Damage identification in a concrete beam using curvature difference ratio

Previous studies utilising changes in mode shape or curvature to locate damage rely on the fact that the greatest change occurs around the defect. However, in concrete beams this fact is undermined due to the nature of the defect as distributed multi-site cracks. In addition, differences in mode shape and curvature as ways to locate the damage is unstable because of occurrence of modal nodes and inflection points. In this paper, one interesting solution to this problem is being tested by establishing a new non-dimensional expression designated the 'Curvature Difference Ratio (CDR)'. This parameter exploits the ratio of differences in curvature of a specific mode shape for a damaged stage and another reference stage. The expression CDR is reasonably used to locate the damage and estimate the dynamic bending stiffness in a successively loaded 6m concrete beam. Results obtained by the proposed technique are tested and validated with a case study results done by Ren and De Roeck [1] also by Maeck and De Roeck [2]. Another contribution of this work is that relating changes in vibration properties to the design bending moment at beam sections as defined in Eurocode 2 specifications [3]. Linking between a beam section condition and the change in vibration data will help to give a better comprehension on the beam condition than the applied load

Damage and repair classification in reinforced concrete beams using frequency domain data

This research aims at developing a new vibration-based damage classification technique that can efficiently be applied to a real-time large data. Statistical pattern recognition paradigm is relevant to perform a reliable site-location damage diagnosis system. By adopting such paradigm, the finite element and other inverse models with their intensive computations, corrections and inherent inaccuracies can be avoided. In this research, a two-stage combination between principal component analysis and Karhunen-Loéve transformation (also known as canonical correlation analysis) was proposed as a statistical-based damage classification technique. Vibration measurements from frequency domain were tested as possible damage-sensitive features. The performance of the proposed system was tested and verified on real vibration measurements collected from five laboratory-scale reinforced concrete beams modelled with various ranges of defects. The results of the system helped in distinguishing between normal and damaged patterns in structural vibration data. Most importantly, the system further dissected reasonably each main damage group into subgroups according to their severity of damage. Its efficiency was conclusively proved on data from both frequency response functions and response-only functions. The outcomes of this two-stage system showed a realistic detection and classification and outperform results from the principal component analysis-only. The success of this classification model is substantially tenable because the observed clusters come from well-controlled and known state conditions

Co-transplantation of Human Embryonic Stem Cell-derived Neural Progenitors and Schwann Cells in a Rat Spinal Cord Contusion Injury Model Elicits a Distinct Neurogenesis and Functional Recovery

Co-transplantation of neural progenitors (NPs) with Schwann cells (SCs) might be a way to overcome low rate of neuronal differentiation of NPs following transplantation in spinal cord injury (SCI) and the improvement of locomotor recovery. In this study, we initially generated NPs from human embryonic stem cells (hESCs) and investigated their potential for neuronal differentiation and functional recovery when co-cultured with SCs in vitro and co-transplanted in a rat acute model of contused SCI. Co-cultivation results revealed that the presence of SCs provided a consistent status for hESC-NPs and recharged their neural differentiation toward a predominantly neuronal fate. Following transplantation, a significant functional recovery was observed in all engrafted groups (NPs, SCs, NPs+SCs) relative to the vehicle and control groups. We also observed that animals receiving co-transplants established a better state as assessed with the BBB functional test. Immunohistofluorescence evaluation five weeks after transplantation showed invigorated neuronal differentiation and limited proliferation in the co-transplanted group when compared to the individual hESC-NPs grafted group. These findings have demonstrated that the co-transplantation of SCs with hESC-NPs could offer a synergistic effect, promoting neuronal differentiation and functional recovery

Non-communicable diseases among Palestinian refugees from Syria: a cross-sectional study on prevalence, case management, access to and utilisation of UNRWA Health Services

BACKGROUND: As of Feb 14, 2014, UNRWA had registered almost 53 000 Palestinian refugees from Syria (PRS) who had fled to Lebanon as the result of the conflict in Syria. Half of the PRS had gone to one of the 12 Palestinian camps, which are overcrowded and of poor infrastructure. Consequently, there is concern for the wellbeing of PRS; in particular, their health status and access to medical care. Little attention has been given to non-communicable diseases (NCDs) in the acute phases of emergencies. Therefore, an assessment of the prevalence of NCDs among PRS, as well as the patterns of use of available health care services by PRS, is warranted. METHODS: A cross-sectional study was conducted in April, 2018, with 1100 PRS residing inside and outside refugee camps across all governorates of Lebanon. A listing of all PRS families was the sampling frame. A random sample of families was selected and contacted, and then one adult randomly selected from each family was approached for data collection. Pregnant women and participants who were too ill to participate were excluded. After obtaining informed verbal consent, we did face-to-face interviews to collect data on household details (such as type of settlement, source of income) and sociodemographic information, major NCDs (for the household representative), lifestyle behaviours, and health-care use. We invited all participants to UNRWA clinics for physical and biochemical measurements. The study protocol was approved by the Institutional Review Board of the American University of Beirut. FINDINGS: We surveyed 959 PRS (59% male [465], 82% married [785], mean age 43 years [SD 12]). A quarter of those interviewed had at least one NCD; the most prevalent were hypertension (23%; 221 of 959), rheumatic diseases (17%; 166), cardiovascular diseases (CVDs, 13%; 126), diabetes (13%; 124), and chronic respiratory diseases (CRDs) (10%; 100). All these NCDs were more prevalent among PRS inside camps than in those residing outside camps, except for diabetes. Most participants who had been diagnosed with NCDs were adhering to their prescribed medications (90-98%). However, of those reporting CVDs, only 56% (71 of 126) had attended at least one follow-up appointment, and of those reporting rheumatic diseases, only 33% (55 of 166) had attended at least one follow-up appointment. About half of participants reported that they checked their blood pressure (55%; 528 of 959) or blood glucose (45%; 430). 111 of 221 (50%) participants with hypertension monitored their blood pressure, and 78 of 124 (63%) participants with diabetes monitored their blood glucose. 133 participants attended UNRWA clinics for measurements; 40% (54) had obesity (>30 kg/cm2), 10% (13) had elevated blood pressure, 12% (16) had stage 1 hypertension, and 8% (10) had stage 2 hypertension. Most participants had normal glucose (67%; 89 of 133), cholesterol (65%; 87), triglyceride (58%; 77), and glycosylated haemoglobin levels (64; 85). A substantial proportion of participants who were tested had undiagnosed diabetes (14%; 33 of 108 reporting no diabetes), undiagnosed hypertension (23%; 19 of 81), uncontrolled diabetes (79% of participants with diabetes; 19 of 24), or uncontrolled hypertension (64% of participants with hypertension; 29 of 45). INTERPRETATION: Further study is needed to understand why the prevalence of NCDs among PRS residing in Palestinian camps is higher than among those living outside, and to understand whether and why access to medicines is a problem, particularly outside camps. The burden of NCDs among PRS is high and their access to services is not optimal; therefore UNRWA should pay special attention to NCD services in this population. UNRWA should invest in efforts to increase awareness of free blood pressure and blood glucose monitoring services in its clinics, and could actively offer free testing in public areas inside camps. Doctors at UNRWA clinics should recommend that patients monitor their disease more frequently and educate them on how to do so. A limitation of the study was the low percentag of participants who attended UNRWA clinics for physical and biochemical measurements.UNRWA. Copyright © 2021 Elsevier Ltd. All rights reserved

Health Care Workers in the setting of the Arab Spring: A scoping review for the Lancet-AUB Commission on Syria

Background Health Care Workers in Conflict Areas emerged as one of the priority themes for a Lancet Commission addressing health in conflict. The objective of our study was to conduct a scoping review on health workers in the setting of the Syrian conflict, addressing four topics of interest: violence against health care workers, education, practicing in conflict setting, and migration. Methods Considering the likelihood of scarcity of data, we broadened the scope of the scoping review to include indirect evidence on health care workers from other countries affected by the Arab Spring. We electronically searched six electronic databases. We conducted descriptive analysis of the general characteristics of the included papers. We also used the results of this scoping review to build an evidence gap map. Results Out of the 11 165 identified citations, 136 met our eligibility criteria. The majority of the articles tackled the issue of violence against health care workers (63%) followed by practicing in conflict setting (19%), migration (17%) and education (10%). Countries in focus of most articles were: Syria (35%), Iraq (33%), and Bahrain (29%). News, editorials, commentaries and opinion pieces made up 81% of all included papers, while primary studies made up only 9%. All the primary studies identified in this review were conducted on Iraq. Most of the articles about violence against health care workers were on Bahrain, followed by Syria and Iraq. The first and corresponding authors were most frequently affiliated with institutions from non-Arab countries (79% and 79% respectively). Conclusions Research evidence on health care workers in the setting of the Arab Spring is scarce. This review and the gap map can inform the research agendas of funders and researchers working in the field of health care workers in conflict setting. More well-designed primary studies are needed to inform the decisions of policymakers and other interested parties. © 2019 The Author(s) JoGH

Visible light‐active pure and lanthanum‐doped copper oxide nanostructures for photocatalytic degradation of methylene blue dye and hydrogen production

Clean water and renewable energy sources are becoming increasingly important in the current era, as well as a future challenge, and one of the potential solutions is photocatalysis. In the current study, a simple one-step hydrothermal technique is employed to fabricate the pure and La-doped CuO (0%, 1%, 3%, 5%, and 7%) photocatalysts. The influence of varying La concentration on structure, morphology, and optical properties is determined by scanning electron microscope (SEM), X-ray diffraction (XRD), ultraviolet (UV)–visible spectroscopy, and photoluminescence. SEM showed that synthesized nanostructures are irregularly spherical and transform into needle-like nanostructures on increasing La concentration. XRD revealed the monoclinic phase with a crystallite size of 15–23 nm. The UV–visible spectrum exhibited a decrease in the band gap of La-doped CuO needle-like nanostructures from UV to visible light. The composition and purity of synthesized nanostructures are evaluated via the energy-dispersive X-ray spectrum which revealed that needle-like nanostructures are pure without any impurity traces. The synthesized nanostructures were used as a photocatalyst against methylene blue dye to examine their photocatalytic activity. The synthesized CuO-3La photocatalyst exhibited excellent photocatalytic performance of dye degradation and hydrogen production 95.3 μmol h−1 g−1 with more than 97% cyclic stability. Therefore, the synthesized La-doped CuO nanostructures are potential candidates for photocatalytic water splitting and hydrogen evolution

First meta-analysis study of cholinesterase inhibition in experimental animals by organophosphate or carbamate insecticides under the influence of diphenhydramine

Background and Aim: Diphenhydramine is an H1-antihistamine that counteracts the toxic effects of organophosphate and carbamate insecticides that inhibit cholinesterase (ChE) activity. This meta-analysis aimed to investigate the effects of diphenhydramine on ChE inhibition induced by these insecticides in the plasma, erythrocytes, or whole brain of experimental animals. Materials and Methods: A data search was performed on erythrocyte, plasma, and brain ChE inhibition caused by organophosphate and carbamate insecticides in experimental animals (mice, rats, and chicks) treated with the antihistamine diphenhydramine in accordance with preferred reporting items for systematic reviews and meta-analysis, which was done by the two-group random-effects model meta-analysis. The meta-analysis included 18 records extracted from six studies that appeared from 1996 to 2022. Results: Using the random-effects model, a two-group meta-analysis revealed that the combined effect size (ChE inhibition) was significantly more favorable in the control group than in the diphenhydramine intervention, as shown by a forest plot. The combined effect size (standardized mean difference) was 0.67, with a standard error of 0.3, a lower limit of 0.04, and an upper limit of 1.29 (p = 0.025). The heterogeneity was moderate, as I2 of the combined effect size was 74%, with a significant Cochrane Q-test result (Q = 65, p < 0.0001). Subgroup analysis indicated that, with brain ChE inhibition, the heterogeneity (I2) became 5%, which was lower than ChE inhibition in plasma (84%) and erythrocytes (78%). No publication bias was identified using the funnel plot and Egger's test. Conclusion: This meta-analysis suggests that, in addition to its documented antidotal action against ChE-inhibiting insecticides, diphenhydramine can also reduce the extent of ChE inhibition, especially in the brain, which is the main site of toxicity of these insecticides. There is a need for additional studies to assess such enzyme inhibition in different parts of the brain

Disparities in cervical cancer mortality rates as determined by the longitudinal hyperbolastic mixed-effects type II model.

We analyze the dynamics of cervical cancer mortality rates for African American and White women residing in 13 states located in the eastern half of the United States of America from 1975 through 2010. Despite decreasing trends in cervical cancer mortality rates for both races, racial disparities in mortality rates still exist. In all 13 states, Black women had higher mortality rates at all times. The degree of disparities and pace of decline in mortality rates over time differed among these states. In all 13 states, cervical cancer mortality rates for both racial groups have fallen. Disparities in the pace of decline in mortality rates in these states may be due to differences in the rates of screening for cervical cancers. Of note, the gap in cervical cancer mortality rates between Black women and White women is narrowing

The association of diabetes, atrial fibrillation and ventricular arrhythmias

Recent evidence suggests that diabetic patients are at increased risk to develop arrhythmias. This brief review presents this evidence and the relationship between diabetes mellitus (DM) and arrhythmias, specifically atrial fibrillation (AF) and ventricular arrhythmias (VAs). Animal studies have demonstrated that hyperglycemia induces oxidative stress that results in myocardial injury and cell ischemia which predispose to AF. Furthermore, prolonged hyperglycemia results in the formation of advanced glycosylation end products which invade the myocardium and lead to diabetic cardiomyopathy forming a substrate for anatomic and electrical atrial remodeling predisposing to AF as well. Patients with DM and without known cardiovascular disease have significantly higher incidences of T-wave alternans (TWA) than non-DM patients. These TWA occurrences are positively correlated to HbA1c level. DM also produces a diabetic myocardium vulnerable to VAs and plays a crucial role in triggering these arrhythmias. In conclusion, further randomized controlled trials are needed to verify the mechanisms that result in arrhythmias in patients with DM and which lead to major cardiovascular complications and mortality.The focus of interventions should be based on primary prevention of diabetes, coronary artery disease, and atherosclerosis until novel mechanism-based approaches that reduce arrhythmias in patients with DM are established. © 2019 Lebanese Order of Physicians. All rights reserved

Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication