bluuebunny/crossref_metadata_2025_split huggingface dataset:
Marked species and age‐dependent differences in cell proliferation and neurogenesis in the hippocampus of wild‐living rodents
Authors: Amrein Irmgard , Slomianka Lutz , Poletaeva Inga I. , Bologova Natasha V. , Lipp Hans‐Peter 
Published: April 2004

AbstractVariations in the extent of adult neurogenesis and natural and experimental factors controlling it have been described in laboratory animals. The wide range of variation seen even within a species, the mouse, raises the question as to which rates of neurogenesis can be expected in natural populations. Answering this question is important to evaluate the functional significance of adult neurogenesis under natural conditions and to define the factors controlling it. To address this issue, we investigated four species of wild‐living rodents and outbred laboratory mice using markers for proliferating cells, Ki‐67, and developing neurons, doublecortin and NeuroD. We found about four times as many Ki‐67‐positive cells per mm3 granule cell layer in two wood mouse species (Muridae; Apodemus spp.) than in bank and pine voles (Arvicolidae; Clethrionomys glareolus and Microtus subterraneus). Laboratory mice show proliferation rates between wood mice and voles. Markers for developing neurons, NeuroD and doublecortin, reflect the findings of proliferation activity. Hippocampal cell proliferation decreases dramatically with age in wild‐living species. The onset of the downregulation varies among species. It occurs late in the life span of the yellow‐necked wood mouse. In aged animals, the number of proliferating cells per mm3 granule cell layer is reduced to 19% of the adult value. Downregulation occurs early in pine voles, in which cell proliferation in adult animals is reduced to 33% of juvenile values. Proliferation and age‐dependent changes along the deep border of the alveus and angular bundle follow those of the dentate gyrus. We conclude that cell proliferation and neurogenesis in the dentate gyrus vary significantly among wild‐living rodents, and that they are downregulated with age, but at species‐specific time points. © 2004 Wiley‐Liss, Inc.
One‐level Newton–Krylov–Schwarz algorithm for unsteady non‐linear radiation diffusion problem
Authors: Ovtchinnikov Serguei , Cai Xiao‐Chuan 
Published: April 2004

AbstractIn this paper, we present a parallel Newton–Krylov–Schwarz (NKS)‐based non‐linearly implicit algorithm for the numerical solution of the unsteady non‐linear multimaterial radiation diffusion problem in two‐dimensional space. A robust solver technology is required for handling the high non‐linearity and large jumps in material coefficients typically associated with simulations of radiation diffusion phenomena. We show numerically that NKS converges well even with rather large inflow flux boundary conditions. We observe that the approach is non‐linearly scalable, but not linearly scalable in terms of iteration numbers. However, CPU time is more important than the iteration numbers, and our numerical experiments show that the algorithm is CPU‐time‐scalable even without a coarse space given that the mesh is fine enough. This makes the algorithm potentially more attractive than multilevel methods, especially on unstructured grids, where course grids are often not easy to construct. Copyright © 2004 John Wiley & Sons, Ltd.
Synthesis and electroluminescence properties of fluorene containing arylamine oligomer
Authors: Li Tingxi , Yamamoto Takashi , Lan Hsing‐Lin , Kido Junhi 
Published: April 2004

AbstractWe synthesized a blue fluorescent fluorene containing arylamine oligomer, bis(9,9,9′,9′‐tetra‐n‐octyl‐2,2′‐difluorenyl‐7‐yl)phenylamine (DFPA), and investigated its electroluminescence (EL) properties. Organic EL devices with a structure of glass/indium‐tin oxide/acid‐doped poly(thiophene) derivative/DFPA/aluminum complex (BAlq)/cesium‐doped macrocyclic compound/Al were fabricated. The device exhibited blue emission, peaking at 432 nm, from the DFPA layer. The maximum luminance of 1800 cd/m2 and an external quantum efficiency of 1.5% were observed. Copyright © 2004 John Wiley & Sons, Ltd.
Layered silicate/epoxy nanocomposites: synthesis, characterization and properties
Authors: Salahuddin Nehal A. 
Published: April 2004

AbstractNovel epoxy‐clay nanocomposites have been prepared by epoxy and organoclays. Polyoxypropylene triamine (Jeffamine T‐403), primary polyethertriamine (Jeffamine T‐5000) and three types of polyoxypropylene diamine (Jeffamine D‐230, D‐400, D‐2000) with different molecular weight were used to treat Na‐montmorillonite (MMT) to form organoclays. The preparation involves the ion exchange of Na+ in MMT with the organic ammonium group in Jeffamine compounds. X‐ray diffraction (XRD) confirms the intercalation of these organic moieties to form Jeffamine‐MMT intercalates. Jeffamine D‐230 was used as a swelling agent for the organoclay and curing agent. It was established that the d001 spacing of MMT in epoxy‐clay nanocomposites depends on the silicate modification. Although XRD data did not show any apparent order of the clay layers in the T5000‐MMT/epoxy nanocomposite, transmission electron microscopy (TEM) revealed the presence of multiplets with an average size of 5 nm and the average spacing between multiplets falls in the range of 100 Å. The multiplets clustered into mineral rich domains with an average size of 140 nm. Scanning electron microscopy (SEM) reveals the absence of mineral aggregate. Nanocomposites exhibit significant increase in thermal stability in comparison to the original epoxy. The effect of the organoclay on the hardness and toughness properties of crosslinked polymer matrix was studied. The hardness of all the resulting materials was enhanced with the inclusion of organoclay. A three‐fold increase in the energy required for breaking the test specimen was found for T5000‐MMT/epoxy containing 7 wt% of organoclay as compared to that of pure epoxy. Copyright © 2004 John Wiley & Sons, Ltd.
Real time monitoring of drug metabolic enzyme response inside human hepatoma GS‐3A4‐HepG2 cells by means of electrochemical impedance measurement
Authors: Kobayashi Masaaki , Sugihara Nobuhiro , Ise Hirohiko , Omasa Takeshi , Negishi Naoki 
Published: April 2004

AbstractCytochrome P‐450s (CYPs) are important biopolymers for the maintenance of cellular function. If metabolic activity of the CYP in the cells can be estimated, so can the function of metabolism, which is closer to the organism. In this research, the method of measuring the drug metabolic activity inside the cell by making use of an electrochemical technique was examined. Human hepatoma GS‐3A4‐HepG2 cells of which the cytochrome P‐4503A4 (CYP3A4) drug metabolic activity is found to be the same as that of primary hepatocytes were used in the experiment. The GS‐3A4‐HepG2 cells were cultured on an indium‐tin oxide (ITO) electrode until they became confluent. Substrate testosterone and inhibitor ketoconazole of CYP3A4 were exposed to cells cultured on an ITO electrode, and the reaction was observed by noting the electrochemical impedance measurement. Impedance was decomposed into the resistance component and the reactance component, and each was examined in detail. As a result, according to testosterone concentration change, there was a remarkable time change in the reactance component. A similar impedance measurement was done by using human hepatoma HepG2 cells in which the drug metabolic activity had extremely decreased. Nevertheless, no time change in the reactance component that was noticed in GS‐3A4‐HepG2 cells was observed. Next, the amount of metabolite in the solution after impedance measurement was measured by means of liquid chromatography‐tandem mass spectroscopy (LC‐MS/MS). In the experiment with GS‐3A4‐HepG2 cells, a testosterone concentration‐dependent correlation was observed between the reactance component change and the amount of metabolite. But, in the impedance measurement by ketoconazole, the change in reactance components was not observed in either the GS‐3A4‐HepG2 cells or the HepG2 cells. Ketoconazole and the heme iron in CYP3A4 effect the coordination bond, but ketoconazole was not metabolized by CYP3A4. It was confirmed that the time change in the reactance component which was caused by the testosterone was detected neither in the cells that take up the substrate, nor in the coordination bond between the CYP enzyme and the drug. Therefore, the time change in the remarkable reactance component observed by this electrochemical impedance measurement is dependent on drug metabolic activity. An electrochemical drug metabolic activity measuring method with the human hepatoma GS‐3A4‐HepG2 cells was able to be established. Copyright © 2004 John Wiley & Sons, Ltd.
Melting process of poly(butylene terephthalate) analyzed by temperature‐modulated differential scanning calorimetry
Authors: Righetti M. C. , Di Lorenzo M. L. 
Published: April 2004

AbstractThis article contains a detailed analysis of the melting process of poly(butylene terephthalate) performed by means of temperature‐modulated differential scanning calorimetry at various temperature‐modulation frequencies. The modulation period largely affects the apparent reversing specific heat capacity (cp), but not the total cp. An interpretation based on the analysis of the latent heat involved in the process is proposed. In addition, a detailed examination of the modulated heat‐flow‐rate curves is presented. The finding is that the melting process of poly(butylene terephthalate) is the sum of simultaneous events of the melting of small and defective crystals and their immediate recrystallization into more stable structures. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2191–2201, 2004
Risk‐based approach for assessing the effectiveness of flow management in controlling cyanobacterial blooms in rivers
Authors: Maier Holger R. , Kingston Greer B. , Clark Timothy , Frazer Ainslie , Sanderson Andrew 
Published: April 2004

AbstractCyanobacterial blooms present significant water quality problems worldwide. Flow management is considered to be one of the most promising approaches for combating the cyanobacterial bloom problem in rivers. In this paper, a new method for evaluating the effectiveness of flow management strategies in reducing the risk of cyanobacterial blooms is developed and applied to the River Murray at Morgan, South Australia. As stratification has been shown to be a necessary condition for significant growth of certain cyanobacteria species, the method uses estimates of the probability that stratification events of various durations will occur in conjunction with estimates of population growth during stratified conditions to determine the probability that blooms of various magnitudes will occur. The results of the case study indicate that the probability that blooms of the cyanobacterium Anabaena circinalis exceeding 15 000 cells/ml will occur in any given year under summer entitlement flow conditions is 11.7%, which is in excellent agreement with results obtained using a Poisson–Bayesian approach applied to 17 years of historical data of cell densities of Anabaena circinalis at the study site. The results obtained also indicate that increasing inflows into South Australia by 10 000 Ml/day, which is the maximum achievable increase given current operational constraints, would not have a significant impact on the occurrence of blooms exceeding 15 000 cells/ml. An additional flow of 19 900 Ml/day into South Australia would be required to reduce the probability of occurrence of blooms exceeding 15 000 cells/ml to 0.01%. Copyright © 2004 John Wiley & Sons, Ltd.
Diffusive fluxes and equilibrium processes in relation to phosphorus dynamics in the Upper Mississippi River
Authors: James William F. , Barko John W. 
Published: April 2004

AbstractWe examined total suspended solids (TSS) and phosphorus (P) dynamics in the Upper Mississippi River (UMR) above naturally impounded Lake Pepin between 1994 and 1996, with attention to P loadings which may be contributing to impaired water quality conditions. The Minnesota River, located 97 km upstream of Lake Pepin, accounted for most of the annual and summer TSS and total P load while the Metropolitan Wastewater Treatment Plant, located 80 km upstream of Lake Pepin, accounted for much of the annual soluble reactive P (SRP) loading to the UMR. Lake Pepin retained 80% and 13% of the TSS and total P load, respectively, during the summer period. However, the lake was a source of SRP during the same period, exporting up to 130% of the summer SRP load it received. Diffusive P flux from profundal sediments averaged 7.5 mg m−2 d−1 during the summer, accounting for 41% of the net SRP export from the lake. Recently deposited sediments in Lake Pepin (originating primarily from the Minnesota River) also exhibited a high equilibrium P concentration (EPC=0.155 mg l−1) and linear adsorption coefficient (Kd=1043 l kg−1). Application of these P equilibrium characteristics to TSS loads entering the system resulted in a calculated potential P desorption flux from TSS of 2.0 mg m−2 d−1 during the summer. Potential P desorption flux to the system was driven by dilution of SRP concentrations in the Mississippi River below the EPC by SRP‐deficient inflows of the St Croix River, located 16 km upstream of the lake. P desorption was, thus, an important additional internal P flux that is not commonly included in P budgets of riverine systems. Published in 2004 by John Wiley & Sons, Ltd.
Relationship of vaginal pH and papanicolaou smear results to vaginal flora and pregnancy outcome
Authors: Minkoff Howard , Grunebaum Amos , Feldman Joseph , Cummings Marinella , McCormack William M. 
Published: April 2004

AbstractPrematurity is a major cause of perinatal morbidity. Studies have implicated components of the vaginal flora in the etiology of some cases of preterm birth. Current scoring systems do not include factors which directly reflect the vaginal flora. Since Papanicolaou smears and the vaginal pH may be affected by the vaginal flora and are easy tests to perform, we studied their relationship to vaginal flora and pregnancy outcome.Among 231 patients, those with a vaginal pH ⩾ 4.4 were significantly more likely to carry Trichomonas vaginalis (P < 0.03); Bacteroides species (P < 0.01), and Mycoplasma hominis (P < 0.001), and to have premature rupture of the membranes (P < 0.01), and preterm rupture of the membranes (P < 0.05). Patients with atypia reported on Papanicolaou smear more frequently carried M. hominis (P < 0.01), and had premature rupture of the membranes (P < 0.01). Although the high sensitivity and negative predictive value of those tests may make them useful additions to current scoring systems, their low specificity prevents them from being independent predictors of risk.
Treatment of hypertension in pregnancy with methyldopa: A randomized double blind study
Authors: Weitz Claire , Khouzami Victor , Maxwell Keith , Johnson John W.C. 
Published: April 2004

AbstractTwenty‐five patients whose pregnancies were complicated by chronic hypertension were entered in a double‐blind study and randomly allocated to treatment with methyldopa (Aldomet) or placebo. Thirteen patients were in the treatment group and 12 in the placebo group. The two groups showed no significant difference in demographic and pretreatment laboratory profiles. Methyldopa‐treated patients registering in the first trimester had a significant reduction in the mean arterial pressure (MAP) during the second and third trimesters (P < 0.025). No significant differences in birth weight (BW), ponderal index (PI) were found when results were corrected for gestational age (GA), race, and sex. The mean GA was significantly prolonged in the methyldopa‐treated group by 10.3 days (P < 0.05). The frequency of superimposed pre‐eclampsia was similar in both groups (33.3% vs. 38.4%). However, 75% of the superimposed pre‐eclampsia occurred antepartum in the placebo group, while 80% of the methyldopa‐treated group developed superimposed pre‐eclampsia intrapartum. The results of this small study suggest that the treatment of hypertension in pregnancy may reduce MAP and possibly delay the occurrence of superimposed pre‐eclampsia and thus afford a prolongation of the pregnancy.
Pregnancy termination: Results of a community‐based study in Lagos, Nigeria
Authors: Olukoya A.A. 
Published: April 2004

AbstractA community survey in the Shomolu area of Lagos Nigeria showed the incidence of induced abortion to be 5.6%. Most of the abortions were carried out under medical supervision, using a combination of methods. Reasons for the abortions suggest that many were carried out on pregnancies that could have been prevented.
Laparoscopic evaluation of the tuboperitoneal factor in infertile Nigerian women
Authors: Otolorin E.O. , Ojengbede O. , Falase A.O. 
Published: April 2004

AbstractLaparoscopy has become the most important investigative tool for the evaluation of tubal disease in developed countries of the world. In this report of 218 diagnostic laparoscopies performed on infertile Nigerian women, bilateral tubal occlusion was found in 35.3% and unilateral occlusion in 9.6%. Pelvic adhesions were present in 55.0% out of which 25.2% and 21.1% were moderate or severe, respectively. Endometriosis and uterine fibroids were present in 1.4% and 26.6% of patients, respectively. The implications of these findings for management of tubal disease in Nigerian women is discussed.
Is maternal alkalosis harmful to the fetus?
Authors: Sachs B.P. , Brown R.S. , Yeh J. , Acker D. , Niaraki M. 
Published: April 2004

AbstractNormal pregnancy is characterized by a compensated respiratory alkalosis. The effect of maternal alkalosis on the fetus is less well understood than the more common problem of maternal acidosis. We present a case of maternal alkalosis, complicated by bronchial asthma, in which the fetus was stillborn. The pathophysiology of this condition is discussed with data to support the potential harm of maternal alkalosis in pregnancies complicated by a fetus with borderline reserve. In such instances, the fetus should be carefully monitored and consideration might be given to therapy such as the use of acetozolomide, discouraging hyperventilation by the mother and even early delivery of the fetus.
The effects of maternal age and parity on birthweight: a population‐based study in New York City
Authors: MacLeod S. , Kiely J.L. 
Published: April 2004

AbstractNew York City birth certificates for single‐tons born from September 1–December 31, 1981 (N = 36 056) were analyzed using multivariate regression techniques. The effects of maternal age and parity on birthweight were assessed. There was a significant progression of birthweight with advancing age. Birthweight similarly increased from parity 1 to parity 3, but dropped markedly in the higher parity groups. On stratification by gestational age, we found that age and parity influence birthweight by affecting fetal growth rather than the length of pregnancy.
Multiple pregnancy in the Maltese population
Authors: Savona‐Ventura C. , Grech E.S. 
Published: April 2004

AbstractThis study analyses the multiple birth statistics for the Maltese Islands since 1959. Hospital twin births delivering during the period of 1983–1985 are analysed for a number of variables. The incidence of multiple pregnancy for the Maltese Islands appears to have decreased slightly since 1959 with an overall rate of 10.21 per 1000 maternities. The ratio of dizygotic to monozygotic twinning was computed to be 1.64. Patients with multiple pregnancies are shown to be generally elderly and multiparous. The pregnancy outcome is more likely to be complicated by an operative delivery, while the infant is more likely to be premature and of low birth weight. The perinatal mortality rate for multiple pregnancies is markedly in excess of that for singleton births.
Effectiveness of indomethacin (indocid) suppositories as post‐episiotomy analgesia
Authors: Odigie E.A. 
Published: April 2004

AbstractA double‐blind, randomised placebo‐controlled study was carried out to assess the efficacy of indometacin suppositories as a post‐episiotomy analgesic. Thirty patients received 2 × 100 mg indometacin suppositories, and 30 patients received placebo suppositories within 15 min of an episiotomy repair operation. Local infiltration of the episiotomy incision was performed using 20 ml of 0.5% lignocaine in every case. Subjective symptoms of pain were evaluated 15, 30, 60 and 90 min post‐episiotomy repair. Average numbers of hours as lying in patients after delivery is 4 h. None of the patients who received indometacin complained of post‐episiotomy pain; whereas the patients on placebo manifested varying degrees of pain.
Ultrasonographic identification and measurement of the human fetal pancreas in utero
Authors: Hata K. , Hata T. , Kitao M. 
Published: April 2004

AbstractOne hundred seventy ultrasonographic examinations, done to identify and measure the fetal pancreas in utero, were performed on 78 women with regular menstrual cycle, at 20–41 weeks of gestation. The pancreas, which could be identified after 20 weeks of gestation was measured in 38.4% at 36–39 weeks and 80.0% at 20–23 weeks gestation. The length of the fetal pancreas from the head to tail (FP‐L) correlated well with the gestational age (r = 0.90, P < 0.001). The normal sonographic characteristics of the fetal pancreas are discussed.
Effect of some recent analgesics on labor pain and maternal and fetal blood gases and pH
Authors: Wahab S.A. , Askalani A.H. , Amar R.A. , Ramadan M.E. , Neweigy S.B. , Saleh A.A. 
Published: April 2004

AbstractThis study attempts to determine the analgesic properties of nalbuphine, pentazocine and butorphanol during labor and their potential effects on maternal and fetal blood gases and pH. Butorphanol analgesia was superior to either nalbuphine or pentazocine in relieving labor pain. The studied analgesics caused significant maternal respiratory acidosis and fetal metabolic acidosis. These acidotic changes were most marked with pentazocine, moderate with nalbuphine and minimal with butorphanol.
The development and use of a standard symphysial‐fundal height growth curve in the prediction of small for gestational age neonates
Authors: Azziz R. , Smith S. , Fabro S. 
Published: April 2004

AbstractThe symphysial‐fundal height (SF) measurement has been routinely used in obstetrics, although its value in the prediction of small‐for‐gestational‐age (SGA) infants remains controversial. A retrospective study was performed in order to assess the sensitivity and specificity of the SF distance and establish guidelines for its use. Local neonatal birthweight distribution and SF growth curves were developed. Eighty‐six percent of 28 SGA infants demonstrated one measurement under — 1 S.D. of the mean SF growth curve as did 36% of appropriate for gestational age (AGA) neonates. Seventy‐five percent of SGA infants subsequently demonstrated a second measurement below — 1 S.D. of the mean curve, 90% prior to 36 weeks. Only 16% of AGA exhibited such a SF growth pattern. A protocol for maximizing the use of this inexpensive and easily obtained parameter is proposed.