bluuebunny/crossref_metadata_2025 huggingface dataset:
Cell electrophoresis — a method for cell separation and research into cell surface properties
Authors: Korohoda Włodzimierz , Wilk Anna
Published: February 2008

In this paper, we discuss the application of various methods of cell electrophoresis in research into cell surface properties (analytical methods), and the separation of uniform cell subpopulations from cell mixtures (preparative methods). The emphasis is on the prospects of the development of simplified and versatile methodologies, i.e. microcapillary cell electrophoresis and horizontal cell electrophoresis under near-isopycnic conditions. New perspectives are considered on the use of analytical and preparative cell electrophoresis in research on cell differentiation, neoplastic transformation, cell-cell interactions and the biology of stem cells.
Fostering Students' Global Awareness: Technology Applications in Social Studies Teaching and Learning
Authors: Crawford Elizabeth , Kirby Misty
Published: February 2008

Global education is essential to students’ development of knowledge, skills, and attitudes necessary for future employment and for building successful relationships in an increasingly interconnected and pluralistic society. Incorporation of technology in meaningful and authentic learning experiences with students in the classroom as supported by the Technological Pedagogical Content Knowledge (TPCK) framework allows teachers to foster students’ understandings of the interrelationships of peoples worldwide, thereby preparing them to participate meaningfully as global citizens. An overview of web-based organizations that foster global awareness and a description of professional development opportunities in global education are provided.
Enzymology
Authors: Cass Tony
Published: February 2008

Enzymes are one of the major molecular components of biosensors and biochips, acting both as specific recognition elements and as “machines” that catalyze chemical transformations that ultimately give rise to a signal. In molecular recognition, they can distinguish very similar molecules, while as catalytic machines they can be enormously efficient with rates of reaction limited by diffusion. Add to their intrinsic properties the ability to introduce or modify functionality through gene technology and it becomes clear that an understanding of enzyme structure, kinetics, and chemical mechanisms is essential if they are to be used effectively in devices. This chapter will provide an overview of the principles of enzymology in sufficient detail to allow the reader to appreciate their function in biosensors and biochips.
Yeast‐Based Biosensors and Their Incorporation of Mammalian Protein Receptors for High‐Throughput Screening
Authors: Findlay John B. C. , Tang Lisa , Whyteside Graham
Published: February 2008

The use of biological entities in diagnostics has recently become widespread. Such devices are called biosensors and consist of a detector and a reporter component, of which one is a biological moiety. Many biological molecules have been incorporated into biosensors with examples being, Abs, enzymes, DNA, and more recently microorganisms. In this chapter we discuss the advantages and disadvantages of using live organisms for biosensors. In particular we discuss the suitability of yeast for biosensor development using mammalian GPCR's. In addition we also discuss the potential use of these biosensors in high‐throughput screening.
Data Validation and Interpretation
Authors: Spichiger‐Keller Ursula E.
Published: February 2008

In this chapter, the technical analytical value of a test result is distinguished from the diagnostic value. The analytical procedure is validated technically in order to provide information on the technical uncertainty of a test result. This validation process follows globally accepted protocols and recommendations, which are cited in this chapter (Internet links are given). The diagnostic value relies primarily on biological uncertainties, on the position of a cutoff limit for two populations from different sources to distinguish between the test results and on other factors, which are described systematically. Models and discussions about how to interpret data are primarily found in the literature, which deals with diagnostic screening tests for medical applications. However, the rules are generally valid in all fields of data interpretation in analytical chemistry. This is the message given in this chapter.
Nanosphere Lithography‐Based Chemical Nanopatterns for Biosensor Design
Authors: Colpo Pascal , Valsesia Andrea , Lisboa Patricia , Rossi François
Published: February 2008

One of the major challenges for the development of analytical devices for biological analysis is the ability to design advanced surfaces that interact properly with the biological world. The special behavior of the biomolecules that interact with nanostructured materials has been the main motivation for the development of submicrometer chemical patterning techniques. The most important aspect of the nanostructuring of biointeracting surfaces is the immobilization of the biomolecular probes with higher binding‐site accessibility for the biorecognition of the target molecules and the reduction in the nonspecific adsorption. In this chapter we describe the concept of fabricating chemical nanopattern using a combination of nanosphere lithography and biofunctional layers produced by plasma‐enhanced chemical vapor deposition (PE‐CVD) and self assembled monolayers (SAMs). Applications of the produced nanopatterns in protein immobilization and biosensing protocols are described.
Label‐Free Gene and Protein Sensors Based on Electrochemical and Local Plasmon Resonance Devices
Authors: Kerman Kagan , Endo Tatsuro , Tamiya Eiichi
Published: February 2008

Label‐free detection systems have become increasingly popular for biosensors with their promising properties that enable convenient bioassay systems. Label‐free biosensors brought several advantages to genetic tests with their short analysis time, minimum liquid handling, and lower sample volume requirement. Thus, if the development of label‐free methods in sensing technologies progresses in parallel with the great demand, label‐free biochips may soon become an important part of routine analysis.
Design of Data Algorithms for Blood Glucose Biosensors
Authors: Rippeth John J. , Ho Wah O.
Published: February 2008

Blood glucose monitors and their test strips are used by diabetics worldwide to control and monitor the concentration of glucose in their blood. These deceptively simple, self‐contained diagnostic systems, which can be held in the palm of a hand, contain a collection of software algorithms that monitor the state of the meter, detect the presence of an inserted test strip, determine whether that strip is faulty or has previously been used, and convert the raw data, such as current, received after a glucose measurement from a test strip into a glucose concentration value displayed to the user. These algorithms are developed over a substantial period of time to suit the specific test system, that is, the meter and the strip. Such algorithms are designed to convert the raw data (e.g., current, charge, temperature) from a glucose biosensor strip in response to an applied sample such as blood or a control solution, and provide the user with a value for glucose concentration in the sample in a matter of seconds. Accuracy and precision of the final glucose value is of paramount importance as the result from a meter is intended to prompt the user to seek treatment, that is, inject insulin, take glucose, or to indicate that no treatment is required. In the worst case, a result indicating a high glucose concentration may prompt the user to inject insulin, when in fact the glucose concentration is already low. Such a contrary action could lead to a dramatic reduction in the glucose concentration leading to coma and be potentially life threatening. Such consequences place great responsibility upon manufacturers to ensure that the data algorithms used are fully tested and robust enough to account for any possible influence from the test sample (e.g., blood types such as capillary, venous, arterial, and neonate, hematocrit, drugs, high concentrations of endogenous substances such as cholesterol, triglyceride, and oxygen level) and diverse external factors such as temperature, humidity, altitude, and strip and meter defects.
Glucose Measurement Within Diabetes via “Traditional” Electrochemical Biosensors
Authors: Hall Elizabeth A. H.
Published: February 2008

By 2025, the International Diabetes Foundation estimates 333 million people will have diabetes, making it one of the most important international health issues. Self‐monitoring of blood glucose levels is an integral part of a care regime. This chapter examines the bio–physico–chemical principles involved in developing an enzyme‐based glucose amperometric biosensor. The enzyme reaction pathway is linked to electrochemically reactive species and influence the electrode design and manufacturing technology considered in a measurement system suitable for a self‐test kit.
Examples of Biosensors for the Measurement of Trace Medical Analytes
Authors: Minunni Maria , Tombelli Sara , Centi Sonia , Mascini Marco
Published: February 2008

The most suitable approach as an analytical alternative methodology for the detection of trace clinical analytes is based on affinity sensing, in which the immobilized biological element (receptor) can be an antibody, a receptor (natural or synthetic), a nucleic acid, or an aptamer.

Immunosensors, based on antibody–antigen interactions, and DNA‐based sensing, based on nucleic acid hybridization, are first reported. Finally an aptasensor, based on a new category of relevant receptors, nucleic acid sequences selected in vitro named aptamers, is shown. The reported examples deal with two different transduction principles, electrochemical and piezoelectric, applied to analyte detection of clinical interest. The development of immunosensors for progesterone detection by electrochemical sensing is first reported. Then DNA‐based sensing, for point mutation detection in the b‐globin gene, occurring in b‐thalassemia, is shown. Finally aptasensing for thrombin detection is discussed.

Both single‐use and multiuse sensing have been shown to be suitable for trace analysis in clinical chemistry. Both approaches possess sensitivity, reproducibility, and analysis times compatible with the final application.
Optical Biosensor for the Determination of Trace Pollutants in the Environment
Authors: Gauglitz Güenter , Proll Güenther , Tschmelak Jens
Published: February 2008

A robust, cost‐effective, automated, and immunoassay‐based water analysis system is used to determine several organic pollutants at low concentration levels (a few nanograms per liter) without requiring any time‐consuming sample preconcentration or pretreatment. This system uses total internal reflection fluorescence (TIRF) as the transduction method employing bulk as well as integrated optical waveguides to allow low limits of detection and quantification. More than 20 analytes have been determined. The system allows remote operation and automated data processing; evaluation strategies and the results of field tests are discussed. Pollutant values exceeding predefined threshold values cause an alarm signal via telemetry.
Regulatory and Validation Issues for Biosensors and Related Bioanalytical Technologies
Authors: Sergeev Nikolay V. , Herold Keith E. , Rasooly Avraham
Published: February 2008

Biosensor‐based clinical diagnostics is a dynamic and rapidly evolving area. Biosensors and bioanalytical technologies have the potential to decrease detection time, lower the detection limit, increase specificity and sensitivity, and allow high‐throughput analysis of biologically important molecules. These characteristics position biosensors as extremely powerful tools for in vitro diagnostics (IVD). The main safety concerns of using biosensors in IVD arise from the risk of misdiagnosis due to a false‐positive or false‐negative result, leading to improper patient management and, in some cases, inappropriate public health response. To reduce risk to public health associated with this type of devices, standardization organizations and regulatory agencies, such as the United States Food and Drug Administration (US FDA), developed guidelines, standards, operating procedures, and performance criteria applicable to major aspects of biosensors manufacturing and use.

Since numerous design variations of biosensors for IVD were developed in recent years, in some cases, it is still left to the manufacturer to determine the best methods to attain quality objectives. However, it is mandatory that the key quality system requirements are met or exceeded to enable development of a safe and effective diagnostics device.

In this chapter we overview the key regulatory and validation issues affecting overall performance of biosensors for IVD, such as intended use, accuracy, reproducibility, analytical sensitivity/specificity, cross‐reactivity, interference, sample matrix effects, limits of detection/quantitation, linearity, range, diagnostic sensitivity/specificity, diagnostic efficiency, and predictive positive/negative values.
Smart Hydrogel Materials
Authors: Moschou Elizabeth A. , Bachas Leonidas G. , Daunert Sylvia
Published: February 2008

“Smart” hydrogel materials constitute a new and emerging category of multifunctional materials with unique characteristics. These hydrogels are based on hydrophilic polymeric networks integrating bio/chemical recognition elements, which are able to identify specifically a selected biochemical agent. Their mechanism of response, most commonly based on the formation of physical interactions in the bulk of their polymeric network, translates the recognition of the specific analyte into controlled phase transitions of the material. These controlled phase transitions can be utilized in a series of real‐life applications, like in bioanalysis and medical diagnostics for the development of biosensors and high‐throughput analysis systems. In this chapter, we discuss some examples of smart hydrogel materials that are based on synthetic and natural recognition elements, and that are selective for a variety of analytes, including ions, carbohydrates, drugs, and proteins.
Quantum Dots: Their Use in Biomedical Research and Clinical Diagnostics
Authors: Abramowitz Stanley
Published: February 2008

The physicochemical properties of quantum dots that have been derivatized for biomedical research and molecular diagnostics are discussed. Several examples of their utility are also discussed.
Life Detection within Planetary Exploration: Context for Biosensor and Related Bioanalytical Technologies
Authors: Cullen David C. , Sims Mark R.
Published: February 2008

Is there life on Mars? This is a major question within the scientific community and one that also has broad appeal within the general community. To date, only three missions have attempted to look for life on Mars—the two NASA Viking missions in the mid‐1970s and the recent UK‐led Beagle 2 mission. In all cases no life was detected—in the case of Beagle 2 due to a nonnominal landing event. Our current view of Mars is that historically there was the potential for life to have existed in the Maritain environment and even the possibility of there being current life on Mars. New analytical techniques are therefore being considered for the next generation of Mars rovers and landers to search for evidence of such life. Biosensors in the form of antibody microarray devices are being considered by a number of groups as potential instruments to detect evidence of life in situ in the form of molecular biomarkers within the Martian surface and near subsurface. Such research is at an early stage of development within the context of development of flight‐qualified instrumentation. Given the extreme environments that will be encountered during various phases of a typical Mars mission, careful consideration of the effect of radiation exposure, instrument sterilization, minimization of instrument contamination, long‐term storage, and various thermal environments will be required in instrument development programmes. It is hoped that pushing the development of biosensor technology for life detection in a planetary exploration context will allow both the eventual answer of a fundamental question within society and also provide new developments and approaches that will benefit existing biosensor developments in other areas of application.
Picoscopes, New Label‐Free Biosensors
Authors: Nikitin Petr I.
Published: February 2008

New true direct methods of sensitive detection of bio‐ and chemical reactions on a surface have been developed. The methods are based on measuring changes of a sensor layer thickness due to binding reactions. A transparent plate or a gap between two surfaces of optical materials is used as the sensor layers. The methods allow either employment of microscopic glass slips as biochips without deposition of any metal or dielectric films or direct pumping liquids under test through the sensing gap with recognition layers. For label‐free biosensing, different optical schemes were realized to record receptor‐ligand thickness changes with picometer scale resolution averaged over sensor channels or recognition spots. Biosensors namedPicoscope™ andAffinoscope™ were developed for real‐time detection of several biological agents by different recognition spots or wells with specific receptors on the biochip surface. The biosensors were also tested as efficient tools for optimization of label‐based biosensors, in particular, those based on using of magnetic nanoparticles. Several other biosensing and biomedical applications of the technology are discussed. Application of the devices can be as wide as that of optical microscopes as they provide standard lateral resolution and, in addition, offer much more comprehensive information with outstanding real‐time resolution in depth, for example, for measuring molecular binding kinetics, monitoring of assembling in molecular structures, and so on.
Remembering and retelling stories in individual and collaborative contexts
Authors: Gagnon Lisa M. , Dixon Roger A.
Published: February 2008

Collaborative cognition, in which two or more people work together on a cognitive task, may be typical of everyday life, and may even represent an important aspect of everyday cognitive adaptation for older adults. We examined collaborative memory for stories by comparing younger (n = 64) and older (n = 66) individuals and dyads with collaborative performance produced by married spouses and stranger dyads. Overall, across four collaborative recall products (two positive and two negative performance indicators), some evidence for our hypothesis of general or selective collaborative effectiveness was observed. Moreover, such evidence was obtained at both an immediate and delayed recall episode. Discussion includes applications, limitations and suggestions for future research. Copyright © 2008 John Wiley & Sons, Ltd.
Who can judge the accuracy of eyewitness statements? A comparison of professionals and lay‐persons
Authors: Lindholm Torun
Published: February 2008

Research suggests that people have difficulty estimating eyewitness accuracy. It is not known whether groups with professional experience of judging eyewitness memory are better at making such judgements than lay‐persons. In the current study, police detectives, judges and lay‐persons judged accuracy of responses to cued recall questions from ethnic in‐ and out‐group witnesses who genuinely tried to remember a crime. Responses were presented in videotape or as transcripts. Detectives outperformed the other groups in discrimination accuracy, and participants performed better when statements were presented in transcribed than in videotaped format. Judges used a liberal response criterion overall, whereas detectives and lay‐persons were more liberal when judging out‐group than in‐group witnesses. Findings indicate that there are observable cues to witnesses' accuracy, that specific professional groups have more knowledge of these cues than others, and that judgements of accuracy based on transcripts rather than live testimony would increase quality of legal decisions. Copyright © 2008 John Wiley & Sons, Ltd.
Genetic and environmental influences on pubertal timing assessed by height growth
Authors: Wehkalampi Karoliina , Silventoinen Karri , Kaprio Jaakko , Dick Danielle M. , Rose Richard J. , Pulkkinen Lea , Dunkel Leo
Published: February 2008

Secular trends towards earlier puberty, possibly caused by new environmental triggers, provide a basis for periodic evaluation of the influence and interaction of genetic and environmental effects on pubertal timing. In such studies, a practical marker that reflects timing of puberty in both genders needs to be used. We investigated genetic and environmental influences on pubertal timing by using change in the relative height between early and late adolescence (HD:SDS, height difference in standard deviations) as a new marker of pubertal timing. HD:SDS correlated well with age at peak height velocity in a population of men and women with longitudinal growth data. In 2,309 twin girls and 1,828 twin boys, HD:SDS was calculated between height SDs at age 11.5 and 17.5, and 14.0 and 17.5 years, respectively. Quantitative genetic models for twin data were fitted to estimate the genetic contribution to HD:SDS. We also investigated whether the same genetic factors influenced individual differences between HD:SDS and development of secondary sex characteristics prospectively collected by pubertal development scale (PDS). Genetic effects contributed to 86 and 82% of the variance in HD:SDS in girls and boys, respectively, when using the same model including additive genetic and specific environmental factors. In girls, 30% and in boys, 49% of the genetic factors affecting PDS and HD:SDS were the same. Future comparison of the results of periodic evaluations allows estimation of possible changes in the effects of environment on timing of puberty. In such studies, HD:SDS can be used as a practical marker of pubertal timing. Am. J. Hum. Biol., 2008. © 2008 Wiley‐Liss, Inc.
Influence of residual peroxide on the degradation of peroxide‐crosslinked ethylene–propylene–diene rubber
Authors: Nakayama Kazumi , Watanabe Tomoko , Ohtake Yoshito , Furukawa Mutsuhisa
Published: February 2008

The influence of residual peroxide on the degradation of ethylene–propylene–diene rubber (EPDM) and detection methods for undercrosslinking were investigated. The undercrosslinking of peroxide‐crosslinked EPDM could be detected by the measurement of the heat generated by the crosslinking reaction due to residual crosslinking agent with differential scanning calorimetry, not by the determination of its amount, the reaction of which was found to correlate with the amounts of remaining dicumyl peroxide (DCP) and triallyl isocyanurate. As to the DCP‐crosslinked EPDM in the undercrosslinking state, softening degradation occurred more remarkably than hardening degradation, whereas the crosslinking agent remained in the rubber. By surface analysis of the aged DCP‐crosslinked EPDM with Fourier transform infrared spectroscopy, we discovered that the oxidative degradation of the undercrosslinked EPDM occurred faster than in the EPDM without crosslinking agent remaining. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Effect of saline degradation on the mechanical properties of vinyl ester matrix composites reinforced with glass and natural fibers
Authors: Nicolai F. N. P. , Botaro V. R. , Lins V. F. Cunha
Published: February 2008

One important application of polymeric composites reinforced with natural fibers is in the area of naval engineering design. The objective of this work was to study the influence of saline degradation on the mechanical properties of vinyl ester matrix composites reinforced with glass, sisal, and coconut fibers and natural fibers modified with bitumen. All samples presented mass loss after exposure in a salt spray chamber. All materials, except the composite reinforced with coconut–bitumen, showed a decrease in toughness after a salt spray test. The fracture of the vinyl ester resin with sisal and sisal–bitumen fibers showed a fiber bridging mechanism. These materials showed the highest value of toughness among the materials studied. The presence of fiber pullout was observed in the samples of vinyl ester resin reinforced with glass, coconut, and coconut fibers covered with bitumen. In these samples, poor adhesion between the fiber and matrix was observed. The treatment of fibers with bitumen increased the mass loss and decreased the stability of samples in a saline atmosphere. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008
The facial expression musculature in primates and its evolutionary significance
Authors: Burrows Anne M.
Published: February 2008

Facial expression is a mode of close‐proximity non‐vocal communication used by primates and is produced by mimetic/facial musculature. Arguably, primates make the most‐intricate facial displays and have some of the most‐complex facial musculature of all mammals. Most of the earlier ideas of primate mimetic musculature, involving its function in facial displays and its evolution, were essentially linear “scala natural” models of increasing complexity. More‐recent work has challenged these ideas, suggesting that ecological factors and social systems have played a much larger role in explaining the diversity of structures than previously believed. The present review synthesizes the evidence from gross muscular, microanatomical, behavioral and neurobiological studies in order to provide a preliminary analysis of the factors responsible for the evolution of primate facial musculature with comparisons to general mammals. In addition, the unique structure, function and evolution of human mimetic musculature are discussed, along with the potential influential roles of human speech and eye gaze. BioEssays 30:212–225, 2008. © 2008 Wiley Periodicals, Inc.
Gene und Allele. Zwei Begriffe – viele Definitionen
Authors: Paulsen Martina , Nellen Wolfgang
Published: February 2008

Die rasante Entwicklung von Genetik und Molekularbiologie hat eine unerwartet komplexe Organisation des Genoms aufgedeckt. Es zeigt sich, dass die Funktionen des Genoms nicht mehr ausschließlich durch proteincodierende Gene beschrieben werden können. Der Genbegriff umfasst heute auch Nukleotidsequenzen, die für eine Vielfalt verschiedener RNAs mit völlig unterschiedlichen Funktionen codieren. Ebenso beschränkt sich der Allelbegriff heute nicht ausschließlich auf Genvarianten, die Veränderungen in proteincodierenden Sequenzen aufweisen, sondern umfasst ein weites Spektrum an genetischen und epigenetischen Variationen. Gene und Allele sind also offensichtlich sehr komplexe Einheiten und entsprechend breit fallen heute die Definitionen dieser Begriffe aus. Weil dies zu sprachlichen Missverständnissen führen kann, muss man sich der zwangsläufigen Unschärfen des Gen‐ und Allelbegriffs bewusst sein.
Coenraad Jacob Temminck
Authors: Irsch Wilhelm
Published: February 2008

Die Freude am Sammeln von Naturalien stand am Anfang der Bemühungen, den Lebewesen der Erde ein gewisses Ordnungsprinzip zu geben. Sie war nirgendwo sonst so verbreitet wie in den Niederlanden seit den Jahren der ersten “Indianischen Schifffahrten”. Coenraad Jacob Temminck, einer der Pioniere und Wegbereiter moderner Naturhistorischer Sammlungen und Museen, starb vor 150 Jahren.
Anatomy of thoracic splanchnic nerves for surgical resection
Authors: Yang Hee‐Jun , Gil Young‐Chun , Lee Woo‐Jung , Kim Tae‐Jong , Lee Hye‐Yeon
Published: February 2008

Thoracic splanchnic nerves conduct pain sensation from the abdominal organs around the celiac ganglion. Splanchnicectomy is the procedure used mainly for the control of intractable visceral pain. Forty‐six human posterior thoracic walls were dissected. The formation pattern, course, and incidence of communication of the thoracic splanchnic nerves were investigated. The greater splanchnic nerves (GSNs) were formed by nerve branches from the T4–T11 thoracic sympathetic ganglia and the most common type was formed by T5–T9 (21.7%). The uppermost branches originated from T4–T9 while the lowermost branches emanated from the T7–T11. Two to seven ganglia contributed to the GSNs. In 54.3% of the specimens, at least one ganglion in the GSN‐tributary ganglionic array did not branch to the GSN. The lesser splanchnic nerves (LSNs) were formed by the nerve branches of the T8–T12 thoracic sympathetic ganglia and the most common type was formed by T10 and T11 (32.6%). One to five ganglia were involved in the LSNs. The least splanchnic nerves (lSNs) were composed of branches from the T10–L1 thoracic sympathetic ganglia and the most common type was composed of nerve branches from T11 and T12 or from T12 only (each 30.4%). One to three ganglia were involved in the lSNs. In 54.3% of the specimens, interconnection between the GSNs and the LSNs existed, bringing the possible bypass around the transection of the GSNs. The splanchnic nerves that appear in textbooks occurred in a minority of our specimens. We provided expanded anatomical data for splanchnicectomy in this report. Clin. Anat. 21:171–177, 2008. © 2008 Wiley‐Liss, Inc.
Anatomical basis of central venous catheter fracture
Authors: Jensen Mark O.
Published: February 2008

Central venous catheter fracture is a rare complication of long‐term indwelling subclavian venous access. Subclavian vein access has been the recommended approach for placing central venous catheters. The anatomical landmark method for subclavian access remains a highly successful and nonequipment‐dependent method for rapid central access. More recently, the internal jugular vein approach has emerged as the preferred route for long‐term central venous access. However, variations in internal jugular vein anatomy make the landmark method less reliable. Use of two‐dimensional real‐time ultrasound during internal jugular vein access is associated with better success, a lower complication rate, and faster access. A case of central venous catheter fracture initiated an internal review of long‐term central venous access procedures. We have converted to a predominantly internal jugular vein approach. This case report and literature review may assist other physicians and institutions in re‐evaluating long‐term central venous access protocols. Clin. Anat. 21:106–110, 2008. © 2008 Wiley‐Liss, Inc.
Assembly and Heterologous Expression of the Coumermycin A1 Gene Cluster and Production of New Derivatives by Genetic Engineering
Authors: Wolpert Manuel , Heide Lutz , Kammerer Bernd , Gust Bertolt
Published: February 2008

Many secondary metabolites of clinical importance have been isolated from different Streptomyces species. As most of the natural producers remain difficult to handle genetically, heterologous expression of an entire biosynthetic gene cluster in a well characterised host allows improved possibilities for modifications of the desired compound by manipulation of the biosynthetic genes. However, the large size of a functional gene cluster often prevents its direct cloning into a single cosmid clone. Here we describe a successful strategy to assemble the entire coumermycin A1 biosynthetic gene cluster (38.6 kb) into a single cosmid clone by λ RED recombination technology. Heterologous expression of the reconstituted gene cluster in Streptomyces coelicolor M512 resulted in the heterologous production of coumermycin A1. Inactivation of the methyltransferase gene couO—responsible for the C‐methylation at the 8‐positions of the aminocoumarin moieties in coumermycin A1—and heterologous expression of the modified cluster resulted in an accumulation of a C‐8‐unsubstituted coumermycin A1 derivative. Subsequent expression of the halogenase gene clo‐hal from the clorobiocin gene cluster in the heterologous producer strain led to the formation of two new hybrid antibiotics, containing either one or two chlorine atoms. The identities of the new compounds were verified by LC‐MS, and their antibacterial activities were tested against Bacillus subtilis in an agar diffusion assay.
Evolving strategies for the treatment of valvular heart disease: Preclinical and clinical pathways for percutaneous aortic valve replacement
Authors: Fann James I. , Chronos Nicolas , Rowe Stanton J. , Michiels Rob , Lyons Bernard E. , Leon Martin B. , Kaplan Aaron V.
Published: February 2008

To decrease the morbidity associated with conventional surgery for calcific aortic stenosis, there has been increasing interest in catheter‐based treatment using a stent or frame mounted bioprosthetic valve. Critical to its success is knowledge of pathoanatomy, risk of embolization of calcific debris, and issues associated with device anchoring and paravalvular leaks. In the absence of a chronic animal model of aortic stenosis, development of a catheter‐based device has been an iterative process based on experimental and early clinical data gathered abroad, where marketing may be permitted with less clinical data than required in the United States. This process has persuaded many companies to circumvent the time delays occasioned by the FDA regulatory validation of iterative design changes by performing initial studies outside the United States. Because percutaneous aortic valve replacement is considered a Class III device, premarket approval, including defining the patient population, inclusion and exclusion criteria, control population, and interpretable clinical endpoints, is required. In the early clinical experience, percutaneous aortic valve replacement has been directed at high‐risk patients who were considered “very poor” or “non‐surgical” candidates. Defining and identifying patients for the clinical trial may be challenging, in part because of the difficult selection of an appropriate control group, e.g., conventional aortic valve replacement, best medical management, and/or balloon valvuloplasty. © 2008 Wiley‐Liss, Inc.
Insights into Sonogashira Cross‐Coupling by High‐Throughput Kinetics and Descriptor Modeling
Authors: an der Heiden Markus R. , Plenio Herbert , Immel Stefan , Burello Enrico , Rothenberg Gadi , Hoefsloot Huub C. J.
Published: February 2008

A method is presented for the high‐throughput monitoring of reaction kinetics in homogeneous catalysis, running up to 25 coupling reactions in a single reaction vessel. This method is demonstrated and validated on the Sonogashira reaction, analyzing the kinetics for almost 500 coupling reactions. First, one‐pot reactions of phenylacetylene with a set of 20 different meta‐ and para‐substituted aryl bromides were analyzed in the presence of 17 different Pd–phosphine complexes. In addition, the temperature‐dependent Sonogashira reactions were examined for 21 different ArX (X=Cl, Br, I) substrates, and the corresponding activation enthalpies and entropies were determined by means of Eyring plots: ArI (ΔH≠=48–62 kJ mol−1; ΔS≠=−71–−39 J mol−1 K; NO2→OMe), ArBr (ΔH≠=54–82 kJ mol−1, ΔS≠=−55–11 J mol−1 K), and ArCl (ΔH≠=95–144 kJ mol−1, ΔS≠=−6–100 J mol−1 K). DFT calculations established a linear correlation of ΔH≠ and the Kohn–Sham HOMO energies of ArX (X=Cl, Br, I) and confirmed their involvement in the rate‐limiting step. However, despite different CX bond energies, aryl iodides and electron‐deficient aryl bromides showed similar activation parameters.
Heteropoly Acid Encapsulated SBA‐15/TiO2 Nanocomposites and Their Unusual Performance in Acid‐Catalysed Organic Transformations
Authors: Sawant Dhanashri P. , Justus Josena , Balasubramanian Veerappan V. , Ariga Katsuhiko , Srinivasu Pavuluri , Velmathi Sivan , Halligudi Shivappa B. , Vinu Ajayan
Published: February 2008

The preparation of SBA‐15/TiO2 nanocomposites with different loadings of Keggin‐type 12‐tungstophosphoric acid (TPA) nanocrystals in their mesochannels through a simple and effective vacuum impregnation method is reported for the first time. The catalysts have been characterised by various sophisticated techniques, including XRD, HRSEM, and TEM. It has been found that the acidity and the textural parameters of the nanocomposites can be controlled by simply changing the loadings of TPA and TiO2 or the calcination temperature. TPA and TiO2 loadings of 15 and 22.4 wt %, respectively, and a calcination temperature of 1123 K have proved to be optimal for obtaining mesoporous nanocomposite materials with the highest acidity. Moreover, the activities of these catalysts in promoting hydroamination as well as Mannich and Claisen rearrangement reactions have been extensively investigated. The results show that the amount of TPA has a great influence on the activity of the nanocomposites in all of the reactions studied. The effects of other reaction parameters, such as temperature and reaction time, on the conversion and product selectivity have also been studied in detail. A kinetic analysis of the formation of the products under various reaction conditions is presented. It has been found that the activity of the nanocomposite composed of 15 wt % TPA deposited on 22.4 wt of TiO2 on SBA‐15 in promoting the studied reaction is remarkably higher than the catalytic activities shown by pure TPA, TiO2‐loaded SBA‐15, or TPA‐loaded SBA‐15. The results obtained have indicated that the acidity and the structural control of the nanocomposite materials are highly critical for obtaining excellent catalytic activity, and the presented highly acidic nanocomposites are considered to show great potential for use as catalysts in promoting many acid‐catalysed organic transformations.
Platinated Copper(3‐Clip‐Phen) Complexes as Effective DNA‐Cleaving and Cytotoxic Agents
Authors: Özalp‐Yaman Şeniz , de Hoog Paul , Amadei Giulio , Pitié Marguerite , Gamez Patrick , Dewelle Janique , Mijatovic Tatjana , Meunier Bernard , Kiss Robert , Reedijk Jan
Published: February 2008

The synthesis and biological activity of three heteronuclear platinum–copper complexes based on 3‐Clip‐Phen are reported. These rigid complexes have been designed to alter the intrinsic mechanism of action of both the platinum moiety and the Cu(3‐Clip‐Phen) unit. The platinum centers of two of these complexes are coordinated to a 3‐Clip‐Phen moiety, an ammine ligand and two chlorides, which are either cis or trans to each other. The third complex comprises two 3‐Clip‐Phen units and two chloride ligands bound in a trans fashion to the platinum ion. DNA‐cleavage experiments show that the complexes are highly efficient nuclease agents. In addition, a markedly difference in their aptitude to perform direct double‐strand cleavage is observed, which appears to be strongly related to the ability of the platinum unit to coordinate to DNA. Indeed, complex 6 is unable to coordinate to DNA, which is reflected by its incapability to carry out double‐strand breaks. Nonetheless, this complex exhibits efficient DNA‐cleavage activity, and its cytotoxicity is high for several cell lines. Complex 6 shows better antiproliferate activity than both cisplatin and Cu(3‐Clip‐Phen) toward most cancer cell lines. Furthermore, the cytotoxicity observed for 1 is for most cell lines close to that of cisplatin, or even better. Cu(3‐Clip‐Phen) induces very low cytotoxic effects, but a marked migratory activity. Complex 6 presents DNA‐cleavage properties comparable to the one of Cu(3‐Clip‐Phen), but it does not show any migratory activity. Interestingly, both Cu(3‐Clip‐Phen) and 6 induces vacuolisation processes in the cell in contrast to complex 1 and cisplatin. Thus, the four complexes cisplatin tested, Cu(3‐Clip‐Phen), 1 and 6 stimulate different cellular responses.
ChemInform Abstract: Chromium‐Doped Germanium Clusters CrGen (n = 1—5): Geometry, Electronic Structure, and Topology of Chemical Bonding
Authors: Hou Xin‐Juan , Gopakumar G. , Lievens Peter , Nguyen Minh Tho
Published: February 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Synthesis and Rietveld Structure Refinement of Americium Pyrochlore Am2Zr2O7.
Authors: Belin R. C. , Valenza P. J. , Raison P. E. , Tillard M.
Published: February 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: High Temperature Transport and Thermoelectric Properties of Ag‐Substituted Ca3Co4O9+δ System.
Authors: Wang Yang , Sui Yu , Cheng Jinguang , Wang Xianjie , Miao Jipeng , Liu Zhiguo , Qian Zhengnan , Su Wenhui
Published: February 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Synthesis and Characterization of Electron and Hole Doped Ternary Palladium Oxide: Sr1‐xAxPd3O4 (A: Na, Bi).
Authors: Ozawa T. C. , Matsushita A. , Hidaka Y. , Taniguchi T. , Mizusaki S. , Nagata Y. , Noro Y. , Samata H.
Published: February 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: A New Phase MgNi3 Synthesized by Mechanical Alloying.
Authors: Liu Guoyuan , Xi Shengqi , Ran Guang , Zuo Kesheng , Li Pengliang , Zhou Jingen
Published: February 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: The First Asymmetric Esterification of Free Carboxylic Acids with Racemic Alcohols Using Benzoic Anhydrides and Tetramisole Derivatives: An Application to the Kinetic Resolution of Secondary Benzylic Alcohols.
Authors: Shiina Isamu , Nakata Kenya
Published: February 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: New Chiral Diamino‐bis(tert‐thiophene): An Effective Ligand for Pd‐ and Zn‐Catalyzed Asymmetric Transformations.
Authors: Bandini Marco , Melucci Manuela , Piccinelli Fabio , Sinisi Riccardo , Tommasi Simona , Umani‐Ronchi Achille
Published: February 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Rhodium‐Catalyzed Addition of Aryl Boronic Acids to 1,2‐Diketones and 1,2‐Ketoesters.
Authors: Ganci Gregory R. , Chrisholm John D.
Published: February 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Reduction of Pentafluorophenyl Esters to the Corresponding Primary Alcohols Using Sodium Borohydride.
Authors: Papavassilopoulou Eleni , Christofis Petros , Terzoglou Despina , Moutevelis‐Minakakis Panagiota
Published: February 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Ruthenium‐Catalyzed Synthesis of Tertiary Amines from Alcohols.
Authors: Hamid M. Haniti S. A. , Williams Jonathan M. J.
Published: February 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Microwave‐Assisted Hydroaminomethylation of Alkenes.
Authors: Petricci Elena , Mann Andre , Salvadori Jessica , Taddei Maurizio
Published: February 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Synthesis of Resorcin[4]arene Cavitands by Ring‐Closing Metathesis.
Authors: Parulekar Sumedh N. , Muppalla Kirankirti , Fronczek Frank R. , Bisht Kirpal S.
Published: February 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: An Alkoxide‐Directed Alkyne—Allene Cross‐Coupling for Stereoselective Synthesis of 1,4‐Dienes.
Authors: Shimp Heidi L. , Micalizio Glenn C.
Published: February 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Gold(III) Catalyzed Oxidation of Sulfides to Sulfoxides with Hydrogen Peroxide.
Authors: Yuan Yu , Bian Yubo
Published: February 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Copper Triflate Catalyzed Regioselective Alkylation of Pyrrole: Conversion of 2‐Alkylates Pyrroles to Novel Pyrrolizine Derivatives by Self‐Cyclization.
Authors: Unaleroglu Canan , Aytac Sertan , Temelli Baris
Published: February 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Highly Diastereoselective Palladium‐Catalyzed Cyclizations of 3,4‐Allenylic Hydrazines and Organic Halides—Highly Stereoselective Synthesis of Optically Active Pyrazolidine Derivatives and the Prediction of the Stereoselectivity.
Authors: Yang Qing , Jiang Xuefeng , Ma Shengming
Published: February 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.