Perleididae is a group of stem neopterygian fishes known only from the Triassic.Here,we report the discovery of a new perleidid,Teffichthys wui sp.nov.,based on six well-preserved specimens from the late Smithian(Olen...Perleididae is a group of stem neopterygian fishes known only from the Triassic.Here,we report the discovery of a new perleidid,Teffichthys wui sp.nov.,based on six well-preserved specimens from the late Smithian(Olenekian,Early Triassic)marine deposits of Jurong,Jiangsu and Chaohu,Anhui,China.This new discovery documents the third and youngest species of Teffichthys,which is slightly younger than the Dienerian(Induan)T.elegans from Guizhou and the early Smithian T.madagascariensis from Madagascar.The new species shows diagnostic features of Teffichthys(presence of a spiracular,38-41 lateral line scales,and no more than three epaxial rays in the caudal fin)but differs from T.madagascariensis and T.elegans in some autapomorphies(e.g.,a horizontal opercle/subopercle contact and smooth scales with a nearly straight posterior margin).The diagnostic features for the genus Teffichthys and the family Perleididae are emended based on detailed comparisons of the new taxon with other perleidids.The phylogenetic relationships of perleidids with other stem neopterygians are discussed using a cladistic approach,and the results provide new insights into the phylogeny and classification of main stem neopterygian clades.展开更多
Objective To observe the value of intravoxel incoherent motion(IVIM)and dynamic contrast-enhanced MRI(DCE-MRI)for assessing abnormalities of brucellosis spondylitis(BS)without conventional MRI changes.Methods Data of ...Objective To observe the value of intravoxel incoherent motion(IVIM)and dynamic contrast-enhanced MRI(DCE-MRI)for assessing abnormalities of brucellosis spondylitis(BS)without conventional MRI changes.Methods Data of 36 brucellosis patients with definite spinal lesions displayed on conventional MRI(BS 1 group),14 cases without brucellosis infection nor abnormal spinal signals on MRI(control group)and 36 brucellosis patients without definite spinal lesions on conventional MRI(BS 2 group)were retrospectively analyzed.The values of IVIM parameters,including perfusion fraction(f),pure water diffusion coefficient(D)and pseudo-diffusion coefficient(D*),also of DCE-MRI parameters,including time-intensity curve(TIC)type,volume transport constant(K trans),the rate constant(K ep)and volume fraction of extravascular extracellular space per unit tissue volume(V e)were compared among groups.Univariate and multivariate logistic regression were used to screen independent factors for discriminating BS 1 and BS 2.Receiver operating characteristic curves were drawn,and the areas under the curve(AUC)were calculated to evaluate the efficiency of the above parameters for discriminating BS 1 and BS 2.Results Among IVIM parameters,compared with control group,D*values decreased but D values increased in BS 1 group,while D*values increased in BS 2 group(all adjusted P<0.05).Compared with BS 2 group,BS 1 group had higher values of f and D and lower D*(all adjusted P<0.05).In BS 1 group,the TIC types were predominantly typeⅠ(23/36,63.89%),which were wholly or predominantly typeⅢin BS 2 group and control group,and of the former was significantly different with latter 2(both adjusted P<0.05).Compared with control group,K trans increased progressively in both BS 1 and BS 2 groups(both adjusted P<0.05).BS 1 group had lower K ep and higher V e than BS 2 and control groups(all adjusted P<0.05).Among univariate logistic regression models,the model including only f had lower capability for discriminating BS 1 and BS 2(AUC=0.759)than those including D,K trans and V e(AUC=0.951,0.833,0.894,all P<0.05).No significant different was found among multivariate logistic regression model including f and D,model including K trans and V e nor model including all above parameters(all P>0.05).Conclusion Both IVIM and DCE-MRI could be used to evaluate BS abnormality without conventional MRI changes.展开更多
Several therocephalian species,mainly represented by cranial material from the late Permian,have been reported from China in recent years.Here we describe a tiny new baurioid therocephalian,Jiucaiyuangnathus confusus ...Several therocephalian species,mainly represented by cranial material from the late Permian,have been reported from China in recent years.Here we describe a tiny new baurioid therocephalian,Jiucaiyuangnathus confusus gen.et sp.nov.,from the Jiucaiyuan Formation,Xinjiang,China.The new taxon is represented by a partial snout with occluded partial lower jaw and two postcranial skeletons.Although juvenile in stage,the new species is diagnosed by the following features:round pit in middle of lateral surface of maxilla;lacrimal contact nasal;fossa for dentary tooth on the posterior end of the premaxilla,lateral to the anterior choana;two small vertical triangular ridges extending dorsally and ventrally on the vomerine anterior portion,and bordering a thin vomerine foramen laterally;anterior projection of the lateral part of the frontal on the nasal;symphyseal region of the dentary projected anteriorly;5 upper premaxillary teeth,upper and lower canines absent,diastema between the last premaxillary upper incisor and first maxillary tooth present,no diastema separating anterior from posterior dentition in the mandible,10 maxillary teeth and 12 dentary teeth,posterior postcanine expands mesiodistally,having a main large cusps and tiny anterior and posterior accessory cusps in line;neural arches of the atlas fused by the neural spine,neural spine of the axis projected posteriorly,procoracoid foramen lies between procoracoid and scapula.Features of the dentition resembles those of the small baurioid Ericiolacerta parva from South Africa and Silphedosuchus orenburgensis from Russia.The specimens provide the rare opportunity to know in detail the postcranial skeleton of baurioids.展开更多
文摘Perleididae is a group of stem neopterygian fishes known only from the Triassic.Here,we report the discovery of a new perleidid,Teffichthys wui sp.nov.,based on six well-preserved specimens from the late Smithian(Olenekian,Early Triassic)marine deposits of Jurong,Jiangsu and Chaohu,Anhui,China.This new discovery documents the third and youngest species of Teffichthys,which is slightly younger than the Dienerian(Induan)T.elegans from Guizhou and the early Smithian T.madagascariensis from Madagascar.The new species shows diagnostic features of Teffichthys(presence of a spiracular,38-41 lateral line scales,and no more than three epaxial rays in the caudal fin)but differs from T.madagascariensis and T.elegans in some autapomorphies(e.g.,a horizontal opercle/subopercle contact and smooth scales with a nearly straight posterior margin).The diagnostic features for the genus Teffichthys and the family Perleididae are emended based on detailed comparisons of the new taxon with other perleidids.The phylogenetic relationships of perleidids with other stem neopterygians are discussed using a cladistic approach,and the results provide new insights into the phylogeny and classification of main stem neopterygian clades.
文摘Objective To observe the value of intravoxel incoherent motion(IVIM)and dynamic contrast-enhanced MRI(DCE-MRI)for assessing abnormalities of brucellosis spondylitis(BS)without conventional MRI changes.Methods Data of 36 brucellosis patients with definite spinal lesions displayed on conventional MRI(BS 1 group),14 cases without brucellosis infection nor abnormal spinal signals on MRI(control group)and 36 brucellosis patients without definite spinal lesions on conventional MRI(BS 2 group)were retrospectively analyzed.The values of IVIM parameters,including perfusion fraction(f),pure water diffusion coefficient(D)and pseudo-diffusion coefficient(D*),also of DCE-MRI parameters,including time-intensity curve(TIC)type,volume transport constant(K trans),the rate constant(K ep)and volume fraction of extravascular extracellular space per unit tissue volume(V e)were compared among groups.Univariate and multivariate logistic regression were used to screen independent factors for discriminating BS 1 and BS 2.Receiver operating characteristic curves were drawn,and the areas under the curve(AUC)were calculated to evaluate the efficiency of the above parameters for discriminating BS 1 and BS 2.Results Among IVIM parameters,compared with control group,D*values decreased but D values increased in BS 1 group,while D*values increased in BS 2 group(all adjusted P<0.05).Compared with BS 2 group,BS 1 group had higher values of f and D and lower D*(all adjusted P<0.05).In BS 1 group,the TIC types were predominantly typeⅠ(23/36,63.89%),which were wholly or predominantly typeⅢin BS 2 group and control group,and of the former was significantly different with latter 2(both adjusted P<0.05).Compared with control group,K trans increased progressively in both BS 1 and BS 2 groups(both adjusted P<0.05).BS 1 group had lower K ep and higher V e than BS 2 and control groups(all adjusted P<0.05).Among univariate logistic regression models,the model including only f had lower capability for discriminating BS 1 and BS 2(AUC=0.759)than those including D,K trans and V e(AUC=0.951,0.833,0.894,all P<0.05).No significant different was found among multivariate logistic regression model including f and D,model including K trans and V e nor model including all above parameters(all P>0.05).Conclusion Both IVIM and DCE-MRI could be used to evaluate BS abnormality without conventional MRI changes.
文摘Several therocephalian species,mainly represented by cranial material from the late Permian,have been reported from China in recent years.Here we describe a tiny new baurioid therocephalian,Jiucaiyuangnathus confusus gen.et sp.nov.,from the Jiucaiyuan Formation,Xinjiang,China.The new taxon is represented by a partial snout with occluded partial lower jaw and two postcranial skeletons.Although juvenile in stage,the new species is diagnosed by the following features:round pit in middle of lateral surface of maxilla;lacrimal contact nasal;fossa for dentary tooth on the posterior end of the premaxilla,lateral to the anterior choana;two small vertical triangular ridges extending dorsally and ventrally on the vomerine anterior portion,and bordering a thin vomerine foramen laterally;anterior projection of the lateral part of the frontal on the nasal;symphyseal region of the dentary projected anteriorly;5 upper premaxillary teeth,upper and lower canines absent,diastema between the last premaxillary upper incisor and first maxillary tooth present,no diastema separating anterior from posterior dentition in the mandible,10 maxillary teeth and 12 dentary teeth,posterior postcanine expands mesiodistally,having a main large cusps and tiny anterior and posterior accessory cusps in line;neural arches of the atlas fused by the neural spine,neural spine of the axis projected posteriorly,procoracoid foramen lies between procoracoid and scapula.Features of the dentition resembles those of the small baurioid Ericiolacerta parva from South Africa and Silphedosuchus orenburgensis from Russia.The specimens provide the rare opportunity to know in detail the postcranial skeleton of baurioids.
