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Sökning: WFRF:(Rahman Hafizur)

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1.
  • Hossain, Aniqa T., et al. (författare)
  • Measuring coverage and quality of supportive care for inpatient neonatal infections : EN-BIRTH multi-country validation study
  • 2022
  • Ingår i: Journal of Global Health. - : International Global Health Society. - 2047-2978 .- 2047-2986. ; 12
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: An estimated 7 million episodes of severe newborn infections occur annually worldwide, with half a million newborn deaths, most oc-curring in low-and middle-income countries. Whilst injectable antibiotics are necessary to treat the infection, supportive care is also crucial in ending preventable mortality and morbidity. This study uses multi-country data to assess gaps in coverage, quality, and documentation of supportive care, considering implications for measurement.Methods: The EN-BIRTH study was conducted in five hospitals in Bangla-desh, Nepal, and Tanzania (July 2017-July 2018). Newborns with an ad-mission diagnosis of clinically-defined infection (sepsis, meningitis, and/or pneumonia) were included. Researchers extracted data from inpatient case notes and interviews with women (usually the mothers) as the primary fam-ily caretakers after discharge. The interviews were conducted using a struc-tured survey questionnaire. We used descriptive statistics to report coverage of newborn supportive care components such as oxygen use, photothera-py, and appropriate feeding, and we assessed the validity of measurement through survey-reports using a random-effects model to generate pooled estimates. In this study, key supportive care components were assessment and correction of hypoxaemia, hyperbilirubinemia, and hypoglycaemia.Results: Among 1015 neonates who met the inclusion criteria, 89% had an admission clinical diagnosis of sepsis. Major gaps in documentation and care practices related to supportive care varied substantially across the par-ticipating hospitals. The pooled sensitivity was low for the survey-reported oxygen use (47%; 95% confidence interval (CI) = 30%-64%) and moderate for phototherapy (60%; 95% CI = 44%-75%). The pooled specificity was high for both the survey-reported oxygen use (85%; 95% CI = 80%-89%) and phototherapy (91%; 95% CI = 82%-97%).Conclusions: The women's reports during the exit survey consistently un-derestimated the coverage of supportive care components for managing infection. We have observed high variability in the inpatient documents across facilities. A standardised ward register for inpatient small and sick newborn care may capture selected supportive care data. However, tracking the detailed care will require standardised individual-level data sets linked to newborn case notes. We recommend investments in assessing the im-plementation aspects of a standardised inpatient register in resource-poor settings.
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2.
  • Hossain, Aniqa T, et al. (författare)
  • Measuring coverage and quality of supportive care for inpatient neonatal infections: EN-BIRTH multi-country validation study.
  • 2022
  • Ingår i: Journal of global health. - : International Global Health Society. - 2047-2986 .- 2047-2978. ; 12
  • Tidskriftsartikel (refereegranskat)abstract
    • An estimated 7 million episodes of severe newborn infections occur annually worldwide, with half a million newborn deaths, most occurring in low- and middle-income countries. Whilst injectable antibiotics are necessary to treat the infection, supportive care is also crucial in ending preventable mortality and morbidity. This study uses multi-country data to assess gaps in coverage, quality, and documentation of supportive care, considering implications for measurement.The EN-BIRTH study was conducted in five hospitals in Bangladesh, Nepal, and Tanzania (July 2017-July 2018). Newborns with an admission diagnosis of clinically-defined infection (sepsis, meningitis, and/or pneumonia) were included. Researchers extracted data from inpatient case notes and interviews with women (usually the mothers) as the primary family caretakers after discharge. The interviews were conducted using a structured survey questionnaire. We used descriptive statistics to report coverage of newborn supportive care components such as oxygen use, phototherapy, and appropriate feeding, and we assessed the validity of measurement through survey-reports using a random-effects model to generate pooled estimates. In this study, key supportive care components were assessment and correction of hypoxaemia, hyperbilirubinemia, and hypoglycaemia.Among 1015 neonates who met the inclusion criteria, 89% had an admission clinical diagnosis of sepsis. Major gaps in documentation and care practices related to supportive care varied substantially across the participating hospitals. The pooled sensitivity was low for the survey-reported oxygen use (47%; 95% confidence interval (CI) = 30%-64%) and moderate for phototherapy (60%; 95% CI = 44%-75%). The pooled specificity was high for both the survey-reported oxygen use (85%; 95% CI = 80%-89%) and phototherapy (91%; 95% CI = 82%-97%).The women's reports during the exit survey consistently underestimated the coverage of supportive care components for managing infection. We have observed high variability in the inpatient documents across facilities. A standardised ward register for inpatient small and sick newborn care may capture selected supportive care data. However, tracking the detailed care will require standardised individual-level data sets linked to newborn case notes. We recommend investments in assessing the implementation aspects of a standardised inpatient register in resource-poor settings.
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3.
  • Hague, Enamul, et al. (författare)
  • Antimicrobial and Cytotoxic Activities of the Crude Extracts and Isolated Compounds of Xylocarpus mollucensis
  • 2008
  • Ingår i: Dhaka University Journal of Pharmaceutical Sciences. - Dhaka, Bangladesh : Bangladesh Journals Online (JOL). - 1816-1839 .- 1816-1820. ; 6:2, s. 109-112
  • Tidskriftsartikel (refereegranskat)abstract
    • The fractionated crude extracts and three isolated pure compounds XM-1, XM-2 and XM-3 from stem bark of Xylocarpus mollucensis were screened for their antibacterial and antifungal activities and cytotoxicity against brine shrimp nauplii. Petroleum ether, ethyl acetate (EtOAc) and methanol (MeOH) extracts and the compounds isolated from EtOAc fractions were studied for their antimicrobial activities. Cytotoxic activities were conducted only with EtOAc extract and its selected fractions. The EtOAc extract showed promising antimicrobial activities against all the gram positive and gram negative bacteria whereas petroleum ether extract showed moderate activities and the MeOH extract did not show any antimicrobial activities. The isolated pure compounds XM-1, XM-2 and XM-3, whose structures were not elucidated, exhibited activities against most of the bacterial strains. The cytotoxicity towards brine shrimp nauplii of the crude EtOAC extract and its selected fractions were studied. The LC50 values of the EtoAc extract was 12.6 µg/ml and for the fractions 2, 5, 8 and 13 were 17.78, 13.34, 14.13 and 15.85 µg/ml, respectively.
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4.
  • Haque, Enamul, et al. (författare)
  • Triterpenoids from the Stem Bark of Avicennia officinalis
  • 2006
  • Ingår i: Dhaka University Journal of Pharmaceutical Sciences. - Dhaka, bangladesh : Bangladesh Journals Online (JOL). - 1816-1839 .- 1816-1820. ; 5:1-2, s. 53-57
  • Tidskriftsartikel (refereegranskat)abstract
    • The triterpinoids, betulinic acid, lupeol and betulinaldehyde, were isolated from the ethyl acetate extract of the stem bark of Avicennia officinalis (Avicenniaceae) by a combination of column and preparative thin- layer chromatography over silica gel. The structures of these compounds were determined by spectroscopic analysis (UV, IR, 1 H NMR, 13 CNMR and EIMS). This is the first report of a systematic phytochemical investigation and the presence of these triterpoids from this plant.
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5.
  • Norlin, Börje, associate professor, 1967-, et al. (författare)
  • Sulfur homogeneity mapping in 2D and 3D can improve packaging paper strength
  • 2023
  • Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
    • Sodium sulfite is commonly used for impregnating wood chips prior to refining when producing high-yield pulps such as CTMP. The impregnation process should ideally result in evenly sulfonated lignin, i.e. similar concentrations of sulfite (SO3 ^2-) ions in all parts of each wood chip. Sulfonated lignin is known to swell the fiber wall, which is beneficial for developing higher joint strength between fibers. In reality, even sulfonation is not easy to achieve considering variations in wood chip size, density, quality, etc. Being able to trace where the sulfite ions end up in the wood or fiber structure can therefore be key to both process and product development in the future. Synchrotron measurements can provide an understanding of the sulfur distribution both inside single wood fibers and on a larger scale between wood fibers. There is little knowledge of wood fiber nanostructures in 3 dimensions, although some interesting research has been conducted recently [1]. We have compared these measurements with 2D synchrotron XRF mappings [2]. The 3D material mapping provides insight into a sub-fiber level, but the 2D mapping technique might be preferable when studying sulfur distributions due to the highly uneven sulfur content observed. We can probably learn more about the development of fiber-joint-strength and strength uniformity in products by characterizing the distribution of sulfur on the sub-fiber level. This paper discusses feasible future measurement strategies.[1] Fernando, D., et.al, Sci Rep 13, 2350 (2023). DOI: 101038/s41598-023-29113-x[2] Norlin, B., et.al, JINST 18 C01012. DOI: 10.1088/1748-0221/18/01/C01012  
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6.
  • Norlin, Börje, associate professor, 1967-, et al. (författare)
  • Visualisation of sulphur on single fibre level for pulping industry
  • 2023
  • Ingår i: Journal of Instrumentation. - : Institute of Physics (IOP). - 1748-0221. ; 18:01, s. C01012-C01012
  • Tidskriftsartikel (refereegranskat)abstract
    • In the pulp and paper industry, about 5 Mt/y chemithermomechanical pulp (CTMP) are produced globally from softwood chips for production of carton board grades. For tailor making CTMP for this purpose, wood chips are impregnated with aqueous sodium sulphite for sulphonation of the wood lignin. When lignin is sulphonated, the defibration of wood into pulp becomes more selective, resulting in enhanced pulp properties. On a microscopic fibre scale, however, one could strongly assume that the sulphonation of the wood structure is very uneven due to its macroscale size of wood chips. If this is the case and the sulphonation could be done significantly more evenly, the CTMP process could be more efficient and produce pulp even better suited for carton boards. Therefore, the present study aimed to develop a technique based on X-ray fluorescence microscopy imaging (µXRF) for quantifying the sulphur distribution on CTMP wood fibres. Firstly, the feasibility of µXRF imaging for sulphur homogeneity measurements in wood fibres needs investigation. Therefore, clarification of which spatial and spectral resolution that allows visualization of sulphur impregnation into single wood fibres is needed. Measurements of single fibre imaging were carried out at the Argonne National Laboratory’s Advanced Photon Source (APS) synchrotron facility. With a synchrotron beam using one micrometre scanning step, images of elemental mapping are acquired from CTMP samples diluted with non-sulphonated pulp under specified conditions. Since the measurements show significant differences between sulphonated and non-sulphonated fibres, and a significant peak concentration in the shell of the sulphonated fibres, the proposed technique is found to be feasible. The required spatial resolution of the µXRF imaging for an on-site CTMP sulphur homogeneity measurement setup is about 15 µm, and the homogeneity measured along the fibre shells is suggested to be used as the CTMP sulphonation measurement parameter.
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7.
  • Rahman, Hafizur, Research Engineer, 1978- (författare)
  • Aspects of optimizing pulp fibre properties for tissue and packaging materials
  • 2021
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • To improve the competitive advantages of pulp fibre-based materials for tissue and packaging over fossil-based products, it is essential to increase knowledge of the selectivity of the cooking and the chemimechanical processes by optimizing the unit operations of impregnation, cooking and refining. A general goal in pulping processes is to achieve as efficient and even fibre separation as possible. A key to achieving this is to improve impregnation uniformity. In the case of chemical pulping, we need to study how a more even distribution of lignin at the fibre level via easily impregnated wood chips can be achieved using classic measures such as equalized hydroxide ion concentration, increased initial sulphide ion concentration, low sodium ion concentration and a low cooking temperature combined with an oxidative and reductive environment. In the case of chemithermomechanical pulp (CTMP) manufacturing, we need to achieve as even a degree of sulphonation as possible at the level of the individual fibres by means of improved sulphite ion distribution within the wood chips before they are pre-heated prior to entering the refiner. Firstly, we have studied selective cooking systems for sulphate pulp manufacturing in oxidative (polysulfide) and reductive (sodium borohydride) environments. The yield increased from 48% to a maximum of 53%, which resulted in faster dewatering when mimicking a tissue papermaking process. This could explain how the advantage of the increased yield (fewer fibres and a more open sheet structure) outweighs the negative effects of the higher hemicellulose content on the dewatering properties. Moreover, the increased proportion of hemicellulose in the fibre walls resulted in improved bonding and increased tensile index at a certain refining energy. Secondly, we have studied the uniformity of impregnation at the fibre level by developing an accurate way of measuring sulphur and sodium content in measuring points that are 5-10 µm in diameter with miniaturized X-ray-based technology. This technology is considered cheap and efficient enough to be introduced in industrial labs and/or in online equipment. Our newly built miniaturized energy dispersive X-ray fluorescence (ED-XRF) demonstrates the capability of imaging sulphur and possibly sodium distribution in wood chip fibres or individual fibres on a micro scale. In parallel, to the above research we have studied a new catalytic lignin-selective cooking method where a substantial portion of the dissolved lignin can be extracted as vanillin, creating significant value and opportunities for new cost-efficient wood biorefinery systems. 
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8.
  • Rahman, Hafizur, Researcher, 1978-, et al. (författare)
  • Characterization of impregnation depth in wood fibers related manufacturing of advanced fiber materials replacing fossil-based materials
  • 2022
  • Ingår i: Proceedings International mechanical Pulping Conference. ; , s. 162-165
  • Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
    • An underestimated problem in the rapidly growing CTMP industry is uneven sulphonation. Optimizing the unit operations before chip refining, chip washing, steaming, impregnation, and preheating improves efficiency, provides smoother fiber properties, and reduces the cost of certain properties in the final product. Impregnation is crucial to the CTMP quality, and a further improvement in its smoothness requires a careful study of the optimization of pulpwood chipping and the chipping process with reduction technology at sawmills. The CTMP system, however, is difficult to optimize due to the lack of rapid measurement methods for determining the smoothness of the impregnation at the fiber level. The ability to study how the processing system can be optimized requires a robust method of measuring the degree of sulphonation at the fiber level. It is possible to study CTMP's degree of sulphonation at the fiber level by measuring the distribution of elemental sulphur and counterions of the sulphonate groups, such as sodium or calcium. Thus, we are developing an XRF (x-ray fluorescence) technology based on scanning imaging and energy-resolved X-ray spectrum from a collimated X-ray source. The measurement technology is developed so that it can be used in pulp industry laboratories.
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9.
  • Rahman, Hafizur, Researcher, 1978-, et al. (författare)
  • Development of improved CTMP with even sulphonate distribution at fibre level using XRF analysis
  • 2022
  • Ingår i: Transactions of the 17th Fundamental Research Symposium held in Cambridge: August/September 2022. - 9780992616366 ; , s. 3-11
  • Konferensbidrag (refereegranskat)abstract
    • Optimizing the fiber property distribution could increase the pulp properties as well as the process efficiency of chemimechanical pulps (CMP/CTMP). This can only be achieved with a better understanding of how evenly distributed sulphonate concentrations are between the individual CTMP fibres. Given that the quality of wood chips varies with the chipping methods used in pulpwood processing and sawmill processing, as well as with the chip screening system, it is a challenge to develop an impregnation process that ensures even distribution of sodium sulphite (Na2SO3) in the liquid used to impregnate the chemimechanical pulp (CMP/CTMP). Therefore, the distribution of sulphonate groups within wood chips and individual fibers must be measured at the microscale level. On a micro level, the degree of unevenness, ie, the amount of fiber sulphonation and softening before defibration, cannot be determined due to the use of excessively robust or complex processing methods. By having it, we could better understand how sulphonation occurs before defibration, so we could improve impregnation. Developing a laboratory-scale miniaturized energy dispersive X-ray fluorescence (ED-XRF) method that measures sulfur distribution at the fiber level can enable us to study the influence of impregnation on improving processes.
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10.
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