Rice stripe virus (RSV) infects rice and is transmitted in a propagative manner by the small brown planthopper.How RSV enters an insect cell to initiate the infection cycle is poorly understood.Sequence analysis revealed that the RSV NSvc2 protein was similar to the membrane glycoproteins of several members in the family Bunyaviridae and might induce cell membrane fusion.To conveniently study the membrane fusion activity of NSvc2,we constructed cell surface display vectors for expressing Nsvc2 on the insect cell surface as the membrane glycoproteins of the enveloped viruses.Our results showed that NSvc2 was successfully expressed and displayed on the surface of insect Sf9 cells.When induced by low pH,the membrane fusion was not observed in the cells that expressed NSvc2.Additionally,the membrane fusion was also not detected when co-expressing Nsvc2 and the viral capsid protein on insect cell surface.Thus,RSV NSvc2 is probably different from the phlebovirus counterparts,which could suggest different functions.RSV might enter insect cells other than by fusion with plasma or endosome membrane.

Objective:To master the iodine nutrition status of children and pregnant women after adjustment of salt iodization content in Shaanxi Province, and provide scientific basis for preventing and treating iodine deficiency disorders.Methods:In 2018, 107 counties (cities, districts) in Shaanxi Province were divided into three districts in Guanzhong, northern Shaanxi and southern Shaanxi for studying iodine nutrition based on terrain distribution. Among them, each monitoring county (city, district) was further divided into 5 sampling areas according to east, west, south, north, and middle locations. One township (street) was selected in each location, and forty-two 8 - 10 years old non-boarding children (age and sex balanced) and 21 pregnant women were selected in each township (street), edible salt samples and random urine samples were collected for salt iodine, urinary iodine testing, and goiter of children was examined.Results:A total of 34 264 edible salt samples from 8 - 10 years old children and pregnant women were collected, the median salt iodine was 23.80 mg/kg, and the qualified iodized salt consumption rate was 96.98% (33 229/34 264). The median salt iodine and the qualified iodized salt consumption rate were statistically significantly different among the three regions in Guanzhong, northern Shaanxi, and southern Shaanxi ( H = 26.471, χ 2 = 32.371, P < 0.05). A total of 22 895 urine samples were collected from children, with a median urinary iodine of 218.00 μg/L, which was at an ultra-suitable level of iodine nutrition; and 11 369 urine samples from pregnant women were collected, with a median urinary iodine of 181.03 μg/L, which was at an appropriate level of iodine nutrition. The median urinary iodine of pregnant women in Guanzhong, northern Shaanxi, and southern Shaanxi was 186.39, 177.52, and 176.00 μg/L, respectively. A total of 22 895 children aged 8 to 10 years old were examined, the goiter rate was 1.35% (309/22 895), and there was no significant difference between different regions (χ 2 = 3.395, P > 0.05). Conclusions:Shaanxi Province has reached the standard for elimination of persistent iodine deficiency, children's iodine nutrition is at a ultra-suitable level, and pregnant women is at an appropriate level.

Objective:To learn about the iodine nutrition level of school-age children aged 8 - 10 in Shaanxi Province.Methods:From 2017 to 2020, in counties (cities, districts) under the jurisdiction of Shaanxi Province, one township (street) was selected from five directions: East, West, South, North and Middle, one primary school was selected from each township (street), and 42 non-boarding school-age children aged 8 - 10 (age balanced, half male and half female) were selected from each primary school. Random urine samples of children were collected once, and urinary iodine was detected by arsenic-cerium catalytic spectrophotometry.Results:A total of 91 766 children's urine samples were tested from 2017 to 2020, and the median urinary iodine was 221.7 μg/L. Urinary iodine < 100 μg/L accounted for 10.4% (9 554/91 766), 100 - < 200 μg/L accounted for 32.3% (29 602/91 766), 200 - < 300 μg/L accounted for 30.6% (28 065/91 766), and ≥300 μg/L accounted for 26.7% (24 545/91 766). The median of children's urinary iodine in each year was 228.5, 218.0, 211.7, and 230.1 μg/L, respectively, the difference between years was statistically significant ( H = 278.66, P < 0.001). Conclusion:From 2017 to 2020, the iodine nutrition of school-age children aged 8 - 10 in Shaanxi Province is generally in an ultra-suitable state.