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| 2. |
- Hamid Muhammed, Hamed, et al.
(författare)
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Evaluation of Dental Implant Osseointegration Using Ultrasonic Spectrometry : A Phantom Study
- 2014
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Ingår i: WSEAS Transactions on Signal Processing. - 1790-5052 .- 2224-3488. ; 10:1, s. 194-204
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Tidskriftsartikel (refereegranskat)abstract
- One of the challenging and important problems that still needs solution within the field of dental implant surgery is to monitor the osseointegration process. Therefore, this work aims to achieve a reliable noninvasive automatic method to evaluate dental implant stability which is directly related to the grade of osseointegration. For this purpose, an experimental phantom study was performed to simulate this process and evaluate it. Ultrasonic pectrometry was proposed and used to take measurements that were processed and analyzed to estimate the stability of the simulated dental implant. The phantom that was designed and used in the experiments simulated a jawbone with a dental implant and was made of a little pool filled with soft-tissueequivalent material (with respect to ultrasound waves) and a solid cylinder of fresh oak-wood immersed into it to simulate the jawbone. A metal screw was used to simulate the dental implant. By screwing this screw into or out of the wooden cylinder, varying grades of stiffness and contact between the screw and the wooden tissues were obtained. And by this way, varying screw stability grades which simulate varying osseointegration grades were achieved. Pulse-echo ultrasound was used to measure the power spectra of the received ultrasonic echosignals. These power spectra were, at first, processed and normalized then analyzed by using the partial least squares method to estimate the corresponding implant stability or stiffness grades. The number of screwing turns (for the screw into or out of the wooden cylinder) was used as a measure of stiffness grade.The feasibility of this approach was investigated through experimental tasks and romising results were achieved. A coefficient of determination R2 of 96.4% and a mean absolute error of ±0.23 screwing turns were achieved when comparing real and estimated stiffness-grade values, indicating the high efficiency and good accuracy of this approach.
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| 3. |
- Hamid Muhammed, Hamed, 1967-, et al.
(författare)
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Temperaturvariationsanalys för hudcancerscreening, Poster, Barncancerfondens tredje konferens
- 2013
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Ingår i: Barncancerfondens tredje konferens: Medicinsk Teknik för Barn med Cancer.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Den här studien visar att det är möjligt att detektera tydliga temperaturskillnader mellan cancervävnad och frisk vävnad. Detta kan vara ett resultat av både angiogenes (processen som leder till nybildning av blodkärl från de minsta befintliga blodkärl) och ökad ämnesomsättning hos cancerceller (medan cancertumörer formas) jämfört med friska normala celler, som ändrar och ökar intensiteten av den termiska IR-strålningen inom cancervävnads områden. Temperaturförändringarna detekterades genom mätningar av termisk IR-strålning inom våglängdsområdet 8-14 μm. Intensiva experiment utfördes på möss med hudcancer. Cancerområdet hade i genomsitt 0.3 – 0.5 °C högre temperatur än de friska grannområdena. Både kvalitativa och kvantitativa statistiska metoder användes för att analysera dessa mätningar. Analysresultaten verifierar användbarheten av att mäta termisk IR-strålning för att kunna detektera hudcancerområden.
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| 4. |
- Hamid Muhammed, Hamed, et al.
(författare)
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Using Ultrasonic Spectrometry to Estimate the Stability of a Dental Implant Phantom
- 2013
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Ingår i: Engineering. - 1947-3931 .- 1947-394X. ; 5, s. 570-574
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Tidskriftsartikel (refereegranskat)abstract
- A challenging problem in dental implant surgery is to evaluate the stability of the implant. In this simulation study, an experimental phantom is used to represent a jawbone with a dental implant. It is made of a little pool filled with soft-tissue equivalent material and a disc of fresh Oakwood with a metal screw. Varying levels of contact between screw and wood are simulated by screwing in or out the screw. Initially, the screw is screwed in and fixed firmly in wood. Thereafter, the screw is screwed out, a half turn each time, to increase the gap gradually between wood and screw. Pulse-echo ultrasound is used and the power spectra of the received echo-signals are computed. These spectra are normalized then analyzed by using the partial least squares method to estimate the corresponding implant stiffness grade in terms of number of turns when beginning from the initial tight-screw state then screwing out the screw. A coefficient of determination R2 of 96.4% and a mean absolute error of ±0.23 turns are achieved when comparing real and estimated values of stiffness grades, indicating the efficiency of this approach.
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| 5. |
- Niimi, Jun, et al.
(författare)
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Characterisation of odour active volatile compounds of New Zealand sea urchin (Evechinus chloroticus) roe using gas chromatography-olfactometry-finger span cross modality (GC-O-FSCM) method
- 2010
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Ingår i: Food Chemistry. - : Elsevier BV. - 0308-8146 .- 1873-7072. ; 121:2, s. 601-607
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Tidskriftsartikel (refereegranskat)abstract
- Sea urchin roe is a high value product; however, previous attempts to market the roe from the New Zealand sea urchin (Evechinus chloroticus) have been unsuccessful due to its inconsistent sensory quality. The current study investigated the odour active volatile profiles of roe from male and female sea urchins, harvested from two locations in New Zealand, using solvent assisted flavour evaporation (SAFE) extracts and a gas chromatography-olfactometry-finger span cross modality (GC-O-FSCM) method. Panellists detected 81 odour active compounds, 18 of which were identified using GC-mass spectrometry (MS). Generalised procrustes analysis (GPA) of the data revealed that there were differences in the volatile profile that were location and gender specific. These differences may have contributed to the inconsistent sensory properties of sea urchin roe. The differences in volatile profiles between sea urchin populations and genders must be appreciated before developing effective strategies to produce consistent sea urchin roe quality. © 2009 Elsevier Ltd. All rights reserved.
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| 6. |
- Phillips, K., et al.
(författare)
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Sensory and volatile analysis of sea urchin roe from different geographical regions in New Zealand
- 2010
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Ingår i: Lebensmittel-Wissenschaft + Technologie. - : Elsevier BV. - 0023-6438 .- 1096-1127. ; 43:2, s. 202-213
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Tidskriftsartikel (refereegranskat)abstract
- Roe from the sea urchin Evechinus chloroticus collected from locations in the North (Mathesons Bay) and South (Doubtful Sound) of New Zealand was characterised according to physical characteristics, sensory properties, and volatile composition. Objective assessment of roe sensory properties (appearance, odour, taste, flavour, texture, and aftertaste) was carried out by a trained sensory panel using descriptive sensory analysis. Proton transfer reaction-mass spectrometry (PTR-MS) was used for headspace analysis of roe, and data were collected over the mass range m/z 22-180. Sea urchins from the Northern population were significantly smaller, and had a lower roe index than those from the Southern population. Roe from Northern sea urchins were rated higher for the attributes of marine, seafood and sharp odour, bitter taste, herbaceous and metallic flavour, astringent texture, and metallic, bitter, and duration of aftertaste than roe from Southern sea urchins, which were rated higher for dairy odour, sweet taste, dairy flavour, moisture content and mouth coating. E. chloroticus roe was also differentiated based on gender by 26 sensory attributes. Volatile analysis significantly discriminated between roe from Northern and Southern sea urchins by 35 mass ions, and between genders of Southern sea urchins by five mass ions.
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| 7. |
- Razavi, R., et al.
(författare)
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Energy-efficient scheduling of real-time cloud services using task consolidation and Dynamic Voltage Scaling
- 2014
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Ingår i: 2014 7th International Symposium on Telecommunications, IST 2014. - 9781479953592 ; , s. 675-682
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Konferensbidrag (refereegranskat)abstract
- Energy consumption has attracted a lot of attention in the past few years, because energy reduction causes a significant mitigation of the negative impact on the environment along with an operational cost reduction. Energy-efficient task scheduling is an effective technique to decrease the energy consumption in the Cloud Computing Systems (CCSs). In this paper, the problem of scheduling a set of precedence-constrained real-time services onto a set of heterogenous servers is investigated. Each service contains a set of tasks bounded with a specific deadline. The main notion applied in this paper is to employ the consolidation approach along with the Dynamic Voltage Scaling (DVS) technique. The proposed scheduler is developed in three phases. Tasks' deadlines and a laxity metric are computed for each service according to the corresponding service deadline prior to the main scheduling phase. Afterwards, in order to consolidate the tasks onto the minimum number of servers, the algorithm estimates the required number of servers. Finally, in the last phase, the tasks are scheduled while the DVS technique is applied with considering the tasks' deadlines. The extensive experimental results clearly demonstrate that the proposed algorithm reduces the energy consumption of a CCS by 14% on average in comparison with beam search algorithm. In addition, it outperforms the non power-Aware algorithm by 84%.
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| 8. |
- Seth-Smith, Helena M. B., et al.
(författare)
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Whole-genome sequences of Chlamydia trachomatis directly from clinical samples without culture
- 2013
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Ingår i: Genome Research. - : Cold Spring Harbor Laboratory Press (CSHL). - 1088-9051 .- 1549-5469. ; 23:5, s. 855-866
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Tidskriftsartikel (refereegranskat)abstract
- The use of whole-genome sequencing as a tool for the study of infectious bacteria is of growing clinical interest. Chlamydia trachomatis is responsible for sexually transmitted infections and the blinding disease trachoma, which affect hundreds of millions of people worldwide. Recombination is widespread within the genome of C. trachomatis, thus whole-genome sequencing is necessary to understand the evolution, diversity, and epidemiology of this pathogen. Culture of C trachomatis has, until now, been a prerequisite to obtain DNA for whole-genome sequencing; however, as C trachomatis is an obligate intracellular pathogen, this procedure is technically demanding and time consuming. Discarded clinical samples represent a large resource for sequencing the genomes of pathogens, yet clinical swabs frequently contain very low levels of C trachomatis DNA and large amounts of contaminating microbial and human DNA. To determine whether it is possible to obtain whole-genome sequences from bacteria without the need for culture, we have devised an approach that combines immunomagnetic separation (IMS) for targeted bacterial enrichment with multiple displacement amplification (MDA) for whole-genome amplification. Using IMS-MDA ill conjunction with high-throughput multiplexed Illumina sequencing, we have produced the first whole bacterial genome sequences direct from clinical samples. We also show that this method can be used to generate genome data from nonviable archived samples. This method will prove a useful tool in answering questions relating to the biology of many difficult-to-culture or fastidious bacteria of clinical concern.
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