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1.
Avian Pathol ; 53(2): 134-145, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38037737

RESUMO

RESEARCH HIGHLIGHTS: Virulent NDV genotypes were repeatedly isolated from pigeons.Evidence of epidemiological links among viruses isolated from various locations.Distinct phylogenetic branches suggest separate, simultaneous evolution of NDVs.Study information could be helpful in the development of an effective vaccine.


Assuntos
Doença de Newcastle , Vírus da Doença de Newcastle , Animais , Columbidae , Variação Genética , Genótipo , Doença de Newcastle/epidemiologia , Paquistão , Filogenia
2.
Microorganisms ; 11(9)2023 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-37764011

RESUMO

The most common DNA virus found in wastewaters globally is the cross-assembly phage (crAssphage). King Saud University wastewater treatment plant (KSU-WWTP); Manfoha wastewater treatment plant (MN-WWTP); and the Embassy wastewater treatment plant (EMB-WWTP) in Riyadh, Saudi Arabia were selected, and 36 untreated sewage water samples during the year 2022 were used in the current study. The meteorological impact on crAssphage prevalence was investigated. CrAssphage prevalence was recorded using PCR and Sanger sequencing. The molecular diversity of crAssphage sequences was studied for viral gene segments from the major capsid protein (MCP) and membrane protein containing the peptidoglycan-binding domain (MP-PBD). KSU-WWTP and EMB-WWTP showed a higher prevalence of crAssphage (83.3%) than MN-WWTP (75%). Phylogenetic analysis of MCP and MP-PBD segments depicted a close relationship to the Japanese isolates. The MCP gene from the current study's isolate WW/2M/SA/2022 depicted zero evolutionary divergence from 3057_98020, 2683_104905, and 4238_99953 isolates (d = 0.000) from Japan. A significant influence of temporal variations on the prevalence of crAssphage was detected in the three WWTPs. CrAssphage displayed the highest prevalence at high temperatures (33-44 °C), low relative humidity (6-14%), and moderate wind speed (16-21 Km/h). The findings provided pioneering insights into crAssphage prevalence and its genetic diversity in WWTPs in Riyadh, Saudi Arabia.

3.
Trop Med Infect Dis ; 8(5)2023 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-37235327

RESUMO

In Saudi Arabia, acute gastroenteritis (GE) is a common illness affecting children and adults; however, the extent to which human rotavirus A (HRV) and human adenovirus (HAdV) strains contribute to the condition is unclear. The surveillance of the GE-causing viruses, HRV and HadV, was performed using polymerase chain reaction, sequencing, and phylogenetic analysis at King Khalid University Hospital. The associations between virus prevalence and meteorological factors were analyzed. The prevalence of HAdV was recorded (7%), followed by HRV (2%). On a gender basis, HAdV infections were found to be dominant in females (5:2) (U = 407.5; p < 0.0001), whereas HRV was only detected in males (U = 50; p < 0.0001). A significantly higher HAdV prevalence was recorded at the age of 3.5 ± 0.63 years (21.1%; p = 0.00047), whereas HRV cases were found equally distributed between <3 years and 3-5 years. The highest HAdV prevalence was recorded in autumn, followed by winter and spring. A significant correlation was detected between humidity and the total number of recorded cases (p = 0.011). Phylogenetic analysis depicted the dominance of HAdV type 41 and the G2 lineage of HRV among circulating strains. The current study uncovered the epidemiology and genotypes of HRV and HadV, and provided forecasting equations for monitoring climatic-mediated outbreaks.

4.
Microorganisms ; 11(4)2023 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-37110461

RESUMO

Several indicators of fecal pollution in water resources are continuously monitored for their reliability and, of particular interest, their correlation to human enteric viruses-not justified by traditional bacterial indicators. Pepper mild mottle virus (PMMoV) has recently been proposed as a successful viral surrogate of human waterborne viruses; however, in Saudi Arabia there are no available data in terms of its prevalence and concentration in water bodies. The concentration of PMMoV in three different wastewater treatment plants (King Saud University (KSU), Manfoha (MN), and Embassy (EMB) wastewater treatment plants (WWTP)) was measured using qRT-PCR during a one-year period and compared to the human adenovirus (HAdV), which is highly persistent and considered an indicator for viral-mediated fecal contamination. PMMoV was found in ~94% of the entire wastewater samples (91.6-100%), with concentrations ranging from 62 to 3.5 × 107 genome copies/l (GC/l). However, HAdV was detected in 75% of raw water samples (~67-83%). The HAdV concentration ranged between 1.29 × 103 GC/L and 1.26 × 107 GC/L. Higher positive correlation between PMMoV and HAdV concentrations was detected at MN-WWTP (r = 0.6148) than at EMB-WWTP (r = 0.207). Despite the lack of PMMoV and HAdV seasonality, a higher positive correlation (r = 0.918) of PMMoV to HAdV was recorded at KSU-WWTP in comparison to EMB-WWTP (r = 0.6401) around the different seasons. Furthermore, meteorological factors showed no significant influence on PMMoV concentrations (p > 0.05), thus supporting the use of PMMoV as a possible fecal indicator of wastewater contamination and associated public health issues, particularly at MN-WWTP. However, a continuous monitoring of the PMMoV distribution pattern and concentration in other aquatic environments, as well as its correlation to other significant human enteric viruses, is essential for ensuring its reliability and reproducibility as a fecal pollution indicator.

5.
Cancers (Basel) ; 15(3)2023 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-36765601

RESUMO

Epstein Barr Virus (EBV) is implicated in the carcinogenesis of nasopharyngeal carcinoma (NPC) and currently associated with at least 1% of global cancers. The differential prognosis analysis of NPC in EBV genotypes remains to be elucidated. Medical, radiological, pathological, and laboratory reports of 146 NPC patients were collected retrospectively over a 6-year period between 2015 and 2020. From the pathology archives, DNA was extracted from tumor blocks and used for EBV nuclear antigen 3C (EBNA-3C) genotyping by nested polymerase chain reaction (PCR). We found a high prevalence of 96% of EBV infection in NPC patients with a predominance of genotype I detected in 73% of NPC samples. Histopathological examination showed that most of the NPC patients were in the advanced stages of cancer: stage III (38.4%) or stage IV-B (37.7%). Only keratinized squamous cell carcinoma was significantly higher in EBV negative NPC patients compared with those who were EBV positive (OR = 0.01, 95%CI = (0.004-0.32; p = 0.009)), whereas the majority of patients (91.8%) had undifferentiated, non-keratinizing squamous cell carcinoma, followed by differentiated, non-keratinizing squamous cell carcinoma (7.5%). Although NPC had metastasized to 16% of other body sites, it was not associated with EBV infection, except for lung metastasis. A statistically significant reverse association was observed between EBV infection and lung metastasis (OR = 0.07, 95%CI = (0.01-0.51; p = 0.008)). Although 13% of NPC patients died, the overall survival (OS) mean time was 5.59 years. Given the high prevalence of EBV-associated NPC in our population, Saudi could be considered as an area with a high incidence of EBV-associated NPC with a predominance of EBV genotype I. A future multi-center study with a larger sample size is needed to assess the true burden of EBV-associated NPC in Saudi Arabia.

6.
Comp Immunol Microbiol Infect Dis ; 94: 101957, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36808017

RESUMO

Pigeon paramyxovirus type-1 (PPMV-1) is an antigenic-variant of Newcastle disease virus (NDV) which is associated with infection in Columbidae family. In this study, we isolated two pigeon-derived strains pi/Pak/Lhr/SA_1/17 (designed as SA_1) and pi/Pak/Lhr/SA_2/17 (designed as SA_2) from diseased pigeons collected in Punjab province in 2017. We performed the whole genome, phylogenetic analysis and comparative clinico-pathological evaluation of two viruses in pigeons. Phylogenetic analysis based on fusion (F) gene and complete genome sequences showed that SA_1 belonged to sub-genotype XXI.1.1 and SA_2 clustered in sub-genotype XXI.1.2. SA_1 and SA_2 viruses contributed to morbidity and mortality in pigeons. Remarkably, although the two viruses resulted in comparatively similar pattern of pathogenesis and replication ability in various tissues of infected pigeons, SA_2 could cause more severe histopathological lesions and had comparatively high replication ability in pigeons than SA_1. Moreover, pigeons infected with SA_2 had higher shedding efficiency than that of pigeons infected with SA_1. Moreover, several aa substitutions in the major functional domains of the F and HN proteins might be contributed to the pathogenic differences between the two isolates in pigeons. Overall, these findings provide us with important insight into the epidemiology and evolution of PPMV-1 in Pakistan and laid the foundation for the further elucidation of the mechanism underlying the pathogenic difference of PPMV-1 in pigeons.


Assuntos
Doença de Newcastle , Vírus da Doença de Newcastle , Animais , Vírus da Doença de Newcastle/genética , Columbidae/genética , Paquistão , Filogenia , Genótipo , Genoma Viral , Genômica
7.
PLoS One ; 17(8): e0273343, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35980993

RESUMO

The diversity among bacteriophages depends on different factors like ecology, temperature conditions and genetic pool. Current study focused on isolation, identification and diversity of phages from 34 sewage water samples collected from two different wastewater treatment plants (WWTPs), King Saud University wastewater treatment plants (KSU-WWTP) and Manfoha wastewater treatment plants (MN-WWTP) in Riyadh, Saudi Arabia. Samples were analyzed by PCR and Next Generation Sequencing (NGS). Siphoviridae, Podoviridae and Myoviridae families were detected by family-specific PCR and highest prevalence of Myoviridae 29.40% was found at MN-WWTP followed by 11.76% at KSU-WWTP. Siphoviridae was detected 11.76% at MN-WWTP and 5.88% at KSU-WWTP. Lowest prevalence for Podoviridae family (5.88%) was recorded at MN-WWTP. Significant influence of temporal variations on prevalence of Myoviridae and Siphoviridae was detected in both WWTP and MN-WWTP, respectively. Highest phage prevalence was obtained in August (75%), followed by September (50%). Highest phage prevalence was recorded at a temperature range of 29-33°C. Significant influence of temperature on the prevalence of Myoviridae phages was detected at MN-WWTP. Four bacteriophages with various abundance levels were identified by NGS. Cronobacter virus Esp2949-1 was found first time with highest abundance (4.41%) in wastewater of Riyadh. Bordetella virus BPP1 (4.14%), Dickeya virus Limestone (1.55%) and Ralstonia virus RSA1 (1.04%) were also detected from samples of MN-WWTP. Highest occurrence of Bordetella virus BPP1 (67%) and (33.33%) was recorded at KSU-WWTP and MN-WWTP, respectively. Highest Bordetella virus BPP1 occurrence was recorded in September (50%) followed by August (40%). The findings of study showed new insights of phage diversity from wastewater sources and further large-scale data studies are suggested for comprehensive understanding.


Assuntos
Bacteriófagos , Podoviridae , Siphoviridae , Bacteriófagos/genética , Humanos , Myoviridae/genética , Arábia Saudita , Águas Residuárias
8.
Saudi J Biol Sci ; 29(6): 103304, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35574285

RESUMO

In this study, the blood volume and oxygen saturation of tumors were measured after photoacoustic imaging (PAI) under conditions of pre-photodynamic therapy (PDT), post-PDT, and 4 hrs, and 24 hrs post-PDT. PDTs with aminolevulinic acid (ALA) and low and high doses of benzoporphyrin derivative (BPD) were conducted to observe oxygen saturation changes, and the rapid oxygen consumption in the blood detected due to the action of BPD at the vascular level resulted in the recovery of PDT completion. Likewise, blood volume changes followed by ALA-PDT and BPD-PDT at low and high doses depicted a fast expansion of the blood volume after treatment. The tumor subjected to a high dose of ALA-PDT showed a partial alteration of Hb-pO2 in the first 24 hrs, as did the tumors treated with two ALA- and BPD-mediated PDTs. The Hb-pO2 started reducing immediately post-PDT and was less than 30% after 4 hrs until 24 hrs post-PDT. Reduced vascular demand was possibly due to tumor necrosis, as shown by the permanent damage in the cancer cells' bioluminescence signal. The ALA-mediated PDT-subjected tumor showed a 50% drop in BV at 24 hrs post-PDT, which is suggestive of vascular pruning. The studied data of blood volume against BLI showed the blood volume and oxygenation variations validating the cells' metabolic activity, including cell death.

9.
Pathogens ; 10(10)2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34684282

RESUMO

Entomologic investigations were conducted in the Al-Darb, Al-Reath, Al-Aridah, Abuareesh, Al-Ahad, Samttah, Sabyah, Damad and Beash areas by CO2-baited CDC miniature light traps in the Jazan region. Vectors were identified morphologically, as well as COI gene segment amplification and sequencing. The relative abundance (RA%) and pattern of occurrence (C%) were recorded. The presence of the Rift Valley fever virus (RVFV) in pooled mosquito samples was investigated by reverse transcriptase-polymerase chain reaction (RT-PCR). Culex pipiens (C. pipiens) and Culex tritaeniorhynchus (C. tritaeniorhynchus) were found with RA% values of 96% and 4%, respectively, in the region. Significant variations in vector population densities were observed in different districts. The C. pipiens was found highly abundant in all districts and RA% value (100%) was recorded in the Al-Darb, Al-Reath, Al-Aridah, Samttah and Damad areas, whereas RA% values (93.75%, 93.33%, 92.30% and 91.66%) were noted in Al-Ahad, Sabyah, Abuareesh and Beash districts, respectively. RA% values for C. tritaeniorhynchus were recorded as 8.33%, 7.70%, 6.66% and 6.25% in Beash, Abuareesh, Sabyah and Al-Ahad areas, respectively. The pattern of occurrence for C. pipiens and C. tritaeniorhynchus was recorded as 100% and 44.4% in the region. Phylogenetic analysis of C. pipiens and C. tritaeniorhynchus exhibited a close relationship with mosquitoes from Kenya and Turkey, respectively. All mosquito samples tested by RT-PCR were found negative for RVFV. In summary, the current study assessed the composition, abundance, distribution of different mosquito vectors and presence of RVFV in different areas of the Jazan region. Our data will help risk assessments of RVFV future re-emergence in the region.

10.
Results Phys ; 28: 104529, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34395185

RESUMO

INTRODUCTION: In December 2019, the city of Wuhan, located in the Hubei province of China became the epicentre of an outbreak of a pandemic called COVID-19 by the World Health Organisation. The detection of this virus by rRTPCR (Real-Time Reverse Transcription-Polymerase Chain Reaction) tests reported high false negative rate. The manifestations of CXR (Chest X-Ray) images contained salient features of the virus. The objective of this paper is to establish the application of an early automated screening model that uses low computational power coupled with raw radiology images to assist the physicians and radiologists in the early detection and isolation of potential positive COVID-19 patients, to stop the rapid spread of the virus in vulnerable countries with limited hospital capacities and low doctor to patient ratio in order to prevent the escalating death rates. MATERIALS AND METHODS: Our database consists of 447 and 447 CXR images of COVID-19 and Nofindings respectively, a total of 894 CXR images. They were then divided into 4 parts namely training, validation, testing and local/Aligarh dataset. The 4th (local/Aligarh) folder of the dataset was created to retest the diagnostics efficacy of our model on a developing nation such as India (Images from J.N.M.C., Aligarh, Uttar Pradesh, India). We used an Artificial Intelligence technique called CNN (Convolutional Neural Network). The architecture based on CNN used was MobileNet. MobileNet makes it faster than the ordinary convolutional model, while substantially decreasing the computational cost. RESULTS: The experimental results of our model show an accuracy of 96.33%. The F1-score is 93% and 96% for the 1st testing and 2nd testing (local/Aligarh) datasets (Tables 3.3 and 3.4). The false negative (FN) value, for the validation dataset is 6 (Fig. 3.6), for the testing dataset is 0 (Fig. 3.7) and that for the local/Aligarh dataset is 2 . The recall/sensitivity of the classifier is 93% and 96% for the 1st testing and 2nd testing (local/Aligarh) datasets (Tables 3.3 and 3.4). The recall/sensitivity for the detection of specifically COVID-19 (+) for the testing dataset is 88% and for the locally acquired dataset from India is 100%. The False Negative Rate (FNR) is 12% for the testing dataset and 0% for the locally acquired dataset (local/Aligarh). The execution time for the model to predict the input images and classify them is less than 0.1 s. DISCUSSION AND CONCLUSION: The false negative rate is much lower than the standard rRT-PCR tests and even 0% on the locally acquired dataset. This suggests that the established model with end-to-end structure and deep learning technique can be employed to assist radiologists in validating their initial screenings of Chest X-Ray images of COVID-19 in developed and developing nations. Further research is needed to test the model to make it more robust, employ it on multiclass classification and also try sensitise it to identify new strains of COVID-19. This model might help cultivate tele-radiology.

11.
Molecules ; 26(15)2021 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-34361812

RESUMO

Metal oxide nanoparticles synthesized by the biological method represent the most recent research in nanotechnology. This study reports the rapid and ecofriendly approach for the synthesis of CeO2 nanoparticles mediated using the Abelmoschus esculentus extract. The medicinal plant extract acts as both a reducing and stabilizing agent. The characterization of CeO2 NPs was performed by scanning electron microscopy (SEM), X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-Vis), and Fourier transform infrared spectroscopy (FTIR). The in vitro cytotoxicity of green synthesized CeO2 was assessed against cervical cancerous cells (HeLa). The exposure of CeO2 to HeLa cells at 10-125 µg/mL caused a loss in cellular viability against cervical cancerous cells in a dose-dependent manner. The antibacterial activity of the CeO2 was assessed against S. aureus and K. pneumonia. A significant improvement in wound-healing progression was observed when cerium oxide nanoparticles were incorporated into the chitosan hydrogel membrane as a wound dressing.


Assuntos
Abelmoschus/química , Antioxidantes/síntese química , Extratos Vegetais/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Antibacterianos/química , Antibacterianos/farmacologia , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Proliferação de Células/efeitos dos fármacos , Cério/química , Química Verde/tendências , Células HeLa , Humanos , Nanopartículas Metálicas/química , Microscopia Eletrônica de Varredura , Extratos Vegetais/química , Espectroscopia de Infravermelho com Transformada de Fourier , Staphylococcus aureus/patogenicidade , Cicatrização/efeitos dos fármacos
12.
J Virol Methods ; 295: 114212, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34126107

RESUMO

Routine wastewater treatment plants (WWTPs) effluents monitoring is essential because of enteric viruses' low infectious dose beyond molecular detectability. In current study methods for concentration and extraction, inter-method compatibility and recovery efficiency of spiked human adenovirus (HAdV) and human rotavirus A (RVA) were evaluated. For virus concentration, polyethylene glycol precipitation (PEG), charged membrane-based adsorption/elution (CMAE), and glass wool-based concentration (GW) methods were used. Nucleic acid was extracted by PowerViral™ Environmental RNA/DNA Isolation (POW), ZymoBIOMICS™ RNA extraction (ZYMO) and Wizard® Genomic DNA Purification (WGDP) and samples were analyzed by Real-Time PCR. CMAE method yielded significantly higher concentrations for both ARQ (Armored-RNA Quant) and RVA compared to PEG (P =  0.001 and 0.003) and GW (P <  0.0001). Highest HAdV concentration was obtained by PEG (P =  0.001 and < 0.0001) in relation to CMAE and GW. ZYMO yielded a significantly higher ARQ and RVA concentrations (P =  0.03 and 0.0057), whereas significantly higher concentration was obtained by POW for HAdV (P =  0.032). CMAE × ZYMO achieved the highest recovery efficiencies for ARQ (69.77 %) and RVA (64.25, respectively, while PEG × POW present efficiency of 9.7 % for HAdV. These findings provide guidance for understanding of method-related biases for viral recovery efficiency.


Assuntos
Adenovírus Humanos , Enterovirus , Rotavirus , Purificação da Água , Adenovírus Humanos/genética , Humanos , Reação em Cadeia da Polimerase em Tempo Real , Rotavirus/genética
13.
Sci Rep ; 11(1): 12132, 2021 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-34108565

RESUMO

The routine evaluation of water environments is necessary to manage enteric virus-mediated fecal contamination and the possible emergence of novel variants. Here, we detected human rotavirus A (HRVA) circulating in two wastewater treatment plants, two lakes, irrigation water and a wastewater landfill located in Riyadh. VP7-derived surface protein sequences were assessed by phylogenetic analyses and inspection of thermotolerance-mediated secondary structure and seasonal variation. HRVA was most prevalent at An-Nazim wastewater landfill (AN-WWLF; 63.89%). Phylogenetic analyzes revealed the predominance of HRVA G2 lineage for the first time in Saudi Arabia. Moreover, a single HRVA sequence (2B64I-ANLF3/2018) was recovered at 45 °C from AN-WWLF; secondary structure prediction indicated that this sequence was thermotolerant with a high hydrophobicity, an absence of Ramachandran outliers, and a higher content of proline patches on the protein surface. Varied relationships were significantly observed between sampling areas influenced by temperature ranges (p < 0.05). HRVA prevalence was influenced by seasonal variations, favoring moderate temperatures in late autumn and early winter in all locations. However, a significant temperature impact was detected in Wadi-Hanifah Lake (p = 0.01). Our study extends the knowledge of currently circulating HRVA genotypes, and indicates the probable emergence of thermotolerant strains and seasonally mediated HRVA prevalence.


Assuntos
Antígenos Virais/genética , Proteínas do Capsídeo/genética , Variação Genética , Infecções por Rotavirus/genética , Rotavirus/classificação , Rotavirus/genética , Termotolerância , Sequência de Aminoácidos , DNA Viral/análise , DNA Viral/genética , Genótipo , Humanos , Filogenia , Rotavirus/isolamento & purificação , Infecções por Rotavirus/epidemiologia , Infecções por Rotavirus/virologia
14.
Artigo em Inglês | MEDLINE | ID: mdl-33947135

RESUMO

The regular monitoring of water environments is essential for preventing waterborne virus-mediated contamination and mitigating health concerns. We aimed to detect human adenovirus (HAdV) in the Wadi Hanifah (WH) and Wadi Namar (WN) lakes, King Saud University wastewater treatment plant (KSU-WWTP), Manfouha-WWTP, irrigation water (IW), and AnNazim landfill (ANLF) in Riyadh, Saudi Arabia. HAdV hexon sequences were analyzed against 71 HAdV prototypes and investigated for seasonal influence. ANLF had the highest HAdV prevalence (83.3%). Remarkably, the F species of HAdV, especially serotype 41, predominated. Daily temperature ranges (22-45 °C and 10-33 °C) influenced the significance of the differences between the locations. The most significant relationship of ANLF and IW to WH and KSU-WWTP was found at the high-temperature range (p = 0.001). Meanwhile, WN was most correlated to ANLF at the low-temperature range (p < 0.0001). Seasonal influences on HAdV prevalence were insignificant despite HAdV's high prevalence in autumn and winter months, favoring low temperatures (high: 22-25 °C, low: 14-17 °C) at five out of six locations. Our study provides insightful information on HAdV prevalence and the circulating strains that can address the knowledge gap in the environmental impacts of viruses and help control viral diseases in public health management.


Assuntos
Infecções por Adenovirus Humanos , Adenovírus Humanos , Adenovírus Humanos/genética , Humanos , Filogenia , Arábia Saudita/epidemiologia , Estações do Ano , Análise de Sequência de DNA , Água
15.
Results Phys ; 27: 104248, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33996398

RESUMO

Coronavirus (COVID-19) outbreak from Wuhan, Hubei province in China and spread out all over the World. In this work, a new mathematical model is proposed. The model consists the system of ODEs. The developed model describes the transmission pathways by employing non constant transmission rates with respect to the conditions of environment and epidemiology. There are many mathematical models purposed by many scientists. In this model, " α E " and " α I ", transmission coefficients of the exposed cases to susceptible and infectious cases to susceptible respectively, are included. " δ " as a governmental action and restriction against the spread of coronavirus is also introduced. The RK method of order four (RK4) is employed to solve the model equations. The results are presented for four countries i.e., Pakistan, Italy, Japan, and Spain etc. The parametric study is also performed to validate the proposed model.

16.
Molecules ; 26(5)2021 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-33807651

RESUMO

A series of cobalt-inserted copper zinc ferrites, Cu0.6CoxZn0.4-xFe2O4 (x = 0.0, 0.1, 0.2, 0.3, 0.4) having cubic spinel structure were prepared by the coprecipitation method. Various characterization techniques, including XRD, FTIR, UV-vis and I-V were used to investigate structural optical and electrical properties, respectively. The lattice constant was observed to be decreased as smaller ionic radii Co2+ (0.74 Å) replaced the higher ionic radii Zn2+ (0.82 Å). The presence of tetrahedral and octahedral bands was confirmed by FTIR spectra. Optical bandgap energy was determined in the range of 4.44-2.05 eV for x = 0.0 to 0.4 nanoferrites, respectively. DC electrical resistivity was measured and showed an increasing trend (5.42 × 108 to 6.48 × 108 Ω·cm) with the addition of cobalt contents as cobalt is more conductive than zinc. The range of DC electrical resistivity (108 ohm-cm) makes these nanomaterials potential candidates for telecommunication devices.


Assuntos
Compostos Férricos/química , Cobre/química , Condutividade Elétrica , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X , Óxido de Zinco/química
17.
Saudi J Biol Sci ; 28(6): 3325-3332, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33679194

RESUMO

The sequences of SARS-CoV-2 spike (S) from Saudi Arabia along with SARS-CoV and bat SARS-like CoVs were obtained. Positive selection analysis and secondary structure investigation of spike sequences were performed. Adaptive molecular evolution was observed in SARS-CoV-2 displayed by positive selection pressure at N-terminal domain (NTD; codons 41, 163, 174 and 218), Receptor binding domain (RBD; codons 378 and 404) and S1/S2 Cleavage site (codon 690). Furthermore, the spike protein secondary structure depicted by the homo-trimer structure showed a high similarity between Saudi SARS-CoV-2 isolate and the parental strain (bat SL-COVZC45). Despite the high similarity depicted in the spike sequence model alignment, it displayed a significant difference when each chain was treated solely owing to 7 motif differences in the three composing chains. In addition, SARS-CoV-2 S trimer model uncovered the presence of N-acetyl glucosamine ligands. Eventually, 3C-like proteinase cleavage site was observed in S2 domain could be used as a site for drug discovery. Genetics and molecular evolutionary facts are useful for assessment of evolution, host adaptation and epidemic patterns ultimately helpful for adaptation of control strategies.

18.
Saudi J Biol Sci ; 28(2): 1226-1232, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33613051

RESUMO

Some nanoscale morphologies of titanium oxide nanostructures blend with gold nanoparticles and act as satellites and targeted weapon methodologies in biomedical applications. Simultaneously, titanium oxide can play an important role when combined with gold after blending with polyethylene glycol (PEG). Our experimental approach is novel with respect to the plasmonic role of metal nanoparticles as an efficient PDT drug. The current experimental strategy floats the comprehensive and facile way of experimental strategy on the critical influence that titanium with gold nanoparticles used as novel photosensitizing agents after significant biodistribution of proposed nanostructures toward targeted site. In addition, different morphologies of PEG-coated Au-doped titanium nanostructures were shown to provide various therapeutic effects due to a wide range of electromagnetic field development. This confirms a significantly amplified population of hot electron generation adjacent to the interface between Au and TiO2 nanostructures, leading to maximum cancerous cell injury in the MCF-7 cell line. The experimental results were confirmed by applying a least squares fit math model which verified our results with 99% goodness of fit. These results can pave the way for comprehensive rational designs for satisfactory response of performance phototherapeutic model mechanisms along with new horizons of photothermal therapy (HET) and photodynamic therapy (HET) operating under visible and near-infrared (NIR) light.

19.
Saudi J Biol Sci ; 28(2): 1233-1238, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33613052

RESUMO

The preparation of a manganese-doped cerium oxide (Mn:CeO2) nanocomposite via hydrothermal route is described. Cubic fluorite structure of single phase was exhibited by studying structural analysis through x-ray diffraction (XRD) technique and morphological analysis was conducted by scanning electron microscope. Surface analytic technique of energy dispersive x-ray spectroscopy (EDX) was conducted to analyze the relative amount of any impurity and doping. Structural changes due to manganese doping such as increment in production of vacancies of oxygen within crystal of cerium oxide, and reduction in size of crystallite and constant of lattice was observed in our research study. Moreover, the Mn:CeO2 nanocomposite demonstrates differential cytotoxicity against MCF-7 adenocarcinoma cell line, which renders it a promising candidate for targeted cancer therapy. The anti-tumorous activity of the cerium oxide nanocomposite was significantly enhanced with doping of manganese, which is directly linked with the generation of highly reactive oxygen facets. The experimental results are supported by a mathematical model that confirms a confidence level of 95%. This research has paved the way for many utilities in therapeutics and magnetic resonance imaging diagnostics through new observations, and hence verified their math model.

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