University of Balamand
  • Amioûn, Lebanon
Recent publications
Background Venous thromboembolism is a primary cause of morbidity and mortality in hospitalised patients. Clinical practice guidelines were developed to prevent venous thromboembolism events. This study adopted the Theoretical Domains Framework to explore the beliefs and perceptions of physicians adoption of clinical practice guidelines for the uptake of venous thromboembolism prevention guidelines. Methods Semi-structured interviews were conducted with a stratified purposive sample of internal medicine physicians in an acute hospital. The interview topic guide was developed using the Theoretical Domains Framework to identify the factors perceived to influence the practice. Two researchers coded the interview transcripts using thematic content analysis. Emerging relevant themes were mapped to TDF domains. Results A total of sixteen medical physicians were interviewed over a six-month period. Nine theoretical domains derived from thirty-three belief statements were identified as relevant to the target behaviour; knowledge (education about the importance of VTE guidelines); beliefs about capabilities (with practice VTE tool easier to implement); beliefs about consequences (positive consequences in reducing the development of VTE, length of stay, financial burden and support physician decision) and (negative consequence risk of bleeding); reinforcement (recognition and continuous reminders); goals (patient safety goal); environmental context and resources (workload and availability of medications were barriers, VTE coordinator and electronic medical record were enablers); social influences (senior physicians and patient/family influence the VTE practice); behavioural regulation (monitoring and mandatory hospital policy); and nature of the behaviour. Conclusions Using the Theoretical Domains Framework, factors thought to influence the implementation of VTE clinical practice guidelines were identified which can be used to design theoretically based interventions by targeting specific psychological constructs and linking them to behaviour change techniques to change the clinical practice of physicians.
Gastric gastrointestinal stromal tumour is an extremely rare condition to occur after bariatric surgery. To the authors’ knowledge, only two cases of gastric gastrointestinal stromal tumours after Roux-en-Y gastric bypass have been reported in the medical literature, both occurring in the excluded gastric remnant. Herein, the authors report the third case of gastric gastrointestinal stromal tumour post-Roux-en-Y gastric bypass, and the first case to occur in the gastric pouch, which was managed surgically by laparoscopic resection. From here, combining the observations of clinicians treating and following up patients post-bariatric surgery in an international database will be beneficial to patients, and aid in development of surveillance guidelines.
Introduction The COVID 19 pandemic has resulted in an increased number of patients requiring intubation and intensive care. This has led to an increased incidence of sacral pressure ulcers requiring surgical management. We report our experience of COVID 19 related sacral pressure ulcers requiring surgical reconstruction. Methods A case series study was performed with 12 patients who presented grade IV sacral pressure ulcers after hospitalization for COVID-19 in a single institution. The mean age was 49.8 years and the most frequent comorbidities were arterial hypertension, diabetes and obesity, each present in 6 patients. All of them were submitted to surgical reconstruction with fasciocutaneous flaps after improvement of their clinical status. Follow up time was of at least 30 days after reconstruction. Preoperative laboratory tests and surgical outcomes were compared to data available in the literature. Results No major dehiscence was observed and minor dehiscence happened in 2 cases (16.7%). Out of the 12 patients, 8 (66.7%) had hemoglobin levels less than 10.0 and 5 (41.7%) had albumin levels less than 3.0, though this did not lead to a higher rate of complications. Conclusion This study showed that ambulating patients with grade IV pressure ulcer after COVID- 19 infection may undergo debridement, negative-pressure wound therapy and closure with local flaps with adequate results and minimal complication rate.
The East Mediterranean and Middle East (EMME) region is a global climate hotspot that suffers from a lack of robust environmental data. This region, especially the Middle East, lacks source apportionment studies that help determine the different contributions of common regional airborne particulate matter sources. This work focuses on two sites in the East Mediterranean, that is, Zouk Mikael and Fiaa, Lebanon. This study shows the comprehensive chemical characterization of PM2.5 samples collected over almost 1 year at two sites, serving as the source apportionment model, positive matrix factorization. Different sources were identified due to the integration of organic markers such as biogenic emissions, cooking, biomass burning, and diesel generators. Crustal dust and ammonium sulfate sources were the major contributors to PM2.5 (43% and 46% at Zouk and Fiaa, respectively). Through cluster analysis, the former originated from the Arabian and Saharan Deserts, while the latter had different local and distant origins (industrial zones of Europe and Turkey), and the contribution of Arabian and African countries to carbonaceous matter concentrations through refinery emissions. Meanwhile, local anthropogenic sources contributed to 36% at both sites, excluding ammonium sulfate. Traffic and industrial emissions, including energy production, contributed more to Zouk (27%) than Fiaa (13%). Site-specific sources were also identified, with open waste burning at Fiaa contributing 16% and diesel generators at Zouk contributing 5%. Biogenic emissions contributed to 9–13%. These results will be important to policymakers to improve air quality in the EMME region while considering the potency of the PM in a region where the world health organization guidelines cannot be reached.
The sustainable production of biodiesel from waste materials has become of utmost importance in recent years. In this study, cheap CaO catalysts were prepared by calcination of waste scallop seashells (Noble Pectin). The seashells were thermally treated at different temperatures (600–1000 °C) and then used in the transesterification of sunflower oil for biodiesel production. The catalysts were characterized using Fourier Transform Infrared Spectroscopy (FTIR) and simultaneous Thermal Gravimetric-Differential Scanning Calorimetry (TG-DSC) techniques. The highest Fatty Acid Methyl Esters (FAME) yield (97%) was obtained in the presence of the catalyst calcined at 700 °C under the following conditions: a methanol-to-oil molar ratio (MOMR) of 12:1, a catalyst-to-oil ratio (CTOR) of 10 wt%, a stirring rate of 700 rpm, a reaction temperature of 65 °C and a reaction time of 4 h. The seashell-derived catalyst was practically stable for at least 4 consecutive runs in the reusability study, maintaining a high FAME yield (>92%). The reaction followed pseudo-first order kinetics, with an activation energy (Ea) of 133.57 kJ/mol and a pre-exponential factor (A) of 4.025 × 10¹⁸ min⁻¹. This catalyst additionally exhibited a very high activity in the transesterification of waste cooking oil, with similar FAME yield of 97%. This shows that this catalyst is promising for potential biodiesel production scale-up schemes and industrial applications.
Objectives: To evaluate the prevalence of carotid intima-media thickness (IMT) and plaques in a cohort of people living with HIV (PLWH), the role of cardiovascular risk factors, the impact of the antiretroviral regimens and the difference between naïve and experienced patients in the onset of carotid lesions. Methods: This project was initiated in 2019 and involves eight Italian centres. Carotid changes were detected using a power colour-Doppler ultrasonography with 7.5 MHz probes. The following parameters were evaluated: IMT of both the right and left common and internal carotids, data regarding risk factors for cardiovascular disease, HIV viral load, CD4 cell counts, serum lipids, glycaemia and body mass index. The associations between pathological findings and potential risk factors were evaluated by logistical regression, with odds ratios (ORs) and 95% confidence intervals (95% CI)s. Results: Among 1147 evaluated PLWH, with a mean age of 52 years, 347 (30.2%) had pathological findings (15.8% plaques and 14.5% IMT). Besides the usual risk factors, such as older age, male sex and dyslipidaemia, CD4 cell nadir < 200 cells/mL (adjusted OR = 1.51, 95% CI: 1.14-1.99) and current use of raltegravir (adjusted OR = 1.54, 95% CI: 1.01-2.36) were associated with higher prevalence of pathological findings. Conclusions: Our data show that the current overall percentage of carotid impairments remains high. Colour-Doppler ultrasonography could play a pivotal role in identifying and quantifying atherosclerotic lesions among PLWH, even at a very premature stage, and should be included in the algorithms of comorbidity management of these patients.
The paper examines the dynamic spillover among traditional currencies and cryptocurrencies before and during the COVID-19 pandemic and investigates whether economic policy uncertainty (EPU) impacts this spillover. Based on the TVP-VAR approach, we find evidence of spillover effects among currencies, which increased widely during the pandemic. In addition, results suggest that almost all cryptocurrencies remain as “safe-haven” tools against market uncertainty during the COVID-19 period. Moreover, comparative analysis shows that the total connectedness for cryptocurrencies is lower than for traditional currencies during the crisis. Further analysis using quantile regression suggests that EPU exerts an impact on the total and the net spillovers with different degrees across currencies and this impact is affected by the health crisis. Our findings have important policy implications for policymakers, investors, and international traders.
The intensification of total phenolic compound (TPC) extraction from blood orange peels was optimized using a novel green infrared-assisted extraction technique (IRAE, Ired-Irrad®) and compared to the conventional extraction using a water bath (WB). Response surface methodology (RSM) allowed for the optimization of ethanol concentration (E), time (t), and temperature (T) in terms of extracted TPC and their antiradical activity, for both WB extraction and IRAE. Using WB extraction, the multiple response optimums as obtained after 4 h at 73 °C and using 79% ethanol/water were 1.67 g GAE/100 g for TPC and 59% as DPPH inhibition percentage. IRAE increased the extraction of TPC by 18% using 52% ethanol/water after less than 1 h at 79 °C. This novel technology has the advantage of being easily scalable for industrial usage. HPLC analysis showed that IRAE enhanced the recovery of gallic acid, resveratrol, quercetin, caffeic acid, and hesperidin. IR extracts exhibited high bioactivity by inhibiting the production of Aflatoxin B1 by 98.9%.
Purpose: This systematized review presents a synthesis of epidemiological studies that examine the association between female reproductive factors and longevity indicators. Methods: A comprehensive literature search was conducted using four bibliographic databases: OVID Medline, Web of Science, PubMed, and Google Scholar, including English language articles published until March 2022. Results from the search strategy yielded 306 articles, 37 of which were included for review based on eligibility criteria. Results were identified within the following nine themes: endogenous androgens and estrogens, age at first childbirth, age at last childbirth, parity, reproductive lifespan, menopause-related factors, hormone therapy use, age at menarche, and offspring gender. Results: Evidence that links reproductive factors and long lifespan is limited. Several female reproductive factors are shown to be significantly associated with longevity, yet findings remain inconclusive. The most consistent association was between parity (fertility and fecundity) and increased female lifespan. Age at first birth and parity were consistently associated with increased longevity. Associations between age at menarche and menopause, premature menopause, reproductive lifespan, offspring gender and longevity are inconclusive. Conclusion: There is not enough evidence to consider sex a longevity predictor. To understand the mechanisms that predict longevity outcomes, it is imperative to consider sex-specific within-population differences.
Altered secretion of cortisol, the primary effector of the hypothalamus–pituitary–adrenal axis, has been proposed as a means by which traumatic experiences compromise later mental health. However, despite the popularity of cortisol as a potential biomarker for stress and adversity, findings are inconsistent, and little is known about the impact of war-related trauma on stress physiology of children and adolescents. Here we aimed to evaluate the relationships between war exposure, current living conditions, hair cortisol concentrations (HCC) and post-traumatic stress disorder (PTSD) symptoms in a large cohort of Syrian refugee children and adolescents (6–18 years) and their caregiver. This longitudinal observational study assessed Syrian refugee children and adolescents in two waves, 1 year apart, within informal tented settlements in Lebanon. The relationships between war exposure, time since leaving Syria, PTSD symptoms and HCC were investigated using linear mixed-model regression utilising both waves of data collected (Y1: N = 1574, Y2: N = 923). Hair cortisol concentration was positively, but weakly associated with the number of war-related events experienced. This was limited to those who were at least 12 years old at the time of war exposure. Conversely, HCC decreased with time since leaving Syria. HCC was also associated with PTSD symptoms but not with the quality of their current living conditions. This study revealed that changes to hypothalamic-pituitary-adrenal axis activity may accompany both earlier war exposure and current PTSD symptoms in children and adolescents. Additionally, early adolescence may be a particularly sensitive time in terms of trauma-related changes to the hypothalamic-pituitary-adrenal axis.
Machine learning has become a key branch in artificial intelligence by providing unique predictive modeling solutions. Predicting the compressive strength of concrete determined using non-destructive test techniques (NDT) includes high levels of uncertainty. This uncertainty directly depends on the repeatability of the measurement and the variability of concrete properties. This study aims to evaluate the effect of mixture composition and age of concrete on the coefficient of variation (CV) of the rebound hammer index applied to various types of concrete. Several supervised machine learning models, including multivariate multiple regression (MMR), support vector machine (SVM), Gaussian process regression (GPR), and Regression tree (RT) were utilized to predict the compressive strength of concrete. A large dataset of 468 cubic concrete specimens was sorted into four categories and employed for simulation. Regardless of the selected dataset, it was concluded that GPR/SVM and RT yielded the most accurate model prediction metrics of compressive strength when using rebound hammer records over MMR model. The results of the adopted models were remarkably better when mixture proportions and age of concrete features (i.e., age and w/p) were considered in the simulation.
Introduction and objectives Most epidemiological data on hepatocellular carcinoma (HCC) originate from resource-rich countries. We have previously described the epidemiology of HCC in South America through the South American Liver Research Network. Here, we provide an update on the changing epidemiology of HCC in the continent seven years since that report. Materials and methods We evaluated all cases of HCC diagnosed between 2019 to 2021 in centers from six countries in South America. A templated, retrospective chart review of patient characteristics at the time of HCC diagnosis, including basic demographic, clinical and laboratory data, was completed. Diagnosis of HCC was made radiologically or histologically for all cases via institutional standards. Results Centers contributed to a total of 339 HCC cases. Peru accounted for 37% (n=125) of patients; Brazil 16% (n=57); Chile 15% (n=51); Colombia 14% (n=48); Argentina 9% (n=29); and Ecuador 9% (n=29). The median age at HCC diagnosis was 67 years (IQR 59-73) and 61% were male. The most common risk factor was nonalcoholic fatty liver disease (NAFLD, 37%), followed by hepatitis C (17%), alcohol use disorder (11%) and hepatitis B (12%). The majority of HCCs occurred in the setting of cirrhosis (80%). HBV-related HCC occurred at a younger age compared to other causes, with a median age of 46 years (IQR 36-64). Conclusion We report dramatic changes in the epidemiology of HCC in South America over the last decade, with a substantial increase in NAFLD-related HCC. HBV-related HCC still occurs at a much younger age when compared to other causes.
This study examines the effect of using ceramic waste (CW) and granulated blast furnace slag (GBFS) as a blended binder on the mechanical and durability characteristics of geopolymer concrete. The experimental design was carried out following the Taguchi approach for five factors, each having four levels, to produce an L16 orthogonal array. The factors included the binder content, CW replacement by GBFS (CW:GBFS), ratio of alkaline solution to binder (AS:B), ratio of sodium silicate solution to sodium hydroxide solution (S:H), and sodium hydroxide (NaOH) solution concentration. The quality criteria were compressive strength, elastic modulus, splitting tensile strength, flexural strength, abrasion resistance, water absorption, sorptivity, ultrasonic pulse velocity, and bulk resistivity. The proportions of CW-GBFS geopolymer concrete mixes were optimized using the best-worst method and TOPSIS approach considering 9, 5, and 2 quality criteria in three scenarios. Experimental test results revealed that the optimum mix was the same for both optimization techniques irrespective of the number of quality criteria considered. The optimum mix comprised a binder content of 450 kg/m³, CW:GBFS ratio of 2:3, AS:B ratio of 1:2, S:H ratio of 3:2, and NaOH solution concentration of 10 M. The anticipated results of the optimum mix were validated through experimental testing. Its experimental test results included compressive, flexural, and splitting tensile strengths of 58.9, 5.72, and 3.81 MPa, respectively. Meanwhile, it had a water absorption of 3.45%, elastic modulus of 27.4 GPa, sorptivity of 0.025 mm/s0.5, bulk resistivity of 4652 Ω•cm, abrasion resistance of 8.98%, and UPV of 6745 m/s.
Fog droplets consist of a mixture of organic and inorganic compounds resulting from scavenging hygroscopic particles and water-soluble trace gases. Organic matters found in fog water are able to accumulate non-volatile, semi-volatile and volatile compounds of different chemical structures and properties (different functional groups and chemical properties). However, their extraction and analysis are still very limited and infrequent. The paper presents a new analytical procedure based on the combination of liquid-liquid extraction (LLE) on a solid support (XTR Chromabond cartridge). It is developed, optimized and validated for the simultaneous analysis of 38 organic acids, 64 phenols, 55 semi-volatile pesticides, 27 non-volatile pesticides, 16 polycyclic aromatic hydrocarbons (PAHs), 20 organochlorine pesticides (OCPs) and 22 polychlorinated biphenyls (PCBs) residues in fog water. The obtained extract is concentrated, derivatized and then analyzed with different chromatographic techniques. Phenols and acids are injected into gas chromatography-mass spectrometry (GC-MS) preceded by a derivatization reaction with N-tert-butyldimethylsilyl-N-methyltrifluoroacetamide (MtBSTFA). Semi-volatile pesticides, PAHs, PCBs and OCPs are injected into gas chromatography-tandem mass spectrometry (GC-MS/MS), while non-volatile pesticides are injected into liquid chromatography-tandem mass spectrometry (LC-MS/MS). The new protocol is validated for its linearity (r²), recovery (R), precisions (inter and intra-day), limit of detection (LOD) and limit of quantification (LOQ). It shows good linearity (r²>0.99) in the concentration ranging from 0.05 to 150 ng L⁻¹. The repeatability and reproducibility of measurements expressed as relative standard deviation (% RSD) is found to be satisfactory (% RSD <20%). Furthermore, the detection limits obtained are in the low order of ng L⁻¹. Then the developed procedure is tested successfully for its efficiency on real fog samples collected from Erstein (Bas-Rhin, Alsace) and Fnaideq (Akkar, North-Lebanon).
A new template-free, porous, and wrinkled ZnO thin films were designed by sol-gel dip-coating technique for enhancing the photocatalytic degradation of organic pollutants in water. The spontaneous formation of such nanostructure represents a certain type of instability-driven organization under intrinsic stress, such as thermal compression. The surface evolution was tracked by in situ thermo-ellipsometry technique through the changes in the film’s thickness and refractive index. The engineered nanostructure was obtained by a pre-heat treatment at 150 ⁰ C in the infrared chamber of the dip-coater followed by a post-annealing in the air at 450 ⁰ C for 1 hour. A wrinkled structure with a porosity of ~ 22 to 25% and an average pore Ferret diameter of ~24 nm were revealed, promoting the adsorption of pollutants onto the films' surface. The photocatalytic activity of ZnO films was tested via the degradation of methylene blue probe molecule under two different irradiation sources. A high removal efficiency above 92% and degradation rate constants of 0.0049 min⁻¹ and 0.0121 min⁻¹ were registered under UVA and visible light respectively.
In this paper, we study the long memory behavior of the hourly cryptocurrency returns during the COVID-19 pandemic period. Initially, we apply different tests against the spurious long memory, with the results indicating the presence of true long memory for most cryptocurrencies. Yet, using the multivariate test, the series are found to be contaminated by level shifts or smooth trends. Then, we adopt the wavelet-based multivariate long memory approach suggested by Achard and Gannaz (2016) to model their long memory connectivity. The findings indicate a change in persistence for all series during the sample period. The fractal connectivity clustering indicates a similarity among Ethereum (ETH) and Litecoin (LTC), Monero (XMR), Bitcoin (BTC), and EOC token (EOS), while Stellar (XLM) is clustered away from the remaining series, indicating the absence of any interdependence with other crypto returns. Overall, shocks arising from COVID-19 crisis have led to changes in long-run correlation structure.
This study investigated the antibacterial activity of the aqueous extract of Ilex paraguariensis against 32 different strains of nontyphoidal Salmonella (NTS) through the determination of the minimum inhibitory concentration (MIC), mutant prevention concentration (MPC), and mutant selection window (MSW) and the detection of virulence genes by multiplex PCR assays. The MIC values of Ilex paraguariensis against Salmonella spp. strains varied between 0.78 mg/ml and 6.25 mg/ml with a MIC90 of 3.12 mg/ml. The highest MPC in this study was 48 mg/ml yielding a mutant selection window of 41.75 mg/ml. The MSW values of the remaining strains varied between 1.56 and 8.87 mg/ml. Genes of pathogenicity detected in Salmonella spp. isolates were most commonly the stn, sdiA, invA, sopB, invH, and sopE genes. The antibacterial activity of yerba mate extract was not affected by the antimicrobial resistance patterns or pathogenicity genes expressed. More work is needed to identify the active antibacterial compound(s) responsible for the antibacterial activity.
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1,642 members
Smart Zeidan
  • Department of Surgery
Mervat El-Hoz
  • Department of Civil Engineering
Abdel-Massih Roula
  • Department of Biology
Bassem S Bassil
  • Department of Chemistry
Amioûn, Lebanon
Head of institution
Elias Warrak, PhD