90 research outputs found

    A Secure and Efficient Cluster-Based Authentication Scheme for Internet of Things (IoTs)

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    IPv6 over Low Power Wireless Personal Area Network 6LoWPAN) provides IP connectivity to the highly constrained nodes in the Internet of Things (IoTs). 6LoWPAN allows nodes with limited battery power and storage capacity to carry IPv6 datagrams over the lossy and error-prone radio links offered by the IEEE 802.15.4 standard, thus acting as an adoption layer between the IPv6 protocol and IEEE 802.15.4 network. The data link layer of IEEE 802.15.4 in 6LoWPAN is based on AES (Advanced Encryption Standard), but the 6LoWPAN standard lacks and has omitted the security and privacy requirements at higher layers. The sensor nodes in 6LoWPAN can join the network without requiring the authentication procedure. Therefore, from security perspectives, 6LoWPAN is vulnerable to many attacks such as replay attack, Man-in-the-Middle attack, Impersonation attack, and Modification attack. This paper proposes a secure and efficient cluster-based authentication scheme (CBAS) for highly constrained sensor nodes in 6LoWPAN. In this approach, sensor nodes are organized into a cluster and communicate with the central network through a dedicated sensor node. The main objective of CBAS is to provide efficient and authentic communication among the 6LoWPAN nodes. To ensure the low signalling overhead during the registration, authentication, and handover procedures, we also introduce lightweight and efficient registration, de-registration, initial authentication, and handover procedures, when a sensor node or group of sensor nodes join or leave a cluster. Our security analysis shows that the proposed CBAS approach protects against various security attacks, including Identity Confidentiality attack, Modification attack, Replay attack, Man-in-the-middle attack, and Impersonation attack. Our simulation experiments show that CBAS has reduced the registration delay by 11%, handoff authentication delay by 32%, and signalling coby 37% compared to the SGMS (Secure Group Mobility Scheme) and LAMS (Light-Wight Authentication & Mobility Scheme)

    Catalytic effectiveness of azobisisobutyronitrile/[SiMes)Ru(PPH3)(Ind)Cl2 initiating system in the polymerization of methyl methacrylate and other vinylic monomers

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    The catalytic system of azo-bis-isobutyronitrile (AIBN) combined with (SiMes)Ru(PPH3)(Ind)Cl-2 [M-20] was investigated for the controlled radical polymerization of methyl methacrylate (MMA) in solution. Various factors that may influence the catalytic polymerization process, such as the aging time of the initiating system, AIBN/M-20 ratio, concentration of monomer, polymerization time, temperature, and the nature of solvent were examined. The results showed that the yield, molecular weight, and molecular distribution are practically unaffected by these parameters; however, the syndiotactic stereo-structure tendency that characterizes the produced poly(methyl methacrylate) (PMMA) varied with temperature. The optimum conditions for PMMA synthesis were determined to produce an essentially syndiotactic material with uniformly high molecular weights. It was also revealed that the kinetics of MMA polymerization is of first order with respect to the concentration of monomer. A comparison was also made for some vinylic polymers synthesized either with the AIBN alone or with the AIBN/M-20 initiating system under the same conditions

    Neuroprotective effect of ranolazine improves behavioral discrepancies in a rat model of scopolamine-induced dementia

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    BackgroundRanolazine (Rn), an antianginal agent, acts in the central nervous system and has been used as a potential treatment agent for pain and epileptic disorders. Alzheimer’s disease (AD) is one of the most prevalent neurodegenerative diseases and the leading factor in dementia in the elderly.AimWe examined the impact of Rn on scopolamine (Sco)-induced dementia in rats.MethodsThirty-two albino male rats were divided into four groups: control, Rn, Sco, and Rn + Sco.ResultsA significant decrease in the escape latency in the Morris water maze test after pre-treatment with Rn explained better learning and memory in rats. Additionally, Rn significantly upregulated the activities of the antioxidant enzymes in the treated group compared to the Sco group but substantially reduced acetylcholinesterase activity levels in the hippocampus. Moreover, Rn dramatically reduced interleukin-1 β (IL-1β) and IL-6 and upregulated the gene expression of brain-derived neurotrophic factor (BDNF). Furthermore, in the Sco group, the hippocampal tissue’s immunohistochemical reaction of Tau and glial factor activating protein (GFAP) was significantly increased in addition to the upregulation of the Caspase-3 gene expression, which was markedly improved by pre-treatment with Rn. The majority of pyramidal neurons had large vesicular nuclei with prominent nucleoli and appeared to be more or less normal, reflecting the all-beneficial effects of Rn when the hippocampal tissue was examined under a microscope.ConclusionOur findings indicated that Rn, through its antioxidative, anti-inflammatory, and anti-apoptotic effects, as well as the control of the expression of GFAP, BDNF, and Tau proteins, has a novel neuroprotective impact against scopolamine-induced dementia in rats

    Partial Nephrectomy A Comparison between Different Modalities

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    Kidney cancer, with 4% of all malignancies, is one of the most common malignancies occurring among in adults. In Saudi Arabia, kidney cancer comprises 2.3% of all cancers, and its incidence has increased by 33%. Partial nephrectomy (PN) is considered as the gold standard for T1 renal masses. In this retrospective study, we did a chart review for all patients who underwent PNs between April 2013 and February 2019. Data comprised pre-sentation, tumor size, type of procedure (open vs. laparoscopic vs. robotic), and intra- and post-operative complications. Chi-square, ANOVA, and cross-tabulation were done using SPSS software. P > 0.05 was considered significant. Approval was obtained from the institutional review board of King Abdullah International Medical Research Center. In all, 69 patients were identified: 26 (37.7%) males and 43 (62.3%) females, with mean age = 54.53 ± 13.21 years; mean body mass index = 32.36 ± 7.03, and mean tumor size = 3.7 ± 1.72 cm. In terms of presentation, most patients (50, 72.4%) presented incidentally as opposed to symptomatic presentation. Of these patients, 18 (26.1%) underwent open partial nephrectomy (OPN), 29 (42%) laparoscopic partial nephrec-tomy (LPN), and 22 (31.9%) robotic partial nephrectomy (RPN). On comparing minimally invasive surgery (MIS) PN with OPN, we found that OPN had more blood loss and a longer hospital stay but a shorter operating room (OR) time. Results of PN irrespective of the procedure type, whether it was OPN, LPN, or RPN, were similar if performed by experienced surgeons. However, open procedures involved a higher blood loss, more operative time, and longer hospital stay when compared with minimally invasive techniques

    Vitamin D serum level predicts stroke clinical severity, functional independence, and disability—A retrospective cohort study

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    BackgroundStroke is a leading cause of mortality and disability and one of the most common neurological conditions globally. Many studies focused on vitamin D as a stroke risk factor, but only a few focused on its serum level as a predictor of stroke initial clinical severity and recovery with inconsistent results. The purpose of this study was to assess the relationship between serum vitamin D levels and stroke clinical severity at admission and functional independence and disability at discharge in Saudi Arabia.MethodologyA retrospective cohort study of adult ischemic stroke patients who had their vitamin D tested and admitted within 7 days of exhibiting stroke symptoms at King Abdulaziz Medical City (KAMC) Jeddah, Saudi Arabia. Based on vitamin D level, the patients were categorized into normal [25(OH)D serum level ≥ 75 nmol/L], insufficient [25(OH)D serum level is 50–75 nmol/L], and deficient [25(OH)D serum level ≤ 50 nmol/L]. The primary outcome was to assess the vitamin D serum level of ischemic stroke patients’ clinical severity at admission and functional independence at discharge. The National Institute of Health Stroke Scale (NIHSS) was used to assess the clinical severity, whereas the modified Rankin scale (mRS) was used to assess functional independence and disability.ResultsThe study included 294 stroke patients, out of 774, who were selected based on the inclusion and exclusion criteria. The mean age of the participants was 68.2 ± 13.4 years, and 49.3% were male. The patients’ distribution among the three groups based on their vitamin D levels is: normal (n = 35, 11.9%), insufficient (n = 66, 22.5%), and deficient (n = 196, 65.6%). After adjusting for potential covariates, regression analysis found a significant inverse relationship of NIHSS based on 25(OH)D serum level (beta coefficient: −0.04, SE: 0.01, p = 0.003). Patients with deficient serum vitamin D level also had significantly higher odds of worse functional independence in mRS score [OR: 2.41, 95%CI: (1.13–5.16), p = 0.023] when compared to participants with normal vitamin D level.ConclusionLow vitamin D levels were associated with higher severity of stroke at admission and poor functional independence and disability at discharge in patients with acute ischemic stroke. Further randomized clinical and interventional studies are required to confirm our findings

    Avoidable emergency department visits among palliative care cancer patients: novel insights from Saudi Arabia and the Middle East

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    Background Several studies emerging from developed countries have highlighted a significant number of potentially avoidable emergency department (ED) visits by cancer patients during the end-of-life period. However, there is a paucity of information from developing nations regarding palliative care practices and the utilization of the ED by palliative care patients. Herein, we aim to characterize ED admissions among patients receiving palliative care at our tertiary center in Saudi Arabia. Methods This is a retrospective, cross-sectional study evaluating ED visits amongst adult patients with advanced cancer who were receiving treatment under the palliative care department. This study took place over a period of 12 months from July 2021 through to July 2022. Three palliative care specialist physicians independently and blindly reviewed each patient’s ED visits and determined whether the visit was avoidable or unavoidable. Results A total of 243 patients were included in the final analysis, of which 189 (78.1%) patients had unavoidable visits and 53 (21.9%) patient visits were classified as avoidable. A significantly higher proportion of breast cancer patients presented with unavoidable admissions (14.3% vs. 3.8%, P = 0.037) compared to other cancer types. The incidence of dyspnea (23.8% vs. 5.7%, P < 0.001) and fevers/chills (23.3% vs. 5.7%, P = 0.005) was significantly higher in patients with unavoidable visits. Patients with avoidable visits had a significantly greater proportion of visits for dehydration (13.2% vs. 2.1%, P = 0.002). Notably, although hospital stay was significantly longer in the unavoidable group (P = 0.045), mortality for palliative care patients—regardless of whether their ED visit was avoidable or unavoidable—was not statistically different (P=-0.069). Conclusion To our knowledge, this is the largest and most comprehensive study from Saudi Arabia and the Middle East providing insights into the utilization of palliative care services in the region and the propensity of advanced cancer patients towards visiting the ED. Future studies ought to explore interventions to reduce the frequency of avoidable ED visits

    Budesonide as a first line therapy in autoimmune hepatitis: A systematic review

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    BackgroundAutoimmune hepatitis (AIH) Is a chronic liver disease with female predominance. Treatment of this condition required usually a long-term corticosteroid therapy.AimsCurrent review aimed to summarize the efficacy of budesonide as a first line treatment in AIH.Methods Pub Med, ‎Google Scholar, and EBSCO ‎ databases were ‎systematically search for relevant articles. The terms ‎ ‎‎autoimmune hepatitis, budesonide, prednisolone and ‎azathioprine ‎were used. out of hundred ‎and six, only ‎five fulfilled ‎the inclusion criteria. Results Out of 106 articles, only 5 included in this review. All patients included in current review were steroid naive. Budesonide in dose of 3 mg trice a day was the used in 2 out of 5 studies both document complete platelet response in 50–80 per cent. Azathioprine was added to budesonide in 3 out of 5 studies, 60 per cent of the budesonide treated patient had a complete platelet response versus 30–40 per cent of prednisolone treated group.ConclusionIn non-cirrhotic AIH patients, budesonide was as effective as prednisolone with fewer steroid related side effects.

    Antimicrobial Usage and Resistance in Makkah Region Hospitals: A Regional Point Prevalence Survey of Public Hospitals

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    (1) Background: Inappropriate use of antimicrobials and subsequently rise of antimicrobial resistance (AMR) remains a major public health priority. Over-prescribing of broad-spectrum antibiotics is one of the main contributing factors for the emergence of AMR. We sought to describe antimicrobial prescribing trends among patients in public hospitals in Makkah hospitals. (2) Method: We undertook a point prevalence survey (PPS) in six hospitals in Makkah, Saudi Arabia, from January 2019 to July 2019. The survey included all the inpatients receiving antimicrobials on the day of PPS. Data was collected using the Global point prevalence survey (PPS) tool developed by the University of Antwerp, Belgium. (3) Results: Of 710 hospitalized patients, 447 patients (61.9%) were treated with one or more antimicrobials during the study period. The average bed occupancy among six hospitals was 74.4%. The majority of patients received antimicrobials parenterally (90.3%). Of the total prescribed antimicrobials, 415 (53.7%) antimicrobials were used in medical departments, 183 (23.7%) in surgical departments, and 175 (22.6%) in ICUs. Pneumonia (17.3%), skin and soft tissue infections (10.9%), and sepsis (6.6.%) were three common clinical indications. Ceftriaxones were the most commonly used antibiotics that were prescribed in 116 (15%) of patients, followed by piperacillin, with an enzyme inhibitor in 84 (10.9%). (4) Conclusion: There was a high prevalence of antibiotic use in the hospitals of Makkah, which could be a potential risk factor for the incidence of resistant strains, particularly MRSA infection. Public health decision-makers should take these findings into consideration to update national policies for antibiotic use in order to reduce the risks of further increases of AMR

    Perspectives, practices, and challenges of online teaching during COVID-19 pandemic: A multinational survey

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    The result of the movement restrictions during the COVID-19 pandemic was an impromptu and abrupt switch from in-person to online teaching. Most focus has been on the perception and experience of students during the process. The aim of this international survey is to assess staffs' perspectives and challenges of online teaching during the COVID-19 lockdown. Cross-sectional research using a validated online survey was carried out in seven countries (Brazil, Saudi Arabia, Jordan, Indonesia, India, the United Kingdom, and Egypt) between the months of December 2021 and August 2022, to explore the status of online teaching among faculty members during the COVID-19 pandemic. Variables and response are presented as percentages while logistic regression was used to assess the factors that predict levels of satisfaction and the challenges associated with online instruction. A total of 721 response were received from mainly male (53%) staffs. Most respondents are from Brazil (59%), hold a Doctorate degree (70%) and have over 10 years of working experience (62%). Although, 67% and 79% have relevant tools and received training for online teaching respectively, 44% report that online teaching required more preparation time than face-to-face. Although 41% of respondents were uncertain about the outcome of online teaching, 49% were satisfied with the process. Also, poor internet bandwidth (51%), inability to track students' engagement (18%) and Lack of technical skills (11.5%) were the three main observed limitations. Having little or no prior experience of online teaching before the COVID-19 pandemic [OR, 1.58 (95% CI, 1.35–1.85)], and not supporting the move to online teaching mode [OR, 0.56 (95% CI,0.48–0.64)] were two main factors independently linked with dissatisfaction with online teaching. While staffs who support the move to online teaching were twice likely to report no barriers [OR, 2.15 (95% CI, 1.61–2.86)]. Although, relevant tools and training were provided to support the move to online teaching during COVID-19 lockdown, barriers such as poor internet bandwidth, inability to track students’ engagement and lack of technical skills were main limitations observed internationally by teaching staffs. Addressing these barriers should be the focus of higher education institution in preparation for future disruptions to traditional teaching modes
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