Yellow sea mediated segregation between North East AsianDryophytesspecies

While comparatively few amphibian species have been described on the North East Asian mainland in the last decades, several species have been the subject of taxonomical debates in relation to the Yellow sea. Here, we sampledDryophytessp. treefrogs from the Republic of Korea, the Democratic People's Republic of Korea and the People's Republic of China to clarify the status of this clade around the Yellow sea and determine the impact of sea level change on treefrogs' phylogenetic relationships. Based on genetics, call properties, adult morphology, tadpole morphology and niche modelling, we determined the segregated status species ofD.suweonensisandD.immaculatus. We then proceeded to describe a new treefrog species,D.flaviventrissp. nov., from the central lowlands of the Republic of Korea. The new species is geographically segregated fromD.suweonensisby the Chilgap mountain range and known to occur only in the area of Buyeo, Nonsan and Iksan in the Republic of Korea. While the Yellow sea is the principal element to the current isolation of the three clades, the paleorivers of the Yellow sea basin are likely to have been the major factor for the divergences within this clade. We recommend conducting rapid conservation assessments as these species are present on very narrow and declining ranges

Influence of wind speed on optical properties of aerosols in the marine boundary layer measured by ship-borne DePolarization Lidar in the coastal area of Korea

Shipboard measurements of microphysical and optical properties of marine boundary-layer aerosols were performed around the Korean Peninsula from 2 to 5 December 2009. The measurements were conducted aboard the Korean icebreaking research vessel Araon during cruise tracks in the East Sea of Korea near Busan and Pohang. This paper describes the results of optical aerosol measurements acquired with a DePolarization Lidar (DPL) and an Optical Particle Counter (OPC) and data on meteorological parameters. Backward trajectory analyses indicate that two different aerosol characteristics according to different pathways of air mass encountered during the cruise. We find a high correlation between wind speeds across the east coast of Korea and extinction coefficient, depolarization ratio and mass concentration with correlation coefficient (R2) of 0.57, 0.52 and 0.67, respectively. The increase of extinction coefficient, depolarization ratio and number concentration with wind speed may have been caused by the increase of sea-salt aerosol production and transport.Peer reviewe

Fabrication and Characterizations of Hot-Melt Extruded Nanocomposites Based on Zinc Sulfate Monohydrate and Soluplus

Zinc sulfate monohydrate (ZnSO4)-loaded nanocomposites (NCs) were fabricated by using a hot-melt extruder (HME) system. Soluplus (SP) was adopted as an amphiphilic polymer matrix for HME processing. The micro-size of ZnSO4 dispersion was reduced to nano-size by HME processing with the use of SP. ZnSO4 could be homogeneously dispersed in SP through HME processing. ZnSO4/SP NCs with a 75 nm mean diameter, a 0.1 polydispersity index, and a −1 mV zeta potential value were prepared. The physicochemical properties of ZnSO4/SP NCs and the existence of SP in ZnSO4/SP NCs were further investigated by solid-state studies. Nano-size range of ZnSO4/SP NC dispersion was maintained in the simulated gastrointestinal environments (pH 1.2 and 6.8 media). No severe toxicity in intestinal epithelium after oral administration of ZnSO4/SP NCs (at 100 mg/kg dose of ZnSO4, single dosing) was observed in rats. These results imply that developed ZnSO4/SP NC can be used as a promising nano-sized zinc supplement formulation. In addition, developed HME technology can be widely applied to fabricate nanoformulations of inorganic materials

Efficient avalanche photodiodes with a WSe₂/MoS₂ heterostructure via two-photon absorption

Two-dimensional (2D) materials-based photodetectors in the infrared range hold the key to enabling a wide range of optoelectronics applications including infrared imaging and optical communications. While there exist 2D materials with a narrow bandgap sensitive to infrared photons, a two-photon absorption (TPA) process can also enable infrared photodetection in well-established 2D materials with large bandgaps such as WSe2 and MoS2. However, most of the TPA photodetectors suffer from low responsivity, preventing this method from being widely adopted for infrared photodetection. Herein, we experimentally demonstrate 2D materials-based TPA avalanche photodiodes achieving an ultrahigh responsivity. The WSe2/MoS2 heterostructure absorbs infrared photons with an energy smaller than the material bandgaps via a low-efficiency TPA process. The significant avalanche effect with a gain of ∼1300 improves the responsivity, resulting in the record-high responsivity of 88 μA/W. We believe that this work paves the way toward building practical and high-efficiency 2D materials-based infrared photodetectors.Ministry of Education (MOE)National Research Foundation (NRF)This work is supported by the Ministry of Education, Singapore, under Grant AcRF TIER 1 (RG 115/21)). This work is also supported by the Ministry of Education, Singapore, under Grant AcRF TIER 2 (MOE2018-T2-2-011 (S)). This work is also supported by the National Research Foundation of Singapore (Competitive Research Program (NRF-CRP19-2017-01)). This work is also supported by the National Research Foundation of Singapore (NRF-ANR Joint Grant (NRF2018-NRF-ANR009 TIGER)). This work is also supported by an iGrant of Singapore (A*STAR AME IRG (A2083c0053)). The authors acknowledge Donghoon Lee and Seok Woo Lee at Nanyang Technological University for the usage of the O2 plasma equipment

Optimizing Active Tumor Targeting Biocompatible Polymers for Efficient Systemic Delivery of Adenovirus

Adenovirus (Ad) has risen to be a promising alternative to conventional cancer therapy. However, systemic delivery of Ad, which is necessary for the treatment of metastatic cancer, remains a major challenge within the field, owing to poor tumor tropism and nonspecific hepatic tropism of the virus. To address this limitation of Ad, we have synthesized two variants of folic acid (FA)-conjugated methoxy poly(ethylene glycol)-b-poly{N-[N-(2-aminoethyl)-2-aminoethyl]-L-glutamate (P5N2LG-FA and P5N5LG-FA) using 5 kDa poly(ethylene glycol) (PEG) with a different level of protonation (N2 < N5 in terms of charge), along with a P5N5LG control polymer without FA. Our findings demonstrate that P5N5LG, P5N2LG-FA, and P5N5LG-FA exert a lower level of cytotoxicity compared to 25 kDa polyethyleneimine. Furthermore, green fluorescent protein (GFP)-expressing Ad complexed with P5N2LG-FA and P5N5LG-FA (Ad/P5N2LG-FA and Ad/P5N5LG-FA, respectively) exerted superior transduction efficiency compared to naked Ad or Ad complexed with P5N5LG (Ad/P5N5LG) in folate receptor (FR)-overexpressing cancer cells (KB and MCF7). All three nanocomplexes (Ad/P5N5LG, Ad/P5N2LG-FA, and Ad/P5N5LG-FA) internalized into cancer cells through coxsackie adenovirus receptor-independent endocytic mechanism and the cell uptake was more efficient than naked Ad. Importantly, the cell uptake of the two FA functionalized nanocomplexes (Ad/P5N2LG-FA and Ad/P5N5LG-FA) was dependent on the complementary interaction of FA–FR. Systemically administered Ad/P5N5LG, Ad/P5N2LG-FA, and Ad/P5N5LG-FA showed exponentially higher retainment of the virus in blood circulation up to 24 h post-administration compared with naked Ad. Both tumor-targeted nanocomplexes (Ad/P5N2LG-FA and Ad/P5N5LG-FA) showed significantly higher intratumoral accumulation than naked Ad or Ad/P5N5LG via systemic administration. Both tumor-targeted nanocomplexes accumulated at a lower level in liver tissues compared to naked Ad. Notably, the nonspecific accumulation of Ad/P5N2LG-FA was significantly lower than Ad/P5N5LG-FA in several normal organs, while exhibiting a significantly higher intratumoral accumulation level, showing that careful optimization of polyplex surface charge is critical to successful tumor-targeted systemic delivery of Ad nanocomplexes

Inclined lidar observations of boundary layer aerosol particles above the Kongsfjord, Svalbard

An inclined lidar with vertical resolution of 0.4 m was used for detailed boundary layer studies and to link observations at Zeppelin Mountain (474 m) and Ny-Ålesund, Svalbard. We report on the observation of aerosol layers directly above the Kongsfjord. On 29 April 2007, a layer of enhanced backscatter was observed in the lowest 25 m above the open water surface. The low depolarization ratio indicated spherical particles. In the afternoon, this layer disappeared. The ultrafine particle concentration at Zeppelin and Corbel station (close to the Kongsfjord) was low. On 1 May 2007, a drying process in the boundary layer was observed. In the morning, the atmosphere up to Zeppelin Mountain showed enhanced values of the backscatter coefficient. Around noon, the top of the highly reflecting boundary layer decreased from 350 to 250 m. The top of the boundary layer observed by lidar was confirmed by radiosonde data

Peptide-Assembled Single-Chain Atomic Crystal Enhances Pluripotent Stem Cell Differentiation to Neurons

Nanomaterials hybridized with biological components havewidespreadapplications. among many candidates, peptides are attractive in thattheir peptide sequences can self-assemble with the surface of targetmaterials with high specificity without perturbing the intrinsic propertiesof nanomaterials. Here, a 1D hybrid nanomaterial was developed throughself-assembly of a designed peptide. A hexagonal coiled-coil motifgeometrically matched to the diameter of the inorganic nanomaterialwas fabricated, whose hydrophobic surface was wrapped along the axisof the hydrophobic core of the coiled coil. Our morphological andspectroscopic analyses revealed rod-shaped, homogeneous peptide-inorganicnanomaterial complexes. Culturing embryonic stem cells on surfacescoated with this peptide-assembled single-chain atomic crystal increasedthe growth and adhesion of the embryonic stem cells. The hybridizednanomaterial also served as an ECM for brain organoids, acceleratingthe maturation of neurons. New methods to fabricate hybrid materialsthrough peptide assembly can be applied.11Nsciescopu