Complex Type (complex + type)

Distribution by Scientific Domains


Selected Abstracts


Biomedical applications of protein chips

JOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 3 2002
Jocelyn H. Ng
Abstract The development of microchips involving proteins has accelerated within the past few years. Although DNA chip technologies formed the precedent, many different strategies and technologies have been used because proteins are inherently a more complex type of molecule. This review covers the various biomedical applications of protein chips in diagnostics, drug screening and testing, disease monitoring, drug discovery (proteomics), and medical research. The proteomics and drug discovery section is further subdivided to cover drug discovery tools (on-chip separations, expression profiling, and antibody arrays), molecular interactions and signaling pathways, the identification of protein function, and the identification of novel therapeutic compounds. Although largely focused on protein chips, this review includes chips involving cells and tissues as a logical extension of the type of data that can be generated from these microchips. [source]


Electromagnetic interference shielding by using conductive polypyrrole and metal compound coated on fabrics

POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 8 2002
C. Y. Lee
Abstract Electromagnetic interference (EMI) shielding materials of complex type of conductive polypyrrole (PPy) as an intrinsically conducting polymer and silver-palladium (AgPd) metal compound coated on woven or non-woven fabrics are synthesized. From dc conductivity and SEM photographs of PPy/fabric complexes, we discuss charge transport mechanism and the homogeneity of coating on the fabrics. The EMI shielding efficiency of PPy/fabric and AgPd/fabric complexes is in the range of 8,,,80 dB depending on the conductivity and the additional Ag vacuum evaporation. The highest EMI shielding efficiency of PPy/fabric complexes vacuum-evaporated by Ag is ,80 dB, indicating potential materials for military uses. We propose that PPy/fabrics are excellent RF and microwave absorber because of the relatively high absorbance and low reflectance of the materials. Copyright © 2002 John Wiley & Sons, Ltd. [source]


Geochemistry of K-feldspar and Muscovite in Rare-element Pegmatites and Granites from the Totoral Pegmatite Field, San Luis, Argentina

RESOURCE GEOLOGY, Issue 4 2009
Julio Oyarzábal
Abstract The geochemistry of K-feldspar for K, P, Sr, Ba, Rb, Cs, Ga, and of muscovite for the same elements plus Nb and Ta, was used for proving the parental relationships of S-type granites and LCT (Li, Cs, Ta) rare-element pegmatites in the southernmost pegmatitic field of the Pampean pegmatite province in Argentina. The variation of K/Rb-Cs, K/Cs-Rb, K/Rb-Rb/Sr, K/Rb-Ba in K-feldspar from the granites and pegmatites show that they form an association with the evolutional sequence: granites , barren- to transitional pegmatites , beryl type, beryl-columbite-phosphate pegmatites , complex type of spodumene subtype pegmatites , albite-spodumene type , albite type pegmatites. This sequence reflects the regional distribution of the different magmatic units. The Ta-Cs diagram for muscovite reveals that none of the studied pegmatites exceed the threshold established in previous studies for being considered with important tantalum oxide mineralization. The granites and pegmatites constitute a rare-element pegmatitic field in which different magmatic units form a continuous fractionation trend, extended from the less evolved granitic facies to the most geochemically specialized pegmatites [source]


Detection of orientation-specific anti-gp120 antibodies by a new N-glycanase protection assay

APMIS, Issue 2 2002
G. J. Gram
Several functions have been assigned to the extensive glycosylation of HIV-1 envelope glycoprotein gp120, especially immune escape mechanisms, but the intramolecular interactions between gp120 and its carbohydrate complement are not well understood. To analyse this phenomenon we established a new microwell deglycosylation assay for determining N-linked glycan accessibility after binding of gp120-specific agents. Orientation-specific exposition of gp120 in ELISA microplates was achieved by catching with either anti-C5 antibody D7324 or anti-V3 antibody NEA-9205. We found that soluble CD4 inhibited the deglycosylation of gp120 only when gp120 was caught by D7324 and not by NEA9205. In contrast, antibodies from HIV-infected individuals inhibited the deglycosylation best when gp120 was caught by NEA9205. These results demonstrated that both the CD4-binding site and the epitopes recognised by antibodies from HIV-infected individuals have N-glycans in the close vicinity. However, the difference in gp120 orientation indicates that antibodies in HIV-infected individuals, at least partly, bind to epitopes different from the CD4-binding site. Finally, we determined the structural class of the glycan of one V1 glycosylation site of prototype HIV-1 LAI gp120, which remained unsolved from previous studies, and found that it belonged to the complex type of glycans. [source]


Simultaneous Kindling of the Bilateral Hippocampi: An Advanced Model for Epilepsy Research

EPILEPSIA, Issue 8 2000
Shinichi Kogure
Summary: Purpose: To examine whether simultaneous kindling of bilateral hippocampi [bilateral kindling (BK)] could accelerate the achievement of seizures by the breakdown of kindling antagonism or decelerate the achievement of seizures by its enhancement. Methods: The hippocampi of 17 adult rabbits were simultaneously kindled bilaterally according to Goddard's method. Results: All animals developed stage 5 convulsions after a mean of 28 stimulations. Six animals showed spontaneous seizure discharges. Afterdischarge duration increased abruptly during the early period of kindling, but thereafter it gradually progressed. Chronological analyses of interictal discharges (HDs) demonstrated that simple as well as complex types of IIDs increased their frequencies during BK. Conclusions: Compared with unilaterally kindled animals, the BK procedure significantly increased the percentage of animals that successfully kindled (100% vs. 59%; p < 0.01), whereas it significantly decelerated the kindling progression (28 days vs. 19 days; p < 0.02). We conclude that the BK procedure represents potentiation of both excitatory and inhibitory mechanisms. Although the reason why such an antagonistic relationship between them breaks down is still unknown, the BK provides an advanced animal model to study the pathogenic mechanisms of kindling and to screen anticonvulsants. [source]


In Quest of the Double Rotaxane Formation of the Bis(coronand) (1,5),(2,4)-Durenetetrayl-bis(18-crown-5) with Organomagnesium Compounds

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 1 2004
Gerard P. M. van Klink
Abstract The interaction between the title compound, bis(coronand) 8,and the diarylmagnesium compounds Ph2Mg and (p - tBuC6H4)2Mg in diethyl ether leads to the formation of 1:2 complexes (9 and 10, respectively), irrespective of the initial ratio of the components. In [D8]toluene, the three complex types can be discerned by 1H NMR spectroscopy: double side-on (9a, 10a), side-on/rotaxane (9b, 10b), and, to a very minor extent, double rotaxane (9c, 10c). In the case of 10a and 10b, the temperature dependence showed that rotaxane formation is enthalpically favored at the expense of a more negative entropy. As crystals suitable for structure determination could not be obtained from 9 and 10, the interaction of 8 with the sterically less demanding Hg(SCN)2 was studied. In this case, analogous pseudorotaxanes are formed exclusively, and both the 1:2 complex [8·{Hg(SCN)2}2] (11) and its 1:1 analogue 12 were observed. The double rotaxane structure of 11 was confirmed by X-ray crystal structure determination. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source]


Characteristics of tissue-centric biomedical researchers using a survey and cluster analysis

JOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, Issue 8 2008
Sujin Kim
The objective of this study was to characterize the types of tissue-centric users based on tissue use, requirements, and their job or work-related variables at the University of Pittsburgh Medical Center (UPMC), Pittsburgh, PA. A self-reporting questionnaire was distributed to biomedical researchers at the UPMC. Descriptive and cluster analyses were performed to identify and characterize the complex types of tissue-based researchers. A total of 62 respondents completed the survey, and two clusters were identified based on all variables. Two distinct groups of tissue-centric users made direct use of tissue samples for their research as well as associated information, while a third group of indirect users required only the associated information. The study shows that tissue-centric users were composed of various types. These types were distinguished in terms of tissue use and data requirements, as well as by their work or research-related activities. [source]


A two-mean reverting-factor model of the term structure of interest rates

THE JOURNAL OF FUTURES MARKETS, Issue 11 2003
Manuel Moreno
This article presents a two-factor model of the term structure of interest rates. It is assumed that default-free discount bond prices are determined by the time to maturity and two factors, the long-term interest rate, and the spread (i.e., the difference) between the short-term (instantaneous) risk-free rate of interest and the long-term rate. Assuming that both factors follow a joint Ornstein-Uhlenbeck process, a general bond pricing equation is derived. Closed-form expressions for prices of bonds and interest rate derivatives are obtained. The analytical formula for derivatives is applied to price European options on discount bonds and more complex types of options. Finally, empirical evidence of the model's performance in comparison with an alternative two-factor (Vasicek-CIR) model is presented. The findings show that both models exhibit a similar behavior for the shortest maturities. However, importantly, the results demonstrate that modeling the volatility in the long-term rate process can help to fit the observed data, and can improve the prediction of the future movements in medium- and long-term interest rates. So it is not so clear which is the best model to be used. © 2003 Wiley Periodicals, Inc. Jrl Fut Mark 23: 1075,1105, 2003 [source]