In this paper, we investigate the complex dynamics of two-species Ricker-type discrete-time competitive model. We perform a local stability analysis for the fixed points and we will discuss about its persistence for b...In this paper, we investigate the complex dynamics of two-species Ricker-type discrete-time competitive model. We perform a local stability analysis for the fixed points and we will discuss about its persistence for boundary fixed points. This system inherits the dynamics of one-dimensional Ricker model such as cascade of period-doubling bifurcation, periodic windows and chaos. We explore the existence of chaos for the equilibrium points for a specific case of this system using Marotto theorem and proving the existence of snap-back repeller. We use several dynamical systems tools to demonstrate the qualitative behaviors of the system.展开更多
The snap fit is a common mechanical mechanism.We have studied the spherical snap fit carefully for its physical asymmetry,which is easy to assemble but difficult to disassemble.Because of the complexity of spherical s...The snap fit is a common mechanical mechanism.We have studied the spherical snap fit carefully for its physical asymmetry,which is easy to assemble but difficult to disassemble.Because of the complexity of spherical snap fit,it is difficult to get a theoretical formula to describe its physical asymmetry.In this paper,the pushing assembly and pulling disassembly of spherical snap fit are studied by both finite element analysis and experiments.The theoretical formulaes of spherical snap fit have been obtained based on numerical simulations and theoretical results of cylindrical snap fit.展开更多
BACKGROUND Snapping triceps syndrome(STS)is a rare disease,while occurrence of bilateral STS is extremely rare.It is usually accompanied by dislocation of the ulnar nerve and double snapping is a clinically important ...BACKGROUND Snapping triceps syndrome(STS)is a rare disease,while occurrence of bilateral STS is extremely rare.It is usually accompanied by dislocation of the ulnar nerve and double snapping is a clinically important feature.However,to the best of our knowledge,there has been no report of bilateral STS in young active patient.CASE SUMMARY A 23-year-old male presented with a complaint of discomfort and snapping on the medial side of both elbows while performing push-ups.On physical examination,two distinct snaps that were both palpable and audible were detected on additional clinical examination.Dynamic ultrasonography showed that the ulnar nerve and the medial head of the triceps were dislocated anteriorly over the medial epicondyle of the elbow during flexion motion.Finally,he was diagnosed as dislocation of the ulnar nerve and STS.Staged anterior subcutaneous transposition of the ulnar nerve combined with partial resection of the snapping portion of the triceps was performed.The patient’s pain and snapping symptoms were resolved immediately after surgery.Three months later,the patient was completely asymptomatic and returned to normal activity.CONCLUSION STS should be included in the differential diagnosis for active young patients who present with painful snapping on the medial side of the elbow joint,particularly when dislocation of the ulnar nerve is detected.Dynamic sonography is used to assist in accurate diagnosis and differentiation between isolated dislocation of the ulnar nerve and STS.展开更多
目的·探讨中国汉族人群突触小体相关蛋白(synaptosomal-associated protein of 25000,SNAP25)基因与精神分裂症(schizophrenia,SZ)的相关性。方法·采用TaqMan探针基因分型技术对434例SZ患者(病例组)和432例健康对照(对照组)的...目的·探讨中国汉族人群突触小体相关蛋白(synaptosomal-associated protein of 25000,SNAP25)基因与精神分裂症(schizophrenia,SZ)的相关性。方法·采用TaqMan探针基因分型技术对434例SZ患者(病例组)和432例健康对照(对照组)的SNAP25基因5个单核苷酸多态性(single nucleotide polymorphism,SNP)位点(rs3746544、rs8636、rs362998、rs6039769、rs6077690)进行分型,比较病例组与对照组间的等位基因、基因型,不同遗传模式下基因型以及单倍型频率分布的差异。结果·rs362998和rs6039769等位基因频率分布在病例组与对照组之间差异有统计学意义(P=0.029,P=0.033),经Bonferroni校正后,差异均无统计学意义(均P>0.05);病例组与对照组间rs362998和rs3746544基因型分布的差异具有统计学意义(P=0.005,P=0.043),校正后rs362998差异仍有统计学意义(P=0.025),rs3746544差异无统计学意义(P>0.05)。rs362998位点在共显性和显性遗传模式下,基因型分布组间比较,差异有统计学意义(均P=0.003),校正后差异仍有统计学意义(均P=0.015);rs3746544位点在共显性和隐性遗传模式下,基因型分布组间比较,差异有统计学意义(P=0.042,P=0.012),校正后差异无统计学意义(均P>0.05)。由rs3746544-rs8636组成的所有单倍型在病例组与对照组间的频率分布差异均未见统计学意义(均P>0.05)。结论·在中国汉族人群中,SNAP25可能是SZ的易感基因,rs362998位点可能与SZ发病有关。展开更多
文摘In this paper, we investigate the complex dynamics of two-species Ricker-type discrete-time competitive model. We perform a local stability analysis for the fixed points and we will discuss about its persistence for boundary fixed points. This system inherits the dynamics of one-dimensional Ricker model such as cascade of period-doubling bifurcation, periodic windows and chaos. We explore the existence of chaos for the equilibrium points for a specific case of this system using Marotto theorem and proving the existence of snap-back repeller. We use several dynamical systems tools to demonstrate the qualitative behaviors of the system.
基金the financial support from Xi’an University of Architecture and Technology(Project No.002/2040221134)。
文摘The snap fit is a common mechanical mechanism.We have studied the spherical snap fit carefully for its physical asymmetry,which is easy to assemble but difficult to disassemble.Because of the complexity of spherical snap fit,it is difficult to get a theoretical formula to describe its physical asymmetry.In this paper,the pushing assembly and pulling disassembly of spherical snap fit are studied by both finite element analysis and experiments.The theoretical formulaes of spherical snap fit have been obtained based on numerical simulations and theoretical results of cylindrical snap fit.
文摘BACKGROUND Snapping triceps syndrome(STS)is a rare disease,while occurrence of bilateral STS is extremely rare.It is usually accompanied by dislocation of the ulnar nerve and double snapping is a clinically important feature.However,to the best of our knowledge,there has been no report of bilateral STS in young active patient.CASE SUMMARY A 23-year-old male presented with a complaint of discomfort and snapping on the medial side of both elbows while performing push-ups.On physical examination,two distinct snaps that were both palpable and audible were detected on additional clinical examination.Dynamic ultrasonography showed that the ulnar nerve and the medial head of the triceps were dislocated anteriorly over the medial epicondyle of the elbow during flexion motion.Finally,he was diagnosed as dislocation of the ulnar nerve and STS.Staged anterior subcutaneous transposition of the ulnar nerve combined with partial resection of the snapping portion of the triceps was performed.The patient’s pain and snapping symptoms were resolved immediately after surgery.Three months later,the patient was completely asymptomatic and returned to normal activity.CONCLUSION STS should be included in the differential diagnosis for active young patients who present with painful snapping on the medial side of the elbow joint,particularly when dislocation of the ulnar nerve is detected.Dynamic sonography is used to assist in accurate diagnosis and differentiation between isolated dislocation of the ulnar nerve and STS.
文摘目的·探讨中国汉族人群突触小体相关蛋白(synaptosomal-associated protein of 25000,SNAP25)基因与精神分裂症(schizophrenia,SZ)的相关性。方法·采用TaqMan探针基因分型技术对434例SZ患者(病例组)和432例健康对照(对照组)的SNAP25基因5个单核苷酸多态性(single nucleotide polymorphism,SNP)位点(rs3746544、rs8636、rs362998、rs6039769、rs6077690)进行分型,比较病例组与对照组间的等位基因、基因型,不同遗传模式下基因型以及单倍型频率分布的差异。结果·rs362998和rs6039769等位基因频率分布在病例组与对照组之间差异有统计学意义(P=0.029,P=0.033),经Bonferroni校正后,差异均无统计学意义(均P>0.05);病例组与对照组间rs362998和rs3746544基因型分布的差异具有统计学意义(P=0.005,P=0.043),校正后rs362998差异仍有统计学意义(P=0.025),rs3746544差异无统计学意义(P>0.05)。rs362998位点在共显性和显性遗传模式下,基因型分布组间比较,差异有统计学意义(均P=0.003),校正后差异仍有统计学意义(均P=0.015);rs3746544位点在共显性和隐性遗传模式下,基因型分布组间比较,差异有统计学意义(P=0.042,P=0.012),校正后差异无统计学意义(均P>0.05)。由rs3746544-rs8636组成的所有单倍型在病例组与对照组间的频率分布差异均未见统计学意义(均P>0.05)。结论·在中国汉族人群中,SNAP25可能是SZ的易感基因,rs362998位点可能与SZ发病有关。
