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1.
Cladistics ; 2024 Jul 17.
Article in English | MEDLINE | ID: mdl-39016633

ABSTRACT

Tooth attachment and replacement play significant roles in the feeding ecology of polyphyodont vertebrates, yet these aspects have remained largely unexplored in non-avialan paravians including troodontids. Here, we describe a new troodontid species, Urbacodon norelli sp.n., recovered from the Upper Cretaceous Iren Dabasu Formation of Inner Mongolia, China, based on an incomplete right dentary and 12 associated replacement teeth. Urbacodon norelli is distinguished from all other known troodontids, including its relative U. itemirensis from Uzbekistan, by several features: the presence of paired dentary symphyseal foramina, the presence of a relatively steep anterior margin of the dentary, the absence of a dentary chin, the presence of a common groove hosting the anterior 12 dentary teeth, and the presence of relatively larger dentary teeth. Phylogenetic analysis places both species of Urbacodon as sister taxa to Zanabazar junior, confirming their status as later-diverging troodontids. Radiographs revealed an alternating tooth replacement pattern in U. norelli, with a maximum Zahnreihen-spacing estimated to be 3. During tooth replacement, the anteriorly inclined interdental septa, which wedge between anterior dentary teeth, underwent frequent remodelling as the developing tooth moved upwards, particularly anterolabially. This rapid turnover left insufficient time for an interdental plate to form, resulting in the absence of such structures in this specimen. The frequent remodelling of periodontal tissues accompanying tooth replacement is likely to account for the absence of interdental plates. The discovery of this new troodontid expands our understanding of paravian theropods from the Upper Cretaceous Iren Dabasu Formation and provides valuable insights into troodontid tooth biology.

2.
Zootaxa ; 4985(2): 294300, 2021 Jun 14.
Article in English | MEDLINE | ID: mdl-34186649

ABSTRACT

Parapteronemobius contains 7 species or subspecies distributed in East Asia with only one species recorded from China. In this study, we reported the second species, P. chenggong He sp. nov., from Zhejiang. The new species differs from P. dibrachiatus in body size, male genitalia and COI gene. The phylogeny of this genus in subfamily Nemobiinae are discussed based on COI, 18S and 28S genes. The type specimens are deposited in the Museum of Biology, East China Normal University (ECNU).


Subject(s)
Orthoptera/classification , Animals , Body Size , China , Genes, Mitochondrial , Genitalia, Male , Male , Orthoptera/anatomy & histology , RNA, Ribosomal, 18S , RNA, Ribosomal, 28S
3.
Zhen Ci Yan Jiu ; 42(5): 377-83, 2017 Oct 25.
Article in Chinese | MEDLINE | ID: mdl-29105463

ABSTRACT

OBJECTIVE: To observe the effect of moxibustion on the learning ability and expression of neurotrophic factors and Notch signaling in vascular dementia (VD) rats, so as to explore its neurogenesis mechanism underlying improvement of VD. METHODS: Sixty SD rats were equally and randomly divided into sham operation (sham), model, medication and moxibustion groups (n=15 rats/group). The VD model was established by occlusion of the bilateral cervical common arteries and reperfusion. Moxibustion was applied to "Dazhui"(GV 14), "Guanyuan"(CV 4) and "Mingmen"(GV 4)for 15 minutes, once daily, 6 times a week for 4 weeks. Rats of the medication group were treated by gavage of nimodipine (2 mg·kg-1·d-1),3 times a day, 6 days a week for 4 weeks. Morris water maze tests were performed to detect the rat's learning-memory ability. The infarcted size of the brain was detected by using 2,3,5-triphenyltetrazolium chloride (TTC) staining, and H.E. staining was used to detect the histopathological changes. The expression level of glia fibrillary acidic protein (GFAP), nerve growth factor (NGF), brain derived neurotrophic factor (BDNF), Notch 1 (a receptor), Hes 3 (a downstream effector) mRNAs and proteins in the hippocampal tissues were detected by quantitative real-time PCR and Western blot, respectively. RESULTS: After 4 weeks' intervention, modeling-induced increase of escape latency was significantly shortened in both moxibustion and medication groups relevant to the model group (P<0.05), and the infarct size was reduced and the damage degree of nerve cells in the brain tissue alleviated. The expression levels of BDNF, NGF, GFAP, Hes 3, Notch 1 genes and proteins were significantly up-regulated in the model group relevant to the sham operation group (P<0.05,P<0.01). After the intervention, the expression levels of hippocampal BDNF, NGF, GFAP, Hes 3 and Notch 1 mRNAs and proteins in the moxibustion group, and NGF and GFAP mRNAs, and BDNF, NGF, GFAP, Hes 3 and Notch 1 proteins in the medication group were further obviously up-regulated relevant to the model group (P<0.05, P<0.01). The effect of moxibustion was significantly superior to that of medication in up-regulating GFAP, Hes 3, Notch 1 mRNAs expression (P<0.05,P<0.01). No significant differences were found in the expression of BDNF, Hes 3 and Notch 1 mRNAs in the medication group relevant to the model group (P<0.05), and between the moxibustion and medication groups in up-regulating the expression of BDNF and NGF mRNAs, and in up-regulating the expression of BDNF, NGF, GFAP, Hes 3 and Notch 1 proteins (P<0.05). CONCLUSIONS: Moxibustion can improve learning ability in VD rats, which may be associated with its effects in up-regulating the expression of neurotrophic factors and in potentiating Notch signaling.


Subject(s)
Dementia, Vascular , Moxibustion , Animals , Hippocampus , Learning , Rats , Rats, Sprague-Dawley
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