Room-Temperature Electroreductiveα-Alkylation of N-Heteroarenes with Styrenes

Despite their interesting applications,direct and diverse syntheses of aryl-fused 2-alkyl cyclic amines still remain challenging.Here,the concept of incorporating a C–C coupling process into the N-heteroaryl reduction was successfully applied to fulfill such a synthetic purpose.Due to our use of controllable electroreduction coupled with proton abstraction,we can report a room-temperature reductiveα-alkylation of the inert N-heteroarenes with abundantly available styrenes in an undivided Zn(+)/C(−)cell.This proceeds with good substrate compatibility and operational simplicity,utilizes cost-effective sacrificial Zn-anode,exhibits high selectivity,and does not need pressurized H2 gas and transition-metal catalysts.This current work offers a useful platform for direct construction of valuable aryl-fused 2-alkyl cyclic amines that are difficult to access with conventional methods.

Formulation and in vitro characterization of long-acting PLGA injectable microspheres encapsulating a peptide analog of LHRH

The present study aimed to formulate triptorelin acetate(TA)into poly(D,L-lactic-co-glycolic)acid(PLGA)based injectable sustained-release microspheres(TA-PLGA-MS)by usingdouble emulsion solvent extraction/evaporation(DESE)technique and investigate the effects of various material attributes and process parameters on the quality attributes such as size,shape,surface morphology,encapsulation efficiency(EE)and in vitro release behavior of these microspheres.Variable compositions of the outer water phase,type of the organic solvents,volume ratios of inner water phase to oil phase,PLGA concentrations,and the powers for emulsification in the preparation of the microspheres showed an influence on their quality attributes.An optimal formulation(F-2)obtained from this univariate approach possess an excellent EE value of 63.5%±3.4%and an average volumetric particle size of 35.3±1.8μm.This formulation was further accomplished with different solidification rates assisted by variable incubation temperatures,which exhibited an impact on the shape/surface and inner morphology of the microspheres.The resultant microspheres also displayed different in vitro release patterns.The matrices processed with a high incubation temperature conferred the fastest and the most complete drug release profile over the period of 63 days.Thus,the solidification rate could be identified as one of the critical process parameters that affected the quality of the PLGA based injectable microspheres specifically designed for the prolonged delivery of TA.

Multi-Material magnetic field-assisted additive manufacturing system for flexible actuators with programmable magnetic arrangements

Manufacturing flexible magnetic-driven actuators with complex structures and magnetic arrangements to achieve diverse functionalities is becoming a popular trend.Among various manufacturing technologies,magnetic-assisted digital light processing(DLP)stands out because it enables precise manufacturing of macro-scale structures and micro-scale distributions with the assistance of an external magnetic field.Current research on manufacturing magnetic flexible actuators mostly employs single materials,which limits the magnetic driving performance to some extent.Based on these characterizations,we propose a multi-material magnetic field-assisted DLP technology to produce flexible actuators with an accuracy of 200μm.The flexible actuators are printed using two materials with different mechanical and magnetic properties.Considering the interface connectivity of multi-material printing,the effect of interfaces on mechanical properties is also explored.Experimental results indicate good chemical affinity between the two materials we selected.The overlap or connection length of the interface moderately improves the tensile strength of multi-material structures.In addition,we investigate the influence of the volume fraction of the magnetic part on deformation.Simulation and experimental results indicate that increasing the volume ratio(20%to 50%)of the magnetic structure can enhance the responsiveness of the actuator(more than 50%).Finally,we successfully manufacture two multi-material flexible actuators with specific magnetic arrangements:a multi-legged crawling robot and a flexible gripper capable of crawling and grasping actions.These results confirm that this method will pave the way for further research on the precise fabrication of magnetic flexible actuators with diverse functionalities.