[Epidemiological and virus molecular characterization of dengue fever outbreak in Hunan province, 2018].

Objective: To analyze the epidemiological and etiological characteristics of a dengue fever outbreak in Hunan province in 2018. Methods: Real-time PCR assay was performed for the laboratory diagnosis of 8 suspected dengue fever cases. Etiological surveillance was performed in 186 suspected dengue fever cases and fever cases who had close contacts with dengue fever patients. C6/36 cells was used for the virus isolation from acute phase serum. By sequencing the full length of E genes of 15 dengue virus strains, phylogenetic analysis was performed based on the sequences obtained, including reference sequences from the NCBI GenBank database, the serotypes and gene subtypes of the virus were analyzed to trace the possible source of transmission. An emergency monitoring of vector density and a retrospective survey of sero-epidemiology in healthy population were conducted in the epidemic area. Results: In the serum samples of 8 suspected patients, 6 were dengue virus RNA positive, and 4 were NS1 antigen positive. In 186 suspected patients, 96 were dengue virus nucleic acid, NS1 antigen or antibody positive in etiological test. A total of 64 dengue virus strains were isolated. The phylogenetic analysis showed that all the dengue virus strains belonged to type 2, which might be from Guangdong or Zhejiang provinces. The Bretub index was up to 65, indicating an extremely high risk of transmission. The positive rate of the dengue virus IgG antibody was 0.53%(2/377) in retrospective survey of 377 healthy people. Conclusion: The field epidemiologic and the molecular genetics analyses showed the outbreak of dengue fever in Hunan in 2018 was caused by imported cases and dengue virus 2.

Electron Bernstein waves driven by electron crescents near the electron diffusion region.

The Magnetospheric Multiscale (MMS) spacecraft encounter an electron diffusion region (EDR) of asymmetric magnetic reconnection at Earth's magnetopause. The EDR is characterized by agyrotropic electron velocity distributions on both sides of the neutral line. Various types of plasma waves are produced by the magnetic reconnection in and near the EDR. Here we report large-amplitude electron Bernstein waves (EBWs) at the electron-scale boundary of the Hall current reversal. The finite gyroradius effect of the outflow electrons generates the crescent-shaped agyrotropic electron distributions, which drive the EBWs. The EBWs propagate toward the central EDR. The amplitude of the EBWs is sufficiently large to thermalize and diffuse electrons around the EDR. The EBWs contribute to the cross-field diffusion of the electron-scale boundary of the Hall current reversal near the EDR.

The value of detecting pepsinogen and gastrin-17 levels in serum for pre-cancerous lesion screening in gastric cancer.

The aim of the study was to estimate the value of detecting pepsinogen (PG) I, PGII, and gastrin-17 (G-17) levels in serum for chronic atrophic gastritis (CAG) screening and to determine the clinical applicability of combined measurement of serum G-17, pepsinogens (PGI, PGII) and PGI/PGII ratio (PGR) as a screening test for CAG. The PGI, PGII, and G-17 levels were detected by ELISA in 68 patients with CAG and 86 healthy volunteers who underwent gastroscopy for gastroduodenal diseases at Taizhou Municipal Hospital between January 2016 and December 2016. Concentrations of all measured serum markers were lower in patients with CAG in comparison to healthy volunteers and achieved statistical significance (P<0.01) in PGI (93.25 vs 126.98) and PGR (12.67 vs 17.09). Receiver operating characteristic (ROC) curve analysis revealed the optimal cut-off values for PGI, PGII, PGR, and G-17 at 98.10 µg/l, 6.92 ng/l, 15.77 and 1.94 pmol/l, with sensitivities of 72.10%, 58.10%, 61.60%, and 59.30% and specificities of 61.8%, 51.50%, 77.90%, and 55.90%, respectively. The areas under the curve (AUCs) of PGI, PGR, and G-17 were 0.728, 0.726, and 0.556, respectively. The increase of AUC was observed only in PGR and G-17 combination (0.741) with increased sensitivity (69.10% vs 61.60%) of screening for CAG, whereas the specificity was reduced (72.10% vs 77.90%) in comparison to PGR alone. Combination of serum indicators can raise the diagnosis accuracy of CAG in some respects. However, further research including a larger sample size is necessary in order to accurately determine the sensitivity and specificity of combined detection of serum indicators.