期刊文献+
共找到10,961篇文章
< 1 2 250 >
每页显示 20 50 100
Cemented vertebra and adjacent vertebra refractured in a chronic kidney disease-mineral and bone disorder patient: A case report
1
作者 Ti-Dong Zhang Shuai Cao +2 位作者 Hui-Yong Ren Yu-Min Li Yi-Ming Yuan 《World Journal of Clinical Cases》 SCIE 2024年第10期1804-1809,共6页
BACKGROUND Although percutaneous vertebral augmentation(PVA)is a commonly used procedure for treating vertebral compression fracture(VCF),the risk of vertebral refracture should be considered.Chronic kidney disease-mi... BACKGROUND Although percutaneous vertebral augmentation(PVA)is a commonly used procedure for treating vertebral compression fracture(VCF),the risk of vertebral refracture should be considered.Chronic kidney disease-mineral and bone disorder(CKD-MBD)is a systemic disease of mineral and bone metabolism.It is associated with an increased risk of fracture.Few studies have reported the use of PVA in patients with CKD-MBD.We herein report a rare case wherein the cemented vertebra and the adjacent vertebra refractured simultaneously in a CKD-MBD patient after PVA.CASE SUMMARY A 74-year-old man suffered from low back pain after taking a fall about 3 wk ago.According to physical examination,imaging and laboratory findings,diagnoses of T12 VCF,CKD-MBD,and chronic kidney disease stage 5 were established.He then received percutaneous vertebroplasty at T12 vertebra.Fourteen weeks later,he presented with T12 and L1 vertebral refractures caused by lumbar sprain.Once again,he was given PVA which was optimized for the refractured vertebrae.Although the short-term postoperative effect was satisfactory,he reported chronic low back pain again at the 3-month follow-up.CONCLUSION It is necessary that patients with CKD-MBD who have received PVA are aware of the adverse effects of CKD-MBD.It may increase the risk of vertebral refracture.Furthermore,the PVA surgical technique needs to be optimized according to the condition of the patient.The medium-and long-term effects of PVA remain uncertain in patients with CKD-MBD. 展开更多
关键词 Chronic kidney disease-mineral and bone disorder Percutaneous vertebral augmentation vertebral compression fracture vertebral refracture Cemented vertebra Adjacent vertebra Case report
下载PDF
“FISH VERTEBRA” about 3 Sickle Cell Patients Followed at Laquintinie Hospital, Douala
2
作者 Same Bebey Francine Mbono Betoko Ritha +5 位作者 Eloundou Onomo Paul Mantho Fopa Pauline Eposse Ekoube Charlotte Megne Tamo Estelle Ebene Mbende Romain Singwe Ngandeu Madeleine 《Open Journal of Rheumatology and Autoimmune Diseases》 2024年第1期20-25,共6页
Vertebral involvement in particular is common in sickle cell patients. We report 3 cases of “fish vertebra” fractures in sickle cell patients aged 16, 18, and 24 years old respectively at Laquintinie Hospital, Doual... Vertebral involvement in particular is common in sickle cell patients. We report 3 cases of “fish vertebra” fractures in sickle cell patients aged 16, 18, and 24 years old respectively at Laquintinie Hospital, Douala. When the vertebral fractures were diagnosed, the 3 patients had back pain and kyphosis deformities of the dorsal spine. Treatment with an infusion of biphosphonates (zoledronic acid at a dose of 0.5 mg·per·kg) was offered to all three patients. Two out of three patients received treatment with biphosphonates with a successful outcome. Profound vitamin D deficiency is associated with increased bone remodeling and a history of fractures. In sickle cell anemia, vertebral fractures may also result from bone fragility, which is often overlooked as aseptic osteonecrosis and osteomyelitis, which are very often suspected. 展开更多
关键词 vertebral Fractures Sickle Cell Anemia vertebral Bone Fragility
下载PDF
Vertebral Artery Stenting for Acute Multiple Cerebral Infarctions Caused by Vertebral Artery Dissection After Massage:A Case Report
3
作者 Ying-Xue Cui Chuan-Jin Song +3 位作者 Xue-Si Hou Gui-Lin Liu Xu Ji Shao-Song Wang 《Chinese Medical Sciences Journal》 CAS CSCD 2024年第2期149-154,共6页
Vertebral artery dissection is a rare pathology that can cause ischemic stroke in young people.Cervical massage,especially improper pulling manipulation,is a cause of vertebral artery dissection.We present a case of 3... Vertebral artery dissection is a rare pathology that can cause ischemic stroke in young people.Cervical massage,especially improper pulling manipulation,is a cause of vertebral artery dissection.We present a case of 32-year old woman who developed acute multiple posterior circulation ischemic cerebral infarctions as a result of left vertebral artery V4 segment dissection after receiving neck massage.She underwent emergency vertebral artery stent implantation at the site of the dissection.Symptoms were relieved the day after treatment.The patient recovered without adverse complications or endovascular restenosis in the following year. 展开更多
关键词 vertebral artery dissection acute ischemic stroke stent implantation endovascular therapy
下载PDF
Spinal Vertebral Fracture Detection and Fracture Level Assessment Based on Deep Learning
4
作者 Yuhang Wang Zhiqin He +3 位作者 Qinmu Wu Tingsheng Lu Yu Tang Maoyun Zhu 《Computers, Materials & Continua》 SCIE EI 2024年第4期1377-1398,共22页
This paper addresses the common orthopedic trauma of spinal vertebral fractures and aims to enhance doctors’diagnostic efficiency.Therefore,a deep-learning-based automated diagnostic systemwithmulti-label segmentatio... This paper addresses the common orthopedic trauma of spinal vertebral fractures and aims to enhance doctors’diagnostic efficiency.Therefore,a deep-learning-based automated diagnostic systemwithmulti-label segmentation is proposed to recognize the condition of vertebral fractures.The whole spine Computed Tomography(CT)image is segmented into the fracture,normal,and background using U-Net,and the fracture degree of each vertebra is evaluated(Genant semi-qualitative evaluation).The main work of this paper includes:First,based on the spatial configuration network(SCN)structure,U-Net is used instead of the SCN feature extraction network.The attention mechanismandthe residual connectionbetweenthe convolutional layers are added in the local network(LN)stage.Multiple filtering is added in the global network(GN)stage,and each layer of the LN decoder feature map is filtered separately using dot product,and the filtered features are re-convolved to obtain the GN output heatmap.Second,a network model with improved SCN(M-SCN)helps automatically localize the center-of-mass position of each vertebra,and the voxels around each localized vertebra were clipped,eliminating a large amount of redundant information(e.g.,background and other interfering vertebrae)and keeping the vertebrae to be segmented in the center of the image.Multilabel segmentation of the clipped portion was subsequently performed using U-Net.This paper uses VerSe’19,VerSe’20(using only data containing vertebral fractures),and private data(provided by Guizhou Orthopedic Hospital)for model training and evaluation.Compared with the original SCN network,the M-SCN reduced the prediction error rate by 1.09%and demonstrated the effectiveness of the improvement in ablation experiments.In the vertebral segmentation experiment,the Dice Similarity Coefficient(DSC)index reached 93.50%and the Maximum Symmetry Surface Distance(MSSD)index was 4.962 mm,with accuracy and recall of 95.82%and 91.73%,respectively.Fractured vertebrae were also marked as red and normal vertebrae were marked as white in the experiment,and the semi-qualitative assessment results of Genant were provided,as well as the results of spinal localization visualization and 3D reconstructed views of the spine to analyze the actual predictive ability of the model.It provides a promising tool for vertebral fracture detection. 展开更多
关键词 Deep learning vertebral fracture detection medical image processing
下载PDF
Factors influencing further vertebral height loss following percutaneous vertebroplasty in osteoporotic vertebral compression fractures:A 1-year follow-up study
5
作者 Zhong-Qiu Tang Shao-Bo He +3 位作者 Dong-Yang Yu Hai-Mao Luo Xue-Hong Xing Yong-Wen Zhou 《World Journal of Clinical Cases》 SCIE 2024年第21期4609-4617,共9页
BACKGROUND Osteoporotic vertebral compression fractures(OVCFs)contribute to back pain and functional limitations in older individuals,with percutaneous vertebroplasty(PVP)emerging as a minimally invasive treatment.How... BACKGROUND Osteoporotic vertebral compression fractures(OVCFs)contribute to back pain and functional limitations in older individuals,with percutaneous vertebroplasty(PVP)emerging as a minimally invasive treatment.However,further height loss post-PVP prompts investigation into contributing factors.AIM To investigate the factors associated with further height loss following PVP with cement augmentation in OVCF patients.METHODS A total of 200 OVCF patients who underwent successful PVP between January 2021 and December 2022 were included in this study.“Further height loss”during 1 year of follow-up in OVCF patients with bone edema was defined as a vertical height loss of≥4 mm.The study population was divided into two groups for analysis:The“No Further Height Loss group(n=179)”and the“Further Height Loss group(n=21).”RESULTS In comparing two distinct groups of patients,significant differences existed in bone mineral density(BMD),vertebral compression degree,prevalence of intravertebral cleft(IVF),type of bone cement used,and cement distribution patterns.Results from binary univariate regression analysis revealed that lower BMD,the presence of IVF,cleft distribution of bone cement,and higher vertebral compression degree were all significantly associated with further height loss.Notably,the use of mineralized collagen modified-poly(methyl methacrylate)bone cement was associated with a significant reduction in the risk of further height loss.In multivariate regression analysis,lower BMD and the presence of IVF remained significantly associated with further height loss.CONCLUSION Further height loss following PVP in OVCF patients is influenced by a complex interplay of factors,especially lower BMD and the presence of IVF.These findings underscore the importance of assessing and managing these factors when addressing height loss following PVP in OVCF patients. 展开更多
关键词 Percutaneous vertebroplasty Osteoporotic vertebral compression fractures Further height loss Bone mineral density Intravertebral cleft
下载PDF
Risk factors and clinical significance of posterior slip of the proximal vertebral body after lower lumbar fusion
6
作者 Jia-Jun Zhu Yi Wang +5 位作者 Jun Zheng Sheng-Yang Du Lei Cao Yu-Ming Yang Qing-Xi Zhang Ding-Ding Xie 《World Journal of Clinical Cases》 SCIE 2024年第26期5885-5892,共8页
BACKGROUND Adjacent segment disease(ASD)after fusion surgery is frequently manifests as a cranial segment instability,disc herniation,spinal canal stenosis,spondylolisthesis or retrolisthesis.The risk factors and mech... BACKGROUND Adjacent segment disease(ASD)after fusion surgery is frequently manifests as a cranial segment instability,disc herniation,spinal canal stenosis,spondylolisthesis or retrolisthesis.The risk factors and mechanisms of ASD have been widely discussed but never clearly defined.AIM To investigate the risk factors and clinical significance of retrograde movement of the proximal vertebral body after lower lumbar fusion.METHODS This was a retrospective analysis of the clinical data of patients who underwent transforaminal lumbar interbody fusion surgery between September 2015 and July 2021 and who were followed up for more than 2 years.Ninety-one patients with degenerative lumbar diseases were included(22 males and 69 females),with an average age of 52.3 years(40-73 years).According to whether there was retrograde movement of the adjacent vertebral body on postoperative X-rays,the patients were divided into retrograde and nonretrograde groups.The sagittal parameters of the spine and pelvis were evaluated before surgery,after surgery,and at the final follow-up.At the same time,the Oswestry Disability Index(ODI)and Visual Analogue Scale(VAS)were used to evaluate the patients’quality of life.RESULTS Nineteen patients(20.9%)who experienced retrograde movement of proximal adjacent segments were included in this study.The pelvic incidence(PI)of the patients in the retrograde group were significantly higher than those of the patients in the nonretrograde group before surgery,after surgery and at the final follow-up(P<0.05).There was no significant difference in lumbar lordosis(LL)between the two groups before the operation,but LL in the retrograde group was significantly greater than that in the nonretrograde group postoperatively and at the final follow-up.No significant differences were detected in terms of the|PI–LL|,and there was no significant difference in the preoperative lordosis distribution index(LDI)between the two groups.The LDIs of the retrograde group were 68.1%±11.5%and 67.2%±11.9%,respectively,which were significantly lower than those of the nonretrograde group(75.7%±10.4%and 74.3%±9.4%,respectively)(P<0.05).Moreover,the patients in the retrograde group had a greater incidence of a LDI<50%than those in the nonretrograde group(P<0.05).There were no significant differences in the ODI or VAS scores between the two groups before the operation,but the ODI and VAS scores in the retrograde group were significantly worse than those in the nonretrograde group after the operation and at the last follow-up,(P<0.05).CONCLUSION The incidence of posterior slippage after lower lumbar fusion was approximately 20.9%.The risk factors are related to a higher PI and distribution of lumbar lordosis.When a patient has a high PI and insufficient reconstruction of the lower lumbar spine,adjacent segment compensation via posterior vertebral body slippage is one of the factors that significantly affects surgical outcomes. 展开更多
关键词 Adjacent segment disease Posterior vertebral slip Sagittal alignment of spine-pelvis Lower lumbar fusion Quality of life
下载PDF
Game-changing insights on vertebral skeletal stem cells in bone metastasis and therapeutic horizons
7
作者 QIUQIANG CHEN XIAOLEI ZHAO WENXUE MA 《Oncology Research》 SCIE 2024年第1期95-98,共4页
Greenblatt and his team have unveiled vertebral skeletal stem cells(vSSCs)as a critical player in the landscape of bone metastasis.This commentary delves into the transformative discoveries surrounding vSSCs,emphasizi... Greenblatt and his team have unveiled vertebral skeletal stem cells(vSSCs)as a critical player in the landscape of bone metastasis.This commentary delves into the transformative discoveries surrounding vSSCs,emphasizing their distinct role in bone metastasis compared to other stem cell lineages.We illuminate the unique properties and functions of vSSCs,which may account for the elevated susceptibility of vertebral bones to metastatic invasion.Furthermore,we explore the exciting therapeutic horizons opened by this newfound understanding.These include potential interventions targeting vSSCs,modulation of associated signaling pathways,and broader implications for the treatment and management of bone metastasis.By shedding light on these game-changing insights,we hope to pave the way for novel strategies that could revolutionize the prognosis and treatment landscape for cancer patients with metastatic bone disease. 展开更多
关键词 vertebral skeletal stem cells(vSSCs) Stem cell research Metastasis Breast prostate and lung cancers Spinal metastasis Matthew Greenblatt Genetic expressions
下载PDF
Delayed Pseudoaneurysms of Vertebral Artery Post Penetrating Trauma: A Case Report
8
作者 Ahmad Rezaee Azandariani Leili Ebrahimi Farsangi Mohammad Mahdi Talimkhani 《Case Reports in Clinical Medicine》 2024年第4期95-100,共6页
Objective: Vascular injuries usually present immediately after the penetration, but the delayed onset of vascular symptoms caused by vessel dissection or aneurysm after a traumatic event is extremely rare. Vertebral a... Objective: Vascular injuries usually present immediately after the penetration, but the delayed onset of vascular symptoms caused by vessel dissection or aneurysm after a traumatic event is extremely rare. Vertebral artery injury is a low-frequency but high-mortality injury. We aim to report evidence of delayed onset of vascular symptoms following penetrating trauma in the neck. Materials and Methods: A case report. Results: A 19-year-old boy was referred to our hospital and complained of a mass in the right part of his neck (right mandibular angle). He gave a history of penetrating trauma to his neck 2 months ago. The mass was expanding during these 2 months and doesn’t respond to antibiotic therapy. In the examination, 3 × 3 cm, firm, nonmobile, and without tenderness and pain mass was palpated in the second level of his neck. Doctors ordered a Doppler sonography in the hospital where a yin-yang pattern was reported. A 36 × 43 × 40 mm heterogeneous, solid, and hypodense area close to C1-C2-C3 with vascular flow was discovered in the right submandibular area after computed tomography (CT)-angiography. The patient was referred to an interventional neurologist for angiography and due to the lack of flow at the distal of the V3 segment, he decided to sacrifice this artery by two coils. Conclusion: Penetrating neck injuries are usually asymptomatic, but these injuries are often accompanied by hemorrhage, neurological symptoms, dysphagia, odynophagia, and windpipe. Penetrating lesions of the vertebral artery are rare and very difficult to diagnose. Also, these lesions are challenging for surgeons due to complex anatomy and difficult surgical exposure. So, endovascular treatment was used to treat the patient. 展开更多
关键词 Penetrating Trauma Delayed Pseudoaneurysms vertebral Artery
下载PDF
Molecular Evolutionary Rate Calculation of Hemoglobin α Chain and γ Chain at Different Stages in Vertebrate Evolution Process
9
作者 龙承星 张波 马绍宾 《Agricultural Science & Technology》 CAS 2010年第9期101-104,220,共5页
Pseudogene and fibrin peptide which has rapid evolve speed and good stability are used in this study to determine the divergence date among groups.Through calculating the evolutionary rate of hemoglobin α chain,γ ch... Pseudogene and fibrin peptide which has rapid evolve speed and good stability are used in this study to determine the divergence date among groups.Through calculating the evolutionary rate of hemoglobin α chain,γ chain in vertebrate(including birds and mammals),it is concluded that the evolutionary rate of hemoglobin α chain,γ chain is not invariable.It shows different evolutionary rates in different periods,that is,faster in early evolution stage and relatively slow in later stage. 展开更多
关键词 Molecular clock Evolutionary rate HEMOGLOBIN vertebrate Fibrin peptide
下载PDF
Stratigraphy and Geochronology of Vertebrate Fossil-Bearing Jurassic Strata from Linglongta,Jianchang County,Western Liaoning,Northeastern China 被引量:6
10
作者 PENG Nan LIU Yongqing +2 位作者 KUANG Hongwei JIANG Xiaojun XU Huan 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2012年第6期1326-1339,共14页
Northeastern China contains widely distributed Jurassic terrestrial strata that have yielded many spectacular mammal and pterosaur fossils, in addition to feathered dinosaur fossils and more recent discoveries from Ji... Northeastern China contains widely distributed Jurassic terrestrial strata that have yielded many spectacular mammal and pterosaur fossils, in addition to feathered dinosaur fossils and more recent discoveries from Jianchang, particularly from western Liaoning. However, the fossil-bearing stratigraphic succession, regional correlation, and age estimates of the fossils found in Jianchang County and nearby areas have been contentious. Here, we report on the vertebrate fossil-bearing Jurassic stratigraphy from Linglongta, Jianchang County, western Liaoning, including a SHRIMP U-Pb zircon date unambiguously associated with the fossil horizons. The primary goal was to determine the vertebrate fossil-bearing succession. A further aim was to provide age estimations for the fossil-bearing horizon as well as the earliest appearance of feathered dinosaurs, the eutherian-placental clade, and transitional pterosaurs. Field investigations showed that the vertebrate fossil-bearing stratigraphic succession in Jianchang County mainly consists of basal andesites overlain by rhythmic tufts and tuffaceous lacustrine sediments, with the upper intermediate or acidic lavas interbedded with laminated more or less tuffaceous lacustrine deposits. This sequence correlates well with the Middle Jurassic Lanqifl'iaojishan Formation in northeastern China. Detailed and accurate field observations showed that the well- preserved vertebrate fossils were buried in either the middle or the upper fine-grained laminated lacustrine deposits. Previous and current SHRIMP U-Pb zircon dates provide an age estimation of 161- 159 Myr for the fossil-bearing horizon and vertebrates. This indicates that the earliest appearance of feathered dinosaurs here was more than 159 Myr ago and unquestionably older than Archaeopteryx from Germany, making these the earliest known feathered dinosaurs in the world. Furthermore, the eutherian-placental clade and the known transitional pterosaurs first emerged no later than 161 Myr. The vertebrate assemblage unearthed recently from Linglongta and neighboring areas in Jianchang County belongs to the Daohugou Biota. In addition to feathered dinosaurs, this biota was characterized by mammals, primitive pterosaurs, insects, and plants and was present in Inner Mongolia, western Liaoning, and northern Hebei in northeastern China during the Middle-Late Jurassic. 展开更多
关键词 JURASSIC vertebrates STRATIGRAPHY GEOCHRONOLOGY northeastern China
下载PDF
VPPDB:Hosting the Data for Vertebrate Paleontology and Paleoanthropology 被引量:4
11
作者 PAN Zhaohui ZHU Min 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2019年第S01期61-63,共3页
1 Background The big data revolution is changing our lives and providing a fresh understanding of the world.Recently,being aware of the importance of Big Earth Data,the Chinese Academy of Sciences launched a project e... 1 Background The big data revolution is changing our lives and providing a fresh understanding of the world.Recently,being aware of the importance of Big Earth Data,the Chinese Academy of Sciences launched a project entitled"Big Earth Data Science Engineering(CASEarth)"in the Strategic Priority Research Program to carry out innovative research on Big Earth Data(Guo,2017).Under this project。 展开更多
关键词 vertebrates PALEONTOLOGY PALEOANTHROPOLOGY ANCIENT DNA morphology DATABASE
下载PDF
Vertebrated图的Hosoya指数和Merrifield指数
12
作者 李霞丽 任海珍 《东北师大学报(自然科学版)》 CAS CSCD 北大核心 2013年第1期31-34,共4页
Pn表示n个顶点的路,在Pn的每个顶点上都悬挂m条边所得到的图称为Vn(m)图,也称为Vertebrated图,Vn(m)图是一类Gutman树.给出了Vn(m)图的Hosoya指数和Merrifield指数的递推关系及其值,这些结论可用于研究链状六角系统的完美匹配数.
关键词 HOSOYA指数 Merrifield指数 vertebrated图
下载PDF
Functional origins of the vertebrate cerebellum from a sensory processing antecedent 被引量:1
13
作者 John MONTGOMERY David BODZNICK 《Current Zoology》 SCIE CAS CSCD 北大核心 2010年第3期277-284,共8页
The structure of the cerebellar cortex is remarkably similar across vertebrate phylogeny. It is well developed in basaljawed fishes, such as sharks and rays with many of the same cell types and organizational features... The structure of the cerebellar cortex is remarkably similar across vertebrate phylogeny. It is well developed in basaljawed fishes, such as sharks and rays with many of the same cell types and organizational features found in other vertebrategroups, including mammals. In particular, the lattice-like organization of cerebellar cortex (with a molecular layer of parallel fibres,interneurons, spiny Purkinje cell dendrites, and climbing fires) is a common defining characteristic. In addition to the cerebellarcortex, fishes and aquatic amphibians have a variety of cerebellum-like structures in the dorso-lateral wall of the hindbrain.These structures are adjacent to, and in part, contiguous with, the cerebellum. They derive their cerebellum-like name from thepresence of a molecular layer of parallel fibers and inhibitory interneurons, which has striking organizational similarities to themolecular layer of the cerebellar cortex. However, these structures also have characteristics which differ from the cerebellum. Forexample, cerebellum-like structures do not have climbing fibres, and they are clearly sensory. They receive direct afferent inputfrom peripheral sensory receptors and relay their outputs to midbrain sensory areas. As a consequence of this close sensory association,and the ability to characterise their signal processing in a behaviourally relevant context, good progress has been made indetermining the fundamental processing algorithm in cerebellar-like structures. In particular, we have come to understand thecontribution to signal processing made by the molecular layer, which provides an adaptive filter to cancel self-generated noise inelectrosensory and lateral line systems. Given the fundamental similarities of the molecular layer across these structures, coupledwith evidence that cerebellum-like structures may have been the evolutionary antecedent of the cerebellum, we address the question:do both share the same functional algorithm? [Current Zoology 56 (3): 277-284, 2010]. 展开更多
关键词 ORIGIN vertebrate CEREBELLUM
下载PDF
Antarctic Paleontological Heritage:Late Cretaceous–Paleogene vertebrates from Seymour(Marambio)Island,Antarctic Peninsula 被引量:1
14
作者 Marcelo A.REGUERO 《Advances in Polar Science》 CSCD 2019年第3期328-355,共28页
Antarctica has significant environmental,scientific,historic,and intrinsic values,all of which are worth protecting into the future.This continent has a discrete number of places of scientific interest that exhibit gr... Antarctica has significant environmental,scientific,historic,and intrinsic values,all of which are worth protecting into the future.This continent has a discrete number of places of scientific interest that exhibit great potential as natural heritage sites;its geodiversity is of fundamental importance to scientific values of the continent,and the pursuit of geological and paleontological knowledge has had a strong influence on its historical values.Seymour Island was once called the‘Rosetta Stone’of Southern Hemisphere paleobiology,because this small island provides the most complete and richly fossiliferous Late Cretaceous–Paleogene sequence in Antarctica.In particular,fossil vertebrates form part of the evidence used in reconstructing the history of life on Antarctica.Paleontological heritage is considered a subset of geo-heritage that embodies both natural and historical components which has received only indirect recognition.Seymour Island is an outstanding paleontological area with high heritage value of its Late Cretaceous/Paleogene vertebrates and should be considered for geo-conservation and protection.This paper reviews vertebrate fossil occurrences and outcrops on Seymour Island and discusses some threats to these fossil sites. 展开更多
关键词 fossil vertebrates geo-heritage geo-conservation Late Cretaceous-Paleogene Seymour ISLAND ANTARCTICA
下载PDF
Evidence for the independent divergence of vertebrate and high C/G ratio invertebrate mitochondria from the same origin 被引量:1
15
作者 Kenji Sorimachi Teiji Okayasu +2 位作者 Shuji Ohhira Ichio Fukasawa Nobuhide Masawa 《Natural Science》 2012年第7期479-483,共5页
The examination of organelle nucleotide contents across a range of groups can provide insight into evolutionary history. We compared the nucleotide contents of a large number of vertebrate and high C/G ratio invertebr... The examination of organelle nucleotide contents across a range of groups can provide insight into evolutionary history. We compared the nucleotide contents of a large number of vertebrate and high C/G ratio invertebrate mitochondria in both coding/non-coding regions and complete strands. For most nucleotides tested, high regression coefficients were obtained;when plotted with lines of best fit, G and T contents formed a cuneiform, and C and A contents overlapped. These findings suggest that vertebrate and high C/G ratio invertebrate mitochondria descended independently from the same origin. 展开更多
关键词 Evolution GENOME MITOCHONDRIA NUCLEOTIDE Contents vertebrate INvertebrate
下载PDF
New early Eocene vertebrate assemblage from western India reveals a mixed fauna of European and Gondwana affinities 被引量:1
16
作者 Thierry Smith Kishor Kumar +6 位作者 Rajendra S.Rana Annelise Folie Floreal Sole Corentin Noiret Thomas Steeman Ashok Sahni Kenneth D.Rose 《Geoscience Frontiers》 SCIE CAS CSCD 2016年第6期969-1001,共33页
The Ypresian Cambay Shale Formation at Vastan and Mangrol lignite mines in Gujarat, western India, has yielded a rich vertebrate fauna with numerous taxa of European affinities. Here we report a new, approximately con... The Ypresian Cambay Shale Formation at Vastan and Mangrol lignite mines in Gujarat, western India, has yielded a rich vertebrate fauna with numerous taxa of European affinities. Here we report a new, approximately contemporary vertebrate assemblage from two fossiliferous layers in the nearby mine of Tadkeshwar. These layers have yielded a similar mammal fauna with the co-occurrence of the perissodactyl-like cambaytheriid Cambaytherium thewissi, the adapoid primates Marcgodinotius indicus and cf. Asiadapis cambayensis, and the hyaenodontid lndohyaenodon raoi. The presence of these species in both Vastan and Tadkeshwar mines and at different levels suggests that the deposits between the two major lignite seams represent a single land mammal age. Apart from the aforementioned species there is a new, smaller species of Cambaytherium, and a new genus and species of esthonychid tillodont. This fauna also contains the first large early Eocene vertebrates from India, including an unidentified Coryphodon-like pantodont, a dyrosaurid crocodyliform and a new giant madtsoiid snake. Among the Tadkeshwar vertebrates several taxa are of Gondwana affinities, such as Pelomedusoides turtles, dyr- osaurids, and large madtsoiids, attesting that the early Eocene was a crucial period in India during which Laurasian taxa of European affinities co-existed with relict taxa from Gondwana before the India-Asia collision. Our results suggest that terrestrial faunas could have dispersed to or from Europe during episodes of contact between the Indian subcontinent and different island blocks along the northern margin of the Neotethys, such as the Kohistan Ladakh island-arc system. Gondwana taxa might represent remnants of ghost lineages shared with Madagascar, which reached the Indian subcontinent during the late Cretaceous; alternatively they might have come from North Africa and passed along the southern margin of the Neotethys to reach the Indian subcontinent. These dispersals would have been possible as a result of favourable paleogeographic conditions such as the particular Neotethys conformation during the beginning of the early Eocene. 展开更多
关键词 vertebrates Snakes Mammals Primates Cambay Shale Formation Ypresian
下载PDF
A COMPARATIVE RESEARCH OF ZYMOGRAMS OF LACTATE DEHYDROGENASE IN DIFFERENT TISSUES 0F 25 SPECIES OF VERTEBRATES
17
作者 Chen Fengying (1) Zeng Kewen (1) +1 位作者 Pan Shi (1) Yang Mingfei (1) 《Journal of Northeast Forestry University》 SCIE CAS CSCD 1991年第1期56-64,共9页
The distribution and characteristics of LDH isoenzymes in different tissues of 25spe-cies of vertebrats were comparativety analysed by discontinuous polyacrylamide gel diskelectrophoresis,combined with experiments on ... The distribution and characteristics of LDH isoenzymes in different tissues of 25spe-cies of vertebrats were comparativety analysed by discontinuous polyacrylamide gel diskelectrophoresis,combined with experiments on heat and urea inhibition.The result showed that indifferent tissues of Cienopharyngodon idellus,Carassius,ayratus,Trichiurus haumete and Miichihysmiiuy in addition to the distribution of LDH isoenzymes,composed of A and B subuits,a E4isoenzyme band,moving very fast to the positive pole,was detectedin the eye tissue of Trichiurushaumele and a F4 isoenzyme hand,moving very slow to the positive pole,was found in liver andkidney of Cienopharyngodon idellus.The A4 isoenzyme band was found in different tisseues ofPleuronichlhys cornulus,inhabiting on the bottom of the ocean.From the amphition to the mammal,with the exception of Hyta arboreu immaculata,Chinnemys reevesii,Trioyx sinensis,Gallus gallusdomeslicus and Corvus macrorhynchos,which have special electrophoretic behaviours.In 展开更多
关键词 vertebrate POLYACRYLAMIDE GEL DISK elcctrophorcsis LDH isocnzyme Tissue SPECIFICITY
下载PDF
Comparative analysis of mitochondrial fragments transferred to the nucleus in vertebrate
18
作者 Hongying Qu Fei Ma Qingwei Li 《Journal of Genetics and Genomics》 SCIE CAS CSCD 北大核心 2008年第8期485-490,共6页
Mitochondrial DNA sequences transferred to the nucleus give rise to the so-called nuclear mitochondrial DNA (numt). In the GenBank database, 244 numts have been found in six orders of birds (Anseriformes, Columbifo... Mitochondrial DNA sequences transferred to the nucleus give rise to the so-called nuclear mitochondrial DNA (numt). In the GenBank database, 244 numts have been found in six orders of birds (Anseriformes, Columbiformes, Falconiformes, Charadriiformes, Galliformes and Passeriformes). Sequences alignment (NCBI-BLASTN) was carded out with mitochondrial and corresponding nuclear genome sequences in nine vertebrate species. The sequences with high homology were considered as numts. The number of numts ranged from 15 in chicken to 159 in chimpanzee. The sequences of numts in macaque, chimpanzee, and human spanned 100% of the entire mammalian mitochondrial genome. The reconstructed frequency of the mitochondrial gene transferred to the nucleus demonstrated that the rRNA genes had high frequencies than other mitochondrial genes. Using the RepeatMasker program, the transposable elements were detected in the flanking regions of each numt. The results showed that less than 5% of the flanking sequences were made up of repetitive elements in chicken. The GC content of 5'- and 3'-flanking regions of numts in nine species was less than 44%. The analysis of the flanking sequences provided a valuable understanding for future study on mechanism of mitochondrial gene transfer to the nucleus and the site of numt integration. 展开更多
关键词 mitochondrial DNA NUMTS nuclear insertion flanking sequence vertebrate
下载PDF
The role of Islet-1 in cell specification,differentiation,and maintenance of phenotypes in the vertebrate neural retina 被引量:1
19
作者 Gervasio Martín-Partido Javier Francisco-Morcillo 《Neural Regeneration Research》 SCIE CAS CSCD 2015年第12期1951-1952,共2页
Many blinding diseases,such as retinitis pigmentosa,age-related macular degeneration,and glaucoma involve the permanent loss of retinal neurons,especially photoreceptors or the centrally projecting retinal ganglion ce... Many blinding diseases,such as retinitis pigmentosa,age-related macular degeneration,and glaucoma involve the permanent loss of retinal neurons,especially photoreceptors or the centrally projecting retinal ganglion cells.Stem cells have been proposed as a potential source of cells for neuronal transplantation. 展开更多
关键词 CELL RGCS The role of Islet-1 in cell specification differentiation and maintenance of phenotypes in the vertebrate neural retina
下载PDF
The inverted retina and the evolution of vertebrates:an evo-devo perspective 被引量:1
20
作者 Francisco Javier Carreras 《Annals of Eye Science》 2018年第1期121-131,共11页
The inverted retina is a basic characteristic of the vertebrate eye.This implies that vertebrates must have a common ancestor with an inverted retina.Of the two groups of chordates,cephalochordates have an inverted re... The inverted retina is a basic characteristic of the vertebrate eye.This implies that vertebrates must have a common ancestor with an inverted retina.Of the two groups of chordates,cephalochordates have an inverted retina and urochordates a direct retina.Surprisingly,recent genetics studies favor urochordates as the closest ancestor to vertebrates.The evolution of increasingly complex organs such as the eye implies not only tissular but also structural modifications at the organ level.How these configurational modifications give rise to a functional eye at any step is still subject to debate and speculation.Here we propose an orderly sequence of phylogenetic events that closely follows the sequence of developmental eye formation in extant vertebrates.The progressive structural complexity has been clearly recorded during vertebrate development at the period of organogenesis.Matching the chain of increasing eye complexity in Mollusca that leads to the bicameral eye of the octopus and the developmental sequence in vertebrates,we delineate the parallel evolution of the two-chambered eye of vertebrates starting with an early ectodermal eye.This sequence allows for some interesting predictions regarding the eyes of not preserved intermediary species.The clue to understanding the inverted retina of vertebrates and the similarity between the sequence followed by Mollusca and chordates is the notion that the eye in both cases is an ectodermal structure,in contrast to an exclusively(de novo)neuroectodermal origin in the eye of vertebrates.This analysis places cephalochordates as the closest branch to vertebrates contrary to urochordates,claimed as a closer branch by some researchers that base their proposals in a genetic analysis. 展开更多
关键词 Cameral eye ectodermal/neuroectodermal origin direct and inverted retina vertebrate/invertebrate eye EVO-DEVO
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部