| 1. |
- Lozano, Rafael, et al.
(författare)
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Measuring progress from 1990 to 2017 and projecting attainment to 2030 of the health-related Sustainable Development Goals for 195 countries and territories: a systematic analysis for the Global Burden of Disease Study 2017
- 2018
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Ingår i: The Lancet. - : Elsevier. - 1474-547X .- 0140-6736. ; 392:10159, s. 2091-2138
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Tidskriftsartikel (refereegranskat)abstract
- Background: Efforts to establish the 2015 baseline and monitor early implementation of the UN Sustainable Development Goals (SDGs) highlight both great potential for and threats to improving health by 2030. To fully deliver on the SDG aim of “leaving no one behind”, it is increasingly important to examine the health-related SDGs beyond national-level estimates. As part of the Global Burden of Diseases, Injuries, and Risk Factors Study 2017 (GBD 2017), we measured progress on 41 of 52 health-related SDG indicators and estimated the health-related SDG index for 195 countries and territories for the period 1990–2017, projected indicators to 2030, and analysed global attainment. Methods: We measured progress on 41 health-related SDG indicators from 1990 to 2017, an increase of four indicators since GBD 2016 (new indicators were health worker density, sexual violence by non-intimate partners, population census status, and prevalence of physical and sexual violence [reported separately]). We also improved the measurement of several previously reported indicators. We constructed national-level estimates and, for a subset of health-related SDGs, examined indicator-level differences by sex and Socio-demographic Index (SDI) quintile. We also did subnational assessments of performance for selected countries. To construct the health-related SDG index, we transformed the value for each indicator on a scale of 0–100, with 0 as the 2·5th percentile and 100 as the 97·5th percentile of 1000 draws calculated from 1990 to 2030, and took the geometric mean of the scaled indicators by target. To generate projections through 2030, we used a forecasting framework that drew estimates from the broader GBD study and used weighted averages of indicator-specific and country-specific annualised rates of change from 1990 to 2017 to inform future estimates. We assessed attainment of indicators with defined targets in two ways: first, using mean values projected for 2030, and then using the probability of attainment in 2030 calculated from 1000 draws. We also did a global attainment analysis of the feasibility of attaining SDG targets on the basis of past trends. Using 2015 global averages of indicators with defined SDG targets, we calculated the global annualised rates of change required from 2015 to 2030 to meet these targets, and then identified in what percentiles the required global annualised rates of change fell in the distribution of country-level rates of change from 1990 to 2015. We took the mean of these global percentile values across indicators and applied the past rate of change at this mean global percentile to all health-related SDG indicators, irrespective of target definition, to estimate the equivalent 2030 global average value and percentage change from 2015 to 2030 for each indicator. Findings: The global median health-related SDG index in 2017 was 59·4 (IQR 35·4–67·3), ranging from a low of 11·6 (95% uncertainty interval 9·6–14·0) to a high of 84·9 (83·1–86·7). SDG index values in countries assessed at the subnational level varied substantially, particularly in China and India, although scores in Japan and the UK were more homogeneous. Indicators also varied by SDI quintile and sex, with males having worse outcomes than females for non-communicable disease (NCD) mortality, alcohol use, and smoking, among others. Most countries were projected to have a higher health-related SDG index in 2030 than in 2017, while country-level probabilities of attainment by 2030 varied widely by indicator. Under-5 mortality, neonatal mortality, maternal mortality ratio, and malaria indicators had the most countries with at least 95% probability of target attainment. Other indicators, including NCD mortality and suicide mortality, had no countries projected to meet corresponding SDG targets on the basis of projected mean values for 2030 but showed some probability of attainment by 2030. For some indicators, including child malnutrition, several infectious diseases, and most violence measures, the annualised rates of change required to meet SDG targets far exceeded the pace of progress achieved by any country in the recent past. We found that applying the mean global annualised rate of change to indicators without defined targets would equate to about 19% and 22% reductions in global smoking and alcohol consumption, respectively; a 47% decline in adolescent birth rates; and a more than 85% increase in health worker density per 1000 population by 2030. Interpretation: The GBD study offers a unique, robust platform for monitoring the health-related SDGs across demographic and geographic dimensions. Our findings underscore the importance of increased collection and analysis of disaggregated data and highlight where more deliberate design or targeting of interventions could accelerate progress in attaining the SDGs. Current projections show that many health-related SDG indicators, NCDs, NCD-related risks, and violence-related indicators will require a concerted shift away from what might have driven past gains—curative interventions in the case of NCDs—towards multisectoral, prevention-oriented policy action and investments to achieve SDG aims. Notably, several targets, if they are to be met by 2030, demand a pace of progress that no country has achieved in the recent past. The future is fundamentally uncertain, and no model can fully predict what breakthroughs or events might alter the course of the SDGs. What is clear is that our actions—or inaction—today will ultimately dictate how close the world, collectively, can get to leaving no one behind by 2030.
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| 2. |
- Stanaway, Jeffrey D., et al.
(författare)
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Global, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks for 195 countries and territories, 1990-2017: A systematic analysis for the Global Burden of Disease Study 2017
- 2018
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Ingår i: The Lancet. - 1474-547X .- 0140-6736. ; 392:10159, s. 1923-1994
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Tidskriftsartikel (refereegranskat)abstract
- Background The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017 comparative risk assessment (CRA) is a comprehensive approach to risk factor quantification that offers a useful tool for synthesising evidence on risks and risk-outcome associations. With each annual GBD study, we update the GBD CRA to incorporate improved methods, new risks and risk-outcome pairs, and new data on risk exposure levels and risk- outcome associations. Methods We used the CRA framework developed for previous iterations of GBD to estimate levels and trends in exposure, attributable deaths, and attributable disability-adjusted life-years (DALYs), by age group, sex, year, and location for 84 behavioural, environmental and occupational, and metabolic risks or groups of risks from 1990 to 2017. This study included 476 risk-outcome pairs that met the GBD study criteria for convincing or probable evidence of causation. We extracted relative risk and exposure estimates from 46 749 randomised controlled trials, cohort studies, household surveys, census data, satellite data, and other sources. We used statistical models to pool data, adjust for bias, and incorporate covariates. Using the counterfactual scenario of theoretical minimum risk exposure level (TMREL), we estimated the portion of deaths and DALYs that could be attributed to a given risk. We explored the relationship between development and risk exposure by modelling the relationship between the Socio-demographic Index (SDI) and risk-weighted exposure prevalence and estimated expected levels of exposure and risk-attributable burden by SDI. Finally, we explored temporal changes in risk-attributable DALYs by decomposing those changes into six main component drivers of change as follows: (1) population growth; (2) changes in population age structures; (3) changes in exposure to environmental and occupational risks; (4) changes in exposure to behavioural risks; (5) changes in exposure to metabolic risks; and (6) changes due to all other factors, approximated as the risk-deleted death and DALY rates, where the risk-deleted rate is the rate that would be observed had we reduced the exposure levels to the TMREL for all risk factors included in GBD 2017.
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| 3. |
- Murray, Christopher J. L., et al.
(författare)
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Population and fertility by age and sex for 195 countries and territories, 1950–2017: a systematic analysis for the Global Burden of Disease Study 2017
- 2018
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Ingår i: The Lancet. - 1474-547X .- 0140-6736. ; 392:10159, s. 1995-2051
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Tidskriftsartikel (refereegranskat)abstract
- Background: Population estimates underpin demographic and epidemiological research and are used to track progress on numerous international indicators of health and development. To date, internationally available estimates of population and fertility, although useful, have not been produced with transparent and replicable methods and do not use standardised estimates of mortality. We present single-calendar year and single-year of age estimates of fertility and population by sex with standardised and replicable methods. Methods: We estimated population in 195 locations by single year of age and single calendar year from 1950 to 2017 with standardised and replicable methods. We based the estimates on the demographic balancing equation, with inputs of fertility, mortality, population, and migration data. Fertility data came from 7817 location-years of vital registration data, 429 surveys reporting complete birth histories, and 977 surveys and censuses reporting summary birth histories. We estimated age-specific fertility rates (ASFRs; the annual number of livebirths to women of a specified age group per 1000 women in that age group) by use of spatiotemporal Gaussian process regression and used the ASFRs to estimate total fertility rates (TFRs; the average number of children a woman would bear if she survived through the end of the reproductive age span [age 10–54 years] and experienced at each age a particular set of ASFRs observed in the year of interest). Because of sparse data, fertility at ages 10–14 years and 50–54 years was estimated from data on fertility in women aged 15–19 years and 45–49 years, through use of linear regression. Age-specific mortality data came from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017 estimates. Data on population came from 1257 censuses and 761 population registry location-years and were adjusted for underenumeration and age misreporting with standard demographic methods. Migration was estimated with the GBD Bayesian demographic balancing model, after incorporating information about refugee migration into the model prior. Final population estimates used the cohort-component method of population projection, with inputs of fertility, mortality, and migration data. Population uncertainty was estimated by use of out-of-sample predictive validity testing. With these data, we estimated the trends in population by age and sex and in fertility by age between 1950 and 2017 in 195 countries and territories. Findings: From 1950 to 2017, TFRs decreased by 49·4% (95% uncertainty interval [UI] 46·4–52·0). The TFR decreased from 4·7 livebirths (4·5–4·9) to 2·4 livebirths (2·2–2·5), and the ASFR of mothers aged 10–19 years decreased from 37 livebirths (34–40) to 22 livebirths (19–24) per 1000 women. Despite reductions in the TFR, the global population has been increasing by an average of 83·8 million people per year since 1985. The global population increased by 197·2% (193·3–200·8) since 1950, from 2·6 billion (2·5–2·6) to 7·6 billion (7·4–7·9) people in 2017; much of this increase was in the proportion of the global population in south Asia and sub-Saharan Africa. The global annual rate of population growth increased between 1950 and 1964, when it peaked at 2·0%; this rate then remained nearly constant until 1970 and then decreased to 1·1% in 2017. Population growth rates in the southeast Asia, east Asia, and Oceania GBD super-region decreased from 2·5% in 1963 to 0·7% in 2017, whereas in sub-Saharan Africa, population growth rates were almost at the highest reported levels ever in 2017, when they were at 2·7%. The global average age increased from 26·6 years in 1950 to 32·1 years in 2017, and the proportion of the population that is of working age (age 15–64 years) increased from 59·9% to 65·3%. At the national level, the TFR decreased in all countries and territories between 1950 and 2017; in 2017, TFRs ranged from a low of 1·0 livebirths (95% UI 0·9–1·2) in Cyprus to a high of 7·1 livebirths (6·8–7·4) in Niger. The TFR under age 25 years (TFU25; number of livebirths expected by age 25 years for a hypothetical woman who survived the age group and was exposed to current ASFRs) in 2017 ranged from 0·08 livebirths (0·07–0·09) in South Korea to 2·4 livebirths (2·2–2·6) in Niger, and the TFR over age 30 years (TFO30; number of livebirths expected for a hypothetical woman ageing from 30 to 54 years who survived the age group and was exposed to current ASFRs) ranged from a low of 0·3 livebirths (0·3–0·4) in Puerto Rico to a high of 3·1 livebirths (3·0–3·2) in Niger. TFO30 was higher than TFU25 in 145 countries and territories in 2017. 33 countries had a negative population growth rate from 2010 to 2017, most of which were located in central, eastern, and western Europe, whereas population growth rates of more than 2·0% were seen in 33 of 46 countries in sub-Saharan Africa. In 2017, less than 65% of the national population was of working age in 12 of 34 high-income countries, and less than 50% of the national population was of working age in Mali, Chad, and Niger. Interpretation: Population trends create demographic dividends and headwinds (ie, economic benefits and detriments) that affect national economies and determine national planning needs. Although TFRs are decreasing, the global population continues to grow as mortality declines, with diverse patterns at the national level and across age groups. To our knowledge, this is the first study to provide transparent and replicable estimates of population and fertility, which can be used to inform decision making and to monitor progress. Funding: Bill & Melinda Gates Foundation.
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| 4. |
- Akbar, Nabeela, et al.
(författare)
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Tunning tin-based perovskite as an electrolyte for semiconductor protonic fuel cells
- 2022
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Ingår i: International journal of hydrogen energy. - : Elsevier BV. - 0360-3199 .- 1879-3487. ; 47:8, s. 5531-5540
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Tidskriftsartikel (refereegranskat)abstract
- The use of ceramic semiconductors to serve as an efficient proton conductor is an evolving approach in the novel emerging field of semiconductor protonic fuel cells (SPFCs). One of the most critical challenges in SPFCs is to design a sufficient proton-conductivity of 0.1 S cm(-1) below <600 degrees C. Here we report to tune the perovskite BaSnO3 (BSO), a semi-conductor single-phase material, to be applied as a proton-conducting electrolyte for SPFC. It was found that the oxygen vacancies play a vital role to promote proton transport while the electronic short-circuiting issue of BSO semiconductor has been justified by the Schottky junction mechanism at the anode/electrolyte interface. We have demonstrated a SPFC device to deliver a maximum power density of 843 mW cm(-2) with an ionic conductivity of 0.23 S cm(-1) for BSO at 550 degrees C. The oxygen vacancy formation by increasing the annealing temperature helps to understand the proton transport mechanism in BSO and such novel low-temperature SPFC (LT-SPFC).
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| 5. |
- Sarfraz, Amina, et al.
(författare)
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Catalytic Effect of Silicon Carbide on the Composite Anode of Fuel Cells
- 2021
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Ingår i: ACS Applied Energy Materials. - : AMER CHEMICAL SOC. - 2574-0962. ; 4:7, s. 6436-6444
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Tidskriftsartikel (refereegranskat)abstract
- High efficiency, fuel flexibility, and sustainable energy conversion make fuel cells attractive compared to conventional energy systems. The direct ethanol fuel cells have attracted much attention because of the direct utilization of ethanol fuel. Anode materials are required to enhance the catalytic activity of the liquid fuel, which oxidize the fuel at lower operating temperature. Therefore, the catalytic effect using silicon carbide has been investigated in the LiNiO2-delta anode. The material has been characterized, and it is found that SiC shows a cubic structure and LiNiO2-delta exhibits a hexagonal structure, while the LiNiO2-delta-SiC composite exhibits a mixed cubic and hexagonal phase. Scanning electron microscopy depicts that the material is porous. The Fourier transform infrared spectroscopy analysis shows the presence of Si-O-Si, Si-C, C=O, and Si-OH bonding. The LiNiO2-delta-SiC composite (1:0.3) exhibited a maximum electrical conductivity of 1.34 S cm(-1) at 650 degrees C with an electrical band gap of 0.84 eV. The fabricated cell with the LiNiO2-delta-SiC anode exhibits a power density of 0.20 W cm(-2) at 650 degrees C with liquid ethanol fuel. The results show that there is a promising catalytic activity of SiC in the fuel cell anode.
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| 6. |
- Ullah, Muhammad Kaleem, et al.
(författare)
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Tri-doped ceria (M0.2Ce0.8O2-δ, M= Sm0.1 Ca0.05 Gd0.05) electrolyte for hydrogen and ethanol-based fuel cells
- 2019
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Ingår i: Journal of Alloys and Compounds. - : Elsevier BV. - 0925-8388. ; 773, s. 548-554
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Tidskriftsartikel (refereegranskat)abstract
- In recent scientific research, an interest has been gained significantly by rare earth metals such as cerium (Ce), samarium (Sm) and gadolinium (Gd) due to their use in fuel cells as electrolyte and catalysts. When used in an electrolyte, these materials lower the fuel cell's operating temperature compared to a conventional electrolyte, for example, yittria-stabilized zirconia (YSZ) which operates at a high temperature (≥800 °C). In this paper, the tri-doped ceria, M0.2Ce0.8O2-δ(M = Sm0.1Ca0.05Gd0.05) electrolyte powders was synthesized using the co-precipitation method at 80 °C. These dopants were used for CeO2with a total molar ratio of 1 M. Dry-pressed powder technique was used to make fuel cell pellets from the powder and placed them in the furnace to sinter at 700 °C for 60 min. Electrical conductivity of such a pellet in air was 1.2 × 10−2S cm−1at 700 °C measured by the ProboStat-NorECs setup. The crystal structure was determined with the help of X-ray diffraction (XRD), which showed that all the dopants were successfully doped in CeO2. Raman spectroscopy and UV-VIS spectroscopy were also carried out to analyse the molecular vibrations and absorbance, respectively. The maximum open-circuit voltages (OCVs) for hydrogen and ethanol fuelled at 550 °C were observed to be 0.89 V and 0.71 V with power densities 314 mW cm−2and 52.8 mW cm−2, respectively.
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| 7. |
- Akbar, Muhammad, et al.
(författare)
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Effect of sintering temperature on properties of LiNiCuZn-Oxide: a potential anode for solid oxide fuel cell
- 2019
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Ingår i: Materials Research Express. - : IOP PUBLISHING LTD. - 2053-1591. ; 6:10
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Tidskriftsartikel (refereegranskat)abstract
- Crystal structure and surface morphology play vital role in the performance of Solid Oxide Fuel cells (SOFCs) anode. Sufficient electrocatalytic activity and high conductivity are the key requirements for anode to enhance the electrochemical capability. In current work, sintering temperature effects are investigated on the properties of advanced LiNiCuZn-Oxide based electrode for solid oxide fuel cells (SOFCs). The powders were prepared by simple solid-state reaction method was followed by sintering at different temperatures (700 degrees C-1200 degrees C). Moreover, various characterization techniques have been employed to investigate the sintering temperatures effects on the crystallite size, morphology, particle size, energy band gap and absorption peaks. The energy gap (Eg) was observed to increase from 2.94 eV to 3.32 eV and dc conductivity decreased from 9.084 Scm(-1) to 0.46 Scm(-1) by increasing sintering temperature from 700 degrees C to 1200 degrees C. Additionally, the best fuel cell performance of 0.90 Wcm(-2) was achieved for LiNiCuZn-Oxide sintered at 700 degrees C using H-2/air as a fuel and oxidant and it decreased to 0.17 Wcm(-2) for powders sintered at 1200 degrees C. Based on these results, we can conclude that 700 degrees C is the best optimum temperature for these chemical compositions, where all parameters of electrode are as per SOFCs requirement.
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| 8. |
- Akbar, Mariam, et al.
(författare)
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Efficient Data Gathering in 3D Linear Underwater Wireless Sensor Networks Using Sink Mobility
- 2016
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Ingår i: Sensors. - : MDPI AG. - 1424-8220. ; 16:3
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Tidskriftsartikel (refereegranskat)abstract
- Due to the unpleasant and unpredictable underwater environment, designing an energy-efficient routing protocol for underwater wireless sensor networks (UWSNs) demands more accuracy and extra computations. In the proposed scheme, we introduce a mobile sink (MS), i.e., an autonomous underwater vehicle (AUV), and also courier nodes (CNs), to minimize the energy consumption of nodes. MS and CNs stop at specific stops for data gathering; later on, CNs forward the received data to the MS for further transmission. By the mobility of CNs and MS, the overall energy consumption of nodes is minimized. We perform simulations to investigate the performance of the proposed scheme and compare it to preexisting techniques. Simulation results are compared in terms of network lifetime, throughput, path loss, transmission loss and packet drop ratio. The results show that the proposed technique performs better in terms of network lifetime, throughput, path loss and scalability
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| 9. |
- Ali, Akbar, et al.
(författare)
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Silver-chitosan nanobiocomposite as urea biosensor
- 2014
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Ingår i: Optoelectronics and Advanced Materials Rapid Communications. - : NATL INST OPTOELECTRONICS. - 1842-6573 .- 2065-3824. ; 8:11-12, s. 1238-1242
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Tidskriftsartikel (refereegranskat)abstract
- Silver nanoparticles (Ag NPs) were synthesized by aqueous chemical growth technique. The above mentioned synthesized materials were characterized by applying scanning electron microscope (SEM) and X-ray diffraction for confirmation of morphological analysis, compositional purity, and crystalline property and emission characteristics as well. In order to fabricate the urea biosensor (potentiometric), a solution of deionized water and chitosan was prepared having Ag NPs. The said solution was dropped on the glass fiber filter having diameter of 2 cm. A wire of copper having thickness of approximately 500 pm was used for the voltage signal to pull out from the said working nanoparticles (NPs). To improve the strength, sensitivity and the quality of the potentiometric urea biosensor, a specific functional surface of Ag NPs was attained by electrostatic restrained of an enzyme (urease) onto the chitosan-Ag (a nanobiocomposite). The potentiometric reaction was measured via electrochemical detection technique. The potentiometric urea biosensor illustrates significant sensibility at room temperature with approximate to 42 mV as per span. Furthermore, the said biosensor showed an appropriate stable response within 7 sec.
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| 10. |
- Ali Ahmad, Syed Ossama, et al.
(författare)
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Application of two-dimensional materials in perovskite solar cells: recent progress, challenges, and prospective solutions
- 2021
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Ingår i: Journal of Materials Chemistry C. - : ROYAL SOC CHEMISTRY. - 2050-7526 .- 2050-7534. ; 9:40, s. 14065-14092
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Forskningsöversikt (refereegranskat)abstract
- Perovskite solar cells (per-SCs) with high performance and cost-effective solution processing have been the center of interest for researchers in the past decade. Power conversion efficiencies (PCEs) have been gradually improved up to 25.2% with relatively improved stability, which is an unparalleled progress in all generations of solar cell (SC) technology. However, there are still some prevailing challenges regarding the stability and upscaling of these promising devices. Recently, 2D layered materials (LMs) have been extensively explored to overcome the prevailing challenges of poor stability (under moisture, light soaking and high temperature), halide segregation, hysteresis, involvement of toxic materials (i.e., lead), and upscaling of devices. A critical review addressing the recent developments in the use of 2D materials, especially transition metal dichalcogenides (TMDCs), is hence necessary. The development of novel synthesis and deposition techniques including liquid-metal synthesis and ultrasonic assisted spray pyrolysis has offered more efficient fabrication of 2D-LMs with controlled thickness and morphology. Effective functionalization approaches to increase the dispersability of 2D-LMs in non-polar solvents has boosted their potential application in solar cell technology as well. Moreover, compositing 2D TMDCs with suitable organic/inorganic compounds has enabled superior charge kinetics in all functional parts of per-SCs. In addition, newly developed materials such as graphyne and graphdyine along with 2D metal organic frameworks (MOFs) and covalent organic frameworks (COFs) have been employed in per-SCs to achieve PCEs up to 20%. This review summarizes the recent progress and challenges in the application of 2D-LMs in per-SCs and outlines the future pathways to further extend the PCE of per-SCs beyond 25%. This review particularly focuses on 2D-LMs as electrode materials and additives, the underlying charge (electron-hole) transport phenomenon in the functional layers, and their chemical and structural stability.
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| 11. |
- Khokhar, Javeria, et al.
(författare)
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Prevalence and determinants of anemia among resident female university students from Southern Punjab, Pakistan
- 2022
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Ingår i: Women and Health. - : Informa UK Limited. - 0363-0242 .- 1541-0331. ; 62:6, s. 488-501
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Tidskriftsartikel (refereegranskat)abstract
- Health and nutritional status of the women of reproductive age (WRA) is expected to be influenced with women literacy status alongside other sociodemographic indicators. However, data are scant to validate if literate young women have lower incidence of anemia prevalence. Nexus to the problem stated, a cross-sectional study was conducted on 1,541 female resident university students (FRUS) aged 17–35 years from a public sector university located in Southern Punjab, Pakistan. Hemoglobin (Hb) led screening for anemia was performed followed by nutritional assessment and structured questionnaire-based sociodemographic and dietary assessment. The data generated were analyzed using independent t-test, Chi-square, and response surface regression models. Response rate for the prevalence of anemia in FRUS was 38 percent with mean Hb levels 10.5 g/dL. With a significant effect (p =.001) of participants’ weight on anemia prevalence, 22.45 percent of the sample population was recorded as underweight. Sociodemographic and dietary parameters analyzed suggested low daily food expenditure (x 2 = 20.59; p =.000) and reduced intake of meat (x 2 = 12.14; p =.01), beans & pulses (x 2 = 18.56; p =.001) to significantly influence rate of anemia prevalence in FRUS. The study concludes high prevalence rate of anemia among FRUS to strongly relate with students’ low monthly stipend, little daily food expenditure, and substandard dietary quality.
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| 12. |
- Qu, Gang, et al.
(författare)
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Enhancing the Performance of the p-n Heterostructure Electrolyte for Solid Oxide Fuel Cells via A-Site-Deficiency Engineering
- 2023
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 15:42, s. 49154-49169
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Tidskriftsartikel (refereegranskat)abstract
- Semiconductor ionic electrolytes are attracting growing interest for developing low-temperature solid oxide fuel cells (LT-SOFCs). Our recent study has proposed a p-n heterostructure electrolyte based on perovskite oxide BaCo0.4Fe0.4Zr0.1Y0.1O3-δ (BCFZY) and ZnO, achieving promising fuel cell performance. Herein, to further improve the performance of the heterostructure electrolyte, an A-site-deficiency strategy is used to solely modify BCFZY for regulating the ionic conduction and catalytic activity of the heterostructure. Two new electrolytes, B0.9CFZY-ZnO and B0.8CFZY-ZnO, were developed and systematically studied. The results show that the two samples gain improved ionic conductivity and auxiliary catalytic activity after A-site deficiency as a result of the increment of the surface and interface oxygen vacancies. The single cells with B0.9CFZY-ZnO and B0.8CFZY-ZnO exhibit enhanced peak power outputs at 450-550 °C compared to the cell based on B1.0CFZY-ZnO (typically, 745 and 795 vs 542 mW cm-2 at 550 °C). Particular attention is paid to the impact of A-site deficiency on the interface energy band alignment between BxCFZY and ZnO, which suggests that the p-n heterojunction effect of BxCFZY-ZnO for charge carrier regulation can be tuned by A-site deficiency to enable high proton transport while avoiding fuel cell current leakage. This study thus confirms the feasibility of A-site-deficiency engineering to optimize the performance of the heterostructure electrolyte for developing LT-SOFCs.
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| 13. |
- Sohail, Muhammad Tayyab, et al.
(författare)
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Impacts of urbanization, LULC, LST, and NDVI changes on the static water table with possible solutions and water policy discussions: A case from Islamabad, Pakistan
- 2023
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Ingår i: Frontiers in Environmental Science. - : Frontiers Media S.A.. - 2296-665X. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Rapid urbanization, coupled with land use land cover changes (LULC), has caused stress on freshwater resources around the globe. As in the case of Islamabad, the capital of Pakistan, the population has increased significantly, creating a deficit of natural resources and affecting the environment adversely. Therefore, the purpose of this study is to examine the effects of urbanization and LULC on the decline of the static water table in Islamabad. It also seeks to analyze water policy issues in order to achieve sustainable water resource development. The excessive pumping of the existing groundwater has exceeded the safe limit, which is justified by the constantly growing population. However, the changes in the LULC of the study area have turned many green pastures into barren land. Our research data were obtained from the Capital Development Authority (CDA), Pakistan Meteorological Department (PMD), and Landsat Satellite images. After analyzing PMD and CDA data for the last 20 years (2000–2020), the results were interpreted using Arc GIS. It has been observed that the Normalized Difference Vegetation Index (NDVI) value increases as the Land Surface Temperature (LST) decreases. Therefore, the overall observation is a decreasing trend in Islamabad temperatures due to the increased vegetation in the study area during the period of 2000–2020. It was observed that there has been a considerable drop in water levels due to over-pumping in a few areas. It is primarily associated with the increasing population of the capital in the last 2 decades. This study uses a survey to explore the potential locations for check dams to enhance and recharge the groundwater aquifers in the capital, Islamabad. It suggests catchment areas throughout the Margalla Hills along with different localities, such as Rumli Village, Trail 5, and Shahdara.
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| 14. |
- Abbafati, Cristiana, et al.
(författare)
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- 2020
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Tidskriftsartikel (refereegranskat)
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| 15. |
- Akbar, Muhammad Usman, 1990-, et al.
(författare)
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Brain tumor segmentation using synthetic MR images - A comparison of GANs and diffusion models
- 2024
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Ingår i: Scientific Data. - : Nature Publishing Group. - 2052-4463. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- Large annotated datasets are required for training deep learning models, but in medical imaging data sharing is often complicated due to ethics, anonymization and data protection legislation. Generative AI models, such as generative adversarial networks (GANs) and diffusion models, can today produce very realistic synthetic images, and can potentially facilitate data sharing. However, in order to share synthetic medical images it must first be demonstrated that they can be used for training different networks with acceptable performance. Here, we therefore comprehensively evaluate four GANs (progressive GAN, StyleGAN 1–3) and a diffusion model for the task of brain tumor segmentation (using two segmentation networks, U-Net and a Swin transformer). Our results show that segmentation networks trained on synthetic images reach Dice scores that are 80%–90% of Dice scores when training with real images, but that memorization of the training images can be a problem for diffusion models if the original dataset is too small. Our conclusion is that sharing synthetic medical images is a viable option to sharing real images, but that further work is required. The trained generative models and the generated synthetic images are shared on AIDA data hub.
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| 16. |
- Baharin, Shamsul Ammar Shamsul, et al.
(författare)
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Electromagnetic Interference From Natural Lightning on 4G Communication Links
- 2024
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Ingår i: IEEE Access. - : Institute of Electrical and Electronics Engineers (IEEE). - 2169-3536. ; 12, s. 14870-14881
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Tidskriftsartikel (refereegranskat)abstract
- In this study, microwave radiation pulses emitted from natural lightning have been found to interfere with the Fourth Generation Long Term Evolution (4G LTE) mobile communication data transmission. Two sets of measurement instruments have been synchronized where lightning electric field sensor together with 4G LTE network were evaluated its performance under two conditions namely fair-weather (four cases) and storm (four lightning cases). The microwave radiation emitted from lightning was directly measured without the use of a mixer and down-convertor to ensure the preservation of information such as the number of pulses and amplitude. A client-server architecture has been set up for data transmission utilizing User Datagram Protocol (UDP) where the packets have been generated by using Internet Performance Working Group Third Version (Iperf3) platform. Under fair-weather conditions, the 4G LTE connection at both the client and server nodes demonstrated stability and experienced minimal impact. On the other hand, natural lightning electromagnetic interference disrupted the 4G LTE communication links. Among the four reported storms, three storms have affected the 4G LTE data transmission. The first and fourth storms resulted in a complete connection drop to zero, lasting for 4 minutes and 2 seconds and for 44 seconds, respectively. The observation of hundreds microwave radiation pulses, each characterized by individual oscillating features suggests a potential disruption to packet transmission. Moreover, negative could-to-ground (-CG) and intra-cloud (IC) lightning flashes have been identified as the primary sources of interference to the 4G LTE data transmission. This information could be useful for future studies and for developers working on improving the reliability and performance of 4G LTE networks, particularly in areas prone to thunderstorms.
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| 17. |
- Bari, Muhammad R., et al.
(författare)
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H2O2-induced Ca2+ influx and its inhibition by N-(p-amylcinnamoyl) anthranilic acid in the beta-cells : involvement of TRPM2 channels
- 2009
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Ingår i: Journal of Cellular and Molecular Medicine (Print). - : Wiley. - 1582-1838 .- 1582-4934. ; 13:9B, s. 3260-3267
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Tidskriftsartikel (refereegranskat)abstract
- Type 2 melastatin-related transient receptor potential channel (TRPM2), a member of the melastatin-related TRP (transient receptor potential) subfamily is a Ca(2+)-permeable channel activated by hydrogen peroxide (H(2)O(2)). We have investigated the role of TRPM2 channels in mediating the H(2)O(2)-induced increase in the cytoplasmic free Ca(2+) concentration ([Ca(2+)](i)) in insulin-secreting cells. In fura-2 loaded INS-1E cells, a widely used model of beta-cells, and in human beta-cells, H(2)O(2) increased [Ca(2+)](i), in the presence of 3 mM glucose, by inducing Ca(2+) influx across the plasma membrane. H(2)O(2)-induced Ca(2+) influx was not blocked by nimodipine, a blocker of the L-type voltage-gated Ca(2+) channels nor by 2-aminoethoxydiphenyl borate, a blocker of several TRP channels and store-operated channels, but it was completely blocked by N-(p-amylcinnamoyl)anthranilic acid (ACA), a potent inhibitor of TRPM2. Adenosine diphosphate phosphate ribose, a specific activator of TRPM2 channel and H(2)O(2), induced inward cation currents that were blocked by ACA. Western blot using antibodies directed to the epitopes on the N-terminal and on the C-terminal parts of TRPM2 identified the full length TRPM2 (TRPM2-L), and the C-terminally truncated TRPM2 (TRPM2-S) in human islets. We conclude that functional TRPM2 channels mediate H(2)O(2)-induced Ca(2+) entry in beta-cells, a process potently inhibited by ACA.
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| 18. |
- Jönemo, Johan, 1974-, et al.
(författare)
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Efficient Brain Age Prediction from 3D MRI Volumes Using 2D Projections
- 2023
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Ingår i: Brain Sciences. - : MDPI. - 2076-3425. ; 13:9
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Tidskriftsartikel (refereegranskat)abstract
- Using 3D CNNs on high-resolution medical volumes is very computationally demanding, especially for large datasets like UK Biobank, which aims to scan 100,000 subjects. Here, we demonstrate that using 2D CNNs on a few 2D projections (representing mean and standard deviation across axial, sagittal and coronal slices) of 3D volumes leads to reasonable test accuracy (mean absolute error of about 3.5 years) when predicting age from brain volumes. Using our approach, one training epoch with 20,324 subjects takes 20–50 s using a single GPU, which is two orders of magnitude faster than a small 3D CNN. This speedup is explained by the fact that 3D brain volumes contain a lot of redundant information, which can be efficiently compressed using 2D projections. These results are important for researchers who do not have access to expensive GPU hardware for 3D CNNs.
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| 19. |
- Kausar, Tehzeeb, et al.
(författare)
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Influence diagnostics for the Cox proportional hazards regression model : method, simulation and applications
- 2023
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Ingår i: Journal of Statistical Computation and Simulation. - : Taylor & Francis. - 0094-9655 .- 1563-5163. ; 93:10, s. 1580-1600
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Tidskriftsartikel (refereegranskat)abstract
- This article investigates the performance of several residuals for the Cox proportional hazards regression model to diagnose the influential observations. The standardized and adjusted forms of residuals are proposed for Cox proportional hazards regression model. In addition, Cook's distance is proposed for both standardized and adjusted residuals. The assessment of different residuals for the identification of influential observations is made through the Monte Carlo simulation. A real dataset of bone marrow transplant Leukaemia is analyzed to show the benefit of the proposed methods. Simulation and application results show that the standardized and adjusted residuals based on the Cox-Snell method perform best for the detection of influential points. Furthermore, the standardized, and adjusted Martingale and deviance residuals work better when the sample size is large.
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| 20. |
- Khan, Rizwan, et al.
(författare)
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Dental image enhancement network for early diagnosis of oral dental disease
- 2023
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Ingår i: Scientific Reports. - : Springer Nature. - 2045-2322. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Intelligent robotics and expert system applications in dentistry suffer from identification and detection problems due to the non-uniform brightness and low contrast in the captured images. Moreover, during the diagnostic process, exposure of sensitive facial parts to ionizing radiations (e.g., X-Rays) has several disadvantages and provides a limited angle for the view of vision. Capturing high-quality medical images with advanced digital devices is challenging, and processing these images distorts the contrast and visual quality. It curtails the performance of potential intelligent and expert systems and disincentives the early diagnosis of oral and dental diseases. The traditional enhancement methods are designed for specific conditions, and network-based methods rely on large-scale datasets with limited adaptability towards varying conditions. This paper proposed a novel and adaptive dental image enhancement strategy based on a small dataset and proposed a paired branch Denticle-Edification network (Ded-Net). The input dental images are decomposed into reflection and illumination in a multilayer Denticle network (De-Net). The subsequent enhancement operations are performed to remove the hidden degradation of reflection and illumination. The adaptive illumination consistency is maintained through the Edification network (Ed-Net). The network is regularized following the decomposition congruity of the input data and provides user-specific freedom of adaptability towards desired contrast levels. The experimental results demonstrate that the proposed method improves visibility and contrast and preserves the edges and boundaries of the low-contrast input images. It proves that the proposed method is suitable for intelligent and expert system applications for future dental imaging.
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| 21. |
- Nazir, S., et al.
(författare)
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Emergence of robust half-metallic spin gap and a sizeable magnetic anisotropy in electron-doped Ca2FeOsO6
- 2023
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Ingår i: Materials Chemistry and Physics. - : Elsevier. - 0254-0584 .- 1879-3312. ; 294
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Tidskriftsartikel (refereegranskat)abstract
- Half-metallic materials having a large band gap (Eg) along with giant magnetocrystalline anisotropy energy (MAE) have been proposed to be crucial for the development of magnetic tunnel junctions. Herein, electron-doped Ca2FeOsO6 (CFOO) double perovskite oxide is investigated by employing ab-initio calculations with the inclusion of Hubbard U and spin–orbit coupling effects. Electron doping is realized by introducing Co+2/Ni+2 ion with 3d7 (t2g3 ↑ t2g2 ↓ eg2 ↑ eg0 ↓)/3d8 (t2g3 ↑ t2g3 ↓ eg2 ↑ eg0 ↓) configuration at Fe+33d5 (t2g3 ↑ t2g0 ↓ eg2 ↑ eg0 ↓) site. The thermodynamical, mechanical, and dynamical stability of these motifs for determining the synthesis feasibility at ambient conditions is established by calculating the formation energetics, elastic constants, and phonon band structure, respectively. The undoped CFOO system displays a ferrimagnetic Mott-insulating behavior due to a strong antiferromagnetic coupling between Fe and Os ions. On the other hand, electron doping induces half metallicity in CFOO, where extra electrons provided by TM-dopants produce a repulsion in the partially filled Os t2g3↓ spin-minority channel. As a consequence, the Os bands near the Fermi level are shifted to higher energetics; resulting in a conducting nature for the doped motifs. Therefore, Os ion remains in the mixed formal valence states of Os+5 and Os+6/Os+7, which reduces the moments as well. Most remarkably, a large Eg of 1.26/1.65 eV exists in the spin-majority channel of Co/Ni-doped structure, which is highly desired to effectively suppress the spin-flipping and affirm the large mean free path for spins along with a high spin-filtering response. Our results also demonstrated that the half metallicity of the studied TM-doped CFOO is robust and can be preserved under a reasonable magnitude of biaxial strains ([110]). Additionally, a sizeable MAE constant of ∼×107 erg/cm3 indicates that these materials could be potential candidates for the data storage devices.
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| 22. |
- Qadri, Syed Furqan, et al.
(författare)
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CT-based automatic spine segmentation using patch-based deep learning
- 2023
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Ingår i: International Journal of Intelligent Systems. - : Hindawi Publishing Corporation. - 0884-8173 .- 1098-111X. ; 2023
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Tidskriftsartikel (refereegranskat)abstract
- CT vertebral segmentation plays an essential role in various clinical applications, such as computer-assisted surgical interventions, assessment of spinal abnormalities, and vertebral compression fractures. Automatic CT vertebral segmentation is challenging due to the overlapping shadows of thoracoabdominal structures such as the lungs, bony structures such as the ribs, and other issues such as ambiguous object borders, complicated spine architecture, patient variability, and fluctuations in image contrast. Deep learning is an emerging technique for disease diagnosis in the medical field. This study proposes a patch-based deep learning approach to extract the discriminative features from unlabeled data using a stacked sparse autoencoder (SSAE). 2D slices from a CT volume are divided into overlapping patches fed into the model for training. A random under sampling (RUS)-module is applied to balance the training data by selecting a subset of the majority class. SSAE uses pixel intensities alone to learn high-level features to recognize distinctive features from image patches. Each image is subjected to a sliding window operation to express image patches using autoencoder high-level features, which are then fed into a sigmoid layer to classify whether each patch is a vertebra or not. We validate our approach on three diverse publicly available datasets: VerSe, CSI-Seg, and the Lumbar CT dataset. Our proposed method outperformed other models after configuration optimization by achieving 89.9% in precision, 90.2% in recall, 98.9% in accuracy, 90.4% in F-score, 82.6% in intersection over union (IoU), and 90.2% in Dice coefficient (DC). The results of this study demonstrate that our model's performance consistency using a variety of validation strategies is flexible, fast, and generalizable, making it suited for clinical application.
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| 23. |
- Ramirez, M. I., et al.
(författare)
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Technical challenges of working with extracellular vesicles
- 2018
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Ingår i: Nanoscale. - : Royal Society of Chemistry (RSC). - 2040-3364 .- 2040-3372. ; 10:3, s. 881-906
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Tidskriftsartikel (refereegranskat)abstract
- Extracellular Vesicles (EVs) are gaining interest as central players in liquid biopsies, with potential applications in diagnosis, prognosis and therapeutic guidance in most pathological conditions. These nanosized particles transmit signals determined by their protein, lipid, nucleic acid and sugar content, and the unique molecular pattern of EVs dictates the type of signal to be transmitted to recipient cells. However, their small sizes and the limited quantities that can usually be obtained from patient-derived samples pose a number of challenges to their isolation, study and characterization. These challenges and some possible options to overcome them are discussed in this review. © 2018 The Royal Society of Chemistry.
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| 24. |
- Rasool, Shahzad, et al.
(författare)
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Insight of proton transport phenomena in semiconductor ionic materials
- 2024
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Ingår i: Journal of Power Sources. - : Elsevier BV. - 0378-7753 .- 1873-2755. ; 598
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Forskningsöversikt (refereegranskat)abstract
- Semiconductor ionic materials (SIM) have recently gained broad attention due to their unique structural and chemical properties that enable efficient proton transport, making them promising materials for advanced fuel cell applications. This mini-review provides an overview of the proton transport phenomena in SIM and discusses their significance and future perspectives. We discuss the different types of SIMs, their proton transport mechanisms, and the factors that affect their performance. Furthermore, we emphasize the correlation between traditional perovskite oxides and SIMs and how this can be leveraged to improve the development of more advanced proton conductors for fuel cells. Also, we have highlighted the Proton-coupled electron transfer (PCET) mechanism in SIM. This mini-review provides a comprehensive overview of the current state of this emerging field, including its scientific foundations, future prospects, and applicable materials, technologies, devices, and basics for proton ceramic fuel cells (PCFCs).
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| 25. |
- Yousaf, M., et al.
(författare)
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Evaluation of rare earth (Yb, La) doped (Sm3Fe5O12) garnet ferrite membrane for LT-SOFC
- 2020
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Ingår i: International journal of hydrogen energy. - : Elsevier Ltd. - 0360-3199 .- 1879-3487.
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Tidskriftsartikel (refereegranskat)abstract
- Rare earth element doping is a popular methodology for improving the electrical and electrochemical properties of materials. Inspired by this ideology, garnet ferrite material Sm3Fe5O12 (SFO) doped by rare earth (Yb, La) metal ions to form Sm3-0.5Yb0.5Fe5O12 (SYFO) and Sm3-0.5La0·5Fe5O12 (SLFO). The samples are synthesized by sol gel auto combustion and have been applied as electrolyte membrane for the first time in low temperature solid oxide fuel cell (LT-SOFC). The results indicate that the as-prepared materials have triple charge transport (H+/O−2/e−) carrier which promotes the hydrogen oxidation reaction (HOR) and oxygen reduction reactions (ORR) in SOFC at triple phase boundary region (TPB). Electrochemical impedance spectroscopy (EIS) reveals that the polarization resistance of SLFO membrane significantly reduces from 0.92 Ω-cm2 to 0.45 Ω-cm2 and the power output improve from 310 mW/cm2 to 650 mW/cm2 at 550 °C temperature in comparison with that of SYFO and SFO electrolyte supported cells. UV-vis diffused spectroscopy explains the semiconducting nature of the prepared materials due to the existence of optical bandgap in the semiconductor region. The further investigation also verifies the protonic conduction of SLFO membrane by constructing oxygen ion blocking fuel cell with configuration of Ni-NCAL/BZCY/SLFO/BZCY/Ni-NCAL having 427.94 mW/Cm2 fuel cell performance with 1.03 OCV at 550 °C temperature.
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| 26. |
- Zahra, M., et al.
(författare)
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Tailoring the ions and bandgaps in a novel semi-ionic energy conversion device for electrochemical performance
- 2020
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Ingår i: Materials Today Energy. - : Elsevier BV. - 2468-6069. ; 18
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Tidskriftsartikel (refereegranskat)abstract
- The new semi-ionic energy conversion (SIEC) device has attracted remarkable attention owing to its clean and environmentally friendly applications. In this device, novel materials and mechanisms have been explored using electronic and ionic conductor materials. The tuning effect of the ions and bandgap has been studied to investigate the structural, optical, and electrochemical performance of the material. Composite materials, gadolinium-doped ceria-cadmium-doped ZnO (GDC-ZnCdO), based on ionic gadolinium-doped ceria (GDC) and semiconductor (ZnCdO) in molar ratios of 1:4, 2:3, 3:2, and 4:1 have been prepared by a wet chemical route. The crystalline structure of the GDC-ZnCdO was studied and found to have cubic and hexagonal wurtzite phases with an average crystallite size of 30–40 nm. The morphology of the prepared composite materials is a homogenous and porous structure. It was found that the addition of GDC increases the transmittance and shows a red shift in the bandgap from 2.70 eV to 2.46 eV. The maximum conductivity of 2.0 S/cm1 was achieved for the sample 4GDC-1ZnCdO at 700°C. Electrochemical impedance spectra and X-ray photoelectron spectroscopy analysis were performed to investigate the electrochemical properties of the prepared semi-ionic composite materials. The SIEC device showed a much better performance than a conventional solid oxide fuel cell. The maximum open-circuit voltage (OCV) of about 1.013 Vand power density of 0.65 W/cm2 were obtained using hydrogen fuel at 600°C, as compared with a conventional fuel cell with 0.72 V and 0.27 W/cm2, respectively. Hence, the results reveal that the ions and bandgap tuning play a crucial role in fuel cell functions. Therefore, it has been determined that the bandgap can be tuned to obtain a better and more stable performance of the SIEC device. This study presents a novel approach to enhance the electrochemical performance with the tailoring of the new semi-ionic materials.
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