The ability to design a particular geometry of porous electrodes at multiple length scales in a lithium‐ion battery can significantly and positively influence battery performance because it enables control over distribution of current and potential and can enhance ion and electron transport. 3D architecturally designed carbon electrodes are developed, whose structural factors are independently controlled and whose dimensions span micrometers to centimeters, using digital light processing and pyrolysis. These free‐standing lattice electrodes are comprised of monolithic glassy carbon beams, are lightweight, with a relative density of 0.1–0.35, and mechanically robust, with a maximum precollapse stress of 27 MPa, which facilitates electrode recycling. The specific strength is 101 kN m kg−1, comparable to that of 6061 aluminum alloy. These carbon electrodes can reach a mass loading of 70 mg cm−2 and an areal capacity of 3.2 mAh cm−2 at a current density of 2.4 mA cm−2. It is demonstrated that this approach allows for independent design of structural factors, i.e., beam diameter, electrode thickness, and surface morphology, enabling control over Li‐ion transport length, overpotential and battery performance, not available for slurry‐based electrodes. This multiscale approach to design of electrodes may open substantial performance‐enhancing capabilities for solid‐ and liquid‐state batteries, flow batteries, and fuel cells.

Metal additive manufacturing (AM) enables the production of high value and high performance components 1 with applications from aerospace 2 to biomedical 3 fields. Layer-by-layer fabrication circumvents the geometric limitations of traditional metalworking techniques, allowing topologically optimized parts to be made rapidly and efficiently 4 , 5 . Existing AM techniques rely on thermally initiated melting or sintering for part shaping, a costly and material-limited process 6 – 8 . We report an AM technique that produces metals and alloys with microscale resolution via vat photopolymerization (VP). Three-dimensional-architected hydrogels are infused with metal precursors, then calcined and reduced to convert the hydrogel scaffolds into miniaturized metal replicas. This approach represents a paradigm shift in VP; the material is selected only after the structure is fabricated. Unlike existing VP strategies, which incorporate target materials or precursors into the photoresin during printing 9 – 11 , our method does not require reoptimization of resins and curing parameters for different materials, enabling quick iteration, compositional tuning and the ability to fabricate multimaterials. We demonstrate AM of metals with critical dimensions of approximately 40 µm that are challenging to fabricate by using conventional processes. Such hydrogel-derived metals have highly twinned microstructures and unusually high hardness, providing a pathway to create advanced metallic micromaterials.

BackgroundInternational clinical trials are now rapidly expanding into Asia. However, the proportion of global trials is higher in South Korea compared to Japan despite implementation of similar governmental support in both countries. The difference in clinical trial environment might influence the respective physicians’ attitudes and experience towards clinical trials. Therefore, we designed a questionnaire to explore how physicians conceive the issues surrounding clinical trials in both countries.MethodsA questionnaire survey was conducted at Kyoto University Hospital (KUHP) and Seoul National University Hospital (SNUH) in 2008. The questionnaire consisted of 15 questions and 2 open-ended questions on broad key issues relating to clinical trials.ResultsThe number of responders was 301 at KUHP and 398 at SNUH. Doctors with trial experience were 196 at KUHP and 150 at SNUH. Among them, 12% (24/196) at KUHP and 41% (61/150) at SUNH had global trial experience. Most respondents at both institutions viewed clinical trials favorably and thought that conducting clinical trials contributed to medical advances, which would ultimately lead to new and better treatments. The main reason raised as a hindrance to conducting clinical trials was the lack of personnel support and time. Doctors at both university hospitals thought that more clinical research coordinators were required to conduct clinical trials more efficiently. KUHP doctors were driven mainly by pure academic interest or for their desire to find new treatments, while obtaining credits for board certification and co-authorship on manuscripts also served as motivation factors for doctors at SNUH.ConclusionsOur results revealed that there might be two different approaches to increase clinical trial activity. One is a social level approach to establish clinical trial infrastructure providing sufficient clinical research professionals. The other is an individual level approach that would provide incentives to encourage doctors to participate in and conduct clinical trials.

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Mg/bioceramic composites fabricated by powder metallurgy technique have been explored for biodegradable load-bearing implants. Although sintering behavior including densi cation and reaction has a signi cant effect on mechanical properties of the composites, little studies have been conducted focusing on both sintering behavior and mechanical properties. In this study, Mg/10 and 20 vol.% β-tricalcium phosphate (β-TCP) composites were fabricated by spark plasma sintering, which achieved high densi cation. Distinct sintering behavior of Mg/β-TCP composites involving reaction was investigated by estimating relative densities during sintering, thermal analyses, X-ray diffractometry and auger electron spectroscopy. The results suggest that Ca solid diffusion into Mg during sintering resulted in melting and penetrating Mg into gaps between β-TCP particles, and nally led to high densi cation. The reaction between Mg and β-TCP produced MgO. Compression tests showed that Mg/β-TCP composites enhanced their mechanical properties compared with Mg sintered at the same route. That s because the high densi cation of Mg/β-TCP composites and high hardness of MgO potentially caused good load transfer from Mg-matrix to the formed MgO as reinforcement. The discoveries regarding the reactions can help the design of Mg/calcium phosphate composites including Mg/β-TCP composites.