Genome assembly and population genomic data of a pulmonate snail Ellobium chinense.

Ellobium chinense is an airbreathing, pulmonate gastropod species that inhabits saltmarshes in estuaries of the northwestern Pacific. Due to a rapid population decline and their unique ecological niche in estuarine ecosystems, this species has attracted special attention regarding their conservation and the genomic basis of adaptation to frequently changing environments. Here we report a draft genome assembly of E. chinense with a total size of 949.470 Mb and a scaffold N50 of 1.465 Mb. Comparative genomic analysis revealed that the GO terms enriched among four gastropod species are related to signal transduction involved in maintaining electrochemical gradients across the cell membrane. Population genomic analysis using the MSMC model for 14 re-sequenced individuals revealed a drastic decline in Korean and Japanese populations during the last glacial period, while the southern Chinese population retained a much larger effective population size (Ne). These contrasting demographic changes might be attributed to multiple environmental factors during the glacial-interglacial cycles. This study provides valuable genomic resources for understanding adaptation and historical demographic responses to climate change.

Charge Carrier Dynamics in Non-Fullerene Acceptor-Based Organic Solar Cells: Investigating the Influence of Processing Additives Using Transient Absorption Spectroscopy.

In this study, we present a comprehensive investigation into the charge generation mechanism in bulk-heterojunction organic solar cells employing non-fullerene acceptors (NFAs) both with and without the presence of processing additives. While photovoltaic devices based on Y6 or BTP-eC9 have shown remarkable power conversion efficiencies, the underlying charge generation mechanism in polymer:NFA blends remains poorly understood. To shed light on this, we employ transient absorption (TA) spectroscopy to elucidate the charge transfer pathway within a blend of the donor polymer PM6 and NFAs. Interestingly, the charge carrier lifetimes of neat Y6 and BTP-eC9 are comparable, both reaching up to 20 ns. However, the PM6:BTP-eC9 blend exhibits substantially higher charge carrier generation and a longer carrier lifetime compared to PM6:Y6 blend films, leading to superior performance. By comparing TA data obtained from PM6:Y6 or PM6:BTP-eC9 blend films with and without processing additives, we observe significantly enhanced charge carrier generation and prolonged charge carrier lifetimes in the presence of these additives. These findings underscore the potential of manipulating excited species as a promising avenue for further enhancing the performance of organic solar cells. Moreover, this understanding contributes to the advancement of NFA-based systems and the optimization of charge transfer processes in polymer:NFA blends.

Discovery of a New Sea Spider Belonging to the Genus Pycnogonum (Pycnogonida: Pycnogonidae) in the Mesophotic Zone of Jejudo Island, Korea.

A new species of the genus Pycnogonum was discovered in the mesophotic zone of Munseom Islet, Jejudo Island, Korea. Pycnogonum (Nulloviger) bifurcatum sp. nov. is the first case of sea spiders in Korean fauna not only included in the subgenus Nulloviger but also collected in the mesophotic zone of Munseom Islet. The new species is morphologically close to Pycnogonum (Pycnogonum) asiaticum and P. (N.) carinatum, sharing the granular integument, the dorsomedian tubercles on the trunk, and the post-ocular tubercle. The new species can be easily distinguished from the congeners by combination of the following characteristics: the prominent dorsomedian tubercles on the trunk, the lateral processes 1-3 touching each other, and the small auxiliary claws. A key is provided to distinguish 12 species of the subgenus Nulloviger morphologically, and molecular data of the new species are provided for species identification and further studies.

Three-dimensional ternary NixCuyZnz(CO3)(OH)2 electrodes for supercapacitors: electrochemical properties and applications.

Transition metal-based binary and ternary compound arrays were directly grown on a porous Ni foam substrate using a facile one-step hydrothermal method. Transition metals are considered ideal electrode materials for faradaic capacitors because they exhibit a wide range of oxidation states enabling effective redox charge transfer. Furthermore, compounds in which two or more transition metals react can help increase the number of active sites for charge-discharge reactions and provide more valence changes for improved charge transfer. In this work, we fabricated ternary electrodes with Ni, Cu, and Zn ions, exhibiting a larger surface area and higher entropy than those made with binary compounds. The NixCuyZnz-based ternary electrode had a shorter diffusion path for the electrolyte ions owing to its larger surface area. Ternary compounds can increase the entropy of the electrode because of the reaction between atoms of different sizes, bringing about a synergistic effect for high characteristic electrochemical values. The optimized NixCuyZnz(CO3)(OH)2 compound showed a maximum specific capacity of 344 mA h g-1 at a current density of 3 A g-1, which was remarkably higher than that of the binary electrode, and a cycling stability of 84.9% after 5000 cycles. An asymmetric supercapacitor produced with this compound as the positive electrode and graphene as the negative electrode exhibited a high energy density of 36.2 W h kg-1 at a power density of 103.1 W kg-1 and a current density of 2 A g-1. The asymmetric supercapacitor fabricated using the NixCuyZnz(CO3)(OH)2 compound as the positive electrode exhibited excellent electrical properties when used in an illuminated LED device.

Morphological and molecular analyses of parasitic barnacles (Crustacea: Cirripedia: Rhizocephala) in Korea: preliminary data for the taxonomy and host ranges of Korean species.

Morphological and molecular analyses of Korean rhizocephalan barnacle species were performed to examine their host ranges and taxonomy. Morphological examination and molecular analysis of mtDNA cox1, 16S, and nuclear 18S rRNA sequences revealed nine rhizocephalan species from three genera of the two families, Sacculinidae and Polyascidae. Phylogenetic analysis of molecular sequences revealed two new species candidates in the genus Parasacculina, and three Sacculina species (S. pilosella, S. pinnotherae, and S. imberbis) were transferred to the genus Parasacculina. Examination of host ranges revealed higher host specificity and lower infestation rates in Korean rhizocephalan species than rhizocephalans from other geographic regions. This is the first report of the taxonomy, species diversity, and host ranges of Korean parasitic rhizocephalan barnacles based on their morphological and molecular analyses. More information from extensive sampling of parasitic barnacles from a wide range of crustacean host species is necessary to fully understand their taxonomy, prevalence on decapod hosts, and phylogenetic relationships among major rhizocephalan taxa.

Synthesis of nickel-copper composite with controllable nanostructure through facile solvent control as positive electrode for high-performance supercapacitors.

The surface characteristics of electrodes vary depending on the solvent used. Furthermore, electrochemical performance varies depending on the surface morphology of the electrode. In this study, we grew 3D binary NiCu-based composites on Ni foam, via a binder-free hydrothermal method, for use as a cathode in high-performance supercapacitors. We employed different solvents to prepare the electrodes by adjusting the ratio of deionized water (DI water) to methanol. The electrode prepared using DI water as the solvent had the largest surface area with a nanowire structure. This morphology allowed for good electrical performance by greatly improving the electrode and electrolyte contact area and shortening the ion diffusion path. The optimized deposition of NiCu(CO3)(OH)2 nanowires (50 mL of DI water as solvent) showed an excellent maximum specific capacity of 758.9 mA h g-1 at a current density of 3 A g-1, as well as outstanding cycling performance with 87.2% retention after 5000 cycles. In this work, we focused on the large specific surface area and suitable electrochemical properties of NiCu(CO3)(OH)2 electrodes with various solvents. As a result, the asymmetric supercapacitor (ASC) using the NiCu(CO3)(OH)2 electrode prepared with 50 ml of DI water as the solvent as the positive electrode and graphene as the negative electrode, exhibited an energy density of 26.7 W h kg-1 at a power density of 2534 W kg-1, and excellent cycling stability with 91.3% retention after 5000 cycles. The NiCu(CO3)(OH)2//graphene ASC could turn on an LED light and demonstrated better electrical performance than most previously reported nickel- and copper-based carbonate hydroxide ASCs. In addition, in the present scenario where many nanoscale studies are conducted, a method of controlling the nanostructure of a material through facile solvent control will be of great help to many researchers.

New species of Pycnogonum (Pycnogonida: Pycnogonidae) from Green Island, Taiwan, with an additional note on the holotype of P. spatium.

We report the discovery of a new species of the genus Pycnogonum Brünnich, 1764 found in the shallow waters of Green Island, Taiwan. Pycnogonum (Nulloviger) granulatum sp. nov. is characterized by the presence of the granular integument, a dorsal tubercle on the proboscis, the transverse ridges on the dorsal surface of the trunk, and the spines on the ventral surface of the tibia, tarsus, and propodus having cleft tips. Because the male gonopores are present and ovigers are absent, the present species belongs to the subgenus Nulloviger. The present species has been compared with P. (N.) moolenbeeki Stock, 1992, P. (N.) lobipes Stock, 1991, P. (N.) tuberculatum Clark, 1963, P. nodulosum Döhrn, 1881, and P. spatium Takahashi, Dick Mawatari, 2007. Among the congeners, P. spatium is geographically the closest congener, of which type locality is Amami Island, Japan. The holotype of P. spatium was loaned from Hokkaido University Museum (ICHUM) and re-examined. To determine the exact gender of the holotype of P. spatium, additional investigations of the coxal pellicula and gonopores are required.

Room-temperature synthesis and CO2-gas sensitivity of bismuth oxide nanosensors.

Room-temperature (27 °C) synthesis and carbon dioxide (CO2)-gas-sensor applications of bismuth oxide (Bi2O3) nanosensors obtained via a direct and superfast chemical-bath-deposition method (CBD) with different surface areas and structures, i.e., crystallinities and morphologies including a woollen globe, nanosheet, rose-type, and spongy square plate on a glass substrate, are reported. Moprhologies of the Bi2O3 nanosensors are tuned through polyethylene glycol, ethylene glycol, and ammonium fluoride surfactants. The crystal structure, type of crystallinity, and surface appearance are determined from the X-ray diffraction patterns, X-ray photoelectron spectroscopy spectra, and high-resolution transmission electron microscopy images. The room-temperature gas-sensor applications of these Bi2O3 nanosensors for H2, H2S, NO2, SO2, and CO2 gases are monitored from 10 to 100 ppm concentrations, wherein Bi2O3 nanosensors of different physical properties demonstrate better performance and response/recovery time measurement for CO2 gas than those for the other target gases employed. Among various sensor morphologies, the nanosheet-type Bi2O3 sensor has exhibited at 100 ppm concentration of CO2 gas, a 179% response, 132 s response time, and 82 s recovery time at room-temperature, which is credited to its unique surface morphology, high surface area, and least charge transfer resistance. This suggests that the importance of the surface morphology, surface area, and crystallinity of the Bi2O3 nanosensors used for designing room-temperature operable CO2 gas sensors for commercial benefits.

Chemically grown bismuth-oxy-iodide (BiOI/Bi9I2) nanostructure for high performance battery-type supercapacitor electrodes.

A dual phase bismuth oxyiodide (BiOI/Bi9I2) nanostructure battery type supercapacitor electrode is synthesized using chemical bath deposition (CBD) and the capacitance and energy/power density (ED/PD) reported. The supercapacitor electrode BiOI/Bi9I2 exhibited a specific capacitance of 515.5 F g-1 (capacity value 143 mA h g-1) at a current density of 2 A g-1, with 80% of the original capacitance retained, even at a high current density of 4 A g-1 over 5000 cycles. A pouch-type symmetric supercapacitor (PSS) device was created, based on BiOI/Bi9I2//BiOI/Bi9I2 electrodes (acting as anode and cathode electrodes) with 6 M KOH as the aqueous electrolyte and with an extended voltage up to 1.5 V. The ED value was 38.2 W h kg-1 at a current density of 2 A g-1, and the PD was 2280.4 W·kg-1. Three PSS type BiOI/Bi9I2//BiOI/Bi9I2 devices were connected in series and used to illuminate a red LED for 20 min with full brightness, confirming potential use as an energy storage device. The above summarized results indicate that BiOI/Bi9I2//BiOI/Bi9I2 could be a potential electrode for battery type supercapacitor applications.

Effect of Nitrogen Flow Ratio on Composition, Microstructure, and Mechanical Properties of Cr-B-O-N Films Deposited by Pulsed Direct Current Magnetron Sputtering.

Nano-crystalline CrB2 and Cr-B-O-N films with various nitrogen flow ratios were deposited using a pulsed direct current (PDC) magnetron sputtering technique. By means of electron probe micro-analysis, X-ray diffraction (XRD), X-ray photoelectron spectroscopy, scanning electron microscopy, high-resolution transmission electron microscopy (HRTEM), and atomic force microscopy, the influences of the nitrogen flow ratio on the phase constituents and microstructures of CrB2/Cr-B-O-N films were systematically investigated. Mechanical properties including the hardness and elastic modulus were explored by a nano-indentation tester. On increasing the nitrogen flow ratio, the N and O contents in films increased linearly and tended to become saturated, whereas the Cr and B contents decreased. With an increasing nitrogen flow ratio, the microstructure changed from a dense columnar structure to a bulky columnar structure, and then to a fine and stacked dense structure. Meanwhile, the deposition rate also changed with increasing nitrogen flow ratio, owing to the changes in structure. Crystalline phases were observed by the XRD and HRTEM analyses, consisting of several nanometer-size crystallites embedded in an amorphous matrix. The dramatically decreased hardness was attributed to the large fractional volume of the softer amorphous phase BN in films.