bluuebunny/crossref_metadata_2025 huggingface dataset:
Folding of Coordination Polymers into Double‐Stranded Helical Organization
Authors: Kim Ho‐Joong , Lee Eunji , Kim Min Gyu , Kim Min‐Cheol , Lee Myongsoo , Sim Eunji
Published: April 2008

Self‐assembling coordination polymers based on PdII and CuII metal ions were prepared from complexation of a bent‐shaped bispyridine ligand and a corresponding transition metal. These coordination polymers were observed to self‐assemble into supramolecular structures that differ significantly depending on the coordination geometry of the metal center. The polymer based on PdII self‐assembles into a layer structure formed by bridging bispyridine ligands connected in a trans‐position of the square‐planar coordination geometry of metal center. In contrast, the polymer based on CuII adopts a double‐helical conformation with regular grooves, driven by interstranded, copper–chloride dimeric interaction. The double‐stranded helical organization is further confirmed by structure optimization from density functional theory with aromatic framework, showing that the optimized double‐helical structure is energetically favorable and consistent with the experimental results. These results demonstrate that weak metal–ligand bridging interactions can provide a useful strategy to construct stable double‐stranded helical nanotubes.
Reduction of phosphorylated histone H3 serine 10 and serine 28 cell cycle marker intensities after DNA damage
Authors: Ozawa Kazuo
Published: April 2008

Phosphorylated histone H3 at serine 10 and serine 28 (H3Ser10 and H3Ser28) have been recognized as cell cycle markers to evaluate the late‐G2/M status of cell and tissue samples. I report about the reduction phenomena of H3Ser10 and Ser28 phosphorylation (H3Ser10P and 28P) at the late‐G2 through M cell cycle phases in association with DNA damage caused by hydrogen peroxide (H2O2). The levels of H3Ser10P and Ser28P decreased between 15 and 60 min after H2O2 addition in an inverse correlation manner with H2AX Ser139 phosphorylation (γH2AX). Experiments using wortmannin suggested that the reduction events of H3Ser10P/28P are under the control of phosphatidylinositol 3‐kinase‐like kinases. Fluorescence microscopic observation showed that H3Ser10 and Ser28 on telomeric portions of condensed M‐phase chromosomes retained their strongly phosphorylated status even after 60 min of H2O2 treatment. In addition, these chromosome parts were poorly γH2AX positive showing mutually exclusive distribution patterns between H3Ser10P/28P and γH2AX. Considering these data, I hypothesize that the reduction of the H3Ser10P/28P is a part of the DNA damage response processes. It is advisable to pay careful attention to these phenomena at the time of designing cell cycle assay protocols with H3Ser10P or Ser28P mitosis markers when DNA damaging process is expected to occur. © 2008 International Society for Advancement of Cytometry
Contrasting cytoskeletal regulation of MHC class II peptide presentation by human B cells or dendritic cells
Authors: Delaguillaumie Alix , Marin‐Esteban Viviana , Setterblad Niclas , Leh Laurence Jeanson , Assier Eric , Gelin Catherine , Charron Dominique , Galy Anne , Mooney Nuala
Published: April 2008

MHC class II‐mediated antigen presentation by B lymphocytes or dendritic cells (DC) initiates CD4+ T lymphocyte activation. In B lymphocytes, MHC class II peptide presentation has been characterised by recruitment of MHC class II, F‐actin and lipid rafts to the B cell–T cell immunological synapse. We now show that MHC class II engagement in B lymphocytes induced lipid raft‐independent Rho and Rac activation and that inhibition of either Rho‐GTPase activation or actin polymerisation in the B cell abrogated T cell activation without altering B cell–T cell conjugate formation. Short‐hairpin RNA studies excluded a role for the Cdc42 effector Wiskott–Aldrich syndrome protein. In contrast, antigen presentation by DC was Rho‐GTPase‐independent although actin was recruited to the DC–T cell interaction site. Moreover, actin depolymerisation in the DC significantly increased T cell activation without altering the number of DC–T cell conjugates. Finally we show that stable recruitment of HLA‐DR to the site of the immunological synapse is not a uniform observation in DC and demonstrate reduced HLA‐DR expression at the site of microtubule organising centre polarization. Therefore although actin accumulates in DC and B lymphocytes at the immunological synapse with antigen‐specific T lymphocytes, this does not reflect comparable functional roles of their actin cytoskeletons in antigen presentation.
Microcapillary electrophoresis chips utilizing controllable micro‐lens structures and buried optical fibers for on‐line optical detection
Authors: Hsiung Suz‐Kai , Lee Chun‐Hong , Lee Gwo‐Bin
Published: April 2008

In this study, a new design of a controllable micro‐lens structure capable of the enhancement of LIF detection system has been demonstrated, which can be further integrated with buried optical fibers on a micro‐CE chip for sample separation and detection. Two pneumatic side‐chambers were placed between a micro‐CE channel and an optical fiber channel. The intervals between the side‐chamber and the microchannel were used to form two surfaces of the controllable micro‐lens structure. Deformations of the two surfaces can be generated after pressurized index‐matching fluid was injected into the pneumatic side‐chambers. The side‐chambers can be deflected as a double convex lens to focus both the excitation light source and the fluorescent emission signal. The profile and the focal length of the micro‐lens structure can be actively adjusted by applying different liquid pressures so that biosamples with a low concentration can be detected. Using low‐cost polymeric materials such as polydimethylsiloxane, rapid and reliable fabrication techniques involving standard lithography and replication process was employed for the formation of the proposed chip device. Experimental results revealed the controllable micro‐lens structure can be successfully deformed as a convex lens to focus the laser light source and the collected fluorescence signal can be enhanced accordingly. The power amplitude of excitation laser light can be enhanced by 5.4‐fold. FITC dye and DNA markers were then utilized for micro‐CE testing. The results indicated that the signal amplitude could be enhanced 2.5‐fold when compared to the case without the activation of the micro‐lens. According to the experimental results, the developed device has a great potential to be integrated with other microfluidic devices for further biomedical applications.
Coupling a microchip with electrospray ionization quadrupole time‐of‐flight mass spectrometer for peptide separation and identification
Authors: Li Hai‐Fang , Liu Jiangjiang , Cai Zongwei , Lin Jin‐Ming
Published: April 2008

The present study reports a simple method of coupling a glass microchip to an electrospray ionization (ESI) quadrupole time‐of‐flight mass spectrometer (QTOF‐MS) for separation and identification of peptides. A sheath‐flow electrospray interface was constructed based on attaching a short fused‐silica capillary to the microchip. The dead volume at the interface was effectively reduced by wet etching an approximate flat‐bottom capillary insertion channel coaxial to the end of separation microchannel and using a wire‐controlled epoxy‐blocking attachment method. The makeup liquid and neb gas were coaxially pumped through two stainless‐steel tees to maintain a stable and efficient electrospray. The coupled microchip/ESI‐QTOF‐MS system was successfully used to carry out electrophoresis separation of peptides and ESI‐QTOF‐MS identification.
Sensitive, label‐free protein assay using 1‐ethyl‐3‐methylimidazolium tetrafluoroborate‐supported microchip electrophoresis with laser‐induced fluorescence detection
Authors: Xu Yuanhong , Li Jing , Wang Erkang
Published: April 2008

Based on the dimer–monomer equilibrium movement of the fluorescent dye Pyronin Y (PY), a rapid, simple, highly sensitive, label‐free method for protein detection was developed by microchip electrophoresis with LIF detection. PY formed a nonfluorescent dimer induced by the premicellar aggregation of an anionic surfactant, SDS, however, the fluorescence intensity of the system increased dramatically when proteins such as BSA, bovine hemoglobin, cytochrome c, and trypsin were added to the solution due to the transition of dimer to fluorescent monomer. Furthermore, 1‐ethyl‐3‐methylimidazolium tetrafluoroborate (EMImBF4) instead of PBS was applied as running buffers in microchip electrophoresis. Due to the excellent properties of EMImBF4, not only nonspecific protein adsorption was more efficiently suppressed, but also approximately ten‐fold higher fluorescence intensity enhancement was obtained than that using PBS. Under the optimal conditions, detection limits for BSA, bovine hemoglobin, cytochrome c, and trypsin were 1.00×10−6, 2×10−6, 7×10−7, and 5×10−7 mg/mL, respectively. Thus, without covalent modification of the protein, a protein assay method with high sensitivity was achieved on microchips.
Mobile communication array processing based on radial‐basis function neural network and fractional lower order statistics
Authors: Zha Daifeng
Published: April 2008

Alpha stable distribution is better for modelling impulsive noises than Gaussian distribution in signal processing. This class of process has no close form of probability density function and finite second order moments. This paper addresses the direction of arrival estimation and beamforming problems of mobile communication system with linear antenna arrays in high impulsive noise environment. In order to reduce the computational complexity, the problems of DOA and beamforming are approached as a nonlinear mapping that can be modelled using a suitable radial‐basis function neural network (RBFNN). This paper also proposes the application of a three–layer RBFNN to perform the DOA estimation and beamforming in presence of alpha stable distribution noises. The performance of the network is compared to that of the fractional lower order statistics based algorithms. Simulations show that the RBFNN is appropriate to approach the DOA estimation and beamforming. At the same time, the RBFNN substantially reduces the computation complexity. Copyright © 2008 John Wiley & Sons, Ltd.
CLUMPHAP: a simple tool for performing haplotype‐based association analysis
Authors: Knight Jo , Curtis David , Sham Pak C.
Published: April 2008

The completion of the HapMap Project and the development of high‐throughput single nucleotide polymorphism genotyping technologies have greatly enhanced the prospects of identifying and characterizing the genetic variants that influence complex traits. In principle, association analysis of haplotypes rather than single nucleotide polymorphisms may better capture an underlying causal variant, but the multiple haplotypes can lead to reduced statistical power due to the testing of (and need to correct for) a large number of haplotypes. This paper presents a novel method based on clustering similar haplotypes to address this issue. The method, implemented in the CLUMPHAP program, is an extension of the CLUMP program designed for the analysis of multi‐allelic markers (Sham and Curtis [1995] Ann. Hum. Genet. 59(Pt1):97–105). CLUMPHAP performs a hierarchical clustering of the haplotypes and then computes the χ2 statistic between each haplotype cluster and disease; the statistical significance of the largest of the χ2 statistics is obtained by permutation testing. A significant result suggests that the presence of a disease‐causing variant in the haplotype cluster is over‐represented in cases. Using simulation studies, we have compared CLUMPHAP and more widely used approaches in terms of their statistical power to identify an untyped susceptibility locus. Our results show that CLUMPHAP tends to have greater power than the omnibus haplotype test and is comparable in power to multiple regression locus‐coding approaches. Genet. Epidemiol. 2008. © 2008 Wiley‐Liss, Inc.
Electrospinning fabrication of high‐trackable catheter tip with gradually graded or gradient flexibility
Authors: Matsuda Takehisa , Kawahara Daigo
Published: April 2008

Increasing demand for a flexible catheter tip exists in the rapidly growing fields of vascular and interventional radiology. This article describes a fabrication technology producing a catheter tip with gradually graded or gradient flexibility. Based on deflection mechanics of a tubular construct, three models were incorporated into structural designs. The models included graded wall thickness, tapered shape, or graded Young's moduli. Electrospinning using elastomeric polymer [poly(L‐lactide‐co‐ε‐caprolactone), polyurethane] solutions on a transversely and rotationally moving mandrel enabled preparation of three prototype tubular tips by either regio‐specific control of wall thickness, tapered mandrel, or regiospecific deposition of polyurethanes with different Young's moduli. All prototype tips exhibited high flexibility at tip ends, as verified using a bifurcated vessel model. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Bone morphogenetic protein‐7 regulates differentially the mRNA expression of bone morphogenetic proteins and their receptors in rat achilles and patellar tendon cell cultures
Authors: Yeh Lee‐Chuan C. , Tsai Alicia D. , Lee John C.
Published: April 2008

Previous animal studies have suggested that certain bone morphogenetic proteins (BMPs) may be useful therapeutically in treating tendon healing. To better understand the relationship among the different BMPs in the healing process, we initiated the present study to examine the effects of a member of the BMP family, BMP‐7 (also called Osteogenic Protein‐1) on the temporal and spatial expression patterns of other BMPs and the BMP receptors in cell cultures of adult rat Achilles and Patellar tendons. Cultures from both tendon types expressed detectable but variable levels of biochemical markers characteristics of tendons. RNAs coding for type II collagen and transcription factors Six1, Scleraxis, and Tendin were detected in both types of cultures. Distinct patterns of expression of several BMP members and their receptors were observed in these cultured cells and BMP‐7 exerted differential effects on their expression. The findings may have implications in the treatment of different tendon injuries with BMPs. J. Cell. Biochem. 104: 2107–2122, 2008. © 2008 Wiley‐Liss, Inc.
Cadmium accumulation in Agaricusblazei Murrill
Authors: Huang Jian Cheng , Li Kai Ben , Yu Ying Rui , Wu Hanwen , Liu De Li
Published: April 2008

BACKGROUND: Agaricus blazei Murrill has become a popular food source of high nutritional and medicinal value in many Asian countries. However, there are growing health concerns on cadmium (Cd) accumulation by A. blazei. Experiments were conducted to investigate Cd accumulation patterns in A. blazei and to identify key factors contributing to Cd accumulation.

RESULTS: Cd concentrations in the substrates and subsequent fruit bodies declined rapidly after the first, second and third harvest wave. A quick rinse of the fruit bodies in water reduced the Cd concentration by 27–54% depending on the strain. The Cd concentration in the fruit bodies decreased as the fruit body yield m−2 or fruit body number m−2 increased, while it increased as the substrate Cd content or fruit body size increased. Cd accumulation was positively associated with phosphorus (P) uptake.

CONCLUSION: The results suggests that, in the A. blazei‐growing region studied, Cd and P concentrations in the substrates and casing soil should be reduced in order to effectively minimise Cd accumulation in the fruit bodies. It is also necessary to improve fruit body yield by increasing the number of medium‐sized fruit bodies. Overgrowth of individual fruit bodies stimulates Cd accumulation in A. blazei. Copyright © 2008 Society of Chemical Industry
Optimal provisioning for bank loan losses in a robust control framework
Authors: Gideon F. , Mukuddem‐Petersen J. , Mulaudzi M. P. , Petersen M. A.
Published: April 2008

The concept of robustness started emerging in financial and economics literature in the late 1990s. In particular, principles from robust control theory have been used by economic decision makers to investigate the fragility of decision rules across a range of economic models. In line with this tendency, our article applies principles from robustness to a situation where the decision maker is a bank owner and the decision rule determines the optimal provisioning strategy for loan losses. In this regard, we recognize that bank provisions are made for debts that have been identified as impaired or non‐performing. Our first objective is to formulate a dynamic banking loan loss model involving a provisioning portfolio consisting of provisions for expected losses and loan loss reserves for unexpected losses. Here, unexpected loan losses and provisioning for expected losses are modeled via a compound Poisson process and an exponential Lévy process, respectively. Historical evidence from Organization for Economic Corporation and Development countries assists in confirming some of the modeling choices made. This setup naturally leads to a finite‐horizon provisioning problem that may be solved via a mixed optimal/robust control approach involving a constraint for risk. Our investigation concludes with a brief analysis of some of the robustness issues and suggestions for topics of possible future research. Copyright © 2008 John Wiley & Sons, Ltd.
Study of oxidation after monoacrylate grafting on polyethylene
Authors: Iguerb Ourida , Demoustier‐Champagne Sophie , Marchand‐Brynaert Jacqueline , Daoust Daniel , Sclavons Michel , Devaux Jacques
Published: April 2008

BACKGROUND: The surface properties of high‐density polyethylene and linear low‐density polyethylene were modified by grafting urethane monoacrylate monomer under UV irradiation. This graft polymerization was carried out on native substrates and on substrates pre‐treated by wet oxidation, for different oxidation times.

RESULTS: As the urethane monacrylate layer is crosslinked, its grafting efficiency was checked by dissolving the polyethylene substrates in hot toluene. Grafting was evidenced by Fourier transform infrared spectroscopy of the obtained residues, which showed that both the characteristic urethane acrylate (3350 cm−1) and polyethylene (2920, 730 and 720 cm−1) bands were observable for any polyethylene oxidation time. For an oxidation time longer than 10 hours, acrylate grafting was homogeneous and the grafted surface was smooth with a roughness of less than 10 nm. In addition, X‐ray photoelectron spectroscopy analysis of the residues revealed that O/C had an average value of 0.19, which is lower than the value corresponding to pure acrylate (0.42), whereas N/C had an average value of 0.068, also lower than that of pure acrylate (0.09), thus confirming the grafting.

CONCLUSION: A urethane monoacrylate layer was grafted on native and oxidized polyethylene films. For highly oxidized films, the grafted surfaces are smooth and homogeneous. Copyright © 2008 Society of Chemical Industry
MolAxis: Efficient and accurate identification of channels in macromolecules
Authors: Yaffe Eitan , Fishelovitch Dan , Wolfson Haim J. , Halperin Dan , Nussinov Ruth
Published: April 2008

Channels and cavities play important roles in macromolecular functions, serving as access/exit routes for substrates/products, cofactor and drug binding, catalytic sites, and ligand/protein. In addition, channels formed by transmembrane (TM) proteins serve as transporters and ion channels. MolAxis is a new sensitive and fast tool for the identification and classification of channels and cavities of various sizes and shapes in macromolecules. MolAxis constructs corridors, which are pathways that represent probable routes taken by small molecules passing through channels. The outer medial axis of the molecule is the collection of points that have more than one closest atom. It is composed of two‐dimensional surface patches and can be seen as a skeleton of the complement of the molecule. We have implemented in MolAxis a novel algorithm that uses state‐of‐the‐art computational geometry techniques to approximate and scan a useful subset of the outer medial axis, thereby reducing the dimension of the problem and consequently rendering the algorithm extremely efficient. MolAxis is designed to identify channels that connect buried cavities to the outside of macromolecules and to identify TM channels in proteins. We apply MolAxis to enzyme cavities and TM proteins. We further utilize MolAxis to monitor channel dimensions along Molecular Dynamics trajectories of a human Cytochrome P450. MolAxis constructs high quality corridors for snapshots at picosecond time‐scale intervals substantiating the gating mechanism in the 2e substrate access channel. We compare our results with previous tools in terms of accuracy, performance and underlying theoretical guarantees of finding the desired pathways. MolAxis is available on line as a web‐server and as a standalone easy‐to‐use program (http://bioinfo3d.cs.tau.ac.il/MolAxis/). Proteins 2008. © 2008 Wiley‐Liss, Inc.
Improved sequence‐based prediction of protein secondary structures by combining vacuum‐ultraviolet circular dichroism spectroscopy with neural network
Authors: Matsuo Koichi , Watanabe Hidenori , Gekko Kunihiko
Published: April 2008

Synchrotron‐radiation vacuum‐ultraviolet circular dichroism (VUVCD) spectroscopy can significantly improve the predictive accuracy of the contents and segment numbers of protein secondary structures by extending the short‐wavelength limit of the spectra. In the present study, we combined VUVCD spectra down to 160 nm with neural‐network (NN) method to improve the sequence‐based prediction of protein secondary structures. The secondary structures of 30 target proteins (test set) were assigned into α‐helices, β‐strands, and others by the DSSP program based on their X‐ray crystal structures. Combining the α‐helix and β‐strand contents estimated from the VUVCD spectra of the target proteins improved the overall sequence‐based predictive accuracy Q3 for three secondary‐structure components from 59.5 to 60.7%. Incorporating the position‐specific scoring matrix in the NN method improved the predictive accuracy from 70.9 to 72.1% when combining the secondary‐structure contents, to 72.5% when combining the numbers of segments, and finally to 74.9% when filtering the VUVCD data. Improvement in the sequence‐based prediction of secondary structures was also apparent in two other indices of the overall performance: the correlation coefficient (C) and the segment overlap value (SOV). These results suggest that VUVCD data could enhance the predictive accuracy to over 80% when combined with the currently best sequence‐prediction algorithms, greatly expanding the applicability of VUVCD spectroscopy to protein structural biology. Proteins 2008. © 2008 Wiley‐Liss, Inc.
The mechanical integrity journey—Equipment identification
Authors: Ali Syed H. , Christman Robert , Frederick Jeffery D. , Stankovich Robert J.
Published: April 2008

The development of a functioning mechanical integrity (MI) program is very much like taking a long journey. The first step in that journey is to develop a practical methodology for determining what equipment is to be inspected and tested. When it comes to equipment that contains or handles hazardous materials, this step is crucial from a catastrophic prevention perspective process safety management (PSM), as well as environmental protection and production/cost perspectives.

A practical methodology to identify MI equipment for inspection and testing, as well as a table that is used to document MI equipment and tests required were developed and are shared in this article.

This article describes an approach that builds on center for chemical process safety guidelines and fulfills both the occupational safety and health administration, process safety management, and environmental protection agency's risk management program regulations, by considering the four following criteria to identify MI equipment:

Equipment that provides containment of hazardous materials.

Equipment that prevents releases of hazardous materials.

Equipment that mitigates releases of hazardous materials.

Equipment that supports containment, prevention, or mitigation of releases of hazardous materials.

© 2008 American Institute of Chemical Engineers Process Saf Prog, 2008
Improving data centric storage with diffuse caching in wireless sensor networks
Authors: Ma Keng‐Teck , Cheng King‐Yip , Lui King‐Shan , Tam Vincent
Published: April 2008

In a sensor network that adopts data‐centric storage (DCS), information of the same kind is kept in the same set of nodes. That is, when a sensor detects a certain event, no matter where it is, it sends the information to the designated location. When another node wants the information, it can send a query to that location to retrieve it. Unfortunately, existing protocols based on DCS are prone to the hot‐spot problem where some nodes have to handle lots of messages. In this paper, we study how to apply diffuse caching on top of DCS. We diffuse popular information to other nodes so as to share the workloads. Our diffusing mechanism is adaptive that the distribution varies based on the popularity of the event type. We evaluate our protocol using simulations and the results show that our protocol successfully alleviates the hot‐spot problem and reduces the message overheads. Copyright © 2008 John Wiley & Sons, Ltd.
Error repair for broadcast transmissions in DVB‐H systems
Authors: Gómez‐Barquero David , Bria Aurelian
Published: April 2008

People travelling in public transportation vehicles are foreseen to be a relevant use case of future Digital Video Broadcast—Handhelds (DVB‐H) systems. However, it is also one of the critical user cases, since, besides the vehicle penetration loss, the received signal quality is strongly affected by the high mobility of the users, which is accompanied by temporary shadowing and fast fading. On the other hand, mobility can be also beneficial thanks to the bursty character of DVB‐H transmissions, as additional repair data can be sent in the time intervals between original service bursts in order to hide the coverage discontinuities from the users' perception. In this way, users which miss the original transmission have more chances to receive the information correctly. By managing the amount of repair data the network operator can trade system capacity and network latency for improved vehicular user satisfaction in a DVB‐H network with imperfect coverage of the service area (as perceived by the vehicular users). To illustrate the potential of this approach, we evaluate the mentioned trade‐off in a DVB‐H system dimensioned for pedestrian outdoor users, for both streaming and filecasting services. To enable an easy and efficient implementation of the repair mechanisms, we adopt application layer forward error correction (FEC), as it can provide a multi‐burst protection of the transmission. Copyright © 2008 John Wiley & Sons, Ltd.
An off‐line system for data acquisition and analysis
Authors: Master Raymond C.
Published: April 2008

A generalized solution to the problem of laboratory data acquisition and data reduction will be discussed. The Nuclear Data 7700 System represents a new approach to laboratory data acquisition and reduction in that it is capable of interfacing with, providing complete data analysis and generating comprehensive output reports for many instruments in the analytical laboratory. Featuring both off‐line data reduction and digital magnetic tape cartridge program storage, it was designed to offer an economical and minimum obsolescence solution to the data reduction problem. The system allows the full capability of a small general purpose computer to be employed with a variety of computer programs to perform data analysis for a variety of instruments. Besides software availability, providing complete data reduction and comprehensive output reports, for the more important analytical instruments such as Gas Chromatographs, IR and Atomic Absorption Spectrophotometers, Physical Testing Instruments, etc., the flexibility of this approach makes computerized data reduction practical for such instruments as Thermal Analyzers, Titrators, etc. The gas chromatography data handling aspects of the system are discussed in detail.
Computer processing of gas chromatographic data: Quantitative analysis of fatty acid methyl esters using an off line magnetic tape system
Authors: Nelson Gary J.
Published: April 2008

This paper describes the off line processing of chromatographic data from fatty acid methyl ester mixtures by a large digital computer. The output of the gas chromatograph is recorded and stored on magnetic tape; the tape can then be processed at any convenient time. The system takes the analog signal from the electrometer and converts it to digital form, adds a time base and records the data using an incremental magnetic tape recorder. The data sampling rate can be varied from 0.05 to 5 times per second. The total number of samples per tape is limited only by the length of the tape. A 1200 ft reel can store up to 30 hr of gas chromatographic runs. The tape is processed by a CDC‐6600 computer. The computer locates all peaks, determines the retention time and calculates the mass percentage of each peak. Along with the numerical output, a cathode ray tube plot of the data is also generated by the computer. The program has provisions for baseline corrections and peak overlap. The program also incorporates corrections for detector nonlinearity and variation in detector response to different molecular species. The accuracy of the system is within 5% based on analysis of fatty acid methyl ester samples of known composition. Computation time for a 1200 ft reel of tape is approximately 20 min.
A computer approach toward automation of a chemical services laboratory: I. Instrument support
Authors: Schneider E. L. , Munson A. W.
Published: April 2008

The use of a medium scale computer for instrument support results in several distinct advantages. Instruments of differing data rates and calculation requirements may be supported on the same system at the same time. There is no interference between any of the instruments since each is assigned its own block of time for scanning and its own set of programs for data support. The use of both the on‐line and off‐line modes permits the easy development of programs and their subsequent incorporation into the program library. It becomes advantageous to look at data supporting instruments that require only small computer support since the off‐line mode can be used for this purpose. Instruments previously considered too low in volume to support can enjoy the benefits of off‐line computer support at little additional cost. The use of high level languages such as are supported on the medium scale computers make it possible to train laboratory personnel to write and modify their own programs. Their involvement in the programming effort can result in a greater acceptance of the computer as a useful tool in the laboratory, instead of the attitude that sometimes prevails that the computer is a hindrance rather than a help. The ease with which program changes can be made makes the program modification task easier for the programming staff of the computer installation, if laboratory personnel do not perform this function. The medium scale computer provides computational power far exceeding that available on a series of small dedicated computers. The “pooling” of resources results in having available a larger scale computer for those programs and instruments that require it. The degree of sophistication of software available on the medium scale computers is far above that available on the smaller units.
A rapid method for the determination of trace Cu and Fe in edible salad oil by graphite furnace atomic absorption spectroscopy
Authors: Sun Houng‐Jen
Published: April 2008

In the determination of trace amounts of copper and iron in edible salad oils by graphite furnace atomic absorption spectroscopy (GFAAS), an ashing method with low temperature oxygen plasma was used to effectively eliminate the interference of the organic matrix. Two sample preparation methods were studied, extraction with concentrated nitric acid followed by ashing with the low temperature oxygen plasma to determine the yield of extraction, and direct analysis of the metal content after dilution with methyl isobutyl ketone (MIBK). Results obtained from these methods were compared with the background absorbance by inductively coupled plasma‐atomic emission spectroscopy (ICP‐AES).
The relationship of peanut maturity to 2‐methylpropanal in headspace volatiles
Authors: Sanders Timothy H. , Greene R. Larry
Published: April 2008

Headspace volatiles from peanuts of five consecutive maturity classes from three soil temperatures were determined to evaluate the relationship of peanut maturity and 2‐methylpropanal. Cured, ground peanuts were held in closed vials for 30 min at 150 C before headspace sampling. Quantitation as percent of total volatiles and ppm in the peanuts revealed a decrease in 2‐methylpropanal as peanuts matured regardless of seed size within maturity class. From peanut lots in which maturity‐size relationships had been determined, headspace analysis of commercial sized lots indicated that the concentration of 2‐methylpropanal was related to the maturity distribution (percent of each maturity class) within each sized lot. These data/techniques may have application in estimating lot‐to‐lot maturity‐related peanut flavor/quality potential.
Reduction of glyceride oils to fatty alcohols with sodium borohydride‐t‐butanol‐methanol
Authors: Rao Y. Rajeswara , Pantulu A. J. , Lakshminarayana G.
Published: April 2008

Various glyceride oils were reduced to fatty alcohols by refluxing them with sodium borohydride in a mixture oft‐butanol and methanol. Chemical characteristics and infrared spectral analyses showed the products to consist mainly of alcohols and the unreduced oils. Olefinic unsaturation was not affected. Castor, coconut and mustard oils yielded 89, 84 and 60% alcohols, respectively, and cottonseed, safflower, linseed, soybean andHydnocarpus wightiana seed oils yielded 72–78% alcohols.
Vesicles from sucrose fatty acid esters
Authors: Ishigami Yutaka , Machida Hajime
Published: April 2008

It has been confirmed, from observations with an electron microscope after staining negatively with aqueous uranyl acetate solutions and using a flourescent microscope, that sucrose fatty acid esters form closed vesicles. The range of particle size of the vesicle, consisting of chromatographically fractionated sucrose dilaurate, was apparently 70–700 nm in the longer diameter of individual vesicles based on the transmission electron microscopic (TEM) observation. The weight‐average particle size was 424 nm as shown by means of the photon‐correlation method. The amounts of 6‐carboxyfluorescein trapped in the vesicles of sucrose fatty acid esters were determined, and it was ascertained that the volumes of the central water phase depended upon the acyl chain lengths of fatty acid residues. Further, the effect of the additives [cholesterol and dicetyl phosphate (DCP) was examined. As an example, the vesicle of sucrose stearate had a central water phase of 1.7 one water/mol ester, and showed a slow release of 6‐carboxyfluorescein from the central water phase after preparation of the vesicle.
Glucose‐6‐phosphate dehydrogenase deficiency protects against coronary heart disease
Authors: Meloni L. , Manca M. R. , Loddo I. , Cioglia G. , Cocco P. , Schwartz A. , Muntoni S. , Muntoni Sa.
Published: April 2008

Previous studies suggest a reduction in cardiovascular risk among subjects expressing the glucose‐6‐phosphate dehydrogenase (G6PD, EC 1.1.1.49) deficient phenotype. We aimed to test this hypothesis in male subjects expressing the G6PD‐deficient phenotype vs wild type G6PD. In a case–control study we examined consecutive patients admitted for acute myocardial infarction or unstable angina, and controls admitted for diagnoses other than coronary heart disease (CHD). The G6PD phenotype was determined by measuring the enzyme activity in erythrocytes, as the absorbance rate change due to NADPH reduction. The CHD risk associated with the G6PD phenotype was assessed with unconditional logistic regression. G6PD‐deficient subjects were less frequently represented among cases (11.8%) than among controls (18.6%, p=0.002). The genetic condition of G6PD deficiency conveyed a significant reduction in CHD risk (OR=0.6; 95% CI 0.4 to 0.9). We confirm the hypothesis that subjects with the G6PD‐deficient phenotype are less prone to CHD. We suggest that such a protective effect may be ascribable to a reduced 3‐hydroxy‐3‐methylglutaryl‐coenzyme A reductase (HMG‐CoA R) activity, a statin‐like effect, as well as to a downregulation in NADPH oxidase activity with a consequent reduction in oxygen‐free radical production.
Multisystem involvement in a patient due to accumulation of amylopectin‐like material with diminished branching enzyme activity
Authors: Eminoglu T. F. , Tumer L. , Okur I. , Olgunturk R. , Hasanoglu A. , Gonul I. I. , Dalgic B.
Published: April 2008

We report a 13‐year‐old boy with multisystem involvement secondary to accumulation of amylopectin‐like material. He was born to consanguineous parents at full term without any complications and his maternal perinatal history was uneventful. His parents were cousins. He had normal growth and development except for his weight. His sister died from an unexplained cardiomyopathy at the age of 8 years. Our patient's initial symptom was severe heart failure. Since he also had a complaint of muscle weakness, electromyography was performed which showed muscle involvement. The diagnosis was suggested by tissue biopsy of skeletal muscle showing intracellular, basophilic, diastase‐resistant, periodic acid–Schiff‐positive inclusion bodies and was confirmed by the presence of a completed branching enzyme deficiency. Similar intracytoplasmic inclusion‐like bodies were also found in liver biopsy, but very few in number compared with the skeletal muscle. The patient died from an intercurrent infection. Postmortem endomyocardial biopsy revealed the same intracytoplasmic inclusions as described above affecting almost all myocardial cells. Ultrastructural examination of liver biopsy was nondiagnostic; however, myocardium showed prominent, large, intracytoplasmic deposits. Glycogen branching enzyme gene sequence was normal, andthus classical branching enzyme deficiency was excluded. Our patient represents the first molecular studyperformed on a patient in whom there was multiplesystem involvement secondary to accumulation of amylopectin‐like material. We suggest that this is an as yet undefined and different phenotype of glycogen storage disease associated with multisystemic involvement.
Pathogenesis of CNS involvement in disorders of amino and organic acid metabolism
Authors: Kölker S. , Sauer S. W. , Hoffmann G. F. , Müller I. , Morath M. A. , Okun J. G.
Published: April 2008

Inherited disorders of amino and organic acid metabolism have a high cumulative frequency, and despite heterogeneous aetiology and varying clinical presentation, the manifestation of neurological disease is common. It has been demonstrated for some of these diseases that accumulating pathological metabolites are directly involved in the manifestation of neurological disease. Various pathomechanisms have been suggested in different in vitro and in vivo models including an impairment of brain energy metabolism, an imbalance of excitatory and inhibitory neurotransmission, altered transport across the blood–brain barrier and between glial cells and neurons, impairment of myelination and disturbed neuronal efflux of metabolic water. This review summarizes recent knowledge on pathomechanisms involved in phenylketonuria, glutaric aciduria type I, succinic semialdehyde dehydrogenase deficiency and aspartoacylase deficiency with examples, highlighting general as well as disease‐specific concepts and their putative impact on treatment.
Flow–orbit equivalence for minimal Cantor systems
Authors: KOSEK WOJCIECH , ORMES NICHOLAS , RUDOLPH DANIEL J.
Published: April 2008

This paper is about flow–orbit equivalence, a topological analog of even Kakutani equivalence. In addition to establishing many basic facts about this relation, we characterize the conjugacies of induced systems that can be extended to a flow–orbit equivalence. We also describe the relationship between flow–orbit equivalence and a distortion function of an orbit equivalence. We show that, if the distortion of an orbit equivalence is zero, then it is in fact a flow–orbit equivalence, and that the converse is true up to a conjugation by an element of the full group.
A configuration design based method for platform commonization for product families
Authors: CORBETT BRIAN , ROSEN DAVID W.
Published: April 2008

Product families help companies reach customers in several different markets, lessen the time needed to develop new products, and reduce costs by sharing common components among many products. The product platform can be considered as a set of technologies, components, or functions, and their arrangements, that are utilized for more than one product. Configuration design focuses on the components in a product and their connections and relationships. Discrete, combinatorial design spaces are used to model design requirements regarding physical connections, module partitions, and assembly sequences for the product family. To ensure that products satisfy all design requirements, it is necessary to combine these design spaces into a common configuration space into which all requirements can be mapped. This paper presents computational methods for modeling and combining design spaces so those configurations can be identified that satisfy all constraints. A new representation of assembly sequences facilitates the development of an assembly design space, elements of which can be enumerated readily. Because the size of the combinatorial design spaces can become quite large, computational efficiency is an important consideration. A new designer guided method, called the partitioning method, is presented for decomposing configuration design problems in a hierarchical manner that enables significant reductions in design space sizes. An example of a family of automotive underbodies illustrates the application of the discrete design space approach to develop a common platform.
Evaluation and selection in product design for mass customization: A knowledge decision support approach
Authors: ZHA XUAN F. , SRIRAM RAM D. , LU WEN F.
Published: April 2008

Mass customization has been identified as a competitive strategy by an increasing number of companies. Family-based product design is an efficient and effective means to realize sufficient product variety, while satisfying a range of customer demands in support for mass customization. This paper presents a knowledge decision support approach to product family design evaluation and selection for mass customization process. Here, product family design is viewed as a selection problem with the following stages: product family (design alternatives) generation, product family design evaluation, and selection for customization. The fundamental issues underlying product family design for mass customization are discussed. Then, a knowledge support framework and its relevant technologies are developed for module-based product family design for mass customization. A systematic fuzzy clustering and ranking model is proposed and discussed in detail. This model supports the imprecision inherent in decision making with fuzzy customers' preference relations and uses fuzzy analysis techniques for evaluation and selection. A neural network technique is also adopted to adjust the membership function to enhance the model. The focus of this paper is on the development of a knowledge-intensive support scheme and a comprehensive systematic fuzzy clustering and ranking methodology for product family design evaluation and selection. A case study and the scenario of knowledge support for power supply family evaluation, selection, and customization are provided for illustration.
Caffeine and other sympathomimetic stimulants: modes of action and effects on sports performance
Authors: Jones Gareth
Published: April 2008

Stimulants, illegal and legal, continue to be used in competitive sport. The evidence for the ergogenic properties of the most potent stimulants, amphetamines, cocaine and ephedrine, is mostly insubstantial. Low doses of amphetamines may aid performance where effects of fatigue adversely affect higher psychomotor activity. Pseudoephedrine, at high doses, has been suggested to improve high intensity and endurance exercise but phenylpropanolamine has not been proven to be ergogenic. Only caffeine has substantial experimental backing for being ergogenic in exercise. The mode of action of these stimulants centres on their ability to cause persistence of catecholamine neurotransmitters, with the exception of caffeine which is an adenosine receptor antagonist. By these actions, the stimulants are able to influence the activity of neuronal control pathways in the central (and peripheral) nervous system. Rodent models suggest that amphetamines and cocaine interact with different pathways to that affected by caffeine. Caffeine has a variety of pharmacological effects but its affinity for adenosine receptors is comparable with the levels expected to exist in the body after moderate caffeine intake, thus making adenosine receptor blockade the favoured mode of ergogenic action. However, alternative modes of action to account for the ergogenic properties of caffeine have been supported in the literature. Biochemical mechanisms that are consistent with more recent research findings, involving proteins such as DARPP-32 (dopamine and cAMP-regulated phosphoprotein), are helping to rationalize the molecular details of stimulant action in the central nervous system.
Magnetic anisotropy of Fe0.34Co0.66(110) on GaAs(110)
Authors: Muermann Björn , Nitsch Florian , Sperl Matthias , Spitzer Alexander , Bayreuther Günther
Published: April 2008

The tailoring of the magnetic properties, especially the anisotropies of ferromagnets on semiconductors, is of prime importance to the field of spintronics, e.g., spin injection. We have investigated the magnetic anisotropy of epitaxial Fe0.34Co0.34(110) films grown by molecular beam epitaxy on GaAs(110). The samples were studied by means of alternating gradient magnetometry and ferromagnetic resonance spectroscopy. The angular dependent magnetic energy density observed can be explained by two main contributions to the magnetic anisotropy: an effective cubic anisotropy K1eff(t) caused by the symmetry of the Fe0.34Co0.66 bcc lattice and an effective uniaxial anisotropy KUeff(t). The strength of these anisotropies is thickness dependent due to a volume and a surface contribution.
A low temperature fabrication of HfO2 films with supercritical CO2 fluid treatment
Authors: Tsai Chih-Tsung , Chang Ting-Chang , Kin Kon-Tsu , Liu Po-Tsun , Yang Po-Yu , Weng Chi-Feng , Huang Fon-Shan
Published: April 2008

To improve the dielectric properties of sputter-deposited hafnium oxide (HfO2) films, the supercritical CO2 (SCCO2) fluid technology is introduced as a low temperature treatment. The ultrathin HfO2 films were deposited on p-type (100) silicon wafer by dc sputtering at room temperature and subsequently treated with SCCO2 fluids at 150°C to diminish the traps in the HfO2 films. After SCCO2 treatment, the interfacial parasitic oxide between the Si substrate and HfO2 layer is only about 5Å, and the oxygen content of the HfO2 films apparently increased. From current-voltage (I-V) and capacitance-voltage (C-V) measurements, the leakage current density of the SCCO2-treated HfO2 films is repressed from 10−2to10−7A∕cm2 at electric field=3MV∕cm due to the reduction of traps in the HfO2 films. The equivalent oxide thickness also obviously decreased. Besides, the efficiency of terminating traps is relative to the pressure of the SCCO2 fluids.