No abstract

Background: The two closely related species of band-winged grasshoppers, Gastrimargus marmoratus and Oedaleus asiaticus, display significant differences in distribution, biological characteristics and habitat preferences. They are so similar to their respective congeneric species that it is difficult to differentiate them from other species within each genus. Hoppers of the two species have quite similar morphologies to that of Locusta migratoria, hence causing confusion in species identification. Thus we determined and compared the mitochondrial genomes of G. marmoratus and O. asiaticus to address these questions.

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Plant invasion is one of the major threats to natural ecosystems. Phenotypic plasticity is considered to be important for promoting plant invasiveness. High tolerance of stress can also increase survival of invasive plants in adverse habitats. Limited growth and conservation of carbohydrate are considered to increase tolerance of flooding in plants. However, few studies have examined whether invasive species shows a higher phenotypic plasticity in response to waterlogging or a higher tolerance of waterlogging (lower plasticity) than native species. We conducted a greenhouse experiment to compare the growth and morphological and physiological responses to waterlogging of the invasive, clonal, wetland species Alternanthera philoxeroides with those of its co-occurring, native, congeneric, clonal species Alternanthera sessilis. Plants of A. philoxeroides and A. sessilis were subjected to three treatments (control, 0 and 60 cm waterlogging). Both A. philoxeroides and A. sessilis survived all treatments. Overall growth was lower in A. philoxeroides than in A. sessilis, but waterlogging negatively affected the growth of A. philoxeroides less strongly than that of A. sessilis. Alternanthera philoxeroides thus showed less sensitivity of growth traits (lower plasticity) and higher waterlogging tolerance. Moreover, the photosynthetic capacity of A. philoxeroides was higher than that of A. sessilis during waterlogging. Alternanthera philoxeroides also had higher total non-structural and non-soluble carbohydrate concentrations than A. sessilis at the end of treatments. Our results suggest that higher tolerance to waterlogging and higher photosynthetic capacity may partly explain the invasion success of A. philoxeroides in wetlands.

Benzofurans are among the most popular structural units in bioactive natural products,h owever,t he synthesis of such structures by radical cyclization cascade reactions is rare. Herein, we report am ild and broadly applicable method for the construction of complex benzofurylethylamine derivatives through au nique radical cyclization cascade mechanism. Single-electron transfer (SET) from 2-azaallyl anions to 2-iodo aryl allenyl ethers initiates aradical cyclization that is followed by intermolecular radical-radical coupling. This expedient approach enables the synthesis of ar ange of polycyclic benzofurans that would otherwise be difficult to prepare.

The research of high efficiency water splitting catalyst is important for the development of renewable energy economy. Here, the progress in the preparation of high efficiency hydrogen evolution reaction (HER) catalyst is reported. The support material is based on a polyhexaphenylbenzene material with intrinsic holes, which heals into carbon materials upon heating. The healing process is found to be useful for anchoring various transition metal atoms, among which the supported Ir Single‐atom catalyst (SAC) catalyst shows much higher electrocatalytic activity and stability than the commercial Pt/C and Ir/C in HER. There is only 17 mV overpotential at 10 mA cm–2, which is significantly lower than that of commercial Pt/C and Ir/C catalysts respectively by 26 and 3 mV, and the catalyst has an ultra‐high mass activity (MA) of 51.6 AmgIr−1${\text{ A mg}}_{{\rm{Ir}}}^{ - 1}$ at 70 mV potential and turn over frequencies (TOF) of 171.61 s–1 at the potential of 100 mV. The density functional theory (DFT) calculation reveals the significant role of carbon coordination around the Ir center. A series of monatomic PBN‐300‐M are synthesized by using of designed carbon materials. The findings provide an enabling and versatile platform for facile accessing SACs toward many industrial important reactions.

The low density lipoprotein receptor related protein 1B (LRP1B) is a large endocytic receptor that was first identified as a candidate tumor suppressor gene. In the current investigation we demonstrate that LRP1B undergoes regulated intramembrane proteolysis in a ␥-secretase-dependent process. The released intracellular domain (ICD) then translocates to the nucleus via a nuclear localization signal that is present within this domain. ICD release first requires shedding of the LRP1B ectodomain, which appears to be catalyzed by a member of the metalloproteinase family. Employing site-directed mutagenesis studies, we identified lysine residues 4432 and 4435 and arginine 4442 as key amino acids important for ectodomain shedding of LRP1B. We also demonstrate that an LRP1B minireceptor as well as the ICD domain alone suppresses anchorage-independent growth of LRP1B-deficient neuroglioma cells (H4 cells). Interestingly, abrogating ectodomain shedding resulted in a loss of the ability of LRP1B minireceptors to suppress anchorage-independent growth. Together, these studies reveal that LRP1B has tumor suppression function that is mediated by proteolytic processing of the receptor resulting in ICD release. The low density lipoprotein (LDL)2 receptor-related protein 1B (LRP1B) is a member of the LDL receptor gene family and was initially identified as a candidate tumor suppressor gene by positional cloning (1, 2). The LRP1B gene is frequently inactivated by homozygous genomic deletions or by the expression of aberrant mRNA transcripts (1). In human esophagus cancer cell lines and primary tumors the LRP1B gene was shown to be inactivated by transcriptional silencing through hypermethylation of its promoter CpG island (3). Homozygous deletions of LRP1B have also been reported in human liver cancers (4) and urothelial cancers (5). By conventional and array-based comparative genomic hybridization analysis, loss of the LRP1B allele was noted in endocervical adenocarcinomas of uterus (6). Thus, collective data indicate that this gene is inactivated during cellular transformation, suggesting that LRP1B is a candidate tumor suppressor gene.Structurally, LRP1B is closely related to LRP1, a receptor that recognizes numerous ligands and is essential for normal development (7). Like LRP1, LRP1B contains a furin cleavage site (REKR) within a ␤-propeller domain that is cleaved by furin during receptor trafficking (8 -10). The major structural differences between LRP1 and LRP1B occur within their intracellular domains (ICD). First, the LRP1B ICD contains an alternatively spliced exon (exon 90) that is not present in LRP1 (1). Second, the LRP1B ICD contains a cluster of basic residues (KRKRRTK) that is similar to basic clusters in BRCA2 tumor suppressor which have been shown to function as a nuclear localization sequence (NLS) (11).Currently, the physiological function of LRP1B remains unknown. In mice, LRP1B expression is primarily restricted to the brain, adrenal glands, salivary gland, and testis (12). However, in humans, LRP1B is widel...

In view of the limitations of vortex generators with polarization dependence at present, we propose a plasmonic vortex generator composed of rectangular holes etched in silver film, in which the optical vortex can be generated under arbitrary linearly polarized light illumination. Two sets of rectangular holes are arranged equidistantly on a circle and rotate in postulate directions. Theoretical analysis provides the design principle for the vortex generator, and numerical simulations give guidance on designating the vortex generator parameters. Experimental measurements verify the performance of the proposed vortex generator. Moreover, two alternative structures for the generation of a plasmonic vortex are also provided in this paper. The resulting perfect vortex, compact structure and flexible illumination conditions will lead to wide applications of this plasmonic vortex generator.