bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessing C/N and δ13C as indicators of Holocene sea level and freshwater discharge changes in the subaqueous Yangtze delta, China
Authors: Zhan Qing , Wang Zhanghua , Xie Yan , Xie Jianlei , He Zhongfa
Published: November 2011

To examine the applicability of C/N and organic carbon stable isotope (δ13C) in studies of the Holocene sea level and freshwater discharge in the large river mouth of Yangtze, we observed the distribution of carbon, nitrogen and δ13C in a late-Quaternary core (ZK9) collected from the present subaqueous delta. We also collected published data of the two proxies for the suspended particulate matter (SPM) and surficial sediments from the lower Yangtze River to the adjacent East China Sea. The results show that the estuarine front is an important boundary for terrestrial and marine contribution of the organic component in the modern sedimentary environment. In the core ZK9, sediments deposited during c. 13–9 cal. ka BP are characterized by high values of TOC (0.54–1.16%), CaCO3 (0.35% on average), and C/N (>12), which reflect an inner tidal estuarine environment dominated by C3 terrestrial organic carbon input. During c. 9–0.7 cal. ka BP, both TOC content (0.57% on average) and C/N ratio (<10) decrease remarkably while TN increases, indicating a lower estuarine or shallow marine environment. An abrupt sea level rise from c. 9 cal. ka BP resulted in a deeper water environment and reduced terrestrial input at the core location. The low δ13C values (−24.23‰ on average) before c. 6 cal. ka BP reflect a dominantly terrestrial source of organic matter associated with increased freshwater discharge into the estuary during that time. The sediments since c. 6 cal. ka BP are characterized by increasing δ13C up to −24.1 to −23.39‰, reflecting more contribution from marine algae as freshwater discharge fell. We suggest that in the Yangtze River mouth the C/N ratio indicates an abrupt sea level rise at c. 9 cal. ka BP, while δ13C is more useful in reflecting freshwater discharge.
One-dimensional Localization Solutions for Time-dependent Damage
Authors: Caillerie D. , Dascalu C.
Published: November 2011

This article presents analytical solutions for a class of one-dimensional time-dependent elasto-damage problems. The considered damage evolution law may be seen as a one-dimensional version of the Kachanov–Rabotnov creep damage model with classical loading–unloading conditions. We construct analytical solutions for the quasistatic one-dimensional problem. The evolution consists of a first regime, in which damage and strain grow uniformly, followed by a regime in which localization occurs. In the second regime, the uniqueness of the solution is lost and the deformation of the body is represented by a sequence of arbitrary alternate loading/unloading regions. Complex evolutions with progressive enlargement of the unloading regions in a finite number of steps are also constructed. We study analytically and numerically the features of the obtained bifurcated solutions. It is shown that, at every instant of time, a lower limit exists for the size of the localization zone. This lower limit is actually realized by the solution with successive unloadings constructed in this article. These features help us to understand the behavior of numerical solutions for time-dependent damage in the quasistatic approximation.
Percentage of Named Offenders on the Registry at the Time of the Assault
Authors: Craun Sarah W. , Simmons Catherine A. , Reeves Kristen
Published: November 2011

Sex offender registries were designed to protect the public from convicted sex offenders and future sexual violence. This study determines the percentage of clients seen at a sexual assault agency whose attacker was on the registry at the time the attack occurred. According to case files, only 3.7% of the identified offenders could possibly have been identified as a registered sex offender at the time of the attack. While considering the limitations of this methodology, the findings highlight a significant limitation of registries and support the idea that registries cannot be relied on exclusively to prevent sexual abuse.
When the lads go hunting: The ‘Hammertown mechanism’ and the conflict over wolves in Norway
Authors: Krange Olve , Skogen Ketil
Published: November 2011

Rural communities are changing. Depopulation and unemployment is accompanied by the advance of new perspectives on nature, where protection trumps resource extraction. These developments are perceived as threatening by rural working-class people with close ties to traditional land use – a situation they often meet with cultural resistance. Cultural resistance is not necessarily launched against institutionalized power, nor does it necessarily imply a desire for fundamental social change. It should rather be seen as a struggle for autonomy. However, autonomy does not entail influence outside the cultural realm. Struggles to uphold traditional rural lifestyles – for example by denouncing the current nature conservation regime – could be understood in much the same conceptual framework as Willis employed in ‘Learning to labour’. Based on an ethnographic study of the conflicts over wolf protection, we demonstrate that ‘the Hammertown mechanism’ is of a more general nature than often implied in the discussion of Willis’ work.
‘Heading for Japan’: Prospective narratives and development among young people living in residential care
Authors: Jansen Anne , Andenæs Agnes
Published: November 2011

Young people who live in residential homes provided by Child Protection Services generally have less favourable life conditions and poorer future prospects than young people in general. Repeated interviews with twelve young persons in residential care brought to attention how their prospective narratives are efficacious and significant for developmental processes. The ideas these youths hold about the future are conditioned by both discourses of development and ideas of what adolescence should lead to, their personal history and the context in which the stories are created and told. Studying these narratives shows how narratives of the future are intertwined with the sense of present being. It illuminates the dynamics between the present and the future and exceeds our understanding of development as a linear track from past to present to future. It also shows how residential care both restricts and gives opportunities for some narratives to be told and interpreted. This approach to studying development may be fruitful in understanding why some youths in residential care manage to overcome adversity while others continue to suffer from it.
Relational poetry in the expression of social identity: Creating interweaving dialogues
Authors: Taiwo Akin
Published: November 2011

Social constructionism holds that meanings are produced in social interactions, which are, in turn, shaped by specific socio-cultural, political, and economic forces. These forces also affect our sense of self, social identities, knowledge, and interpretation of realities. Following the work of Witkin (2007) on relational poetry, this author interweaves a second poem within the lines and verses of Kumsa’s (2007) poem, thereby producing a poetic dialogue and a new poem. This article highlights the inter-subjectivities of the human experience and the co-construction of meaning arising from multiple experiences, realities and truths. It presents relational poetry as another entrée into our co-constructed realities. It is an experiment with a mode of writing and engagement about inter-subjectivities. In using this literary style, this article also fulfills the ethical responsibility within social work of bringing awareness to voices and perspectives that have been marginalized and oppressed.
Tensioning of Prolene reduces creep under cyclical load: relevance to a simple pre-operative manoeuvre
Authors: Smith G. H. , Huntley J. S. , Anakwe R.E. , Wallace R.J. , McEachan J. E.
Published: November 2011

A longitudinal stretch or ‘pre-tensioning’ is a method employed by some surgeons to improve the handling characteristics of a suture. We used a tensile tester to assess the effect of pre-tensioning on the mechanical properties of two suture materials (3-0 Prolene and 3-0 Ethibond) commonly used for flexor tendon repair. A cyclical loading programme was used to simulate an early rehabilitation regime. All sutures were subsequently tested to failure (for ultimate tensile strength). The pre-tensioned Prolene sutures showed significantly less creep after cyclical loading in comparison to controls. Conversely pre-tensioning had no measurable effect on the deformation of Ethibond by creep. There was no effect on ultimate tensile strength for either material. The propensity of Prolene to creep (and thereby form a ‘gap’ in tendon repairs) can be reduced by pre-tensioning.
Mobile telecommunications and health: report of an investigation into an alleged cancer cluster in Sandwell, West Midlands
Authors: Stewart Antony , Rao Jammi N , Middleton John D , Pearmain Philippa , Evans Tim
Published: November 2011

Aims:

Residents of one street expressed concern about the number of incident cancers, following the installation of a nearby mobile phone base station. The investigation explored whether the base station could be responsible for the cancers.

Methods:

Data were collected from residents’ medical records. GPs and oncologists provided further information.

Results:

Ward-level cancer incidence and mortality data were also obtained, over four three-year time periods. A total of 19 residents had developed cancer. The collection of cancers did not fulfil the criteria for a cancer cluster. Standardized mortality ratios (SMRs) for all malignant neoplasms (excluding non-melanoma skin cancers) in females (1.38 (95% CI, 1.08–1.74)) and all persons (1.27 (CI, 1.06–1.51)) were significantly higher than in the West Midlands during 2001–3. There were no significant differences for colorectal, female breast and prostate cancers, for any time period. Standardized incidence ratios (SIRs) for non-melanoma skin cancers in males and all persons was significantly lower than in the West Midlands during 1999–2001, and significantly lower in males, females and all persons during 2002–4.

Conclusions:

We cannot conclude that the base station was responsible for the cancers. It is unlikely that information around a single base station can either demonstrate or exclude causality.
Assessment of intermetallic compound formation during solidification of Al–Si piston alloys through thermal analysis technique
Authors: Shabestari S G , Gholizadeh R
Published: November 2011

Multicomponent Al–Si–Ni–Cu–Mg alloys are widely used as automotive piston materials. The aim of the present work is to study the complicated formation of different intermetallic compounds during the solidification of two types of piston alloys: LM13 alloy with 0·9Ni–0·9Cu–1Mg and 3HA alloy containing 2·6Ni–3Cu–0·2Mg. Solidification events were detected by three-thermocouple thermal analysis technique, and microstructure evaluations were carried out using optical microscopy, scanning electron microscopy, energy dispersive X-ray analysis and quantitative image analysis. In addition to the (Al)+(Si) eutectic reaction, the results show a complicated precipitation of different post-eutectic phases, the most important of which are Al9FeNi, Al3Ni, Al3CuNi and Mg2Si. Ni rich Al9FeNi and Al3Ni phases have the highest formation temperatures among other intermetallics, which are detected in the range of 553–558°C in 3HA alloy and 546–553°C in LM13 alloy.
Electron backscatter diffraction analysis of strain distribution in adiabatic shear band and its nearby area in Ti–3Al–5Mo–4·5V alloy
Authors: Yang Y , Jiang F , Yang M , Li X M , Zheng H G , Zhang Q M
Published: November 2011

Adiabatic shear bands (ASBs) were produced in the hat shaped specimen of Ti–3Al–5Mo–4·5V alloy by split Hopkinson pressure bar technique. Strain distribution in the ASB and its nearby area was investigated by electron backscatter diffraction technology. Image quality, confidential index and Fit value treated as strain sensitive parameters are applied to evaluate the strain field in the present study. The results show that the region including the ASB and its nearby area can be divided into three parts according to the strain gradient. The first part is the area of the ASB, which has the largest strain in the whole region; the second part is the area within ∼2 μm on both sides of the ASB, where the strain is second only to the ASB area; and the last part is far from the ASB area, and the strain there is the smallest. In addition, further analysis reveals that the initiation and propagation of the microcrack could occur more likely in the ASB area than in the other areas.
Impact toughness of spot welds on prestrained interstitial free steel sheets
Authors: Mukhopadhyay G , Bhattacharya S , Ray K K
Published: November 2011

A series of impact tensile tests of spot welded joints made on interstitial free steel sheets have been carried out using a fabricated fixture. Spot welded samples were made from as received as well as prestrained steel sheets with the aim of examining the effect of prestrain on the impact tensile toughness of spot welds. The impact tensile toughness values of spot welds were found to be higher than their corresponding quasi-static toughness determined using tensile shear specimens. While the quasi-static toughness of spot welds decreases with increasing prestrain, the impact tensile toughness exhibits an opposite trend with prestrain within the range of investigation. The observed results have been discussed with considerations of specimen configurations, test procedure, microstructure, substructure, hardness profiles along the welds and post-failure examinations.
Simultaneous effect of nano-Al2O3 and micrometre Cu particulates on microstructure and mechanical properties of magnesium alloy AZ31
Authors: Nguyen Q B , Tun K S , Chan J , Kwok R , Kuma J V M , Phung T H , Gupta M
Published: November 2011

In the present study, magnesium composites are synthesised through the addition of nano-alumina and micrometre copper particulates in AZ31 magnesium alloy using the technique of disintegrated melt deposition. Nano-alumina and micrometre size copper particulates are known to significantly enhance the ductility and strength of magnesium materials respectively. The simultaneous addition of Cu and nano-Al2O3 particulates led to an overall improvement in both microstructural characteristics in terms of distribution and morphology of intermetallics/particulates and mechanical response of AZ31. The 0·2 yield strength increased from 180 to 300 MPa (67), while the ductility increased by almost 24. The overall tensile properties assessed in terms of work of fracture improved by 66. An attempt is made to correlate the tensile response of composites with their microstructural characteristics. The results suggest that these alloy composites have significant potential in diverse and wider engineering applications when compared to AZ31 alloy.
Novel process to refine grain size of NiCrMoV steel
Authors: Chen R K , Gu J F , Han L Z , Pan J S
Published: November 2011

The present study focuses on the grain refining of NiCrMoV steel. All the samples were austenitised at 1230°C for 10 h, followed by holding at 350°C for 20 h and then experienced different heat treatment processes to refine the grain. It is proved that the isothermal treatment newly proposed in the present paper is much more effective than the conventional normalising process due to the formation of pearlite, which can cut off the structural heredity between parent austenite and martensitic or ferritic product in NiCrMoV steel.
Effect of temperature on impact properties and microstructural evolution of twinning induced plasticity steel
Authors: Li D Z , Wei Y H , Hou L F , Chu G D
Published: November 2011

The Charpy V notch impact toughness of twinning induced plasticity steels was investigated at 20, −50, −80, −110 and −196°C. The fracture morphologies were analysed by scanning electron microscopy. The microstructural characteristic near the fractures is investigated by optical microscopy, X-ray diffraction and transmission electron microscopy. The impacted twinning induced plasticity steels exhibit better impact toughness due to the simultaneous generation of deformation twins and martensite, which hinders crack propagation and does not display ductile to brittle transition. The ruptures exhibit cleavage characteristic, and traces of deformation twins can be observed in the cleavage facets, so the cracks should propagate through the deformation twin, martensite and grain. The martensite transformation occurs because of the intensive high rate force with rapidly changing direction. The nucleation and growth of deformation twins are accomplished by the pile-up of dislocations at the positions of stress concentration, and the stacking fault grows through the moving and vanishing dislocation.
Simple approach for description of undercooled solidification
Authors: Xu J F , Liu F , Zhang K , Gong M M
Published: November 2011

Assuming constant rates for nucleation and growth and neglecting thermal gradient in the melt, an analytical approach to describe the undercooled solidification was proposed in terms of ξα( x) function. This approach was adopted to study the solidification of undercooled Ni–B alloy. With increasing melt undercooling, good model fits to recalescences arising from the solidification of the primary and eutectic phases were obtained. The fitting results are consistent with the structure evolution upon solidification.
Determination of hot and cold rolling textures of steels: Combined Bayesian neural network model
Authors: Capdevila C , Toda I , Caballero F G , Garcia-Mateo C , de Andres C G
Published: November 2011

The work reported in the present paper outlines the use of a combined artificial neural network model capable of fast online prediction of textures in low and extralow carbon steels. We approach the problem by a Bayesian framework neural network model that takes into account as input to the model the influence of 23 parameters describing the chemical composition and the thermomechanical processes, such as austenite and ferrite rolling, coiling, cold working and subsequent annealing, involved in the production route of low and extralow carbon steels. The output of the model is in the form of fibre texture data. The predictions of the network provide an excellent match to the experimentally measured data. The results presented in the present paper demonstrate that this model can help in optimising the normal anisotropy rm of steel products.
Study of deleterious phase precipitation under continuous cooling of superduplex stainless steel UNS S32750
Authors: Pardal J M , Tavares S S M , Cindra Fonseca M P , da Silva M R , Ferreira M L R
Published: November 2011

Duplex and superduplex stainless steels have high strength and high corrosion resistance with a crescent demand in chemical and petrochemical industries. The best mechanical properties of this family of steels are obtained with approximately equal parts of ferrite and austenite. Grain refinement increases the toughness and resistance to environmentally assisted cracking. The precipitation of tertiary phases, such as σ, χ and secondary austenite, decreases the mechanical and corrosion resistance properties. The σ phase is the most dangerous of these deleterious phases and the one that precipitates in higher amounts. The majority of research works on deleterious phases in duplex and superduplex steels evaluate the kinetics of precipitation in specimens isothermally treated. In the present work, the precipitation of deleterious phases during continuous cooling from 1100°C was evaluated by optical and scanning electron microcopies, hardness measurements and electrochemical corrosion tests. Two superduplex stainless steel steels UNS S32750 with similar composition but quite different grain sizes were analysed in order to evaluate the influence of this microstructural feature.
Grain refinement of pure aluminium and Al–7Si with Al–3B master alloy
Authors: Birol Y
Published: November 2011

The potential of AlB2 particles in the grain refinement of aluminium alloys with and without Si was investigated in an effort to develop potent grain refiners for Al–Si based foundry alloys. The Al–Si alloys are grain refined with the Al–3B alloy, whereas pure aluminium is not. The cast grain size in the former decreases with increasing Si content. The addition of 200 ppm B into the Al–7Si alloy, the basis of most commercial foundry alloys, produces remarkably fine grains with no fading effect. The Al–B system relies on a eutectic reaction L→ α (Al)+AlB2 at 659·7°C to offer grain refinement, which occurs predominantly via heterogeneous nucleation of α (Al) grains on AlB2 particles thus made available. The grain refinement starts at a critical Si content enough to depress the liquidus temperature of the alloy sufficiently below the eutectic reaction temperature. The grain refining efficiency improves with increasing Si content owing to a decreasing liquidus temperature, which in turn facilitates the formation of an increasing number of solid nuclei. Alloys with insufficient level of Si to displace the liquidus temperature of the alloy below the eutectic reaction temperature cannot take advantage of this reaction and thus enjoy grain refinement. This is clearly why pure aluminium with a liquidus point above the eutectic reaction temperature is not grain refined with the Al–3B alloy at all.
Laser weld pool management through diffractive holographic optics
Authors: Kell J , Tyrer J R , Higginson R L , Jones J C , Noden S
Published: November 2011

Conduction laser welding involves initiating a melt pool by exposure to high power laser induced light and controlled thermal conduction. Existing welding techniques generally provide enough energy to join the component but have no real control over the melt pool. This process can invariably lead to overheating in adjacent areas or even the melt pool itself, often causing unavoidable effects, such as ‘burn through’. The present work presents a procedure in which a desired melt pool shape is conceived, and a bespoke beam irradiance distribution is designed to match. The beam is shaped not by conventional lenses but by a diffractive holographic optical element (DHOE). The DHOE utilises holography to wholly create highly complex three-dimensional energy distributions through constructive and destructive interference. This technique allows novel beam irradiance distributions to be applied to conduction mode laser welding, with the melt pool transverse profile being shaped to a specific design. Holographic conduction laser welding has been shown to be successful and represents a significant step forward in the industry, as demonstrated in this case in both mild and stainless steels. The fusion zone is shown to be particularly influenced by the shape of the illuminating laser beam profile, and many of the welds demonstrate a highly novel weld profile because of this. The use of a bespoke beam irradiance distribution allows control of the heat flow to the workpiece, and this allows greater control over material migration due to surface tension effects. Many of the welds demonstrate unique surface solidification patterns directly linked to the beam profile used. The DHOE also presents a number of additional advantages, such as an increased usable depth of field, allowing for less stringent set-up tolerances. Comprehensive metallography has been performed on samples of these welds through the use of optical microscopy, electron microscopy, electron backscatter diffraction and energy dispersive (X-ray) spectroscopy. These techniques offer in depth analysis of crystal size, shape, orientation and phase. By incorporating DHOEs into a laser welding process, not only does the melt pool shape become controllable, but also the crystal growth is highly influenced. Many of the undesirable attributes of a conventional laser weld are reduced by using a beam distribution created by a DHOE, bringing the microstructure of the weld pool closer to that of the parent material.
Microstructural characterisation of deformation behaviour of nickel base superalloy IN625
Authors: Behjati P , Asgari S
Published: November 2011

Simple compression and microscopy techniques were employed to characterise the microstructural origin of the deformation behaviour of nickel base superalloy IN625 during large strain testing. The alloy exhibited a four-stage strain hardening response similar to that previously reported for low stacking fault energy face centred cubic alloys. At strains lower than about −0·06 (stage A), a falling regime of the hardening rate was observed. This stage was followed by a second stage (stage B) of slow increasing hardening rate, which was found to be coincident with the formation of Lomer–Cottrell locks. The second falling regime of strain hardening (stage C) was seen in the strain range of −0·25 to −0·65. The occurrence of this stage was attributed to the increasing ease of dislocation cross-slip with increasing strain and consequently to the decreasing Lomer–Cottrell lock efficiency in hindering dislocation movement. Beyond a strain of −0·65, a final slightly constant hardening regime (stage D) was developed. The initiation of this stage was concurrent with the onset of deformation twinning in the microstructure.
On material flow and aspects of structural modification during direct and indirect extrusion of aluminium alloy
Authors: Niu L J , Velay X , Sheppard Terry
Published: November 2011

In this paper, both direct and indirect extrusions are simulated using a viscoplastic constitutive model. The simulated velocity fields for both direct and indirect extrusions are discussed and compared with experimental results. Advanced numerical techniques are used to trace backward and forward discrete particles of the billet. The effect of friction on the material flow is discussed. Back-end defects are simulated and practical methodologies are derived to minimise such defects using finite element modelling (FEM). Peak loads, temperatures and strain rate distribution are also compared between direct and indirect extrusions. Numerical subroutines have been developed and integrated into the FEM software in order to introduce the possibility of prediction of microstructural evolution. The results of such numerical simulations to increase productivity within the extrusion industry are currently limited only by the lack of sufficient physical metallurgical detail and by obstacles preventing the FEM simulation to be directly applied. This aspect is discussed in some detail.
Study on preparation of Co–Pt–W alloy films by electrodeposition
Authors: Yu Y D , Lou J W , Li W , Sun L X , Ge H L , Wei G Y
Published: November 2011

Co–Pt–W alloy films were prepared by the electroplating method to replace costly sputtering on a copper substrate. Effects of different pH values and current densities on composition, microstructure and magnetic properties of films were investigated. With the rise in pH values, the amounts of tungsten and cobalt decrease simultaneously as a result of less tungstate oxides in higher OH– concentration solution. Almost all the deposited films were crystalline and formed fcc CoPt(111) and hcp CoPt(002). Co–Pt–W alloy films intend to change from fcc to hcp structure when the current density was >20 mA cm−2. It was found that hcp structures of Co–Pt–W alloy films possess high coercivity performance. Moreover, higher pH values induced lower saturation magnetisation while higher current densities could result in larger saturation magnetisation. Dissimilar surface morphology could be detected under different current densities. With increasing the current density, grains of films tend to agglomerate and grow perpendicularly to substrate. Bigger agglomerated particles and ‘hill-like’ structure could be observed when the current density was up to 30 mA cm−2.
Effect of rare earth metals on solidification behaviour in nickel based superalloy
Authors: Pan X L , Yu H Y , Tu G F , Sun W R , Hu Z Q
Published: November 2011

The effect of rare earth metals (REMs) on the microstructure and segregation during solidification in a highly alloyed Ni based superalloy was investigated. Rare earth metals considerably decrease the amounts of coarse columnar grains and increase the amounts of equiaxed grains. They are segregated to the interdendritic regions mainly as the precipitate of Ni5Ce. Both the dimension and distribution of γ′ particles and MC carbide are modified by REM. Eutectic ( γ+ γ′), Laves phase, δ phase and σ phase are precipitated in the interdendritic regions because of the serious segregation of niobium and titanium aggravated by REM. The differential thermal analysis indicates that the precipitation temperature of phases and the solidification sequence of the superalloy can be changed due to the additions of REM.
Development of texture during ARB in metal matrix composite
Authors: Jamaati R , Toroghinejad M R , Hoseini M , Szpunar J A
Published: November 2011

In the present study, the accumulative roll bonding (ARB) process was used as a technique for manufacturing aluminium–alumina composites. Textural evolution during the ARB process of composites was evaluated using X-ray diffraction. After the first ARB cycle, copper {112}〈111〉 and brass {011}〈211〉 were the major texture components. However, with the progress of deformation after 5 cycles, the components transformed completely, and the rotated cube {001}〈110〉 component became dominant, which remained as the major component in higher cycles (ninth and thirteenth). This shear texture was developed due to the shear deformation induced by the high level of friction between the rolls and the strips. Generally, the intensity of all the texture components, except that of the rotated cube, was very weak. This result is attributed to the presence of second phase particles.
Effects of spiral geometries on grain selection during casting of single crystal superalloys
Authors: Gao S F , Liu L , Zhao X B , Huang T W , Zhang J , Fu H Z
Published: November 2011

Grain texture evolution in starter block during single crystal (SX) casting with a grain selector had been investigated. Several spiral grain selectors with different spiral geometries were designed to investigate the effects of spiral geometries on grain selection in spiral passage. The results indicated that the percentage of grains with a deviation angle of <10° from the axial orientation increased simultaneously with distance from the chill plate. When the distance reached 36·1 mm, nearly 90 of the grains’ misorientations were <10°, and the minor grains deviated >12°. As the spiral angle θ and the spiral thickness T decrease, the SX structure occurred at the lower position of the grain selector. In addition, it was concluded that the SX structure cannot be selected when the spiral angle is <15°. Moreover, the effect of spiral geometries on grain selection has also been discussed.
Microscopy of heat treated titanium alloy BT16
Authors: Wu G Q , Song H , Sha W , Zhang Z G
Published: November 2011

Metallographic characterisation is combined with statistical analysis to study the microstructure of a BT16 titanium alloy after different heat treatment processes. It was found that the length, width and aspect ratio of α plates in this alloy follow the three-parameter Weibull distribution. Increasing annealing temperature or time causes the probability distribution of the length and the width of α plates to tend toward a normal distribution. The phase transformation temperature of the BT16 titanium alloy was found to be 875±5°C.
Molecular markers to characterize the hermaphroditic reproductive system of the planarian Schmidtea mediterranea
Authors: Chong Tracy , Stary Joel M , Wang Yuying , Newmark Phillip A
Published: November 2011

Background

The freshwater planarian Schmidtea mediterranea exhibits two distinct reproductive modes. Individuals of the sexual strain are cross-fertilizing hermaphrodites with reproductive organs that develop post-embryonically. By contrast, individuals of the asexual strain reproduce exclusively by transverse fission and fail to develop reproductive organs. These different reproductive strains are associated with distinct karyotypes, making S. mediterranea a useful model for studying germline development and sexual differentiation.

Results

To identify genes expressed differentially between these strains, we performed microarray analyses and identified >800 genes that were upregulated in the sexual planarian. From these, we characterized 24 genes by fluorescent in situ hybridization (FISH), revealing their expression in male germ cells or accessory reproductive organs. To identify additional markers of the planarian reproductive system, we also used immuno- and fluorescent lectin staining, identifying several antibodies and lectins that labeled structures associated with reproductive organs.

Conclusions

Collectively, these cell-type specific markers will enable future efforts to characterize genes that are important for reproductive development in the planarian.
Association between carotid area calcifications and periodontal risk: a cross sectional study of panoramic radiographic findings
Authors: Tiller Ralph , Bengel Wolfgang , Rinke Sven , Ziebolz Dirk
Published: November 2011

Background

The aim was to investigate the extent to which it is possible to diagnose suspected carotid calcification from dental panoramic radiography (PR) and to establish an association to periodontal risk.

Methods

824 PRs from one dental practice were investigated. Parameters considered were gender, age, bone loss - age index, tooth loss, periodontal risk and suspected carotid calcification (left, right, both sides). Periodontal risk was classified: low risk (under 4 missing teeth, bone loss - age index under 0.5), moderate risk (5 to 8 missing teeth and/or bone loss - age index 0.5 to 1.0) and high risk (more than 9 missing teeth and or bone loss - age index greater than 1.0).

Results

Of 824 patients, 349 were male (42.4%) and 475 female (57.6%); the mean age was 48.32 ± 16.52 years. In 9.0% (n = 74) of PRs, suspected carotid calcification was diagnosed (right: 5.5%, left: 2.3%, both sides: 1.2%). The mean tooth loss was 4.16 ± 5.39 teeth. In the case of 282 patients (34.2%), there was a low, in 335 patients (40.7%) a moderate, and in 207 patients (25.1%) a high periodontal risk. There was a significant correlation found between number of cases of suspected carotid calcification and periodontal risk, tooth loss and age (p = 0.0001). However, only age showed a significant association (OR: 4.9; CI: 2.4-9.8; p < 0.0001) in contrast to periodontal risk (OR 1.4; CI: 0.9-2.4).

Conclusion

PR can provides indication of carotid calcification as a secondary (chance) finding. In addition, periodontal risk may be correlated with positive findings of carotid calcification.
Immunohistochemical localization of hepatopancreatic phospholipase in gastropods mollusc, Littorina littorea and Buccinum undatum digestive cells
Authors: Zarai Zied , Boulais Nicholas , Marcorelles Pascale , Gobin Eric , Bezzine Sofiane , Mejdoub Hafedh , Gargouri Youssef
Published: November 2011

Background

Among the digestive enzymes, phospholipase A2 (PLA2) hydrolyzes the essential dietary phospholipids in marine fish and shellfish. However, we know little about the organs that produce PLA2, and the ontogeny of the PLA2-cells. Accordingly, accurate localization of PLA2 in marine snails might afford a better understanding permitting the control of the quality and composition of diets and the mode of digestion of lipid food.

Results

We have previously producted an antiserum reacting specifically with mSDPLA2. It labeled zymogen granules of the hepatopancreatic acinar cells and the secretory materials of certain epithelial cells in the depths of epithelial crypts in the hepatopancreas of snail. To confirm this localization a laser capture microdissection was performed targeting stained cells of hepatopancreas tissue sections. A Western blot analysis revealed a strong signal at the expected size (30 kDa), probably corresponding to the PLA2.

Conclusions

The present results support the presence of two hepatopancreatic intracellular and extracellular PLA2 in the prosobranchs gastropods molluscs, Littorina littorea and Buccinum undatum and bring insights on their localizations.
Comparison of the effect of a CIDR-Select Synch versus a long-term CIDR based AI protocol on reproductive performance in multiparous dairy cows in Swiss dairy farms
Authors: Rudolph Jürn , Bruckmaier Rupert M , Kasimanickam Ramanathan , Steiner Adrian , Kirchhofer Marc , Hüsler Jürg , Hirsbrunner Gaby
Published: November 2011

Background

Synchronization programs have become standard in the dairy industry in many countries. In Switzerland, these programs are not routinely used for groups of cows, but predominantly as a therapy for individual problem cows. The objective of this study was to compare the effect of a CIDR-Select Synch and a 12-d CIDR protocol on the pregnancy rate in healthy, multiparous dairy cows in Swiss dairy farms.

Methods

Cows (N = 508) were randomly assigned to CIDR-Select Synch (N = 262) or 12-d CIDR (N = 246) protocols. Cows in the CIDR-Select Synch group received a CIDR and 2.5 ml of buserelin i.m. on d 0. On d 7, the CIDR insert was removed and 5 ml of dinoprost was administered i.m.. Cows in the 12-d CIDR group received the CIDR on d 0 and it was removed on d 12 (the routine CIDR protocol in Swiss dairies). On d 0 a milk sample for progesterone analysis was taken. Cows were inseminated upon observed estrus. Pregnancy was determined at or more than 35 days after artificial insemination. As a first step, the two groups were compared as to indication for treatment, breed, stud book, stall, pasture, and farmer's business using chi square tests or Fisher's exact test. Furthermore, groups were compared as to age, DIM, number of AI's, number of cows per farm, and yearly milk yield per cow using nonparametric ANOVA. A multiple logistic model was used to relate the success of the protocols to all of the available factors; in particular treatment (CIDR-Select Synch/12-d CIDR), milk progesterone value, age, DIM, previous treatment of the uterus, previous gynecological treatment, and number of preceding inseminations.

Results

The pregnancy rate was higher in cows following the CIDR-Select Synch compared to the 12-d CIDR protocol (50.4% vs. 22.4%; P < 0.0001).

Conclusion

The CIDR-Select Synch protocol may be highly recommended for multiparous dairy cows. The reduced time span of the progesterone insert decreased the number of days open, improved the pregnancy rate compared to the 12-d CIDR protocol and the cows did not to have to be handled more often.
Drug-eluting Ti wires with titania nanotube arrays for bone fixation and reduced bone infection
Authors: Gulati Karan , Aw Moom Sinn , Losic Dusan
Published: November 2011

Current bone fixation technology which uses stainless steel wires known as Kirschner wires for fracture fixing often causes infection and reduced skeletal load resulting in implant failure. Creating new wires with drug-eluting properties to locally deliver drugs is an appealing approach to address some of these problems. This study presents the use of titanium [Ti] wires with titania nanotube [TNT] arrays formed with a drug delivery capability to design alternative bone fixation tools for orthopaedic applications. A titania layer with an array of nanotube structures was synthesised on the surface of a Ti wire by electrochemical anodisation and loaded with antibiotic (gentamicin) used as a model of bone anti-bacterial drug. Successful fabrication of TNT structures with pore diameters of approximately 170 nm and length of 70 μm is demonstrated for the first time in the form of wires. The drug release characteristics of TNT-Ti wires were evaluated, showing a two-phase release, with a burst release (37%) and a slow release with zero-order kinetics over 11 days. These results confirmed our system's ability to be applied as a drug-eluting tool for orthopaedic applications. The established biocompatibility of TNT structures, closer modulus of elasticity to natural bones and possible inclusion of desired drugs, proteins or growth factors make this system a promising alternative to replace conventional bone implants to prevent bone infection and to be used for targeted treatment of bone cancer, osteomyelitis and other orthopaedic diseases.
"Soft and rigid" dithiols and Au nanoparticles grafting on plasma-treated polyethyleneterephthalate
Authors: Švorčík Václav , Kolská Zdeňka , Kvítek Ondřej , Siegel Jakub , Řezníčková Alena , Řezanka Pavel , Záruba Kamil
Published: November 2011

Surface of polyethyleneterephthalate (PET) was modified by plasma discharge and subsequently grafted with dithiols (1, 2-ethanedithiol (ED) or 4, 4'-biphenyldithiol) to create the thiol (-SH) groups on polymer surface. This "short" dithiols are expected to be fixed via one of -SH groups to radicals created by the plasma treatment on the PET surface. "Free" -SH groups are allowed to interact with Au nanoparticles. X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR) and electrokinetic analysis (EA, zeta potential) were used for the characterization of surface chemistry of the modified PET. Surface morphology and roughness of the modified PET were studied by atomic force microscopy (AFM). The results from XPS, FTIR, EA and AFM show that the Au nanoparticles are grafted on the modified surface only in the case of biphenyldithiol pretreatment. The possible explanation is that the "flexible" molecule of ethanedithiol is bounded to the activated PET surface with both -SH groups. On the contrary, the "rigid" molecule of biphenyldithiol is bounded via only one -SH group to the modified PET surface and the second one remains "free" for the consecutive chemical reaction with Au nanoparticle. The gold nanoparticles are distributed relatively homogenously over the polymer surface.
Outcomes of usual chiropractic, harm & efficacy, the ouch study: study protocol for a randomized controlled trial
Authors: Walker Bruce F , Losco Barrett , Clarke Brenton R , Hebert Jeff , French Simon , Stomski Norman J
Published: November 2011

Background

Previous studies have demonstrated that adverse events occur during chiropractic treatment. However, because of these studies design we do not know the frequency and extent of these events when compared to sham treatment. The principal aims of this study are to establish the frequency and severity of adverse effects from short term usual chiropractic treatment of the spine when compared to a sham treatment group. The secondary aim of this study is to establish the efficacy of usual short term chiropractic care for spinal pain when compared to a sham intervention.

Methods

One hundred and eighty participants will be randomly allocated to either usual chiropractic care or a sham intervention group. To be considered for inclusion the participants must have experienced non-specific spinal pain for at least one week. The study will be conducted at the clinics of registered chiropractors in Western Australia. Participants in each group will receive two treatments at intervals no less than one week. For the usual chiropractic care group, the selection of therapeutic techniques will be left to the chiropractors' discretion. For the sham intervention group, de-tuned ultrasound and de-tuned activator treatment will be applied by the chiropractors to the regions where spinal pain is experienced. Adverse events will be assessed two days after each appointment using a questionnaire developed for this study. The efficacy of short term chiropractic care for spinal pain will be examined at two week follow-up by assessing pain, physical function, minimum acceptable outcome, and satisfaction with care, with the use of the following outcome measures: Numerical Rating Scale, Functional Rating Index, Neck Disability Index, Minimum Acceptable Outcome Questionnaire, Oswestry Disability Index, and a global measure of treatment satisfaction. The statistician, outcome assessor, and participants will be blinded to treatment allocation.

Trial registration

Australia and New Zealand Clinical Trials Register (ANZCTR): ACTRN12611000542998
Significant impact of different oxygen breathing conditions on noninvasive in vivo tumor-hypoxia imaging using [18F]-fluoro-azomycinarabino-furanoside ([18F]FAZA)
Authors: Maier Florian C , Kneilling Manfred , Reischl Gerald , Cay Funda , Bukala Daniel , Schmid Andreas , Judenhofer Martin S , Röcken Martin , Machulla Hans-Jürgen , Pichler Bernd J
Published: November 2011

Background

[18F]FAZA is a PET biomarker with great potential for imaging tumor hypoxia. Aim of our study was to compare [18F]FAZA uptake in mice with subcutaneous exogenous CT26 colon carcinomas and endogenous polyoma middle-T (PyV-mT) mammary carcinomas and to analyze the influence of different breathing protocols in CT26 colon carcinomas as well as the reversibility or irreversibility of [18F]FAZA uptake.

Methods

We injected subcutaneous CT26 colon carcinoma or polyomavirus middle-T (PyV-mT) mammary carcinoma-bearing mice intravenously with18F-FAZA and performed PET scans 1-3 h post injection (p.i.). To analyze the impact of oxygen supply in CT26 carcinomas we used three different breathing protocols: (P0) air; (P1) 100% oxygen 1 h prior injection until 3 h p.i.; (P2) 100% oxygen breathing starting 2 min prior tracer injection until 1 h p.i. and during the PET scans; mice were breathing air between the 2 h and 3 h 10 min static scans. Normalized PET images were analyzed by using defined regions of interest. Finally, some mice were dissected for pimonidazole immunohistochemistry.

Results

There was no difference in18F-FAZA uptake 1-3 h p.i. between the two carcinoma types (CT26: 1.58 ± 0.45%ID/cc; PyV-mT: 1.47 ± 0.89%ID/cc, 1 h p.i., tumor size < 0.5 cm3). We measured a significant tracer clearance, which was more pronounced in muscle tissue (P0). The [18F]FAZA tumor-to-muscle-ratios in CT26 colon carcinoma-bearing mice 2 h and 3 h, but not 1 h p.i. were significantly higher when the mice breathed air (P0: 3.56 ± 0.55, 3 h) compared to the oxygen breathing protocols (P1: 2.45 ± 0.58; P2: 2.77 ± 0.42, 3 h). Surprisingly, the breathing protocols P1 and P2 showed no significant differences in T/M ratios, thus indicating that the crucial [18F]FAZA uptake phase is during the first hour after [18F]FAZA injection. Importantly, the muscle clearance was not affected by the different oxygen breathing conditions while the tumor clearance was lower when mice were breathing air.

Conclusion

Exogenous CT26 colon carcinomas and endogenous polyoma middle-T (PyV-mT) mammary carcinomas showed no differences in [18F]FAZA uptake 1-3 h p.i. Our analysis using various breathing protocols with air (P0) and with pure oxygen (P1, P2) clearly indicate that [18F]FAZA is an appropriate PET biomarker for in vivo analysis of hypoxia revealing an enhanced tracer uptake in tumors with reduced oxygen supply. [18F]FAZA uptake was independent of tumor-type.