Molecular generation and characterization of an efficient recombinant vaccine for avian influenza A/H5N8 in Saudi Arabia

Purpose: To characterize a highly pathogenic avian influenza (HPAI) H5N8 for engineering recombinant 6-+ 2 vaccine strain based on reverse genetic technology. Methods: A total of 135 swab samples from various birds were collected from different parts of Saudi Arabia as part of an influenza surveillance activity. The samples were checked for influenza virus infection using reverse transcriptase-polymerase chain reaction (RT-PCR). Furthermore, Avian influenza H5N8 (A/chicken/KSA/1-NRC/2018), was used for the generation of H5N8 vaccine strain. The vaccine was tested on specific pathogen-free (SPF) chicken purchased from a local market. Results: The results indicate that the candidate vaccine (rgH5N8/KSA) induced specific neutralizing antibodies in chicken, and thereby protected the chickens from subsequent infections of H5N8. Conclusion: The study reinforces the development of a vaccine against avian influenza H5N8 virus isolated in Saudi Arabia, suggesting its possible application against the influenza virus associated with bird fl

Evaluation of alternative preservation treatments (water heat treatment, ultrasounds, thermosonication and UV-C radiation) to improve safety and quality of whole tomato

Previously optimised postharvest treatments were compared to conventional chlorinated water treatment in terms of their effects on the overall quality of tomato (‘Zinac’) during storage at 10 °C. The treatments in question were water heat treatment (WHT = 40 °C, 30 min), ultrasounds (US = 45 kHz, 80 %, 30 min), thermosonication (TS =40 °C, 30 min, 45 kHz, 80 %) and ultraviolet irradiation (UV-C: 0.97 kJ m−2). The quality factors evaluated were colour, texture, sensorial analysis, mass loss, antioxidant capacity, total phenolic content, peroxidase and pectin methylesterase enzymatic activities, and microbial load reduction. The results demonstrate that all treatments tested preserve tomato quality to some extent during storage at 10 °C. WHT, TS and UV-C proved to be more efficient on minimising colour and texture changes with the additional advantage of microbial load reduction, leading to a shelf life extension when compared to control trials. However, at the end of storage, with exception of WHT samples, the antioxidant activity and phenolic content of treated samples was lower than for control samples. Moreover, sensorial results were well correlated with instrumental colour experimental data. This study presents alternative postharvest technologies that improve tomato (Zinac) quality during shelf life period and minimise the negative impact of conventional chlorinated water on human safety, health and environment.info:eu-repo/semantics/publishedVersio

Single-dose administration and the influence of the timing of the booster dose on immunogenicity and efficacy of ChAdOx1 nCoV-19 (AZD1222) vaccine: a pooled analysis of four randomised trials.

BACKGROUND: The ChAdOx1 nCoV-19 (AZD1222) vaccine has been approved for emergency use by the UK regulatory authority, Medicines and Healthcare products Regulatory Agency, with a regimen of two standard doses given with an interval of 4-12 weeks. The planned roll-out in the UK will involve vaccinating people in high-risk categories with their first dose immediately, and delivering the second dose 12 weeks later. Here, we provide both a further prespecified pooled analysis of trials of ChAdOx1 nCoV-19 and exploratory analyses of the impact on immunogenicity and efficacy of extending the interval between priming and booster doses. In addition, we show the immunogenicity and protection afforded by the first dose, before a booster dose has been offered. METHODS: We present data from three single-blind randomised controlled trials-one phase 1/2 study in the UK (COV001), one phase 2/3 study in the UK (COV002), and a phase 3 study in Brazil (COV003)-and one double-blind phase 1/2 study in South Africa (COV005). As previously described, individuals 18 years and older were randomly assigned 1:1 to receive two standard doses of ChAdOx1 nCoV-19 (5 × 1010 viral particles) or a control vaccine or saline placebo. In the UK trial, a subset of participants received a lower dose (2·2 × 1010 viral particles) of the ChAdOx1 nCoV-19 for the first dose. The primary outcome was virologically confirmed symptomatic COVID-19 disease, defined as a nucleic acid amplification test (NAAT)-positive swab combined with at least one qualifying symptom (fever ≥37·8°C, cough, shortness of breath, or anosmia or ageusia) more than 14 days after the second dose. Secondary efficacy analyses included cases occuring at least 22 days after the first dose. Antibody responses measured by immunoassay and by pseudovirus neutralisation were exploratory outcomes. All cases of COVID-19 with a NAAT-positive swab were adjudicated for inclusion in the analysis by a masked independent endpoint review committee. The primary analysis included all participants who were SARS-CoV-2 N protein seronegative at baseline, had had at least 14 days of follow-up after the second dose, and had no evidence of previous SARS-CoV-2 infection from NAAT swabs. Safety was assessed in all participants who received at least one dose. The four trials are registered at ISRCTN89951424 (COV003) and ClinicalTrials.gov, NCT04324606 (COV001), NCT04400838 (COV002), and NCT04444674 (COV005). FINDINGS: Between April 23 and Dec 6, 2020, 24 422 participants were recruited and vaccinated across the four studies, of whom 17 178 were included in the primary analysis (8597 receiving ChAdOx1 nCoV-19 and 8581 receiving control vaccine). The data cutoff for these analyses was Dec 7, 2020. 332 NAAT-positive infections met the primary endpoint of symptomatic infection more than 14 days after the second dose. Overall vaccine efficacy more than 14 days after the second dose was 66·7% (95% CI 57·4-74·0), with 84 (1·0%) cases in the 8597 participants in the ChAdOx1 nCoV-19 group and 248 (2·9%) in the 8581 participants in the control group. There were no hospital admissions for COVID-19 in the ChAdOx1 nCoV-19 group after the initial 21-day exclusion period, and 15 in the control group. 108 (0·9%) of 12 282 participants in the ChAdOx1 nCoV-19 group and 127 (1·1%) of 11 962 participants in the control group had serious adverse events. There were seven deaths considered unrelated to vaccination (two in the ChAdOx1 nCov-19 group and five in the control group), including one COVID-19-related death in one participant in the control group. Exploratory analyses showed that vaccine efficacy after a single standard dose of vaccine from day 22 to day 90 after vaccination was 76·0% (59·3-85·9). Our modelling analysis indicated that protection did not wane during this initial 3-month period. Similarly, antibody levels were maintained during this period with minimal waning by day 90 (geometric mean ratio [GMR] 0·66 [95% CI 0·59-0·74]). In the participants who received two standard doses, after the second dose, efficacy was higher in those with a longer prime-boost interval (vaccine efficacy 81·3% [95% CI 60·3-91·2] at ≥12 weeks) than in those with a short interval (vaccine efficacy 55·1% [33·0-69·9] at <6 weeks). These observations are supported by immunogenicity data that showed binding antibody responses more than two-fold higher after an interval of 12 or more weeks compared with an interval of less than 6 weeks in those who were aged 18-55 years (GMR 2·32 [2·01-2·68]). INTERPRETATION: The results of this primary analysis of two doses of ChAdOx1 nCoV-19 were consistent with those seen in the interim analysis of the trials and confirm that the vaccine is efficacious, with results varying by dose interval in exploratory analyses. A 3-month dose interval might have advantages over a programme with a short dose interval for roll-out of a pandemic vaccine to protect the largest number of individuals in the population as early as possible when supplies are scarce, while also improving protection after receiving a second dose. FUNDING: UK Research and Innovation, National Institutes of Health Research (NIHR), The Coalition for Epidemic Preparedness Innovations, the Bill & Melinda Gates Foundation, the Lemann Foundation, Rede D'Or, the Brava and Telles Foundation, NIHR Oxford Biomedical Research Centre, Thames Valley and South Midland's NIHR Clinical Research Network, and AstraZeneca

The numerical solutions of Korteweg- de Vries Burgers' (KdVB) with finite elelment methods

Bu yüksek lisans tezinin giriş kısmında B- spline fonksiyonlar, sonlu eleman yöntemleri, Korteweg- de Vries (KdV), Burgers' ve Korteweg- de Vries Burgers' (KdVB) denklemleri hakkında temel bilgiler verildi. Tezin ikinci bölümünde KdVB denkleminin sayısal çözümleri quartic B- spline fonksiyonlar kullanılarak Galerkin sonlu eleman yöntemi ile elde edildi. Elde edilen sayısal sonuçlar literatürdeki sayısal sonuçlar ile karşılaştırılarak tablolar halinde verildi. Elde edilen sonuçlara ait grafikler çizildi. Tezin üçüncü bölümünde KdVB denkleminin sayısal çözümleri Kollokasyon sonlu eleman yöntemi ile elde edildi. Elde edilen sayısal sonuçlar tablolar halinde verilerek grafikleri çizildi. Tezin dördüncü bölümünde KdVB denkleminin sayısal çözümleri Petrov- Galerkin sonlu eleman yöntemi ile elde edildi. Elde edilen sayısal sonuçlar literatürdeki mevcut sonuçlar ile karşılaştırılarak tablolar halinde verildi. Elde edilen sonuçlara ait grafikler çizildi. Tezin beşinci bölümünde KdVB denkleminin sayısal çözümleri Subdomain sonlu eleman yöntemi ile elde edildi.Introduction of the thesis, fundamental informations about B- spline functions, finite element methods, Korteweg- de Vries (KdV), Burgers' and Korteweg- de Vries Burgers' (KdVB) equations are given. In the second part, numerical solutions of KdVB equation are obtained by Galerkin finite element method with quartic B- spline functions. The obtained numerical results are compared with existing results in the literature and given in the form of tables. Figures, related to the obtained results are plotted. In the third part, numerical solutions of KdVB equation are obtained by Collocation finite element methods. The obtained numerical results are given in the form of tables and their figures are plotted. In the fourth part, numerical solutions of KdVB equation are obtained by Petrov- Galerkin finite element methods. The obtained numerical results are compared with existing results in the literature and given in the form of tables. Figures related to the obtained results are plotted. In the fifth part, numerical solutions of KdVB equation are obtained by Subdomain finite element methods