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Feather evolution: looking up close and through deep time

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Science Bulletin 2019年第9期64卷 563-564页

作者： xing xu Key Laboratory of Vertebrate Evolution and Human Origins Institute of Vertebrate Paleontology & PaleoanthropologyChinese Academy of Sciences Center for Excellence in Life and Paleoenvironment Chinese Academy of Sciences

The last two decades have witnessed significant advances in our understanding of the evolution of major avian characteristics(1–6)In particular, the spectacular discoveries of fossilized feathered dinosaurs from China and elsewhere have provided key insights into feather evolution (1,2)These fossils indicate that many non-avialan dinosaurs were feathered animals just like living birds.

关键词： looking up close and through deep time

New Construction of Complex Manifold via Conifold Transition

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Acta Mathematica Sinica,English Series 2012年第7期28卷 1347-1368页

作者： Jin xing xu School of Mathematical Sciences Peking University

For a generic anti-canonical hypersurface in each smooth toric Fano 4-fold with rank 2 Picard group, we prove there exist three isolated rational curves in it. Moreover, for all these 4-folds except one, the contractions of generic anti-canonical hypersurfaces along the three rational curves can be deformed to smooth threefolds which is diffeomorphic to connected sums of S3 ~ S~. In this manner, we obtain complex structures with trivial canonical bundles on some connected sums of S^3 × S^3. This construction is an analogue of that made by Friedman [On threefolds with trivial canonical bundle. In： Complex Geometry and Lie Theory, volume 53 of Proc. Sympos. Pure Math., Amer. Math. Soc., Providence, RI, 1991, 103-134], Lu and Tian [Complex structures on connected sums of S^3× S^3. In： Manifolds and Geometry, Pisa, 1993, 284 293] who used only quintics in P^4.

关键词： Calabi Yau threefolds conifold transitions complex structures on connected sums of S^3× S^3

The spatial distribution characteristics of shallow fissures of a landslide in the Wenchuan earthquake area

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Journal of Mountain Science 2016年第9期13卷 1544-1557页

作者： xu xing-qian Key Laboratory of Mountain Hazards and Earth Surface Process Chinese Academy of SciencesChengdu 610041China Institute of Mountain Hazards and Environment Chinese Academy of SciencesChengdu 610041China CAS Center for Excellence in Tibetan Plateau Earth Sciences Beijing 100101China University of Chinese Academy of Sciences Beijing 100049China

Shallow fissures, being the main infiltration paths of fluid on the surface of a slope, played an important role in the whole process of a landslide. However, the spatial distribution characteristics of fissures in the slope are difficult to be determined. In this study, we attempted to characterize the variation pattern of slope fissures along depth in the Wenchuan earthquake area in Sichuan Province by combining engineering geological investigation, geomorphologic analysis and geophysical investigation. The geophysical methods that were used in this study include Multichannel Analysis of Surface Wave(MASW), Ground Penetrating Radar(GPR) and Electrical Resistivity Tomography(ERT). The results suggested that geophysical parameters(shear wave velocity, electromagnetic signals attenuation and resistivity) could provide valuable information for the spatial network of shallow fissures. Through the verification by engineering geological survey and geophysical sensitivity analysis, this work highlighted that MASW was the most appropriate technique to delineate the propagation of shallow fissures in a gravel soil slope.

关键词： Shallow fissures Landslide Wenchuanearthquake Geophysical prospecting

Mutations of N-Methyl-D-Aspartate Receptor Subunits in Epilepsy

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Neuroscience Bulletin 2018年第3期34卷 549-565页

作者： xing-xing xu Jian-Hong Luo Department of Neurobiology Key Laboratory of Medical Neurobiology(Ministry of Health of China) Collaborative Innovation Center for Brain Science Zhejiang University School of Medicine

Epilepsy is one of the most common neurological diseases. Of all cases, 70%–80% are considered to be due to genetic factors. In recent years, a large number of genes have been identified as being involved in *** them, N-methyl-D-aspartate receptor（NMDAR）subunit-encoding genes represent a large proportion, suggesting an important role for NMDARs in epilepsy. In this review, we summarize and analyze the genotypes, functional alterations, and clinical aspects of NMDAR subunit mutations/variants identified from patients with *** data will help to throw light upon the pathogenicity of these NMDAR mutations and advance our understanding of the subtle and complicated role of NMDARs in epilepsy. It will also offer new insights into precision therapy for this disorder.

关键词： Epilepsy NMDA receptors Subunit Mutation

Feathered dinosaurs from China and the evolution of major avian characters

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Integrative Zoology 2006年第1期1卷 4-11页

作者： xing xu Institute of Vertebrate Paleontology and Paleoanthropology Chinese Academy of SciencesBeijingChina

Recent discoveries of feathered dinosaurs from Early Cretaceous deposits in Liaoning,China,have not only lent strongest support for the dinosaurian hypothesis of bird origins,but have also provided much-needed information about the origins of feathers and avian *** analysis of character evolution suggests that the major avian osteological characters were acquired during the early evolution of maniraptoran *** available evidence also suggests that the first feathers with a filamentous morphology probably evolved in basal coelurosaurs and pennaceous feathers(including those with aerodynamic features)were developed in non-avian maniraptorans,indicating that feathers evolved before the origin of birds and their *** evolutionary model is proposed here to describe the major stages of feather evolution,a process characterized by a combination of both transformational and innovative *** model is different from some recent developmental models,which suggest that feathers are evolutionary novelties without a homologous relationship to reptilian *** non-avian theropods are traditionally regarded as distinctly cursorial animals,recent discoveries suggest that the closest relatives of birds might be arboreal *** bird features,such as the furcula and pennaceous feathers,evolved in a terrestrial context,whereas others,such as some pedal modifications,may have evolved in an arboreal ***,arboreality may have also contributed to the origin of avian flight.

关键词： birds feathered dinosaurs feathers flight

Mesenchymal stem cells for retinal diseases

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International Journal of Ophthalmology(English edition) 2011年第4期4卷 413-421页

作者： Wei xu Guo-xing xu Fujian Institute of Ophthalmology the First Affiliated Hospital of Fujian Medical University Fuzhou 350005 Fujian Province China

Retinal diseases are featured with the common result of retinal cell apoptosis that will cause irreversible vision loss. Various attempts have been made for the solution against cell death. However, few approaches turn out to be effective. With the progress in mesenchymal stem cells (MSCs) research, MSCs were considered as a promising source for cell replacement or neuroprotection in retinal disorders. MSCs have the property of self-renewal and are multipotent cells derived from various mesenchymal tissues, which were demonstrated being capable of differentiating into multilineage tissue cells. Some works were also done to differentiate MSCs into retinal cells. MSCs could be induced to express retinal cell markers under certain stimuli. Recent studies also suggest that MSCs should be an ideal source for neuroprotection via the secretion of a variety of neurotrophins. Engineered MSCs were also used as vehicles for continuous delivery of neurotrophins against retinal degeneration with encouraging results. Since there are still barriers on the differentiation of MSCs into functional retinal cells, the use of MSCs for neuroprotection in retinal diseases seems to be a more practicable approach and worthy of further investigations.

关键词： mesenchymal stem cells differentiation neurotrophin retina

An Efficient WRF Framework for Discovering Risk Genes and Abnormal Brain Regions in Parkinson's Disease Based on Imaging Genetics Data

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Journal of Computer Science & Technology 2021年第2期36卷 361-374页

作者： Xia-An Bi Zhao-xu xing Rui-Hui xu Xi Hu College of Information Science and Engineering Hunan Normal UniversityChangsha 410006China Hunan Provincial Key Laboratory of Intelligent Computing and Language Information Processing Hunan Normal UniversityChangsha 410006China

As an emerging research field of brain science,multimodal data fusion analysis has attracted broader attention in the study of complex brain diseases such as Parkinson's disease(PD).However,current studies primarily lie with detecting the association among different modal data and reducing data *** data mining method after fusion and the overall analysis framework are *** this study,we propose a weighted random forest(WRF)model as the feature screening *** interactions between genes and brain regions are detected as input multimodal fusion features by the correlation analysis *** implement sample classification and optimal feature selection based on WRF,and construct a multimodal analysis framework for exploring the pathogenic factors of *** experimental results in Parkinson's Progression Markers Initiative(PPMI)database show that WRF performs better compared with some advanced methods,and the brain regions and genes related to PD are *** fusion of multi-modal data can improve the classification of PD patients and detect the pathogenic factors more comprehensively,which provides a novel perspective for the diagnosis and research of *** also show the great potential of WRF to perform the multimodal data fusion analysis of other brain diseases.

关键词： multimodal fusion feature Parkinson's disease pathogenic factor detection sample classification weighted random forest model

Synthesis and Crystal Structure of K_3[HO{VO(O_2)_2}_2]·H_2O

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Chinese Journal of Structural Chemistry 2004年第11期23卷 1252-1255页

作者： ZHANGHong-Yan HUANGZun-xing GUOHong-xu DepartmentofChemistry FuzhouUniversityFuzhou350002China

The title compound K3[HO{VO(O2)2}2]H2O has been synthesized and its crystal structure was determined by X-ray diffraction method. The crystal is of monoclinic, space group P21/c with a = 6.7078(3), b = 9.9539(6), c = 15.8182(9) ? = 93.702(3), V = 1053.96(10) ?, Mr = 414.20, Dc = 2.610 g/cm3, Z = 4, ?(MoKa) = 0.71073 ? F(000) = 808, = 3.014 mm-1, the final R = 0.0173 and wR = 0.0466 for 2178 observed reflections with I > 2s(I). X-ray diffraction reveals that the coordination polyhedra of V atoms are not chemically equivalent: the V(1) and V(2) polyhedra can be described as pentagonal pyramid and pentagonal bipyramid, respectively.

关键词： peroxovanadate synthesis crystal structure

Pathophysiological mechanisms of chronic compressive spinal cord injury due to vascular events

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Neural Regeneration Research 2023年第4期18卷 790-796页

作者： Zhen-Xiao Ren Jing-Hui xu xing Cheng Gui-xing xu Hou-Qing Long Guangdong Provincial Key Laboratory of Orthopaedics and Traumatology/Department of Spine Surgery The First Affiliated HospitalSun Yat-sen UniversityGuangzhouGuangdong ProvinceChina Department of Neurosurgery The First Affiliated HospitalSun Yat-sen UniversityGuangzhouGuangdong ProvinceChina

Cervical spondylotic myelopathy is the main cause of non-traumatic spinal cord injury,with chronic static and/or dynamic compressive spinal cord injury as the unique *** the progression of this condition,the microvascular network is compressed and destroyed,resulting in ischemia and *** main pathological changes are inflammation,damage to the blood spinal cord barriers,and cell apoptosis at the site of *** have confirmed that vascular regeneration and remodeling contribute to neural repair by promoting blood flow and the reconstruction of effective circulation to meet the nutrient and oxygen requirements for nerve *** decompression is the most effective clinical treatment for this condition;however,in some patients,residual neurological dysfunction remains after *** revascularization during compression and after decompression is therefore complementary to surgical *** this review,we summarize the progress in research on chronic compressive spinal cord injury,covering both physiological and pathological changes after compression and decompression,and the regulatory mechanisms of vascular injury and repair.

关键词： angiogenesis cervical spondylotic myelopathy hypoxia inflammation ischemia spinal cord injury surgical decompression