Effect of fluoridated toothpicks and dental flosses on enamel and dentine and on plaque composition in situ

The aim was to evaluate the effect of two toothpicks and two dental flosses on demineralized enamel and dentine and on plaque composition, using an in situ model with simulated approximal spaces within dentures. Fifteen subjects with full dentures were recruited and 14 completed the study. It consisted of two crossover periods, the first comparing a birch toothpick with AmF and a birch toothpick with NaF, and the second comparing a dental floss with AmF + NaF and a dental floss without F. Between these four periods, there was a control period without any approximal cleaning. In small, rectangular sample holders, one enamel and one dentine specimen were embedded, forming a triangular, approximal-like space. Two sample holders were mounted in the premolar-molar region of the upper or lower dentures. The subjects used the toothpicks or dental flosses 3 times/day for 4 weeks. The results showed that all toothpicks and dental flosses inhibited further demineralization compared to the control period ( p <0.001). The dental flosses were somewhat more effective in this respect than the toothpicks, especially in dentine. There were relatively small numerical differences between AmF and NaF toothpicks, but in favour of NaF regarding mineral gain ( p <0.05). The fluoridated floss gave somewhat less lesion depth in dentine than the non-fluoridated floss ( p <0.01). Toothpicks and flosses resulted in lower counts of microorganisms in plaque compared to the control period ( p <0.001); the AmF toothpick gave a more pronounced reduction than the NaF toothpick ( p <0.001). Copyright (C) 2005 S. Karger AG, Basel

Gas phase thermometry of hot turbulent jets using laser induced phosphorescence

This article is made available through the Brunel Open Access Publishing Fund. Copyright @ 2013 OSAThe temperature distributions of heated turbulent jets of air were determined using two dimensional (planar) laser induced phosphorescence. The jets were heated to specific temperature increments, ranging from 300 – 850 K and several Reynolds numbers were investigated at each temperature. The spectral ratio technique was used in conjunction with thermographic phosphors BAM and YAG:Dy, individually. Single shot and time averaged results are presented as two dimensional stacked images of turbulent jets. YAG:Dy did not produce a high enough signal for single shot measurements. The results allowed for a direct comparison between BAM and YAG:Dy, revealing that BAM is more suitable for relatively lower temperature, fast and turbulent regimes and that YAG:Dy is more suited to relatively higher temperature, steady flow situations

Solvent effects on two-line atomic fluorescence of indium

We aim to investigate the potential of four different organic solvents, namely, acetone, ethanol, methanol, and isopropanol, and the organic-solvent-water mixtures as a seeding medium for the two-line atomic fluorescence technique. Water is used as the reference case. Indium, which has been previously shown to have suitable spectroscopic attributes, is chosen as the thermometry species in the present study. Acetone and methanol are shown to enhance the fluorescence signal intensity the most (approximately threefold to fivefold at stoichiometric conditions) when used. Acetone and methanol are shown to improve the fluorescence emission over the entire stoichiometric envelope of flame, most significantly in the rich combustion region, as well as a twofold enhancement in the signal-to-noise ratio.Qing N. Chan, Paul R. Medwell, Peter A. M. Kalt, Zeyad T. Alwahabi, Bassam B. Dally, and Graham J. Natha

On Approximal Caries Prevention using Fluoridated Toothpicks, Dental Floss and Interdental Brushes

Although dental health has improved during the last 40-50 years, approximal caries still constitutes a problem in many age groups. It is important that fluoride (F) toothpaste is used when brushing the teeth. In some subjects, there may be a need for supplementary F products, especially in the caries-prone approximal area. Aim: The aims of this thesis were: i) to study the F release of F-containing approximal oral hygiene aids both in vitro and in vivo, ii) to evaluate different methods for the administration of F in vivo, iii) to study the effect of the frequent use of F-containing toothpicks and floss on demineralised enamel and dentine in situ and iv) to evaluate recommendations and the use of oral hygiene products for approximal cleaning in a Swedish adult population. Material and methods and Results: The F release of 26 brands of toothpicks and floss was followed for 24 hrs in vitro. A large variation in the release between these products was found; in general, toothpicks resulted in larger amounts of F compared with floss. The release in vivo was studied using single and multiple fluoridated toothpicks and dental floss, as well as in combination with toothbrushing or a mouthrinse with 0.2% NaF. Moreover, the administration of F by an interdental brush dipped in 0.2% NaF gel (here called the “Inter Dental Brush Gel Method”) was evaluated. Approximal saliva was collected, using paper points, before and up to 60 min after treatment. Both toothpicks and floss resulted in enhanced F concentrations in vivo. An interdental brush dipped in 0.2% NaF gel and a mouthrinse with 0.2% NaF resulted in the same F concentration as after using multiple toothpicks. All combinations of toothpicks and dental floss with F rinsing resulted in higher concentrations than after only toothbrushing or in combination with brushing. The most optimal order was to use toothpicks and dental floss after toothbrushing and before rinsing. Fifteen adults with full dentures, in which demineralised enamel and dentine specimens had been mounted, were included in an in situ experimental caries model. Toothpicks or floss, impregnated with NaF and amine fluoride (AmF), were used regularly for four weeks. All the products inhibited continuous demineralisation - dental floss somewhat more than toothpicks. A reduction in plaque micro-organisms was also found. Recommendations made by dental staff in relation to approximal cleaning aids were evaluated by a questionnaire sent to 500 dentists, 500 dental hygienists and 1000 patients in Sweden. The ability to remove approximal plaque was also evaluated in 60 regular users of approximal aids. Recommendations by dental staff are mostly given to children and adolescents in order to prevent dental caries and to older individuals to prevent gingivitis and periodontal disease. Approximal plaque appears to be more easily removed by regular users of interdental brushes compared with the use of toothpicks and dental floss. Conclusions: The use of fluoridated interproximal aids appears to be important in order to reduce approximal caries. An interdental brush dipped in a NaF gel is an interesting method for increasing approximal F concentration

Management Buyout

Uppsatsen behandlar bolagsförvärv genom management buyout (MBO), vilket innebär att styrelse och/eller ledning förvärvar bolaget i vilket de verkar. Syftet med uppsatsen är dels att beskriva hur en MBO går till, dels att påvisa de speciella problem som aktualiseras vid förvärv genom MBO. Flera av de problem som behandlas i uppsatsen kan visserligen även uppkomma vid andra typer av förvärv men är av särskilt intresse just vid MBO. Ett sådant exempel är användandet av det uppköpta bolagets kapital till finansieringen av förvärvet. Flera frågeställningar är dock ovanliga i andra sammanhang. Detta gäller i synnerhet den jävsproblematik som uppkommer genom att ledningen är köpare. Jag har valt att dela upp problemen i tre grupper, bolagsledningens informationsövertag, bolagsledningens lojalitet och det aktiebolagsrättsliga kapitalskyddet. Vad gäller bolagsledningens informationsövertag så är det uppenbart att bolagsledningen i många fall kan ha en bättre kännedom om bolaget än dess ägare. Särskilt om ägandet är spritt och utgörs av många småsparare. För att begränsa bolagsledningens möjligheter att utnyttja sitt informationsövertag har marknaden utformat regler bl.a. om medverkan av oberoende värderingsmän vid förvärvet. Reglerna kan dock inte enligt min mening anses vara tillfyllest. Som antytts ovan medför bolagsledningens förvärv komplicerade jävsfrågor. De aktiebolagsrättsliga reglerna om jäv måste anses inneböra att ledningen varken kan medverka i handläggningen eller medverka vid beslutsfattandet eller den föregående handläggningen av förvärvsfrågan. Som konstateras i uppsatsen har marknaden valt en mycket mer liberal tolkning av reglerna. Det avslutande problemområdet avser kapitalskyddet. Kapitalskyddets betydelse måste ses mot bakgrund av bolagsledningens svårigheter att uppbringa tillräckligt med kapital. Detta gör att det kan vara frestade för bolagsledningen att utnyttja det köpta bolagets kapital, och så sker också ofta i praktiken. Det är därför av vikt att försöka fastslå inom vilka ramar så kan ske. Helt klart är att man ofta kringgår de bestämmelser som finns

Laser-Induced Emission Techniques for Concentration and Temperature Probing in Combustion

The work in this thesis is aimed at the development of temperature and gas concentration measurement techniques in laser diagnostics for use in combustion research. The techniques are developed as tools for the combustion community to meet future demands on combustion efficiency and legislation of exhaust gases. Thermometry based on the use of laser-induced phosphorescence has been further developed and performed inside internal combustion engines, in a gas turbine afterburner, in burning liquids, and in research on oxy-fuel flame heat transfer. In work carried out within the EU 6:th framework program, an attempt was made to find new suitable thermographic phosphors for high temperature two-dimensional measurements in gas turbines. The gas turbine industry has a strong interest in better methods of thermometry at high temperatures for optimizing performance of combustion and engine parts. Measurements on spinning objects require the use of fast phosphors, previously unavailable for high-temperature two-dimensional measurements. A variety of inorganic phosphor materials, not previously used in thermometry, were investigated, some of them being very promising for thermographic use. Laser-induced oxygen sensing using a commercial pressure sensitive paint has been applied in low-temperature combustion. The material has been calibrated to oxygen and temperature. The work show on the potential of using oxygen quenched materials in combustion research even though it involves organic sensing materials. Laser-Induced Fluorescence was employed for visualization of formaldehyde both in Homogeneous Charge Compression Ignition, HCCI, and in Diesel combustion engines. Formaldehyde formed in HCCI combustion during low temperature reactions was shown to be able to function as fuel marker. This was demonstrated in simultaneous visualization of the traditional fuel tracer toluene and formaldehyde during operation of an HCCI engine. The use of formaldehyde as a fuel marker was also demonstrated in Diesel combustion, which is characterized by a lack of low temperature reactions and where the location of intermediate species is not obvious. Fuel visualization was also employed for the visualization of jet fuel in a jet stream of a fighter-jet gas turbine. Un-burnt fuel was found to exist in the exhaust for some engine conditions

Investigations of blue emitting phosphors for thermometry

Blue emitting phosphors are investigated and reported for possible use in thermometry. Currently reported thermographic phosphors in general have the drawback of long emission lifetimes obstructing the possibility to time gate for background discrimination. An additional problem is that many thermographic phosphors have emission in the red spectral region, making them vulnerable for black body radiation at high temperatures. This work reports the temperature sensitivity for nine phosphors considered suitable for accurate temperature measurements in harsh conditions both in single points and in two dimensions (2D)

Go In and Out and Turn Inside Out : A Qualitative Study Regarding How Professional Caregivers in Homecare Organisations Work to Insure a Life with Dignity for the Elderly

The aim of this study was to increase the knowledge about if and how the National Value System’s goal of a life with dignity for the elderly pervades the work in home care organisations. The study was based on a qualitative research method and was conducted through interviews with professional care givers in home care organisations, there were five individual interviews and one pair interview. The background for this study was the National Value System for the eldercare that was introduced in 2011. The theory of New Public Management and the concept of Rationality of Caring were used to analyse the result. New Public Management introduces a strategy of competition tendering by signing deals with the company that give the best offer, in order to increase the quality and efficiency of organisations. An important part of New Public Management is that the leaders in organisations have control of what is happening in the organisation in order to further increase the quality and efficiency. The Rationality of Caring is about having the care recipients’ needs and wishes as a primary force of action. The study shows that professional care givers work in a way that promotes a life with dignity for the elderly and that they act with a rationality of caring, but the rationality that rules the organisations in which they work precludes their way of working. The Politicians definition of rationality, which is about the efficiency and quality that can be measured, is the one that is prioritized. It also shows that the organisation priorities small time-consumption and standardized services in order to increase the efficiency. It is found that the professional caregivers perceive that the demand for documentation and other administrative tasks has increased and as a result of this the elderly does not receive the time they have been granted