bluuebunny/crossref_metadata_2025_split huggingface dataset:
On‐vehicle low‐profile metal‐plate antenna for AMPS/GSM/DCS/PCS/UMTS multiband operations
Authors: Liu Yung‐Tao , Su Saou‐Wen , Tang Chia‐Luan , Chen Hong‐Twu , Wong Kin‐Lu 
Published: March 2004

AbstractA novel low‐profile metal‐plate antenna capable of generating two wide resonant modes for covering the AMPS/GSM (824–894 MHz/890–960 MHz) bands and the DCS/PCS/UMTS (1710–1880 MHz/1850–1990 MHz/1920–2170 MHz) bands for mobile communications in vehicles is presented. The proposed antenna is easily achieved by folding a stamped metal plate into a swanlike shape and then feeding it by using a matching‐bridge technique. The proposed antenna has a low profile of 27 mm (about 8% of the free‐space wavelength at 900 MHz) above the ground plane and shows conical radiation patterns for frequencies across the operating bands. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 144–146, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20074
New compact configuration of a stepped‐impedance ceramic bandpass filter
Authors: Wang Xuedong , Liu Peitao , Liu Xiangyang , Li Ying 
Published: March 2004

AbstractA new compact configuration of a stepped‐impedance comb‐line filter is proposed. By reversing one of the two resonators, the size of the filter becomes much smaller than that of the former. The impedance ratio has a small effect on the filter's size. The filter is made of low‐temperature co‐fired ceramic (LTCC). The simulated frequency characteristics are compared with the measured data of the fabricated filter and good agreement is reported. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 146–149, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20075
Novel low‐loss wide‐angle Y‐junctions of optical waveguides with graded‐index profiles
Authors: Yongjun Yang , Fushen Chen 
Published: March 2004

AbstractA low‐loss wide‐angle Y‐junction with graded‐index optical waveguides which can change the optical propagation direction, is proposed. The optical power is divided equally into two branching waveguides with a wide angle. Device performance is examined numerically by the finite‐difference beam propagation method (FDBPM). The simulated results show that the output optical power can be more than 96%, even if a branching angle is as large as 53.1°. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 156–159, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20078
Präzise Dichtemessungen mit schwebenden Festkörpern: Flotation
Authors: Toth Hans , Fehlauer Heinz 
Published: March 2004

AbstractDie Druckflotationsapparatur der Physikalisch‐Technischen Bundesanstalt kann relative Dichtedifferenzen von Siliziumproben mit sehr hoher Präzision messen. Dazu taucht die Probe vollständig in eine schwere Flüssigkeit ein. Sie wird darin frei schwebend austariert, indem die Dichte der Flüssigkeit gesteuert wird: Dazu variiert ein höhenverstellbares Ausgleichsgefäß den hydrostatischen Druck auf die Flüssigkeitssäule. Die Druckflotationsapparatur kann auch kleine und geometrisch nicht perfekte Festkörper messen. Solche hoch präzisen Dichtemessungen eröffnen eine neue Möglichkeit, Dichtenormale aus Silizium auf die SI‐Einheiten Kilogramm und Meter mit kleinstmöglicher Messunsicherheit zurückzuführen. Auch im Alltag werden Flotationsverfahren für verschiedenste Dichtemessungen eingesetzt.
Eier im Wellensalat: Experimente mit der Haushaltsmikrowelle
Authors: Karstädt Detlef , Möllmann Klaus‐Peter , Vollmer Michael 
Published: March 2004

AbstractHaushaltsmikrowellen bieten ein interessantes Feld für einfache, teilweise spektakuläre Vorführexperimente. Mit Thermofaxpapier und Infrarotkamera lassen sich zum Beispiel die Modenverteilungen des Zentimeterwellenfeldes im Garraum sichtbar machen. Eine Reihe von Versuchen kann die Absorption durch Metalle zeigen, besonders interessant sind dabei dünne Drähte und Drahtspitzen: Lampenbirnen glühen und Wunderkerzen zünden von selbst. Mikrowellen können auch Entladungslampen starten, Wasser im Eisblock erhitzen und Eier explodieren lassen.
Photovoltaik auf Glas: CIS‐Dünnschicht‐Solarzellen
Authors: Meyer Nikolaus 
Published: March 2004

AbstractHeutige Solarmodule bestehen aus kristallinem Silizium. Ihre Herstellung benötigt eine aufwändige Prozesstechnik und verbraucht viel Material und Energie. Das Hahn‐Meitner‐Institut (HMI) in Berlin hat als interessante Alternative eine Dünnschichttechnologie entwickelt. Bei ihr wirkt Kupfer‐Indium‐Disulfid (CIS) als direkter Halbleiter: Er kann die Energie auftreffender Photonen direkt in freie Ladungsträger und damit elektrischen Strom umsetzen. Deshalb brauchen CISSolarmodule nur eine sehr dünne Halbleiterschicht von etwa 1 μm Dicke, die auf Glas aufgebracht ist. CIS‐Module können geschätzt etwa 50 % billiger als heutige Silizium‐Solarzellen hergestellt werden. Die aus dem HMI heraus gegründete Sulfurcell Solartechnik GmbH baut nun eine Pilotproduktion auf.
Einsteins politische Akte: Physikgeschichte
Authors: Hoffmann Dieter 
Published: March 2004

AbstractEinstein war nicht nur der geniale Physiker, der die Relativitätstheorie entwickelt und der Quantentheorie den Weg bereitet hat. Er war auch ein Mann, der wegen seiner politischen Überzeugungen vielfachen Anfeindungen, Missgunst und Gesinnungsschnüffelei ausgesetzt war. Insbesondere sein demokratisches und pazifistisches Engagement machte ihn in Deutschland für viele zum Feind. Sein Eintreten für Menschenrechte und gegen Rassismus ließ ihn später auch in den USA ins Visier des Geheimdienste und des FBI geraten.
Röntgenbilder von Kristallen
Authors: Loos Andreas 
Published: March 2004

Abstract„Mit dem Fahrrad war er gekommen, sportlich und mit Rucksack”︁, erinnert sich ein Zeitgenosse an sein erstes Treffen mit dem ebenso unkonventionellen wie einflussreichen Physiker. Das war wohlgemerkt mitten im Winter. Und der Radfahrer war bereits 60 Jahre alt.
Kann auch Kohlenstoff magnetisch sein?
Authors: Esquinazi Pablo D. 
Published: March 2004

AbstractMagnetische Ordnung war bislang nur in bestimmten Stoffen bekannt, die Atome mit 3d‐ oder 4f‐Elektronen enthalten. Einer Gruppe an der Universität Leipzig gelang es durch Protonenimplantation auch in reinem Graphit eine ferromagnetische Ordnung zu erzeugen.
Organische Dünnschichttransistoren entwickelt
Authors: Leute Angelika 
Published: March 2004

AbstractOrganische Halbleiter, die sich in gelöster Form verarbeiten lassen, haben in den vergangenen Jahren große Fortschritte gemacht und werden bereits in Displays eingesetzt. Eine neue Anwendung, die zur Zeit von Wissenschaftlern der Siemens AG in Erlangen und der Universität Oldenburg erforscht wird, sind Dünnschichttransistoren auf der Basis eines organischen Halbleiters [1]. Elektronische Eigenschaften und Stabilität reichen für erste technische Anwendungen aus.
Laserlicht aus photonischem Kristall
Authors: Drach Volker 
Published: March 2004

AbstractFortschrittliche Prozesstechniken zur Herstellung und Strukturierung von Halbleitermaterialien ermöglichten neuartige Konzepte für elektronische und optoelektronische Bauteile. So genannte Quanten‐Kaskaden‐Laser und photonische Kristalle sind Beispiele hierfür. Diese beiden Konzepte zu kombinieren und dabei eine neuartige, miniaturisierte Laserquelle für Infrarotlicht mit senkrechter Emission herzustellen, gelang nun einer Forschergruppe an den Bell Laboratories (Lucent Technologies, Murray Hill, USA) um Raffaele Colombelli [1].
Physikportale im Test
Authors: Radons Gunnar 
Published: March 2004

AbstractZwei Internetportale befassen sich in Deutschland mit Inhalten der Physik: Welt der Physik (www.weltderphysik.de), verfasst von der Deutschen Physikalischen Gesellschaft und vom Bundesministerium für Bildung und Forschung, und Pro‐Physik.de (www.pro‐physik.de), ebenfalls von der DPG in Zusammenarbeit mit Wiley‐VCH herausgegeben. Wir vergleichen die beiden Portale.
Changing patterns of gallstone disease in Korea
Authors: Park Yong ‐Hyun , Park Sang ‐Jae , Jang Jin ‐Young , Ann Young Joon , Park Youn ‐Chan , Yoon Yong Bum , Kim Sun ‐Whe 
Published: March 2004

AbstractThe aim of this study was to investigate the epidemiologic characteristics and changing patterns of gallstone disease in Korea over a recent 20‐year period. A total of 4020 gallstone patients who had undergone surgery at Seoul National University Hospital during 1981–2000 were analyzed according to periods: period I (1981–1985: 831 cases); period II (1986–1990: 888 cases); period III (1991–1995: 1040 cases); period IV (1996–2000:1261 cases). The literature from 13 institutes in Korea reporting a total of 13,101 gallstone cases were reviewed to elucidate the nation‐wide trend. The number of gallstone cases gradually increased. A female predominance was not noted (F/M = 1.17–1.37) as is seen in Western countries. The patients with common bile duct (CBD) stones were older than those with gallbladder (GB) stones or intrahepatic duct (IHD) stones. Over time, the relative proportion of those with a GB stone increased, plateauing (80–85%) during the 1990s; that of patients with CBD stones decreased (34% → 19%); and that of those with IHD stones remained unchanged (11–15%). Over the entire period, the rural pattern of gallstone formation (low number of GB stones, high numbers of CBD and IHD stones) has become similar to the urban pattern. The body mass index (BMI) of the GB stone group was above average, as were the BMIs of the CBD stone and IHD stone groups. Throughout the literature review, this same changing pattern of the relative proportion of gallstone disease was confirmed. Thus the pattern of gallstone disease in Korea has become similar to that seen in Western countries except for a high prevalence of hepatolithiasis.
Treatment of uncomplicated hydatid cyst of the liver by closed marsupialization and fibrin glue obliteration
Authors: Hofstetter Christian , Segovia Eduardo , Vara‐Thorbeck Rafael 
Published: March 2004

AbstractTreatment of hepatic echinococcosis remains a surgical problem not only in endemic countries. Between January 1983 and December 1999 a total of 29 patients underwent surgical treatment for hepatic hydatidosis at the Department of General Surgery at the University Hospital of Granada. The diagnosis was based on clinical criteria, serology, and imaging techniques. There were 16 male and 12 female patients (ages 7–67 and 30–74 years, respectively). Concomitant extrahepatic complications were found in seven patients. Among them, five had secondary parasitic cysts in the peritoneal cavity. In one case an intrathoracic rupture was found, and one patient suffered an intraabdominal rupture with anaphylactic shock. The right lobe was affected in 62% (18 patients). Hepatic cysts were multiple in 4 cases and calcified in 13. Conservative surgical procedures were performed in 23 patients (closed marsupialization with fibrin glue obliteration in 17 and drainage‐marsupialization in 6), and radical surgical procedures were undertaken in 6 (pericystectomy in 5 and hemihepatectomy in 1). One patient underwent an explorative laparotomy with intraabdominal lavage followed by pericystectomy after primary resuscitation due to anaphylactic shock. The mean period of hospitalization was 15.9 days, and there were no serious postoperative complications or fatal outcomes. The perioperative morbidity rate was 2.5%. One patient suffered a recurrence of the disease following drainage marsupialization after an interval of 5 years. Our results indicate that the closed marsupialization technique is a safe, sparing method for treating uncomplicated hepatic hydatidosis. The results were also compared to those of a former study reported by our group in which the experience of another 19 years was presented.
Rectus abdominis muscle flap for high‐output duodenal fistula: Novel technique
Authors: Chander Jagdish , Lal Pawan , Ramteke Vinod K. 
Published: March 2004

AbstractDuodenal fistula after closure of peptic ulcer perforation, though rare, is difficult to manage and carries a high mortality. The high mortality is associated with the poor nutritional status of the patient, high output from the fistula, and late development of peritonitis and septicemia. The various techniques described in the literature for the closure of the postsurgical external duodenal fistulas range from conservative management with total parenteral nutrition (TPN), serosal patch repair, and Roux‐en‐y procedures to radical surgery like Billroth II gastrectomy. Total parenteral nutrition achieves spontaneous closure in 70% to 80% of cases, but it is very expensive and requires prolonged hospitalization. In addition, some surgical procedures have yielded poor results in our setting, so we sought a new modality of treatment. We describe a novel technique for repair of postsurgical external fistula of the duodenum with a rectus abdominis muscle flap. The rectus abdominis muscle is detached from its superior attachment and mobilized from the rectus sheath. The flap, based on the deep inferior epigastric artery, is raised and sutured to the duodenal fistula with thick silk sutures. We treated six patients with post‐surgical duodenal fistulas with this technique between 1995 and 2002. The leak was completely sealed in all patients. One patient died of septicemia. We recommend this technique for the management of postsurgical external duodenal fistula as an alternative to other surgical techniques.
Quantitative evaluation of the utero‐ovarian venous pattern in the adult human female cadaver with plastination
Authors: Pavkov Mircea L. , Koebke Jürgen , Notermans Hans ‐P. , Brökelmann Jost 
Published: March 2004

AbstractWe described the anatomy of the utero‐ovarian venous system in the adult postmenopausal female cadaver using casts and the von Hagen’s plastination technique. To qualitatively and quantitatively evaluate the uterine vein, the utero‐ovarian arcade, the ovarian vein and the ramus communicans between left and right parametrium, we injected epoxy resin into the internal iliac vein and artery and the ovarian vein and artery in six cadavers. In two cases the internal genital organs were excised before injection and in the other four after the injection and polymerization of the resin. All specimens were macroscopically examined and venous diameters were digitally measured, the average values of the measured diameters being 3.38 mm for the uterine vein, 3.71 mm for the utero‐ovarian arcade, 3.49 mm for the ovarian vein, and 3.71 mm for the ramus communicans. The veins were completely filled out and could be best examined in the four cases where in situ injection was performed. We could observe that the utero‐ovarian arcade is an important vein with a caliber similar to that of the ovarian and uterine veins, that there is an impressive network of venous anastomoses between the left and right parametrium and that the fallopian tubes are drained by three separate veins: internal, median, and external tubal veins. Pelvic venous congestion was present in two specimens; in one of them it was located in the region of the left uterine vein and in the other one in the region of the left ovarian vein. Given the similar average diameters of the uterine vein, ovarian vein, and utero‐ovarian arcade, we assume that there is no preferential uterine or ovarian venous drainage and that the veins of the internal genital organs are behaving like a venous pool. Nevertheless, congestion can affect limited sites, which can and should be treated locally.
Barrett’s esophagus: Histopathologic definitions and diagnostic criteria
Authors: Mueller James , Werner Martin , Stolte Manfred 
Published: March 2004

AbstractAdenocarcinoma of the distal esophagus is rising more rapidly in incidence than any other visceral malignancy in the Western world. It is well established that most, if not all, of these tumors develop in Barrett’s esophagus via the metaplasia‐dysplasia‐carcinoma sequence and could theoretically be detected at an early stage, but despite this, the majority of these tumors are still detected late in their course. This highlights the fact that the goal of effective surveillance for patients at risk for developing an adenocarcinoma of the distal esophagus is still far off. In addition, adenocarcinomas of the esophagogastric junction and gastric cardia are also rising in incidence, but their carcinogenesis and their relation to Barrett’s esophagus are still being defined, as are the meaning and significance of the relatively new entities “short‐segment Barrett’s” and “ultra‐short‐segment Barrett’s”. This review attempts to clarify the main histopathologic issues concerned with the definition of Barrett’s esophagus, its distinction from intestinal metaplasia of the gastric cardia, as well as the criteria for the histologic diagnosis of dysplasia and carcinoma in Barrett’s esophagus.
Special wound healing methods used in ancient Egypt and the mythological background
Authors: Sipos Péter , Gyõry Hedvig , Hagymási Krisztina , Ondrejka Pál , Blázovics Anna 
Published: March 2004

AbstractThe Egyptian civilisation is one of the oldest in history and was renowned for its scientific and artistic achievements, and medicine was no exception. The ancient Egyptians were masters in applying and arranging bandages, and they recognized the cardinal signs of infection and inflammation. Egyptian drug therapy can be regarded as having evolved from a system rooted in magic and empirical observation. To illustrate how the Egyptian wound healing methods provided a major stimulus for the development of surgery, we conducted a literature search.
Appraisal of surgical treatment for pT2 gallbladder carcinomas
Authors: Suzuki Shohachi , Yokoi Yoshihiro , Kurachi Kiyotaka , Inaba Keisuke , Ota Shigeyasu , Azuma Masaki , Konno Hiroyuki , Baba Satoshi , Nakamura Satoshi 
Published: March 2004

AbstractThis retrospective study was designed to appraise the surgical procedures for pT2 gallbladder (GB) carcinomas. Twenty patients with pT2 GB carcinomas underwent surgical resection. Hepatectomy of segments 4b and 5 was performed in 19 patients, and an extended right hepatic lobectomy was performed in 1. The extrahepatic bile duct was preserved in 8 patients in whom the disease was limited to the GB fundus and/or body. Regional lymphadenectomy was performed in 18 patients. A separate radical second operation was performed in 8 patients after cholecystectomy. Final pathological staging was stage IB in 15 patients, IIB in 4, and IV in 1. Overall 5‐year survival rate in those 20 patients was 77% without operative deaths. The 5‐year survival rate in 5 patients with nodal metastasis and in 8 patients without extrahepatic biliary resection was 80% and 100%, respectively. A separate radical second operation in 8 patients yielded 75% survival after 5 years. Perineural invasion as a prognostic determinant was closely associated with tumor extending to the neck or the cystic duct. Partial hepatectomy, usually with extrahepatic biliary resection and regional lymphadenectomy, was appropriate as a standard radical operation for pT2 GB carcinoma, but preservation of extrahepatic bile duct is advocated for disease limited to the GB fundus and/or body. Radical second operation enhanced the chance for cure in patients with pT2 GB carcinoma.
Presentation and prognosis of gastric cancer in patients aged 80 years and older
Authors: Rabunal Ramón R. , Pita Salvador F. , Rigueiro M. Teresa V. , Casariego Emilio V. , Pértega Sonia D. , García‐Rodeja Eugenia , Abraira Victor 
Published: March 2004

AbstractThe aim of this study was to analyze the characteristics of the presentation and prognosis of patients aged ≥ 80 who were diagnosed with gastric adenocarcinoma. We have used a retrospective cohort study of 2334 patients diagnosed between 1975 and 1993 in northwestern Spain, 263 (11.3%)of whom were ≥ 80 years of age. No differences were observed with respect to patients of a younger age at diagnosis regarding the site of the tumor, extension of the disease, or Laurén’s histologic type. However, fewer resections with curative intent were performed in the older group (49.1% vs. 30.1%; p < 0.0001). Among those operated on with curative or palliative intent, at the end of the first month the survival probability was 0.9 and the 0.95% confidence interval (CI 95%) was 0.93–0.97 for patients < 80 years of age and 0.93 (CI 95% 0.89–0.98) for the older group (p = 0.19). At the end of 5 years of follow‐up these probabilities were 0.29 (CI 95% 0.27–0.31) and 0.18 (CI 95% 0.14–0.23), respectively (p < 0.0001). If we consider only those patients undergoing curative resection, the survival probability for the two groups (p = 0.4) was not statistically different. In conclusion, although the two groups showed similar characteristics at presentation, patients ≥ 80 years of age underwent surgery with curative intent less frequently and their general prognosis was worse. Our data support the idea that curative surgery should not be ruled out exclusively for reasons of age.
Serum monocyte chemoattractant protein‐1 in patients with postoperative infectious complications from gastrointestinal surgery for cancer
Authors: Tonouchi Hitoshi , Miki Chikao , Ohmori Yukinari , Kobayashi Minako , Mohri Yasuhiko , Tanaka Kouji , Konishi Naomi , Kusunoki Masato 
Published: March 2004

AbstractWe examined the kinetics of serum monocyte chemoattractant protein‐1 (MCP‐1) perioperatively and clarified its significance regarding the development of infectious complications. We studied 94 patients who underwent gastrointestinal surgery for gastric or colorectal cancer at Mie University Hospital from 1996 to 2000. Serum concentrations of MCP‐1 and interleukin‐6 (IL‐6) were measured perioperatively. The number of circulating lymphocytes and neutrophils were counted to assess the apoptotic rate of neutrophils. Patients were divided into two groups at the median preoperative MCP‐1 level obtained from 40 gender‐and agematched healthy volunteers. The rate of developing infectious complications was significantly higher and tumor size was significantly larger in the low MCP‐1 group than in the high MCP‐1 group. The increasing IL‐6 ratio (postoperative/preoperative IL‐6 level) in the low MCP‐1 group was about twofold greater than that in the high MCP‐1 group. The neutrophil level calculated for the low MCP‐1 group was significantly higher than that in the high MCP‐1 group on postoperative day 3. We concluded that a decreased level of serum MCP‐1 reflected tumorrelated immunosuppression. Low MCP‐1 levels were associated with an exaggerated postoperative IL‐6 response and delayed neutrophil apoptosis, which affected the incidence of postoperative infectious complications developing in patients with gastrointestinal malignancies.