bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural characterization of temperature‐sensitive hydrogels by field emission scanning electron microscopy (FESEM)
Authors: Reichelt Rudolf , Schmidt Thomas , Kuckling Dirk , Arndt Karl‐Friedrich 
Published: May 2004

AbstractThe submicrometer structure of the temperature‐sensitive hydrogels was observed by field emission scanning electron microscopy (FESEM), using synthesized hydrogels of different outer size and shape. The hydrogel structure strongly depends on the homogeneity of the polymer chains during the crosslinking process. A porous structure of the poly(vinyl‐methyl‐ether) (PVME) bulkgel, synthesized by electron beam irradiation of a concentrated polymer solution, was observed in the swollen state because the phase transitions temperature is acquired through the crosslinking process. Photo‐crosslinking reaction of the poly(N‐isopropylacrylamide) (PNIPAAm) copolymer in the dry state to form PNIPAAm thin films leads to a rather homogeneous structure. In the shrunk state both gels possess structure being more compact than in the swollen state. We also synthesized PVME and PNIPAAm gels with small outer dimensions in the range of some 100 nm. Heating of the thermo‐sensitive polymer in diluted solutions collapses the polymer chains or aggregates. The crosslinking reaction (initiated by electron beam or UV irradiation) of these phase separated structures produces thermo‐sensitive microgels. These microgel particles of PVME and PNIPAAm are spherical shape having diameters in the range of 30 ‐ 500 nm.
A method for interleaved acquisition of a vascular input function for dynamic contrast‐enhanced MRI in experimental rat tumours
Authors: McIntyre Dominick J. O. , Ludwig Christian , Pasan Amit , Griffiths John R. 
Published: May 2004

AbstractDynamic contrast‐enhanced MRI is widely used for the evaluation of the response of experimental rodent tumours to antitumour therapy, particularly for the newly developing antiangiogenic and antivascular agents. However, standard models require a time‐course for the plasma concentration of contrast agent (usually referred to as the arterial input function) to calculate the transfer constant Ktrans from the dynamic time‐course data. Ideally, the plasma concentration time‐course should be measured during each experiment to obtain the most accurate measure of Ktrans. This is technically difficult in rodents, so assumed values are generally used. A method is presented here using interleaved acquisitions from a tail coil to obtain the plasma concentration simultaneously with DCE‐MRI data obtained from a solenoid coil around the tumour. The SNR of the resulting vascular input function data is high compared with methods using a volume coil to acquire plasma concentrations from the aorta and vena cava. Copyright © 2004 John Wiley & Sons, Ltd.
Fluoropyrimidine chemotherapy in a rat model: comparison of fluorouracil metabolite profiles determined by high‐field 19F‐NMR spectroscopy of tissues ex vivo with therapy response and toxicity for locoregional vs systemic infusion protocols
Authors: Lutz Norbert W. , Naser‐Hijazi Belal , Koroma Squire , Berger Martin R. , Hull William E. 
Published: May 2004

AbstractA Sprague–Dawley rat model with DS sarcoma transplanted in the thigh was used to compare transcatheter locoregional i.a. and systemic i.v. administration of 5‐fluorouracil (FU) at 12 dose‐rate schedules: 25, 50 and 100 mg/kg; bolus, 1, 5 and 24 h infusions. In experiment A tumor (62/67 animals) as well as liver and kidney (56/67 animals) were excised 1 h after a single bolus or 1 h infusion or at the end of 5 and 24 h infusions. 19F‐NMR spectroscopy at 11.7 T was used to quantitate FU and its metabolites in ca. 1 g of tissue at 4°C. In experiment B analogous FU treatments were repeated for 5 days (rats 80+11 controls). Tumor volumes vs time, various blood parameters and survival times were recorded, and a log growth rate parameter log GR, a response index RI, and a toxicity index TI were calculated. The i.a. vs i.v. ratios for tumor concentrations of FU and total anabolites (F‐Nucl) were >1 for nearly all treatments and increased with infusion time at the higher doses. F‐Nucl in tumor correlated linearly with total fluorine concentration (Tot. F range 30–1100 nmol/g) over all treatments (r=0.92, slope=0.45, p<0.0001). For non‐bolus i.v. treatments [FU+F‐Nucl] decreased linearly with decreasing FU dose rate (r2=0.74, zero intercept), while i.a. treatments showed non‐linear behavior. For non‐bolus treatments the mean log GR per treatment group showed a negative correlation (r=−0.87) with log[F‐Nucl]. The most effective non‐toxic treatments were 25 mg/kg over 5 or 24 h; the i.a. route was superior to i.v. on the basis of [FU+F‐Nucl], RI, the reduction in log GR, and Kaplan–Meier survival statistics. For liver and kidney Tot. F (>83% FU catabolites) reached ca. 3–4 and 6–7 μmol/g, respectively, at the highest dose rates for either route; F‐Nucl were detected only for Tot. F>500 nmol/g and increased exponentially as Tot. F increased (toxic treatments). The concentrations of the main catabolite (α‐fluoro‐β‐alanine, FBAL) in tumor did not correlate with Tot. F but rather with FBAL levels in kidney (r=0.90, all treatments), indicating that uptake of liver‐derived FBAL from the circulation is the major source of FBAL in tumor. Copyright © 2004 John Wiley & Sons, Ltd.
SNMP for home automation
Authors: Giladi Ran 
Published: May 2004

AbstractHome and building automation applications impose the need for convergence, or at least interoperability, of data networks with intelligent building networks. This situation entails the use of a unified management system. In this paper we extend the traditional SNMP‐based network management system paradigm by creating an integrated site network management system that contains data elements, telecommunication equipment and intelligent building devices. A possible architecture based on a proxy gateway is presented and analyzed. We suggest an implementation and potential applications. Copyright © 2004 John Wiley & Sons, Ltd.
A new approach to ensure fairness over the Internet
Authors: Salim Zabir Salahuddin Muhammad , Ashir Ahmed , Kitagata Gen , Shiratori Norio 
Published: May 2004

AbstractCongestion signaling is an essential issue for ensuring a high network performance. Explicit congestion notification (ECN) has been proved to provide a faster indication of congestion and thus improve the QoS of a TCP/IP network. In this paper, we present a new scheme for ECN named fair in‐time marking (FIM), which employs a mechanism that as well as providing an indication of incipient congestion, assures a fair service to all the connections. To facilitate such services using FIM, we propose inclusion of some simple yet effective functionalities in the routers. This is important as the client base of the Internet is increasing rapidly and the demand for a reasonably fair service is getting stronger. Experiments show that FIM offers the best fairness, sometimes better by around 20% or more without affecting efficiency, compared with other proposed schemes for ECN. Copyright © 2004 John Wiley & Sons, Ltd.
Favorable response to soft tissue sarcoma therapy in an adolescent with embryonal renal sarcoma
Authors: Hummel Trent , Hord Jeffrey D. 
Published: May 2004

AbstractEmbryonal renal sarcomas were first identified in 1995 among banked tumor samples originally classified as adult Wilms tumor. Few long‐term remissions were observed when these rare tumors were treated with chemotherapy usually used for childhood Wilms. Data were collected from the medical record of an adolescent female with embryonal renal sarcoma and treated with sarcoma‐directed chemotherapy and radiation. At 66 months following diagnosis, the patient has no evidence of tumor but has experienced severe renal dysfunction and ovarian failure. We believe there is a subset of patients with disseminated embryonal renal sarcoma that respond to intense sarcoma‐directed therapy. © 2004 Wiley‐Liss, Inc.
Plasticized microporous poly(vinylidene fluoride) separators for lithium‐ion batteries. III. Gel properties and irreversible modifications of poly(vinylidene fluoride) membranes under swelling in liquid electrolytes
Authors: Saunier J. , Alloin F. , Sanchez J. Y. , Maniguet L. 
Published: May 2004

AbstractMicroporous poly(vinylidene fluoride) (PVdF) separators for lithium‐ion batteries, used in liquid organic electrolytes, have been characterized with respect to the swelling phenomena on dense PVdF membranes (obtained through hot pressing). In the first and second parts of this study, we have described the swelling equilibria and swelling kinetics of dense PVdF. Here the thermal properties of PVdF gels and their irreversible modifications induced by swelling are characterized. Particular attention is paid to crystallinity modifications, polymer plasticization, and membrane degradation. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2308–2317, 2004
Changes in the near‐edge X‐ray absorption fine structure spectra of long‐chain diacetylene derivatives through photopolymerization in Langmuir–Blodgett films
Authors: Fujimori Atsuhiro , Ishitsuka Mikako , Nakahara Hiroo , Ito Eisuke , Hara Masahiko , Kanai Kaname , Ishii Hisao , Ouchi Yukio , Seki Kazuhiko 
Published: May 2004

AbstractPhotopolymerization of cadmium 10,12‐pentacosadiynoate (CdDA) in Langmuir–Blodgett (LB) films, with the molecular packing well arranged by moderate preannealing, was investigated with near‐edge X‐ray absorption fine structure (NEXAFS) spectroscopy. Greenish films of polydiacetylene with an absorption wavelength of 705 nm were obtained through the photopolymerization of preannealed monomer LB films, and this resulted in an extended π‐conjugate system based on the well‐ordered monomer in a two‐dimensional arrangement. The electronic structures of the polydiacetylenes were found to be correlated to the variation of the molecular arrangements in the films from the changes in the NEXAFS spectra through photopolymerization in the LB films. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2329–2336, 2004
Split and sealing of dislocated pipes at the front of a growing crystal
Authors: Gutkin M. Yu. , Sheinerman A. G. 
Published: May 2004

AbstractA model is suggested for the split of dislocated pipes at the front a growing crystal. Within the model, the pipe split occurs through the generation of a dislocation semi‐loop at the pipe and crystal surfaces and its subsequent expansion into the crystal interior. The strain energy of such a dislocation semi‐loop as well as the stress field of a dislocated pipe perpendicular to a flat crystal surface are calculated. The parameter regions are determined at which the expansion of the dislocation semi‐loop is energetically favorable and, thus, the pipe split becomes irreversible. A mechanism is proposed for the formation of a stable semi‐loop resulting in the split and possible subsequent overgrowth of the dislocated pipe. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ferroelectric relaxor behaviour of Na0.5Bi0.5TiO3–SrTiO3 ceramics
Authors: Gomah‐Pettry J. R. , Salak A. N. , Marchet P. , Ferreira V. M. , Mercurio J. P. 
Published: May 2004

AbstractThe dielectric properties of (Na0.5Bi0.5)xSr1−xTiO3 (0 ≤ x ≤ 0.2) ceramic materials were studied from 10 to 300 K between 100 Hz and 1 MHz. At low substitution rates (0 ≤ x ≤ 0.02), two thermally activated relaxation modes were observed and attributed to non interacting dipoles. For x > 0.02, the highest temperature mode, independent on the composition, remains but its intensity decreases and eventually vanishes for x = 0.20. In addition the observed strong dispersion of the permittivity was connected with a relaxor behaviour the origin of which being due to the increasing density of interacting dipoles or dipole clusters. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Quantum and transport lifetimes of a two‐dimensional hole gas in the presence of spin–orbit interaction
Authors: Xu W. , Vasilopoulos P. , Wang X. F. 
Published: May 2004

AbstractWe present a simple theoretical approach for evaluating the spin‐dependent carrier distribution as well as quantum and transport lifetimes in a two‐dimensional hole gas (2DHG) in the presence of spin–orbit interaction (SOI) induced by the Rashba effect. For low temperatures and over a wide range of the sample parameters, the SOI can enhance the mobility of the sample system and the quantum and transport lifetimes of a 2DHG due to background‐impurity scattering do not differ significantly between different spin branches. These are mainly due to the unique features of the hole‐impurity scattering in the presence of the SOI. A small difference of the quantum lifetimes in different spin branches has been observed experimentally in spin‐split two‐dimensional electron gas systems. Our results indicate that this interesting observation can be made in spin‐split 2DHGs as well. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Sonographic imaging of cervical scars after Cesarean section
Authors: Zimmer E. Z. , Bardin R. , Tamir A. , Bronshtein M. 
Published: May 2004

AbstractObjectiveTo investigate whether uterine contractions at the time of a Cesarean section have an impact on future presence and location of a cervical Cesarean scar.MethodsA targeted transvaginal ultrasound examination of the fetus, uterus and cervix was done in 2973 consecutive women at 14–16 weeks' gestation. The sonographer was blinded to the women's previous obstetric histories. The presence and location of a sonographic cervical hypoechogenic line, which probably represented a Cesarean scar, was recorded.ResultsThere were 180 women with a previous Cesarean section performed before the start of uterine contractions and 173 with a Cesarean section performed during contractions in labor. The cervical hypoechogenic line was more common in sections performed during contractions (75.7% vs. 52.7%; P < 0.001) and was more distally located from the internal os (17.9 ± 9.4 vs. 14.6 ± 9.1 mm; P = 0.01). A hypoechogenic line was observed in 21/2620 women without a previous Cesarean section, representing a false‐positive rate of 0.8%.ConclusionCesarean sections, especially those done during uterine contractions, are actually performed through cervical tissue. This finding is in agreement with the physiological process of cervical effacement during contractions. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Prenatal diagnosis of intrauterine premature closure of the ductus arteriosus following maternal diclofenac application
Authors: Auer M. , Brezinka C. , Eller P. , Luze K. , Schweigmann U. , Schwärzler P. 
Published: May 2004

AbstractWe report a case of prenatal diagnosis of premature closure of the ductus arteriosus following maternal diclofenac therapy at 35 weeks of gestation. Fetal echocardiography at 37 weeks of gestation revealed a dilated right ventricle with moderate tricuspid regurgitation, pulmonary insufficiency and complete closure of the ductus arteriosus. Immediate Cesarean section resulted in an excellent neonatal outcome. Whereas the effect of indomethacin on prenatal ductal constriction is well known, widely prescribed non‐steroidal anti‐inflammatory drugs such as diclofenac can have an equally deleterious effect and are best avoided in the third trimester of pregnancy. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Predicting the severity of fetal anemia using time‐domain measurement of volume flow in the fetal aorta
Authors: Harrington K. , Fayyad A. , Nicolaides K. H. 
Published: May 2004

AbstractObjectivesTo assess the value of fetal aortic time‐domain measurement of volume flow (using color velocity imaging quantification (CVI‐Q)) in predicting the severity of fetal anemia.MethodsThis was a prospective observational study, in which 24 pregnant women with suspected fetal anemia due to rising anti‐red blood cell antibody titers underwent cordocentesis. The fetal aortic time‐domain volume flow was measured before fetal blood sampling for fetal hemoglobin investigation. We examined the correlation between increased fetal aortic time‐domain volume flow (>2 SD for gestational age) and fetal anemia (hemoglobin level <2 SD for gestational age).ResultsSeventeen fetuses had anemia, and seven had normal hemoglobin. There was a strong correlation between the increase in fetal aortic time‐domain volume flow and the drop in hemoglobin value (r = 0.81; P < 0.01). The sensitivity of this technique to predict fetal anemia was 81.3% and the specificity was 71.4%. The mean increase over time in aortic CVI‐Q in anemic fetuses was 323.2 mL/min (95% CI, 200.1 to 446.4) compared with 86.9 mL/min (95% CI, −17.7 to 191.5) in the non‐anemic group (P = 0.004).ConclusionFetal aortic time‐domain measurement of volume flow is significantly increased in cases of fetal anemia due to red‐cell alloimmunization. These findings can be used to improve the sensitivity, specificity and positive predictive value of the non‐invasive techniques used to predict fetal anemia, and may help in the selection of pregnancies that require cordocentesis and transfusion. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Early prenatal diagnosis by celocentesis
Authors: Makrydimas G. , Georgiou I. , Bouba I. , Lolis D. , Nicolaides K. H. 
Published: May 2004

AbstractBackgroundCelocentesis is the ultrasound‐guided aspiration of fluid from the extra‐amniotic cavity at 7–8 weeks of gestation. This paper reports on the clinical application of celocentesis for early prenatal diagnosis.MethodsCelocentesis was successfully performed in nine pregnancies and 1–2 mL of fluid were obtained after one needle insertion. The indications were prenatal diagnosis of β‐thalassemia or sickle cell disease (n = 6), Marfan syndrome (n = 1) and paternity testing (n = 2). Molecular biological techniques were used to analyze the celomic fluid and this was successfully carried out in all cases.ResultsIn two cases pregnancy termination was performed at the request of the mother because in one case the fetus was found to have sickle cell anemia and in the second case paternity testing demonstrated that the father was not the woman's husband. In both cases the results were confirmed using the placental samples collected after pregnancy termination. In six of the seven pregnancies with desirable results, amniocentesis was performed at 16 weeks and the results were concordant with those obtained from celocentesis. All pregnancies were uneventful and resulted in the delivery of healthy and appropriately grown babies.ConclusionCelocentesis may be a viable alternative to the currently used tests of chorionic villus sampling and amniocentesis. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Comparison of pregnancy outcome of euploid fetuses with increased nuchal translucency (NT) expressed in NT MoM or delta‐NT
Authors: Maymon R. , Tercanli S. , Dreazen E. , Sartorius G. , Holzgreve W. , Herman A. 
Published: May 2004

AbstractObjectiveTo evaluate the outcome of euploid fetuses with increased nuchal translucency thickness (NT) expressed in multiples of the median (MoM) or delta‐NT.MethodsIncluded in the study were euploid fetuses with increased NT ≥ 95th centile, for which information about pregnancy outcome was available. The following parameters were defined as an adverse outcome: miscarriage, structural anomalies justifying termination of pregnancy, and structural anomalies, genetic syndromes and neurodevelopmental problems diagnosed postnatally. Fetal outcome according to NT MoM and delta‐NT was calculated using different cut‐off values. Calculations of the odds ratio for adverse outcome were performed using either NT MoM or delta‐NT as a predictor in logistic regression models.ResultsThe study comprised 168 euploid fetuses. Of these, 38 (23%) had an adverse outcome: 11 (6%) had miscarriages, 14 (8%) were terminated because of fetal abnormalities detected on the prenatal scan and 13 (7%) were found postnatally to have abnormalities. The incidence of cases exhibiting an adverse outcome was 5.3%, 19.2% and 58.5% for NT values of 1.6–1.9, 2.0–3.0 and >3.0 MoM, respectively (P < 0.0001, χ2 test), and 3.9%, 16.7% and 62.8% for delta‐NT values of 1.0–1.4, 1.5–2.5 and >2.5 mm, respectively (P < 0.0001, χ2 test). Using cut‐offs of 2.0 MoM and delta‐NT of 1.5 mm, the odds ratios for adverse outcome were 10.2 (95% CI, 3.4–30.4) and 15.4 (95% CI, 4.2–43.6), respectively.ConclusionBoth the NT MoM and delta‐NT approaches may be used to determine cases which require additional antenatal investigation as well as fetal karyotyping. For this purpose we suggest using a cut‐off of either 2.0 MoM or a delta‐NT of 1.5 mm. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
An assertional proof for a construction of an atomic variable
Authors: Hesselink Wim H. 
Published: May 2004

Abstract.
The paper proves by assertional means the correctness of a construction of Haldar and Subramanian of an atomic shared variable for one writer and one reader. This construction uses four unsafe variables and four safe boolean variables. Assignment to a safe but nonatomic variable is modelled as a repetition of random assignments concluded by an actual assignment. The proof obligation consists of four invariants. These are proved using 25 auxiliary invariants. The proof has been constructed and verified with the theorem prover NQTHM.
Effect of Pharmacologic Preconditioning with Tetrandrine on Subsequent Ischemia/Reperfusion Injury in Rat Liver
Authors: Liu Zhongmin , Xu Zhenping , Shen Wenlu , Li Yi , Zhang Jun , Ye Xin 
Published: May 2004

AbstractThe effect of tetrandrine (TET) pretreatment of Wistar rats subjected to warm hepatic ischemia/reperfusion (I/R) was investigated. After 50 minutes of ischemia in the left and median lobes of the liver and 24 hours of reperfusion (I/R group), the rats were killed. The TET+I/R group rats were pretreated with TET (50 mg/kg body weight IP) 30 minutes prior to the onset of ischemia. Blood samples were taken for measurement of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH). Tissue was taken from the ischemic lobes for measurement of superoxide dismutase (SOD), malonyldialdehyde (MDA), and myeloperoxidase (MPO); determination of the wet/dry weight (W/D) ratio; and histologic studies. The results showed that ALT, AST, and LDH levels in serum were increased in the I/R group; tissue MDA generation, MPO activity, and the W/D ratio were also increased, accompanied by decreased SOD activity. The serum ALT, AST, and LDH levels, as well as the tissue MPO level and W/D ratio, were lower in the TET+I/R group than in the I/R group; and the SOD level was higher in the TET+IR group than in the I/R group. Moreover, the serum ALT and AST, tissue MDA, and W/D ratio in the TET+I/R group were higher, and the SOD was lower than in the sham group. The histologic examination showed protection against liver damage in the TET+I/R group. The results demonstrated that pretreatment with TET could somewhat protect the liver against I/R injury but does not prevent it. The simultaneous decrease of both lipid peroxide generation and polymorphonuclear neutrophil infiltration in the ischemic liver may explain the acquisition of tolerance following administration of TET.