461 research outputs found

    TRASYS: Checkout of accuracy of direct irradiation calculations for discs, trapezoids, cones, and circular paraboloids

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    Results of the direct irradiation link of the TRASYS program are evaluated. Several surface configurations were investigated. The accuracy of the results was examined for simple cases where the answers were analytically known. By varying an accuracy factor in the program, the amount of computer time needed to achieve different degress of accuracy was determined

    Do No Harm: Best Practices and Tools to Develop Global Health Experiences for Nursing Students

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    Nurses are strong social justice advocates who often serve the most marginalized communities. Nursing has responded to social changes and globalization by developing into a multifaceted profession that integrates cultural competency, education, empathy, advocacy, and interdisciplinary collaboration. However, throughout its growth as a profession, the guiding principles of nursing have remained consistent, foremost among them being nonmaleficence – or do no harm. Nursing schools across the United States are responding to the need to develop cultural competency and are offering innovative ways for students to build their skills and experiences through international nursing experiences. This is a positive trend, as research demonstrates that international experiences benefit nursing students’ personal and professional development. However, ethical challenges exist, primarily regarding the positive or negative impact a student experience has on the host community. Poorly planned and executed international experiences for nursing students have been shown to destabilize local health systems, undermine local providers, and displace local economies. Therefore nurse educators should balance the academic needs of their students against the health and development needs of host communities. Nurse education does not include substantial experience in program design for international efforts. However, the fields of international development and public health share the principle of nonmaleficence and have established best practices for program design to mitigate and prevent unintended adverse consequences on host communities. By incorporating best practices from international development and public health, nurse educators can better develop ethically sound international experiences for their students, develop nurses with greater cultural competency, and best support the development of host communities.Bachelor of Scienc

    Bioassay-Guided Isolation, and Identification of Bioactive Compounds from Garcinia Atroviridis (Asam Gelugor)

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    This study was undertaken to characterise the biological activities of Garcinia atroviridis, a food plant and traditional vegetable, as well as to isolate and identify its bioactive constituents Ethnobotanical reports on the use of G atroviridis as an anti-infective agent and biopreservative, coupled with the paucity of scientific reports on the biological activities of G atroviridis were the basis for selecting this plant as the subject of this study Crude extracts (methanol dimethyl sulfmade-91) of various parts of this plant were screened for antimicrobial (disc diffusion method), Cytotoxic (microtitration method), brine shrimp toxic, antitumour-promoting (Epstem Barr Virus activation assay) and antioxidant (ferric thiocyanate and thiobarbitunc assays) activities. The crude extracts exhibited predominantly antibacterial activity with the roots showing the strongest inhibition against the test bacteria at the minimum inhibitory dose (MID) of 156µg/disc. Although all the extracts failed to inhibit the growth of most of the test fungi, significant antifungal activity against Cladosporium herbarum was exhibited by most notably the fruit extract (MID 100 µg), and the leaf extract (MID 400 µg) None of the extracts were Significantly cytotoxic and lethal towards brine shrimps. The root, leaf, trunk and stem bark extracts (except for the fruits) showed strong antioxidant activity exceeding that of the standard antioxidant, α-tocopherol. Antitumour promoting activity (> 95% inhibition) was shown by the fruit, leaf, stem and trunk bark extracts

    Which criteria should be used for starting pharmacologic therapy for management of gestational diabetes in pregnancy? Evidence from randomized controlled trials

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    Introduction: There is inconclusive evidence to support any specific criteria for starting pharmacologic therapy after diet in women with gestational diabetes mellitus (GDM). We aimed to analyze the most used criteria for starting pharmacologic treatment for patients with GDM. Material and methods: Electronic databases were searched from their inception to September 2017. We included all the randomized controlled trials (RCTs) of GDM managed initially by diet and exercise reporting criteria for starting pharmacologic therapy. RCTs in women with pregestational diabetes were excluded. Data regarding glucose values used for starting pharmacologic therapy were extracted and carefully reviewed. Results: We included 15 RCTs (4307 women) in the meta-analysis. For fasting glucose target, 8/14 (57%) used a value lower or equal to 90 mg/dL and the remainder used values 50% of the values higher than the target values and another one (7%) used >30%. Conclusion: The majority of RCTs (87%) used very tight criteria of either 1 or 2 values over the target values in the 1 or 2-week period for starting pharmacologic treatment for patients with GDM; more than 50% used 2 values. Key Message Pharmacologic therapy should be considered in women with gestational diabetes when, despite an adequate diet and exercise, 1 or 2 blood glucose values are over the target values of 90mg/dL fasting or 120mg/dL 2-hour postprandial over 1 or 2 weeks

    Bioassay-guided isolation of deoxypodophyllotoxin, the cytotoxic constituent of Juniperus chinensis

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    The ethanol extract from the leaves of Juniperus chinensis was found to be cytotoxic towards HeLa cells. Bioassay-guided fractionation of the EtOAc soluble faction directed by the microtitration cytotoxic assay revealed that the cytotoxic compound was deoxypodophyllotoxin. All the tumour cell lines tested (KU8112F-chronic mylogeneous leukemia, TK 10-renal carcinoma, UACC 62-melanoma and CEM-SS - T-lymphoblastic leukemia) were found to be susceptible to deoxypodophyllotoxin, however, the minimum effective concentration (MEC) required to reduce the cell population by 100 percent was different between cell lines

    Antiviral and cytotoxic activities of some plants used in Malaysian indigenous medicine

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    Ethanolic extracts of 61 medicinal plants used in Malaysia were screened for antiviral and cytotoxic activities. Antiviral activity was tested against the herpes simplex type-1 (HSV-1) and vesicular stomatitis (VSV) viruses, and cytotoxicity was assayed using the HeLa cell line. Antiviral activity against both viruses was present in the extracts from Calotropis gigantea, Costus speciosus, Eugenia michelii, Hedyotis auricularia, Mentha arvensis, Orthosiphon aristatus, Polygonum minus and Ricinus communis (MIG: 0.002-0.1 mg/ml). The extracts from Alternanthera sessilis, Blumea chinensis, Eleusine indica, Euphorbia hirta, Freycinetia malaccensis, Leea indica and Solanum americanum were active in selectively inhibiting HSV-1 (0.001-0.1 mg/ml). Selective activity against VSV was shown by the extracts from Acalypha indica, Bertholletia excelsa, Cerbera manghas, Codiaeum variegatum, Plectranthus amboinicus, Centella asiatica, Mirabilis jalapa, Morinda elliptica, Oenanthe javanica, Piper sarmentosum and Premna odorata (MIG: 0.005-0.1 mg/ml). Gytotoxic activity was present in the extracts from Acalypha indica, Andrographis paniculata, Cerbera manghas, Codiaeum variegatum, Cosmos caudatus, Elephantopus scaber, Etlingera elatior, Eugenia michelii, Freycinetia malaccensis, Hibiscus rosa-sinensis,Cen~ella asiati~a, Lecythis ollaria, Mentha arvensis, Mirabilis jalapa, Morinda elliptica, Ocimum tenUlflorum, PIper sarmentosum and Polygonum minus (CD50: 0.001-0.1 mgjml).Co-existing antiviral and cytotoxic activities were shown by Eugenia michelii, Mentha arvensis and Polygonum minus

    Cellobiohydrolase B of Aspergillus niger over-expressed in Pichia pastoris stimulates hydrolysis of oil palm empty fruit bunches

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    Background. Aspergillus niger, along with many other lignocellulolytic fungi, has been widely used as a commercial workhorse for cellulase production. A fungal cellulase system generally includes three major classes of enzymes i.e.,β-glucosidases, endoglucanases and cellobiohydrolases. Cellobiohydrolases (CBH) are vital to the degradation of crystalline cellulose present in lignocellulosic biomass. However, A. niger naturally secretes low levels of CBH. Hence, recombinant production of A. niger CBH is desirable to increase CBH production yield and also to allow biochemical characterisation of the recombinant CBH from A. niger. Methods. In this study, the gene encoding a cellobiohydrolase B (cbhB) from A. niger ATCC 10574 was cloned and expressed in the methylotrophic yeast Pichia pastoris X-33. The recombinant CBHB was purified and characterised to study its biochemical and kinetic characteristics. To evaluate the potential of CBHB in assisting biomass conversion, CBHB was supplemented into a commercial cellulase preparation (Cellic ® CTec2) and was used to hydrolyse oil palm empty fruit bunch (OPEFB), one of the most abundant lignocellulosic waste from the palm oil industry. To attain maximum saccharification, enzyme loadings were optimised by response surface methodology and the optimum point was validated experimentally. Hydrolysed OPEFB samples were analysed using attenuated total reflectance FTIR spectroscopy (ATR-FTIR) to screen for any compositional changes upon enzymatic treatment. Results. Recombinant CBHB was over-expressed as a hyperglycosylated protein attached to N-glycans. CBHB was enzymatically active towards soluble substrates such as 4-methylumbelliferylβ-D-cellobioside (MUC), p-nitrophenyl-cellobioside (pNPC) and p-nitrophenyl-cellobiotrioside (pNPG3) but was not active towards crystalline substrates like Avicel ® and Sigmacell cellulose. Characterisation of purified CBHB using MUC as the model substrate revealed that optimum catalysis occurred at 50 °C and pH 4 but the enzyme was stable between pH 3 to 10 and 30 to 80 °C. Although CBHB on its own was unable to digest crystalline substrates, supplementation of CBHB (0.37%) with Cellic ® CTec2 (30%) increased saccharification of OPEFB by 27%. Compositional analyses of the treated OPEFB samples revealed that CBHB supplementation reduced peak intensities of both crystalline cellulose Iα and Iβ in the treated OPEFB samples. Discussion. Since CBHB alone was inactive against crystalline cellulose these data suggested that it might work synergistically with other components of Cellic R CTec2. CBHB supplements were desirable as they further increased hydrolysis of OPEFB when the performance of Cellic® CTec2 was theoretically capped at an enzyme loading of 34% in this study. Hence, A. niger CBHB was identified as a potential supplementary enzyme for the enzymatic hydrolysis of OPEFB

    Antiviral, cyototoxic and antimicrobial activities of anthraquinones isolated from the roots of Morinda elliptica

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    2-Formyl-1-hydroxyanthraquinone, along with ten other known anthraquinones (1-hydroxy-2-methylanthraquinone, nordamnacanthal, damnacanthal, lucidin-?-methyl ether, rubiadin, rubiadin-1-methyl ether, soranjidiol, morindone, morindone-5-methyl ether and alizarin-1-methyl ether), isolated from the roots of Morinda elliptica , were assayed for anti-HIV, cytotoxic and antimicrobial activites. Only damnacanthal showed moderate activity against HIV. It was cytotoxic towards the MCF-7 (breast carcinoma) and CEM-SS (T-lymphoblastic leukaemia) cell line. Nordamnacanthal was very cytotoxic against the CEM-SS cell lines. Other anthraquinones that showed strong cytotoxicity towards the cell lines tested were lucidin-?-methyl ether (CEM-SS and MCF-7) and rubiadin (CEM-SS). Three anthraquinones viz., nordamnacanthal, damnacanthal and morindone, were found to have strong antimicrobial activity
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