bluuebunny/crossref_metadata_2025 huggingface dataset:
The CGRP-Antagonist, BIBN4096BS Does not Affect Cerebral or Systemic Haemodynamics in Healthy Volunteers
Authors: Petersen KA , Birk S , Lassen LH , Kruuse C , Jonassen O , Lesko L , Olesen J
Published: January 2005

BIBN4096BS is a CGRP-antagonist effective in the treatment of migraine. Blocking the receptor of a strong vasodilator involves a theoretical risk of causing cerebral vasoconstriction, a probability not previously investigated with BIBN4096BS. Seven healthy volunteers completed this double-blinded placebo-controlled crossover study. The volunteers received randomly 10 min infusions of either placebo, 2.5 mg or 10 mg of BIBN4096BS on 3 separate days. Transcranial Doppler was used to measure the middle cerebral artery blood flow velocity (VMCA); global and regional cerebral blood flow (rCBFMCA) was measured by 133-Xenon inhalation SPECT. The diameter of the temporal and radial artery was measured by highresolution ultrasound. Systemic haemodynamics and partial pressure of CO2 (PetCO2), and adverse events were monitored regularly. BIBN4096BS had no influence on global or regional cerebral blood flow, or on the blood flow velocity in the middle cerebral artery. There was no effect on systemic haemodynamics and adverse events were minor. We conclude that there is no effect of CGRP-receptor blockade on the cerebral or systemic circulation in humans. Circulating CGRP is therefore not likely to exert a vasodilatory activity in the resting state and the use of BIBN4096BS for acute migraine seems to be without risk of cerebral vasoactivity. These data suggest that BIBN4096BS is the first specific antimigraine drug without vasoactive effect.
An Assessment of the Burden of Migraine using the Willingness to Pay Model
Authors: Hamelsky SW , Lipton RB , Stewart WF
Published: January 2005

Willingness to pay methods measure treatment preferences and also measure the burden of illness in economic terms. We used a contingent valuation method to measure migraine sufferers' willingness to pay (WTP) for acute medication for their most severe headache attacks, based on various profiles of treatment benefits and the characteristics of the migraine sufferer. Subjects were identified from a population-based database of migraine sufferers, previously recruited by random digit dialling. Telephone interviews ( n = 1428) were used to gather demographic and headache characteristics. Subjects who met the International Headache Society criteria for migraine with or without aura and satisfied the other inclusion criteria based on telephone interview ( n = 312) were invited to participate in a mailed questionnaire study. The questionnaire was mailed to the 310 subjects who agreed to participate and 201 (65%) surveys were returned. The survey included questions on the demographics, the migraine characteristics, and the psychological disposition of the respondents. WTP for an acute migraine treatment with 14 different hypothetical treatment profiles was explored. Responders and non-responders to the survey were generally similar. The newly designed WTP questionnaire had high internal consistency (Cronbach's α 0.90) and test-retest reliability (Spearman's corrleation coefficients 0.71-0.77). Study subjects were willing to pay a median price of 5 for a migraine treatment that provided complete relief in 30 min and worked 100% of the time, with no side-effects and no headache recurrence. Median WTP decreased as treatment attributes deviated from this ideal. For example, WTP declined to a median of 1 for complete relief in 2 h and to $0.25 for complete relief in 4 h. All of the medication attributes powerfully influenced WTP. Several variables predicted WTP including current payment for medication, MIDAS (Grade III), and those with headaches of long duration. Subjects who employed a greater number of coping skills were less willing to pay. Patient demographics and migraine severity predict WTP, but treatment attributes were also important. As treatment improves, WTP for migraine medications is likely to increase.
Posturographic description of the regaining of postural stability following stroke
Authors: Rogind Henrik , Christensen Jon , Danneskiold‐Samsøe Bente , Bliddal Henning
Published: January 2005

Background:  Failing balance and increased liability to falling are common complaints among hemiplegic subjects. During rehabilitation much effort is put into regaining postural stability.

Purpose:  To describe the regaining of postural stability during rehabilitation for the first year following stroke in hemiplegic patients

Materials and methods:  Twenty‐six patients were included within 5 days of suffering a stroke resulting from a CT‐verified clearly defined thromboembolic lesion, localized in the vascular bed of middle cerebral artery on either side. Posturographic evaluation of sway was performed on a commercially available force plate system (Balance Master Pro®). Measured parameters included per cent maximum stability (PMS), per cent ankle strategy (AST), and average angular velocity (AVE). An additional parameter was derived by calculating the slope (SLP) of the linear relationship between stability and ankle strategy. SLP reflects the predisposition of the stroke patient to keep using ankle strategy when faced with increasingly difficult balance tasks. The presence of familiarization to the measurement method was examined by including a preliminary measurement not otherwise included in the analysis of changes during the first year of follow‐up. The temporal evolvement of sway was described by measuring sway parameters 1, 2, 4, 8 and 52 weeks following stroke. The proportions of the variation in sway caused by measurement error and between patients were compared.

Results:  All parameters improved over time, as demonstrated by significant improvements from each of week 1, 2, 4 and 8 to week 52. There was evidence of familiarisation for PMS, AST and AVE, but not for SLP. Estimation of variance components showed that between patient variation accounts for between two‐thirds and four‐fifths of the total variation. A considerable part of this variation was caused by individual differences in the temporal improvement of sway over time. Patients considered the evaluation of postural sway demanding and time consuming resulting in a relatively large loss to follow‐up: 15 patients completed the 8‐week visit while seven completed the 1 year visit.

Conclusion:  Postural stability increases for the first year following stroke. There is evidence of familiarization towards the measurements process for the traditional posturographic parameters PMS, AST and AVE, but not for the derived parameter SLP, which might make the latter a candidate for a sway parameter reflecting basic mechanisms of upholding upright stance in hemiplegic patients. The estimated variance components stress the considerable between‐patient variation and question the ability of the force plate method to monitor individual sway performance of such patients during the rehabilitation process.
Iodine 123‐metaiodobenzylguanidine imaging reflect generalized sympathetic activation in patients with left ventricular dysfunction
Authors: Yuyama Reisuke , Yuasa Fumio , Hikosaka Makoto , Mimura Jun , Kawamura Akihiro , Hatada Kengo , Motohiro Masayuki , Iwasaki Masayoshi , Sugiura Tetsuro , Iwasaka Toshiji
Published: January 2005

Background:  Iodine 123‐metaiodobenzylguanidine (MIBG) imaging has been used to assess cardiac sympathetic nerve abnormalities. To determine the role of MIBG imaging as a measure of generalized sympathetic nerve activity, MIBG imaging was evaluated with muscle sympathetic nerve activity (MSNA) and plasma norepinephrine (noradrenaline) level in patients with old myocardial infarction.

Methods:  Myocardial MIBG scintigraphy, MSNA and plasma norepinephrine measurement were performed within 3 days in 35 patients with old myocardial infarction. Patients were divided into three groups according to their ejection fraction (EF); preserved (EF ≥ 50%, 12 patients), intermediate (35% < EF < 50%, 13 patients), or depressed (EF ≤ 35%, 10 patients).The heart to mediastinum (H/M) ratio was obtained 4 h after tracer injection from the chest anterior view image. MIBG washout rate was calculated from the early and delayed images. MSNA was recorded by microneurography.

Results:  Plasma norepinephrine level had weak negative correlations with early H/M ratio (r = 0·37, P<0·05) and delayed H/M ratio (r = 0·33, P<0·05), and a positive correlation with MIBG washout rate (r = 0·54, P<0·01). MSNA had weak negative correlations with early H/M ratio (r = 0·51, P<0·05) and delayed H/M ratio (r = 0·52, P<0·05). However, a strong correlation was found between MSNA and MIBG washout rate (r = 0·88, P<0·001). Despite no significant differences in plasma norepinephrine level and H/M ratio, patients with intermediate and depressed EF had higher MIBG washout rate and MSNA compared with those with preserved EF.

Conclusions:  Increased in cardiac sympathetic nerve activity was associated with augmented sympathetic outflow of the skeletal muscle and hence, MIBG washout rate allow the assessment of general sympathetic nerve activity.
Forearm vascular reactivity is differentially influenced by gliclazide and glibenclamide in chronically treated type 2 diabetic patients
Authors: Wascher Thomas C. , Boes Ursula
Published: January 2005

Sulphonylureas (SUs) act by inhibition of β‐cell KATP channels after binding to the sulphonylurea receptor SUR1. KATP channels are also expressed in cardiac and vascular myocytes coupled to SUR2A and SUR2B involved into adaptations of vascular tone and myocardial contractility. Different influence of SUs on vascular function is based on different binding to the SUR family. Few data on the effect of different SUs, used in patients in therapeutic doses, on vascular function are currently available. We investigated possible effects of acute and chronic treatment with glibenclamide and gliclazide on forearm postischaemic reactive hyperaemia (RH) in type 2 diabetic patients. To that purpose a double‐blind, randomized, cross‐over study with gliclazide (80 mg, b.i.d.) and glibenclamide (5 mg, b.i.d.) was performed in 15 type 2 diabetic patients. Forearm vascular reactivity was measured after 5 min of ischaemia by plethysmography before and after 4 weeks treatment. After acute administration of gliclazide (80 mg) or glibenclamide (5 mg) RH was not influenced. After 4 weeks of treatment, no influence of either drug was seen in the steady state before dosing. After dosing glibenclamide induced a significant (P = 0·004) reduction of RH from 26·4 ± 6·9 to 21·9 ± 7·6 ml min−1/100 ml after 4 h. Gliclazide, conversely, did not induce a reduction of RH (23·9 ± 6·0 to 23·3 ± 6·6 ml min−1/100 ml). No influence of HbA1c or actual glycaemia on RH was observed. Our results indicate that in chronically treated patients with type 2 diabetes ingestion of glibenclamide but not gliclazide results in sustained reduction of postischaemic RH. This difference is most probably based on different SUR binding.
Bone infection in patients suspected of complicating osteomyelitis: the diagnostic value of dual isotope bone‐granulocyte scintigraphy
Authors: Buhl Thora , Stentzer Kim , Hede Adam , Kjær Andreas , Hesse Birger
Published: January 2005

Aim:  The purpose of this study was to evaluate the diagnostic value of dual isotope bone‐granulocyte scintigraphy in patients with known bone pathology clinically suspected of osteomyelitis, i.e. complicating osteomyelitis, using per‐operative bacterial culture from bone as reference.

Methods:  Simultaneous dual isotope bone‐granulocyte scintigraphic images were obtained in 42 consecutive patients in whom conventional X‐ray, erythrocyte sedimentation rate, and C‐reactive protein were also available. 99mTc MDP bone and 111In labelled granulocyte imaging was obtained simultaneously. The images were interpreted as positive for osteomyelitis if regions of interests of pathologic 111In granulocyte accumulation included 99mTc MDP activity on the bone images (except in the spine).

Results:  The sensitivity, specificity, and accuracy were 84, 71 and 79%, respectively, for simultaneous, dual isotope bone‐granulocyte scintigraphy, higher than the other diagnostic parameters.

Conclusion:  Simultaneous bone‐granulocyte scintigraphy is a valuable diagnostic tool in diagnosing osteomyelitis complicating other bone pathology with or without soft‐tissue infection.
Dizziness is associated with decreased vasoreactivity in right cerebral hemisphere for head‐down manoeuvre – near‐infrared spectroscopy study
Authors: Shinoura Nobusada , Yamada Ryozi
Published: January 2005

To investigate the vasoreactivity of cerebral hemisphere in patients with dizziness and syncope, we compared changes in total haemoglobin (THbl) and regional oxygen saturation (rSO2) of the right and left frontal lobes in response to head‐down manoeuvre. Ninety‐six right‐handed subjects (aged 59 ± 19 years) were asked to perform a head‐down or a standing manoeuvre. Head‐down manoeuvre produced a greater increase in right side THbl in subjects under 70 years of age (8·5 ± 3·1) when compared with subjects older than 70 years (0·40 ± 0·08). In contrast, the head‐down manoeuvre had no effects on left side THbl, irrespective of patient age. Similarly, the head‐down manoeuvre resulted in a greater decrease of right side rSO2 in subjects under 70 years of age (−5·2 ± 2·1%) when compared with subjects older than 70 years (0·31 ± 0·9%). In contrast, the head‐down manoeuvre had no effects on left side rSO2, irrespective of patient age. The head‐down manoeuvre produced a smaller increase in right side THbl in subjects with dizziness (0·38 ± 0·19) than in those without dizziness (9·4 ± 3·5). A standing manoeuvre produced a smaller increase in right side THbl in subjects with syncope (−0·057 ± 0·047) than in those without syncope (0·063 ± 0·028). The head‐down manoeuvre produced a decrease in right side rSO2 in subjects without dizziness (−6·4 ± 2·4%) and a slight increase in right side rSO2 in subjects with dizziness (1·1 ± 0·4%). Subjects with dizziness (67 ± 2·1 years) were significantly older than those without dizziness (53 ± 2·7 years) or those with syncope (44 ± 4·2 years). These data indicate that reduced vasoreactivity to right hemispheric pressure changes is associated with dizziness in older subjects. Further, decreases in right hemispheric THbl during a standing manoeuvre are associated with syncope in relatively younger subjects.
Heart rate variability during sedentary work and sleep in normal and sleep‐deprived states
Authors: van den Berg Johannes , Neely Gregory , Wiklund Urban , Landström Ulf
Published: January 2005

The possibility of using heart rate variability (HRV) as an indicator of sleepiness was investigated by analysing heart rate (HR) activity and electroencephalography (EEG) recordings from 10 individuals who performed a monotonous attention task for 120 min in both sleep‐deprived and rested states. In both conditions, measurements were collected during 60 min of sleep immediately following a 120 min of non‐sleep (awake phase). Although HR decreased significantly in both the rested and the sleep‐deprived states during the awake phase, HR significantly changed sooner when subjects were sleep‐deprived than when they were rested. No significant changes in HRV were found during the awake phase; however, HRV correlated significantly with alpha and theta power densities when rested but not when sleep‐deprived. During the sleep phase, the total HRV and very low and low frequency HRV components significantly decreased approximately 40 min after sleeping in the sleep‐deprived condition. These HRV components were also significantly and negatively correlated with delta power densities. HRV does not seem to be a viable indicator of sleepiness; however, HRV may be useful for determining sleep stages.
Limitations of non‐invasive endothelial function assessment by brachial artery flow‐mediated dilatation
Authors: Šejda Tomáš , Pit'ha Jan , Švandová Eva , Poledne Rudolf
Published: January 2005

A non‐invasive technique using high‐frequency ultrasound brachial artery imaging to assess endothelium‐dependent flow‐mediated vasodilatation is a widely used test, but interpretation of results is not consistent. This study was designed to assess the method of non‐invasive endothelial function determination of a brachial artery. Endothelial function was assessed by two physicians in 18 young, healthy volunteers. Each volunteer was examined by both physicians on the same day using an identical protocol; a second assessment was carried out at an interval of 6–7 days. When comparing arterial dilatation at first and second measurements by one physician, there were no statistically significant differences (first physician: 5·95 ± 2·93% versus 7·63 ± 4·3%;P = 0·21; second physician: 4·23 ± 1·6% versus 4·94 ± 2·69%;P = 0·22). Further, we found statistically significant differences in artery dilatation when comparing measurements made separately by both physicians on the same day (5·95 ± 2·93% versus 4·23 ± 1·6%;P = 0·03, and 7·63 ± 4·3% versus 4·94 ± 2·69%;P = 0·003). Our results suggest a large inter‐individual variability of measurements within the whole group, if made on the same day and at the same time by two physicians. On the contrary, no significant differences were noted when comparing measurements of the whole group by the one physician at an interval of 1 week. It can be concluded that the degree of brachial artery flow‐mediated dilatation is difficult to evaluate on the basis of a predefined cut‐off point as a single‐measurement screening test.
Assessment of lung volumes in children and adolescents: comparison of two plethysmographic techniques
Authors: Halvorsen Thomas , Skadberg Britt Torunn , Eide Geir Egil , Røksund Ola Drange , Bakke Per , Thorsen Einar
Published: January 2005

Thoracic gas volume (Vtg) can be measured with body plethysmography by either repetitive panting or one single inspiratory effort against a shutter occluding the airways. The panting technique is preferred, but may be demanding. We aimed to assess the precision of these two methods and the degree of agreement between them. Vtg and functional residual capacity (FRC) were measured in 155 subjects with a standard, commercially available plethysmograph, acting as a variable‐pressure, constant‐volume device when Vtg is determined. Total lung capacity (TLC) and residual lung volume (RV) were calculated subsequent to a full vital capacity manoeuvre. For non‐asthmatic healthy subjects, the standard deviations (SD) of the differences between two replicate measurements of FRC, TLC and RV were respectively 0·16, 0·13 and 0·14 litres with the panting technique, and 0·18, 0·18 and 0·23 litres with the single inspiratory effort technique. In percentage of the respective lung volumes, the corresponding 1·96 SDs were 20%, 8% and 40% with the panting technique and 23%, 12% and 67% with the single inspiratory effort technique. Between the two techniques, 95% limits of agreement were 21% for FRC, 11% for TLC and 58% for RV. The variability of Vtg and FRC accounted for most of the variability of TLC and RV. In conclusion, the panting and the single inspiratory effort technique produced results that were comparable in magnitude, however with a better precision with the panting technique. The single inspiratory effort technique can be used as an alternative if the panting technique fails.
Intra‐tree variability in wood anatomy and its implications for fossil wood systematics and palaeoclimatic studies
Authors: FALCON‐LANG HOWARD J.
Published: January 2005

Abstract:  The validity of using quantitative analyses of wood anatomical characters as systematic tools and as palaeoenvironmental proxies has been questioned on the basis that natural variability, and in particular intra‐tree variability, tends to drown out the signal being sought. A detailed quantitative description of the wood anatomy of a balsam fir tree was undertaken along root–stump–trunk–branch transects to ascertain intra‐tree variability, and to assess noise‐to‐signal ratio. Results demonstrate significant ontogenetic trends for anatomical parameters such as tracheid pit distribution, cross‐field pit frequency, ray dimensions, ray spacing, tracheid diameter, mean ring width and mean sensitivity. However, although intra‐tree variability is great, results suggest that fossil taxa nevertheless may be distinguished from one another on the basis of standard qualitative and quantitative procedures. With regard to palaeoenvironmental studies, results indicate that a significant, but not unrealistic, increase in sample size and an improved knowledge of specimen ontogeny is needed in the future if signals are to be distinguished from background intra‐tree variability for some parameters.
Late Ordovician vertebrates from the Bighorn Mountains of Wyoming, USA
Authors: SANSOM IVAN J. , SMITH M. PAUL
Published: January 2005

Abstract:  Late Ordovician vertebrate faunas occur in clastic sedimentary units along the length of the Rocky Mountains from Colorado to Montana, and across the border into Canada. Most research has, however, been conducted on localities in the southern part of the outcrop belt, particularly the Harding Sandstone Formation of Colorado. Micropalaeontological sampling of the coeval South Piney Member (Winnipeg Formation) in the Bighorn Mountains of Wyoming has revealed an abundant vertebrate fauna. The vertebrate assemblage includes a low‐abundance fauna of 13 conodont taxa that together indicate an undatus Chronozone age (mid‐Mohawkian; mid‐Caradoc; Late Ordovician). The pteraspidomorphs Astraspis desiderata Walcott and Eriptychius americanus Walcott are also present together with one new taxon, Eleochera glossa gen. et sp. nov., which is interpreted as a derived stem‐gnathostome on the basis of its scale histology and morphology. The fauna bears a strong similarity to that of the Harding Sandstone but is of lower diversity. In particular, it lacks the fine‐grained, deeper water component of the Harding Sandstone that contains, inter alia, thelodonts and stem‐chondrichthyans.
Early Triassic coprolites from Australia and their palaeobiological significance
Authors: NORTHWOOD CAROLINE
Published: January 2005

Abstract:  Coprolites from the Arcadia Formation, Queensland, Australia, were studied in conjunction with the vertebrate fossil assemblages from two localities to maximize our understanding of the palaeoecology of these Early Triassic deposits. Criteria used by other researchers to identify the producers of coprolites were found to be of little value in the Arcadia Formation specimens. Using a combination of shape, biostratigraphic distribution, size and included remains some of the coprolites are attributed to basal archosauromorphs and fish whereas others could not be identified. Perhaps the most important attribute of the Arcadia coprolites is that they preserved rare organisms such as cyanobacteria, insects and other arthropods, and a diversity of fish. Estimates of the number of actinopterygians and dipnoans preserved in coprolites significantly increased relative abundance estimates based on skeletal elements alone. Although coprolites are an important source of palaeobiological information, this information is limited by our poor understanding of the taphonomic processes involved in the fossilization of faecal matter and by the near impossibility of assigning coprolites to specific producers.
Evidence of predation damage in Pliocene Apletosia maxima (Brachiopoda)
Authors: HARPER ELIZABETH M.
Published: January 2005

Abstract:  Little is known about predation of Mesozoic and Cenozoic articulated brachiopods, but it is far from clear whether this is because they suffered very little predation pressure or because there have been few attempts to search for evidence of it. A study of 248 museum specimens of the large Pliocene terebratulid Apletosia maxima from the Coralline Crag (UK) has revealed that more than 16 per cent of them show evidence of having been attacked by predators. The styles of damage can be attributed to drilling muricid gastropods (most of which were successful) and failed crushing attacks probably by decapods. Brachiopods are usually thought to offer a poor tissue yield to potential predators, but in this instance it appears that A. maxima was attractive to predators even though they were living with a rich molluscan fauna. It is suggested that the mass of adductor and diductor muscles (likely to be spicule‐free) of these particularly large brachiopods may have made them profitable. Further studies of post‐Palaeozoic brachiopod faunas are required, particularly those from mixed shallow‐water communities, before it can be established whether articulated brachiopods have or have not been driven into refugia by increasing predation pressure.
The marine diapsid reptile Endennasaurus from the Upper Triassic of Italy
Authors: MÜLLER JOHANNES , RENESTO SILVIO , EVANS SUSAN E.
Published: January 2005

Abstract:  The marine reptile Endennasaurus from the Upper Triassic Zorzino Limestone of northern Italy is redescribed and reassessed. New details of the skull and postcranial skeleton are revealed, confirming the attribution of this genus to the diapsid reptile clade Thalattosauriformes. Phylogenetic analysis suggests that Endennasaurus was related to the European genus Askeptosaurus and the Chinese Anshunsaurus. Despite a rather conservative postcranial morphology, Endennasaurus clearly occupied a highly specialized dietary niche as it combined a slender tapering premaxillary rostrum with a complete absence of either marginal or palatal teeth.
Taxonomic revision of the Late Devonian tetrapod Ichthyostega from East Greenland
Authors: BLOM H.
Published: January 2005

Abstract:  Two morphologically distinct assemblages of the Late Devonian tetrapod Ichthyostega from East Greenland are described on the basis of a large collection of skulls and postcranial elements. Skull specimens collected on Gauss Halvø show that the assemblage from the lower Aina Dal Formation has proportionally narrower skulls and finer skull roof sculpture than the assemblage from the higher Britta Dal Formation. The assemblages are compared with the stratigraphically unconstrained type material from the north side of Celsius Bjerg on Ymer Ø, allowing a taxonomic revision. From the original description of seven taxa, three species are recognized and related to the assemblages from Gauss Halvø. I. stensioei is comparable with the Aina Dal Formation assemblage while I. eigili and I. watsoni are valid for specimens found in the Britta Dal Formation. Ichthyostegopsis wimani is not a valid genus or species and may be regarded as a juvenile I. eigili. This example of species‐level variability is the earliest known from the fossil record of early tetrapods.
Osteology and relationships of a new theropod dinosaur from the Middle Jurassic of Patagonia
Authors: RAUHUT OLIVER W. M.
Published: January 2005

Abstract:  A new taxon of theropod dinosaur is described as Condorraptor currumili gen. et sp. nov., from the Middle Jurassic (Callovian) Cañadón Asfalto Formation of Chubut Province, Argentinean Patagonia. The taxon is represented by a single fragmentary postcranial skeleton. Although incompletely known, Condorraptor is the second most complete theropod from the Middle Jurassic of Gondwana. The new taxon is characterized by the absence of a posterior incision between the fibular condyle and the medial side of the proximal articular end of the tibia, the pleurocoels in the anterior cervicals being situated posteroventral to the parapophyses, and the presence of a pronounced ‘step’ between the distal articular facet and shaft of Mt IV. Pneumatic features of the vertebral column show strong variation between the left and right side. Condorraptor gen. nov. can be referred to the Tetanurae and is a representative of a global radiation of basal tetanurans in the Early to Mid Jurassic.
Pterosaur and dinosaur remains from the Middle Jurassic Balabansai Svita in the northern Fergana Depression, Kyrgyzstan (Central Asia)
Authors: AVERIANOV ALEXANDER O. , MARTIN THOMAS , BAKIROV AIZEK A.
Published: January 2005

Abstract: Isolated pterosaur and dinosaur teeth and a sauropod metatarsal I and manual phalanx V‐1 from the Middle Jurassic (Callovian) Balabansai Svita in the northern Fergana Valley, Kyrgyzstan, are described and attributed to the pterosaur taxon Rhamphorhynchinae indet., a theropod Tetanurae indet., a sauropod Neosauropoda indet., and a new pachycephalosaurid Ferganocephale adenticulatum gen. et sp. nov. The Balabansai theropod is possibly a stem‐lineage representative of Dromaeosauridae. The new pachycephalosaurid is the oldest representative of the group and extends its known history by 10–20 myr. The Balabansai vertebrate assemblage is most similar to the Callovian assemblages from the Qigu and Upper Shaximiao formations in China, and intermediate in the evolutionary level of the taxa present between the Bathonian assemblages from Wucaiwan and the Lower Shaximiao formations (China) and the Late Jurassic Shar Teg fauna from Mongolia.
A new rauisuchian archosaur from the Middle Triassic of India
Authors: SEN KASTURI
Published: January 2005

Abstract:  Yarasuchus deccanensis gen. and sp. nov. is a new addition to the poorly known Middle Triassic terrestrial vertebrates. It is described on the basis of the fossil material of at least two incompletely preserved individuals and several isolated bones. It was a long‐necked, gracile animal and might have had a facultatively bipedal gait. Apart from its characteristic elongate cervical vertebrae, other osteological features of Y. deccanensis resemble those of Prestosuchus, Saurosuchus, Ticinosuchus and ‘Mandasuchus’. It is therefore referred to the Rauisuchian family Prestosuchidae despite the debated validity of this taxon.
Remarkably preserved annelid worms from the La Meseta Formation (Eocene), Seymour Island, Antarctica
Authors: SCHWEITZER CARRIE E. , FELDMANN RODNEY M. , MARENSSI SERGIO , WAUGH DAVID A.
Published: January 2005

Abstract: Worm tubes, which exhibit the replaced tube‐lining membrane, have been collected from the lowermost Lower Eocene Acantilados Allomember of the La Meseta Formation, Seymour Island, Antarctica. The discovery represents the oldest examples of preservation of the tube‐lining membrane of tube‐dwelling Polychaeta in the fossil record. A new genus and species, Caprascolex antarcticus, are described. The specimens are preserved as thin coatings of amorphous iron oxide on the inner surface of the moulds interpreted to be the replaced tube‐lining membrane. Examination of the rarely described tube‐lining mucosoid membrane in extant polychaetes shows that the fossils are nearly identical in morphology and scale to extant forms. These fossils record in remarkable detail the morphology of the tube‐lining membrane, which appears to be composed of growth bands formed as the worm constructed the tube. The tube‐lining is believed to have been originally preserved as pyrite, with subsequent oxidation to iron oxide. The tube‐lining membrane of worm tubes possibly is known from only one other fossil occurrence.
Role of adrenergic receptors in the reflex diuresis in rabbits during pulmonary lymphatic obstruction
Authors: McCormick K. M. , Bravo E. M. , Kappagoda C. T.
Published: January 2005

The role of adrenergic receptors in the reflex diuresis in response to pulmonary lymphatic drainage was examined in anaesthetized, artificially ventilated New Zealand White rabbits. Pulmonary lymphatic drainage was obstructed by raising the pressure in a pouch created from the right external jugular vein. This pulmonary lymphatic obstruction results in a reflex increase in urine flow and sodium excretion. This reflex is abolished by renal denervation and by administration of l‐NAME, a non‐selective inhibitor of nitric oxide synthase. Also, infusion of the relatively selective neuronal nitric oxide synthase blocker, 7‐nitroindazole sodium salt, into the renal medulla abolished the reflex diuresis. In this study the effects of adrenergic receptor antagonists on the reflex increase in urine were observed. Both ureters were cannulated in order to determine urine flow from both kidneys separately. Prazosin, an α1 adrenergic receptor antagonist, was infused into the renal medulla of the right kidney, while the left kidney acted as control. Administration of prazosin in this manner did not block the reflex diuresis in response to pulmonary lymphatic obstruction in either kidney. However, rauwolscine, an α2 adrenergic receptor antagonist, abolished the reflex increase in urine and sodium excretion in the ipsilateral kidney while preserving it in the contralateral kidney. These findings suggest that the increase in urine flow in rabbits caused by pulmonary lymphatic obstruction is dependent upon activation of α2 adrenergic receptors within the renal medulla.
SPUTTERED AMORPHOUS CARBON FILMS: MICRO-STRUCTURE, DENSITY, OPTICAL AND MECHANICAL PROPERTIES
Authors: LOGOTHETIDIS S.
Published: January 2005

Amorphous carbon (a-C) films, single and multilayered, were deposited by rf magnetron sputtering, from graphite, on c-Si substrates. In-situ and real-time Spectroscopic Ellipsometry (SE) was used to determine the optimum deposition conditions where the formation of controllable sp 3 sties can be achieved. The growth mechanisms of sputtered a-C films and their properties (optical, compositional, density and mechanical) were studied using a variety of novel characterization techniques. SE data analysis provides: (i) the sp 3 and sp 2 volume fractions and (ii) the optical properties, that are combined well with the density, the internal stresses and the elastic properties of ultra-thin to thick a-C films. In sputtering, the applied substrate bais voltage Vb (up to -200V) controls the energy (30≤E≤230 eV) of the Ar+ ions bombarding the growing film surface, affecting all film properties and responses and classifying the films in three types. The film developed with E≈30 eV (rich in sp 2 sites) and 30130 eV, where the formation of a new and dense carbon phase is deteched, exhibiting a semi-metallic optical behavior. The experimental results show: a) in films of type I and II the stress, density, hardness and elastic modulus are directly related with the sp 3 content and described well with the so far proposed models on the formation mechanism of tetrahedral carbon, and b) the density and the elastic properties, in type III films, depend not only on the sp 3 content but also on the new carbon phase. a-C films deposited by sputtering exhibit unique properties that can be tailored to meet specific application requirements. For example, the combination of single a-C films of type I and II in developing multilayered films resulted to the growth of stable, thick and highly sp 3 bonded films with improved elastic properties.
DEPOSITION OF DLC FILMS USING MAGNETRON PLASMA IN AN UNBALANCED MAGENTIC FIELD
Authors: FUJIMAKI S. , KASHIWASE H. , KOKAKU Y. , OHNO T. , HONDA Y. , INABA H.
Published: January 2005

A new type of unbalanced magnetic field for planer magnetron cathode was applied to conduct PE-CVD by the assistance of dc magnetron discharge. A carbon thin carbon was formed on a negatively biased substrated by supplying Ar and CH4. This coating was found to have the physical properties equivalent to the DLC sample by ECR-CVD. This paper describes the sample and efficient DLC coating method based on the PE-CVD mechanism.
THE DOUBLE BEND FILTERED CATHODIC ARC TECHNOLOGY AND ITS APPLICATIONS
Authors: Shi X. , Tay B. K. , Lau S. P.
Published: January 2005

A new Filtered Cathodic Vacuum Arc coating system with a magnetic macroparticle filter design consisting of an off-plane double-bend (OPDB) filter is described. The transport of the vacuum arc plasma through this OPDB filter is investigated using Langmuir and deposition probes. Films of amorphous hard carbon have been deposited a 90° single bend and the OPDB filter and the macroparticle contents of the films are compared. The experimental results were found to be in good agreement with the simulations results based on an improved drift approximation model. The results demonstrate the OPDB filter has a relatively better transmission efficiency than the 90° single bend filter, lower macroparticle counts and is suitable for preparation of diamond-like carbon coatings with high quality. Some important applications of the ta-C coating produced by using the new FCVA system have been identified and where applicable industrial testing results are presented.
X-RAY REFLECTIVITY STUDY OF TETRAHEDRAL AMORPHOUS CARBON FILMS
Authors: Tay B. K. , Shi X. , Lau S. P. , Zhang Q. , Chua H. C. , Shi J. R. , Lim E. C. , Lee H. Y.
Published: January 2005

Hydrogen-free amorphous carbon films were deposited at different deposition bais voltage on a single silicon wafer by a process known as Filtered Cathodic Vacuum Arc (FCVA). The influences of different deposition bias voltages on the microstructure and the properties of thin tetrahedral amorphous carbon (ta-C) films, such as surface roughness, film mass density and thickness, have been studied by means of the x-ray reflectivity technique (XRR) for the first time. The microstructure of these films deposited on silicon wafers was stimulated by a four-layer model consisting of a ta-C layer, a mixed ta-C:Si layer, Si-O layer and the silicon subtrate. The mixed ta-C:Si layer consisting of the mixture of ta-C and silicon simulates the carbon ion impinging / diffusion into the surface of the silicon substrate. The mass density and the roughness of the film are found to be dependent on the impinging ion bombardment energy. The mass density increases with increase in ion bombardment energy up to 100 eV. Beyond 100 eV, the mass density decreases with further increase in ion bombardment energy up to 100 eV. Beyond 100 EV, the mass density decreases with further increase in ion bombardment energy. The surface roughness decreases with increasing ion bambardment energy to a minimum value at 100 eV, after which it increases with further increase in ion bombardment energy. The thickness of the films obtained by XRR technique correlates well with the thickness measurement obtained by spectral reflectometry. The existence of the Si-O layer was verified by Auger depth profiling.
ELECTRONIC CONDUCTION IN ION IMPLANATED AMORPHOUS CARBON THIN FILMS
Authors: KHAN R. U. A. , SILVA S. R. P.
Published: January 2005

The electronic conduction mechanism occuring in amorphous thin films is quite complicated. In amorphous carbon films it is further exacerbated by the rich diversity of its microstructure as well as the large number of gap states present in the films. One of the main reasons for the tunability of the optical band gaps of these films not being exploited in active devices, has been the inability firstly to reduce the gap states to an acceptable level, and secondly finding suitable dopants that are electrically active at room temperature. The large number of gap states in the films further exacerbates its problems by not allowing suitable barriers (eg. Schottky) to be formed on to the amorphous carbon films.

In this paper we hope to first divide the amorphous carbon thin films into two main categories. Namely, diamond-like carbon films which have a high precentage of C-C sp 3 bonding, and polymer-like carbon films that also have a high percentage of sp 3 bonding which is a mixture of C-C and C-H bonds, and have a high percentage of hydrogen as well as large optical band gaps. Recent results based on ion implantation using ions such as N, B, C will be contrasted to in-situ dopant incorporation via a gaseous source., and is shown to be a very powerful technique of modifying the conduction properties.

It will be shown that in the diamond-like films the conduction properties are usually controlled via Poole-Frenkel type defect conduction, while for the polymer-like films it is more a space charge based bulk and possibly, barrier controlled process. But, due to the large band gaps of these films it is difficult to distinguish between the bulk effects and the barrier effects.
AMORPHOUS CARBON THIN FILMS FOR OPTOELECTRIC DEVICE APPLICATION
Authors: SOGA T. , JIMBO T. , KRISHNA K. M. , UMENO M.
Published: January 2005

Thin films of amorphous carbon (a-C and a-C:H) have been deposited using different carbon precursor materials such as camphor - a natural source, graphite and CH4/H2 mixture by different deposition methods, such as ion beam sputtering, pyrolysis, pulsed laser deposition and r.f. plasma CVD. The films are subjected to various standard characterization techniques in order to tailor the required structural and opto-electrical properties for device applications. The effects of deposition parameters and annealing temperatures on the properties of carbon thin films have been investigated. Both p- and n- type of carbon films have been obtained either through controlling the deposition parameters of a particular method or by doping. Solar cells of various configurations, such as n-C/p-Si, p-C/n-Si and n-C/p-C/p-Si, have been fabricated and their photoresponse characteristics are studied. An efficiency of 1.52% has been obtained, so far, for the cell of configuration n-C/p-C/p-Si. Effects of substrate temperature on the photovoltaic properties are also outlined in brief.
THE ELECTRONIC STRUCTURE AND MEMORY DEVICE APPLICATIONS OF TETRAHEDRAL AMORPHOUS CARBON
Authors: McKENZIE D. R. , GERSTNER E. G. , MERCHANT A. R. , McCULLOCH D. G. , GOA P. E. , COOPER N. C. , GORINGE C. M.
Published: January 2005

The introduction of nitrogen dopant sites into tetrahedral amorphous carbon produces changes in the structure and the electronic density of states that can be modelled using molecular dynamics. In this work we use both a tight-binding approach and a Car-Parrinello density functional theory approach. In a comparison of these, we found that the former tends to overestimate the strain energy of 3 membered carbon rings relative to the latter and to experiment, explaining the reduced occurrence of 3 membered rings in networks and simulated using tight-binding. Experiment shows that at approximately 3% of nitrogen, the network begins to change rapidly with nitrogen content. In this form, an additional electronic conduction mode is found experimentally, of the Poole-Frenkel type, which can be turned on and off at will. The conduction is turned on by negative voltage excursion and quenched by a positive one. This conduction bistability can be exploited to produced a simple new type of memory device in which the high conductivity state (''on'') is a digital ''1'' and the low conductivity state (''off'') is a digital ''0''. The operating characteristics of the device are excellent, with more than one million read cycles having been demonstrated without deterioration of the discrimination between the ''on'' and ''off'' states. Molecular dynamics is used to study the configuration of the nitrogen atoms, yielding a possible candidate for the site responsible for the Poole-Frenkel conduction.
DENSITY-OF-STATES AND OPTICAL PROPERTIES IN AMORPHOUS CARBON THIN FILMS
Authors: EMELLI E. , FANCHINI G. , TAGLIAFERRO A.
Published: January 2005

In this paper we will link the local structure of amorphous carbon and the semi-empirical model which assumes the density of π and π* states as having Gaussian shapes and to be symmetrical with respect to Fermi level. We will show that the effect of charge transfer from sp3 to sp2 sites due their difference in electron-negativity, when coupled with the disorder effect (taken into account by assuming Gaussian distribution of the amount of charge transfer) lead to a sum of Gaussian symmetrical bands. Moreover, we will show that the sp2 pairs are responsible for most of the joint density-of-states (i.e. the imaginary part of the dielectric constant) in the visible region. The limits of the approach will be discussed as well.
RAMAN AND PEELS STUDIES ON MAGNETRON SPUTTERED a-C
Authors: ZHANG SAM , JEN TAN MING , ZENG XIANTING , XIE HONG , HING PETER
Published: January 2005

Amorphous carbon coatings (a-C, a-C:H) of less than 100 nm thick were deposited on KBr pellets and silicon wafer substrate via magnetron sputtering of graphite target in argon, argon/hydrogen and argon/nitrogen atmosphere. Parallel electron energy loss spectroscopy (PEELS) analysis was used to quantify the sp 2/ sp 3 bonding in carbon films. Stand-alone films of amorphous carbon were produced by sputtering onto compressed KBr pellets and then floating off is distilled water for PEELS study. Raman spectroscopy was used to measure the peak intensity ratio of D-band to that of the G-band (IdIg). It shows that higher sp 3 fraction often associates with lower Raman peak ratio (IdIg). At the same time, G-band peak position P g decreases while sp 3 fraction increases.
PHOTOLUMINESCENE PROPERTIES AND LOCAL STRUCTURE OF POLYMER-LIKE A-C:H FILMS
Authors: GODET C. , HEITZ T. , BOURÉE J. E.
Published: January 2005

In order to understand better the electronic properties of π-bonded materials, some optical and photoluminescence properties of amorphous carbon films have been investigated as a function of film density (0.9 to 1.7 g.cm-3). This study gives an overview of the radiative recombination properties in relation with local structure characterizations (in situ infrared ellipsometry and Raman spectroscopies) for a series of dual-plasma deposited polymer-like a-C:H films. Medium range topology has consequences in the hyperconjugation effects seen on infrared bands, as well as in optical and resonant Raman characteristics. Photoluminescence (PL) excitation spectroscopy reveals resonance features which are attributed to exciton-like electron-hole pairs in close Coulomb interaction. The PL efficiency shows a sharp quenching for densities above 1.3 g.cm -3 where a clear transition also occurs in the Raman "fingerprint". In addition, quantiative analysis of IR ellipsometry and Elastic Recoil Detection give evidence of a strong decrease of both the effective dynamical charge e*(C-H) and the bandwidth of sp 3 C-H vibrations; this is interpreted as being a result of the increase of local strains in the carbon skeleton, meaning that matrix distortions already appear at H content values as high as 46 H at .% due to film densification. An expected consequence is the mixing between π and σ molecular orbitals and the enhancement of the dissociation rate of confined electron-hole pairs. PL quenching would thus result form both a decrease of exciton confinement and an increase of the density of accessible nonradiative centers.
FIELD EMISSION FROM CARBON NANOTUBES PRODUCED USING MICROWAVE PLASMA ASSISTED CVD
Authors: ZHANG QING , YOON S. F. , AHN J. , GAN BO , RUSLI  , YU M.-B , CHEAH L. K. , SHI X.
Published: January 2005

Electron field emission from carbon nanotubes prepared using microwave plasma assisted CVD has been investigated. The nanotubes, ranging from 50 to 120 nm in diameter and a few tens of microns in length, were formed under methane and hydrogen plasma at 720°C with the aid of iron-oxide particles. The morphology and growth direction of the nanotubes are found to be strongly influenced by the flow ratio of methane to hydrogen. However, the electron field emission from these massive mantubes show similar characteristics, i.e., high emission current at low electric fields.