6 research outputs found

    Characterizing soil nutrient status and growth performance of planted dipterocarp and non-dipterocarp species on degraded forest land in Peninsular Malaysia

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    This study aims to assess the soil nutrient status and growth performance of selected six dipterocarp species namely Dryobalanops aromatica , Hopea nervosa , Neobalanocarpus heimii , Shorea parvifolia , S. assamica and S. leprosula and three non-dipterocarp species of Azadirachta excelsa , Cinnamomum iners and Intsia palembanica were performed six years after planting on degraded forest land in Pasoh Forest Reserve, Negeri Sembilan, Peninsular Malaysia. This assessment consists of determining soil nutrient status based on physico-chemical properties both in rehabilitated and adjacent secondary forests along with measurement of diameter at breast height and height and survival rate. The results showed that rehabilitating degraded forest land with dipterocarp and non-dipterocarp species had improved both soil nutrient status and valuable timber stocks. The soils were acidic with low levels of organic matter and exchangeable bases associated with high level of Al saturation. The negative charges derived from the organic matter and clay minerals play an important role in retaining soil nutrients and probably influence the soil nutrient status. Principal component analysis revealed three most important PC scores which explained 73.8% of total variation. PC1 represents cation retention capacity and soil organic matter. PC2 infers soil acidity, while PC3 related to physical properties of the soils. In the case of growth performance, A. excelsa and C. iners showed significantly high mean annual increments in diameter and height and survival rate at six years after planting. Irrespective of different ages after planting, the growth performance and survival rate of planted dipterocarp species especially S. leprosula and S. parvifolia were comparable to similar species grown at other planting trials in Malaysia

    Use of Curcuma longa in cosmetics: extraction of curcuminoid pigments, development of formulations, and in vitro skin permeation studies

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    Curcuma longais a ginger family aromatic herb (Zingiberaceae) whose rhizomes contain curcuminoid pigments, including curcumin, a compound known for its anti-inflammatory effects. The objective of this study was to obtain curcuminoid-rich extracts, develop topical formulations thereof, and assess the stability and skin permeation of these formulations. Curcuma longa extracts were obtained and used to develop formulations. Skin permeation studies were conducted in a modified Franz diffusion cell system, and skin retention of curcuminoid pigments was quantified in pig ear membrane. Prepared urea-containing gel-cream formulations were unstable, whereas all others had satisfactory stability and pseudoplastic rheological behavior. The amount of curcuminoid pigments recovered from the receptor solution was negligible. The skin concentration of curcuminoid pigments retained was positive (>20 µg/g of skin, mostly in the stratum corneum), considering the low skin permeability of curcumin. We conclude that development of topical formulations containing curcumin or Curcuma longaextract is feasible, as long as adjuvants are added to improve preservation and durability. The formulations developed in this study enabled penetration of curcumin limited to the superficial layers of the skin and then possibly without a risk of systemic action, thus permitting local use as a topical anti-inflammatory

    Global Retinoblastoma Presentation and Analysis by National Income Level

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    Importance: Early diagnosis of retinoblastoma, the most common intraocular cancer, can save both a child's life and vision. However, anecdotal evidence suggests that many children across the world are diagnosed late. To our knowledge, the clinical presentation of retinoblastoma has never been assessed on a global scale. Objectives: To report the retinoblastoma stage at diagnosis in patients across the world during a single year, to investigate associations between clinical variables and national income level, and to investigate risk factors for advanced disease at diagnosis. Design, Setting, and Participants: A total of 278 retinoblastoma treatment centers were recruited from June 2017 through December 2018 to participate in a cross-sectional analysis of treatment-naive patients with retinoblastoma who were diagnosed in 2017. Main Outcomes and Measures: Age at presentation, proportion of familial history of retinoblastoma, and tumor stage and metastasis. Results: The cohort included 4351 new patients from 153 countries; the median age at diagnosis was 30.5 (interquartile range, 18.3-45.9) months, and 1976 patients (45.4) were female. Most patients (n = 3685 84.7%) were from low-and middle-income countries (LMICs). Globally, the most common indication for referral was leukocoria (n = 2638 62.8%), followed by strabismus (n = 429 10.2%) and proptosis (n = 309 7.4%). Patients from high-income countries (HICs) were diagnosed at a median age of 14.1 months, with 656 of 666 (98.5%) patients having intraocular retinoblastoma and 2 (0.3%) having metastasis. Patients from low-income countries were diagnosed at a median age of 30.5 months, with 256 of 521 (49.1%) having extraocular retinoblastoma and 94 of 498 (18.9%) having metastasis. Lower national income level was associated with older presentation age, higher proportion of locally advanced disease and distant metastasis, and smaller proportion of familial history of retinoblastoma. Advanced disease at diagnosis was more common in LMICs even after adjusting for age (odds ratio for low-income countries vs upper-middle-income countries and HICs, 17.92 95% CI, 12.94-24.80, and for lower-middle-income countries vs upper-middle-income countries and HICs, 5.74 95% CI, 4.30-7.68). Conclusions and Relevance: This study is estimated to have included more than half of all new retinoblastoma cases worldwide in 2017. Children from LMICs, where the main global retinoblastoma burden lies, presented at an older age with more advanced disease and demonstrated a smaller proportion of familial history of retinoblastoma, likely because many do not reach a childbearing age. Given that retinoblastoma is curable, these data are concerning and mandate intervention at national and international levels. Further studies are needed to investigate factors, other than age at presentation, that may be associated with advanced disease in LMICs. © 2020 American Medical Association. All rights reserved

    Numerical simulation of homojunction p-i-n In0.4Ga0.6N solar cell with different absorber layer configurations

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    The effects of thickness, carrier densities, and absorber layer (p-In0.4Ga0.6N) configurations were evaluated. Numerical studies were performed to optimize the homojunction p-i-n In0.4Ga0.6N solar cell using SCAPS-1D. With the optimized thicknesses and carrier densities, the p-i-n In0.4Ga0.6N solar cell shows a maximum conversion efficiency of 18.74 %. By changing the fixed indium composition of the absorber layer into step- and linear-graded configurations, the conversion efficiency, open-circuit voltage, and short-circuit current density of the solar cell were further improved. The results showed that the solar cells with step- and linear-graded absorbers attained maximum conversion efficiency of 19.77 % and 19.84 %, respectively. These results implied that the absorber with the graded compositional design helps to reduce the barrier height of electron-hole transport for band-to-band and inter-band absorption. This eventually reduces the energy loss caused by phonon emission and heat thermalization

    Global Retinoblastoma Presentation and Analysis by National Income Level

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    This cross-sectional analysis reports the retinoblastoma stage at diagnosis across the world during a single year, investigates associations between clinical variables and national income level, and investigates risk factors for advanced disease at diagnosis. Key PointsQuestionIs the income level of a country of residence associated with the clinical stage of presentation of patients with retinoblastoma? FindingsIn this cross-sectional analysis that included 4351 patients with newly diagnosed retinoblastoma, approximately half of all new retinoblastoma cases worldwide in 2017, 49.1\% of patients from low-income countries had extraocular tumor at time of diagnosis compared with 1.5\% of patients from high-income countries. MeaningThe clinical stage of presentation of retinoblastoma, which has a major influence on survival, significantly differs among patients from low-income and high-income countries, which may warrant intervention on national and international levels. ImportanceEarly diagnosis of retinoblastoma, the most common intraocular cancer, can save both a child's life and vision. However, anecdotal evidence suggests that many children across the world are diagnosed late. To our knowledge, the clinical presentation of retinoblastoma has never been assessed on a global scale. ObjectivesTo report the retinoblastoma stage at diagnosis in patients across the world during a single year, to investigate associations between clinical variables and national income level, and to investigate risk factors for advanced disease at diagnosis. Design, Setting, and ParticipantsA total of 278 retinoblastoma treatment centers were recruited from June 2017 through December 2018 to participate in a cross-sectional analysis of treatment-naive patients with retinoblastoma who were diagnosed in 2017. Main Outcomes and MeasuresAge at presentation, proportion of familial history of retinoblastoma, and tumor stage and metastasis. ResultsThe cohort included 4351 new patients from 153 countries; the median age at diagnosis was 30.5 (interquartile range, 18.3-45.9) months, and 1976 patients (45.4\%) were female. Most patients (n=3685 {[}84.7\%]) were from low- and middle-income countries (LMICs). Globally, the most common indication for referral was leukocoria (n=2638 {[}62.8\%]), followed by strabismus (n=429 {[}10.2\%]) and proptosis (n=309 {[}7.4\%]). Patients from high-income countries (HICs) were diagnosed at a median age of 14.1 months, with 656 of 666 (98.5\%) patients having intraocular retinoblastoma and 2 (0.3\%) having metastasis. Patients from low-income countries were diagnosed at a median age of 30.5 months, with 256 of 521 (49.1\%) having extraocular retinoblastoma and 94 of 498 (18.9\%) having metastasis. Lower national income level was associated with older presentation age, higher proportion of locally advanced disease and distant metastasis, and smaller proportion of familial history of retinoblastoma. Advanced disease at diagnosis was more common in LMICs even after adjusting for age (odds ratio for low-income countries vs upper-middle-income countries and HICs, 17.92 {[}95\% CI, 12.94-24.80], and for lower-middle-income countries vs upper-middle-income countries and HICs, 5.74 {[}95\% CI, 4.30-7.68]). Conclusions and RelevanceThis study is estimated to have included more than half of all new retinoblastoma cases worldwide in 2017. Children from LMICs, where the main global retinoblastoma burden lies, presented at an older age with more advanced disease and demonstrated a smaller proportion of familial history of retinoblastoma, likely because many do not reach a childbearing age. Given that retinoblastoma is curable, these data are concerning and mandate intervention at national and international levels. Further studies are needed to investigate factors, other than age at presentation, that may be associated with advanced disease in LMICs
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