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The Russia government is paying more attention to domestic problems and is also trying to become the leader among neighboring countries and to reestablish its supremacy in Central and Eastern Europe. The elections held in Dec 1993 revealed that Russians are not happy with the economic condition and the rising social chaos in the country. The increase in the strength of the army, military industry and information services in Russia has upset the plans of Western countries who thought that problems would increase in Russia after the fall of the Soviet Union.

Russia's new foreign policy goal is to regain world power status through integration with the western democracies. However, domestic opposition to this goal and the West's caution against a possible Russian resurgence have prevented Russia from implementing such a foreign policy. Russian Pres Boris Yeltsin faces stiff opposition on his pro-West policy from politicians who believe that Russia should not renege on its East Asian heritage. Meanwhile, the Western democracies remain unwilling to extend full support to Yeltsin because a possible Russian reemergence as a world power poses major political and military threats.

Tafazzin has been found to be associated with tumor progression. Mitochondrial homeostasis regulates cancer cell viability and metastasis. However, the roles of Tafazzin and mitochondrial homeostasis in thyroid cancer have not been explored. The aim of our study is to investigate the influences of Tafazzin on thyroid cancer apoptosis with a focus on mitochondrial fission. Our results indicated that Tafazzin deletion induced death in thyroid cancer via apoptosis. Biological analysis demonstrated that mitochondrial stress, including mitochondrial bioenergetics disorder, mitochondrial oxidative stress, and mitochondrial apoptosis, was activated by Tafazzin deletion. Furthermore, we found that Tafazzin affected mitochondrial stress by triggering inverted formin 2 (INF2)‐related mitochondrial fission. The loss of INF2 sustained mitochondrial function and promoted cancer cell survival. Molecular investigation illustrated that Tafazzin regulated INF2 expression via the JNK signaling pathway; moreover, the blockade of JNK prevented Tafazzin‐mediated INF2 expression and improved cancer cell survival. Taken together, our results highlight the key role of Tafazzin as a master regulator of thyroid cancer viability via the modulation of INF2‐related mitochondrial fission and the JNK signaling pathway. These findings defined Tafazzin deletion and INF2‐related mitochondrial fission as tumor suppressors that act by promoting cancer apoptosis via the JNK signaling pathway, with potential implications for new approaches to thyroid cancer therapy. [ABSTRACT FROM AUTHOR]

A series of 3‐(thiophen‐2‐yl)‐1,5‐dihydro‐2H‐pyrrol‐2‐one derivatives bearing a carbonic ester group were designed and synthesized by integrating a thiophene nucleus and a pyrroline‐2‐one scaffold in a single molecular architecture. Their structures were confirmed by IR, 1H‐NMR, EI‐MS, and elemental analyses, and their antifungal activities against Fusarium graminearum (Fg), Rhizoctorzia solani (Rs), and Botrytis cinerea (Bc) were evaluated. The antifungal bioassays indicated that some title compounds exhibited desirable antifungal effects against the tested fungi. Strikingly, the title compounds 4i, 4k, 4n, and 4o showed obvious antifungal activities against Rs, with corresponding EC50 values of 35.26, 33.56, 23.90, and 30.48 μg/mL, respectively, which are better than that of hymexazol (37.86 μg/mL). These results indicated that 3‐(thiophen‐2‐yl)‐1,5‐dihydro‐2H‐pyrrol‐2‐one derivatives bearing a carbonic ester group can serve as potential structural templates in the search for novel high‐efficient fungicides. [ABSTRACT FROM AUTHOR]

This paper addresses the problem of rigid-flexible coupling dynamic modeling and active control of a novel flexible parallel manipulator (PM) with multiple actuation modes. Firstly, based on the flexible multi-body dynamics theory, the rigid-flexible coupling dynamic model (RFDM) of system is developed by virtue of the augmented Lagrangian multipliers approach. For completeness, the mathematical models of permanent magnet synchronous motor (PMSM) and piezoelectric transducer (PZT) are further established and integrated with the RFDM of mechanical system to formulate the electromechanical coupling dynamic model (ECDM). To achieve the trajectory tracking and vibration suppression, a hierarchical compound control strategy is presented. Within this control strategy, the proportional-differential (PD) feedback controller is employed to realize the trajectory tracking of end-effector, while the strain and strain rate feedback (SSRF) controller is developed to restrain the vibration of the flexible links using PZT. Furthermore, the stability of the control algorithm is demonstrated based on the Lyapunov stability theory. Finally, two simulation case studies are performed to illustrate the effectiveness of the proposed approach. The results indicate that, under the redundant actuation mode, the hierarchical compound control strategy can guarantee the flexible PM achieves singularity-free motion and vibration attenuation within task workspace simultaneously. The systematic methodology proposed in this study can be conveniently extended for the dynamic modeling and efficient controller design of other flexible PMs, especially the emerging ones with multiple actuation modes. [ABSTRACT FROM AUTHOR]

Abstracts This paper proposes an analytical method based on conformal geometrical algebra to implement and unify type synthesis of one translational and two rotational (1T2R) parallel mechanisms and two rotational and one translational (2R1T) parallel mechanisms. Firstly, conformal geometrical algebra is introduced in this paper to describe finite motions and carry out type synthesis of parallel mechanisms in an algebraic way. Secondly, the finite motions of 1T2R and 2R1T parallel mechanisms are described and their relations are explored, and this results in unifying the type synthesis of these two types of parallel mechanisms in the same procedure. Then, a parametric and algebraic generation method is proposed to obtain available limbs and axes layout of joints with these limbs. Finally, the assembly conditions among available limbs are given to synthesize systematically 2R1T parallel mechanisms with non-overconstrained or overconstrained property, as well as 1T2R parallel mechanisms with the same properties. This method proposed in this paper is valid in carrying out finite motion representation and type synthesis of parallel mechanisms in an algebraic and analytical way, and then is beneficial to an automatic manner using computer programming languages. Furthermore, the method may solve type synthesis of special parallel mechanisms, such as parallel mechanisms with varied output rotational axes. [ABSTRACT FROM AUTHOR]

In order to meet the requirements of large downward force and high stiffness performance for the friction stir welding process, this paper proposes a 5 degree-of-freedom hybrid manipulator as friction stir welding robot. It is composed of a 3 degree-of-freedom redundant parallel module and a 2 degree-of-freedom rotating head. Semi-analytical stiffness model of the hybrid manipulator is firstly established by compliance models of the two substructures. Virtual work principle, deformation superposition principle and twist/wrench mapping model are applied to this compliance modeling process. A novel instantaneous stiffness performance index is then proposed on the basis of instantaneous energy defined by reciprocal product of external payload screw and corresponding deformation screw. It solves the problems of inconsistent physical unit of linear/angular stiffness and is able to evaluate overall and worst-case stiffness performance. Next, stiffness/compliance experiments are carried out to verify the stiffness model and the novel instantaneous stiffness performance index. Finally, stiffness performance of 5 degree-of-freedom hybrid manipulator is thoroughly discussed in terms of engineering requirements, worst-case stiffness performance and stiffness singularities. It can be summarized that the semi-analytical stiffness model and the novel instantaneous stiffness index are effective in analyzing and evaluating stiffness performance of the 5 degree-of-freedom hybrid manipulator. [ABSTRACT FROM AUTHOR]

In order to obtain the real material parameters of heterogeneous rock, the material parameters of red sandstone specimens under uniaxial compression tests are inverted based on the Digital Image Correlation (DIC) method and the Finite Element Model Updating (FEMU) method. The DIC method is employed to calculate the displacement field of red sandstone specimens during uniaxial compression loading. Concurrently, a uniaxial compression elastic–plastic finite element numerical model with non-uniform material parameters is developed based on the FEMU method. The model adopts the Mohr–Coulomb yield criterion and adjusts the boundary conditions in real-time to maintain consistency with the test. The vertical displacement field of the numerical model is juxtaposed with that of the test to construct the objective function. Optimization is achieved using the Artificial Fish Swarm algorithm, which enables the acquisition of the non-uniform distribution and evolution process of the material parameters of specimens at different loading moments. The results indicate that this method can spatially obtain the non-uniform distribution field of material parameters and temporally track the evolution of material parameters during the loading process. This research lays a solid foundation for enhancing the accuracy of intelligent coal mining and dynamic disaster monitoring and early warning in coal mines. [ABSTRACT FROM AUTHOR]

A systematic dynamic modeling methodology is presented to develop the rigid-flexible coupling dynamic model (RFDM) of an emerging flexible parallel manipulator with multiple actuation modes. By virtue of assumed mode method, the general dynamic model of an arbitrary flexible body with any number of lumped parameters is derived in an explicit closed form, which possesses the modular characteristic. Then the completely dynamic model of system is formulated based on the flexible multi-body dynamics (FMD) theory and the augmented Lagrangian multipliers method. An approach of combining the Udwadia-Kalaba formulation with the hybrid TR-BDF2 numerical algorithm is proposed to address the nonlinear RFDM. Two simulation cases are performed to investigate the dynamic performance of the manipulator with different actuation modes. The results indicate that the redundant actuation modes can effectively attenuate vibration and guarantee higher dynamic performance compared to the traditional non-redundant actuation modes. Finally, a virtual prototype model is developed to demonstrate the validity of the presented RFDM. The systematic methodology proposed in this study can be conveniently extended for the dynamic modeling and controller design of other planar flexible parallel manipulators, especially the emerging ones with multiple actuation modes. [ABSTRACT FROM AUTHOR]

Determining the motions and constraints of serial kinematic chains in a concise and visual way is an inevitable step in the analysis and design of both serial and parallel mechanisms. The now most used method is the numerical approach which resorts to solving linear equations. By introducing Clifford algebra, this paper intends to propose an analytical approach to determine the unknown 6-n (n < 6) constraints (motions) from the known n motions (constraints) of serial kinematic chains in different configurations only by drawing some auxiliary points, lines, and planes. The axes and action lines of motions and constraints are characterized by the lines that would be described by Clifford algebra. These lines can be determined analytically according to the relations among points, lines, and planes, which have been expressed by using the operation rules of Clifford algebra Cl(0, 3, 1) such as inner, outer, dual, and shuffle products. Based upon the mechanics principle that the constraint does not work on the motion, the unknown 6-n constraints (motions) of serial kinematic chains from known n motions (constraints) are determined both in an analytical algebraic form and in a visual manner. Finally, four examples are given to demonstrate how to use this approach and test its validity. The merit of this approach is beneficial to the digital analysis and design of both the serial and parallel mechanisms by means of computer and programming languages. [ABSTRACT FROM AUTHOR]

A star k -edge coloring is a proper edge coloring such that there are no bichromatic paths or cycles of length four. The smallest integer k such that G admits a star k -edge coloring is the star chromatic index of G. Deng et al. [5] , and Bezegová et al. [1] independently proved that the star chromatic index of a tree is at most ⌊ 3 Δ 2 ⌋ , and the bound is sharp. Han et al. [8] strengthened the result to list version of star chromatic index, and proved that ⌊ 3 Δ 2 ⌋ is also the sharp upper bound for the list star chromatic index of trees. A generalized Halin graph is a plane graph that consists of a plane embedding of a tree T with Δ (T) ≥ 3 , and a cycle C connecting all the leaves of the tree such that C is the boundary of the exterior face. In this paper, we prove that if H ≔ T ∪ C is a generalized Halin graph with | C | ≠ 5 , then its list star chromatic index is at most max ⁡ { ⌊ θ (T) + Δ (T) 2 ⌋ , 2 ⌊ Δ (T) 2 ⌋ + 7 } , where θ (T) = max x y ∈ E (T) ⁡ { d T (x) + d T (y) }. As a consequence, if H is a (generalized) Halin graph with maximum degree Δ ≥ 13 , then the list star chromatic index is at most ⌊ 3 Δ 2 ⌋. Moreover, the upper bound for the list star chromatic index is sharp. [ABSTRACT FROM AUTHOR]

This paper proposes a novel parallel manipulator with 1 translational and 3 rotational degrees of freedom, which may be designed as the docking equipment for large-scale component assemblage in the aircraft industry. First, the mobility and kinematic analysis of the novel manipulator is performed using the screw theory and the closed-loop vector method. To evaluate the kinematic performance of the manipulator, its workspace is calculated, and the dimensional homogeneous Jacobian matrix of this manipulator is deduced. Mainly based on a nonlinear programming approach, the kinematic dimensional synthesis is performed to optimise the dimensional parameters of this novel parallel manipulator in a prescribed workspace. The results of this paper may lay a solid foundation for the prototype design and manufacture of the novel parallel manipulator. [ABSTRACT FROM AUTHOR]

• An IDM of dimensional parameters and structural topology is proposed. • A machinability processing algorithm is developed to meet the manufacturability. • The stiffness obtained by the IDM is almost twice that of the PDM under the same mass. Dimensional parameters and structural topology have crucial impacts on the performance of robots. However, they are disjointed from each other in the design phase. To fill this gap, an integrated design method (IDM) of dimensional parameters and structural topology is proposed. The experiment is designed with dimensional parameters and mass retention ratio as variables. The topology optimization of components is implemented for minimum compliance. Then, a machinability processing algorithm is developed to make components satisfy the manufacturability. The stiffness matrix of each component is extracted by the finite element analysis (FEA) software, and the stiffness–mass metamodel is established by the response surface method (RSM). Finally, the performance models and optimization model are built, and the stiffness–mass metamodels are embedded in them. The optimization is conducted by particle swarm optimization (PSO) algorithm. A planar five-rotational joint (5R) parallel machining robot is considered to verify the effectiveness and superiority of the proposed method. Results indicate that the stiffness obtained by the proposed approach is approximately double that obtained by the parametric design method (PDM). [ABSTRACT FROM AUTHOR]