bluuebunny/crossref_metadata_2025 huggingface dataset:
Separation and quantification of lignans in Phyllanthus species by a simple chiral densitometric method
Authors: Srivastava Vandana , Singh Manju , Malasoni Richa , Shanker Karuna , Verma Ram K. , Gupta Madan M. , Gupta Anil K , Khanuja Suman P. S.
Published: December 2007

A sensitive, selective, and robust high‐performance TLC (HPTLC) method using chiral TLC plates for qualitative and quantitative analysis of phyllanthin (A), hypophyllanthin (B), niranthin (C), and nirtetralin (D), the active lignans of Phyllanthus species, was developed and validated. The effectiveness and role of various stationary phases viz TLC silica gel 60F254, HPTLC silica gel 60F254, and chiral TLC plates in the quantitation were evaluated. A precoated chiral TLC plate was found suitable for the simultaneous analysis of four pharmacologically active lignans. For achieving good separation, the optimized mobile phase of n‐hexane/acetone/1,4‐dioxane (9:1:0.5 by volume) was used (Rf = 0.30, 0.36, 0.41, and 0.48 for compounds A, B, C, and D, respectively). A densitometric determination of the above compounds was carried out in reflection/absorption mode at 620 nm. Optimized chromatographic conditions provide well‐separated compact bands for the tested lignans. The calibration curves were found linear in the concentration range of 100–500 ng/band. Recoveries of A–D were 99.98, 100.51, 99.22, and 98.74%, respectively. The method was validated according to ICH guidelines. The method reported here is reproducible and applied for the quantitative analysis of the above lignans in the leaves of four Phyllanthus species, i. e., P. amarus, P. maderaspatensis, P. urinaria, and P. virgatus.
Polyetherimide substrates for future high density optical data storage
Authors: Kim Jin‐Hong
Published: December 2007

Polyetherimide (PEI) substrate for next‐generation high density optical data storage is fabricated and characterized. Cover‐layer incident or first‐surface recording configurations do not require optical properties of the substrate, which are the prerequisite conditions for the conventional material of polycarbonate (PC). Instead of the optical properties, good mechanical properties with a sufficient transcribability are required. Even though PEI has higher glass transition temperature than that of PC, a microscopic transcribability of PEI is comparable with PC by laminating a thermal insulation layer on the backside of a stamper to retard the heat flow. A macroscopic warpage of PEI substrate is smaller than that of PC substrates, which reduces tilt and servo burden. The lowest critical speed coupled with the flutter of PEI substrate is larger than that of PC substrate because of the mechanical properties of PEI. POLYM. ENG. SCI., 48:97–101, 2008. © 2007 Society of Plastics Engineers
Numerical simulation of a polypropylene foam bead expansion process
Authors: Nakai Sho , Taki Kentaro , Tsujimura Isao , Ohshima Masahiro
Published: December 2007

The production process for expanded polypropylene foam beads (EPP), which consists of steaming, depressurizing, cooling, and ageing operations, was consistently simulated by a set of mathematical models. The models, developed from Yang and Lee's ageing models (Yang and Lee,J. Cell. Plast.,39, 59 (2003)) for extrusion foam products, were extended in terms of the fundamental aspects of mass and heat transport phenomena. Evaporation and condensation of blowing agents and heat conduction during the steam chest molding and ageing processes were modeled. The governing equations were established by integrating the mass transfer equations of steam and air at the intercellular walls with the constitutive equations of evaporation and condensation in each cell, the equation of heat conduction from the mold to the foam, and the mechanical force balance equation on the cell walls. The models simulate the stress exerted on the steaming chest mold and predict the expansion behavior of cells in the EPP bead‐foam board throughout the ageing process. A sensitivity analysis was also performed by the models to find the key factors which might allow the theoretical determination of the ejection time and shortening of the length of the ageing process. POLYM. ENG. SCI., 48:107–115, 2008. © 2007 Society of Plastics Engineers
Synthesis and thermal characterization of novel poly(tetramethyl‐1,3‐silphenylenesiloxane) derivative with phenol moiety in the main chain
Authors: Niwa Yoshinori , Kouno Shigeki , Sayama Wakako , Nemoto Nobukatsu
Published: December 2007

Novel poly(tetramethyl‐1,3‐silphenylenesiloxane) derivative with phenol moiety in the main chain, that is, poly(tetramethyl‐5‐hydroxy‐1,3‐silphenylenesiloxane) (P1), was synthesized and the thermal properties were investigated by differential scanning calorimetry (DSC) and thermogravimetry (TG). P1 was obtained via deprotective hydrogenation of poly(tetramethyl‐5‐benzyloxy‐1,3‐silphenylenesiloxane) (Pre‐P1) catalyzed by 10% palladium on charcoal as well as via direct polycondensation of 3,5‐bis(dimethylhydroxysilyl)phenol (M2). Pre‐P1 was obtained by polycondensation of 1,3‐bis(dimethylhydroxysilyl)‐5‐benzyloxybenzene (M1), catalyzed by 1,1,3,3‐tetramethylguanidinium 2‐ethylhexoate. M1 was prepared by the Grignard reaction using chlorodimethylsilane and 1,3‐dibromo‐5‐benzyloxybenzene followed by the hydrolysis catalyzed by 5% palladium on charcoal. M2 was prepared by deprotective hydrogenation of M1 catalyzed by 10% palladium on charcoal. The obtained P1 was soluble in common organic solvents such as tetrahydrofuran, chloroform, dichloromethane, toluene, and so forth as well as in highly polar solvents as ethanol and methanol in which poly(tetramethyl‐1,3‐silphenylenesiloxane) is insoluble. The glass transition temperature (Tg) of P1 was determined to be 40 °C from DSC, which was much higher than that of poly(tetramethyl‐1,3‐silphenylenesiloxane) (−52 °C), indicating that the intermolecular and/or intramolecular hydrogen bondings based on hydroxyl groups restricted the mobility of the main chain. The temperature at 5% weight loss (Td5) of P1 (393 °C) determined by TG was lower than that of poly(tetramethyl‐1,3‐silphenylenesiloxane) (ca. 500 °C), indicating that the phenol moieties decline the thermal stability; however, the obtained P1 would promise to be a new reactive‐polymer with phenolic–hydroxyl moieties to develop new functional materials. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 692–701, 2008
Linear π‐conjugated polymers containing 2,4,6‐tris(thiophen‐2‐yl)‐1,3,5‐triazine unit: Synthesis and optical properties
Authors: Zou Li , Fu Yang , Yan Xiaobing , Chen Xingguo , Qin Jingui
Published: December 2007

Some linear π‐conjugated polymers containing 2,4,6‐tris(thiophen‐2‐yl)‐1,3,5‐triazine unit were synthesized via Sonogashira or Suzuki reaction for the first time and characterized by IR, NMR, and GPC. Because of the introduction of 2,4,6‐tris(thiophen‐2‐yl)‐1,3,5‐triazine unit into π‐conjugated system, all polymers exhibited good thermal stability with high decomposition temperature. Their optical and electrochemical properties were investigated. Based on the 2,4,6‐tris(thiophen‐2‐yl)‐1,3,5‐triazine unit linked with different aromatic rings, the polymers showed the tunable fluorescence from blue to blue‐green emission with satisfied quantum yield. Cyclic voltammetry measurement indicated that the LUMO and HOMO levels of the polymers could be adjustable through the main‐chain structural modification. All polymers had low LUMO level (−2.86 to −3.06 eV) due to the high‐electron affinity of triazine unit. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 702–712, 2008
Systematic Management of Postoperative Enterocutaneous Fistulas: Factors Related to Outcomes
Authors: Martinez Jose L. , Luque‐de‐Leon Enrique , Mier Juan , Blanco‐Benavides Roberto , Robledo Felipe
Published: December 2007

Background

Most enterocutaneous fistulas are postoperative in origin. Sepsis, malnutrition, and hydroelectrolytic deficit are still the most important complications to which patients with postoperative enterocutaneous fistulas (PEF) are exposed. Knowledge of prognostic factors related to specific outcomes is essential for therapeutic decision‐making processes.

Methods

We reviewed files of all consecutive patients with PEF treated in our hospital during a 10‐year period. Our aim was to identify factors related to spontaneous closure, need for operative treatment, and mortality. Univariate and multivariate analyses were performed.

Results

A total of 174 patients were treated. The most frequent site of origin was the small bowel (90 patients: 48 jejunal, and 42 ileal), followed in frequency by the colon (50 patients). Postoperative enterocutaneous fistula closure was achieved in 151 patients (86%), being spontaneous in 65 (37%) and surgical in 86 (49%). Factors that significantly precluded spontaneous closure were jejunal site, multiple fistulas, sepsis, high output, and hydroelectrolytic deficit at diagnosis or referral. Origin of PEF at our hospital was the only factor significantly associated with spontaneous closure. The most frequent operative indication was PEF persistence without sepsis. Factors significantly associated with the need for operative treatment were high output, jejunal site, and multiple fistulas. Closure was achieved in 84% of patients who underwent operation. A total of 23 patients died (13%). Factors associated with mortality were serum albumin <3.0 g/dl (at diagnosis or referral), high output, hydroelectrolytic deficit, multiple fistulas, jejunal site, sepsis, and a complex fistulous tract.

Conclusions

In spite of advances in management of PEF, the associated morbidity and mortality remain high. Among several variables influencing outcome, our multivariate analysis disclosed high output, jejunal site, multiple fistulas, and sepsis as independent adverse factors related to non‐spontaneous closure, need for operative treatment, and/or death.
Setting Up a Surgical Skills Center
Authors: MacRae Helen M. , Satterthwaite Lisa , Reznick Richard K.
Published: December 2007

With the increasing use of simulation in medicine, many departments of surgery are considering the development of a surgical skills center. This article focuses on practical issues that must be considered when setting up a surgical skills center. The importance of developing a mission statement and including relevant stakeholders is discussed. The types of curricula that can be developed as well as the appropriate equipment purchased to support different curricula are considerations. Space requirements, funding sources, and staffing are also covered. Setting up a surgical skills center requires institutional buy‐in and planning from the outset. Various models of skills centers, depending on local politics, are discussed.
Depression and school performance in middle adolescent boys and girls
Authors: Fröjd Sari A. , Nissinen Eeva S. , Pelkonen Mirjami U.I. , Marttunen Mauri J. , Koivisto Anna‐Maija , Kaltiala‐Heino Riittakerttu
Published: December 2007

The study aimed to investigate the associations between different levels of depression with different aspects of school performance. The target population included 2516 7th–9th grade pupils (13–17 years) of whom 90% completed the questionnaire anonymously in the classroom. Of the girls 18.4% and of the boys 11.1% were classified as being depressed (R‐Beck Depression Inventory (BDI), the Finnish version of the 13‐item BDI). The lower the self‐reported grade point average (GPA) or the more the GPA had declined from the previous term, the more commonly the adolescents were depressed. Depression was associated with difficulties in concentration, social relationships, self‐reliant school performance and reading and writing as well as perceiving schoolwork as highly loading. The school performance variables had similar associations with depression among both sexes when a wide range of depression was studied but gender differences appeared when studying the severe end of the depression scale. Our study indicates that pupils reporting difficulties in academic performance should be screened for depression.
Panic Disorder With Nocturnal Panic Attacks: Symptoms and Comorbidities
Authors: Sarísoy Gökhan , Böke Ömer , Arík Ali C. , Şahin Ahmet R.
Published: December 2007

The aim of this study was to determine the relationship between nocturnal panic attacks and comorbidities, clinical variables and panic attack symptoms. One hundred and six consecutive patients with DSM-IV panic disorder were enrolled in the study. The patients were divided into two groups depending on the presence of nocturnal panic attacks. Comorbidities were diagnosed with the help of SCID-I and SCID-II. The groups were compared using the Beck Depression Inventory, State-Trait Anxiety Inventory and Symptom Checklist. Nocturnal panic attacks were not related to comorbidities or age at the onset of the disease. The scores from the Beck Depression Inventory, general scores from the Symptom Checklist, somatization, obsession-compulsion, interpersonal sensitivity and anger-hostility sub-scale scores were higher in the nocturnal panic attack group. Patients with nocturnal panic attacks experience more frequent respiratory symptoms, suggesting that nocturnal panic attacks may be related to respiratory symptoms. Our findings demonstrate that patients with nocturnal panic attacks have more respiratory symptoms of panic, depressive and other psychiatric symptoms than the no nocturnal panic group.
Chemical DNA damage activates p21WAF1/CIP1‐dependent intra‐S checkpoint
Authors: Kan Qiuming , Jinno Shigeki , Yamamoto Hanako , Okayama Hiroto
Published: December 2007

When cells progressing in G1 phase are irradiated with UV light, two damage checkpoint pathways are activated: CHK1–Cdc25A and p53–p21WAF1/CIP1, both targeting Cdk2 but the latter inducing long lasting inactivation. In similarly irradiated S phase cells, however, p21WAF1/CIP1‐dependent checkpoint is largely inactive. We report here that p21‐dependent checkpoint can effectively be activated and induce a prolonged S phase arrest with similarly extended inactivation of Cdk2 by association of p21 if mid‐S phase cells are damaged with a base‐modifying agent instead of UV light, indicating that the poor utilization of p21‐dependent checkpoint is not an innate property of S phase cells.
Ore-magmatic systems and metallogeny of gold and silver in Northeastern Asia
Authors: Gamyanin G.N. , Goryachev N.A. , Savva N.E.
Published: December 2007

Regional ore-magmatic systems (OMS’s) and metallogenic gold-silver belts in northeastern Asia are considered, with emphasis placed on their relationships owing to the effect of geodynamic settings and underlying and host rock sequences on the localization of gold and silver deposits of different types. Particular types of lithologic assemblages with specific mineralogical and geochemical features are persistent throughout the metallogenic belts, controlled by regional noble-metal OMS’s. Regional OMS’s with one-, two-, and multilevel local OMS’s producing different types of noble-metal mineralization are described. The problem of mineral typomorphism in metallogenic analysis has been first raised. This analysis permits one to recognize indicators of ore formation (a particular genetic type of deposits, their formation and denudation levels), sources of ore-forming fluids, regional specific geochemistry and its relationship with magmatism. Regular presence of platinum in gold-bearing metallogenic zones is shown.
Serum fatty acid composition and indices of stearoyl-CoA desaturase activity are associated with systemic inflammation : longitudinal analyses in middle-aged men
Authors: Petersson Helena , Basu Samar , Cederholm Tommy , Risérus Ulf
Published: December 2007

Altered fatty acid (FA) composition is related to insulin resistance and CVD. One possible mediator may be inflammation, but longitudinal data relating FA composition to inflammation taking insulin resistance into account are limited. We investigated the long-term association between FA composition and C-reactive protein (CRP) concentrations in a large population-based cohort study in 767 men followed for 20 years. The association between FA composition in serum cholesteryl esters at age 50 and CRP concentrations at age 70 was investigated using linear regression. In addition, desaturase activities (stearoyl-CoA desaturase-1 (SCD-1), Δ5- and Δ6-desaturase) were estimated using FA product-to-precursor ratios. Insulin resistance was measured directly at follow-up by euglycaemic clamp. After adjusting for confounders (smoking, physical activity, alcohol intake, obesity and erythrocyte sedimentation rate) CRP concentrations were inversely associated with the proportion of 18 : 2n-6 (P = 0·002) and positively associated with 16 : 1n-7 (P = 0·008), 18 : 1n-9 (P = 0·0003), 20 : 5n-3 (P = 0·04) and estimated SCD-1 (P = 0·005) and Δ6-desaturase (P = 0·02) activities. After adding insulin resistance to the model, 18 : 1n-9, 18 : 2n-6 and SCD-1 remained significant predictors of CRP. A FA composition indicating low intake of 18 : 2n-6, high intake of SFA and high SCD-1 activity is, in a Swedish population of middle-aged men, associated with CRP concentrations 20 years later, even independently of obesity and insulin resistance.
Whey protein isolate and glycomacropeptide decrease weight gain and alter body composition in male Wistar rats
Authors: Royle Peter J. , McIntosh Graeme H. , Clifton Peter M.
Published: December 2007

The effect of feed protein type on body composition and growth has been examined. Evidence exists that whey protein concentrate is effective at limiting body fat expansion. The presence of caseinomacropeptide, a mixture of glycosylated and non-glycosylated carbohydrate residues, in particular glycomacropeptide (GMP) in whey protein concentrate may be important for this effect. The influence of whey protein isolate (WPI) and GMP on weight gain and body composition was examined by feeding Wistar ratsad libitumfor 7 weeks with five semi-purified American Institute of Nutrition-based diets differing in protein type: (1) casein; (2) barbequed beef; (3) control WPI (no GMP); (4) WPI+GMP at 100 g/kg; (5) WPI+GMP at 200 g/kg. Body composition was assessed, and plasma samples were assayed for TAG, insulin and glucose. Body-weight gain was lower ( − 21 %) on the control WPI diet relative to casein, with a non-significant influence associated with GMP inclusion ( − 30 %), the effect being equivalent at both levels of GMP addition. Renal and carcass fat mass were reduced in the highest GMP diet when compared with WPI (P < 0·05). Plasma insulin was lowered by GMP at the highest addition compared with WPI alone ( − 53 %;P < 0·01). Plasma TAG in the WPI+GMP (200 g/kg) group were lower ( − 27 %;P < 0·05) than the casein and beef groups. In conclusion, GMP appears to have a significant additional influence when combined with WPI on fat accumulation. WPI alone appears to have the predominant influence accounting for 70 % of the overall effect on body-weight gain. Mechanisms for this effect have not been identified but food intake was not responsible.
Seasonal contamination of public squares and lawns by parasites with zoonotic potential in southern Brazil
Authors: Tiyo R. , Guedes T.A. , Falavigna D.L.M. , Falavigna-Guilherme A.L.
Published: December 2007

The presence of helminths and protozoans in public squares and lawns of the city of Maringá, southern Brazil, during winter and summer was assessed in order to evaluate their seasonal fluctuations in relation to edaphic and climatic factors. Samples were collected from January 2003 through June 2004 in 90% (13) of all public squares covered by sand, and in 30% (4) of all lawns used as leisure areas. The samples were analysed quantitatively by modified centrifugal-flotation and sedimentation in water techniques, and qualitatively by a method based on positive larval thermo-hydrotropism. Meteorological data were recorded, and physical, chemical and structural characteristics of the soil were analysed. One hundred and thirty samples of sand from squares, 65 in summer and 65 in winter, and 40 samples of grass from lawns, 20 in each season, were collected. All samples from lawns, 62 (95.38%) from squares in winter and 45 (69.23%) in summer, contained protozoans and/or helminths. Eggs ofToxocaraspp. were the most frequently observed parasites in both winter and summer in squares (P < 0.0001) and in lawns (P = 0.6142), being equally distributed among the different locations (P = 0.2038). Species diversity was lower in winter; fewer parasites were found in summer. This region, with a tropical climate and a mild winter dry season, has favourable edaphic and climatic conditions for soil contaminants to persist year-round. In addition, the high frequency of animals such as dogs and cats and the poor sanitary measures in force made it possible for zoonoses to be transmitted in the public spaces.
Glycogen catabolism enzymes and protein fractions in the third and fourth larval stages ofAnisakis simplex
Authors: Łopieńska-Biernat E. , Żółtowska K. , Rokicki J.
Published: December 2007

Extracts ofAnisakis simplexthird (L3) and fourth (L4) larval stages were assayed for protein content and activity and properties of α-amylase, glucoamylase and glycogen phosphorylase. Protein content in L4 was twice that in L3. SDS–PAGE applied to both larval stages revealed 22 protein fractions in each, including five stage-specific fractions in each larval stage. The L3 extracts contained three amylase isoenzymes: α1, α2 and α3; their molecular weights were 64, 29 and 21 kDa, respectively. Only one amylase isoenzyme (64 kDa) was found in the L4 extracts. Glycogen in L3 was found to be broken down mostly by hydrolysis because of low glycogen phosphorylase activity. The α-amylase activity in L4 was higher than that in L3 by half and the glycogen phosphorylase activity was ten times higher. In addition, the same enzymes isolated from L3 and L4 were found to differ in their properties. These differences could be manifestations of metabolic adaptations ofA. simplexlarvae to host switch from fish (L3) to mammals (L4), i.e. adaptations to a new habitat.
Experimental infection of the cockroachPeriplaneta americanawithToxocara canisand the establishment of patent infections in pups
Authors: Sasmal N.K. , Pahari T.K. , Laha R.
Published: December 2007

The possible role of the cockroachPeriplaneta americanain the transmission ofToxocara caniseggs and larvae via faeces and tissue migration was studied. Cockroaches fed with 3 × 105and 5 × 105embryonated eggs were found to harbour viable eggs and larvae from days 1 to 5 post-infection (DPI). At necropsy on 5 DPI, eggs and larvae were also recovered from the rectal contents but not from the tissues of cockroaches. In addition patent infections were established in pups fed on infected faeces of cockroaches, with eggs first appearing in the faeces of pups at 38 DPI. Adult worms ofT. caniswere also recovered at necropsy. Therefore the importance of cockroaches as good mechanical disseminators of ascarid eggs, especiallyT. canis, is discussed.
The fictive quality of glass
Authors: Ersoy Ufuk
Published: December 2007

‘The fire is burning. Is it burning for me or against me? Will it give tangible shape to my dreams, or will it eat them up? I know pottery traditions going back thousands of years; all the potters’ tricks I know, I have used them all. But we have not yet reached the end. The spirit of the material has not yet been overcome.’

(Adolf Loos, ‘Pottery’)
Architecture as such: refutations and conjectures of quality in the work of Kengo Kuma and W. G. Clark
Authors: Weiner Frank H.
Published: December 2007

‘[W]hat do we mean when we speak of architectural quality? It is a question that I have little difficulty answering. […] Quality architecture to me is when a building manages to move me. What on earth moves me? How can I get this into my own work?’

(Peter Zumthor, Atmospheres)
Geriatrischer Hausbesuch: Ins Pflegeheim per FFE?
Authors: Wettstein
Published: December 2007

Anhand einer Fallbeschreibung wird die Problematik, welche die Betreuung von Demenzkranken für die betreuenden Angehörigen bedeuten kann, aufgezeigt. Es kann zu Belastung kommen, die für letztere kaum mehr zu ertragen sind. Wegen fehlender Krankheitseinsicht lehnen die Patienten oft jegliche fremde Hilfe wie auch medizinische Abklärungen strikte ab. Können keine Angehörigen (mehr) die Angelegenheiten des Demenzkranken vertreten, muss als gesetzliche Vertretung ein Beistand ernannt werden. Droht wegen mangelnder Versorgung vitale Gefährdung, kann ein Demenzkranker als ultima ratio per Fürsorgerischen Freiheitsentzug (FFE) institutionalisiert werden.
Transport and mixing of chemical air masses in idealized baroclinic life cycles
Authors: Polvani L. M. , Esler J. G.
Published: December 2007

The transport, mixing, and three‐dimensional evolution of chemically distinct air masses within growing baroclinic waves are studied in idealized, high‐resolution, life cycle experiments using suitably initialized passive tracers, contrasting the two well‐known life cycle paradigms, distinguished by predominantly anticyclonic (LC1) or cyclonic (LC2) flow at upper levels. Stratosphere‐troposphere exchange differs significantly between the two life cycles. Specifically, transport from the stratosphere into the troposphere is significantly larger for LC2 (typically by 50%), due to the presence of large and deep cyclonic vortices that create a wider surf zone than for LC1. In contrast, the transport of tropospheric air into the stratosphere is nearly identical between the two life cycles. The mass of boundary layer air uplifted into the free troposphere is similar for both life cycles, but much more is directly injected into the stratosphere in the case of LC1 (fourfold, approximately). However, the total mixing of boundary layer with stratospheric air is larger for LC2, owing to the presence of the deep cyclonic vortices that entrain and mix both boundary layer air from the surface and stratospheric air from the upper levels. For LC1, boundary layer and stratospheric air are brought together by smaller cyclonic structures that develop on the poleward side of the jet in the lower part of the middleworld, resulting in correspondingly weaker mixing. As both the El Niño‐Southern Oscillation and the North Atlantic Oscillation are correlated with the relative frequency of life cycle behaviors, corresponding changes in chemical transport and mixing are to be expected.
Self-consistent Langmuir waves in resonantly driven thermal plasmas
Authors: Lindberg R. R. , Charman A. E. , Wurtele J. S.
Published: December 2007

The longitudinal dynamics of a resonantly driven Langmuir wave are analyzed in the limit that the growth of the electrostatic wave is slow compared to the bounce frequency. Using simple physical arguments, the nonlinear distribution function is shown to be nearly invariant in the canonical particle action, provided both a spatially uniform term and higher-order spatial harmonics are included along with the fundamental in the longitudinal electric field. Requirements of self-consistency with the electrostatic potential yield the basic properties of the nonlinear distribution function, including a frequency shift that agrees closely with driven, electrostatic particle simulations over a range of temperatures. This extends earlier work on nonlinear Langmuir waves by Morales and O’Neil [G. J. Morales and T. M. O’Neil, Phys. Rev. Lett. 28, 417 (1972)] and Dewar [R. L. Dewar, Phys. Plasmas 15, 712 (1972)], and could form the basis of a reduced kinetic treatment of plasma dynamics for accelerator applications or Raman backscatter.
Extended study of molecular dynamics simulation of homogeneous vapor-liquid nucleation of water
Authors: Matsubara Hiroki , Koishi Takahiro , Ebisuzaki Toshikazu , Yasuoka Kenji
Published: December 2007

Using the simple point charge/extended water model, we performed molecular dynamics simulations of homogeneous vapor-liquid nucleation at various values of temperature T and supersaturation S, from which the nucleation rate J, critical nucleus size n*, and the cluster formation free energy ΔG were derived. As well as providing lots of simulation data, the results were compared with theories on homogeneous nucleation, including the classical, semiphenomenological, and scaled models, but none of these gave a satisfactory explanation for our results. It was found that two main factors made the theories fail: (1) The average cluster structure including the nonspherical shape and the core structure that is not like the bulk liquid and (2) the forward rate which is larger than assumed by the theories by about one order of magnitude. The quantitative evaluation of these factors is left for future investigations.
Stabilization of flat aromatic Si6 rings analogous to benzene: Ab initio theoretical prediction
Authors: Zdetsis Aristides D.
Published: December 2007

It is shown by ab initio calculations, based on density functional (DFT/B3LYP), and high level coupled-cluster [CCSD(T)] and quadratic CI [QCISD(T)] methods, that flat aromatic silicon structures analogous to benzene (C6H6) can be stabilized in the presence of lithium. The resulting planar Si6Li6 structure is both stable and aromatic, sharing many key characteristics with benzene. To facilitate possible synthesis and characterization of these species, routes of formation with high exothermicity are suggested and several spectral properties (including optical absorption, infrared, and Raman) are calculated.
Linear instability of pressure-driven channel flow of a Newtonian and a Herschel-Bulkley fluid
Authors: Sahu K. C. , Valluri P. , Spelt P. D. M. , Matar O. K.
Published: December 2007

The linear stability characteristics of pressure-driven two-layer channel flow are considered, wherein a Newtonian fluid layer overlies a layer of a Herschel-Bulkley fluid. A pair of coupled Orr-Sommerfeld eigenvalue equations are derived and solved using an efficient spectral collocation method for cases in which unyielded regions are absent. An asymptotic analysis is also carried out in the long-wave limit, the results of which are in excellent agreement with the numerical predictions. Our analytical and numerical results indicate that increasing the dimensionless yield stress, prior to the formation of unyielded plugs below the interface, is destabilizing. Increasing the shear-thinning tendency of the lower fluid is stabilizing.
Experimental observations of transport of picosecond laser generated electrons in a nail-like target
Authors: Pasley J. , Wei M. , Shipton E. , Chen S. , Ma T. , Beg F. N. , Alexander N. , Stephens R. , MacPhee A. G. , Hey D. , Le Pape S. , Patel P. , Mackinnon A. , Key M. , Offermann D. , Link A. , Chowdhury E. , Van-Woerkom L. , Freeman R. R.
Published: December 2007

The transport of relativistic electrons, generated by the interaction of a high intensity (2×1020W∕cm2) laser, has been studied in a nail-like target comprised of a 20μm diameter solid copper wire, coated with ∼2μm of titanium, with an 80μm diameter hemispherical termination. A ∼500fs, ∼200J pulse of 1.053μm laser light produced by the Titan Laser at Lawrence Livermore National Laboratory was focused to a ∼20μm diameter spot centered on the flat face of the hemisphere. Kα fluorescence from the Cu and Ti regions was imaged together with extreme ultraviolet (XUV) emission at 68 and 256eV. Results showed a quasiexponential decline in Kα emission along the wire over a distance of a few hundred microns from the laser focus, consistent with bulk Ohmic inhibition of the relativistic electron transport. Weaker Kα and XUV emission on a longer scale length showed limb brightening suggesting a transition to enhanced transport at the surface of the wire.
The structural evolution of boron carbide via ab initio calculations
Authors: Saal James E. , Shang Shunli , Liu Zi-Kui
Published: December 2007

The distribution of boron and carbon atoms in boron carbide (B4C), the third hardest naturally occurring material, is a hotly debated subject. In the current work, an ab initio approach is applied to the entire composition range of boron carbide (∼8–20at.%C) to determine what disordering mechanisms are responsible for such a large single-phase region. Based on the correctly predicted crystal structures, enthalpy of formation, and infrared phonon modes, we reveal direct evidence in support of a new defect model for boron carbide, where mixing occurs in the icosahedron for carbon-rich compositions and in the chain for boron-rich compositions.
Adaptation of the Bridgman anvil cell to liquid pressure mediums
Authors: Rüetschi A.-S. , Jaccard D.
Published: December 2007

The advantage of Bridgman anvil pressure cells is their wide pressure range and the large number of wires which can be introduced into the pressure chamber. In these pressure cells, soft solid pressure mediums such as steatite are used. We have succeeded in adapting the Bridgman cell to liquid pressure mediums. With this breakthrough, it is now possible to measure in very good hydrostatic pressure conditions up to 7GPa, which is about twice the pressure attainable in piston-cylinder cells. The pressure gradient in the cell, estimated from the superconducting transition width of lead, is reduced by a factor of 5 in the liquid medium with respect to steatite. By using nonmagnetic materials for the anvils and the clamp and due to the small dimensions of the latter, our device is specially suitable for magnetotransport measurements in dilution fridges. This pressure cell has been developed to measure very fragile and brittle samples such as organic conductors. Resistivity measurements of (TMTTF)2BF4 performed in a solid and a liquid pressure medium demonstrate the necessity of hydrostatic pressure conditions for the study of organic conductors at high pressures.
Degradation of low frequency noise in SiGe- and SiGeC-surface channel p-type metal-oxide-semiconductor field effect transistor due to consuming the Si cap
Authors: Yang R. , Xiong Y. Z. , Loh W. Y. , Ye J. D. , Yu M. B. , Shen C. , Yang J. J. , Chua K. T. , Hoe K. M. , Lo G. Q. , Balasubramanian N. , Kwong D. L.
Published: December 2007

This letter reports on the noise degradation mechanism in SiGe- and SiGeC-surface channel p-type metal-oxide-semiconductor field-effect transistors (pMOSFETs). Compared to their Si reference, the surface SiGe pMOSFETs show only slightly lower or even comparable noise (at low gate bias), while the SiGeC devices exhibit higher noise amplitude for the full bias range, unlike previously reported buried SiGe pMOSFETs with significantly improved noise over their Si control. The degradation can be attributed to Si-cap consumption and thus the cancellation of buried channel operation. [C] incorporation further degrades noise characteristics due to inferior quality of epilayer and higher interface trap density.
Two-dimensional signal reconstruction: The correlation sampling method
Authors: Roman H. E.
Published: December 2007

An accurate approach for reconstructing a time-dependent two-dimensional signal from non-synchronized time series recorded at points located on a grid is discussed. The method, denoted as correlation sampling, improves the standard conditional sampling approach commonly employed in the study of turbulence in magnetoplasma devices. Its implementation is illustrated in the case of an artificial time-dependent signal constructed using a fractal algorithm that simulates a fluctuating surface. A statistical method is also discussed for distinguishing coherent (i.e., collective) from purely random (noisy) behavior for such two-dimensional fluctuating phenomena.
Selective etching of Pt with respect to PtSi using a sacrificial low temperature germanidation process
Authors: Breil N. , Halimaoui A. , Skotnicki T. , Dubois E. , Larrieu G. , Łaszcz A. , Ratajczak J. , Rolland G. , Pouydebasque A.
Published: December 2007

A soft and scalable etching procedure that selectively eliminates Pt without altering PtSi is proposed. The selective etch is based on the low temperature transformation of the excess Pt into a more reactive PtxGey phase that is easily etched in a sulfuric peroxide mixture. The mechanism of PtxGey alloying is detailed based on x-ray diffraction analysis. The innocuousness of the germanidation-based selective etch on the integrity of the PtSi∕Si junction is consolidated by Schottky barrier measurements. This process is expected to facilitate the integration and the scalability of PtSi on ultrathin silicon layers.
Tailoring the intrinsic metallic states of double-walled nanotube films by self-soldered laser welding
Authors: Zhang Yong , Gong Tao , Jia Yi , Liu Wenjin , Wei Jinquan , Ma Mingxing , Wang Kunlin , Zhong Minlin , Wu Dehai , Cao Anyuan
Published: December 2007

The metallic state and resistivity of interconnected double-walled carbon nanotube bundles have been tuned by modifying two major components, including (1) structure of the bundles and (2) contacts at the heterojunctions between the bundles. Infrared laser illumination at controlled intensity on the nanotubes produces an amorphous carbon coating that subsequently serves as the solder material to weld the bundles at their heterojunction sites. The results show that without selective etching of metallic or semiconductor species, the crossover temperature at which metallic behavior changes to semiconducting can be tuned within a wide range (25–150K).
Effect of electrode material on the resistance switching of Cu2O film
Authors: Yang Woo-Young , Rhee Shi-Woo
Published: December 2007

The effect of the bottom electrode material on the resistance switching characteristics was evaluated on the structure of Pt∕Cu2O/bottom electrode). It was confirmed that Ohmic or low Schottky contact is needed to induce the effective electric field for resistance switching across the Cu2O film. Pt, TiN, TaN, and strontium-ruthenium oxide belong to this group. For high Schottky contact, the resistance switching characteristics could not be observed due to a large voltage drop at the rectifying interface with insufficient electric field in the Cu2O film. Also, it was confirmed that interlayer formation from the reaction at the electrode-oxide interface increased the barrier height and brought about the switching failure in the case of Ru. The resistance switching properties depend on the barrier height and the reactivity between metal and Cu2O film.
A look at the CLAW hypothesis from an atmospheric chemistry point of view
Authors: von Glasow Roland
Published: December 2007

Environmental context. Feedbacks in the climate system as suggested by, for example, the CLAW hypothesis have often been accepted as fact whereas many open questions remain. In this manuscript some of these uncertainties and their implications are discussed and additional processes that might drastically change the importance of this suggested feedback loop are highlighted.
Plankton modelling and CLAW
Authors: Cropp Roger , Norbury John
Published: December 2007

Environmental context. The prospect of human-induced climate change provides a compelling imperative for an improved understanding of living systems, especially those involving ocean plankton that are proposed to have an important role in regulating climate. Ecosystems are complex, adaptive systems and mathematical modelling has proved to be a powerful tool in understanding such systems. The present article considers some of the fundamental issues currently constraining such understanding with particular consideration to modelling ecosystems that underpin the CLAW hypothesis and how they might behave in response to global warming.
Using epidemiological and molecular methods to investigate an outbreak of gonorrhoea associated with heterosexual contact in Newcastle, NSW, Australia
Authors: Todd Kerry , Durrheim David , Pickles Robert , Eastwood Keith , Merritt Tony , Tapsall John , Ray Sanghamitra , Limnios Athena
Published: December 2007

Background: We report a cluster of gonorrhoea among mainly heterosexual men that occurred in October 2005, which was first identified when routine weekly surveillance review procedures indicated a three-fold increase in reporting rates compared with historical data. Methods: Each case was followed up with the treating medical officer to review treatment regimes and risk exposures, and to carry out enhanced contact tracing. The phenotype and genotype of the outbreak gonococcal isolates and gonococci prevalent in the months preceding and following the cluster were determined. Links between cases reported from the local Sexual Health Clinic and those reported by general practitioners were established. Results: Laboratory data indicated that a particular gonococcal subtype (ST225 and NR/Brpyst) was prevalent during the outbreak. Conclusions: Gonorrhoea rates returned to pre-outbreak levels following a targeted health promotion intervention with no further cases of the outbreak subtype detected.
17. PATIENTS' PERSPECTIVES ON THE BEST WAYS TO TELL PARTNERS ABOUT CHLAMYDIA: HOW ACCEPTABLE ARE THE NEW TECHNOLOGIES?
Authors: Hopkins C. A. , Temple-Smith M. J. , Fairley C. K. , Tomnay J. E. , Pavlin N. L. , Parker R. M. , Russell D. B. , Bowden F. J. , Hocking J. S. , Chen M. Y.
Published: December 2007

As part of a larger, combined qualitative-quantitative methods study of partner notification, 40 in-depth telephone interviews were conducted with patients diagnosed with Chlamydia from clinics in Victoria, ACT and Queensland to determine their usage and opinions of different methods partner notification. Overwhelmingly, personal methods such as telling partners face-to-face or over the phone were preferred to impersonal methods such as email, SMS and letter. Face-to-face was considered the "gold standard" in partner notification because it demonstrated courage, caring and respect. Phone contact, while considered insensitive and cowardly by some, was often used because it was quick, convenient and less confronting. Email was viewed as only being acceptable in certain circumstances, such as if the partner was overseas, because it was seen as impersonal and uncaring. SMS was considered the least acceptable method for telling partners with most interviewees seeing it as cold, disrespectful and "gutless". However, interviewees who were fearful of their partner's reaction or who had high numbers of casual partners were enthusiastic about an anonymous SMS facility. For both emails and SMS, interviewees were concerned that the message could be misunderstood, not taken seriously or shown to others. Letters, both from the patients or from their doctor, while not viewed as unfavourably as the newer technologies were less likely to be used. These findings suggest that people diagnosed with Chlamydia are reluctant to use the new technologies for partner notification, except in specific circumstances, and our efforts in developing partner notification resources may best be focused on giving patients the skills and confidence for personal interaction.
2. VAGINISMUS, VULVODYNIA AND PELVIC FLOOR MUSCLE ACTIVITY
Authors: Sapsford R.
Published: December 2007

The pelvic floor muscles form the base of the abdominal cylinder and work in synergy with other muscles around the cylinder - the abdominal muscles and the diaphragm. Activity in each muscle group affects the others. Coordinated recruitment of these muscle groups is necessary for generation and maintenance of intra-abdominal pressure, postural support of the trunk, and during functional tasks such as lifting, coughing and nose blowing. Coordinated release of these groups is required for micturition, while defaecation may need activity in some muscles and release in others. Vaginismus and vulvodynia both have a component of over activity of the pelvic floor muscles which impairs normal function, though this over activity may only occur at the time of attempted penetration. Some of the physiological factors that contribute to this overactivity come from outside the pelvic floor muscle complex itself and can be ameliorated by understanding and management of these muscle synergies. An EMG study of muscle activity of the abdominal and pelvic floor muscles during a simulated body posturing for female sexual arousal will help to explain how the pelvic floor muscle over activity in vaginismus arises. Treatment programmes that have been used to successfully address these problems will be explained.
20. SEXUAL HEALTH SERVICES & HIV PREVENTION: IMPROVING INTERVENTION OPPORTUNITIES
Authors: Powell S.
Published: December 2007

Objective: This descriptive study was undertaken to determine the presence of key indicators which might alert clinicians that a Melbourne Sexual Health Centre (MSHC) client is at increased risk of HIV acquisition and, if so, lead to recommendations for changes to clinical practice.
Method: We identified and reviewed the most recent medical files of clients who received an HIV positive diagnosis and who had also received a negative result at MSHC within the preceding two years (n�=�20). Quantitative epidemiological and demographic data were collected and analyzed using SPSS software. Qualitative data analysis of annotated entries both pre and post HIV diagnosis included transcription and examination for emergent themes.
Results: Quantitative data analysis revealed the following; all 20 clients were male and identified MSM behaviour. Median age at diagnosis was 34.5 years (95% CI�:�28.3-37.6 years). The median number of partners in the 3 months preceding HIV diagnosis was 4 (95% CI�:�3.4-9.6; p�=�0.005) and in the preceding 12 months 23 (95% CI�:�11.4-61.4; p�<�0.05). 85% of men reported inconsistent condom use, and one reported no anal sex in the preceding 12 months. None reported a history of IDU and three men reported sex overseas in the preceding 12 months.
Qualitative analysis revealed some emergent themes which included histories of mental illness, drug and alcohol use, childhood abuse, HIV serodiscordant relationships and confusion surrounding sexual orientation.
Discussion: Clinicians have an obligation to assist clients, within their scope of practice, to remain HIV negative. Results from this study have implications for the method of identification of clients at risk and also for the utilization of intervention opportunities which impact on risk behaviour. The challenge for MSHC is to adapt our practice in order to maximize these opportunities.
24. ELECTRONIC HEALTH RECORD SYSTEMS IN AUSTRALIA & NEW ZEALAND SH/HIV/HEP C/WOMEN'S HEALTH CLINICS 2006 - A PILOT PROJECT
Authors: Chuah J. , Fankhauser W. , Page M. , Dickson B.
Published: December 2007

Objective: This pilot study examined the utility pattern of electronic health record & clinic management systems in the region.
Methods: An anonymous one-paged survey form was sent either by email or facsimile to 100 randomly selected public & private Sexual Health/ HIV/ Hep C/ Women's Health/ GP (High Case Load ) listed in the Australasian Chapter of Sexual Health Medicine Register of Public SH Clinics 2006 and the ASHM Directory 2006-2007. Responses on the clinics activities & utility for 2006 were collated.
Results: Response rate = 20% N = 20 clinics
Mean Occasion of service (OS) = 4812 MedianOS = 4150
(Range 162-20 000) 25% of clinics provided estimated figures only
Mean No. tests done = 5467 Median = 5474 (Range 224-20 000)
Nature of Clinics: SH 81.3% FP/Women's Health 18.8% GP 6.3% Other 6.3%
Clinic Software: SHIP 50% Other 25% Nil 25%
Regular Reports: None 62.5% Daily 37.1% Weekly 6.4% Monthly 37.5%
Quarterly 31.5% Annually 43.8% QA 37.5% Research 31.3%
Automatic Results download: Yes 43.8% No, plan to 25% No Plan 12.5% Unsure 18.7%
Hours of training provided to staff on clinic software: mean 61.8 hrs median 1 h (Range 0-500)
Funding allocated for clinic IT support in 2007: None 37.5% Unsure 56.3%
Yes 6.25% (Max $6000)
Funding allocated for IT support in next 3-5 yrs: None 100%
Discussion: Limitations of study: Small sample (100/355 clinics) and limited response rate (20%), the latter may indicate that issues of eHealth have not featured in the priority list of most clinics surveyed, as evident in the poor level of funding (>90% none or unsure) and training (median 1 h for 2006) allocations. Others trends and issues include: low ratio of utility compared to the functionality of the softwares & technology available; competing interests of policy & privacy etc. will be discussed with recommendations proffered.