bluuebunny/crossref_metadata_2025_split huggingface dataset:
Embryonic stem‐cell research and the moral status of embryos
Authors: Chu G. 
Published: November 2003

Abstract Stem‐cell research has the potential to significantly advance our knowledge of cell differentiation with the promise of exciting and innovative therapeutic applications for otherwise incurable genetic and degenerative disorders. The issue has been the subject of debate in federal and state parliament as research of embryonic stem cells and their application have come under intense scrutiny. Scientists and medical practitioners are highly skilled in the technical aspects of biomedicine but are decidedly less comfortable with ethics. The place of novel and controversial biomedical technology is commonly left to an ad hoc and complex process whereby social acceptability eventually becomes the final arbiter. Utilitarianism is a popular ethical approach that attempts to weigh all the known and anticipated merits and pitfalls. The scientific background of biomedical professionals, the vast explosion of information, and specialization and subspecialization, have all contributed to a reductionistic view of life and ethics. The ‘sanctity of life’ doctrine is altogether quite different, as secular and religious advocates appear inflexible and unyielding to the logical propositions of utilitarianism and reductionism or to the consensus of democracy. These four major ethical approaches are discussed with reference to the embryonic stem‐cell research debate. (Intern Med J 2003; 33: 530−531)
New and emerging drug therapies for the management of acute heart failure
Authors: Krum H. , Liew D. 
Published: November 2003

Abstract In recent times, there have been many developments in therapies for acute heart failure, in contrast to the preceding 20 years. These have been mainly fuelled by new and expanding knowledge about the pathophysiology of heart failure, which has allowed for insight into potential therapeutic strategies. This review will examine the key emerging therapies for acute heart failure, in light of available pathophysiological and clinical evidence. (Intern Med J 2003; 33: 515−520)
Communism's Posthumous Trial
Authors: Aronson Ronald 
Published: November 2003

Books reviewed in this article:Stéphane Courtois et al.,The Black Book of Communism: Crimes, Terror, RepressionFrançois Furet, The Passing of an Illusion: The Idea of Communism in the Twentieth CenturyTony Judt, The Burden of Responsibility: Blum, Camus, Aron, and the French Twentieth CenturyMichel Dreyfus et al., Le Siècle des communismes
CTP Limitation Increases Expression of CTP Synthase in
Lactococcus lactis
Authors: Jørgensen Casper Møller , Hammer Karin , Martinussen Jan 
Published: November 2003

ABSTRACT

CTP synthase is encoded by the
pyrG
gene and catalyzes the conversion of UTP to CTP. A
Lactococcus lactis pyrG
mutant with a cytidine requirement was constructed, in which β-galactosidase activity in a
pyrG
-
lacLM
transcriptional fusion was used to monitor gene expression of
pyrG
. A 10-fold decrease in the CTP pool induced by cytidine limitation was found to immediately increase expression of the
L. lactis pyrG
gene. The final level of expression of
pyrG
is 37-fold higher than the uninduced level. CTP limitation has pronounced effects on central cellular metabolism, and both RNA and protein syntheses are inhibited. Expression of
pyrG
responds only to the cellular level of CTP, since expression of
pyrG
has no correlation to alterations in UTP, GTP, and ATP pool sizes. In the untranslated
pyrG
leader sequence a potential terminator structure can be identified, and this structure is required for regulation of the
pyrG
gene. It is possible to fold the
pyrG
leader in an alternative structure that would prevent the formation of the terminator. We suggest a model for
pyrG
regulation in
L. lactis
, and probably in other gram-positive bacteria as well, in which
pyrG
expression is directly dependent on the CTP concentration through an attenuator mechanism. At normal CTP concentrations a terminator is preferentially formed in the
pyrG
leader, thereby reducing expression of CTP synthase. At low CTP concentrations the RNA polymerase pauses at a stretch of C residues in the
pyrG
leader, thereby allowing an antiterminator to form and transcription to proceed. This model therefore does not include any
trans-
acting protein for sensing the CTP concentration as previously proposed for
Bacillus subtilis
.
Relative Roles of Nitric Oxide, Prostanoids and Angiotensin II in the Regulation of Canine Glomerular Hemodynamics
Authors: Kramer Herbert J. , Horacek Vladislav , Bäcker Angela , Vaneckova Ivana , Heller Jiri 
Published: October 2003

Glomerular hemodynamics are controlled by a variety of physical, nervous and hormonal factors including the potent vasoconstrictors, angiotensin (ANG) II and endothelin-1 (ET-1), and the vasodilator prostanoids (prostaglandin = PG) and nitric oxide (NO). Since no micropuncture data on the canine kidney exist with respect to the relative roles of the endogenous vasoactive hormones/autacoids NO, PG and ANG II in modulating glomerular hemodynamics, in the present study using the micropuncture technique in anesthetized dogs on a normal salt intake, we investigated the relative effects of these hormones/autacoids by means of the <i>L</i>-arginine analog, N<sup>ω</sup>-nitro-<i>L</i>-arginine methyl ester hydrochloride (<i>L</i>-NAME), a competitive NO synthase (NOS) inhibitor, the cyclooxygenase inhibitor indomethacin (INDO), and the AT<sub>1</sub> receptor blocker EXP 3174. An intrarenal arterial (i.r.a.) bolus (within 5 min) of 2.5 mg of <i>L</i>-NAME led to a significant decrease in total renal blood flow (RBF) and single nephron glomerular blood flow (SNGBF) from 4.46 ± 0.51 to 3.52 ± 0.41 ml/min/g kidney weight and from 0.393 ± 0.041 to 0.341 ± 0.037 µl/min (p < 0.01), respectively, without a change in glomerular filtration rate (GFR). The increase in arteriolar resistance was more pronounced at the efferent (+31%) than at the afferent (+13%) arteriole, and K<sub>f</sub> decreased from 4.5 ± 0.5 to 3.7 ± 0.4 nl/min/mm Hg (p < 0.01). INDO (5 mg/kg i.v. bolus followed by 0.17 mg/kg/min i.v.) had no effect on glomerular hemodynamics. EXP 3174 (30 µg/kg/min i.r.a.) increased RBF and SNGBF from 4.35 ± 0.45 to 4.99 ± 0.50 ml/min/g kidney weight and from 0.403 ± 0.028 to 0.478 ± 0.039 µl/min (p < 0.01), respectively, without an effect on GFR. It reduced the efferent arteriolar resistance by 25% as compared to 13% at the afferent arteriolar level. EXP 3174 increased K<sub>f</sub> from 5.1 ± 0.4 to 8.1 ± 0.6 mm Hg (p < 0.01) in the presence of a decrease in effective filtration pressure from 13.2 ± 1.7 to 8.3 ± 1.0 mm Hg (p < 0.01). The glomerular hemodynamic effects of <i>L</i>-NAME were unaltered by pretreatment with INDO or EXP 3174, whereas its tubular effects were restored in the presence of EXP 3174. Thus, from these first micropuncture data in the anesthetized dog on a normal sodium intake we conclude that (1) acute intrarenal inhibition of NOS by <i>L</i>-NAME decreases RBF and SNGBF due to vasoconstriction of the afferent and, more pronounced, efferent arterioles. Since <i>L</i>-NAME simultaneously decreases K<sub>f</sub>, GFR remains unaltered. (2) These renal hemodynamic effects of NOS inhibition were not mediated by prostanoids or intrarenal ANG II. Thus, the tonic activity of intrarenal NOS plays an important role in maintaining glomerular hemodynamics in the canine kidney.
Tóπoι e i'δια nella Retorica di Aristotele
Authors: Rubinelli Sara 
Published: November 2003

AbstractIl passo della Retorica (1358 a 10-21) dove è introdotta la distinzione τóπoι e i'δια è uno dei più controversi dell'opera aristotelica. Il presente lavoro propone un chiarimento della natura e del ruolo di τóπoι e i'δια nella costruzione di un'argomentazione dialettico-retorica. Tale chiarimento viene presentato attraverso un confronto tra Topici e Retorica che, se pur espressamente evidenziato da Aristotele stesso, sembra essere stato trascurato da quanti si sono occupati dell'esegesi di tale sezione della Retorica.
Treatment of chronic respiratory failure: lung volume reduction surgeryversusrehabilitation
Authors: Decramer M. 
Published: October 2003

Several treatment options are available for end-stage chronic obstructive pulmonary disease (COPD). Respiratory rehabilitation and lung volume reduction surgery are reviewed here. Respiratory rehabilitation can now be considered a prime treatment for COPD. Indeed, it has been clearly shown to improve exercise capacity and health status in these patients. Improvements in the former fell just below the minimal clinically important difference, whereas those in the latter exceeded it. In addition, after a respiratory rehabilitation programme, a reduction in the number of hospital admissions and duration of each admission was demonstrated.It remains, however, difficult to predict accurately which patients will improve after rehabilitation and which will not. Factors that may contribute to this prediction are: baseline peak exercise ventilation/maximal voluntary ventilation, maximal inspiratory pressure, peripheral muscle force, and 6‐min walking distance. Several studies have clearly shown that training effects are as pronounced in patients with severe as in those with moderate airflow obstruction. This is the most significant insight in this area of the 1990s.Lung volume reduction surgery may also be of benefit in patients with end-stage COPD. It is clear that lung function, exercise capacity and health status improve after this procedure, although the results of only six randomised studies are currently available.It remains difficult to accurately predict which patients will benefit from the procedure. From a model analysis, the most important action mechanism appears to be resizing of the lungs. Only in patients with an increased residual volume/total lung capacity ratio are beneficial effects expected. The model analysis, however, did not fit the experimental data very well in a recent publication. Emphysema heterogeneity is also likely to be related to the response. The question remains as to whether or not lung volume reduction surgery accelerates the decline in forced expiratory volume in one second in the long run. The technique is undergoing considerable progress as numerous new surgical and endoscopic procedures are currently being developed. The results of these procedures have not yet been systematically evaluated.
Physical and biological triggers of ventilator-induced lung injury and its prevention
Authors: Gattinoni L. , Carlesso E. , Cadringher P. , Valenza F. , Vagginelli F. , Chiumello D. 
Published: October 2003

Ventilator-induced lung injury is a side-effect of mechanical ventilation. Its prevention or attenuation implies knowledge of the sequence of events that lead from mechanical stress to lung inflammation and stress at rupture.A literature review was undertaken which focused on the link between the mechanical forces in the diseased lung and the resulting inflammation/rupture.The distending force of the lung is the transpulmonary pressure. This applied force, in a homogeneous lung, is shared equally by each fibre of the lung's fibrous skeleton. In a nonhomogeneous lung, the collapsed or consolidated regions do not strain, whereas the neighbouring fibres experience excessive strain. Indeed, if the global applied force is excessive, or the fibres near the diseased regions experience excessive stress/strain, biological activation and/or mechanical rupture are observed. Excessive strain activates macrophages and epithelial cells to produce interleukin‐8. This cytokine recruits neutrophils, with consequent full-blown inflammation.In order to prevent initiation of ventilator-induced lung injury, transpulmonary pressure must be kept within the physiological range. The prone position may attenuate ventilator-induced lung injury by increasing the homogeneity of transpulmonary pressure distribution. Positive end-expiratory pressure may prevent ventilator-induced lung injury by keeping open the lung, thus reducing the regional stress/strain maldistribution. If the transpulmonary pressure rather than the tidal volume per kilogram of body weight is taken into account, the contradictory results of the randomised trials dealing with different strategies of mechanical ventilation may be better understood.
Fourier analysis of holographic data from a noisy disc brake and its implication for modelling
Authors: Talbot C , Fieldhouse J D 
Published: October 2003

Double pulsed laser holography is used to obtain images with fringe lines giving detailed information about the mode of vibration of a braking system generating high-frequency noise or squeal. If the images obtained are digitized, it is shown to be possible, using image processing techniques, to develop algorithms that determine the displacement field of the exposed part of the disc surface. Using least-squares mathematical approximations it is then feasible to generate Fourier series type representations of the out-of-plane motion of the vibrating disc. Holograms of the disc rim can also be analysed to show how the vibrating motion varies throughout the thickness of the disc (in-plane motion). The results demonstrate the existence of travelling waves as well as significantly large amplitude and quite complex in-plane vibrations. Implications for the construction of mathematical models of disc brake noise are discussed.
Image Threshold and Segmentation
Authors: Russ John C. 
Published: October 2003

Abstract
The process of reducing a gray scale or color image to a binary (black and white) image in which distinct features are isolated (usually for measurement) is called thresholding or segmentation. The words refer to slightly different but overlapping sets of procedures. Thresholding usually implies the selection of a range of gray scale or color values that distinguish the features from the background. It is widely used and very fast since it operates globally on images, but often does not provide perfect delineation of features because some pixels (particularly along feature edges) are misclassified, and features may touch each other. Segmentation implies the separation of features from the background and each other, usually based on local comparison of pixel values along feature boundaries. These methods are often slow, may not find all of the features present, and sometimes require assumptions about the shape or size of the features.
Infrared Thermography
Authors: Griffith Brent , Türler Daniel , Goudey Howdy 
Published: October 2003

AbstractInfrared (IR) thermographic systems, or IR imagers, provide images that represent surface temperatures, orthermograms, by measuring the magnitude of infrared radiation emanating from the surface of an object. Because IR imagers see the radiation naturally emitted by objects, imaging may be performed in the absence of any additional light source. Modern IR imagers resolve surface temperature differences of 0.1 °C or less. At this high sensitivity, they can evaluate subtle thermal phenomena that are revealed only as slight temperature gradients. Some applications that employ IR thermography include inspections for predictive maintenance, nondestructive evaluation of thermal and mechanical properties, building science, military reconnaissance and weapons guidance, and medical imaging.Infrared thermography can be used both as a qualitative and a quantitative tool. Some applications do not require exact surface temperatures. In such cases, it is sufficient to acquirethermal signatures, characteristic patterns of relative temperatures of phenomena or objects. This method of qualitative visual inspection is expedient for collecting a large number of detailed data and conveying them, so that they can be easily interpreted. In contrast, accurate quantitative thermography demands a more rigorous procedure to extract valid temperature maps from raw thermal images. However, the extra effort can produce large arrays of high‐resolution temperature data that are unrivaled by contact thermal measurement techniques, such as using thermocouple wires. A skilled operator of an IR thermographic system, orthermographer, must be conscious of the possibility that reflected or transmitted, rather than emitted, IR radiation may be emanating from an object. These additional sources manifest themselves as signals that appear to be, but are not actually, based exclusively on the temperature of the spot being imaged.To understand the challenges and possibilities of IR thermography, it is necessary to review the principles of physics on which it relies. Types of imaging systems, guidance and good practice in operation are covered.
Wavelet Transforms
Authors: Rao Raghuveer 
Published: October 2003

Abstract
In a 1984 paper, Grossman and Morlet investigated the problem of representing square‐integrable functions by using shifts and dilations of a single function called a wavelet. The motivation lay in the fact that there is evidence for the usefulness of such representations in analyzing seismic traces. Although earlier articles dealing with similar problems can be found, the Grossman–Morlet paper provides an integral transform along with conditions under which one can invert the transform. Thus was born the field of wavelet transforms. Subsequent developments in the field such as the formulation of discrete basis functions, the relationship to subband filtering, and the application to signal/image processing have contributed to widespread interest in the subject. The purpose of this article is to provide a short overview of wavelet transforms and their application to certain image processing problems.
Evidence for shared susceptibility in bipolar disorder and schizophrenia
Authors: Berrettini Wade 
Published: October 2003

AbstractThis article reviews evidence that bipolar disorder (BPD) and schizophrenia (SZ) share familial risk characteristics. The topic is introduced with a brief discussion of various shared epidemiologic characteristics of SZ and BPD. Family studies of BPD and SZ, conducted by multiple independent groups of investigators, are consistent with partial overlap in familial susceptibility. Given that the family study data suggest overlap in familial susceptibility for BPD and SZ, several confirmed linkages of BPD or SZ are reviewed, with the conclusion that there are five genomic regions for which evidence suggests shared genetic susceptibility of BPD and SZ. It is suggested that nosology must be changed to reflect the genetic origins of the multiple disorders that are collectively described by the terms BPD and SZ. © 2003 Wiley‐Liss, Inc.
Epigenetics and bipolar disorder: New opportunities and challenges
Authors: Petronis Arturas 
Published: October 2003

AbstractDespite significant effort, understanding of the molecular causes and mechanisms of bipolar disorder (BD) remains a major challenge. Numerous molecular genetic linkage and association studies have been conducted over the last two decades; however, the data are quite inconsistent or even controversial. This article develops an argument that molecular studies of BD would benefit significantly from adding an epigenetic (epiG) perspective. EpiG factors refer to modifications of DNA and chromatin that “orchestrate” the activity of the genome, including regulation of gene expression. EpiG mechanisms are consistent with various non‐Mendelian features of BD such as the relatively high degree of discordance in monozygotic (MZ) twins, the critical age group for susceptibility to the disease, clinical differences in males and females, and fluctuation of the disease course, including interchanges of manic and depressive phases, among others. Apart from the phenomenological consistency, molecular epiG peculiarities may shed new light on the understanding of controversial molecular genetic findings. The relevance of epigenetics for the molecular studies of BD is demonstrated using the examples of genetic studies of BD on chromosome 11p and the X chromosome. A spectrum of epiG mechanisms such as genomic imprinting, tissue‐specific effects, paramutagenesis, and epiG polymorphism, as well as epiG regulation of X chromosome inactivation, is introduced. All this serves the goal of demonstrating that epiG factors cannot be ignored anymore in complex phenotypes such as BD, and systematic large‐scale epiG studies of BD have to be initiated. © 2003 Wiley‐Liss, Inc.
Synthesechemie expandierter Porphyrine
Authors: Sessler Jonathan L. , Seidel Daniel 
Published: October 2003

AbstractExpandierte Porphyrine sind synthetische Analoga der Porphyrine und unterscheiden sich von diesen und anderen natürlichen makrocyclischen Tetrapyrrolen durch einen größeren zentralen Ring mit mindestens 17 Atomen, wobei die ausgedehnte Konjugation erhalten bleibt, die die biologischen Pigmente kennzeichnet. Durch die Erweiterung des zentralen Rings entstehen Verbindungen mit neuen spektralen und elektronischen Merkmalen, ungewöhnlichen Komplexbildungseigenschaften und in vielen Fällen der Eigenschaft, in bestimmten Protonierungszuständen Anionen zu binden. Zum Interesse an den expandierten Porphyrinen trägt auch ihre Schlüsselrolle bei der Klärung von Fragen zur Aromatizität bei. In vielen Fällen weisen sie in der Chemie der Porphyrine einmalige Strukturmerkmale auf, z. B. die nichtplanaren Figure‐Eight‐Konformationen. Dieser Aufsatz beschreibt schwerpunktmäßig die heute verwendeten Syntheseverfahren für expandierte Porphyrine und geht daneben auf spezielle Anwendungsaspekte ein.
Advances in the Synthesis of Inorganic Nanotubes and Fullerene‐Like Nanoparticles
Authors: Tenne Reshef 
Published: October 2003

AbstractIn analogy to graphite, nanoparticles of inorganic compounds with lamellar two‐dimensional structure, such as MoS2, are not stable against folding, and can adopt nanotubular and fullerene‐like structures, nicknamed inorganic fullerenes or IF. Various applications for such nanomaterials were proposed. For instance, IF‐WS2 nanoparticles were shown to have beneficial effects as solid lubricants and as part of tribological surfaces. Further applications of IF for high‐tensile‐strength fibers, hydrogen storage, rechargeable batteries, catalysis, and in nanotechnology are being contemplated. This Minireview highlights some of the latest developments in the synthesis of inorganic nanotubes and fullerene‐like structures. Some structural aspects and properties of IF, which are distinct from the bulk materials, are briefly discussed.