Fluid Mode Spectroscopy for measuring dynamic viscosity of fluids in open cylindrical containers

On a daily basis we stir tee or coffee with a spoon and leave it to rest. We know empirically the larger the stickiness, viscosity, of the fluid, more rapidly its velocity slows down. It is surprising, therefore, that the variation has not been utilized for measuring (dynamic) viscosity of fluids. This study shows that a spectroscopy decomposing a velocity field into fluid modes (Stokes eigenmodes) allows us to measure accurately the dynamic viscosity. The method, Fluid Mode Spectroscopy (FMS), is based on the fact that each Stokes eigenmode has its inherent decay rate of eigenvalue and that the dimensionless rate of the slowest decaying mode (SDM) is constant, dependent only on the normalized shape of a fluid container, obtained analytically for some shapes including cylindrical containers. The FMS supplements major conventional measuring methods with each other, particularly useful for measuring low dynamic viscosity.Comment: 18 pagese, 6 figure

Effectiveness of mRNA COVID-19 vaccines against symptomatic SARS-CoV-2 infections during the SARS-CoV-2 Omicron BA.1 and BA.2 epidemic in Japan: vaccine effectiveness real-time surveillance for SARS-CoV-2 (VERSUS)

Background: Evaluating COVID-19 vaccine effectiveness (VE) domestically is crucial for assessing and determining national vaccination policy. This study aimed to evaluate VE of mRNA COVID-19 vaccines in Japan. Methods: We conducted a multicenter test-negative case-control study. The study comprised indivi-duals aged ≥16 visiting medical facilities with COVID-19-related signs or symptoms from 1 January to 26 June 2022, when Omicron BA.1 and BA.2 were dominant nationwide. We evaluated VE of primary and booster vaccination against symptomatic SARS-CoV-2 infections and relative VE of booster compared with primary.Results: We enrolled 7,931 episodes, including 3,055 test positive. The median age was 39, 48.0% were male, and 20.5% had underlying medical conditions. In individuals aged 16 to 64, VE of primary vaccination within 90 days was 35.6% (95% CI, 19.0–48.8%). After booster, VE increased to 68.7% (60.6–75.1%). In individuals aged ≥65, VE of primary and booster was 31.2% (−44.0–67.1%) and 76.5% (46.7–89.7%), respectively. Relative VE of booster compared with primary vaccination was 52.9% (41.0– 62.5%) in individuals aged 16 to 64 and 65.9% (35.7–81.9%) in individuals aged ≥65.Conclusions: During BA.1 and BA.2 epidemic in Japan, mRNA COVID-19 primary vaccination provided modest protection. Booster vaccination was necessary to protect against symptomatic infections

Effectiveness of mRNA COVID-19 vaccines against symptomatic SARS-CoV-2 infections during the SARS-CoV-2 Omicron BA.1 and BA.2 epidemic in Japan: vaccine effectiveness real-time surveillance for SARS-CoV-2 (VERSUS)

Background Evaluating COVID-19 vaccine effectiveness (VE) domestically is crucial for assessing and determining national vaccination policy. This study aimed to evaluate VE of mRNA COVID-19 vaccines in Japan. Methods We conducted a multicenter test-negative case-control study. The study comprised individuals aged ≥16 visiting medical facilities with COVID-19-related signs or symptoms from 1 January to 26 June 2022, when Omicron BA.1 and BA.2 were dominant nationwide. We evaluated VE of primary and booster vaccination against symptomatic SARS-CoV-2 infections and relative VE of booster compared with primary. Results We enrolled 7,931 episodes, including 3,055 test positive. The median age was 39, 48.0% were male, and 20.5% had underlying medical conditions. In individuals aged 16 to 64, VE of primary vaccination within 90 days was 35.6% (95% CI, 19.0–48.8%). After booster, VE increased to 68.7% (60.6–75.1%). In individuals aged ≥65, VE of primary and booster was 31.2% (−44.0–67.1%) and 76.5% (46.7–89.7%), respectively. Relative VE of booster compared with primary vaccination was 52.9% (41.0–62.5%) in individuals aged 16 to 64 and 65.9% (35.7–81.9%) in individuals aged ≥65. Conclusions During BA.1 and BA.2 epidemic in Japan, mRNA COVID-19 primary vaccination provided modest protection. Booster vaccination was necessary to protect against symptomatic infections

Effectiveness of primary series, first, and second booster vaccination of monovalent mRNA COVID-19 vaccines against symptomatic SARS-CoV-2 infections and severe diseases during the SARS-CoV-2 omicron BA.5 epidemic in Japan: vaccine effectiveness real-time surveillance for SARS-CoV-2 (VERSUS)

This study aimed to evaluate VE of primary, first, and second booster ancestral-strain monovalent mRNA COVID-19 vaccination against symptomatic infections and severe diseases in Japan. We conducted a test-negative case-control study. We included medically attended episodes and hospitalizations involving individuals aged ≥16 with signs and symptoms from July to November 2022, when Omicron BA.5 was dominant nationwide. To evaluate VE, we calculated adjusted ORs of vaccination among test-positive versus test-negative individuals using a mixed-effects logistic regression. For VE against symptomatic infections among individuals aged 16 to 59, VE of primary vaccination at > 180 days was 26.1% (95% CI: 10.6–38.8%); VE of the first booster was 58.5% (48.4–66.7%) at ≤90 days, decreasing to 41.1% (29.5–50.8%) at 91 to 180 days. For individuals aged ≥60, VE of the first booster was 42.8% (1.7–66.7%) at ≤90 days, dropping to 15.4% (−25.9–43.2%) at 91 to 180 days, and then increasing to 44.0% (16.4–62.5%) after the second booster. For VE against severe diseases, VE of the first and second booster was 77.3% (61.2–86.7%) at ≤90 days and 55.9% (23.4–74.6%) afterward. mRNA booster vaccination provided moderate protection against symptomatic infections and high-level protection against severe diseases during the BA.5 epidemic in Japan.</p