Impact of online learning during COVID-19 pandemic on digital device related ocular health.

Objective: The aim of this study was to evaluate the impact of the COVID-19 pandemic on ocular health related to digital device usage among university students in Lebanon. Design: A cross-sectional design was utilized to examine the association between the pandemic and ocular health. Participants: A total of 255 university students in Lebanon participated in the study, selected based on their enrollment during the pandemic. Methods: An online survey assessed participants' digital device usage, awareness of digital eye strain, and experienced symptoms. The study addressed the relationship between symptom frequency and screen time, especially in their connection to the pandemic and online learning. Results: Prior to the pandemic, the majority of participants (73.0 %) were unaware of digital eye strain. Following the transition to online learning, nearly half of the participants (47.0 %) reported using digital devices for 12 or more hours. The majority (92.0 %) experienced a substantial increase in daily digital device usage for learning, with an average increase of 3-5 h. Symptoms of digital eye strain, including headache, burning of eyes, blurry vision, sensitivity to light, worsening of vision and dryness of the eyes intensified in both frequency and severity during the pandemic and online learning period. Conclusions: The study emphasizes the importance of promoting healthy habits and implementing preventive measures to reduce the prevalence of digital eye strain symptoms among university students. Healthcare professionals and public health authorities should educate individuals on strategies to alleviate digital eye strain, considering the persistent reliance on digital devices beyond the pandemic.

Long-term surgical outcomes of one-muscle vs. two-muscle horizontal strabismus surgery.

PURPOSE: While horizontal strabismus surgery is generally considered to have favorable outcomes, success rates can vary by type of procedure. Our purpose is to compare the long-term outcomes of patients who underwent one-muscle vs. two-muscle horizontal strabismus surgery. METHODS: This is a retrospective study comparing one-muscle to two-muscle strabismus surgery for small to moderate angle horizontal strabismus. Demographic data and eye exam parameters were compared at baseline and postoperatively (6 months up to 6 years). Surgical success was defined as a post-operative angle of 10 PD or less. We also compared outcomes by strabismus type: esotropia vs exotropia and adjusted the analysis for previous strabismus surgery. RESULTS: Out of 89 patients with moderate angle horizontal strabismus (25 PD or less), 17 patients had a one-muscle operation, and 72 patients had two-muscle surgery. The mean age was 14.12 ± 9.30 years and 11.70 ± 11.30 years for the one-muscle and two-muscle groups, respectively (p = .74). The baseline characteristics of both groups were comparable. Follow-up time was 32.82 ± 26.93 months in one-muscle and 37.67 ± 23.81 in two-muscle groups (p = .29). Success rate was 70.6% for the one-muscle group and 68.10% for the two-muscle group (p = .69). Outcomes were similar when divided into esotropia and exotropia. The success rate was not affected by previous strabismus surgeries nor by the initial angle of deviation. CONCLUSION: One-muscle and two-muscle horizontal strabismus surgery had similar long-term outcomes and did not differ by strabismus type nor by angle of deviation.

Corneal Deposits: A Presentation of Arthrobacter Keratitis.

Introduction: Infectious keratitis, an inflammatory condition of the cornea, poses a significant public health concern globally. Bacterial keratitis, the most common type, primarily involves Staphylococcus aureus and Pseudomonas aeruginosa. Timely diagnosis and treatment are crucial to prevent vision loss. Case Presentation: This case report presents a 78-year-old male patient with a burning sensation persisting for 1 week. The patient was diagnosed with keratitis caused by Arthrobacter, a Gram-positive coccobacillus commonly found in the environment. While the literature reports a few cases of Arthrobacter species keratitis, limited data exist regarding its clinical course and outcomes. Treatment with ciprofloxacin eye drops resulted in complete resolution of symptoms and a clear cornea upon final follow-up. Conclusion: Arthrobacter, a rare causative agent of keratitis, requires early suspicion for accurate diagnosis and treatment. Despite the limited literature on Arthrobacter keratitis, this case highlights the importance of considering uncommon pathogens in corneal infections. Further research is necessary to understand the prevalence and clinical course of Arthrobacter keratitis.

Impact of the economic crisis, COVID-19 and the Beirut explosion on ophthalmology training in Lebanon: an observational cohort survey-based study.

OBJECTIVES: The objective of the study is to investigate the effects of the COVID-19 pandemic, the economic crisis and the Beirut explosion on the training and work of ophthalmology residents and faculty in Lebanon. DESIGN: This is an observational cohort survey-based research conducted between January and December 2022. SETTING: The study targeted all ophthalmology residents and core faculty in Lebanon. PARTICIPANTS: A total of 52 participants, including 27 residents and 25 core faculty members, completed the survey. PRIMARY OUTCOME MEASURE: Primary outcomes comprised the subjectively reported effect of the three major external stressors on the training and well-being of ophthalmology trainees and educators in Lebanon. RESULTS: The study found that the majority of ophthalmology residents and core faculty members were significantly affected by the COVID-19 pandemic, Beirut explosion and the economic crisis in Lebanon. Significant percentage reported financial burden, decrease in outpatient and surgical load and educational activities. Furthermore, most participants reported higher levels of stress, anxiety and depression during the time of crises. CONCLUSIONS: This study emphasises the need to support healthcare professionals during times of crisis, as they are on the frontlines and can experience high levels of stress, anxiety and depression. By providing support and resources to healthcare professionals, they can better cope with the challenges they face and continue to provide essential care to their patients.

Glutaraldehyde and terephthaldehyde-crosslinked chitosan for cationic and anionic dyes removal from aqueous solutions: Experimental, DFT, kinetic and thermodynamic studies.

Novel chitosan polymers were synthesized using two cross-linkers, Glutaraldehyde and Terephthaldehyde, to enhance stability and efficiency. Characterization techniques (XRD, FTIR, FE-SEM, TGA, DTG, BJH, and BET) confirmed successful synthesis. These polymers were employed as adsorbents for removing Malachite Green (MG) and Congo Red (CR) dyes from water. Batch experiments and DFT calculations investigated the adsorption process, thermodynamics, and kinetics. Results showed the CSGT-III polymer achieved the highest removal efficiency. For initial dye concentrations ([CR]o = 50 mg/L, [MG]o = 20 mg/L) and adsorbent doses (0.8 g/L for CR, 0.4 g/L for MG), removal efficiencies were 96.99 % for CR and 99.07 % for MG. Thermodynamic analysis confirmed the spontaneous nature of adsorption, and the process was endothermic for both dyes. The Langmuir model fitted adsorption isotherms well, indicating a homogeneous surface. Kinetic analysis revealed a pseudo-second-order model for both dyes.

DNA G-Quadruplexes Activate Heme for Robust Catalysis of Carbene Transfer Reactions.

Guanine-rich single-stranded DNAs and RNAs that fold into G-quadruplexes (GQs) are known to complex tightly with FeII-heme and FeIII-heme (hemin), ubiquitous cellular cofactors. Heme-GQ (DNA) complexes, known as heme·DNAzymes, are able to utilize hydrogen peroxide as an oxidant to vigorously catalyze a variety of one-electron (peroxidase) and two-electron (peroxygenase) oxidation reactions. Herein, we show that complexes of FeII-heme with GQs also robustly catalyze a mechanistically distinct reaction, carbene transfer to an alkene substrate. Significant enhancements were seen in both reaction kinetics and product turnover (∼180) relative to disaggregated FeII-heme in the absence of DNA or in the presence of other DNA folds, such as single-stranded or double-stranded DNA. Heme binds to GQs by end-stacking. Simple, intramolecularly folded GQs are unable to provide a complexly structured "distal side" environment to the bound heme; therefore, such DNAzymes do not display significant product stereoselectivity. However, intermolecular GQs with multiple pendant nucleotides show increasing stereoselectivity in addition to their enhanced catalytic rates. These results recapitulate the unique functional synergy and highlight the surprising catalytic versatility of complexes formed between heme and DNA/RNA GQs. Our findings suggest that heme·DNAzymes and heme·ribozymes may prove to be useful reagents for carbon-carbon bond forming "green" reactions carried out in vitro and likely within living cells.

1,6-Diphenyl-1,3,5-hexatriene (DPH) as a Novel Matrix for MALDI MS Imaging of Fatty Acids, Phospholipids, and Sulfatides in Brain Tissues.

1,6-Diphenyl-1,3,5-hexatriene (DPH) is a commonly used fluorescence probe for studying cell membrane-lipids due to its affinity toward the acyl chains in the phospholipid bilayers. In this work, we investigated its use in matrix-assisted laser desorption/ionization (MALDI) as a new matrix for mass spectrometry imaging (MSI) of mouse and rat brain tissue. DPH exhibits very minimal matrix-induced background signals for the analysis of small molecules (below m/z of 1000). In the negative ion mode, DPH permits the highly sensitive detection of small fatty acids (m/z 200-350) as well as a variety of large lipids up to m/z of 1000, including lyso-phospholipid, phosphatidic acid (PA), phosphoethanolamine (PE), phosphatidylserine (PS), phosphatidylglycerol (PG), phosphatidylinositol (PI), and sulfatides (ST). The analytes were mostly detected as the deprotonated ion [M - H]-. Our results also demonstrate that sublimated DPH is stable for at least 24 h under the vacuum of our MALDI mass spectrometer. The ability to apply DPH via sublimation coupled with its low volatility allows us to perform tissue imaging of the above analytes at high spatial resolution. The degree of lipid fragmentation was determined experimentally at varying laser intensities. The results illustrated that the use of relatively low laser energy is important to minimize the artificially generated fatty acid signals. On the other hand, the lipid fragmentation obtained at higher laser energies provided tandem MS information useful for lipid structure elucidation.

Interest of fluorescence derivatization and fluorescence probe assisted post-column detection of phospholipids: a short review.

Phospholipids are essential constituents of all living cell membranes. There are many analytical methods available for the quantitative and qualitative determination of phospholipids, but since these molecules lack chromophores, common absorbance based methods are of limited use. Beside mass spectrometry, some less specific approaches that are routinely used are evaporative light scattering detection or fluorescence, which exhibit sufficient sensitivity. Here, we focus on fluorescence, which remains an interesting way to quantify phospholipids. Two ways of detecting phospholipids by fluorescence are possible coupled with separation techniques such as thin layer chromatography (TLC), high performance liquid chromatography (HPLC) and capillary electrophoresis (CE): firstly, pre-column derivatization procedures and secondly, probe assisted post-column detection with suitable fluorescence reagents. In both cases, the common purpose is to increase the detection sensitivity. It is shown that, whereas pre-column derivatization is characterized by selectivity due to the chemical functionality of the analyte involved in the derivatization process, in supramolecular post-column derivatization, the selectivity only proceeds from the capacity of the lipid to involve supramolecular assemblies with a fluorescence probe. The aim of this review is to summarize available experiments concerning fluorescence detection of phospholipids. The interest and limitation of such detection approaches are discussed.