bluuebunny/crossref_metadata_2025 huggingface dataset:
Commonplace Tools for Studying Commonplace Interactions: Practitioners' Notes on Entry-Level Video Analysis
Authors: Loehr Dan , Harper Lisa
Published: July 2003

The advent of two technologies - inexpensive video recorders and digital video annotation software - is revolutionizing the study of human interaction. With palm-held camcorders, researchers can now easily collect video data in the field, where humans interact most naturally. More important, using free digital video annotation software, one can annotate and analyze video data on a laptop. In this methods review, we discuss our own experience with such tools in the study of gesture and language. We note points of general interest to researchers of other disciplines, and conclude with a discussion of new issues raised by the presence of readily available multimedia data.
Equality, Coercion, Culture and Social Norms
Authors: Arneson Richard J.
Published: July 2003

Against the libertarian view, this essay argues that coercion aimed at bringing about a more equal distribution across persons can be morally acceptable. Informal social norms might lead toward equality (or another social justice goal) without coercion. If coercion were unnecessary, it would be morally undesirable. A consequentialist integration of social norms and principles of social justice is proposed. The proposal is provided with a preliminary defense against the non-consequentialist egalitarianism of G.A. Cohen and against liberal criticisms directed against the common ground that Cohen and the proposed consequentialist egalitarianism occupy.
The Public Goods Rationale for Government and the Circularity Problem
Authors: Cowen Tyler , Kavka Gregory
Published: July 2003

It has been suggested that the production of public goods through a government involves a circularity problem. Since government itself is a public good, how can we use government to produce other public goods? Several solutions to this supposed circularity are offered. Government is a unique kind of public good with some potentially self-generating and self-supporting features. The public goods theory of government remains intact, and this enterprise helps shed some light on the special features of government.
Learning Radical Planning: The Power of Collective Action
Authors: Beard Victoria A.
Published: July 2003

This article examines how citizens in authoritarian political contexts learn radical planning for social transformation. After identifying a series of gaps in the radical planning literature, the article uses a longitudinal study (1994-2001) of collective action in an urban settlement in Indonesia as a heuristic device to develop a more nuanced model of radical planning. The study illustrates how cumulative participation in state-directed planning, community-based planning, and covert planning over time resulted in a sense of collective agency that served as a foundation for demanding political reform at a moment when state control was weakened.
`Agon'izing Over Consensus: Why Habermasian Ideals cannot be `Real'
Authors: Hillier Jean
Published: July 2003

I explore the core Habermasian concept of rational consensus-formation and its counterfactuality before introducing the possibility of permanence of conflict, non-reciprocity and domination (i.e. of agonism) which may productively explain some of the powergames enacted in planning decision-making. In so doing I draw on the concept of agonism and introduce the political into Habermas' moral theorization. Where the personal and the political intersect there is a role for psychology. I illustrate how Habermas' communicative theorizing was itself partly developed from a psychoanalytical tradition before introducing some of the concepts popularized by Jacques Lacan. I conclude that development of communicative planning theory could usefully retain some of Habermas' psychological foundations while turning to the work of Lacan as a basis for an enhanced understanding of the realities of planning practice.
HDPE Barrier Film Resins - MW and MWD Effects - and their Blends with mLLPDE
Authors: Cowell Timothy J. , Johnson Jerry M.
Published: July 2003

High density polyethylene (HDPE) resins were produced via the multi-reactor, Mitsui, stirred slurry process to give a `four corners' type of product matrix with high and low molecular weights (MW) and broad and narrow molecular weight distributions (MWDs). Density was kept constant. Film processing and physical properties - including oxygen, carbon dioxide, and water vapor transmission rates - are presented. Lower MW and narrower MWD favor better barrier properties. The best barrier HDPE resin was blended with mLLDPE and films blown from these blends demonstrated the potential for application specific film strength and optical property tailoring while maintaining high barrier performance.
Correlations between Orientation and Some Properties of Polymer Films and Sheets
Authors: Ajji A. , Zhang X.
Published: July 2003

The orientation effects of biaxially stretched polystyrene (PS) sheets and polyethylene (PE) blown films were investigated. The study mainly focused on the relationships between orientation of amorphous PS and semicrystalline PE and their shrinkage, tensile properties and tear resistance. For low orientations, it was found that the stress and strain (shrinkage in films) can be simply related to birefringence for both PS and PE. For tear properties of PE films, better correlations were observed with crystalline orientation factors.
New MDO Medium Molecular Weight High Density Polyethylene Films
Authors: Hatfield Eric , Tate Richard , Williams Kelly , Todd William
Published: July 2003

Machine Direction Orientation (MDO) can enhance many film properties such as tensile strength, elongation, stiffness, optics (haze and gloss) and water vapor transmission rate (WVTR). Although MDO can be used with high molecular weight-high density polyethylene (HMW-HDPE) resins, few or no medium molecular weight-high density polyethylene (MMW-HDPE) films have previously been available due to MDO processing issues, namely stretch resonance, which is a phenomena where the film stretches unevenly. Thus it has not been possible to take advantage of the better barrier properties and improved process capabilities of the MMW resin. This paper describes a new line of machine direction orientable MMW-HDPE films that are now commercially available; these were made possible through the use of a proprietary processing aid (PA) that overcomes the stretching problem previously encountered with MMW-HDPE resins. Physical property data for two MDO MMW-HDPE films are presented.
Resection rates and postoperative mortality in 7,899 patients with lung cancer
Authors: Damhuis RA , Schutte PR
Published: July 2003

Postoperative death used to be an important complication of resections for lung cancer, especially in elderly patients. To support decision making in a general situation, contemporary results and prognostic factors were evaluated. The computer records of 7899 lung cancer patients, diagnosed from 1984 until 1992 in hospitals connected to the Rotterdam Cancer Registry, were analysed to evaluate resection rates and 30 day postoperative mortality. Resections were carried out in 20% of all patients. In patients 70 yrs of age and older, the resection rate was 14%, and in younger patients 26%. The postoperative mortality was 3.1%; 3.6% for males and 0.4% for females. According to multivariate analysis, age and extent of surgery were the major determinants of operative risk. For patients aged 0-59, 60-69 and > or = 70, postoperative mortality rates were 1.4, 3.5 and 4.0%, respectively. The operative risk was 5.7% after pneumonectomy, 4.4% after bilobectomy, and 1.4% after lesser resections. Pneumonectomies were performed less often in elderly patients: 27% of operations in patients > or = 70 yrs versus 37% of operations in younger patients. Age appears to be related to treatment choice and postoperative mortality in patients with lung cancer. However, even in patients over 70 yrs of age, resections can be performed at acceptable risk, implying that chronological age should not automatically determine treatment decisions.
Acute influence of cigarette smoke on secretion of pulmonary surfactant in rat alveolar type II cells in culture
Authors: Wirtz HR , Schmidt M
Published: July 2003

It has been shown, that smoking results in a lower yield of surfactant associated phospholipids in bronchoalveolar lavage (BAL). Indirect evidence suggests impaired secretion. In the present study, we investigated the influence of cigarette smoke on surfactant secretion in cultured rat alveolar type II cells. Smoke exposure was achieved by bubbling the smoke of four cigarettes through Dulbecco's modified Eagle's medium (DMEM) which was adjusted to a reference absorption value of 1.36 at 320 nm. Cells were preincubated with various dilutions of cigarette smoke-treated medium for 30 min, and were then exposed to this medium for 2 h. After this time, secretion of 3H-choline-labelled phosphatidylcholine (PC) was measured as a marker of surfactant secretion. A 10 fold dilution of cigarette smoke-treated medium inhibited PC secretion stimulated by a combination of terbutaline, adenosine triphosphate and 12-O-tetradecanoylphorbol-13-acetate by over 50%, but did not alter basal secretion. Exposure to less concentrated cigarette smoke-treated medium resulted in less inhibition. Cellular injury was not observed with the concentrations of cigarette smoke-treated medium used in this study. The gas phase of cigarette smoke was not inhibitory at comparable concentrations. Longer exposure to cigarette smoke-treated medium resulted in increased inhibition of PC secretion. The cigarette smoke ingredients, nicotine and benzo[a]pyrene, failed to inhibit PC secretion. Secretion of type II cells exposed to cigarette smoke-treated medium at lower temperatures was not affected. Addition of antioxidants to medium and cells during the preincubation and secretion period did not alter cigarette smoke-treated medium-induced inhibition of stimulated PC secretion. These results demonstrate a direct inhibitory effect of cigarette smoke constituents on surfactant secretion in type II cells. Inhibition is mediated by compounds contained predominantly in the particulate phase of cigarette smoke. Inactivation of the inhibitory effect by lower temperatures suggests involvement of processes such as enzymatic bioactivation or active transport mechanisms.
Tracheal epithelial damage alters the effects of luminal histamine on blood flow and tracer flux in anaesthetized sheep
Authors: Wells UM , Hanafi Z , Widdicombe JG
Published: July 2003

Epithelial damage greatly increases the flux of a low molecular weight tracer 99mtechnetium-diethylenetriamine penta-acetic acid (99mTc-DTPA) from tracheal lumen to venous-blood in anaesthetized sheep. We have now investigated whether epithelial damage induced by the detergent, Triton X-100, alters the effects of luminal histamine on blood flow and 99mTc-DTPA flux. The cervical trachea was filled with Krebs-Henseleit solution containing 99mTc-DTPA. Tracheal arterial flow was measured and tracheal venous blood collected. The lumen was exposed to 100 microM histamine on two occasions (Hist 1 and Hist 2) for 15 min. In six out of 11 sheep, the lumen was also exposed to 0.2% Triton X-100 between Hist 1 and Hist 2. Triton X-100 increased the baseline 99mTc-DTPA permeability coefficient from -5.3 x 10(-7) to -400 +/- 130 x 10(-7) cm.s-1. After epithelial damage, Hist 2 produced significantly greater changes in arterial and venous flows than Hist 1 (n = 5) (0-5 min: Hist 1 Q1a = +6.4 +/- 0.8%, Q1v = +6.2 +/- 6.2%; Hist 2 Q1a = +36.7 +/- 12.2%, Q1v = +35.4 +/- 8.8%). Similar changes did not occur in the controls. Venous 99mTc-DTPA concentration during Hist 2 after epithelial damage (0-5 min -37.7 +/- 6.9%) was significantly different from Hist 1 (+5.2 +/- 7.0%). Thus, after epithelial damage, luminal histamine produces more rapid and larger changes in blood flow and a greater reduction in venous 99mTc-DTPA concentration.
Interaction between calcium, neutral endopeptidase and the substance P mediated ciliary response in human respiratory epithelium
Authors: Smith RP , Shellard R , Di Benedetto G , Magnus CJ , Mehta A
Published: July 2003

Following irritation of the airway, the ciliostimulatory effects of the tachykinin, substance P (SP), are thought to be secondary to mucus release. We hypothesized that SP also induces small increases in ciliary beat frequency (CBF) via a calcium-mediated process. Brushed ciliated cells from the nasal epithelium of healthy human subjects were suspended in tissue culture fluid and the acute effects of SP upon these cells were studied in a mucus-free environment. In some preparations, changes in CBF in response to SP were measured with a video-based system. The effect of an SP antagonist, of Ca2+ channel block with verapamil, and of the calcium analogue lanthanum on the SP response were also tested. In other preparations, the ciliated cells were preloaded with Fura-2, a dye which fluoresces with Ca2+ ions, and the response of intracellular Ca2+ to SP was monitored. SP (10(-9)-10(-6) M) transiently increased CBF in a dose-dependent manner, with the maximal response occurring at 10 min. The response was small, with a maximum increase of 8.9%. The SP receptor antagonist (D-pro2,D-trp7,9)-SP (10(-5) M) abolished this effect. Verapamil (10(-5) M) attenuated the response to SP (10(-7) M), whilst lanthanum chloride (250 microM) abolished it. Inhibition of SP destruction by phosphoramidon (10(-6) M) also eliminated the transient rise in CBF. However, compared to SP alone, the combination of SP and phosphoramidon induced a novel delayed lanthanum-sensitive rise in CBF. In other experiments, SP (10(-7) M) induced a transient increase in free intracellular Ca2+ concentration (maximal rise 73%), which returned to baseline before the expected onset of the CBF response. We conclude that substance P induces either a transient or sustained increase in CBF dependent on the rate of destruction of this peptide around tachykinin receptors. These receptors are likely to be linked to lanthanum- and verapamil-sensitive pathways for the entry of Ca2+ into cells. The small magnitude of the rise in CBF makes its physiological role uncertain at present.
Comparison of nebulized glycopyrrolate and metaproterenol in chronic obstructive pulmonary disease
Authors: Tzelepis G , Komanapolli S , Tyler D , Vega D , Fulambarker A
Published: July 2003

We assessed the bronchodilating effect of glycopyrrolate (GP) and compared it with that of metaproterenol (MP), alone and in combination (GP+MP), in patients with chronic obstructive pulmonary disease (COPD). In a double-blind study, 11 patients (aged (mean +/- SD) 69 +/- 6 yrs; forced expiratory volume in one second (FEV1) 1.2 +/- 0.4 L) with stable COPD inhaled nebulized GP 1.0 mg, MP 15 mg, or GP 1.0 mg+MP 15 mg. Spirometry was performed before inhalation and at hourly intervals for 8 h after inhalation. It was found that GP produced a bronchodilating effect that was about equal to that of MP but lasted longer (8 vs 5 h). The combination of GP and MP produced a bronchodilating effect that was greater than that of either drug alone and was evident mostly during the effect of MP. The mean peak percentage improvement in FEV1 over baseline was 35% for GP+MP and 25% for either drug alone. These data suggest that nebulized glycopyrrolate is an effective bronchodilator in some patients with chronic obstructive pulmonary disease. Concurrent administration of glycopyrrolate and metaproterenol produces additional bronchodilation that is primarily apparent during the bronchodilator effect of metaproterenol.
Total respiratory impedance measured by means of the forced oscillation technique in subjects with and without respiratory complaints
Authors: Pasker HG , Schepers R , Clement J , Van de Woestijne KP
Published: July 2003

The purpose of this study was to determine whether the forced oscillation technique is more sensitive than spirometry to detect lung function alterations in subjects with respiratory complaints. The input impedance of the respiratory system (between 2 and 24 Hz) and maximal expiratory flows and volumes were measured in 1,255 subjects referred for routine spirometry. A questionnaire concerning respiratory complaints was administered. A discriminant analysis was performed between subgroups of subjects without (137 males and 140 females), with moderate (115 males and 109 females) and with marked respiratory complaints (149 males and 132 females). A clear-cut separation was achieved by this analysis only between those subjects without and with marked complaints. Both lung volumes and flows as well as impedance parameters (mean value and frequency dependence of resistance in females, mean resistance in males) contributed to the discrimination of subjects without and with marked respiratory complaints, although there was only a moderate decrease of discriminative power when the impedance parameters were excluded. The contribution of the forced oscillation parameters to discriminative power was larger in females than in males (40 vs 19%), which may be related to the higher prevalence of asthma in our population of females. Excluding the subjects with marked functional impairment improved the share of forced oscillation parameters only slightly with respect to lung volumes and flows (females 54 vs males 23%). Considered separately, however, the sensitivity of spirometry and forced oscillation technique to detect symptomatic people appeared to be similar. We conclude that impedance measurements by forced oscillation technique and routine spirometry are both associated with respiratory complaints. Our results indicate that the information provided by impedance measurements can be complimentary to that obtained by spirometric indices.
Mechanical coupling between the hemithoraces in humans
Authors: Johansen B , Giaever P , Aspestrand F , Kolbenstvedt A
Published: July 2003

Unilateral airway occlusion permits measurement of single lung function. Since the results suggest that the occluded lung influences the mobility of the contralateral hemithorax, we wanted to test this hypothesis. In eight healthy subjects, we measured, using computed tomography, lung parenchymal area and inner rib cage parasagittal and transverse diameters at three different levels and at maximal inspiration and expiration. These measurements were made without and during balloon occlusion of one mainstem bronchus at residual volume (RV) and at total lung capacity (TLC). Unilateral occlusion at RV reduced the ipsilateral diameters in maximal inspiration, but the increase during inspiration was still 39-50% of that without occlusion. The inspiratory increase in contralateral diameters was reduced to 64-80% of the increase without occlusion. Occlusion at TLC reduced the expiratory decrease in ipsilateral diameters to 37-57% of that without occlusion. The expiratory decrease on the contralateral side was reduced to 56-70% of that without occlusion. Due to accompanying mediastinal shifts the parenchymal areas of the occluded lung barely changed. In contrast, the contralateral area was 86-97% of that without occlusion. We conclude that the movement of the two hemithoraces are, at least partially, interdependent. The occluded hemithorax prevents full expansion/compression of the nonoccluded contralateral side, whilst its own mobility appears to be increased by the presence of this nonoccluded side. Potential negative effects are outweighed by the physiological benefit of the coupling, as this mechanism could secure ventilation to a chest half without own movement.
Interactions of glucocorticoids and beta 2-agonists
Authors: Adcock IM , Stevens DA , Barnes PJ
Published: July 2003

Beta 2-adrenoreceptor agonists and glucocorticosteroids are the two most effective treatments for asthma and are often used in combination. Glucocorticoids mediate their anti-inflammatory effects through the action of activated glucocorticoid receptors (GRs). Many of the effects of GRs on the synthesis of cytokines and other inflammatory mediators are due to a direct interaction with other deoxyribonucleic acid (DNA)-binding proteins belonging to the basic leucine zipper (bZIP) group of transcription factors, such as activator protein-1 (AP-1) and nuclear factor-kappa B (NF-kappa B). Beta 2-agonists are potent bronchodilators at low doses and at high doses can activate gene transcription via a bZIP protein, cyclic adenosine monophosphate (cAMP) response element binding protein (CREB). Activated GRs and CREB can interact with each other within the nucleus to modulate both DNA-binding and gene transcription in either a positive or inhibitory manner, depending on cell type. In lung cells, high doses of beta 2-agonists reduce the ability of GR to bind DNA, a process which is mediated by CREB activation. Inhibition of GR DNA-binding by CREB raises the possibility that high-dose beta 2-agonists could have functional antiglucocorticoid activity and may be a basis for the reported increase in asthma morbidity and mortality in industrialized countries, which have increasing per capita beta 2-agonist use.
Myositis ossificans of the chest wall
Authors: Nisolle JF , Delaunois L , Trigaux JP
Published: July 2003

We report the unusual case of a young man with progressive pain in the thoracic wall. The radionuclide bone scan revealed an increased uptake, and the bone roentgenogram, a calcified soft-tissue mass. Based on computed tomography findings, biopsy was avoided, and evolution was favourable for myositis ossificans. Although rare, myositis ossificans is one of the potential causes of thoracic pain, not to be mistaken for a malignant or infectious lesion.
New surgical adjuncts in the treatment of rhinophyma: the microdebrider and FloSeal®
Authors: Kaushik Vivek , Tahery Jawed , Malik Tassadaque H. , Jones Philip H.
Published: July 2003

Rhinophyma is considered to be the final stage of rosacea and has an unknown aetiology. We present two new surgical adjuncts for the treatment of this condition. The microdebrider is easy to use and allows precise contouring of the nose. It shares the same underlying principle as free-hand scalpel shaving but outperforms this method in key areas. We also describe a novel use for FloSeal®, a gelatin-thrombin co-mixture, utilizing its haemostatic properties to address bleeding from the re-shaped denuded nose.
Promoting higher‐order learning benefits by building lower‐order mnemonic connections
Authors: Carney Russell N. , Levin Joel R.
Published: June 2003

Two experiments were conducted in an effort to combine a mnemonic strategy for remembering individual items with a mnemonic procedure for remembering, and reasoning about, inter‐item relationships. In Experiment 1, students using the combined mnemonic approach were able to identify more individual items (fish names from their pictures) and were subsequently able to remember more components of six studied hierarchies (order, family, and species names of the fish) than did students in an ‘own best method’ control condition. Additionally, and importantly, mnemonic students outperformed control students on an analogy task requiring inferences about superordinate, subordinate, and coordinate relationships. In Experiment 2, the initial number of to‐be‐learned fish was reduced so that the performance of both mnemonic and control students was comparable with respect to fish identification. Despite such item‐level comparability, an advantage for mnemonically instructed students was observed on both immediate and two‐day‐delayed hierarchy tests. We suggest that by cementing lower‐order connections, mnemonic strategies facilitate students' learning of higher‐order information. Copyright © 2003 John Wiley & Sons, Ltd.
Cover Picture: Spirodiporphyrins—As Binuclear Metal Complexes (Angew. Chem. Int. Ed. 25/2003)
Authors: Vogel Emanuel , Michels Martin , Zander Lars , Lex Johann , Tuzun Nurcan S. , Houk Kendall N.
Published: June 2003

The “figure‐eight” cyclooctapyrrole octaphyrin‐(1.1.1.0.1.1.1.0), a compound susceptible to versatile functionalization, opens a pathway to the first dispirodiporphyrinoid obtained as a binuclear nickel complex. The stage for this transformation is set by the regioselective oxidation of octaphyrin to give the diketo derivative shown in the background. Nickel ions initiate a reaction cascade with the diketone, which leads to the nickel complex of spirodicorrole. For more information see the communication by E. Vogel and K. N. Houk et al. on page 2857ff.
Creating a histology–embryology free digital image database using high‐end microscopy and computer techniques for on‐line biomedical education
Authors: Silva‐Lopes Victor W. , Monteiro‐Leal Luiz H.
Published: June 2003

The development of new technology and the possibility of fast information delivery by either Internet or Intranet connections are changing education. Microanatomy education depends basically on the correct interpretation of microscopy images by students. Modern microscopes coupled to computers enable the presentation of these images in a digital form by creating image databases. However, the access to this new technology is restricted entirely to those living in cities and towns with an Information Technology (IT) infrastructure. This study describes the creation of a free Internet histology database composed by high‐quality images and also presents an inexpensive way to supply it to a greater number of students through Internet/Intranet connections. By using state‐of‐the‐art scientific instruments, we developed a Web page (http://www2.uerj.br/∼micron/atlas/atlasenglish/index.htm) that, in association with a multimedia microscopy laboratory, intends to help in the reduction of the IT educational gap between developed and underdeveloped regions. Anat Rec (Part B: New Anat) 273B:126–131, 2003. © 2003 Wiley‐Liss, Inc.
Electronic removal of encrustations inside the Steinheim cranium reveals paranasal sinus features and deformations, and provides a revised endocranial volume estimate
Authors: Prossinger Hermann , Seidler Horst , Wicke Lothar , Weaver Dave , Recheis Wolfgang , Stringer Chris , Müller Gerd B.
Published: June 2003

Features in the endocranium, as revealed by computed tomography (CT) scans of largely complete mid‐Pleistocene crania, have helped elucidate unexpected affinities in the genus Homo. Because of its extensive encrustations and deformations, it has been difficult to repeat such analyses with the Steinheim cranium. Here, we present several advances in the analysis of this Homo heidelbergensis cranium by applying filter algorithms and image editing techniques to its CT scan. First, we show how the encrustations have been removed electronically, revealing interesting peculiarities, particularly the many directions of the deformations. Second, we point out similarities and differences between the frontal and sphenoidal sinuses of the Steinheim, Petralona, and Broken Hill (Kabwe) crania. Third, we assess the extent of the endocranial deformations and, fourth, their implications for our estimation of the braincase volume. Anat Rec (Part B: New Anat) 273B:132–142, 2003. © 2003 Wiley‐Liss, Inc.
The four‐state model of a linear lattice: Application to ligand‐controlled hybridization of short duplex DNAs
Authors: Benight Albert S.
Published: June 2003

An algorithm for calculating the order–disorder transition of a four‐state linear lattice is presented. Recursion schemes for the probabilities of each site along the lattice occupying one of the four possible states were derived following the work of D. Poland (Biopolymers, 1974, Vol. 13, pp. 1859–1871) and H. Tachibana and A. Wada (Biopolymers, 1982, Vol. 21, pp. 1873–1885). The algorithm was parameterized to consider melting of short duplex DNA in the presence of duplex and single‐strand binding ligands. Model calculations were performed for two 31 base‐pair duplex DNAs with very different percent guanine–cytosine base pairs, and thus very different thermodynamic stabilities. In the absence of ligands, calculated melting curves of the two DNAs under identical solvent conditions and identical concentrations were separated by over 15°C. In the presence of either duplex or single‐strand binding ligands, if a sequence dependence to ligand binding is assumed, the melting curves of the two DNAs can be made to coalesce, i.e., stability of the two DNAs can be normalized! This example demonstrates the feasibility of controlling hybridization of short DNAs by sequence specific ligand binding. © 2003 Wiley Periodicals, Inc. Biopolymers 69: 405–420, 2003
A simple lattice model that exhibits a protein‐like cooperative all‐or‐none folding transition
Authors: Kolinski Andrzej , Gront Dominik , Pokarowski Piotr , Skolnick Jeffrey
Published: June 2003

In a recent paper (D. Gront et al.,Journal of Chemical Physics, Vol. 115, pp. 1569, 2001) we applied a simple combination of the Replica Exchange Monte Carlo and the Histogram methods in the computational studies of a simplified protein lattice model containing hydrophobic and polar units and sequence‐dependent local stiffness. A well‐defined, relatively complex Greek‐key topology, ground (native) conformations was found; however, the cooperativity of the folding transition was very low. Here we describe a modified minimal model of the same Greek‐key motif for which the folding transition is very cooperative and has all the features of the “all‐or‐none” transition typical of real globular proteins. It is demonstrated that the all‐or‐none transition arises from the interplay between local stiffness and properly defined tertiary interactions. The tertiary interactions are directional, mimicking the packing preferences seen in proteins. The model properties are compared with other minimal protein‐like models, and we argue that the model presented here captures essential physics of protein folding (structurally well‐defined protein‐like native conformation and cooperative all‐or‐none folding transition). © 2003 Wiley Periodicals, Inc. Biopolymers 69: 399–405, 2003
Biophysical and structural property of the putative DNA‐binding protein, BldB, from Streptomyces lividans
Authors: Mishig‐Ochiriin Tsogbadrakh , Won Hyung‐Sik , Lee Chang‐Jin , Kang Sa‐Ouk , Lee Bong‐Jin
Published: June 2003

The bldB gene from Streptomyces lividans was cloned, and its product was overexpressed in Escherichia coli using a T7 expression system. Gel mobility shift assays showed that the BldB protein was functionally expressed in the E. coli system and may negatively regulate its own expression. The comparative analyses by mass spectrometry, Tris‐Tricine sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS‐PAGE), and analytical ultracentrifuge established that BldB is a dimeric protein with 24 kDa molecular mass, of which monomers do not covalently interact with each other. Gel filtration result implied that the protein shape would not be globular. More detailed structural investigations by CD and NMR spectroscopy confirmed that the majority of the BldB structure is not only disordered but also highly flexible. The highly reversible, but hardly cooperative, property of the thermal denaturation also supported the idea that the protein structure is not compact. However, the existence of a structural nucleus, of which the ordered conformation remains stabilized even at more than 80°C, was evidenced. The overall structure and the thermal stability of BldB were sensitive to pH, suggesting a proton‐induced conformation change. Altogether, the results provide the first detailed characterization on the biophysical and structural property of the putative DNA‐binding protein, BldB. © 2003 Wiley Periodicals, Inc. Biopolymers 69: 343–350, 2003
Anchorage of oligonucleotide hybridization by tethered phenazine nucleoside analogue
Authors: Zozulya V. , Blagoi Yu. , Dubey I. , Fedoryak D. , Makitruk V. , Ryazanova O. , Shcherbakova A.
Published: June 2003

UV absorption and fluorescence techniques with a thermal denaturation procedure were used in studies of the anchorage of an oligonucleotide hybridization by a covalently tethered nucleoside analogue of an intercalating imidazophenazine derivative (Pzn). The formation by the (dT)10Pzn conjugate of the duplex complex with (dA)15 and the triplex complex with (dA)15 or poly(dA)·poly(dT) was studied in buffered solutions with 0.11 and/or 1M sodium ions at the oligomer strand concentration of 10 μM. Because of the Pzn emission sensitivity to the interaction with adenine bases, a fluorescence technique was found to be effective in the detection of melting transitions. The attached Pzn substantially enhanced the thermal stability of complexes formed by (dT)10 because of the intercalation mechanism, which increased the temperature of half‐dissociation of the duplex by 10–12°C and of the triplexes by ∼13°C. With the assumption of a two‐state model of transition, the thermodynamic parameters for duplex formations were derived. The investigated variant of conjugation has a certain advantage over the widely used attachment via a flexible linker, consisting of a predetermined location of the Pzn chromophore in target sequences that makes it useful as a fluorescent reporter of the hybridization correctness. Molecular modeling was used to construct the geometries of the intercalation sites that turned out to be in conformity with the behavior of the Pzn fluorescence. © 2003 Wiley Periodicals, Inc. Biopolymers (Biospectroscopy), 2003
Direct determination of estriol 3‐ and 16‐glucuronides in pregnancy urine by column‐switching liquid chromatography with electrospray tandem mass spectrometry
Authors: Yang Yoon Jung , Lee Jeongae , Choi Man Ho , Chung Bong Chul
Published: June 2003

Using column‐switching liquid chromatography/tandem mass spectrometry (LC‐MS/MS), we developed an improved analytical method of urinary estriol glucuronides. This new method is derived predominantly from maternal and fetal precursors in pregnancy. We used in the following procedure: first, we filtered urine samples with a membrane filter. Next, we directly injected the 50 µL aliquot of urine samples onto a pre‐column. Then, after activating the column‐switching valve, we backflushed the loaded samples onto the C18 analytical column. Urine samples can be assayed within 20 min without any sample preparation steps. We monitored separated estriol glucuronides by negative electrospray ionization (ESI) and selected‐reaction monitoring (SRM). The calibration range of estriol‐3‐glucuronide (E3‐3G) and estriol‐16‐glucuronide (E3‐16G) was 0.1–20 µg/mL and the linearity of the method was 0.9984 for E3‐3G and 0.9987 for E3‐16G. The limits of detection at a signal‐to‐noise (S/N) ratio of 3 were 10 ng/mL (E3‐3G) and 5 ng/mL (E3‐16G). The analytical recovery was over 85% and, in general, inter‐day and intra‐day variability for precision and accuracy were less than 10%. When applied to a pregnancy urine sample to biomedical monitoring of the function of the maternal/fetal unit, the proposed method allowed rapid and sensitive screening for the detection of E3‐3G and E3‐16G. Copyright­© 2003 John Wiley & Sons, Ltd.
Interaction of soybean agglutinin with leukemic T‐cells and its use for their in vitro separation from normal lymphocytes by lectin‐affinity chromatography
Authors: Bakalova R. , Ohba H.
Published: June 2003

A procedure for separation of leukemic T‐cells from normal lymphocytes, using lectin‐affinity column chromatography, is described. CNBr‐activated Sepharose 6MB was used as a non‐mobile phase. The gel was covalently coupled with soybean agglutinin (SBA), then served as an affinity probe for fractionation of mixture of normal lymphocytes and leukemic cells. Leukemic cell lines, derived from acute lymphoblastic leukemia (Jurkat, MOLT‐4, RPMI‐8402), were tested. The elution of normal lymphocytes was carried out by PBS(−). The leukemic T‐cells, interacting with SBA, were removed by N‐acetyl‐D‐galactosamine or low‐concentration acetic acid. The type and viability of the separated cell fractions were analyzed by flow cytometry and fluorescent microscopy, using adequate fluorescent antibodies. The interaction of leukemic T‐cells with free SBA, as well as with SBA‐conjugated Sepharose beads, was examined fluorimetrically and visualized by fluorescent microscopy, using FITC‐SBA as a marker. The rate of cell elution on SBA‐affinity column decreased in order: normal > leukemic T‐cells. Both normal lymphocytes and leukemic T‐cells were removed in a mixture from SBA‐free Sepharose 6MB by PBS(−) and were not fractionated discretely. The leukemic T‐cells specifically interacted with SBA as well as with SBA‐affinity adsorbent. In contrast, the normal lymphocytes did not interact with free SBA as well as with SBA‐conjugated Sepharose beads in the concentrations applied. The method potentially combines a discrete cell fractionation with manifestation of a specific target cytotoxicity of SBA against leukemic T‐cells, without any influence on normal lymphocytes. Copyright © 2003 John Wiley & Sons, Ltd.
Plasticizers, antioxidants, and other contaminants found in air delivered by PVC tubing used in respiratory therapy
Authors: Hill Sandra S. , Shaw Brenda R. , Wu Alan H. B.
Published: June 2003

Of the many compounds that leach from respiratory therapy tubing into air passing through it, we selected five compounds to analyze. The five compounds are known to be potentially carcinogenic, toxic or known to induce estrogenic activity. Parts‐per‐million and parts‐per‐billion concentrations of these species were found in the air passing through the tubing: the plasticizers di‐(2‐ethylhexyl) phthalate (DEHP) and di‐ethyl phthalate (DEP), the antioxidants butylated hydroxy toluene (BHT) and p‐nonylphenol (p‐NP), and the contaminant (from commercial preparation of DEHP) 2‐ethylhexanol (2‐EH). These levels are high enough to cause some concern about exposure for patients who use oxygen on a long‐term basis, those sensitive or allergic to these species, or those with asthma. A method was developed for analysis of solid tubing samples, showing great variability in concentrations of small, volatile molecules from sample to sample. A method was also developed for pre‐concentration of small molecules onto Tenax adsorbants from air passing through the tubing. Both solid samples and adsorbant loaded with analyte were analyzed by direct dynamic thermal desorption gas chromatography mass spectrometry (GCMS). This study does not imply that adverse reactions by patients to chemical compounds leaching from respiratory medical tubing will occur but that further investigation is warranted. Copyright © 2003 John Wiley & Sons, Ltd.
Simultaneous determination of 16 estrogens, dehydroepiandrosterone and their glucuronide and sulfate conjugates in serum using sodium cholate micelle capillary electrophoresis
Authors: Katayama Masatoki , Matsuda Yoshifumi , Shimokawa Ken‐ichi , Kaneko Satoru
Published: June 2003

The simultaneous determination of 16 estrogens, dehydroepiandrosterone (DHEA) and their glucuronide and sulfate conjugates by micellar electrokinetic chromatography (MEKC) with sodium cholate micelle is reported. Sodium cholate, sodium dodecylsulfate (SDS) and α‐, β‐, γ‐cyclodextrins were studied as micelle reagents in the pH range of 7.0–10.0. Estrogens, DHEA and their glucuronide and sulfate conjugates were separated using a 50 cm × 50 µm capillary with 10 mM borate–phosphate buffer (pH 8.0) containing 50 mM sodium cholate as carrier. The method could simultaneously determine 1.0–1000 µg/mL of steroids and metabolites in 100 µL of serum by photometric detection at 214 nm within 14 min and 80 ng/mL steroids could be determined by using 2.0 mL of serum. The relative standards deviations were 6.7–7.7% at 10 µg/mL in serum. The recoveries were 89.1–92.0% with 10 µg/mL serum samples. Copyright © 2003 John Wiley & Sons, Ltd.
Consideration of the Effect of Irregular Catalytic Active Component Distributions in Mesopores – Extension of a Model for Wall Catalyzed Reactions in Microchannel Reactors
Authors: Platzer B. , Xu Y. , Roßmann T. , Födisch R. , Hönicke D.
Published: July 2003

Data available from the literature and experimental results have shown that the distribution of the catalytic active components can be irregular already for fresh catalysts. The determination of the local concentrations of the catalytic active components using wavelength dispersive X‐ray spectroscopy confirms this for microstructured wafers used in microchannel reactors. Considering this nonuniform distribution, the used model gives the relation between the local concentration profiles of the reactants inside the pores and the product yield in the entire pore. These results were used in an equation for the diffusion flux at the pore mouth, which is useful for a microchannel model developed in a recent paper [1]. The theoretical considerations deal with cylindrical pores with known reactant concentrations at the pore mouth and known distribution of the catalytic active component within the pore. Beside numerical results, some analytical solutions with low mathematical expense, applicable to special cases, are discussed. The nonconsideration of the irregular distribution of the catalytic active component can be the reason for difficulties during the extrapolation of experimental results to slightly different conditions and can have a great influence on the reaction results. The regarded examples are typical of wall‐catalyzed reactions in microchannel reactors with mesopores.
Volumetric Mass Transfer Coefficient in non‐Newtonian Fluids in Spout Fluid Beds
Authors: Anabtawi M.Z. , Hilal N. , Al Muftah A.E.
Published: July 2003

The volumetric liquid‐phase mass transfer coefficient, kLa, was determined by absorption of oxygen in air using six different carboxy‐methyl cellulose (CMC) solutions with different rheological values in three phase spout‐fluid beds operated continuously with respect to both gas and liquid. Three cylindrical columns of 7.4 cm, 11.4 cm, and 14.4 cm diameters were used. Gas velocity was varied between 0.00154–0.00563 m/s, liquid velocity between 0.0116–0.0387 m/s, surface tension between 0.00416–0.0189 N/m, static bed height between 6.0–10.8 cm, and spherical glass particles of 1.75 mm diameter were used as packing material. A single nozzle sparger of 1.0 cm diameter was used in the spouting line. The volumetric mass transfer coefficient was found to increase with gas velocity, liquid velocity, and static bed height and to decrease with the increase of the effective liquid viscosity of the CMC solution. A dimensionless correlation was developed and compared with those listed in the literature.
An Extended Planar C5 Conformation and a 310‐Helical Structure of Peptide Foldamer Composed of Diverse α‐Ethylated α,α‐Disubstituted α‐Amino Acids
Authors: Tanaka Masakazu , Nishimura Shin , Oba Makoto , Demizu Yosuke , Kurihara Masaaki , Suemune Hiroshi
Published: June 2003

Optically active peptide foldamers Tfa‐[(S)‐(αEt)Leu]‐[(S)‐(αEt)Nva]‐Deg‐[(S)‐(αEt)Nle]‐OEt (10) and Tfa‐[(S)‐(αEt)Val]‐[(S)‐(αEt)Leu]‐[(S)‐(αEt)Nva]‐Deg‐[(S)‐(αEt)Nle]‐OEt (11) composed of diverse α‐ethylated α,α‐disubstituted α‐amino acids were synthesized. The dominant conformation of these peptides in solution was an unusual, fully extended planar conformation, and that in the crystal state was both right‐handed (P) and left‐handed (M) 310‐helical structures in 10 and a P 310‐helical structure in 11, respectively. The preferred planar C5 conformation of the peptides prepared from chiral α‐ethylated α,α‐disubstituted α‐amino acids was drastically different from the 310‐helical structure of the peptides prepared from chiral α‐methylated α,α‐disubstituted α‐amino acids.
A Combined Experimental and Theoretical Electron Density Study of Intra‐ and Intermolecular Interactions in ThioureaS,S‐Dioxide
Authors: Lee Chi‐Rung , Tang Ting‐Hua , Chen Likey , Wang Yu
Published: June 2003

The thioureaS,S‐dioxide molecule is recognized as a zwitterion with a high dipole moment and an unusually long CS bond. The molecule has a most interesting set of intermolecular interactions in the crystalline state—a relatively strong O⋅⋅⋅HN hydrogen bond and very weak intermolecular C⋅⋅⋅S and N⋅⋅⋅O interactions. The molecule hasCssymmetry, and each oxygen atom is hydrogen‐bonded to two hydrogen atoms with O⋅⋅⋅HN distances of 2.837 and 2.826 Å and angles of 176.61 and 158.38°. The electron density distribution is obtained both from Xray diffraction data at 110 K and from a periodic density functional theory (DFT) calculation. Bond characterization is made in terms of the analysis of topological properties. The covalent characters of the CN, NH, CS, and SO bonds are apparent, and the agreement on the topological properties between experiment and theory is adequate. The features of the Laplacian distributions, bond paths, and atomic domains are comparable. In a systematic approach, DFT calculations are performed based on a monomer, a dimer, a heptamer, and a crystal to see the effect on the electron density distribution due to the intermolecular interactions. The dipole moment of the molecule is enhanced in the solid state. The typical values ofρbandHbof the hydrogen bonds and weak intermolecular C⋅⋅⋅S and N⋅⋅⋅O interactions are given. All the interactions are verified by the location of the bond critical point and its associated topological properties. The isovalue surface of Laplacian charge density and the detailed atomic graph around each atomic site reveal the shape of the valence‐shell charge concentration and provide a reasonable interpretation of the bonding of each atom.
Efficient Domino Process Based on the Catalytic Generation of Non‐Metalated, Conjugated Acetylides in the Presence of Aldehydes or Activated Ketones
Authors: Tejedor David , García‐Tellado Fernando , Marrero‐Tellado José Juan , de Armas Pedro
Published: June 2003

The extremely mild and highly efficient catalytic generation of non‐metalated, conjugated acetylides is reported. These acetylides are used to generate enol‐protected functionalized propargylic alcohols 1, 1,3‐dioxolane compounds 2, or 3,4,5‐trisubstituted 4,5‐dihydrofurans 4 through serial multibond‐forming processes. The method calls for a nucleophile (a tertiary amine or phosphine) as a chemical activator, a conjugated terminal acetylene as the acetylide source, and an aldehyde or activated ketone as the electrophilic partner. The chemical outcome of this process depends on the nature of the nucleophile, the temperature, stoichiometry and solvent, and it can be tailored selectively by the appropriate choice of the experimental conditions.