582 research outputs found

    Asymmetric planar terahertz metamaterials

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    We report an experimental observation of three distinct resonances in split ring resonators (SRRs) for both vertical and horizontal electric field polarizations at normal incidence by use of terahertz time domain spectroscopy. Breaking the symmetry in SRRs by gradually displacing the capacitive gap from the center towards the corner of the ring allows for an 85% modulation of the fundamental inductive-capacitive resonance. Increasing asymmetry leads to the evolution of an otherwise inaccessible high quality factor electric quadrupole resonance that can be exploited for bio-sensing applications in the terahertz region.Comment: 8 pages, 5 figure

    Coulomb breakup effects on the optical potentials of weakly bound nuclei

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    The optical potential of halo and weakly bound nuclei has a long range part due to the coupling to breakup that damps the elastic scattering angular distributions. In order to describe correctly the breakup channel in the case of scattering on a heavy target, core recoil effects have to be taken into account. We show here that core recoil and nuclear breakup of the valence nucleon can be consistently taken into account. A microscopic absorptive potential is obtained within a semiclassical approach and its characteristics can be understood in terms of the properties of the halo wave function and of the reaction mechanism. Results for the case of medium to high energy reactions are presented.Comment: 25 latex pages, 4 tables, 6 figures. Submitted to Nucl. Phys.

    Extremely large extinction efficiency and field enhancement in terahertz resonant dipole nanoantennas

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    The distinctive ability of nanometallic structures to manipulate light at the nanoscale has recently promoted their use for a spectacular set of applications in a wide range of areas of research including artificial optical materials, nano-imaging, biosensing, and nonlinear optics. Here we transfer this concept to the terahertz spectral region, demonstrating a metal nanostructure in shape of a dipole nanoantenna, which can efficiently resonate at terahertz frequencies, showing an effective cross section >100 times larger than its geometrical area, and a field enhancement factor of ~280, confined on a lateral section of ~λ/1,000. These results lead to immediate applications in terahertz artificial materials exhibiting giant dichroism, suggest the use of dipole nanoantennas in nanostructure-based terahertz metamaterials, and pave the way for nanoantenna-enhanced terahertz few-molecule spectroscopy and localized terahertz nonlinear optics

    Effect of Antibiotics on the Pathogenic Bacteria (K. pneumonia and P. aeruginosa) Isolated Around the Dental Implant Area

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    In this study, the bacterial isolates (36) were obtained from total 52 samples were taken Twenty K. pneumonia and sixteen P. aeruginosa isolates were found in the dental implant region of individuals of varying ages and sexes who visited a single dental clinic. It was determined what kind of bacteria had been identified by culture, microscopic characteristics and biochemical tests. The resistance and sensitivity of isolates to eight antibiotics (Ceftazidime CAZ, Amikacin Ak, Ciprofloxacin CIP, Chloramphenicol C, Meropenem MEM, Gentamycin GN, Imipenem IMI, Amoxicillin Clavulanate AMC) were studied, with depending on the diameter of the inhibition on Muller-Hinton Agar medium and its comparison with the standard ratios in the Clinical and Laboratory Standards Institute (CLSI, 2018). The results showed that the highest percentage of resistance K. pneumonia bacteria was to Ceftazidime and Amoxicillin Clavulanate, which reached (100% ,90%), respectively. It was followed by Gentamycin (77%), Ciprofloxacin (67%) and Amikacin was (40%). While the lowest percentage of resistance to the antibiotics (Imipenem, and Meropenem) were (25%) and Chloramphenicol was (20%). As for bacteria. aeruginosa the highest percentage of resistance was to the antibiotic Ceftazidime (93%), followed by the antibiotic Amikacin by (71%), Chloramphenicol (58%), Gentamycin (47%), Meropenem (42%), then the antibiotic Imipenem (40%) While the lower percentage of resistance to the antibiotic Amoxicillin Clavulanic (39%) and Ciprofloxacin (20%). This review provides a complex effect of antibiotics to understand of mechanism and effects of the antibiotic is the base for the new approaches in clinical treatments by which can effectively fight the groups of the resistant pathogens, in patients who are at high risk specially when undergo dental procedures

    A Study of Female Students Perceptions of the Barriers to Participate in Physical and Sports Activities at Al-Hussein Bin Talal University

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    The study aimed to examine the perceived barriers to participate in physical and sports activities among female university students as well as the potential differences of their perceptions of the barriers based on their academic discipline, academic year, and Grade Point Average (GPA) level. The participants in this study were 221 female students at Al-Hussein Bin Talal University. All the participants were undergraduate students. The study took place in the second semester of 2015/2016 academic year. Survey research approach was selected to guide the investigation. A questionnaire instrument, with five-point likert scale, was developed by the researchers as a data collection tool. The questionnaire instrument consisted from four parts that included:  social and religious barriers; university related barriers; academic barriers; and psychological barriers. The results indicated that the level of perceived barriers to participate in physical and sports activities was moderate. In addition, the results indicated that there were significant differences (α =.05) between the students’ means of perceptions of some types of barriers to participate in physical and sports activities based on their academic discipline and academic year. Keywords: physical and sports activities, female students, perceived barriers, Jorda

    Effectiveness of a pharmacist-led educational intervention to reduce the use of high-risk abbreviations in an acute care setting in Saudi Arabia: A quasi-experimental study

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    Objectives: To evaluate the effectiveness of a pharmacist-led educational intervention to reduce the use of high-risk abbreviations (HRAs) by healthcare professionals. Design: Quasi-experimental study consisting of a single group before-and-after study design. Setting: A public emergency hospital in Mecca, Saudi Arabia. Participants: 660 (preintervention) and then 498 (postintervention) handwritten physician orders, medication administration records (MRAs) and pharmacy dispensing sheets of 482 and 388 patients, respectively, from emergency wards, inpatient settings and the pharmacy department were reviewed. Intervention: The intervention consisted of a series of interactive lectures delivered by an experienced clinical pharmacist to all hospital staff members and dissemination of educational tools (flash cards, printed list of HRAs, awareness posters) designed in line with the recommendations of the Institute for Safe Medical Practices and the US Food and Drug Administration. The duration of intervention was from April to May 2011. Main outcome: Reduction in the incidence of HRAs use from the preintervention to postintervention study period. Findings: The five most common abbreviations recorded prior to the interventions were 'IJ for injection' (28.6%), 'SC for subcutaneous' (17.4%), drug name and dose running together (9.7%), 'OD for once daily' (5.8%) and 'D/C for discharge' (4.3%). The incidence of the use of HRAs was highest in discharge prescriptions and dispensing records (72.7%) followed by prescriptions from in-patient wards (47.3%). After the intervention, the overall incidence of HRA was significantly reduced by 52% (ie, 53.6% vs 25.5%; p=0.001). In addition, there was a statistically significant reduction in the incidence of HRAs across all three settings: the pharmacy department (72.7% vs 39.3%), inpatient settings (47.3% vs 23.3%) and emergency wards (40.9% vs 10.7%). Conclusions: Pharmacist-led educational interventions can significantly reduce the use of HRAs by healthcare providers. Future research should investigate the long-term effectiveness of such educational interventions through a randomised controlled trial

    Diagnostic and Assessment Benefits and Barriers of BIM in Construction Project Management

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    This paper aims to diagnostic and assessment the benefits and barriers of Building Information Modelling in the construction project management. Both open and closed questionnaire was used to explore the views of a number of Iraqi engineers; in order to investigate the level of BIM implementation in Iraq construction sector. Questionnaire indicated an acceptable awareness of (BIM) in Iraq, especially among the young generation of engineers which indicates the arrival of the evolutionary stream of BIM in the next few years. Moreover, questionnaire showed that the most important advantage of implementing BIM in the Iraqi construction sector was the ability to generate accurate 2D plans at any stage, while the least important advantage was the ability to provide a careful planning of the site facilities, with a relative importance of (82 %) and (33 %) respectively. Furthermore, the most important barrier to its implementation was the unspecified responsibilities for data content, as presented by questionnaire, while the least important barrier was the lack of programs efficiency in data exchange and internal collaboration, with a relative importance of (81 %) and (34 %) respectively

    Anti-Disturbance Compensation-Based Nonlinear Control for a Class of MIMO Uncertain Nonlinear Systems

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    Multi-Inputs-Multi-Outputs (MIMO) systems are recognized mainly in industrial applications with both input and state couplings, and uncertainties. The essential principle to deal with such difficulties is to eliminate the input couplings, then estimate the remaining issues in real-time, followed by an elimination process from the input channels. These difficulties are resolved in this research paper, where a decentralized control scheme is suggested using an Improved Active Disturbance Rejection Control (IADRC) configuration. A theoretical analysis using a state-space eigenvalue test followed by numerical simulations on a general uncertain nonlinear highly coupled MIMO system validated the effectiveness of the proposed control scheme in controlling such MIMO systems. Time-domain comparisons with the Conventional Active Disturbance Rejection Control (CADRC)-based decentralizing control scheme are also included

    DNA Polymorphism of Gaucher Disease in Iraqi Patients

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    Gaucher disease is the autosomally recessively inherited deficiency of the lysosomal enzyme glucocerebrosidase. Increasing storage of glucocerebrosides leads to a multisystem disease, the prevalence of which is about 1 : 40,000 in central Europe and up to 1 : 2,000 in some other countries (e. g. Israel). The acute and chronic neuronopathic forms of the disease (formerly defined as Gaucher types 2 and 3) account for only 5 to 10% of all Gaucher patients in Central Europe and Germany and are thus less frequent than the nonneuronopathic disease (formerly defined as Gaucher type 1). Gaucher's disease is usually associated with splenoand hepatomegaly, fatigue, skeletal complications, and several corresponding hematological and laboratory abnormalities. In 5 to 10% of the patients there are also central nervous symptoms such as myoclonic seizures, oculomotoric apraxia and a slight mental retardation. Recent epidemiological data indicate that only 10 to 20% of all Gaucher patients are correctly diagnosed (and treated) in Germany. The diagnosis today can be done in all patients by noninvasive methods, i. e. determination of the glucocerebrosidase activity in peripheral leukocytes and of the genetic defect, in this research the PCR technique was used to analyze the mutation in glucocerebrosidases gene (G ---C). Key words: Gaucher disease (GD), lysosomal storage disorder (LSD),lysosomal enzyme glucocerebrosidase, PCR, Mutation
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