The short-term effects of intravitreal injection of bevacizumab on the plasma levels of vascular endothelial growth factor, insulin-like growth factor-1, and growth parameters in infants with retinopathy of prematurity

Purpose: To determine the changes in serum levels of free vascular endothelial growth factor (VEGF), insulin-like growth factor-1 (IGF-1), and growth parameters in infants with retinopathy of prematurity (ROP) who received intravitreal injection of the bevacizumab (IVB). Methods: A prospective interventional case series study, including 10 infants with Type 1 ROP was conducted. Using the enzyme-linked immunosorbent assay, serum levels of VEGF and IGF-1 were measured before, 1 month and 2 months after treatment with IVB in both eyes. Growth parameters, including weight, length, and head circumference and their Fenton's z-score, were also measured. Results: Serum VEGF levels were suppressed 1 month after IVB (P = 0.007) and then increased between 1 and 2 months (P = 0.064). Z-scores of all growth parameters except weight z-score decreased in the 1st and 2nd months. Conclusion: Serum VEGF levels showed a transient reduction after IVB which lasted at least 2 months. Growth velocity of premature infants may be affected by anti-VEGF therapy and should be followed with particular attention. © 2020 Journal of Current Ophthalmology | Published by Wolters Kluwer-Medknow

Endophthalmitis caused by Acinetobacter spp. as the presenting manifestation of diabetes mellitus

Purpose We describe a patient with endogenous endophthalmitis caused by Acinetobacter spp. as the first clinical presentation of diabetes mellitus. Method A 48-year-old otherwise healthy woman was referred with signs and symptoms of acute endophthalmitis in the left eye. Systemic work-up, vitreous tap, and intravitreal antibiotic injection were performed followed by pars plana vitrectomy. Results The laboratory tests confirmed the diagnosis of diabetes mellitus. Vitreous culture was positive for Acinetobacter spp., and the organism was sensitive to colistin. One month after surgery, vision was no light perception, and the eye was phthisical. Conclusion Diagnostic work-up should be performed even in otherwise healthy patients with endogenous endophthalmitis. © 2016 Iranian Society of Ophthalmolog

Nonlinear primary resonance of micro/nano-beams made of nanoporous biomaterials incorporating nonlocality and strain gradient size dependency

A wide range of biological applications such as drug delivery, biosensors and hemodialysis can be provided by nanoporous biomaterials due to their uniform pore size as well as considerable pore density. In the current study, the size dependency in the nonlinear primary resonance of micro/nano-beams made of nanoporous biomaterials is anticipated. To accomplish this end, a refined truncated cube is introduced to model the lattice structure of nanoporous biomaterial. Accordingly, analytical expressions for the mechanical properties of material are derived as functions of pore size. After that, based upon a nonlocal strain gradient beam model, the size-dependent nonlinear Duffing type equation of motion is constructed. The Galerkin technique together with the multiple time-scales method is employed to obtain the nonlocal strain gradient frequency-response and amplitude-response related to the nonlinear primary resonance of a micro/nano-beam made of the nanoporous biomaterial with different pore sizes. It is indicated that the nonlocality causes to decrease the response amplitudes associated with the both bifurcation points of the jump phenomenon, while the strain gradient size dependency causes to increase them. Also, it is found that increasing the pore size leads to enhance the nonlinearity, so the maximum deflection of response occurs at higher excitation frequency. Keywords: Biomechanics, Size effect, Nonlinear oscillation, Porosity, Nonlocal strain gradient elasticit

Static analysis of rectangular thick plates resting on two-parameter elastic boundary strips

In this paper, the Generalized Differential Quadrature (GDQ) method is used to obtain bending solution of moderately thick rectangular plates. The plate is resting on two-parameter elastic (Pasternak) foundation or strips with a finite width. Various combinations of clamped, simply supported and free boundary conditions are considered. According to the first-order shear deformation theory, the governing equations of the problem consist of three second-order partial differential equations (PDEs) in terms of displacement and rotations of the plate. The governing equations and solution domain is discretized based on the GDQ method. It is demonstrated that the method converges rapidly while providing accurate results with relatively small number of grid points. Accuracy of the results is examined using available data in the literature for Pasternak foundation. Furthermore, due to lack of data for Pasternak strips, all predictions are verified by finite element analysis which can be used as benchmark in future studies

Application of refined beam elements to the coupled-field analysis of magnetostrictive microbeams

Bending of magnetostrictive unimorph microbeams is investigated using a one-dimensional refined finite element model based on the Carrera Unified Formulation. Since these type of smart devices are usually being used in low magnetic fields, the linear coupled magnetomechanical constitutive relations are used to characterize their coupling behavior. With the use of the principle of virtual displacement, components of the fundamental nucleus matrix are obtained and the governing equations are discretized. 2, 3 and 4-node beam elements are used for modelling the beam major axis while linear 4-node and quadratic 9-node Lagrange elements are used as expansion functions over the cross-section. Two examples of unimorph micro-devices are considered and the results of present work are compared with those of experimental and conventional finite element works existing in the literature. It is shown that the one-dimensional refined finite element model, which is capable of generating three-dimensional results, can accurately catch the experimental data with a lower computational cost than the classical models

Remifentanil infusion during emergence moderates hemodynamic and cough responses to the tracheal tube: A randomized controlled trial

Objective To examine the severity of cough and straining at the time of emergence from anesthesia. Design Double-blind randomized, placebo-controlled study. Setting University-affiliated hospital. Patients Sixty-two American Society of Anesthesiologists 2 patients undergoing craniotomy and excision of supratentorial cerebral tumors. Intervention Intravenous infusion of remifentanil (REM) at 0.05 μg/kg/min or normal saline (NS) upon termination of the surgical procedure. Measurements Heart rate (HR) and mean arterial pressure (MAP) along with the frequency and severity of cough response (Modified Minogue Scale) to the endotracheal tube were recorded at different time points. The frequency of cough and straining was analyzed with �2 tests. HRs and MAP were analyzed by repeated-measures analysis of variance between REM and NS groups. Main Results There was no case of significant cough in the REM group, and all of the patients in the NS group developed some extent of cough varying from mild retching to severe coughing episodes (P <.001). Both the HR and MAPs were consistently lower in the REM group compared to the NS group. Conclusion Infusion of REM at the end of craniotomy procedures results in significant reduction of the frequency and severity of coughing and straining. Compared to placebo, REM moderates increases in MAP upon emergence from general anesthesia until the time of extubation. © 201