bluuebunny/crossref_metadata_2025 huggingface dataset:
A 2‐year follow‐up study of cigarette smoking and risk of dementia
Authors: Juan D. , Zhou D. H. D. , Li J. , Wang J. Y. J. , Gao C. , Chen M.
Published: April 2004

The report focused on investigating the relationship between cigarette smoking and dementia in elderly people through prospective studies. We did a 2‐year follow‐up study of elderly people. A total of 2820 participants aged 60 years old and over from six communities of Chongqing agreed to take part. Dementia was diagnosed with MMSE (Mini‐Mental State Examination) and DSM‐III‐R (Diagnostic and Statistical Manual of Mental Disorders). Participants were classified as never smokers, past smokers, and current smokers. During follow‐up, we recorded incident cases of dementia. The association of smoking and dementia was investigated using proportional hazards regression analysis. A total of 121 incident cases of dementia were detected, of which 84 (69%) were Alzheimer's disease, 17 (14%) were vascular dementia, and 21(17%) were other dementia. Compared with never smokers, current smokers had an increased risk of Alzheimer's disease (RR = 2.72; 95% CI = 1.63–5.42) and vascular dementia (RR = 1.98; 95% CI = 1.53–3.12) adjusting for age, sex, education, blood pressure, and alcohol intake. Compared with light smokers, the adjusted risk of Alzheimer's disease was significantly increased among smokers with a medium level of exposure (RR = 2.56; 95% CI = 1.65–5.52), with an even higher risk of Alzheimer's disease in the heavy smoking group (RR = 3.03; 95% CI = 1.25–4.02). Smoking was associated with the risk of dementia. This study suggests that both smoking status and amount is associated with dementia.
Ionotropic Glutamate Receptor Antagonists Modulate Cue‐Induced Reinstatement of Ethanol‐Seeking Behavior
Authors: Bäckström Pia , Hyytiä Petri
Published: April 2004

Abstract: Background: Glutamatergic neurotransmission has been implicated in drug‐environment conditioning, but little is known about the role of glutamate in alcohol seeking maintained by alcohol‐associated cues. Therefore, we examined the effects of ionotropic glutamate receptor antagonists on cue‐induced ethanol‐seeking behavior in the extinction/reinstatement model.

Methods: Rats were trained to orally self‐administer ethanol (10% w/v) and a nonrewarding (80 μM) quinine solution on randomly alternating days. Ethanol and quinine availability were signaled by olfactory discriminative stimuli (S+/S−). In addition, ethanol delivery was accompanied by a light stimulus (CS+) and quinine delivery by an auditory stimulus (CS−). Thereafter, rats were subjected to extinction training during which responding had no programmed consequences. Reinstatement of responding was tested under three conditions: in the presence of the S−/CS−, S+/CS+, and S+/CS+ together with a small (0.2 ml) response‐contingent oral ethanol dose at the beginning of the reinstatement session (S+/CS+/priming). We examined the effects of the noncompetitive NMDA receptor antagonist MK‐801 (0, 0.05, 0.15 mg/kg intraperitoneally), the competitive NMDA antagonist CGP39551 (0, 5, 10 mg/kg intraperitoneally), the NMDA/glycine receptor antagonist L‐701,324 (0, 2, 4 mg/kg intraperitoneally), the AMPA/kainate receptor antagonist CNQX (0, 0.5, 1.5 mg/kg intraperitoneally), and the opioid receptor antagonist naltrexone (0, 0.3, 1 mg/kg subcutaneously) on ethanol seeking under the S+/CS+/priming condition.

Results: Presentation of the S+/CS+ stimulus condition reinstated extinguished responding, whereas presentation of the S−/CS− condition did not. Response‐contingent ethanol priming enhanced reinstatement further. Under these reinstatement conditions, L‐701,324, CNQX, and naltrexone inhibited ethanol‐seeking behavior significantly. In contrast, MK‐801 and CGP39551 failed to affect reinstated responding.

Conclusions: These results show that glutamate antagonism suppresses ethanol‐seeking behavior induced by ethanol‐paired stimuli. Furthermore, the data suggest that ionotropic glutamate receptors may have differential roles in mediation of this behavior.
Elastase and elastase inhibitor from Aspergillus fumigatus, Aspergillus flavus and Aspergillus niger
Authors: Okumura Yoshiyuki , Ogawa Kenji , Nikai Toshiaki
Published: April 2004

Elastolytic and elastase inhibitory activities were investigated for 13 strains ofAspergillus fumigatus, three strains ofAspergillus flavusand three strains ofAspergillus niger. Nine of the 13 strains ofA. fumigatusand all strains ofA. flavusdemonstrated elastase activity (more than 1 unit ml−1). Six of the 13 strains ofA. fumigatusand all strains ofA. flavusexpressed elastase inhibitory activity (more than 2 units ml−1). However, no elastase or elastase inhibitory activities were observed withA. niger. It was also found that crude elastase inhibitors from six strains ofA. fumigatusand two strains ofA. flavuswere stable to heat treatment at 100 °C for 10 min. In addition, human leukocyte elastases were inhibited by crude elastase inhibitors fromA. fumigatusandA. flavus; however, no effect was observed on the elastase derived from porcine pancreas.
Searching for folded proteins in vitro and in silico
Authors: Watters Alexander L. , Baker David
Published: April 2004

Understanding the sequence determinants of protein structure, stability and folding is critical for understanding how natural proteins have evolved and how proteins can be engineered to perform novel functions. The complexity of the protein folding problem requires the ability to search large volumes of sequence space for proteins with specific structural or functional characteristics. Here we describe our efforts to identify novel proteins using a phage‐display selection strategy from a ‘mini‐exon’ shuffling library generated from the yeast genome and from completely random sequence libraries, and compare the results to recent successes in generating novel proteins using in silico protein design.
Selection of stably folded proteins by phage‐display with proteolysis
Authors: Bai Yawen , Feng Hanqiao
Published: April 2004

To facilitate the process of protein design and learn the basic rules that control the structure and stability of proteins, combinatorial methods have been developed to select or screen proteins with desired properties from libraries of mutants. One such method uses phage‐display and proteolysis to select stably folded proteins. This method does not rely on specific properties of proteins for selection. Therefore, in principle it can be applied to any protein. Since its first demonstration in 1998, the method has been used to create hyperthermophilic proteins, to evolve novel folded domains from a library generated by combinatorial shuffling of polypeptide segments and to convert a partially unfolded structure to a fully folded protein.
Phage‐display as a tool for quantifying protein stability determinants
Authors: Kotz Joanne D. , Bond Christopher J. , Cochran Andrea G.
Published: April 2004

To address questions of protein stability, researchers have increasingly turned to combinatorial approaches that permit the rapid analysis of libraries of protein variants. Phage‐display has proved to be a powerful tool for analyzing protein stability due to the large library size and the robustness of the phage particle to a variety of denaturing conditions. With the B1 domain of protein G (GB1) and a camelid heavy chain antibody as model systems, we are using phage‐display libraries to experimentally address questions that have generally been addressed in silico, either through computational studies or statistical analysis of known protein structures. One effort has focused on identifying novel solutions to repacking the hydrophobic core of GB1, while maintaining stability comparable to the wild type protein. In a second study, a small set of substitutions in complimentarity‐determining region 3 was found to stabilize the framework of the camelid antibody. Another major focus has been to obtain quantitative data on β‐sheet stability determinants. We have successfully adapted a phage‐display method for quantitating affinities of protein variants (shotgun alanine scanning) to analysis of GB1 stability. Using this method, we have analyzed the energetic contributions of cross‐strand side chain–side chain interactions. Finally, we discuss parameters to consider in using phage‐display to discriminate subtle stability differences among fully folded variants. Overall, this method provides a fast approach for quantitatively addressing biophysical questions.
Unique features of recombinant heme oxygenase of Drosophila melanogaster compared with those of other heme oxygenases studied
Authors: Zhang Xuhong , Sato Michihiko , Sasahara Masanao , Migita Catharina T. , Yoshida Tadashi
Published: April 2004

We cloned a cDNA for a Drosophila melanogaster homologue of mammalian heme oxygenase (HO) and constructed a bacterial expression system of a truncated, soluble form of D. melanogaster HO (DmΔHO). The purified DmΔHO degraded hemin to biliverdin, CO and iron in the presence of reducing systems such as NADPH/cytochrome P450 reductase and sodium ascorbate, although the reaction rate was slower than that of mammalian HOs. Some properties of DmHO, however, are quite different from other known HOs. Thus DmΔHO bound hemin stoichiometrically to form a hemin–enzyme complex like other HOs, but this complex did not show an absorption spectrum of hexa‐coordinated heme protein. The absorption spectrum of the ferric complex was not influenced by changing the pH of the solution. Interestingly, an EPR study revealed that the iron of heme was not involved in binding heme to the enzyme. Hydrogen peroxide failed to convert it into verdoheme. A spectrum of the ferrous–CO form of verdoheme was not detected during the reaction from hemin under oxygen and CO. Degradation of hemin catalyzed by DmΔHO yielded three isomers of biliverdin, of which biliverdin IXα and two other isomers (IXβ and IXδ) accounted for 75% and 25%, respectively. Taken together, we conclude that, although DmHO acts as a real HO in D. melanogaster, its active‐site structure is quite different from those of other known HOs.
Vasoactive intestinal peptide and pituitary adenylate cyclase‐activating polypeptide attenuate the cigarette smoke extract‐induced apoptotic death of rat alveolar L2 cells
Authors: Onoue Satomi , Ohmori Yuki , Endo Kosuke , Yamada Shizuo , Kimura Ryohei , Yajima Takehiko
Published: April 2004

Chronic obstructive pulmonary disease is a major clinical disorder usually associated with cigarette smoking. A central feature of chronic obstructive pulmonary disease is inflammation coexisting with an abnormal protease/antiprotease balance, leading to apoptosis and elastolysis. In an in vitro study of rat lung alveolar L2 cells, cigarette smoke extract (CSE) induced apoptotic cell death. Exposure of L2 cells to CSE at a concentration of 0.25% resulted in a 50% increase of caspase‐3 and matrix metalloproteinase (MMP) activities. Specific inhibitors for caspases and MMPs attenuated the cytotoxicity of CSE. RT‐PCR amplification identified VPAC2 receptors in L2 cells. A radioligand‐binding assay with 125I‐labeled vasoactive intestinal peptide (VIP) found high affinity and saturable 125I‐labeled VIP‐binding sites in L2 cells. VIP and pituitary adenylate cyclase‐activating polypeptide (PACAP27) were approximately equipotent for both VIP receptor binding and stimulation of cAMP production in L2 cells. Both neuropeptides, at concentrations higher than 10−13 m, produced a concentration‐dependent inhibition of CSE‐induced cell death in L2 cells. VIP, at 10−7 m, reduced CSE‐stimulated MMP activity and caspase‐3 activation. The present study has shown that VIP and PACAP27 significantly attenuate the cytotoxicity of CSE through the activation of VPAC2 receptor, and the protective effect of VIP may partly be the result of a reduction in the CSE‐induced stimulation of MMPs and caspases.
Purification and structural study of the β form of human cAMP‐dependent protein kinase inhibitor
Authors: Jin Rong , Dai Linsen , Zheng Jinbiao , Ji Chaoneng
Published: April 2004

The β form of human cAMP‐dependent protein kinase inhibitor (human PKIβ), a novel heat‐stable protein, was isolated with high yield using a bacterial expression system. Assays of PKI activity demonstrated that purified PKIβ inhibits the catalytic subunit of cAMP‐dependent protein kinase. FTIR, Raman spectroscopy and CD experiments implied that human PKIβ contained only small amounts of α‐helix and β‐structures, but large amounts of random coil and turn structures, which may explain its high thermostability. The details of its conformational changes in response to heat were studied by CD experiments for the first time, revealing that the protein unfolded at high temperature and refolded when decreased to room temperature.
Transient‐phase kinetic studies on the nucleotide binding to 3α‐hydroxysteroid dehydrogenase from Pseudomonas sp. B‐0831 using fluorescence stopped‐flow procedures
Authors: Ueda Shigeru , Oda Masayuki , Imamura Shigeyuki , Ohnishi Masatake
Published: April 2004

The dual nucleotide cofactor‐specific enzyme, 3α‐hydroxysteroid dehydrogenase (3α‐HSD) from Pseudomonas sp. B‐0831, is a member of the short‐chain dehydrogenase/reductase (SDR) superfamily. Transient‐phase kinetic studies using the fluorescence stopped‐flow method were conducted with 3α‐HSD to characterize the nucleotide binding mechanism. The binding of oxidized nucleotides, NAD+, NADP+ and nicotinic acid adenine dinucleotide (NAAD+), agreed well with a one‐step mechanism, while that of reduced nucleotide, NADH, showed a two‐step mechanism. This difference draws attention to previous characteristic findings on rat liver 3α‐HSD, which is a member of the aldo‐keto reductase (AKR) superfamily. Although functionally similar, AKRs are structurally different from SDRs. The dissociation rate constants associated with the enzyme–nucleotide complex formation were larger than the kcat values for either oxidation or reduction of substrates, indicating that the release of cofactors is not rate‐limiting overall. It should also be noted that kcat for a substrate, cholic acid, with NADP+ was only 6% of that with NAD+, and no catalytic activity was detectable with NAAD+, despite the similar binding affinities of nucleotides. These results suggest that a certain type of nucleotide can modulate nucleotide‐binding mode and further the catalytic function of the enzyme.
Relation of ANP and BNP to their N‐terminal fragments in fetal circulation: evidence for enhanced neutral endopeptidase activity and resistance of BNP to neutral endopeptidase in the fetus
Authors: Walther Thomas , Stepan Holger , Pankow Kristin , Gembardt Florian , Faber Renaldo , Schultheiss Heinz‐Peter , Siems Wolf‐Eberhard
Published: April 2004

Objectives  To investigate the role of neutral endopeptidase in the turnover of atrial (ANP) and brain (BNP) natriuretic peptides and their N‐terminal fragments in human fetal circulation.

Design  Retrospective case–control study.

Setting  Department of Obstetrics and Gynaecology, University of Leipzig, Germany.

Sample  Nine control pregnancies and nine pregnancies with rhesus isoimmunisation before and after intravascular transfusion.

Methods  Natriuretic peptides and N‐terminal fragments in maternal and fetal blood were measured by radio‐immunoassay. Neutral endopeptidase activity was determined by HPLC.

Main outcome measures  Maternal and fetal plasma concentrations of ANP, NT‐proANP, BNP, NT‐proBNP as well as neutral endopeptidase activity. Ratios between mature peptide and N‐terminal fragment. Feto‐maternal ratio.

Results  Plasma NT‐proANP concentrations are 11.7 times higher in fetal than in maternal circulation. The ANP concentration is only 1.8 times higher, probably due to doubled neutral endopeptidase activity. In contrast, both NT‐proBNP and BNP are doubled in fetal plasma. Fetuses with Rh isoimmunisation had significantly higher NT‐proBNP but not NT‐proANP and neutral endopeptidase activity than controls. An additional volume load by intravascular transfusion did not influence N‐terminal fragments or neutral endopeptidase activity.

Conclusions  Our study is the first to determine NT‐pro natriuretic peptide concentrations and neutral endopeptidase activity in human fetuses. The results show that increased fetal neutral endopeptidase activity shifts the ANP/NT‐proANP but not the BNP/NT‐proBNP ratio and that the shifted BNP/NT‐proBNP ratio in fetuses with Rh isoimmunisation does not involve increased neutral endopeptidase activity. These findings point to a BNP degradation that is not dependent on neutral endopeptidase.
Agitation in Older Persons with Dementia: A Research Synthesis
Authors: Williams‐Burgess Christine , Ugarriza Doris , Gabbai Mary
Published: April 2004

(1) Caregiver stress can result in rapid turnover of qualified personnel thus negatively affecting the care of elderly agitated clients. Three areas of nursing research address the treatment of agitation in demented elders. Subject‐centered studies address the effect of interventions such as massage, familiar voices, and light. Environment‐centered studies address settings such as dining room location. Caregiver‐centered studies address variables such as staff educational level and staff‐client ratio. In spite of the promising findings testing these interventions, physical and chemical restraints are still being used ineffectively and often indiscriminately to treat agitation in cognitively impaired elders.
A Conversation with Stephan Schmidheiny
Authors: Lank Alden G.
Published: April 2004

This interview with Stephan Schmidheiny, a leading Swiss owner-manager with a strong international background, brings out his involvement with his fourth-generation family enterprise and also his provocative views on the present and future role of family business throughout the world.
The Family Business Market: A Conversation with Laura Yanes
Authors: Astrachan Joseph H.
Published: April 2004

Laura Yanes examines the complex nature of the family business market and discusses the design of conferences for family businesses.
Capitalism and Kinship: Do Institutions Matter in the Labor Market?
Authors: Doeringer Peter B. , Moss Philip I. , Terkla David G.
Published: April 2004

This study examines the determination of employment and pay on capitalist and kinship vessels in the New England fishing industry. Capitalist vessels resemble standard competitive firms in the way that employment and pay respond to changing market conditions; kinship vessels operate under work guarantees and income-sharing rules. These differences in institutional rules lead to different patterns of income, employment, growth, and labor adjustment. The study shows how an understanding of the institutional structure of labor markets can contribute to the design of public policies to facilitate adjustment to change and to promote industrial growth.
Profiling Preference for Employment in Family-Owned Firms
Authors: Covin Teresa Joyce
Published: April 2004

This article summarizes findings from an exploratory investigation of factors related to preference for employment in family-owned firms. The sample for the study consists of undergraduate and graduate students enrolled in business management classes. Discriminant analysis was used to identify life history and job characteristic variables that distinguish between groups of individuals who expressed a high and low preference for working in a family-owned firm. Additional findings from the study are summarized, and implications for the management of family firms are discussed.
Forced Response of a Squeeze Film Damper and Identification of Force Coefficients From Large Orbital Motions
Authors: San Andre´s Luis , De Santiago Oscar
Published: April 2004

Experimentally derived damping and inertia force coefficients from a test squeeze film damper for various dynamic load conditions are reported. Shakers exert single frequency loads and induce circular and elliptical orbits of increasing amplitudes. Measurements of the applied loads, bearing displacements and accelerations permit the identification of force coefficients for operation at three whirl frequencies (40, 50, and 60 Hz) and increasing lubricant temperatures. Measurements of film pressures reveal an early onset of air ingestion. Identified damping force coefficients agree well with predictions based on the short length bearing model only if an effective damper length is used. A published two-phase flow model for air entrainment allows the prediction of the effective damper length, and which ranges from 82% to 78% of the damper physical length as the whirl excitation frequency increases. Justifications for the effective length or reduced (flow) viscosity follow from the small through flow rate, not large enough to offset the dynamic volume changes. The measurements and analysis thus show the pervasiveness of air entrainment, whose effect increases with the amplitude and frequency of the dynamic journal motions. Identified inertia coefficients are approximately twice as large as those derived from classical theory.
Axial Load Effect on Contact Fatigue Life of Cylindrical Roller Bearings
Authors: Cheng Wangquan (Winston) , Shih Shan , Grace John , Tu Wenke
Published: April 2004

Besides primarily carrying radial load, cylindrical roller bearings with flanges or lips on both inner and outer raceways need also carry axial load in some applications. Because of the axial load, the equivalent dynamic load of the bearing will be increased and the bearing contact fatigue life will be decreased accordingly. The axial load effect on the roller bearing fatigue life had been studied by researchers in the past. Because of different assumptions used in their models, quite different predictions were made in their analysis. This work combines the methods used in the Fernlund-Synek and Brandlein models and studies general contact conditions such as partial contact along the roller length, partial loading zone of the bearing race, manufacturing tolerance and running-in effects on roller length, etc. New formulas for equivalent dynamic loads of the rotating and stationary races are derived. A fatigue limit load is also included in the life calculation to reflect the latest development in contact fatigue life analysis.
Dynamic Response of Eccentric Face Seals to Synchronous Shaft Whirl
Authors: Wileman J.
Published: April 2004

This work provides an analytical technique for computing the seal face misalignment which results from synchronous whirl of the shaft. The eccentric dynamic response is obtained for seals in which both mating faces are mounted on flexible supports. Responses for seals with a single flexibly mounted stator or rotor are also obtained as degenerate cases of the more general result. Synchronous shaft whirl is shown to have a significant effect on the steady-state response of all these seals, while not affecting the stability threshold. The steady-state response is obtained by solution of a simple matrix equation for the general case, and can be obtained in closed form for the degenerate cases of the flexibly mounted stator or flexibly mounted rotor. A numerical example of the solution technique is presented, and the influence of speed is examined. Extension of the method to shaft motions other than synchronous whirl is briefly discussed.
On the Frictional Heating in Single Summit Contacts: Towards Failure at Asperity Level in Lubricated Systems
Authors: van der Heide E. , Schipper D. J.
Published: April 2004

The influence of surface roughness and thermal conductivity on seizure in lubricated contacts is described in this work by quantifying the action of individual asperities in relation to local surface temperature rise. Application of the model to a contact situation in metal forming of stainless steel sheet material reveals the importance of a high quality finish in terms of the center line average roughness of the surface. Calculations show that seizure of single summit contacts can be avoided by surfaces with enhanced thermal conductivity.
Acoustic properties of coral sands, Waikiki, Hawaii
Authors: Fu S. S. , Tao C. , Prasad M. , Wilkens R. H. , Frazer L. N.
Published: April 2004

An in situ experimental study of variations of compressional wave speed and attenuation with depth in natural coral sands has been made offshore of Oahu, Hawaii. In situ data were collected at a center frequency of 7.5 kHz. Compressional wave speed averages around 1620 m/s and attenuation (expressed as Qp−1, the reciprocal of the quality factor) decreases from 0.04 at the seafloor to 0.01 at 2 m depth. Very little change in compressional wave speed is seen to 9 m below the seafloor. Coral sand sound speeds are lower than those reported elsewhere for quartz sand. Waveforms recorded over the upper 9 m below the seafloor exhibit virtually no peak broadening, suggesting that scattering contributes little to the in situ attenuation. The relationship of attenuation to frequency in the coral sands agrees with Hamilton’s observations of attenuation in other sediments, although the coral sand attenuation is slightly higher than in other sediments. The coral sand relationship between attenuation and porosity also agrees with Hamilton’s when the volume of intraparticle voids is deducted from the total porosity.
Auditory steady-state responses reveal amplitude modulation gap detection thresholds
Authors: Ross Bernhard , Pantev Christo
Published: April 2004

Auditory evoked magnetic fields were recorded from the left hemisphere of healthy subjects using a 37-channel magnetometer while stimulating the right ear with 40-Hz amplitude modulated (AM) tone-bursts with 500-Hz carrier frequency in order to study the time-courses of amplitude and phase of auditory steady-state responses (ASSRs). The stimulus duration of 300 ms and the duration of the silent periods (3–300 ms) between succeeding stimuli were chosen to address the question whether the time-course of the ASSR can reflect both temporal integration and temporal resolution in the central auditory processing. Long lasting perturbations of the ASSR were found after gaps in the AM sound, even for gaps of short duration. These were interpreted as evidences for an auditory reset mechanism. Concomitant psycho-acoustical tests corroborated that gap durations perturbing the ASSR were in the same range as the threshold for AM gap detection. Magnetic source localizations estimated the ASSR sources in the primary auditory cortex, suggesting that the processing of temporal structures in the sound is performed at or below the cortical level.
Lamb wave propagation in elastic plates coated with viscoelastic materials
Authors: Simonetti F.
Published: April 2004

This paper addresses the effects of attenuative coatings on the dispersion characteristics of Lamb wave propagation in elastic plates. The topology of phase velocity and guided wave attenuation spectra is analyzed as a function of the coating internal damping (longitudinal and shear bulk attenuations) and it is proved that in contrast to elastic plates, all modes are propagating albeit with large attenuation in some cases. An energy-based correspondence between the dispersion of the attenuative bilayer and that of a related elastic bilayer is derived in order to investigate separately the effects of the longitudinal and shear bulk attenuations on the attenuation of the guided modes. It is shown that at low frequency the guided wave attenuation is only slightly affected by the longitudinal bulk attenuation, while the contribution of the shear bulk attenuation is substantial. The attenuation characteristics of shear horizontal modes are compared with those of Lamb modes in order to identify the mode and the frequencies which result in minimum guided wave attenuation.
SUSTAINING SUPERCOOLED MIXED PHASE VIA RESONANT OSCILLATIONS OF THE ORDER PARAMETER
Authors: RAY RAJARSHI , SANYAL SOMA , SRIVASTAVA AJIT M.
Published: April 2004

We investigate the dynamics of a first order transition when the order parameter field undergoes resonant oscillations, driven by a periodically varying parameter of the free energy. This parameter could be a background oscillating field as in models of pre-heating after inflation. In the context of condensed matter systems, it could be temperature T, or pressure, external electric/magnetic field etc. We show that with suitable driving frequency and amplitude, the system remains in a type of mixed phase, without ever completing transition to the stable phase, even when the oscillating parameter of the free energy remains below the corresponding critical value (for example, with oscillating temperature, T always remains below the critical temperature Tc). This phenomenon may have important implications. In cosmology, it will imply prolonged mixed phase in a first order transition due to coupling with background oscillating fields. In condensed matter systems, it will imply that using oscillating temperature (or, more appropriately, pressure waves) one may be able to sustain liquids in a mixed phase indefinitely at low temperatures, without making transition to the frozen phase.
RARE HADRONIC B DECAYS
Authors: FRY J. R.
Published: April 2004

Recent data from the rare decays of B mesons into hadronic final states is presented from BaBar, Belle, CDF and CLEO. Where possible the data are compared with theoretical calculations, with the twin aims of further testing the Standard Model and searching for evidence of new physics. A brief description is given of some theoretical approaches in order to indicate which decays are the most sensitive for further study.
RADIATIVE AND ELECTROWEAK RARE B DECAYS
Authors: NAKAO M.
Published: April 2004

This report summarizes the latest experimental results on radiative and electroweak rare B meson decays. These rare decay processes proceed through the Flavor-Changing-Neutral-Current processes, and thus are sensitive to the postulated new particles in the theories beyond the Standard Model. Experiments at e+e- colliders, Belle, BaBar and CLEO, have been playing the dominant role, while the CDF and D0 experiments have just started to provide new results from Tevatron Run-II. The most significant achievement is the first observation of the decay B→K*ℓ+ℓ-, which opens a new window to search for new physics in B meson decays.
Optical vortices in dispersive nonlinear Kerr‐type media
Authors: Kovachev Lubomir M.
Published: April 2004

The applied method of slowly varying amplitudes gives us the
possibility to reduce the nonlinear vector integrodifferential
wave equation of the electrical and magnetic vector fields to the
amplitude vector nonlinear differential equations. Using this
approximation, different orders of dispersion of the linear and
nonlinear susceptibility can be estimated. Critical values of
parameters to observe different linear and nonlinear effects are
determined. The obtained amplitude equations are a vector version
of 3D + 1 nonlinear Schrödinger equation (VNSE)
describing the evolution of slowly varying amplitudes of
electrical and magnetic fields in dispersive nonlinear Kerr‐type
media. We show that VNSE admits exact vortex solutions with
classical orbital momentum ℓ = 1 and finite energy. Dispersion
region and medium parameters necessary for experimental
observation of these vortices are determined.
Global boundedness, interior gradient estimates, and boundaryregularity for the mean curvature equation with boundaryconditions
Authors: Liang Fei-Tsen
Published: April 2004

We obtain global estimates for the modulus, interior gradient
estimates, and boundary Hölder continuity estimates for
solutions u to the capillarity problem and to the Dirichlet
problem for the mean curvature equation merely in terms of the
mean curvature, together with the boundary contact angle in the
capillarity problem and the boundary values in the Dirichlet
problem.
Effect of Substitution on the Change of Refractive Index in Dithienylethenes: An Ellipsometric Study
Authors: Bertarelli C. , Bianco A. , D'Amore F. , Gallazzi M. C. , Zerbi G.
Published: April 2004

An ellipsometric study was carried out in order to investigate the photoinduced change of the refractive index (Δn) of a series of diarylethenes across the entire spectral range 260–1700 nm. This technique allowed examination of the influence of the resonance conditions on the refractive index. Changing the chemical design of diarylethenes by introducing electron‐donating or electron‐withdrawing substituents in 5,5′‐positions of thiophyene allowed derivation of some correlations between chemical structure and Δn. A strong donor substituent directly linked to the 5,5′‐position of the diarylethene moiety gave rise to an increase in the change of the refractive index. 1,2‐bis(2‐methyl‐5‐formyl‐3‐thienyl)perfluorocyclopentene phenyl hydrazone showed a large and stable Δn of 0.005 at 1.5 μm and appeared to be a good candidate for the development of telecommunication devices.
Predictive dynamic model of single‐stage ultra‐rapid pressure swing adsorption
Authors: Kopaygorodsky E. M. , Guliants V. V. , Krantz W. B.
Published: April 2004

A dynamic model is developed based on the preliminary set of assumptions to determine the viability of a pulsed Ultra‐Rapid Pressure Swing Adsorption (URPSA) air‐separation process using a 5A zeolite monolith adsorbent. The new model was shown to predict the performance of the Rapid PSA process investigated experimentally in 1986 by Pritchard and Simpson. The model predicts that single‐stage URPSA is capable of producing oxygen purities of 85%, product recoveries of around 60%, and a bed‐size factor of around 0.00073. A very small bed‐size factor and large product recoveries are characteristic of this novel process, which implies improved efficiency of separation per unit mass of adsorbent material. The model developed here provides the first assessment of the viability of ultra‐rapid cycles and thin monolithic adsorbents for air separation by PSA. © 2004 American Institute of Chemical Engineers AIChE J, 50: 953–962, 2004
Total Syntheses of Colchicine in Comparison: A Journey through 50 Years of Synthetic Organic Chemistry
Authors: Graening Timm , Schmalz Hans‐Günther
Published: April 2004

Colchicine, the major alkaloid of the meadow saffron, is one of the most prominent natural products and, like other tubulin‐binding natural products (e.g. taxol and the epothilones), exhibits great pharmaceutical potential. The first syntheses in the late 1950s were milestones in natural product synthesis. But even today this structurally supposedly simple molecule poses a challenge to synthetic chemists. Only in the last years have syntheses been developed that are efficient enough to provide novel structurally modified colchicine analogues. The comparative examination of all known colchicine total syntheses undertaken in this Review not only reveals the tremendous progress in synthetic organic methodology over the past decades, but also shows how the unique synthetic problems posed by this molecule can be solved in an exceptionally creative manner. Only a few target molecules have been synthesized in such multifaceted ways.
Sentinel lymph node biopsy is not accurate in predicting lymph node status for patients with cervical carcinoma
Authors: Marchiolè Pierangelo , Buénerd Annie , Scoazec Jean‐Yves , Dargent Daniel , Mathevet Patrice
Published: April 2004

BACKGROUND

The authors evaluated the accuracy of sentinel lymph node biopsy in predicting lymph node status for patients with early cervical carcinoma. In particular, the authors set out to determine the false‐negative rate associated with sentinel lymph node biopsy in this setting.

METHODS

Twenty‐nine consecutive patients with early cervical carcinoma who were treated with pelvic laparoscopic lymphadenectomy and radical surgery underwent sentinel lymph node biopsy following lymphatic mapping with patent blue dye. All sentinel and nonsentinel lymph nodes were evaluated for micrometastases via multilevel sectioning followed by immunohistochemical staining.

RESULTS

At least one sentinel lymph node was identified for each patient. On routine pathologic evaluation, 3 patients (10%) were found to have positive lymph nodes. Among the remaining 26 patients, multilevel sectioning in conjunction with immunohistochemical analysis identified 5 patients (19%) who had micrometastases in the pelvic lymph nodes. Two of these five patients had micrometastases in a sentinel lymph node; however, the more notable finding was that the other three patients had micrometastases in nonsentinel pelvic lymph nodes despite having negative findings on sentinel lymph node biopsy. Thus, the negative predictive value of sentinel lymph node biopsy in the current study was 87.5%.

CONCLUSIONS

Multilevel sectioning followed by cytokeratin immunohistochemistry may identify additional patients who have lymph node micrometastases; in the current study, this technique identified cases in which micrometastases were present in nonsentinel lymph nodes even when sentinel lymph nodes were found to be negative for disease on biopsy. This high false‐negative rate associated with sentinel lymph node biopsy, raises questions regarding the validity of the sentinel lymph node concept in cervical carcinoma. Cancer 2004. © 2004 American Cancer Society.
Use of 1,8‐bis‐(dimethylamino)‐naphthalene/H18F complex as new radiofluorinating agent
Authors: Pascali Giancarlo , Kiesewetter Dale O. , Salvadori Piero A. , Eckelman William C.
Published: April 2004

Radiopharmaceuticals containing an 18F label are of increasing interest due to their utilization in PET imaging. However, the bottleneck in these applications is the limited methods available for introduction of this radionuclide into biologically interesting molecules. In this work, we have evaluated a new radiofluorination method based on the properties of the complex between 1,8‐(dimethylamino)‐naphthalene (PS) and [18F]–HF. The results obtained on various model substrates suggest that, in some limited cases, this new procedure can be regarded as a possible alternative to the traditional nucleophilic route using K222/K2CO3 in CH3CN. Copyright © 2004 John Wiley & Sons, Ltd.
Spectral correlative chromatography and its application to analysis of chromatographic fingerprints of herbal medicines
Authors: Li Bo‐Yan , Hu Yun , Liang Yi‐Zeng , Huang Lan‐Fang , Xu Cheng‐Jian , Xie Pei‐Shan
Published: April 2004

A signal‐processing method known as spectral correlative chromatography (SCC) for two‐dimensional data obtained from hyphenated chromatography is developed and applied to chemical chromatographic fingerprint data sets of herbal medicine under specific experimental conditions. The method can judge the presence or absence of a spectral correlative peak among the spectrochromatograms. A local least squares regression model (LLS) is constructed in a piecewise manner to correct the shifts of retention time of some peaks of interest in the chromatograms of various test samples. The results compare favorably with those obtained by a two‐point calibrated algorithm. It is shown that performing SCC and LLS on the piecewise clusters of various chromatographic fingerprints is more helpful in practice in revealing their common nature and for characterizing the chemical constituents. This approach holds great potential for facilitating quality control of herbal medicines.
Non‐recursive solution of sparse block Hessenberg systems
Authors: Favati P. , Lotti G. , Menchi O.
Published: April 2004

A double‐phase algorithm, based on the block recursive LU decomposition, has been recently proposed to solve block Hessenberg systems with sparsity properties. In the first phase the information related to the factorization of A and required to solve the system, is computed and stored. The solution of the system is then computed in the second phase. In the present paper the algorithm is modified: the two phases are merged into a one‐phase version having the same computational cost and allowing a saving of storage. Moreover, the corresponding non‐recursive version of the new algorithm is presented, which is especially suitable to solve infinite systems where the coefficient matrix dimension is not a priori fixed and a subsequent size enlargement technique is used. A special version of the algorithm, well suited to deal with block Hessenberg matrices having also a block band structure, is presented. Theoretical asymptotic bounds on the computational costs are proved. They indicate that, under suitable sparsity conditions, the proposed algorithms outperform Gaussian elimination. Numerical experiments have been carried out, showing the effectiveness of the algorithms when the size of the system is of practical interest. Copyright © 2004 John Wiley & Sons, Ltd.
Physical aging of an epoxy subsequent to relative humidity jumps through the glass concentration
Authors: Zheng Y. , Priestley R. D. , McKenna G. B.
Published: April 2004

In our previous work, we showed that the structural recovery responses of an epoxy after relative humidity (RH)‐jumps through the glass concentration have similar phenomenology to, but different kinetics from, those obtained by temperature (T)‐jumps. In this article, we report results from physical aging experiments of the same epoxy after RH‐jumps. The results show that time‐RH superposition and time–aging time superposition can be used to describe the viscoelastic responses in RH‐jump experiments. The similarities and differences between RH‐jump and T‐jump conditions are also presented. In addition, the difficulties in modeling the combined effects of temperature and relative humidity changes that result from these differences are discussed. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2107–2121, 2004
Time effect on bentazone sorption and degradation in soil
Authors: Boivin Arnaud , Cherrier Richard , Perrin‐Ganier Corinne , Schiavon Michel
Published: April 2004

Previous sorption/desorption batch experiments have indicated that bentazone is weakly sorbed by soils. In addition, field experiments have shown that 4% of the bentazone sprayed can be leached to drainage water. In order to complete bentazone characterisation, we have assessed the effect of time on its behaviour in contrasting soils. In laboratory studies, bentazone was added to three topsoils (sandy, loamy and clay soils). Bentazone degradation, sorption/desorption kinetics and isotherm measurements were carried out at different times. At 160 days after treatment, bentazone mineralisation amounts varied from 2.1% (sandy soil) to 14% (clay soil). The extractable amounts became lower (from 97% after treatment to 12% after 160 days for the clay soil) and a greater number of desorption series was needed to obtain these products. Nevertheless, at the end of the experiments, a small amount of bentazone was still extracted by water. At the same time, bound residues of bentazone reached 65% in clay soil. Statistical analysis indicated effects of both residence time and soil type on bentazone behaviour. Copyright © 2004 Society of Chemical Industry
Antimalarial activity of extracts of Abutilon grandiﬂorum G. Don – a traditional Tanzanian medicinal plant
Authors: Beha E. , Jung A. , Wiesner J. , Rimpler H. , Lanzer M. , Heinrich M.
Published: April 2004

The Tanzanian medicinal plant Abutilon grandiﬂorum G. Don was studied for its in vivo and in vitro antiplasmodial effects. The ethyl acetate extract showed prominent in vivo activity against P. vinckei vinckei in mice and in vitro against P. falciparum strains HB3 and FCB. The extract was only moderately cytotoxic if tested in vitro against the colon cell line HT29. In the in vivo study, the results were signiﬁcantly inﬂuenced by the treatment schedule used, i.e. early treatment with higher doses was more successful than applying the same overall amount over a longer period. Phytochemical analysis of the extract provided no conclusive evidence for the observed parasitological effects. Copyright © 2004 John Wiley & Sons, Ltd.
Insular Carcinoma: Infrequent Subtype of Thyroid Cancer with Aggressive Clinical Course
Authors: Chao Tzu‐Chieh , Lin Jen‐Der , Chen Miin‐Fu
Published: April 2004

Data on four male and four female patients with insular carcinoma of the thyroid were reviewed to elucidate the clinical characteristics of this malignancy. The median age of the patients was 62.5 years (range 29–78 years). The size of the tumors ranged from 3.0 to 10.0 cm (median 4.7 cm). One patient with extensive neck disease and distant metastases underwent palliative debulking of the tumor mass and died of respiratory failure 10 days after surgery. Seven patients underwent total thyroidectomy. In addition to being given thyroxine supplement, three patients were treated with postoperative iodine‐131 (131I) therapy, two with external radiation after 131I treatment, and two with external radiation. Local invasion of the malignancy into strap muscles was observed in two patients, into the trachea in two patients, into the recurrent laryngeal nerve in one patient, and into the internal jugular vein in one patient. The median follow‐up was 26 months (range 3–80 months). Lung metastases occurred in four patients and metastases at the neck lymph nodes in four patients; recurrence at the thyroid bed was observed in one patient. Four patients died of distant metastases and progressive recurrent disease. Of the three surviving patients, two remained disease‐free, and one remained alive with lung metastases. In conclusion, insular carcinomas behave aggressively, so we believe they should be treated by total thyroidectomy plus neck dissection when nodal metastases are present.
Cerebral bloodflow and oxygen metabolism in borderzone and territorial infarcts due to symptomatic carotid artery occlusion
Authors: De Reuck J. , Paemeleire K. , Decoo D. , Van Maele G. , Strijckmans K. , Lemahieu I.
Published: April 2004

It remains controversial whether borderzone infarcts are due to compromised cerebral perfusion and whether territorial infarcts are caused by artery‐to‐artery emboli in case of occlusion of the internal carotid artery. The present positron emission tomography study compares with normal controls, the average regional cerebral bloodflow (rCBF), regional oxygen extraction fraction (rOEF) and regional cerebral metabolic rate for oxygen (rCMRO2) in the infarct area, the peri‐infarct zone, the remaining homolateral hemisphere and in the contralateral hemisphere of 10 patients with borderzone and 17 patients with territorial infarcts, due to internal carotid artery occlusion by atherosclerosis and by cervical dissection. The steady‐state technique with oxygen‐15 was used. A nearly significant increase of rOEF with lowered rCBF and rCMRO2 was observed in the peri‐infarct zone of patients with territorial infarcts. In patients with borderzone infarcts rCMRO2 was decreased in the peri‐infarct zone, in the remaining homolateral hemisphere and in the contralateral hemisphere without changes in rCBF and rOEF. The present study finds no arguments that impaired cerebral perfusion is a more frequent cause of borderzone than of territorial infarcts.
On the mode-coupling theory of vibrational line broadening in near-critical fluids
Authors: Lawrence C. P. , Skinner J. L.
Published: April 2004

Molecular-dynamics simulations of a neat atomic fluid, coupled with a simple model for vibrational frequency perturbations, are used to investigate vibrational line broadening near the liquid–gas critical point. All features of our simulations are in qualitative agreement with recent Raman experiments on nitrogen. We also use our simulation results to assess the validity of the mode-coupling theories that have been used to analyze experiment. We find that the theoretical results are not in good agreement with simulation, both for the temperature dependence of the linewidth, and for the frequency time-correlation functions. However, the mode-coupling prediction that critical line broadening is due to the diverging correlation time of the frequency fluctuations is shown to be correct.