ObjectiveTo identify the pathogen species responsible for the wilt disease of Tetradium ruticarpum in Chongqing， investigate there biological characteristics， and screen effective fungicides， so as to provide a theoretical basis for disease control in production. MethodsThe pathogen was isolated via the tissue culture method. Pathogenicity was verified according to Koch's postulates. The pathogen was identified based on morphological characteristics and multi-gene phylogenetic analysis. The mycelial growth rate method was used for biological characterization of the pathogen and fungicide screening. ResultsThe pathogen colonies were nearly circular with irregular edges， white， short， velvety aerial hyphae， and pale purple undersides. Macroconidia were colorless， sickle-shaped， with 3-5 septa， while microconidia were transparent， elliptical， aseptate or with 1-2 septa. Multi-gene phylogenetic analysis showed that the pathogen clustered in the same clade as Fusarium fujikuroi with 100% support， which， combined with morphological characteristics， identified the pathogen causing wilt of T. ruticarpum in Chongqing as F. fujikuroi. The optimal conditions for the mycelial growth of F. fujikuroi were mung bean agar （MBA） with glucose as the carbon source， beef extract and yeast powder as nitrogen sources， 28 ℃， pH 7.0， and alternating light/dark conditions. The optimal conditions for sporulation were potato dextrose agar （PDA） with glucose as the carbon source， beef extract as the nitrogen source， 28 ℃， pH 7.0， and complete darkness. Among chemical fungicides， phenazine-1-carboxylic acid exhibited the strongest inhibitory effect on F. fujikuroi. Shenqinmycin and tetramycin were the most effective bio-fungicides. ConclusionThis study is the first to report F. fujikuroi as the causal agent of wilt disease in T. rutaecarpa. The chemical fungicide phenazine-1-carboxylic acid and the bio-fungicides shenqinmycin and tetramycin showed strong inhibitory effects against F. fujikuroi.

Objective:To explore the feasibility of long board detector of digital radiography(DR)in clinical application.Methods:The long board detector(detector)was erected and placed upright.The scale long ruler with marked metal lead wire was placed at 20 cm in front of the center of long axis of the board of detector,which paralleled medial axis.Three test cards of spatial resolution were respectively placed at three positions(upper,middle and lower)of detector,and they were stuck on the board of detector as 30cm intervals between each other and 45° position.The exposures were conducted at 100,150,and 200 cm of source image distance(SID).The incident doses were tested,which obtained from different SID spots of upper,middle and lower positions of detector.The spatial resolutions of 3 positions were determined through observed the images of cards.The ratio of the marked scale length with metal lead wire to actual length of lead wire was measured through the projection of the scale length,so as to obtain the amplification rate of different spot positions.The spatial distribution of effective focal plane on the direction of long axis of detector,and the morphological change of that were observed.Results:When SID spots were respectively 100,150 and 200cm,the amplification rates of images decreased with increasing SID.The difference of amplification rates among three SID spots was significant(F=223.80,P<0.001).There was significant difference in the corresponding radiation doses among different SID spots(F=7.57,P<0.05).The spatial resolution was constantly 1.8 LP/mm.There was heel effect along with the direction of short axis of detector.The effective focal spot on the direction of long axis of detector appeared up-down symmetrical display.Conclusion:The long board detector of DR equipment has realized the capture for the images of the overall length of spine or the overall length of lower limbs in one exposure,which can meet the clinical requirement,and improve the detection efficiency of X-ray.

Two cases of incomplete regression of ventral mesogastrium were reported. Their nomenclature, etiology, symptoms and characteristic roentgenologic findings were discussed in relation to anatomical study. Because of its unique etiology and symptoms, charecteristic roentgenologic findings, and effectual remedy, it is suggested that this disease should be distinguished from "abnormal adhesion of fibrous bands" as an independent anomaly called incomplete regression of ventral mesogastrium. The roentgenological findings were: An incisure was found in the upper portion of pars descendens duodeni. It sank deeply and reduced two thirds of the normal diameter of the intestinal lumen to form an eccentrie intestinal stenosis. The intestinal lumen, near the inner border of the incisure was smooth, and there was no sign of serrated image formed by intestinal mucosa. The part of intestinal lumen was not distended in hypotonic radiography. All the above signs were caused by the traction and binding of the nonregressed mesogastrium.