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61.
A mathematical model is developed and validated to predict the depth of cut in potato tuber slabs as a function of laser power and travel speed. The model considers laser processing parameters such as input power, spot size and exposure time as well as the properties of the material being cut such as specific heat, thermal conductivity, surface reflectance, etc. The model also considers the phase change of water in potato and the ignition temperature of the solid portion. The composition of the potato tuber is assumed to be of water and solid. The model also assumes that the ablation process is accomplished through ejection of liquid water, debris and water vapour, and combustion of solid. A CO2 laser operating in c.w. mode was chosen for the experimental work because water absorbs laser energy highly at 10.6 μm, and CO2 laser units with relatively high output power are available. Slabs of potato tuber were chosen to be laser processed since potato contains high moisture and large amounts of relatively homogeneous tissue. The results of the preliminary calculations and experiments concluded that the model is able to predict the depth of cut in potato tuber parenchyma when subjected to a CO2 laser beam. 相似文献
62.
El-Farrash MA Aly HH Watashi K Hijikata M Egawa H Shimotohno K 《Microbiology and immunology》2007,51(1):127-133
Hepatitis C virus (HCV) is a major cause of liver cirrhosis and hepatocellular carcinoma worldwide. We previously reported that cyclosporin A (CsA) inhibits HCV-1b replication. However, its inhibition of JFH-1 (HCV-2a) was much less. Since HCV genotype clearly affects the in vitro and in vivo response to anti-viral therapy, we wished to examine the effect of CsA and its non-immunosuppressive derivative NIM811 on HCV genotype 4a replication. We first established an in vitro system supporting HCV-4a infection and replication using immortalized human hepatocytes, HuS-E7/DN24 (HuS) cells, and these cells were infected with sera obtained from Egyptian patients with chronic HCV-4a infection. HuS cells supported more robust HCV-4a replication than both HuH-7.5 and PH5CH8 cells, and HCV-4a infection and replication were completely inhibited by 3 mug/ml CsA and 0.5 mug/ml NIM811. Thus, HuS cells are a good model system supporting the infection and high-level replication of HCV-4a, and both CsA and NIM811 effectively inhibit HCV-4a replication in this system. 相似文献
63.
Narzt Marie-Sophie Kremslehner Christopher Golabi Bahar Nagelreiter Ionela-Mariana Malikovic Jovana Hussein Ahmed M. Plasenzotti Roberto Korz Volker Lubec Gert Gruber Florian Lubec Jana 《Amino acids》2022,54(9):1311-1326
Amino Acids - Loss of cognitive function is a typical consequence of aging in humans and rodents. The extent of decline in spatial memory performance of rats, assessed by a hole-board test, reaches... 相似文献
64.
Hyper-pigmentation of the skin is a common problem that is prevalent in middle aged and elderly people. It is caused by over production of melanin. Tyrosinase is known to be the key enzyme in melanin production. Ethanolic extract of Greyia flanaganii leaves showed significant (P < 0.05) antityrosinase activity exhibiting the IC50 of 32.62 μg/ml. The total extract was further investigated for its toxicity and effect on melanin production by melanocytes cells, and showed significant inhibition (P < 0.05) (20%) of melanin production at 6.25 μg/ml and low levels of cytotoxicity (IC50 < 400 μg/ml). The amount of antioxidants necessary to decrease the initial DPPH absorbance by 50% (EC50) by the total ethanolic extract was found to be 22.01 μg/ml. The effect of G. flanaganii against acne causing bacteria, Propionibacterium acnes, was investigated using microdilution assay. The MIC of the extract of G. flanaganii was found to be 250 μg/ml. Bioassay-guided fractionation led to the isolation of (3S)-4-hydroxyphenethyl 3-hydroxy-5-phenylpentanoate (1), 2′,4′,6′-trihydroxydihydrochalcone (2), 2′,6′,4-trihydroxy-4′-methoxydihydrochalcone (3), 2′,6′-dihydroxy-4′-methoxydihydrochalcone (4), 5,7-dihydroxyflavanone [(2S)-pinocembrin] (5), 2′,6′-dihydroxy-4′,4-dimethoxy dihydrochalcone (6) and (2R,3R)-3,5,7-trihydroxy-3-O-acetylflavanone (7). The isolated compounds were tested for their antioxidant, cytotoxicity, tyrosinase inhibition and antibacterial activities. Compound 2 exhibited significant (P < 0.05) antityrosinase activity exhibiting the IC50 of 69.15 μM. The isolated compounds showed low toxicity of the cells with reduction of melanin content of the cells. All compounds tested showed good radical scavenging activity. These data indicates that G. flanaganii extract and its isolated phenolic constituents could be possible skin lightening agents. 相似文献
65.
Simplified method for the collection, storage, and comet assay analysis of DNA damage in whole blood
Al-Salmani K Abbas HH Schulpen S Karbaschi M Abdalla I Bowman KJ So KK Evans MD Jones GD Godschalk RW Cooke MS 《Free radical biology & medicine》2011,51(3):719-725
Single-cell gel electrophoresis (comet assay) is one of the most common methods used to measure oxidatively damaged DNA in peripheral blood mononuclear cells (PBMC), as a biomarker of oxidative stress in vivo. However, storage, extraction, and assay workup of blood samples are associated with a risk of artifactual formation of damage. Previous reports using this approach to study DNA damage in PBMC have, for the most part, required the isolation of PBMC before immediate analysis or freezing in cryopreservative. This is very time-consuming and a significant drain on human resources. Here, we report the successful storage of whole blood in ~ 250 μl volumes, at − 80 °C, without cryopreservative, for up to 1 month without artifactual formation of DNA damage. Furthermore, this blood is amenable for direct use in both the alkaline and the enzyme-modified comet assay, without the need for prior isolation of PBMC. In contrast, storage of larger volumes (e.g., 5 ml) of whole blood leads to an increase in damage with longer term storage even at − 80 °C, unless a cryopreservative is present. Our “small volume” approach may be suitable for archived blood samples, facilitating analysis of biobanks when prior isolation of PBMC has not been performed. 相似文献
66.
Vella P Hussein WM Leung EW Clayton D Ollis DL Mitić N Schenk G McGeary RP 《Bioorganic & medicinal chemistry letters》2011,21(11):3282-3285
The emergence of metallo-β-lactamases (MBLs) capable of hydrolysing a broad spectrum of β-lactam antibiotics is particularly concerning for the future treatment of bacterial infections. This work describes the discovery of lead compounds for the development of new inhibitors using a competitive colorimetric assay based on the chromogenic cephalosporin CENTA, and a 500 compound Maybridge™ library suitable for fragment-based screening. The interactions between identified inhibitory fragments and the active site of the MBL from Klebsiella pneumoniae and Pseudomonas aeruginosa were probed by in silico docking studies. 相似文献
67.
Mohamed A Bedaiwy Mahmoud A Abdelaleem Mostafa Hussein Noha Mousa Lisa N Brunengraber Robert F Casper 《Reproductive biology and endocrinology : RB&E》2011,9(1):1-6
Background
To investigate the effect of pelvic floor Neuromuscular Electrical Stimulation (NMES) Therapy in improving endometrial thickness in women with thin endometrium.Methods
41 patients undergoing assisted reproduction with a thin endometrium (less than or equal to7 mm) were recruited and advised to go for a pelvic floor NMES in frozen-thawed embryo transfer cycle. PHENIX Neuromuscular Electrical Stimulation Therapy System was used according to the manufacturer's recommended protocol for 20 to 30 minutes of intermittent vaginal electrical stimulation on the treatment days.Results
A total of 20 and 21 were included in the NMES and non-NMES groups respectively. 12 out of 20 (60%) patients developed endometrial thickness equal to or more than 8 mm after the NMES therapy, which was the primary outcome. The mean thickness of endometrium before and after was respectively 5.60 mm (0.82 mm) and 7.93 mm (1.42 mm) in the therapy group versus 5.50 mm (1.00) and 6.78 mm (0.47) in the control group; the difference was statistically significant (P = 0.002). There was higher pregnancy rate in the NMES group (42% versus 35%) but the difference was not statistically significant.Conclusion
Neuromuscular Electrical stimulation therapy may be effective for the patients with a thin endometrium. Further studies are needed to investigate its effectiveness. 相似文献68.
69.
Hussein YR Bandyopadhyay S Semaan A Ahmed Q Albashiti B Jazaerly T Nahleh Z Ali-Fehmi R 《Translational oncology》2011,4(6):321-327
INTRODUCTION: Glucose transporter 1 (Glut-1) is a facilitative glucose transporter expressed in many cancers including breast cancer. Basal-like breast cancer (BLBC) is a high-risk disease associated with poor prognosis and lacks the benefit of targeted therapy. The aim of this study was to characterize the immunohistochemical (IHC) expression of Glut-1 in patients with BLBC compared with non-BLBC. MATERIALS AND METHODS: We identified 523 cases of invasive breast carcinoma from our database. The clinicopathologic findings and the biologic markers including estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (Her2) status were reviewed. IHC stains for cytokeratin 5/6 (CK5/6), epidermal growth factor receptor (EGFR), p53, and Glut-1 were performed on tissue microarray using standard procedures. BLBC was defined as ER-,PR-, Her2-, and CK5/6+ and/or EGFR+. RESULTS: Of informative cases, 14.7% were categorized as BLBC versus 85.3% as non-BLBC. Glut-1 was expressed in 42 (76.4%) of 55 BLBCs, whereas only 55 (23.8%) of 231 non-BLBCs showed immunostaining for Glut-1 (P < .001). Overall, Glut-1 expression was significantly associated with high histologic grade, ER negativity, PR negativity, CK5/6 positivity, EGFR expression, and high p53 expression (P < .001). However, there was no correlation between Glut-1 immunostaining and patient's outcome. CONCLUSIONS: Our results show that Glut-1 is significantly associated with BLBC and might be a potential therapeutic target for this aggressive subgroup of breast cancer, and this warrants further investigations. 相似文献
70.