bluuebunny/crossref_metadata_2025 huggingface dataset:
Managing Business Records in Malaysia: awareness and attitudes among business managers
Authors: Yusof Zawiyah M. , Chell Robert W.
Published: October 2003

The government of Malaysia is aware of the importance of record keeping in business as part of its effort to cultivate a well-informed society. Businesses are encouraged to manage their information in order to be competent and responsible. Within this environment, a research project was carried out to investigate whether businesses in Malaysia manage their records (as one part of their information resource). The project’s aim was to create an awareness of the importance to businesses of adopting records management programmes, given that Malaysia is moving toward an information society. The study used a survey approach, which employed a questionnaire for data collection, amongst business organizations listed on the Kuala Lumpur Stock Exchange, as the sample population. The findings showed that a records management programme is an uncommon practice in business in Malaysia. This is not surprising, given that records management is a relatively new discipline in information studies. It is hoped that this research will help to promote records management in Malaysian businesses and will allow further research in this field, especially in respect of the legal and regulatory requirements for record-keeping in Malaysia.
Application of Nanoindentation Development of Biomedical to Materials
Authors: Haque F.
Published: October 2003

The use of nanoindentation techniques to characterise biomedical materials is reviewed. Nanoindentation, which allows measurement of material hardness and elastic properties at submicrometre depths, has found application in many areas and is increasingly being used to probe microstructural components of mammalian bone. This is in addition to more long standing work on indentation of orthopaedic coatings, dental restorative materials and even thin films of phase transforming (shape memory) alloys. The ability of the technique to test samples of limited dimensions is key for biomedical materials. One important emerging application relates to in vivo glucose sensor technology, where initial contact with blood and subcutaneous tissue results in mass protein deposition on the outer surface of the sensor. The molecular size range within which proteins are categorised makes nanoindentation attractive as a novel technique to probe surface protein films.
Laser Cladding of Austenitic Stainless Steel with Hardfacing Alloy Nickel Base
Authors: Kaul R. , Ganesh P. , Albert S. K. , Jaiswal A. , Lalla N. P. , Gupta A. , Paul C. P. , Nath A. K.
Published: October 2003

A nickel base alloy Colmonoy 6 was chosen as a candidate material for hard facing many components in the prototype fast breeder reactor. This alloy offers outstanding wear resistance and high hardness at elevated temperatures. Previous research using the gas tungsten arc welding process revealed that the hardness of the deposit is influenced by the dilution from the base metal up to a deposit thickness as high as 2.5 mm. The present study aims to control the level of dilution in the hard face deposits by carrying out deposition using a low heat input laser cladding process. The samples were characterised by macroscopic and metallographic examination, and microhardness measurements, SEM - EDAX and XRD analysis were used to determine their properties. The study demonstrated that by controlling laser cladding parameters, thin deposits with a low level of dilution can be laid on austenitic stainless steel substrate. Cracking of the deposit was minimised by controlling the heating and cooling rates.
Effects of Heater Surface Precoating and Plasma Treatment on Deposited TiN Film Thickness
Authors: Zhong Z. W. , Lye T. M.
Published: October 2003

Titanium nitride (TiN) films are widely used in integrated circuits as diffusion barrier and adhesion layer materials. Process kits in the chemical vapour deposition (CVD) chamber, which have been in service for a long time, become coated with a thick TiN film and must be replaced with new or recycled parts during chamber preventive maintenance. However, after the replacement of the process kits and the chamber preventive maintenance, it is difficult to achieve the required uniformity and thickness and this results in a delay before the chamber can be released for production. The present paper evaluates the effects of two methods: heater surface precoating and plasma treatment. Experimental results show that these two methods are useful and effective in controlling the deposition rate and improving thickness uniformity in the TiN CVD process. The recovery time after preventive maintenance can also be shortened, improving chamber utilisation and reducing costs.
Wear Performance of Ultra High Molecular Polyethylene Ion Implanted Weight
Authors: Shi W. , Dong H. , Bell T.
Published: October 2003

Surface modification of ultra high molecular weight polyethylene (UHMWPE) was explored using ion implantation with different dosages (1 × 1015 - 1 × 1017 ions cm -2) of nitrogen. The modified surfaces were characterised by SEM, nanoindentation and tribological tests. The experimental results showed that ion implantation can significantly increase the surface hardness of UHMWPE. However, the improvement in wear resistance of the modified UHMWPE is highly dose dependent. Compared with the untreated material, the low dose implanted UHMWPE exhibited a three fold improvement in wear resistance, while the high dose ion implanted material showed hardly any improvement although it possessed the highest hardness.
Development of Compound Layer of Iron (Carbo)Nitrides during Nitriding of Steel
Authors: Ratajski J. , Tacikowski J. , Somers M. A. J.
Published: October 2003

The composition and phase constitution of a compound layer developing during gaseous nitriding was investigated at 853 K for three commercial steels (AISI 120, 4340 and 1090) and Armco iron. The compound layers were characterised by light optical microscopy, X-ray diffraction and electron probe microanalysis. The formation of the compound layer occurs along two distinct sequences: α→γ′→ϵ and/or α ( θ)→ϵ2→γ′→ϵ1. The preferred sequence depends mainly on the chemical composition of steel and on the nitriding potential.
Study of Sliding Wear Behaviour at High Temperature of PVD MoZrSiAIN Coating Deposited on Aisi 1045 Steel
Authors: Staia M. H. , D'Alessandria M. , Cruz M. R. , Castro A.
Published: October 2003

The present study investigates the microstructure, mechanical properties and wear resistance at high temperature of MoZrAlSiN coating on an AISI 1045 substrate. The coatings were characterised by SEM and X-ray diffraction. Tribological behaviour of the coatings was determined by ball on disc wear tests without lubrication. The effect of temperature was investigated for the coated discs at temperatures of 25 ° C, 300 ° C and 500 ° C. The values of the friction coefficient increased with temperature achieving aver. age values as high as 0 9 to 1. The coating deposition has a beneficial effect on the wear performance of the AISI 1045 steel at any tested temperature, contributing to a substantial decrease in the wear volume value. The wear mechanisms are discussed and related to changes in the dynamic friction coefficient values and the corresponding topographical analysis of the worn surface.
Superelastic Fullerene-like Carbon Nitride Coatings Synthesised by Reactive Unbalanced Sputtering Magnetron
Authors: Neidhardt J. , Czigány Zs. , Hultman L.
Published: October 2003

The present paper presents the results of in depth process characterisation and microstructural investigation of fullerene-like carbon nitride (FL - CNx) coatings combined with deformation analysis, such as indentation testing, in order to assess its performance. Unbalanced reactive magnetron sputtering of graphite in a nitrogen containing atmosphere is essential for the growth of FL - CNx structures due to CxNy molecules, which are preformed in the process and may act as precursors or growth templates. The deposition process is best described as a hybrid of plasma vapour deposition and chemical vapour deposition. The fullerene-like (FL) structure leads to extraordinary mechanical properties which are assessed by nanoindentation. It exhibits a low work of indentation (usually a property associated with superhard materials) and also a low to moderate resistance to penetration. Therefore, deformation energy is predominantly stored elastically and released after unload giving it a tough and resilient character. In addition, the relatively low modulus leads to a spreading of the contact stresses over a larger volume and consequently to low stress gradients at the substrate/film interface. This hinders substrate/film delamination under load and therefore results in a high load bearing capability, while the coating asperities behave elastically with no tendency to brittle fracture in tribological contact. This characteristic combined with the low coefficient of friction reveals a coating which may be suitable for many tribological applications.
PVD Aluminium Alloy Coatings: Environmentally Friendly Alternative to Protect Steel Parts against Corrosion
Authors: De Araujo P. , Steyer P. , Millet J.-P. , Damond E. , Stauder B. , Jacquot P.
Published: October 2003

In the automotive and aeronautic industries, security is of prime importance and so corrosion prevention is essential. Steel parts were once protected with deposits such as cadmium or zinc - nickel produced using a chromatation treatment but recent environmental directives dictate that these methods are no longer acceptable. Aluminium sacrificial coatings have excellent corrosion behaviour but unfortunately they have poor mechanical characteristics and a fast dissolution rate. The present study investigated a possible solution: alloying the aluminium with a more noble element, chromium, in order to decrease the sacrificial galvanic effect of the deposit and therefore improve its lifetime. The corrosion protection afforded by such coatings in relation to their structure and mechanical properties was investigated. The coatings were produced on carbon steel by a vacuum PVD arc evaporation process at a pilot scale. Intrinsic electrochemical properties were determined on pure materials and on layers deposited on glass strip. Several elaboration configurations (pure as well as composite targets) were investigated. In most cases the coatings were stratified and composed of pure aluminium and numerous hardened AlxCry intermetallic phases. Chromium enrichment of aluminium based coatings induces not only a beneficial hardening effect on the surface characteristics (> 700 HV) but also significantly improves the corrosion behaviour of the coated pieces (increasing lifetime by up to three times compared to pure Aluminium).
Edge Related Effects during Ion Assisted PVD on Sharp Edges and Implications for Coating of Cutting Tools
Authors: MacAk E. B. , Münz W.-D. , Rodenburg J. M.
Published: October 2003

During ion assisted physical vapour deposition on sharp edges and corners, interaction between the plasma and the samples can lead to significant changes in the morphological and compositional properties of the coatings in the edge region. These edge related effects were studied on wedge shaped samples coated with TiAlN/VN coating in an industrial deposition process using low energy high flux Ar+ ion irradiation (Ji/Jme∼4, Ei = 75 - 150 eV). The magnitude and spatial extent of edge related changes are directly related to the characteristics of the plasma sheath around the edges. The influence of the edge geometry and the deposition conditions (substrate bias) is examined, as well as the implication for the coating of cutting tools.
Use of multiple orientation cues by juvenile loggerhead sea turtlesCaretta caretta
Authors: Avens Larisa , Lohmann Kenneth J.
Published: October 2003

Although the orientation cues used by hatchling sea turtles have been studied extensively, little is known about the mechanisms of orientation and navigation that guide older turtles. To investigate the orientation cues used by juvenile loggerheads Caretta caretta L., captured turtles were tethered in a water-filled arena located outdoors. Turtles tested under these conditions established and maintained headings in specific directions in the absence of wave cues, familiar landmarks and chemical gradients. Distorting the magnetic field around the anterior part of a turtle's body did not disrupt orientation if vision remained unimpaired. Similarly, eliminating visual cues by attaching frosted goggles did not disrupt orientation if the magnetic environment was undisturbed. However, when turtles experienced a simultaneous disruption of magnetic and visual cues, their orientation was altered. These results imply that sea turtles, like migratory birds and homing pigeons, are able to maintain headings using multiple sources of directional information.
The aerodynamics of insect flight
Authors: Sane Sanjay P.
Published: October 2003

The flight of insects has fascinated physicists and biologists for more than a century. Yet, until recently, researchers were unable to rigorously quantify the complex wing motions of flapping insects or measure the forces and flows around their wings. However, recent developments in high-speed videography and tools for computational and mechanical modeling have allowed researchers to make rapid progress in advancing our understanding of insect flight. These mechanical and computational fluid dynamic models, combined with modern flow visualization techniques, have revealed that the fluid dynamic phenomena underlying flapping flight are different from those of non-flapping,2-D wings on which most previous models were based. In particular, even at high angles of attack, a prominent leading edge vortex remains stably attached on the insect wing and does not shed into an unsteady wake, as would be expected from non-flapping 2-D wings. Its presence greatly enhances the forces generated by the wing, thus enabling insects to hover or maneuver. In addition, flight forces are further enhanced by other mechanisms acting during changes in angle of attack, especially at stroke reversal, the mutual interaction of the two wings at dorsal stroke reversal or wing–wake interactions following stroke reversal. This progress has enabled the development of simple analytical and empirical models that allow us to calculate the instantaneous forces on flapping insect wings more accurately than was previously possible. It also promises to foster new and exciting multi-disciplinary collaborations between physicists who seek to explain the phenomenology, biologists who seek to understand its relevance to insect physiology and evolution, and engineers who are inspired to build micro-robotic insects using these principles. This review covers the basic physical principles underlying flapping flight in insects, results of recent experiments concerning the aerodynamics of insect flight, as well as the different approaches used to model these phenomena.
Introductory tail-flick of the Jacky dragon visual display: signal efficacy depends upon duration
Authors: Peters Richard A. , Evans Christopher S.
Published: October 2003

Many animal signals have introductory components that alert receivers. Examples from the acoustic and visual domains show that this effect is often achieved with high intensity, a simple structure and a short duration. Quantitative analyses of the Jacky dragon Amphibolurus muricatusvisual display reveal a different design: the introductory tail-flick has a lower velocity than subsequent components of the signal, but a longer duration. Here, using a series of video playback experiments with a digitally animated tail, we identify the properties responsible for signal efficacy. We began by validating the use of the computer-generated tail, comparing the responses to digital video footage of a lizard tail-flick with those to a precisely matched 3-D animation (Experiment 1). We then examined the effects of variation in stimulus speed, acceleration, duration and period by expanding and compressing the time scale of the sequence (Experiment 2). The results identified several variables that might mediate recognition. Two follow-up studies assessed the importance of tail-flick amplitude (Experiment 3),movement speed and signal duration (Experiment 4). Lizard responses to this array of stimuli reveal that duration is the most important characteristic of the tail-flick, and that intermittent signalling has the same effect as continuous movement. We suggest that signal design may reflect a trade-off between efficacy and cost.
Catecholamine secretion in trout chromaffin cells experiencing nicotinic receptor desensitization is maintained by non-cholinergic neurotransmission
Authors: McNeill Brian , Montpetit Colin J. , Perry Steve F.
Published: October 2003

The goal of the present study was to assess the catecholamine secretory capabilities of rainbow trout Oncorhynchus mykiss chromaffin cells experiencing desensitization of the nicotinic receptor. It was hypothesized that the potential to secrete catecholamines could be maintained under conditions of nicotinic receptor desensitization owing to activation of non-cholinergic release pathways. An in situ model for chromaffin cell nicotinic receptor desensitization was developed by perfusing a posterior cardinal vein preparation with saline containing 10–5 mol l–1 nicotine. Under such conditions of desensitization, the chromaffin cells were largely unresponsive to high-frequency (20 Hz)electrical stimulation; the minimal remaining secretory response was abolished by addition of the nicotinic receptor antagonist hexamethonium(10–3 mol l–1). In marked contrast, however,the capacity to secrete catecholamines in response to low-frequency (1 Hz)electrical stimulation was unaffected by nicotinic receptor desensitization or by cholinergic receptor blockade (hexamethonium plus atropine). In preparations experiencing nicotinic receptor desensitization, the stimulatory effect of low-frequency (1 Hz) stimulation on catecholamine secretion was reduced by 43% in the presence of the VPAC receptor antagonist,VIP6-28. The stimulatory effect of high-frequency (20 Hz)stimulation was unaffected by VIP6-28. Catecholamine secretion evoked by cod VIP (10–11 mol kg–1) and homologous angiotensin II ([Asn1, Val5] Ang II;5×10–7 mol kg–1) was markedly enhanced(107 and 97%, respectively) in desensitized preparations. However, the secretory response to the muscarinic receptor agonist methylcholine(1×10–3 mol kg–1) was unchanged by desensitization. The results of this study demonstrate that exploitation of non-cholinergic mechanisms, including peptidergic pathways activated during low-frequency neuronal stimulation, is a potential strategy whereby catecholamine secretion from trout chromaffin cells can be maintained during periods of nicotinic receptor desensitization.
Limits to sustained energy intake VIII. Resting metabolic rate and organ morphology of laboratory mice lactating at thermoneutrality
Authors: Król E. , Johnson M. S. , Speakman J. R.
Published: October 2003

We have previously shown that the food intake and milk production of MF1 laboratory mice lactating at 30°C, 21°C and 8°C increase as temperature declines. These data suggest that mice are not limited peripherally by the capacity of the mammary glands to produce milk but are limited by the capacity of the animal to dissipate body heat generated as a by-product of food processing and milk production. Here, we measure resting metabolic rate (RMR; prior to breeding and at peak lactation) and organ morphology (at peak lactation) in MF1 mice exposed to 30°C(thermoneutrality) and compare these traits with the same parameters measured previously in mice at 21°C and 8°C. The masses of visceral organs primarily responsible for energy flux (heart, lungs, stomach, small intestine,large intestine, liver, pancreas, spleen and kidneys) increased as temperature declined. The masses of all these organs differed between mice exposed to 8°C and 21°C, whereas only the masses of heart, liver and kidneys differed between mice at 21°C and 30°C. The increases in organ masses were paralleled by increases in RMR at peak lactation above the levels measured prior to breeding, with mice at 8°C and 21°C having significantly higher increases in RMR than mice at 30°C (29.6 kJ day–1, 25.5 kJ day–1 and 8.1 kJ day–1, respectively). The observed changes in visceral organs and RMR are consistent with both the heat dissipation and peripheral limit hypotheses. However, mice exposed to 8°C had substantially larger mammary glands than mice at 21°C or 30°C (2.450 g, 1.115 g and 0.956 g dry mass, respectively), which argues against the peripheral limitation hypothesis and is consistent with the heat dissipation limit hypothesis. In addition, cold exposure resulted in greater masses of brown adipose tissue,white adipose tissue, pelage and tail. We discuss these changes in the context of the potential thermoregulatory benefits from use of the heat generated as a by-product of milk synthesis.
MysteriousMystacina: how the New Zealand short-tailed bat(Mystacina tuberculata) locates insect prey
Authors: Jones Gareth , Webb Peter I. , Sedgeley Jane A. , O'Donnell Colin F. J.
Published: October 2003

The New Zealand short-tailed bat Mystacina tuberculata evolved in the absence of terrestrial mammals and initially with few potential predators. Unusual among bats, it is well adapted for the capture of prey on the ground. Bats from Fiordland, New Zealand had relatively low wing loadings and aspect ratios adapted for flight in cluttered habitats. We predicted that M. tuberculata would locate prey in air (uncluttered space) by echolocation. Echolocation call sequences associated with prey capture (terminal buzzes)were heard in the field, and bats detected and localized prey suspended on fishing line by echolocation in a flight cage. The bats emitted brief,multiharmonic echolocation calls at low duty cycle during search phase, and 64% of calls contained most energy in the fundamental harmonic. Approach- and terminal-phase calls were also broadband and multiharmonic. We predicted that bats would not use echolocation to locate prey hidden on the ground in leaf litter (cluttered space). Bats seemed unable to locate hidden prey precisely from the air and instead hunted for such prey while crawling. Echolocation calls were emitted at a low repetition rate on the ground, suggesting that here echolocation was used for orientation and not for prey detection. We experimentally removed cues available to the bats and showed that bats located mealworms in leaf litter by listening for prey-generated noises and possibly by olfaction.
Hot bees in empty broodnest cells: heating from within
Authors: Kleinhenz Marco , Bujok Brigitte , Fuchs Stefan , Tautz Jürgen
Published: October 2003

Honeybee colonies maintain brood nest temperatures of 33–36°C. We investigated brood nest thermoregulation at the level of individual worker behaviour and the transfer of heat from workers to the brood. Worker bees contribute to the regulation of brood nest temperature by producing heat while sitting motionless on the caps of brood cells. We report here an additional,newly observed heating strategy where heating bees enter empty cells between sealed brood cells and remain there motionless for periods of up to 45 min.

Individually marked worker bees on the surface of sealed brood cells maintained thorax temperatures (Tth) between 32.2±1.0°C and 38.1±2.5°C (mean ± s.d.; N=20 bees) with alternating warming and cooling periods. Most of the observed bees made one or several long-duration visits(>2 min) to empty cells within the sealed brood area. Tth at the time bees entered a cell[Tth(entry)] was 34.1–42.5°C (N=40). In 83% of these cell visits, Tth(entry) was higher (up to 5.9°C; mean 2.5±1.5°C; N=33) than the mean Tth of the same bee. High values of Tth(entry) resulted from preceding heating activity on the comb surface and from warm-ups just prior to cell visits during which Tth increased by up to +9.6°C.

Bees inside empty cells had mean Tth values of 32.7±0.1°C (resting bees) to 40.6±0.7°C (heat-producing bees) during long-duration cell visits without performing any visible work. Heating behaviour inside cells resembles heating behaviour on the brood cap surface in that the bees appear to be inactive, but repeated warmings and coolings occur and Tth does not fall below the optimum brood temperature.

Bees staying still inside empty cells for several minutes have previously been considered to be `resting bees'. We find, however, that the heating bees can be distinguished from the resting bees not only by their higher body temperatures but also by the continuous, rapid respiratory movements of their abdomens. By contrast, abdominal pumping movements in resting bees are discontinuous and interrupted by long pauses.

Heat transfer to the brood from individual bees on the comb surface and from bees inside empty cells was simulated under controlled conditions. Heating on the comb surface causes a strong superficial warming of the brood cap by up to 3°C within 30 min. Heat transfer is 1.9–2.6 times more efficient when the thorax is in touch with the brood cap than when it is not. Heating inside empty cells raises the brood temperature of adjacent cells by up to 2.5°C within 30 min. Heat flow through the comb was detectable up to three brood cells away from the heated thorax.
Ventricular haemodynamics inPython molurus: separation of pulmonary and systemic pressures
Authors: Wang Tobias , Altimiras Jordi , Klein Wilfried , Axelsson Michael
Published: October 2003

Vascular pressure separation by virtue of a two-chambered ventricle evolved independently in mammals and birds from a reptilian ancestor with a single ventricle, and allowed for high systemic perfusion pressure while protecting the lungs from oedema. Within non-crocodilian reptiles, ventricular pressure separation has only been observed in varanid lizards and has been regarded as a unique adaptation to an active predatory life style and high metabolic rate. The systemic and pulmonary sides of the ventricle in Python molurusare well separated by the muscular ridge, and a previous study using in situ perfusion of the heart revealed a remarkable flow separation and showed that the systemic side can sustain higher output pressures than the pulmonary side. Here we extend these observations by showing that systemic blood pressure Psys exceeded pulmonary pressure Ppul almost seven times (75.7±4.2 versus11.6±1.1 cm H2O). The large pressure difference between the systemic and pulmonary circulation persisted when Psys was altered by infusion of sodium nitroprusside or phenylephrine. Intraventricular pressures, measured in anaesthetised snakes, showed an overlap in the pressure profile between the pulmonary side of the ventricle (cavum pulmonale) and the pulmonary artery, while the higher pressure in the systemic side of the ventricle (cavum arteriosum) overlapped with the pressure in the right aortic arch. This verifies that the pressure differences originate within the ventricle, indicating that the large muscular ridge separates the ventricle during cardiac contraction.
Aggregation through the Quadrupole Interactions of Gold(I) Complex with Triphenylphosphine and Pentafluorobenzenethiolate
Authors: Watase Seiji , Kitamura Takayuki , Kanehisa Nobuko , Shizuma Motohiro , Nakamoto Masami , Kai Yasushi , Yanagida Shozo
Published: October 2003

A new class of the aggregation of the gold(I) phosphine complex with pentafluorobenzenethiolate ligand through intermolecular quadrupole interactions was designed and characterized both by X-ray crystallography in solid state and by electrospray ionization mass spectroscopy in solution.
Liquid Phase Hydrogenation of Phenol to Cyclohexenone Over A Pd–La–B Amorphous Catalyst
Authors: Zhuang Li , Li Hexing , Dai Weilin , Qiao Minghua
Published: October 2003

A La-doped Pd–B amorphous catalyst (Pd–La–B) was prepared by chemical reduction of mixed PdCl2 and LaCl3 with KBH4. The La-dopant played a key role in stabilizing the amorphous structure since only the crystalline Pd–B was obtained without the La-dopant. During liquid phase phenol hydrogenation, the as-prepared Pd–La–B exhibited higher activity and better selectivity to cyclohexanone than the undoped Pd–B.
Trimethylsilylated Chitosan: A Convenient Precursor for Chemical Modifications
Authors: Kurita Keisuke , Hirakawa Masaaki , Aida Kaori , Yang Jin , Nishiyama Yasuhiro
Published: October 2003

Trimethylsilylation of chitosan was attained efficiently with hexamethyldisilazane and chlorotrimethylsilane. The resulting silylated derivative was characterized by remarkable reactivity as well as improved solubility and proved to be a convenient precursor for modification reactions.
UV Light-assisted Chemical Vapor Deposition of TiO2 for Efficiency Development at Dye-sensitized Mesoporous Layers on Plastic Film Electrodes
Authors: Murakami Takurou N , Kijitori Yujiro , Kawashima Norimichi , Miyasaka Tsutomu
Published: October 2003

Chemical vapor deposition of TiO2 combined with UV light irradiation at nanocrystalline TiO2 particle layers coated on plastic film electrodes (ITO-PET) drastically enhanced dye-sensitized photocurrent and improved photovoltage up to 750 mV, achieving energy conversion efficiency of 3.8%.
Synthesis and Photochromism of Diarylethenes with Isopropyl Groups at the Reactive Carbons and Long π-Conjugated Heteroaryl Groups
Authors: Kobatake Seiya , Irie Masahiro
Published: October 2003

Diarylethenes with long π-conjugated heteroaryl groups were synthesized and their absorption spectra, photocyclization and cycloreversion quantum yields, and thermal stability were examined. The diarylethene with isopropyl groups at the reactive carbons was found to have a low decoloration quantum yield and thermal reversibility at high temperature above 100 °C.
Cu(II)-assisted Helicity Induction on a Poly(phenylacetylene) Derivative Bearing an Achiral Glycine Residue with Amino Acids in Water
Authors: Kawamura Hiroaki , Ishikawa Miki , Maeda Katsuhiro , Yashima Eiji
Published: October 2003

Poly(phenylacetylene) bearing an achiral glycine residue exhibits an induced circular dichroism in the UV–vis region upon complexation with free amino acids in water due to a predominantly one-handed helix formation and the Cotton effect intensity is amplified in the presence of a Cu(II) ion.
Reductive Coupling of Acid Chlorides with Nitriles Promoted by Titanium Tetraiodide. A Rapid Access to α-Imino Ketones
Authors: Shimizu Makoto , Manabe Nobuyuki , Goto Hiroshi
Published: October 2003

Reductive coupling reactions of carboxylic acid chlorides and alkyl nitriles were efficiently promoted by titanium tetraiodide to give α-imino ketones in good yields.
Recruitment and Retention of Dental Nurses and Dental Hygienists in General Practice
Authors: Allen Christopher D , Newton Paul D , Newton J Tim
Published: October 2003

Purpose of study

To explore the recruitment and retention of dental nurses and dental hygienists working in general dental practice in West Kent, and to identify training needs.

Basic procedure

Questionnaire survey of 195 general dental practices in West Kent.

Main findings

Problems with turnover of staff were reported by 19% of practices. Some 49% of practices reported difficulties in recruiting dental nurses, 6% had experienced difficulties recruiting dental hygienists, and 15% had difficulties recruiting both nurses and hygienists. The median length of service for both dental nurses and dental hygienists was five years. Approximately 39% of practices had advertised single posts three or more times. Difficulties in recruiting were related more strongly to ensuring the right person for the job, than to a shortage of applicants.

Principal conclusions

Difficulties in the recruitment and retention of dental nurses and dental hygienists were reported by dental practices in West Kent. These are likely to be exacerbated by the requirement that all dental nurses be registered with the General Dental Council.
Current Issues in Dental Practice Management Part 2. Pricing Policy in Dental Practice
Authors: Newsome Philip RH
Published: October 2003

This is the second in a series of articles exploring some of the issues facing dentists coming to terms with working in the ‘brave new world’. It examines the complex issues of understanding how pricing works, determining the price of a product or service, communicating this to customers, and understanding how people perceive prices and price changes
Diplomates Day 2003
Authors: Moss Adèle
Published: October 2003

On Saturday 1st March 2003 the Faculty of General Dental Practitioners (UK) hosted its annual Diplomates Day. A total of 85 individuals received diplomas in one of the largest ceremonies in the history of the FGDP(UK), which took place in the grand setting of the Edward Lumley Hall at The Royal College of Surgeons of England.
GDPs’ Self-perceived Confidence and Anxiety in Their Clinical and Communication Skills Used When Screening for Oral Cancer: UK Variations
Authors: Farrand Paul , Clover Henry , Hutchison Iain L
Published: October 2003

Objective

To compare anxieties of general dental practitioners (GDPs) across the UK in communicating with patients about oral cancer and confidence in clinical skills required to perform soft tissue screening for oral cancer.

Design

A questionnaire was sent to 2200 randomly selected GDPs from across the UK. Responses to the questionnaires were analysed using 95% confidence intervals.

Setting

Dental practitioners in general practice within England, Northern Ireland, Scotland and Wales.

Results

The response rate varied between 57% in England and 65% in Northern Ireland. A high percentage of dental practitioners across all UK regions reported performing soft tissue examinations (range 78% to 88%). The number of soft tissue examinations per month varied between 129 (95% CI 109, 148) and 162 (95% CI 154, 170) indicating criteria when selecting patients for screening. Using a nine-point rating scale (1 = not at all, 9 = extremely), confidence in the clinical skills required during oral cancer screening was generally good (ratings varying between 5.4 and 6.7). With the exception of reporting positive findings to patients (rating 4.5 to 5.2), anxiety in communication skills used during oral cancer screening was generally low (ratings varying between 1.8 and 3.9).

Conclusion

While concerns over generalising the results exist, the situation with respect to the clinical and communication skills required by GDPs during oral cancer screening is generally encouraging. An area of concern is discussing positive findings with patients. This may be overcome by developing specialist courses on breaking bad news within undergraduate dental curricula and programmes of continuing professional development.
A Survey of Current Practices among General Dental Practitioners in Manchester in 2002
Authors: Seow Liang Lin , Toh Chooi Gait , Wilson Nairn HF
Published: October 2003

Aim

The purpose of this study was to obtain data on current approaches for the restoration of endodontically treated teeth among general dental practitioners (GDPs) in Manchester, United Kingdom.

Method

A questionnaire containing 19 single-answer, multiple-choice type questions was mailed to 503 GDPs practising in the Greater Manchester area in January 2002. An explanatory covering letter and a stamped addressed return envelope were enclosed. The data obtained were processed using SPSS statistical software.

Results

Three hundred and fifty-one (70%) of the practitioners responded to the questionnaire. The restoration of root-filled teeth was normally undertaken within 1–2 weeks of completing root canal therapy by 63% of the practitioners. Only 35% of the GDPs used posts routinely in the restoration of root-filled anterior teeth; the corresponding figure for posterior teeth was 15%. While a cast, precious metal post was the preferred choice in the restoration of anterior teeth, the use of prefabricated posts and related techniques predominated in the restoration of posterior teeth. Composite resin was the most popular choice of material for core build-up procedures in anterior teeth. Amalgam tended to be favoured for core build-ups in posterior teeth. The majority of the practitioners (56%) routinely restored root-filled anterior teeth by means of porcelain-fused-to-metal crowns. Seventy-three per cent of the GDPs preferred to restore root-filled posterior teeth by means of a full veneer crown.

Conclusions

The results of this study suggest that the practitioners surveyed had a sound understanding of the principles involved in the restoration of endodontically treated teeth, with the possible exception of the need to establish a durable coronal seal as soon as possible after the placement of a root filling.
Emergency Dental Services: Review of the Community Health NHS Trust Service in Birmingham between 1997 and 2000
Authors: Khaleeq-Ur-Rehman
Published: October 2003

Aims and Objectives

To confirm the need for an emergency dental service in Birmingham and to review the emergency dental service run by the South Birmingham Community Health NHS Trust.

Design

A retrospective study of patients attending the emergency dental service from March 1997 to August 2000, using computerised patient records and a supplementary questionnaire for a nine-month period between August 1997 and April 1998.

Setting

Birmingham Dental Hospital.

Results

A review of the computerised records revealed that a total of 10,799 patients were seen during the study period. In the first year, on average five patients were seen on weekday evening sessions and 13 patients at weekends/public holidays. By the final year of the study, these figures increased to ten on weekday evenings and 16 at weekends/public holidays. Forty-three per cent of the attendees were in the 31–50 year age group and 33% in 19–30 year age group. Twenty-five per cent of patients required extractions, 20% received temporary dressings, 17% a prescription for antibiotics and 9% were treated for acute mucosal conditions such as pericoronitis. The remainder received other items of treatments, such as for dry sockets. The supplementary questionnaire revealed that during the period August 1997 to April 1998, 67% of the patients lived in Birmingham and the other 33% in the surrounding areas, and some 59% of patients claimed that they were registered with a dentist of whom 60% of patients were not exempt from NHS charges.

Conclusions

The results indicate that the service was widely and increasingly used during the study period. A similar pattern of emergency dental care in dedicated clinics could be established throughout the United Kingdom. A profile of users of the service during its first three-and-a-half years has been established.
A Combined Approach of Enamel Matrix Derivative Gel and Autogenous Bone Grafts in Treatment of Intrabony Periodontal Defects. A Case Report
Authors: Leung George , Jin Lijian
Published: October 2003

Enamel matrix derivative (EMD) has recently been introduced as a new modality in regenerative periodontal therapy. This case report demonstrates a combined approach in topical application of EMD gel (Emdogain®) and autogenous bone grafts for treatment of intrabony defects and furcation involvement defects in a patient with chronic periodontitis. The seven-month post-surgery clinical and radiographic results were presented. The combined application of EMD gel with autogenous bone grafts in intrabony osseous defects resulted in clinically significant gain of attachment on diseased root surfaces and bone fill on radiographs. Further controlled clinical studies are required to confirm the long-term effectiveness of the combination of EMD gel and autogenous bone grafts in treatment of various osseous defects in subjects with chronic periodontitis.
Restorative Management of the Elderly Patient
Authors: Gilmour A Graham , Morgan Claire L
Published: October 2003

It is predicted that geriatric patients will dramatically increase in number within our working lives. Although they are considered to demand treatment less frequently than the younger age groups, there are specific issues that need to be considered when providing dental treatment for these patients. The term gerodontics has been coined to describe this subject. The need to consider family relationships and the role of carers may play a greater part in their dental management than that of the general population. As well as oral disease, the incidence of general disease is higher in this population, as is the amount of medication prescribed to treat it; these factors often complicate dental management. Special problems that will have a high dental impact on the geriatric patient may be lack of adaptive potential, poor plaque control, root caries, periodontal breakdown and levels of toothwear.
Dentists’ Perceptions of Trends in Restorative Dentistry in the UK
Authors: Randall Ros C , Vrijhoef Matthijs MA , Wilson Nairn HF
Published: October 2003

Purpose of study

To obtain responses to a questionnaire on likely trends in the clinical practice of restorative dentistry from a national sample of general dental practitioners (GDPs) who were principals of group practices in the UK.

Basic procedures

A panel of nine experts had been convened previously to define areas of trends in restorative dentistry in the UK and to formulate these into statements. Twenty trends were identified and framed into a 22-item questionnaire based on the trend statements. The questionnaire was sent to a national sample of 2800 principal dentists in group practices. Names of principal dentists were taken from the Yellow Pages directories, a group practice being defined as at least one principal dentist and one other practitioner. Levels of agreement for questionnaire scores of ≥70% for all segments of a statement were taken as indicating a possible trend.

Main findings

Of the 2800 questionnaires sent out, 1448 were returned, a return rate of 52%. Of these, 1217 questionnaires were usable, an overall response rate of 44%. Good agreement was obtained for 14 statements (64%). Principal conclusion: The 14 trend statements that scored a level of good agreement were taken as indicating possible trends in dentistry in the UK as perceived by those GDPs who responded to the questionnaire. However, in view of the fact that the 1217 usable questionnaires received reflected the opinions of 10% of the principal dentists in group practice in the UK, this will not be representative of all principal dentists in practice. Nevertheless for the purposes of gaining some insight into trends in restorative dentistry, it could be considered to be of value.
Reasons for the Placement and Replacement of Crowns in General Dental Practice
Authors: Wilson Neil A , Whitehead Shaun A , Mjör Ivar A , Wilson Nairn HF
Published: October 2003

Aims

The purpose of the study was to apply established methods to survey reasons for the placement and replacement of crowns in general dental practice in the United Kingdom.

Materials and Methods

One hundred and twenty-eight general dental practitioners were recruited. Participants recorded the principal reason for the provision of each initial and replacement crown they provided over a 12-week period.

Results

Overall, data were collected from 92 practitioners in respect of 1714 patients and 2164 crowns, of which 1452 (67%) were initial placements and 712 (33%) replacements. The teeth most frequently crowned were maxillary incisors (33%), with 72% of the crowns surveyed being of the porcelain bonded to metal variety. Overall 64% of the initial placement crowns were provided because of restoration failure (26%) or tooth fracture (38%). The most common reason for crown replacement was crown failure (27%).

Conclusion

It is concluded that surveys of the type reported may provide new insights into the reasons for and pattern of provision of initial placement and replacement crowns in clinical practice. In this study the most common reason for the provision of initial placement crowns was tooth fracture. The most common reason for the replacement of crowns, notably porcelain jacket crowns, was crown fracture.
Risk Assessment of Dental Unit Waterline Contamination
Authors: Pankhurst Caroline L
Published: October 2003

Biofilms form rapidly on dental unit waterlines. The majority of the organisms in the biofilm are harmless environmental species, but some dental units may harbour opportunistic respiratory pathogens. This paper describes a risk assessment approach to analysing the hazard from biofilm organisms contaminating dental unit waterlines on the respiratory health of both the dental team and patients.

The health risk from the respiratory pathogens Legionella spp, Mycobacterium spp and Pseudomonads was found to be low. Nevertheless, in order to satisfy water regulations and comply with health and safety legislation dentists should institute infection-control measures to maintain the dental unit water at the standard of less than 200 colony-forming units per ml of aerobic bacteria.
Rotational Path of Insertion for Removable Partial Dentures with an Anterior Saddle
Authors: Yip Kevin H-K , Fang Daniel T-S , Smales Roger J , Newsome Philip RH , Chow Tak W
Published: October 2003

The provision of removable partial dentures remains a viable treatment modality for many partially dentate patients. Replacing missing anterior teeth with a removable partial denture using a rotational path of insertion provides improved retention and appearance. The use of a rotational path of insertion also provides additional retention for a removable partial denture restoring combined anterior and posterior bounded saddles. Two case reports demonstrate the use of the rotational path of insertion for partial denture design.
Dentistry for those Requiring Special Care
Authors: Scully Crispian , Kumar Navdeep
Published: October 2003

Individuals with special needs, namely those whose dental care is complicated by a physical, mental or social disability, often have a higher level of unmet dental need and poorer oral hygiene than the general population, and offer unique challenges to the dental practitioner. This paper outlines the dental management of the three most common groups of individuals with special needs.
Occupational Exposures Occurring among Dental Assistants in a UK Dental School
Authors: Stewardson Dominic A , McHugh Siobhan , Palenik Charles J , Burke FJ Trevor
Published: October 2003

Purpose

The cross-infection risks for dentists have been well recognised, and much has been published regarding the incidence of occupational exposures to patient body fluids. Less has been reported regarding the risks to dental assistants. The purpose of this study was to evaluate the incidence of occupational exposures to patient body fluids among dental assistants, to assess the rate of reporting of such incidents, and to evaluate the association of various factors with these exposures.

Method

All 84 dental assistants working at Birmingham Dental Hospital were asked to complete a confidential questionnaire to provide retrospective information regarding the nature and incidence of any occupational exposures they had experienced.

Results

An overall response rate of 94% was achieved. Dental nurses experienced fewer occupational exposures than dental students at the same institution, and reported incidents more frequently. More injuries occurred after the treatment session. Handling local anaesthetic syringes was associated with more injuries, and percutaneous injuries predominated. Trainee nurses had experienced more occupational injuries in the preceding six months than their qualified colleagues. There was no significant association with any of the other factors evaluated.

Conclusions

The general incidence of occupational exposures among the dental assistants in this survey was low in comparison to dental students at the same institution. A further reduction may be possible by increasing the training of unqualified nurses with particular regard to post-treatment handling of sharp dental instruments and equipment.