Transfer Mechanism, Uptake Kinetic Process, and Bioavailability of P, Cu, Cd, Pb, and Zn in Macrophyte Rhizosphere Using Diffusive Gradients in Thin Films

The transfer-uptake-bioavailability of phosphorus (P), Cu, Cd, Zn, and Pb in rhizosphere of <i>Zizania latifolia</i> (ZL) and <i>Myriophyllum verticiilaturn</i> (MV) cultivated in rhizoboxes in Lake Erhai (China) is evaluated by DGT (diffusive gradients in thin films) technique. DGT induced fluxes in sediments (DIFS) model reveals that resupply ability (r), liable pool size in sediment solid (<i>k</i>_d), kinetic parameter (<i>k</i>_–1), or response time (<i>T</i>_c) control the diffusion-resupply characters of P and Cu (standing for four metals) in rhizosphere interface. The linear fitting curves of element content in ZL or MV roots (<i>C</i>_root) against DGT (<i>C</i>_DGT), porewater (<i>C</i>₀), or sediment concentration demonstrate that <i>C</i>_root for five elements can be predicted by <i>C</i>_DGT more effectively than the other methods. (I) DOC (dissolved organic carbon) in porewater controlled by OM (organic matter) in solid plus pH for Cu and Cd or (II) DOP/DTP ratio in porewater (between dissolved organic P and dissolved total P) for P controlled by Fe-bound P and OM in solid, can affect phytoavailability in rhizosphere. They lead to (I) the larger slope (<i>s</i>) and the linear regression coefficient (<i>R</i>²) in the first part than those for the complete fitting curve (ZL or MV root against <i>C</i>_DGT(Cu) or <i>C</i>₀(Cu) and MV root against <i>C</i>_DGT(Cd)) or (II) the outliers above or below the fitting curve (ZL root (P) against <i>C</i>₀(P) or <i>C</i>_DGT(P)) and the larger <i>R</i>² without outliers. DGT–rhizobox–DIFS should be a reliable tool to research phytoremediation mechanism of macrophytes

Visualization 1: Parametric distortion-adaptive neighborhood for omnidirectional camera

Video demonstration of human tracking with NEB-HW-PF. Originally published in Applied Optics on 10 August 2015 (ao-54-23-6969

Hydrocarbon Waxes from a Salt in Water: The C1 Polymerization of Trimethylsulfoxonium Halide

We report the synthesis of polymethylene waxes, a surrogate of PE waxes, by a controlled polymerization reaction in water at or near r.t. and under atmospheric pressure. The monomer, dimethylsulfoxonium methylide, is generated in situ from a salt, trimethylsulfoxonium halide. The carbon sources for the polymerizations are C1 molecules, which can be derived from nonpetroleum feedstock. DMSO serves as the C1 carrier and is not consumed. The reaction is initiated and catalyzed by trialkylboranes, compounds that are stable in water. A certain degree of molecular weight control is achieved by adjusting the stoichiometry of “salt” to organoborane. Polymethylene, the simplest hydrocarbon polymer, is a semicrystalline material. The room temperature polymerization produces a linear polymer approximately 100 °C below its melting temperature (<i>T</i>_m). The supercooled polymers rapidly crystallize into flat nanoparticles comprised of stacked lamellae

Crystal Structure and Chemical Bonding of Layered α‑In₂Se₃

Layered α-In2Se3 has found widespread applications in the electronic, optoelectronic, and thermoelectric fields. However, the crystal structure of α-In2Se3, which plays a fundamental role in understanding its diverse physical properties, remains poorly explored. In this study, we present a comprehensive analysis of the temperature-dependent evolution of lattice constants, fractional coordinates, and atomic displacement parameters of α(3R)-In2Se3 using high-resolution synchrotron powder X-ray diffraction. The temperature range of investigation spans from 114.2 to 472.2 K. From temperature-dependent cell parameters, the linear thermal expansion coefficients along the a-axis and c-axis at room temperature are determined as 0.71 × 10–5 K–1 and 1.83 × 10–5 K–1, respectively, giving rise to a marked anisotropy owing to the weak interlayer interactions along the c-axis. Through modeling of isotropic atomic displacement parameters, the Debye temperature is evaluated to be 173 K, showing good agreement with the result by fitting the low-temperature heat capacity data. Furthermore, we conduct chemical bonding analysis within the quantum theory of atoms in molecules and reveal that α(3R)-In2Se3 exhibits polar covalent intralayer bonds with weak van der Waals interlayer interaction

TaFeSb-Based Half-Heusler Thermoelectrics with High <i>zT</i> > 1 through the Alloying Effect

Ternary half-Heusler (HH) alloys have been extensively studied because of their various intriguing functionalities, such as thermoelectric (TE), magnetic, superconductive, and topological properties. Recently, TaFeSb-based HH alloys have been determined to be potential high-temperature TE materials with a dimensionless TE figure of merit zT > 1 for the application of power generation. Herein, we simultaneously optimize the electrical and thermal properties of TaFeSb-based materials through the alloying effect of elemental substitution, leading to a maximum zT of 1.20 at 1025 K. Furthermore, the co-alloying effect not only optimizes the electrical transport performances but also significantly diminishes the lattice thermal conductivity. In comparison with that of pristine TaFeSb, a remarkable reduction of 65% is achieved at room temperature for the (Ta0.8V0.2)0.84Ti0.16FeSb sample, which can be correlated to the mass and strain field fluctuations. Our work highlights the significance of the alloying effect as a design factor and demonstrates the advantages of p-type TaFeSb-based HHs due to their excellent TE performance

Nickel Cobalt Thiospinel Nanoparticles as Hydrodesulfurization Catalysts: Importance of Cation Position, Structural Stability, and Sulfur Vacancy

First-row transition metal-based thiospinels are prepared via a one-pot versatile strategy and for the first time investigated as hydrodesulfurization (HDS) catalysts. X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy analysis confirm that these thiospinels consist of agglomerated nanoparticles (NPs) and contain multivalent metal cations. Among the sulfides synthesized at 230 °C, NiCo₂S₄ presents the highest thiophene conversion. This high intrinsic activity is found to be correlated with the normal spinel structure with Ni cations located on the tetrahedral sites and Co cations on the octahedral sites. However, the spent NiCo₂S₄ NPs experience phase transformation because of the relatively low synthetic temperature. Accordingly, six NiCo₂S₄ samples are prepared in the temperature range of 180–350 °C, and their HDS activity increases monotonically with the synthetic temperature, which is attributed to the higher structural stability and more surface sulfur vacancy of the NiCo₂S₄ NPs prepared at higher temperatures. Notably, the NiCo₂S₄ NPs synthesized at 350 °C exhibit a much higher thiophene conversation of 62.9% than the classic MoS₂ catalyst (39.3%) as well as excellent reusability. Our study suggests that the NiCo₂S₄ thiospinels with high activity and stability can represent a new promising class of industrial HDS catalysts

Highly Fluorescent, Near-Infrared-Emitting Cd²⁺-Tuned HgS Nanocrystals with Optical Applications

Bulk HgS itself has proven to be a technologically important material; however, the poor stability and weak emission of HgS nanocrystals have greatly hindered their promising applications. Presently, a critical problem is the uncontrollable growth of HgS NCs and their intrinsic surface states which are susceptible to the local environment. Here, we address the issue by an ion-tuning approach to fabricating stable, highly fluorescent Cd:HgS/CdS NCs for the first time, which efficiently tuned the band-gap level of HgS NCs, pushing their intrinsic states far away from the surface, reducing the strong interaction of the environment with surface states and hence drastically boosting the exciton transition. As compared to bare HgS NCs, the obtained Cd:HgS/CdS NCs exhibited tunable luminescence peaks from 724 to 825 nm with an unprecedentedly high quantum yield up to 40% at room temperature and excellent thermal and photostability. Characterized by TEM, XRD, XPS, and AAS, the resultant Cd:HgS/CdS NCs possessed a zinc-blende structure and was composed of a homogeneous alloyed HgCdS structure coated with a thin-layer CdS shell. The formation mechanism of Cd:HgS/CdS NCs was proposed. These bright, stable HgS-based NCs presented promising applications as fluorescent inks for anticounterfeiting and as excellent light converters when coated onto a blue-light-emitting diode

Tabercarpamines A–J, Apoptosis-Inducing Indole Alkaloids from the Leaves of <i>Tabernaemontana corymbosa</i>

A total of 10 new indole alkaloids, tabercarpamines A–J (<b>1</b>–<b>10</b>), were isolated from the leaves of <i>Tabernaemontana corymbosa</i>. Tabercarpamines C–F (<b>3</b>–<b>6</b>) are rare C-14/C-15-<i>seco</i>-tabersonine-type monoterpenoid indole alkaloids, and <b>5</b> and <b>6</b> are the first examples with a lactone linkage between C-14 and C-20. The structures of these alkaloids were elucidated using spectroscopic methods, and the absolute configurations of <b>1</b> and <b>2</b> were determined using the ECD exciton chirality method. In addition, an MTT assay was used to examine the growth-inhibitory effects of all new isolates and of two known isolates on MCF-7, HepG2, and SMMC-7721 cells; <b>1</b> exhibited significant inhibitory effects against these three human cancer cell lines with IC₅₀ values of 8.54, 3.31, and 6.76 μM, respectively. Additionally, the results from the annexin-V/PI double-staining assay indicated that <b>1</b> might inhibit the proliferation of HepG2 cells by inducing apoptosis

MiR-103 Controls Milk Fat Accumulation in Goat (<i>Capra hircus</i>) Mammary Gland during Lactation

<div><p>Milk is the primary source of nutrition for young mammals including humans. The nutritional value of milk is mainly attributable to fats and proteins fractions. In comparison to cow milk, goat milk contains greater amounts of total fat, including much higher levels of the beneficial unsaturated fatty acids. MicroRNAs (miRNAs), a well-defined group of small RNAs containing about 22 nucleotides (nt), participate in various metabolic processes across species. However, little is known regarding the role of miRNAs in regulating goat milk composition. In the present study, we performed high-throughput sequencing to identify mammary gland-enriched miRNAs in lactating goats. We identified 30 highly expressed miRNAs in the mammary gland, including miR-103. Further studies revealed that miR-103 expression correlates with the lactation. Further functional analysis showed that over-expression of miR-103 in mammary gland epithelial cells increases transcription of genes associated with milk fat synthesis, resulting in an up-regulation of fat droplet formation, triglyceride accumulation, and the proportion of unsaturated fatty acids. This study provides new insight into the functions of miR-103, as well as the molecular mechanisms that regulate milk fat synthesis.</p></div

Palladium-Catalyzed C(sp³)–H Nitrooxylation of Aliphatic Carboxamides with Practical Oxidants

Here we report the palladium-catalyzed β-C(sp3)−H nitrooxylation of aliphatic carboxamides using a modified quinoline auxiliary. Notably, Al(NO3)3·9H2O was used as a nitrate source as well as a practical oxidant. The 5-chloro-8-aminoquinoline auxiliary was nitrated in situ during the reaction, which may enhance its directing ability and help its removal. The reaction has a broad substrate scope with a variety of aliphatic carboxamides. The multiple substituted auxiliary can be easily removed and recovered. Two C–H-insertion palladacycle intermediates were isolated and characterized to elucidate the mechanism