The ongoing COVID-19 pandemic is caused by SARs-CoV-2. The virus is transmitted from person to person through droplet infections i.e. when infected person is in close contact with another person. In ...January 2020, first report of detection of SARS-CoV-2 in faeces, has made it clear that human wastewater might contain this virus. This may illustrate the probability of environmentally facilitated transmission, mainly the sewage, however, environmental conditions that could facilitate faecal oral transmission is not yet clear. We used existing Pakistan polio environment surveillance network to investigate presence of SARs-CoV-2 using three commercially available kits and E-Gene detection published assay for surety and confirmatory of positivity. A Two-phase separation method is used for sample clarification and concentration. An additional high-speed centrifugation (14000Xg for 30 min) step was introduced, prior RNA extraction, to increase viral RNA yield resulting a decrease in Cq value. A total of 78 wastewater samples collected from 38 districts across Pakistan, 74 wastewater samples from existing polio environment surveillance sites, 3 from drains of COVID-19 infected areas and 1 from COVID 19 quarantine center drainage, were tested for presence of SARs-CoV-2. 21 wastewater samples (27%) from 13 districts turned to be positive on RT-qPCR. SARs-COV-2 RNA positive samples from areas with COVID 19 patients and quarantine center strengthen the findings and use of wastewater surveillance in future. Furthermore, sequence data of partial ORF 1a generated from COVID 19 patient quarantine center drainage sample also reinforce our findings that SARs-CoV-2 can be detected in wastewater. This study finding indicates that SARs-CoV-2 detection through wastewater surveillance has an epidemiologic potential that can be used as supplementary system to monitor viral tracking and circulation in cities with lower COVID-19 testing capacity or heavily populated areas where door-to-door tracing may not be possible. However, attention is needed on virus concentration and detection assay to increase the sensitivity. Development of highly sensitive assay will be an indicator for virus monitoring and to provide early warning signs.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Pakistan has been experiencing intervals of sporadic cases and localized outbreaks in the last two decades. No proper study has been carried out in order to find out the environmental burden of ...toxigenic V. cholerae as well as how temporal and environmental factors associated in driving cholera across the country.
We tested waste water samples from designated national environment surveillance sites in Pakistan with RT-PCR assay. Multistage sampling technique were utilized for samples collection and for effective sample processing Bag-Mediated Filtration system, were employed. Results were analysed by district and month wise to understand the geographic distribution and identify the seasonal pattern of V. cholera detection in Pakistan.
Between May 2019, and February 2020, we obtained and screened 160 samples in 12 districts across Pakistan. Out of 16 sentinel environmental surveillance sites, 15 sites showed positive results against cholera toxigenic gene with mostly lower CT value (mean, 34±2) and have significant difference (p < 0.05). The highest number of positive samples were collected from Sindh in month of November, then in June it is circulating in different districts of Pakistan including four Provinces respectively.
V. cholera detection do not follow a clear seasonal pattern. However, the poor sanitation problems or temperature and rainfall may potentially influence the frequency and duration of cholera across the country. Occurrence of toxigenic V. cholerae in the environment samples showed that cholera is endemic, which is an alarming for a potential future cholera outbreaks in the country.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The revolutionary technology of CRISPR/Cas systems and their extraordinary potential to address fundamental questions in every field of biological sciences has led to their developers being awarded ...the 2020 Nobel Prize for Chemistry. In agriculture, CRISPR/Cas systems have accelerated the development of new crop varieties with improved traits-without the need for transgenes. However, the future of this technology depends on a clear and truly global regulatory framework being developed for these crops. Some CRISPR-edited crops are already on the market, and yet countries and regions are still divided over their legal status. CRISPR editing does not require transgenes, making CRISPR crops more socially acceptable than genetically modified crops, but there is vigorous debate over how to regulate these crops and what precautionary measures are required before they appear on the market. This article reviews intended outcomes and risks arising from the site-directed nuclease CRISPR systems used to improve agricultural crop plant genomes. It examines how various CRISPR system components, and potential concerns associated with CRISPR/Cas, may trigger regulatory oversight of CRISPR-edited crops. The article highlights differences and similarities between GMOs and CRISPR-edited crops, and discusses social and ethical concerns. It outlines the regulatory framework for GMO crops, which many countries also apply to CRISPR-edited crops, and the global regulatory landscape for CRISPR-edited crops. The article concludes with future prospects for CRISPR-edited crops and their products.
This study was conducted to analyze the efficacy of Polyalthia longifolia branches as an effective biosorbent for elimination of textile dye stuff brilliant yellow. Different operating conditions ...were tested (adsorbent dose, dye concentration, contact time, pH and temperature) to investigate their relationship with adsorption strength of Polyalthia longifolia and subsequently to eliminate toxic color. The absorbent was also characterized by Fourier Transform Infrared (FTIR). Optimum adsorption was observed at pH 6. Model of kinetic explored the adsorption data showing pseudo 2nd order with high correlation coefficient R2 of 0.996. Langmuir model followed well to equilibrium data relative to Freundlich and Temkin models. Thermodynamic property was also observed, where Gibbs free energy, entropy and enthalpy were analyzed. Through Gibbs free energy it was found that absorbent has endothermic nature. Thermodynamic properties have depicted that adsorption process was natural, endothermic and suitable for treatment of toxic dye.
To understand the interactions of microwaves with dielectric materials and their conversion to thermal energy in aqueous systems, the effect of ionic concentration has been studied. Aqueous solutions ...of inorganic ions were exposed to microwaves (2.45GHz) in a modified oven under identical conditions. Difference in solution temperatures with reference to pure (deionized) water was monitored in each case. A significant decrease in the temperature was observed with an increase in the quantity of ions. Experiments were repeated with several inorganic ions varying in size and charge. The information can be helpful in understanding the role of ions during dielectric heating.
The development of
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–rGO nanocomposite-based photoanode is an efficient way to enhance the power conversion efficiency (PCE) of dye-sensitized solar cells (DSSCs).
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–rGO nanocomposite has ...been synthesized for the modified photoanode of DSSCs. GO has been synthesized by modified Hummer’s method, and rGO was achieved by two more steps.
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nanoparticles have been synthesized by the sol–gel approach followed by composition with rGO. The
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–rGO nanocomposites were analyzed by Field-Emission Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDX), X-Ray Diffraction (XRD), UV–Vis Spectroscopy, and IV measurements. The as synthesized
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–rGO nanocomposite-based photoanode showed a higher PCE than pure
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nanoparticles-based photoanode. Moreover,
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–rGO nanocomposite-based photoanode presented enhanced efficiency of 4.09% in DSSCs because rGO has better charge collection ability, which is more convenient to reduce the electron recombination rate.
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•CRISPR effector Cas13a can be reprogrammed to target ssRNA virus in a eukaryotic system.•Cas13a is effective at targeting hepatitis C virus in cell culture.•Several of potential ...Cas13a target sites are present in HCV-IRES.•Optimal Cas13a target sites are identified via computational analysis.•Cas13a-based targeting of HCV-IRES can be used to develop broad genotypic therapeutics.
Hepatitis C is an inflammatory liver disease caused by the single-stranded RNA (ssRNA) hepatitis C virus (HCV). The genetic diversity of the virus and quasispecies produced during replication have resulted in viral resistance to direct-acting antivirals (DAAs) as well as impediments in vaccine development. The recent adaptation of CRISPR-Cas as an alternative antiviral approach has demonstrated degradation of viral nucleic acids in eukaryotes. In particular, the CRISPR-effector Cas13 enzyme has been shown to target ssRNA viruses effectively. In this work, we have employed Cas13a to knockdown HCV in mammalian cells. Using a computational screen, we identified several potential Cas13a target sites within highly conserved regions of the HCV internal ribosomal entry site (IRES). Our results demonstrate significant inhibition of HCV replication as well as translation in huh-7.5 cells with minimal effects on cell viability. These findings were validated using a multi-modality approach involving qRT-PCR, luciferase assay, and MTT cell viability assay. In conclusion, the CRISPR-Cas13a system efficiently targets HCV in vitro, suggesting its potential as a programmable therapeutic antiviral strategy.
PurposeThis study examines the role of continuous trust (i.e., a trust that develops over time as a result of continuous usage interactions) in determining customers' intention to continue using ...online product recommendations (OPRs).Design/methodology/approachBased on information system (IS), continuance model, and continuous trust, we propose that continuous trust will influence customers’ intention to continue OPRs’ use directly and indirectly via their satisfaction and usefulness of the OPRs. The research model is tested using data collected via an online survey from 626 existing users of OPRs in 15 different countries.FindingsThe empirical results revealed that continuous trust is shown to be a significant predictor of customers’ intention to continue OPRs use for future purchases. Additionally, the customers’ perceived confirmation and continuous trust positively influence their perceived usefulness and satisfaction with the OPRs, which subsequently influence customers’ OPRs continuous usage intention.Research limitations/implicationsThe saliency of continuous trust and usefulness of OPRs present e-retailers with potential fruitful areas to shape future usage of OPRs. In addition, e-retailers must understand that improving the OPR usefulness on its own may not lead to OPRs continuous usage until OPRs trustworthiness is not continually improved. OPRs itself may be convenient and useful, but trustworthy OPRs will pay stronger dividends for customer satisfaction and OPRs’ continuous usage.Originality/valueThe incorporation of continuous trust into the IS continuance model offers a new theoretical lens and an alternative explanation for the OPR continuous usage intention. This study stands in contrast to the large majority of research concerning initial trust and OPRs adoption, in that it focuses on continuous trust (as opposed to initial trust) and on a customers’ OPRs continuous usage intention as opposed to the initial adoption decision.
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