bluuebunny/crossref_metadata_2025 huggingface dataset:
Structural Studies of Five Layer Aurivillius Oxides: A2Bi4Ti5O18 (A = Ca, Sr, Ba and Pb)
Authors: Ismunandar  , Kamiyama T. , Hoshikawa A. , Zhou Q. , Kennedy B.J.
Published: February 2005

The room temperature structures of the five layer Aurivillius phases A2Bi4Ti5O18 (A = Ca, Sr, Ba and Pb) have been refined from powder neutron diffraction data using the Rietveld method. The structures consist of [Bi2O2]2+ layers interleaved with perovskite-like [A2Bi2Ti5O16]2− blocks. The oxides were found to be orthorhombic (space group B2cb) as a consequence of tilting of the TiO6 octahedra coupled with cation displacement. The tilting is a consequence of the mismatch between the Bi2O2 and perovskite-like layers.
Crystal Field Effects in CeIrIn5
Authors: Christianson A.D. , Lawrence J.M. , Riseborough P.S. , Moreno N.O. , Pagliuso P.G. , Bauer E.D. , Sarrao J.L. , Bao W. , Goremychkin E.A. , Kern S. , Trouw F.R. , Hehlen M.P.
Published: February 2005

In this work, we study crystalline electric field effects in the heavy fermion superconductor CeIrIn5. We observe two regions of broad magnetic response in the inelastic neutron scattering (INS) spectra at 10 K. The first corresponds to the transition between the Γ7 groundstate doublet and the first excited state doublet at 4 meV interwoven with a broad quasielastic contribution. The second region corresponds to the transition between the ground state and the second excited state doublet at 28 meV. The large Lorentzian half-widths of the peaks (∼10 meV) calls into question calculations for the specific heat and magnetic susceptibility that assume sharp crystal field (CF) levels. Consequently, we have calculated the INS spectra and magnetic susceptibility using the Anderson impurity model within the non-crossing approximation including the effects of CF level splitting.
Search for Orbital Excitation in YTiO3 by Neutron Scattering
Authors: Shamoto Shin-Ichi , Tsubota Masami , Iga Fumitoshi , Fåk Björn , Kajitani Tsuyoshi
Published: February 2005

YTiO3 with Tc ∼ 30 K has been studied by the MARI spectrometer with Ei = 130 and 500 meV at T = 5, 40 and 200 K. We have not found any clear orbital excitation in a wide Q–E range (0.5 < Q < 25 Å−1, 6 < E < 350 meV). The intensity of orbital excitation would be significantly weak in comparison with the phonon.
Structural Studies on New Superionic (AgI)0.8–(NaPO3)0.2 and (AgI)0.7–(NaPO3)0.3 at Room Temperature
Authors: Purwanto A. , Kamiyama T. , Hoshikawa A. , Harjo S. , Kartini E. , Collins M.F. , Sakuma T.
Published: February 2005

Room temperature powder neutron diffractions have been performed to investigate the structure of (AgI)0.8– (NaPO3)0.2 and (AgI)0.7–(NaPO3)0.3 composites consisting of AgI crystalline precipitated in a glassy NaPO3 network. Unlike (AgI)0.8–(NaPO3)0.2 and most silver-based superionic materials, (AgI)0.7–(NaPO3)0.3 contains Ag5IP2O7 instead of βAgI and less γAgI. The diffuse background levels of both composites are similar and largely dominated by NaPO3 amorphous phase.
Drabkin Energy Filter for Pulse Shaping and Energy Analysis
Authors: Yamazaki D. , Soyama K. , Ebisawa T. , Tasaki S.
Published: February 2005

We have been developing Drabkin energy filters for pulse shaping and energy analysis at the J-PARC spallation neutron source. By installing two Drabkin energy filters in sequence (a double Drabkin filter), subsidiary peaks of the resonant spin-flip are suppressed and pulse shaping could be performed more effectively. In this contribution, simulation results of pulse shaping by a double Drabkin filter for the J-PARC moderators are presented.
Dynamic Structure of Liquid Chalcogens in the Semiconductor-to-Metal Transition Range
Authors: Chiba Ayano , Yao Makoto , Ohmasa Yoshinori , Hiejima Yusuke , Kawakita Yukinobu , Bennington Stephen M.
Published: February 2005

Dynamic structures of liquid Te70Se30 and Te50Se50 were investigated by inelastic neutron scattering experiments in the semiconductor-to-metal transition range. The bond-stretching modes for the both liquid mixtures were found to clearly soften when the transition occurs. We discuss the change of static and dynamic structures that accompany the transition.
Structure of New Superionic Glasses (CuI)x(AgPO3)1–x
Authors: Kartini E. , Arai M. , Iwase H. , Yokoo T. , Itoh K. , Kamiyama T. , Purnama S.
Published: February 2005

New superionic glasses (CuI)x(AgPO3)1–x with x = 0.1, 0.2 and 0.3 have been prepared by rapid quenching method. Neutron diffraction experiments have been performed by a HIT-II spectrometer at the Neutron Spallation Source, KEK, Japan. A small first diffraction peak at low Q around 0.8 Å was observed in the structure factor for x = 0.2 and x = 0.3, but for x = 0.1 it shows only a shoulder that is similar to the undoped glass AgPO3. Three new peaks appear at the radial distribution function of (CuI)x(AgPO3)1–x at ∼ 1.9, 2.7 and 3.4 Å, that may correspond to the Cu–O, Cu–I and Cu–Cu pair correlations, respectively. Those peaks increase with the amount of CuI. These results indicate that there are two different kinds of Cu atoms. Cu–I bond in the glass is very similar to that in crystalline α-CuI, and Cu–O bond is very similar to that in Cu2O insulating crystal.
Four indicators of socioeconomic position: relative ranking across causes of death
Authors: Næss Øyvind , Claussen Bjørgulf , Thelle Dag S. , Smith George Davey
Published: February 2005

Objective: A study was undertaken to examine the relative ability of occupational class, education, household income, and housing conditions to discriminate all cause and cause-specific mortality-risk in Oslo, and to see if this relative ability is consistent across the 12 most common causes of death. Design and setting: Census records of inhabitants in Oslo 1990 aged 45 to 64 were linked to death records 1990—98 (n=88,159). All inhabitants were included except those who lacked census data on the independent variables. The relative index of inequality (RII) for each indicator was calculated. Main results: Education, occupation, and housing conditions had similar RIIs for all-cause mortality in both sexes. Household income had low RIIs, particularly in men. For the 12 most common causes of death some heterogeneity in the relative ranking between the four indicators was observed, with causes of death known to be related to early-life social circumstances (stomach cancer, cardiovascular disease, chronic obstructive pulmonary disease) being particularly strongly related to education, and causes of death which were likely to be determined by adult social circumstances (violence, sudden unexpected death) being particularly strongly related to occupation and housing conditions. Conclusions: Education, occupational class, and housing conditions all seemed to discriminate all-cause mortality to a similar degree. However, the cause-specific analysis revealed a heterogeneous pattern.
Self-rated health in relation to age and gender: Influence on mortality risk in the Malmö Preventive Project
Authors: Af Sillén Ulrika , Nilsson Jan-Åke , Månsson Nils-Ove , Nilsson Peter M.
Published: February 2005

Aims: A study was undertaken to examine whether poor self-rated health (SRH) can independently predict all-cause mortality during 22-year follow-up in middle-aged men and women. Subjects and methods: Data are derived from a population-based study in Malmö, Sweden. This included baseline laboratory testing and a self-administered questionnaire. The question on global SRH was answered by 15,590 men (mean age 46.4 years) and 10,089 women (49.4 years). Social background characteristics (occupation, marital status) were based on data from national censuses. Mortality was retrieved from national registers. Results: At screening 4,261 (27.3%) men and 3,085 (30.6%) women reported poor SRH. Among subjects rating their SRH as low, 1,022 (24.0%) men and 228 (7.4%) women died during follow-up. Corresponding figures for subjects rating their SRH as high were 1801 (15.9%) men and 376 (5.4%) women. An analysis of survival in subjects reporting poor SRH revealed an age-adjusted hazard risk ratio (HR, 95%CI) for men HR 1.5 (1.4—1.7), and for women HR 1.4 (1.2—1.6). The corresponding HR after adjusting for possible social confounders was for men HR 1.3 (1.1—1.4), and women HR 1.1 (0.9—1.4). When additional adjustment was made for biological risk factors the association for men was still significant, HR 1.2 (1.1—1.3). Conclusion: Poor SRH predicts increased long-term mortality in healthy, middle-aged subjects. For men the association is independent of both social background and selected biological variables. The adjustment for biological variables can be questioned as they might represent mediating mechanisms in a possible causal chain of events.
The AIDS epidemic in the city of Copenhagen, Denmark: Potential years of life lost and impact on life expectancy
Authors: Johansen Jeanne D. , Smith Else , Juel Knud , Rosdahl Nils
Published: February 2005

Aims: This study seeks to describe the impact of AIDS on the city of Copenhagen by estimating potential years of life lost (PYLL) before the age of 65 years and to estimate the impact of AIDS deaths on life expectancy for males and females. Methods: All AIDS cases reported to the national AIDS surveillance register for residents in the city of Copenhagen in the period 1983—98 were included. For comparative purposes data were obtained on six other causes of death: accidents, suicide, lung cancer, ischaemic heart disease, testicular cancer, and breast cancer. Results: Overall, deaths from AIDS accounted for 8% of all PYLL in men and showed an increasing tendency from 1983 to 1991, when it became the leading cause of PYLL. AIDS had most impact in men in the age group 25—44 years and accounted for 29% of all PYLL in this group at the peak in 1993, decreasing significantly after the introduction of anti-retroviral treatments to 5% of PYLL in 1998. Other leading causes of PYLL, accidents and suicide, also showed a decreasing tendency over the years, but of a much smaller magnitude than AIDS. The impact of AIDS in women was more modest. In the entire study period suicide, accidents, and breast cancer were the leading causes of PYLL in women. It was shown that AIDS deaths at the top of the epidemic in 1991—95 were responsible for a loss of 0.76 years in life expectancy for men and 0.08 years for women. Conclusions: AIDS has had a considerable impact on potential years of life lost. A significant decline in AIDS deaths has been seen since 1995 with an effect on life expectancy for men in the city of Copenhagen.
Role dilemmas among health-workers in cross-cultural patient encounters around dietary advice
Authors: Fagerli Rønnaug A.A. , Lien Marianne E. , Botten Grete S. , Wandel Margareta
Published: February 2005

Aim: The aim of this paper is to explore Norwegian health workers' experiences from cross-cultural patient encounters, and how they understand and enact their role when meeting patients with Pakistani background to whom they give dietary advice related to type 2 diabetes. Methods: Qualitative in-depth interviews have been performed with six hospital dietitians and six general practitioners in Oslo. Results: The health workers consider themselves to be patient-centred and stress the importance of the two dimensions, empathy and equality. However, they often experience that patients want them to be more authoritarian, a way of acting that would be totally in disagreement with their convictions, although some occasionally do adopt an authoritarian style. More striking is that some health workers' moral engagement to involve and empower patients actually leads them to be authoritarian. For others, a fear of insulting the patient results in their advice being too diffuse. Conclusions: A possible explanation for such ways of responding to the patient may be that the health workers, in their articulation of patient-centredness, draw on a repertoire of social conduct that involves an effort to level out, or tacitly deny, hierarchic structures, and that this becomes more pronounced in cross-cultural encounters. Patient-centredness and empowerment are results of long ongoing processes in Western countries, based on ideals of equality and individual freedom. The results from this study indicate that these approaches may pose intricate dilemmas for the health workers in their cross-cultural encounters, and need further attention.
Few middle-aged women with severe mental symptoms use psychotropic drugs: The Women's Health in Lund Area (WHILA) Study
Authors: Rundberg Jenny , Lidfeldt Jonas , Nerbrand Christina , Samsioe Göran , Romelsjö Anders , Öjehagen Agneta
Published: February 2005

Aims: In a population of middle-aged women a survey was carried out to ascertain the prevalence of mental symptoms and psychotropic drug use, and further to investigate whether severe mental symptoms are associated with social situation, alcohol consumption, smoking, and physical health. Methods: All women (n=10,766) aged 50—59 years and living in the Lund area were invited to the WHILA study, a health survey including laboratory examinations and a self-administered questionnaire; 6,917 (64.2%) participated. This study is based on the questionnaire only. Results: During the past three months 25.4% (n=1,709) had been troubled by none or 1 mental symptom (labelled ``absent/slight''), 52.8% (n=3,555) by 2—6 mental symptoms (``moderate'') and 21.8% (n=1,471) by 7—10 mental symptoms (``severe''). Among women with severe mental symptoms 15.4% regularly used psychotropic drugs, mainly antidepressants. A multiple logistic regression analysis showed that women with severe mental symptoms had higher odds for living alone (OR 1.7; CI 1.3—2.2) or as single parents (OR 2.1; CI 1.2—3.6), being university-educated (OR 1.5; CI 1.1—2.0), being on long-term sick-leave (OR 8.8; CI 3.0—25.5), using hormone replacement therapy (OR 1.3; CI 1.1—1.6), and having severe physical symptoms (136.8; CI 89.2—209.7) compared with women with absent/slight mental symptoms. Conclusion: Mental symptoms were common among the participating women. The presence of severe mental symptoms was strongly associated with severe physical symptoms. Few women with severe mental symptoms used psychotropic drugs. Middle-aged women with severe mental symptoms need to be identified and provided with appropriate psychopharmacological, hormonal, and/or psychosocial treatment.
Comparative Genomics of Two Closely Related Unicellular Thermo-Acidophilic Red Algae, Galdieria sulphuraria and Cyanidioschyzon merolae, Reveals the Molecular Basis of the Metabolic Flexibility of Galdieria sulphuraria and Significant Differences in Carbohydrate Metabolism of Both Algae
Authors: Barbier Guillaume , Oesterhelt Christine , Larson Matthew D. , Halgren Robert G. , Wilkerson Curtis , Garavito R. Michael , Benning Christoph , Weber Andreas P.M.
Published: February 2005

Unicellular algae serve as models for the study and discovery of metabolic pathways, for the functional dissection of cell biological processes such as organellar division and cell motility, and for the identification of novel genes and gene functions. The recent completion of several algal genome sequences and expressed sequence tag collections and the establishment of nuclear and organellar transformation methods has opened the way for functional genomics approaches using algal model systems. The thermo-acidophilic unicellular red alga Galdieria sulphuraria represents a particularly interesting species for a genomics approach owing to its extraordinary metabolic versatility such as heterotrophic and mixotrophic growth on more than 50 different carbon sources and its adaptation to hot acidic environments. However, the ab initio prediction of genes required for unknown metabolic pathways from genome sequences is not trivial. A compelling strategy for gene identification is the comparison of similarly sized genomes of related organisms with different physiologies. Using this approach, candidate genes were identified that are critical to the metabolic versatility of Galdieria. Expressed sequence tags and high-throughput genomic sequence reads covering >70% of the G. sulphuraria genome were compared to the genome of the unicellular, obligate photoautotrophic red alga Cyanidioschyzon merolae. More than 30% of the Galdieria sequences did not relate to any of the Cyanidioschyzon genes. A closer inspection of these sequences revealed a large number of membrane transporters and enzymes of carbohydrate metabolism that are unique to Galdieria. Based on these data, it is proposed that genes involved in the uptake of reduced carbon compounds and enzymes involved in their metabolism are crucial to the metabolic flexibility of G. sulphuraria.
Benchmarking the CATMA Microarray. A Novel Tool forArabidopsis Transcriptome Analysis
Authors: Allemeersch Joke , Durinck Steffen , Vanderhaeghen Rudy , Alard Philippe , Maes Ruth , Seeuws Kurt , Bogaert Tom , Coddens Kathleen , Deschouwer Kirsten , Van Hummelen Paul , Vuylsteke Marnik , Moreau Yves , Kwekkeboom Jeroen , Wijfjes André H.M. , May Sean , Beynon Jim , Hilson Pierre , Kuiper Martin T.R.
Published: February 2005

Transcript profiling is crucial to study biological systems, and various platforms have been implemented to survey mRNAs at the genome scale. We have assessed the performance of the CATMA microarray designed for Arabidopsis (Arabidopsis thaliana) transcriptome analysis and compared it with the Agilent and Affymetrix commercial platforms. The CATMA array consists of gene-specific sequence tags of 150 to 500 bp, the Agilent (Arabidopsis 2) array of 60mer oligonucleotides, and the Affymetrix gene chip (ATH1) of 25mer oligonucleotide sets. We have matched each probe repertoire with the Arabidopsis genome annotation (The Institute for Genomic Research release 5.0) and determined the correspondence between them. Array performance was analyzed by hybridization with labeled targets derived from eight RNA samples made of shoot total RNA spiked with a calibrated series of 14 control transcripts. CATMA arrays showed the largest dynamic range extending over three to four logs. Agilent and Affymetrix arrays displayed a narrower range, presumably because signal saturation occurred for transcripts at concentrations beyond 1,000 copies per cell. Sensitivity was comparable for all three platforms. For Affymetrix GeneChip data, the RMA software package outperformed Microarray Suite 5.0 for all investigated criteria, confirming that the information provided by the mismatch oligonucleotides has no added value. In addition, taking advantage of replicates in our dataset, we conducted a robust statistical analysis of the platform propensity to yield false positive and false negative differentially expressed genes, and all gave satisfactory results. The results establish the CATMA array as a mature alternative to the Affymetrix and Agilent platforms.
Genome-Wide Annotation and Expression Profiling of Cell Cycle Regulatory Genes in Chlamydomonas reinhardtii
Authors: Bisova Katerina , Krylov Dmitri M. , Umen James G.
Published: February 2005

Eukaryotic cell cycles are driven by a set of regulators that have undergone lineage-specific gene loss, duplication, or divergence in different taxa. It is not known to what extent these genomic processes contribute to differences in cell cycle regulatory programs and cell division mechanisms among different taxonomic groups. We have undertaken a genome-wide characterization of the cell cycle genes encoded by Chlamydomonas reinhardtii, a unicellular eukaryote that is part of the green algal/land plant clade. Although Chlamydomonas cells divide by a noncanonical mechanism termed multiple fission, the cell cycle regulatory proteins from Chlamydomonas are remarkably similar to those found in higher plants and metazoans, including the proteins of the RB-E2F pathway that are absent in the fungal kingdom. Unlike in higher plants and vertebrates where cell cycle regulatory genes have undergone extensive duplication, most of the cell cycle regulators in Chlamydomonas have not. The relatively small number of cell cycle genes and growing molecular genetic toolkit position Chlamydomonas to become an important model for higher plant and metazoan cell cycles.
Medication errors in anaesthesia and critical care
Authors: Wheeler S. J. , Wheeler D. W.
Published: February 2005

There is an increasing recognition that medication errors are causing a substantial global public health problem, as many result in harm to patients and increased costs to health providers. However, study of medication error is hampered by difficulty with definitions, research methods and study populations. Few doctors are as involved in the process of prescribing, selecting, preparing and giving drugs as anaesthetists, whether their practice is based in the operating theatre, critical care or pain management. Anaesthesia is now safe and routine, yet anaesthetists are not immune from making medication errors and the consequences of their mistakes may be more serious than those of doctors in other specialties. Steps are being taken to determine the extent of the problem of medication error in anaesthesia. New technology, theories of human error and lessons learnt from the nuclear, petrochemical and aviation industries are being used to tackle the problem.
Effect‐site controlled patient maintained propofol sedation: a volunteer safety study*
Authors: Anderson K. J. , Leitch J. A. , Green J. S. , Kenny G. N. C.
Published: February 2005

Effect‐site concentration is a mathematical term related to the clinical effect of a drug. We have designed a patient‐maintained sedation system for delivering propofol to the predicted effect‐site concentration rather than plasma concentration. To assess its efficacy and safety, 20 healthy volunteers deliberately attempted to over‐sedate themselves using the system. The new effect‐site concentration driven system delivered sedation successfully, and more rapidly than its predecessor. Fifteen volunteers ended the study when the system automatically reduced the effect‐site concentration after 6 min of no button presses despite verbal contact and maintenance of arterial oxygen saturation (at effect‐site concentration 1.8–3.8 μg.ml−1). Four out of 20 volunteers ended with minor arterial desaturation (lowest 88% at effect‐site concentration 2.6–3.4 μg.ml−1). One volunteer ended after loss of verbal contact at effect‐site concentration 3.4 μg.ml−1. Further modification of the system's design is necessary before it can be recommended for routine practice.
Nitrous oxide diffusion into the cuffs of disposable laryngeal mask airways
Authors: Maino P. , Dullenkopf A. , Bernet V. , Weiss M.
Published: February 2005

The aim of this study was to investigate cuff pressure changes found in disposable size 3 laryngeal mask airways (LMAs) from different manufacturers during nitrous oxide exposure and to compare the results with the re‐usable Classic LMA. In an in vitro experiment, laryngeal mask airway cuff pressures starting from a baseline pressure of 40 cm H2O were recorded using a pressure transducer for 60 min with the laryngeal mask airway cuff exposed to 66% N2O in oxygen. Cuff pressure increases within 5 min of nitrous oxide exposure were > 250% in the Classic LMA and were not significantly different from those found in the Marshall laryngeal mask airway. However, they were significantly greater than those in the Soft Seal, the Unique, the AMBU, and Intersurgical laryngeal mask airways, all of which demonstrated stable cuff pressure levels within the first 5 min. The cuff pressure increase following 60 min of nitrous oxide exposure was 13.0 ± 1.1 and 14.6 ± 0.7 cm H2O in the Intersurgical and Unique laryngeal mask airways, respectively, which was significantly lower than the cuff pressure increase in the Soft Seal and in the Ambu laryngeal mask airways (28.3 ± 2.9 and 30.9 ± 1.2 cm H2O, respectively). Unlike the re‐usable Classic LMA and the disposable Marshall laryngeal mask airway, which have silicone cuffs, the disposable Ambu, Intersurgical, Portex Soft Seal and Unique laryngeal mask airways have cuffs constructed from PVC, which seems to be less susceptible to hyperinflation caused by nitrous oxide diffusion.
Psychometric characteristics of simulation‐based assessment in anaesthesia and accuracy of self‐assessed scores*
Authors: Weller J. M. , Robinson B. J. , Jolly B. , Watterson L. M. , Joseph M. , Bajenov S. , Haughton A. J. , Larsen P. D.
Published: February 2005

The purpose of this study was to define the psychometric properties of a simulation‐based assessment of anaesthetists. Twenty‐one anaesthetic trainees took part in three highly standardised simulations of anaesthetic emergencies. Scenarios were videotaped and rated independently by four judges. Trainees also assessed their own performance in the simulations. Results were analysed using generalisability theory to determine the influence of subject, case and judge on the variance in judges' scores and to determine the number of cases and judges required to produce a reliable result. Self‐assessed scores were compared to the mean score of the judges. The results suggest that 12–15 cases are required to rank trainees reliably on their ability to manage simulated crises. Greater reliability is gained by increasing the number of cases than by increasing the number of judges. There was modest but significant correlation between self‐assessed scores and external assessors' scores (rho = 0.321; p = 0.01). At the lower levels of performance, trainees consistently overrated their performance compared to those performing at higher levels (p = 0.0001).
Transient fixation on a non‐native language associated with anaesthesia
Authors: Webster C. S. , Grieve R. O. S.
Published: February 2005

We report a patient with the unusual language disturbance of transient fixation on a non‐native language after otherwise uneventful general anaesthesia. The patient was unable to speak his native language for a period of 5–10 min, despite a desire to do so. He fully and spontaneously recovered from the episode. The phenomenon raises a number of interesting questions about the nature of human language, anaesthesia and consciousness. We discuss our patient in the context of some of these questions and present a review of three similar patients reported in the anaesthetic literature.
Flow cytometric investigation of peri‐anaesthetic anaphylaxis using CD63 and CD203c
Authors: Sudheer P. S. , Hall J. E. , Read G. F. , Rowbottom A. W. , Williams P. E.
Published: February 2005

The investigation of anaphylactic reactions in the peri‐operative period is difficult. Elevation of serum tryptase levels is a good indicator of an anaphylactic event but the ability of subsequent investigations to identify the drug(s) responsible for the reaction is still potentially unreliable. The aim of this study was to examine basophil activation as an investigative tool. We performed flow cytometric analysis of the expression on the cell surface of the basophil activation markers CD63 and CD203c and measured histamine release in 21 patients who were referred with possible peri‐operative anaphylaxis. The sensitivity of CD63, CD203c, basophil histamine release and skin prick for the muscle relaxants was found to be 79%, 36%, 36% and 64%, respectively; the specificity was found to be 100%. These results demonstrate the difficulty in investigating the cause of an unexpected clinical event following drug administration, but the higher sensitivity of neo‐expression on the cell surface of CD63 suggests that flow cytometric analysis of its neo‐expression on basophils in vitro may be a diagnostic aid.
SNAP index and Bispectral index during different states of propofol/remifentanil anaesthesia*
Authors: Schmidt G. N. , Bischoff P. , Standl T. , Lankenau G. , Hellstern A. , Hipp C. , Schulte am Esch J.
Published: February 2005

The accuracy of the new SNAP index with the Bispectral index (BIS) to distinguish different states of propofol/remifentanil anaesthesia was compared in 19 female patients who were undergoing minor gynaecological surgery. Comparisons of the SNAP index, BIS, spectral edge frequency, mean arterial blood pressure and heart rate were performed. The ability of all parameters to distinguish between the steps of anaesthesia –awake vs. loss of response, awake vs. anaesthesia, anaesthesia vs. first reaction and anaesthesia vs. extubation – were analysed with the prediction probability. The prediction probability to differentiate between two interesting nuances of anaesthetic states –loss of response vs. first reaction – was calculated. Only the BIS showed no overlap between the investigated steps of anaesthesia. Both the SNAP index and BIS failed to differentiate the nuances of anaesthesia. The SNAP index and BIS were superior to mean arterial blood pressure and heart rate and spectral edge frequency in distinguishing between different steps of anaesthesia with propofol and remifentanil and provided useful additional information.
Drug error in anaesthetic practice: a review of 896 reports from the Australian Incident Monitoring Study database
Authors: Abeysekera A. , Bergman I. J. , Kluger M. T. , Short T. G.
Published: February 2005

Eight hundred and ninety‐six incidents relating to drug error were reported to the Australian Incident Monitoring Study. Syringe and drug preparation errors accounted for 452 (50.4%) incidents, including 169 (18.9%) involving syringe swaps where the drug was correctly labelled but given in error, and 187 (20.8%) due to selection of the wrong ampoule or drug labelling errors. The drugs most commonly involved were neuromuscular blocking agents, followed by opioids. Equipment misuse or malfunction accounted for a further 234 (26.1%) incidents; incorrect route of administration 126 (14.1%) incidents; and communication error 35 (3.9%) incidents. The outcomes of these events included minor morbidity in 105 (11.7%), major morbidity in 42 (4.7%), death in three (0.3%) and awareness under anaesthesia in 40 (4.4%) incidents. Contributing factors included inattention, haste, drug labelling error, communication failure and fatigue. Factors minimising the events were prior experience and training, rechecking equipment and monitors capable of detecting the incident. The information gained suggests areas where improved guidelines are required to reduce the incidence of drug error. Further research is required into the effectiveness of preventive strategies.
Endogenous serum levels of thrombopoietic cytokines in healthy whole‐blood and platelet donors: implications for plateletpheresis
Authors: Tacke F. , Schöffski P. , Trautwein C. , Martin M. U. , Stangel W. , Seifried E. , Manns M. P. , Ganser A. , Petersen D.
Published: February 2005

Serum concentrations of the thrombopoiesis‐enhancing cytokines thrombopoietin (TPO), erythropoietin (EPO), interleukin (IL)‐6 and IL‐11 were determined in 119 healthy whole‐blood (WBD) and 101 platelet donors (PD) prior to donation. The 90% TPO reference interval in WBD of 64–867 pg/ml (median 163, 100% range 45–7572) was significantly higher than in PD of 56–524 (median 122, range 44–801, P = 0.004), whereas their platelet counts were lower (P < 0.001). EPO levels were not different (WBD 7.7 ± 3.8, PD 8.0 ± 4.9 IU/l), IL‐6 and IL‐11 were below the detection limit in 90% of cases (IL‐6 < 3.2 pg/ml, IL‐11 < 31.2 pg/ml). None of the cytokines correlated with platelet counts, other blood parameters, or in the PD group with the frequency of platelet donations within the last 6 months. We conclude that plateletpheresis does not lead to a lasting increase of thrombopoietic cytokines and provide reference data for potential platelet mobilization strategies with recombinant growth factors.
Repeatability enhancement in deep‐water permanent seismic installations: a dynamic correction for seawater velocity variations
Authors: Bertrand Alexandre , MacBeth Colin
Published: February 2005

With the increasing use of permanently installed seismic installations, many of the issues in time‐lapse seismic caused by the lack of repeatability can be reduced. However, a number of parameters still influence the degree of reliability of 4D seismic data. In this paper, the specific impact of seawater velocity variations on time‐lapse repeatability is investigated in a synthetic study. A zero‐lag time‐lapse seabed experiment with no change in the subsurface but with velocity changes in the water column is simulated. The velocity model in the water column is constant for the baseline survey while the model for the repeat survey is heterogeneous, designed from sea salinity and temperature measurements in the West of Shetlands. The difference section shows up to 80% of residual amplitude, which highlights the poor repeatability. A new dynamic correction which removes the effect of seawater velocity variations specifically for permanent installations is developed. When applied to the synthetic data, it reduces the difference residual amplitude to about 3%. This technique shows substantial improvement in repeatability beyond conventional time‐lapse cross‐equalization.
Rock physics analysis for time‐lapse seismic at Schiehallion Field, North Sea
Authors: Meadows Mark , Adams Don , Wright Rich , Tura Ali , Cole Steve , Lumley David
Published: February 2005

Rock physics analysis plays a vital role in time‐lapse seismic interpretation because it provides the link between changes in rock and fluid properties and the resulting seismic data response. In this case study of the Schiehallion Field, we discuss a number of issues that commonly arise in rock physics analyses for time‐lapse studies. We show that:

Logarithmic fits of dry bulk (Kdry) and shear (Gdry) moduli vs. effective pressure (Peff) are superior to polynomial fits.

2D surface fits of Kdry and Gdry over porosity (φ) and effective pressure using all the core data simultaneously are more useful and accurate than separate 1D fits over φ and Peff for each individual core.

One average set (facies) of Kdry(φ, Peff) and Gdry(φ, Peff) can be chosen to represent adequately the entire Schiehallion reservoir.

Saturated velocities and densities modelled by fluid substitution of Kdry(φ, Peff), Gdry(φ, Peff) and the dry bulk density ρdry(φ) compare favourably with well‐log velocities and densities.

P‐ and S‐wave impedance values resulting from fluid substitution of Kdry(φ, Peff), Gdry(φ, Peff) and ρdry(φ) show that the largest impedance changes occur for high porosities and low effective pressures.

Uncertainties in Kdry(φ, Peff) and Gdry(φ, Peff) derived for individual cores can be used to generate error surfaces for these moduli that represent bounds for quantifying uncertainties in seismic modelling or pressure–saturation inversion.
4D seismic for oil‐rim monitoring
Authors: Staples Rob , Hague Paul , Weisenborn Toon , Ashton Peter , Michalek Barbara
Published: February 2005

In the central North Sea ‘Gannet‐A’ field, a 50 ft oil rim is overlain by a gas cap of variable thickness. Oil is produced from horizontal wells which initially produced dry oil, but as the field became more mature, a significant water cut was seen in several wells. A dedicated 4D seismic monitor survey was acquired in order to assess the remaining distribution of oil reserves. By forward modelling the synthetic seismic response to parameters such as contact movement and residual saturations (using 2D and 3D wedge models), and comparing the results with real seismic data, we are able to decipher the contact movements across the field. It is shown that, in one part of the field, the increased water cut is caused primarily by the vertical displacement of the entire oil rim into the initial gas cap. This oil‐rim displacement produces a very different 4D seismic response from the case of a static gas–oil contact and rising oil–water contact (normal production). As a result of these observations, we are able to optimize field production by both re‐perforation of existing wells and by drilling sidetracks into the displaced rim: a brown‐field development opportunity that might otherwise be missed.
4D technology: where are we, and where are we going?
Authors: Calvert Rodney
Published: February 2005

4D reservoir monitoring is now becoming established as a normal part of business in some companies, in some regions such as the North Sea, and for some applications, such as thermally enhanced oil recovery. Some spectacular technical successes have been reported, mostly in monitoring water floods. We are beginning to understand how to acquire and process surveys to achieve good results. There is still, however, much to improve in how we use 4D technology to capture its potential value in field management and still some way to go in the tool itself, to make it faster, cheaper and more sensitive to small production effects.
Cross‐matching with interpreted warping of 3D streamer and 3D ocean‐bottom‐cable data at Valhall for time‐lapse assessment
Authors: Hall Stephen A. , MacBeth Colin , Barkved Olav I. , Wild Philip
Published: February 2005

Legacy streamer data and newer 3D ocean‐bottom‐cable data are cross‐matched and analysed for time‐lapse analysis of geomechanical changes due to production in the Valhall Field. The issues relating to time‐lapse analysis using two such distinctly different data sets are addressed to provide an optimal cross‐matching workflow that includes 3D warping. Additionally an assessment of the differences between the imaging using single‐azimuth streamer and multi‐azimuth ocean‐bottom‐cable data is provided. The 3D warping utilized in the cross‐matching procedure is sensitive to acquisition and processing differences but is also found to provide valuable insight into the geometrical changes that occur in the subsurface due to production. As such, this work also provides a demonstration of the use of high‐resolution 3D interpreted warping to resolve the 3D heterogeneity of the compaction and subsidence. This is an important tool for Valhall, and possibly other fields, where compaction and subsidence (and monitoring thereof) are key factors in the reservoir management since the predominant observed production‐induced changes are compaction of the soft, high‐porosity chalk reservoir, due to pore‐pressure reduction, and the resultant overburden subsidence. Such reservoir compaction could have significant implications for production by changing permeabilities and production rates. Furthermore the subsidence effects could impact upon subsea installations and well‐bore stability. Geomechanical studies that have previously been used to model such subsidence and compaction are only constrained by observed surface displacements and measured reservoir pressure changes, with the geological overburden being largely neglected. The approaches suggested herein provide the potential for monitoring and assessment in three dimensions, including the probable heterogeneity and shearing, that is needed for full understanding of reservoir compaction and the resultant effects on the overburden to, for example, mitigate well‐bore failures.
When 4D seismic is not applicable: Alternative monitoring scenarios for the Arab‐D reservoir in the Ghawar Field
Authors: Dasgupta Shiv N.
Published: February 2005

Ghawar, the largest oilfield in the world, produces oil from the Upper Jurassic Arab‐D carbonate reservoir. The high rigidity of the limestone–dolomite reservoir rock matrix and the small contrast between the elastic properties of the pore fluids, i.e. oil and water, are responsible for the weak 4D seismic effect due to oil production. A feasibility study was recently completed to quantify the 4D seismic response of reservoir saturation changes as brine replaced oil. The study consisted of analysing reservoir rock physics, petro‐acoustic data and seismic modelling. A seismic model of flow simulation using fluid substitution concluded that time‐lapse surface seismic or conventional 4D seismic is unlikely to detect the floodfront within the repeatability of surface seismic measurements. Thus, an alternative approach to 4D seismic for reservoir fluid monitoring is proposed. Permanent seismic sensors could be installed in a borehole and on the surface for passive monitoring of microseismic activity from reservoir pore‐pressure perturbations. Reservoir production and injection operations create these pressure or stress perturbations. Reservoir heterogeneities affecting the fluid flow could be mapped by recording the distribution of epicentre locations of these microseisms or small earthquakes. The permanent borehole sensors could also record repeated offset vertical seismic profiling surveys using a surface source at a fixed location to ensure repeatability. The repeated vertical seismic profiling could image the change in reservoir properties with production.
4D signal enhancement using singular‐value decomposition: application to mapping oil–water contact movement across the Nelson Field
Authors: Reid Fiona J.L. , Bertrand Alexandre , McInally Alan T. , MacBeth Colin
Published: February 2005

A new method for time‐lapse signal separation and enhancement using singular‐value decomposition is presented. Singular‐value decomposition is used to separate a 4D signal into its constituent parts: common geology, time‐lapse response and noise. Synthetic tests which demonstrate the advantages of the singular‐value decomposition technique over traditional differencing methods are also presented. This signal separation and enhancement technique is used to map out both the original and moved oil–water contacts across the Nelson Field. The singular‐value decomposition technique allows the oil–water contact to be mapped across regions which would have been missed using traditional differencing methods. In particular, areas toward the edges of the field are highlighted by the technique. The oil–water contact is observed to move upwards across the field, with the largest movements being associated, as anticipated, with natural production. The results obtained are broadly consistent with those predicted by the reservoir simulator model. Singular‐value decomposition is demonstrated to be a useful tool for enhancing the time‐lapse signal and for gaining confidence in areas where traditional differencing fails.
Antithetical effects of hemicellulase‐treated Agaricus blazei on the maturation of murine bone‐marrow‐derived dendritic cells
Authors: Kawamura Masaki , Kasai Hirotake , He Limin , Deng Xuewen , Yamashita Atsuya , Terunuma Hiroshi , Horiuchi Isao , Tanabe Fuminori , Ito Masahiko
Published: February 2005

We report the effects of hemicellulase‐treated Agaricus blazei (ABH) on the maturation of bone‐marrow‐derived dendritic cells (BMDCs). ABH activated immature BMDCs, inducing up‐regulation of surface molecules, such as CD40, CD80 and major histocompatibility complex class I antigens, as well as inducing allogeneic T‐cell proliferation and T helper type 1 cell development. However, unlike lipopolysaccharide (LPS), ABH did not stimulate the BMDCs to produce proinflammatory cytokines, such as interleukin‐12 (IL‐12) p40, tumour necrosis factor‐α, or IL‐1β. In addition, ABH suppressed LPS‐induced DC responses. Pretreatment of DCs with ABH markedly reduced the levels of LPS‐induced cytokine secretion, while only slightly decreasing up‐regulation of the surface molecules involved in maturation. ABH also had a significant impact on peptidoglycan‐induced or CpG oligodeoxynucleotide‐induced IL‐12p40 production in DCs. The inhibition of LPS‐induced responses was not associated with a cytotoxic effect of ABH nor with an anti‐inflammatory effect of IL‐10. However, ABH decreased NF‐κB‐induced reporter gene expression in LPS‐stimulated J774.1 cells. Interestingly, DCs preincubated with ABH and then stimulated with LPS augmented T helper type 1 responses in culture with allogeneic T cells as compared to LPS‐stimulated but non‐ABH‐pretreated DCs. These observations suggest that ABH regulates DC‐mediated responses.
Signal transducer and activator of transcription (STAT) signalling and T‐cell lymphomas
Authors: Mitchell Tracey J. , John Susan
Published: February 2005

Interaction of cytokines with their cognate receptors leads to the activation of latent transcription factors – the signal transducers and activators of transcription (STAT) proteins – whose biological activities ultimately regulate many critical aspects of cell growth, survival and differentiation. Dysregulation of the JAK‐STAT pathway is frequently observed in many primary human tumours, reflecting the importance of this pathway in the maintenance of cellular integrity. Here we review the current progress in STAT structure and function, and the contribution of STAT signalling to the pathogenesis of T‐cell lymphomas.
Exposure to mercuric chloride during the induction phase and after the onset of collagen‐induced arthritis enhances immune/autoimmune responses and exacerbates the disease in DBA/1 mice
Authors: Hansson Monika , Djerbi Mounira , Rabbani Hodjattallah , Mellstedt Håkan , Gharibdoost Farhad , Hassan Moustapha , DePierre Joseph W. , Abedi‐Valugerdi Manuchehr
Published: February 2005

In susceptible mice, mercuric chloride induces a systemic autoimmune response that is characterized by elevated serum levels of immunoglobulin G1 (IgG1) and immunoglobulin E (IgE), production of anti‐nucleolar antibodies (ANolAs) and the formation of renal IgG deposits. We have previously shown that mercury can also enhance immune/autoimmune responses in mouse strains genetically prone to develop spontaneous autoimmune disease. Here, we investigated whether mercury can enhance the severity of murine collagen‐induced arthritis (CIA), an inducible (acquired) autoimmune disease that cannot be induced by mercury itself. While mercury administered prior to the induction phase of CIA exerted little, if any, influence, administration of mercury during the induction phase and following onset aggravated the symptoms of this disease and increased the serum levels of IgE and IgG2a antibodies directed against collagen type II (CII). Furthermore, while animals injected with mercury alone exhibited a significant decrease in the ratio of the levels of interferon‐γ (IFN‐γ) to interleukin‐4 (IL‐4) mRNA in their spleens, this ratio was increased in mice with CIA, with or without administration of mercury. Finally, the production of anti‐nuclear antibodies, a hallmark of autoimmunity in response to mercury, was observed in all mice with CIA treated with this heavy metal. Our findings suggest that exposure to mercury during the development of CIA may influence immunological factors in such a way as to synergistically promote disease development.