bluuebunny/crossref_metadata_2025_split huggingface dataset:
Disturbed surround inhibition in focal hand dystonia
Authors: Sohn Young H. , Hallett Mark 
Published: September 2004

AbstractDisturbances in surround inhibition could account for various movement disorders. Here we test the functional operation of surround inhibition in focal hand dystonia. Transcranial magnetic stimulation was set to be triggered by self‐initiated voluntary flexion of the index finger. During this movement, motor‐evoked potential amplitudes from the little finger muscle were significantly suppressed in healthy subjects but enhanced in dystonia patients. This result supports the idea that disturbed surround inhibition is a principal pathophysiological mechanism of dystonia. Ann Neurol 2004;56:595–599
Rapid eye movement sleep behavior disorder in parkinsonism with parkin mutations
Authors: Kumru Hatice , Santamaria Joan , Tolosa Eduardo , Valldeoriola Francesc , Muñoz Esteban , Marti Maria J. , Iranzo Alex 
Published: September 2004

AbstractRapid eye movement sleep behavior disorder (RBD) in the setting of parkinsonism or dementia often reflects an underlying synucleinopathy. Lewy bodies, intraneuronal aggregates containing abnormal α‐synuclein, are absent in most cases of parkinsonism with parkin mutations (Park2). We performed clinical history and video‐polysomnography in 10 Park2 patients (seven men; age, 51.2 ± 11.6 years; parkinsonism duration, 18.3 ± 11.2 years) and found RBD in 6. In all instances, RBD followed the onset of motor symptoms by several years. Our study shows that RBD is frequent in Park2, suggesting that mechanisms other than synuclein deposition can cause RBD in neurodegenerative disorders. Ann Neurol 2004;56:599–603
A novel RAB7 mutation associated with ulcero‐mutilating neuropathy
Authors: Houlden Henry , King Rosalind H. M. , Muddle John R. , Warner Thomas T. , Reilly Mary M. , Orrell Richard W. , Ginsberg Lionel 
Published: September 2004

AbstractThere are two known autosomal dominant genes for the hereditary ulcero‐mutilating neuropathies: SPTLC1 (hereditary sensory neuropathy type 1) and RAB7 (Charcot–Marie–Tooth disease type 2B). We report a family with autosomal dominant ulcero‐mutilating neuropathy, developing in the teens and characterized by ulcers, amputations, sensory involvement in the feet but no motor features. Sequencing the RAB7 gene showed a novel heterozygous A to C mutation, changing asparagine to threonine at codon 161. The mutation is situated adjacent to a previously identified valine to methionine mutation at codon 162, implying a hotspot for mutations in the highly conserved C terminus of RAB7. Ann Neurol 2004;56:586–590
Im Goldenen Zeitalter der Organokatalyse
Authors: Dalko Peter I. , Moisan Lionel 
Published: September 2004

AbstractUnter dem Begriff “Organokatalyse” werden chemische Reaktionen zusammengefasst, die durch Zusatz substöchiometrischer Mengen von organischen Verbindungen beschleunigt werden. Das Interesse an diesem Forschungsgebiet und den damit verbundenen neuen Konzepten hat in den vergangenen Jahren stark zugenommen. Viele der bekannten organokatalytischen Reaktionen sind bezüglich ihrer Effizienz und Selektivität mit etablierten organischen Reaktionen vergleichbar, und die Organokatalyse hat sich beim Aufbau komplexer Molekülgerüste bewährt. Die verschiedenartigen Beispiele zeigen, dass sich die Organokatalyse in den letzten Jahren zu einem selbständigen Teilgebiet der Organischen Chemie entwickelt hat, dessen “Goldenes Zeitalter” bereits angebrochen ist.
Wann und wie dimerisieren Diaminocarbene?
Authors: Alder Roger W. , Blake Michael E. , Chaker Leila , Harvey Jeremy N. , Paolini François , Schütz Jan 
Published: September 2004

AbstractBisher wurde kein eindeutiger Nachweis für eine einfache, nicht katalysierte Dimerisierung von Diaminocarbenen gefunden. Es ist somit an der Zeit zu hinterfragen, welche Faktoren die Thermodynamik dieser Reaktion steuern und welche Mechanismen für die beobachteten Dimerisierungen verantwortlich sind. In Übereinstimmung mit qualitativen experimentellen Beobachtungen ergab die Berechnung, dass die Dimerisierung von einfachen Fünf‐ und Sechsringdiaminocarbenen um 100 kJ mol−1 weniger begünstigt ist als die der acyclischen Pendants. Dieser große Unterschied kann halbquantitativ durch die Änderung von Bindungs‐ und Torsionswinkeln um die Carbenzentren herum erklärt werden. Carbene wie (Et2N)2C sind, in Einklang mit den berechneten Energiebarrieren, in THF bei 25 °C kinetisch stabil, aber sie dimerisieren schnell in Gegenwart des entsprechenden Formamidiniumions. Dieser protonenkatalysierte Prozess ist wahrscheinlich der häufigste Mechanismus der Dimerbildung. Er führt zur Bildung von C‐protonierten Dimeren, was in geeigneten Fällen beobachtet werden kann. Es wird auch die Möglichkeit der durch Alkalimetalle geförderten Dimerisierung diskutiert; hierfür werden einige Belege vorgestellt.
In the Golden Age of Organocatalysis
Authors: Dalko Peter I. , Moisan Lionel 
Published: September 2004

AbstractThe term “organocatalysis” describes the acceleration of chemical reactions through the addition of a substoichiometric quantity of an organic compound. The interest in this field has increased spectacularly in the last few years as result of both the novelty of the concept and, more importantly, the fact that the efficiency and selectivity of many organocatalytic reactions meet the standards of established organic reactions. Organocatalytic reactions are becoming powerful tools in the construction of complex molecular skeletons. The diverse examples show that in recent years organocatalysis has developed within organic chemistry into its own subdiscipline, whose “Golden Age” has already dawned.
When and How Do Diaminocarbenes Dimerize?
Authors: Alder Roger W. , Blake Michael E. , Chaker Leila , Harvey Jeremy N. , Paolini François , Schütz Jan 
Published: September 2004

AbstractNo example of a simple uncatalyzed dimerization of a diaminocarbene has been clearly established, so it is timely to ask what factors control the thermodynamics of this reaction, and what mechanisms are responsible for the observed dimerizations? In agreement with qualitative experimental observations, the dimerizations of simple five‐ and six‐membered‐ring diaminocarbenes are calculated to be 100 kJ mol−1 less favorable than those of acyclic counterparts. This large difference is semiquantitatively accounted for by bond and torsional angle changes around the carbene centers. Carbenes such as (Et2N)2C are kinetically stable in THF at 25 °C in agreement with calculated energy barriers, but they rapidly dimerize in the presence of the corresponding formamidinium ion. This proton‐catalyzed process is probably the most common mechanism for dimer formation, and involves formation of C‐protonated dimers, which can be observed in suitable cases. The possibility of alkali‐metal‐promoted dimerization is raised, and circumstantial evidence for this is presented.
Einfluß einer Mörtelschicht auf die Quertragfähigkeit von Dübelbefestigungen
Authors: Mallée Rainer 
Published: September 2004

AbstractZum Ausgleich von Unebenheiten auf der Betonoberfläche oder zur Überbrückung von Höhentoleranzen werden bei nachträglichen Befestigungen mit Dübeln zwischen Beton und Anbauteil häufig Mörtelschichten angeordnet. Auf Basis von Versuchsergebnissen wird der Einfluß der Schichtdicke auf die Quertragfähigkeit von Dübelgruppen abgeschätzt.
Quertragfähigkeit randnaher Befestigungsmittel mit Belastung senkrecht zum Bauteilrand
Authors: Hofmann Jan , Fuchs Werner , Eligehausen Rolf 
Published: September 2004

AbstractBefestigungen mit Einlegeteilen sowie chemischen und mechanischen Metalldübeln werden in allen Bereichen des Bauwesens häufig eingesetzt. Bei Produkten mit Europäisch Technischen Zulassungen (ETAs) oder neueren Zulassungen des Deutschen Instituts für Bautechnik (DIBt) wird der Nachweis der Versagensart Betonbruch in der Bemessung nach der sog. CC‐Methode, die in ETAG 001, Annex C und die DIBt‐Richtlinie (1993) Eingang gefunden hat, durchgeführt. In diesem Beitrag wird erläutert, wie die sog. CC‐Methode für den Fall von randnahen querbelasteten Befestigungen mit der Versagensart Betonkantenbruch verbessert werden kann. Dieser verbesserte Ansatz wird in der künftigen europäischen Norm zur Bemessung von Befestigungsmitteln enthalten sein.
Lineares oder nichtlineares Kriechen bei Druckgliedern?
Authors: Quast Ulrich 
Published: September 2004

AbstractDie neue Normengeneration beschert der Baupraxis auch lineares und nichtlineares Kriechen. Ob nichtlineares Kriechen besser mit den in der Forschung bevorzugten rheologischen Kriechmodellen erfaßt werden kann, oder ob das einfachere Vorgehen mit den für lineares Kriechen bekannten Kriechzahlen ausreicht, wird an Einzelbeispielen sehr schlanker Druckglieder miteinander verglichen. Es wird erläutert, wie die unter ständiger Gebrauchslast entstehenden Kriechauswirkungen schlanker Druckglieder in den Nachweisen im Grenzzustand der Tragfähigkeit auf vereinfachte Weise berücksichtigt werden können.
Pressure dependence of human fibrinogen correlated to the conformational α‐helix to β‐sheet transition: An Fourier transform infrared study microspectroscopic study
Authors: Lin Shan‐Yang , Wei Yen‐Shan , Hsieh Tzu‐Feng , Li Mei‐Jane 
Published: September 2004

AbstractWe used Fourier transform infrared (FTIR) microspectroscopy to investigate pressure‐induced conformational changes in secondary structure of fibrinogen (FBG). Solid state FBG was compressed on a KBr pellet (1KBr method) or between two KBr pellets (2KBr method). The peak positions of the original and second‐derivative ir spectra of compressed FBG samples prepared by the 1KBr method were similar to FBG sample without pressure. When FBG was prepared by the 2KBr method and pressure was increased up to 400 kg/cm2, peaks at 1625 (intermolecular β‐sheet) and 1611 (β‐sheet aggregates structure and/or the side‐chain absorption of the tyrosine residues) cm−1 were enhanced. The peaks near 1661 (β‐sheet) and 1652 (α‐helix) cm−1 also exhibited a marked change with pressure. A linear correlation was found between the peak intensity ratio of 1611/1652 cm−1 (r = 0.9879) or 1625/1652 cm−1 (r = 0.9752) and applied pressure. The curve‐fitted compositional changes in secondary structure of FBG also indicate that the composition of the α‐helix structure (1657–1659 cm−1) was gradually reduced with the increase in compression pressure, but the composition of the β‐sheet structure (1681, 1629, and 1609 cm−1) gradually increased. This indicates that pressure‐induced conformational changes in FBG include not only transformations from α‐helix to β‐sheet structure, but also unfolding and denaturation of FBG and the formation of aggregates. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004
Gelation of gellan gum aqueous solutions studied by polarization modulation spectroscopy
Authors: Horinaka Jun‐ichi , Kani Kohei , Itokawa Yoshimi , Ogawa Etsuyo , Shindo Yohji 
Published: September 2004

AbstractCircular birefringence (CB, or optical rotation) and linear birefringence (LB) were measured for gellan gum aqueous solutions with and without salt to examine the gelling system in the helical structure as well as in the orientation. It was found that gelling samples with salt show nonzero LB values, whereas LB is zero for the samples without salt even in the gel state. This difference can be explained by the thermal deformation of the system containing anisotropic aggregations of helices formed with the shielding effect of the added salt on the intramolecular and intermolecular electrostatic repulsions. Considering that the presence of LB in the system affects the estimation of CB, we developed an original procedure of the CB measurement to eliminate the contribution of LB. It was shown that our methods for eliminating the contribution of LB can improve the CB measurement for the gellan gum gel. The temperature dependence of [α] for the samples with salt in the gel state is quite different from that for the samples without salt, suggesting that the aggregates of helices in the samples containing a high concentration of salt form a supramolecular structure that contributes to CB. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004
Removal of the side‐chain glucose groups from schizophyllan improves the thermal stability of the polycytidylic acid complexes under the physiological conditions
Authors: Koumoto Kazuya , Karinaga Ryouji , Mizu Masami , Anada Takahisa , Sakurai Kazuo , Kunitake Toyoki , Shinkai Seiji 
Published: September 2004

AbstractThermal stabilization of the complex between polycytidylic acid [poly(C)] and the modified schizophyllan (SPG) whose hydrophilic side‐chain glucose groups are selectively removed utilizing mild Smith‐degradation has been investigated. With the decrease in the side‐chain glucose groups of schizophyllan, the complex with poly(C) can be considerably stabilized compared with unmodified SPG; for example, the Tm value after the removal of the side‐chain glucose groups from 33.3 (unmodified) to 1.0 is enhanced by 14°C. In addition, the thermal stabilization effect is even operative under the physiological conditions ([NaCl] = 0.15 mol dm−3). This effect is exerted owing to the construction of the hydrophobic atmosphere around the complex. Although schizophyllan lost the side‐chain glucose groups, it still kept the protection effect of the bound poly(C) chain against RNaseA‐mediated hydrolysis as observed for unmodified schizophyllan. The assessment of the cytotoxicity for A375:human malignant melanoma, and HL60:human promyelocytic leukemia revealed that the modified schizophyllan scarcely increases the cytotoxicity. These results indicate that the present modification for schizophyllan is of great significance in a viewpoint to develop the practical gene carriers operative even under the physiological conditions. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004
NMR solution structure of a highly stable de novo heterodimeric coiled‐coil
Authors: Lindhout Darrin A. , Litowski Jennifer R. , Mercier Pascal , Hodges Robert S. , Sykes Brian D. 
Published: September 2004

AbstractThe NMR solution structure of a highly stable coiled‐coil IAAL‐E3/K3 has been solved. The E3/K3 coiled‐coil is a 42‐residue de novo designed coiled‐coil comprising three heptad repeats per subunit, stabilized by hydrophobic contacts within the core and electrostatic interactions at the interface crossing the hydrophobic core which direct heterodimer formation. This E3/K3 domain has previously been shown to have high α‐helical content as well as possessing a low dissociation constant (70 nM). The E3/K3 structure is completely α‐helical and is an archetypical coiled‐coil in solution, as determined using a combination of 1H‐NOE and homology based structural restraints. This structure provides a structural framework for visualizing the important interactions for stability and specificity, which are key to protein engineering applications such as affinity purification and de novo design. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004
Inflamatory bowel diseases as an intermediate stage between normal and cancer: A FTIR‐microspectroscopy approach
Authors: Argov Shmuel , Sahu Ranjit K. , Bernshtain Evgenia , Salman Ahmad , Shohat Guy , Zelig Udi , Mordechai Shaul 
Published: September 2004

AbstractElucidation of the evolution of inflammatory bowel disease (IBD) to cancer by clinical symptoms and histopathology of biopsies is important. Fourier transform infrared microspectroscopy (FTIR‐MSP) has shown promise as a diagnostic tool for distinction of normal and cancer cells and tissues. In the present work, FTIR‐MSP is used to evaluate IBD cases and to study the IR spectral characteristic with respect to cancer and normal tissues from formalin‐fixed colonic biopsies from patients. Specific regions of the spectra were analyzed by statistical tools to study variations in metabolites that signified changes between the two pathological conditions: IBD and cancer. IBD tissues can be grouped with cancer or normal tissue using certain parameters such as phosphate content and RNA/DNA ratio as calculated from the spectra and show intermediate levels with regard to these metabolites. Further classification of the spectra by cluster analysis indicated which cases of Crohn's disease (3 of 10 cases) or ulcerative colitis (7 of 10 cases) were more likely to progress to cancer. The study exhibits that FTIR‐MSP can detect gross biochemical changes in morphologically identical IBD and cancer tissues and suggest which cases of IBD may require further evaluation for carcinogenesis. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004
Beneficial effect of helicopter emergency medical services on survival of severely injured patients
Authors: Frankema S P G , Ringburg A N , Steyerberg E W , Edwards M J R , Schipper I B , van Vugt A B 
Published: September 2004

AbstractBackgroundIn Rotterdam, the Netherlands, a helicopter-transported medical team (HMT), staffed with a trauma physician, provides additional therapeutic options at the scene of injury. This study evaluated the influence of the HMT on the chance of survival of severely injured trauma victims.MethodsThis was a 2-year prospective observational study of consecutive adults who suffered multiple trauma (Injury Severity Score (ISS) 16 or more) and presented to the Erasmus Medical Centre emergency ward. The effect of the HMT was quantified by an odds ratio (OR), adjusted for confounding variables in logistic regression models.ResultsComplete data for a total of 346 patients were available for analysis. Two hundred and thirty-nine patients were treated by ambulance personnel alone and 107 received additional HMT assistance. Patients in the HMT group had significantly lower Glasgow Coma Scale scores (mean 8·9 versus 10·6; P = 0·001) and a higher ISS (mean 30·9 versus 25·3; P &lt; 0·001). The unadjusted OR for death was 1·7 in favour of the group treated by ambulance staff only (OR for survival 0·61 (95 per cent confidence interval (c.i.) 0·37 to 1·0, P = 0·048)). After adjustment, however, patients in the HMT group had an approximately twofold better chance of survival (all injuries: OR 2·2 (95 per cent c.i. 0·92 to 5·9), P = 0·076; blunt injuries: OR 2·8 (95 per cent c.i. 1·07 to 7·52), P = 0·036).ConclusionThe presence of the HMT may increase chances of survival for patients suffering multiple trauma, especially for those with blunt trauma.
Systematic review of sacral nerve stimulation for faecal incontinence and constipation
Authors: Jarrett M E D , Mowatt G , Glazener C M A , Fraser C , Nicholls R J , Grant A M , Kamm M A 
Published: September 2004

Abstract

Background and method
This systematic review assesses the efficacy and safety of sacral nerve stimulation (SNS) for faecal incontinence and constipation. Electronic databases and selected websites were searched for studies evaluating SNS in the treatment of faecal incontinence or constipation. Primary outcome measures included episodes of faecal incontinence per week (faecal incontinence studies) and number of evacuations per week (constipation studies).

Results
From 106 potentially relevant reports, six patient series and one crossover study of SNS for faecal incontinence, and four patient series and one crossover study of SNS for constipation, were included. After implantation, 41–75 per cent of patients achieved complete faecal continence and 75–100 per cent experienced improvement in episodes of incontinence. There were 19 adverse events among 149 patients. The small crossover study reported increased episodes of faecal incontinence when the implanted pulse generator was switched off. Case series of SNS for constipation reported an increased frequency of evacuation. There were four adverse events among the 20 patients with a permanent implant. The small crossover study reported a reduced number of evacuations when the pulse generator was switched off.

Conclusion
SNS results in significant improvement in faecal incontinence in patients resistant to conservative treatment. Early data also suggest benefit in the treatment of constipation.
Evaluating the subtle impact of a ban on corporal punishment of children in Germany
Authors: Bussmann Kai‐D. 
Published: September 2004

AbstractIn 2000, the German Government passed a law prohibiting physical punishment in the family. A pre–post research design allows for an examination of its effects. The results of nationwide representative surveys on the experiences, perceptions, legal knowledge and attitudes of adolescents and parents are discussed. The recent surveys reveal a signiﬁcant decrease in the prevalence of corporal punishments and a high acceptance of the legal prohibition. In particular, awareness of the legal limits of parental physical sanctions has increased signiﬁcantly. For these reasons, the prohibition of corporal punishment can be said to have had an impact on the reduction of family violence against children in Germany. Copyright © 2004 John Wiley & Sons, Ltd.
Computational Design of Reduced Metabolic Networks
Authors: Holzhütter Scott , Holzhütter Hermann‐Georg 
Published: September 2004

AbstractCellular functions are based on thousands of chemical reactions and transport processes, most of them being catalysed and regulated by specific proteins. Systematic gene knockouts have provided evidence that this complex reaction network possesses considerable redundancy, that is, alternative routes exist along which signals and metabolic fluxes may be directed to accomplish an identical output behaviour. This property is of particular importance in cases where parts of the reaction network are transiently or permanently impaired, for example, due to an infection or genetic alterations. Here we present a computational concept to determine enzyme‐reduced metabolic networks that are still sufficient to accomplish a given set of cellular functions. Our approach consists of defining an objective function that expresses the compromise that has to be made between successive reduction of the network by omission of enzymes and its decreasing thermodynamic and kinetic feasibility. Optimisation of this objective function results in a linear mixed‐integer program. With increasing weight given to the reduction of the number of enzymes, the total flux in the network increases and some of the reactions have to proceed in thermodynamically unfavourable directions. The approach was applied to two metabolic schemes: the energy and redox metabolism of red blood cells and the carbon metabolism of Methylobacterium extorquens. For these two example networks, we determined various variants of reduced networks differing in the number and types of disabled enzymes and disconnected reactions. Using a comprehensive kinetic model of the erythrocyte metabolism, we assess the kinetic feasibility of enzyme‐reduced subnetworks. The number of enzymes predicted to be indispensable amounts to 14 (out of 28) for the erythrocyte scheme and 13 (out of 77) for the bacterium scheme, the largest group of enzymes predicted to be simultaneously dispensable amounts to 3 and 37 for these two systems. Our approach might contribute to identifying potential target enzymes for rational drug design, to rationalising gene‐expression profiles of metabolic enzymes and to designing synthetic networks with highly specialised metabolic functions.