| 1. |
- Feng, Zhaoxuan
(author)
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From Polysaccharides to Functional Materials for Trace Pharmaceutical Adsorption
- 2019
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Doctoral thesis (other academic/artistic)abstract
- The transition to bioeconomy will reduce our dependency on fossil fuels as well as contribute to a more sustainable society. Within this framework, exploitation and development of renewable substitutes to petroleum-based products provides feasible roadmap for the material design. Here a perspective is provided to how the natural polysaccharides chitosan (CS) and/or cellulose (CL) could be elaborated and transformed to high-performance materials with the explicit aim of removing trace pharmaceutical contaminants from the wastewater, thus facilitating the sustainable development. In the first part of the thesis, chitosan and cellulose were converted to the carbon spheres (C-sphere) through a microwave-assisted hydrothermal carbonization process, and C-sphere was further broken down to the nanographene oxide (nGO) via a simple oxidation route. On this foundation, a green pathway was developed for fabrication of biobased materials for wastewater purification. First, macroporous chitosan-based composite hydrogels with controllable properties were developed, where chitosan-derived nGO worked as a functional property enhancer. Second, a further development changing from the bulky hydrogels to microgels consisting of CS composite particles in the microscopic size was achieved by a fast one-pot spraying-drying process. The crosslinking reaction occurred in situ during the spray-drying. Last, the C-sphere by-itself was also believed to be a potential adsorbent for wastewater contaminants. In the next step the prepared systems were evaluated for their capacity to adsorb pharmaceutical contaminants. Diclofenac sodium (DCF) was utilized as the model drug, and the three fabricated bio-adsorbents all demonstrated effective DCF adsorption performance, with the adsorption efficiency varying from 65.6 to 100%. Moreover, the DCF adsorption kinetics, isotherms and thermodynamic study were also investigated to reveal the nature of the adsorption process with the different materials. Finally, chitosan-based microspheres were selected for the reusability study, with the adsorption efficiency above 70% retained after six adsorption-desorption cycles, thus further endowing the promising potential of the fabricated bio-adsorbents for commercial applications.
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| 2. |
- Algaba Brazalez, Astrid, 1983, et al.
(author)
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Improving microstrip filters with gap waveguide packaging
- 2011
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In: Proceedings of the 5th European Conference on Antennas and Propagation, EUCAP 2011. Rome, 11-15 April 2011. - 9781457702501 ; , s. 1080-1084
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Conference paper (peer-reviewed)abstract
- A study is presented of the performance of microstrip filters packaged with Perfect Magnetic Conductor (PMC) and realization of the PMC using a lid of nails. A 3rd order parallel coupled-line bandpass filter is designed and packaged with a lid of nails at the Ku-band. The study shows the PMC packaging technique is very efficient in improving the filter characteristics including the insertion loss in the bandpass region.
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| 3. |
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| 4. |
- Adams, A. M., et al.
(author)
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Growth dynamics among adolescent girls in Bangladesh : Evidence from nationally representative data spanning 2011-2014
- 2021
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In: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 16:7
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Journal article (peer-reviewed)abstract
- BackgroundAdolescence is the last opportunity to reverse any growth faltering accumulated from fetal life through childhood and it is considered a crucial period to optimize human development. In Bangladesh, a growing double burden of underweight and obesity in adolescents is recognized, yet limited data exists on how, when, and where to intervene. This study assesses the dynamics of growth among adolescent girls in Bangladesh, providing insight about critical junctures where faltering occurs and where immediate interventions are warranted.MethodsWe pooled data from Bangladesh’s Food Security and Nutrition Surveillance Project collected between 2011 and 2014 to document the age dynamics of weight and linear growth. 20,572 adolescent girls were measured for height and 19,345 for weight. We constructed growth curves for height, weight, stunting, and underweight. We also stratified growth dynamics by wealth quintile to assess socioeconomic inequities in adolescent trajectories.ResultsHeight-for-age z-score (HAZ) in Bangladeshi girls deteriorates throughout adolescence and especially during the early years. Mean HAZ decreases by 0.20 standard deviations (sd) per year in early adolescence (10–14 years) vs 0.06 sd/year during late adolescence (15–19 years), while stunting increases by 16 percentage points (pp) vs 6.7 pp, respectively. Conversely, BMI-for-age z-score (BAZ) increases by 0.13 sd/year in early adolescence vs 0.02 sd/year in late adolescence, and underweight decreases by 12.8 pp vs 3.2 pp. Adolescent girls in all socioeconomic groups show a similar pattern of HAZ and BAZ dynamics, but the curve for the richest quintile stays above that of the poorest across all ages.ConclusionsTrends and levels of stunting and underweight among adolescent girls in Bangladesh are worrisome, suggesting substantial linear growth faltering in early adolescence, with improving weight-for-age occurring only as linear growth slows and stops. Given the rising burden of non-communicable diseases (NCDs) in Bangladesh and emerging evidence of the link between stunting and later chronic diseases, greater attention to adolescent growth and development is needed. Our findings suggest that, to address stunting, interventions in early adolescence would have the greatest benefits. School-based interventions could be a way to target this population.
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| 5. |
- Patel, Chirag J., et al.
(author)
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Systematic assessment of pharmaceutical prescriptions in association with cancer risk : a method to conduct a population-wide medication-wide longitudinal study
- 2016
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In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6
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Journal article (peer-reviewed)abstract
- It is a public health priority to identify the adverse and non-adverse associations between pharmaceutical medications and cancer. We search for and evaluate associations between all prescribed medications and longitudinal cancer risk in participants of the Swedish Cancer Register (N = 9,014,975). We associated 552 different medications with incident cancer risk (any, breast, colon, and prostate) during 5.5 years of follow-up (7/1/2005-12/31/2010) in two types of statistical models, time-to-event and case-crossover. After multiple hypotheses correction and replication, 141 (26%) drugs were associated with any cancer in a time-to-event analysis constraining drug exposure to 1 year before first cancer diagnosis and adjusting for history of medication use. In a case-crossover analysis, 36 drugs (7%) were associated with decreased cancer risk. 12 drugs were found in common in both analyses with concordant direction of association. We found 14, 10, 7% of all drugs associated with colon, prostate, and breast cancers in time-to-event models. We only found 1, 2%, and 0% for these cancers, respectively, in case-crossover analyses. Pharmacoepidemiologic analyses of cancer risk are sensitive to modeling choices and false-positive findings are a threat. Medication-wide analyses using different analytical models may help suggest consistent signals of increased cancer risk.
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| 6. |
- Baruah, S., et al.
(author)
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Effect of seeded substrates on hydrothermally grown ZnO nanorods
- 2009
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In: Journal of Sol-Gel Science and Technology. - : Springer Berlin/Heidelberg. - 0928-0707 .- 1573-4846. ; 50:3, s. 456-464
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Journal article (peer-reviewed)abstract
- We report a study on the effect of seeding on glass substrates with zinc oxide nanocrystallites towards the hydrothermal growth of ZnO nanorods from a zinc nitrate hexahydrate and hexamethylenetetramine solution at 95 °C. The seeding was done with pre-synthesized ZnO nanoparticles in isopropanol with diameters of about 6–7 nm as well as the direct growth of ZnO nanocrystallites on the substrates by the hydrolysis of pre-deposited zinc acetate film. The nanorods grown on ZnO nanoparticle seeds show uniform dimensions throughout the substrate but were not homogenously aligned vertically from the substrate and appeared like nanoflowers with nanorod petals. Nanorods grown from the crystallites formed in situ on the substrates displayed wide variations in dimension depending upon the preheating and annealing conditions. Annealing the seed crystals below 350 °C led to scattered growth directions whereupon preferential orientation of the nanorods perpendicular to the substrates was observed. High surface to volume ratio which is vital for gas sensing applications can be achieved by this simple hydrothermal growth of nanorods and the rod height and rod morphology can be controlled through the growth parameters.
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| 7. |
- Baruah, Sunandan, et al.
(author)
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Enhanced visible light photocatalysis through fast crystallization of zinc oxide nanorods
- 2010
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In: Beilstein Journal of Nanotechnology. - : Beilstein-Institut. - 2190-4286. ; 1:1, s. 14-20
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Journal article (peer-reviewed)abstract
- Hydrothermally grown ZnO nanorods have inherent crystalline defects primarily due to oxygen vacancies that enhance optical absorption in the visible spectrum, opening up possibilities for visible light photocatalysis. Comparison of photocatalytic activity of ZnO nanorods and nanoparticle films on a test contaminant methylene blue with visible light irradiation at 72 kilolux (klx) showed that ZnO nanorods are 12–24% more active than ZnO nanoparticulate films. This can be directly attributed to the increased effective surface area for adsorption of target contaminant molecules. Defects, in the form of interstitials and vacancies, were intentionally created by faster growth of the nanorods by microwave activation. Visible light photocatalytic activity was observed to improve by ≈8% attributed to the availability of more electron deficient sites on the nanorod surfaces. Engineered defect creation in nanostructured photocatalysts could be an attractive solution for visible light photocatalysis.
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| 8. |
- LANDEGREN TEDGÅRD, EVA, et al.
(author)
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Vulnerable parenting among mothers with substance abuse in their family of origin: a cross-sectional comparative study of mothers in an infant and toddler program
- 2016
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In: SpringerPlus. - : Springer Science and Business Media LLC. - 2193-1801. ; 5:1
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Journal article (peer-reviewed)abstract
- Objective: To investigate whether women raised in a family with substance abuse constitute a particularly vulnerable group of patients in an infant psychiatry setting and to identify the risk factors of suspected parental malfunctioning in women referred to treatment in an infant and toddler intervention program. Background: A history of family substance abuse can severely disrupt the caretaking abilities of parents in ways that can have far-reaching consequences, and children growing up with insufficient parental care may incorporate this deficiency into their own parental behavior. Methods: In total, 126 mothers completed self-report questionnaires assessing their substance abuse and health problems as well as problems in their family of origin. The index group was defined as women who reported substance abuse in their family of origin (n=35). The comparison group was defined as women who denied substance abuse in their family of origin (n=91). Results: Symptoms of depression and anxiety were overrepresented in the total group of mothers compared with the Swedish norm. The index group had experienced parental divorce and traumatic life events more often and reported earlier substance abuse of their own. They had significantly more depression and ADHD symptoms and were more often single parents. All these factors can have a negative influence, separately or in combination, on the ability to practice sensitive parenting. Conclusions: Female offspring of substance-abusing parents are an especially vulnerable group of patients. To prevent the intergenerational transmission of alcohol and drug abuse, it is important to identify parents with specific needs and to administer targeted treatment and support at primary health care centers and child psychiatric clinics. © 2016, The Author(s).
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| 9. |
- Jonsson, KR, et al.
(author)
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Social Capital, Deprivation and Psychological Well-Being among Young Adolescents: A Multilevel Study from England and Wales
- 2020
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In: International journal of environmental research and public health. - : MDPI AG. - 1660-4601. ; 17:10
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Journal article (peer-reviewed)abstract
- Examining the mechanisms influencing mental health and life satisfaction simultaneously allows for a better understanding of adolescents psychological well-being. Six indicators of neighbourhood social capital (NSC), neighbourhood socioeconomic deprivation (SecD) and their association with psychological well-being among young adolescents aged 10-15 from England and Wales were investigated. Using a random sample of 5201 adolescents (7253 observations) from the UK Household Longitudinal Study merged to aggregated local area census measures, we fitted a series of multilevel models. The findings showed that not being worried about crime and friendship networks mitigated the negative effects of deprivation on adolescent’s psychological well-being. These findings suggest that some forms of NSC may have a buffering and protective function, with the strongest effects in deprived neighbourhoods. We further found that psychological well-being of adolescents is dependent on both individual vulnerabilities and neighbourhood context. However caution is required if, and when public health policies are formulated to address this issue, given significant variations (27-36%) in the inter- and intra-individual psychological well-being were found among this group over time. Thus, policies designed to improve psychological well-being among adolescents should take into account the role of social processes in transmitting deprivation’s effects, as well as the various forms of social capital.
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| 10. |
- Patel, Chirag I., et al.
(author)
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Histogram of Oriented Gradient-Based Fusion of Features for Human Action Recognition in Action Video Sequences
- 2020
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In: Sensors. - : MDPI. - 1424-8220. ; 20:24
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Journal article (peer-reviewed)abstract
- Human Action Recognition (HAR) is the classification of an action performed by a human. The goal of this study was to recognize human actions in action video sequences. We present a novel feature descriptor for HAR that involves multiple features and combining them using fusion technique. The major focus of the feature descriptor is to exploits the action dissimilarities. The key contribution of the proposed approach is to built robust features descriptor that can work for underlying video sequences and various classification models. To achieve the objective of the proposed work, HAR has been performed in the following manner. First, moving object detection and segmentation are performed from the background. The features are calculated using the histogram of oriented gradient (HOG) from a segmented moving object. To reduce the feature descriptor size, we take an averaging of the HOG features across non-overlapping video frames. For the frequency domain information we have calculated regional features from the Fourier hog. Moreover, we have also included the velocity and displacement of moving object. Finally, we use fusion technique to combine these features in the proposed work. After a feature descriptor is prepared, it is provided to the classifier. Here, we have used well-known classifiers such as artificial neural networks (ANNs), support vector machine (SVM), multiple kernel learning (MKL), Meta-cognitive Neural Network (McNN), and the late fusion methods. The main objective of the proposed approach is to prepare a robust feature descriptor and to show the diversity of our feature descriptor. Though we are using five different classifiers, our feature descriptor performs relatively well across the various classifiers. The proposed approach is performed and compared with the state-of-the-art methods for action recognition on two publicly available benchmark datasets (KTH and Weizmann) and for cross-validation on the UCF11 dataset, HMDB51 dataset, and UCF101 dataset. Results of the control experiments, such as a change in the SVM classifier and the effects of the second hidden layer in ANN, are also reported. The results demonstrate that the proposed method performs reasonably compared with the majority of existing state-of-the-art methods, including the convolutional neural network-based feature extractors.
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