64 research outputs found

    3D seismic geomorphology of fluvial systems

    Get PDF
    Fluvial sandstones constitute one of the major clastic petroleum reservoir types in many sedimentary basins around the world. This is especially true in the Tertiary basins of Southeast Asia, which display a wide range of fluvial channel reservoir types. This study is based on the analysis of high-resolution, shallow (seabed to ca. 500 m depth) 3D seismic data which provide exceptional imaging of the geometry, dimension and temporal and spatial distribution of fluvial channels. The Malay Basin comprises a thick (>8 km), rift to post-rift Oligo-Miocene to Pliocene basin-fill. The youngest (Miocene to Pliocene), post-rift succession is dominated by a thick (1-5 km), cyclic succession of coastal plain and coastal deposits, which accumulated in a humidtropical climatic setting. This study focuses on the Pleistocene to Recent (ca. 500 m thick) succession, which comprises a range of seismic facies, mainly reflecting changes in fluvial channel style and gross stratigraphic architecture. The succession has been divided into four seismic units (Unit 1-4), bounded by basin-wide stratal surfaces. Units 3 and 4 have been further divided into two sub-units. Two types of boundaries have been identified: 1) a boundary that is defined by a regionally-extensive erosion surface at the base of a prominent incised valley (e.g. Horizons C.1 and D.1); 2) a sequence boundary that is defined by more weakly-incised, straight and low-sinuosity channels which is interpreted as lowstand alluvial bypass channel systems (e.g. Horizons A, B, C, and D). Each unit displays a predictable vertical change of the channel pattern and scale, with wide low-sinuosity channels at the base passing gradationally upwards into narrow high-sinuosity channels at the top. The wide variation in channel style and size is interpreted to be controlled mainly by the sea-level fluctuations on the widely flat and tectonically-quiescent Sundaland Platform

    Acute Appendicitis among Saudi and Non-Saudi Patients: A Cross-Sectional Based Study

    Get PDF
    Objective: We conduct this study to discuss the differences between Saudi and non- Saudi patients with acute appendicitis.Background: Acute appendicitis is one of emergency surgeries in developing and developed countries. Its symptoms are vomiting, lower abdominal pain and decreased appetite. Appendicitis needs urgent surgical prouder to avoid its perforation and associated complications which may lead to death. Method: We conduct cross-sectional based study in one of khamis Mushayt, Saudi Araba. 136 patients diagnosed with acute appendicitis were included and their medical records were reviewed after getting their informed consent.Results: We included 136 patients, 90 were non-Saudi and 46 were Saudi. There were no statistically differences in their diagnosis but the distribution of the diagnosis was different.Conclusion: Acute appendicitis was more prevalent among non-Saudi patients, the diagnosis between both was with no significant differences. Keywords: acute appendicitis, Saudi, non-Saudi, diagnosis, cross-sectional, Saudi Arabia and khamis Mushayt

    First evidence for human occupation of a lava tube in Arabia: The archaeology of Umm Jirsan Cave and its surroundings, northern Saudi Arabia

    Get PDF
    Recent advances in interdisciplinary archaeological research in Arabia have focused on the evolution and historical development of regional human populations as well as the diverse patterns of cultural change, migration, and adaptations to environmental fluctuations. Obtaining a comprehensive understanding of cultural developments such as the emergence and lifeways of Neolithic groups has been hindered by the limited preservation of stratified archaeological assemblages and organic remains, a common challenge in arid environments. Underground settings like caves and lava tubes, which are prevalent in Arabia but which have seen limited scientific exploration, offer promising opportunities for addressing these issues. Here, we report on an archaeological excavation and a related survey at and around Umm Jirsan lava tube in the Harrat Khaybar, north-western Saudi Arabia. Our results reveal repeated phases of human occupation of the site ranging from at least the Neolithic through to the Chalcolithic/Bronze Age. Pastoralist use of the lava tube and surrounding landscape is attested in rock art and faunal records, suggesting that Umm Jirsan was situated along a pastoral route linking key oases. Isotopic data indicates that herbivores primarily grazed on wild grasses and shrubs rather than being provided with fodder, while humans had a diet consistently high in protein but with increasing consumption of C3 plants through-time, perhaps related to the emergence of oasis agriculture. While underground and naturally sheltered localities are globally prominent in archaeology and Quaternary science, our work represents the first such combined records for Saudi Arabia and highlight the potential for interdisciplinary studies in caves and lava tubes

    Seroprevalence of antibodies to SARS-CoV-2 among blood donors in the early month of the pandemic in Saudi Arabia

    Get PDF
    Background: Serologic testing provides better understanding of SARS-CoV-2 prevalence and its transmission. This study was an investigation of the prevalence of antibodies to SARS-CoV-2 among blood donors in Saudi Arabia. Objective: To estimate the seroprevalence of anti-SARS-CoV-2 antibodies among blood donors in Saudi Arabia during the early phase of the COVID-19 pandemic. Methods: Serology results and epidemiological data were analyzed for 837 adult blood donors, with no confirmed SARS-CoV-2 infection, in Saudi Arabia from 20th to 25th May 2020. Seroprevalence was determined using electrochemical immunoassay to detect anti-SARS-CoV-2 antibodies. Results: The overall seroprevalence of anti-SARS-CoV-2 antibodies was 1.4% (12/837). Non-citizens had higher seroprevalence compared with citizens (OR 13.6, p = 0.001). Secondary education was significantly associated with higher seroprevalence compared with higher education (OR 6.8, p = 0.005). The data showed that the highest seroprevalence was in Makkah (8.1%). Uisng Makkah seroprevalence as the reference, the seroprevalence in other areas was: Madinah 4.1% (OR 0.48, 95% CI 0.12-1.94), Jeddah 2.3% (OR 0.27, 95% CI 0.31-2.25), and Qassim 2.9 % (OR 0.34, 95% CI 0.04-2.89) and these were not statistically different from seroprevalence in the Makkah region. Conclusions: At the early months of the COVID-19 pandemic in Saudi Arabia, the seroprevalence of antibodies to SARS-CoV-2 among blood donors was low, but was higher among non-citizens. These findings may indicate that non-citizens and less educated individuals may be less attentive to preventive measures. Monitoring seroprevalence trends over time require repeated sampling

    Surveillance and treatment of primary hepatocellular carcinoma (aka. STOP HCC): protocol for a prospective cohort study of high-risk patients for HCC using GALAD-score.

    Get PDF
    Vietnam and Saudi Arabia have high disease burden of primary hepatocellular carcinoma (HCC). Early detection in asymptomatic patients at risk for HCC is a strategy to improve survival outcomes in HCC management. GALAD score, a serum-based panel, has demonstrated promising clinical utility in HCC management. However, in order to ascertain its potential role in the surveillance of the early detection of HCC, GALAD needs to be validated prospectively for clinical surveillance of HCC (i.e., phase IV biomarker validation study). Thus, we propose to conduct a phase IV biomarker validation study to prospectively survey a cohort of patients with advanced fibrosis or compensated cirrhosis, irrespective of etiologies, using semi-annual abdominal ultrasound and GALAD score for five years. We plan to recruit a cohort of 1,600 patients, male or female, with advanced fibrosis or cirrhosis (i.e., F3 or F4) and MELD ≤ 15, in Vietnam and Saudi Arabia (n = 800 each). Individuals with a liver mass ≥ 1 cm in diameter, elevated alpha-fetoprotein (AFP) (≥ 9 ng/mL), and/or elevated GALAD score (≥ -0.63) will be scanned with dynamic contrast-enhanced magnetic resonance imaging (MRI), and a diagnosis of HCC will be made by Liver Imaging Reporting and Data System (LiRADS) assessment (LiRADS-5). Additionally, those who do not exhibit abnormal imaging findings, elevated AFP titer, and/or elevated GALAD score will obtain a dynamic contrast-enhanced MRI annually for five years to assess for HCC. Only MRI nearest to the time of GALAD score measurement, ultrasound and/or AFP evaluation will be included in the diagnostic validation analysis. MRI will be replaced with an abdominal computed tomography scan when MRI results are poor due to patient conditions such as movement etc. Gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced MRI will not be carried out in study sites in both countries. Bootstrap resampling technique will be used to account for repeated measures to estimate standard errors and confidence intervals. Additionally, we will use the Cox proportional hazards regression model with covariates tailored to the hypothesis under investigation for time-to-HCC data as predicted by time-varying biomarker data. The present work will evaluate the performance of GALAD score in early detection of liver cancer. Furthermore, by leveraging the prospective cohort, we will establish a biorepository of longitudinally collected biospecimens from patients with advanced fibrosis or cirrhosis to be used as a reference set for future research in early detection of HCC in the two countries. Name of the registry: ClinicalTrials.gov Registration date: 22 April 2022 Trial registration number: NCT05342350 URL of trial registry record

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

    Get PDF
    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Left Main Coronary Artery Revascularization in Patients with Impaired Renal Function: Percutaneous Coronary Intervention versus Coronary Artery Bypass Grafting

    Get PDF
    Introduction: The evidence about the optimal revascularization strategy in patients with left main coronary artery (LMCA) disease and impaired renal function is limited. Thus, we aimed to compare the outcomes of LMCA disease revascularization (percutaneous coronary intervention [PCI] vs. coronary artery bypass grafting [CABG]) in patients with and without impaired renal function. Methods: This retrospective cohort study included 2,138 patients recruited from 14 centers between 2015 and 2,019. We compared patients with impaired renal function who had PCI (n= 316) to those who had CABG (n = 121) and compared patients with normal renal function who had PCI (n = 906) to those who had CABG (n = 795). The study outcomes were in-hospital and follow-up major adverse cardiovascular and cerebrovascular events (MACCE). Results: Multivariable logistic regression analysis showed that the risk of in-hospital MACCE was significantly higher in CABG compared to PCI in patients with impaired renal function (odds ratio [OR]: 8.13 [95% CI: 4.19–15.76], p < 0.001) and normal renal function (OR: 2.59 [95% CI: 1.79–3.73]; p < 0.001). There were no differences in follow-up MACCE between CABG and PCI in patients with impaired renal function (HR: 1.14 [95% CI: 0.71–1.81], p = 0.585) and normal renal function (HR: 1.12 [0.90–1.39], p = 0.312). Conclusions: PCI could have an advantage over CABG in revascularization of LMCA disease in patients with impaired renal function regarding in-hospital MACCE. The follow-up MACCE was comparable between PCI and CABG in patients with impaired and normal renal function

    The Saudi Critical Care Society practice guidelines on the management of COVID-19 in the ICU: Therapy section

    Get PDF
    BACKGROUND: The rapid increase in coronavirus disease 2019 (COVID-19) cases during the subsequent waves in Saudi Arabia and other countries prompted the Saudi Critical Care Society (SCCS) to put together a panel of experts to issue evidence-based recommendations for the management of COVID-19 in the intensive care unit (ICU). METHODS: The SCCS COVID-19 panel included 51 experts with expertise in critical care, respirology, infectious disease, epidemiology, emergency medicine, clinical pharmacy, nursing, respiratory therapy, methodology, and health policy. All members completed an electronic conflict of interest disclosure form. The panel addressed 9 questions that are related to the therapy of COVID-19 in the ICU. We identified relevant systematic reviews and clinical trials, then used the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach as well as the evidence-to-decision framework (EtD) to assess the quality of evidence and generate recommendations. RESULTS: The SCCS COVID-19 panel issued 12 recommendations on pharmacotherapeutic interventions (immunomodulators, antiviral agents, and anticoagulants) for severe and critical COVID-19, of which 3 were strong recommendations and 9 were weak recommendations. CONCLUSION: The SCCS COVID-19 panel used the GRADE approach to formulate recommendations on therapy for COVID-19 in the ICU. The EtD framework allows adaptation of these recommendations in different contexts. The SCCS guideline committee will update recommendations as new evidence becomes available

    SPINE20 A global advocacy group promoting evidence-based spine care of value

    Get PDF
    PURPOSE: The Global Burden of Diseases (GBD) Studies have estimated that low back pain is one of the costliest ailments worldwide. Subsequent to GBD publications, leadership of the four largest global spine societies agreed to form SPINE20. This article introduces the concept of SPINE20, the recommendations, and the future of this global advocacy group linked to G20 annual summits. METHODS: The founders of SPINE20 advocacy group coordinated with G20 Saudi Arabia to conduct the SPINE20 summit in 2020. The summit was intended to promote evidence-based recommendations to use the most reliable information from high-level research. Eight areas of importance to mitigate spine disorders were identified through a voting process of the participating societies. Twelve recommendations were discussed and vetted. RESULTS: The areas of immediate concern were "Aging spine," "Future of spine care," "Spinal cord injuries," "Children and adolescent spine," "Spine-related disability," "Spine Educational Standards," "Patient safety," and "Burden on economy." Twelve recommendations were created and endorsed by 31/33 spine societies and 2 journals globally during a vetted process through the SPINE20.org website and during the virtual inaugural meeting November 10-11, 2020 held from the G20 platform. CONCLUSIONS: This is the first time that international spine societies have joined to support actions to mitigate the burden of spine disorders across the globe. SPINE20 seeks to change awareness and treatment of spine pain by supporting local projects that implement value-based practices with healthcare policies that are culturally sensitive based on scientific evidence
    corecore