Characterization Of Superparamagnetic Iron Oxide Nanoparticles With Different Surfactants - In Search Of Optimum Synthesis Parameters For Mri Application

Superparamagnetic iron oxide nanoparticles (SPIONs) have been extensively studied for various biomedical applications, such as magnetic resonance imaging (MRI) contrast agents, and hyperthermia. The most common approach used to produce SPIONs is co-precipitation method. However, problem due to agglomeration and the broad size distribution of nanoparticles prepared by co-precipitation method hinder their application progress in MRI. Therefore, this study aims to produce a highly stabilized and monodispersed SPIONs for MRI contrast agents. In this thesis, SPIONs were synthesized with different surfactants (tri-sodium citrate, polyvinylpyrrolidone (PVP), chitosan, cetyl trimethylammonium bromide (CTAB) and citric acid) using the one pot co-precipitation method for surface modification and to ensure excellent colloidal stability in water. In addition, the synthesis parameters such as surfactant concentration, pH, and temperature of reaction were optimized to obtain stabilized SPIONs. The SPIONs prepared in the presence of tri-sodium citrate formed the most stable SPIONs due to improved physiological condition, dispersion and stabilization in aqueous solution. In addition, citrate-SPIONs displayed the highest zeta potential (ζ= -44.0 mV) and saturation magnetization (Ms=53.9 emu g-1) compared with other samples, due to the ability of three carboxylate groups dissociated from the citrate to strongly bind to the surface of SPIONs. The TEM measurements of the different SPIONs indicated that the type of surfactant affects their average particle sizes and size distribution. In addition, the presence of defects within the spinel structure, i.e., oxidation of the SPIONs, seems to be also influenced by the choice of surfactant

Performance analysis of a cognitive radio network with imperfect spectrum sensing

In Cognitive Radio Networks (CRNs), spectrum sensing is performed by secondary (unlicensed) users to utilize transmission opportunities, so-called white spaces or spectrum holes, in the primary (licensed) frequency bands. Secondary users (SUs) perform sensing upon arrival to find an idle channel for transmission as well as during transmission to avoid interfering with primary users (PUs). In practice, spectrum sensing is not perfect and sensing errors including false alarms and misdetections are inevitable. In this paper, we develop a continuous-time Markov chain model to study the effect of false alarms and misdetections of SUs on several performance measures including the collision rate between PUs and SUs, the throughput of SUs and the SU delay in a CRN. Numerical results indicate that sensing errors can have a high impact on the performance measures

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Integrating M-Learning in Teaching ECG Reading and Arrhythmia Management for Undergraduate Nursing Students

Use of mobile devices among nursing students is recently a widespread approach. Integrating mobile devices in education can improve the quality of nursing education by engaging students in learning experience. The present study aims at investigating theeffect of using Mobile Learning (M-learning) on students’ academicachievements and satisfaction. Therefore, quasi-experimental design was used. The study included 104 students who were enrolled in a critical care course at the faculty of Nursing. During the study, the participant were divided into control and experimental groups. The experimental group 52 students were able to use a developed mobile application, which includes learning materials and multimedia resources, dedicated to critical care course.  On the other hand, control group 52 students were able to explore the classical learning materials form the course. The study included students’ attitudes, students’ satisfaction, and students’ academic achievements. Differences between the two groups were considered significant as the result was p &lt; 0.05. The obtained results showed significance difference between pre-post quizzes achievements between the experimental and control group (p&lt;0.000). Additionally, 76% of the students were satisfied with using M-learning. The study revealed that there was improvement in the student academic achievements and satisfaction when integrating mobile learning into nursing education.</p

Performance Evaluation of Cognitive Radio Networks with Imperfect Spectrum Sensing and Bursty Primary User Traffic

In this paper, we introduce a four-dimensional continuous-time Markov chain model to evaluate the performance of cognitive radio networks. In such networks, secondary (unlicensed) users may opportunistically use the frequency channels not currently occupied by primary (licensed) users in order to increase the utilization of the wireless spectrum. Secondary users perform channel sensing before as well as during transmission in order not to interfere with primary users. The proposed model assumes that primary users arrive according to a bursty arrival process and moreover takes the possible occurrence of sensing errors (false alarms and misdetections) into account. Several performance measures including the collision rate between primary and secondary users, the blocking probabilities of primary or secondary users, and the mean delay of secondary users are derived and illustrated through numerical examples. The results show that the system performance strongly depends on the degree of burstiness in the arrival process of primary users. It is also observed that the quality of service of the primary network can be seriously compromised due to misdetection by secondary users

GPS Navigation and Tracking Device

Since the introduction of GPS Navigation systems in the marketplace, consumers and businesses have been coming up with innovative ways to use the technology in their everyday life. GPS Navigation and Tracking systems keep us from getting lost when we are in strange locations, they monitor children when they are away from home, keep track of business vehicles and can even let us know where a philandering partner is at all times. Because of this we attend to build a GPS tracking device to solve the mentioned problems. Our work consists of the GPS module that collects data from satellites and calculates the position information before transmitting them to the user’s PC (of Navigation system) or observers (of Tracking System) using wireless technology (GSM)

Hyperbaric oxygen therapy for the treatment of Steinberg I and II avascular necrosis of the femoral head: a report of fifteen cases and literature review

Purpose This article aimed to report a case series of pre-collapse avascular necrosis of the femoral head treated with hyperbaric oxygen and review the most recent literature on the topic. Methods The data from a prospectively followed registry of 15 patients with Steinberg I and II avascular necrosis of the femoral head was collected. Functional outcome, pain scores, and radiographic changes at an average follow-up of 22 months were analyzed and reported. Results Thirteen patients had satisfactory outcome at final follow-up with an average Oxford hip score of 37.3, pain scores were significantly improved at final follow-up (P  Conclusion Hyperbaric oxygen treatment for pre-collapse avascular necrosis of the femoral head is considered a safe alternative with satisfactory clinical and radiological outcomes and low complications rate.Other Information Published in: International Orthopaedics License: https://creativecommons.org/licenses/by/4.0See article on publisher's website: http://dx.doi.org/10.1007/s00264-021-05120-3</p