| 1. |
- Khan, Kifayatullah, et al.
(författare)
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Heavy Metal Occurrence, Pathways, and Associated Socio-ecological Risks in Riverine Water : Application of Geographic Information System, Multivariate Statistics, and Risk Assessment Models
- 2023
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Ingår i: Water, Air and Soil Pollution. - 0049-6979 .- 1573-2932. ; 234:7
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Tidskriftsartikel (refereegranskat)abstract
- Heavy metal (HM) pollution is one of the major issues of concern in the world due to its serious health consequences on humans and ecology. In this study, riverine water from the River Kabul in Pakistan was studied using inductively coupled plasma mass spectrometry (ICP-MS) to determine the variation, routes, and possible socio-ecological hazards of chromium (Cr), manganese (Mn), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn) cadmium (Cd), mercury (Hg), and lead (Pb). The results revealed significant HMs variation (p < 0.05) in the sequence of Cr > Zn > Ni > Cu > Cd > Pb > Mn > Co > Hg, indicating prevalent metal contaminations in the river. Multivariate statistics showed significant strong positive correlations (p ≤ 0.01) between the individual HMs contents along the monitoring sites. The strong-moderate levels of Cu, Co, Zn, Mn, Pb, and Cd in riverine systems were observed to be caused by surrounding industrial, agrochemicals, mining, and domestic wastewater discharges along with geogenic sources, the weak levels of Cr and Ni could be induced by erosion of mafic and ultramafic rocks, and mining activities, whereas the low contamination of Hg suggests minimal atmospheric deposition with fewer industrial discharges in the environment. The overall mass flux of the ∑HMs was estimated to be around 164.10 kg/year, with significant HM pollution index (HPI) and pollution index (PI) variations along the river characterizing the potential risk of HMs in decreasing order of Cd > Hg > Cr > Ni > Co > Pb > Mn > Cu > Zn and Cd > Hg > Ni > Pb > Cr > Co > Cu > Mn > Zn, respectively. Individual HM contamination was within the ecological risk threshold (ERI < 110), where, the chronic daily intake (CDIs), hazard quotients (HQs), health indices (HIs), and cancer risks (CRs) of Cd, Ni, Co, Cr, and Pb by daily riverine water ingestion and dermal contact posing considerable human health concerns. To protect the environment and public health, our findings suggest that untreated anthropogenic wastewater discharge into the river system be strictly controlled and regulated through public awareness campaigns and legislation prohibiting the use of herbicides and fertilizers containing high levels of Cr, Ni, Co, Cd, and Pb.
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| 2. |
- Khan, Kifayatullah, et al.
(författare)
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Heavy metal pollution in the soil of a riverine basin : distribution, source, and potential hazards
- 2022
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Ingår i: Environmental Monitoring & Assessment. - : Springer Science and Business Media LLC. - 0167-6369 .- 1573-2959. ; 194:9
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Tidskriftsartikel (refereegranskat)abstract
- Soil pollution with heavy metals (HMs) has become a world environmental problem. This study focuses on surface soil contamination with Cr, Mn, Co, Ni, Cu, Zn, Cd, Hg, Pb, Fe, and Al, their sources, and potential hazards along the basin of River Swat, Pakistan. The average concentrations (mg/kg) of HMs were the most abundant for Al (24,730.19) followed by Fe (22,419.41) > Mn (386.78) > Zn (57.75) > Cr (38.07) > Ni (32.46) > Cu (23.43) > Pb (19.59) > Co (10.77) > Cd (3.18) > Hg (0.12). The concentrations of Cr and Mn in 5.45% each, Co in 10.90%, Zn in 27.27%, Cu in 36.36%, Ni in 41.81%, and Hg in 92.72% of the total soil samples exceeded their respective background values. The geostatistical approaches determined the distribution patterns of HM pollution along the basin, whereas the statistics of principal component analysis exposed the likely sources of HM contamination in the area. Pollution indices evaluated the overall HM distribution and pollution status in the area. Contamination factor showed a high degree of HM contamination in 82% of the total sampling sites, while the geo-accumulation index designated low to moderate contamination with Cr, Mn, Co, Ni, Cu, Zn, Hg, and Pb, and moderate to extreme contamination with Cd, Fe, and Al. The trend of ecological toxicity showed potential ups and downs along with the sites from low to considerable hazard (< 95 < PEHI < 190), whereas the human carcinogenic hazard was within the USEPA acceptable limits (1 x 10(-7)-1 x 10(-4)), but the non-carcinogenic hazard was higher than the threshold (HI > 1) for children because they are more exposed than adults.
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| 3. |
- Malik, Muhammad Fraz, et al.
(författare)
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Multi-Agent based Functional Testing in the Distributed Environment
- 2017
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Ingår i: INTERNATIONAL JOURNAL OF ADVANCED COMPUTER SCIENCE AND APPLICATIONS. - 2158-107X. ; 8:8, s. 137-143
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Tidskriftsartikel (refereegranskat)abstract
- Verification and testing are two formal techniques of defect reduction applied on designing and development phases of SDLC to rationalize quality assurance activities. The process of testing applications in the distributed environment becomes too complex. This study discusses a distributed testing framework that consists of many parallel tester components. The idea is based on utilizing client server environment to conduct software testing efficiently and in a short span of time. It is pertinent to mention that this study is restricted to testing of functional aspects of the software while testing of performance and other quality-of-service aspects are outside the scope of the study. An important factor influencing the use of agent technology in software testing is the dynamic nature of events. Since agents are characterized by intelligence and autonomy, their ability to interact with the environment offers added functionality to make decisions based on the needs of the scenarios that are dynamic in nature. This study shows that the use of agents to build a dynamic model for software testing in the distributed environment results in a more robust and efficient design. The proposed framework is based on distribution of test cases among multiple agents deployed across a distributed system which collaborate with each other to perform testing in an efficient manner. The proposed framework also provides an in-depth visibility into the software quality by providing the defect statistics on-the-fly. The experiments have been conducted using Selenium test automation tool. The test cases along with their test scripts and the test run results are described herein.
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| 4. |
- Zulfiqar, Shumaila, et al.
(författare)
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Identification of a novel variant in GPR56/ADGRG1 gene through whole exome sequencing in a consanguineous Pakistani family
- 2021
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Ingår i: Journal of clinical neuroscience. - : Elsevier. - 0967-5868 .- 1532-2653. ; 94, s. 8-12
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Tidskriftsartikel (refereegranskat)abstract
- GPR56 gene is best known for its pivotal role in cerebral cortical development. Mutations in GPR56 give rise to cobblestone-like brain malformation, white matter changes and cerebellar dysplasia. This study aimed to identify causative variant in a consanguineous family having five individuals affected with developmental delay, mild to severe intellectual disability, speech impairment, strabismus and seizures. Whole exome sequencing was performed to identify mutation in affected individuals. Variants were filtered and further validated by Sanger sequencing and segregation analysis. A novel frameshift variant c.1601dupT leading to p.Ala535GlyfsTer17) was identified in GPR56 gene by whole exome sequencing and subsequent filtering. All five affected individuals were homozygous for the mutant allele while four asymptomatic individuals carried the variant in heterozygous state. Radiological findings of a representative patient presented features of GPR56-associated cobblestone like brain malformation. MRI findings suggested paucity of sulci, dilated ventricular system and brainstem atrophy. The microgyria were observed in a simplified gyral pattern (cobblestone). This single bp insertion, and the consequent frame-shift, results in the truncation of GPR56 protein. This could result in a malformed cortex giving the brain a cobblestone like shape. Our study identified a 7th novel frameshift variant from Pakistani population in GPR56 gene, thus broadening mutation spectrum.
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| 5. |
- Abuhussain, Mohammed Awad, et al.
(författare)
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Data-driven approaches for strength prediction of alkali-activated composites
- 2024
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Ingår i: Case Studies in Construction Materials. - : Elsevier. - 2214-5095. ; 20
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Tidskriftsartikel (refereegranskat)abstract
- Alkali-activated composites (AACs) have attracted considerable interest as a promising alternative to reduce CO2 emissions from Portland cement production and advance the decarbonisation of concrete construction. This study describes the data-driven predictive modelling to anticipate the compressive strength (CS) of AACs. Four different modelling techniques have been chosen to forecast the CS of AACs using the selected data set. The decision tree (DT), multi-layer perceptron (MLP), bagging regressor (BR), and AdaBoost regressor (AR) were employed to investigate the precision level of each model. When it comes to predicting the CS of AACs, the results show that the AR model performs better than the BR model, the MLP model, and the DT model by providing a higher value for the coefficient of determination, which is equal to 0.91, and a lower MAPE value, which is equal to 13.35%. However, the accuracy level of the BR model was very near to that of the AR model, with the R2 value suggesting a value of 0.90 and the MAPE value indicating a value of 14.43%. Moreover, the graphical user interface has also been developed for the strength prediction of alkali-activated composites, making it easy to get the required output from the selected inputs.
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| 6. |
- Arif, Muhammad, et al.
(författare)
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Unraveling the synergy of interface engineering α-MnO2/Bi2WO6 heterostructures and defective active sites for superdurable photocatalysis: Mechanistic insights into charge separation/transfer
- 2023
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Ingår i: Chemical Engineering Journal. - : ELSEVIER SCIENCE SA. - 1385-8947 .- 1873-3212. ; 475
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Tidskriftsartikel (refereegranskat)abstract
- The construction of visible-light-driven hybrid heterostructure photocatalysts is of great significance for environmental remediation, although the utilization of strong visible-light response photocatalysts with high efficiency and stability remains a major challenge. Defect engineering is an excellent way to introduce metal cation vacancies in materials, thereby ensuing in highly enhanced catalytic performance. Inspired by this, we effectively constructed a built-in interface alpha-MnO2/Bi2WO6 heterostructure with abundant intimate interfaces and defective Mn3+/Mn4+ active sites for photocatalytic tetracycline hydrochloride (TC-HCl), hexavalent chromium Cr6+ reduction, and Escherichia coli (E. coli) inactivation. The experimental results, such as the active species test and X-ray photoelectron spectroscopy, indicated that the defective sites Mn3+/Mn4+, surface oxygen vacancies, and Bi(3+x)+ boosted the visible light absorption, and highly enhanced the photoinduced charge separation/transfer. Furthermore, experimental and DFT calculations reveal the high charge density at the built-in interface heterostructure and the Z-scheme charge transfer mechanism during the photocatalytic process. The results further reveal that O-2(-) and O-1(2) are the main reactive active species contributing to the photocatalytic reaction. The exceptional TC-HCl decomposition activity of the alpha-MnO2/Bi2WO6 heterostructure (97.56%, 2.31, and 2.04 times higher than bulk), enhanced reaction kinetics (K-app = 0.041 min(-1), 6.4, and 5.2 times higher than bulk), removal rate of 80.3%, Cr6+ reduction to Cr3+ (98.56%, K-app = 0.0599 min(-1)), and almost 100% bacterial inactivation compared to bulk alpha-MnO2 (42.22%) and Bi2WO6 (47.76%), were mainly due to the enhanced charge separation/transfer at the built-in interface and high charge density. This study opens new horizons for constructing Z-scheme MnO-based interface heterostructures with abundant defect sites for exceptional photocatalytic applications.
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| 7. |
- Ayaz, Muhammad, et al.
(författare)
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Improved Dye Regeneration through Addition of a Triphenylamine Electron Donor in Iodide-Based Electrolytes for Dye-Sensitized Solar Cells
- 2022
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Ingår i: ACS Applied Energy Materials. - : American Chemical Society (ACS). - 2574-0962. ; 5:4, s. 4240-4246
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Tidskriftsartikel (refereegranskat)abstract
- The addition of a small organic electron donor, tris(p-anisyl)amine (TPAA), to an iodide/triiodide electrolyte for dye-sensitized solar cells was found to give pronounced effects on charge transfer reactions. When using the organic dye LEG4 as a sensitizer, an improved solar cell performance was found, which could be attributed to the extremely rapid dye regeneration reaction when TPAA is added. In contrast, for the ruthenium dye N719, no significant solar cell improvement was found, despite rapid dye regeneration. Using transient absorption measurements, it was found that reduction of the intermediate TPAA(+) by iodide is sluggish. This allows for significant recombination of electrons in TiO2 to TPAA(+) when the adsorbed dye layer does not have sufficient electron-blocking properties.
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| 8. |
- Cheng, Haoliang, et al.
(författare)
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Assessing the effect of surface states of mesoporous NiO films on charge transport and unveiling an unexpected light response phenomenon in tandem dye-sensitized solar cells
- 2022
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Ingår i: Energy Advances. - : Royal Society of Chemistry. - 2753-1457. ; 1:5, s. 303-311
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, the role of NiO surface states is assessed in a tandem dye-sensitized solar cell (t-DSSC) consisting of a 4-(Bis-{4-[5-(2,2-dicyano-vinyl)-thiophene-2-yl]-phenyl}-amino)-benzoic acid (P1) dye-sensitized NiO photocathode, a VG1-C8 dye-sensitized TiO2 photoanode and the I−/I3− redox couple. The NiO surface states are proved to participate in the reduction of the I−/I3− electrolyte in the t-DSSCs. By adjusting the thickness of the TiO2 film, the charge transport processes of the t-DSSCs are significantly affected by the photocurrent and the NiO surface states, resulting in various photovoltaic properties. This work also proves that the NiO surface states together with energy transfer between the desorbed P1 dye from the NiO photocathode and the VG1-C8 dye from the TiO2 photoanode are responsible for the light response from both dyes observed in the IPCE spectra of the t-DSSCs.
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| 9. |
- Nguyen, Thanh N, et al.
(författare)
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Global Impact of the COVID-19 Pandemic on Stroke Volumes and Cerebrovascular Events: A 1-Year Follow-up.
- 2023
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Ingår i: Neurology. - 1526-632X. ; 100:4
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Tidskriftsartikel (refereegranskat)abstract
- Declines in stroke admission, IV thrombolysis (IVT), and mechanical thrombectomy volumes were reported during the first wave of the COVID-19 pandemic. There is a paucity of data on the longer-term effect of the pandemic on stroke volumes over the course of a year and through the second wave of the pandemic. We sought to measure the effect of the COVID-19 pandemic on the volumes of stroke admissions, intracranial hemorrhage (ICH), IVT, and mechanical thrombectomy over a 1-year period at the onset of the pandemic (March 1, 2020, to February 28, 2021) compared with the immediately preceding year (March 1, 2019, to February 29, 2020).We conducted a longitudinal retrospective study across 6 continents, 56 countries, and 275 stroke centers. We collected volume data for COVID-19 admissions and 4 stroke metrics: ischemic stroke admissions, ICH admissions, IVT treatments, and mechanical thrombectomy procedures. Diagnoses were identified by their ICD-10 codes or classifications in stroke databases.There were 148,895 stroke admissions in the 1 year immediately before compared with 138,453 admissions during the 1-year pandemic, representing a 7% decline (95% CI [95% CI 7.1-6.9]; p < 0.0001). ICH volumes declined from 29,585 to 28,156 (4.8% [5.1-4.6]; p < 0.0001) and IVT volume from 24,584 to 23,077 (6.1% [6.4-5.8]; p < 0.0001). Larger declines were observed at high-volume compared with low-volume centers (all p < 0.0001). There was no significant change in mechanical thrombectomy volumes (0.7% [0.6-0.9]; p = 0.49). Stroke was diagnosed in 1.3% [1.31-1.38] of 406,792 COVID-19 hospitalizations. SARS-CoV-2 infection was present in 2.9% ([2.82-2.97], 5,656/195,539) of all stroke hospitalizations.There was a global decline and shift to lower-volume centers of stroke admission volumes, ICH volumes, and IVT volumes during the 1st year of the COVID-19 pandemic compared with the prior year. Mechanical thrombectomy volumes were preserved. These results suggest preservation in the stroke care of higher severity of disease through the first pandemic year.This study is registered under NCT04934020.
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| 10. |
- Zulfiqar, Shumaila, et al.
(författare)
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Whole exome sequencing identifies novel variant underlying hereditary spastic paraplegia in consanguineous Pakistani families
- 2019
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Ingår i: Journal of clinical neuroscience. - : Elsevier BV. - 0967-5868 .- 1532-2653. ; 67, s. 19-23
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Tidskriftsartikel (refereegranskat)abstract
- Hereditary Spastic paraplegias (HSPs) are heterogeneous group of degenerative disorders characterized by progressive weakness and spasticity of the lower limbs, combined with additional neurological features. This study aimed to identify causative gene variants in two nonrelated consanguineous Pakistani families segregating HSP. Whole exome sequencing (WES) was performed on a total of five individuals from two families including four affected and one phenotypically normal individual. The variants were validated by Sanger sequencing and segregation analysis. In family A, a novel homozygous variant c.604G > A (p.Glu202Lys) was identified in the CYP2U1 gene with clinical symptoms of SPG56 in 3 siblings. Whereas, a previously reported variant c.5769delT (p.Ser1923Argfs*28) in the SPG11 gene was identified in family B manifesting clinical features of SPG11 in 3 affected individuals. Our combined findings add to the clinical and genetic variability associated with CYP2U1 and SPG11 variants highlighting the complexity of HSPs. These findings further emphasize the usefulness of WES as a powerful diagnostic tool.
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