bluuebunny/crossref_metadata_2025 huggingface dataset:
Field‐Assisted Bonding of Beta‐Alumina to Metals
Authors: DUNN BRUCE
Published: June 2006

The ionic transport properties of β‐alumina enable it to be bonded to many metals by a low‐temperature, field‐assisted process. Adherence mechanisms appear to be similar to those operating in field‐assisted glass‐to‐metal seals, with some differences arising from the crystalline nature of the solid electrolyte. Surface finish of the β‐alumina plays a prominent role in determining adherence. Although good bonding was achieved with all samples, the relatively poor surface conditions resulted in aluminum being the only metal to produce hermetic seals.
Contact‐Damage Resistance of Partially Leached Glasses
Authors: CHANTIKUL P. , MARSHALL D. B. , LAWN B. R. , DREXHAGE M. G.
Published: June 2006

Strength degradation characteristics of partially leached glass rods damaged in sharp contact are investigated. Residual compressive stresses in the outer layer (clad) of the treated rods inhibit the growth of surface cracks toward the inner region (core). The strength of rods indented quasi‐statically with a Vickers diamond pyramid shows functional dependences on contact load and clad stress in good agreement with predictions based on indentation fracture theory. The analysis identifies the degree of residual compression as the key parameter in the strengthening effect; however, in designing for high‐performance applications it may be necessary to optimize material properties (e.g. toughness, elastic moduli) and dimensions of the clad/core composite. Partial leaching, with its potential for developing high, uniform stresses over the clad thickness, may be advocated as a most useful means of obtaining high resistance to adverse contact conditions.
Effect of CO 2 Pressure on the Reaction with CaO
Authors: OAKESON WENDELL G. , CUTLER IVAN B.
Published: June 2006

The effect of temperature and CO2 pressure on the kinetics of the reaction CaO + CO2°CaCO3 was studied. The reaction rapidly becomes diffusion‐controlled as CaCO3 builds up on the surface of CaO. The pressure dependence of the diffusion‐controlled reaction approximated that expected for a Langmuir adsorption isotherm. Temperature affected the extent of CO2 adsorption through θ, the fraction of surface sites covered, as well as the diffusion coefficient, D. The relation Rate =θKD describes the reaction where K is a constant containing geometrical factors, etc. The diffusion activation energy equals 29±6 kcal/mol.
SiC‐Fission Product Reactions in HTGR TRISO UC2 and UCxOy Fissile Fuel: I, Kinetics of Reactions in a Thermal Gradient
Authors: SMITH C. L.
Published: June 2006

The potential for SiC‐lanthanide fission product reactions on the cool side of TRISO‐coated UC2 and UC4.3O1.3 fuel particles was studied in postirradiation thermal‐gradient heating experiments. The kinetics of the reactions were obtained by determining the rate of decrease in SiC thickness as‐a function of temperature and fission density. Reaction rates are independent of the fission density for UC2 kernel burnups >5% FIMA. The rate of change in SiC thickness for TRISO UC2 in a temperature gradient isX (μm/h) = 4.2×107 exp(‐3.283×105/8.313T). No reduction in SiC thickness was observed in TRISO UC4.3O1.3fuel; the rates of SiC fission product reactions are at least an order of magnitude slower than those observed in UC2. No metallic fission product release from TRISO particles was indicated until the SiC layer thickness was reduced by 50%.
The System CaO‐P2O5‐H2O at 200°C
Authors: FENG SHIH‐SHING , ROCKETT T. J.
Published: June 2006

The phase diagram was established for the ternary system CaO‐P2O5‐H2O at 200°C and 1700 kPa. The solubility isotherm was determined by direct observation. Solid phases were analyzed by X‐ray powder diffraction techniques and microscopy. Four solid phases were observed in equilibrium with liquid phases: portlandite, Ca(OH)2, hydroxylapatite, Ca3(PO4)3OH, monetite, CaHPO4, and monocalcium or‐thophosphate monohydrate (MCPM), Ca(H2PO4)2·H2O.
Hydration of Various Beta‐Dicalcium Silicate Preparations
Authors: KANTRO DAVID L. , WEISE CHARLES H.
Published: June 2006

Beta‐dicalcium silicates were prepared with three stabilizers, fired at different temperatures, and ground to different finenesses. Pastes were prepared and hydrated for various periods. Compressive strengths and compositions were determined. Strength apparently depends on fineness. Hydration rate depends in part on the preparation parameters. Hydration product composition is generally independent of the preparation parameters.
Thermal Expansions and Chemical Modifications of Cordierite
Authors: EVANS D. L. , FISCHER G. R. , GEIGER J. E. , MARTIN F. W.
Published: June 2006

The small differences in thermal expansion behavior between stoichiometric cordierites fabricated by different methods were measured using an XRD film method which records the complete diffraction patterns, at two temperatures, on one film. Examples of the extensive chemical family that can be obtained with this structure type are given and their widely varying expansions and distribution of diffracted intensities are demonstrated.
Erosion of Silicon Single Crystals
Authors: ROUTBORT J. L. , SCATTERGOOD R. O. , KAY E. W.
Published: June 2006

The erosion of Si single crystals by angular Al2O3 particles was investigated over a range of particle diametersD (23 to 270 μm), velocities v (32 to 134 m/s), and impact angles α (22° to 90°). For α≥45°, the steady‐state erosion rate can be described within the framework of existing models by the modified relation ΔW∞(v sin α‐v0)2.6(D‐D0)0.6. The results are consistent with the relation D0v=Dv02200 × 10−6 m2/s for the threshold values D0 and v0. For α=22°, another term must be added, and could represent a contribution of plasticity. The results also indicate that surface morphology and/or subsurface‐damage structures are important.
Sintering of Si3N4‐Y2O3‐Al2O3
Authors: LOEHMAN RONALD E. , ROWCLIFFE DAVID J.
Published: June 2006

Sintering kinetics of the system Si3N4‐Y2O3‐Al2O3 were determined from measurements of the linear shrinkage of pressed disks sintered isothermally at 1500° to 1700°C. Amorphous and crystalline Si3N4 were studied with additions of 4 to 17 wt% Y2O3 and 4 wt% A12O3. Sintering occurs by a liquid‐phase mechanism in which the kinetics exhibit the three stages predicted by Kingery's model. However, the rates during the second stage of the process are higher for all compositions than predicted by the model. X‐ray data show the presence of several transient phases which, with sufficient heating, disappear leaving mixtures of β′ ‐Si3N4 and glass or β′‐Si3N4, α′‐Si3N4, and glass. The compositions and amounts of the residual glassy phases are estimated.
Electrical Properties of Yttrium‐Aluminum‐Silicon Oxynitride Glasses
Authors: LEEDECKE C. J. , LOEHMAN RONALD E.
Published: June 2006

The ac electrical properties of several Y‐Al‐Si oxynitride glasses were measured as a function of temperature at 20° to 625°C in the frequency range 50 to 105 Hz. The low‐field dc conductivity was also determined. Dispersions in the dielectric constant associated with the peaks in the tan δ curves were observed in all cases. The peaks in tan δ shifted to higher frequencies with increasing temperature. Below ∼400°C, the ac conductivity was proportional to ωn with 0.5<n<l. The characteristic relaxation time, T0, and the density of defect states were estimated using a model consisting of carrier hopping over a potential barrier. At all temperatures the dc conductivity could be described by an Arrhenius equation.
Stoichiometry Effects on the Fracture of TiO2−x
Authors: MINNEAR W. P. , BRADT R. C.
Published: June 2006

Fracture characteristics of TiO2−x were studied as a function of Stoichiometry. With increasing x, the fracture toughness KIe and the fracture surface energy γf decrease and the amount of transgranular cleavage increases, corresponding to the increased concentration of planar defects within the grains. Increasing nonstoichiometry also shifted the (KI‐V) diagram to lower KI values, commensurate with the KIe decrease. Water accelerated stress corrosion by promoting intergranular failure during subcritical crack growth.
Phase Diagram of the System Na2O·Ga2O3‐Ga2O3 and its Relation to the System Na2O·Al2O3‐Al2O3
Authors: FOSTER L. M. , CHANDRASHEKHAR G. V. , SCARDEFIELD J. E. , BRADFORD R. B.
Published: June 2006

A new phase diagram for the system Na2O‐Ga2O3 (>50 mol% Ga2O3) is presented. It is based on information from differential thermal analysis, X‐ray examination of quenched samples, and a radiochemical technique for determining the compositions of a primary phase and a liquid in equilibrium with it. The diagram provides a guide for the growth of primary crystals of the two ionically conducting sodium gallates that are analogs of the technologically important β‐ and β″‐aluminas.
Investigation of Grain‐Boundary Segregation in Ceramic Oxides by Analytical Scanning Transmission Electron Microscopy
Authors: BENDER B. , WILLIAMS D. B. , NOTIS M. R.
Published: June 2006

Analytical scanning transmission electron microscopy (AEM) was used to study grain‐boundary solute segregation in the systems MgO‐NiO, A12O3‐Y, O3, NiO‐Cr2O3, and NiO‐Al2O3. Electron beam spreading within the specimen was incorporated into a model to quantitatively measure solute segregation. Grain‐boundary segregation occurred in A12O3‐Y2O3 and NiO‐Cr2O3 but was not detected in MgO‐NiO and NiO‐Al2O3 specimens. These results and the quantitative measurements agree with equilibrium solute segregation theories. Microhard‐ness measurements indicate no difference in hardness between the grain boundary and the matrix for Cr‐doped NiO, a system in which segregation was detected.
Self‐Diffusion of Carbon‐14 in High‐Purity and N‐Doped α‐SiC Single Crystals
Authors: HONG J. D. , DAVIS R. F.
Published: June 2006

The self‐diffusion coefficients of 14C in high‐purity, essentially intrinsic and N‐doped, n‐type α‐SiC single crystals were measured at 2123 to 2453 K. The Si14C tracer was chemically bonded by a traveling solvent technique. The Dc* in the doped crystals is smaller than that of the pure materials because of the decreased concentration of the charged donor‐type C vacancies in the presence of the donor N species.
Elastic/Plastic Indentation Damage in Ceramics: The Median/Radial Crack System
Authors: LAWN B. R. , EVANS A. G. , MARSHALL D. B.
Published: June 2006

A theory for describing the evolution of the median/radial crack system in the far field of sharp‐indenter contacts is developed. Analysis is based on a model in which the complex elastic/plastic field beneath the indenter is resolved into elastic and residual components. The elastic component, being reversible, assumes a secondary role in the fracture process: although it does enhance downward (median) extension during the loading half‐cycle, it suppresses surface (radial) extension to the extent that significant growth continues during unloading. The residual component accordingly provides the primary driving force for the crack configuration in the final stages of evolution, where the crack tends to near‐half‐penny geometry. On the hypothesis that the origin of the irreversible field lies in the accommodation of an expanding plastic hardness impression by the surrounding elastic matrix, the ensuing fracture mechanics relations for equilibrium crack growth are found to involve the ratio hardness‐to‐modulus as well as toughness. Observations of crack evolution in soda‐lime glass provide a suitable calibration of indentation coefficients in these relations. The calibrated equations are then demonstrated to be capable of predicting the widely variable median and radial growth characteristics observed in other ceramic materials. The theory is shown to have a vital bearing on important practical areas of ceramics evaluation, including toughness and strength.
Self‐Diffusion of 45Ca and 88Y in Pure and YF3‐Doped CaF2 Single Crystals
Authors: KUCHERIA CHHATTAR S. , BERARD M. F.
Published: June 2006

Tracer self‐diffusion coefficients for Ca and Y were measured in pure and YF3‐doped CaF2 crystals for dopant levels ranging from 2 to 10 mol% and temperatures between 960° and 1212°C. Coefficients for both cations increased approximately linearly with the square of the dopant concentration at constant temperature, with D*Ca>D*Y in doped crystals but D*Ca>D*Y in pure crystals. The activation energies for diffusion of both cations decreased with increasing dopant concentration. Atomic jump pathways are considered and the decrease in activation energy is explained in terms of reduction in the enthalpy of motion accompanying the formation of Willis anion defect clusters in the more heavily doped crystals.
Activation Energies for Densification, Creep, and Grain‐Boundary Sliding in Nitrogen Ceramics
Authors: Raj R. , Morgan P. E. D.
Published: June 2006

The activation energies for densification, creep, and grain‐boundary sliding in HP‐Si3N4 are consistent and large, approaching the heat of sublimation of Si3N4. If solution‐precipitation through the intergranular glass (or fluid) is invoked as a common underlying mechanism, then it can be concluded that the high activation energy results from the high heat of solution of the crystal into the glass. This is consistent with the finding that it is difficult to retain Si3N4 in a glassy state.
Liquid Immiscibility in the System K2O‐B2O3‐SiO2
Authors: TAYLOR Peter , Owen Derrek G.
Published: June 2006

The subliquidus miscibility gap in the system K2O‐B2O3‐SiO2 has been determined for compositions with molar ratios SiO2/B2O3<2 and T≥550°C. The shape of the miscibility gap is an elongated dome similar in form to, but less extensive than those in the lithium and sodium borosilicate systems. The consolute composition (molar) and temperature are estimated to be 4 ± 1 K2O ‐30±8 B2O3‐66±8 SiO2 and 629±5°C, respectively.
Stress Corrosion of Silica Glass
Authors: Ito S. , Tomozawa M.
Published: June 2006

Dissolution rate of silica glass in water was measured as a function of hydrostatic pressure at 285°C and was found to increase with increasing pressure. This observation appears to be contrary to the stress‐corrosion hypothesis of the static fatigue of glass.
Densification of Si3N4‐Y2O3/Al2O3 by a Dual N2 Pressure Process
Authors: Gazza G. E. , Katz R. N. , Priest H. F.
Published: June 2006

Sintering studies of Si3N4‐Y2O3/Al2O3 compositions indicated that increased densification could be produced using a dual N2 pressure process. RT modulus of rupture values and microstructures were found to be similar to hot‐pressed material. The technique should be adaptable to complex shaped Si3N4 bodies where high density and strength are required.
Strength Distributions of SiC Ceramics After Oxidation and Oxidation Under Load
Authors: EASLER T. E. , BRADT R. C. , TRESSLER R. E.
Published: June 2006

The room‐temperature strength distributions of a sintered and a hot‐pressed SiC were examined as‐machined, after oxidation at 1370°C, and after oxidation under load at 1370°C. The strengths were observed to be dependent on both the duration of oxidation and the magnitude of the applied load. Processes resulting in both strengthening and weakening behavior were observed to occur, at times simultaneously within the same strength distribution. This dynamic situation indicates that the strength‐controlling flaw populations are highly transient in nature.
Influence of Stoichiometry on the PTCR Effect in Porous Barium Titanate Ceramics
Authors: Kuwabara Makoto
Published: June 2006

Porous semiconducting barium titan ate ceramics with small grain sizes (2 to 5 tun) exhibit large PTCR effects (>7 orders of magnitude). The magnitude of PTCR in the ceramic bodies is significantly affected by the grain structure. This study shows the influences of Stoichiometry on both the magnitude of PTCR and resultant grain structures in the sintered bodies.
Solid‐State Reactions in the System PbO‐TiO2‐ZrO2
Authors: Hankey Dana L. , Diggers James V.
Published: June 2006

The reaction sequence and the calcination reaction diagrams for the formation of lead zirconate titanate (PZT) solid solutions were investigated. The formation reactions were studied by differential thermal analyses, wet chemical titrimetric techniques for determining uncombined PbO, and by X‐ray diffraction for phase determinations as a function of calcining temperatures and times.
CD47 regulation of epithelial cell spreading and migration, and its signal transduction
Authors: Shinohara Masahiko , Ohyama Naoko , Murata Yoji , Okazawa Hideki , Ohnishi Hiroshi , Ishikawa Osamu , Matozaki Takashi
Published: June 2006

CD47 is an integrin‐associated penta‐transmembrane protein that possesses an immunoglobulin‐like domain in its extracellular region. We have now investigated the role of CD47 in the regulation of epithelial cell spreading and migration. CD47 is colocalized with E‐cadherin at cell–cell adhesion sites of epithelial cells. A Ca2+ switch experiment showed that CD47 was endocytosed and then relocalized to cell–cell adhesion sites in a similar manner to E‐cadherin. Such polarized localization of CD47 required the multiple spanning region of this protein. Forced expression of CD47 induced cell spreading with marked lamellipodium formation and resulted in both partial disruption of cell–cell adhesion and enhancement of the hepatocyte growth factor‐stimulated scattering of Madin–Darby canine kidney cells. The CD47‐induced cell spreading was blocked by inhibition of Src and mitogen‐activated protein kinase kinase. Thus, these results suggest that CD47 participates in the regulation of cell–cell adhesion and cell migration through reorganization of the actin cytoskeleton in epithelial cells. This function of CD47 is mediated by the activation of Src and mitogen‐activated protein kinase kinase. (Cancer Sci 2006; 97: 889–895)
Parental tobacco smoking behaviour and their children’s smoking and cessation in adulthood
Authors: McGee Rob , Williams Sheila , Reeder Anthony
Published: June 2006

Aims  To examine the extent to which childhood exposure to parental tobacco smoking, smoking cessation and parental disapproval of smoking predicts daily smoking and attempts to quit in adulthood.

Design  A longitudinal prospective design was used to examine the possible association between parental smoking variables in childhood and adolescence and subsequent smoking and cessation by age 26 years.

Participants  Interview data were collected as part of a longitudinal study of some 950 individuals followed from birth to age 26 years. Outcome measures were daily smoking and self‐reported attempts to quit smoking.

Findings  Less daily smoking among the participants at age 26 was related more strongly to parental smoking cessation in the adolescent years than the childhood years. By contrast, inconsistent advice about smoking in childhood and adolescence predicted later daily smoking. Cessation attempts to age 26 were unrelated to earlier parental quitting but were related to consistent advice in adolescence from both parents about smoking.

Conclusions  Encouraging parents to voice consistent messages about their disapproval of smoking has a significant role to play in discouraging smoking in their adult children and promoting attempt to quit where their children are smokers.
The prevalence of psychotic symptoms among methamphetamine users
Authors: McKetin Rebecca , McLaren Jennifer , Lubman Dan I. , Hides Leanne
Published: June 2006

Aims  To examine the prevalence of psychotic symptoms among regular methamphetamine users.

Design  Cross‐sectional survey.

Setting  Participants were recruited from Sydney, Australia, through advertisements in free‐press magazines, flyers and through word‐of‐mouth.

Participants  Methamphetamine users (n = 309) who were aged 16 years or over and took the drug at least monthly during the past year.

Measurements  A structured face‐to‐face interview was used to assess drug use, demographics and symptoms of psychosis in the past year. Measures of psychosis included: (a) a psychosis screening instrument derived from the Composite International Diagnostic Interview; and (b) the Brief Psychiatric Rating Scale subscales of suspiciousness, unusual thought content, and hallucinations. Dependence on methamphetamine was measured using the Severity of Dependence Scale.

Findings  Thirteen per cent of participants screened positive for psychosis, and 23% had experienced a clinically significant symptom of suspiciousness, unusual thought content or hallucinations in the past year. Dependent methamphetamine users were three times more likely to have experienced psychotic symptoms than their non‐dependent counterparts, even after adjusting for history of schizophrenia and other psychotic disorders.

Conclusion  The prevalence of psychosis among the current sample of methamphetamine users was 11 times higher than among the general population in Australia. Dependent methamphetamine users are a particularly high‐risk group for psychosis.
Variability of the inhibition by total immunoglobulin ofin vitroautoantibody-mediated erythrophagocytosis by mouse macrophages
Authors: Léonard S , Pierard I , Michaelsen T E , Izui S , Masson P L , Coutelier J-P
Published: June 2006

Several autoimmune diseases, mainly autoantibody-mediated, are attenuated by infusion of total IgG (IVIg). The efficacy varies widely from one patient to another. Using an experimental model of in vitro phagocytosis of autoantibody-coated erythrocytes by mouse macrophages, we analysed the possible causes for such a variability. Our results indicated that the efficacy of the phagocytosis inhibition depends upon different factors, such as the isotype and the extent of polymerization of the immunoglobulin used for the treatment as well as the genetic background of the mice and the state of macrophage activation that can be influenced by concomitant viral infection. The development of an in vitro assay for the phagocytic activity of macrophages might improve the selection of patients susceptible to benefit from IVIg treatment.
Autoimmunity to type VII collagen in SKH1 mice is independent of regulatory T cells
Authors: Chen L , Peterson J D , Zheng W-Y , Lin S-X , Chan L S
Published: June 2006

Epidermolysis bullosa acquisita is an autoimmune blistering disease characterized by circulating and skin basement membrane-bound IgG autoantibodies to type VII collagen, a major structural protein of the dermal–epidermal junction. Regulatory T cells (Treg) suppress self antigen-mediated autoimmune responses. To investigate the role of Treg in the the autoimmune response to type VII collagen in a mouse model, a monoclonal antibody against mouse CD25 was used to deplete Treg. A recombinant mouse type VII collagen NC1 domain protein and mouse albumin were used as antigens. SKH1 mice were used as a testing host. Group 1 mice received NC1 immunization and were functionally depleted of Treg; group 2 mice received NC1 immunization and rat isotype control; and group 3 mice received albumin immunization and were functionally depleted of Treg. Results demonstrated that anti-NC1 IgG autoantibodies with high titres, as determined by enzyme-linked immunosorbent assay and Western blotting, developed in all mice immunized with NC1 (groups 1 and 2), but were undetected in group 3 mice. The predominant subclasses of anti-NC1 autoantibodies were IgG1, IgG2a and IgG2b; furthermore, these antibodies carried only the kappa light chain. IgG autoantibodies in the sera of NC1-immunized mice reacted with mouse skin basement membrane in vitro and deposited in skin basement membrane in vivo as detected by indirect and direct immunofluorescence microscopy, respectively. Our data suggest that the development of autoimmunity against type VII collagen in mice is independent of Treg function and the autoimmune response is mediated by both Th1 and Th2 cells. We speculate that the basement membrane deposition of IgG may eventually lead to blister development.
Toll-like receptors TLR2 and TLR4 initiate the innate immune response of the renal tubular epithelium to bacterial products
Authors: Chowdhury P , Sacks S H , Sheerin N S
Published: June 2006

Renal tubular epithelial cells (TECs) respond diffusely to local infection, with the release of multiple cytokines, chemokines and other factors that are thought to orchestrate the cellular constituents of the innate immune response. We have investigated whether the Toll-like receptors TLR4 and TLR2, which are present on tubular epithelium and potentially detect a range of bacterial components, co-ordinate this inflammatory response acting through nuclear factor-kappa B (NF-κB). Primary cultures of TECs were grown from C57BL/6, C3H/HeN, C3H/HeJ, TLR2 and TLR4 knock-out mice. Cell monolayers were stimulated with lipopolysaccharide (LPS) and synthetic TLR2 and 4 agonists. The innate immune response was quantified by measurement of the cytokines tumour necrosis factor (TNF)-α and KC (IL-8 homologue) in cell supernatants by enzyme-linked immunosorbent assay. Cultured TECs grown from healthy mice produced the cytokines TNF-α and KC in response to stimulation by LPS and synthetic TLR2 and TLR4 agonists. Cells lacking the respective TLRs had a reduced response to stimulation. The TLR2- and TLR4-mediated response to stimulation was dependent on NF-κB signalling, as shown by curcumin pretreatment of TECs. Finally, apical stimulation of these TLRs elicited basal surface secretion of TNF-α and KC (as well as the reverse), consistent with the biological response in vivo. Our data highlight the potential importance of TLR-dependent mechanisms co-ordinating the innate immune response to upper urinary tract infection.
Insulin‐like growth factor‐binding protein‐2 in patients with prostate carcinoma and benign prostatic hyperplasia
Authors: Jean Ho P. , Baxter Robert C.
Published: June 2006

OBJECTIVE Insulin‐like growth factor‐binding protein (IGFBP)‐2 is a major prostatic IGFBP and may be involved in regulating prostate growth. Patients with prostate carcinoma (PC) have elevated serum IGFBP‐2 levels which correlate with the specific PC marker, prostate‐specific antigen (PSA). The aims of this study were (i) to investigate whether elevated serum IGFBP‐2 is unique to PC or also occurs in benign prostatic hyperplasia (BPH), (ii) to examine the relationships among age, PSA and IGFBP‐2 levels, and (iii) to examine longitudinal changes in serum IGFBP‐2 with PSA in PC.

DESIGN AND PATIENTS Sixteen patients (61–83 years) with inoperable PC attending the Oncology Unit at a tertiary referral hospital were studied. Some serum samples were obtained retrospectively while the majority were collected prospectively over 13 months of treatment. The patients with PC were compared to eight patients (66–73 years) with histologically‐proven BPH and seven male control subjects (61–82 years) with no known prostate abnormality.

MEASUREMENTS A new IGFBP‐2 RIA was developed. Serum PSA (by EIA), and IGFBP‐2, IGFBP‐3, IGF‐I and IGF‐II (by RIA) were measured in all subjects, and serially in patients with PC.

RESULTS Serum IGFBP‐2 was significantly higher in PC with high PSA (560 ±66 μg/l, n =12) than PC with normal PSA (292 ±65 μg/l, n =4, P =0.02), BPH (364 ±61 μg/l, P =0.03) and controls (367 ±44 μg/l, P =0.04). Mean IGFBP‐2 in BPH was not different from controls. IGFBP‐2 and PSA were significantly correlated with age (r =0.543 and r =0.433 respectively) and with each other even when the age effect was removed. Serum IGFBP‐2 and PSA levels changed concordantly in all seven PC patients who had serial sampling. Serum IGF‐II but not IGF‐I or IGFBP‐3 was higher in PC and BPH than controls (PC 332 ±23 μg/l, BPH 359 ±26 μg/l vs. controls 241 ±37 μg/l; P =0.03 and 0.02 respectively).

CONCLUSIONS Serum IGFBP‐2 levels are uniquely elevated in active prostate carcinoma but not in benign prostatic hyperplasia. In prostate carcinoma, serum IGFBP‐2 levels closely parallel those of prostate‐specific antigen and probably reflect tumour burden. The relationship between prostatic‐specific antigen and IGFBP‐2 is partially independent of their individual relationships with age. Although serum IGFBP‐2 is less sensitive than prostate‐specific antigen in prostate carcinoma it may have adjunctive value in its management.
Effect of an acute hyperinsulinaemic clamp on post‐prandial lipaemia in subjects with insulin resistance
Authors: Allister E. M. , James A. P. , Watts G. F. , Barrett P. H. R. , Mamo J. C. L.
Published: June 2006

Background  Obese, insulin‐resistant individuals have raised levels of intestinal and hepatic lipoproteins. Insulin decreases the production of hepatic lipoproteins in vivo and so this study aimed to investigate whether an acute hyperinsulinaemic, euglycaemic clamp could correct fasting and post‐prandial dyslipidaemia.

Subjects and methods  In a randomized, cross‐over design, post‐prandial lipaemia was compared in subjects infused either with insulin to achieve a steady‐state concentration of 100 mU L−1 or with saline. Nine obese (Body Mass Index > 26 kg m−2; waist : hip > 1·0) insulin‐resistant (Homeostatic Model Assessment score > 2·0) male subjects were given an oral fat load 3 h after the infusions began, and sampling continued for 6 h. Plasma apoB‐48, triglyceride and nonesterified fatty acid (NEFA) were measured hourly.

Results  Average steady‐state serum insulin levels during the hyperinsulinaemic clamp were 123 ± 4·4 mU L−1. A paired analysis showed no net effect of insulin on post‐prandial chylomicron metabolism when calculated as the (apoB‐48) incremental area under the curve (IAUC). However, there was a trend towards a delay in the apoB‐48 peak, consistent with possible changes in the rates of chylomicron biogenesis, lipolysis and/or clearance. Similarly, post‐prandial lipaemia (depicted as triglyceride IAUC) was similar for subjects infused with insulin or saline, but the peak post‐prandial response was delayed during insulin infusion. The NEFA were rapidly decreased by 83% after 3 h of insulin infusion.

Conclusions  In obesity and insulin resistance, short‐term changes in plasma insulin do not appreciably exert a regulatory effect on exogenously‐derived post‐prandial lipoproteins. The data suggest that hyperchylomicronaemia in insulin‐resistant subjects is a result of chronic aberrations in insulin‐mediated regulation of post‐prandial lipid metabolism.
Sounding airflow enhances aerosol delivery into the paranasal sinuses
Authors: Maniscalco M. , Sofia M. , Weitzberg E. , Lundberg J. O.
Published: June 2006

Background  The use of aerosol therapy is commonly suggested in the treatment of paranasal disorders but it is difficult to achieve an effective penetration of drugs into the sinuses. The authors have recently shown that an oscillating airflow produced by phonation (nasal humming) causes a large increase in the gas exchange between the nose and the paranasal sinuses. This is reflected by a high peak in nasally exhaled nitric oxide (NO) levels because NO accumulated in the sinuses is rapidly washed‐out via the sinus ostia.

Objective  This study was designed to test whether the increase in sinus gas exchange caused by an oscillating airflow could be used to enhance penetration of a drug into the sinuses.

Materials and methods  In six healthy subjects a nitric oxide‐synthase inhibitor L‐NAME was administrated into the nostrils by a jet nebulizer connected to a duck call, which could be modified to generate either a sounding airflow or a non‐sounding airflow. The degree of L‐NAME penetration into the sinuses was judged from the reduction in nasal NO during humming exhalations. Sinus drug deposition was also studied in a model of the nose and sinus.

Results  In humans the delivery of L‐NAME with the non‐sounding airflow had no effect on the NO levels achieved during humming, whereas L‐NAME administration with sound caused a significant 22–35% reduction in nasal NO. In the model the aerosol delivery with the sounding airflow caused a fourfold increase in sinus drug deposition as compared with an aerosol without sound.

Conclusion  A sounding airflow increases the delivery of an aerosolized drug into the paranasal sinuses.
Circulating ghrelin levels after food intake during different phases of the migrating motor complex in man
Authors: Schmidt P. T. , Degerblad M. , Lindström E. , Sundqvist M. , Näslund E. , Gillberg P. G. , Husebye E. , Theodorsson E. , Hellström P. M.
Published: June 2006

Background  The timing of the migrating motor complexes (MMC) at food intake may influence gastric emptying and release of regulatory hormones. This report studies the relationships between phases I (motor quiescence) and II (intermediate frequency contractions) of MMC and prandial gut hormone response.

Materials and methods  Seven fasting volunteers ingested a meal during phase I or II of MMC verified by manometry, using paracetamol as a marker for gastric emptying. Blood was sampled before, during and 210 min after food intake for analysis of ghrelin, motilin, insulin and paracetamol.

Results  The basal level of ghrelin during phase I was 127·5 ± 25·4 pmol L−1 and during phase II was 132·4 ± 24·8 pmol L−1. After food intake during phase I, ghrelin fell to 77·2 ± 10 pmol L−1; in phase II it fell to 82·7 ± 17·8 pmol L−1 within 60 min and returned to baseline levels after 120 min. Baseline levels of motilin were 16 ± 2 pmol L−1 and 18 ± 3 pmol L−1 during phases I and II, respectively. After food, motilin decreased to 8·5 ± 0·7 pmol L−1 and 8·7 ± 1·0 pmol L−1 within 60 min and returned to baseline after 90 min. Insulin levels in phases I and II were 8·1 ± 1·2 mU L−1 and 8·6 ± 0·7 mU L−1, respectively, reaching 138·9 ± 35·6 mU L−1 and 167·4 ± 30·0 mU L−1 at 45 min postprandially.

Conclusions  The nutritional status of the gastrointestinal tract at food intake had only a limited impact on plasma ghrelin. After food intake, plasma ghrelin drops, similar to motilin, and resumes preprandial levels within 120 min.
Intraguild predation reduces redundancy of predator species in multiple predator assemblage
Authors: GRIFFEN BLAINE D. , BYERS JAMES E.
Published: June 2006

Interference between predator species frequently decreases predation rates, lowering the risk of predation for shared prey. However, such interference can also occur between conspecific predators.

Therefore, to understand the importance of predator biodiversity and the degree that predator species can be considered functionally interchangeable, we determined the degree of additivity and redundancy of predators in multiple‐ and single‐species combinations.

We show that interference between two invasive species of predatory crabs, Carcinus maenas and Hemigrapsus sanguineus, reduced the risk of predation for shared amphipod prey, and had redundant per capita effects in most multiple‐ and single‐species predator combinations.

However, when predator combinations with the potential for intraguild predation were examined, predator interference increased and predator redundancy decreased.

Our study indicates that trophic structure is important in determining how the effects of predator species combine and demonstrates the utility of determining the redundancy, as well as the additivity, of multiple predator species.
Quantitative analysis of dental microwear in threespine stickleback: a new approach to analysis of trophic ecology in aquatic vertebrates
Authors: PURNELL MARK A. , HART PAUL J. B. , BAINES DAVID C. , BELL MICHAEL A.
Published: June 2006

The threespine sticklebackGasterosteus aculeatusis an important model organism in studies of genomic and phenotypic evolution, adaptation and speciation. FossilGasterosteusoffer the potential to test models derived from studies of extant fishes over true evolutionary time‐scales. Competition for food resources, for example, plays an important part in stickleback speciation, causing divergence in food gathering traits and ecological character displacement, but it is not possible to test this model in fossils because evidence of diet is almost never preserved.

We demonstrate here that quantitative analysis of dental microwear, a technique previously applied only to mammals, provides a reliable guide to the dietary preferences of stickleback. Teeth from stickleback raised under laboratory conditions exhibit microwear patterns that vary systematically according to substrate coarseness and whether fishes feed onDaphniawithin the water column, or on chironomid larvae from the bottom. Furthermore, microwear data exhibit a progressive shift in their distribution that tracks differences in experimental feeding treatments.

Microwear in wild populations also exhibits a relationship with feeding. In blind assessments of trophic niche based on microwear patterns we were able to correctly assign all but one equivocal population to trophic group. Microwear data from wild stickleback exhibit a shift in distribution comparable with that observed across the range of treatments in the laboratory and these allow populations to be ranked according to the degree to which they approach fully benthic or fully limnetic feeding.

Our results demonstrate that microwear has the potential to be a powerful tool in the analysis of fish trophic ecology, particularly in the analysis of species pairs and niche differentiation. It has advantages over the trophic snapshot provided by analysis of stomach contents in that microwear reflects feeding and food preferences over a longer period of time, and can be applied where these data are unavailable. Furthermore, it is applicable to extinct organisms and fossils, allowing the role of trophic ecology, niche partitioning and competition over evolutionary time‐scales to be investigated for the first time.
Protein N‐glycosylation in Archaea: defining Haloferax volcanii genes involved in S‐layer glycoprotein glycosylation
Authors: Abu‐Qarn Mehtap , Eichler Jerry
Published: June 2006

In this study, characterization of the N‐glycosylation process in the haloarchaea Haloferax volcanii was undertaken. Initially, putative Hfx. volcanii homologues of genes involved in eukaryal or bacterial N‐glycosylation were identified by bioinformatics. Reverse transcription polymerase chain reaction (RT‐PCR) confirmed that the proposed N‐glycosylation genes are transcribed, indicative of true proteins being encoded. Where families of related gene sequences were detected, differential transcription of family members under a variety of physiological and environmental conditions was shown. Gene deletions point to certain genes, like alg11, as being essential yet revealed that others, such as the two versions of alg5, are not. Deletion of alg5‐A did, however, lead to slower growth and interfered with surface (S)‐layer glycoprotein glycosylation, as detected by modified migration on SDS‐PAGE and glycostaining approaches. As deletion of stt3, the only component of the oligosaccharide transferase complex detected in Archaea, did not affect cell viability, it appears that N‐glycosylation is not essential in Hfx. volcanii. Deletion of stt3 did, nonetheless, hinder both cell growth and S‐layer glycoprotein glycosylation. Thus, with genes putatively involved in Hfx. volcanii protein glycosylation identified and the ability to address the roles played by the encoded polypeptides in modifying a reporter glycoprotein, the steps of the archaeal N‐glycosylation pathway can be defined.
Effect of Pepino mosaic virus on the yield and quality of glasshouse‐grown tomatoes in the UK
Authors: Spence N. J. , Basham J. , Mumford R. A. , Hayman G. , Edmondson R. , Jones D. R.
Published: June 2006

Two fully replicated trials were conducted with glasshouse‐grown tomatoes, under conditions similar to commercial production, to define the impact of Pepino mosaic virus (PepMV). PepMV was not found to reduce bulk yields in these trials, but the quality of tomato fruits harvested was reduced significantly. Compared with uninoculated, PepMV‐free control plants, 6·5% of fruits of PepMV‐affected cv. Espero were downgraded from class 1 in trial 1. In trial 2, an average 38% of class 1 fruits from PepMV‐affected cvs Espero and Encore were lost as a result of downgrading. Loss of quality was mainly a result of blotchy ripening, gold marbling, gold spot, and symptoms directly attributed to PepMV infection. PepMV infection also affected fruit size. The results are discussed in relation to the demands of multiple retailers in the UK for class 1 tomatoes only.
Ternary complex formation between HvMYBS3 and other factors involved in transcriptional control in barley seeds
Authors: Rubio‐Somoza I. , Martinez M. , Abraham Z. , Diaz I. , Carbonero P.
Published: June 2006

The SHAQKYF R1MYB transcription factor (TF) HvMYBS3 from barley is an activator of gene expression both during endosperm development and in aleurone cells upon seed germination. Its mRNA was detected as early as 10 days after flowering in developing barley endosperm, with a peak at 18 days, and in aleurone cells at 8 h after water imbibition, as shown by Northern blot and in situ hybridization analyses. The HvMYBS3 protein expressed in bacteria binds to oligonucleotides containing a GATA core derived from the promoters of: (i) the developing endosperm gene Itr1 (5′‐GATAAGATA‐3′) encoding trypsin inhibitor BTI‐CMe, and (ii) the post‐germinating aleurone gene Amy6.4 (5′‐TATCCAC‐3′/5′‐GTGGATA‐3′) encoding a high‐pI α‐amylase. Transient expression experiments in co‐bombarded developing endosperms and in barley aleurone layers demonstrated that HvMYBS3 trans‐activated transcription both from Itr1 and Amy6.4 promoters, in contrast with a previously reported seed‐expressed R1MYB, HvMCB1, which was an activator of Itr1 and a transcriptional repressor of the Amy6.4 gene. In the yeast three‐hybrid system, the HvMYBS3 protein formed a ternary complex with BPBF and BLZ2, two important seed TFs. However, no binary interactions could be detected between HvMYBS3 and BLZ2 or between HvMYBS3 and BPBF.
Cardiopulmonary bypass surgery in a patient with paroxysmal nocturnal haemoglobinuria
Authors: Dinesh D. , Baker B. , Carter J. M.
Published: June 2006

summary.  Paroxysmal nocturnal haemoglobinuria (PNH) is a rare acquired haemolytic anaemia. Cardiac bypass surgery in patients with PNH may be complicated by aggravation of haemolysis in addition to increased risk of infection, renal failure, bleeding and thrombosis.

We describe a case of uncomplicated cardiopulmonary bypass surgery for aortic valve replacement and aortoplasty in a patient with PNH and discuss some recommendations to reduce the risk of peri‐operative complications.
Sperm competition in a fish with external fertilization: the contribution of sperm number, speed and length
Authors: Stoltz J. A. , Neff B. D.
Published: June 2006

The role of sperm number and quality in male competitiveness was investigated using in vitro fertilization experiments with bluegill (Lepomis macrochirus). Bluegill males use one of three mating tactics: ‘sneakers’, which streak spawn; ‘satellites’, which mimic females; and ‘parentals’, which are territorial. The in vitro experiments mimicked natural spawning by incorporating these males’ mean proximity to eggs and timing of sperm release. Using a maximum-likelihood algorithm, raffle equations were fit to paternity data, which revealed a strong effect of sperm number on male competitiveness. There was no difference in sperm flagellum length, curvilinear swim speed or path linearity among the three male mating types, and these traits did not explain any additional variation in male competitiveness. It was estimated that, given closer proximity to eggs, satellites need release only 0.34 times as many sperm as parentals to obtain equal paternity. Despite being farther from the eggs and releasing sperm about half a second after parentals, sneakers need only release 0.58 times as many sperm as parentals to obtain equal paternity. Thus, the increased competitiveness of sneakers’ sperm must come from a component of sperm quality other than speed or length.
Factors affecting mortality and morbidity in patients with peptic ulcer perforation
Authors: Kocer Belma , Surmeli Suleyman , Solak Cem , Unal Bulent , Bozkurt Betul , Yildirim Osman , Dolapci Mete , Cengiz Omer
Published: June 2006

Background and Aim:  With the introduction of H2 receptor antagonists and proton pump inhibitors, the incidence of elective surgery for peptic ulcer (PU) diseases has decreased, although complications of PU such as perforation and bleeding have remained fairly constant. The purpose of this study was to identify the risk factors that predict morbidity and mortality in patients with perforated PU.

Methods:  The records of 269 patients who were operated on for perforated PU were reviewed retrospectively. The following factors were analyzed in terms of morbidity and mortality: age >65 years; gender; associated medical illness; chronic ingestion of non‐steroidal anti‐inflammatory drugs, aspirin, corticosteroids or immunosuppressants; alcohol ingestion and smoking habits; American Society of Anesthesiologist (ASA) status; season; delayed operation; site of ulcer perforation; and shock on admission and type of operation.

Results:  There were 30 female (11.16%) and 239 male (88.84%) patients. Seventy‐one (26.4%) patients had associated diseases. Simple closure was performed in 257 (95.5%) patients; 12 patients (4.5%) underwent definitive operations. A total of 108 postoperative complications were present in 65 (24.2%) patients. Twenty‐three patients died (8.55%). Multivariate analysis showed that only age, ASA score, treatment delay, presence of shock and definitive operation were independent predictors of mortality. Significant risk factors that led to morbidity were ASA status, time of surgery, season, presence of shock and type of surgery. There was a significant difference concerning morbidity and mortality between simple closure of the perforation and definitive surgery.

Conclusions:  Age, delayed surgery, presence of shock, ASA risk and definitive surgery are factors significantly associated with fatal outcomes in patients undergoing emergency surgery for perforated PU. Therefore, proper resuscitation from shock, improving ASA grade, decreasing delay and reserving definitive surgery for selected patients is needed to improve overall results.
Multidetector computed tomography cholangiography with multiplanar reformation for the assessment of patients with biliary obstruction
Authors: Kim Hong Joo , Park Dong Il , Park Jung Ho , Cho Yong Kyun , Sohn Chong Il , Jeon Woo Kyu , Kim Byung Ik , Kim Seung Kwon
Published: June 2006

Background:  We sought to evaluate the diagnostic use of multidetector computed tomography (MDCT) cholangiography with multiplanar reformation (MPR) for the assessment of patients with biliary obstruction.

Methods:  MDCT cholangiography with the MPR technique was performed in 58 patients who were thought to have biliary obstruction. No cholangiographic contrast agent was administered. MRCP in 24 patients, Endoscopic retrograde cholangiopancreatography (ERCP) in 46 patients and percutaneous transhepatic cholangiography (PTC) in 24 patients were performed. Eighteen patients underwent biopsy or surgery. The findings on MDCT cholangiography were compared with those of MRCP, ERCP, PTC, biopsy or surgery.

Results:  The findings of MDCT cholangiography were as follows: choledocholithiasis (n = 34, 56.7%), malignant stricture (n = 14, 23.3%), benign stricture (n = 1, 1.7%), and cholelithiasis (n = 11, 18.3%). A small common bile duct (CBD) stone in one patient could not be detected on MDCT cholangiography. One patient with a small stone in distal CBD detected on MDCT cholangiography had no stone on ERCP. Two patients with initial diagnoses of CBD stones by MDCT cholangiography were disclosed to have malignant bile duct stricture by reference examination. The sensitivity and specificity of MDCT cholangiography for the diagnosis of bile duct stones were 96.9% and 96.2%, respectively. The sensitivity and specificity of MDCT cholangiography for the diagnosis of bile duct stricture were 85.7% and 100%, respectively. The overall accuracy of MDCT cholangiography for the diagnoses of the causes of biliary obstruction was 89.8%.

Conclusion:  MDCT cholangiography with the MPR technique is a fast and non‐invasive technique with relatively high sensitivity and specificity for the diagnoses of the causes of biliary obstruction.