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Flow Cytometry Sensor System Targeting Escherichia Coli as an Indicator of Faecal Contamination of Water SourcesBenselfelt, Tobias January 2014 (has links)
Poor water quality is a global health concern affecting one billion people around the world. It is important to monitor water sources in order to maintain the quality of our drinking water and to avoid disease outbreaks. Targeting Escherichia coli as a faecal indicator is a widely used procedure, but the current methods are time consuming and not adequate to prevent spreading of faecal influence. This Master thesis demonstrates the development of a near infrared fluorescence flow cytometer sensor system targeting Escherichia coli, using fluorescently labeled chicken IgY antibodies. The near infrared light was chosen to avoid fluorescence from blue-green algae that are present in the water source. The hardware was developed with a 785 nm laser line to detect Alexa Fluor 790 labeled antibodies, using a photomultiplier tube or two different CMOS cameras. The antibodies were labeled using a commercial labeling kit, and evaluated using antibody binding assays and the developed hardware. The IgY antibodies were successfully labeled with Alexa Fluor 790 and the function was maintained after the labeling process. The result demonstrates the principles of the sensor system and how it solved to the problem with fluorescence from blue-green algae. An aperture was used to overcome the suboptimal laser and filter setup, and to increase the sensitivity of the system. However, only a small fraction of the cells could be detected, due to challenges with the focal depth and loss of sensitivity in the photomultiplier tube at near infrared wavelengths. Further development is required to create a working product.
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Overcoming biological barriers to control pollinated seed production in Eucalyptus.Horsley, Tasmien Nadine. January 2009 (has links)
The overall aim of this PhD study was to develop protocols to improve the efficiency of eucalypt controlled pollinations (CPs) in order to make it more cost-effective for forestry companies to perform them on a commercial scale on small-flowered species. To achieve this, three research areas were explored, namely pollen handling, breeding systems and controlled pollination technique. Study species were Eucalyptus grandis, E. dunnii, E. smithii, E. nitens, E. urophylla and E. macarthurii.
The first specific aim of the study was to identify a suitable liquid in vitro germination medium for reliably testing pollen viability of all six study species. Six levels of sucrose [0, 10, 20, 30, 40 and 50% (w/v)] were tested, both with (0.15 mg l-1) and without boric acid. The optimal sucrose concentration was found to be 30% (w/v), with boric acid stimulating pollen tube growth. A second aim was to determine temperatures suitable for the short-, medium- and long-term storage of E. smithii, E. nitens and E. grandis pollen. Pollen samples were stored at room (25oC), refrigerator (4oC), freezer (-10oC) and liquid nitrogen (-196oC) temperatures, and pollen viability tested every two months over a 12-month period. There was a rapid decline in the germination of pollen stored at 25oC, while temperatures cooler than 4oC appeared to maintain pollen viability for the duration of the 12-month study. Recommendations were thus to use a refrigerator for short-term (< 2 months), a freezer for medium-term (up to 10 months) and cryopreservation for longer-term storage.
In the second part of the study, breeding systems of E. urophylla and E. grandis were examined by studying pollen-tube growth in the style after single-donor self- and cross-pollinations. Results showed that, in addition to both species exhibiting reduced seed yields following self-pollination, pollen tubes from self-pollen took significantly longer than those from cross-pollen to grow to the base of the style. This suggested the presence of both late-acting self-incompatibility and cryptic self-incompatibility (CSI) as possible mechanisms responsible for outcrossing in these two species. In a follow-up study, the siring ability of self- and cross-pollen was examined after single- and mixed-donor pollinations were performed on E. grandis. Once again, single-donor cross-pollinations resulted in a significantly higher number of seeds compared to self-pollinations. In addition, microsatellite molecular markers
revealed that 100% of the progeny from mixed (self + outcross) pollinations were outcrossed, confirming the competitive advantage of cross-pollen. To date, CSI has never been associated with Eucalyptus, making this the first study to suggest its presence in the genus.
For the final study area, three CP-techniques were compared, namely the Conventional method, One Stop Pollination (OSP) and Artificially Induced Protogyny (AIP), in E. grandis, E. smithii and E. macarthurii maternal parents. Although the AIP technique produced the highest seed yields in all three species, it also resulted in high self- and foreign-pollen contamination (determined using microsatellite markers). This necessitated exploration of different methods of isolating the pollinated flower, and this led to the identification of a novel method which uses sodium alginate gel. Flowers hand-pollinated and isolated with sodium alginate produced progeny that were 100% outcrossed with the applied pollen, confirming the superiority of this innovative isolation technique compared to the currently used exclusion bag. Sodium alginate isolation also increased the efficiency of CPs as the gel was naturally shed, removing the need for operators to return to the tree to remove the isolation material, and thereby reducing the cost per seed.
Application of these results should make commercial CP-seed production of small-flowered eucalypts a practical reality. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2009.
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Slaugytojų žinios ir įgūdžiai atliekant tracheostomos priežiūrą / Nurses’ knowledge and skills in tracheostomy careKostyliovienė, Silva 11 July 2014 (has links)
Tracheostomos priežiūros veiksmai bei sekreto išsiurbimo iš tracheostominio vamzdelio technika gali įtakoti komplikacijų dažnumą ir lemti paciento saugumą, pasveikimo galimybę, gydymo trukmę bei gydymo kainą. Svarbu, kad slaugytojai žinotų mokslo tyrimais pagrįstas rekomendacijas apie tracheostomos priežiūrą ir jas pritaikytų klinikinėje praktikoje.
Tyrimo tikslas – Išanalizuoti slaugytojų žinias ir įgūdžius atliekant tracheostomos priežiūrą.
Tyrimo uždaviniai. 1.Ištirti slaugytojų žinias apie tracheostomos priežiūrą prieš ir po mokymų. 2. Nustatyti slaugytojų įgūdžius atliekant tracheostomos priežiūros veiksmus. 3. Palyginti slaugytojų žinias apie tracheostomos priežiūrą ir jų taikymą praktikoje.
Tyrimo metodai: Tyrimas buvo vykdomas 2013.04.20–12.20 LSMUL Kauno Klinikų keturiuose skyriuose bei vienoje iš Slaugos ir palaikomojo gydymo ligoninių. Tyrimo duomenims rinkti buvo naudojamas tyrimo autorių sukurta anketa ir slaugytojų praktikinių veiksmų stebėjimo protokolas. Slaugytojų anketinė apklausa buvo vykdoma du kartus: prieš (n=90, atsako dažnis–96,77 proc.) ir po (n=86, atsako dažnis–92,47 proc.) mokymo. Stebėtos 99 sekreto išsiurbimo iš tracheostomos vamzdelio procedūros. Tyrimui atlikti buvo gautas LSMU Bioetikos centro pritarimas BEC-KS(M)-198.
Išvados. 1. Prieš mokymus didžioji dalis slaugytojų teisingai žinojo požymius, rodančius siurbimo poreikį, sekreto išsiurbimo trukmę, kiek giliai įvesti atsiurbimo kateterį, galimas sekreto siurbimo komplikacijas. Po mokymo... [toliau žr. visą tekstą] / Actions of tracheostomy care as well as the technique of secretion suctioning from tracheostomy tube can influence the incidence of complications and determine patient‘s safety, possibility of recovery, the duration of treatment and the cost of treatment. It is critical for nurses to be aware of tracheostomy care recommendations based on scientific research and to apply them in clinical practice.
The aim – to analyze nurses’ knowledge and skills in tracheostomy care.
Objectives:1.To examine nurses’ knowledge on tracheostomy care prior to training and after the training. 2. To identify nurses’ skills while performing actions of tracheostomy care. 3. To compare nurses’ knowledge on tracheostomy care and their application in practice.
Research methods: The research was conducted on 20-04-2013 - 20-12-2013 at the hospital of Lithuanian University of Health Sciences Kauno Klinikos in four departments and in one of the Nursing and supportive care hospital. A questionnaire created by the authors of the research and an observation protocol of nurses’ actions in practice was used to collect the data of the research. A survey on nurses’ was conducted twice: prior to training (n=90, response rate – 96.77%) and after the training (n=86, response rate – 92.47%). We observed 99 procedures of secretion suctioning from tracheostomy tube. The research was conducted with the approval BEC-KS (M)-198 from the center of Bioethics of Lithuanian University of Health Sciences.
Conclusions. 1... [to full text]
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Laboratory Aerosol Kinetics Studies of the Hydrolysis Reaction of N2O5 Using a Flow Tube Coupled to a New Chemical Ionization Mass SpectrometerEscorcia, Egda Nadyr 26 July 2010 (has links)
The hydrolysis reaction of N2O5 was investigated at room temperature on two aerosol types using a flow tube coupled to a newly built Chemical Ionization Mass Spectrometer (CIMS). This instrument was fully constructed and optimized during this research period, as well as employed to conduct one of two aerosol studies. The first examined the reaction on ammonium bisulphate aerosols using a new ion detection method, I-•N2O5 cluster formation, which proved to be highly advantageous over the common approach of dissociative charge transfer, yielding a sensitivity for I-•N2O5 of 0.024 Hz/pptv. The uptake coefficients at 30% and 50% relative humidity were 0.0067 ± 0.0002 and 0.0120 ±0.0014, respectively. The second study was performed using a different CIMS previously assembled in the laboratory. In this case, the reaction was investigated on secondary organic aerosols produced through the ozonolysis of α-pinene, and resulted in an uptake coefficient of 8.5x10-5 ± 7x10-6 at 0% relative humidity.
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Laboratory Aerosol Kinetics Studies of the Hydrolysis Reaction of N2O5 Using a Flow Tube Coupled to a New Chemical Ionization Mass SpectrometerEscorcia, Egda Nadyr 26 July 2010 (has links)
The hydrolysis reaction of N2O5 was investigated at room temperature on two aerosol types using a flow tube coupled to a newly built Chemical Ionization Mass Spectrometer (CIMS). This instrument was fully constructed and optimized during this research period, as well as employed to conduct one of two aerosol studies. The first examined the reaction on ammonium bisulphate aerosols using a new ion detection method, I-•N2O5 cluster formation, which proved to be highly advantageous over the common approach of dissociative charge transfer, yielding a sensitivity for I-•N2O5 of 0.024 Hz/pptv. The uptake coefficients at 30% and 50% relative humidity were 0.0067 ± 0.0002 and 0.0120 ±0.0014, respectively. The second study was performed using a different CIMS previously assembled in the laboratory. In this case, the reaction was investigated on secondary organic aerosols produced through the ozonolysis of α-pinene, and resulted in an uptake coefficient of 8.5x10-5 ± 7x10-6 at 0% relative humidity.
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Compatibility of X-ray Tubes with Magnetic Resonance Imaging Scanners for Aortic Valve ReplacementBracken, John Allan 18 February 2010 (has links)
Aortic stenosis is the most common acquired heart valve condition. Open-heart surgical aortic valve replacement is an effective treatment for patients who receive it. However, approximately one-third of patients who require this treatment do not receive it due to the risks associated with the surgery. Percutaneous aortic valve replacement (PAVR) is a minimally invasive technique that can replace the aortic valve of patients contraindicated for open-heart surgery.
Although PAVR is now entering clinical practice, a closed bore hybrid x-ray/MRI (CBXMR) imaging system is under development to improve the safety and efficacy of PAVR. This system will harness the complementary strengths of x-ray imaging (surgical tool/vascular imaging) and MRI (cardiac soft tissue contrast) to deploy a bioprosthesis in the aortic annulus. An x-ray C-arm will be placed about 1 m from the entrance of the MRI scanner to facilitate smooth intermodality patient transfer during the procedure.
The performance of a rotating-anode x-ray tube in the magnetic fringe field of a 1.5 T MRI scanner was investigated. A rotating-anode x-ray tube provides the fluoroscopy and angiography needed for PAVR.
The magnetic fringe field can affect the ability of the x-ray tube to dissipate heat. It was shown that the fringe field perpendicular to the anode rotation axis can reduce anode rotation frequency. These effects can limit the maximum permissible power that can be safely dissipated on the anode track during a single exposure. In the fringe field strengths at the C-arm position (4-5 mT), anode rotation frequency only decreased by about 1%, which will have negligible impact on tube heat loadability.
The fringe field can cause a field of view shift. The field of view shifted by approximately 3 mm, which can be corrected by active magnetic shielding and further collimation. An active magnetic shielding system was constructed that can correct focal spot deflection. These results are facilitating the construction of a prototype CBXMR system, the goal of which is to improve success rates for PAVR procedures.
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Experimental Investigation For Mechanical Properties Of Filament Wound Composite TubesErdiller, Emrah Salim 01 July 2004 (has links) (PDF)
The aim of this study is to investigate the mechanical properties of continuous fiber reinforced composite tubes, produced by filament winding technique. For this purpose, tensile and split-disk tests were performed with specimens produced with five different fiber materials and two different resin systems. Longitudinal tensile and hoop tensile properties of the selected specimens were determined and the effect of reinforcement direction on the mechanical performance of these composites was investigated. In addition, the effect of a filament-winding processing variable (fiber tension) on longitudinal and hoop tensile properties of the selected composites was obtained. A slight increase in hoop/longitudinal tensile properties of specimens was observed for specimens wounded with tension and with winding angles greater than 60o. The tests were performed according to American Society for Testing and Materials (ASTM) standards.
The split-disk tests of selected composite specimens were simulated by the finite element method. For this purpose, a commercial finite element package program was used. Experimental results were used both as input in terms of material data for the finite element study and for comparison purposes. A good agreement was obtained between the simulation results and the experimental data.
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Electric Field Analysis In Stress Controlled High Voltage CablesBas, Gokcen 01 January 2005 (has links) (PDF)
The terminations and the joints are the basic accessories of the power cables. Power cables require electrical stress control when terminated.
Since there are different types of terminations, the analysis should be done to choose the proper method for electric field control problem at the terminations.
Throughout this study two different types of termination methods are investigated by using the finite element analysis program (ANSYS): Stress Controlled Termination Model with Deflector and Stress Control Tube (SCT). The results are compared with those obtained for a cable without stress control model termination.
The numerical calculations are also compared with the measurements obtained by an experimental model: the electrolytic tank model.
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Transcriptomics and proteomics applied to developmental toxicology /Kultima, Kim, January 2007 (has links)
Diss. (sammanfattning) Uppsala : Uppsala universitet, 2007. / Härtill 5 uppsatser.
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Study of tubular linear induction motor for pneumatic capsule pipeline systemPlodpradista, Wisuwat, January 2002 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2002. / Typescript. Vita. Includes bibliographical references (leaves 198-201). Also available on the Internet.
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