Academia Sinica

About: Academia Sinica is a facility organization based out in Taipei, Taiwan. It is known for research contribution in the topics: Population & Gene. The organization has 52086 authors who have published 65998 publications receiving 1728114 citations. The organization is also known as: Central Research Academy.

Early Homo and associated artefacts from Asia

Abstract: THE site of Longgupo Cave was discovered in 1984 and excavated in 1985–1988 by the Institute of Vertebrate Paleontology and Paleoanthropology (Beijing) and the Chongqing National Museum (Sichuan Province). Important finds include very archaic hominid dental fragments, Gigantopithecus teeth and primitive stone tools. Palaeomagnetic analysis and the presence of Ailuropoda microta (pygmy giant panda) suggested that the hominid-bearing levels dated to the earliest Pleistocene1. In 1992, joint Chinese–American–Canadian geochronological research corroborated the age using electron spin resonance (ESR) analysis. We report here that the hominid dentition and stone tools from Longgupo Cave are comparable in age and morphology with early representives of the genus Homo (H. habilis and H. ergaster) and the Oldowan technology in East Africa. The Longgupo dentition is demonstr-ably more primitive than that seen in Asian Homo erectus. Long-gupo's diverse and well preserved Plio-Pleistocene fauna of 116 species provide a sensitive contextual base for interpreting the early arrival of the genus Homoin Asia.

Band gap opening of graphene by doping small boron nitride domains

Abstract: Boron nitride (BN) domains are easily formed in the basal plane of graphene due to phase separation. With first-principles calculations, it is demonstrated theoretically that the band gap of graphene can be opened effectively around K (or K′) points by introducing small BN domains. It is also found that random doping with boron or nitrogen is possible to open a small gap in the Dirac points, except for the modulation of the Fermi level. The surface charges which belong to the π states near Dirac points are found to be redistributed locally. The charge redistribution is attributed to the change of localized potential due to doping effects. The band opening induced by the doped BN domain is found to be due to the breaking of localized symmetry of the potential. Therefore, doping graphene with BN domains is an effective method to open a band gap for carbon-based next-generation microelectronic devices.

FeS2 Nanocrystal Ink as a Catalytic Electrode for Dye‐Sensitized Solar Cells

Abstract: In the last decade, dye-sensitized solar cells (DSSCs) have attracted great interest for the fabrication of low-cost largearea photovoltaic devices as an alternative to conventional inorganic counterparts. The counter electrode (CE) is a critical component in DSSCs, where electrons are injected into the electrolyte to catalyze iodine reductions (I3 to I ). The most commonly used CE is based on indium-doped tin oxide (ITO)-coated glass loaded with platinum by sputtering. Platinum has a high catalytic activity for triiodide reduction and presents sufficient corrosion resistance. However, Pt is expensive because of its scarcity, and thus, the development of so-called Pt-free CEs for DSSCs using cheaper and abundant materials becomes technologically desirable. Recently, carbon-based materials, such as graphite, graphene, carbon nanotubes, and conducting polymers, have been used to replace Pt as electrocatalysts for triiodide reduction in DSSCs, although these devices still suffer from poor thermal stability and weak corrosion resistance. Extensive research has been performed on using inorganic compounds such as transitional metal carbides, nitrides, oxides, and sulfides as a new class of alternative catalytic materials for Pt in DSSC systems. Therefore, pursuing low-cost and stable CE materials as alternatives to expensive Pt is crucial to make DSSC systems more competitive for future commercial applications. Pyrite iron disulfide (FeS2, so-called fool s gold) is an interesting next-generation photovoltaic material candidate that is abundant in nature and is nontoxic. It is ranked as having the highest material availability among 23 existing semiconducing photovoltaic systems that could potentially lead to lower costs compared to conventional silicon solar cells. Colloidal pyrite nanocrystals (NCs) were recently synthesized and characterized, providing great potential for developing low-cost fabrications of FeS2-based photovoltaic devices using solution processes. We first demonstrated pyrite NC-based photodiode devices with a spectral response extended to near infrared (NIR) wavelengths because of its large optical absorption coefficient (> 10 cm ) and narrow band gap of 0.95 eV, which provided a crucial step toward success in producing colloidal pyrite NCs thin films as photovoltaic absorption layers. This study demonstrates an important photovoltaic application using FeS2 nanocrystal pyrite ink to fabricate a cost-effective CE in DSSCs, which has the unique advantages of earth abundance and of being solution-processable. The DSSC device with the CE using the FeS2 NC ink exhibits a promising power conversion efficiency of 7.31% comparable to that of the cell using the precious metal of Pt deposited by sputtering (7.52 %), as well as remarkable electrochemical stability of greater than 500 consecutive cycle scans. Solution-processable and semi-transparent FeS2 NC-based CEs also enable the fabrication of flexible and bifacial DSSCs. The results indicate that FeS2 NC ink is an extremely promising candidate for replacing Pt to substantially reduce the cost of DSSCs in future commercial applications and have also shed light on employing the low-cost FeS2 NC catalyst in other electrochemical cells. The FeS2 NCs were prepared using wet solution-phase chemical syntheses with a number of modifications according to our previous reports. 25] Figure 1a shows a highresolution transmission electron microscopy (HR-TEM) image of an FeS2 NC with a diameter of 15 3 nm. The clear lattice fringes of the FeS2 NCs with a lattice spacing of 0.31 nm matched the (111) plane of pyrite. The fast Fourier transform (FFT) patterns shown in Figure 1b exhibited various index facets, including {210}, {211}, and {311} on the NC, showing typical signatures of a pyrite-phased crystal structure.Figure 1 c shows a photograph of the FeS2 NCs ink. For fabricating the FeS2 NC CE, FeS2 NC ink of concentration 30 mg mL 1 was spin-coated onto an ITO glass substrate at 4000 rpm for 20 s, as shown in Figure 1d. Because as[*] Y.-C. Wang, Dr. D.-Y. Wang, H.-A. Chen, Prof. C.-W. Chen Department of Materials Science and Engineering National Taiwan University No. 1, Sec. 4, Roosevelt Rd., Taipei, 10617 (Taiwan) E-mail: chunwei@ntu.edu.tw

The genome and life-stage specific transcriptomes of Globodera pallida elucidate key aspects of plant parasitism by a cyst nematode

Abstract: Globodera pallida is a devastating pathogen of potato crops, making it one of the most economically important plant parasitic nematodes. It is also an important model for the biology of cyst nematodes. Cyst nematodes and root-knot nematodes are the two most important plant parasitic nematode groups and together represent a global threat to food security. We present the complete genome sequence of G. pallida, together with transcriptomic data from most of the nematode life cycle, particularly focusing on the life cycle stages involved in root invasion and establishment of the biotrophic feeding site. Despite the relatively close phylogenetic relationship with root-knot nematodes, we describe a very different gene family content between the two groups and in particular extensive differences in the repertoire of effectors, including an enormous expansion of the SPRY domain protein family in G. pallida, which includes the SPRYSEC family of effectors. This highlights the distinct biology of cyst nematodes compared to the root-knot nematodes that were, until now, the only sedentary plant parasitic nematodes for which genome information was available. We also present in-depth descriptions of the repertoires of other genes likely to be important in understanding the unique biology of cyst nematodes and of potential drug targets and other targets for their control. The data and analyses we present will be central in exploiting post-genomic approaches in the development of much-needed novel strategies for the control of G. pallida and related pathogens.