71 research outputs found

    COVID – 19: Lessons to Learn.

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    We witness a dramatic change, in all aspect of Life, throughout the world after Covid-19. It started in Wuhan, Hubei Province, China where few cases of atypical pneumonia presented in late November and early December 2019.  Clinical picture mimicking viral pneumonia1. According to an unpublicized report from the Chinese government, the first case can be traced back to 17 November 2019; the person was a 55-year-old citizen in the Hubei province. There were four men and five women reported to be infected in November.  The number of coronavirus cases in Hubei gradually increased, reaching 60 by 20 December and at least 266 by 31 December2. A coronavirus was soon identified as the cause of the outbreak and tentatively named as the 2019-nCoV by the World Health Organization. On 11 Feb 2020, the World Health Organization officially named it SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus-2) and the SARS-CoV-2 infection was named COVID-19.1 One can easily understand the impact upon routine life just by seeing these numbers; As on 30 Nov 2020, there were 63, 360234 confirmed cases and 1, 475825 confirmed deaths.

    Robust Watermarking Using FFT and Cordic QR Techniques

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    Digital media sharing and access in today’s world of the internet is very frequent for every user. The management of digital rights may come into threat easily as the accessibility of data through the internet become wide. Sharing digital information under security procedures can be easily compromised due to the various vulnerabilities floating over the internet. Existing research has been tied to protecting internet channels to ensure the safety of digital data. Researchers have investigated various encryption techniques to prevent digital rights management but certain challenges including external potential attacks cannot be avoided that may give unauthorized access to digital media. The proposed model endorsed the concept of watermarking in digital data to uplift media security and ensure digital rights management. The system provides an efficient procedure to conduct over-watermarking in digital audio signals and confirm the avoidance of ownership of the host data. The proposed technique uses a watermark picture as a signature that has been initially encrypted with Arnold's cat map and cyclic encoding before being embedded. The upper triangular R-matrix component of the energy band was then created by using the Fast Fourier transform and Cordic QR procedures to the host audio stream. Using PN random sequences, the encrypted watermarking image has been embedded in the host audio component of the R-matrix. The same procedure has been applied to extract the watermark image from the watermarked audio. The proposed model evaluates the quality of the watermarked audio and extracted watermark image. The average PSNR of the watermarked audio is found to be 37.01 dB. It has also been seen that the average PSNR, Normal cross-correlation, BER, SSMI (structure similarity index matric) value for the extracted watermark image is found to be 96.30 dB, 0.9042 units, 0.1033 units, and 0.9836 units respectively. Further, the model has been tested using various attacks to check its robustness. After applying attacks such as noising, filtering, cropping, and resampling on the watermarked audio, the watermark image has been extricated and its quality has been checked under the standard parameters. It has been found that the quality of the recovered watermark image satisfying enough to justify the digital ownership of the host audio. Hence, the proposed watermarking model attains a perfect balance between imperceptibility, payload, and robustness

    FREQUENCY OF HCV INFECTION AND ITS GENOTYPES AMONG PATIENTS ATTENDING A LIVER CLINIC AND VOLUNTARY BLOOD DONORS IN A RURAL AREA OF PAKISTAN

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    ABSTRACT Objectives: To determine the frequency of Hepatitis C virus (HCV) infection and its genotypic distribution in a rural area of Sindh, Pakistan. Methodology: Retrospective study of patients attending the Free Liver Clinic (FLC), and investigated for detectable HCV antibodies (n=1638), and those screened for HCV infection prior to voluntary blood donation (n=804) at a teaching hospital, located in rural Sindh. All patients had HCV antibodies tested by ELISA. A total of 1022 patients, who tested 'reactive' to HCV antibodies, and who could financially afford to have HCV RNA tested by PCR, had their results analysed. A total of 200 patients also had their HCV genotyped and analysed. Results: Patients at FLC had a higher chance of being reactive for HCV antibodies, compared to voluntary blood donors (20% VS 14% -p = 0.004). HCV RNA was detectable in 904/1022 (88%) patients. Among typeable genotypes, 125/166 (75%) had a single genotype, and 7 patients (4%) were infected with genotype 1, either alone (n=4) or in combination with 3a. Conclusions: One out of every five people tested in our FLC, and 14% of "healthy" voluntary blood donors were seropositive for HCV antibodies. Genotype 1 is very rare in our region

    Search for magnetoelectric monopole response in Cr\u3csub\u3e2\u3c/sub\u3eO\u3csub\u3e3\u3c/sub\u3e powder

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    Powder samples have been suggested as a pathway to fabricate isotropic magnetoelectric (ME) materials which effectively only have a pseudoscalar or monopole ME response. We demonstrate that random distribution of ME grains alone does not warrant isotropic ME response because the activation of a nonvanishing ME response requires a ME field cooling protocol which tends to induce preferred axes.We investigate the evolution of ME susceptibility in powder chromia samples for various ME field cooling protocols both theoretically and experimentally. In particular, we work out the theoretical expressions for ME susceptibility for powder chromia in the framework of statistical mechanics where Boltzmann factors weigh the orientation of the Néel vector relative to the local orientation of the c axis of a grain. Previous approximations oversimplified the thermodynamic nature of the annealing process giving rise to misleading conclusions on the role of the magnitude of the applied product of electric and magnetic fields on the ME response. In accordance with our refined theory, a strong dependence of the functional form of α vs T of chromia powders on the ME field cooling protocol is observed. It shows that chromia powder is not generically an isotropic ME effective medium but provides a pathway to realize the elusive isotropic ME response

    Nanoscale imaging of antiferromagnetic domains in epitaxial films of Cr\u3csub\u3e2\u3c/sub\u3eO\u3csub\u3e3\u3c/sub\u3e via scanning diamond magnetic probe microscopy

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    We report direct imaging of boundary magnetization associated with antiferromagnetic domains in magnetoelectric epitaxial Cr2O3 thin films using diamond nitrogen vacancy microscopy. We found a correlation between magnetic domain size and structural grain size which we associate with the domain formation process. We performed field cooling, i.e., cooling from above to below the Néel temperature in the presence of a magnetic field, which resulted in the selection of one of the two otherwise degenerate 180° domains. Lifting of such a degeneracy is achievable with a magnetic field alone due to the Zeeman energy of a weak parasitic magnetic moment in Cr2O3 films that originates from defects and the imbalance of the boundary magnetization of opposing interfaces. This boundary magnetization couples to the antiferromagnetic order parameter enabling selection of its orientation. Nanostructuring the Cr2O3 film with mesa structures revealed reversible edge magnetic states with the direction of magnetic field during field cooling

    Correction: Nanoscale imaging of antiferromagnetic domains in epitaxial films of Cr2O3 via scanning diamond magnetic probe microscopy

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    Correction for ‘Nanoscale imaging of antiferromagnetic domains in epitaxial films of Cr2O3 via scanning diamond magnetic probe microscopy’ by Adam Erickson et al., RSC Adv., 2023, 13, 178–185, https:// doi.org/10.1039/D2RA06440

    Post deposition interfacial N\'eel temperature tuning in magnetoelectric B:Cr2O3

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    Boron (B) alloying transforms the magnetoelectric antiferromagnet Cr2O3 into a multifunctional single-phase material which enables electric field driven {\pi}/2 rotation of the N\'eel vector. Nonvolatile, voltage-controlled N\'eel vector rotation is a much-desired material property in the context of antiferromagnetic spintronics enabling ultra-low power, ultra-fast, nonvolatile memory, and logic device applications. N\'eel vector rotation is detected with the help of heavy metal (Pt) Hall-bars in proximity of pulsed laser deposited B:Cr2O3 films. To facilitate operation of B:Cr2O3-based devices in CMOS environments, the N\'eel temperature, TN, of the functional film must be tunable to values significantly above room temperature. Cold neutron depth profiling and x-ray photoemission spectroscopy depth profiling reveal thermally activated B-accumulation at the B:Cr2O3/ vacuum interface in thin films deposited on Al2O3 substrates. We attribute the B-enrichment to surface segregation. Magnetotransport data confirm B-accumulation at the interface within a layer of about 50 nm thick where the device properties reside. Here TN enhances from 334 K prior to annealing, to 477 K after annealing for several hours. Scaling analysis determines TN as a function of the annealing temperature. Stability of post-annealing device properties is evident from reproducible N\'eel vector rotation at 370 K performed over the course of weeks

    EFFECT OF SUPPLEMENTAL IRRIGATION ON WHEAT WATER PRODUCTIVITY UNDER RAINFED ECOLOGY OF POTHOHAR, PAKISTAN

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    For rainfed ecology, water is the most limiting natural resource and its effective utilization is indispensable in order to optimize crop water productivity. A field study on wheat crop was carried out to asses the impact of different irrigation depths through sprinkler irrigation system at three phonological stages viz. tilleing, anthesis and grain filling. Randomized Complete Block Design (RCBD) was used in the trail and had three repeats.  The area under study received 195 mm seasonal rainfall. Supplemental irrigation depths at three phonological stages, using small quantities of water through sprinkler irrigation system, significantly promoted the crop growth. The irrigation depth 25 mm gave the maximum output for biological yield (6504 ), grain yield (2030 ), thousand grain weight (28), plant height (87 ) and spike length (10 ). The highest water productivity of 0.97 kg/m3 was achieved with 25 mm supplemental irrigation depth when applied at tillering and anthesis stages

    A novel mutation in GRK1 causes Oguchi disease in a consanguineous Pakistani family

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    Contains fulltext : 76070.pdf (publisher's version ) (Open Access)PURPOSE: The purpose of this study was to identify the underlying molecular genetic defect in a large consanguineous Pakistani family with Oguchi disease who had been given a diagnosis of autosomal recessive retinitis pigmentosa. METHODS: The family was genotyped with the Affymetrix 10K single nucleotide polymorphism array. Fine-mapping of a common homozygous region on chromosome 13q was performed using fluorescent microsatellite markers. Mutation analysis was done by direct sequencing of the candidate gene GRK1 located in the region. The segregation of a novel mutation in the family and the frequency of the identified mutation in the Pakistani population were determined by StuI RFLP analysis. RESULTS: Genetic mapping supported the diagnosis of typical Oguchi disease in a Pakistani family and also resulted in the identification of a novel nonsense mutation (c.614C>A; p.S205X) in exon 1 of GRK1. This mutation is predicted to result in premature termination of the protein product, thereby affecting the phototransduction cascade. A clinical reappraisal of the family revealed that all patients homozygous for this variant had Oguchi disease. CONCLUSIONS: This is the first report to describe a mutation causing typical Oguchi disease in a large consanguineous Pakistani family. This mutation segregated in eight affected members.6 p

    In vitro and in vivo evaluation of alginate hydrogel-based wound dressing loaded with green chemistry cerium oxide nanoparticles

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    Interactive wound dressings have displayed promising outcomes in enhancing the wound healing process. This study focuses on creating a nanocomposite wound dressing with interactive and bioactive properties, showcasing potent antioxidant effects. To achieve this, we developed cerium oxide nanoparticles utilizing curcumin as both the reducing and capping agent. Characterization techniques such as SEM, EDX, DLS, Zetasizer, FTIR, and XRD were utilized to analyze the cerium oxide nanoparticles synthesized through a green approach. The image analysis on the obtained TEM images showed that the curcumin-assisted biosynthesized CeO2NPs have a size of 18.8 ± 4.1 nm. The peaks located at 28.1, 32.7, 47.1, 56.0, 58.7, 69.0, and 76.4 correspond to (111), (200), (220), (311), (222), (400), and (331) crystallographic planes. We applied the Debye–Scherrer equation and observed that the approximate crystallite size of the biosynthesized NPs is around 8.2 nm based on the most intensive broad Bragg peak at 28.1°. The cerium oxide nanoparticles synthesized were integrated into an alginate hydrogel matrix, and the microstructure, porosity, and swelling behavior of the resulting wound dressing were assessed. The characterization analyses provided insights into the physical and chemical properties of the green-synthesized cerium oxide nanoparticles and the alginate hydrogel-based wound dressing. In vitro studies demonstrated that the wound dressing based on alginate hydrogel exhibited favorable antioxidant properties and displayed hemocompatibility and biocompatibility. Animal studies conducted on a rat full-thickness skin wound model showed that the alginate hydrogel-based wound dressing effectively accelerated the wound healing process. Overall, these findings suggest that the alginate hydrogel-based wound dressing holds promise as a highly effective material for wound healing applications
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