Effective Stress Change and Post-Earthquake Settlement Properties of Granular Materials Subjected to Multi-Directional Cyclic Simple Shear

In order to investigate the effect of cyclic shear direction on the properties of saturated granular materials, such as effective vertical stress reduction and post-earthquake settlement, several series of multi-directional cyclic simple shear tests under constant volume conditions are performed on Toyoura sand and granulated blast furnace slag (GBFS), as an alternative material. The GBFS has particular properties such as light weight, high shear strength and high permeability, and it is considered to be one of the most promising materials in geotechnical engineering. From the test results, it is clarified that the shear strain amplitude has a significant effect on the changes in the effective stress of granular materials. However, at higher levels of shear strain amplitude, the cyclic shear direction has little influence on the effective stress reduction. It is found that the vertical strain, after the cyclic shearing of the GBFS samples, was lower than that of the Toyoura sand under the same test conditions. Finally, to evaluate the changes in effective stress under uni-directional and multi-directional cyclic simple shear conditions, an estimation method is represented by a function of cumulative shear strain G* and resultant shear strain Γ. The validity of this proposed model is confirmed by comparing the experimental and the calculated data obtained under multi-directional cyclic simple shear conditions.     

Molecular cloning, identification and characterization of 2-methyl-3-hydroxypyridine-5-carboxylic-acid-dioxygenase-coding gene from the nitrogen-fixing symbiotic bacterium Mesorhizobium loti

The gene (mlr6788) of a nitrogen-fixing symbiotic bacterium Mesorhizobium loti MAFF303099 has been identified as a gene coding for 2-methyl-3-hydroxypyridine-5-carboxylic acid dioxygenase (MHPCO), the seventh enzyme in degradation pathway I for pyridoxine, a free form of vitamin B(6). The gene was cloned and overexpressed in Escherichia coli cells co-transformed with chaperonin genes. The homogeneous recombinant enzyme showed similar enzymatic properties to the enzyme from Pseudomonas sp. MA-1. MHPCO was essential for the assimilation of pyridoxine in M. loti, but not for its growth in a nutrient-rich medium. From the infection experiment of a symbiotic plant Lotus japonicus with an M. loti mlr6788 gene disruptant, MHPCO was demonstrated to be dispensable for at least nodule formation on roots of seedlings in symbiosis.     

Fast-scanning atomic force microscopy reveals the molecular mechanism of DNA cleavage by ApaI endonuclease

Newly developed fast-scanning atomic force microscopy (AFM) allows the dissection of molecular events such as DNA-enzyme reactions at the single-molecule level. With this novel technology, a model is proposed of the DNA cleavage reaction by a type IIP restriction endonuclease ApaI. Detailed analyses revealed that ApaI bound to DNA as a dimer and slid along DNA in a one-dimensional diffusion manner. When it encountered a specific DNA sequence, the enzyme halted for a moment to digest the DNA. Immediately after digestion, the ApaI dimer separated into two monomers, each of which remained on the DNA end and then dissociated from the DNA end. Thus, fast-scanning AFM is a powerful tool to aid the understanding of protein structures and dynamics in biological reactions at the single-molecule level in sub-seconds.     

An OTFT‐driven rollable OLED display

Abstract— An 80‐μm‐thick rollable AMOLED display driven by an OTFT is reported. The display was developed so as to be rollable in one direction with an integrated OTFT gate driver circuit. It was successfully operated by an originally developed organic semiconductor, a peri‐xanthenoxanthene derivative. The display retained its initial electrical properties and picture quality even after being subjected to 1000 cycles of a roll‐up‐and‐release test with a radius of 4 mm.     

Making 2D Map of Environments Based upon Routes Scenes

This paper proposes a method for making a map of large scale environment based upon route scenes, assuming that the topological relation of routes at intersections is known. A panoramic representation is used for describing route scenes, and the number of routes connecting at an intersection is assumed to be known. The idea is to decompose a 2D graph into a number of closed loops. By detecting the closed loops and storing the relation among them, we can describe the 2D map based upon route scenes. A robot can obtain a closed loop by taking the same turn (leftmost for example) at every intersection when it moves along routes. According to the information on routes at intersections, the robot can select unmoved routes for finding new closed loops. By fusing new closed loops with found ones, the robot can, further, build the map of environments. The effectiveness of our method are shown by experiment in a real-world environment.     

刺绣仿真的建模与实现

分析了真实刺绣图案的立体感以及纹理特性,并在此基础上,采用局部仿真的方法,从几何角度提出了基本模型及纹理模型,解决了计算复杂度与仿真效果之间的矛盾,仿真结果表明,该模型是简便有效的。     

Changes in Ovulation-Related Gene Expression during Induced Ovulation in the Amur Sturgeon (Acipenser schrenckii) Ovarian Follicles

The luteinizing hormone (LH) and maturation-inducing steroids (MIS), such as 17α,20β-dihydroxy-4-pregnen-3-one, regulate the final oocyte maturation in teleosts. Oocyte maturational competence (OMC) and ovulatory competence measure the sensitivity to MIS for oocyte maturation and ovulation, respectively. However, the molecular mechanisms underlying the acquisition of ovulatory competence remain unknown. Sturgeons are an excellent research model for investigating these mechanisms. We examined the seasonal profiles of OMC and ovulatory competence in vitro and the expression of 17 ovulation-related gene candidates using quantitative PCR in Amur sturgeon ovarian follicles. The ovulatory competence was induced by the LH-releasing hormone analog (LHRHa) priming injection after acquiring the OMC, which was spontaneously induced in spring or autumn. Seven genes, including the tissue-type plasminogen activator (plat), were enhanced following the LHRHa priming injection in ovarian follicles sampled from anovulated and ovulated fish. The activin receptor type 1 (acvr1) and prostaglandin G/H synthase 2 (ptgs2) were only upregulated in ovulated fish. Our results suggest that plat/plasmin and prostaglandin (PG)/PG receptor systems are essential for sturgeon ovulation, similar to other vertebrates. Notably, successful ovulation depends on a sufficient PG synthesis, and mediators activating the PG/PG receptor system are essential for acquiring the ovulatory competence. We provide the first report of ovulation-related gene alterations in the ovarian follicles of Amur sturgeons.     

A Review on Current Nanofiber Technologies: Electrospinning,Centrifugal Spinning,and Electro-Centrifugal Spinning

Nanofiber-based products are widely used in the fields of public health, air/water filtration, energy storage, etc. The demand for nonwoven products is rapidly increasing especially after COVID-19 pandemic. Electrospinning is the most popular technology to produce nanofiber-based products from various kinds of materials in bench and commercial scales. While centrifugal spinning and electro-centrifugal spinning are considered to be the other two well-known technologies to fabricate nanofibers. However, their developments are restricted mainly due to the unnormalized spinning devices and spinning principles. High solution concentration and high production efficiency are the two main strengths of centrifugal spinning, but beaded fibers can be formed easily due to air perturbation or device vibration. Electro-centrifugal spinning is formed by introducing a high voltage electrostatic field into the centrifugal spinning system, which suppresses the formation of beaded fibers and results in producing elegant nanofibers. It is believed that electrospinning can be replaced by electro-centrifugal spinning in some specific application areas. This article gives an overview on the existing devices and the crucial processing parameters of these nanofiber technologies, also constructive suggestions are proposed to facilitate the development of centrifugal and electro-centrifugal spinning.