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排序方式: 共有1129条查询结果,搜索用时 15 毫秒
101.
Hassan Ouachtak Anouar El Guerdaoui Rachid El Haouti Redouane Haounati Hamza Ighnih Yahya Toubi Fadi Alakhras Rabia Rehman Naima Hafid Abdelaziz Ait Addi Mohamed Labd Taha 《RSC advances》2023,13(8):5027
In recent years, the combination of experimental and theoretical study to explain adsorbate/adsorbent interactions has attracted the attention of researchers. In this context, this work aims to study the adsorption of two cationic dyes, namely methylene blue (MB) and crystal violet (CV), on a green adsorbent Montmorillonite@activated carbon (Mt@AC) composite and to explain the adsorption behavior of each dye by the molecular dynamics (MD) simulation method. The eco-friendly nanocomposite Mt@AC is synthesized and characterized by the analysis methods: XRD, FTIR, BET, TGA/DTA, SEM-EDS, EDS-mapping and zeta potential. The experimental results of adsorption equilibrium show that the adsorption of the two dyes is well suited to the Langmuir adsorption model. The maximum adsorption capacity of the two dyes reaches 801.7 mg g−1 for methylene blue and 1110.8 mg g−1 for crystal violet. The experimental kinetics data fit well with a pseudo-first order kinetic model for the two dyes with coefficient of determination R2 close to unity, non-linear chi-square χ2 close to zero and lower Root Mean Square Error RMSE (R2 → 1 and χ2 → 0, RMSE lower). Molecular dynamic simulations are run to gain insights on the adsorption process. According to the RDF analysis and interaction energy calculations, the obtained results reveal a better affinity of the CV molecule with both the AC sheet and montmorillonite framework as compared with MB. This finding suggests that CV is adsorbed to a larger extent onto the nanocomposite material which is in good agreement with the adsorption isothermal experiment observations.Eco-friendly Mt@AC composite material was prepared and characterized for removal of cationic dyes from aqueous solutions. The Molecular dynamics simulation was applied for evaluating the adsorption mechanisms. 相似文献
102.
Sehirli O Ozel Y Dulundu E Topaloglu U Ercan F Sener G 《Phytotherapy research : PTR》2008,22(1):43-48
This study was designed to determine the possible protective effect of grape seed extract (GSE), a widely used antioxidant dietary supplement, on hepatic ischemia/reperfusion (I/R) injury. Wistar albino rats were subjected to 45 min of hepatic ischemia, followed by a 60 min reperfusion period. GSE was administered in a dose of 50 mg/kg/day orally for 15 days before I/R injury and repeated before the reperfusion period. Liver samples were taken for histological examination or determination of hepatic malondialdehyde (MDA), glutathione (GSH) and myeloperoxidase (MPO) activity. Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were determined to assess liver functions. Lactate dehydrogenase (LDH) and cytokines (TNF-alpha and IL-1 beta) were also assayed in serum samples for the evaluation of generalized tissue damage. Ischemia/reperfusion caused a significant decrease in hepatic GSH, and significant increases in MDA level, and MPO activity. Serum AST and ALT levels, as well as LDH activity and plasma TNF-alpha and IL-1beta levels were also elevated in the I/R group. Treatment with GSE reversed all these biochemical parameters as well as histological alterations induced by I/R. In conclusion, GSE reduced I/R-induced organ injury through its ability to balance the oxidant-antioxidant status, to inhibit neutrophil infiltration and to regulate the release of inflammatory mediators. 相似文献
103.
Bilgen D?lek Serpil Eraslan Sevim Ero?lu Belgin Eroglu Kesim Turgut Ulutin Altan Yal?iner Yahya R Laleli Nermin G?zükirmizi 《Clinical and applied thrombosis/hemostasis》2007,13(4):435-438
Inherited gene disorders related to the hemostatic system have been documented as risk factors for thrombosis. The roles of factor V Hong Kong (FV Hong Kong), factor V Leiden (FV Leiden), factor II G20210A (FII G20210A), methylenetetrahydrofolate reductase (MTHFR) C677T, and MTHFR A1298C mutations in Turkish patients with thrombosis (270 patients) compared with healthy controls (114 subjects) were evaluated. Polymerase chain reaction-based restriction enzyme analysis was carried out to screen these mutations, and single-strand conformation analysis was established to identify variations using the primers selected for restriction enzyme analysis studies. As a result, a significant relationship was determined among FV Leiden, FII G20210A, and thrombosis. The FV Hong Kong mutation was observed in only 2 patients with pulmonary vein thrombosis who are FV Leiden/FV Hong Kong compound heterozygous for FV gene. MTHFR C677T and A1298C were equally distributed in the patient group compared with the control group. All named mutations were also identified with single-strand conformation analysis, but a new variant/polymorphism during studies was not found. Because some inherited abnormalities are associated with thromboembolic disorders, determining the mutations and gene-to-gene interactions in patients with thrombosis history has a great impact on diagnosis and treatment of these diseases. 相似文献
104.
Omer A. Algonaid Abdulrahman S. Almoukirish Yahya H. Almashham 《Journal of the Saudi Heart Association》2019,31(1):9-11
Kawasaki disease (KD) is a potentially decapacitating multisystemic vasculitis with unknown etiology that acquired worldwide attention due to associated coronary aneurysms leading to life-threatening complications in very young babies including thrombosis, ischemia, and rupture. High levels of suspicion for early diagnosis and prompt treatment are crucial in preventing serious complications. We report here one of the patients who developed a giant coronary aneurysm but fortunately not a life-threatening complication after 5?years of follow-up. We conclude that later intravenous immunoglobulins (IVIG) treatment could be an important factor—among others—that precipitate into such complications. 相似文献
105.
Yahya Açil Matthias Gierloff Carolin Behrens Björn Möller Volker Gassling Peter Niehoff Jörg Wiltfang Maciej Simon 《Calcified tissue international》2013,92(3):251-260
Radiotherapy can lead to a reduction of bone density with an increased risk of pathological fractures. Bisphosphonates may represent a preventive treatment option by increasing the density of anorganic bone mineral. Yet it is unknown how bisphosphonates act on irradiated collagen cross-links, which play an essential role for the mechanical stability of bone. The aim of this study was to evaluate the effects of zoledronate on bone collagens and their cross-links after irradiation. The right femur of 37 rats was irradiated with a single dose of 9.5 Gy at a high dose rate using an afterloading machine. Half of the rats (n = 18) received additionally a single dose zoledronate (0.1 mg/kg body weight). Fourteen and 100 days after irradiation the femora were collected for histologic evaluation and determination of the collagen cross-links lysylpyridinoline, hydroxylysylpyridinoline, and hydroxyproline. The collagen types were characterized by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Fourteen days after treatment the lysylpyridinoline levels of all treatment groups were significantly lower compared to the untreated control. After 100 days, in the combined radiotherapy + zoledronate group significantly lower lysylpyridinoline values were determined (p = 0.009). Radiotherapy and/or zoledronate did not change significantly the level of hydroxylysylpyridinoline. The concentration of hydroxyproline was 14 days after irradiation significantly higher in the combined treatment group compared to the control. No significant differences were observed 100 days after treatment. Zoledronate does not have the ability to restore the physiological bone collagen cross-link levels after radiotherapy. However, this would be necessary for regaining the physiological mechanical stability of bone after irradiation and therefore to prevent effectively radiation-induced fractures. 相似文献
106.
107.
Tamimi Y Ziebart K Desaulniers N Dietrich K Grundy P 《Genes, chromosomes & cancer》2007,46(4):327-335
We have analyzed the short arm of chromosome 1 using loss of heterozygosity (LOH) analysis in Wilms tumors (WT) to identify a minimal region of loss. 1909 WT, 22 malignant rhabdoid tumors of the kidney and 90 clear cell carcinomas of the kidney (CCSK) were subjected to LOH analysis using five markers flanked by D1S243 and D1S244. 225 WT and 4 CCSK displayed LOH for this region. A group of 16 cases which had lost heterozygosity for at least one locus but also retained heterozygosity for at least one locus within this region were more finely analyzed using a panel of 24 microsatellite markers. A minimum region of loss located between D1S2694 and D1S244 spanning an area of 3.23 Mb was found in 15/16 of these tumors. No evidence for a second locus within this region was identified. This region of loss overlaps that found in neuroblastoma and harbors candidate genes highly expressed in fetal kidney i.e., LZIC, ICAT, and DNB5. Denaturing HPLC and quantitative RT-PCR analysis of these three genes, however, revealed no aberrations in WT samples retaining heterozygosity (8 cases) or displaying LOH 1p (8 cases). Further studies are required to identify the presumed tumor suppressor gene located within this region of 1p. 相似文献
108.
This study elucidated the in vitro physicomechanical transitions of a crosslinked polylactic-co-glycolic acid (PLGA) scaffold, utilizing quantum mechanics to compute the ab initio energy requirements of a salted-out and subsequently crosslinked PLGA scaffold interacting with simulated physiological fluid, phosphate buffered saline (PBS) (pH 7.4, 37 degrees C) at a molecular level. Twenty-six salted-out PLGA scaffolds were formulated using a four factor, two centerpoint quadratic Face-Centered Central Composite Design (FCCD). PLGA molecular mass, PLGA concentration, water volume and salting-out reaction time were the dependant formulation variables. Subsequent to PLGA solubilization in dimethyl formamide (DMF), protonated water was added to induce salting-out of PLGA into a scaffolds that were immersed in PBS, oscillated at 100 rpm, and analyzed at pre-determined time intervals for their physicomechanical and ab initio quantum energy transitions. Results indicated that the matrix resilience (MR) decreased with longer incubation periods (MR=35-45%) at day 30. Scaffolds salted-out using higher PLGA concentrations exhibited minimal changes in MR and the matrix ability to absorb energy was found to closely correlate with the scaffold residence time in PBS. Spartan-based ab initio quantum energy predictions elucidated the potential scaffold stability from a molecular viewpoint and its suitability for use in rate-modulated drug delivery. 相似文献
109.
Yahya Elsayed Tommaso Ranzani Matteo Cianchetti Mario Morino Alberto Arezzo 《Minimally invasive therapy & allied technologies》2015,24(4):204-210
Background: This paper investigates different types of crimped, braided sleeve used for a soft arm for robotic abdominal surgery, with the sleeve required to contain balloon expansion in the pneumatically actuating arm while it follows the required bending, elongation and diameter reduction of the arm. Material and methods: Three types of crimped, braided sleeves from PET (BraidPET) or nylon (BraidGreyNylon and BraidNylon, with different monofilament diameters) were fabricated and tested including geometrical and microstructural characterisation of the crimp and braid, mechanical tests and medical scratching tests for organ damage of domestic pigs. Results: BraidPET caused some organ damage, sliding under normal force of 2-5 N; this was attributed to the high roughness of the braid pattern, the higher friction coefficient of polyethylene terephthalate (PET) compared to nylon, and the high frequency of the crimp peaks for this sleeve. No organ damage was observed for the BraidNylon, attributed to both the lower roughness of the braid pattern and the low friction coefficient of nylon. BraidNylon also required the lowest tensile force during its elongation to similar maximum strain as that of BraidPET, translating to low power requirements. Conclusion: BraidNylon is recommended for the crimped sleeve of the arm designed for robotic abdominal surgery. 相似文献
110.
Yahya Açil Mia Leena Arndt Aydin Gülses Henning Wieker Hendrik Naujokat Mustafa Ayna Jörg Wiltfang 《Journal of cranio-maxillo-facial surgery》2018,46(4):538-546