bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adaptive urn designs for estimating several percentiles of a dose–response curve
Authors: Mugno Raymond , Zhus Wei , Rosenberger William F. 
Published: June 2004

AbstractDose–response experiments are crucial in biomedical studies. There are usually multiple objectives in such experiments and among the goals is the estimation of several percentiles on the dose–response curve. Here we present the first non‐parametric adaptive design approach to estimate several percentiles simultaneously via generalized Pólya urns. Theoretical properties of these designs are investigated and their performance is gaged by the locally compound optimal designs. As an example, we re‐investigated a psychophysical experiment where one of the goals was to estimate the three quartiles. We show that these multiple‐objective adaptive designs are more efficient than the original single‐objective adaptive design targeting the median only. We also show that urn designs which target the optimal designs are slightly more efficient than those which target the desired percentiles directly. Guidelines are given as to when to use which type of design. Overall we are pleased with the efficiency results and hope compound adaptive designs proposed in this work or their variants may prove to be a viable non‐parametric alternative in multiple‐objective dose–response studies. Copyright © 2004 John Wiley & Sons, Ltd.
Adjusting for differential proportions of second‐line treatment in cancer clinical trials. Part I: Structural nested models and marginal structural models to test and estimate treatment arm effects
Authors: Yamaguchi Takuhiro , Ohashi Yasuo 
Published: June 2004

AbstractIn randomized trials, post‐randomization variables such as compliance, prescription of alternative treatments and so on are usually ignored to compare treatment arms. Intent‐to‐treat (ITT) analysis is a standard approach but it does not adjust for those variables. However, we may need to evaluate treatment arm effects that have the desired causal interpretation. Previously proposed methods such as time‐dependent Cox model may not properly adjust for post‐randomization variables and may produce biased results. Alternatively, we propose to use two causal models, structural nested models and marginal structural models. The two models appropriately adjust for such variables. We apply these models to adjust for differential proportions of post‐randomization second‐line treatment in cancer clinical trials. With sufficient care to several assumptions, these methods, especially structural nested failure time models with randomized analyses, are useful to take the influence of second‐line treatment into account and to test and estimate the direct treatment arm effect. Copyright © 2004 John Wiley & Sons, Ltd.
Adjusting for differential proportions of second‐line treatment in cancer clinical trials. Part II: An application in a clinical trial of unresectable non‐small‐cell lung cancer
Authors: Yamaguchi Takuhiro , Ohashi Yasuo 
Published: June 2004

AbstractThe CPT‐11 trial was conducted to confirm the superiority of CDDP+CPT‐11 (CPT‐P) arm to CDDP+VDS (VDS‐P) arm with regard to survival for patients with previously untreated advanced (stage IIIB/IV) non‐small‐cell lung cancer. However, the CPT‐P arm did not show the survival benefit for patients with stage IIIB. The proportion of patients with stage IIIB treated by active radiation given as second‐line treatment (second‐line radiotherapy) after initial (first‐line) treatment was 45 per cent in the CPT‐P arm while 61 per cent in the VDS‐P arm. This showed that not proving survival advantage in the CPT‐P arm might be due to the benefits of second‐line radiotherapy. We apply two causal models appeared in the companion paper to test and estimate the survival differences that would have been observed if all the patients had been received the same second‐line radiotherapy. Based on several assumptions, we inferred that the CPT‐P arm still would not have showed survival advantage if all the patients had been given identical second‐line radiotherapy. Copyright © 2004 John Wiley & Sons, Ltd.
JAC: an aspect‐based distributed dynamic framework
Authors: Pawlak Renaud , Seinturier Lionel , Duchien Laurence , Florin Gérard , Legond‐Aubry Fabrice , Martelli Laurent 
Published: June 2004

AbstractIn this paper, we present the Java Aspect Components (JAC) framework for building aspect‐oriented distributed applications in Java. This paper describes the aspect‐oriented programming model and the architectural details of the framework implementation. The framework enables extension of application semantics for handling well‐separated concerns. This is achieved with a software entity called an aspect component (AC). ACs provide distributed pointcuts, dynamic wrappers and metamodel annotations. Distributed pointcuts are a key feature of our framework. They enable the definition of crosscutting structures that do not need to be located on a single host. ACs are dynamic. They can be added, removed, and controlled at runtime. This enables our framework to be used in highly dynamic environments where adaptable software is needed. Copyright © 2004 John Wiley & Sons, Ltd.
The WTO and entry modes in China
Authors: Teng Bing‐Sheng 
Published: June 2004

AbstractFor years, multinational enterprises (MNEs) vying for the Chinese market used joint ventures (JVs) as an entry mode. However, there has been a growing frustration with the JV mode. It is reported that MNEs are increasingly opting for wholly owned subsidiaries for better control. This article examines the recent development of the business environment in China. It concludes that there are now real entry options for MNEs, including exporting, JVs, wholly owned subsidiaries, and acquisitions. China's accession into the World Trade Organization (WTO) will accelerate the change process and make non‐JV options even more viable. A few decision rules for choosing an entry mode in China are discussed. © 2004 Wiley Periodicals, Inc.
Learning from the implementation of the internet strategy at the Guayaquil stock exchange
Authors: Montealegre Ramiro 
Published: June 2004

AbstractThis article examines how an Ecuadorian stock exchange pioneered a strategy to use the Internet to educate its local market and reach investors worldwide. The findings suggest that in the initial phase of its strategy development the actions that contributed the most were benchmarking and training, learning from past experience/history, and developing a shadow organization. Actions that helped during the middle phase were providing focus, experimenting, and developing, co‐opting, and securing the resources. In the final phase, actions that contributed the most were gaining internal commitment, investing in infrastructure, and appealing to existing relationships. These findings should be useful for organizational and information technology researchers and practitioners in developed and less‐developed countries. © 2004 Wiley Periodicals, Inc.
Effect of hindered piperidine light stabilizer molecular structure and UV‐absorber addition on the oxidation of HDPE. Part 1: Long‐term thermal and photo‐oxidation studies
Authors: Liauw Christopher M. , Quadir Angela , Allen Norman S. , Edge Michele , Wagner Alan 
Published: June 2004

AbstractThis series of papers explores the effect of structural characteristics of 2,2,6,6‐tetramethylpiperidine‐based hindered amine light stabilizers (HALS) on the long‐term (40 months) thermal (110°C in air) and photo‐stabilization (Microscal unit wavelength >300 nm) performance characteristics of high‐density polyethylene formulations. Possible synergism with a triazine functional UV absorber is also explored. Under thermal degradation (measured by carbonyl index) the polymeric HALS performed best, mainly because of reduced volatilization. Additionally, >N‐methyl HALS generally showed superior performance under thermal degradation. There was no synergism between an N‐CH3 polymeric HALS and the UV1164 triazine additive. However, the equivalent N‐H polymeric HALS interacted in a complex manner with UV1164, giving synergism and antagonism, depending on HALS/UV1164 ratio. Strong synergism was evident with the monomeric HALS when the total stabilizer level was 0.2% w/w. Reduction in the overall stabilizer level to 0.05% w/w eliminated the synergism. The UV1164 alone led to rapid and intense yellowing; however, the rate and intensity of yellowing reduced dramatically upon combination with HALS, particularly when the UV1164 level was above 0.1% w/w. When the formulation was under UV attack, the molar mass and the type of N‐substitution had no influence on stabilization performance because of the relatively low temperature of testing (leading to reduced volatilization), and the similarly effective UV‐stabilization routes for N‐methyl HALS and N‐H HALS. Under UV attack, yellowing reached a maximum and then decreased to approximately the initial level, while HALS/UV1164 combinations generally showed weak antagonism. J. Vinyl Addit. Technol. 10:79–87, 2004. © 2004 Society of Plastics Engineers.
Überschreitungen der konventionellen Zahl von Clusterelektronen in Metallhalogeniden des M6X12‐Typs: W6Cl18, (Me4N)2[W6Cl18] und Cs2[W6Cl18]
Authors: Dill Simone , Glaser Jochen , Ströbele Markus , Tragl Sonja , Meyer H.‐Jürgen 
Published: June 2004

AbstractSchwarze oktaedrische Einkristalle von W6Cl18 wurden bei der Reduktion von WCl4 mit Graphit in einer Kieselglasampulle bei 600 °C erhalten. Die Einkristall‐Strukturanalyse ergab (Raumgruppe R 3¯, Z = 3, a = b = 1498, 9(1) pm, c = 845, 47(5) pm) die schon früher aus Pulverdaten ermittelte Kristallstruktur von W6Cl18.(Me4N)2[W6Cl18] und Cs2[W6Cl18] entstanden aus Lösungen von W6Cl18 und Me4NCl bzw. CsCl in Methanol. Die Struktur von (Me4N)2[W6Cl18] wurde röntgenographisch an einem Einkristall bestimmt (Raumgruppe P 3¯m1, Z = 1, a = b = 1079, 3(1) pm, c = 857, 81(7) pm). Die Struktur von Cs2[W6Cl18] wurde aus Röntgen‐Pulverdaten gelöst und verfeinert (Raumgruppe P 3¯, Z = 1, a = b = 932, 10(7) pm, c = 853, 02(6) pm).In der Kristallstruktur von W6Cl18 sind die molekularen W6Cl18‐Einheiten wie in einer kubisch dichtesten Kugelpackung angeordnet. Die Strukturen von (Me4N)2[W6Cl18] bzw. Cs2[W6Cl18] können als Substitutionsvarianten der Kristallstruktur von W6Cl18 aufgefasst werden, in der 2/3 der W6Cl18‐Einheiten durch Me4N+‐Ionen bzw. Cs+‐Ionen ersetzt sind.Mit 18 Elektronen in den Metall—Metall‐Zuständen von W6Cl18 und 20 Elektronen in jenen von (Me4N)2[W6Cl18] und Cs2[W6Cl18] wird die konventionelle Anzahl von 16 Elektronen/Cluster überschritten. Cs2[W6Cl18] zeigt temperaturunabhängiges paramagnetisches Verhalten.
Zintl‐Verbindungen mit Gold und Germanium: M3AuGe4 mit M = K, Rb und Cs
Authors: Zachwieja Uwe , Wlodarski Jörg 
Published: June 2004

AbstractSchwarz‐glänzende, spröde Einkristalle von M3AuGe4 mit M = K, Rb, Cs wurden durch Umsetzung von Alkalimetallaziden MN3 mit Goldschwamm und Germaniumpulver bei T = 1120 K synthetisiert. Die Strukturen der Verbindungen (Raumgruppe Pmmn, Z = 2, K3AuGe4: a = 6, 655(1)Å, b = 11, 911(2)Å, c = 6, 081(1)Å; Rb3AuGe4: a = 6, 894(1)Å, b = 12, 421(1)Å, c = 6, 107(1)Å; Cs3AuGe4: a = 7, 179(1)Å, b = 12, 993(2)Å, c = 6, 112(2)Å) wurden aus Röntgen‐Einkristall‐Diffraktometerdaten bestimmt. Die elektrisch halbleitenden Verbindungen enthalten [AuGe4]‐Ketten, in denen P4‐analoge Ge4‐Tetraeder über μ2‐verbrückende Goldatome mit verzerrt tetraedrischer Koordination am Germaniumatom verknüpft werden.
The Stereospecific Substitution of the Xenon Atom in cis‐Perfluoroalk‐1‐enylxenon(II) Salts by Hydrogen, Halogens, and the Phenyl Group
Authors: Frohn Hermann‐Josef , Bardin Vadim V. 
Published: June 2004

AbstractThe substitution of the xenon atom in reactions of [cis‐CnF2n+1CF=CFXe][Y] salts with benzene, iodide, and bromide anions in propionitrile solution by the phenyl group, or iodine, and bromine atoms, respectively, occurred stereospecifically. When a propionitrile solution of [cis‐C2F5CF=CFXe][AsF6] was kept at —40 °C without an additional reactant, the fluoroalkene cis‐C2F5CF=CFH was the only isomer obtained.
Pt2(HSO4)2(SO4)2, the First Binary Sulfate of Platinum
Authors: Pley Martin , Wickleder Mathias S. 
Published: June 2004

AbstractRed single crystals of Pt2(HSO4)2(SO4)2 were obtained by the reaction of elemental platinum with conc. sulfuric acid at 350 °C in sealed glass ampoules. The crystal structure (monoclinic, P21/c, Z = 2, a = 868.6(2), b = 826.2(1), c = 921.8(2) pm, β=116.32(1)°, Rall = 0.0348) shows dumbbell shaped Pt26+ cations which are coordinated by four SO42— and two HSO4— ions. Each of the sulfate ions is attached to another Pt26+ ion yielding layers according to [Pt2(SO4)4/2(HSO4)2/1]. The layers are connected by hydrogen bonds with the OH group of the hydrogensulfate ion as donor and the non‐bonding oxygen atom of the sulfate ion as acceptor.
Über Münzmetall‐Quecksilber‐Chalkogenidhalogenide. V1) Solvothermalsynthese und Kristallstruktur der Hochtemperatur‐Modifikation von AgHgSI
Authors: Beck Johannes , Keller Hans‐Lothar , Rompel Matthias , Wimbert Lars , Ewald Bastian 
Published: June 2004

Abstractα‐AgHgSI wird aus AgI und α‐HgS durch solvothermale Umsetzung bei 300 °C in verdünnter HI‐Lösung in Form von gelben Kristallen erhalten. Die Substanz kristallisiert in der Raumgruppe P212121 mit a = 707, 47(1), b = 773, 18(2), c = 847, 53(2) pm und Z = 4. Innerhalb der Kristallstruktur bilden Schwefel und Iod das Motiv einer verzerrt hexagonal dichtesten Packung, in der Silber ein Viertel der Tetraederlücken und Quecksilber die Hälfte der Oktaederlücken besetzt. Die Verzerrungen werden durch den sterischen Anspruch freier Elektronenpaare hervorgerufen, was durch Berechnungen der Elektronenlokalisierungsfunktion (ELF) bestätigt werden konnte. Die hier beschriebene Modifikation von AgHgSI kann bei 273 °C aus dem schon bekannten β‐AgHgSI gebildet werden und wird somit als α‐AgHgSI bezeichnet.
Synthese und Kristallstruktur von Vanadium(III)‐borophosphat, V2[B(PO4)3]
Authors: Meisel Manfred , Päch Michael , Wilde Lutz , Wulff‐Molder Dirk 
Published: June 2004

AbstractSynthesis and Crystal Structure of Vanadium(III) Borophosphate, V2[B(PO4)3]By reaction of boron phosphate, BPO4, and vanadium(IV)‐oxide, VO2, at 1050 °C a hitherto unknown vanadium(III)‐borophosphate is formed. Its composition was found to be V2BP3O12, its structure was elucidated by single crystal X‐ray diffraction, the cell parameters are: a = b = 13.9882Å; c = 7.4515Å; α = β = 90°, γ = 120°; Z = 6; space group: P6 3/m. Noteworthy features of the structure are V2O9 units (two VIIIO6 octahedra connected via their faces) and isolated trisphosphatoborate groups, B(PO4)3. By shared oxide ions, the aforementioned groups are interconnected, thus forming a three dimensional network. The structural relation between the title compound and an analogous chromium compound is discussed.
Calix[4]arene stabilized Transition Metal Imido Complexes
Authors: Radius U. 
Published: June 2004

AbstractThe usage of calix[n]arenes as ancillary poly(phenolate) ligands is a rapidly developing area in coordination chemistry. This article focuses on the synthesis, structure and reactivity of calix[4]arene‐ and calix[4]arene ether‐stabilized imido complexes of group 4 — 6 transition metals as well as on the comparison of calix[4]arene dialkyl ethers in particular with other widely employed related ligand systems such as salenes, porphyrins and tetraazaannulenes. Contrary to these nitrogen containing systems, it is much easier to control the charge of the ligand system through the degree of alkylation of the calixarene's lower rim without a major change in the geometry of the resulting metal complex. This could lead to isoelectronic and structurally closely related transition metal complex fragments for metals in neighboring groups of the periodic table or for metals in different oxidation states. The “intrinsic” reactivity of metal imido linkages might therefore be explored using calix[4]arenes and calix[4]arene ethers and first results are summarized in this research report.
Measuring split renal function in renal donors: can computed tomography replace renography?
Authors: Nilsson H. , Wadström J. , Andersson L.‐G. , Raland H. , Magnusson A. 
Published: June 2004

Purpose: To develop and evaluate a method of calculating split renal function from computed tomography (CT) images based on the assumption that the accumulation of contrast medium is proportional to the renal function, and to compare the results with the renogram. Material and Methods: The study comprised a retrospective analysis of CT images and renograms from previous donors. Twenty‐seven potential renal donors were studied using a technique for measuring the area and mean attenuation of the separate CT slices, and for calculating the volume and total attenuation of the whole kidney. Results: Correlation between CT and renography was moderate ( r=0.43), but the range of results was narrow. The ratio between the two kidneys was more even with CT (50±2.1%) than with the renogram (48±2.9%) (right kidney), and the mean difference between the two methods was 3±2.3 percentage points. Conclusion: The renogram can be replaced using calculations from the CT examination in estimating split renal function in potential renal donors.
Color Doppler ultrasonography findings of bladder tumors: correlation with stage and histopathologic grade
Authors: Karahan O. I. , Yikilmaz A. , Ekmekcioglu O. , Ozturk F. , Sevinc H. 
Published: June 2004

Purpose: To describe color Doppler ultrasonography findings of bladder tumors and to investigate the correlation between these findings with stage and histopathological grade. Material and Methods: Twenty‐four patients with bladder tumors were assessed with color Doppler ultrasonography for tumor size, presence of vascularity, vascular pattern, and spectral properties. All patients underwent surgery. Stage and histopathological grades of tumors were determined and compared with color Doppler ultrasonography findings. Results: Presence of vascularity was related to tumor size ( P<0.05) and color Doppler signal was detected when tumors reached 24 mm in size. There was no statistically significant relationship between tumor stage and histopathological grade with tumor size, presence and pattern of vascularity, and spectral color Doppler ultrasonography findings ( P>0.05). Conclusion: The evaluation of vascularity in bladder tumors by color Doppler ultrasonography is not helpful in predicting tumor stage and histopathological grade before surgery.
Visualization of pancreaticobiliary reflux in anomalous pancreaticobiliary junction by secretin‐stimulated dynamic magnetic resonance cholangiopancreatography
Authors: Hosoki T. , Hasuike Y. , Takeda Y. , Michita T. , Watanabe Y. , Sakamori R. , Tokuda Y. , Yutani K. , Sai C. , Mitomo M. 
Published: June 2004

Purpose: To assess the utility of secretin‐stimulated dynamic MR cholangiopancreatography (MRCP) for the visualization of pancreaticobiliary reflux in patients with anomalous pancreaticobiliary junction (PBJ). Material and Methods: Ten controls and seven patients diagnosed as having anomalous PBJ were prospectively examined by dynamic MRCP after secretin injection using a breath‐hold, single‐shot turbo spin‐echo T2‐weighted sequence. The optimal MRCP section was repeated 35 times at approx. 10‐second interval after secretin injection; the acquisition time was 4 s per image. The signal intensity (SI) changes of the extrahepatic and intrahepatic bile ducts, presence or absence of intraluminal signal void, caliber change of the bile duct, duodenal filling, and peak time of the SI ratio of the extrahepatic bile duct after secretin injection were compared between the controls and patients. Results: In the controls, the extrahepatic and intrahepatic bile ducts showed neither enhancement nor caliber change over the observation period, providing no apparent peak time. Of the seven patients, the extrahepatic bile duct showed retrograde enhancement and sequential delay in occurrence of the peak time from its distal third to its proximal third ( n=6) with a signal void in its distal part ( n=4); its caliber increased subsequently to pancreatic secretion ( n=5); the intrahepatic bile ducts showed a slight enhancement following SI increase of the proximal extrahepatic bile duct ( n=6); duodenal filling grade tended to be lower in the patients than volunteers ( P<.005). Conclusion: In patients with anomalous PBJ pancreaticobiliary reflux were demonstrated by dynamic secretin‐stimulated MRCP.
Volume adjustment of lung density by computed tomography scans in patients with emphysema
Authors: Shaker S. B. , Dirksen A. , Laursen L. C. , Skovgaard L. T. , Holstein‐Rathlou N.‐H. 
Published: June 2004

Purpose: To determine how to adjust lung density measurements for the volume of the lung calculated from computed tomography (CT) scans in patients with emphysema. Material and Methods: Fifty patients with emphysema underwent 3 CT scans at 2‐week intervals. The scans were analyzed with a software package that detected the lung in contiguous images and subsequently generated a histogram of the pixel attenuation values. The total lung volume (TLV), lung weight, percentile density (PD), and relative area of emphysema (RA) were calculated from this histogram. RA and PD are commonly applied measures of pulmonary emphysema derived from CT scans. These parameters are markedly influenced by changes in the level of inspiration. The variability of lung density due to within‐subject variation in TLV was explored by plotting TLV against PD and RA. Results: The coefficients for volume adjustment for PD were relatively stable over a wide range from the 10th to the 80th percentile, whereas for RA the coefficients showed large variability especially in the lower range, which is the most relevant for quantitation of pulmonary emphysema. Conclusion: Volume adjustment is mandatory in repeated CT densitometry and is more robust for PD than for RA. Therefore, PD seems more suitable for monitoring the progression of emphysema.
Risk factors of new compression fractures in adjacent vertebrae after percutaneous vertebroplasty
Authors: Kim S. H. , Kang H. S. , Choi J.‐A. , Ahn J. M. 
Published: June 2004

Purpose: To evaluate the risk factors related to the development of new fractures in adjacent vertebrae after vertebroplasty. Material and Methods: The study was conducted on 106 patients in whom 212 vertebroplasties were performed during a period of 3 years. Evaluations of the five vertebrae superior and inferior to the treated vertebra were performed. Consequently, 913 vertebrae were evaluated and the fracture‐free interval of the vertebral body adjacent to the treated vertebra was calculated. Survival analysis was performed using the Kaplan‐Meier method and Cox proportional hazards regression analysis. Results: Seventy‐two (7.9%) new fractures were revealed. The Kaplan‐Meier estimate of the 1‐year fracture‐free rate was 93.1%. The mean fracture‐free interval was 32 months (95% CI, 32∼33 months). The greater degree of height restoration of the treated vertebra, the location of the adjacent vertebra in the TL junction, and the shorter distance between the treated and the adjacent vertebra increased the risk of new vertebral fractures. Conclusion: Thoracolumbar junction, shorter distance from the treated vertebrae, and greater degree of height restoration of the cemented vertebrae may increase the fracture risk of vertebrae adjacent to cement vertebrae after vertebroplasty.