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1.
Drs.Rosen et Parenti,1981建议将大颌Jiang亚目自Jiang形目改隶颌针鱼目,并对新的Jiang形目及颌针鱼目各规定了7条主要特征,此建议已被鱼类学家Nelson专著《世界鱼类,1994》第3版等采纳,本文著者在写《中国动物志》中的Jiang形目及颌针鱼目时,详细比较了大颌Jiang亚目与颌针鱼目的关系,说明大颌Jiang亚目仍隶Jiang形目为宜。  相似文献   

2.
目的:通过明尼苏达多项人格测验评估牙颌面畸形患者术前的人格特征。方法:采用随机对照的方法,选取2012年5月~2013年5月在第四军医大学口腔医学院颅颌面创伤整形外科病区就诊的先天性牙颌面畸形患者102例,利用DXC-6型软件进行筛选,将其中64例纳入病例组;同时选取第四军医大学经过征兵心理测试且成绩合格的本科学员、八年制学员及硕/博士研究生83例,利用DXC-6型软件进行筛选,将其中57例纳入对照组。以问卷调查的方式对两组进行人格特征评估并比较其结果。结果:病例组MAS量表、Si量表评分与对照组比较存在显著性差异(P0.05),病例组显著高于对照组,两组其余各因素评分比较未见显著性差异(P0.05)。不同学历、年龄及性别的牙颌面畸形患者MAS量表和Si量表各项指标评分比较均无显著性差异(P0.05)。结论:牙颌面畸形患者存在对周围人反应过于敏感,缺乏自信等心理问题,可能与其异常面容有关,而与患者的学历、年龄及性别无关。  相似文献   

3.
以动物进化为主线,论述了颌的起源和由无颌脊椎动物到颌口类颌的演化过程,并对颌的结构及其它鳃弓的演化进行了概述。  相似文献   

4.
目的介绍一种简易、可重复、采血量较大的小鼠采血方法——改良小鼠颌下采血法。方法解剖观察小鼠面部血管,选取最佳体表进针点;选用微量毛细吸管快速高效采集小鼠血液。选用20只18~22 g SPF级ICR雄性小鼠,用改良采血针通过面部进针点采血。结果单人40~60 s内可完成1只小鼠颌下采血,采血量0.5~0.7 m L。结论改良颌下采血法具有对实验动物创伤小、采血量大并可重复采血等优点,尤为适用于初学者及大批量实验动物采血者。它是一种可广泛推广的简便、安全、快速、高效、采血量多的采血方法。  相似文献   

5.
通过介绍我国发现的几种古生代鱼类化石,简单阐述鱼类的分类及演化。  相似文献   

6.
目的:探讨偏突颌畸形患者手术后面部软组织变化规律,明确其正侧面部对称性改变及各标志点变化范围,以指导手术方案设计。方法:收集于我科行正畸正颌联合治疗的15例偏突颌畸形患者,分别在正颌手术前后采集患者面部软组织三维扫描数据,建立统一坐标系,测量术前和术后软组织解剖标志点的坐标变化。统计分析不对称性系数及各标志点变化,比较术前术后数据。结果:患者手术前后面部对称性改变结果中,颏前点、颏顶点、颏下点、双侧鼻翼基点、双侧颊点的不对称系数比较差异有统计学意义(P0.05)。患者正面像中除上唇缘点外各选择标志点水平方向的坐标变化均有统计学意义(P0.05),且可见颏顶点、颏下点、双侧鼻翼基点呈显著变化(P0.001),说明其面下1/3对称性得到改善,各标志点纠偏程度也整体呈自上而下的逐渐增强的变化趋势。结论:正颌手术能够有效改善偏突颌畸形患者面部软组织的不对称性。  相似文献   

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目的:对小型猪下颌骨升支部植入自行设计的钛板,通过机械力限制下颌骨生长,建立一种无髁状突直接损伤或破坏的发育性偏颌畸形的动物模型,为研究发育性偏颌畸形提供一种可靠的动物建模方法.方法:4月龄贵州小型猪(8只)单侧下颌骨升支后缘植入并螺钉固定末端卷曲的T形钛板,对侧假手术作为对照.术后24周处死动物,进行下颌骨大体形态观察、咬合关系观察下颌骨组织学检查.结果:大体观察显示小型猪下颌骨发生向植入侧的偏斜,牙列发生代偿性倾斜.组织学检查显示,植入侧后缘成骨活性低,骨质致密,未见明显成骨活动.对照侧成骨活跃,骨小梁结构疏松,有明显的成骨活动存在.结论:通过植入钛板影响下颌骨生长发育的方法,能够有效建立小型猪发育性偏颌畸形的动物模型.可能主要是机械力的作用直接导致骨骼大小与形态的改变;肌力等局部环境改变的变化、手术所造成的创伤与瘢痕也可能参与了这一过程.该方法成功率较高,为发育性偏颌畸形的发生、发展以及对骨性偏颌畸形的治疗策略的研究提供了一种可靠而有效的建立动物模型方法.  相似文献   

9.
颞颌关节的磁共振成像   总被引:3,自引:0,他引:3  
磁共振成像与CT相比具有软组织分辨率高,无离子辐射,可任意方向成像的优点,它可显示关节的硬,软件组织的结构及周围组织,于颞颌关节疾病的诊治中有具有重要价值。  相似文献   

10.
11.
The third part of the work provides a continuation of the annotated list of fish species found in freshwater and coastal brackish waters of Sakhalin Island: 60 species belonging to 42 genera, 21 families (Gadidae, Lotidae, Scomberesocidae, Belonidae, Hemiramphidae, Hypoptychidae, Gasterosteidae, Syngnathidae, Sebastidae, Hexagrammidae, Cottidae, Hemitripteridae, Agonidae, Liparidae, Percichthyidae, Lateolabracidae, Carangidae, Mugilidae, Zoarcidae, Stichaeidae, Cryptacanthodidae) and six orders (Gadiformes, Beloniformes, Gasterosteiformes, Syngnathiformes, Scorpaeniformes, Perciformes).  相似文献   

12.
Needlefishes (Beloniformes) were observed employing a range of stalking and attacking behaviours to attack schools of bait fishes ranging from the use of tactics common to predatory fishes to a novel behaviour: the use of leaping, aerial attacks. These aerial attacks are suggested to serve two purposes: to extend the attack range of the needlefishes and to reduce their prey's potential for evasion. Furthermore, a third purpose is hypothesized that the needlefishes are taking advantage of Snell's Window, an optical effect which may mask their approach to their prey.  相似文献   

13.
The genus Oryzias contains nearly 20 species, including the Japanese medaka (Oryzias latipes). Because each species exhibits different adaptability to environmental salinity, Oryzias fishes offer unique opportunities for comparative studies. To understand the mechanisms of osmotic adaptation, we are studying the functional evolution of the natriuretic peptide (NP) family??a group of small peptide hormones involved in body fluid regulation??by using Oryzias fishes. Analysis of the Japanese medaka genome revealed that 7 NP subtypes, namely, Atrial NP (ANP), B-type NP (BNP), Ventricular NP (VNP), and 4?C-type NPs (CNP-1 through CNP-4) were generated from a CNP-4-like ancestral gene discovered in the cyclostomes before the ray-finned fish/lobe-finned fish divergence. This evolutionary history has been confirmed by the discovery of hidden NP genes in tetrapods. Through analyses of phylogenetic distribution of NP subtypes, we also found that specific losses of subtypes have occurred in each vertebrate lineage. For example, ANP is absent in the Japanese and Indian medaka and the flying fish, suggesting that loss of the ANP gene occurred after the divergence of Beloniformes from Cyprinodontiformes. This fact also supports the inclusion of Oryzias into Beloniformes as suggested by phylogenetic analysis using whole mitochondrial genome sequences. How Oryzias fishes have retained their euryhalinity with a reduced number of NPs is an interesting question. CNP-3, which is functionally flexible, may be a substitute for the lost cardiac NPs.  相似文献   

14.
The power of comparative phylogenomic analyses also depends on the amount of data that are included in such studies. We used expressed sequence tags (ESTs) from fish model species as a proof of principle approach in order to test the reliability of using ESTs for phylogenetic inference. As expected, the robustness increases with the amount of sequences. Although some progress has been made in the elucidation of the phylogeny of teleosts, relationships among the main lineages of the derived fish (Euteleostei) remain poorly defined and are still debated. We performed a phylogenomic analysis of a set of 42 of orthologous genes from 10 available fish model systems from seven different orders (Salmoniformes, Siluriformes, Cypriniformes, Tetraodontiformes, Cyprinodontiformes, Beloniformes, and Perciformes) of euteleostean fish to estimate divergence times and evolutionary relationships among those lineages. All 10 fish species serve as models for developmental, aquaculture, genomic, and comparative genetic studies. The phylogenetic signal and the strength of the contribution of each of the 42 orthologous genes were estimated with randomly chosen data subsets. Our study revealed a molecular phylogeny of higher-level relationships of derived teleosts, which indicates that the use of multiple genes produces robust phylogenies, a finding that is expected to apply to other phylogenetic issues among distantly related taxa. Our phylogenomic analyses confirm that the euteleostean superorders Ostariophysi and Acanthopterygii are monophyletic and the Protacanthopterygii and Ostariophysi are sister clades. In addition, and contrary to the traditional phylogenetic hypothesis, our analyses determine that killifish (Cyprinodontiformes), medaka (Beloniformes), and cichlids (Perciformes) appear to be more closely related to each other than either of them is to pufferfish (Tetraodontiformes). All 10 lineages split before or during the fragmentation of the supercontinent Pangea in the Jurassic. [Reviewing Editor: Dr. Rafael Zardoya]  相似文献   

15.
16.
本文以陕西8个主要小麦品种为供试材料,采用田间实验与室内分析相结合的方法,从作物品种的相对含水量、细胞膜相对透性等抗早性能和光合面积、光合强度等丰产性能入手,探讨了作物的抗早、丰产性能及品种在雨养农业地区的适用性.确定陕229、822—10可望在该地区推广.同时提出采用相对含水量与细胞膜透性相结合的方法可准确地确定作物的抗旱性.  相似文献   

17.
We mapped 633 markers (488 AFLPs, 28 RAPDs, 34 IRSs, 75 ESTs, 4 STSs, and 4 phenotypic markers) for the Medaka Oryzias latipes, a teleost fish of the order Beloniformes. Linkage was determined using a reference typing DNA panel from 39 cell lines derived from backcross progeny. This panel provided unlimited DNA for the accumulation of mapping data. The total map length of Medaka was 1354.5 cM and 24 linkage groups were detected, corresponding to the haploid chromosome number of the organism. Thirteen to 49 markers for each linkage group were obtained. Conserved synteny between Medaka and zebrafish was observed for 2 independent linkage groups. Unlike zebrafish, however, the Medaka linkage map showed obvious restriction of recombination on the linkage group containing the male-determining region (Y) locus compared to the autosomal chromosomes.  相似文献   

18.
A new halfbeak species (Beloniformes, Hemiramphidae), Hyporhamphus tatjanchenkoi sp. nov., is described from the Lower Sarmatian fish-bearing deposits cropping out along the Pshekha River (Northern Caucasus). Comparative osteological analysis of this new fossil and extant representatives of Hyporamphus seem to indicate that Hyporhamphus tatjanchenkoi sp. nov. is in some ways related to the Indo–Pacific species H. affinis (Günther) and H. gamberur (Rüppell).  相似文献   

19.
Novel evolutionary relationship among four fish model systems   总被引:13,自引:0,他引:13  
Knowledge of the correct phylogenetic relationships among animals is crucial for the valid interpretation of evolutionary trends in biology. Zebrafish, medaka, pufferfish and cichilds are fish models for development, genomics and comparative genetics studies, although their phylogenetic relationships have not been tested rigorously. The results of phylogenomic analysis based on 20 nuclear protein-coding genes confirmed the basal placement of zebrafish in the fish phylogeny but revealed an unexpected relationship among the other three species, contrary to traditionally held systematic views based on morphology. Our analyses show that medaka (Beloniformes) and cichlids (Perciformes) appear to be more closely related to each other than either of them is to pufferfish (Tetraodontiformes), suggesting that a re-interpretation of some findings in comparative biology might be required. In addition, phylogenomic analyses show that fish typically have more copies of nuclear genes than land vertebrates, supporting the fish-specific genome duplication hypothesis.  相似文献   

20.
小嘴贝类腕足动物Planovatirostrum形态奇特,在我国,目前仅在新疆北部和布克赛尔蒙古族自治县和什托洛盖镇北10余公里处七里沟剖面洪古勒楞组中段底部层位中发现,化石大致呈簇状密集或花斑状分布。经过对产Planovatirostrum planoovale岩性、岩相和生物相的综合分析得知,这段地层是一套深水相沉积,P.pla-noovale生活在水体宁静、海水较深的软质基底上。  相似文献   

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