Effect of Gamma Irradiation on the Structural and Optical Properties of Bayfol CR1-4 Nuclear Track Detector

Bayfol is class of solid state nuclear track detectors (SSNTDs). Bayfol (a polycarbonate/ polyester blend) was irradiated with different doses of gamma ranging from 0 to 300 kGy. The effects of irradiation on the structural and optical properties of Bayfol were studied using X-ray diffraction (XRD) and UV spectroscopy. The XRD pattern was taken for the original (non-irradiated) sample and for samples irradiated with increasing doses of gamma irradiation. The "Intensity" and the "FWHM" were obtained; both values decrease up to a dose of 100 kGy and increase subsequently. This indicates a change in structure caused by gamma irradiation. The UV spectra of irradiated samples indicate that the absorption edge shifts towards the longer wavelengths relative to the original (non-irradiated) sample. This shows that there is a decrease in the band-gap and Urbach energy after irradiation. The refractive index decreases, with increased gamma dose, to a minimum at the 100 kGy dose and increases thereafter. Keywords: Bayfol, gamma irradiation, X-ray diffraction, UV spectr

Evaluation of fluoride release and mechanical properties of different glass ionomers

OBJECTIVE: To assess the fluoride release and mechanical properties of four restorative glass ionomer cements (GIC) and to determine the correlation between the mechanical properties and fluoride release. MATERIALS AND METHODS: Four restorative glass ionomers were studied: ChemFil ROCK (DENSPLY), Fuji IX (GC), Riva self cure (SDI), and Ketac Nano (3M ESPE). Fluoride release in deionized water from the tested specimens was measured using a fluoride-selective ion electrode for 9 days. The compressive strengths and diametral tensile strengths after storing in distilled water (room temperature, 24) were tested. Glass ionomer surface wear by dental ceramic (Vita Mark II cylinders) was evaluated by a depth micro analyzer. Data were analyzed using ANOVA followed by Tukey’s test or Bonferroni method (p= 0.05). RESULTS: The fluoride release exhibited high concentration, following by a significant drop on the second day. Fuji IX had the highest fluoride release followed by “Ketac”,” Riva”, and “ChemFil”. Compressive strength results ranked that ChemFil as the highest value, followed by Fuji IX, Ketac, and Riva. The diametral tensile strength test ranked ChemFil and Ketac as the highest values. Surface ear against dental ceramic (Vita Mark II cylinders) revealed that Fuji IX had the lowest material loss, followed by Ketac, ChemFil, and Riva. Data showed significant differences between all of them. After coating the glass ionomer, the surface wear loss was reduced significantly in Riva and ChemFil. CONCLUSIONS: The tested restorative glass ionomers showed differences in fluoride release and the differences decreased over time, with Fuji IX releasing the highest amount of fluoride ion. ChemFil Rock showed the highest mechanical properties but the lowest fluoride release. Riva self cure had the highest material loss value in wear test. There was a weak inverse correlation between fluoride release and compressive strength (r = - 0.32); fluoride release and diametral tensile strength (r = - 0.60), and fluoride release and surface wear against dental ceramic (Vita Mark II cylinders) (r = - 0.55)

Gendered discourses and discursive strategies employed in Twitter-hashtagged debates about Saudi-women’s issues

This study is motivated by Twitter’s growing popularity as a space where Saudi men and women discuss issues pertaining to their lives without being stigmatised in an otherwise gender-segregated society. It aims to shed light on the multiple perspectives adopted by them to reveal an existing tension between tradition and modernity in SA (Yamani, 2000). Adopting an eclectic qualitative method, I draw from Critical Discourse Analysis (CDA) tools to analyse the constellation of discourses that are related to gender and the discursive strategies used as resources for stance taking in a corpus of 1000 unique text-based tweets derived from two selected topical hashtags collected in June, 2015. These two hashtags mark the public reaction to a) newly-announced travel controls for Saudi women and b) statistics about the percentages of unmarried Saudi women. in. The data provides evidence that voices of difference, protest, and dissent regarding women’s rights and their social role are in a dialogic relation with dominant conservative discourses. The analysis reveals that hashtag contributors mainly engage in the evaluation of gendered discourses, epitomised by a predominant Discourse of Patriarchy, and a Discourse of Gender Equality and Human Rights. A Discourse of Patriarchy manifests in two mutually-supporting discourses: a discourse of dominance that privileges men and gives them control over women, and a discourse about the subordination of women. The Discourse of Gender Equality discusses women’s retrieval of their full citizenship status, without the need for guardianship, and an equal social respect for their life choices, including those related to marriage and mobility. While drawing on these discourses, contributors position themselves on a spectrum of conservative (anti-change) and progressive (pro-change) stances. By way of critiquing them, and sometimes, constructing new democratic social worldviews, the contributors show signs of engaging in a form of linguistic intervention to promote social change. Invocations of these discourses were manipulated for the macro-functions of perpetuating, undermining, or transforming existing discriminatory practices against women. Within these macro-strategies, other meso-discursive strategies were employed, namely referential and predicational strategies, assimilation and differentiation, legitimation and delegitimation, intensification and mitigation, and humour. These meso-strategies were fulfilled drawing on linguistic and semantic means including sarcasm, laughter, mock suggestions, comparison, metaphors, etc. I argue that the identified patterns found in the Twitter data reflect as well as facilitate (on the discursive level) an ongoing gradual social change in the Saudi society since the unheard can now be heard and the dominant social practices involving women are being presented for public deliberation. In addition to contributing to the Arabic literature on discourse and gender, this study engages in an act of historicising these changes in SA and provides an assessment of the transformative potential of Twitter

Metabolic, Endocrine, and Immune Consequences of Sleep Deprivation

Over the last three to four decades, it has been observed that the average total hours of sleep have decreased to less than seven hours per person per night. Concomitantly, global figures relating to obesity and diabetes mellitus have increased in an alarming fashion in adults and children, and it has been hypothesized that neuro-hormonal changes accompanying this behavioral sleep deprivation may lead to insulin resistance and, subsequently, to diabetes mellitus. Sleep deprivation has been associated with multiple physiological changes, including increased cortisol and ghrelin levels, decreased leptin levels and impaired glucose metabolism. Experimental studies have also shown an increase in inflammatory and pro-inflammatory markers, which are indicators of body stress, under sleep deprivation. This review elaborates further on this hypothesis, exploring the molecular basis for the link between both entities and the underlying pathophysiology that results in insulin resistance and diabetes mellitus. We review the results of experimental and epidemiological studies, specifically examining the relationship between sleep duration and the immune and endocrine systems

Sleep-related breathing disorders in obese patients presenting with acute respiratory failure

SummaryIntroduction: The study was conducted to assess the clinical and polysomnographic characteristics of patients with sleep-related breathing disorders who presented to the intensive care unit (ICU) with acute respiratory failure and the practicability of performing polysomnography for such patients.Material and methods: We analyzed clinical presentation, cause of admission to the ICU, ICU course and outcome of 11 subjects with acute respiratory failure who were diagnosed to have sleep disordered breathing based on polysomnography between October 1999 and January 2003. Subjects were compared to 11 patients with obstructive sleep apnea syndrome matched to each subject using body mass index, age and apnea hypopnea index measured at the time of diagnosis (matched comparison group). Repeated arterial blood gases and polysomnography were done for 8 subjects compliant to treatment 6–8 months after discharge from ICU.Results: The reason for ICU admission for all subjects was hypercapnic respiratory failure. pH and daytime PaO2 were significantly lower in studied subjects compared to the matched comparison group while awake daytime PaCO2 was significantly higher. Subjects had frequent episodes of hypoventilation. Follow up arterial blood gases and polysomnography 6–8 months after treatment (non-invasive ventilation) in compliant subjects showed significant improvement in all blood gases parameters.Conclusions: Early polysomnography (or portable cardio-respiratory monitoring) allows accurate diagnosis and institution of the appropriate ventilation method Further studies should assess the evolution of respiratory drive in patients with sleep disordered breathing and hypercapnia under therapy (non-invasive ventilation)

Current clinical practice for the use of hypnotics to manage primary insomnia in adults in a tertiary hospital in Saudi Arabia: an audit study

Despite the risks associated with hypnotics and their recent increased use in Saudi Arabia, there are no specific national guidelines for using these medicines to treat insomnia nor are there any data on how these medicines are currently prescribed. There is the potential, however, that some physicians might be adhering to the US guidelines. The current audit study was aimed to assess the current practice in treating insomnia with hypnotics in Saudi Arabia, and to evaluate its agreement with the US guidelines. The audit was conducted using data collected between April 2012 and March 2017 at King Fahad Central Hospital (KFCH; Jazan), of patients who were either prescribed benzodiazepines (BZDs) or Z-drugs or diagnosed with insomnia. The audit criteria followed two US guidelines for the management of insomnia in adults. Data included documented diagnosis, use of CBT-I (Cognitive Behavioral Therapy for Insomnia), use of BZDs and Z-drugs including treatment regimen, and whether physicians prescribed anti-histamines for insomnia. The data were analyzed using STATA 14 after transcription to a MS XL file. Of the 504 records reviewed, 379 patients (75%) were prescribed BZDs or Z-drugs; only 182 (48%) of them had clearly documented indications for their use. Three hundred and seven patients (60%) were diagnosed with insomnia; none of them received CBT-I as initial treatment. No patients on long-term use of hypnotics were reviewed by their physicians after they began using the medication. More than 43% of patients were prescribed anti-histamines for insomnia. No records met all (or even six) of the seven criteria. KFCH physicians do not follow US guidelines. Therefore, the Ministry of Health (MOH) should improve its administrative systems including documentation, and instead of using international guidelines that are seldom followed, physicians should be trained in prescribing hypnotics and national guidelines need to be developed

Using benzodiazepines and Z-Drugs for managing primary insomnia in adults in Saudi Arabia: an e-Delphi study to aid the development of clinical guidelines

Purpose: To obtain consensus statements required for the development of clinical guidelines for the use of benzodiazepines (BZDs) and Z-drugs for the management of primary insomnia in adults in Saudi Arabia. Methods: Three rounds of the e-Delphi technique using a Bristol Online Survey (BOS) were conducted between May and August 2018. The Director of the Saudi Sleep Medicine Group helped recruit the country’s sleep medicine experts. Snowballing was used to forward invitation emails, information sheets and the survey to known sleep medicine experts and physicians deemed to be interested in the field. All participants’ details were anonymized except to the researcher. Results: Fifteen experts from four different regions and specialities in Saudi Arabia participated in Round 1. Twenty-one statements originated from participants’ responses. In Round 2, there were 17 respondents and 16 of the statements obtained the required consensus of 70% or higher. Eleven experts participated in Round 3 and eight statements received 100% agreement, two received 91%, and six received 82%. Having obtained the required consensus of 80% or higher in Round 3, these 16 statements fulfilled the criteria to be included in future guidelines. The five statements that failed to attain the required consensus were rejected as inappropriate for inclusion in Saudi Arabian clinical guidelines. Conclusions: The items that achieved the required consensus can be included in future guidelines for the use of BZDs and Z-drugs in the treatment of primary insomnia in adults to standardize best practices in sleep medicine in Saudi Arabia

Social needs of the users in public open space : the involvement of socio-cultural aspects in landscape design of the outdoor urban environment in Ar-Riyadh, Saudi Arabia

With the modern development and urbanisation in the city of Ar Riyadh, the capital of Saudi Arabia, public gardens were introduced as the major public recreational facilities. The establishment of the public gardens commenced at the beginning of the 1980s. Since that time, the number of public gardens has reached 34. They vary in size, the smallest is about 3,000 sq. m. and the largest is about 455,000 sq. m. The rapid development of these facilities, in such a short time, did not allow for extensive assessment of the residents' needs. Rather, the design of these gardens emerged without precedent, based on foreign examples. Because of the adoption of foreign design ideas, the outcome did not respond to the socio-cultural aspects which existed in and were respected by the society. The study was an attempt to recognise and understand the relationship between the sociocultural aspects that govern and guide people's behaviour and the outdoor recreational environment. In order to investigate the relation between human behaviour and the physical environment, three research techniques were defined by which the various dimensions and details concerning the socio-cultural aspects which govern human behaviour can be identified, described and clarified. The techniques used are archive search, observing the behaviour-environment and a questionnaire survey. As a results of the analytical process, specific issues which strongly related to the socio-cultural aspects of human behaviour in the outdoors were identified as important in determining the level of compatibility between the intended behaviours and their meanings and the physical setting of the recreational environment. In order to create a coherent built environment that responds positively to the intended functions expected by certain people, knowledge and understanding of their socio-cultural values and behaviours must be acquired and applied in the design process

Investigation of oral health assessment measures for the care planning of dependent adults

Ph. D. Thesis.Dependent adults (i.e. eighteen-year-old or older who need or receives assistance due to a reduction in mental capacity or physical capability) can experience oral health problems. Whilst the reasons behind these problems are complex, evidence suggests that caregivers’ limited knowledge about oral health and care may play a role. Oral health measurement instruments could provide one means by which to help caregivers establishing appropriate oral care plans for dependent adults and, thus, preventing or managing these problems. This project aimed to investigate oral health assessment measures for oral care planning of dependent adults through three separate studies. A qualitative evidence synthesis was undertaken to establish an empirical conceptual model of oral health in dependent adults. It showed that oral health in dependent adults is a dynamic and multidimensional construct that consists of four domains: the intactness and cleanliness of oral structures; oral pain and discomfort; oral functions; and noticeable oral health aspects. A systematic review was undertaken to critically appraise published oral health measurement instruments for dependent adults. It revealed many instruments have been proposed, but none of these instruments has been adequately and comprehensively tested to establish strong evidence in relation to their measurement properties, feasibility and interpretability. Finally, a qualitative interview study was undertaken to explore healthcare service providers’ perspectives on barriers and implementation issues in relation to measuring oral health in dependent adults. The consistent theme was that the implementation of oral health measurement instruments may not be easy due to multiple potential barriers. These barriers therefore need to be considered during implementation, including those related to instruments, service providers, dependent adults and implementation environment. The findings in this thesis support a recommendation that multiple perspectives need to be considered when designing and evaluating oral health measurement instruments used to guide oral care planning for dependent adults. By doing this, these instruments are more likely to meet different stakeholders’ needs and, thus, can be successfully implemented.King Saud bin Abdulaziz University for Health Science