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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A Study of Fission Yields Using a High Sensitivity Mass Spectrometer

Kennett, Terence 10 1900 (has links)
An electron multiplier has been developed which has increased the sensitivity of an existing mass spectrometer toy a factor of 10^5. This increased sensitivity has permitted determination of fission yields of substances that have undergone little fission. Two such samples, for which the rare gas isotopes have been analysed, are Bohemian pitchblende and the products resulting from the neutron fission of Th232, The Bohemian ore exhibited more neutron fission than any uranium deposit previously analysed. An explanation of this effect may be obtained by considera­tion of the geological and chemical nature of the deposit. The neutron fission of thorium, which shows fine structure in both the xenon and krypton regions, is similar to the patterns of u235 U235 and pu239, / Thesis / Master of Science (MS)
2

Evaluation of Cardiotoxicity Using Blood Biomarkers in Breast Cancer and Lymphoma Patients Undergoing Curative Treatment

Mackett, Katharine January 2019 (has links)
Objective: To evaluate whether abnormal concentrations in cardiac and inflammatory biomarkers could predict reductions in left ventricular ejection fraction (LVEF) for cancer patients undergoing curative treatment. Materials and Methods: Longitudinal testing was performed for high-sensitivity cardiac troponin I (hs-cTnI), N-terminal pro-B-type natriuretic peptide (NT-proBNP), heart-type fatty acid binding protein (H-FABP) and C-reactive protein (CRP) in HER2+ breast cancer (BC) patients receiving adjuvant trastuzumab treatment (n=22) and in lymphoma patients treated with radiotherapy (n=4). Sex-specific and overall upper limit of normal (ULN) cutoffs were used to identify abnormal results with a reduction in LVEF (<50% and decrease of ≥10% from baseline) indicative of cardiotoxicity. A secondary analysis was performed on the BC patients with normal LVEFs (n=12 with baseline prior to chemotherapy through to 6-months on trastuzumab) with 15 blood collections spaced between 6- and 254-days post-baseline LVEF measurement. Results: A majority of the BC patients had evidence of myocardial injury (hs-cTnI >female ULN=90%) or myocardial dysfunction (NT-proBNP >overall ULN=91%) at any timepoint with fewer patients having abnormal CRP or H-FABP concentrations (H-FABP >ULN=14%; CRP >ULN=45%). Myocardial injury and dysfunction were most evident during the first two cycles of trastuzumab treatment, with myocardial injury also evident during this early timeframe in the female lymphoma patients (3 with hs-cTnI >ULN). In the 12 patients who completed trastuzumab with normal LVEFs (median=60% at 6-months), myocardial injury (hs-cTnI >ULN) and dysfunction (NT-proBNP >ULN) was evident in >50% of patients. Four of the 22 patients did develop cardiotoxicity, but there was no difference in biomarker concentrations between patients with or without cardiotoxicity. Conclusion: The use of the recommended ULN cutoffs identified myocardial injury and dysfunction in a majority of cancer patients in this setting. Biomarker assessments did not relate to cardiac functional imaging studies. Future studies are warranted to assess different cutoffs or biomarker combinations for predicting cardiotoxicity. / Thesis / Master of Science (MSc)
3

Det är svårt att vara mig… : Om skolelever som kategoriserar sig som högkänsliga

Eklund Tegar, Nina January 2014 (has links)
The aim of this study was to describe and analyze the problems caused by students that characterize themselves as highly sensitive. The issue of high sensitivity and other categorizations are fiercely debated in the research. This empirical study was conducted in light of literature about high sensitivity, pedagogies, and interview methods. The students answered questions about what makes them categorize themselves and how they believe that the categorization affects their learning and social development. They also responded to questions about what they consider appropriate measures to improve their situation. The most obvious outcome is that students do not feel safe in the large classes that they are a part of-, as the learning environment is perceived too large and tough. The students can not do themselves justice despite their ability and willingness to learn. Students also feel that they are placed into incorrect categorizations such as shy, introverted or different. This fact show links to the ongoing debate related to inclusion and appears to provide a critical illumination of it. The study was completed by a comprehensive discussion of the inquiry results from a special education perspective.
4

Moderní markery orgánového poškození v klinické praxi / Modern Markers of Organ Damage in Clinical Practice

Brož, Pavel January 2019 (has links)
Physical activity is a useful tool in the prevention of many diseases. Hospitalization after strenuous exercise from cardiac or noncardiac causes, even in young athletes without previous symptoms, can occur. These situations are not uncommon and e.g. after completing a half- marathon clinical symptoms suspicious from cardiac etiology can be present. Limitations of biomarkers used in daily clinical practice can lead to misinterpretation with additional consequences to the patient's outcome. Our goal was to describe changes of markers used in daily clinical practice after extreme physical activity and after exercise under laboratory conditions. We performed two studies in cooperation with Department of cardiology and Department of sports medicine. The goal of our first study was to examine high sensitivity troponin I (hsTnI), galectin-3, cystatin C, NGAL and ultrasensitive CRP (uCRP) after extremely long run during the competition in long distance running. The goal of our second study was to examine high- sensitivity troponin T (hsTnT) and hsTnI, creatinine and cystatin C, and urine albumin and NGAL after a standardized two-hour treadmill run under laboratory conditions and to find possible connection with echocardiographic, laboratory and other assessed parameters. The second goal of study under laboratory...
5

Du bara överreagerar! - Ja, det ligger i min natur : En studie om högkänslighet som påverkan på identitetsskapandet i skolan

Löfström, Madelene January 2016 (has links)
Sammanfattning Högkänslighet är något som på senare år arbetat sig in i media och blivit ett ämne värt att tala om. Högkänsliga individer tar in fler intryck från sin omgivning och bearbetar dem på ett djupare plan än vad andra gör. Dessa personer har även lätt att känna av andra individers känslor och sinnesstämning och blir lätt överstimulerade vid för mycket yttre eller inre stimuli. Enkelt beskrivet är dessa människor lite extra känsliga för saker som sker. De spenderar mycket tid med sina egna tankar som ständigt processar intryck, men visar även på stor empatisk förmåga och är duktiga på att uppmärksamma detaljer. Genom livsberättelser delges människors personliga erfarenheter och upplevelser om högkänslighet. Varje berättelse är unik och har tillfört kunskap till studien. Syftet med forskningen har varit att undersöka hur högkänsliga individer väljer att utrycka sin identitet och hur den formas och förändras. Studien är baserad på tre livsberättelseintervjuer med högkänsliga kvinnor. Varje intervju har transkriberats och analyserats vilket redogörs i ett tematiskt resultat. Varje intervju tillförde ny information gällande hur högkänsliga personer uttrycker sin identitet men gemensamma drag kunde även urskiljas. Ett av de främsta dragen var känslan av att vara oförstådd eller annorlunda. Vid kontakt med fenomenet högkänslighet delade de även en känsla av lättnad att äntligen veta varför man är annorlunda. Resultatet visar att det behöver göras mer forskning inom området och att det undersöks hur högkänslighet kan ses som en del i identitetsskapandet. / Abstract High Sensitivity is a personality trait that has, in recent years, worked its way into the media and become a subject worth talking about. Highly Sensitive individuals take in more impressions from their surroundings and process them at a deeper level than other people. People who are Highly Sensitive have an increased understanding of other people’s feelings and tempers but easily become overstimulated by too much external or internal stimuli. In simple terms, these individuals are extra sensitive to things that happen around them. They spend a lot of time with their own thoughts and constantly process impressions. However, these individuals also show a great empathic ability and tend to pay attention to small details. People’s personal experiences of High Sensitivity can be communicated through life stories. Every story is unique and has brought insight to the study. The aim of the research at hand was to investigate how the Highly Sensitive individuals choose to express their identity and how it is formed and changed. The study is based on qualitative research through life story interviews with three Highly Sensitive women. Each interview has been transcribed and analysed thoroughly leading to a thematic conclusion. Each interviewee came with new information on how the High-Sensitive individuals express their identity, nevertheless a few common qualities could be distinguished. One of the common features that the interviewees shared, was the feeling of not being fully understood or feeling different than the rest. Another trait they all shared was the relief when finally learning the underlying reason they felt different, as they came in contact with the phenomenon of High Sensitivity and could identify themselves having this personality trait. The result of this study shows that more research in the area is needed to better understand the individual perceptions and feelings. How High Sensitivity can be identified as a part of identity creation must also be further explored to gain deeper understanding in this field.
6

Serum High Sensitivity C-Reactive Protein, White Blood Cell Count, and High-Density Lipoprotein Cholesterol Levels are Associated with Coronary Artery Lesions in Kawasaki Disease

Ou, Chum-yen 04 July 2007 (has links)
Background: Kawasaki disease (KD) affects mainly children younger than five years of age, leading to coronary artery lesions, and even to life-threatening myocardial infarctions. Since 1976, Kawasaki disease has occurred among thousands of children in Taiwan. Evidence suggests that inflammation plays a key role in the pathogenesis of atherosclerosis. Significant determinants of high sensitivity C-reactive protein (hs-CRP), which is a sensitive indicator of inflammation, as well as white blood cell (WBC) count, and high-density lipoprotein cholesterol (HDLc) and coronary artery lesion were identified. The relationships between these factors¡¦ concentration and arterial lesion were likewise investigated and had reported. The aim of this study was to determine the serum levels of the hs-CRP, WBC count, and plasma HDLc levels in patients with later phase of KD. Methods and Materials: From July 2005 to June 2006, 97 children with Kawasaki disease at least 1 year after diagnosis were recruited in this study. These participated children had been diagnosed as KD and collected at the interval of 2001 to 2004. Diagnosis was based on the 1984 revised by the KD Research Committee in Japan. The participants were grouped into 45 patients with KD and coronary aneurysms (Group I), 52 patients with KD and normal coronary arteries (Group II), and 50 healthy age-matched children (Control Group III). Their WBC count, systemic and diastolic blood pressures, body mass index, age, sex, fasting total cholesterol concentrations, triglyceride, high-density lipoprotein cholesterol (HDLc), low-density lipoprotein cholesterol, serum hs-CRP levels, and coronary artery lesion by cardioechography were recorded and compared. The analytical differences between hs-CRP, WBC count, and plasma HDLc levels and the coronary artery events in KD were examined. Results: Serum hs-CRP levels of Group I patients (mean 0.264 mg/dl) was significantly greater than that of Group II (mean 0.155 mg/dl, p=0.006) and Group III patients (mean 0.116 mg/dl, p =0.017). Similarly, the WBC count of Group I patients (mean 6,543.11/mm3) was significantly greater than that of Group II (mean 5,720.19/mm3, p=0.029), and Group III patients (mean 5,611.27/mm3, p =0.012). However, plasma HDLc levels of Group I patients (mean 41.42 mg/dl) was significantly lesser than that of Group II (mean 44.79 mg/dl, p=0.035), and Control Group III patients (mean 46.58 mg/dl, p=0.027). There was a positive association between hs-CRP and WBC count levels (r = 0.641, p < 0.05), but none between hs-CRP and plasma HDLc levels. Conclusions: There is the possibility of ongoing low-grade inflammation late after the convalescent phase of Kawasaki disease in children with coronary aneurysms, which may have a role in increasing coronary artery dysfunction. These results also suggest that hs-CRP, WBC count, and plasma HDLc levels are useful parameters for predicting formation of coronary artery lesion even in children after onset of KD.
7

Dynamic dark state depletion a path to high sensitivity imaging

Richards, Christopher I. 06 October 2009 (has links)
Photophysical characterization of several species of fluorescent silver nanoclusters, encapsulated in oligonucleotide scaffolds, was achieved at the bulk and single molecule level. These studies reveal the presence of a short-lived microsecond blinking component which leads to higher emission rates than exhibited by common organic dyes. This dark state was found to be photo-accessible with a very efficient depopulation transition leading to repopulation of the emissive state. Secondary excitation on resonance with this transition significantly shortens the residence time in the dark state giving rise to as much as 5-fold fluorescence enhancement. Manipulation of the secondary laser can be used to impose a regularly modulated waveform onto the fluorescent signal. Signal processing techniques can be employed to extract the modulated signal from large backgrounds, leading to drastically improved sensitivity. This new imaging concept can be extended, beyond Ag nanoclusters, to common organic fluorophores that demonstrate large dark state quantum yields. These fluorophores simultaneously illustrate the utility of this technique and help to define a general set of parameters for engineering ideal dyes for modulated signal extraction. Ideally suited for fluorescence enhancement, FRET pairs can be used to engineer a wide range of modulatable systems, based on detecting donor emission in the presence of a laser directly exciting the acceptor. The utility of Ag nanoclusters, organic dyes, and FRET systems for improved sensitivity are investigated in this work.
8

The use of interactive stories to deal with awareness of high sensitivity in middle childhood / Durbach L.M.

Durbach, Lisa-Mandi January 2011 (has links)
One in five children are born highly sensitive (HS), with nervous systems that are more sensitive to sensory subtleties. The highly sensitive child (HSC) presents with behaviour that is often a way of coping with sensory overload from their environment. The symptoms of HS are often mistaken for shyness, introversion, timidity and a low sensory threshold. Because of their lack of understanding, teachers mislabel and misdiagnose these children as being mentally ill, or as suffering from, inter alia, ADHD or learning problems. When such children (HSC) are misunderstood, they begin to feel ‘different’ and ‘flawed’, which can lead to low self–esteem. The purpose of this study is to explore perceptions by HS children in middle childhood, to explore how aware they are of HS, and to discover the extent to which they have been affected by negative labelling often caused by being misunderstood, misdiagnosed and misinterpreted. The structured interviews conducted with HSC comprised of an interactive story, which had been written and illustrated to create explicit awareness of HS. After the storybook had been read, an interview schedule on HS was applied. Next, a focus group interview was conducted with the teachers to gather more rich data, thereby ensuring its trustworthiness. The aim was to explore the teachers’ perceptions of HSC in middle childhood. This exploration was necessary for making effective recommendations for managing and supporting HSC, so that the children can reach their full potential. Many HSC are gifted, and often become visionaries and pioneers in their particular fields. / Thesis (M.A. (Psychology))--North-West University, Potchefstroom Campus, 2012.
9

The use of interactive stories to deal with awareness of high sensitivity in middle childhood / Durbach L.M.

Durbach, Lisa-Mandi January 2011 (has links)
One in five children are born highly sensitive (HS), with nervous systems that are more sensitive to sensory subtleties. The highly sensitive child (HSC) presents with behaviour that is often a way of coping with sensory overload from their environment. The symptoms of HS are often mistaken for shyness, introversion, timidity and a low sensory threshold. Because of their lack of understanding, teachers mislabel and misdiagnose these children as being mentally ill, or as suffering from, inter alia, ADHD or learning problems. When such children (HSC) are misunderstood, they begin to feel ‘different’ and ‘flawed’, which can lead to low self–esteem. The purpose of this study is to explore perceptions by HS children in middle childhood, to explore how aware they are of HS, and to discover the extent to which they have been affected by negative labelling often caused by being misunderstood, misdiagnosed and misinterpreted. The structured interviews conducted with HSC comprised of an interactive story, which had been written and illustrated to create explicit awareness of HS. After the storybook had been read, an interview schedule on HS was applied. Next, a focus group interview was conducted with the teachers to gather more rich data, thereby ensuring its trustworthiness. The aim was to explore the teachers’ perceptions of HSC in middle childhood. This exploration was necessary for making effective recommendations for managing and supporting HSC, so that the children can reach their full potential. Many HSC are gifted, and often become visionaries and pioneers in their particular fields. / Thesis (M.A. (Psychology))--North-West University, Potchefstroom Campus, 2012.
10

Atrial fibrillation : treatment, associated conditions and quantification of symptoms

Höglund, Niklas January 2017 (has links)
Background: Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia. There is a need for new pharmacological treatment strategies since the current antiarrhythmic drugs have a modest efficacy and may have severe side effects. Cardioversion (CV) of AF offers an opportunity to study related conditions in sinus rhythm (SR) and during AF. Since catheter ablation of AF is a symptomatic treatment, it is important to have tools for measurement of arrhythmia-related symptoms. Aims: To evaluate the effect of atorvastatin on maintaining SR after CV of persistent AF. To assess if highsensitivity C-reactive protein (hsCRP) predicts the recurrence of AF after CV in a population randomized to treatment with either atorvastatin or placebo. To quantify the symptomatic effect of left atrial catheter ablation of AF. To assess if the restoration of SR by CV, in a population with persistent AF, affects sleep apnea. Methods: Paper I: A total of 234 patients were randomized to treatment with either high dose atorvastatin or placebo prior to CV. Paper II: In a pre-specified substudy which included 128 of the patients in study I, hsCRP was analyzed before and after CV. Paper III: Umea 22 Arrhythmia Questions (U22) is a questionnaire that quantifies paroxysmal tachycardia symptoms. A total of 105 patients underwent first-time pulmonary vein isolation and answered U22 forms at baseline and follow-up 304 (SD 121) days after ablation. Paper IV: Polysomnography was performed before and after CV in 23 patients with persistent AF scheduled for elective CV. Results: Paper I: An intention-to-treat analysis with the available data, by randomization group, showed that 57 (51%) in the atorvastatin group and 47 (42%) in the placebo group were in SR 30 days after CV (OR 1.44, 95%CI 0.85–2.44, P=0.18). Paper II: HsCRP did not significantly predict recurrence of AF at 30 days. However, after adjusting for treatment with atorvastatin, hsCRP predicted the recurrence of AF (OR 1.14, 95% CI 1.01–1.27). Six months after CV, hsCRP at randomization predicted recurrence of AF in both univariate analysis (OR 1.30, 95% CI 1.06–1.60) and in multivariate logistic regression analysis (OR 1.33, 95% CI 1.06– 1.67). Paper III: The U22 scores for well-being, arrhythmia as cause for impaired well-being, derived timeaspect score for arrhythmia, and discomfort during attack detected relevant improvements of symptoms after the ablation. U22 showed larger improvement in patients undergoing only one procedure than in patients who later underwent repeated interventions. Paper IV: Obstructive sleep apnea occurred in 17/23 patients (74%), and central sleep apnea in 6/23 patients (26%). Five patients had both obstructive and central sleep apnea. SR at follow-up was achieved in 16 patients. The obstructive apnea-hypopnea index, central apneahypopnea index, and the number of patients with obstructive or central sleep apnea did not differ before and after restoration of SR. Conclusions: Atorvastatin is not a treatment option with regards to maintaining SR after CV in patients with persistent AF. HsCRP was associated with AF recurrence 1 and 6 months after successful CV of persistent AF. U22 quantifies the symptomatic improvement after AF ablation with adequate internal consistency and construct validity. Both obstructive and central sleep apneas are highly prevalent in patients with persistent AF. Obstructive sleep apneas are unaffected by the CV of AF to SR.

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