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Incomplete knowledge of the mechanisms at work continues to hamper efforts to maximize reprogramming efficiency. Here, we present a systematic genome-wide RNAi screen to determine the global regulators during the early stages of human reprogramming. Our screen identifies functional repressors and effectors that act to impede or promote the reprogramming process. Repressors and effectors form close interacting networks in pathways, including RNA processing, G protein signaling, protein ubiquitination, and chromatin modification. Combinatorial knockdown of five repressors (SMAD3, ZMYM2, SFRS11, SAE1, and ESET) synergistically resulted in ∼85% TRA-1-60-positive cells. Removal of the novel splicing factor SFRS11 during reprogramming is accompanied by rapid acquisition of pluripotency-specific spliced forms. Mechanistically, SFRS11 regulates exon skipping and mutually exclusive splicing of transcripts in genes involved in cell differentiation, mRNA splicing, and chromatin modification. Our study provides insights into the reprogramming process, which comprises comprehensive and multi-layered transcriptional, splicing, and epigenetic machineries.

The PBL (Perfobond Leiste) shear key has advantages such as high load capacity and high restraint capacity. However, at the same time, there are also problems such as insufficient deformation capacity and low stiffness along the weak axis direction. In addition, shear key performance degradation, ductility, and other problems are not yet clear under the reciprocal seismic action. To this end, a folded perfobond shear key is proposed in this paper to solve the problems of insufficient deformation capacity and uneven stiffness distribution of the traditional PBL shear key. At the same time, numerical analysis is carried out to investigate the seismic performance of the shear key under earthquakes, such as stiffness degradation, ductility, and energy dissipation. Through the push-out test, it is found that the steel plate outside the shear key deforms, showing a certain semi-rigid characteristic; concrete forms a trapezoidal constraint area centered on shear keys, and the constraint effect is significantly improved compared with the point constraint of studs. On the whole, under the condition of a similar shear section, the bearing capacity of the shear key is 1.5 times that of the stud. The ductility coefficient is above 3.0, showing good deformation ability. Through parameter analysis, it is found that the bearing capacity of shear keys increases with the increase of web width-thickness ratio, but the deformation capacity degenerates. The opening rate mainly affects the embedded effect of shear keys and concrete. Based on the fitting analysis, the variation laws of web width influence coefficient γB, web height influence coefficient γH, and embedded effect influence coefficient γD are obtained, and the calculation formula of shear key bearing capacity is proposed. Finally, based on the push-out test, the hysteretic behavior of the shear key is studied. It is found that the load-displacement hysteretic curve of the shear key is full, the ductility coefficient is 4.2, and the equivalent viscous damping coefficient is 0.27, which shows good seismic capacity. In summary, the new shear key realizes the good unity of bearing capacity and deformation and has high engineering application value.

A group of highly efficient chiral titanium catalysts for sharpless epoxidation reaction of allylic alcohols are discovered through ligand diversity. The influences of substitutent in chiral tartrate ligands on the enantioselectivities of the epoxidation reactions are discovered.

Glass Fiber Reinforced Plastic (GFRP) composite material has good insulation and stain resistance, and can be efficiently used in an electric transmission tower. Based on static tension and compression research, full-scale tests for GFRP were carried out on composite steel casing joints. The fatigue life and the failure mode of this kind of connection were analysed in different stress amplitude and loading conditions. The whole process of development of cracks at the adhesive joint was revealed under constant amplitude cyclic loading. Also, the load-displacement curves and the load-strain curves were received and analysed. The results showed that when the end of the connection using epoxy resin adhesives as bonding materials between the composite bar and the steel sleeve were pulled out, there was a typical brittle failure. Additionally, the bearing capacity only decreased by 6.8% after 2 million cycles under the tension-compression conditions, indicating that the adhesive joints had excellent shock absorption and anti-fatigue performance. Finally, some suggestions were proposed to provide a basis for engineering applications and theoretical analysis of complex tower structure. [ABSTRACT FROM AUTHOR]

Fibre reinforced plastic (FRP) composite has been widely used in engineering due to its light weight, high strength, and corrosion resistance. Joint behaviour is important in structural design. This research investigated the ultimate tensile and compressive bearing capacities of bonding joints of Φ200 mm × 10 mm steel casing. By conducting full-scale tests, the load-displacement curve and strain distribution in joints in an FRP composite steel casing were analysed, and the ultimate bearing capacity, stiffness, and failure mode were obtained. The research showed that under axial compression, joints underwent brittle failure, and the steel casing exerted a greater lateral restraint to the composite pipe, which resulted in a decrease of bearing capacity of its components. While under axial tension, the failure mode of joints was such that the FRP composite pipe was pulled off and the bearing capacity of its joints was determined by the strength of the binders used. This study forms an experimental basis for engineering application. [ABSTRACT FROM AUTHOR]

The article talks about enantiopure trifluoromethylated molecules. Fluorine has been one of the elements that played a critical role in the pharmaceutical and material sciences. The addition of one or two flourine atoms has been a familiar technique in every new drug discovery and one of the leading fluorine compounds that has been recently discovered is the enantiopure trifluoromethylated molecule which is often included in biologically active compounds, chiral reagents, and in materials for optoelectronic devices.

In traditional eccentrically braced steel frames, damages and plastic deformations are limited to the links and the main structure members are required tremendous sizes to ensure elasticity with no damage based on the force-based seismic design method, this limits the practical application of the structure. The high strength steel frames with eccentric braces refer to Q345 (the nominal yield strength is 345 MPa) steel used for links, and Q460 steel utilized for columns and beams in the eccentrically brace steel frames, the application of high strength steels not only brings out better economy and higher strength, but also wider application prospects in seismic fortification zone. Here, the structures with four type eccentric braces are chosen, including K-type, Y-type, D-type and V-type. These four types EBFs have various performances, such as stiffness, bearing capacity, ductility and failure mode. To evaluate the seismic behavior of the high strength steel frames with variable eccentric braces within the similar performance objectives, four types EBFs with 4-storey, 8-storey, 12-storey and 16-storey were designed by performance-based seismic design method. The nonlinear static behavior by pushover analysis and dynamic performance by time history analysis in the SAP2000 software was applied. A total of 11 ground motion records are adopted in the time history analysis. Ground motions representing three seismic hazards: first, elastic behavior in low earthquake hazard level for immediate occupancy, second, inelastic behavior of links in moderate earthquake hazard level for rapid repair, and third, inelastic behavior of the whole structure in very high earthquake hazard level for collapse prevention. The analyses results indicated that all structures have similar failure mode and seismic performance. [ABSTRACT FROM AUTHOR]