204 research outputs found

    Modeliranje hrapavosti obrađene površine i optimiranje parametara obrade pri čeonom glodanju

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    The influence of cutting parameters on surface roughness in face milling has been examined. Cutting speed, feed rate and depth of cut have been taken into consideration as the influential factors. A series of experiments have been carried out in accordance with a design of experiment (DOE). In order to obtain mathematical models that are able to predict surface roughness two different modeling approaches, namely regression analysis and neural networks, have been applied to experimentally determined data. Obtained results have been compared and neural network model gives better explanation of the observed physical system. Optimal cutting parameters have been found using simplex optimization algorithm.U ovom radu istražen je utjecaj parametara obrade (brzina rezanja, posmak i dubina rezanja) na hrapavost obrađene površine pri čeonom glodanju. Obavljen je niz pokusa u skladu sa planom eksperimenta. U cilju dobivanja matematičkog modela kojim se može predvidjeti hrapavost obrađene površine, eksperimentalni podaci obrađeni su metodologijom regresijske analize i neuronskih mreža. Uspoređeni su dobiveni rezultati i neuronska mreža daje bolji opis promatranog fizikalnog sustava. Primjenom simplex algoritma za optimiranje dobivene su optimalne vrijednosti ispitivanih parametara

    Modeliranje hrapavosti obrađene površine i optimiranje parametara obrade pri čeonom glodanju

    Get PDF
    The influence of cutting parameters on surface roughness in face milling has been examined. Cutting speed, feed rate and depth of cut have been taken into consideration as the influential factors. A series of experiments have been carried out in accordance with a design of experiment (DOE). In order to obtain mathematical models that are able to predict surface roughness two different modeling approaches, namely regression analysis and neural networks, have been applied to experimentally determined data. Obtained results have been compared and neural network model gives better explanation of the observed physical system. Optimal cutting parameters have been found using simplex optimization algorithm.U ovom radu istražen je utjecaj parametara obrade (brzina rezanja, posmak i dubina rezanja) na hrapavost obrađene površine pri čeonom glodanju. Obavljen je niz pokusa u skladu sa planom eksperimenta. U cilju dobivanja matematičkog modela kojim se može predvidjeti hrapavost obrađene površine, eksperimentalni podaci obrađeni su metodologijom regresijske analize i neuronskih mreža. Uspoređeni su dobiveni rezultati i neuronska mreža daje bolji opis promatranog fizikalnog sustava. Primjenom simplex algoritma za optimiranje dobivene su optimalne vrijednosti ispitivanih parametara

    One Year Sustainability of Risk Factor Change from a 9-Week Workplace Intervention

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    We examined the effect of a 9-week diet and physical activity intervention provided in the workplace by a group education session where personal dietary and physical activity goals were proposed. Measurements of anthropometry, fasting blood lipids, glucose and insulin, assays for antioxidant activity (AOA) and questionnaires were completed at 0, 3, 6, 9, and 12 weeks in 50 healthy workers (50% male, mean age 46y). Followup measurements in 39 (56% male) were possible at 52 weeks. At week 3 a group dietary and physical activity “motivational seminar” was held. At week 6, half the group were supplied daily kiwifruit for 3 weeks with cross over at week 9 until week 12. Compared to baseline, lipid, glucose, insulin and AOA measurements were improved at 12 and 52 weeks. Body measurements did not change. Group diet and physical activity advice reinforced over 9 weeks is associated with a sustained improvement in cardiovascular risk factors at 52 weeks

    Examination of Prooxidative Activity of Red Wine in Melanoma Cells

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    Melanoma is responsible for 75% of all deaths from skin cancer. Its lethality arises from its rapid progression, easy metastasis and drug-resistance as well. Red wine is a natural product rich in polyphenolic compounds with potent anticancer activities. It seems that in cancer cells these compounds behave as prooxidants initiating reactive oxygen species mediated cellular DNA breakage and consequent cell death. The aim of this study was to investigate prooxidative activity of red wine samples (Merlot variety, commercial as well as VCR1 and VCR101 clonal wines) in melanoma A375 cells, through measuring the relationship of reduced and oxidized form of glutathione (GSH/GSSG) and comparison with the GSH/GSSG ratio in control (untreated melanoma cells). The data obtained showed that tested red wine samples decrease GSH/GSSG ratio in A375 cells compared to control (4.6 ± 0), with the largest decrease noticed in treatment with VCR101 wine (0.66 ± 0.05)

    Dittrichia graveolens (L.) Greuter, a Rapidly Spreading Invasive Plant: Chemistry and Bioactivity

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    Dittrichia graveolens L. Greuter belonging to the Asteraceae family, is an aromatic herbaceous plant native to the Mediterranean region. This plant species has been extensively studied for its biological activities, including antioxidant, antitumor, antimicrobial, antifungal, anti-inflammatory, anticholinesterase, and antityrosinase, and for its peculiar metabolic profile. In particular, bioactivities are related to terpenes and flavonoids metabolites, such as borneol (40), tomentosin (189), inuviscolide (204). However, D. graveolens is also well known for causing health problems both in animals and humans. Moreover, the species is currently undergoing a dramatic northward expansion of its native range related to climate change, now including North Europe, California, and Australia. This review represents an updated overview of the 52 literature papers published in Scopus and PubMed dealing with expansion, chemistry (262 different compounds), pharmacological effects, and toxicology of D. graveolens up to October 2021. The review is intended to boost further studies to determine the molecular pathways involved in the observed activities, bioavailability, and clinical studies to explore new potential applications

    Associations between Overall and Abdominal Obesity and Suicidal Ideation among US Adult Women

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    Obesity is associated with increased risks for mental disorders. This study examined associations of obesity indicators including body mass index (BMI), waist circumference, and waist-height ratio with suicidal ideation among U.S. women. We analyzed data from 3,732 nonpregnant women aged ≥20 years who participated in the 2005–2008 National Health and Nutrition Examination Survey. We used anthropometric measures of weight, height, and waist circumference to calculate BMI and waist-height ratio. Suicidal ideation was assessed using the Item 9 of the Patient Health Questionnaire-9. Odds ratios with 95% conference intervals were estimated using logistic regression analyses after controlling for potential confounders. The age-adjusted prevalence of suicidal ideation was 3.0%; the prevalence increased linearly across quartiles of BMI, waist circumference, and waist-height ratio (P for linear trend <0.01 for all). The positive associations of waist circumference and waist-height ratio with suicidal ideation remained significant (P < 0.05) after adjustment for sociodemographics, lifestyle-related behavioral factors, and having either chronic conditions or current depression. However, these associations were attenuated after both chronic conditions and depression were entered into the models. Thus, the previously reported association between obesity and suicidal ideation appears to be confounded by coexistence of chronic conditions and current depression among women of the United States

    New Insight on the Bioactivity of Solanum aethiopicum Linn. Growing in Basilicata Region (Italy): Phytochemical Characterization, Liposomal Incorporation, and Antioxidant Effects

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    Food extract’s biological effect and its improvement using nanotechnologies is one of the challenges of the last and the future decades; for this reason, the antioxidant effect of scarlet eggplant extract liposomal incorporation was investigated. Scarlet eggplant (Solanum aethiopicum L.) is a member of the Solanaceae family, and it is one of the most consumed vegetables in tropical Africa and south of Italy. This study investigated the antioxidant activity and the phytochemical composition of S. aethiopicum grown in the Basilicata Region for the first time. The whole fruit, peel, and pulp were subjected to ethanolic exhaustive maceration extraction, and all extracts were investigated. The HPLC-DAD analysis revealed the presence of ten phenolic compounds, including hydroxycinnamic acids, flavanones, flavanols, and four carotenoids (one xanthophyll and three carotenes). The peel extract was the most promising, active, and the richest in specialized metabolites; hence, it was tested on HepG2 cell lines and incorporated into liposomes. The nanoincorporation enhanced the peel extract’s antioxidant activity, resulting in a reduction of the concentration used. Furthermore, the extract improved the expression of endogenous antioxidants, such as ABCG2, CAT, and NQO1, presumably through the Nrf2 pathway

    New Insight on the Bioactivity of Solanum aethiopicum Linn. Growing in Basilicata Region (Italy): Phytochemical Characterization, Liposomal Incorporation, and Antioxidant Effects

    Get PDF
    Food extract’s biological effect and its improvement using nanotechnologies is one of the challenges of the last and the future decades; for this reason, the antioxidant effect of scarlet eggplant extract liposomal incorporation was investigated. Scarlet eggplant (Solanum aethiopicum L.) is a member of the Solanaceae family, and it is one of the most consumed vegetables in tropical Africa and south of Italy. This study investigated the antioxidant activity and the phytochemical composition of S. aethiopicum grown in the Basilicata Region for the first time. The whole fruit, peel, and pulp were subjected to ethanolic exhaustive maceration extraction, and all extracts were investigated. The HPLC-DAD analysis revealed the presence of ten phenolic compounds, including hydroxycinnamic acids, flavanones, flavanols, and four carotenoids (one xanthophyll and three carotenes). The peel extract was the most promising, active, and the richest in specialized metabolites; hence, it was tested on HepG2 cell lines and incorporated into liposomes. The nanoincorporation enhanced the peel extract’s antioxidant activity, resulting in a reduction of the concentration used. Furthermore, the extract improved the expression of endogenous antioxidants, such as ABCG2, CAT, and NQO1, presumably through the Nrf2 pathway
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