bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ursache des Muskelschwunds geklärt?
Authors: Dingermann Theo , Zündorf Ilse 
Published: October 2004

AbstractSo ganz en passant konnte die Gruppe um Ralf Baumeister in Freiburg auf der Suche nach der Entstehungsursache des Morbus Parkinson auch den Mechanismus für Auf‐ und Abbau der Muskulatur aufklären.
Das Springkraut – Von explosiver Ungeduld
Authors: Junghans Thomas 
Published: October 2004

AbstractVon den vier Vertretern der Springkrautgewächse (Balsaminaceae) sind drei monotypisch, d.h. sie bestehen nur aus einer einzigen Art, so dass die etwa 600 Arten der Familie fast vollständig auf das Springkraut selbst (Gattung Impatiens) entfallen.
Processing of ultra‐high molecular weight polyethylene by hot isostatic pressing, and the effect of processing parameters on its microstructure
Authors: Gul Rizwan M. , McGarry Frederick J. 
Published: October 2004

AbstractThe processing techniques available for ultra‐high molecular weight polyethylene (UHMWPE) do not lead to a homogeneous material. The processed material exhibits particle boundaries (fusion defects) reflecting the powder flakes of the virgin resin. Hot isostatic pressing has been used in this study as a possible technique to produce a homogeneous, defect‐free material, and to study the effect of processing parameters on consolidation and other properties. The extent of consolidation was determined by optical microscopy using thin sections, and by scanning electron microscopy using cryofractured and solvent‐etched specimens. Processing temperature is the most important variable affecting consolidation; fusion defects can be eliminated by increasing the processing temperature. This is sometimes accompanied by the appearance of spherulties; however, the degree of crystallinity, melting point, and density remain constant. DMA results show that the molecular weight between entanglements increases and the entanglement structure changes with an increase in processing temperature. Polym. Eng. Sci. 44:1848–1857, 2004. © 2004 Society of Plastics Engineers.
A temperature‐dependent adaptive controller. Part I: Controller methodology and open‐loop testing
Authors: Dubay Rickey , Lakhram Rodney 
Published: October 2004

AbstractCurrently, the controllers for achieving a desired injection velocity setpoint profile are independent of processing conditions in plastic injection molding. The dynamics of the reciprocating screw during injection mold filling is complex and temperature‐dependent. This complexity is based on process parameters that are nonlinear, which can vary spatially in time. Open‐loop tests were performed on two polymers at three melt temperatures and three mold‐fill velocity regimes: low, medium, and high. These tests were based on close‐loop injection mold‐fill setpoints and a derived voltage velocity relationship for the injection velocity hydraulic valve. The results of the open‐loop tests show that mold‐filling injection velocity is polymer‐ and melt temperature‐dependent. Polym. Eng. Sci. 44:1925–1933, 2004. © 2004 Society of Plastics Engineers.
A parallel coextrusion technique for simultaneous measurements of radial die swell and velocity profiles of a polymer melt in a capillary rheometer
Authors: Intawong N.‐T. , Sombatsompop N. 
Published: October 2004

AbstractThis article proposes a new experimental technique to simultaneously measure radial die swell and velocity profiles of polystyrene melt flowing in the capillary die of a constant shear rate rheometer. The proposed technique was based on parallel coextrusion of colored melt‐layers into uncolored melt‐stream from the barrel into and out of the capillary die. The size (thickness) ratio of the generated melt layers flowing in and out of the die was monitored to produce the extrudate swell ratio for any given radial position across the die diameter. The radial velocity profiles of the melt were measured by introducing relatively light and small particles into the melt layers, and the times taken for the particles to travel for a given distance were measured. The proposed experimental technique was found to be both very simple and useful for the simultaneous and accurate measurement of radial die swell and velocity profiles of highly viscous fluids in an extrusion process. The variations in radial die swell profiles were explained in terms of changes in melt velocity, shear rate, and residence time at radial positions across the die. The radial die swell and velocity profiles for PS melt determined experimentally in this work were accurate to 92.2% and 90.8%, respectively. The overall die swell ratio of the melt ranged from 1.25 to 1.38. The overall die swell ratio was found to increase with increasing piston speed (shear rate). The radial extrudate swell profiles could not be reasoned by the shear rate change, but were closely linked with the development of the velocity profiles of the melt in the die. The die swell ratio was high at the center (∼1.9) and low (∼0.9) near the die wall. The die swell ratio at the center of the die reduced slightly as the piston speed was increased. Polym. Eng. Sci. 44:1960–1969, 2004. © 2004 Society of Plastics Engineers.
Relationship between multiple sequence alignments and quality of protein comparative models
Authors: Cozzetto Domenico , Tramontano Anna 
Published: October 2004

AbstractComparative modeling is the method of choice, whenever applicable, for protein structure prediction, not only because of its higher accuracy compared to alternative methods, but also because it is possible to estimate a priori the quality of the models that it can produce, thereby allowing the usefulness of a model for a given application to be assessed beforehand.By and large, the quality of a comparative model depends on two factors: the extent of structural divergence between the target and the template and the quality of the sequence alignment between the two protein sequences. The latter is usually derived from a multiple sequence alignment (MSA) of as many proteins of the family as possible, and its accuracy depends on the number and similarity distribution of the sequences of the protein family.Here we describe a method to evaluate the expected difficulty, and by extension accuracy, of a comparative model on the basis of the MSA used to build it. The parameter that we derive is used to compare the results obtained in the last two editions of the Critical Assessment of Methods for Structure Prediction (CASP) experiment as a function of the difficulty of the modeling exercise. Our analysis demonstrates that the improvement in the scope and quality of comparative models between the two experiments is largely due to the increased number of available protein sequences and to the consequent increased chance that a large and appropriately spaced set of protein sequences homologous to the proteins of interest is available. Proteins 2005. © 2004 Wiley‐Liss, Inc.
Effects of pressure on the phonon–phonon and electron–phonon interactions in semiconductors
Authors: Cardona M. 
Published: October 2004

AbstractWe discuss the dependence of phonon frequencies on hydrostatic pressure for tetrahedrally bonded semiconductors, in particular the linear term represented by mode Grüneisen parameters. The relation between these parameters and the thermal expansion is also elucidated. Emphasis is placed on recent results that concern the zero‐point renormalization of lattice parameters and its dependence on isotopic masses. The pressure dependence of transverse charges of ir‐active phonons is also touched upon. We also discuss strong pressure and isotopic mass effects on phonon widths and line shapes that are occasionally observed for selected materials. Finally, we present recently observed effects of pressure on the luminescence of isotopically pure silicon which are strong enough to be easily detected in the 0–1 bar range. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Prospects for the development of pre‐mortem laboratory diagnostic tests for Creutzfeldt‐Jakob disease
Authors: Dabaghian Reza H. , Mortimer Philip P. , Clewley Jonathan P. 
Published: October 2004

AbstractAt present the diagnosis of Creutzfeldt‐Jakob disease (CJD) and related transmissible spongiform encephalopathies in humans is based on clinical criteria and (at post‐mortem) the histopathological and immunological examination of brain tissue. The misfolded prion protein, PrPSc, is the single most significant marker, but its recognition by standard serological methods is complicated by its antigenic similarity to the normal prion protein, PrPC. Although there are commercial diagnostic assays available for bovine spongiform encephalopathy using brain specimens taken at slaughter, there are no suitable pre‐mortem assays for cattle and none either for pre‐mortem human disease. Especially in view of the recent report of variant CJD transmission by blood transfusion, it is important that tests for pre‐symptomatic infections are developed. This will safeguard the blood supply and, for example, prevent the transmission of CJD in neurosurgery. This paper reviews the current and prospective approaches to the pre‐mortem diagnosis of CJD, in particular its variant form. Copyright © 2004 John Wiley & Sons, Ltd.
Mobile internet access using satellite networks
Authors: Loreti P. , Luglio M. , Kapoor R. , Stepanek J. , Gerla M. , Vatalaro F. , Vazquez‐Castro M. A. 
Published: October 2004

AbstractSatellites offer a promising alternative for mobile access to the Internet by both pedestrians, and more importantly, from vehicles. As such, satellites provide an essential complement to the cellular radio (UMTS) infrastructure in sparsely populated areas where high bandwidth UMTS cells cannot be economically deployed. In this paper, we analyse various mobile Internet applications in representative urban scenarios for two LEO constellations (one with polar orbits and the other with inclined orbits), as well as for some simple GEO configurations. To this end, we develop a satellite channel propagation model that includes shadowing from surrounding building skylines based on actual data in a built‐up area.Using these tools, we analyse various Internet applications and the performance of various TCP schemes in different topologies. Copyright © 2004 John Wiley & Sons, Ltd.
Transport protocols in multicast via satellite
Authors: Akkor Gun , Hadjitheodosiou Michael , Baras John S. 
Published: October 2004

AbstractIn a wide variety of broadband applications, there is a need to distribute information to a potentially large number of receiver sites that are widely dispersed from each other. Communication satellites are a natural technology option and are extremely well suited for carrying such services because of the inherent broadcast capability of the satellite channel. Despite the potential of satellite multicast, there exists little support for multicast services over satellite networks. Although several multicast protocols have been proposed for use over the Internet, they are not optimized for satellite networks. One of the key multicast components that is affected when satellite networks are involved in the communication is the transport layer. In this paper, we attempt to provide an overview of the design space and the ways in which the network deployment and application requirements affect the solution space for transport layer schemes in a satellite environment. We also highlight some of the issues that are critical in the development of next generation satellite multicast services. Copyright © 2004 John Wiley & Sons, Ltd.
A capture‐assisted random access scheme for multi‐beam LEO satellite packet data networks
Authors: Thomas George 
Published: October 2004

AbstractA CDMA‐based satellite switch is proposed for use in multi‐beam satellites carrying random‐access packet‐switched data. Applications include the emerging new low‐earth‐orbit (LEO) satellite networks which support global wireless networking. Capture phenomenon is used to advantage in increasing the random access throughput, and the on‐board switch is at once simple and specially designed to handle full loads with minimal complexity. Copyright © 2004 John Wiley & Sons, Ltd.
Stimulation of wound healing by the immunomodulator LS‐2616 (Linomide)
Authors: Lepistö Jyri , Laato Matti , Niinikoski Juha , Lundberg Claes , Gerdin Bengt 
Published: October 2004

AbstractLS‐2616 (Linomide), a quinoline‐3‐carboxamide, is an immunomodulator that has been suggested to act on macrophage‐like cells. Based on a hypothesis that LS‐2616 would stimulate macrophages in the wound and affect the healing process, the effects of LS‐2616 on developing granulation tissue were evaluated using a wound model in rats. Subcutaneously implanted cylindrical cellulose sponges were used as an inductive matrix for the ingrowth of granulation tissue. LS‐2616 was continuously present at a concentration of 1.2 mg/ml in the drinking water either for 7 days before implantation or starting at the implantation of sponges. Seven days after implantation LS‐2616 treatment increased the mean amounts of nitrogen and collagen hydroxyproline over the control level 1+20% (p<0.05) and +59% (p<0.05), respectively]. The effect was less pronounced in the rats receiving LS‐2616 in advance [+7% (NS) and +38% (p<0.05), respectively]. The mean amounts of nucleic acids and protcoglycans tended to decrease in the rats receiving LS‐2616 in advance compared to the control rats [‐12% to 13% (NS) and‐25% (p<0.05), respectively]. It was concluded that continuous oral administration of LS‐2616 enhanced wound repair in the rat. This immunoenhancement of round healing results in increased accumulation of collagen.
En bloc resection for extensive hepatocellular carcinoma: Is it advisable?
Authors: Jeng Kuo‐Shyang , Chen Bee‐Fong , Lin Hong‐Jyh 
Published: October 2004

AbstractWhen the adjacent organ is partially invaded by a hepatocellular carcinoma (HCC), whether to go on an aggressive resection is a difficult but challenging problem. To investigate the worth of en bloc resections, a retrospective controlled study was conducted. During a 9‐year period, nine patients (seven men, two women: group I) who had HCC with invasions to extrahepatic adjacent organs had undergone en bloc resections. The adjacent organs included diaphragm (eight cases), adrenal gland (two cases), abdominal wall (one case), and spleen (one case). The patients selected for en bloc resections were those with a solitary tumor without evidence of vascular invasion or intravascular tumor thrombi, daughter nodule(s), or distant metastasis. The evidence was based on preoperative evaluation by ultrasonography, computed tomography, arteriography, and intraoperative ultrasonography. Eighteen matched patients with HCC but no involvement of neighboring organs were selected as controls (14 men, 4 women: group II). Though patients of group I had wider invasion of HCC and more extensive resection, their surgical morbidity, mortality, hospital mortality, disease‐free interval, and survival time were similar to those of group II, who had more limited HCC and resections. Eighteen months after operation, the HCC recurrence rate was 44% and 41% in groups I and II, respectively, and the percent survivals were 71% and 63%, respectively. We suggest that in cases of large HCC with local invasion to neighboring organs, aggressive en bloc resection is recommended after appropriate patient selection.
Diagnostic evaluation and surgical management of hydatid disease of the liver
Authors: Safioleas Michael , Misiakos Evangelos , Manti Christine , Katsikas Demetrios , Skalkeas Gregory 
Published: October 2004

AbstractHuman echinococcosis is still endemic in some areas of the world, including Mediterranean countries. Because there is no effective medical therapy, surgery remains the principal mode of treatment. A consecutive series of 132 patients operated on for liver hydatid disease between January 1977 and February 1993 were analyzed. There were 60 men (45.4%) and 72 women (54.6%) aged 31 to 88 years (mean 56 years). The right lobe of the liver was affected in 68 cases (51.5%), the left lobe in 31 cases (23.5%), and both lobes in 14 cases (10.6%); there were multiple liver cysts in 7 cases (5.3%), concomitant cysts in other parenchymal organs in 4 cases (3.0%), and disseminated intraabdominal hydatid disease in 8 cases (6.1%). Clinical symptomatology consisted of abdominal pain, fever, jaundice, urticaria, and an abdominal mass. Preoperative diagnosis was established using imaging studies: plain abdominal films, ultrasonography, computed tomography, and serologic tests. Three patients (2.3%) underwent simple closure without drainage, 7 patients (5.3%) cyst excision, 4 patients (3.0%) marsupialization, 1 patient (0.8%) left lateral segmentectomy, 15 patients (11.3%) external drainage, 69 patients (52.3%) omentoplasty, and 33 patients (25.0%) combinations of procedures. Postoperative morbidity was low and consisted of hepatic abscess development, wound infection, bowel obstruction, and biliary leaks. Six patients (4.5%) had recurrent disease. One patient died during the postoperative period because of septic complications. Among the surgical techniques we used, excision of the cyst (when feasible) and omentoplasty produced the lowest complication rates and the best clinical results.
Impact of transjugular intrahepatic portosystemic shunt on orthotopic liver transplantation
Authors: Menegaux Fabrice , Baker Edward , Keeffe Emmet B. , Monge Humberto , Egawa Hiroto , Esquivel Carlos O. 
Published: October 2004

AbstractTransjugular intrahepatic portosystemic shunt (TIPS) is being increasingly utilized prior to liver transplantation for portal hypertensive bleeding refractory to sclerotherapy or as initial management of variceal bleeding. The impact of TIPS on subsequent orthotopic liver transplantation (OLT) is uncertain. The purpose of this study was to analyze the effect of TIPS on OLT in terms of operative transfusion requirements, operative time, length of hospital stay, and graft and patient survival. The results in 17 patients undergoing TIPS for control of initial or recurrent variceal bleeding prior to OLT between June 1991 and December 1992 were compared to two other groups undergoing transplantation: 32 control patients with a history of variceal bleeding not treated by TIPS and 11 patients with a previous surgical portosystemic shunt. Compared with control and surgical shunt patients, patients who underwent TIPS had less transfusion requirement for packed red blood cells and fresh frozen plasma during OLT. The operative time and hospital stay of the TIPS patients were slightly, but not significantly, less. In contrast to patients having TIPS, the patients with a history of a previous surgical shunt had an increased requirement for packed red blood cells, longer operative time, and longer stay in the intensive care unit and hospital. Two patients had recurrent variceal bleeding after TIPS; one patient was found to have an occluded stent, and the other patient (with a patent stent) responded to sclerotherapy. Of the 14 patients with ascites, 8 patients improved and 6 patients had complete resolution after TIPS. There were no major complications related to TIPS, although 3 patients had new or recurrent hepatic encephalopathy that was easily manageable. Thus the preoperative performance of TIPS is associated with less operative transfusion requirement during OLT, presumably secondary to a reduction in portal hypertension. TIPS is preferred to surgical shunt for pretransplant refractory variceal bleeding, as the latter is associated not only with significant morbidity and mortality but also increased transfusion requirements and prolonged operative time and hospital stay.
Simultaneous surgery for coronary artery disease and gastric cancer
Authors: Kamiike Wataru , Miyata Masahiko , Izukura Massaki , Itoh Toshinori , Nezu Riichiro , Nakamuro Makoto , Hatanaka Nobutaka , Shimizu Shigeomi , Takahashi Toshiki , Shimazaki Yasuhisa , Nakano Susumu , Matsuda Hikaru 
Published: October 2004

AbstractOr 26 patients who underwent both coronary artery bypass grafting and abdominal surgery at our institution between 1977 and 1992, nine had severe coronary artery disease associated with UICC stage I gastric cancer. They were treated by coronary artery bypass grafting followed by a curative operation for gastric cancer, the initial four patients underwent two‐staged surgery (group A), and the most recent five patients underwent simultaneous surgery (group B). The cardiac surgery was performed first in all patients, and in group A the interval between the two procedures was 2 to 7 weeks. There were no significant differences between the two groups in terms of preoperative characteristics: sex, age, preoperative complications, NYHA class, prior myocardial infarction, ejection fraction, cardiac index, number of vessels diseased, or number of grafts. There were no significant differences between the two groups in terms of blood loss during the gastric operation (A: 649±194 ml; B: 842±326 ml) or the operating time (A: 371±106 minutes; B: 343±46 minutes). Two group A patients had postoperative complications (one had arrhythmia, and one died of sepsis caused by sutural insufficiency). On the other hand, four group B patients had complications (three cases of transient hyperbilirubinemia and one case of postoperative bleeding: none died). The postoperative hospital stay after gastrectomy was not prolonged in group B compared with group A (A: 41.7±22.7 days; B: 46.0±25.0 days). In conclusion, simultaneous procedure of coronary artery bypass grafting and gastric surgery can be performed safely, although careful management is indispensable.