bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hepatic gluconeogenesis and Krebs cycle fluxes in a CCl4 model of acute liver failure
Authors: Carvalho Rui A. , Jones John G. , McGuirk Chris , Sherry A. Dean , Malloy Craig R. 
Published: August 2002

AbstractAcute liver failure was induced in rats by CCl4 administration and its effects on the hepatic Krebs cycle and gluconeogenic fluxes were evaluated in situ by 13C NMR isotopomer analysis of hepatic glucose following infusion of [U‐13C]propionate. In fed animals, CCl4 injury caused a significant increase in relative gluconeogenic flux from 0.80 ± 0.10 to 1.34 ± 0.24 times the flux through citrate synthase (p < 0.01). In 24‐h fasted animals, CCl4‐injury also significantly increased relative gluconeogenic flux from 1.36 ± 0.16 to 1.80 ± 0.22 times the flux through citrate synthase (p < 0.01). Recycling of PEP via pyruvate and oxaloacetate was extensive under all conditions and was not significantly altered by CCl4 injury. CCl4 injury significantly reduced hepatic glucose output by 26% (42.8 ± 7.3 vs 58.1 ± 2.4 µmol/kg/min, p = 0.005), which was attributed to a 26% decrease in absolute gluconeogenic flux from PEP (85.6 ± 14.6 vs 116 ± 4.8 µmol/kg/min, p < 0.01). These changes were accompanied by a 47% reduction in absolute citrate synthase flux (90.6 ± 8.0 to 47.6 ± 8.0 µmol/kg/min, p < 0.005), indicating that oxidative Krebs cycle flux was more susceptible to CCl4 injury. The reduction in absolute fluxes indicate a significant loss of hepatic metabolic capacity, while the significant increases in relative gluconeogenic fluxes suggest a reorganization of metabolic activity towards preserving hepatic glucose output. Copyright © 2002 John Wiley & Sons, Ltd.
The simplex algorithm for multicommodity networks
Authors: Detlefsen Nina K. , Wallace Stein W. 
Published: August 2002

AbstractWe consider multicommodity network flow problems, where external flow is allowed to vary and where flows of individual commodities may be constrained. For this problem, we describe the simplex algorithm. The simplex algorithm is based upon the inverse of the basis matrix. We discuss an approach where we only have to invert a working matrix with dimension at most equal to the number of arcs in the network. The dimension is independent of the number of commodities. The reduced cost of a nonbasic variable is found only using the working matrix that is explicitly inverted and some simple network operations. We also discuss how to pivot in the working matrix. The focus is on the detailed interpretation of the network structures arising in terms of cycles for the individual commodities. © 2002 John Wiley & Sons, Inc.
Early activation of Ca2+‐permeable AMPA receptors reduces neurite outgrowth in embryonic chick retinal neurons
Authors: Catsicas Marina , Allcorn Suzette , Mobbs Peter 
Published: August 2002

AbstractCalcium entry through Ca2+‐permeable AMPA/kainate receptors may activate signaling cascades controlling neuronal development. Using the fluorescent Ca2+‐indicator Calcium Green 1‐AM we showed that the application of kainate or AMPA produced an increase of intracellular [Ca2+] in embryonic chick retina from day 6 (E6) onwards. This Ca2+ increase is due to entry through AMPA‐preferring receptors, because it was blocked by the AMPA receptor antagonist GYKI 52466 but not by the N‐methyl‐D‐aspartic acid (NMDA) receptor antagonist AP5, the voltage‐gated Ca2+ channel blockers diltiazem or nifedipine, or by the substitution of Na+ for choline in the extracellular solution to prevent the depolarizing action of kainate and AMPA. In dissociated E8 retinal cultures, application of glutamate, kainate, or AMPA reduced the number of neurites arising from these cells. The effect of kainate was prevented by the AMPA/kainate receptor antagonist CNQX and by GYKI 52466 but not by AP5, indicating that the reduction in neurite outgrowth resulted from the activation of AMPA receptors. Blocking Ca2+ influx through L‐type voltage‐gated Ca2+ channels with diltiazem and nifedipine prevented the effect of 10–100 μM kainate but not that of 500 μM kainate. In addition, joro spider toxin‐3, a blocker of Ca2+‐conducting AMPA receptors, prevented the effect of all doses of kainate. Neither GABA, which is depolarizing at this age in the retina, nor the activation of metabotropic glutamate receptors with tACPD mimicked the effects of AMPA receptor activation. Calcium entry via AMPA receptor channels themselves may therefore be important in the regulation of neurite outgrowth in developing chick retinal cells. © 2001 John Wiley & Sons, Inc. J Neurobiol 49: 200–211, 2001
Model updating by adding known masses
Authors: Cha P. D. , de Pillis L. G. 
Published: August 2002

AbstractNew approaches are developed that use measured data to adjust the analytical mass and stiffness matrices of a system so that the agreement between the analytical modes of vibration and the modal survey is improved. By adding known masses to the structure of interest, measuring the modes of vibration of this mass‐modified system, and finally using this set of new data in conjunction with the initial modal survey, the analytical mass matrix of the structure can be corrected, after which the analytical stiffness matrix can be readily updated. By manipulating the correction matrices into vector forms, the connectivity information can be enforced, thereby preserving the physical configuration of the system and reducing the sizes of the least‐squares problems that need to be solved. Solution techniques for updating the system matrices are introduced, and the numerical issues associated with solving overdetermined and underdetermined least squares problems are investigated. The effects of round‐off errors are also studied, and heuristic criteria are given for determining the minimum number of modes that need to be measured in order to ensure sufficiently accurate updated mass and stiffness matrices. Numerical experiments are presented to validate the proposed model‐updating techniques, to illustrate the effects of the number of measured modes on the quality of the updated model, to show how the magnitudes and locations of the added masses influence the updated matrices, and to highlight the numerical issues discussed in this paper. Copyright © 2001 John Wiley & Sons, Ltd.
Pacific ‘Babes’: issues in the origins and dispersal of Pacific pigs and the potential of mitochondrial DNA analysis1
Authors: Allen Melinda S. , Matisoo‐Smith Elizabeth , Horsburgh Ann 
Published: August 2002

AbstractWe explore potential sources of genetic variation in Pacific pigs over the duration of their commensal relationships with Pacific people. Three time periods are identified as critical to understanding the history of pigs in the Pacific region: (1) the late Pleistocene–early Holocene following from human movement into Near Oceania; (2) with Lapita colonization of Remote Oceania beginning ca. 3000 bp, and (3) in Polynesia, shortly after sustained Euro‐American contact (ca. late 1700s) when several new breeds were introduced into the region. This paper highlights the important role mitochondrial DNA (mtDNA) work can play in detailing the origins, directions, and frequency of pig transfers, and by extension, the movements of their human carriers. Our preliminary molecular studies identify a hypervariable region of mtDNA in the genus Sus, rendering it an ideal taxon for detailed study of the issues we raise herein. Copyright © 2001 John Wiley & Sons, Ltd.
Ancient injury recidivism: an example from the Kerma period of ancient Nubia
Authors: Judd Margaret 
Published: August 2002

AbstractA topical trend in clinical research has been the study of repeat trauma, referred to by clinicians as “injury recidivism,” which lends itself to the assessment of accumulated injuries among ancient people. The present investigation examined the healed injuries among two archaeological skeletal samples from the Kerma period (ca. 2500–1500 BC) of Sudanese Nubia. Both groups were known to have a high prevalence of multiple trauma—80% of 54 adults from the rural sites (O16 and P37) located near Dongola and 42% of 212 adults from the urban site of Kerma sustained nonfatal injuries. It was observed that a higher frequency of multi‐injured adults displayed one or more violence‐associated injury (cranial trauma, parry fracture). When all injuries were considered 38% of individuals with violence‐related injuries had other traumatic lesions in contrast to 22% of individuals who experienced injuries associated with accidental falls (e.g., Colles', Smiths', Galeazzi, and paired forearm fractures), although this difference was not significant. When only the skulls and long bones were evaluated 81% of adults with multiple injuries to these major bones bore one or more violence‐related injuries, while 60% of adults with single injuries sustained violence‐related injuries. Most individuals with multiple injuries were male and less than 35 years of age; there was no significant difference in the frequency of violence‐ or accident‐related multiple injury between the rural and urban communities. Although it cannot be established whether or not some of an individual's injuries were experienced during simultaneous or independent incidents, the pattern of multiple injury among these two ancient Nubian skeletal samples reflected the profile of injury recidivism observed by modern clinicians cross‐culturally. Copyright © 2002 John Wiley & Sons, Ltd.
The long‐term effects of public housing on self‐sufficiency
Authors: Newman Sandra J. , Harkness Joseph M. 
Published: August 2002

AbstractRecent years have witnessed an intensification of the debate about the fundamental purpose of public assistance to the poor and the effects of these programs on children. This study uses enriched data from the Panel Study of Income Dynamics to examine the effects of living in public housing as a child at some point between 1968 and 1982 on four young adult outcomes: welfare receipt; individual earnings; household earnings relative to the federal poverty line; and employment. Living in public housing during childhood increased employment, raised earnings, and reduced welfare use, but had no effect on household earnings relative to the poverty line. The beneficial effects could have arisen because public housing improved physical living conditions, reduced residential mobility, or enabled families to spend more of their income on items that benefit children's development. Whether these effects apply to contemporary public housing is unknown. © 2002 by the Association for Public Policy Analysis and Management.
High resolution solid‐state 13C‐NMR study of as‐cured and irradiated epoxy resins
Authors: Ngono‐Ravache Yvette , Foray Marie‐Francoise , Bardet Michel 
Published: August 2002

AbstractThis article presents the effects of strong ionizing radiations on the physico‐chemical modifications of aliphatic or aromatic amine‐cured epoxy resins based on diglycidyl ether of bisphenol A (DGEBA). Such epoxy resins have a considerable number of applications in the nuclear industrial field and are known to be very stable under moderate irradiation conditions.Using extensively high resolution solid‐state 13C‐NMR spectroscopy we show that the aliphatic amine‐cured resin (DGEBA‐TETA) appears much more sensitive to gamma rays than the aromatic amine‐cured one (DGEBA‐DDM). On the one hand, qualitative analyses of the high resolution solid‐state 13C‐NMR spectra of both epoxy resins, irradiated under similar conditions (8.5 MGy), reveal almost no change in the aromatic amine‐cured resin whereas new resonances are observed for the aliphatic amine‐cured resin. These new peaks were interpreted as the formation of new functional groups such as amides, acids and/or esters and to alkene groups probably formed in the aliphatic amine skeleton. On the other hand, molecular dynamics of these polymers are investigated by measuring the relaxation times, TCH, T1ρH and T1C , before and after irradiation. The study of relaxation data shows the formation, under irradiation, of a more rigid network, especially for the aliphatic amine‐cured system and confirms that aromatic amine‐cured resin [DGEBA‐4,4′‐diaminodiphenylmethane(DDM)] is much less affected by ionizing radiations than the aliphatic amine‐cured resin [DGEBA‐triethylenetetramine(TETA)]. Moreover, it has been shown that the molecular modifications generated by irradiation on the powder of the aliphatic‐amine‐cured resin appear to be homogeneously distributed inside the polymers as no phase separations can be deduced from the above analyses. Copyright © 2001 John Wiley & Sons, Ltd.
Microtubules of polyaniline as new microwave absorbent materials
Authors: Wan Meixiang , Li Junchao , Li Shuzhen 
Published: August 2002

AbstractThe microtubules of polyaniline (PANI) with room temperature conductivity of 3.5–2.6 S/cm were synthesized by a template‐free method. The structural characterizations by UV‐vis and FT‐IR spectra as well as ­X‐ray diffraction showed that the polymer chain of the resulting microtubules was identical to the PANI doped with HCl, but its crystallinity was higher than that of PANI‐HCl. Moreover, the resulting microtubules exhibited an unusual magnetic loss at the microwave frequency (f = 1–18 GHz) arose from order arrangement of polaron as charge carrier caused by a tubular morphology. Copyright © 2001 John Wiley & Sons, Ltd.
Evaluation of detection methods for the reversed‐phase HPLC determination of 3′,4′,5′‐trimethoxyflavone in different phytopharmaceutical products and in human serum
Authors: Huck Christian W. , Bonn Günther K. 
Published: August 2002

AbstractQuantitative determination of the major compound, 3′,4′,5′‐trimethoxyflavone (1), in plant extracts, in tablets of Flos and of Radix Primulae veris and in human serum has been accomplished using reversed‐phase HPLC with UV, fluorescence and mass spectrometric (MS) detection. Compared to UV detection, fluorescence detection showed greater selectivity, was 10‐fold more sensitive and allowed the determination of 1 in human serum after sample pre‐treatment by solid‐phase extraction. MS detection of 1 using electrospray ionisation (ESI) interface could be improved by substituting trifluoroacetic acid with the more polar and less conductive additive acetic acid, giving rise to a 230‐fold improvement in analyte detectability at the cost of an increase of only 45% in the peak width of the eluting peak at its half height. Further optimisation of the acetic acid concentration showed the highest signal intensity at 1.25% for HPLC‐atmospheric pressure chemical ionisation (APCI)‐MS and at 0.75% for HPLC‐ESI‐MS. The optimised MS method proved to be extremely selective, 50 times more sensitive than UV detection and 5 times more sensitive than fluorescence detection. Furthermore, fragment‐ion spectra produced by collision induced dissociation‐MS have been used as “fingerprints” for identifying compounds in the highly complex mixtures examine. Copyright © 2001 John Wiley & Sons, Ltd.
Analysis of precocenes in the essential oil of Ageratum spp. by reverse‐phase high‐performance liquid chromatography
Authors: Sharma Kiran , Sharma Om P. 
Published: August 2002

AbstractThe chromenes precocene I (7‐methoxy‐2,2‐dimethylchromene) and precocene II (6,7‐methoxy‐2,2‐dimethylchromene) extracted from Ageratum houstonianum and A. conyzoides have been analysed by reverse‐phase high‐performance liquid chromatography. Separation was achieved using a C18 column eluted with a linear gradient of acetonitrile and water. Precocenes I and II in the essential oils were determined to be 270 ± 23 and 482 ± 34 mg/mL in A. houstonianum, and 687 ± 21 and 20 ± 2 mg/mL in A. conyzoides. Copyright © 2001 John Wiley & Sons, Ltd.
Identification of benzophenanthridine alkaloids from Bocconia arborea by gas chromatography–Mass spectrometry
Authors: Gutierrez R. M. Perez , Vargas Solis R. , Gutierrez G. Diaz , Martinez‐Martinez F. J. 
Published: August 2002

AbstractA methanol extract of the bark of Bocconia arborea was fractionated on silica gel and the fractions analysed using gas chromatography coupled with mass spectrometry (GC‐MS). Several benzophenanthridine alka‐loids were identified including dihydrosanguinarine, oxysanguinarine, 11‐acetonyldihydrochelerythrine, dihydrochelerythrine, chelerythrine, chelerythridimerine and angoline as the principal constituents. The results show that the direct GC‐MS analysis of these alkaloids is possible with a clear distinction between the compounds. The technique is shown to be a valuable tool and an alternative technique to classical phytochemical procedures permitting the fast analysis of alkaloids mixtures. Copyright © 2002 John Wiley & Sons, Ltd.
Maternal smoking: age distribution, levels of alpha‐fetoprotein and human chorionic gonadotrophin, and effect on detection of Down syndrome pregnancies in second‐trimester screening
Authors: Crossley J. A. , Aitken D. A. , Waugh S. M. L. , Kelly T. , Connor J. M. 
Published: August 2002

AbstractObjectivesTo study the levels of maternal serum alpha‐fetoprotein (AFP) and human chorionic gonadotrophin (hCG) in the second trimester in smokers and non‐smokers with unaffected and Down syndrome pregnancies; to examine the rate of smoking in different maternal age groups in a population having routine prenatal screening; and to assess the effect of smoking on the detection rates for Down syndrome and corresponding false‐positive rates, both overall and in different maternal age groups.MethodsInformation on maternal smoking status, maternal age and serum marker levels was collected from case note searches and the screening programme database on 2272 unaffected singleton pregnancies, 36 unaffected twin pregnancies and 103 singleton Down syndrome pregnancies.ResultsIn unaffected pregnancies the smokers had a median age 3.3 years less than the non‐smokers, while in the Down syndrome cases the corresponding age difference was 2.0 years. Median analyte levels in multiples of the median (MoM) in the unaffected singleton pregnancies were, for non‐smokers: AFP=0.97, hCG=1.04; and for smokers, AFP=1.04, hCG=0.80. In the Down syndrome pregnancies the medians were, for non‐smokers: AFP=0.69, hCG=2.49; and for smokers, AFP=0.70, hCG=1.53. Correction for smoking status gave median MoMs of 1.0 for both AFP and hCG in the unaffected pregnancies in both smokers and non‐smokers. In the Down syndrome cases the corrected medians were, for non‐smokers: AFP=0.67, hCG=2.29; and for smokers, AFP=0.73, hCG=1.99. Before correction for maternal smoking the overall detection rate for Down syndrome was 66.7% with a false‐positive rate of 6.2%. After correction the detection rate was 67.7% with a false‐positive rate of 4.9%. Between the smoking and non‐smoking groups there was a significant difference in the detection rate (37.5% versus 76.0%) and the false‐positive rate (1.8% versus 8.1%), which disappeared after correction for smoking status (detection rate 62.5% versus 69.3%, false‐positive rate 3.9% versus 5.4%). No evidence of a lower incidence of Down syndrome in smokers was found.ConclusionsWhile correcting AFP and hCG results for maternal smoking status will have little impact on the overall detection rate for Down syndrome, it may reduce the false‐positive rate and will improve the accuracy of the risks given to individual women. Copyright © 2002 John Wiley & Sons, Ltd.
The incidence of pressure sores following lower limb amputations
Authors: Spittle M. , Collins R.J. , Conner H. 
Published: August 2002

AbstractIn a retrospective survey of lower limb amputations (diabetic major amputations n=34, minor n=33; non‐diabetic major 28, minor 27), pressure sores developed following 55% of major and 20% of minor amputations (p<0.001). Sores developed after major amputations in 68% of diabetic but in only 39% of non‐diabetic patients (p=0.018). The incidence of sores after minor operations did not differ between the two groups. After major amputations sacral sores were more common in diabetic than in non‐diabetic patients (59 versus 36%, p=0.041), but the incidence of heel ulcers was similar. The mean age of patients developing sores was greater than in those who did not, in both diabetic (p<0.025) and non‐diabetic patients (p<0.01). Peripheral vascular disease appeared to be a more important risk factor than neuropathy for pressure sore development. Sores were no more common after epidural or spinal than after general anaesthesia. The Waterlow score was a poor predictor of the risk of developing a sore. The incidence of sores was not related to pre‐operative creatinine or albumin concentrations, but was greater in those whose haemoglobin concentration on the first or second post‐operative day was <10 g/dL (p=0.015). In conclusion, pressure sores are very common following amputation and especially so after major amputations in diabetic patients. All potential amputees should be managed as being at high risk of developing sores. Copyright © 2001 John Wiley & Sons, Ltd.
Impact of a diabetes midwifery educator on the diabetes in pregnancy service at Middlemore Hospital
Authors: Simmons D. , Conroy C. , Scott D.J. 
Published: August 2002

AbstractWe have assessed the effectiveness of a diabetes midwifery educator within a diabetes‐in‐pregnancy service serving a predominantly Polynesian population. A retrospective audit was undertaken of the charts of all women seen by the diabetes‐in‐pregnancy service at Middlemore Hospital, South Auckland for 8 months prior to introduction (n=76) and the same 8 months the following year (n=93). The women were well matched for age, ethnicity and past obstetric history. Previously known diabetes was present in 10%. After introduction of the role, insulin therapy (65% versus 50%. p<0.05), and maternal mean laboratory 2 hour post prandial glucose concentration (6.3±1.3 versus 5.7±1.0 mmol/l, p<0.01) were reduced and the proportion starting insulin as outpatients was increased (14% versus 89%, p<0.001). Birthweight and proportion receiving Caesarean delivery were non‐significantly lower. Total antenatal length of stay (7.5±6.6 vs 3.0±3.3 per patient, p<0.001) was reduced. The proportion receiving a post natal oral glucose tolerance test remained low but increased after the introduction of the follow up role (10% versus 29%, p<0.01). The introduction of the diabetes midwifery educator was associated with substantial reductions in resource utilisation with an improvement in glycaemic control and postnatal follow up. Copyright © 2001 John Wiley & Sons, Ltd.
Insulin injection practices
Authors: Partanen T‐M , Rissanen A 
Published: August 2002

AbstractThe purpose of this study was to investigate the practices of insulin injection and the grounds on which diabetic patients make decisions in relation to insulin therapy. The data for this study were collected by a structured questionnaire with a few open‐ended questions. The study group of 100 patients with type 1 diabetes was collected from two sources. The first half of them (50) came from the Central Hospital of North Karelia and the second half from the Diabetes Education Centre of the Finnish Diabetes Association. The study group consisted of 56 women and 44 men. The range of age was 17–64 (mean 32 years) and the duration of diabetes 1–40 years (mean 11 years). Injection site problems were reported by 65% of the patients. Patients utilising a small skin area for injections (the size of a stamp), or patients who had poor metabolic control (HbA1c>8.6%), reported more problems than other patients. 30% of the patients occasionally injected through clothing during unusual situations (e.g. parties, busy work etc). Occasional skipping of injections was reported by 31% of the patients for reasons such as oblivion or on purpose (e.g. low blood glucose). The most general basis for their injection routines was reported to be a habit and the other basis was patient education. The study suggests problems in insulin injection practices. Systematic checking of the injection sites and technique and the improvement of patient education are recommended. Copyright © 2000 John Wiley & Sons, Ltd.