Cell polarity protein Par3 complexes with DNA-PK via Ku70 and regulates DNA double-strand break repair

The partitioning-defective 3 （Par3）, a key component in the conserved Par3/Par6/aPKC complex, plays fundamental roles in cell polarity. Herein we report the identification of Ku70 and Ku80 as novel Par3-interacting proteins through an in vitro binding assay followed by liquid chromatography-tandem mass spectrometry. Ku70/Ku80 proteins are two key regulatory subunits of the DNA-dependent protein kinase （DNA-PK）, which plays an essential role in repairing double-strand DNA breaks （DSBs）. We determined that the nuclear association of Par3 with Ku70/Ku80 was enhanced by γ-irradiation （IR）, a potent DSB inducer. Furthermore, DNA-PKcs, the catalytic subunit of DNA-PK, interacted with the Par3/Ku70/Ku80 complex in response to IR. Par3 over-expression or knockdown was capable of up- or downregulating DNA-PK activity, respectively. Moreover, the Par3 knockdown cells were found to be defective in random plasmid integration, defective in DSB repair following IR, and radiosensitive, phenotypes similar to that of Ku70 knockdown cells. These findings identify Par3 as a novel component of the DNA-PK complex and implicate an unexpected link of cell polarity to DSB repair.

非线性方程分歧理论中广义Lyapunov-Schmidt过程及应用

本文讨论带有参数的算子方程 f ( x,λ) =0的分歧问题 ,其中 f :X×Λ→ Y,X,Y为 Banach空间 ,Λ =R为参数空间 .利用 A =f′x( x0 ,λ0 )的有界线性广义逆 A+ ,引入广义 Lyapunov-Schmidt过程 ,当 A为 Fredholm算子时 ,这种广义 Lyapunov-Schmidt过程就成为通常的 Lyapunov-Schmidt过程 .本文利用所引进的广义Lyapunov-Schmidt过程 ,证得关于抽象方程 f ( x,λ) =0的一个分歧定理 .

An Action Research of Using Problem-Centered Double-Cycles Instructional Model to Implement ModeI-Elicitng Activity

The purpose of the study was to use the Problem-Centered Double-Cycles Instructional Model （PCDC-IM） （1995, Chang） to help the teacher （Lin） implement model-eliciting activity （MEA） in her mathematics classes. In this study, there were 31 students divided in 10 groups and engaged in the MEA ＂Who saved the oriental cherry trees＂. Data collections included the learning sheets, journals and debriefing forms of students, teaching and reflection journals, observation reports, and field notes of teachers, reflection journals and interview reports of researchers, video tapes and records of the classes and meetings. There were four parts of the teaching cycle in PCDC-IM, namely task, guidance, environment and analysis. We summarized developing and implementing the MEA in ＂Task＂ aspect, 5 principles and 5 kinds of teachers＇ roles in ＂Guidance＂ aspect, 2 elements and 5 features in ＂Environment＂ aspect and data in ＂Analysis＂ aspect. The findings showed that PCDC-IM was helpful for mathematics teachers who want to change their instruction from lecture into modeling teaching.

Controllable synthesis of a self-assembled ultralow Ru,Ni-doped Fe_(2)O_(3) lily as a bifunctional electrocatalyst for large-current-density alkaline seawater electrolysis

Highly efficient and stable bifunctional electrocatalysts that can be used for large-current-density electrolysis of alkaline seawater are highly desirable for carbon-neutral economies,but their facile and controllable synthesis remains a challenge.Here,self-assembled ultralow Ru,Ni-doped Fe_(2)O_(3) with a lily shaped morphology was synthesized on iron foam(RuNi-Fe_(2)O_(3)/IF)via a facile one-step hydrothermal process,in which the intact lily shaped RuNi-Fe_(2)O_(3)/IF was obtained by adjusting the ratio of Ru/Ni.Benefitting from the Ru/Ni chemical substitution,the as-synthesized RuNi-Fe_(2)O_(3)/IF can act as free-standing dual-function electrodes that are applied to electrocatalysis for the hydrogen evolution(HER)and oxygen evolution reactions(OER)in 1.0 mol L^(-1) KOH,requiring an overpotential of 75.0 mV to drive 100 mA cm^(-2) for HER and 329.0 mV for OER.Moreover,the overall water splitting catalyzed by RuNi-Fe_(2)O_(3)/IF only demands ultralow cell voltages of 1.66 and 1.73 V to drive 100 mA cm^(-2) in 1.0 mol L^(-1) KOH and 1.0 mol L^(-1) KOH seawater electrolytes,respectively.The electrodes show remarkable long-term durability,maintaining current densities exceeding 100 mA cm^(-2) for more than 100 h and thus outperforming the two-electrode system composed of noble catalysts.This work provides an efficient,economical method to synthesize self-standing bifunctional electrodes for large-current-density alkaline seawater electrolysis,which is of significant importance for ecological protection and energy exploitation.

Commercial Test of Flexible Dual-Riser Catalytic Cracking Process

The technical features and commercial test results of flexible dual-riserfluidized catalytic cracking (FDFCC) process are presented for refiners to choose an efficientprocess to upgrade FCC naphtha and boost propylene production in a RFCC unit. The commercial testresults indicate that the olefin content of catalyti-cally cracked gasoline can be significantlyreduced to less than 20 v%, while sulfur content reduced by 15%-25% and RON increased by 0.5―2units in a RFCC unit. In addition, propylene yield and the production ratio of diesel to gasolinecan also be remarkably enhanced in the RFCC unit.

Fracture analysis near the interface crack tip for mode Ⅰ of orthotropic bimaterial

The mechanical behaviors near the interface crack tip for mode Ⅰ of orthotropic bimaterial are researched. With the help of the complex function method and the undetermined coefficient method, non-oscillatory field if the singularity exponent is a real number, and oscillatory field if the singularity exponent is a complex number are discussed, respectively. For each case, the stress functions are constructed which contain twelve undetermined coefficients and an unknown singularity exponent. Based on the boundary conditions, the system of non-homogeneous linear equations is obtained. According to the necessary and sufficient condition for the existence of solution for the system of non-homogeneous linear equations, the singularity exponent is determined under appropriate condition using bimaterial parameters. Both the theoretical formulae of stress intensity factors and analytic solutions of stress or displacement field near the interface crack tip are given. When the two orthotropic materials are the same, the classical results for orthotropic single material are deduced.

On the hyperbolicity of flows

Let X be a C1 vector field on a compact boundaryless Riemannian manifold M（dim M≥2）,and A a compact invariant set of X.Suppose that A has a hyperbolic splitting,i.e.,T∧M = Es Eu with Es uniformly contracting and Eu uniformly expanding.We prove that if,in addition,A is chain transitive,then the hyperbolic splitting is continuous,i.e.,A is a hyperbolic set.In general,when A is not necessarily chain transitive,the chain recurrent part is a hyperbolic set.Furthermore,we show that if the whole manifold M admits a hyperbolic splitting,then X has no singularity,and the flow is Anosov.