20 research outputs found
Markers characterizing corneal damage during aging of rat
Aging is a biological phenomenon that involves an increase of oxidative stress associated with gradual degradation of the structure and function of the cornea. Gender differences and subsequent deterioration of cornea is an interesting topic, especially yet few data are available concerning the impact of age, especially on the corneal. One hundred male and female Wistar albino rats ages 3, 6, 18, 24, and 30 months (n=10 equal for male and female) were used. At the time interval, cornea were investigated by light and transmission electron microscopy (TEM), immunohistochemistry of caspase 3 (casp3), glial fibrillar acidic protein(GFAP) and CD45 and flow cytometry of DNA, bcl-2-like protein 4 (BAX), transforming growth factor beta (TGF-β) and Cd45 (lymphocyte common antigen). Light and TEM investigation revealed apparent deterioration of atrophy of corneal epithelium with vesicular vacuolar degeneration, hyalinization of stromal collagen fibrils and swelling and degeneration of the endothelial lining the descemet's membrane. There was apparent loss of keratocytes within corneal stroma. Immunohistochemistry of casp 3 and CD45 were markedly increased manifesting cell damage. GFAP showed apparent reduction of innervation of corneal stroma and endothelium layer. Flow cytometry of DNA, Bax and TGF revealed increased apoptic cell death of cornea of 30M-old rats. We concluded that aging contributed to an apparent increase of cellular damage of different corneal region associated with alterations of cell markers
MINERAL MAPPING USING CHANDRAYAAN-1 HYPERSPECTRAL (HYSI) DATA FROM MARE VAPORUM
The imaging spectroscopy offers an opportunity to map and discriminate different minerals on the lunar surface which further helps to understand the origin, evolution process, and the crustal composition on the surface of the moon. Compositional mapping of the lunar surface is considered as a standard approach for mineral mapping. This paper reports surface mineralogy of the lunar surface from Mare Vaporum using Chandrayaan-1 Hyperspectral remotely sensed data from HySi sensor. False color composite is created using different band shaping algorithms like band strength; band curve and band tilt parameters at crucial wavelength for spatial analysis. The Spectral analysis has been done by deriving reflectance spectra at varying locations from the area under study. The Study shows the mineral map with different categories of minerals which are high-Ca pyroxene and/or olivine and low Ca-pyroxene. However because of the limited spectral coverage of HySi, data at the longer wavelengths required to discriminate among different group of minerals
Strain Anisotropy Driven Spontaneous Formation of Nanoscrolls from Two-Dimensional Janus Layers
Two-dimensional Janus transition metal dichalcogenides (TMDs) have attracted
attention due to their emergent properties arising from broken mirror symmetry
and self-driven polarisation fields. While it has been proposed that their vdW
superlattices hold the key to achieving superior properties in piezoelectricity
and photovoltiacs, available synthesis has ultimately limited their
realisation. Here, we report the first packed vdW nanoscrolls made from Janus
TMDs through a simple one-drop solution technique. Our results, including
ab-initio simulations, show that the Bohr radius difference between the top
sulphur and the bottom selenium atoms within Janus M_Se^S (M=Mo, W) results in
a permanent compressive surface strain that acts as a nanoscroll formation
catalyst after small liquid interaction. Unlike classical 2D layers, the
surface strain in Janus TMDs can be engineered from compressive to tensile by
placing larger Bohr radius atoms on top (M_S^Se) to yield inverted C scrolls.
Detailed microscopy studies offer the first insights into their morphology and
readily formed Moir\'e lattices. In contrast, spectroscopy and FETs studies
establish their excitonic and device properties and highlight significant
differences compared to 2D flat Janus TMDs. These results introduce the first
polar Janus TMD nanoscrolls and introduce inherent strain-driven scrolling
dynamics as a catalyst to create superlattices
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Reaching the Excitonic Limit in 2D Janus Monolayers by In Situ Deterministic Growth.
Named after the two-faced Roman god of transitions, transition metal dichalcogenide (TMD) Janus monolayers have two different chalcogen surfaces, inherently breaking the out-of-plane mirror symmetry. The broken mirror symmetry and the resulting potential gradient lead to the emergence of quantum properties such as the Rashba effect and the formation of dipolar excitons. Experimental access to these quantum properties, however, hinges on the ability to produce high-quality 2D Janus monolayers. Here, these results introduce a holistic 2D Janus synthesis technique that allows real-time monitoring of the growth process. This prototype chamber integrates in situ spectroscopy, offering fundamental insights into the structural evolution and growth kinetics, that allow the evaluation and optimization of the quality of Janus monolayers. The versatility of this method is demonstrated by synthesizing and monitoring the conversion of SWSe, SNbSe, and SMoSe Janus monolayers. Deterministic conversion and real-time data collection further aid in conversion of exfoliated TMDs to Janus monolayers and unparalleled exciton linewidth values are reached, compared to the current best standard. The results offer an insight into the process kinetics and aid in the development of new Janus monolayers with high optical quality, which is much needed to access their exotic properties
Taylor spatial frame in the treatment of open tibial shaft fractures
<b>Background:</b> The Taylor spatial frame (TSF) is a modern multiplanar external fixator that combines the ease of application and computer accuracy in the reduction of fractures. A retrospective review of our prospective TSF database for the use of this device for treating open tibial fractures in pediatric, adolescent, and adult patients was carried out to determine the effectiveness and complications of TSF in the treatment of these fractures. <b> Materials and Methods:</b> Nineteen male patients with open tibial fractures were included. Of these fractures, 10 were Gustilo Type II, five were Gustilo Type IIIA (two had delayed primary closure and three had split thickness skin grafting), and four were Gustilo Type IIIB (all had rotational flaps). Twelve of our patients presented immediately to the emergency room, and the remaining seven cases presented at a mean of 3 months (range, 2.2-4.5 months) after the initial injury. The fractures were located in proximal third (n=1), proximal/middle junction (n=2), middle third (n=3), middle/distal junction (n=8), distal third (n=3), and segmental fractures (n=2). Patients were of an average age of 26 years (range, 6-45years). Mean duration of follow-up was 3.5 years. <b> Results:</b> All fractures healed over a mean of 25 weeks (range, 9-46 weeks). All were able to participate in the activities of daily living without any difficulty and most were involved in sports during the last follow-up. Postoperative complications included pin tract infection in 12 patients. <b>Conclusion:</b> The TSF is an effective definitive method of open tibial fracture care with the advantage of early mobilization, ease of soft tissue management through gradual fracture reduction, and the ability to postoperatively manipulate the fracture into excellent alignment
Effect of Gamma-Rays on the Growth and Penicillin Production of Penicillium chrysogenum
This study aimed to investigate the effects of different doses (25, 50, 75, 100, 125, 150, 200, 250, 500,
1000 and 2000 Gy) of gamma radiation on spore germination in Penicillium chrysogenum and on the
production and efficacy of penicillin in this fungus. A dose of 200 Gy of gamma radiation increased
spore germination by 70.2% after 20 hours of incubation compared to control cultures. It was also
found that penicillin yield increased by 95.2% at this dose of gamma radiation. The efficacy of penicillin
was remarkably enhanced, resulting in a 99.6% reduction in the total count of Staphylococcus aureus
treated with penicillin from irradiated P. chrysogenum compared with that of S. aureus treated with
commercially available and purified penicillin from nonirradiated fungi. The results obtained highlighted
the potential of this technology for production of penicillin
Unveiling biological activities of biosynthesized starch/silver-selenium nanocomposite using Cladosporium cladosporioides CBS 174.62
Abstract Background and objectives Microbial cells capability to tolerate the effect of various antimicrobial classes represent a major worldwide health concern. The flexible and multi-components nanocomposites have enhanced physicochemical characters with several improved properties. Thus, different biological activities of biosynthesized starch/silver-selenium nanocomposite (St/Ag-Se NC) were assessed. Methodology The St/Ag-Se NC was biosynthesized using Cladosporium cladosporioides CBS 174.62 (C. cladosporioides) strain. The shape and average particle size were investigated using scanning electron microscope (SEM) and high-resolution transmission electron microscope (HR-TEM), respectively. On the other hand, the St/Ag-Se NC effect on two cancer cell lines and red blood cells (RBCs) was evaluated and its hydrogen peroxide (H2O2) scavenging effect was assessed. Moreover, its effects on various microbial species in both planktonic and biofilm growth forms were examined. Results The St/Ag-Se NC was successfully biosynthesized with oval and spherical shape and a mean particle diameter of 67.87 nm as confirmed by the HR-TEM analysis. St/Ag-Se NC showed promising anticancer activity toward human colorectal carcinoma (HCT-116) and human breast cancer (MCF-7) cell lines where IC50 were 21.37 and 19.98 µg/ml, respectively. Similarly, little effect on RBCs was observed with low nanocomposite concentration. As well, the highest nanocomposite H2O2 scavenging activity (42.84%) was recorded at a concentration of 2 mg/ml. Additionally, Staphylococcus epidermidis (S. epidermidis) ATCC 12,228 and Candida albicans (C. albicans) ATCC 10,231 were the highly affected bacterial and fungal strains with minimum inhibitory concentrations (MICs) of 18.75 and 50 µg/ml, respectively. Moreover, the noticeable effect of St/Ag-Se NC on microbial biofilm was concentration dependent. A high biofilm suppression percentage, 87.5% and 68.05%, were recorded with S. epidermidis and Staphylococcus aureus (S. aureus) when exposed to 1 mg/ml and 0.5 mg/ml, respectively. Conclusion The biosynthesized St/Ag-Se NC showed excellent antioxidant activity, haemocompatibility, and anti-proliferative effect at low concentrations. Also, it exhibited promising antimicrobial and antibiofilm activities