bluuebunny/crossref_metadata_2025 huggingface dataset:
Soil CO2 efflux of two silver birch clones exposed to elevated CO2 and O3 levels during three growing seasons
Authors: Kasurinen Anne , Kokko‐Gonzales Paula , Riikonen Johanna , Vapaavuori Elina , Holopainen Toini
Published: October 2004

In the present open‐top chamber experiment, two silver birch clones (Betula pendula Roth, clone 4 and clone 80) were exposed to elevated levels of carbon dioxide (CO2) and ozone (O3), singly and in combination, and soil CO2 efflux was measured 14 times during three consecutive growing seasons (1999–2001). In the beginning of the experiment, all experimental trees were 7 years old and during the experiment the trees were growing in sandy field soil and fertilized regularly. In general, elevated O3 caused soil CO2 efflux stimulation during most measurement days and this stimulation enhanced towards the end of the experiment. The overall soil respiration response to CO2 was dependent on the genotype, as the soil CO2 efflux below clone 80 trees was enhanced and below clone 4 trees was decreased under elevated CO2 treatments. Like the O3 impact, this clonal difference in soil respiration response to CO2 increased as the experiment progressed. Although the O3 impact did not differ significantly between clones, a significant time × clone × CO2× O3 interaction revealed that the O3‐induced stimulation of soil respiration was counteracted by elevated CO2 in clone 4 on most measurement days, whereas in clone 80, the effect of elevated CO2 and O3 in combination was almost constantly additive during the 3‐year experiment. Altogether, the root or above‐ground biomass results were only partly parallel with the observed soil CO2 efflux responses. In conclusion, our data show that O3 impacts may appear first in the below‐ground processes and that relatively long‐term O3 exposure had a cumulative effect on soil CO2 efflux. Although the soil respiration response to elevated CO2 depended on the tree genotype as a result of which the O3 stress response might vary considerably within a single tree species under elevated CO2, the present experiment nonetheless indicates that O3 stress is a significant factor affecting the carbon cycling in northern forest ecosystems.
Cultivation, nitrogen fertilization, and set‐aside effects on methane uptake in a drained marsh soil in Northeast China
Authors: Ding Weixin , Cai Zucong , Tsuruta Haruo
Published: October 2004

To evaluate the effect of cultivation, nitrogen fertilizer, and set aside on CH4 uptake after drained marshland was converted into agricultural fields, CH4 fluxes and CH4 concentrations in soil gas were in situ measured in a drained marsh soil, a set‐aside cultivated soil, and cultivated soils in Sanjiang Plain of Northeast China in August 2001. Over the measuring period, the highest CH4 uptake rate was 120.7±6.2 μg CH4 m−2 h−1 in the drained marsh soil and the lowest was 29.5±4.9 μg CH4 m−2 h−1 in the set‐aside cultivated soil, showing that there was no significant recovery of CH4 uptake ability 5 years after cultivation activity was stopped. CH4 uptake rates were significantly less in the cultivated soils than in the drained marsh soil by 30.1–74.6%, which resulted mainly from cultivation and partly from nitrogen addition. A significantly negative correlation between CH4 flux and bulk density in the cultivated soils tilled by machine suggests that cultivation reduced CH4 uptake through compaction, because of the enhanced diffusion resistance for CH4 and O2. Nitrogen fertilization slowly reduced but persistently affected CH4 uptake even after long‐term application of nitrogen.
Human‐induced changes in US biogenic volatile organic compound emissions: evidence from long‐term forest inventory data
Authors: Purves Drew W. , Caspersen John P. , Moorcroft Paul R. , Hurtt George C. , Pacala Stephen W.
Published: October 2004

Volatile organic compounds (VOCs) emitted by woody vegetation influence global climate forcing and the formation of tropospheric ozone. We use data from over 250 000 re‐surveyed forest plots in the eastern US to estimate emission rates for the two most important biogenic VOCs (isoprene and monoterpenes) in the 1980s and 1990s, and then compare these estimates to give a decadal change in emission rate. Over much of the region, particularly the southeast, we estimate that there were large changes in biogenic VOC emissions: half of the grid cells (1°× 1°) had decadal changes in emission rate outside the range −2.3% to +16.8% for isoprene, and outside the range 0.2–17.1% for monoterpenes. For an average grid cell the estimated decadal change in heatwave biogenic VOC emissions (usually an increase) was three times greater than the decadal change in heatwave anthropogenic VOC emissions (usually a decrease, caused by legislation). Leaf‐area increases in forests, caused by anthropogenic disturbance, were the most important process increasing biogenic VOC emissions. However, in the southeast, which had the largest estimated changes, there were substantial effects of ecological succession (which decreased monoterpene emissions and had location‐specific effects on isoprene emissions), harvesting (which decreased monoterpene emissions and increased isoprene emissions) and plantation management (which increased isoprene emissions, and decreased monoterpene emissions in some states but increased monoterpene emissions in others). In any given region, changes in a very few tree species caused most of the changes in emissions: the rapid changes in the southeast were caused almost entirely by increases in sweetgum (Liquidambar styraciflua) and a few pine species. Therefore, in these regions, a more detailed ecological understanding of just a few species could greatly improve our understanding of the relationship between natural ecological processes, forest management, and biogenic VOC emissions.
Primary adrenal insufficiency in childhood and adolescence: Advances in diagnosis and management
Authors: Simm PJ , McDonnell CM , Zacharin MR
Published: October 2004

Objectives:  Primary adrenal insufficiency occurring in childhood and adolescence is due to abnormalities of gland development, gland responsiveness, and steroid biosynthesis or target organ response. Causes include autoimmune Addison's disease, tuberculosis, HIV, adrenoleukodystrophy, adrenal hypoplasia congenita and syndromes including triple A and IMAGe. We aimed to define the causes of adrenal insufficiency for a cohort of children in Melbourne.

Methods:  We reviewed the frequency and variety of presentation of primary adrenal insufficiency to the Royal Children's Hospital over the past 10 years through an audit of patient records, collating demographic information, presentation and investigations.

Results:  Sixteen cases (13 male, 3 female) of primary adrenal insufficiency were diagnosed at this hospital between January 1993 and July 2003. Median age at presentation was 7.7 years (range: birth to 14.8 years). Symptoms at presentation included weakness, increased pigmentation, abdominal pain, nausea, developmental delay or a reduction in school performance. Four patients presented with adrenal crisis. Median adrenocorticotrophic hormone (ACTH) at diagnosis was 246 pmol/L (range 30−969 pmol/L). Autoantibodies were positive in five patients. Five patients had elevation of very long chain fatty acids. Five patients were diagnosed with autoimmune adrenal insufficiency, five with adrenal hypoplasia congenita, five with adrenoleukodystrophy and one with IMAGe syndrome.

Conclusions:  A high index of suspicion results in earlier detection and possible prevention of adrenal crisis with a reduction in associated morbidities. Definitive diagnosis is now possible for almost all cases of primary adrenal insufficiency using technologies for screening autoimmunity, adrenoleukodystrophy (ALD) and genetic screening.
Increased rates of ENT surgery among young children: Have clinical guidelines made a difference?
Authors: Rob MI , Westbrook JI , Taylor R , Rushworth RL
Published: October 2004

Objectives:  To examine the association between introduction of paediatric ear, nose and throat (ENT) surgery guidelines and population procedure rates. To determine changes in children's risk of undergoing ENT surgery.

Methods:  Trend analysis of incidence of myringotomy, tonsillectomy and adenoidectomy among New South Wales (NSW) children aged 0−14 between 1981 and mid 1999. Poisson regression models were used to estimate annual rates of change pre and postguidelines introduction and age/gender specific rates, and lifetable methods to determine risk of undergoing an ENT procedure by age 15.

Results:  ENT surgery rates increased by 21% over the study period. Children's risk of surgery increased from 17.9% in 1981 to 20.2% in 1998/99. Guideline introduction was associated with moderate short‐term decreases in rates. For tonsillectomy, rates decreased between 1981 and 1983, but then rose continually until the introduction of myringotomy guidelines in 1993, when they fell, only to recommence rising until the end of the study period. For myringotomy, rates rose annually from 1981 to 1992/93 and fell in the 3 years following guideline introduction, after which they rose again. Increases were almost exclusively restricted to children aged 0−4 and correspond with increased use of formal childcare. The prevalence of myringotomy by the age of 5 years rose from 5.6% of children born in 1988/89 to 6.4% of those born in 1994/95, and the prevalence of tonsillectomy from 2.4% to 2.7%.

Conclusions:  The risk of young Australian children undergoing ENT surgery increased significantly over the last two decades despite the introduction of guidelines and no evidence of an increase in otitis media, one condition prompting surgery. Surgery increased most among the very young. We hypothesize this is related to increasing use of childcare.
Perforation of jejunal duplication lined with ectopic gastric mucosa
Authors: Bazlul Karim ASM , Matiur Rahman MD , Kamal M
Published: October 2004

Abstract:  Alimentary tract duplications are rare congenital anomalies that occasionally contain ectopic gastric mucosa that secretes acid peptic juice and can cause pain, ulceration, bleeding and rarely perforation. We report a case of a 2‐year‐old girl who developed perforation of a jejunal duplication lined with ectopic gastric mucosa who was managed surgically.
Two Views of Accounting Measurement
Authors: Staubus George J.
Published: October 2004

The two views to be addressed here are the Chambers/Sydney view that accepts only one measurement method—current net realizable price—and the Staubus/mainstream view that accepts several measurement methods in the same financial report. These two views became well‐established in the literature of accounting in the 1960s and their proponents have clung tenaciously to their oft‐criticized positions for some forty years. However commendable their original expositions may have been, their continuing existence does no credit to the small coterie of accountants now interested in theory.

This article is aimed at ‘narrowing the areas of difference’ between adherents to the two views by isolating fundamental bases for them and exposing the reasoning supporting their structures. In a nutshell, they differ in their objectives and they can be expected to survive unless their adherents agree on the objectives of financial reporting.
Reporting and the Politics of Difference: (Non)Disclosure on Ethnic Minorities
Authors: Adams Carol A. , McPhail Ken J.
Published: October 2004

This article is based on two related research questions. First, what is the level of disclosure on ethnic minorities in the two sectors of the U.K. economy that historically have employed the most ethnic minorities: the banking and retail sectors? And secondly, what influences the (non)disclosure? It specifically investigates the level of disclosures from 1935 to 1998 and situates them within the changing social, political and economic context of this period. It is contended that the changing pattern of disclosure during this period can be understood with reference to changes in the political strategies for managing the threat of racism adopted by successive governments. The article provides some tentative theoretical reflections on the nature of the racism problematic and the way in which power may be seen to operate through (non)disclosure in this particular instance.
Desilication veins in the Cadillac Mountain granite (Maine, USA): a record of reversals in the SiO2 solubility of H2O‐rich vapour released during subsolidus cooling
Authors: NICHOLS* G. T. , WIEBE R. A.
Published: October 2004

Late‐stage hydrous fluids, which evolved during the cooling of the Cadillac Mountain granite, Maine, USA, produced narrow veins that transect the pluton. The vein margins contain microstructures transitional between granite and the vein centre. They preserve the vestige shapes of original Na‐rich alkali feldspar crystals that have been pseudomorphed by cordierite+quartz+K‐rich alkali feldspar. Closer to the centres of the veins, the minerals change from an outer zone with cordierite, hercynitic–galaxite spinel, minor corundum, K‐feldspar and plagioclase to an inner zone with remnant cordierite, hercynitic gahnite, strongly zoned almandine–spessartine garnet, chlorite and quartz. Three allochemical reactions are inferred to have occurred with the influx of hydrous fluids during the replacement process. Reaction (1) is Na‐rich alkali feldspar+iron ions in solution=Fe‐cordierite+quartz+K‐feldspar+sodium ions in solution. Reactions (2) and (3) occurred during desilication. Reaction (2) is Fe‐cordierite=hercynite+silica in solution, and reaction (3)isFe‐cordierite+water=corundum+iron hydroxide in solution+silicic acid in solution.Two independent techniques, experimental silica‐solubility data and spinel–cordierite thermobarometry, constrain the conditions of vein formation to c. 1.0 kbar and both methods indicate that the progressive mineral reactions occurred during cooling of the hydrous fluids from c. 775° to 400–340 °C. This cooling trend is consistent with the petrographic evidence, which demonstrates that reactions occurred before desilication, during desilication, and then diminished with a final phase of resilication. Although the veins are minor features of the Cadillac Mountain granite, they provide insight into the conditions that prevailed during cooling of the pluton, and similar features may be important for constraining the cooling history of shallow‐level plutonic complexes elsewhere.
A second natural occurrence of yoderite
Authors: JOHNSON S. P. , OLIVER* G. J. H.
Published: October 2004

A second example of yoderite has been discovered in whiteschists from the Southern Chewore Hills of northern Zimbabwe. The mineral is pale green in colour and occurs in an equilibrium assemblage with talc+chlorite+kyanite+dravite+hematite. There is no quartz present. Recalculated microprobe analyses give a structural formula of Mg2Al5.7Fe0.3Si4O18(OH)2, similar to that obtained for the type locality at Mautia Hill, Tanzania, i.e. Mg2Al5.6Fe0.4Si4O18(OH)2. Textural relationships and relative proportions of minerals suggest that the yoderite was formed by reaction between talc, chlorite, kyanite and hematite. Experimental evidence suggests high‐water‐pressure metamorphic conditions at temperatures exceeding a reaction curve that extends between 13 kbar at 590 °C and 21 kbar at 650 °C. The yoderite‐bearing whiteschist is associated with a 1.4 Ga dismembered ophiolite. It is proposed that this yoderite occurrence is associated with a relict subduction/suture zone.
Assessment and evaluation of individual prerequisites for dental education
Authors: Heintze U. , Radeborg K. , Bengtsson H. , Stenlåås A.
Published: October 2004

Since 2001 the School of Dentistry of Malmö University in Sweden has used an alternative admissions procedure based on results of an investigation supported by the Swedish Council for the Renewal of Undergraduate Education. The investigation concerned possibilities of predicting dental school performance on the basis of an interview, as well as tests of general intelligence, spatial ability, manual dexterity, empathy and social competence. Two groups of incoming students were followed from start to completion of their training. Significant relationships were found between (i) number of course examinations failed and poor results on interviews, as well as low scores on intelligence, spatial ability, and a test of spatial‐manual ability, (ii) good results in a pre‐clinical course in cavity preparation and high scores on spatial ability, (iii) assessments of high social competence during training and good results on interviews, as well as high scores on empathy and non‐verbal intelligence. Dropout from the study programme could not be predicted, possibly due to the varying reasons for it.
The role of exercise on long‐term effects of alloxan administered in neonatal rats
Authors: De Oliveira Camila Aparecida Machado , Luciano Eliete , De Mello Maria Alice Rostom
Published: October 2004

The present study was designed to analyse the effects of aerobic exercise on the metabolic effects of alloxan. Male Wistar newborn rats (2 days old) received alloxan (200 mg (kg body weight)−1) intraperitoneally (A rats). Vehicle‐injected rats were used as controls (C rats). At 28 days old, some of the A rats were subjected to swimming for 1 h day−1, 5 day week−1 (AT rats). At 28, 60 and 90 days old the animals were subjected to glucose (GTTo) and insulin (ITTsc) tolerance tests. All the animals were then killed by decapitation for blood and tissue evaluations. On the 60th day, there was a reduction in blood glucose level during the GTTo (mmol l−1 (90 min)−1) in the AT rats (7640.7 ± 694.0) with respect to C (7057.5 ± 776.9) and A (8555.6 ± 1096.7) rats. However on the 90th day, AT rats showed higher glucose levels (8004.6 ± 267.9) when compared to the other groups (C, 7305.5 ± 871.2; A, 7088.8 ± 536.9). The serum free fatty acid (FFA) concentration (μEq l−1) was higher in the alloxan‐treated animals (A, 231.1 ± 58.5; AT, 169.8 ± 20.1) than in controls (C, 101.4 ± 22.4). In conclusion, although the high blood glucose level is transitory in the A animals, some blood and tissue alterations remain and can be harmful to the maintenance of homeostasis. Physical exercise counteracted only partially these alterations. Furthermore, training worsened glucose tolerance at the 90th day, suggesting that exercise intensity should be adjusted to the diabetic condition.
Effect of oestrogen on myofibre size and myosin expression in growing rats
Authors: Piccone Christy M. , Brazeau Gayle A. , McCormick Kathleen M.
Published: October 2004

This study examined the effect of oestrogen deprivation and replacement on plantaris muscle size and myosin heavy chain (MHC) isoform composition in rats during a period of physiological growth. Seven‐week‐old female Sprague–Dawley rats were assigned to one of the three treatment groups: (1) control animals (Sham); (2) ovariectomized animals without oestrogen replacement (OVX/CO); and (3) ovariectomized animals with 17β‐oestradiol replacement (OVX/E2). OVX/CO and OVX/E2 animals were pair‐fed with Sham animals to rule out the potentially confounding effects of differences in food intake and weight gain. Rats were killed 4 weeks after surgery and the plantaris muscle was removed for analysis. Ovariectomy had no effect on muscle fibre size, but reduced the relative amount of type IIx MHC. This was reversed with oestrogen replacement, suggesting that the reduction in type IIx MHC expression was an oestrogen‐mediated effect. Oestrogen replacement reduced type IIb MHC expression and fast muscle fibre size. Changes in fast fibre size and type IIb MHC expression were not seen with ovariectomy, indicating that these changes were not simply due to the presence of oestrogen in the ovariectomized, oestrogen‐replaced animals. These results suggest that another ovarian hormone may counteract the effect of oestrogen on fast fibre size and type IIb MHC expression in intact animals.
Pregnancy influences the plasma cytokine response to intraperitoneal administration of bacterial endotoxin in rats
Authors: Fofie Anita E. , Fewell James E. , Moore Sherry L.
Published: October 2004

Rats have an attenuated febrile response to intraperitoneal (i.p.) administration of exogenous pyrogen (e.g. bacterial endotoxin) near the term of pregnancy. To investigate possible mechanisms of this unique thermoregulatory response, the present experiments were carried out on 18 non‐pregnant and 16 near‐term pregnant Sprague‐Dawley rats to test the hypothesis that pregnancy alters the balance of pyrogenic cytokines and antipyretic and/or cryogenic (antipyretic/cryogenic) cytokines in response to exogenous pyrogen. To test our hypothesis, we measured plasma levels of interleukin (IL)‐1β, IL‐6, interleukin‐1 receptor antagonist (IL‐1ra) and tumour necrosis factor α(TNFα) at 2 and 4 h following i.p. administration of 160 μg kg−1E. coli lipopolysaccharide (LPS) (i.e. EC100 dose, or the smallest dose that elicits a maximal febrile response in non‐pregnant rats) in non‐pregnant as well as pregnant rats at day 20 of gestation (term ∼21 days). In non‐pregnant rats, E. coli LPS elicited statistically significant increases in plasma concentrations of IL‐1β, IL‐6, IL‐1ra and TNFα as compared to that observed following administration of vehicle. However in pregnant rats, E. coli LPS elicited statistically significant increases in antipyretic/cryogenic cytokines (IL‐1ra and TNFα) but not in pyrogenic cytokines (IL‐1β and IL‐6). Thus, a differential pyrogenic and antipyretic/cryogenic plasma cytokine response may mediate in part the attenuated febrile response to exogenous pyrogen observed in rats near the term of pregnancy.
Process issues with Mo∕a-Si:H Schottky diode and thin film transistors integration for direct x-ray detection
Authors: Lee Czang-Ho , Vygranenko Yuriy , Nathan Arokia
Published: October 2004

This article presents an alternate strategy to reduce mechanical stress issues pertinent to the process integration of molybdenum/hydrogenated amorphous silicon (Mo∕a-Si:H) Schottky diodes and thin film transistors (TFTs), used as x-ray sensor pixels for medical imaging. The previous approach was to minimize the intrinsic stress in the Mo layer through appropriate process conditions and film thickness. However, that approach resulted in narrow process latitude and compromised x-ray sensitivity. Alternatively, the mechanical stress in the Mo can be reduced by reducing and/or avoiding the extrinsic stress exerted on the Mo by the underlying films through a different masking sequence in the fabrication. This modified process allows for a more flexible design of the Mo layer for enhanced x-ray sensitivity, while maintaining the mechanical integrity of the various layers. Also, the performance of the Schottky diode is improved in terms of its forward current. The x-ray sensitivity has been measured at different x-ray spectra in the range of 40–100kVp. The pixel shows good linearity with x-ray dosage and high detection efficiency at low x-ray tube voltages.
An investigation of amorphous hydrogenated carbon (a-C:H) coatings using x-ray reflectivity and scratch testing
Authors: Rabbani F. , Staakman R. , Ettema A. R.H.F.
Published: October 2004

X-ray reflectivity was used to differentiate between two hydrogenated amorphous carbon (a-C:H) coatings with distinct Raman signatures proving that they are layered, with the top-layer characterized by a density that is either higher or lower than the averaged film density of the coating. The density of the upper-layer was found to be 1.3g∕cm3 for the coating with the greater intensity ratio Id∕Ig [the intensity ratio of the raman D-band (1350cm−1) and the G-band (1530cm−1)], as compared with 2.2g∕cm3 for the “typical” a-C:H. The coating with the lower-density 8nm top-layer was manufactured under conditions that allow for the trapping of physisorbed hydrogen. It is likely that this polymeric top-layer was necessary in trapping unbound hydrogen. This coating was also distinguished by a higher surface roughness of 0.98nm as compared with 0.68nm for the denser coating. A very low coefficient of friction, 0.02–0.04, was recorded during scratch testing using progressive loading. The critical load to failure was in the range of 28–40N; and the failure mode was brittle as determined by the Si substrate.
Hollow electrode enhanced radio frequency glow plasma and its application to the chemical vapor deposition of microcrystalline silicon
Authors: Tabuchi Toshihiro , Mizukami Hiroyuki , Takashiri Masayuki
Published: October 2004

A hollow electrode enhanced radio frequency (rf) glow plasma excitation technique and its application to the chemical vapor deposition of microcrystalline silicon films have been studied. In this technique, the reactor has two types of hollow structure. One is a hollow counterelectrode, and the other serves as both a hollow counterelectrode and a hollow rf electrode. The application of these discharge types to semiconductor processing is studied in the case of plasma enhanced chemical vapor deposition of hydrogenated microcrystalline silicon thin films. High crystallinity, photosensitivity and a maximum deposition rate of 6.0nm∕s can all be achieved at plasma excitation frequency of 13.56MHz and substrate temperature of 300°C. Properties of these plasmas are investigated by observing the plasma emission pattern, optical emission spectrum analysis and electrical parameters of the rf electrode. It is found that the plasma technique using both types of hollow discharge not only results in higher intensity of SiH* and Hα but also in much smaller self-bias voltage of the rf electrode. Faster processing of device grade hydrogenated microcrystalline silicon films can also be achieved under lower rf power compared to use of the hollow counterelectrode technique alone.
Real-time acoustic sensing and control of metalorganic chemical vapor deposition precursor concentrations delivered from solid phase sources
Authors: Henn-Lecordier L. , Kidder J. N. , Rubloff G. W.
Published: October 2004

We have investigated the performance and potential benefit of acoustic sensing for real-time monitoring and closed loop control of binary gas mixture compositions delivered from low vapor pressure metalorganic sources. Two solid phase sources were investigated in the presence of H2 as a carrier gas: (1) trimethylindium (TMI) and (2) bis(cyclopentadienyl) magnesium (Cp2Mg), which have room temperature (25°C) vapor pressures of 2.5 and 0.04Torr, respectively. An acoustic sensor was implemented on the gas feed line to measure the concentration-dependent speed of sound in the gas mixture. This enabled sensitivity and control at precursor levels as low as 0.6ppm in H2. Closed loop process control was implemented to maintain TMI and Cp2Mg concentration target in the presence of intentionally introduced long term temperature drifts. Despite induced variations of the precursor vapor pressure up to 50%, the delivered composition was controlled to within ±0.15% for TMI (at 0.5mol% set point) and ±0.3% for Cp2Mg (at 0.01mol% set point). Short term variability could also be substantially reduced by the control scheme. This work demonstrates the feasibility of sensor-driven control systems for stable delivery of low vapor pressure, normally problematic precursor materials. In turn, this opens the door to utilization of a broader range of species which can be synthesized as chemical precursors.
Effect of nano-crystallization of high velocity oxy-fuel-sprayed amorphous NiCrBSi alloy on properties of the coatings
Authors: Li Chang-Jiu , Wang Yu-Yue , Li Hua
Published: October 2004

NiCrBSi self-fluxing alloy coatings were deposited by high velocity oxy-fuel (HVOF) spraying. Annealing treatment was applied to the as-sprayed coatings to develop the microstructure of the Ni-based coating. The microstructure of the coating was characterized using optical microscopy, x-ray diffraction and transmission electron microscopy. The crystallization behavior of the amorphous coating was also characterized by differential scanning calorimetry. The properties of the coating were characterized by microhardness and abrasive wear tests. The results showed that the as-sprayed HVOF coating deposited by well melted spray particles exhibited a dense microstructure of amorphous phase. It was revealed that the crystallization of the amorphous phase in HVOF NiCrBSi coating occurs at a temperature of about 502°C. Annealing at temperature a little higher than recrystallization temperature leads to the formation of the nano-crystalline microstructure. The subsequent nanostructured Ni-based coating presents higher microhardness and excellent wear performance. With the further increase in annealing temperature, the growth of the nano-crystalline grains occurs and, accordingly, the microhardness of the coating and the wear performance decrease. Thereafter, the microstructure and properties of the Ni-based self-fluxing alloy coating can be controlled through postannealing treatment.
Chemical vapor deposition boron carbo–nitride deposited using dimethylamine borane with ammonia and ethylene
Authors: Engbrecht E. R. , Sun Y.-M. , Junker K. H. , White J. M. , Ekerdt J. G.
Published: October 2004

Amorphous boron carbo–nitride films, BCxNy, (0.05⩽x⩽1.51,0.05⩽y⩽0.67), were deposited on SiO2 at 360°C and 1Torr using dimethylamine borane [NH(CH3)2:BH3] with ammonia and/or ethylene. The film composition could be controlled by varying the flow of ammonia and ethylene. X-ray photoelectron spectroscopy indicated a change in bonding environments, increasing the B–N bonding with the addition of ammonia and increasing B–C and C–C bonding with the addition of ethylene. The film dielectric constant, k, was 4.62 without coreactant, decreased to 4.11 by adding ammonia and 3.66 upon adding ethylene. The index of refraction ranged from 2.069 to 1.826 with correlation to k depending on the coreactant added. The root mean square surface roughness ranged from 0.30to0.65nm, increasing with the use of ethylene. A 1μm film deposited at 3.60°C using C2H4 had a hardness of 8.7GPa and modulus of 71.3GPa.
Microstructure and Mg concentration of Mg–Si thin film deposited by ion beam sputtering on glass substrate
Authors: Serikawa T. , Henmi M. , Kondoh K.
Published: October 2004

Mg–Si thin films are deposited by ion beam sputtering from the target composed of Mg and Si with 50%:50% area ratios. Intermetallic compound magnesium silicide (Mg2Si) films are obtained at room temperature on glass substrates. Observation of the thin film by cross sectional transmission electron microscopes indicates that films of 1μm thickness show a microstructure composed of a crystalline upper layer of Mg2Si with columnar structure 300nm thick and an amorphous bottom layer with uniform structure 700nm in thickness. Energy dispersive x-ray measurements show that magnesium concentration in the crystalline Mg2Si upper layer are larger than in the amorphous bottom layer. Moreover, the magnesium concentration at grain boundaries is larger than that in grains in the crystalline Mg2Si upper layer. It is also observed that magnesium segregates on the film surface. The film formation is explained in terms of magnesium migration-to-surface and magnesium evaporation from film surface.
Pressure field in a tube with a general and arbitrary time- and position-dependent gas source
Authors: Degasperi F. T. , Martins M. N. , Takahashi J. , Verardi S. L. L.
Published: October 2004

In this article we present analytical and numerical results for a pressure profile along the axis of a tube with a general and arbitrary time- and position-dependent gas source. The model is able to determine the pressure values along the tube, once the pumping speed at each extremity and the gas sources are specified. The time evolution of the pressure along a tube is presented for situations commonly found in high-vacuum applications, such as particle accelerators, colliders, storage rings, and synchrotron light sources.
Influence of substrate bias on practical adhesion, toughness, and roughness of reactive dc-sputtered zirconium nitride films
Authors: Chen Cheng-Shi , Liu Chuan-Pu , Yang Heng-Ghieh , Tsao C.-Y. A.
Published: October 2004

The ZrN films were grown on Si (100) substrates using dc magnetron sputtering where the substrate bias was varied from −45to50V. In this article, the film/substrate practical adhesion of the ZrN films were measured by scratch testing while the hardness, elastic modulus, and fracture toughness were measured by nanoindentation. The structures and morphologies of the ZrN films were analyzed using scanning electron microscopy, atomic force microscopy, and x-ray diffraction. The results indicate that the introduction of either negative or positive bias results in the degradation of the practical adhesion properties, while the films under zero bias exhibit the best adhesion. In addition, positive bias results in the increase in both the hardness and elastic modulus, while negative bias enhances the hardness and toughness of the ZrN thin films. The mechanical properties are greatly influenced by substrate bias and can be correlated to microstructure variations. The detailed mechanisms accounted for these phenomena are discussed.
Pressure measurement repeatability in high current ion implanters using hot cathode ionization gauge with design and operation optimized for stability
Authors: Johnson Ronald C. , Tysinger Randy , Arnold Paul
Published: October 2004

Long-term pressure measurement repeatability in high current ion implanters is an important factor for ion beam current measurement and repeatable dose delivery. In the Axcelis GSD® end station, the issue is particularly acute owing to the small volume of the process chamber. High pressure conditions arise during ion beam irradiation of photoresist layers which, in turn, leads to significant ion beam current neutralization. The GSD design employs a “pressure compensation” algorithm (PCOMP) to offset potential ion beam current measurement errors; the success of this technique depends entirely on accurate and repeatable ion gauge pressure measurement. Incorrect pressure measurement directly leads to dose errors. For example, the dose equation using PCOMP tells us that for a modest PCOMP value of 30%, a chamber pressure measurement error of 2.0E−5Torr can result in a dose error of 5% at normal process pressures. Standard hot cathode ion gauges used for pressure measurement are not capable of meeting the requirements for good dose control since gauge to gauge differences are not well controlled and gauge accuracy is only on the order of 30%. Of more consequence is the degradation of gauge response over time. Axcelis introduced the Stabil-Ion® Bayard-Alpert (BA) gauge to improve dose reproducibility through much improved gauge to gauge matching (±6%) and more accurate gauge output. This article discusses the operation of this gauge system in a production environment and its impact on process dose and process trends. The focus of the discussion is directed to a particular ion implanter design (Axcelis GSD®) since it is unique in its dependence on a PCOMP scheme to counter the effects of ion beam neutralization. However, the above gauge or any similarly stabilized BA gauge would be of benefit to the long-term output and process trends of most ion implant systems.
High resolution, high speed ultrahigh vacuum microscopy
Authors: Poppa Helmut
Published: October 2004

The history and future of transmission electron microscopy (TEM) is discussed as it refers to the eventual development of instruments and techniques applicable to the real time in situ investigation of surface processes with high resolution. To reach this objective, it was necessary to transform conventional high resolution instruments so that an ultrahigh vacuum (UHV) environment at the sample site was created, that access to the sample by various in situ sample modification procedures was provided, and that in situ sample exchanges with other integrated surface analytical systems became possible. Furthermore, high resolution image acquisition systems had to be developed to take advantage of the high speed imaging capabilities of projection imaging microscopes. These changes to conventional electron microscopy and its uses were slowly realized in a few international laboratories over a period of almost 40 years by a relatively small number of researchers crucially interested in advancing the state of the art of electron microscopy and its applications to diverse areas of interest; often concentrating on the nucleation, growth, and properties of thin films on well defined material surfaces. A part of this review is dedicated to the recognition of the major contributions to surface and thin film science by these pioneers. Finally, some of the important current developments in aberration corrected electron optics and eventual adaptations to in situ UHV microscopy are discussed. As a result of all the path breaking developments that have led to today’s highly sophisticated UHV–TEM systems, integrated fundamental studies are now possible that combine many traditional surface science approaches. Combined investigations to date have involved in situ and ex situ surface microscopies such as scanning tunneling microscopy/atomic force microscopy, scanning Auger microscopy, and photoemission electron microscopy, and area-integrating techniques such as x-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy, Auger electron spectroscopy, low-energy electron diffraction, temperature programmed desorption, high-resolution electron energy-loss and Fourier-transform infrared spectroscopies, and others. Material systems ranging from atomic layers of metals and semiconductors to biology related depositions are being investigated. In the case of biological materials, however, strict limitations to high-resolution applications are imposed by electron radiation damage considerations.
Chemical state of nitrogen in a high nitrogen face-centered-cubic phase formed on plasma source ion nitrided austenitic stainless steel
Authors: Lei M. K. , Zhu X. M.
Published: October 2004

A single high nitrogen face-centered-cubic phase (γN) was formed on the plasma source ion nitrided 1Cr18Ni9Ti (18-8 type) austenitic stainless steel. Auger electron spectroscopy and x-ray photoelectron spectroscopy, in conjuction with ion beam sputtering, were used to determine the chemical composition and bonding of nitrogen in the γN phase. The chemical composition of the γN phase was shown as a formula with atomic fraction (Fe0.60,Cr0.22,Ni0.18)2N. The γN phase possessed weaker Cr–N ionic-type bonds and stronger Fe–N ionic-type bonds, compared with the stoichiometric nitrides. The Cr2p3∕2 binding energy was 1.1eV lower than that of CrN and Cr2N phases (at 575.5eV). The chemical shift of the Fe–N bonding compared with the Fe–Fe bonding was nearly 2.1eV. The N1s binding energies showed that the nitrogen was in the chemical state with iron (at 396.6eV) and chromium (at 397.7eV). All the chromium appeared to be in the Cr–N bond. A part of iron was also observed in the nitride state, and all the nickel was contained in the metallic state.
13.56
MHz
radio frequency plasma properties on hemispheric electrodes and diamond-like carbon films deposition on three-dimensional polyurethane diaphragms
Authors: Ohgoe Yasuharu , Hirakuri Kenji K.
Published: October 2004

The characteristics of the radio frequency (rf) plasma that could hold an entire hemispheric polyurethane diaphragm generated using the hemispheric-type electrode were investigated. The plasma states were measured using Langmuir probe. Although the common rf plasma chemical vapor deposition technique using planar electrodes makes it difficult to apply uniform plasma to three-dimensional structures, the hemispheric-type electrode process could uniformly hold a hemispheric polyurethane diaphragm at self-bias voltage. As a result, this process could uniformly keep the ion sheath on the diaphragm. In case of using this process for diamond-like carbon (DLC) film deposition, the DLC film was deposited uniformly on the diaphragm at approximately 300nm. Besides electron temperatures and electron number of densities were similar to the behavior of common rf plasma. This means that the characteristics of plasma are kept in the same states even if the plasma form is controlled using such a hemispheric-type electrode. Based on these results, this hemispheric-type electrode process was observed to be quite applicable to three-dimensional insulator structures.
Radio frequency line-plasma source using permanent magnets
Authors: Sakawa Youichi , Yano Kentaro , Shoji Tatsuo
Published: October 2004

A high-density and uniform line-plasma source is developed by an inductive rf discharge using a rectangular discharge chamber (200×100×20mm) with a pair of permanent magnets placed on top and bottom of the chamber. Ion-saturation current-density Jis profile is controlled by varying the width of the magnets and the distance between the antenna and the magnets. A 140-mm-wide plasma [plasma density ≃(1.8-2.5)×1012cm−3 for electron temperature =4–8eV] of a uniformity variation within 90% is produced using a 140-mm-long antenna for an Ar pressure of 20mTorr and a rf power of 3kW. The measured Jis profiles are explained by solving the equation of motion for electrons under a magnetic field structure of longitudinal line cusps.
Molecular Detection and Genotyping of Male-Specific Coliphages by Reverse Transcription-PCR and Reverse Line Blot Hybridization
Authors: Vinjé Jan , Oudejans Sjon J. G. , Stewart Jill R. , Sobsey Mark D. , Long Sharon C.
Published: October 2004

In recent years, there has been increased interest in the use of male-specific or F+ coliphages as indicators of microbial inputs to source waters. Sero- or genotyping of these coliphages can also be used for microbial source tracking (MST). Among the male-specific coliphages, the F+ RNA (FRNA) viruses are well studied, while little is known about the F+ DNA (FDNA) viruses. We have developed a reverse line blot hybridization (RLB) assay which allows for the simultaneous detection and genotyping of both FRNA as well as FDNA coliphages. These assays included a novel generic duplex reverse transcription-PCR (RT-PCR) assay for FRNA viruses as well as a generic PCR for FDNA viruses. The RT-PCR assays were validated by using 190 field and prototype strains. Subsequent DNA sequencing and phylogenetic analyses of RT-PCR products revealed the classification of six different FRNA clusters, including the well-established subgroups I through IV, and three different FDNA clusters, including one (CH) not previously described. Within the leviviruses, a potentially new subgroup (called JS) including strains having more than 40% nucleotide sequence diversity with the known levivirus subgroups (MS2 and GA) was identified. We designed subgroup-specific oligonucleotides that were able to genotype all nine (six FRNA, three FDNA) different clusters. Application of the method to a panel of 351 enriched phage samples from animal feces and wastewater, including known prototype strains (MS2, GA, Qβ, M11, FI, and SP for FRNA and M13, f1, and fd for FDNA), resulted in successful genotyping of 348 (99%) of the samples. In summary, we developed a novel method for standardized genotyping of F+ coliphages as a useful tool for large-scale MST studies.
Cloning and Expression of a Phloretin Hydrolase Gene from
Eubacterium ramulus
and Characterization of the Recombinant Enzyme
Authors: Schoefer Lilian , Braune Annett , Blaut Michael
Published: October 2004

Phloretin hydrolase catalyzes the hydrolytic C-C cleavage of phloretin to phloroglucinol and 3-(4-hydroxyphenyl)propionic acid during flavonoid degradation in
Eubacterium ramulus
. The gene encoding the enzyme was cloned by screening a gene library for hydrolase activity. The insert of a clone conferring phloretin hydrolase activity was sequenced. Sequence analysis revealed an open reading frame of 822 bp (
phy
), a putative promoter region, and a terminating stem-loop structure. The deduced amino acid sequence of
phy
showed similarities to a putative protein of the 2,4-diacetylphloroglucinol biosynthetic operon from
Pseudomonas fluorescens
. The phloretin hydrolase was heterologously expressed in
Escherichia coli
and purified. The molecular mass of the native enzyme was approximately 55 kDa as determined by gel filtration. The results of sodium dodecyl sulfate-polyacrylamide gel electrophoresis and the deduced amino acid sequence of
phy
indicated molecular masses of 30 and 30.8 kDa, respectively, suggesting that the enzyme is a homodimer. The recombinant phloretin hydrolase catalyzed the hydrolysis of phloretin to equimolar amounts of phloroglucinol and 3-(4-hydroxyphenyl)propionic acid. The optimal temperature and pH of the catalyzed reaction mixture were 37°C and 7.0, respectively. The

K
m

for phloretin was 13 ± 3 μM and the
k
cat
was 10 ± 2 s
−1
. The enzyme did not transform phloretin-2′-glucoside (phloridzin), neohesperidin dihydrochalcone, 1,3-diphenyl-1,3-propandione, or
trans
-1,3-diphenyl-2,3-epoxy-propan-1-one. The catalytic activity of the phloretin hydrolase was reduced by
N
-bromosuccinimide,
o
-phenanthroline,
N
-ethylmaleimide, and CuCl
2
to 3, 20, 35, and 85%, respectively. Phloroglucinol and 3-(4-hydroxyphenyl)propionic acid reduced the activity to 54 and 70%, respectively.
The convention on human rights and biomedicine and the use of coercion in psychiatry
Authors: Tannsjo T
Published: October 2004

According to a recent convention on human rights and biomedicine, coercive treatment of psychiatric patients may only be given if, without such treatment, serious harm is likely to resultto the health of the patient; it must not be given in the interest ofotherpeople. In the present article a discussion is undertaken about the implication of this stipulation for the use of coercion in psychiatry in general and in forensic psychiatry in particular.
Are patents for methods of medical treatment contrary to theordre publicand morality or “generally inconvenient”?
Authors: Mitnovetski O , Nicol D
Published: October 2004

“No one has advanced a just and logical reason why reward for service to the public should be extended to the inventor of a mechanical toy and denied to the genius whose patience, foresight, and effort have given a valuable new [discovery] to mankind” (Katopis CJ. Patents v patents: policy implications of recent patent legislation.St John’s Law Review1997;71:329). The law around the world permits the granting of patents fordrugs,medical devices, andcosmetic treatmentof the human body. At the same time, patentability for amethodof treatment of the same body is denied in some countries on various public policy grounds. Is there any logical justification for this distinction? Are methods of medical treatment not as vital to the health or even to the life of a patient as drugs or medical devices? Why is a cosmetic result patentable and a curative result not?