The role of the government in promoting industrialization and human capital accumulation in Korea

노트 : - This PDF is a selection from an out-of-print volume from the National Bureau of Economic Research - Volume Title: Growth theories in light of the East Asian experienc

Single Cell Manipulation using Ferromagnetic Composite Microtransporters

For biomedical applications, such as single cell manipulation, it is important to fabricate microstructures that can be powered and controlled wirelessly in fluidic environments. In this letter, we describe the construction and operation of truly micron-sized, biocompatible ferromagnetic microtransporters driven by external magnetic fields. Microtransporters were fabricated using a simple, single step fabrication method and can be produced in large numbers. We demonstrate that they can be navigated to manipulate single cells with micron-size precision without disturbing the local environment

Alpha-Methylacyl-Coenzyme A Racemase-Expressing Urachal Adenocarcinoma of the Abdominal Wall

Urachal adenocarcinomas are very rare and about one third of these neoplasms arise in urachal remnants. To demonstrate the origin of the urachal adenocarcinoma is not easy, but it is very important for managing patient care. We report on a 35-year-old man who complained of a palpable mass in the periumbilical area. The mass was incidentally identified 10 days earlier. Computed tomography revealed a well-defined enhancing mass with internal calcification and septation abutting on the dome of the urinary bladder. The clinical diagnosis was urachal cancer, which seemed to invade the urinary bladder. Thus, we performed mass excision and partial resection of the bladder. Histopathologically, the mass was diagnosed as mucinous cystadenocarcinoma originating from urachal remnants that showed an unusual expression of alpha-methylacyl-coenzyme A racemase (AMACR). To our knowledge, this report is the first case of AMACR-expressing urachal adenocarcinoma arising in the abdominal wall

Material enhancements of newly developed stiff type polyurea for retrofitting of concrete structures

Recently, polyurea (PU) has been receiving great interest from the construction industry as a structural retrofitting and strengthening material due to its simple application of spraying on the structural member surface without creating an epoxy bonding interface. In this study, based on knowledge gained from developing flexible-type PU (FTPU) in preceding studies, stiff-type PU (STPU) is developed by varying the prepolymer/hardener ratio of FTPU. A mechanical property evaluation of STPU is performed through tensile strength, percent elongation, pull-off, and Shore hardness tests. Furthermore, a durability property evaluation of STPU is performed through acid environmental and ultraviolet (UV) exposure tests. In addition, concrete carbonation exposure and freeze–thaw tests are performed for STPU. The experimental results show that STPU has a higher tensile strength and lower elongation percentage than FTPU with excellent mechanical and durability properties. Using the optimal mix proportion of STPU, the surfaces of concrete specimens sprayed with STPU are tested under uniaxial compression loading. The uniaxial test results show that the strengthened concrete specimens have maximum load ratios 1.14–1.20 times those of the non-strengthened concrete specimens. Based on the test results, STPU can be used as a retrofitting and strengthening material for concrete members to resist seismic and extreme loading (e.g., impact, blast)

PRMT1 Deficiency in Mouse Juvenile Heart Induces Dilated Cardiomyopathy and Reveals Cryptic Alternative Splicing Products

Protein arginine methyltransferase 1 (PRMT1) catalyzes the asymmetric dimethylation of arginine residues in proteins and methylation of various RNA-binding proteins and is associated with alternative splicing in vitro. Although PRMT1 has essential in vivo roles in embryonic development, CNS development, and skeletal muscle regeneration, the functional importance of PRMT1 in the heart remains to be elucidated. Here, we report that juvenile cardiomyocyte-specific PRMT1-deficient mice develop severe dilated cardiomyopathy and exhibit aberrant cardiac alternative splicing. Furthermore, we identified previously undefined cardiac alternative splicing isoforms of four genes (Asb2, Fbxo40, Nrap, and Eif4a2) in PRMT1-cKO mice and revealed that eIF4A2 protein isoforms translated from alternatively spliced mRNA were differentially ubiquitinated and degraded by the ubiquitin-proteasome system. These findings highlight the essential roles of PRMT1 in cardiac homeostasis and alternative splicing regulation

A search for ferromagnetism in transition-metal-doped piezoelectric ZnO

We present the results of a computational study of ZnO in the presence of Co and Mn substitutional impurities. The goal of our work is to identify potential ferromagnetic ground states within the (Zn,Co)O or (Zn,Mn)O material systems that are also good candidates for piezoelectricity. We find that, in contrast to previous results, robust ferromagnetism is not obtained by substitution of Co or Mn on the Zn site, unless additional carriers (holes) are also incorporated. We propose a practical scheme for achieving such $p$-type doping in ZnO