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排序方式: 共有424条查询结果,搜索用时 15 毫秒
1.
Md Imdadul Haque Kamrun Nahar Md Humayun Kabir Abdus Salam 《Air quality, atmosphere, & health》2018,11(8):925-935
Eighteen brick kilns of three brick-making technologies (Fixed Chimney Kiln (FCK), Zigzag, and Hoffmann) were selected to measure the concentrations of particulate matter (PM2.5) with Aerocet 531S (USA) sampler, black carbon (BC) with Magee Scientific, OT-21 Soot scan Transmissometer (USA), and gaseous pollutants (CO2, CO, SO2, NOx, and volatile organic carbon (VOC)) with Aeroqual 500 gas sampler (New Zealand) to understand the emission scenario from brick sector in Greater Dhaka region, Bangladesh. Emission factor (EF) of each pollutant was computed from their respective concentration for three brick kiln technologies. Ambient PM2.5 and PM10 were measured in brick kiln premises and 1 km far from the respective kilns to see the effect on the surrounding areas. The PM2.5 concentration was found on an average of 141?±?86, 128?±?72, and 110?±?53 mg/m3 in FCK, Zigzag, and Hoffmann kilns, respectively. The average BC concentration was found 16.6?±?7.1 (FCK), 11.8?±?4.2 (Zigzag), and 8.9?±?4.4 (Hoffmann) mg/m3. FCK has a greater emission of CO, whereas Zigzag has a higher CO2 emission. A comparatively higher value of CO2 and lower value of CO indicates effective combustion of coal, and this is found to be more efficient for Zigzag and Hoffmann compared to traditional FCK. SO2 and VOC emissions were depending not only on the kiln types but also on the fuel qualities. From EF calculation, approximately 4526 t of PM2.5, 340 t of BC, 209,776 t of CO2, 8700 t of CO, 19,441 t of SO2, and 835,450 t of VOC per year found to emit from 1000 brick kilns. The conversion of traditional FCK to improved one, i.e., Zigzag and/or Hoffman is not a straight forward solution, as CO2 emission was higher in Zigzag whereas BC and PM2.5 emissions were higher in FCK. Therefore, considering EF of various pollutants from these three types of kilns, conversion of FCK to Zigzag or Hoffmann could be a better choice. 相似文献
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P C Singhal R T Sankaran N Nahar N Shah P Patel 《Journal of investigative medicine》2000,48(2):110-117
BACKGROUND: Macrophages seem to play an important role in the development of glomerulosclerosis. In both human and experimental animal models of focal glomerulosclerosis (FSGS), infiltration of macrophages in the mesangium has been considered key in the development of FSGS. METHODS: In the present study, we evaluated the effect of vasoactive agents on the migration of monocytes across a filter in a modified Boyden chamber as well as across a cultured glomerular endothelial cell layer (in vitro model of glomerular mesangium). Both light as well as scanning electron microscopic studies were performed. We evaluated the effect of vasoactive agents including histamine, prostaglandin (PG) E2, angiotensin II, endothelin-1, platelet-activating factor, and interleukin-1 (IL) on the migration of monocytes/macrophages across an endothelial cell layer as well as a gelatin-coated filter. In addition, we evaluated the effect of cyclic adenosine 3',5' cyclic monophosphate (cAMP) and PGE2 on vasoactive-induced migration of monocytes. RESULTS: Histamine increased (P < 0.003) the migration of monocytes across the filter. This effect of histamine was dose-dependent. Histamine at concentrations of 10(-8) to 10(-5) mol/L induced optimal migration across the filter (control, 16.6 +/- 1.1 vs histamine, 10(-8) mol/L, 40.9 +/- 0.9 monocytes/high power field). Cimetidine, an H2 receptor blocker, attenuated (P < 0.001) the effect of histamine on the migration of monocytes. PGE2 inhibited the migration of monocytes in a dose-dependent manner. Histamine increased (P < 0.001) the passage of monocytes across the glomerular endothelial cell layer (control, 1012 +/- 37 vs 1711 +/- 163 cpm/well). Histamine also increased the migration of murine macrophages across the glomerular endothelial cell layer. PGE2 inhibited the migration of monocytes across the endothelial cell layer under basal as well as histamine-stimulated states. Dibutyryl cyclic (DBc) AMP also attenuated the migration of monocytes under basal as well as histamine-stimulated states. Both PGE2 and DBcAMP also attenuated the IL-1 beta-stimulated migration of monocytes. Angiotensin II, endothelin-1, and platelet-activating factor did not modulate the migration of monocytes. CONCLUSIONS: Vasoactive agents directly modulate the transmigration of monocytes. The present in vitro study provides a basis for a hypothesis that vasoactive agents may also be modulating the migration of monocytes across the glomerular endothelial cell layer (into the mesangium). 相似文献
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Comparative Cytotoxicity of Glycyrrhiza glabra Roots from Different Geographical Origins Against Immortal Human Keratinocyte (HaCaT), Lung Adenocarcinoma (A549) and Liver Carcinoma (HepG2) Cells 下载免费PDF全文
Norazah Basar Olayinka Ayotunde Oridupa Kenneth J. Ritchie Lutfun Nahar Nashwa Mostafa M. Osman Angela Stafford Habibjon Kushiev Asuman Kan Satyajit D. Sarker 《Phytotherapy research : PTR》2015,29(6):944-948
Glycyrrhiza glabra L. (Fabaceae), commonly known as ‘liquorice’, is a well‐known medicinal plant. Roots of this plant have long been used as a sweetening and flavouring agent in food and pharmaceutical products, and also as a traditional remedy for cough, upper and lower respiratory ailments, kidney stones, hepatitis C, skin disorder, cardiovascular diseases, diabetes, gastrointestinal ulcers and stomach ache. Previous pharmacological and clinical studies have revealed its antitussive, antiinflammatory, antiviral, antimicrobial, antioxidant, immunomodulatory, hepatoprotective and cardioprotective properties. While glycyrrhizin, a sweet‐tasting triterpene saponin, is the principal bioactive compound, several bioactive flavonoids and isoflavonoids are also present in the roots of this plant. In the present study, the cytotoxicity of the methanol extracts of nine samples of the roots of G. glabra, collected from various geographical origins, was assessed against immortal human keratinocyte (HaCaT), lung adenocarcinoma (A549) and liver carcinoma (HepG2) cell lines using the in vitro 3‐[4,5‐dimethylthiazol‐2‐yl]‐2,5‐diphenyl tetrazoliumbromide cell toxicity/viability assay. Considerable variations in levels of cytotoxicity were observed among various samples of G. glabra. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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B Nahar MI Hossain JD Hamadani T Ahmed S Grantham-McGregor LA Persson 《BMC public health》2012,12(1):622
ABSTRACT: BACKGROUND: Parenting programmes are effective in enhancing parenting practices and child development. This study evaluated the effects of a intervention with psychosocial stimulation (PS) on the quality of the home environment and mothers' child-rearing practices in a community-based trial with severely malnourished Bangladeshi children. METHOD: Severely underweight children (n = 507), 6-24 months of age, were randomly assigned to five groups: PS; food supplementation (FS); PS + FS; clinic-control (CC); and, hospital-control (CH). PS included fortnightly follow-up visits for six months at community clinics where a play leader demonstrated play activities and gave education on child development and child rearing practices. FS comprised cereal-based supplements (150-300 kcal/day) for three months. All groups received medical care, micronutrient supplements and growth monitoring. Mothers were given the Home Observation for Measurement of the Environment (HOME) inventory and a questionnaire on parenting at baseline and after six months to assess the outcome. RESULTS: 322 children completed the study. After six months of intervention the PS + FS and PS groups benefitted in the total HOME score (depending on the comparison group, effect sizes varied from 0.66 to 0.33 SD) The PS + FS and PS groups also benefitted in two HOME subscales: maternal involvement (effect sizes: 0.8 to 0.55 SD) and play materials, (effect sizes: 0.46 to 0.6 SD), and child-rearing practices scores (effect size: 1.5 to 1.1 SD). The PS + FS group benefitted 4.0 points in total HOME score compared with CH, 4.8 points compared with CC and 4.5 points compared with FS (p < 0.001 for all). The PS group benefitted 2.4 points compared with CH (p = 0.035), 3.3 points compared with CC (p = 0.004), and 2.9 points compared with FS (p = 0.006). Child-rearing practice scores of the PS + FS group improved 7.7, 6.4 and 6.6 points and the PS group improved 8.5, 7.2 and 7.4 points more than CH, CC and FS, respectively (p < 0.001 for all). CONCLUSIONS: Child-rearing practices of mothers of severely malnourished children and the quality of their home environment can be improved through community-based psychosocial stimulation with or without food supplementation. This may be of importance to promote child development. 相似文献
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T2182C mutation in 23S rRNA is associated with clarithromycin resistance in Helicobacter pylori isolates obtained in Bangladesh 总被引:8,自引:0,他引:8 下载免费PDF全文
Khan R Nahar S Sultana J Ahmad MM Rahman M 《Antimicrobial agents and chemotherapy》2004,48(9):3567-3569
Twelve clarithromycin-resistant (MIC, > or = 1 microg/ml) Helicobacter pylori isolates were analyzed for point mutations in the 23S rRNA gene. Sequence analysis of all of the resistant isolates revealed a T-to-C transition mutation at position 2182. Transformation experiments confirmed that a single T-to-C transition mutation at position 2182 is associated with clarithromycin resistance. 相似文献
10.
Katherine A. Benfer Kelly A. Weir Kristie L. Bell Baitun Nahar Robert S. Ware Peter S. W. Davies 《Disability and rehabilitation》2017,39(23):2404-2412
Purpose: There is paucity of research investigating oropharyngeal dysphagia (OPD) in young children with cerebral palsy (CP), and most studies explore OPD in high-resource countries. This study aimed at determining the proportion and severity of OPD in preschool children with CP in Bangladesh, compared to Australia.Method: Cross-sectional, comparison of two cohorts. Two hundred and eleven children with CP aged 18–36 months, 81 in Bangladesh (mean?=?27.6 months, 61.7% males), and 130 in Australia (mean?=?27.4 months, 62.3% males). The Dysphagia Disorders Survey (DDS) – Part 2 was the primary OPD outcome for proportion and severity of OPD. Gross motor skills were classified using the Gross Motor Function Classification System (GMFCS), motor type/distribution.Results: (i) Bangladesh sample: proportion OPD?=?68.1%; severity?=?10.4 SD?=?7.9. Australia sample: proportion OPD?=?55.7%; severity?=?7.0 SD?=?7.5. (ii) There were no differences in the proportion or severity of OPD between samples when stratified for GMFCS (OR?=?2.4, p?=?0.051 and β?=?1.2, p?=?0.08, respectively).Conclusions: Despite overall differences in patterns of OPD between Bangladesh and Australia, proportion and severity of OPD (when adjusted for the functional gross motor severity of the samples) were equivalent. This provides support for the robust association between functional motor severity and OPD proportion/severity in children with CP, regardless of the resource context.
- Implications for Rehabilitation
The proportion and severity of OPD according to gross motor function level were equivalent between high- and low-resource countries (LCs).
Literature from high-resource countries may be usefully interpreted by rehabilitation professionals for low-resource contexts using the GMFCS as a framework.
The GMFCS is a useful classification in LCs to improve earlier detection of children at risk of OPD and streamline management pathways for optimal nutritional outcomes.
Rehabilitation professionals working in LCs are likely to have a caseload weighted towards GMFCS III–V, with less compensatory OPD management options available (such as non-oral nutrition through tubes).