Lower respiratory tract samples are reliable for severe acute respiratory syndrome coronavirus 2 nucleic acid diagnosis and animal model study

Severe acute respiratory syndrome coronavirus 2(SARS-Co V-2) and coronavirus disease 2019(COVID-19) continue to impact countries worldwide.At present, inadequate diagnosis and unreliable evaluation systems hinder the implementation and development of effective prevention and treatment strategies. Here, we conducted a horizontal and longitudinal study comparing the detection rates of SARS-Co V-2 nucleic acid in different types of samples collected from COVID-19 patients and SARS-Co V-2-infected monkeys. We also detected anti-SARS-Co V-2 antibodies in the above clinical and animal model samples to identify a reliable approach for the accurate diagnosis of SARS-Co V-2 infection. Results showed that, regardless of clinical symptoms, the highest detection levels of viral nucleic acid were found in sputum and tracheal brush samples, resulting in a high and stable diagnosis rate. Anti-SARS-Co V-2 immunoglobulin M(Ig M) and G(Ig G) antibodies were not detected in6.90% of COVID-19 patients. Furthermore,integration of nucleic acid detection results from the various sample types did not improve the diagnosis rate. Moreover, dynamic changes in SARS-Co V-2 viral load were more obvious in sputum and tracheal brushes than in nasal and throat swabs. Thus,SARS-Co V-2 nucleic acid detection in sputum and tracheal brushes was the least affected by infection route, disease progression, and individual differences. Therefore, SARS-Co V-2 nucleic acid detection using lower respiratory tract samples alone is reliable for COVID-19 diagnosis and study.

Ion-beam-assisted characterization of quinoline-insoluble particles in nuclear graphite

The irradiation behavior of graphite is essential for its applications in the nuclear industry.However,the behavioral differences of graphite remain obscure because of the very limited comprehension of its microstructural differences.One typical structure,the quinoline-insoluble(QI)particle,was investigated using IG-110 and NBG-18 graphite.After irradiation,the QI particles on the polished surface were proven to become hillocks,which were easily identifiable via scanning electron microscopy(SEM).Thus,a method that combined ion irradiation and SEM characterization was proposed to study the distribution and concentration of QI particles in graphite.During irradiation,the QI particles were found to evolve into densified spheres,which were weakly bonded with the surrounding graphite structures,thereby indicating that the densification of QI particles did not evidently contribute to graphite dimensional shrinkage.A much higher concentration of QI particles in NBG-18 than IG-110,which was suggested to be responsible for the smaller maximum dimensional shrinkage of former over the latter during irradiation,was characterized.

Longitudinal transcriptome analyses show robust T cellimmunity during recovery from COVID-19

Understanding the processes of immune regulation in patients infected with the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)is crucial for improving treatment.Here,we performed longitudinal whole-transcriptome RNA sequencing on peripheral blood mononuclear cell(PBMC)samples from 18 patients with coronavirus disease 2019(COVID-19)during their treatment,convalescence,and rehabilitation.After analyzing the regulatory networks of differentially expressed messenger RNAs(mRNAs),microRNAs(miRNAs)and long non-coding RNAs(lncRNAs)between the different clinical stages,we found that humoral immunity and type I interferon response were significantly downregulated,while robust T-cell activation and differentiation at the whole transcriptome level constituted the main events that occurred during recovery from COVID-19.The formation of this T cell immune response might be driven by the activation of activating protein-1(AP-1)related signaling pathway and was weakly affected by other clinical features.These findings uncovered the dynamic pattern of immune responses and indicated the key role of T cell immunity in the creation of immune protection against this disease.

Longitudinal transcriptome analyses show robust T cell immunity during recovery from COVID-19

Understanding the processes of immune regulation in patients infected with the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)is crucial for improving treatment.Here,we performed longitudinal whole-transcriptome RNA sequencing on peripheral blood mononuclear cell(PBMC)samples from 18 patients with coronavirus disease 2019(COVID-19)during their treatment,convalescence,and rehabilitation.After analyzing the regulatory networks of differentially expressed messenger RNAs(mRNAs),microRNAs(miRNAs)and long non-coding RNAs(lncRNAs)between the different clinical stages,we found that humoral immunity and type I interferon response were significantly downregulated,while robust T-cell activation and differentiation at the whole transcriptome level constituted the main events that occurred during recovery from COVID-19.The formation of this T cell immune response might be driven by the activation of activating protein-1(AP-1)related signaling pathway and was weakly affected by other clinical features.These findings uncovered the dynamic pattern of immune responses and indicated the key role of T cell immunity in the creation of immune protection against this disease.