68 research outputs found

    Sound propagation in viscous flows using piezoelectric sensors and non-destructive propagation techniques and its applications

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    Structural non-destructive evaluation techniques are applied to viscous flows to detect fluid property changes. The main operating principle consists of an actuator which provides a stimulus, and a sensor to receive a signal traveling to a fluid domain. The main challenge of the operating principle consists of investigating waves traveling in a viscous flow. Traveling waves utilizing a piezoelectric actuator-sensor pair are modeled and the results are validated experimentally. ANSYS models, coupled with a two-way fluid-solid interaction model, are built to investigate how far a signal travels and what frequency ranges are of interest. The numerical model includes modeling three different geometries (square, circular, triangular) for the actuator-sensor pair manufactured with three different piezoelectric materials (PZT4, PZT5A, PMN32). Numerical work is validated with experimental work using a pair of circular actuator-sensors manufactured with PZT5A and immersed in a large container of water and glycerin. Furthermore, in order to establish mesh independence of the results, three mesh refinement levels (coarse, medium and fine) were utilized with different materials, geometries and fluid viscosity values. The actuator receives a 0.5 VAC signal ranging from 100 Hz to 40 MHz. The sensor records the signal at varying distances from the actuator, and the result is labeled as the gain or the ratio of received to send wave magnitude. The pattern of decay for both numerical and experimental results are in close agreement (the numerical decay are 10.825 and 11.4 for water and glycerin, respectively, while the experimental are 11.254 and 14.48 for water and glycerin, respectively). Numerically, the results show that the maximum acoustic pressure can be obtained by using a square piezoelectric actuator- sensor pair fabricated with PMN32. Numerically, the results show that the maximum acoustic pressure can be obtained by using a square piezoelectric actuator- sensor pair fabricated with PMN32. A viscosity probe for medical applications is developed using a piezoelectric actuator-sensor pair. The design constraints were size and cost. The actuator-sensor pair is manufactured with PZT5A with a rectangular shape to fit a 3 mL vacutainer. The actuator is excited by 0.5 VAC sinusoidal waves with varying frequencies ranging from 100Hz to 40 MHz. The sensor will detect the produced wave in the fluid. Also, the phase shift is recorded for different concentrations of glycerin and water to simulate different viscosities ranging from 1 to 1600 cP. The numerical analysis, a modal analysis, of the probe was performed and the results showed that the first, second and third modes of the device were in the range of 684–2358 Hz for air, 500–1080 Hz for water, and 469–625 Hz for glycerin. From the harmonic acoustic analysis, the results showed that the highest phase shifts, and maximum gain, occurs at the ultrasonic frequency range, 6 to 9 MHz. Hence, there is no relation between the natural frequencies of the probe and the ultrasonic frequency for the phase shift. Most importantly, a correlation between the phase shift and viscosity is found, making the probe a feasible device for measuring viscosity in an inexpensive, small, and disposable way

    SPECTRAL STUDIES AND ANTIMICROBIAL SCREENING FOR SOME NOVEL CHALCONES ANALOGUES

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    Objective: The present work aim to study the spectral and antimicrobial activity for synthesized chalcones Methods: The synthesized Chalcones were characterized by Physical and spectral methods such as melting point, IR, 1H-NMR and Mass analysis. The synthesized compounds have been screened for their antimicrobial activity. Results: The biological data showed that compounds III, VII had strong activities against the Staphylococcus aureus, Bacillus subtilis, and Pseudomonas aeruginosa, but not activity against fungus. Conclusion: The main purpose to use an easy and useful method to synthesize biologically active chalcone

    New Radiation Pattern-Reconfigurable 60-GHz Antenna for 5G Communications

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    Reconfigurable beam steering using circular disc microstrip patch antenna with a ring slot is proposed. The overall dimension of the antenna is 5.4 × 5.4 mm2 printed on 0.504 mm thick, RT5870 substrate with relative permittivity 2.3 and loss tangent 0.0012. The designed antenna operates at the expected 60 GHz 5G frequency band with a central coaxial probe feed. Two NMOS switches are utilized to generate three different beam patterns. Activating each switch individually results in a 70° shift in the main beam direction with constant frequency characteristics. The power gain is 3.9–4.8 dB in the three states of switch configurations. Simulated results in terms of return loss, peak gains and radiation pattern are presented and show good performance at the expected 60 GHz band for 5G applications

    Cyber-Security Incidents: A Review Cases In Cyber-Physical Systems

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    Cyber-Physical Systems refer to systems that have an interaction between computers, communication channels and physical devices to solve a real-world problem. Towards industry 4.0 revolution, Cyber-Physical Systems currently become one of the main targets of hackers and any damage to them lead to high losses to a nation. According to valid resources, several cases reported involved security breaches on Cyber-Physical Systems. Understanding fundamental and theoretical concept of security in the digital world was discussed worldwide. Yet, security cases in regard to the cyber-physical system are still remaining less explored. In addition, limited tools were introduced to overcome security problems in Cyber-Physical System. To improve understanding and introduce a lot more security solutions for the cyber-physical system, the study on this matter is highly on demand. In this paper, we investigate the current threats on Cyber-Physical Systems and propose a classification and matrix for these threats, and conduct a simple statistical analysis of the collected data using a quantitative approach. We confirmed four components i.e., (the type of attack, impact, intention and incident categories) main contributor to threat taxonomy of Cyber-Physical System

    Risk Assessment Of In-Vitro Fertilization, Review Article

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    Since its remarkable inception in 1978, IVF has garnered significant public interest.   Currently, assisted reproductive technology is widely accessible in most developed countries, and the methods employed have significantly evolved since its inception.   Advancements in laboratory technology and clinical practice have enabled IVF to develop into a medical process that is highly efficient, safe, easily accessible, and comparatively affordable. Over 2 million children conceived by IVF have been born so far, and it is probable that ongoing improvements will increase its attractiveness and suitability. There has been a rising interest in the topic of risk assessment in IVF in recent years, with a significant amount of research focused on detecting and reducing the potential dangers linked to the operation.   This review article seeks to offer a thorough and all-encompassing analysis of the present understanding of risk assessments in IVF, encompassing the diverse range of risks and complications linked to the operation

    Assessment of burnout, resilience, and thriving among academic health professionals: findings from an international study

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    Introduction: Burnout, resilience, and thriving significantly impact academics, particularly in health professions, where responsibilities are extensive. This study aimed to explore these constructs among academic health professionals, examining sociodemographic and work-related factors influencing these outcomes.Methods: A cross-sectional study was conducted among academic health professionals via web-based professional networks from August 2022 to February 2023. Validated tools were used, and descriptive and inferential statistics were applied.Results: 505 participants were included, predominantly female (63%), with a mean age of 38.15 ± 9.6 years. High burnout was reported by 10.9%, 13.7% experienced exhaustion, and 6.3% were disengaged. Resilience and thriving were moderate at 59.2 and 51.9%, respectively. Age correlated negatively with burnout (r = −0.131, p = 0.003) but positively with resilience (r = 0.178, p < 0.001). Females reported higher exhaustion (p = 0.014), while males showed greater resilience (p = 0.016). Instructors exhibited lower resilience compared to assistant professors (p < 0.001) and associate professors (p < 0.001). Those at public universities reported higher exhaustion than those at private universities (p < 0.001).Conclusion: Variable levels of burnout, resilience, and thriving were observed among academic health professionals, influenced by sociodemographic and work-related factors. Interventions targeting resilience and thriving may mitigate burnout risk and enhance engagement among academics in health professions

    Epidemiology and antimicrobial resistance trends of Acinetobacter species in the United Arab Emirates: a retrospective analysis of 12 years of national AMR surveillance data

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    Introduction: Acinetobacter spp., in particular A. baumannii, are opportunistic pathogens linked to nosocomial pneumonia (particularly ventilator-associated pneumonia), central-line catheter-associated blood stream infections, meningitis, urinary tract infections, surgical-site infections, and other types of wound infections. A. baumannii is able to acquire or upregulate various resistance determinants, making it frequently multidrug-resistant, and contributing to increased mortality and morbidity. Data on the epidemiology, levels, and trends of antimicrobial resistance of Acinetobacter spp. in clinical settings is scarce in the Gulf Cooperation Council (GCC) and Middle East and North Africa (MENA) regions. Methods: A retrospective 12-year analysis of 17,564 non-duplicate diagnostic Acinetobacter spp. isolates from the United Arab Emirates (UAE) was conducted. Data was generated at 317 surveillance sites by routine patient care during 2010-2021, collected by trained personnel and reported by participating surveillance sites to the UAE National AMR Surveillance program. Data analysis was conducted with WHONET. Results: Species belonging to the A. calcoaceticus-baumannii complex were mostly reported (86.7%). They were most commonly isolated from urine (32.9%), sputum (29.0%), and soft tissue (25.1%). Resistance trends to antibiotics from different classes during the surveillance period showed a decreasing trend. Specifically, there was a significant decrease in resistance to imipenem, meropenem, and amikacin. Resistance was lowest among Acinetobacter species to both colistin and tigecycline. The percentages of multidrug-resistant (MDR) and possibly extensively drug-resistant (XDR) isolates was reduced by almost half between the beginning of the study in 2010 and its culmination in 2021. Carbapenem-resistant Acinetobacter spp. (CRAB) was associated with a higher mortality (RR: 5.7), a higher admission to ICU (RR 3.3), and an increased length of stay (LOS; 13 excess inpatient days per CRAB case), as compared to Carbapenem-susceptible Acinetobacter spp. Conclusion: Carbapenem-resistant Acinetobacter spp. are associated with poorer clinical outcomes, and higher associated costs, as compared to carbapenem-susceptible Acinetobacter spp. A decreasing trend of MDR Acinetobacter spp., as well as resistance to all antibiotic classes under surveillance was observed during 2010 to 2021. Further studies are needed to explore the reasons and underlying factors leading to this remarkable decrease of resistance over time

    Consanguinity and reproductive health among Arabs

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    Consanguineous marriages have been practiced since the early existence of modern humans. Until now consanguinity is widely practiced in several global communities with variable rates depending on religion, culture, and geography. Arab populations have a long tradition of consanguinity due to socio-cultural factors. Many Arab countries display some of the highest rates of consanguineous marriages in the world, and specifically first cousin marriages which may reach 25-30% of all marriages. In some countries like Qatar, Yemen, and UAE, consanguinity rates are increasing in the current generation. Research among Arabs and worldwide has indicated that consanguinity could have an effect on some reproductive health parameters such as postnatal mortality and rates of congenital malformations. The association of consanguinity with other reproductive health parameters, such as fertility and fetal wastage, is controversial. The main impact of consanguinity, however, is an increase in the rate of homozygotes for autosomal recessive genetic disorders. Worldwide, known dominant disorders are more numerous than known recessive disorders. However, data on genetic disorders in Arab populations as extracted from the Catalogue of Transmission Genetics in Arabs (CTGA) database indicate a relative abundance of recessive disorders in the region that is clearly associated with the practice of consanguinity

    Elective Cancer Surgery in COVID-19-Free Surgical Pathways During the SARS-CoV-2 Pandemic: An International, Multicenter, Comparative Cohort Study.

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    PURPOSE: As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS: This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS: Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION: Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

    Elective cancer surgery in COVID-19-free surgical pathways during the SARS-CoV-2 pandemic: An international, multicenter, comparative cohort study

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    PURPOSE As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19–free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19–free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19–free surgical pathways. Patients who underwent surgery within COVID-19–free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19–free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score–matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19–free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION Within available resources, dedicated COVID-19–free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks
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