60 research outputs found

    Phytochemical analysis and antioxidative properties of Centaurea albonitens

    Get PDF
    Background and objectives: Thegenus Centaurea from the Asteraceae family is one of the most widely distributed plant genera worldwide that has been extensively used in folk medicine for hundreds of years. The present study is the first investigation about the principal constituents of Centaurea albonitens Turrill which is native to Iran. Methods: Theaerial parts of C. albonitens were extracted via maceration. Phytochemical analysis of the methanol extract was carried out via different chromatography approaches like HPLC, SPE and preparative TLC. Structures of the purified compounds were revealed through spectral analysis from 1D and 2D NMR including DQF-COSY, HSQC and DEPT in comparison with the relative data in published reports. Subsequently, the antioxidant property of the extract was evaluated via scavenging the free DPPH radicals. In addition, the total phenolic and flavonoid contents of the extract were ascertained based on Folin-Ciocalteu and colorimetric aluminum chloride methods, correspondingly. Results: Analysis of the extract yielded in the isolation and identification of arctiin and apigenin-4'-O-rhamnoside. Moreover, the antioxidant assessment determined IC50 value of 389.9 µg/mL for the plant extract in DPPH assay. The total phenolics and flavonoids content of the plant extract were 2.87 g gallic acid equivalent and 0.28 g quercetin equivalent both in 100 g dried plant material. Conclusion: The findings of this study introduce C. albonitens as a suitable source for isolation of lignans (like arctiin)

    Effects of long-term exposure to amoxicillin residues on stress resistance and body compositions of Penaeus vannamei

    Get PDF
    Background and Objective: Occurrence of the pharmaceutical active residues (particularly antibiotics) threatens the health of the environment and human society. Therefore, this research aimed to investigate the impacts of the Amoxicillin (AMX) residues on resistance to environmental stress and biochemical compositions of the body in Penaeus vannamei. Materials and Methods: Six-hundred specimens with a mean (±SD) weight and total length of 9.23±1.77 g and 9.28±0.73 cm were randomly experimented in four triplicate treatments, namely T1(control): without AMX residues in a rearing environment, T2: 100 μg/L AMX residues concentration in water, T3: 300 μg/L and T4: 500 μg/L for 60 days. At the end of the experimental trial, five specimens for biochemical body composition analyses were separately sampled. Ten shrimps from each treatment were also randomly selected and exposed to 50 ppt salinity stress for 48 hours, and then survival rates were computed. Results: Body composition analyses showed that moisture and protein not differed among the treatments (p>0.05), while fat in T2 (28.29±5.50) was significantly more than in others (p<0.05). The lowest values of ash were obtained in T1 and T4, and they differed with T2 and T3 (p<0.05). The highest survival rate of shrimps exposed to salinity stress (50 ppt in 48 h) was observed in T2 and T3, in contrast, the lowest value was recorded for T4 (p<0.01). Conclusion: Findings of the present research indicate that the occurrence of high doses of AMX residues pollution in the rearing water affects the stress resistance of P. vannamei which can be due to disruption of protein and fat metabolisms in the shrimp body

    Diagnostic accuracy of a clinical diagnosis of idiopathic pulmonary fibrosis: An international case-cohort study

    Get PDF
    We conducted an international study of idiopathic pulmonary fibrosis (IPF) diagnosis among a large group of physicians and compared their diagnostic performance to a panel of IPF experts. A total of 1141 respiratory physicians and 34 IPF experts participated. Participants evaluated 60 cases of interstitial lung disease (ILD) without interdisciplinary consultation. Diagnostic agreement was measured using the weighted kappa coefficient (\u3baw). Prognostic discrimination between IPF and other ILDs was used to validate diagnostic accuracy for first-choice diagnoses of IPF and were compared using the Cindex. A total of 404 physicians completed the study. Agreement for IPF diagnosis was higher among expert physicians (\u3baw=0.65, IQR 0.53-0.72, p20 years of experience (C-index=0.72, IQR 0.0-0.73, p=0.229) and non-university hospital physicians with more than 20 years of experience, attending weekly MDT meetings (C-index=0.72, IQR 0.70-0.72, p=0.052), did not differ significantly (p=0.229 and p=0.052 respectively) from the expert panel (C-index=0.74 IQR 0.72-0.75). Experienced respiratory physicians at university-based institutions diagnose IPF with similar prognostic accuracy to IPF experts. Regular MDT meeting attendance improves the prognostic accuracy of experienced non-university practitioners to levels achieved by IPF experts

    Effect of Structure and Surface Roughness on Wetting Angle of a Hypoeutectic Cast Iron

    No full text
    Preliminary results of a research on the effects of microstructure and surface roughness of a hypoeutectic cast iron on its wetting angle are presented in this article. For this purpose, molten cast iron was solidified at different cooling rates to produce two samples of the same composition, i.e. a gray cast iron with A type flake graphite and a white cast iron. Two samples were then prepared in polished, electroetched (four different stages) and mechanically abraded (four different stages) conditions and their wetting angles were measured after evaluating their roughness profile. Maximum and minimum wetting angles were observed on white cast iron surfaces roughened with 80 and 800 sand papers which were equal to 42 and 13 degrees, respectively.Wetting angles of electroetched white cast iron surfaces varied between 25 and 31 degrees by varying surface roughness. Maximum and minimum wetting angles on the surface of gray cast iron were obtained in stage one (40 degree) and stage three (25 degree) of electroetching, respectively. Wetting angles on mechanically abraded surfaces of this sample varied between 27 and 31 degrees. Then, the surface roughness factor and the solid fraction in contact with water were calculated using Wenzel equation and Cassie Baxter equation, respectively, and Wenzel and Cassie-Baxter wetting angles of the surfaces were calculated and were compared with their corresponding measured wetting angles. The results indicated that the surface microstructure and the type of constituents present at the surface, surface-roughening method and surface-roughness value influence the cast iron surface wettability, and it is possible to modify metal wetting angle by modification of its structure, surface-roughness method and surface-roughness value. It was also shown that in gray cast iron, the wetting behavior of the electroetched surfaces followed Cassie-Baxter equation in the first and second stages of electroetching and followed Wenzel equation at higher surface roughness (third and fourth stages of electroetching). In all stages of mechanically abrading, the surface of this sample followed Wenzel equation. The wetting behavior of the white cast iron followed Wenzel equation in all electroetching stages. In mechanically abraded conditions, the white cast iron wettability was variable and depended on the surface roughness

    Performance of helical anchors in sand

    Get PDF
    Helical anchor consist of some steel shafts with a series of helical steel plates welded on a pitch. During installation, helical anchor was screwed into the ground by using a standard truck or trailer mounted augering equipment. The equipment will apply a rotating moment to the steel shafts to screw the anchors into ground. The torque resistance of the anchor will be monitoring along the installation. When the torque resistance achieved its designed values, it verified that capacity of anchor achieved. Behavior of helical anchor under uplift load in cohesionless soil has been studied using previous researches. Based on a few number of laboratory model results many investigators reported the uplift loading of helical anchor embedded in cohesionless soil, a review of related last works shows that not much research has been done to define the uplift capacity in cohesionless soil, a problem that is often encountered in field. The paper observed that the ultimate uplift capacity is dependent on the relative undrained/drained shear strength of cohesionless soil, the depth ratio of embedment and soil thickness ratio
    corecore