The aim was to determine whether various clinical specimens obtained from COVID-19 patients contain the infectious virus.
To demonstrate whether various clinical specimens contain the viable virus, ...we collected naso/oropharyngeal swabs and saliva, urine and stool samples from five COVID-19 patients and performed a quantitative polymerase chain reaction (qPCR) to assess viral load. Specimens positive with qPCR were subjected to virus isolation in Vero cells. We also used urine and stool samples to intranasally inoculate ferrets and evaluated the virus titres in nasal washes on 2, 4, 6 and 8 days post infection.
SARS-CoV-2 RNA was detected in all naso/oropharyngeal swabs and saliva, urine and stool samples collected between days 8 and 30 of the clinical course. Notably, viral loads in urine, saliva and stool samples were almost equal to or higher than those in naso/oropharyngeal swabs (urine 1.08 ± 0.16–2.09 ± 0.85 log10 copies/mL, saliva 1.07 ± 0.34–1.65 ± 0.46 log10 copies/mL, stool 1.17 ± 0.32 log10 copies/mL, naso/oropharyngeal swabs 1.18 ± 0.12–1.34 ± 0.30 log10 copies/mL). Further, viable SARS-CoV-2 was isolated from naso/oropharyngeal swabs and saliva of COVID-19 patients, as well as nasal washes of ferrets inoculated with patient urine or stool.
Viable SARS-CoV-2 was demonstrated in saliva, urine and stool samples from COVID-19 patients up to days 11–15 of the clinical course. This result suggests that viable SARS-CoV-2 can be secreted in various clinical samples and respiratory specimens.
The outbreak of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in China and rapidly spread worldwide. To prevent SARS-CoV-2 ...dissemination, understanding the in vivo characteristics of SARS-CoV-2 is a high priority. We report a ferret model of SARS-CoV-2 infection and transmission that recapitulates aspects of human disease. SARS-CoV-2-infected ferrets exhibit elevated body temperatures and virus replication. Although fatalities were not observed, SARS-CoV-2-infected ferrets shed virus in nasal washes, saliva, urine, and feces up to 8 days post-infection. At 2 days post-contact, SARS-CoV-2 was detected in all naive direct contact ferrets. Furthermore, a few naive indirect contact ferrets were positive for viral RNA, suggesting airborne transmission. Viral antigens were detected in nasal turbinate, trachea, lungs, and intestine with acute bronchiolitis present in infected lungs. Thus, ferrets represent an infection and transmission animal model of COVID-19 that may facilitate development of SARS-CoV-2 therapeutics and vaccines.
Display omitted
•SARS-CoV-2-infected ferrets exhibit elevated body temperature and virus replication•SARS-CoV-2 is shed in nasal washes, saliva, urine and feces•SARS-CoV-2 is effectively transmitted to naive ferrets by direct contact•SARS-CoV-2 infection leads acute bronchiolitis in infected ferrets
The outbreak of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) rapidly spreads, leading to a pandemic infection. Kim et al. show that ferrets are highly susceptible to SARS-CoV-2 infection and effectively transmit the virus by direct or indirect contact, recapitulating human infection and transmission.
Display omitted
•Green reductive preparation of superparamagnetic iron ferrite nanoparticles.•Well characterization of inverse spinel iron ferrite using PXRD, BET, AFM and XPS.•The superparamagnetic ...property of MISFNPs measured by MPM system.•Well applied of MISFNPs for adsorptive removal of heavy metals.•Thermodynamic studies and adsorption mechanism were also studied.
The accumulation of heavy metal ions in living cells impairs the organ function of living creatures. So, needs to develop new materials with high efficiency of heavy metals removal from the environment. As part of this effort, here, synthesized magnetic inverse spinel iron oxide nanoparticles (MISFNPs) using a biogenic methodology. To synthesize the biogenic MISFNPs, we used the seed extract of Cnidiummonnieri (L.) Cuss (CLC) as a precursor. The prepared MISFNPs was characterized using PXRD, FT-IR, SEM-EDX, SEM, BET, AFM and XPS. We also investigated the size, surface area, structure and magnetic properties of MISFNPs. Additionally, magnetic property measurement system (MPMS) studies show that our prepared MISFNPs was superparamagnetic at room temperature. Further, we used the MISFNPs for the removal of Pb(II) and Cr(III) from aqueous solutions through batch studies. Batch adsorption studies revealed that Pb(II) and Cr(III) follow pseudo-second-order kinetics during adsorption onto the homogenous surface of MISFNPs. Besides, we also found that the adsorption of Pb(II) and Cr(III) on nanoparticles followed an endothermic process. Lastly, we concluded that MISFNPs synthesized by a green route is capable of recycling and removal of heavy metals without loss of its stability.
Multi virtual cathodes (MVCs) were created in an axial vircator utilizing two dielectric reflectors (DRs). The wall charge of drifting electrons on the surface of DRs led to the creation of VC2 and ...VC3 in the downstream area of drift tube, according to phase space simulations. The microwave generated by VC1 interacted with the charge of VC2 and VC3 to raise the power amplitude, resulting in an increase in output power from 284 MW to 1028 MW. The use of two dielectric reflectors was proven to have a remarkable impact in reducing electron loss, increasing output power, and improving efficiency. The suggested vircator's efficiency with MVCs improved from 7.9 % to 28.6 %. The findings indicate important signs of progress in vircator research to decrease electron losses and boost beam-wave interaction, which might lead to the advancement of high-efficiency vircators.
While the seroprevalence of SARS-CoV-2 in healthy people does not differ significantly among age groups, those aged 65 years or older exhibit strikingly higher COVID-19 mortality compared to younger ...individuals. To further understand differing COVID-19 manifestations in patients of different ages, three age groups of ferrets are infected with SARS-CoV-2. Although SARS-CoV-2 is isolated from all ferrets regardless of age, aged ferrets (≥3 years old) show higher viral loads, longer nasal virus shedding, and more severe lung inflammatory cell infiltration, and clinical symptoms compared to juvenile (≤6 months) and young adult (1-2 years) groups. Furthermore, direct contact ferrets co-housed with the virus-infected aged group shed more virus than direct-contact ferrets co-housed with virus-infected juvenile or young adult ferrets. Transcriptome analysis of aged ferret lungs reveals strong enrichment of gene sets related to type I interferon, activated T cells, and M1 macrophage responses, mimicking the gene expression profile of severe COVID-19 patients. Thus, SARS-CoV-2-infected aged ferrets highly recapitulate COVID-19 patients with severe symptoms and are useful for understanding age-associated infection, transmission, and pathogenesis of SARS-CoV-2.
Plasma-activated water (PAW) has been in use for the past decade in sanitization against bacteria and other microorganisms. This research study compared PAW generated by a DC positive flyback ...transformer (FBT) underwater plasma jet with delivery of reactive species underwater by cylindrical dielectric barrier discharge (C-DBD) with a neon transformer. A Box–Behnken design was adopted as a response surface methodology (RSM) to design the experimental plan and optimize operating parameters including time, gas flow, and gas ratio. The physical responses comprise optical emission spectroscopy (OES), pH, oxidation-reduction potential (ORP), and electrical conductivity (EC). The chemical responses consist of hydrogen peroxide (H2O2) and hydroxyl radicals (OH·). The biological responses include Escherichia coli reduction and Staphylococcus aureus reduction. The optimal condition for underwater plasma jet was found to be Ar gas with a flow rate of 3 slm for 6.5 min of treatment time, which can reduce E. coli and S. aureus to 7.14 ± 0.14 and 3.10 ± 0.26 in log, respectively. Also, the optimal condition for delivery of reactive species underwater by C-DBD plasma was found to be Ar (99%): O2 (1%) gas mixture with an Ar gas flow rate of 4 slm for a treatment time of 11.5 min, which could reduce E. coli and S. aureus to 0.45 ± 0.07 and 2.45 ± 0.23 in log, respectively.
Display omitted
•A comparison of two plasma-activated water (PAW) sources, plasma jet with a DC positive flyback transformer (FBT) and cylindrical dielectric barrier discharge (C-DBD) with neon transformer.•The Box–Behnken design (BBD) was applied for the PAW treatment.•The multiple response desirability function and response surface methodology (RSM) were used to find the optimum conditions.
Summary Background In 2015, a large outbreak of Middle East respiratory syndrome coronavirus (MERS-CoV) infection occurred following a single patient exposure in an emergency room at the Samsung ...Medical Center, a tertiary-care hospital in Seoul, South Korea. We aimed to investigate the epidemiology of MERS-CoV outbreak in our hospital. Methods We identified all patients and health-care workers who had been in the emergency room with the index case between May 27 and May 29, 2015. Patients were categorised on the basis of their exposure in the emergency room: in the same zone as the index case (group A), in different zones except for overlap at the registration area or the radiology suite (group B), and in different zones (group C). We documented cases of MERS-CoV infection, confirmed by real-time PCR testing of sputum samples. We analysed attack rates, incubation periods of the virus, and risk factors for transmission. Findings 675 patients and 218 health-care workers were identified as contacts. MERS-CoV infection was confirmed in 82 individuals (33 patients, eight health-care workers, and 41 visitors). The attack rate was highest in group A (20% 23/117 vs 5% 3/58 in group B vs 1% 4/500 in group C; p<0·0001), and was 2% (5/218) in health-care workers. After excluding nine cases (because of inability to determine the date of symptom onset in six cases and lack of data from three visitors), the median incubation period was 7 days (range 2–17, IQR 5–10). The median incubation period was significantly shorter in group A than in group C (5 days IQR 4–8 vs 11 days 6–12; p<0·0001). There were no confirmed cases in patients and visitors who visited the emergency room on May 29 and who were exposed only to potentially contaminated environment without direct contact with the index case. The main risk factor for transmission of MERS-CoV was the location of exposure. Interpretation Our results showed increased transmission potential of MERS-CoV from a single patient in an overcrowded emergency room and provide compelling evidence that health-care facilities worldwide need to be prepared for emerging infectious diseases. Funding None.
We report the effects of reactive compatibilization on the morphology, microstructure, and physical properties of thermotropic liquid crystalline polyester/poly(1,4‐cyclohexylenedimethylene ...terephthalate) (TLCP/PCT, 75/25 by wt%) blends, which are fabricated via melt‐compounding in the presence of different catalyst types and contents. Among three different catalysts, titanium butoxide (TBT) is found to be most effective in the reactive compatibilization of TLCP/PCT blends, which is confirmed by SEM images. FT‐IR spectroscopic analysis reveals the formation of copolyesters by catalyst‐induced transesterification between TLCP and PCT components during melt‐compounding with 0.5 and 1.0 phr TBT loadings. Nonetheless, X‐ray diffraction analysis confirms that the crystal structures of TLCP/PCT blends are not affected by reactive compatibilization. The melting and crystallization transition temperatures of the PCT component in the compatibilized blends decrease owing to the shortening of crystallizable PCT segments by the transesterification. TGA data show that the residue at 800°C increases for the blends melt‐compounded with higher TBT catalyst loadings. The shear moduli and complex viscosity of compatibilized TLCP/LCP blends at a melt state are found to be even higher than neat TLCP and PCT. Although the elastic storage moduli of compatibilized TLCP/PCT blends are slightly lower than neat TLCP, they are far higher than neat PCT.
Reactive compatibilization of TLCP/PCT blends via catalyst‐induced transesterification.
Due to the urgent need of a therapeutic treatment for coronavirus (CoV) disease 2019 (COVID-19) patients, a number of FDA-approved/repurposed drugs have been suggested as antiviral candidates at ...clinics, without sufficient information. Furthermore, there have been extensive debates over antiviral candidates for their effectiveness and safety against severe acute respiratory syndrome CoV 2 (SARS-CoV-2), suggesting that rapid preclinical animal studies are required to identify potential antiviral candidates for human trials. To this end, the antiviral efficacies of lopinavir-ritonavir, hydroxychloroquine sulfate, and emtricitabine-tenofovir for SARS-CoV-2 infection were assessed in the ferret infection model. While the lopinavir-ritonavir-, hydroxychloroquine sulfate-, or emtricitabine-tenofovir-treated group exhibited lower overall clinical scores than the phosphate-buffered saline (PBS)-treated control group, the virus titers in nasal washes, stool specimens, and respiratory tissues were similar between all three antiviral-candidate-treated groups and the PBS-treated control group. Only the emtricitabine-tenofovir-treated group showed lower virus titers in nasal washes at 8 days postinfection (dpi) than the PBS-treated control group. To further explore the effect of immune suppression on viral infection and clinical outcome, ferrets were treated with azathioprine, an immunosuppressive drug. Compared to the PBS-treated control group, azathioprine-immunosuppressed ferrets exhibited a longer period of clinical illness, higher virus titers in nasal turbinate, delayed virus clearance, and significantly lower serum neutralization (SN) antibody titers. Taken together, all antiviral drugs tested marginally reduced the overall clinical scores of infected ferrets but did not significantly affect
virus titers. Despite the potential discrepancy of drug efficacies between animals and humans, these preclinical ferret data should be highly informative to future therapeutic treatment of COVID-19 patients.
The SARS-CoV-2 pandemic continues to spread worldwide, with rapidly increasing numbers of mortalities, placing increasing strain on health care systems. Despite serious public health concerns, no effective vaccines or therapeutics have been approved by regulatory agencies. In this study, we tested the FDA-approved drugs lopinavir-ritonavir, hydroxychloroquine sulfate, and emtricitabine-tenofovir against SARS-CoV-2 infection in a highly susceptible ferret infection model. While most of the drug treatments marginally reduced clinical symptoms, they did not reduce virus titers, with the exception of emtricitabine-tenofovir treatment, which led to diminished virus titers in nasal washes at 8 dpi. Further, the azathioprine-treated immunosuppressed ferrets showed delayed virus clearance and low SN titers, resulting in a prolonged infection. As several FDA-approved or repurposed drugs are being tested as antiviral candidates at clinics without sufficient information, rapid preclinical animal studies should proceed to identify therapeutic drug candidates with strong antiviral potential and high safety prior to a human efficacy trial.
Mechanically resilient optoelectronic devices are relevant for a wide range of applications, including portable and wearable devices. Perovskite thin film‐based devices are a suitable choice for ...designing such resilient systems as it demonstrates high performance while preserving moderate mechanical compliance. Yet its mechanical property can be improved further by integrating the energy dissipation system and self‐healing ability into the thin film. Copolymers containing Lewis‐base functional groups, elastomer chains, and cyclic linkages are synthesized and introduced into the perovskite precursor. The polymers impart multifunctional effect of controlled crystal growth, defect passivation, protection against moisture, mechanical energy dissipation, and self‐recoverability. The polymer‐added perovskite solar cells are shown to provide a power conversion efficiency of 23.25% (a steady‐state efficiency of 22.61%), due to the strong coordinative covalent interaction between the polymer and the perovskite. An operational lifetime of solar cells under harsh conditions is also substantially extended by the polymer incorporation. Furthermore, the interchain hydrogen‐bond strength controlled by the cyclic linkage, and hybrid cross‐linked network formed within the thin film significantly improves the mechanical stability and self‐recoverability of the thin film. As a result, the devices demonstrate robustness under 2000 cyclic flex tests at a bending radius of 1 mm.
Newly designed copolymers with multi‐functionalities are synthesized and incorporated in perovskite solar cells to simultaneously improve device efficiency, stability, and mechanical resilience. The polymers form a hybrid cross‐linked network composed of mixed physical and chemical bonds within the perovskite thin film, which provides controlled crystal growth and surface defect passivation, as well as effective energy dissipation and self‐healing behaviors during and after mechanical deformation of devices.
PDF
