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Rapid qualitative antigen testing is essential in the clinical management of COVID-19. However, most evaluations of antigen tests have been performed before the emergence of the Omicron variant.This prospective observational study evaluated QuickNavi-COVID19 Ag, a rapid antigen detection test between December 2021 and February 2022 in Japan, using real-time reverse transcription (RT)-PCR as a reference. Two nasopharyngeal samples were simultaneously collected for antigen testing and for RT-PCR. Variant analysis of the SARS-CoV-2 genomic sequencing was also performed.In total, nasopharyngeal samples were collected from 1073 participants (417 positive; 919 symptomatic; 154 asymptomatic) for analysis. Compared with those of RT-PCR, the sensitivity, specificity, positive predictive value, and negative predictive value were 94.2% (95% CI: 91.6%-96.3%), 99.5% (95% CI: 98.7%-99.9%), 99.2% (95% CI: 97.8%-99.8%), and 96.5% (95% CI: 94.8%-97.7%), respectively. The sensitivity among symptomatic individuals was 94.3% (95% CI: 91.5%-96.4%). Overall, 85.9% of sequences were classified as Omicron sublineage BA.1, 12.4% were Omicron sublineage BA.2, and 1.6% were Delta B.1.617.2. (Delta variant). Most of the samples (87.1%) had Ct values of25, and the sensitivity was 47.4% for low viral load samples (Ct ≥ 30); a similar trend has been observed in both symptomatic and asymptomatic groups.The QuickNavi-COVID19 Ag test showed sufficient diagnostic performance for the detection of the SARS-CoV-2 Omicron sublineages BA.1 and BA.2 from nasopharyngeal samples. However, the current study was mainly performed in symptomatic patients and the results are not sufficiently applicable for asymptomatic patients.

Since respiratory sample collection is an uncomfortable experience, simultaneous detection of pathogens with a single swab is preferable. We prospectively evaluated the clinical performance of a newly developed antigen test QuickNavi-Flu+COVID19 Ag (Denka Co., Ltd., Tokyo, Japan) which can detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza viruses at the same time with a single testing device.We included those who were suspected of contracting coronavirus disease 2019 (COVID-19) and were referred to a PCR center at Ibaraki prefecture in Japan, between August 2, 2021 to September 13, 2021, when the variant carrying L452R spike mutation of SARS-CoV-2 were prevalent. Additional nasopharyngeal samples and anterior nasal samples were obtained for the antigen test and were compared with a reference real-time reverse transcription PCR (RT-PCR) using nasopharyngeal samples.In total, 1510 nasopharyngeal samples and 862 anterior nasal samples were evaluated. During the study period, influenza viruses were not detected by QuickNavi-Flu+COVID19 Ag and reference real-time RT-PCR. For SARS-CoV-2 detection in nasopharyngeal samples, the sensitivity and specificity of the antigen test were 80.9% and 99.8%, respectively. The sensitivity and specificity using anterior nasal samples were 67.8% and 100%, respectively. In symptomatic cases, the sensitivities increased to 88.3% with nasopharyngeal samples and 73.7% with anterior nasal samples. There were three cases of discrepant results between the antigen test and the real-time RT-PCR. All of them were positive with the antigen test but negative with the real-time RT-PCR in SARS-CoV-2 detection.A combo kit, QuickNavi-Flu+COVID19 Ag, showed an acceptable sensitivity and sufficient specificity for SARS-CoV-2 detection, especially using nasopharyngeal sample collected from symptomatic patients.

Introduction Smart Gene is a point-of-care (POC)-type automated molecular testing platform that can be performed with 1 min minute of hands-on-time. Smart Gene SARS-CoV-2 is a newly developed Smart Gene molecular assay for the detection of SARS-CoV-2. The analytical and clinical performance of Smart Gene SARS-CoV-2 has not been evaluated. Methods Nasopharyngeal and anterior nasal samples were prospectively collected from subjects referred to the local PCR center from March 25 to July 5, 2021. Two swabs were simultaneously obtained for the Smart Gene SARS-CoV-2 assay and the reference real-time RT-PCR assay, and the results of Smart Gene SARS-CoV-2 were compared to the reference real-time RT-PCR assay. Results Among a total of 1150 samples, 68 of 791 nasopharyngeal samples and 51 of 359 anterior nasal samples were positive for SARS-CoV-2 in the reference real-time RT-PCR assay. In the testing of nasopharyngeal samples, Smart Gene SARS-CoV-2 showed the total, positive and negative concordance of 99.2% (95% confidence interval [CI]: 98.4–99.7%), 94.1% (95% CI: 85.6–98.4%) and 99.7% (95% CI: 99.0–100%), respectively. For anterior nasal samples, Smart Gene SARS-CoV-2 showed the total, positive and negative concordance of 98.9% (95% CI: 97.2–99.7%), 98.0% (95% CI: 89.6–100%) and 99.0% (95% CI: 97.2–99.8%), respectively. In total, 5 samples were positive in the reference real-time RT-PCR assay and negative in the Smart Gene SARS-CoV-2 assay, whereas 5 samples were negative in the reference real-time RT-PCR assay and positive in the Smart Gene SARS-CoV-2 assay. Conclusion Smart Gene SARS-CoV-2 showed sufficient analytical performance for the detection of SARS-CoV-2 in nasopharyngeal and anterior nasal samples.

Antigen tests for severe acute respiratory coronavirus 2 sometimes show positive lines earlier than their specified read time, although the implication of getting the results at earlier time is not well understood. This study aimed to evaluate the clinical utility of an antigen test by evaluating the time period to get positive results and by comparing the test sensitivity with that of a digital immunoassay (DIA) test.We prospectively collected additional nasopharyngeal samples from patients who had already tested positive for SARS-CoV-2 by reverse transcription PCR. The additional swab was used for an antigen test, QuickNavi™-COVID19 Ag, and the time periods to get positive results were measured. The sensitivity of QuickNavi™-COVID19 Ag was also compared with that of a DIA.In 84 of 96 (87.5%) analyzed cases, the results of QuickNavi™-COVID19 Ag were positive. The time to obtain positive results was 15.0 seconds in median (inter quartile range: 12.0-33.3, range 11-736), and was extended in samples with higher cycle thresholds (Ct) (p32.QuickNavi™-COVID19 Ag immediately showed positive results in most cases, and the time to a positive reaction may have indicated the viral load. In addition, the sensitivity of the test was comparable to the DIA.

IntroductionRapid qualitative antigen testing has been widely used for the laboratory diagnosis of COVID-19 with nasopharyngeal samples. Saliva samples have been used as alternative samples, but the analytical performance of those samples for qualitative antigen testing has not been sufficiently evaluated.MethodsA prospective observational study evaluated the analytical performance of three In Vitro Diagnostics (IVD) approved COVID-19 rapid antigen detection kits for saliva between June 2022 and July 2022 in Japan using real-time reverse transcription polymerase chain reaction (RT-PCR) as a reference. A nasopharyngeal sample and a saliva sample were simultaneously obtained, and RT-PCR was performed.ResultsIn total, saliva samples and nasopharyngeal samples were collected from 471 participants (140 RT-PCR-positive saliva samples and 143 RT-PCR-positive nasopharyngeal samples) for the analysis. The median Ct values were 25.5 (interquartile range [IQR]: 21.9-28.8) for saliva samples and 17.1 (IQR: 15.5-18.7) for nasopharyngeal samples (p90% for saliva samples with a moderate-to-high viral load (CtConclusionCOVID-19 rapid antigen detection kits with saliva showed high specificities, but the sensitivities varied among kits, and the analytical performance of saliva qualitative antigen detection kits was much worse than that of kits using nasopharyngeal samples.

Molecular tests are the mainstay of detecting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, their accessibility can be limited by the long examination time and inability to evaluate multiple samples at once. This study evaluated the analytical performance of the newly developed rapid molecular assays GENECUBE® HQ SARS-CoV-2 and GENECUBE® FLU A/B. This prospective study was conducted between 14 December 2020 and 9 January 2021 at a polymerase chain reaction (PCR) center. Samples were collected from the nasopharynx with flocked swabs. Molecular tests were performed with the GENECUBE® system and reference reverse transcription (RT)-PCR, and the results of the two assays were compared. Among 1065 samples, 81 (7.6%) were positive for SARS-CoV-2 on the reference RT-PCR. Three showed discordance between GENECUBE® HQ SARS-CoV-2 and the reference RT-PCR; the total, positive, and negative samples of concordance for the two assays were 99.7%, 100%, and 99.7%, respectively. All discordant cases were positive with GENECUBE® HQ SARS-CoV-2 and negative with the reference RT-PCR. SARS-CoV-2 was detected in all three samples using another molecular assay for SARS-CoV-2. For GENECUBE® FLU A/B, the total, positive, and negative samples of concordance for the two assays were 99.5%, 100%, and 99.1%. The GENECUBE® HQ SARS-CoV-2 and GENECUBE® FLU A/B demonstrated sufficient analytical performance to detect SARS-CoV-2 and influenza virus A/B.

IntroductionAntigen testing is essential in the clinical management of COVID-19. However, most evaluations of antigen tests have been performed before the emergence of the Omicron variant. Thus, an assessment of the diagnostic performance of antigen tests for the detection of SARS-CoV-2 during the circulation of Omicron variant is required.MethodsThis prospective observational study evaluated QuickNavi-COVID19 Ag, a rapid antigen detection test between December 2021 and February 2022 in Japan, using real-time reverse transcription (RT)-PCR as a reference. Two nasopharyngeal samples were simultaneously collected for antigen testing and for RT-PCR. Variant analysis of the SARS-CoV-2 genomic sequencing was also performed.ResultsIn total, nasopharyngeal samples were collected from 1,073 participants (417 positive; 919 symptomatic; 154 asymptomatic) for analysis. Compared with those of RT-PCR, the sensitivity, specificity, positive predictive value, and negative predictive value were 94.2% (95% CI: 91.6%–96.3%), 99.5% (95% CI: 98.7%–99.9%), 99.2% (95% CI: 97.8%–99.8%), and 96.5% (95% CI: 94.8%–97.7%), respectively. The sensitivity among symptomatic individuals was 94.3% (95% CI: 91.5%–96.4%). Overall, 85.9% of sequences were classified as Omicron sublineage BA.1, 12.4% were Omicron sublineage BA.2, and 1.6% were Delta B.1.617.2. (Delta variant). Most of the samples (87.1%) had Ct values ConclusionsThe QuickNavi-COVID19 Ag test showed high diagnostic performance for the detection of the SARS-CoV-2 Omicron sublineages BA.1 and BA.2 from nasopharyngeal samples.

Point-of-care type molecular diagnostic tests have been used for detecting SARS-CoV-2, although their clinical utility with nasal samples has yet to be established. This study evaluated the clinical performance of the cobas Liat SARS-CoV-2Influenza A/B (Liat) assay in nasal samples.Nasal and nasopharyngeal samples were collected and were tested using the Liat, the cobas 6800 system and the cobas SARS-CoV-2Influenza A/B (cobas), and a method developed by National Institute of Infectious Diseases, Japan (NIID).A total of 814 nasal samples were collected. The Liat assay was positive for SARS-CoV-2 in 113 (13.9%). The total, positive, and negative concordance rate between the Liat and cobas/NIID assays were 99.3%/98.4%, 99.1%/100%, and 99.3%/98.2%, respectively. Five samples were positive only using the Liat assay. Their Ct values ranged from 31.9 to 37.2. The Ct values of the Liat assay were significantly lower (p0.001) but were correlated (p0.001) with those of other molecular assays. In the participants who tested positive for SARS-CoV-2 on the Liat assay using nasopharyngeal samples, 88.2% of their nasal samples also tested positive using the Liat assay.The Liat assay showed high concordance with other molecular assays in nasal samples. Some discordance occurred in samples with Ct values30 on the Liat assay.

Pneumocystis jirovecii pneumonia (PCP) in patients with acquired immune deficiency syndrome (AIDS) shows eosinophilic pneumonia like condition. The detailed mechanisms how AIDS-associated PCP causes eosinophilic pneumonia has not been elucidated, but it has been suggested that beta-D-glucan, a major component of Pneumocystis jirovecii, and T helper type 2 immunity may be involved in the mechanism of eosinophilia in the lung. We experienced the case who developed an eosinophilic pneumonia-like condition in a patient with AIDS-associated PCP, whose clinical course indicated the importance of TARC/CCL17 but not IL-4 and IL-5 as involved in eosinophilia caused by HIV and Pneumocystis jirovecii infection.

Background and ObjectivePoint-of-care type molecular diagnostic tests have been used for detecting SARS-CoV-2, although their clinical utility with nasal samples has yet to be established. This study evaluated the clinical performance of the cobas Liat SARS-CoV-2 & Influenza AB (Liat) in nasal samples.MethodsNasal and nasopharyngeal samples were collected and were tested using the Liat, the cobas 6800 system and the cobas SARS-CoV-2 & Influenza AB (cobas), and a method developed by National Institute of Infectious Diseases, Japan (NIID).ResultsA total of 814 nasal samples were collected. The Liat assay was positive for SARS-CoV-2 in 113 (13.9%). The total, positive, and negative concordance rate between the Liat and cobas/NIID assays were 99.3%/98.4%, 99.1%/100%, and 99.3%/98.2%, respectively. Five samples were positive only using the Liat assay. Their Ct values ranged from 31.9 to 37.2. The Ct values of the Liat assay were significantly lower (p < 0.001) but were correlated (p < 0.001) with those of other molecular assays. In the participants who tested positive for SARS-CoV-2 on the Liat assay using nasopharyngeal samples, 88.2% of their nasal samples also tested positive using the Liat assay.ConclusionThe Liat assay showed high concordance with other molecular assays in nasal samples. Some discordance occurred in samples with Ct values > 30 on the Liat assay.Key PointsThe cobas Liat SARS-CoV-2 & Influenza AB assay showed high concordance with other molecular assays in nasal and nasopharyngeal samples, providing results within 20 minutes.Some discordance occurred in samples with Ct values > 30 on the Liat assay.The Liat assay may be suitable for use in a variety of clinical situations, primarily where accurate detection of SARS-CoV-2 is necessary.

IntroductionSince respiratory sample collection is an uncomfortable experience, simultaneous detection of pathogens with a single swab is preferable. We prospectively evaluated the clinical performance of a newly developed antigen test QuickNavi-Flu+COVID19 Ag (Denka Co., Ltd., Tokyo, Japan) which can detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza viruses at the same time with a single testing device.MethodsIncluded were those who were suspected of contracting coronavirus disease 2019 (COVID-19) and referred to a PCR center at Ibaraki prefecture in Japan, between August 2, 2021 to September 13, 2021, when the L452R mutant strains of SARS-CoV-2 were prevalent. Additional nasopharyngeal samples and anterior nasal samples were obtained for the antigen test and were compared with a reference reverse transcription PCR (RT-PCR) using nasopharyngeal samples.ResultsIn total, 1510 nasopharyngeal samples and 862 anterior nasal samples were evaluated. For SARS-CoV-2 detection in nasopharyngeal samples, the sensitivity and specificity of the antigen test were 80.9% and 99.8%, respectively. The sensitivity and specificity using anterior nasal samples were 67.8% and 100%, respectively. In symptomatic cases, the sensitivities increased to 88.3% with nasopharyngeal samples and 73.7% with anterior nasal samples. There were three cases of discrepant results between the antigen test and the real-time RT-PCR. All of them were positive with the antigen test but negative with the real-time RT-PCR in SARS-CoV-2 detection. During the study period, influenza viruses were not detected.ConclusionA combo kit, QuickNavi-Flu+COVID19 Ag, showed an acceptable sensitivity and sufficient specificity for SARS-CoV-2 detection, especially using nasopharyngeal sample collected from symptomatic patients.

The diagnostic accuracy of antigen testing of anterior nasal (AN) samples for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has not been evaluated in the Japanese population. This study assessed the diagnostic accuracy of the Roche SARS-CoV-2 rapid antigen test (rapid antigen test) using AN samples.Two AN samples and one nasopharyngeal (NP) sample were collected from individuals undergoing screening for SARS-CoV-2 infection. The results of the rapid antigen test and the reverse-transcription polymerase chain reaction (RT-PCR) test using AN samples were compared to those of RT-PCR tests using NP samples.Samples were collected from 800 participants, 95 and 110 of whom tested positive for SARS-CoV-2 on RT-PCR tests of AN and NP samples, respectively. The overall sensitivity/specificity of the AN rapid antigen test and AN RT-PCR were 72.7%/100% and 86.4%/100%, respectively. In symptomatic cases, the sensitivities of the AN rapid antigen test and AN RT-PCR were 84.7% and 94.9%, respectively. In asymptomatic cases, the sensitivities of the AN rapid antigen test and AN RT-PCR were 58.8% and 76.5%, respectively. The sensitivity of the AN rapid antigen test was over 80% in cases with cycle threshold (Ct) values 25; it significantly decreased with an increase in the Ct values (p 0.001).The rapid antigen test with AN samples had a favorable sensitivity, especially in symptomatic cases or in cases with Ct values 25. It gave no false-positive results. Compared with AN-RT PCR, the AN rapid antigen test had a modestly lower sensitivity in asymptomatic cases.

Introduction Digital immunoassays are generally regarded as superior tests for the detection of infectious disease pathogens, but there have been insufficient data concerning SARS-CoV-2 immunoassays. Methods We prospectively evaluated a novel digital immunoassay (RapidTesta SARS-CoV-2). Two nasopharyngeal samples were simultaneously collected for antigen tests and Real-time RT-PCR. Results During the study period, 1127 nasopharyngeal samples (symptomatic patients: 802, asymptomatic patients: 325) were evaluated. For digital immunoassay antigen tests, the sensitivity was 78.3% (95% CI: 67.3%–87.1%) and the specificity was 97.6% (95% CI: 96.5%–98.5%). When technicians visually analyzed the antigen test results, the sensitivity was 71.6% (95% CI: 59.9%–81.5%) and the specificity was 99.2% (95% CI: 98.5%–99.7%). Among symptomatic patients, the sensitivity was 89.4% (95% CI; 76.9%–96.5%) with digital immunoassay antigen tests, and 85.1% (95% CI; 71.7%–93.8%) with visually analyzed the antigen test, respectively. Conclusions The sensitivity of digital immunoassay antigen tests was superior to that of visually analyzed antigen tests, but the rate of false-positive results increased with the introduction of a digital immunoassay device.

IntroductionDigital immunoassays are generally regarded as superior tests for the detection of infectious disease pathogens, but there have been insufficient data concerning SARS-CoV-2 immunoassays.MethodsWe prospectively evaluated a novel digital immunoassay (RapidTesta SARS-CoV-2). Two nasopharyngeal samples were simultaneously collected for antigen tests and RT-PCR. Real-time RT-PCR for SARS-CoV-2, using a method developed by the National Institute of Infectious Diseases, Japan, served as the reference RT-PCR method.ResultsDuring the study period, 1,127 nasopharyngeal samples (symptomatic patients: 802, asymptomatic patients: 325) were evaluated. For digital immunoassay antigen tests, the sensitivity was 78.3% (95% CI: 67.3%–87.1%) and the specificity was 97.6% (95% CI: 96.5%–98.5%). When technicians visually analyzed the antigen test results, the sensitivity was 71.6% (95% CI: 59.9%–81.5%) and the specificity was 99.2% (95% CI: 98.5%–99.7%). Among symptomatic patients, the sensitivity was 89.4% (95% CI; 76.9%–96.5%) with digital immunoassay antigen tests, and 85.1% (95% CI; 71.7%–93.8%) with visually analyzed the antigen test, respectively.ConclusionsThe findings indicated that RapidTesta SARS-CoV-2 analysis with the DIA device had sufficient analytical performance for the detection of SARS-CoV-2 in nasopharyngeal samples. When positive DIA results are recorded without a visually recognizable red line at the positive line location on the test cassette, additional RT-PCR evaluation should be performed.

Immiscible two-phase flows in porous media is of concern for various problems such as underground water pollution by non-aqueous phase liquid and enhanced oil recovery. It is understood that the drainage process in porous media exhibits patterns of either stable displacement, viscous fingering flow or capillary fingering flow depending on the conditions. However, the physical mechanism of the invasion and critical conditions for different invasion patterns have not been universally identified. This study employed a numerical two-phase flow simulation using the Color Gradient Lattice Boltzmann Method (CG-LBM) in a simplified pore network model with different capillary numbers and viscosity ratios between the two fluids. Simulation results confirm that flows for a low capillary number produce the preferential flow for pores with the least threshold pressure, which corresponds to capillary fingering flow. In addition, the retreat of the invading fluid caused by the Haines jump was observed. When the capillary number is higher, these two phenomena were not observed. Flows with a higher capillary number lead the invading fluid to simultaneously displace different pores when its viscosity is higher than that of the invaded fluid (stable displacement), and the viscous fingering flow happens otherwise. These findings suggest that capillary number and viscosity ratio, and occurrence of the preferential flow and Haines jump are key factors that determine invasion patterns.

The clinical utility of antigen test using anterior nasal samples has not been well evaluated. We conducted a prospective study in a drive-through testing site located at a PCR center to evaluate the diagnostic performance of the antigen test QuickNavi-COVID19 Ag using anterior nasal samples and to compare the degrees of coughs or sneezes induction and the severity of pain between anterior nasal collection and nasopharyngeal collection. The study included a total of 862 participants, of which 91.6% were symptomatic. The median duration from symptom onset to sample collection was 2.0 days. Fifty-one participants tested positive for severe acute respiratory syndrome coronavirus 2 on reverse transcription PCR (RT-PCR) with nasopharyngeal samples, and all of them were symptomatic. In comparison to the findings of RT-PCR, the antigen test using anterior nasal samples showed 72.5% sensitivity (95% confidence interval [CI] 58.3–84.1%) and 100% specificity (95% CI 99.3–100%). Anterior nasal collection was associated with a significantly lower degree of coughs or sneezes induction and the severity of pain in comparison to nasopharyngeal collection (p

IntroductionAntigen testing may help screen for and detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in asymptomatic individuals. However, limited data regarding the diagnostic performance of antigen tests for this group are available.MethodsWe used clinical samples to prospectively evaluate the analytical and clinical performance of the antigen test QuickNavi™-COVID19 Ag. This study was conducted at a PCR center between October 7, 2020 and January 9, 2021. Two nasopharyngeal samples per patient were obtained with flocked swabs; one was used for the antigen test, and the other for real-time reverse transcription PCR (RT-PCR). The diagnostic performance of the antigen test was compared between asymptomatic and symptomatic patients, and the RT-PCR results were used as a reference.ResultsAmong the 1,934 collected samples, SARS-CoV-2 was detected by real-time RT-PCR in 188 (9.7%); 76 (40.4%) of these samples were from asymptomatic individuals. Over half of the total samples (1,073; 55.5%) were obtained from asymptomatic volunteers. The sensitivity of the antigen test was significantly lower for asymptomatic group than for symptomatic patients (67.1% vs 89.3%, p < 0.001). The specificity was 100% for both groups, and no false positives were observed among all 1,934 samples. The median Ct value for the asymptomatic group was significantly higher than that of the symptomatic group (24 vs 20, p < 0.001).ConclusionsThe QuickNavi™-COVID19 Ag showed a lower sensitivity for asymptomatic group than for symptomatic patients. However, its specificity was consistently high, and no false positives were found in this study.

We conducted a prospective study in Japan to evaluate the diagnostic performance of the antigen test QuickNavi-COVID19 Ag using anterior nasal samples and to compare the degrees of coughs or sneezes induction and the severity of pain between anterior nasal collection and nasopharyngeal collection. A total of 862 participants were included in the analysis. In comparison to the findings of reverse transcription PCR using nasopharyngeal samples, the antigen test using anterior nasal samples showed 72.5% sensitivity (95% confidence interval [CI]: 58.3%-84.1%) and 100% specificity (95% CI: 99.3%-100%). Anterior nasal collection was associated with a significantly lower degree of coughs or sneezes induction and the severity of pain in comparison to nasopharyngeal collection (p < 0.001). The antigen test using anterior nasal samples showed moderate sensitivity but was less painful and induced fewer coughs or sneezes.

IntroductionSeveral antigen tests for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been developed worldwide, but their clinical utility has not been well established. In this study, we evaluated the analytical and clinical performance of QuickNavi™-COVID19 Ag, a newly developed antigen test in Japan.MethodsThis prospective observational study was conducted at a PCR center between October 7 and December 5, 2020. The included patients were referred from a local public health center and 89 primary care facilities. We simultaneously obtained two nasopharyngeal samples with flocked swabs; one was used for the antigen test and the other for real-time reverse transcription PCR (RT-PCR). Using the results of real-time RT-PCR as a reference, the performance of the antigen test was evaluated.ResultsA total of 1186 patients were included in this study, and the real-time RT-PCR detected SARS-CoV-2 in 105 (8.9%). Of these 105 patients, 33 (31.4%) were asymptomatic. The antigen test provided a 98.8% (95% confident interval [CI]: 98.0%-99.4%) concordance rate with real-time RT-PCR, along with a sensitivity of 86.7% (95% CI: 78.6%-92.5%) and a specificity of 100% (95% CI: 99.7%-100%). False-negatives were observed in 14 patients, 8 of whom were asymptomatic and had a low viral load (cycle threshold (Ct) >30). In symptomatic patients, the sensitivity was 91.7% (95% CI: 82.7%-96.9%).ConclusionQuickNavi™-COVID19 Ag showed high specificity and sufficient sensitivity for the detection of SARS-CoV-2. This test is a promising potential diagnostic modality especially in symptomatic patients.

BackgroundMolecular tests are the mainstay for detecting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, their accessibility can be limited by the long examination time and inability to evaluate multiple samples at once. This study evaluated the analytical performance of the newly developed rapid molecular assays GENECUBE® HQ SARS-CoV-2 and the GENECUBE® FLU A/B.MethodThis prospective study was conducted between December 14, 2020, and January 9, 2021, at a polymerase chain reaction (PCR) center. Samples were collected from the nasopharynx with flocked swabs. Molecular tests were performed with the GENECUBE® system and reference reverse transcription (RT)-PCR, and the results of the two assays were compared.ResultAmong 1065 samples, 81 (7.6%) were positive for SARS-CoV-2 on the reference RT-PCR. Three showed discordance between GENECUBE® HQ SARS-CoV-2 and the reference RT-PCR; the total, positive and negative samples of concordance for the two assays were 99.7%, 100%, and 99.7%, respectively. All discordant cases were positive for GENECUBE® HQ SARS-CoV-2 and negative for the reference RT-PCR. SARS-CoV-2 was detected from all three samples by another molecular assay for SARS-CoV-2. For the GENECUBE® FLU A/B, the total, positive and negative samples of concordance for the two assays were 99.5%, 100%, and 99.1%.ConclusionThe GENECUBE® HQ SARS-CoV-2 and GENECUBE® FLU A/B demonstrated sufficient analytical performance to detect SARS-CoV-2 and influenza virus A/B.Key pointsWe prospectively evaluated the analytical performance of the newly developed rapid molecular assays GENECUBE® HQ SARS-CoV-2 and the GENECUBE® FLU A/B. The two assays showed >99% concordance rate compared with a reference PCR, which indicated their sufficient analytical performance to detect SARS-CoV-2 and influenza virus A/B.

This study simulates pore-scale two-dimensional flows through porous media composed of circular grains with varied pore-scale heterogeneity to analyze non-Darcy flow effects on different types of porous media using the lattice Boltzmann method. The magnitude of non-Darcy coefficients and the critical Reynolds number of non-Darcy flow were computed from the simulation results using the Forchheimer equation. Although the simulated porous materials have similar porosity and representative grain diameters, larger non-Darcy coefficients and an earlier onset of non-Darcy flow were observed for more heterogeneous porous media. The simulation results were compared with existing correlations to predict non-Darcy coefficients, and the large sensitivity of non-Darcy coefficients to pore-scale heterogeneity was identified. The pore-scale heterogeneity and resulting flow fields were evaluated using the participation number. From the computed participation numbers and visualized flow fields, a significant channeling effect for heterogeneous media in the Darcy flow regime was confirmed compared with that for homogeneous media. However, when non-Darcy flow occurs, this channeling effect was alleviated. This study characterizes non-Darcy effect with alleviation of the channeling effect quantified with an increase in participation number. Our findings indicate a strong sensitivity of magnitude and onset of non-Darcy effect to pore-scale heterogeneity and imply the possibility of evaluating non-Darcy effect through numerical analysis of the channeling effect.

Community-acquired pneumonia (CAP) is a common illness that can lead to mortality. β-lactams are ineffective against atypical pathogen including Mycoplasma pneumoniae. We used molecular examinations to develop a decision tree to predict atypical pathogens with CAP and to examine the prevalence of macrolide resistance in Mycoplasma pneumoniae. We conducted a prospective observational study of patients aged ≥ 18 years who had fever and respiratory symptoms and were diagnosed with CAP in one of two community hospitals between December 2016 and October 2018. We assessed combinations of clinical variables that best predicted atypical pathogens with CAP by classification and regression tree (CART) analysis. Pneumonia was defined as respiratory symptoms and new infiltration recognized on chest X-ray or chest computed tomography. We analyzed 47 patients (21 females, 44.7%, mean age: 47.6 years). Atypical pathogens were detected in 15 patients (31.9%; 12 Mycoplasma pneumoniae, 3 Chlamydophila pneumoniae). Ten patients carried macrolide resistant Mycoplasma pneumoniae (macrolide resistant rate 83.3%). CART analysis suggested that factors associated with presence of atypical pathogens were absence of crackles, age

Abiotic synthesis of biomolecules is an essential step for the chemical origin of life. Many attempts have succeeded in synthesizing biomolecules, including amino acids and nucleobases (e.g., via spark discharge, impact shock, and hydrothermal heating), from reduced compounds that may have been limited in their availabilities on Hadean Earth and Noachian Mars. On the other hand, formation of amino-acids and nucleobases from CO2 and N2 (i.e., the most abundant C and N sources on Earth during the Hadean) has been limited via spark discharge. Here, we demonstrate the synthesis of amino acids by laboratory impact-induced reactions among simple inorganic mixtures: Fe, Ni, Mg2SiO4, H2O, CO2, and N2, by coupling the reduction of CO2, N2, and H2O with the oxidation of metallic Fe and Ni. These chemical processes simulated the possible reactions at impacts of Fe-bearing meteorites/asteroids on oceans with a CO2 and N2 atmosphere. The results indicate that hypervelocity impact was a source of amino acids on the Earth during the Hadean and potentially on Mars during the Noachian. Amino acids formed during such events could more readily polymerize in the next step of the chemical evolution, as impact events locally form amino acids at the impact sites.

Erypoegin K, an isoflavone isolated from the stem bark of Erythrina poeppigiana, has potent apoptosis-inducing effect on human leukemia HL-60 cells. Erypoegin K has a chiral carbon at the C-2′′ position of its furan ring and naturally occurs as a racemic mixture of (S)- and (R)-isomers. In the present study, we semi-synthesized (RS)-erypoegin K from genistein and separated the optical isomers by HPLC using a chiral column to characterize its apoptosis-inducing activity. Apoptotic cell death was assessed by analyzing caspase-3 and caspase-9 activation, nuclear fragmentation, and genomic DNA ladder formation. (S)-erypoegin K showed exclusive anti-proliferative and apoptosis-inducing activity, with an IC50 value of 90 nM, about 50% lower than that of its racemic mixture (175 nM). By contrast, no apoptosis-inducing activity was shown by the (R)-isomer. In addition, methylglyoxal accumulation in the culture medium was observed only in cells treated with (S)-erypoegin K. These results demonstrated that (S)-erypoegin K is a unique bioactive component that has potent apoptosis-inducing activity on HL-60 cells.

Background Patients with acute respiratory tract infections are frequently prescribed antimicrobials despite high rates of virus detection. Physicians may overprescribe antimicrobials owing to the concern of bacterial infections, including those because of atypical pathogens. We investigated the accuracy of clinical predictions concerning atypical pathogen infections. Methods We prospectively enrolled adult patients who presented with a fever and cough in outpatient clinics between December 2016 and August 2018. After taking a history and performing physical examinations, physicians predicted the possibility of respiratory infections because of atypical pathogens. Disease probabilities were categorized into 3 grades (high: ≥50%, intermediate: 20% ≥ and, Our study indicates that while physicians' predictions were associated with the detection of atypical pathogens, overestimation was observed. The criteria for atypical pneumonia did not perform well for accurately diagnosing atypical pathogen infection in patients with a fever and cough.

Matrix metalloproteinase 13 (MMP13) is indispensable for normal skeletal development and is also a principal proteinase responsible for articular joint pathologies. MMP13 mRNA level needs to be tightly regulated in both positive and negative manners to achieve normal development and also to prevent joint destruction. We showed previously that Kruppel-like factor 4 (KLF4) strongly induces the expression of members of the MMP family of genes including that for MMP13 in cultured chondrocytes. Through expression-based screening of approximately 400 compounds, we identified several that efficiently downregulated MMP13 gene expression induced by KLF4. Compounds grouped as topoisomerase inhibitors (transcriptional inhibitors) downregulated MMP13 expression levels, which proved the validity of our screening method. In this screening, trichostatin A (TSA) was identified as one of the most potent repressors. Mechanistically, increased MMP13 mRNA levels induced by KLF4 were not mainly caused by increased rates of RNA polymerase II-mediated MMP13 transcription, but arose from escaping mRNA decay. TSA treatment almost completely blunted the effect of KLF4. Importantly, KLF4 was detected in chondrocytes at the joint destruction sites in a rodent model of osteoarthritis. Our results partially explain how KLF4 regulates numerous proteinase gene expressions simultaneously in chondrocytes. Also, these observations suggest that modulation of KLF4 activity or expression could be a novel therapeutic target for osteoarthritis.

Tricho-rhino-phalangeal syndrome (TRPS) is a rare congenital disorder that is characterized by abnormal hair growth and skeletal deformities. These result in sparse hair, short stature, and early onset of joint problems. Recent reports have shown that a relatively high proportion of patients with TRPS exhibit a broad range of congenital heart defects. To determine the regulation of Trps1 transcription in vivo, we generated novel transgenic mice, which expressed Cre recombinase under the murine Trps1 proximal promoter sequence (Trps1-Cre). We crossed these mice with Cre reporter mice to identify Trps1 daughter cells. Labeled cells were observed in the appendicular joint tissue, dermal papilla of the hair follicles, cardiac valves, aortic sinus, atrial walls, and the interventricular septum. In situ analysis showed restricted Trps1 expression, which was observed in endocardial cushions of the outflow tract, and in leaflets of all mature cardiac valves. These results suggest that the Trps1 proximal promoter sequence contains some of the tissue-specific Trps1 regulatory region. Further, our findings partially explain why patients with TRPS show a broad range of congenital cardiac defects, although Trps1 expression is observed in a more restricted fashion. genesis 54:379-388, 2016. © 2016 Wiley Periodicals, Inc.

Thermal and structural responses of divertor target were evaluated by using finite element method. High heat flux simulating ELMs at the level of 100 MW/m 2 was assumed onto the tungsten armor, and surface temperature profile was obtained. When dynamic heat load over 100 MW/m 2 was applied, the maximum surface temperature exceeded 1300 °C, and it caused recrystallization of tungsten regardless of the heat transfer below it. The result was used to conduct dynamic heat load experiment on tungsten, and material behavior of tungsten was evaluated under dynamic heat load. This study also proposed new concept of divertor heat sink which can distribute high heat flux and transfers the heat to high temperature medium. It consists of tungsten armor, composite enhanced with high thermal conductivity fiber, and heat transport system applying phase transition. High heat flux simulating ELMs was also applied to target surface of the divertor, temperature gradient, thermal stress of tungsten and composite were evaluated. Based on the results of analysis, thermal structural requirement was considered.

Background: Cathode materials of biofuel cells sometimes contain mediator (metal complexes) to improve electron transfer efficiency between electrode and laccase. Laccase is an enzyme which catalyzes four-electron reduction of oxygen to water. Methods: We have synthesized new four anthraquinone and L-amino acid (L-alanine, L-valine, L-leucin, and L-isoleucin) derivatives Schiff base Cu(II) complexes aiming at low cost materials using abundant Cu metal instead of Os or Ru metals employed commonly. Conclusion: By means of spectroscopic, electrochemical, and docking simulation studies, the complex of L-valine derivative ligand exhibited the best performance as a mediator among these four complexes in view of low reduction potentials, high current density, and appropriate docking features.

Natural convection heat transfer from horizontal rod bundles in Nxm × Nym arrays (Nxm, Nym = 5–9) in liquid sodium was numerically analyzed for three types of the bundle geometry (in-line rows, staggered rows I and II). The unsteady laminar two-dimensional basic equations for natural convection heat transfer caused by a step heat flux were numerically solved until the solution reaches a steady state. The PHOENICS code was used for the calculation considering the temperature dependence of thermophysical properties concerned. The surface heat fluxes for each cylinder were equally given for a modified Rayleigh number, Rf, ranging from 0.0637 to 63.1 (q = 1×104 to 7×106 W/m2). Sx/D and Sy/D for the rod bundle, which are the ratios of the distance between center axes on the abscissa and the ordinate to the rod diameter, respectively, were ranged from 1.6 to 2.5 on each bundle geometry. The spatial distribution of Nusselt numbers, Nu, on horizontal rods of a bundle was clarified. The average value of Nusselt nu...

Tricho-rhino-phalangeal syndrome (TRPS) is a rare congenital disorder that is characterized by abnormal hair growth and skeletal deformities. These result in sparse hair, short stature, and early onset of joint problems. Recent reports have shown that a relatively high proportion of patients with TRPS exhibit a broad range of congenital heart defects. To determine the regulation of Trps1 transcription in vivo, we generated novel transgenic mice, which expressed Cre recombinase under the murine Trps1 proximal promoter sequence (Trps1-Cre). We crossed these mice with Cre reporter mice to identify Trps1 daughter cells. Labeled cells were observed in the appendicular joint tissue, dermal papilla of the hair follicles, cardiac valves, aortic sinus, atrial walls, and the interventricular septum. In situ analysis showed restricted Trps1 expression, which was observed in endocardial cushions of the outflow tract, and in leaflets of all mature cardiac valves. These results suggest that the Trps1 proximal promoter sequence contains some of the tissue-specific Trps1 regulatory region. Further, our findings partially explain why patients with TRPS show a broad range of congenital cardiac defects, although Trps1 expression is observed in a more restricted fashion. genesis 54:379-388, 2016. © 2016 Wiley Periodicals, Inc.

A three-dimensional (3D) integration based on wafer-to-wafer bonding using through-silicon vias (TSVs) has been developed for the fabrication of new 3D large-scale integrated chips. To balance between cost and performance, and to explore 3D field-programmable gate array (FPGA) with realistic 3D integration processes, we propose spatially distributed and functionally distributed types of 3D FPGA architectures. The functionally distributed architecture consists of two wafers, a logic layer and a routing layer, and is stacked by a face-down process technology. Since vertical wires pass through microbumps, no TSVs are needed. In contrast, the spatially distributed architecture is divided into multiple layers with the same structure, unlike in the functionally distributed type. This architecture can be expanded to more than two layers by stacking multiples of the same die. The goal of this paper is to elucidate the advantages and disadvantages of these two types of 3D FPGAs. According to our evaluation, when only two layers are used, the functionally distributed architecture is more effective. When higher performance is achieved by using more than two layers, the spatially distributed architecture achieves better performance.

By introducing an induction heater and combination of a compact heat exchanger and a helium loop as a cooler, high temperature operation of lithium-lead loop at Kyoto University was perform...