bluuebunny/crossref_metadata_2025_split huggingface dataset:
On‐line fault/damage detection schemes for mechanical and structural systems
Authors: Demetriou Michael A. , Hou Zhikun 
Published: March 2003

AbstractOn‐line monitoring has become an attractive approach to detecting faults in a system during its service time. Once a fault is detected, necessary measures can be employed to ensure satisfactory system performance and to prevent drastic economic loss that may be caused by the fault. This paper presents a performance study of two fault detection/diagnosis approaches, namely the wavelet‐based and the neural‐network‐based on‐line schemes. A brief summary of the wavelet‐based approach and two theorems on the neural‐network‐based on‐line approximation scheme are given. The schemes are illustrated for a single‐degree‐of‐freedom (SDOF) oscillator and a three‐degree‐of‐freedom mechanical system with damageable springs. Only harmonic excitations and abrupt changes in the system stiffness due to breakage of springs caused by the first passage of a threshold value are considered. Extensive numerical studies show that both approaches may be successfully implemented on‐line to detect the times when faults occurred and to locate regions where faults occurred. In addition, the on‐line neural network scheme is able to provide diagnosis of the fault by correctly identifying the stiffness change. In contrast to the neural‐network‐based on‐line approximation, where information on the healthy system and both displacement and velocity response measurements are required, the wavelet approach seems less model‐dependent and only the acceleration measurement is required. This study demonstrates the great promise of these schemes for on‐line structural health monitoring. Copyright © 2003 John Wiley & Sons, Ltd.
The ‘virtual’ cervical internal os: diagnosis during the first trimester of pregnancy
Authors: Shalev J. , Mashiach R. , Bar‐Chava I. , Kaplan B. , Bar J. , Orvieto R. , Meizner I. 
Published: March 2003

AbstractObjectiveTo determine the appropriate time during gestation for assessing the cervix for possible incompetence by ascertaining the gestational week at which the sac reaches the level of the internal os.MethodsThree hundred and eighteen women with an intact singleton pregnancy at 5 to 15 weeks' gestation underwent endovaginal sonographic examination to measure the distance between the gestational sac and the cervical internal os. The change in location of the gestational sac in the endometrial cavity over time, and the earliest gestational week at which the gestational sac reached the level of the internal os, were calculated and analyzed with one‐way analysis of variance.ResultsThe distance between the gestational sac and the ‘virtual’ cervical internal os decreased from a mean of 4.72 cm at 5 weeks to 1.71 cm at 13 weeks. This distance decreased significantly during the early first trimester (weeks 5 to 7) (P = 0.004), but remained almost unchanged from 12 to 15 weeks. Only at 12 weeks' gestation could the entire cervical length be determined and the configuration of the cervical internal os assessed for incompetence.ConclusionsTransvaginal sonography is a good method for evaluating the cervix during pregnancy. The location of the ‘virtual’ internal os can be determined in the first trimester using the urinary bladder as a reference point. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.
BaC4O44 — Ein kristallwasserfreies Erdalkaliquadratat mit dreidimensionaler Gerüststruktur und schichtartiger Trennung von Kationen und Anionen
Authors: Köferstein Roberto , Robl Christian 
Published: March 2003

BaC4O44 — An Alkaline‐Earth Squarate Free from Water of Crystallization with Three‐dimensional Framework Structure Featuring a Layer‐like Separation of Cations and AnionsColourless single crystals of BaC4O4 have been obtained from aqueous solution at 80 °C. BaC4O4 is stable in air up to 490 °C. BaCO3 is formed by further increase of temperature. BaC4O4 crystallizes in the tetragonal space group I4/mcm (nr. 140) with a=635.95(5), c=1240.77(13) pm, Z=4. Ba2+ is coordinated by eight oxygen atoms of the squarate dianions; Ba—O 276.1(1) pm. The coordination polyhedron is a distorted, square anti‐prism. The squarate dianions occupy crystallographic mirror planes and posses approximately 4/mmm symmetry; C—C 145.7(5) and 146.5(5) pm, C—O 125.9(3) pm. A layer‐like separation between the cations and anions exists with respect to the [001] direction.
Die Kristallstrukturen der Hexachlorometallate NH4[SbCl6], NH4[WCl6], [K(18‐Krone‐6)(CH2Cl2)]2[WCl6]·6CH2Cl2 und (PPh4)2[WCl6]·4CH3CN
Authors: Lau C. , Dietrich A. , Plate M. , Dierkes P. , Neumüller B. , Wocadlo S. , Massa W. , Harms K. , Dehnicke K. 
Published: March 2003

AbstractDie Kristallstrukturen der Titelverbindungen werden mit Hilfe von Röntgen‐Einkristall‐Strukturanalysen ermittelt. NH4[SbCl6] und NH4[WCl6] kristallisieren isotyp miteinander in der Raumgruppe C2/c mit vier Formeleinheiten pro Elementarzelle. Die NH4+‐Ionen liegen auf einer zweizähligen Drehachse, die Metallatome der [MCl6]—‐Ionen besetzen ein Inversionszentrum. Es bestehen schwache interionische Wasserstoffbrückenbindungen.[K(18‐Krone‐6)(CH2Cl2)]2[WCl6]·6CH2Cl2 kristallisiert orthorhombisch in der Raumgruppe R3¯/m mit Z = 3. Die Verbindung bildet zentrosymmetrische Ionentripel, in denen die Kaliumionen mit je einer WCl3‐Fläche koordinieren. In trans‐Position hierzu koordiniert das Cl‐Atom eines CH2Cl2‐Moleküls, so daß zusammen mit den O‐Atomen des Kronenethers Koordinationszahl 10 resultiert.(PPh4)2[WCl6]·4CH3CN kristallisiert monoklin in der Raumgruppe P21/c mit Z = 4. Auch diese Verbindung bildet zentrosymmetrische Ionentripel, in denen zusätzlich die Acetonitrilmoleküle über schwache C—H···Cl‐Kontakte mit dem [WCl6]2—‐Ion verbunden sind.
Die Zahl der Substitutions‐ und Leerstellenvarianten des NaCl‐Typs bei verdoppelter Elementarzelle (a, b, 2c)
Authors: Sens Irina , Müller Ulrich 
Published: March 2003

AbstractMit Hilfe eines Bärnighausen‐Stammbaums von kristallographischen Gruppe‐Untergruppe‐Beziehungen wurden alle Raumgruppen hergeleitet, die auftreten können, wenn im NaCl‐Typ Atome partiell substituiert oder entfernt werden und die Elementarzelle auf a, b, 2c verdoppelt wird. Für jede Raumgruppe wurde berechnet, wie viele verschiedene Strukturtypen für verschiedene chemische Zusammensetzungen auftreten können. Die Zahl der Möglichkeiten nimmt stark zu, je geringer die Raumgruppensymmetrie und je größer die Zahl der symmetrieunabhängigen Lagen der Kationen‐ und Anionenplätze ist. Die Gegenüberstellung mit bekannten Strukturen läßt die herausragende Bedeutung des Symmetrieprinzips in der Kristallchemie erkennen. Vor allem sind solche Strukturen bevorzugt, bei denen Atome einer Sorte möglichst wenig inäquivalente Lagen einnehmen. Dazu gehören Anatas, α‐LiFeO2, SnF4, SrSnP, BaNiSn3, BaCl(OH)(OH2), GdCoC, KNb4O6, LaxNb2O6; mit einiger Verzerrung auch ThCr2Si2, LaNiB2C und LiNCN. Es gibt Strukturmöglichkeiten, für die trotz hoher Symmetrie noch keine Vertreter bekannt sind. Für Verbindungen wie PdAg2O2 oder PdHgO2 werden in Betracht kommende Strukturen vorhergesagt.
Neue Alkalimetall‐halogenopalladate(II) mit Iodeinlagerung — Kristallstrukturen, Phasenübergänge und Spektroskopie
Authors: Heines Peter , Keller Hans‐Lothar , Bouvier Pierre , Hanfland Michael 
Published: March 2003

AbstractCs2[PdBr4]I2, Cs2[PdCl4]I2 und Rb2[PdBr4]I2 wurden solvothermal bei 423 K aus verdünnten Halogenwasserstoffsäuren in Form dunkelroter bis schwarzer Kristalle erhalten, die im Raumgruppentyp I4/mmm mit Z = 2 kristallisieren. Die Elementarzellenparameter für Cs2[PdBr4]I2 betragen a = 848, 96(1) pm und c = 908, 53(2) pm, für Cs2[PdCl4]I2 a = 814, 65(2) pm und c = 899, 10(1) pm, und für Rb2[PdBr4]I2 a = 840, 9(1) pm und c = 902, 3(1) pm. Die Verbindungen enthalten isolierte [PdX4]‐Baugruppen (X = Cl, Br), die von eingelagerten Iodmolekülen überkappt werden. Cs2[PdBr4]I2 und Cs2[PdCl4]I2 zeigen druckinduzierte reversible Phasenübergänge oberhalb 78 kbar bzw. 199 kbar.
Tamoxifen and Gallstone Formation in Postmenopausal Breast Cancer Patients: Retrospective Cohort Study
Authors: Akin Mehmet L. , Uluutku Haldun , Erenoglu Cengiz , Karadag Ahmet , Gulluoglu Bahadır M. , Sakar Burak , Celenk Tuncay 
Published: March 2003

AbstractTamoxifen is being used successfully in breast cancer patients as adjuvant hormonal therapy. The aim of this retrospective cohort study is to evaluate the impact of tamoxifen on gallstone formation in postmenopausal breast cancer patients. A total of 3165 patients who were treated for invasive breast cancer between 1990 and 1997 were reviewed. The data were collected from four university hospitals in a population‐based registry. Among these patients, 2462 were excluded from the study owing to improper follow‐up and other reasons. Premenopausal patients were also excluded. Of the 703 patients included in the study, 457 had received adjuvant therapy including tamoxifen, and the other 246 had not. Gallstone formation was assessed by annual abdominal ultrasonography. The mean follow‐up period was 4.6 years (range 1–7 years). There were no significant differences between the groups of breast cancer patients treated with or without tamoxifen regarding the age of the patients at the time of breast cancer diagnosis, the age at menopause, the duration between the onset of menopause and the time the breast cancer was diagnosed, the presence of diabetes, and the body mass index. At the end of 5 years the incidence of gallstone formation in tamoxifen‐treated patients was 37.4%, whereas it was 2.0% in patients who did not receive tamoxifen (p < 0.0001). The incidences of gallstones being detected in 171 tamoxifen‐treated patients were 0.4%, 3.7%, 24.4%, 33.1%, and 37.4% cumulatively during the first, second, third, fourth, and fifth years, respectively. Hence adjuvant tamoxifen therapy leads to gallstone formation in postmenopausal breast cancer patients and is most apparent after 3 years of treatment.
Non‐heart‐beating Donors: Renewed Source of Organs for Renal Transplantation during the Twenty‐first Century
Authors: Gerstenkorn Clemens 
Published: March 2003

AbstractThe growing demand of organs for renal transplantation makes it necessary to explore alternative routes for kidney donation. Non‐heart‐beating donors (NHBDs) are a valuable source of cadaveric organs and have been the subject of renewed interest in recent years. In addition to difficulties with legal and ethical acceptability, there are concerns regarding medical safety. The current NHBD program at St. George’s Hospital in London was started in March 1995. A total of 41 kidneys from category I to III donors (according to the Maastricht classification) were retrieved from the Accident and Emergency Department and several intensive care units and were subsequently transplanted. Cold in situ perfusion was commenced via femoral access or rapid aortic cannulation in most donors. Of these transplanted kidneys, 35 started functioning within 4 weeks. The permanent nonfunction (PNF) rate was 14.6% (6/41) and the estimated 1‐year graft survival 82.9% (34/41). The delayed graft function (DGF) rate (defined as recipients requiring posttransplant dialysis for 3 days or longer) was 80.0% (28/35). The median serum creatinine concentration in patients with a functioning graft at 1 year was 165 μmol/L. NHBD kidneys have contributed about 15% to the regional transplant activity over the last 6 years, even though not all potential NHBDs were used. It was possible to lower the PNF rate with strict donor selection criteria and more recently with pulsatile machine perfusion. NHBDs represent a valuable source for kidneys and can extend the donor pool. More experience is currently needed to continue to lower PNF rates reliably before promoting more widespread use of NHBDs for renal transplantation.
Treatment of Human Pancreatic Cancer in Mice with Angiogenic Inhibitors
Authors: Prox Daniela , Becker Christian , Pirie‐Shepherd Steven R. , Celik Ilhan , Folkman Judah , Kisker Oliver 
Published: March 2003

AbstractTumor growth is dependent on the balance of positive and negative regulators of angiogenesis. Antiangiogenic compounds inhibit endothelial cell biology in vitro and angiogenesis in vivo. Therefore antiangiogenic therapy presumes to be an effective treatment for pancreatic cancer. We wanted to determine the effect of antiangiogenic therapy on the growth of human pancreatic cancer in a mouse model. The angiogenesis inhibitors TNP‐470 and antiangiogenic antithrombin III (aaATIII) were tested in vitro for their ability to inhibit endothelial cell proliferation. These inhibitors, along with the known antiangiogenic molecule endostatin, were then employed to treat two different primary human pancreatic cancers implanted subcutaneously into the dorsa of immunodeficient (SCID) mice. Treated tumors were examined histologically for microvessel density, apoptosis, and proliferation. All three inhibitors suppressed the growth of pancreatic tumors in vivo. Immunohistochemical analysis revealed increased degrees of apoptosis and reduced microvessel density in treated tumors compared to untreated tumors, although tumor cell proliferation was the same in both groups. None of the inhibitors tested significantly inhibited proliferation of human pancreatic cancer cells, although both TNP‐470 and aaATIII were able to inhibit the proliferation of endothelial cells. The observed tumor suppression may be due to increased tumor cell apoptosis as a result of capillary dropout. These studies show that after the angiogenic switch in a human tumor, there is residual production of angiogenesis inhibitors.
Gliding resistance versus work of flexion—two methods to assess flexor tendon repair
Authors: Tanaka Tatsuro , Amadio Peter C. , Zhao Chunfeng , Zobitz Mark E. , An Kai‐Nan 
Published: March 2003

AbstractTwo methods for measuring the ability of the flexor tendon to glide following repair are commonly cited in the literature; gliding resistance (GR) at the tendon–pulley interface and work of flexion. The GR measures the friction force at the tendon–pulley interface, while the work of flexion characterizes whole finger function during flexion. Since a portion of the total work of flexion (TWOF), termed the internal work of flexion (IWOF), is expended due to the tendon–pulley interaction, a relationship between the work of flexion and GR should be present. The purpose of this study was to quantify this correlation. Forty‐eight flexor digitorum profundus tendons in 48 mongrel dogs were transected and repaired with a modified Kessler technique and an epitenon running suture. Post‐operatively, the operated paw was immobilized in a cast. Dogs were sacrificed at 1, 3, 5 or 7 days after surgery. In each repaired digit work of flexion and GR were measured. While the GR was not significantly different over the time points, the TWOF decreased at 5 days after surgery and then increased at 7 days (p < 0.05). There was little correlation between TWOF and GR (r = 0.25, p = 0.07). However, there was a strong correlation between IWOF and GR (r = 0.76, p < 0.05) suggesting that measurement of GR could be used as a predictor of IWOF within the short term after tendon repair. © 2003 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Hyalgan® has a dose‐dependent differential effect on macrophage proliferation and cell death
Authors: Sheehan Kyle M. , Delott Lindsey B. , Day Susan M. , Deheer David H. 
Published: March 2003

AbstractThe intra‐articular injection of high molecular weight hyaluronic acid (HA) has been reported to be an effective treatment for pain of osteoarthritis of the knee. However, the mechanism by which HA exerts its effect is unknown. To explore HA's influence on the growth of U937 human macrophages, cells were incubated for 168 h with three concentrations, 1, 0.1 and 0.01 mg/mL, of Hyalgan®, a high molecular weight HA preparation. At 24‐h increments, the cells were examined for proliferation, cell cycle distribution as well as the number of apoptotic and dead cells. Exposing macrophages to 1 mg/mL Hyalgan® significantly reduced the rate of cellular proliferation and altered the cell cycle distribution to yield decreased proportions of G0/G1 cells but increased S and G2/M cells. Concomitantly, a 10‐fold increase in apoptotic cells and a 12‐fold increase in dead cells were observed. The population doubling time (PDT) for cells treated with 1.0 mg/mL Hyalgan® increased from 23.6 to 52.9 h. By contrast, the two lower Hyalgan® concentrations significantly promoted macrophage proliferation in a dose‐dependent manner. They also increased the proportion of G2/M cells, but had no effect on the number of apoptotic or dead cells. The PDTs of 21.5 and 22.2 h were less than the control time of 23.6 h. These results demonstrate that Hyalgan® concentrations have a differential effect on macrophage growth dynamics and suggest an anti‐inflammatory effect at high HA concentrations. © 2003 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Effects of receptor activator of NFκB (RANK) signaling blockade on fracture healing
Authors: Flick Lisa M. , Weaver Jason M. , Ulrich‐Vinther Michael , Abuzzahab Faruk , Zhang Xinping , Dougall William C. , Anderson Dirk , O'Keefe Regis J. , Schwarz Edward M. 
Published: March 2003

AbstractAs dominant regulators of osteoclastogenesis and bone resorption, receptor activator of NFκB (RANK), receptor activator of NFκB ligand, and OPG have been identified as ideal drug targets for the treatment of metabolic bone disease. One concern regarding the therapeutic use of RANK signaling inhibitors is their effect on fracture healing. Therefore we tested if uncoupling and osteoclast depletion via RANK blockade affects callus formation, maturation and matrix remodeling, as well as union rates in a mouse tibia fracture model. Low dose (1 mg/kg i.p.) RANK:Fc therapy had no effect on callus formation, matrix maturation and remodeling, and resulted in 100% bony union by day 28. High dose RANK:Fc treatment (10 mg/kg i.p.) effectively eliminated osteoclasts at the fracture site on day 14, with no significant effects on fracture healing. When therapy was discontinued, normal numbers of osteoclasts were observed at the fracture site by day 28. However, continuous therapy resulted in a large osteopetrotic callus consisting of both mineralized and unmineralized matrix that was void of osteoclasts, but bony union was unaffected at day 28. We also evaluated this process in the complete absence of RANK signaling using RANK ‐/‐ mice. These animals exhibited significant radiographic and histologic evidence of callus formation, indicating that RANK signaling is not required for fracture callus formation. However, only 33% of RANK ‐/‐ animals formed bony unions compared to 100% of the osteopetrotic control mice. This defect was most likely a result of decreased blood flow, as evidenced by fewer blood vessels in the RANK ‐/‐ animals. Together, these data imply that osteoclast depletion via inhibition of RANK signaling is a viable option for the treatment of pathological bone loss since no adverse effects on fracture healing are observed when therapy is discontinued. © 2003 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Vascular adaptation of intact joint stabilizing structures in the posterior cruciate ligament deficient rabbit knee
Authors: Bray Robert C. , Leonard Catherine A. , Salo Paul T. 
Published: March 2003

AbstractLoss of the posterior cruciate ligament (PCL) of the knee has a significant impact on joint stability and biomechanical function. Changes in joint biomechanics may result in mal‐adaptive tissue degeneration and functional alteration of supporting ligaments. This study examines the effects of joint laxity on the vascular physiology of the intact anterior cruciate (ACL) and medial collateral (MCL) ligaments after PCL transection in rabbits.One‐year‐old female New Zealand white rabbits were assigned to control (n = 12), sham‐operated (n = 12) or PCL transected (2, 6 or 16 weeks, n = 12 per time point) groups. Half of the animals (n = 6 per group) were used for ACL and MCL blood flow determination using coloured microsphere infusion (ml/min/100 g), and half were used for vascular volume determination (given as vascular index, μl/g).In the MCL, PCL transection induced large, significant (4–5‐fold) increases in blood flow (peak at 2 weeks) and vascular index (peak at 6 weeks) compared to sham‐operated animals that returned towards control values by 16 weeks. In contrast, the ACL showed no increase in blood flow in lax joints, and a relatively small (2‐fold) increase in vascular index at 6 weeks only. The wet weight and water content of both the MCL and ACL were significantly increased in PCL‐deficient joints.We conclude that joint laxity (instability) subsequent to loss of the PCL in rabbits impacts the vascular physiology of intact supporting ligaments, inducing both vasomotor and angiogenic responses in the MCL. Changes in wet weight and water content of both the MCL and ACL demonstrate prolonged physiological adaptation of intact structures in lax joints. © 2003 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Leukemia inhibitory factor is augmented in the heart in experimental heart failure
Authors: Jougasaki Michihisa , Leskinen Hanna , Larsen Amy M. , Cataliotti Alessandro , Chen Horng H. , Burnett John C. 
Published: March 2003

AbstractLeukemia inhibitory factor (LIF) is a pleiotropic cytokine that induces cardiac myocyte hypertrophy through the signal transducing molecule, glycoprotein 130. To date, localization of LIF in the heart and regulation of cardiac LIF expression in congestive heart failure (CHF) remain undefined. The present study investigates the potential activation of LIF expression in the failing canine heart that was produced by progressive rapid ventricular pacing. Immunohistochemistry for LIF revealed that LIF immunoreactivity was present in the atrial and ventricular myocytes of the normal heart and was markedly increased in the failing heart as compared to the normal heart. Northern blot analysis demonstrated that cardiac LIF mRNA was increased in both atrium and ventricle in CHF as compared to the normal heart (P<0.01). Linear regression analysis revealed a positive correlation between atrial LIF mRNA and atrial pressure (r=0.87, P<0.001 in right atrium and r=0.86, P<0.001 in left atrium). Positive correlations between left ventricular LIF mRNA and left ventricular dimensions (r=0.91, P<0.0001 in end‐systolic diameter; r=0.86, P<0.001 in end‐diastolic diameter), and an inverse correlation between left ventricular LIF mRNA and left ventricular ejection fraction (EF) were observed (r=−0.93, P<0.0001). There was a positive correlation between left ventricular LIF mRNA and left ventricular mass index (LVMI) (r=0.85, P<0.001). The present study demonstrates that cardiac LIF immunoreactivity and its gene expression are increased in a canine model of experimental CHF and suggests a potential role for LIF in the pathophysiology of CHF.