Manual small incision cataract surgery in dense cataract: Morocco comparative study

BACKGROUND: The purpose of this study was to compare manual small incision cataract surgery (MSICS) with phacoemulsification and manual extracapsular extraction in terms of corneal edema, endothelial loss, and induced astigmatism. MATERIAL AND METHODS: A prospective study carried out in the ophthalmology department of the military hospital of Rabat in Morocco, including 15 eyes of 15 patients with brown cataracts. All patients were operated on by the same surgeon: 5 by phacoemulsification (PKE), 5 by manual extracapsular extraction (EEC) via corneal incision, and 5 by MSICS via tunneled sclero-corneal incision. Each patient underwent pre-, intra- and post-operative evaluation including: 1 — measurement of astigmatism before surgery and 3 months after (after removal of EEC threads); 2 — specular microscopy before and 3 months after surgery; 3 — clinical assessment of corneal edema before and at each follow-up: 1st and 7th day, 1st and 3rd month; 4 — evaluation of operating time. RESULTS: 9 men and 6 women were included. Mean age was 67 years. The mean axial length was 22.98mm. All surgeries were uneventful, and all patients were implanted in the capsular bag with a monofocal implant. Initial endothelial cell count was comparable in the 3 groups (p = 0.48). The endothelial loss was most significant in the PKE group (16%), followed by the EEC group (5.1%) and then the MSICS group (4.5%) (p < 0.01). The change in corneal astigmatism was most significant in the EEC group (2.1D), followed by the MSICS group (0.88 D), then the PKE group (0.65 D) (p = 0.01). In the PKE group, all patients showed moderate to severe corneal edema at 1st postoperative, and in 2 cases, the edema persisted at the 7th day and then regressed at the 1st and 3rd month. Only 2 cases of moderate edema at day 1 in the EEC group, and 1 case in the MSICS group, regressed at the 7th day. Phacoemulsification was the least time-consuming, with an average operating time of 13 minutes, compared with 28 minutes for MSICS and 34 minutes for EEC (p < 0.01). CONCLUSION: MSICS is a technique that resembles manual EEC, with a self-sealing tunneled scleral-corneal incision that avoids a full-thickness corneal incision and, consequently, sutures at the end of the procedure. It requires a learning curve. Our results concur with most of the data in the literature. MSICS is a safe technique, but it remains little used in cataract surgery. We believe that it should be preferred in patients with dense cataracts

Improvement of crack tip position estimation in DIC images by image processing methods

The study presents and compares an application of two procedures to identify the crack tip location in PVC Sent samples under a uniaxial tensile test based on the image processing method. An IDS camera captures several photos of the PVC surface as part of the image analysis procedure. All relevant data on crack initiation and propagation is collected and assessed using ImageJ software using image processing methods for detecting cracks. However, the second procedure involves a developed algorithm detecting the discontinuity using digital image correlation (DIC) measurement. Although, because of the experimental conditions, the acquisition of images by the digital camera is never perfect. This noise comes from several sources, including the digital camera, image distortion due to lens magnification or lens angle, the shape and size of the pattern, and electronic noise; ... This article discusses image enhancement methods to overcome these objectionable characteristics using and comparing several filters:  Gaussian, median, and Unsharp Mask filters. The performance of the Gaussian filter is better than the Median and Unsharp mask filters. This research demonstrates that DIC is an effective technique for monitoring deformation and understanding the failure mechanism with the best-suited filter

Dynamique spatio-temporelle d'un jet d'air libre évoluant à nombre de Reynolds modéré

Ce travail présente des résultats expérimentaux pour un jet d'air libre injecté dans l'air ambiant à nombre de Reynolds 1600. La dynamique du jet est observée par visualisation des images de l'écoulement des fumées d'encens enregistrées par une caméra rapide. Une analyse temporelle des séries d'images acquises a permis de mettre en évidence les détails du comportement de l'écoulement. Les résultats démontrent l'existence d'anneaux tourbillonnaires au bord du jet. La taille, la distribution et la fréquence d'apparition de ces anneaux tourbillonnaires sont examinées

Olefin Metathesis by Group VI (Mo, W) Metal Compounds

Olefin metathesis is an important reaction not only in petroleum chemistry but also in fine chemistry. Professors Grubbs, Schrock, and Chauvin obtained the Nobel Prize in 2005 for the development of this reaction (determination of the mechanism and synthesis of homogeneous catalysts). This reaction can be described as the redistribution of carbon chains of olefins via a breaking of their C═C double bonds. It is catalyzed by metal carbenes and the catalytic cycle passes through a metallacyclobutane. The purpose of this chapter is to give an overview of catalysts based on tungsten or molybdenum active for this reaction. Numerous tungsten and molybdenum organometallic complexes displaying a carbene functionality were synthesized. Some of them are highly active in olefin metathesis. Industrially, tungsten oxide on silica is used as a precursor of the propene production by olefin metathesis of but-2-ene and ethylene. However, the active sites are not well known but they can be modeled by grafting, via surface organometallic chemistry, perhydrocarbyl complexes of molybdenum or tungsten on oxide surfaces. After a review of the complexes used in homogeneous catalysis, a review of the industrial catalysts and their models will be given

Basal cell carcinoma of the medial canthus: resection and reconstruction by glabellar flap

The inner canthus is the site of aggressive basal cell carcinomas. The management of these tumors requires knowledge of the basic principles of reconstruction in reconstructive surgery. Surgical resection with exhaustive control of the excision margins should be performed. Even when the tumor is small, the need for healthy margins often results in a moderate to a large palpebral defect that cannot be repaired with direct sutures. The goal of reconstruction is to achieve a mobile eyelid, good corneal protection, and a good aesthetic result with acceptable donor site sequelae. In this manuscript, we describe a case of basal cell carcinoma of the medial canthus that underwent resection followed by reconstruction with a glabellar flap

A giant dermoid cyst of the orbit present in adulthood — a case report

Dermoid cysts are common orbital developmental tumors in childhood. They account for 3 to 9% of primary orbital tumors. They are considered to be congenital, but not all of them are diagnosed at birth. Dermoid cysts are benign choristomas that arise from sequestration of ectoderm along the lines of embryonic fusion of mesodermal processes destined to be bone. In most cases, the lesion is close to the zygomatic-frontal suture leading to a superotemporal subcutaneous mass in the eyebrow or eyelid. The intraorbital location is relatively rare and more prone to complications, particularly compressive. We report the case of a 41-year-old man with a large intraorbital tumor. The imaging aspects were evocative of an extraconal dermoid cyst. The tumor was resected through a transconjunctival route. Histopathologic examination confirmed the diagnosis of dermoid cyst

CD25 Appears Non Essential for Human Peripheral Treg Maintenance In Vivo

Background: IL-2 has been reported to be critical for peripheral T reg survival in mouse models. Here, we examined T reg maintenance in a series of paediatric liver transplant recipients who received basiliximab, a therapeutic anti-CD25 monoclonal antibody. Methodology/Principal Findings: FoxP3 + CD4 T cells were analyzed by flow cytometry before liver grafting and more than 9 months later. We found that in vivo CD25 blockade did not lead to Treg depletion: the proportion of FoxP3 + cells among CD4 T cells and the level of FoxP3 expression were both unchanged. IL-2Rb expression was enhanced in FoxP3 + cells both before and after basiliximab treatment, while the level of IL-2Rc expression was similar in Tregs and non-Tregs. No significant change in the weak or absent expression of IL-7Ra and IL-15Ra expression on FoxP3 + cells was observed. Although the proportion of FoxP3 + cells among CD4 T cells did not vary, food allergies occurred more rapidly after liver grafting in patients who received basiliximab, raising questions as to T reg functionality in vivo in the absence of functional CD25. Conclusions: CD25 appears non essential for human Treg peripheral maintenance in vivo. However, our results rais

Improvement of crack tip position estimation in DIC images by image processing methods

The study proposes and compares two procedures to identify the crack tip location in PVC Sent samples under a uniaxial tensile test based on the image processing method

Effect of plastic anisotropy on the prediction of the ductility for HCP sheet metals

Due to their lightness, low stiffness and high strength, Hexagonal Closed Packed (HCP) materials are widely used in aeronautic and aerospace industries. In this paper, the ductility limit of HCP sheet materials at room temperature (25° C) is predicted by coupling the Cazacu yield function and the Marciniak and Kuczyński (MK) necking criterion. Based on transformed principal stresses, the phenomenological constitutive model of Cazacu is used to take into account the initial plastic anisotropy and strength differential (SD) effects. For plane stress and orthotropic symmetry, two linear transformations are required to use a number of anisotropy coefficients which are more suitable for practical applications. Under these circumstances, a prediction of formability for HCP sheet materials with more than one linear transformation is performed using the numerical tool Mathematica

Prediction of the ductility limit of magnesium AZ31B alloy

In many engineering applications (automotive, computer and mobile device industries, etc.), magnesium alloys have been widely used owing to their interesting physical and mechanical parameters. However, magnesium alloys are identified by the low ductility at room temperature, due to their strong plastic anisotropy and the yielding asymmetry between tension and compression. In this work, the ductility limit of a rolled magnesium AZ31 sheet metal at room temperature is numerically investigated. This investigation is based on the coupling between a reduced-order crystal plasticity model and the Marciniak– Kuczyński localized necking approach. This reduced-order model is used to describe the anisotropic behavior of this material taking into account the strong plastic anisotropy (e.g., yielding asymmetry between tension and compression) due to the limited number of slip systems (i.e., twinning mode). To accurately describe the plastic anisotropy due to slip and twinning modes, a combination of two separate yield functions (according to Barlat and Cazacu) is used. The coupling between the adopted constitutive framework and the Marciniak–Kuczyński instability approach is numerically implemented via an implicit algorithm. Comparisons between experimental results from the literature and numerical results obtained by using our calculation tool are carried out to validate the choice of the reducedorder crystal plasticity model