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THEORETICAL RESULTS ON THE EXISTENCE,REGULARITY AND ASYMPTOTIC STABILITY OF ENHANCED PULLBACK ATTRACTORS:APPLICATIONS TO 3D PRIMITIVE EQUATIONS
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作者 王仁海 郭柏灵 黄代文 《Acta Mathematica Scientia》 SCIE CSCD 2023年第6期2493-2518,共26页
Several new concepts of enhanced pullback attractors for nonautonomous dynamical systems are introduced here by uniformly enhancing the compactness and attraction of the usual pullback attractors over an infinite forw... Several new concepts of enhanced pullback attractors for nonautonomous dynamical systems are introduced here by uniformly enhancing the compactness and attraction of the usual pullback attractors over an infinite forward time-interval under strong and weak topologies.Then we provide some theoretical results for the existence,regularity and asymptotic stability of these enhanced pullback attractors under general theoretical frameworks which can be applied to a large class of PDEs.The existence of these enhanced attractors is harder to obtain than the backward case[33],since it is difficult to uniformly control the long-time pullback behavior of the systems over the forward time-interval.As applications of our theoretical results,we consider the famous 3D primitive equations modelling the large-scale ocean and atmosphere dynamics,and prove the existence,regularity and asymptotic stability of the enhanced pullback attractors in V×V and H^(2)×H^(2) for the time-dependent forces which satisfy some weak conditions. 展开更多
关键词 3D primitive equations pullback attractors REGULARITY FATTENING stability
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ON THE RIGOROUS MATHEMATICAL DERIVATION FOR THE VISCOUS PRIMITIVE EQUATIONS WITH DENSITY STRATIFICATION
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作者 蒲学科 周文利 《Acta Mathematica Scientia》 SCIE CSCD 2023年第3期1081-1104,共24页
In this paper, we rigorously derive the governing equations describing the motion of a stable stratified fluid, from the mathematical point of view. In particular, we prove that the scaled Boussinesq equations strongl... In this paper, we rigorously derive the governing equations describing the motion of a stable stratified fluid, from the mathematical point of view. In particular, we prove that the scaled Boussinesq equations strongly converge to the viscous primitive equations with density stratification as the aspect ratio goes to zero, and the rate of convergence is of the same order as the aspect ratio. Moreover, in order to obtain this convergence result, we also establish the global well-posedness of strong solutions to the viscous primitive equations with density stratification. 展开更多
关键词 Boussinesq equations primitive equations density stratification hydrostatic approximation strong convergence
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Gradient descent decomposition of force-field motor primitives optogenetically elicited for motor mapping of the murine lumbosacral spinal cord
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作者 Paola Salmas Vincent C.K Cheung 《Zoological Research》 SCIE CAS CSCD 2023年第3期604-619,共16页
Generating diverse motor behaviors critical for survival is a challenge that confronts the central nervous system(CNS)of all animals.During movement execution,the CNS performs complex calculations to control a large n... Generating diverse motor behaviors critical for survival is a challenge that confronts the central nervous system(CNS)of all animals.During movement execution,the CNS performs complex calculations to control a large number of neuromusculoskeletal elements.The theory of modular motor control proposes that spinal interneurons are organized in discrete modules that can be linearly combined to generate a variety of behavioral patterns.These modules have been previously represented as stimulus-evoked force fields(FFs)comprising isometric limb-endpoint forces across workspace locations.Here,we ask whether FFs elicited by different stimulations indeed represent the most elementary units of motor control or are themselves the combination of a limited number of even more fundamental motor modules.To probe for potentially more elementary modules,we optogenetically stimulated the lumbosacral spinal cord of intact and spinalized Thy1-ChR2 transgenic mice(n=21),eliciting FFs from as many single stimulation loci as possible(20-70 loci per mouse)at minimally necessary power.We found that the resulting varieties of FFs defied simple categorization with just a few clusters.We used gradient descent to further decompose the FFs into their underlying basic force fields(BFFs),whose linear combination explained FF variability.Across mice,we identified 4-5 BFFs with partially localizable but overlapping representations along the spinal cord.The BFFs were structured and topographically distributed in such a way that a rostral-to-caudal traveling wave of activity across the lumbosacral spinal cord may generate a swing-to-stance gait cycle.These BFFs may represent more rudimentary submodules that can be flexibly merged to produce a library of motor modules for building different motor behaviors. 展开更多
关键词 Motor mapping OPTOGENETICS Spinal cord Motor primitives Traveling wave
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The Exponent Set of Central Symmetric Primitive Matrices
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作者 陈佘喜 胡亚辉 《Northeastern Mathematical Journal》 CSCD 2004年第4期424-434,共11页
This paper first establishes a distance inequality of the associated dia-graph of a central symmetric primitive matrix, then characters the exponent set of central symmetric primitive matrices, and proves that the exp... This paper first establishes a distance inequality of the associated dia-graph of a central symmetric primitive matrix, then characters the exponent set of central symmetric primitive matrices, and proves that the exponent set of central symmetric primitive matrices of order n is {1, 2,…, n - 1}. There is no gap in it. 展开更多
关键词 EXPONENT primitive matrix primitive symmetric diagraph shortest path
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ON THE 3D VISCOUS PRIMITIVE EQUATIONS OF THE LARGE-SCALE ATMOSPHERE 被引量:10
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作者 郭柏灵 黄代文 《Acta Mathematica Scientia》 SCIE CSCD 2009年第4期846-866,共21页
This paper is devoted to considering the three-dimensional viscous primitive equations of the large-scale atmosphere. First, we prove the global well-posedness for the primitive equations with weaker initial data than... This paper is devoted to considering the three-dimensional viscous primitive equations of the large-scale atmosphere. First, we prove the global well-posedness for the primitive equations with weaker initial data than that in [11]. Second, we obtain the existence of smooth solutions to the equations. Moreover, we obtain the compact global attractor in V for the dynamical system generated by the primitive equations of large-scale atmosphere, which improves the result of [11]. 展开更多
关键词 primitive equations Navier-Stokes equations global well-posedness smooth solutions
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Non-Acceleration Theorem in a Primitive Equation System: I. Acceleration of Zonal Mean Flow 被引量:11
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作者 吴国雄 陈彪 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1989年第1期1-20,共20页
Non-acceleration theorem in a primitive equation system is developed to investigate the influences of waves on the mean flow variation against external forcing. Numerical results show that mechanical forcing overwhelm... Non-acceleration theorem in a primitive equation system is developed to investigate the influences of waves on the mean flow variation against external forcing. Numerical results show that mechanical forcing overwhelms thermal forcing in maintaining the mean flow in which the internal mechanical forcing associated with horizontal eddy flux of momentum plays the most important roles. Both internal forcing and external forcing are shown to be active and at the first place for the mean flow variations, whereas the forcing-induced mean meridional circulation is passive and secondary. It is also shown that the effects on mean flow of external mechanical forcing are concentrated in the lower troposphere, whereas those due to wave-mean flow interaction are more important in the upper troposphere. These act together and result in the vertically easterly shear in low latitudes and westerly shear in mid-latitudes. This vertical shear of mean flow is to some extent weakened by thermal forcing. 展开更多
关键词 Non-Acceleration Theorem in a primitive Equation System Acceleration of Zonal Mean Flow Mean
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Peripheral primitive neuroectodermal tumor of the kidney presenting with pulmonary tumor embolism: A case report 被引量:7
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作者 Sathya Chinnaa Chandan J Das +4 位作者 Sanjay Sharma Prabhjot Singh Amlesh Seth Suvendu Purkait Sandeep R Mathur 《World Journal of Radiology》 CAS 2014年第10期846-849,共4页
Peripheral primitive neuroectodermal tumor(PNET) of the kidney is a rare, aggressive tumor known for its recurrence and metastatic potential. Despite the frequency of venous extension to the renal veins and inferior v... Peripheral primitive neuroectodermal tumor(PNET) of the kidney is a rare, aggressive tumor known for its recurrence and metastatic potential. Despite the frequency of venous extension to the renal veins and inferior vena cava, pulmonary tumor embolism at the initial presentation is not common. We report a case of 22-year-old female with PNET of the kidney who presented with tumor embolism in the inferior vena cava(IVC) and bilateral pulmonary artery. The patient underwent surgical resection and histopathological analysis confirmed the presence of tumor within the IVC and pulmonary arteries. The patient received adjuvant chemotherapy and is currently doing well on follow-up. 展开更多
关键词 primitive neuroectodermal TUMOR PULMONARY TUMOR EMBOLISM COMPUTED tomography
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Huge peripheral primitive neuroectodermal tumor of the small bowel mesentery at nonage:A case report and review of the literature 被引量:2
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作者 Zhe Liu Yuan-Hong Xu +3 位作者 Chun-Lin Ge Jin Long Rui-Xia Du Ke-Jian Guo 《World Journal of Clinical Cases》 SCIE 2016年第9期306-309,共4页
Extraskeletal Ewing's sarcoma/peripheral primitive neuroectodermal tumor(E-EWS/pP NET) is a rare aggressive malignant small round cell tumor. In this report, we present the case of a 15-year-old boy who suffered f... Extraskeletal Ewing's sarcoma/peripheral primitive neuroectodermal tumor(E-EWS/pP NET) is a rare aggressive malignant small round cell tumor. In this report, we present the case of a 15-year-old boy who suffered from acute abdominal pain accompanied by hematemesis and melena, and was eventually diagnosed with E-EWS/p PNET. To date, there have been only five reported cases of E-EWS/pP NET of the small bowel including the patient in this report. To the best of our knowledge, this is the first documentation of a pP NET of the small bowel mesentery at nonage. All these have made this report rare and significant. 展开更多
关键词 EXTRASKELETAL Ewing’s SARCOMA Peripheral primitive neuroectodermal tumor Nonage Small BOWEL MESENTERY Spontaneous rupture
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A primitive mantle source for the Neoarchean mafic rocks from the Tanzania Craton 被引量:7
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作者 Y.A.Cook I.V.Sanislav +2 位作者 J.Hammerli T.G.Blenkinsop P.H.G.M.Dirks 《Geoscience Frontiers》 SCIE CAS CSCD 2016年第6期911-926,共16页
Mafic rocks comprising tholeiitic pillow basalt, dolerite and minor gabbro form the basal stratigraphic unit in the ca. 2.8 to 2.6 Ga Geita Greenstone Belt situated in the NW Tanzania Craton. They outcrop mainly along... Mafic rocks comprising tholeiitic pillow basalt, dolerite and minor gabbro form the basal stratigraphic unit in the ca. 2.8 to 2.6 Ga Geita Greenstone Belt situated in the NW Tanzania Craton. They outcrop mainly along the southern margin of the belt, and are at least 50 million years older than the supracrustal assemblages against which they have been juxtaposed. Geochemical analyses indicate that parts of the assemblage approach high Mg-tholeiite (more than 8 wt.% MgO). This suite of samples has a restricted compositional range suggesting derivation from a chemically homogenous reservoir. Trace element modeling suggests that the mafic rocks were derived by partial melting within the spinel peridotite field from a source rock with a primitive mantle composition. That is, trace elements maintain primitive mantle ratios (Zr/Hf = 32-35, Ti/Zr - 107-147), producing flat REE and HFSE profles [(La/Yb)pm = 0.9 -1.3], with abundances of 3-10 times primitive mantle and with minor negative anomalies of Nb [(Nb/ La)pm - 0.6-0.8] and Th [(Th/La)pm = 0.6-0.9]. Initial isotope compositions (εNd) range from 1.6 to 2.9 at 2.8 Ga and plot below the depleted mantle line suggesting derivation from a more enriched source compared to present day MORB mantle. The trace element composition and Nd isotopic ratios are similar to the mafic rocks outcropping -50 km south. The mafic rocks outcropping in the Geita area were erupted through oceanic crust over a short time period, between -2830 and-2820 Ma; are compositionally homogenous, contain little to no associated terrigenous sediments, and their trace element composition and short emplacement time resemble oceanic plateau basalts. They have been interpreted to be derived from a plume head with a primitive mantle composition. 展开更多
关键词 Mafic rocks Archean Tanzania Craton primitive mantle MORB Oceanic plateau
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Genomic Instability in Cancer I: DNA-Repair Triggering Primitive Hereditary 4n-Skewed, Amitotic Division-System, the Culprit in EMT/MET/Metaplasia Cancer-Concepts 被引量:3
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作者 Kirsten H. Walen 《Journal of Cancer Therapy》 2018年第12期974-997,共24页
The objective was to gain proof of genome damage-repair induced mitotic slippage process (MSP) to 4n-diplochromosome skewed division-system, earlier suggested to have “cancer-deciding” consequences. Our damage-model... The objective was to gain proof of genome damage-repair induced mitotic slippage process (MSP) to 4n-diplochromosome skewed division-system, earlier suggested to have “cancer-deciding” consequences. Our damage-model showed two succeeding phases: molecular mutations for initiation of fitness-gained cells, and large chromosomal changes to aneuploidy from inherited DNA-breakage-repair inaccuracies. The mutations were gained while DNA-repair and DNA-replication, co-existed in the route to tetraploidy, a phenomenon also expressed for some existing unicellular organisms. These organisms also showed genome reductive, amitotic, meioticlike division, and was the origin of human genome conserved, self-inflicted 90° reorientation of the 4n nucleus relative to the cytoskeleton axis. In the in vitro DNA-damage model, this remarkable 4n-event deciding “flat-upright” cell-growth characteristics showed several consequences, for example, cancer-important, E-cadherin-β-catenin cell-to-cell adherence destruction, which gave diploid progeny cells, mobility freedom from cell contact inhibition, likely in renewal tissues. This 4n-skewed division-system with inheritance in progeny cells for repeat occurrences as mentioned for flat-up-right growth patterns is similar to claimed concepts of metaplasia-EMT/MET embryogenesis events in cancer evolution. A scrutiny of this literature, proof-wise invalidated this embryological concept by tetraploid 8C cells occurring in MET events and, was noted for small cell occurrence, i.e., diploidy from 4n-8C reductive division, an also event for tumor relapse cells, derived from genome damaging therapy agents. Pre-cancer hyperplasia reported MSP, cadherincatenin destruction and 90° perpendicularity to basal cell membrane. The DNA-damage-repair model can weed-out therapy-agents triggering 4n-skewed division. Cancer-control, beginning-information, is likely from mutational identity of the 4n derived fitness-gained cells. 展开更多
关键词 CANCER Evolution DNA-Damage-Repair Mitotic Slippage HEREDITARY primitive Tetraploidy 90° Amitotic Skewed DIVISION Fitness-Gain Embryogenesis-Type EMT/MET Human Cell Conservation
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Evolution from Primitive Life to Homo sapiens Based on Visible Genome Structures: The Amino Acid World 被引量:3
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作者 Kenji Sorimachi 《Natural Science》 2009年第2期107-119,共13页
It is not too much to say that molecular biology, including genome research, has progressed based on the determination of nucleotide or amino acid sequences. However, these ap-proaches are limited to the analysis of r... It is not too much to say that molecular biology, including genome research, has progressed based on the determination of nucleotide or amino acid sequences. However, these ap-proaches are limited to the analysis of relatively small numbers of the same genes among spe-cies. On the other hand, by graphical presenta-tion of the ratios of the numbers of amino acids present to the total numbers of amino acids presumed from the target gene(s) or genome or those of the numbers of nucleotides present to the total numbers of nucleotides calculated from the target gene(s) or genome, we can readily draw conclusions from extraordinarily huge data sets integrated by human intelli-gence. 1) Assuming polymerization of amino acids or nucleotides in a simulation analysis based on a random choice, proteins were formed by simple amino acid polymerization, while nucleotide polymerization to form nucleic acids encoding specific proteins needed certain specific control. These results proposed that protein formation chronologically preceded codon formation during the establishment of primitive life forms. In the prebiotic phase, amino acid composition was a dominant factor that determined protein characteristics;the “Amino Acid World”. 2) The genome is constructed homogeneou- sly from putative small units displaying similar codon usages and coding for similar amino acid compositions;the unit is a gene assembly en-coding 3,000 - 7,000 amino acid residues and this unit size is independent not only of genome size, but also of species. 3) In codon evolution, all nucleotide alterna-tions are correlated, not only in coding regions, but also in non-coding regions;the correlations can be expressed by linear formulas;y = ax + b, where “y” and “x” represent nucleotide con-tents, and “a” and “b” are constant. 4) The basic pattern of cellular amino acid compositions obtained from whole cell lysates is conserved from bacteria to Homo sapiens, and resembles that calculated from complete genomes. This basic pattern is characterized by a “star-shape” that changes slightly among species, and changes in amino acid composi-tion seem to reflect biological evolution. 5) Organisms can essentially be classified according to two codon patterns. Biological evolution due to nucleotide sub-stitutions can be expressed by simple linear formulas based on mathematical principles, while natural selection must affect species pre- servation after nucleotide alternations. There-fore, although Darwin’s natural selection is not directly involved in nucleotide alternations, it contributes obviously to the selection of nu-cleotide alternations. Thus, Darwin’s natural selection is doubtless an important factor in biological evolution. 展开更多
关键词 EVOLUTION primitive LIFE Form Genome NUCLEOTIDE Content Chargaff’s PARITY Rules CODON Amino Acids Linear Formula Classification
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Long-term survival of a patient with a large adrenal primitive neuroectodermal tumor: A case report 被引量:1
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作者 Jun Dai Hong-Chao He +3 位作者 Xin Huang Fu-Kang Sun Yu Zhu Dan-Feng Xu 《World Journal of Clinical Cases》 SCIE 2019年第3期340-346,共7页
BACKGROUND Adrenal primitive neuroectodermal tumor(PNET) is an extremely rare malignant tumor with poor prognosis and of neural crest origin. Herein, we report a case of adrenal PNET and summarized its clinical and pa... BACKGROUND Adrenal primitive neuroectodermal tumor(PNET) is an extremely rare malignant tumor with poor prognosis and of neural crest origin. Herein, we report a case of adrenal PNET and summarized its clinical and pathological characteristics on the basis of 16 patients reported recently.CASE SUMMARY A female patient aged 25 years presented with right lumbago for 12 mo, and preoperative computed tomography showed a huge right adrenal mass. She received tumorectomy, and post-operative pathological examination showed adrenal PNET. After surgery, she underwent adjuvant chemotherapy and was followed up 31 mo after surgery. She received brachytherapy for right paracolic and hepatic metastases. She was alive and followed up for 60 mo. In available studies, only 57.14%(4/7) and 44.44%(4/9) were positive for the expression of neuron-specific enolase and synaptophysin, respectively, although CD99 expression was found in all the patients(100%; 10/10).CONCLUSION It is concluded that adrenal PNET is very rare and highly malignant, and histology is a golden standard in its diagnosis. Surgery and adjuvant therapy is the main treatment. 展开更多
关键词 primitive neuroectodermal TUMOR ADRENAL GLAND Case REPORT
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Coordinating control of multiple rigid bodies based on motion primitives 被引量:1
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作者 Fan Wu Zhi-Yong Geng 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2012年第2期482-489,共8页
This paper studies the problem of coordinated motion generation for a group of rigid bodies. Two classes of coordinated motion primitives, relative equilibria and ma- neuvers, are given as building blocks for generati... This paper studies the problem of coordinated motion generation for a group of rigid bodies. Two classes of coordinated motion primitives, relative equilibria and ma- neuvers, are given as building blocks for generating coordi- nated motions. In a motion-primitive based planning frame- work, a control method is proposed for the robust execution of a coordinated motion plan in the presence of perturba- tions. The control method combines the relative equilibria stabilization with maneuver design, and results in a close- loop motion planning framework. The performance of the control method has been illustrated through a numerical sim- ulation. 展开更多
关键词 Coordinating control Motion plan execution Motion primitive. Relative equilibrium. Maneuver
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Extraction of Robot Primitive Control Rules from Natural Language Instructions 被引量:1
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作者 Guang-Hong Wang Ping Jiang Zu-Ren Feng 《International Journal of Automation and computing》 EI 2006年第3期282-290,共9页
A support vector rule based method is investigated for the construction of motion controllers via natural language training. It is a two-phase process including motion control information collection from natural langu... A support vector rule based method is investigated for the construction of motion controllers via natural language training. It is a two-phase process including motion control information collection from natural language instructions, and motion information condensation with the aid of support vector machine (SVM) theory. Self-organizing fuzzy neural networks are utilized for the collection of control rules, from which support vector rules are extracted to form a final controller to achieve any given control accuracy. In this way, the number of control rules is reduced, and the structure of the controller tidied, making a controller constructed using natural language training more appropriate in practice, and providing a fundamental rule base for high-level robot behavior control. Simulations and experiments on a wheeled robot are carried out to illustrate the effectiveness of the method. 展开更多
关键词 Support vector machines (SVMs) fuzzy neural networks motion primitives motion controller language instruction based training natural language programming.
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The Conflicts Between Primitiveness and Civilization:an Analysis of Heart of Darkness
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作者 白雪 《海外英语》 2011年第6X期231-232,236,共3页
Heart of Darkness, a chilling tale of horror set in the Congo during the period of rapid colonial expansion in the 19th century written by the renowned British novelist Joseph Conrad, is a world famous novella. Since ... Heart of Darkness, a chilling tale of horror set in the Congo during the period of rapid colonial expansion in the 19th century written by the renowned British novelist Joseph Conrad, is a world famous novella. Since its publication, it remains an indisputably classic text and arguably Conrad's finest work. And it has been regarded as a significant text in British literature because of its modernistic features, innovative narration and artistic style. Heart of Darkness deals with the highly disturbing effects of economic, social and political exploitation of European and African societies. It has inspired filmmakers and such authors as F. Scott Fitzgerald, Gabriel Garica Marquez, D. H. Lawrence and Virginia,Woolf. This article is aimed to analyse it from the perspective of primitiveness and civilization. Through the analysis, readers can sense Conrad's attitude towards the two aspects. 展开更多
关键词 HEART of DARKNESS AFRICA EUROPE primitiveness CIVILIZATION
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Primitive neuroectodermal tumors of the abdominal wall and vulva in children: Report of two cases and review of the literature
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作者 Qiong-Qian Xu Wen-Wen Xing +5 位作者 Gang Chen Yi-Wu Dang Yi-Ge Luo Peng Chen Song-Wu Liang Jia-Bo Chen 《World Journal of Clinical Cases》 SCIE 2019年第21期3671-3682,共12页
BACKGROUND Primitive neuroectodermal tumors are rare,highly malignant small round cell tumors belonging to the Ewing sarcoma family.The purpose of this article is to present clinical manifestation,histology,treatment,... BACKGROUND Primitive neuroectodermal tumors are rare,highly malignant small round cell tumors belonging to the Ewing sarcoma family.The purpose of this article is to present clinical manifestation,histology,treatment,and prognosis of two primitive neuroectodermal tumors(PNETs)in extremely rare anatomic locations,the abdominal wall and vulva.CASE SUMMARY Case 1 was a 66-month-old girl with lesions on the abdominal wall;tumor size was about 3.4 cm×6.1 cm×2 cm.The patient underwent radical resection of the tumor.After the operation,an alternating vincristine,doxorubicin,and cyclophosphamide/ifosfamide and etoposide(IE)regimen was given for eight cycles,and the patient survived for 66 mo without progression.Case 2 was a 40-month-old girl,with a vulvar lesion;tumor size was about 3.3 cm×5 cm×2.5 cm.The tumor was partially resected by surgery.The family left treatment after two cycles of vincristine,pirarubicin,and cyclophosphamide/IE chemotherapy,and the patient died at home six months after surgery.CONCLUSION PNET is a rare,fast-growing,highly malignant tumor that requires histologic and molecular analyses for exact diagnosis,and multimodal treatment is required to achieve a good prognosis. 展开更多
关键词 primitive neuroectodermal TUMOR Therapy PROGNOSIS Case REPORT
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AN INTEGRATION METHOD WITH FITTING CUBIC SPLINE FUNCTIONS TO A NUMERICAL MODEL OF 2ND-ORDER SPACE-TIME DIFFERENTIAL REMAINDER——FOR AN IDEAL GLOBAL SIMULATION CASE WITH PRIMITIVE ATMOSPHERIC EQUATIONS
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作者 辜旭赞 张兵 王明欢 《Journal of Tropical Meteorology》 SCIE 2013年第4期388-396,共9页
In this paper,the forecasting equations of a 2nd-order space-time differential remainder are deduced from the Navier-Stokes primitive equations and Eulerian operator by Taylor-series expansion.Here we introduce a cubi... In this paper,the forecasting equations of a 2nd-order space-time differential remainder are deduced from the Navier-Stokes primitive equations and Eulerian operator by Taylor-series expansion.Here we introduce a cubic spline numerical model(Spline Model for short),which is with a quasi-Lagrangian time-split integration scheme of fitting cubic spline/bicubic surface to all physical variable fields in the atmospheric equations on spherical discrete latitude-longitude mesh.A new algorithm of"fitting cubic spline—time step integration—fitting cubic spline—……"is developed to determine their first-and2nd-order derivatives and their upstream points for time discrete integral to the governing equations in Spline Model.And the cubic spline function and its mathematical polarities are also discussed to understand the Spline Model’s mathematical foundation of numerical analysis.It is pointed out that the Spline Model has mathematical laws of"convergence"of the cubic spline functions contracting to the original functions as well as its 1st-order and 2nd-order derivatives.The"optimality"of the 2nd-order derivative of the cubic spline functions is optimal approximation to that of the original functions.In addition,a Hermite bicubic patch is equivalent to operate on a grid for a 2nd-order derivative variable field.Besides,the slopes and curvatures of a central difference are identified respectively,with a smoothing coefficient of 1/3,three-point smoothing of that of a cubic spline.Then the slopes and curvatures of a central difference are calculated from the smoothing coefficient 1/3 and three-point smoothing of that of a cubic spline,respectively.Furthermore,a global simulation case of adiabatic,non-frictional and"incompressible"model atmosphere is shown with the quasi-Lagrangian time integration by using a global Spline Model,whose initial condition comes from the NCEP reanalysis data,along with quasi-uniform latitude-longitude grids and the so-called"shallow atmosphere"Navier-Stokes primitive equations in the spherical coordinates.The Spline Model,which adopted the Navier-Stokes primitive equations and quasi-Lagrangian time-split integration scheme,provides an initial ideal case of global atmospheric circulation.In addition,considering the essentially non-linear atmospheric motions,the Spline Model could judge reasonably well simple points of any smoothed variable field according to its fitting spline curvatures that must conform to its physical interpretation. 展开更多
关键词 NUMERICAL forecast and NUMERICAL SIMULATION 2nd-order SPACE-TIME differential REMAINDER NUMERICAL model cubic spline functions Navier-Stokes primitive EQUATIONS quasi-Lagrangian time-split integration scheme global SIMULATION case
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From Civilization to Primitiveness——On Social Darwinism in Jack London’s The Call of the Wild
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作者 林芊芊 《海外英语》 2019年第22期236-237,254,共3页
The Call of the Wild by Jack London depicts the protagonist Buck’s transition,i.e.from a dog to a wolf,as well as those victims eliminated in the selecting of nature.All of these reflect the perpetual theme in this n... The Call of the Wild by Jack London depicts the protagonist Buck’s transition,i.e.from a dog to a wolf,as well as those victims eliminated in the selecting of nature.All of these reflect the perpetual theme in this novel—social Darwinism which advo⁃cates“survival of the fittest”. 展开更多
关键词 Social Darwinism The Call of the Wild CIVILIZATION primitiveNESS
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MRI Features of Intracranial Primitive Neuroectodermal Tumors in Adults:Comparing with Histopathological Findings
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作者 石浩军 孔祥泉 +2 位作者 徐海波 徐丽莹 刘定西 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2004年第1期99-102,共4页
The MRI appearances of 7 adult patients with pathologically proven intracranial primitive neuroectodermal tumors (PNET) were retrospectively analyzed. The MRI features were compared with findings in pathology and surg... The MRI appearances of 7 adult patients with pathologically proven intracranial primitive neuroectodermal tumors (PNET) were retrospectively analyzed. The MRI features were compared with findings in pathology and surgery. In this group, the tumor masses were most commonly found in the semisphere of cerebrum and in the vermis of cerebellum. They were relatively large and 4 were in lobulated shape. All of them had well defined margins. MR images showed the tumors to be mildly or obviously hypointense on T 1 weighted images and hyperintense on T 2 weighted images. Most masses had heterogeneous appearances with some cystic and necrotic areas. Intratumoral haemorrhage and focal calcification were occasionally seen. Mostly, there was no or only mild surrounding edema. Marked inhomogeneous contrast enhancement on MRI was seen in 6 cases except one. Two patients with multiple intracranial metastases were revealed on MR images. In this series, there was good correlation between MRI features and findings in pathology and surgery. These results showed that certain MRI features might suggest the diagnosis of intracranial PNET in adults. MRI is an effective technique to detect these tumors and is helpful to treatment planning and follow up. 展开更多
关键词 neuroectodermal tumors primitive brain neoplasms ADULTS magnetic resonance imaging PATHOLOGY
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Primitive Neuroectodermal Tumor as the Second Malignant Neoplasm in a Long-Term Survivor Child of Acute Lymphoblastic Leukemia: A Case Report
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作者 Aoli Zhang Xiaojuan Chen +1 位作者 Zhanqi Li Xiaofan Zhu 《Chinese Medical Sciences Journal》 CAS CSCD 2020年第2期186-190,共5页
Acute lymphoblastic leukemia(ALL)is a common pediatric cancer.The second malignant neoplasms(SMNs)in long-term survivors of pediatric ALL are relatively rare.Herein we report a 10-year-old girl who was diagnosed as pr... Acute lymphoblastic leukemia(ALL)is a common pediatric cancer.The second malignant neoplasms(SMNs)in long-term survivors of pediatric ALL are relatively rare.Herein we report a 10-year-old girl who was diagnosed as primitive neuroectodermal tumor(PNET)5 years after the initial diagnosis of ALL with radiotherapy・free treatment.PNET is an exceedingly rare neoplasm in SMNs of survivors of childhood ALL.It is predisposed to be misdiagnosed and the pathogenesis is unclear.The outcome is poor.Long-term follow-up is necessary for the survival children of ALL. 展开更多
关键词 primitive neuroectodermal tumor second malignant neoplasms CHILDHOOD acute lymphoblastic leukemia
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