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- Abro, Shahid, hussain, et al.
(författare)
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Characterization and analysis of the full-length genome of a strain of the European QX-like genotype of infectious bronchitis virus
- 2012
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Ingår i: Archives of Virology. - : Springer Science and Business Media LLC. - 0304-8608 .- 1432-8798. ; 157, s. 1211-1215
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Tidskriftsartikel (refereegranskat)abstract
- In recent years, strains of infectious bronchitis virus belonging to the QX-like genotype have been causing huge economic losses in commercial chicken flocks in different countries in Europe. In order to expand the knowledge of the molecular features of these viruses, we have sequenced and characterized the complete genome of European QX-like IBV strain CK/SWE/0658946/10, which was isolated in 2010 in Sweden. The genome is 27664 nucleotides in length, comprising six genes and 5' and 3' untranslated regions. The ORF1a, spike and nucleocapsid genes were under strong positive selective pressure that resulted in genetic diversity in relation to classical IBV isolates. The full-length genome of the CK/SWE/0658946/10 strain has the highest nucleotide sequence identity (93.18%) to ITA/90254/2005 and the lowest nucleotide identity (89.10%) to strain CQ04-1. Phylogenetic analysis of partial S1 gene sequences of IBV strains showed that the European QX-like genotype comprises strains that have been predominantly circulating in this continent for the past decade.
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| 3. |
- Abro, Shahid, hussain, et al.
(författare)
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Emergence of novel strains of avian infectious bronchitis virus in Sweden
- 2012
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Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 155, s. 237-246
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Tidskriftsartikel (refereegranskat)abstract
- Infectious bronchitis virus (IBV) causes avian infectious bronchitis, an important disease that produces severe economic losses in the poultry industry worldwide. Recent IBV infections in Sweden have been associated with poor growth in broilers, drop in egg production and thin egg shells in layers. The complete spike gene of selected isolates from IBV cases was amplified and sequenced using conventional RT-PCR. Nucleotide and amino acid sequence comparisons have shown that the recent isolates bear 98.97% genetic similarity with strains of the QX-like genotype. The phylogenetic analysis revealed that strains predominant in the nineties, which were of the Massachusetts type, have been replaced by D388/QX-Iike strains, however the evolutionary link could not be established. The homology between the two genotypes was 79 and 81%. Remarkably, a strong positive selection pressure was determined, mostly involving the S1 subunit of the S gene. This strong selective pressure resulted in recombination events, insertions and deletions in the S gene. Two new isolates generated from recombination were found with nucleotide sequence diverging 1.7-2.4% from the D388/QX-Iike branch, indicating the emergence of a new lineage. The study demonstrates a constant evolution of IBV that might be in relation to increased poultry farming, trade and vaccine pressure. The findings underscore the importance of continuous monitoring to control spread of infections, as well as to timely adjust diagnostic methods, molecular epidemiological studies, development and use of vaccines that are adapted to the changing disease scenario. (C) 2011 Elsevier B.V. All rights reserved.
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| 4. |
- Abro, Shahid, hussain
(författare)
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Molecular characterization and detection of infectious bronchitis virus
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis deals with the molecular characterization and detection of infectious bronchitis virus (IBV), an important pathogen that causes heavy losses in the poultry populations worldwide. The aim of the research was to better understand the molecular characteristics of the virus and to investigate the factors behind the continuous emergence of new genetic variants and the occurrence of outbreaks. The studies showed that the viral genome is under a continuous evolution, due to mutations, strong selective pressure and recombination events. These forces lead to a wide genetic diversity and the generation of new variants of this virus. The viral genes encoding the spike, envelope and membrane proteins can be considered the main genomic regions, which are indicating the evolution processes of IBV. The various strains contain specific structural and functional motifs in their genes and the alterations in these motifs may affect the infection biology of the virus. The constant emergence of new variants in Sweden is likely due to the introduction of novel IBV strains from other European countries through the import of poultry products, or by the continuous migration of wild birds. The in silico investigations of the spike glycoprotein coding regions of the Massachusetts and QX-like genotypes demonstrated molecular differences between these genotypic variants. It is hypothesized that the genetic diversity in the spike gene of IBV and of other avian coronaviruses, as well as of human, bat, and other animal coronaviruses could be associated with the adaptation and host specificity of these infectious agents. The data obtained by molecular characterization approach was also used for the development of a new molecular method for the improved detection and genotyping of this virus. A microarray platform was developed for the simultaneous detection and rapid typing of IBV variants. This assay provides a practical tool for better diagnosis, for studying the effectiveness of vaccination and for performing large-scale epidemiological studies.
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| 5. |
- Mugheri, Abdul Qayoom, et al.
(författare)
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A Low Charge Transfer Resistance CuO Composite for Efficient Oxygen Evolution Reaction in Alkaline Media
- 2021
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Ingår i: Journal of Nanoscience and Nanotechnology. - : AMER SCIENTIFIC PUBLISHERS. - 1533-4880 .- 1533-4899. ; 21:4, s. 2613-2620
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Tidskriftsartikel (refereegranskat)abstract
- An efficient, simple, environment-friendly and inexpensive cupric oxide (CuO) electrocatalyst for oxygen evolution reaction (OER) is demonstrated. CuO is chemically deposited on the porous carbon material obtained from the dehydration of common sugar. The morphology of CuO on the porous carbon material is plate-like and monoclinic crystalline phase is confirmed by powder X-ray diffraction. The OER activity of CuO nanostructures is investigated in 1 M KOH aqueous solution. To date, the proposed electrocatalyst has the lowest possible potential of 1.49 V versus RHE (reversible hydrogen electrode) to achieve a current density of 20 mA/cm(2) among the. CuO based electrocatalysts and has Tafel slope of 115 mV dec(-1). The electrocatalyst exhibits an excellent long-term stability for 6 hours along with significant durability. The enhanced catalytic active centers of CuO on the carbon material are due to the porous structure of carbon as well as strong coupling between CuO-C. The functionalization of metal oxides or other related nanostructured materials on porous carbon obtained from common sugar provides an opportunity for the development of efficient energy conversion and energy storage systems.
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