[The identification of a novel reassortant H3N2 avian influenza virus based on nanopore sequencing technology and genetic characterization].

Objective: To identify a novel reassortant H3N2 avian influenza virus using nanopore sequencing technology and analyze its genetic characteristics. Methods: The positive samples of the H3N2 avian influenza virus, collected from the external environment in the farmers' market of Guangzhou, were cultured in chicken embryos. The whole genome was sequenced by targeted amplification and nanopore sequencing technology. The genetic characteristics were analyzed using bioinformatics software. Results: The phylogenetic trees showed that each gene fragment of the strain belonged to the Eurasian evolutionary branch, and the host source was of avian origin. The HA gene was closely related to the origin of the H3N6 virus. The NA gene was closely related to the H3N2 avian influenza virus from 2017 to 2020. The PB1 gene was closely related to the H5N6 avian influenza virus in Guangxi Zhuang Autonomous Region and Fujian Province from 2016 to 2022 and was not related to the PB1 gene of the H5N6 avian influenza epidemic strain in Guangzhou. The other internal gene fragments had complex sources with significant genetic diversity. Molecular characteristics indicated that the strain exhibited the molecular characteristics of a typical low pathogenic avian influenza virus and tended to bind to the receptors of avian origin. On important protein sites related to biological characteristics, this strain had mutations of PB2-L89V, PB1-L473V, NP-A184K, M1-N30D/T215A, and NS1-P42S/N205S. Conclusions: This study identified a novel reassortant H3N2 avian influenza virus by nanopore sequencing, with the PB1 gene derived from the H5N6 avian influenza virus. The virus had a low ability to spread across species, but further exploration was needed to determine whether its pathogenicity to the host was affected.

[A clinical application study of digital manufacturing simple intraoral Gothic arch-tracing device in determining the centric relation of complete dentures].

OBJECTIVE: To verify the consistency between the digital manufacturing simple intraoral Gothic arch-tracing device and the traditional intraoral Gothic arch-tracing device in determining the centric relation of complete dentures restoration. METHODS: Ten outpatients with edentulous jaws were selec-ted, and the centric relation of the patients was determined by digital manufacturing of simple intraoral Gothic arch-tracing device (T1) and traditional intraoral Gothic arch-tracing device (T2); the difference of clinical operation time between the two methods was recorded; the upper and lower edentulous jaw plaster models were scanned with two kinds of centric relation, the Standard Triangle Language (STL) files imported into Geomagic studio software to apply the best fitting of multiple points of the both upper jaw models, the fitted STL files imported into the 3 shape viewer software, and the maximum position deviations of the vertical, labial (buccal) and lingual directions of the mandibular midline area and molar areas in T1 and T2 groups measured. During the clinical complete dentures try-in, we observed whether there was midline deviation in the mouth of T1 group and T2 group, and whether the occlusion of posterior teeth was stable or not. RESULTS: The mean time spent on determining the centric relation of T1 and T2 groups was (41.90±2.64) min, (57.50±2.37) min respectively. Paired t test was conducted in the two groups, P < 0.01 with significant statistical difference; The mean maximum position deviation between T1 group and T2 group of the midline mandibular region in labial lingual direction was (0.32±0.14) mm, that was (0.40±0.23) mm in vertical direction; the mean maximum position deviation of molar area in buccal lingual direction was (0.35±0.23) mm and that was (0.33±0.20) mm in vertical direction. In the vertical and horizontal directions, the maximum position deviation of mandibles between group T1 and group T2 was controlled within 0.5 mm. In the process of clinical complete dentures try-in, there was no deviation from the center line of dentures. There was not warping, swinging and other poor stability phenomena in T1 and T2 groups. CONCLUSION: The digital manufacturing of simple intraoral Gothic arch-tracing device can be used to determine the centric relation of complete dentures, which can not only save time of clinical operation, but also ensure the accuracy of the centric relation.

Experimental Evidence of Intrinsic Current Generation by Turbulence in Stationary Tokamak Plasmas.

High-ß_{θe} (a ratio of the electron thermal pressure to the poloidal magnetic pressure) steady-state long-pulse plasmas with steep central electron temperature gradient are achieved in the Experimental Advanced Superconducting Tokamak. An intrinsic current is observed to be modulated by turbulence driven by the electron temperature gradient. This turbulent current is generated in the countercurrent direction and can reach a maximum ratio of 25% of the bootstrap current. Gyrokinetic simulations and experimental observations indicate that the turbulence is the electron temperature gradient mode (ETG). The dominant mechanism for the turbulent current generation is due to the divergence of ETG-driven residual flux of current. Good agreement has been found between experiments and theory for the critical value of the electron temperature gradient triggering ETG and for the level of the turbulent current. The maximum values of turbulent current and electron temperature gradient lead to the destabilization of an m/n=1/1 kink mode, which by counteraction reduces the turbulence level (m and n are the poloidal and toroidal mode number, respectively). These observations suggest that the self-regulation system including turbulence, turbulent current, and kink mode is a contributing mechanism for sustaining the steady-state long-pulse high-ß_{θe} regime.

Five-channel tunable W-band Doppler backscattering system in the experimental advanced superconducting tokamak.

A 5-channel Doppler backscattering system has been designed and installed in the Experimental Advanced Superconducting Tokamak (EAST). Through an I/Q-type double sideband modulator and a frequency multiplier, an array of finely spaced (Δf = 400 MHz) frequencies that span 1.6 GHz has been created. The center of the array bandwidth is tunable within the range of 75-97.8 GHz, which covers most of the W band (75-110 GHz). The incident angle can be adjusted from -4° to 12°, and the wavenumber range is 4-15 cm-1 with a wavenumber resolution of Δk/k ≤ 0.35. Ray tracing is used to calculate the scattering location and the scattering wavenumber. This article details the hardware design, the ray tracing, and the preliminary experimental results from EAST plasmas.

[Clinical observation of the restoration of computer aided designed and manufactured one-piece zirconia posts and cores: a 5-year prospective follow-up study].

OBJECTIVE: To evaluate the effect of computer aided design and computer aided manufacture (CAD/CAM) one-piece zirconia posts and cores for the restoration of defective teeth. METHODS: In the study, 72 defective teeth of 47 patients who had proper root canal therapy were restored with CAD/CAM one-piece zirconia posts and cores. All the ceramic crowns were finally used to restore contour and function of the teeth. The defective teeth were divided into two groups on the basis of the teeth defect degree. Group A: 39 defective teeth presented with three or four coronal residual walls, and group B: 33 defective teeth presented with less than two coronal residual walls. During the clinical observation period, the stability, dislocation of posts and the occurrence of fractures in either teeth or posts and cores were assessed and analyzed with a paired t test(α=0.05). Meanwhile shade matching was conducted between the restored teeth and normal reference teeth, the marginal fitness of the restored teeth were recorded according to the standard of United States Public Health Service (USPHS) and analyzed with descriptive statistics. RESULTS: The average follow up was (65.0±4.8) months. During the observation period, the restorations were examined both clinically and with periapical radiograph. No incidence of teeth fracture or posts and cores complications were observed in both groups, and all CAD/CAM one-piece zirconia posts and cores remained intact with restored teeth. There were no post and core dislodgement or fracture. There was no difference between group A and group B (P>0.05). The restorative effect of CAD/CAM one-piece zirconia posts and cores with all the ceramic crowns were assessed according to the standard of USPHS, and the number of the restored tooth shade matching with level A was 67, and 5 with level B. The rate of shade matching was 93.06%. As the marginal fitness, 64 restored teeth were level A, and 8 with level B. The rate of restorative teeth marginal fitness was 88.89%. CONCLUSION: CAD/CAM one-piece zirconia posts and cores were successfully used to restore defective teeth and received excellent clinical effect. So, it can be a good choice for defective teeth which need post-cores and crowns restoration.

[Preliminary clinical evaluation of the esthetic effect of deep discolored anterior teeth restored with zirconia veneers].

OBJECTIVE: To observe the esthetic effect of deep discolored anterior teeth restored by zirconia veneers. METHODS: Small defected deep discolored anterior teeth with complete root canal therapy were restored by zirconia veneers (n=15). The same name teeth on the other side of the same dental arch were chosen as control teeth. The color difference values ΔE of the neck 1/3, the middle 1/3 and the incisor 1/3 between the deep discolored tooth and the normal control tooth before and after therapy were measured to evaluate the esthetic effect of zirconia veneer restoration. At the same time, the marginal fit of zirconia veneers was checked by the standard of United States Public Health Service (USPHS). The integrity of the veneers was also examined. RESULTS: On the labial side, fibers color difference values ΔE of the neck 1/3, the middle 1/3 and the incisor 1/3 between deep discolored teeth and normal control teeth were measured by the electronic colorimeter, which were 24.92±3.00,26.64±4.00 and 21.94±3.31 respectively. All the values were above 4.0, which were considered unacceptable in clinic. After restoration by zirconia veneers, the color difference values ΔE of the middle 1/3 and the incisor 1/3 between the restored and control teeth were 1.82±0.17 and 1.84±0.21. Both values were less than 2.0, which indicated both good color matching. The color difference value ΔE of the neck 1/3 was 3.92±0.48, which was less than 4.0 and could be accepted in clinic. The statistical analysis of the colors of the teeth before and after restoration compared with the control teeth was done by Paired t test. The t values in the neck 1/3, the middle 1/3 and the incisor 1/3 were 30.37, 21.56, 23.37 respectively. In the three group, all the P<0.001. There were obvious statistical differences. According to the standard of USPHS, the marginal fit of all the restored teeth was perfect (grade A). No zirconia veneers were broken or detached in the period of observation. CONCLUSION: Zirconia veneers can be a good method to restore deep discolored anterior teeth. However, it should be used cautiously when the patient's esthetic expectation was too high.

Screening of differentially expressed genes and small molecule drugs of pediatric allergic asthma with DNA microarray.

BACKGROUND: Asthma is a disease resulting from a complex interaction of multiple genetic and environmental factors. More than 200 asthma candidate genes have been identified in the past decades by using genetic association studies, positional cloning and knockout mouse approaches. AIM: This study was to identify differentially expressed genes and provide direction for medicine design related to pediatric allergic asthma with DNA microarray. MATERIALS AND METHODS: The gene expression profile of pediatric allergic asthma GSE18965 was downloaded from Gene Expression Omnibus database which includes 16 samples, 7 normal and 9 pediatric allergic asthma samples. The differentially expressed genes between normal and disease samples were identified by using R language. The co-expression coefficient was calculated among the differentially expressed genes to construct co-expression networks with String Software. Software DAVID and FuncAssociate were used to analyze the functions of genes in the co-expression networks. RESULTS: A total of 133 genes were identified as differentially expressed genes between normal and disease samples, and 8 related small medicine molecules were also obtained (penbutolol, felbinac, iodixanol, josamycin, oxolamine, 3-nitropropionic acid, scriptaid, and sanguinarine) from database CMAP. The differentially expressed genes were enriched in several biological processes, in which viral transcription and lysosome were the most significant GO term of up- or down-regulated genes. CONCLUSIONS: Our present findings shed new light on the molecular mechanism of allergic asthma and provide three small molecular medicines (3-nitropropionic acid, scriptaid, and sanguinarine) which have the potential to use in clinic for treatment of allergic asthma in future.

Pulsed electrospray for mass spectrometry.

Pulsed electrospray has been developed and been reported for the first time. This new technique is based on the principle of pulsed ion sources, combined with the conventional electrospray. The pulsed ion spray was realized by a homemade pulsed HV circuit and was monitored by a digital microscope and an oscilloscope. Results show that the pulsed ESI device can be operated under proper conditions for a clear on-and-off spray process and that the device was kept in good electric contact for electrospray when pulsed HV was on. A pulsed ion current and pulsed mass spectra can be achieved with this pulsed ESI device. Furthermore, it has been noted that, under the same conditions (i.e., shape and size of sprayer tip, distance from sprayer tip to sampling nozzle, and other parameters for mass spectrometer), stable electrospray could be obtained for lower flow rates with a pulsed spray device. This experimental fact indicates the possible reduction in the total sample consumed could be realized by exploiting this novel design.

Diagnostic contrast echocardiography in children with congenital heart disease.

905 diagnostic contrast echocardiographic studies (DCE) were performed on 223 children. Carbon dioxide microbubble was used as contrast agent in various age groups, especially in newborns and infants because of its safety in application, stable contrast effect, and peripheral vein injection. Two-dimensional echocardiography (2-DCE), a useful tool in diagnosis of left to right shunt lesions reduced false negative diagnoses for ventricular septal defects and eliminated false positive diagnosis for atrial septal defects and patent ductus arteriosus. The accuracy of diagnosis in this series was 97%. The results of this series showed that 2-DCE is also valuable in the diagnosis of congenital heart disease with right to left shunts, and can be used to evaluate shunt levels and determine the obstructive sites on the right side of the heart.

Valve-incompetent foramen ovale in premature infants with ductus arteriosus: a Doppler echocardiographic study.

In a 1 year period, 56 neonates with a clinical diagnosis of ductus arteriosus had Doppler echocardiographic confirmation of the ductus; 33 (59%) had additional, turbulent left to right flow at the atrial level through a valve-incompetent foramen ovale. Normalized left atrial dimensions in the group with the atrial shunt were significantly larger than when there was a competent foramen ovale; when the ductus closed and left atrial enlargement receded, the atrial shunt disappeared. However, several infants with large left chambers had no interatrial shunting. When the atrial shunt was present, there were up to three flow pulses, corresponding to atrial systole, ventricular systole and ventricular diastole, but these were frequently fused into two pulses or even one pulse per cycle. The atrial septal morphology provided supporting clues: general bowing of the septum or a localized bulge in the region of the foramen ovale indicated relatively high left atrial pressure, and frequently a slitlike dropout could be seen at the superior edge of the foramen. During the study, three additional neonates with a ductus arteriosus were found to have a secundum atrial septal defect with a typical echographic image, "matchhead" appearance of the septal rim of the defect, but the Doppler flow patterns were indistinguishable from those of a valve-incompetent foramen ovale. The hemodynamic effects of the interatrial shunt, from either cause, seemed slight during the hospital course, but the presence of a valve-incompetent foramen ovale indicated a relatively large ductal shunt. Quantification of the ductal shunt, however, continues to rely primarily on measurement of the left atrial and ventricular size.