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Evaluation of Microstructure and Properties for Multi-Materials Laser Densification of Dental Restoration 159
Traditional dental restorations are produced by the porcelain-fused-to-metal (PFM) process, in which a dental restoration is cast from a metallic alloy and then covered with dental porcelains by several firing processes, which is both labor intensive and expensive. In this paper, the feasibility of dental restorations is investigated using a multi-materials laser densification
(MMLD) process. To evaluate the effectiveness of the MMLD process, nickel powders and commercial dental porcelain powders are laser densified using YAG and CO2 lasers respectively. Effects of processing parameters, e.g. laser scanning rate and target temperature, are evaluated and the microstructure of processed nickel and porcelain materials are characterized for the
optimization of laser densification. Results indicate that densities of laser processed nickel and dental porcelain are strongly dependent of processing parameters. Fully dense layers are achievable with proper processing conditions.Mechanical Engineerin
The pre-main sequence binary HK Ori : Spectro-astrometry and EXPORT data
In this paper we present multi-epoch observations of the pre-main sequence
binary HK Ori. These data have been drawn from the EXPORT database and are
complemented by high quality spectro-astrometric data of the system. The
spectroscopic data appear to be very well represented by a combination of an A
dwarf star spectrum superposed on a (sub-)giant G-type spectrum. The radial
velocity of the system is consistent with previous determinations, and does not
reveal binary motion, as expected for a wide binary. The spectral, photometric
and polarimetric properties and variability of the system indicate that the
active object in the system is a T Tauri star with UX Ori characteristics. The
spectro-astrometry of HK Ori is sensitive down to milli-arcsecond scales and
confirms the speckle interferometric results from Leinert et al. The
spectro-astrometry allows with fair certainty the identification of the active
star within the binary, which we suggest to be a G-type T Tauri star based on
its spectral characteristics.Comment: MNRAS in press 8 pages 7 figure
Long-term health status and trajectories of seriously injured patients: A population-based longitudinal study
Improved understanding of the quality of survival of patients is crucial in evaluating trauma care, understanding recovery patterns and timeframes, and informing healthcare, social, and disability service provision. We aimed to describe the longer-term health status of seriously injured patients, identify predictors of outcome, and establish recovery trajectories by population characteristics.A population-based, prospective cohort study using the Victorian State Trauma Registry (VSTR) was undertaken. We followed up 2,757 adult patients, injured between July 2011 and June 2012, through deaths registry linkage and telephone interview at 6-, 12-, 24-, and 36-months postinjury. The 3-level EuroQol 5 dimensions questionnaire (EQ-5D-3L) was collected, and mixed-effects regression modelling was used to identify predictors of outcome, and recovery trajectories, for the EQ-5D-3L items and summary score. Mean (SD) age of participants was 50.8 (21.6) years, and 72% were male. Twelve percent (n = 333) died during their hospital stay, 8.1% (n = 222) of patients died postdischarge, and 155 (7.0%) were known to have survived to 36-months postinjury but were lost to follow-up at all time points. The prevalence of reporting problems at 36-months postinjury was 37% for mobility, 21% for self-care, 47% for usual activities, 50% for pain/discomfort, and 41% for anxiety/depression. Continued improvement to 36-months postinjury was only present for the usual activities item; the adjusted relative risk (ARR) of reporting problems decreased from 6 to 12 (ARR 0.87, 95% CI: 0.83-0.90), 12 to 24 (ARR 0.94, 95% CI: 0.90-0.98), and 24 to 36 months (ARR 0.95, 95% CI: 0.95-0.99). The risk of reporting problems with pain or discomfort increased from 24- to 36-months postinjury (ARR 1.06, 95% CI: 1.01, 1.12). While loss to follow-up was low, there was responder bias with patients injured in intentional events, younger, and less seriously injured patients less likely to participate; therefore, these patient subgroups were underrepresented in the study findings.The prevalence of ongoing problems at 3-years postinjury is high, confirming that serious injury is frequently a chronic disorder. These findings have implications for trauma system design. Investment in interventions to reduce the longer-term impact of injuries is needed, and greater investment in primary prevention is needed
Using Cepheids to determine the galactic abundance gradient I. The solar neighbourhood
A number of studies of abundance gradients in the galactic disk have been
performed in recent years. The results obtained are rather disparate: from no
detectable gradient to a rather significant slope of about -0.1 dex kpc -1. The
present study concerns the abundance gradient based on the spectroscopic
analysis of a sample of classical Cepheids. These stars enable one to obtain
reliable abundances of a variety of chemical elements. Additionally, they have
well determined distances which allow an accurate determination of abundance
distributions in the galactic disc. Using 236 high resolution spectra of 77
galactic Cepheids, the radial elemental distribution in the galactic disc
between galactocentric distances in the range 6-11 kpc has been investigated.
Gradients for 25 chemical elements (from carbon to gadolinium) are derived...Comment: 28 pages, 14 postscript figures, LaTeX, uses Astronomy and
Astrophysics macro aa.cls, graphicx package, to be published in Astronomy and
Astrophysics (2002) also available at
http://www.iagusp.usp.br/~maciel/index.htm
Dynamics of the circumstellar gas in the Herbig Ae stars BF Orionis, SV Cephei, WW Vulpeculae and XY Persei
We present high resolution (lambda / Delta_lambda = 49000) echelle spectra of
the intermediate mass, pre-main sequence stars BF Ori, SV Cep, WW Wul and XY
Per. The spectra cover the range 3800-5900 angstroms and monitor the stars on
time scales of months and days. All spectra show a large number of Balmer and
metallic lines with variable blueshifted and redshifted absorption features
superimposed to the photospheric stellar spectra. Synthetic Kurucz models are
used to estimate rotational velocities, effective temperatures and gravities of
the stars. The best photospheric models are subtracted from each observed
spectrum to determine the variable absorption features due to the circumstellar
gas; those features are characterized in terms of their velocity, v, dispersion
velocity, Delta v, and residual absorption, R_max. The absorption components
detected in each spectrum can be grouped by their similar radial velocities and
are interpreted as the signature of the dynamical evolution of gaseous clumps
with, in most cases, solar-like chemical composition. This infalling and
outflowing gas has similar properties to the circumstellar gas observed in UX
Ori, emphasizing the need for detailed theoretical models, probably in the
framework of the magnetospheric accretion scenario, to understand the complex
environment in Herbig Ae (HAe) stars. WW Vul is unusual because, in addition to
infalling and outflowing gas with properties similar to those observed in the
other stars, it shows also transient absorption features in metallic lines with
no obvious counterparts in the hydrogen lines. This could, in principle,
suggest the presence of CS gas clouds with enhanced metallicity around WW Vul.
The existence of such a metal-rich gas component, however, needs to be
confirmed by further observations and a more quantitative analysis.Comment: 21 pages, 13 figures. Accepted for publication by Astronomy &
Astrophysic
EXPORT: optical photometry and polarimetry of Vega-type and pre-main sequence stars
This paper presents optical UBVRI broadband photo-polarimetry of the EXPORT
sample obtained at the 2.5m Nordic Optical Telescope. The database consists of
multi-epoch photo-polarimetry of 68 pre-main-sequence and main-sequence stars.
An investigation of the polarization variability indicates that 22 objects are
variable at the 3sigma level in our data. All these objects are pre-main
sequence stars, consisting of both T Tauri and Herbig Ae/Be objects while the
main sequence, Vega type and post-T Tauri type objects are not variable. The
polarization properties of the variable sources are mostly indicative of the
UXOR-type behaviour; the objects show highest polarization when the brightness
is at minimum. We add seven new objects to the class of UXOR variables (BH Cep,
VX Cas, DK Tau, HK Ori, LkHa 234, KK Oph and RY Ori). The main reason for their
discovery is the fact that our data-set is the largest in its kind, indicating
that many more young UXOR-type pre-main sequence stars remain to be discovered.
The set of Vega-like systems has been investigated for the presence of
intrinsic polarization. As they lack variability, this was done using indirect
methods, and apart from the known case of BD +31.643, the following stars were
found to be strong candidates to exhibit polarization due to the presence of
circumstellar disks: 51 Oph, BD +31.643C, HD 58647 and HD 233517.Comment: A&A accepte
Discrimination of Methionine Sulfoxide and Sulfone by Human Neutrophil Elastase
Human neutrophil elastase (HNE) is a uniquely destructive serine protease with the ability to unleash a wave of proteolytic activity by destroying the inhibitors of other proteases. Although this phenomenon forms an important part of the innate immune response to invading pathogens, it is responsible for the collateral host tissue damage observed in chronic conditions such as chronic obstructive pulmonary disease (COPD), and in more acute disorders such as the lung injuries associated with COVID-19 infection. Previously, a combinatorially selected activity-based probe revealed an unexpected substrate preference for oxidised methionine, which suggests a link to oxida-tive pathogen clearance by neutrophils. Here we use oxidised model substrates and inhibitors to confirm this observation and to show that neutrophil elastase is specifically selective for the di-oxygenated methionine sulfone rather than the mono-oxygenated methionine sulfoxide. We also posit a critical role for ordered solvent in the mechanism of HNE discrimination between the two oxidised forms methionine residue. Preference for the sulfone form of oxidised methionine is especially significant. While both host and pathogens have the ability to reduce methionine sulfoxide back to methionine, a biological pathway to reduce methionine sulfone is not known. Taken to-gether, these data suggest that the oxidative activity of neutrophils may create rapidly cleaved elas-tase “super substrates” that directly damage tissue, while initiating a cycle of neutrophil oxidation that increases elastase tissue damage and further neutrophil recruitment
Serial killing and the postmodern self
© 2006 by SAGE PublicationsThe self has been a consistently central theme in philosophy and the social sciences and, in the last decades of the 20th century, the fragmentation of the modern self has engendered extensive academic commentary. In order to contribute to current discussions about self, it is perhaps most effective to map the transformation of a single representation of the self in contemporary culture. As a cultural ‘flashpoint’, the serial killer could provide an apposite analytical focus. Drawing critically on Mark Seltzer's work on serial killers this article interprets serial killing as a form of commodified transgression. In contrast to the modern self, established through state-institutionalized routines, serial killers establish their identities through ecstatic intercourse. These acts of bodily and ethical transgression are facilitated by the use of commodities. In this way, the serial killer represents a self which is consistent with the colonization of interpersonal relations by multinational capital. The serial killer signifies the appearance of a postmodern self
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