摘要：We present an example of applying'need-driven'product design principle to the development of a rapid test kit to detect SARS-COV-2(COVID-19).The tests are intended for use in the field and,longer term,for home *** detect whether a subject is currently infected with the virus and is *** urgent need for large numbers of tests in field setting imposes constraints such as short test time and lack of access to specialist equipment,laboratories and skilled technicians to perform the test and interpret *** meet these needs,an antigen test based on RT-LAMP with colorimetric readout was *** use of swab sample with no RNA extraction was *** extensive experimental study(reported elsewhere),a rapid test kit has been fabricated to satisfy all design criteria.

摘要：In this study, seven pinned double-rectangular tube assembled buckling-restrained brace （DRT-ABRB） specimens were experimentally charaeterised by means of an axial cyclic test. The core member of the specimens was a single flat-plate. Two rectangular tubes were assembled using high strength bolts to form an external restraining member. Each rectangular tube was composed of an external steel channel and a cover plate. A gap or thin rubber filler was set between the core and the external restraining member to form an unbonded layer. The influence of several design parameters on the failure mode and energy dissipation capacity of the ABRB was investigated, including the height of the core wing plate, thickness of the external cover plate, and height of the external channel flange. This experimental study demonstrated that a local pressure-bearing failure at the end of the external member arises when the external cover plate is too thin or if the end construction detail is unreasonable. When the end rotations of the DRT-ABRB were restricted, the hysteretic performance was shown to be superior to that of a pure pinned DRT-ABRB. Finally, all the tested DRT-ABRBs exhibited excellent energy dissipation performance which amply satisfied existing regulation requirements.

摘要：The significance of bioink suitability for the extrusion bioprinting of tissue-like constructs cannot be ***,derived from the hydrolysis of collagen,not only can mimic the extracellular matrix to immensely support cell function,but also is suitable for extrusion under certain ***,gelatin has been recognized as a promising bioink for extrusion ***,the development of a gelatin-based bioink with satisfactory printability and bioactivity to fabricate complex tissue-like constructs with the desired physicochemical properties and biofunctions for a specific biomedical application is still in its ***,in this review,we aim to comprehensively summarize the state-of-the-art methods of gelatin-based bioink application for extrusion ***firstly outline the properties and requirements of gelatin-based bioinks for extrusion bioprinting,highlighting the strategies to overcome their main limitations in terms of printability,structural stability and cell ***,the challenges and prospects are further discussed regarding the development of ideal gelatin-based bioinks for extrusion bioprinting to create complex tissue-like constructs with preferable physicochemical properties and biofunctions.

摘要：As a promising anode material candidate for sodium-ion batteries,antimony(Sb)has attracted enormous research interest due to its high specific capacity and low sodiation ***,its dramatic volume expansion upon sodiation adversely affects its cycle *** have developed an oxidation-coating-reduction strategy for fabricating yolk-shell Sb@C rods from commercially available Sb *** particular,the thermal reduction of vaporized Sb_(2)O_(3) generates densely distributed Sb single atoms and clusters on the carbon *** sodiation process of the Sb@C sample was recorded through in situ transmission electron *** expansion of Sb particles was observed,and it was also revealed that the carbon shell could deform with the expanded Sb *** the intuitively understood advantage that internal voids can provide space for expansion of internal active materials,the deformability of carbon shells can add further ability to withstand the volume *** two structural merits of the yolk-shell construction enable the Sb@C material to deliver an enhanced cycle *** reversible capacity exceeds 620 mA h g^(−1) at 0.1C,with an initial coulombic efficiency of up to 84.9%,and about 95%of the capacity in the charging voltage profile is delivered below 1.0 V ***+/*** performance metrics are very promising for potential practical applications.

摘要：Sodium-ion batteries have been achieving widespread attentions in grid-scale electrical energy storage systems owing to their earth abundant resources[1].However,the energy-density ceiling from cathode materials has been one of primary factors precluding the further practical applications of sodium-ion batteries[2].

摘要：Rotational atherectomy is an effective treatment for severe vascular calcification obstruction,and relies on high-speed grinding(typically 130,000–210,000 r/min)with miniature grinding tools to remove calcified tissue and restore blood ***,reports of intraoperative complications are common because of the grinding force,temperature,and debris directly acting on the body during the grinding process,which can easily cause damage to *** this study,three novel grinding tools were designed and fabricated and a series of experiments have been conducted to analyze the effects of tool geometry and parameters on grinding performance,that is,force,temperature,and specimen surface *** results show that these tools can effectively remove simulated calcified tissue and that they have two motions,rotation and revolution,in the *** higher rotational speeds,grinding force and temperature increase noticeably,while the amount of debris decreases *** addition,by observing the surface morphology of the specimens,we concluded that the material removal rate per unit time is influenced by both rotational speed and tool geometry,and that high rotational speed and a rough tool surface can improve the material removal rate efficiently.

摘要：We report the design and fabrication of a novel and fully integrated polymer-based centrifugal microfluidic disc for rapid automatic allergens detection. All essential steps for a single test including flow valving, sequencing, mixing, separation, extraction, and sedimentation for final detection are automatically conducted within 30 min on a centrifugal microfluidic disc. Our design features a siphon-based valving and analyte extraction structure where the released analyte is separated and subsequently extracted by a siphon valve into the detection chamber. Incorporating the siphon valve and a series of capillary valves, we realize automated detection of allergic reaction on a centrifugal microfluidic disc.

摘要：Efficient charge separation and rapid interfacial reaction kinetics are crucial factors that determine the efficiency of photocatalytic hydrogen ***,a fascinating 2D heterojunction photocatalyst with superior photocatalytic hydrogen evolution performance–holey C_(3)N_(4)nanosheets nested with TiO_(2)nanocrystals(denoted as HCN/TiO_(2))–is designed and fabricated via an in situ exfoliation and conversion *** HCN/TiO_(2)is found to exhibit an ultrathin 2D heteroarchitecture with intimate interfacial contact,highly porous structures and ultrasmall TiO_(2)nanocrystals,leading to drastically improved charge carrier separation,maximized active sites and the promotion of mass transport for ***,the HCN/TiO_(2)delivers an impressive hydrogen production rate of 282.3 lmol h^(-1)per10 mg under AM 1.5 illumination and an apparent quantum efficiency of 13.4%at a wavelength of 420 nm due to the synergetic enhancement of surface reactions and charge *** present work provides a promising strategy for developing high-performance 2D heterojunctions for clean energy applications.

摘要：Magnesium alloys have shown prospective applications as a new biodegradable metal within bone. To garantee the longterm biocompatibility, a Mg-Zn-Ca alloy,composing of essential elements for human, was prepared and its feasibility for orthopedic applications was investigated. The in vitro and in vivo corrosion of Mg-Zn-Ca alloy as well as the biocompatibility were studied. The in vitro corrosion tests in five kinds of physiological solutions showed that the corrosion rates and corrosion morphologies of the alloy were strongly influenced by the solution used. The addition of serum in Hank’s and MEM significantly slowed down the corrosion rate and improved the corrosion uniformity of the alloy. The corrosion rate decreased with increasing serum *** alloy showed the slowest corrosion rate as well as homogeneous corrosion morphology in MEM＋10%FBS. Both the indirect and direct cell experiments indicated good cytocompatibility of the extruded Mg-Zn-Ca alloy. In vivo, we observed a gradual degradation process from the surface of extruded Mg-Zn-Ca alloy and only 40% in volume of implant was left after 4 weeks implantation in medullary cavities of mice. The micro-CT and histological analyses revealed its good biocompatibility with peri-implant new bone formation and increasing cortical bone thickness with increasing implantation period. This study showed that the extruded MgZn-Ca alloy provided sufficient biocompatibility for orthopedic application, though the in vivo corrosion rate should be further reduced for clinical use.

摘要：Emerging quantum dots(QDs)based light-emitting field-effect transistors(QLEFETs)could generate light emission with high color purity and provide facile route to tune optoelectronic properties at a low fabrication *** efforts have been devoted to designing device structure and to understanding the underlying physics,yet the overall performance of QLEFETs remains low due to the charge/exciton loss at the interface and the large band offset of a QD layer with respect to the adjacent carrier transport ***,we report highly efficient QLEFETs with an external quantum efficiency(EQE)of over 20%by employing a dielectric-QDs-dielectric(DQD)sandwich *** DQD structure is used to control the carrier behavior by modulating energy band alignment,thus shifting the exciton recombination zone into the emissive ***,enhanced radiative recombination is achieved by preventing the exciton loss due to presence of surface traps and the luminescence quenching induced by interfacial charge *** DQD sandwiched design presents a new concept to improve the electroluminescence performance of QLEFETs,which can be transferred to other material systems and hence can facilitate exploitation of QDs in a new type of optoelectronic devices.