bluuebunny/crossref_metadata_2025 huggingface dataset:
The information content of the yield curve for predicting property performance
Authors: Tsolacos Sotiris
Published: July 2006

The present study applies GARCH models to explain and forecast the variation in monthly IPD total returns for office, retail and industrial space. With the exception of retail returns, the forecasting performance of the estimated GARCH models is very good. Over the 16‐month period from January 2000 to April 2001 total office returns were 17 per cent and industrial returns 16.2 per cent. The GARCH models would have predicted 21 per cent for offices and 18.3 per cent for industrial units. Improvements in the forecast performance are sought with the inclusion of information based on the yield curve, a well‐known indicator of future economic conditions. The volatility of the yield curve and a ‘good and bad news’ variable, based on the changes in the yield spread through time, are used as inputs in the variance equation of the GARCH specification to help model the unexplained variance of the return series and improve the forecasts. The forecasts seem to improve in the case of office returns but slightly worsen for retail returns. Yield curve information was not relevant in the model of industrial returns. The findings of the present study suggest that situations of clusters of large and small errors arising from speculative behaviour should be tested in models and treated accordingly. They also show that the contributions of expectation variables such as the yield spread should be examined within forecasting methodologies more extensively. Omission of such series may come at the expense of producing more accurate forecasts. Copyright © 2002 Henry Stewart Publications
The US economy: the real estate outlook for 2002
Authors: Louargand Marc
Published: July 2006

The combined impact of recession and terrorist attacks on America on US real estate markets has already proved troublesome for investors and operators and is likely to be felt in 2002 as well. Stresses on US real estate include a slowing economy, the hangover of excess real estate consumption from the bubble year of 2000 and a widespread reluctance to travel domestically or internationally. Herein, we take our annual look at the space markets and capital markets in the USA. Copyright © 2002 Henry Stewart Publications
Calendar anomalies in the stock returns of real estate investment trusts
Authors: Connors David N. , Jackman Matthew L. , Lamb Reinhold P. , Rosenberg Sidney B.
Published: July 2006

Recurring behaviours of broad market stock returns around various calendar dates have been widely documented in the finance literature. Some studies have exposed similar performances in subsectors of the market. This paper considers such anomalous return behaviour in REITs from 1994–99. Rather than finding January and Monday effects, like are present in the broad market, we report on December and Friday effects in the REIT market. December returns are higher than those experienced in other months. Friday produces the highest returns during the week and Monday returns are positive and not significantly different from those of Tuesday to Thursday. Consistent with other research, we find support for a holiday effect and a turn‐of‐the‐month effect. Most of the findings hold across industry subsamples within the REIT market. Copyright © 2002 Henry Stewart Publications
Pricing lending in the current market: securing the capital — security value sensitivities
Authors: Edwards Elizabeth
Published: July 2006

There is always a danger when writing a paper on the pricing of lending that it will become immediately historic. The market for property finance in the UK is a constantly moving target, probably even considered too erratic by some foreign lenders. However, this is precisely why the UK market is so attractive and, at the end of the day, so liquid. Lending figures are subject to scrutiny, but the most recent Bank of England figures reported some £73bn of debt as at December 2001. This accounted for approximately 9.5 per cent of all reported bank lending in the UK. The issues of capital availability and security values are covered in this paper: these are intrinsically linked and an attempt will be made to cover some of the contemporary micro and macro issues affecting them. Copyright © 2002 Henry Stewart Publications.
The evolution of innovative debt and equity structures: the securitisation of US lodging real estate finance
Authors: Singh Arjun J.
Published: July 2006

The mid‐1990s saw the alignment of real estate and capital markets. The primary driver of this convergence was the emergence of securitisation for real estate debt and equity markets. The evolution of the innovative instruments introduced during this period and their resulting impact on financing the US lodging industry are discussed in this paper. Copyright © 2002 Henry Stewart Publications.
Managing risk in apartment development
Authors: Louargand Marc A. , Murdy Brian T.
Published: July 2006

Multifamily investment is popular with US institutional investors at present despite weak fundamentals in the rental market. There is evidence that apartments provide some protection from recessionary forces and are the first product type to recover from a downturn. Capital flows have increased to the sector, putting downward pressure on capitalisation rates. Development of new stock allows investors to capture the spread between return on cost to build and capitalisation rates on existing properties. Managing the risks inherent in development is a different prospect than underwriting existing properties. This paper examines methods for managing the risks associated with construction, marketing, financing and interest rate risk, among other factors. Copyright © 2002 Henry Stewart Publications
Best practices in commercial real estate financing: essential issues in negotiating A/B note intercreditor agreements
Authors: Stewart David M.
Published: July 2006

In this quarterly feature the nuts and bolts of loan document structuring and negotiations are investigated, as well as the closing process and loan administration. This issue's paper examines the most hotly negotiated legal issues between the senior and junior lenders in the context of A/B notes originated for the REMIC securitisation market, where both the senior (A) and junior (B) note share a mortgage interest in the same real property. The paper outlines the ways in which the holder of the B note may attempt to protect its interest in the face of actions by the A note holder that could otherwise modify or reduce the borrower's obligations to the B note holder, or eliminate the collateral for the B note. In each case, the author suggests typical compromise positions that should satisfy both the B note holder and the holders of all tranches of the securities backed by the A note. Copyright © 2002 Henry Stewart Publications
Research review
Authors: Adair Alastair
Published: July 2006

The aim of the Research Reviews is to focus on current academic research which contributes to and enhances professional practice. The objective is to provide the busy practitioner with a synopsis of leading edge research in the area and hopefully to stimulate a desire for greater understanding and application of knowledge and techniques that will enhance professional practice. The reader is encouraged to examine in depth each of the reviewed papers. Copyright © 2003 Henry Stewart Publications
Property investment and development finance in certain continental European jurisdictions part 1: the Netherlands
Authors: Murray Neil
Published: July 2006

In this short series of papers, points of law and practice in relation to a lender wishing to undertake a property investment or development finance transaction in particular jurisdictions will be examined.

The specific jurisdictions which will be dealt with are the Netherlands, France, Germany, Spain and Italy. Copyright © 2003 Henry Stewart Publications
Financial performance effects of synthetic leases
Authors: Danvers Kreag , Reinstein Alan , Jones Lawrence S.
Published: July 2006

This paper examines selected financial performance measures of companies using synthetic leases. First, an example is provided of some advantages of using a synthetic lease. Synthetic lease announcements are then identified for retail and manufacturing sectors from 1997–2002 through Academic LexisNexis searches, and performance measures statistically compared from pre‐ to post‐disclosure for synthetic lease companies, relative to a control sample of companies. While observing some differences in interest coverage and profitability across samples in the year prior to lease disclosure, logistic regression results indicate that the measures do not statistically discriminate between synthetic lease and control companies. These findings suggest that the level at which companies use synthetic leases does not appear to significantly influence basic financial performance measures. Besides showing the little ‘real’ benefit of establishing such types of leases for non‐economic reasons, the results suggest that capital allocation decisions should focus on the substance rather than the form of such synthetic lease transactions. Copyright © 2003 Henry Stewart Publications
Determinants of environmental innovation adoption in the printing industry: the importance of task environment
Authors: Rothenberg Sandra , Zyglidopoulos Stelios C.
Published: July 2006

In this paper, we investigate the impact that the task environment has on the adoption of environmental innovations by firms. Specifically, we investigate the impact of two dimensions of a firm's external context – munificence and dynamism. We investigate both of these factors by drawing on the relevant literatures, developing hypotheses and testing our hypotheses with data drawn from the US printing industry. Our major findings are that firms in highly dynamic environments, as well as firms that have adopted other productive innovations, are more likely to adopt a greater number of environmental innovations. Copyright © 2006 John Wiley & Sons, Ltd and ERP Environment.
Relationship between environmental performance and financial performance: an empirical analysis of japanese corporations
Authors: Nakao Yuriko , Amano Akihiro , Matsumura Kanichiro , Genba Kiminori , Nakano Makiko
Published: July 2006

The hypotheses that a firm's environmental performance has a positive impact on its financial performance and vice versa are statistically supported by Japanese data. However, this tendency for two‐way positive interaction appears to be only a relatively recent phenomenon. The tendency for realizing the two‐way interaction is not limited to the top‐scoring firms in terms of both financial and environmental performance. On the contrary, this is also a trend that can be observed fairly generally. Obviously, when we consider only scores of those companies that published the relevant information in their environmental reports, and conduct the statistical causality test with such information as additional input to the pooled time‐series and cross‐section data of financial performance, the results become more strongly significant. From the recent experience of environmental policies in Japan, we infer that information‐based environmental policy measures are effective to encourage the ongoing transition toward a more sustainable market economy. Copyright © 2006 John Wiley & Sons, Ltd and ERP Environment.
End‐of‐pipe or cleaner production? An empirical comparison of environmental innovation decisions across OECD countries
Authors: Frondel Manuel , Horbach Jens , Rennings Klaus
Published: July 2006

While both fundamental types of abatement measure mitigate the adverse environmental impacts of production, cleaner production technologies are frequently more advantageous than end‐of‐pipe technologies for environmental and economic reasons. This paper analyzes a variety of factors that might enhance firms' propensity to implement cleaner production technologies instead of end‐of‐pipe technologies. On the basis of a unique facility‐level data set derived from a recent OECD survey, we find a clear dominance of cleaner production in seven OECD countries: 76.8% of the facilities report that they invest predominantly in cleaner production technologies, above all in new production processes, but not so much in new products. Based on a discrete choice model, our estimation results indicate that regulatory measures and the stringency of environmental policies are more important for end‐of‐pipe technologies, while cost savings, general management systems and specific environmental management tools tend to favor clean production. We conclude that improvements towards cleaner production may be reached by the continuous development and wider diffusion of these management tools. Improvements may also be stimulated by widening the cost gap between the two types of technology, for instance by additionally charging for waste and energy use. Copyright © 2006 John Wiley & Sons, Ltd and ERP Environment.
Empirical analysis of the integration of environmental risks into the credit risk management process of European banks
Authors: Weber Olaf , Fenchel Marcus , Scholz Roland W.
Published: July 2006

About 15 years ago, banks started to integrate environmental risks into their credit risk management procedures. In this article, a survey of the European banking sector focusing on the analysis of the integration of environmental risks into all phases of the credit risk management, rating, costing, pricing, monitoring and work‐out, is presented. The integration of environmental risks into the whole credit risk management process is important because only then is an adequate risk management guaranteed. The results show that banks integrate environmental risks especially into the rating phase, but not in all phases of the credit management process, though this is recommendable because these risks influence all phases of the credit management process. Furthermore, significant differences in integrating environmental risks between banks that are signatories of the UNEP statement by banks on the environment and sustainable development and banks that had not signed this agreement so far could be found. Copyright © 2006 John Wiley & Sons, Ltd and ERP Environment.
Characterization of Structure and Transport in Porous Media by Pulsed Field Gradient (PFG) NMR Technique. Part I: Master Curve and Characteristic Inner Length
Authors: Bardakci M. , Tillich J. E. , Holz M.
Published: July 2006

Systematic experimental studies focusing on the practical application of observation time dependent pulsed‐field‐gradient (PFG) NMR were performed. The objective was to provide engineering scientists with a reliable experimental tool for characterizing the structure and transport in fluid‐filled porous media. Observation time dependent self‐diffusion in glass bead packs as model systems was investigated, where the diffusing species (molecules of the solvent or dissolved particles) served as probes for the confining geometry in the porous medium. First, the basic question whether the obtainable structure information is independent of the actual mobility of the diffusing probe particles was examined experimentally. It could be demonstrated that plotting the normalized time‐dependent diffusion coefficient D(t)/D0 versus the actual migration length lD(t) during a given observation time t indeed yields a characteristic “master curve” that is independent of the mobility of the diffusing species, thus reflecting, as desired for a reliable method, solely the effects of the confining geometry of the porous system of interest. It was further shown that from the master curve a new quantity, i.e., a “characteristic inner length” or “correlation length” ξD can be derived that corresponds to a path length in the porous medium, after which particles in the pore fluid experience an averaged restricting geometry and diffuse with an effective diffusion coefficient Deff. It turned out that ξD is surprisingly short, that is, in the order of the bead radius. Moreover, it was demonstrated that normalization of this migration length with the bead radius yields a common master curve for all monodisperse bead packs used and thus, it is obviously possible to derive and record master curves for different kinds of packs, beds or other porous media as references that can be used to characterize or certify the kind of the porous matrix of interest.
Newtonian and Non‐Newtonian Low Re Number Flow Through Bead Packings
Authors: Mertens D. , Heinen C. , Hardy E. H. , Buggisch H. W.
Published: July 2006

The results of measurements of velocity distributions of Newtonian and non‐Newtonian fluids flowing through porous media are described in this contribution. The porous matrix was modeled by glass beads of different diameters forming a random bead packing confined by a circular tube. These packings were passed through by aqueous solutions of glucose and xanthane gum. Nuclear magnetic resonance (NMR) methods were applied to investigate the flow field in the packing. Spatially resolved and integral displacement distribution measurements were reported.
Kinetic Analysis of Semisynthetic Peroxidase Enzymes Containing a Covalent DNA–Heme Adduct as the Cofactor
Authors: Fruk Ljiljana , Müller Joachim , Niemeyer Christof M.
Published: July 2006

The reconstitution of apo enzymes with DNA oligonucleotide‐modified heme (protoporphyrin IX) cofactors has been employed as a tool to produce artificial enzymes that can be specifically immobilized at the solid surfaces. To this end, covalent heme–DNA adducts were synthesized and subsequently used in the reconstitution of apo myoglobin (aMb) and apo horseradish peroxidase (aHRP). The reconstitution produced catalytically active enzymes that contained one or two DNA oligomers coupled to the enzyme in the close proximity to the active site. Kinetic studies of these DNA–enzyme conjugates, carried out with two substrates, ABTS and Amplex Red, showed a remarkable increase in peroxidase activity of the DNA–Mb enzymes while a decrease in enzymatic activity was observed for the DNA–HRP enzymes. All DNA–enzyme conjugates were capable of specific binding to a solid support containing complementary DNA oligomers as capture probes. Kinetic analysis of the enzymes immobilized by the DNA‐directed immobilization method revealed that the enzymes remained active after hybridization to the capture oligomers. The programmable binding properties enabled by DNA hybridization make such semisynthetic enzyme conjugates useful for a broad range of applications, particularly in biocatalysis, electrochemical sensing, and as building blocks for biomaterials.
Investigation of the Pathways of Excess Electron Transfer in DNA with Flavin‐Donor and Oxetane‐Acceptor Modified DNA Hairpins
Authors: Breeger Sascha , von Meltzer Martin , Hennecke Ulrich , Carell Thomas
Published: July 2006

Oxetane is a potential intermediate that is enzymatically formed during the repair of (6–4) DNA lesions by special repair enzymes (6–4 DNA photolyases). These enzymes use a reduced and deprotonated flavin to cleave the oxetane by single electron donation. Herein we report synthesis of DNA hairpin model compounds containing a flavin as the hairpin head and two different oxetanes in the stem structure of the hairpin. The data show that the electron moves through the duplex even over distances of 17 Å. Attempts to trap the moving electron with N2O showed no reduction of the cleavage efficiency showing that the electron moves through the duplex and not through solution. The electron transfer is sequence dependent. The efficiency is reduced by a factor of 2 in GC rich DNA hairpins.
Ordered Mesoporous Materials in the Context of Drug Delivery Systems and Bone Tissue Engineering
Authors: Vallet‐Regí María
Published: July 2006

Chemistry, materials science and medicine are research areas that converge in the field of drug delivery systems and tissue engineering. This paper tries to introduce an example of such an interaction, aimed at solving health issues within the world of biomaterials. Ordered mesoporous materials can be loaded with different organic molecules that would be released afterwards, in a controlled fashion, inside a living body. These materials can also react with the body fluids giving rise to carbonated nanoapatite particles as the products of such a chemical interaction; these particles, equivalent to biological apatites, enable the regeneration of bone tissue.
Combining Enabling Techniques in Organic Synthesis: Continuous Flow Processes with Heterogenized Catalysts
Authors: Kirschning Andreas , Solodenko Wladimir , Mennecke Klaas
Published: July 2006

The concepts article describes enabling techniques (solid‐phase assisted synthesis, new reactor design, microwave irradiation and new solvents) in organic chemistry and emphasizes the combination of several of them for creating new synthetic technology platforms. Particular focus is put on the combination of immobilized catalysts as well as biocatalysts with continuous flow processes. In this context, the PASSflow continuous flow technique fulfils both chemical as well as chemical engineering requirements. It combines reactor design with optimized, monolithic solid phases as well as reversible immobilization techniques for performing small as well as large scale synthesis with heterogenized catalysts under continuous flow conditions.
Improving Potency, Selectivity, and Water Solubility of Adenosine A1Receptor Antagonists: Xanthines Modified at Position 3 and Related Pyrimido[1,2,3‐cd]purinediones
Authors: Weyler Stefanie , Fülle Friederike , Diekmann Martina , Schumacher Britta , Hinz Sonja , Klotz Karl‐Norbert , Müller Christa E.
Published: July 2006

The structure–activity relationships of xanthine derivatives related to the adenosine A1receptor antagonists 8‐cyclopentyl‐1,3‐dipropylxanthine (DPCPX) and 1,3‐dipropyl‐8‐(3‐noradamantyl)xanthine (KW3902) were investigated by focusing on variations of the 3‐substituent. Aromatic residues were well tolerated by the A1receptor in that position. A moderate effect of stereochemistry was found for the 3‐(1‐phenylethyl)‐substituted analogue of DPCPX (S>R) at A1and A3receptors, whereas the opposite stereoselectivity was observed at the A2receptor subtypes. A 3‐hydroxypropyl substituent was found to be optimal for high A1affinity and selectivity. The most potent compound of the present series was 1‐butyl‐3‐(3‐hydroxypropyl)‐8‐(3‐noradamantyl)xanthine (10 c), which exhibits aKivalue of 0.124 nMat rat, and 0.7 nMat human adenosine A1receptors, combined with high selectivity (≫200‐fold) versus the other receptor subtypes. The similarly potent 8‐cyclopentyl‐3‐(3‐hydroxypropyl)‐1‐propylxanthine was converted into a water‐soluble phosphate prodrug, which may become a useful pharmacological tool for in vivo studies. 8‐Alkyl‐2‐(3‐noradamantyl)pyrimido[1,2,3‐cd]purine‐8,10‐diones, which can be envisaged as xanthine analogues with a fixed 3‐propyl substituent, were identified as a new class of potent, selective adenosine A1receptor antagonists. For example, compound14(8‐butyl‐substituted) exhibits aKivalue of 13.8 nMat human A1receptors. A selection of the most potent compounds was investigated in [35S]GTPγS binding assays and showed inverse agonistic activity. Their efficacy was generally lower than that of the full inverse agonist DPCPX, and depended on subtle structural changes. Some of the new compounds belong to the most potent and selective A1antagonists described to date.
Integrated Approach Using Protein and Ligand Information to Analyze Selectivity‐ and Affinity‐Determining Features of Carbonic Anhydrase Isozymes
Authors: Hillebrecht Alexander , Supuran Claudiu T. , Klebe Gerhard
Published: July 2006

The application and comparison of selected protein‐ and ligand‐based approaches to elucidate factors important for affinity and selectivity towards the carbonic anhydrase isozymes I, II, and IV are described. Carbonic anhydrases are abundant in pro‐ and eukaryotes. These enzymes catalyze the reversible hydration of carbon dioxide to bicarbonate and H+ ions and are thus involved in many important physiological and pathophysiological processes. Due to the fact that the human carbonic anhydrase family consists of 16 closely related isozymes, the design of selective inhibitors is a special challenge for medicinal chemists. In order to extract selectivity‐determining features, we applied purely ligand‐based 3D QSAR techniques as well as qualitative comparative molecular field analyses of the targets’ binding sites using consensus principal component analysis (CPCA). The dataset for the QSAR studies was deliberately compiled from 1748 inhibitors and comprises about 140 ligands, mainly of the sulfonamide type. Additionally, we employed the novel AFMoC approach, which intrinsically combines protein and ligand information. The simultaneous use of these different techniques gives deeper insight into selectivity and affinity‐determining features and provides quantitative models for prediction.
Role of angiogenesis in chronic lymphocytic leukemia
Authors: Letilovic Tomislav , Vrhovac Radovan , Verstovsek Srdan , Jaksic Branimir , Ferrajoli Alessandra
Published: July 2006

Angiogenesis is a physiologic process of new blood vessels formation mediated by various cytokines called angiogenic and angiostatic factors. Although its potential pathophysiologic role in solid tumors has been extensively studied for more than 3 decades, enhancement of angiogenesis in chronic lymphocytic leukemia (CLL) and other malignant hematological disorders has been recognized more recently. An increased level of angiogenesis has been documented by various experimental methods both in bone marrow and lymph nodes of patients with CLL. Although the role of angiogenesis in the pathophysiology of this disease remains to be fully elucidated, experimental data suggest that several angiogenic factors play a role in the disease progression. Biologic markers of angiogenesis were also shown to be of prognostic relevance in CLL. The current findings provide the rationale for investigating antiangiogenic agents in CLL. In the current review angiogenesis in CLL is discussed and its potential diagnostic and therapeutic applications. Cancer 2006. © 2006 American Cancer Society.
Phase II study of single‐agent bortezomib for the treatment of patients with fludarabine‐refractory B‐cell chronic lymphocytic leukemia
Authors: Faderl Stefan , Rai Kanti , Gribben John , Byrd John C. , Flinn Ian W. , O'Brien Susan , Sheng Shihong , Esseltine Dixie‐Lee , Keating Michael J.
Published: July 2006

Therapeutic options are limited and the prognosis is poor for patients with fludarabine‐refractory B‐cell chronic lymphocytic leukemia (CLL). Bortezomib induces apoptosis in vitro in CLL cells, both alone and in combination, including in cells resistant to fludarabine or other agents. The aim of the current randomized, open‐label, Phase II study was to investigate the clinical activity of bortezomib in patients with fludarabine‐refractory B‐cell CLL. Twenty‐two patients with histologically confirmed B‐cell CLL were treated with bortezomib at doses of 1.0 mg/m2, 1.3 mg/m2, or 1.5 mg/m2 on Days 1, 4, 8, and 11 of a 21‐day treatment cycle for a maximum of 9 cycles. None of 19 patients evaluable for response achieved complete remission or partial response; however, signs of biologic activity based on disease site responses (e.g., reduction in lymphocytosis, splenomegaly, and lymphadenopathy) were observed. In the 1.5 mg/m2 dose group, a higher proportion of patients had stable disease, and a lower proportion had progressive disease compared with the 2 lower‐dose groups. Eleven patients, all in the 2 higher dose groups, experienced Grade 3/4 adverse events (AEs) (according to National Cancer Institute Common Toxicity Criteria [version 2.0]); 2 patients experienced Grade 4 neutropenia. Grade 3 hematologic AEs included anemia, neutropenia, thrombocytopenia, and hemolytic anemia; Grade 3 nervous system AEs included aphasia; peripheral neuropathy, not otherwise specified; and peripheral sensory neuropathy. Although no objective responses were achieved in patients with fludarabine‐refractory B‐cell CLL, single‐agent bortezomib demonstrated biologic activity. In view of the evidence for its activity, further exploration of bortezomib in combination with other agents is warranted. Cancer 2006. © 2006 American Cancer Society.
New Experimental and Theoretical Results for Argon Broadening and Shift of HCO+ Rotational Lines
Authors: Buffa Giovanni , Dore Luca , Tinti Francesca , Meuwly Markus
Published: July 2006

An experimental and theoretical study of the pressure broadening and the pressure shift of three HCO+ rotational lines (j=4←3, 5←4 and 6←5) perturbed by collisions with Ar is presented. The measurements are carried out at 77 K and are compared to close‐coupling calculations performed on an accurate potential energy surface for the Ar–HCO+ interaction extending from small to very large separations between the ion and the perturber. For the pressure broadening, agreement between experiment and theory is satisfactory for both close‐coupling and semiclassical calculations. For the pressure shift, however, close‐coupling calculations are superior. The results agree with experiment in sign and order of magnitude, while semiclassical calculations are inaccurate for the shift of the presently studied lines because they neglect the contribution of strong collisions.
DNA Tile Based Self‐Assembly: Building Complex Nanoarchitectures
Authors: Lin Chenxiang , Liu Yan , Rinker Sherri , Yan Hao
Published: July 2006

DNA tile based self‐assembly provides an attractive route to create nanoarchitectures of programmable patterns. It also offers excellent scaffolds for directed self‐assembly of nanometer‐scale materials, ranging from nanoparticles to proteins, with potential applications in constructing nanoelectronic/nanophotonic devices and protein/ligand nanoarrays. This Review first summarizes the currently available DNA tile toolboxes and further emphasizes recent developments toward self‐assembling DNA nanostructures with increasing complexity. Exciting progress using DNA tiles for directed self‐assembly of other nanometer scale components is also discussed.
The Recognition of Growth Conditions and Metabolic Type of Plants by a Potentiometric Electronic Tongue
Authors: Ciosek Patrycja , Pokorska Berenika , Romanowska Elżbieta , Wróblewski Wojciech
Published: July 2006

The application of a potentiometric electronic tongue for the recognition and classification of plant samples is presented. Homogenates from the leaves of various plants subtypes (maize and guinea grass) were measured with the use of sensor array based on ion‐selective and partially selective electrodes. It was found that this device is capable of recognizing with high correctness, the type of plant metabolism (distinguishing between two types of cereals) and the factors affecting nutritional values of plants such as cultivation time and light intensity during growth. The obtained results led to the conclusion that the presented system can be used for the monitoring of crops and estimation of the quality of plants.
Linear models with nearly frequency independent complex stiffness leading to causal behaviour in time domain
Authors: Muravskii G. B.
Published: July 2006

In the paper, several causal linear models leading to nearly frequency independent complex stiffness are studied in time and frequency domains. Along with Biot model other three hereditary models are introduced into analysis. They all ensure practical constancy for damping properties but have limitations concerned with an increase in the real part of complex stiffness of corresponding material elements, as frequency grows. A new suggested method deals with given mechanical system as a whole: the imaginary part of the system compliance is constructed assuming that all elements have constant stiffness (with a modification for imaginary parts near zero frequency) and further the imaginary part of the system is used directly for studying transient vibrations supposing causality of the given mechanical system. The corresponding real part (not needed in the transient response analysis) is determined by Hilbert transformation. Examples relating to systems with one, two and infinite (shear beam) degrees of freedom are carried out for five compared models, allowing to reveal advantages and shortcomings of the models. Copyright © 2006 John Wiley & Sons, Ltd.
Improved protonation, collision‐induced decomposition efficiency and structural assessment for ‘red tide’ brevetoxins employing nanoelectrospray mass spectrometry
Authors: Wang Weiqun , Cole Richard B.
Published: July 2006

Brevetoxins are a group of natural neurotoxins found in blooms of red tide algae. Previous electrospray mass spectrometry (ES‐MS) studies show that all brevetoxins have high affinities for sodium ions, and they form abundant sodium adduct ions, [M + Na]+, in ES‐MS, even when trace contamination is the only source of sodium ions. Attempts to obtain informative product ions from the collision‐induced decomposition (CID) of [M + Na]+ brevetoxin precursor ions resulted only in uninformative sodium ion signals, even under elevated collision energies. In this study, a nano‐ES‐MS approach was developed wherein ammonium fluoride was used to form cationic [M + NH4]+ adducts of brevetoxin‐2 and brevetoxin‐3; a significant increase in the abundance of protonated brevetoxin molecules [M + H]+ also resulted, whereas the abundance of sodium adducts of brevetoxins [M + Na]+ was observed to decrease. Under CID, both [M + NH4]+ and [M + H]+ gave similar, abundant product ions and thus underwent the same types of fragmentation. This indicated that ammonium ions initially attached to brevetoxins forming [M + NH4]+ easily lose neutral ammonia in a first step in the gas phase, leaving protonated brevetoxin [M + H]+ to readily undergo further fragmentation under CID. Copyright © 2006 John Wiley & Sons, Ltd.
Evaluation of the protonation thermochemistry obtained by the extended kinetic method
Authors: Bouchoux Guy
Published: July 2006

An evaluation of the results obtained by the extended kinetic method for a series of representative bases is presented here. Analysis of the original experimental data is conducted using the orthogonal distance regression (ODR) statistical treatment. A comparison with the proton affinities and protonation entropies obtained from variable temperature equilibrium constant measurements demonstrate deviations, which may be ascribed to random and systematic errors. Considerable random errors are associated with the extended kinetic method if the number of reference bases and the range of effective temperatures are too low. It is also confirmed that large systematic errors on proton affinities and protonation entropies are obtained when large protonation entropy is associated with the considered system. It is, however, encouraging to note that the gas phase basicities obtained by the extended kinetic method are generally comparable to that obtained by other methods within a few kJ/mol. Copyright © 2006 John Wiley & Sons, Ltd.
Neutral loss of water from the b ions with histidine at the C‐terminus and formation of the c ions involving lysine side chains
Authors: Fu Qiang , Li Lingjun
Published: July 2006

Neutral loss of water from the amide bond induced by the His side chain has been reported. The proposed fragmentation pathway is a retro‐Ritter reaction catalyzed by the imidazole nitrogen. In our MS/MS study of the neuropeptide GAHKNYLRFamide, we observed that the neutral loss of water from the b3 ion is abundant. The b3 ion has a His residue at the C‐terminus. As reported previously, in the b ions with His at the C‐terminus, the imidazole residue is connected to the carbonyl carbon to form a five‐membered ring. Therefore, it is unlikely that the neutral loss of water from the b3 ion is catalyzed by the imidazole nitrogen. Through MS2 and MS3 studies of a synthetic peptide standard AGHKLL and its chemically labeled and isotope‐encoded forms, we discovered that the water loss from the b3 ion involves the carbonyl group of His, the hydrogen connected to the α‐carbon of Gly, and the amide hydrogen of His. We also discovered the formation of an unusual cx ion in peptides with a Lys or Arg residue at the (x + 1) position of the peptide. Copyright © 2006 John Wiley & Sons, Ltd.
Stability analysis for double‐stranded DNA oligomers and their noncovalent complexes with drugs by laser spray
Authors: Shi Xiangguo , Takamizawa Atsushi , Nishimura Yoshifumi , Hiraoka Kenzo , Akashi Satoko
Published: July 2006

Laser spray, which is a newly developed ionization technique, can characterize the stability of noncovalent complexes in the solution phase. By using this advantage, laser spray has been applied to probe the intrinsic stability of double‐stranded DNA (dsDNA) sequences and their binding affinities with various drugs in the solution phase. Systematic experiments were carried out using six 16‐mer and three 22‐mer dsDNA oligomers, together with the complexes of the 16‐mer dsDNA with minor groove binders: berenil, Hoechst 33342, DAPI, and netropsin. Dissociation curves for each dsDNA or each complex were plotted as a function of laser power. The laser power (E50%), where 50% of each dsDNA or each complex was dissociated, was compared with its melting temperature (Tm) determined by UV spectroscopy. Linear correlations between E50% and Tm were obtained not only for the dsDNA oligomers (correlation factor r = 0.9835) but also for the 16‐mer dsDNA complexes with minor groove binders (r = 0.9966). In addition, laser spray has successfully clarified the binding affinities of a 16‐mer dsDNA with two intercalators: daunomycin and nogalamycin. In the case of the dsDNA–daunomycin complex, by changing the molar ratio of dsDNA : drug from 1 : 1 to 1 : 5, the concentration‐dependent stability of the complex was confirmed by laser spray. The present results demonstrate that laser spray mass spectrometry can be a powerful and convenient method to investigate the relative binding affinities of dsDNA–ligand complexes in the solution phase, which could be applied to the early stage of high‐throughput screening of drugs targeting for dsDNA. Copyright © 2006 John Wiley & Sons, Ltd.
Application of a lipase in cake manufacture
Authors: Guy Robin CE , Sahi Sarabjit S
Published: July 2006

The effects of the addition of a new form of lipase, reported to form polar monoacyl lipids in wheat flour doughs, were studied in high‐ratio layer cake batters and the baked products. Measurement of surface phenomena of the air/water interface in the batter showed a slight lowering of surface tension and significant lowering of surface viscosity. In contrast, the bulk viscosity of the batter was increased. These changes indicated that surface‐active materials had been formed and were causing important changes in the batter. Their effects on processing were to reduce the time needed to aerate the batter to the target density. Measurements on the baked cakes using six commercial cake flours showed increased specific volume and some improvement in appearance, particularly the evenness of the crack in the top crust and lack of large holes in the crumb. More detailed examination of the cellular crumb structure by image analysis showed that the overall expansion was largely due to greater expansion of individual gas cells. This indicated that there was an increase in bubble stability during baking. Storage tests on the cakes over 15 days showed improvements in softness due to the increased volume and in some cases a small anti‐firming effect. The rate of moisture diffusion from crumb to crust, which plays an important role in cake staling, was not significantly different for cakes with added lipase. Copyright © 2006 Society of Chemical Industry
Chromic acid oxidation of hexitols in the presence of 2,2′‐bipyridyl catalyst in aqueous micellar media: A kinetic study
Authors: Islam Monirul , Saha Bidyut , Das Asim K.
Published: July 2006

In aqueous H2SO4 media, chromic acid oxidation of hexitols (D‐sorbitol and D‐mannitol) to their corresponding aldohexoses in presence and absence of 2,2′‐bipyridyl (bipy) have been studied under the experimental conditions, [hexitols]T ≫ [Cr(VI)]T and [bipy]T ≫ [Cr(VI)]T (subscript T stands for the total concentration). Under the conditions, both the slower uncatalyzed and faster bipy‐catalyzed paths go on simultaneously. The monomeric species of Cr(VI) has been found to be kinetically active in absence of bipy whereas in the bipy‐catalyzed path, the Cr(VI)–bipy complex has been found to be the active oxidant. Both the paths show first‐order dependence on [hexitol]T and [Cr(VI) ]T. The uncatalyzed path shows a second‐order dependence on [H+]. The bipy‐catalyzed path is first order in [bipy]T. These rate‐dependence patterns remain the same in the presence of externally added surfactants. Sodium dodecyl sulfate (SDS), an anionic surfactant, has been found to accelerate both the uncatalyzed and bipy‐catalyzed paths while N‐cetylpyridinium chloride (CPC), a cationic surfactant, shows the rate‐retarding effect for both the uncatalyzed and bipy‐catalyzed paths. The observed micellar effects have been rationalized by considering the distribution of the reactants between the aqueous and micellar phases in terms of the proposed reaction mechanism. © 2006 Wiley Periodicals, Inc. Int J Chem Kinet 38: 531–539, 2006
Study on the consecutive reaction kinetics of synthesis of di(2‐ethylhexyl) terephthalate under nonisothermal conditions
Authors: Dazhuang Liu , Shaohui Sun , Jianguo Wei , Peiqin Sun
Published: July 2006

Since more information concerning kinetic parameters can be obtained from a nonisothermal reaction, it was selected to investigate the consecutive esterification kinetics of terephthalic acid with 2‐ethylhexanol in the presence of tetrabutyl titanate catalyst. This is an equilibrium reaction that is carried out in industry to completion by removing the water formed. It results in an automatic rise in the esterifying temperature, from 453 to 519 K. Research shows that the first step of esterification carried out in a heterogeneous system has a slow reaction rate, but the second step of esterification in a homogeneous system has a relatively fast reaction rate. Based on the quasi‐homogeneous assumption, first the differential method is presented to deal with nonisothermal reaction data. Arrhenius equations of the two steps are established by using this method. It was found that the apparent activation energy of the first step of esterification was about 55 kJ/mol higher than that of the second step. The ratio (K) of reaction rate constants of the two steps decreases gradually with the increase in the reaction temperature. An equation of K vs. temperature is also derived from Arrhenius equations. Subsequently, integral expressions of components' concentrations are used to simulate experimental results of the nonisothermal reaction as well as a three‐stage isothermal reaction. The obtained simulations show that the determined kinetic equations and the parameters are reasonable. © 2006 Wiley Periodicals, Inc. Int J Chem Kinet 38: 577–584, 2006
Ruthenium(III) catalysis in polymerization of vinyl monomers by charge‐transfer mechanism with aminoalcohols and carbontetrachloride: A kinetic study
Authors: Tiwari Rajesh , Upadhyay S. K. , Rai J. S. P.
Published: July 2006

The kinetics of ruthenium(III) catalyzed polymerization of vinyl monomers (M) (methyl‐, ethyl‐, and butylacrylates) by charge‐transfer mechanism with aminoalcohols (AA) (namely, ethanol‐, diethanol‐, and triethanol amines) and carbontetrachloride in dimethylsulfoxide medium have been studied. The rate of polymerization depends on the [CCl4]/[AA] ratio and may be represented as

equation image

and

equation image

The rate of polymerization of monomers with each aminoalcohol was found to be in the order Rp (methyl‐)> Rp (ethyl‐)> Rp (butylacrylate) while that of each monomer with different aminoalcohols was found to be in the order of Rp tertiary > Rp secondary > Rp primary aminoalcohol. The suitable mechanism for the polymerization process consistent with kinetic data has been proposed. © 2006 Wiley Periodicals, Inc. Int J Chem Kinet 38: 585–592, 2006
Improved Anti‐Inflammatory Properties for Naproxen with Cyclodextrin‐Grafted Polysaccharides
Authors: Ramírez Héctor L. , Cao Roberto , Fragoso Alex , Torres‐Labandeira Juan J. , Dominguez Amalia , Schacht Etienne H. , Baños Maysa , Villalonga Reynaldo
Published: July 2006

Summary: Mannan and carboxymethylcellulose, previously activated by periodate oxidation, were grafted with mono‐6‐butylenediamino‐6‐deoxy‐β‐cyclodextrin derivatives by reductive alkylation in the presence of sodium borohydride. The formation of supramolecular complexes between these polymers and Naproxen was confirmed by fluorescence spectroscopy. The solubility of the drug was 3.8–4.6 fold increased in the presence of the cyclodextrin‐grafted polysaccharides. The in vivo anti‐inflammatory property of Naproxen was 1.7 times higher after supramolecular association with β‐cyclodextrin‐branched mannan.

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Nanofiber Formation of Hydroxylpropylcellulose (HPC)
Authors: Yan Lifeng , Lin Wei , Bangal Prakriti R.
Published: July 2006

Summary: The aggregative behaviors of hydroxypropylcellulose (HPC) molecules in aqueous solution and on substrates have been observed by employing laser light scattering (LLS) and, after deposition on a mica surface, atomic force microscopy (AFM). LLS studies showed that the HPC molecules formed large aggregates through self‐association when the concentration of the solution was above the critical concentration ct. AFM measurements revealed that when a dilute aqueous solution of HPC molecules was deposited onto a mica substrate at a temperature below its lower critical solution temperature (LCST) thin nanofibers were formed with a height of 0.9 nm, whereas thick nanofibers were formed when an aqueous solution of HPC molecules was deposited onto a substrate above its LCST. Furthermore, the growth of nanofibers led to the formation of fan structures.

AFM image of the HPC fan‐like structures on the surface of mica.

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AFM image of the HPC fan‐like structures on the surface of mica.
Gold Nanoparticles as a Versatile Platform for Optimizing Physicochemical Parameters for Targeted Drug Delivery
Authors: Bergen Jamie M. , von Recum Horst A. , Goodman Thomas T. , Massey Archna P. , Pun Suzie H.
Published: July 2006

Summary:The development of targeted vehicles for systemic drug delivery relies on optimizing both the cell‐targeting ligand and the physicochemical characteristics of the nanoparticle carrier. A versatile platform based on modification of gold nanoparticles with thiolated polymers is presented in which design parameters can be varied independently and systematically. Nanoparticle formulations of varying particle size, surface charge, surface hydrophilicity, and galactose ligand density were prepared by conjugation of PEG‐thiol and galactose‐PEG‐thiol to gold colloids. This platform was applied to screen for nanoparticle formulations that demonstrate hepatocyte‐targeted deliveryin vivo. Nanoparticle size and the presence of galactose ligands were found to significantly impact the targeting efficiency. Thus, this platform can be readily applied to determine design parameters for targeted drug delivery systems.

Modified gold nanoparticles are a suitable model for nanoparticle‐based gene carriers.

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Modified gold nanoparticles are a suitable model for nanoparticle‐based gene carriers.
Cover Picture: Macromol. Biosci. 7/2006
Authors: Bergen Jamie M. , von Recum Horst A. , Goodman Thomas T. , Massey Archna P. , Pun Suzie H.
Published: July 2006

Cover: The picture depicts a versatile, goldbased platform developed to optimize nanoparticle properties. Nanoparticles with optimal size, hydrophilicity and ligand display successfully target hepatocytes. The design properties determined by this method can be applied to develop targeted nanoparticulate drug carriers. Further details can be found in the article by J. M. Bergen, H. A. von Recum, T. T. Goodman, A. P. Massey, and S. H. Pun* on page 506.