form distinct, completely separated clusters with no overlap. Therefore, the nasopharyngeal cancer group can be unambiguously discriminated from the normal group, i.e., with both diagnostic sensitivity and specificity of 100%. These results are very promising for developing a label‐free, noninvasive, and reliable clinical tool for rapid cancer detection and screening. Copyright © 2011 John Wiley & Sons, Ltd.
Microwave monitoring of silver nanoparticle sintering for surface‐enhanced Raman scattering substrates
Authors: Figueroa Manuel , Pourrezaei Kambiz , Tyagi Somdev
Published: October 2011

One of the most widely used methods for surface‐enhanced Raman scattering (SERS) employs silver or gold nanoparticles either in colloidal suspension or in the dry‐drop form. In such substrates the SERS amplification factors depend critically on the interparticle distances. Here, we report that microwave absorption as a function of temperature in dry‐drop substrates can be used as a probe to demarcate temperature regions for thermal annealing to produce SERS substrates with very high amplification factors. Copyright © 2011 John Wiley & Sons, Ltd.
Reparaturlösungen für höchste Ansprüche
Authors: Candel‐Ruiz Antonio , Metzger Jürgen
Published: October 2011

Das Laserauftragschweißen wird heutzutage als etablierte Technik zur Instandsetzung von Bauteilen und Herstellung von Schichtsystemen mit definierten Eigenschaften betrachtet. Das Verfahren ermöglicht auch das Generieren von 3‐D‐Strukturen und die Fertigung von kompletten Bauteilen. Anwendungen für diese Technologie sind bei der petrochemischen, Automobil‐ und Schwerindustrie, in der Medizintechnik und in der Luftfahrttechnik zu finden. Dies lässt sich durch die Vorteile dieser laserbasierten Technik gegenüber konventionellen Auftragschweißverfahren begründen: minimaler Verzug des Bauteils bei lokaler Wärmeeinbringung, erhöhter Automatisierungsgrad und die Möglichkeit, endkonturnahe Volumina aufzutragen.