117 results match your criteria: "National Institute of Laser Enhanced Science[Affiliation]"

The current study proposes a novel optical approach based on an adaptive optics (AO) system to enhance the fluorescence intensity in the laser-induced fluorescence (LIF) technique. The proposed method, wavefront-enhanced LIF (WELIF), relies mainly on compensating for the aberrations arising from the excitation-laser wavefront. The AO system consists of an active correction element (deformable mirror (DM)) integrated with a Shack-Hartmann wavefront sensor (SHWFS).

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Reflection-enhanced laser-induced fluorescence spectroscopy to improve the analytical sensitivity in liquids.

Spectrochim Acta A Mol Biomol Spectrosc

March 2023

Cairo University, Laser Applications in Metrology, Photochemistry and Agriculture Dept., National Institute of Laser Enhanced Science, Egypt.

The current work demonstrates a novel approach to enhancing the analytical sensitivity of the laser-induced fluorescence (LIF) technique in liquids. An increase in the fluorescence spectral band intensity of about sixfold compared to the conventional LIF has been achieved. Such betterment has been accomplished by having the fluorophore liquid in a cuvette having a reflecting mirror-like side facing the exciting incident laser beam.

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Upstream crude oil production equipment is always exposed to destruction damagingly which is caused by sulfate-reducing bacterium (SRB) activities that produce HS gas, which leads to increased metal corrosion (bio-fouling) rates and inflicts effective infrastructure damage. Hence, oil and gas reservoirs must be injected with biocides and inhibitors which still offer the foremost protection against harmful microbial activity. However, because of the economic and environmental risks associated with biocides, the oil and gas sectors improve better methods for their usage.

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Background: As a promising strategy to overcome the therapeutic disadvantages of 6-mercaptopurine (6MP), we proposed the encapsulation of 6MP in chitosan nanoparticles (CNPs) to form the 6MP-CNPs complexes. The encapsulation was followed by the loading of complexes on gold nanoparticles (AuNPs) to generate a novel 6MP-CNPs-AuNPs nanocomposite to facilitate the chemo-photothermal therapeutic effect.

Methods: CNPs were produced based on the ionic gelation method of tripolyphosphate (TPP).

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Background: The difficulty of achieving targeted drug delivery following administration of presently marketed anticancer therapeutics is still a concern. Metallic nanoparticles (NPs) appear to be promising in this regard. The present study focused on the use of gold nanoparticles (AuNPs) as a drug carrier for anticancer Doxorubicin (DOX) forming DOX-AuNPs nanocomposite.

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Enhanced photothermal heating and combination therapy of gold nanoparticles on a breast cell model.

BMC Chem

September 2022

Pharmacology Unit, Cancer Biology Department, National Cancer Institute (NCI), Cairo University, Giza, Egypt.

Multi-drug resistance (MDR) in addition to the damage to non-malignant normal cells are the most difficult in cancer treatment. Drug delivery and Plasmonic photothermal therapy based on the use of resonant metallic nanoparticles have developed as promising techniques to destroy cancer cells selectively. In the present work, gold nanoparticles (AuNPs) were synthesized using trisodium citrate.

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Background: Keratoconus (KC) is degenerative corneal disorder, with central and paracentral thinning and corneal ectasia. For KC progressive cases, primary treatment included corneal collagen cross linking (CXL) to stabilize coning and intracorneal rings segment (ICRS) to correct visual acuity.

Aim: The aim of the study is to assess efficacy and safety of ICRS and CXL on one session (Simultaneous) or two sessions (sequential) with maximum of 1 month apart.

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With the increase of the contagiousness rates of Coronavirus disease (COVID-19), new strategies are needed to halt virus spread. Blocking virus entry by capturing its spike (S) protein is one of the effective approaches that could help in eliminating or reducing transmission rate of viruses. Herein, we aim to develop a nanofiber-based filter for protective face masks, composed of polyacrylonitrile (PAN) nanofibers (NFs)-loaded with Angiotensin Converting Enzyme-2 (ACE-2) for capturing the spike protein of severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2) and blocking its entry.

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ZnO-NPs loaded polyvinylidene fluoride (PVDF) composite nanofibers were fabricated by electrospinning and optimized using different concentrations (0, 2, and 5 wt %) of ZnO-NPs. Characterization techniques, for example, FTIR, SEM, XRD, and tensile strength analysis were performed to analyze the composite nanofibers. Molecular docking calculations were performed to evaluate the binding affinity of PVDF and ZnO@PVDF against the hexon protein of adenovirus (PDB ID: 6CGV).

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Hyperoxygenation is linked to numerous effects in a variety of organ systems. It can cause tissue damage by generating reactive oxygen species (ROS), increasing oxidative stress, and inducing cell death by apoptosis. The present study aimed to evaluate the effects of low-level laser therapy on the retina in response to acute hyperoxia in animals.

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A straightforward and simple method has been proposed in the current work to improve the signal-to-noise ratio of the LIBS spectrum of transparent samples. The idea is to benefit from a highly polished metallic reflector in direct contact with the rear surface of the transparent target. Copper and silver metals have been used as reflectors for the focused laser beam and force it to pass through the plasma plume induced initially onto the front surface of the target.

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This manuscript includes some photophysical parameters and some optical properties such as absorption and emission spectra of the (E, E)-2,5-bis (3,4-dimethoxystyryl) pyrazine (BDP) by applying sol-gel and copolymer matrices. The BDP molecular structure is incorporated in sol-gel matrix and copolymer of methyl methacrylate (MMA) and 2-hydroxyethyl methacrylate (HEMA). In case of sol-gel matrix, the BDP molecular structure has higher quantum yield in addition to photostability maxima.

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Low-Level Laser Therapy with 670 nm Alleviates Diabetic Retinopathy in an Experimental Model.

J Curr Ophthalmol

July 2021

Department of Medical Application of Laser, Ophthalmic Unit, National Institute of Laser Enhanced Science, Cairo University, Giza, Egypt.

Purpose: To evaluate the effects of low-level laser therapy (LLLT) on the retina with diabetic retinopathy (DR).

Methods: Eight Wistar rats were used as a control group, and 64 rats were injected intraperitoneally with 55 mg/kg of streptozotocin to induce diabetes and served as a diabetic group. After the establishment of the DR, the rats were separated into (a) 32 rats with DR; did not receive any treatment, (b) 32 rats with DR were exposed to 670 nm LLLT for 6 successive weeks (2 sessions/week).

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Chlorophyll, the essential green pigment in plants, is considered a promising natural photosensitizer (PS) for photodynamic therapy (PDT). However, it suffers from lower stability in the physiological conditions that depress its efficacy in the PDT. The combination of nanotechnology and PDT is becoming a promising approach to combat tumors.

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Background: Diabetes mellitus (DM) is a metabolic disorder resulting from hyperglycemia. Hyperglycemia contributes to oxidative stress, and the release of advanced glycation end products (AGEs) further promotes disease pathogenesis. Uncontrolled diabetes reflects great oral complications and affects human oral health.

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Significant improvement of the catalytic activity of palladium-based catalysts toward carbon monoxide (CO) oxidation reaction has been achieved through alloying and using different support materials. This work demonstrates the promoting effects of the nanointerface and the morphological features of the support on the CO oxidation reaction using a Pd-Cu/TiO catalyst. Pd-Cu catalysts supported on TiO were synthesized with wet chemical approaches and their catalytic activities for CO oxidation reaction were evaluated.

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Pesticides are chemicals used to control pests, such as aquatic weeds, insects, aquatic snails, and plant diseases. They are extensively used in forestry, agriculture, veterinary practices, and of great public health importance. Pesticides can be categorized according to their use into three major types (namely insecticides, herbicides, and fungicides).

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CO elimination through oxidation over highly active and cost-effective catalysts is a way forward for many processes of industrial and environmental importance. In this study, doped CeO with transition metals (TM = Cu, Co, Mn, Fe, Ni, Zr, and Zn) at a level of 20 at. % was tested for CO oxidation.

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Quantitative measurement of nanoscale surface roughness of articular cartilage tissue is significant to assess the surface topography for early treatment of osteoarthritis, the most common joint disease worldwide. Since it was not established by clinical diagnostic tools, the current studies have been suggesting the use of alternative diagnostic tools using pre-clinical methods. This study aims to measure the nanoscale surface roughness of articular cartilage tissue utilizing biospeckle which is used as a non-destructive and non-contact optical imaging technique.

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In the present work, nanoparticle-enhanced laser-induced breakdown spectroscopy was used to analyze an aluminum alloy. Although LIBS has numerous advantages, it suffers from low sensitivity and low detection limits compared to other spectrochemical analytical methods. However, using gold nanoparticles helps to overcome such drawbacks and enhances the LIBS sensitivity in analyzing aluminum alloy in the current work.

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Photobiomodulation of avian embryos by red laser.

Lasers Med Sci

August 2021

The National Institute of Laser Enhanced Science, Cairo University, Giza, Egypt.

The current research focuses on the effect of variable doses of red laser on the chick embryonic development. He-Ne laser of 632-nm wavelength was used as an irradiation source in the first 48 h post-laying of chicken eggs. We have used five different doses: 2, 1, 0.

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Probiotic lactic acid bacteria are crucial producers of fermented dairy products that are popular functional foods in many countries. The health benefits of probiotic bacteria are mainly attributed to their effective bioactive metabolites. The quality of fermented milk is mainly dependent on the bacterial strain used in the fermentation process.

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Exploring optical spectroscopic techniques and nanomaterials for virus detection.

Saudi J Biol Sci

January 2021

Council for Scientific and Industrial Research (CSIR), National Laser Centre, P.O. Box 395, Pretoria 0001, South Africa.

Viral infections pose significant health challenges globally by affecting millions of people worldwide and consequently resulting in a negative impact on both socioeconomic development and health. Corona virus disease 2019 (COVID-19) is a clear example of how a virus can have a global impact in the society and has demonstrated the limitations of detection and diagnostic capabilities globally. Another virus which has posed serious threats to world health is the human immunodeficiency virus (HIV) which is a lentivirus of the retroviridae family responsible for causing acquired immunodeficiency syndrome (AIDS).

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Spectroscopic and photostability study of water-soluble hypericin encapsulated with polyvinylpyrrolidone.

Biophys Chem

November 2020

National Institute of Laser Enhanced Science, Cairo University, Giza 12613, Egypt; Egypt Nanotechnology Center (EGNC), Cairo University, El-Sheikh Zayed, 12588, Egypt. Electronic address:

Hypericin has gained great attention as a powerful photosensitizing and fluorescent agent for photodynamic therapy (PDT) and fluorescence diagnosis (FD) of cancer. However, native hypericin is hydrophobic and nearly insoluble in aqueous media which hinders its photobiological activity. Herein, we demonstrate the encapsulation of hypericin and polyvinylpyrrolidone (hypericin@PVP) as an attractive class of water-soluble formula of hypericin with improved absorption and emission characteristics in water.

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The current study designed to evaluate the effect of oligosaccharide supplemented diets on growth performance, histomorphometric changes, economic efficiency and genetic expression of some growth and immunity-relative genes. One hundred and twenty weaned male rabbits, six weeks of age of two breeds (NZW and APPRI) were randomly allocated into six equal groups; the first supplemented with 0.3% Mannan-oligosaccharide (MOS), the second supplemented with 0.

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