Synthesis and Characterization of Nonaqueous Deposited Nanocrystalline Cds Film

A nanocrystallineCdS film can be deposited by chemical bath deposition using non aqueous medium. XRD analysis confirms the crystalline structure of CdS (002) with 34 nm crystallite size. The as deposited films are stoichiometric in nature with Cd and S atomic % ratio equal to 1.0. The field emission scanning electron miceoscope and atomic force microscopy studies revels a densely packed non porous granular deposit with RMS value of roughness equal to 92nm. The band gap of the film is measures by spectroscopy and it is observed to 2.40 eV which is good agreement with the reported result. The photoluminescence prominent peak of the CdS film is observed to be 392 nm

Restoration of Corneal Transparency by Mesenchymal Stem Cells

Summary Transparency of the cornea is indispensable for optimal vision. Ocular trauma is a leading cause of corneal opacity, leading to 25 million cases of blindness annually. Recently, mesenchymal stem cells (MSCs) have gained prominence due to their inflammation-suppressing and tissue repair functions. Here, we investigate the potential of MSCs to restore corneal transparency following ocular injury. Using an in vivo mouse model of ocular injury, we report that MSCs have the capacity to restore corneal transparency by secreting high levels of hepatocyte growth factor (HGF). Interestingly, our data also show that HGF alone can restore corneal transparency, an observation that has translational implications for the development of HGF-based therapy

Types of organisms and in-vitro susceptibility of bacterial isolates from patients with microbial keratitis: A trend analysis of 8 years

Purpose: To report the distribution and trends of types of organisms and antibiotic susceptibility of the bacterial isolates obtained from patients with microbial keratitis. Methods: Microbiology records of culture-positive microbial keratitis that underwent a diagnostic corneal scraping and cultures were reviewed. Fungal, bacterial, and parasitic culture results and antibiotic susceptibility profile of bacteria were analyzed and comparisons were made between two halves of the study period (2007–2010 vs. 2011–2014). Results: A total of 3981 corneal scrapings were processed during the 8-year study period. Pathogen was recovered in culture in 1914 (48.1%) samples. Fungi, bacteria, and parasites constituted 38.7%, 60%, and 1.3% of the total isolates, respectively. The common fungal isolates were Aspergillus spp. (224/868, 25.8%) and Fusarium spp. (200/868, 23.0%), while common Gram-positive bacteria were Streptococcus pneumoniae (217/1125, 19.3%) and Staphylococcus aureus (185/1125, 16.4%), and common Gram-negative bacteria was Pseudomonas spp. (99/219, 45.2%). There was no significant difference in proportion of bacterial (P = 0.225) and fungal (P = 0.421) keratitis between the first half and second half of the study period. There was a significant increase in proportion of Gram-positive isolates (P = 0.015) [353/758 (46.6%) vs. 772/1482 (52.1%)] and decrease in proportion of Gram-negative organisms (P = 0.044) [88/758 (11.6%) vs. 131/1482 (8.8%)] in the recent years. In-vitro antibiotic susceptibility testing showed decrease in susceptibility to moxifloxacin for Pseudomonas spp. (P = 0.016) in recent years. Conclusion: Prevalence of fungal and bacterial keratitis has remained unchanged over the years. This study shows a significant increase in Gram-positive bacterial infection and decrease in Gram-negative bacterial infection of the cornea in the recent years

Coexistence of herpes simplex virus infection in microsporidial stromal keratitis associated with granulomatous inflammation

Background: Microsporidial stromal keratitis poses several diagnostic challenges. Patients may present with corneal ulceration, marked stromal thinning, or even as a quite corneal scar. The presentation of microsporidial stromal keratitis commonly mimics viral keratitis. Microbiology scrapings are usually helpful; however, scraping and culture-negative cases pose a significant diagnostic dilemma. Histopathological examination is diagnostic but shows varying degree of inflammation, predominantly composed of polymorphonuclear leukocytes. Granulomatous inflammation, in microsporidial stromal keratitis, is never well described, and the authors in this article aim to describe the presence of granulomatous inflammation in microsporidial stromal keratitis, in patients with associated herpes simplex virus (HSV) keratitis. Methods: This was a retrospective and observational study conducted at a tertiary eye care center. Results: Of 263 patients who underwent therapeutic penetrating keratoplasty for infectious keratitis, during 2011–2013, seven patients were diagnosed as microsporidial stromal keratitis. Microsporidial spores could be demonstrated on microbiological scrapings in 5/7 (71%) of cases, but identified on histopathological examination and also confirmed on polymerase chain reaction (PCR) for microsporidium in 100% of cases. There was evidence of diffuse stromal necrosis with markedly severe degree of polymorphonuclear leukocytic infiltrates, with granulomatous inflammation in 42% of cases. Interestingly, these were positive for HSV-1 DNA on PCR. Review of medical records revealed much severe clinical presentations in patients with granulomatous inflammation, in comparison to cases without granulomatous inflammation. Conclusions: The authors hereby recommend that severe clinical presentation in patients with microsporidial stromal keratitis, markedly dense polymorphonuclear leukocytic infiltrates or the presence of granulomatous inflammation on the histopathological examination, should be investigated further for the presence of HSV-1 DNA for better patient management and good visual outcome

Fractal behavior of surface oxide crack patterns on AISI 4140 high-strength low-alloy steel exposed to the simulated offshore environment

Wear and corrosion are surface-dependent degradation phenomena pertinent to the hostile environment existing in deep-sea oil and gas wells containing aggressive chemical species such as chloride/bromide salts, organic acids, carbon dioxide, and hydrogen sulfide,etc. Apart from the identification of the potential failures of alloys that can occur on a large and devastating scale by its interaction with these deleterious species, it is also essential to comprehend the nature and character, particularly the cracking pattern of the surface oxides formed on alloys undergoing corrosion in a particular environment. This article uses fractal geometry to study the branching of the surface oxide crack patterns in AISI 4140 high-strength low-alloy steel after exposure in a simulated offshore corrosive environment containing aqueous 3.5 wt.% sodium chloride solution. The fractal geometry was evaluated using the box-count technique in three different electrolytic test conditions: Electrochemical Anodic Polarization, Electrochemical Cathodic Polarization, and Immersion Corrosion for 24 h. Our results showed that the magnitude of fractal dimension is highest during immersion corrosion for 24 h and lowest during anodic polarization. Fractals can provide complementary quantifiable information about the surface geometries and fracture crack patterns from macrostructural to microstructural length scales by image analysis. This approach can be leveraged by emerging technologies like Artificial Intelligence (AI), Machine Learning (ML) and Computer Vision (CV), in structural health monitoring of alloys used in exotic and challenging conditions

Natamycin in the treatment of keratomycosis: Correlation of treatment outcome and in vitro susceptibility of fungal isolates

In this study, 60 fungal isolates from 60 patients with fungal keratitis were tested in vitro for their susceptibility to natamycin and the mean minimum inhibitory concentrations of natamycin (MICn) were correlated with clinical outcome. The mean MICn for various groups of fungi from patients with either early (<10 days) or late (≥10 days) presentation was correlated with the outcome. Aspergillus flavus showed resistance to natamycin with a high mean MICn (>16 μg/ml). While the clinical response in all patients with early A. flavus keratitis was good it was poor in late cases (5/8 patients, 62.5%). Fusarium species, Acremonium species and dematiaceous fungi were sensitive with low mean MICn (Fusarium: 5.7-7.2 μg/ml, Acremonium: 5.7-6.8 μg/ml, dematiaceous: (1.6-4 μg/ml). However, 46.6% (7/15) patients in Fusarium and 57.1% (4/7) in Acremonium group needed keratoplasty. We conclude that despite susceptibility of most fungal species causing keratitis to natamycin, the treatment outcome is poor in advanced fungal keratitis

Demographic profile and clinical characteristics of Fuchs' endothelial corneal dystrophy in a tertiary eye care center

Purpose: This study was performed to determine the demographic profile and clinical characteristics in patients with Fuchs' endothelial corneal dystrophy (FECD) reporting to a tertiary eye care center in India. It is a retrospective, single-center, observational study. Methods: The study included 280 patients (559 eyes) diagnosed with FECD presenting between January 2013 and December 2020. The data was collected from the electronic medical record system of the institute. Patient data included demographic features, clinical characteristics, investigations, and surgical interventions. Results: The mean age of the patients was 62 years. Late-onset FECD (95.7%) was more common than early-onset FECD (4.3%). Male: female ratio for late-onset FECD and early-onset FECD was 1:1.65 and 3:1, respectively. More than one-third of the patients had associated systemic history. Preexisting ocular diseases were seen in 5.9% of eyes. Blurring of vision was seen in 383 eyes (68.5%), 13 eyes (2.1%) had glare, and 163 eyes (29.2%) were asymptomatic. A total of 113 surgical interventions were done in 108 eyes (including repeat transplants). Only cataract surgery was done in 40 (7.2%) eyes, whereas penetrating keratoplasty, Descemet stripping endothelial keratoplasty, and Descemet membrane endothelial keratoplasty without or with cataract surgery (sequential or triple procedure) were done in 12 (2.1%), 47 (8.4%), and 14 (2.5%) eyes, respectively. Conclusion: Patients with FECD present mostly during the sixth decade. Posterior lamellar keratoplasty is the most common transplant procedure being performed on FECD patients

Mast Cells Initiate the Recruitment of Neutrophils Following Ocular Surface Injury

Purpose The purpose of this study was to investigate the contribution of mast cells to early neutrophil recruitment during ocular inflammation. Methods: In a murine model of corneal injury, the epithelium and anterior stroma were removed using a handheld motor brush. Cromolyn sodium (2% in PBS) eye drops were administered topically for mast cell inhibition. In vitro, bone marrow–derived mast cells were cultured alone or with corneal tissue. The frequencies of CD45+ inflammatory cells, CD11b+Ly6G+ neutrophils, and ckit+FcεR1+ mast cells in the cornea were assessed by flow cytometry. mRNA expression of CXCL2 was evaluated by real-time PCR and protein expression by ELISA. β-Hexosaminidase assays were performed to gauge mast cell activation. Results: Neutrophil infiltration of the cornea was observed within 1 hour of injury, with neutrophil frequencies increasing over subsequent hours. Concurrent expansion of mast cell frequencies at the cornea were observed, with mast cell activation (assessed by β-hexosaminidase levels) peaking at 6 hours after injury. Evaluation of CXCL2 mRNA and protein expression levels demonstrated augmented expression by injured corneal tissue relative to naïve corneal tissue. Mast cells were observed to constitutively express CXCL2, with significantly higher expression of CXCL2 protein compared with naïve corneal tissue. Culture with harvested injured corneas further amplified CXCL2 expression by mast cells. In vivo, mast cell inhibition was observed to decrease CXCL2 expression, limit early neutrophil infiltration, and reduce inflammatory cytokine expression by the cornea. Conclusions: Our data suggest that mast cell activation after corneal injury amplifies their secretion of CXCL2 and promotes the initiation of early neutrophil recruitment