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The adsorption behaviors of hydrated manganese oxide (HMD) for Strontium and Yttrium in hydrochloric acid and nitric acid solutions were studied. HMD does not adsorb Strontium in various concentrations of hydrochloric acid and nitric acid solutions. HMD have no absorbability for Yttrium in hydrochloric acid and in nitric acid solution when the concentration of nitric acid is higher than 1 mol/L. But it shows a good absorbability for Yttrium when the concentration of nitric acid is among 0.001-0.1 mol/L. So Strontium and Yttrium can be separated in low concentration nitric acid solution. The best height-to-diameter ratio of the HMD column is 5∶1 when it used for the separation of Sr and Y. When the Sr(NO3)2-Y(NO3)3-HNO3 mixed in 0.1 mol/L nitric acid solution passed through the HMD column, more than 90% of Yttrium were adsorbed on the column, but Strontium were not adsorbed and still remains in the solution; After the 0.1 mol/L nitric acid cleaning process, the Yttrium adsorbed on the HMD column can be eluted with 1 mol/L nitric acid to obtain a purified Y(NO3)3 solution. The Strontium impurity is very low in the purified Y(NO3)3 solution. Therefore, HMD is expected to be used for the preparation of 90Y generator.

The 90YCl3 solution for medical use is generally extracted from the 90Sr/90Y radioactive decay equilibrium system. The 90Y solution obtained from 90Sr/90Y has no carrier, but contains a certain amount of metal impurity. A further purification by using of the concentration of hydrochloric acid is needed before it used for the preparation of 90Y radiopharmaceuticals. The adsorption behavior of Y3+, Fe3+, Al3+, Zn2+ and Mg2+ on AE4 strongly basic anion exchange was studied. AE4 have no adsorbability for Al3+, Zn2+ and Mg2+ in HCl solution. Fe3+ was strongly adsorbed by AE4 in hydrochloric acid solution when the concentration above 3 mol/L, and Y3+ was also adsorbed by AE4 in hydrochloric acid solution when the concentration above 7 mol/L. By adjusting the concentration of hydrochloric acid in the solution, Y3+, Fe3+, Al3+, Zn2+, Mg2+ in hydrochloric acid solution can quantitatively passing the solution successively through the first AE4 column where Fe3+ is separated and the second AE4 column where Y3+ is adsorbed. Finally, a purified YCl3 solution can be obtained by using 0.01 mol/L HCl elutes. The result of both the stable nuclide and 90Y tracer shows that AE4 resin can be used to remove the main impurity metal elements such as Fe, Al, Zn and Mg in 90YCl3 solution.

The regional amplitude and phase characteristics of surface (2 m) air temperature (SAT) annual cycle (AC) over the Northern Hemisphere land area are analysed by the clustering method for the period 1953–2018. The five clusters are found in the nonlinear changes of AC amplitude and the six clusters are found in the AC phase. The spatial distributions of clusters are not the same for amplitude and phase, but the similarity is that both the amplitude and phase have remarkably different trends in the mainland of Eurasia and North America, even though these two regions locate over the similar latitudinal zone. Descending trends of AC amplitude are found for the whole period 1953–2018 in most areas, except in and around Greenland. However, when checking the nonlinear variation and making a piece‐wise linear fit, the abnormal increasing trend (stronger seasonality) appears in the major part of Eurasia after the year 1990. The comparisons of surface radiation fluxes in Eurasia and North America indicate that the long‐term reduction of the reflection and absorption of clouds and aerosols with the declined surface albedo after 1980–1985 may lead to the amplitude amplification after 1990 in Eurasia. In contrast, the variation of surface radiation in North America remains unchanged, where the decreasing trend of amplitude may result from other causes. The overall phase trend is increasing (toward earlier season), but in North America after 1990, the phase shift becomes delayed. The phase variations are correlated to North Atlantic Oscillation (NAO) cold season index over almost all regions, especially in Europe. [ABSTRACT FROM AUTHOR]

Influenza neuraminidase (NA) is able to induce cross-subtype immunity and is considered as a promising target for the development of universal influenza vaccines. However, commercial influenza vaccines only induced low NA-specific immune responses due to the low amounts and the denatured conformation of NA proteins in current inactivated or split influenza vaccines. Here we investigated the protective efficacy of recombinant tetrameric and monomeric NA proteins to determine whether the conformation contributed to induce protective immunity. We found that H1N1 P R 8NA tetramer (NA tet ) could provide complete homologous protection against A/PR8 (H1N1) virus infection in mice, while the protection of H1N1 P R 8NA monomer (NA mono ) was moderate. Higher levels of NA-reactive binding and inhibition antibodies and less weight loss were observed in the H1N1 P R 8NA tet -vaccinated group. Similarly, H5N1 V N NA tet immunization exhibited a preferable heterologous protection than H5N1 V N NA mono , but neither H7N9 S H NA tet nor H7N9 S H NA mono vaccination showed heterosubtypic protection. We also compared the effect of three adjuvants, aluminum, 3′3′-cGAMP (cGAMP), and Poly(I:C), on the humoral response and protective efficacy induced by H1N1 P R 8NA tet . H1N1 P R 8NA tet protein adjuvanted with aluminum was observed to exhibited better capacity in inducing NA-specific humoral immunity and preventing weight loss than with cGAMP or Poly(I:C). In conclusion, our data demonstrate that tetrameric NA with natural conformation is required to induce protective anti-NA immunity. The NA tetramer could provide homologous protection and subtype-specific cross-protection. In addition, the aluminum adjuvant is preferable in recombinant NA protein vaccination. [ABSTRACT FROM AUTHOR]

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