141 research outputs found
Alarming Antibiotic Resistance in Pediatric Oncology Patients: A Three-Year Prospective Cohort Study from Oman
No full textAbeer Al Battashi,1 Bishara Al Harrassi,2 Nawal Al Maskari,3 Hilal Al Hashami,3 Salah Al Awaidy4 1Department of Pediatric Hematology and Oncology, The National Oncology Centre, Royal Hospital, Ministry of Health, Muscat, Oman; 2Oman Medical Specialty Board, Muscat, Oman; 3Pediatric Infectious Diseases, Child Health Department, Royal Hospital, Ministry of Health, Muscat, Oman; 4Office of Health Affairs, Ministry of Health, Muscat, OmanCorrespondence: Salah Al Awaidy, Office of Health Affairs, Ministry of Health, Al Khuwair Street, Muscat, Oman, Tel +968 99315063, Fax +968 24946381, Email [email protected]: Bloodstream infections (BSI) are severe and challenging oncological complications, with a consequent high morbidity and mortality in the immunocompromised. We reviewed the profile and susceptibility of bacteria associated with infections in children under 13 years of age receiving chemotherapy.Methods: Prospective cohort study of pediatric oncology patients was conducted between January 2015 and October 2017 at the Royal Hospital in Oman. Patient demographics, clinical data, laboratory parameters, microbial etiology and susceptibility, and outcomes were retrieved and analyzed.Results: A total of 74 episodes of positive bacterial blood cultures were detected in 38 oncology patients (positive blood culture rate of 51%). Fifty-seven percent were positive for gram-negative organisms with Klebsiella (21%) being the most common gram-negative organism cultured, and the most common gram-positive organism was Staphylococcus (coagulase negative Staphylococcus (CONs) and S. Aureus) (30%). The majority of patients had gastrointestinal complaints (74%), and almost half (51%) had prolonged periods of neutropenia (> 7 days). One third of gram-negative organisms were resistant to four or more antibiotics with a major resistance of 31% to piperacillin-tazobactam. Of the gram-positive organisms, 38% were resistant to at least four antibiotics and 30% were pan-resistant (except for vancomycin).Conclusion: The gram-negative organisms were dominant in BSIs with Klebsiella being the most common culprit. Bacteremia was prevalent, however, high resistance to first-line antibiotics was documented amongst gram-negative isolates, demanding strategies to ensure our patients’ safety.Keywords: neutropenia, pediatric oncology, bloodstream infections, antibiotic susceptibility, Oma
Bioinspired Material Design: Modeling and Optimization of Nacre-like Materials
No full textNacre is an inner layer of seashells that is a tough yet stiff natural composite composed of microscopic mineral polygonal tablets bonded by a tough biopolymer. This type of structure is called staggered structure and it has been observed in other biological materials such as bone and teeth. The high stiffness of nacre is known to be due to its high mineral content. In spite of the high mineral content that is mainly ceramic, nacre exhibit high values of toughness. This high value of toughness is explained by its ability to deform past a yield point and develop large inelastic strain over a large volume around defects and cracks. It has been known that the high strain is mainly due to sliding and waviness of the tablets.
Researchers have been motivated by the structure of nacre and its mechanical properties in order to mimic this natural material to create new engineering composites with superior mechanical properties. However, mimicking nacre���s remarkable properties, to date, is still a challenge. This is due to fabrication challenges, lack of models that captures the important mechanics and difficulties in selecting the best combination of tablets and matrix materials, and system geometry for optimal mechanical performance (e.g., stiffness, strength and toughness) of the staggered structure. Previous attempts to create analytical models for nacre include tablet sliding but don���t account for the waviness of the tablets. In this work, mathematical models for calculating the elastic modulus and toughness of nacre-like material are proposed to account for the waviness of the tablet. In addition, a multi-objective optimization problem is formulated and solved using an optimization method called ���genetic algorithm���.
Using the models developed in this work, a better prediction of the elastic modulus and toughness are obtained which agrees with experimental results found in the literature. The multi-objective optimization problem solved here results in a set of optimal solutions that the designers can select according to their preferences. This work will aid in the design and optimization of nacre-like materials that can enhance the performance of ceramic materials in different applications in areas such as material science, biomaterials development, civil, petroleum, biomedical and nanotechnology
Role of Basal-Charged Clays in Low Salinity Effect in Sandstone Reservoirs: Adhesion Force on Muscovite using Atomic Force Microscope
No full textLow salinity water flooding appears to be an important means to improved oil recovery in sandstone reservoirs. Wettability alteration has been identified as the main effect behind low salinity water flooding due to the interaction of oil-brine-rock interfaces, where clay minerals play a significant role. While how edge-charged clays (kaolinite-bearing sandstone) contribute to wettability alteration during low salinity water flooding has been well-studied, the role of basal charged clays (smectite, illite, and chlorite) in wettability alteration remains unclear. We previously confirmed that basal charged clays trigger pH increases (2 to 3) due to ion exchange with added impetus of mineral dissolution by means of geochemical modeling (Chen et al. Fuel 2018, 112a117). In this work, we hypothesized that the pH increase triggers negative zeta potential of both oil-brine and brine-clays, thus increasing double layer expansion, as well as hydrophilicity. To test our hypothesis, we measured adhesion force between functional groups (aCH 3 and aCOOH) and muscovite using atomic force microscope (AFM) at pH of 7 and 11 with NaCl at a concentration of 10※000 mg/L NaCl. To gain a better isotherm thermodynamic understanding, we measured zeta potential of brine-muscovite and oil-brine and computed total disjoining pressure under constant potential condition using flat to flat and sphere to flat thermodynamic models. Zeta potential measurements show that increasing pH shifted the zeta potential of oil-brine and brine-muscovite to more negative values thus increasing the electrical double layer force. Our AFM measurements show that increasing pH from 7 to 11 indeed decreased 80% of the adhesion force for both functional groups. Total disjoining pressure calculation predicts the same trend as the AFM adhesion measurements. However, the sphere to flat thermodynamic model predicts a correct degree of decrease in adhesion force compared to AFM, implying that the sphere to flat model should be applied to interpret AFM results. Together, our results confirm that basal-charged clays can significantly contribute to low salinity effect due to electrical double layer expansion, thus expanding the application envelope of low salinity flooding in sandstone reservoirs bearing basal-charged clays
A mixed methods study exploring the barriers and facilitators of screening for autism spectrum disorder in Oman
No full textBackground:
Within the routine practice, specific screening for autism spectrum disorder (ASD) has been recommended, in order to facilitate early intervention and improve outcomes. Despite the substantial advantages of this process, it has also presented a variety of challenges, across clinical settings, which have not yet been explored sufficiently. There is little information available to support the introduction of ASD screening in Oman. Research is required to identify the potential facilitators of and barriers to ASD screening in Oman, prior to the implementation of a screening programme, to ensure its successful introduction.
Method:
An exploratory mixed-methods design was adopted, in two sequential phases. Phase 1 involved two focus group discussions, with seven nurses and six GPs, from primary health care (PHC) settings in Oman. The participants were recruited using a purposive and snowballing technique. The discussions were audio-taped and transcribed verbatim. Framework Analysis was used to identify recurrent themes within and across groups. Data from the focus groups was then used to inform the development of a questionnaire, which was piloted on a sub-sample of volunteers from both groups. Phase two (quantitative phase) comprised of sending the final draft of the questionnaire to a random sample of primary health care providers (PHPs) (n=571) across Oman. The returned data was analysed statistically with the software program SPSS (Statistical Package for Social Sciences version 22.0). The Social Ecological Model (SEM) was then applied to interpret the final data from both phases and to draw conclusions.
Results:
Qualitative data analysis revealed five themes, which voiced the major challenges facing ASD screening in Oman, as well as highlighting a few facilitators. The findings revealed that both nurses and GPs believed that introducing screening for ASD would be a positive step. However, they felt overwhelmed by their responsibilities and believed that their workplaces lacked the necessary infrastructure. Practitioners’ awareness of ASD services was identified as poor, as were the essential skills required for undertaking screening. Additionally, limited public awareness of ASD and a strong interest in traditional medicine, as well as the social stigma attributed to ASD, were thought to create barriers to screening. The groups also discussed their preference for a clear, simple, paper-based questionnaire, supported with guidance and researcher availability to reward their willingness to participate.
The findings from the focus group informed the development of a 38-item questionnaire to explore the potential barriers to and facilitators of the introduction of ASD screening in Oman. The questionnaire was short so that it could be completed within 15 minutes.
Five hundred and seventy-one questionnaires were sent to a random sample of PHP providers across Oman. Of those, five hundred and sixteen questionnaires were returned, in phase 2 (response rate 90.37%). The quantitative results of this phase were congruent with the qualitative findings, in that they suggested a deficit in the knowledge of professionals, among both older respondents and nurse respondents. In addition, a lack of resources, time constraints, workload issues and staff shortages were highlighted. The respondents also emphasised the ambiguity surrounding their role and the lack of guidance on protocols to identify or refer suspected cases. This was compounded by a lack of public awareness and knowledge of ASD identification and its potential causes, as well as the attributed social stigma.
Conclusions:
The root challenges and potential facilitators for screening for ASD were examined, through the SEM. Challenges were addressed and resolved across three levels (intrapersonal, organisational, and community). At the intrapersonal level, more training and knowledge regarding ASD is required. Organisations need to implement a clear protocol, to guide the process, with greater coordination and collaboration among services. A country-wide awareness campaign, targeting social issues, may reduce the stigma and improve the uptake of screening
The prevalence of macrovascular complications among diabetic patients in the United Arab Emirates
No full textAbstract Background Diabetes Mellitus (DM) is a major public health problem in the UAE with a prevalence rate reaching 24% in national citizens and 17.4% in expatriates. The aim of this study was to determine the prevalence and risk factors of macrovascular complications among diabetic patients in the Al-Ain district of the United Arab Emirates (UAE). Methods The study was part of a general cross-sectional survey carried out to assess the prevalence of diabetes (DM) complications among known diabetic patients in Al-Ain District, UAE. Patients were randomly selected during 2003/2004. Patients completed an interviewer-administered questionnaire carried out by treating doctors and underwent a complete medical assessment including measurement of height, weight, blood pressure and examination for evidence of macrovascular complications. A standard ECG was recorded and blood samples were taken to document fasting blood sugar, glycosylated haemoglobin (HbA1C) and lipid profile. Results A sample of 513 diabetic patients was selected with a mean age of 53 years (SD ± 13.01). Overall, 29.5% of DM patients had evidence of macrovascular complications: 11.6% (95% CI: 8.8–14.4) of patients had peripheral vascular disease (PVD), 14.4% (95% CI: 11.3–17.5) had a history of coronary artery disease (CAD) and 3.5% (95% CI: 1.9–5.1%) had cerebrovascular disease (CVD). Of the total population surveyed 35% (95%CI: 30.8–39) had hypertension. The analysis showed that macrovascular complications in diabetic patients were more common among males, increased with age, were more common among hypertensive patients and its prevalence increased steadily with duration of DM. Conclusion Our data revealed a significant association between hypertension and presence of macrovascular disease among diabetic patients. However, the risk of CAD in the UAE was relatively low compared to that seen in patients in other geographical settings. In addition, a lack of correlation between macrovascular disease and glycemic control among patients with DM was observed.</p
The influence of cycocel on the responses of wheat plants to water limitations
No full textConsiderable research has been concentrated on the foliage application of Cycoce, whereas little attention has focused on its use in seed application. Imbibition of caryopses of wheat (Triticum aestivum L.) in (2-chloroethyl) trimethylammonium chloride (Cycocel/CCC) resulted in a reduction in germination rate and a stunting of seedling growth. This was consistent with the appearance of a thicker stem, with shorter leaves than the control. Chlorophyll content per unit weight of leaf and numbers of tillers initiated both increased in comparison to controls. However, Cycocel treatment was accompanied by an enhanced survival capacity of seedlings when they were subjected to water limitation under growth room conditions. Seedlings grown from caryopses imbibed in 0.4 % Cycocel and exposed to a 7-day cycle of watering remained green and turgid beyond the time when the controls had wilted and died. Seedlings, at the fourth leaf stage, showed no wilting 23 days after watering had been withheld totally. Enhanced survival was also noted in seedlings when caryopses had been imbibed in Cycocel for 24 hours followed by a period of dry storage for up to 2 weeks prior to sowing. Enhanced survival was also detected as a carryover into the tillers, and the subsequent GEN2 seedlings, derived from GEN1plants. Cycocel pre-treatment did not alter Stomatal Index to an extent which could lead to enhanced water use efficiency, nor to the accumulation of proline to bring compatible solutes into equilibrium. However, the pre-treatment with Cycocel was found to enhance growth as a counter to water stress, and maintained fresh and dry weight of shoots when examined under the polyethylene glycol (PEG) induced stress. At the anatomical level the microscopic investigation of the GEN2 leaf tissues, derived from GENl plant, revealed a fully turgid cell structure, cells did not collapse and tissues were not distorted after the extraction of chlorophyll when compared with the control of the continuous watering as well as the moderate watering regime. Additionally, the cortex of GENl plants derived from pre-treated caryopses, showed a bright fluorescing unidentified deposition under Nutrient Solution (NS). This was more much greater when sampled from the NS + PEG treatments. From the results achieved Cycocel pre-treatment of caryopses appeared to have potential in manipulating wheat plants against water limitation. However, the mechanism (s) by which this can be achieved was not fully resolved in this study. Further investigations are required at the biochemistry and molecular level, particularly in relation to potential carryover effects between generations
Participants characteristics by Metabolic Syndrome (MetS), aged 12 to 18 years (n = 1018), Al Ain, UAE, 2010: univariate analysis.
No full text<p>Participants characteristics by Metabolic Syndrome (MetS), aged 12 to 18 years (n = 1018), Al Ain, UAE, 2010: univariate analysis.</p
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