128 research outputs found

    Evaluation of thermally stable phosphor screens for application in laser diode excited high brightness white light modules

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    A study on the preparation of thermally stable phosphor targets based on yttrium aluminum garnet doped with cerium (YAG:Ce) when excited by a high power laser diode is described. The luminous flux, chromaticity and radial spectral flux of the targets along with their thermal stability have been determined when exposed to laser powers of up to 5000 mW. This report presents successful high brightness light sources with adjustable emission properties achieved by utilizing thermally stable phosphor targets excited by high power laser diodes.Brunel University London, No. EP/K504208/

    Decreased expression of heat shock protein HSP90α after exposure to doxorubicin in breast cancer cell lines (MCF-7 and MDA-MB-231)

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    Background and purpose: Incidence of breast cancer is increasing day by day. Scientists are interested in the effects of inhibition of breast cancer cell on treatment of this cancer. The aim of this study was to determine IC50 of doxorubicin in 24 hours on cell lines MCF-7 and MDA-MB-231 and the expression of heat shock protein HSP90α as a factor in the cell before and after 24 hours exposure to doxorubicin in both breast cancer cell lines. Materials and methods: A descriptive interventional study was done in two cell lines MCF-7 and MDA-MB-231` after 24 hours exposure to doxorubicin. Sensitivity of cells to doxorubicin was determined using MTT Assay in excel software. HSP90α heat shock protein expression were qualitatively compared in both cell lines before and after exposure to doxorubicin using immunofluorescent techniques (Immunocytochemistry). Results: MTT Assay showed that IC50 value in MDA-MB-231 and MCF7 cells after 24 hours exposure to doxorubicin (the dose that kills 50% of cells) were 14.521 and 16.3315µM, respectively. Immunocytochemistry revealed that HSP90α protein expression in both cell lines after exposure to doxorubicin decreased compared to the control group. Conclusion: Cell density in cell lines (ER-) MDA-MB-231 and line MCF-7 (ER+) after exposure to doxorubicin and increasing the dose of medication, decreased indicating a dose dependent effect. Also, apoptosis occurred in both cell lines and expression of HSP90α decreased but MDA-MB-231 cells were found to be more sensitive. © 2017, Mazandaran University of Medical Sciences. All rights reserved

    The Effect of Platelet Rich Plasma Dressing on Healing Diabetic Foot Ulcers

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    Background: Some of the studies confirmed the effectiveness of platelet rich plasma (PRP) in the treatment of diabetic foot ulcers (DFU). However, these studies had small sample size and used different methods such as PRP gel or PRP injections. The results are also contraversial. Objectives: This study aimed to investigate the effect of PRP dressing on healing of DFUs. Patients and Methods: A randomized, controlled trial was conducted on 50 patients with DFUs referred to Kashan’s Shahid Beheshti hospital. Patients were randomly allocated to control (n = 25) and experimental (n = 25) groups. Data collection instrument consisted of two checklists; one for gathering demographic information and the other one included questions about ulcer characteristics and its treatment. After surgical debridement, ulcers depth and surface area were measured. Then, the ulcers of the control group were irrigated and dressed with sterile gauzes. However, in the intervention group, ulcers were dressed with sterile gauzes impregnated with PRP. Ulcers depth and surface area of all ulcers were measured on the days 0, 7, 14 and 21 after debridement. Independent-samples t-test, Mann–Whitney U and repeated measures analysis of variance were used to analyze data. Results: At baseline, the mean ulcer depth were 15.08 ± 10.43 and 19.08 ± 14.01 mm in the control and intervention groups, respectively (P = 0.26), which decreased to 13.03 ± 14.1 and 4.560 ± 5.76 after three weeks (P = 0.04). Moreover, the mean ulcer surface area were 14.17 ± 8.52 and 12.791 ± 14.86 mm2 in control and intervention groups respectively (P = 0.69), which decreased to 11.88 ± 13.65 and 2.68 ± 5.94 after three weeks (P = 0.03). Conclusions: PRP dressing could significantly decrease the depth and surface area of DFUs in a three-week period

    Mouse Lung Conditioned Medium Induces Short Term Erythropoiesis in Mouse Long Term Bone Marrow Culture System

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    Dexter-type long-term bone marrow culture is a myelopoietic culture system that allows maintenance of  mouse and human hematopoiesis in vitro over a period of several months. In mouse unperturbed long-term  bone marrow culture, erythropoiesis activity is limited to the production of immature erythroid progenitors  (BFU-E) from primitive hematopoietic stem cells. In this study the effects of mouse lung conditioned  medium (MLCM) as a source of myeloid growth factors, on long-term mouse bone marrow cultures was  studied. Numbers of cells in adherent and non-adherent layers of cultures were counted weekly and the  morphological appearances of mature cells that were produced in non-adherent layers were analyzed. In the  presence of MLCM, mature nonnucleated and hemoglobinized red blood cells were produced in the nonadherent  layers of the cultures.

    Ultrasound and Perforated Viscus; Dirty Fluid, Dirty Shadows, and Peritoneal Enhancement.

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    Early detection of free air in the peritoneal cavity is vital in diagnosis of life-threatening emergencies, and can play a significant role in expediting treatment. We present a series of cases in which bedside ultrasound (US) in the emergency department accurately identified evidence of free intra-peritoneal air and echogenic (dirty) free fluid consistent with a surgical final diagnosis of a perforated hollow viscus. In all patients with suspected perforated viscus, clinicians were able to accurately identify the signs of pneumoperitoneum including enhanced peritoneal stripe sign (EPSS), peritoneal stripe reverberations, and focal air collections associated with dirty shadowing or distal multiple reflections as ring down artifacts. In all cases, hollow viscus perforation was confirmed surgically. It seems that, performing US in patients with suspected perforated viscus can accurately identify presence of intra-peritoneal echogenic or dirty free fluid as well as evidence of free air, and may expedite patient management

    A benchmark activity on the fatigue life assessment of AlSi10Mg components manufactured by L-PBF

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    One of the challenges associated with additive manufacturing (AM) is the definition of an assessment route which considers the main process signatures of the AM process. To this end, this work presents a complete benchmark activity for the assessment of an AlSi10Mg component produced by a laser pow- der bed fusion process, aimed at advancing the understanding of the fatigue resistance of AM materials with particular focus on the comparison between the fatigue performances of small coupons and demon- strators. Four builds of AlSi10Mg specimen geometries were manufactured to: (i) determine the fatigue curves for both as-built and machined conditions; (ii) measure the fatigue crack growth rate; (iii) produce and test under fatigue a benchmark component used as a reference for the validation of the fatigue assessment procedure. Tools and concepts of flaw tolerance were then used to perform the fatigue assess- ment of the benchmark component and were shown to be successful in the life prediction. Results obtained from this wide database (related to internal defects and surface features) show that only a fracture-based fatigue assessment is able to provide precise life estimates consistent with material crack growth properties. Eventually, all the experimental results including specimens design, analysis of frac- ture surfaces and raw tests’ data will be made available in a database which can be accessed and used by the industrial and scientific communities to calibrate and validate alternative fatigue assessment proce- dures of AM parts

    Antifungal activity in vitro of aqueous and total flavnoids extracts of plant myrtus communis L. against two pathogenically important fungi, Saprolegnia and Fusarrium isolated from rainbow trout eggs

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    In the present study, the efficiency of the flavonoid and aqueous extracts of M. communis L. tree leaves, a recognized Iranian medicinal plant, were assessed in vitro on the growth of isolated fungi, Saprolegnia and Fusarrium using the agar disc and well diffusion methods in flat-bottom microplates in the presence of various extract concentrations. The isolated fungi were sampled from the fertilized eggs of rainbow trout fish incubation farms. The leaves were collected from the natural habitats of the province of Chaharmahal-o-Bakhtiary in the earlysummer and extrcation took place through maceration methods with water solvent as well as by flavonoid extraction methods with methanol solvent. During the succeeding trials, the antifungal effects of the flavonoid extracts (by the disk diffusion method) and the aqueous extracts (by the well diffusion method) against isolated Saprolegnia were revealed by MFC (Minimum Fatal Concentration) values 50 and 100 mg/ml, respectively. The only effect of the methanolic and aqueous extracts of M. communis leaves revealed the in vitro inhibiting effect on the growth of isolated Fusarium by MIC values 25 and 12.5 mg/ml, in disc diffusion and well diffusion methods, respectively. The antifungal effects obtained by the extracts had more effective aspects on isolated Saprolegnias in comparison to Fusariums. The results of the study indicate that M. communis could be considered as a potential candidate for designing effective antifungal extracts suitable for the treatment of the fish eggs fungal infections

    Effective removal of organic pollution by using sonochemical prepared LaFeO3 perovskite under visible light

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    In the present work, LaFeO3 perovskite was prepared via ultrasonic probe with power of 60 W and frequency of 18 KHz. LaFeO3 nanorods were formed when sonication time was 20 min. In this research, green materials including corn, starch, and rice were used to control the size, morphology, and purity of final products. As-prepared LaFeO3 nanostructures were used to purify water containing organic contaminants. LaFeO3 nanostructures prepared by using corn, starch, and rice showed higher photocatalytic activity compare to LaFeO3 nanostructures without natural capping agents. Using corn increased degradation efficiency by 65 under visible light. XRD results show that Fe2O3 appeared as an impurity when starch was used to prepare LaFeO3 nanostructures. This impurity significantly boosts the degradation efficiency under UV light. Fe2O3 under UV light act as co-absorbent and boost efficiency by 43. LaFeO3 nanostructures were characterized by XRD, EDX, SEM, CV, BET, TEM, DRS and FT-IR. © 2019 Elsevier B.V

    Production of recombinant CAMP – Sialidase protein and preparation of chitosan nanoparticles carrying this protein to be used as a candidate for vaccines targeting Propionibacterium acnes

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    BACKGROUND AND OBJECTIVE: Acne vulgaris is one of the most common skin diseases that imposes too much mental pressure and high costs on patients. The existing treatments have low efficacy and include antibiotics and anti-inflammatory drugs, which have many complications due to the chronic nature of the disease, especially at young age, including antibiotic resistance and allergic reactions. For this reason, one of the new therapeutic approaches is the use of a vaccine with the help of the bacterium or its components. The aim of this study is to produce nanoparticles carrying the recombinant CAMP – Sialidase protein as a new chimeric antigen to be used in acne vaccine. METHODS:To express the recombinant CAMP – Sialidase protein, E. coli BL21 DE3 was used as the host. Purification of protein was done through combined urea/imidazole method and using a nickel-nitroacetic acid column. The recombinant protein was confirmed using Western Blotting by Anti – Histidine Antibody. Then, the loaded nanoparticles were prepared by recombinant protein using ionic gelation technique and tripolyphosphate. Finally, the size and zeta potential of the nanoparticles were determined by the DLS device. FINDINGS: The recombinant CAMP – Sialidase protein was confirmed after expression and purification. The size and zeta potential of nanoparticles containing recombinant CAMP – Sialidase protein at a concentration of 0.6 mg / ml were determined to be 80 nm and +27 mV, respectively, using the DLS device. The loading rate of the protein in the nanoparticles was found to be 88%. CONCLUSION: The results show that the recombinant protein is expressed completely and is successfully encapsulated in the chitosan nanoparticles
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