5,095 research outputs found
Direct synthetic route to shape-controlled Pt-based electrocatalysts for oxidation of small organic molecules and reduction of oxygen
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Tattoo sticker-like 3D flexible Cell sheet transfer platform based on Spontaneous Interfacial cell migration
No full textCell sheet technology is a remarkable option to avoid the limitations of conventional tissue engineering techniques. Cell sheets are maintained intact cell-cell junction and extracellular matrix proteins by a protease-free cell harvesting and scaffold-free cell delivery system. Most cell sheet studies use a thermo-responsive cell harvesting system. However, here, we introduce another unique and flexible cell delivery platform. Our cell sheet transferring system uses a parylene flexible thin-film cell transfer carrier to culture and transfer cell sheet. With the support of the parylene film, cell sheets can be simply designed in any shape and size, and easily transferred to the target surface while maintaining the original cell sheet design and even single-cell spreading morphologies like tattoo stickers. Using our delivery platform, each cell could maintain its cytoskeletal structures after transfer to the target. Different from other cell sheet harvesting methods, a parylene film cell delivery system is based on spontaneous interfacial cell migration without any artificial triggers such as lowering the temperature, electrical stimuli, or PH change. In addition, the cell sheets could be easily stacked in heterotypic multilayered forms and applied to a wound site, confirming its potential application for in situ patient-specific wound patch transplantation. This easy-to-use cell delivery platform can contribute to the wider therapeutic application of cell sheet technology and our deeper understanding of cellular behaviors with interfacial migratory capability.1
A direct one-step synthetic route to Pd-Pt nanostructures with controllable shape, size, and composition for electrocatalytic applications
No full textPd-Pt branched nanocrystals have been known to exhibit a synergistic effect in many electrocatalytic reactions such as reduction of oxygen and oxidation of small organic molecules. However, Pd-Pt branched structures have generally been synthesized using a two-step seed-mediated approach, which is unbeneficial for large-scale synthesis. Therefore, it is necessary to develop a one-step route to Pd-Pt branched structures. Herein, we developed a direct one-step synthetic route to obtain Pd-Pt structures with controllable shape, size, and composition. In this system, KBr plays a critical role in controlling the size and shape of the Pd-Pt NCs. The resulting Pd1Pt5 branched nanocrystals showed 3.4 and 6.2 times higher mass activity toward oxygen reaction and formic acid oxidation than commercial Pt/C, respectively.
Capturing an Eigen complex in an acid-base reaction shows step-resolved molecularity
No full textIn the Eigen-Weller framework, acid-base reactions are described as those consisting of serial steps. The steps include the encounter of acid and base compounds, short-range proton transfer within the encounter complexes, and separation of the resulting Eigen complexes (ECs) equivalent to long-range proton diffusion. Although the initial proton transfer step in the encounter complexes has been extensively explored, the final step requisite to terminating the acid-base reactions has been overlooked. Using time-resolved fluorescence spectroscopy and chemical kinetics analysis, we track the excited-state proton transfer of a cationic acid to an aprotic base in binary solvent mixtures, where the lifetimes of ECs are prolonged. Identifying the ECs spectrally and kinetically, we investigate the molecularity in the consecutive steps of the hydrogen-bond formation between the acid and base and the dissociation of the EC to unveil the cooperative nature of the aprotic base molecules in the model reaction.
Valleriola bui Li, Jin & Ye 2023, sp. nov.
No full textValleriola bui Li, Jin & Ye, sp. nov. (Figs. 4, 9, 22–24, 32, 43–45, 49, 50, 57–59, 63) Meterial examined. Holotype: male, LAOS, Vientiane, Vang Veihg, Kaeng Yui Waterfall, 15 November 2018, Zhen Ye leg. (NKUM). Paratypes: 1 male, 2 females, LAOS, Vientiane, same data as holotype (NKUM); 3 males, 3 females, THAILAND, Nong Bua Lamphu, Na Klang, 13 August 2018, Zhen Ye leg. (NKUM). Diagnosis. Body length: 4.75–4.90, ground color dark-brown with yellowish spots and stripes dorsally. Head mainly yellowish except the frons and the posterior area around compound eyes black. Abdominal segments black in male but yellowish-white in female. Comparative notes. Valleriola bui sp. nov. appears to be closely related to V. javanica. However, V. bui sp. nov. can be distinguished by its remarkable coloration of head: most of the head of V. bui sp. nov. is yellowish except the black frons and the posterior area around compound eyes, whereas the head of V. javanica is mainly blackish and only the clypeus and post-ocellar spot are yellowish (Figs. 22–27). Moreover, V. bui sp. nov. has other characteristics different from V. javanica: the stripes and spots on the sub-basal area of the hemelytra are relatively ambiguous, without distinct margins as in V. javanica (Fig. 32, 33); the stripe on the clavus is isolated and not merged with the apical spots (Fig. 32); the paramere is mushroom-like and apically extended with a small process on the inner side, without hook-like structure (Figs. 57–59). Description. Male. Color: ground color dark-brown (Figs. 4, 9). Head mainly yellowish, clypeus orange, venter of head yellowish, frons and posterior area around compound eyes black, area behind ocelli with an orange spot; bucculae yellowish; labiomere I completely hidden beneath bucculae, labiomere II yellowish-white, labiomere III yellowish-brown, labiomere IV brown to blackish-brown; compound eyes and ocelli silvery; antennomere I yellowish, antennomeres II–IV dark-brown (Figs. 4, 9, 22–24). Pronotum mainly dark-brown, collar and callus blackish, median part of collar with an orange spot, merged with the spot behind ocelli, posterior lobe of pronotum dark-brown, posterior margin yellowish, median part with a yellowish stripe, posterior angles of pronotum shinning black; scutellum blackish, with a yellowish apex (Figs. 4, 9). Hemelytra mainly brown, margins of clavus yellowishbrown, clavus with a yellowish stripe in middle and a spot on apex, lateral margin of hemelytra pale, spots and stripes on corium and membrane pale yellowish, middle part of corium with a spot on the inner side of R+M vein, r cell and membrane cell IV with pale yellowish spots (Fig. 32). Legs yellowish, fore femur with a wide, brown stripe on outer side; all tibiae and tarsi infuscated (Figs. 4, 43–45). Abdominal segments black, with white sutures (Fig. 49). Paramere yellowish, with a dark-brown apex (Figs. 57–59). Structural characteristics: body elongated, bearing sparse, short, pale setae (Figs. 4, 9). Head short and wide, dorsally bearing dense, short pubescence except two circular areas, venter of head with three spines beneath each compound eye; compound eyes distinctly large, without sparse, short, spine-like setae; bucculae clearly visible; labium short, labiomere I completely hidden beneath bucculae, labiomere II with two spines on each side; antennomere I short and stout, antennomeres II–IV extremely long and slender (Figs. 4, 9, 22–24). Pronotum sub-triangular, densely punctured except callus; callus relatively rough, distinctly swollen, with a deep impression on median line; posterior angles of pronotum glossy, without punctures; scutellum triangular, medially with a sub-circular depression, laterally serrated, with a distinct process on each side (Figs. 4, 9). Hemelytra elongated, clavus and sc cell of corium with dense punctures; membrane opaque, with four closed cells (Fig. 32). Legs long and slender, fore coxa strong, slightly elongated, with two long spines anteriorly directed; fore femur incrassate, ventrally with seven large spines (three spines on outer side and four on inner side) and two rows of dense, small, black spines (Figs. 43–45); fore tibia ventrally with a row of dense, brown spines. Middle and hind legs slender, distinctly elongated. Abdomen slender, tubular-like (Fig. 49). Paramere small, apically with a mushroom-like extension, covered by dense punctures and long, curved hairs, with a spine-like process on inner side (Figs. 57–59). Female. Color and structural characteristics similar to male, but abdominal segments of female are yellowishwhite except abdominal segment VII mainly brown (Fig. 50). Genital segments of female hidden in abdominal segment VII, not visible in vitro. Measurements. Male. Body length: 4.75–4.90 (holotype: 4.80), body width across hemelytra: 1.25–1.35. Head width: 1.25–1.30, head length: 0.65–0.68, head width about 1.92 times head length; antenna about 1.31 times as long as body, length of antennomeres I–IV: 0.38, 0.90, 1.90, 2.88. Pronotum width across collar: 0.49–0.51, pronotum width across posterior angles: 1.15–1.20, pronotum length: 0.98–1.00; scutellum width: 0.53–0.56, scutellum length: 0.54–0.55; length of femur, tibia and tarsus (tarsomeres I+II+III): fore leg: 1.85, 1.48 and 0.42 (0.06+0.23+0.13), middle leg: 1.88, 2.10 and 0.50 (0.09+0.25+0.16), hind leg: 2.30, 3.00 and 0.52 (0.10+0.23+0.19). Female. Body length: 4.90–5.00, body width across hemelytra: 1.30–1.35. Head width: 1.29–1.31, head length: 0.63–0.64, head width about 2.06 times head length; antenna about 1.18 times as long as body, length of antennomere I–IV: 0.38, 0.86, 1.85, 2.75. Pronotum width across collar: 0.50–0.54, pronotum width across posterior angles: 1.20–1.30; pronotum length: 0.98–1.05; scutellum width: 0.56–0.60, scutellum length: 0.55–0.56; length of femur, tibia and tarsus (tarsomeres I+II+III): fore leg: 1.85, 1.48 and 0.38 (0.09+0.16+0.13), middle leg: 1.98, 2.10 and 0.53 (0.09+0.24+0.20), hind leg: 1.01, 1.60 and 0.57 (0.09+0.25+0.23). Etymology. This species is named in honor of Prof. Wenjun Bu for his outstanding contributions to the study of taxonomy, phylogeny and biogeography of Heteroptera, on the occasion of his 60th birthday. Remarks. Valleriola bui sp. nov. is sexually dimorphic in appearance, with the male having a black abdomen whereas that of females is yellowish-white (Figs. 49, 50). The third author (DP) has seen additional undescribed species from Thailand and Vietnam, to be described in a forthcoming work, that also share this interesting sexual dimorphism in regard to abdominal pigmentation. Distribution. Laos, Thailand (Fig. 61).Published as part of Li, Zihe, Jin, Zezhong, Polhemus, Dan A. & Ye, Zhen, 2023, Two new species of Valleriola (Hemiptera: Heteroptera: Leptopodidae) and taxonomic notes on the tribe Leptopodini Brullé, 1836 from East and Southeast Asia, pp. 329-344 in Zootaxa 5256 (4) on pages 342-343, DOI: 10.11646/zootaxa.5256.4.2, http://zenodo.org/record/775510
CollaGAN: Collaborative GAN for Missing Image Data Imputation
No full textIn many applications requiring multiple inputs to obtain a desired output, if any of the input data is missing, it often introduces large amounts of bias. Although many techniques have been developed for imputing missing data, the image imputation is still difficult due to complicated nature of natural images. To address this problem, here we proposed a novel framework for missing image data imputation, called Collaborative Generative Adversarial Network (CollaGAN). CollaGAN convert the image imputation problem to a multi-domain images-to-image translation task so that a single generator and discriminator network can successfully estimate the missing data using the remaining clean data set. We demonstrate that CollaGAN produces the images with a higher visual quality compared to the existing competing approaches in various image imputation tasks
Simple Synthesis of Platinum Dendritic Aggregates Supported on Conductive Tungsten Oxide Nanowires as High-Performance Methanol Oxidation Electrocatalysts
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