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Alexandre Assi,1 Ahmad M Mansour,2 Abdul Razzak Charbaji,3 Maurizio Battaglia Parodi4 1Beirut Eye Clinic and VitreoRetinal Department, Beirut Eye Specialist Hospital, Beirut, Lebanon; 2Department of Ophthalmology, American University of Beirut, Beirut, Lebanon; 3Department of Statistics and Research Methodology, Lebanese American University, Beirut, Lebanon; 4Department of Ophthalmology and IRCCS Ospedale San Raffaele, University Vita-Salute, Milan, ItalyCorrespondence: Ahmad M Mansour, Department of Ophthalmology, American University of Beirut, POB 113-6044, Beirut, Lebanon, Tel +9613377633, Email ammansourmd@gmail.comPurpose: To study the anatomic outcome of leaving vitreous cortex remnants (VCR) during pars plana vitrectomy (PPV) for primary rhegmatogenous retinal detachment (RRD).Methods: The study comprised patients with RRD who had PPV by a single surgeon between January 2019 and December 2020 and followed for 6 months. After intravitreal injection of triamcinolone acetonide, the topographic pattern of VCR at the periphery (p) and macula (m) was divided into 2 types by extent: complete or 4 quadrants (pVCR4Q), and between 2 and 4 quadrants ≥ 2 quadrants (pVCR> 2Q), or by location > 1 inferior retinal quadrant (pVCR> 1InfQ), and at the macula (mVCR). Anatomical failure or retinal re-detachment within 6 months after surgery was the primary outcome measures. The occurrence of grade C proliferative vitreoretinopathy (PVR) and epiretinal membrane (ERM) were used as secondary outcome indicators.Results: A 6-month prospective follow-up was performed on 103 patients. pVCR4Q was detected in 31 eyes, pVCR> 2Q in 40 eyes, pVCR> 1InfQ in 40 eyes and mVCR in 54 eyes. Recurrent RRD developed in 9 (8.7%) eyes, PVR grade C in 6 (5.8%) eyes and ERM in 11 (10.7%) eyes. According to multivariate regression analysis, the existence of any type of VCR did not correlate with anatomical failure, PVR or ERM.Conclusion: The initial success rate of PPV and the growth of PVR or ERM do not appear to be impacted by keeping VCR.Keywords: vitreous cortex remnants, pars plana vitrectomy, primary rhegmatogenous retinal detachment, epiretinal membrane, proliferative vitreoretinopathy

Solar stills are used in distant and arid areas to convert brackish or salty water into potable water fit for human use in a simple, affordable, and effective manner. Even when PCM materials are used, typical solar systems still have minimal production per day. In this study, experimental tests were carried out in order to increase the performance of a single-slope solar still combined with PCM material (paraffin wax) and a solar-powered electric heater. Two identical single-slope solar stills were designed, fabricated, and tested under the same climatic conditions during the summer and spring seasons of 2021 in Al-Arish, Egypt. The first is a conventional solar still (CVSS), and the other is also a conventional still but with PCM and an electric heater (CVSSWPCM). Several parameters were measured during the experiments, including sun intensity, meteorological aspects, cumulative freshwater production, average glass, and water temperatures and PCM temperature. The improved solar still was evaluated at different operating temperatures and was compared to the conventional traditional one. There were four cases studied: one case without a heater (paraffin wax only) and three other cases with a heater operating at 58 °C, 60 °C, and 65 °C, respectively. The experimental results revealed that activating the heater inside the paraffin wax increased daily production (i) in the spring by 2.38, 2.66, and 3.1 times and (ii) and in the summer by 2.2, 2.39, and 2.67 times at the three above-mentioned temperatures respectively (when compared to the traditional still). In addition, the maximum rate of daily freshwater production was achieved at paraffin wax temperature of 65 °C in both spring and summer (Case 5). Finally, the economic evaluation of the modified solar still was carried out according to cost per litre. The modified solar still with a heater operating at 65 °C has a higher exergoeconomic value than the traditional one. The maximum CO2 mitigation in cases 1 and 5 was approximately 28 tons and 160 tons, respectively.

Larvae of greater wax moth, Galleria mellonella L., can be a devastating pest of honeybee combs in storage. Current control measures may not be adequate or with some drawbacks. Treatment with ionizing radiation could be a possible alternative. Determining the dose, however, requires a detailed study on the radiosensitivity of this stage. In this study, the sensitivity of the greater wax moth mature larvae to ionizing radiation was examined. Larvae were exposed to gamma radiation dosages (50 to 400 Gy) and effects on rate of development, pupation and pupal eclosion (adult emergence) were investigated. In addition, large scale confirmatory tests were conducted to validate treatment efficacy at statistical confidence levels needed for phytosanitary (quarantine and disinfestations) security. Results showed that radiation sensitivity of G. mellonella mature larvae increased, as expected, with increasing radiation dose. The magnitude of the effect, however, depends on the criterion used for measuring effectiveness. Both pupation and pupal eclosion were significantly affected at 50 Gy dose and no emergence was recorded at 300 Gy. Results of large scale confirmatory trials (>30,000 mature larvae) supported the results of the small scale studies. According to probit analysis of dose mortality data for pupation and pupal eclosion, the LD99 for preventing development of mature larvae to pupae and adults is 576 and 318 Gy, respectively. In addition, the developmental rate of mature larvae to adults was negatively affected. This suggests that a dose of 250 Gy may be adequate for disinfesting honeybee products infested with greater wax moth larvae.

Background The three-dimensional (3D) evaluation of skeletal stability after orthognathic surgery is a time-consuming and complex procedure. The complexity increases further when evaluating the surgery-first orthognathic approach (SFOA). Herein, we propose and validate a simple time-saving method of 3D analysis using a single software, demonstrating high accuracy and repeatability. Methods This retrospective cohort study included 12 patients with skeletal class 3 malocclusion who underwent bimaxillary surgery without any presurgical orthodontics. Computed tomography (CT)/cone-beam CT images of each patient were obtained at three different time points (preoperation [T0], immediately postoperation [T1], and 1 year after surgery [T2]) and reconstructed into 3D images. After automatic surface-based alignment of the three models based on the anterior cranial base, five easily located anatomical landmarks were defined to each model. A set of angular and linear measurements were automatically calculated and used to define the amount of movement (T1–T0) and the amount of relapse (T2–T1). To evaluate the reproducibility, two independent observers processed all the cases, One of them repeated the steps after 2 weeks to assess intraobserver variability. Intraclass correlation coefficients (ICCs) were calculated at a 95% confidence interval. Time required for evaluating each case was recorded. Results Both the intra- and interobserver variability showed high ICC values (more than 0.95) with low measurement variations (mean linear variations: 0.18 mm; mean angular variations: 0.25 degree). Time needed for the evaluation process ranged from 3 to 5 minutes. Conclusion This approach is time-saving, semiautomatic, and easy to learn and can be used to effectively evaluate stability after SFOA.