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Chronic rhinosinusitis is a chronic mucosal inflammation of the nasal cavity and sinuses. It is classified into CRS without nasal polyps (CRSsNP) and CRS with nasal polyps (CRSwNP). CRSwNP has high recurrence, especially CRSwNP with massive eosinophil infiltration(ECRSwNP) which is mediated by type 2 inflammatory response. ECRSwNP is a serious problem for patients because of its easy recurrence and poor response to hormonal treatment. Melatonin has been widely studied for its powerful antioxidant and anti-inflammatory effects. In this study, we used melatonin to treat a cell model of chronic rhinosinusitis. Subsequently, MTT assay was performed to examine the cell viability of HNEpCs, a ROS kit to detect ROS production, an MDA kit to detect the MDA content in the cell culture supernatant, and an apoptosis kit and Western blotting to detect apoptosis. The expressions of Nrf2, HO-1, IL-33, TSLP, and IL-25 were detected by Western blotting. Melatonin improved the viability of HNEpCs, reversed LPS-induced ROS, reduced the MDA content, and inhibited their apoptosis. More importantly, melatonin reduced the expression of IL-33 and TSLP, an important phenomenon for the treatment of CRSwNP. This study provides preliminary evidence for using melatonin therapy to treat chronic rhinosinusitis.

By using the daily averages of F 10.7 in 1956—2003 and adopting the method of Morelet wavelet transform, the characteristics of the quasi-27d oscillations and their relation with the 11-year cycle of solar activity are analyzed. The results demonstrate that the amplitude and period of the quasi-27d oscillations of F 10.7 exhibit obvious phenomena of short-tern variations. The degrees of variations in various years differ greatly. In some years, the undulations are quite violent. In periods of several days to several tens of days, the change of amplitude may attain ten more times, and the period may change abruptly by several days or even ten more days. In some years, the changes of amplitude are rather large, yet the undulations are small and the period is comparatively steady. In the annual averages of the variation of quasi-27d oscillaions there appear evident changes from year to year, and this is conspicuouly related to solar activity. Generally speaking, the higher is F 10.7 , the larger is the amplitude of quasi-27d oscillations. Nevertheless, in the peak of the 19th cycle the values of F 10.7 is higher than those of all the other cycles, yet the amplitude of quasi-27d oscillations is lower than those of other cycles. The period of quasi-27d oscillations also exhibits evident changes from year to year. Except certain individual years (e.g., 1987), the annual averages vary in the range from 24 to 31 days, and this has no evident relation with the period of solar activity. The mean period in 48 years is 27.3d. On the whole, the period shows a tendency of gradual shortening. In 48 years, it has decreased by about 1.5d. The causes of quasi-27d oscillations are very complicated, and this awaits further deepgoing investigation.

In order to explore the distribution characteristics of organic carbon of different forms and the active enzymes in soil aggregates with different particle sizes, soil samples were chosen from forest zone, forest-grass zone and grass zone in the Yanhe watershed of Loess Plateau to study the content of organic carbon, easily oxidized carbon, and humus carbon, and the activities of cellulase, β-D-glucosidase, sucrose, urease and peroxidase, as well as the relations between the soil aggregates carbon and its components with the active soil enzymes were also analyzed. It was showed that the content of organic carbon and its components were in order of forest zonegrass zoneforest-grass zone, and the contents of three forms of organic carbon were the highest in the diameter group of 0.25-2 mm. The content of organic carbon and its components, as well as the activities of soil enzymes were higher in the soil layer of 0-10 cm than those in the 10-20 cm soil layer of different vegetation zones. The activities of cellulase, β-D-glucosidase, sucrose and urease were in order of forest zonegrass zoneforest-grass zone. The peroxidase activity was in order of forest zoneforest-grass zonegrass zone. The activities of various soil enzymes increased with the decreasing soil particle diameter in the three vegetation zones. The activities of cellulose, peroxidase, sucrose and urease had significant positive correlations with the contents of various forms of organic carbon in the soil aggregates.

The ionospheric conductivity is influenced by solar and geomagnetic conditions and has some changes. We calculated the conductivity and the collision frequency between the electrons and ions through models NRLMSISE-00 (Neutral Atmosphere Empirical Model-2000) and IRI2001 (International Reference Ionosphere-2001). We discussed the seasonal change of the conductivities at 120km and 300km and their change under different solar and geomagnetic conditions. The result shows that (1) the conductivity distribution is affected by the sunlight, and changes with the solar activities. (2) The geomagnetic disturbance can affect the ionospheric conductivity, but the effect is smaller than that of solar variations. (3) At 120km, the geomagnetic disturbance leads to the opposite change between Pedersen conductivity and Hall conductivity at different latitudes. At 300km, the geomagnetic disturbance will make the same trend for Pedersen conductivity and Hall conductivity, and the change extent is bigger than that at 120km. But the change becomes larger in the direction of pole either at 120km or 300km.

Ionospheric data observed at different geomagnetic latitudes in East Asia and Australia sector and two polar stations during 1974-1986 are used to analyse the characteristics of f0F2 semiannual variation. A new mechanism of the semiannual variation of ionospheric f0F2 is put forward in this paper. The semiannual variation of the diurnal tide in the lower thermosphere induces the semiannual variation of the amplitude of equatorial electrojet. This causes the semiannual variation of the amplitude of ionospheric equatorial anomaly through the fountain effect. This process induces the semiannual variation of f0F2.

Background Hepatitis B virus (HBV) infection is strictly species and tissue specific, therefore none of the cell models established previously can reproduce the natural infection process of HBV in vitro . The aim of this study was to establish a new cell line that is susceptible to HBV and can support the replication of HBV. Methods A hybrid cell line was established by fusing primary human hepatocytes with HepG2 cells. The hybrid cells were incubated with HBV-positive serum for 12 hours. HBV DNA was detected by quantitative fluorescence polymerase chain reaction (QF-PCR). HBsAg (surface antigen) and HBeAg (extracellular form of core antigen) were observed by electrochemiluminescence (ECL). HBcAg (core antigen) was detected by the indirect immunofluorescence technique. HBV covalently closed circular DNA (cccDNA) was analyzed by Southern blot hybridization and quantified using real-time PCR. Results A new cell line was established and named HepCHLine-7. The extracellular HBV DNA was observed from Day 2 and the levels ranged from 9.80 (± 0.32) × 10 2 copies/mL to 3.12 (± 0.03) × 10 4 copies/mL. Intracellular HBV DNA was detected at Day 2 after infection and the levels ranged from 7.92 (± 1.08) × 10 3 copies/mL to 5.63 (± 0.11) × 10 5 copies/mL. HBsAg in the culture medium was detected from Day 4 to Day 20. HBeAg secretion was positive from Day 5 to Day 20. HBcAg constantly showed positive signals in approximately 20% (± 0.82%) of hybrid cells. Intracellular HBV cccDNA could be detected as early as 2 days postinfection and the highest level was 15.76 (± 0.26) copies/cell. Conclusion HepCHLine-7 cells were susceptible to HBV and supported the replication of HBV. They are therefore suitable for studying the complete life cycle of HBV.

Background Hepatitis B virus (HBV) infection is a blood borne infectious disease that affects the liver. Human bone marrow mesenchymal stem cells (BMSCs) may serve as a cell source for adult stem cell transplantation in liver repair. However, the susceptibility of human BMSCs to HBV infection is poorly understood. The aim of this study was to investigate the infection and replication of HBV in cultures of human BMSCs. Results Human BMSCs were confirmed using flow cytometry. Intracellular HBV DNA was detected at d 2 after infection and maintained at relatively high levels from d 6 to d 12. The maximal level of intracellular HBV DNA was 9.37 × 105 copies/mL. The extracellular HBV DNA was observed from d 3 to d 15, and the levels ranged from 3.792 × 102 copies/mL to 4.067 × 105 copies/mL. HBsAg in the culture medium was detected from d 2 to d 16. HBeAg secretion was positive from d 5 to d 13. HBcAg constantly showed positive signals in approximately 7%-20% of BMSCs from 2 days after exposure. Intracellular HBV covalently closed circular DNA (cccDNA) could be detected as early as 2 days postinfection, and strong signals were obtained with increasing time. Conclusion HBV can infect and replicate in human BMSCs. Human BMSCs may be a useful tool for investigating HBV life-cycle and the mechanism of initial virus-cell interactions.