413 research outputs found
Fano Resonance in High-Permittivity Objects
In this chapter, Fano resonances in simple structures with high permittivity such as spheres or core-shell particles are analyzed by Mie theory. The Mie scattering coefficients can be decomposed into slow varying backgrounds and narrow resonances, which cause the Fano resonances in scattered field. For structures of arbitrary shapes, temporal coupled-mode theory is applied to explain the Fano resonances found in the scattering cross section. At last, we analyze the periodic structures by using band diagram, and it shows that the Fano resonances can be viewed as the superposition of the Bloch wave and the Mie scattering wave
La loi chinoise sur le contrat de travail et les coûts de production liés à la main-d’œuvre
La publication de la loi sur le contrat de travail en Chine a suscité un vif débat à propos du fardeau économique que représentent, pour les entreprises, les coûts de production liés à la main-d’œuvre. S’appuyant sur des données recueillies dans la province du Guangdong, dans le sud de la Chine, les résultats empiriques indiquent qu’en moyenne, pour les entreprises échantillonnées, l’augmentation du coût de la main-d’œuvre pouvant être attribuée à l’entrée en vigueur de la loi est de l’ordre de 2,54 à 4,9 %, ce qui n’est pas si important en termes économiques
China’s Labour Contract Law and Labour Costs of Production
The promulgation of the Labour Contract Law in China has aroused heated debate about the financial burden of the new labour costs for firms. However, based on a data set collected in Guangdong Province in southern China, the empirical findings suggest that, on average, the increase in labour costs per capita in the sample firms due to the effects of the law ranges between 2.54 percent and 4.90 percent, which seems to be economically insignificant
Adaptive Geometry Images for Remeshing
Geometry images are a kind of completely regular remeshing methods for mesh representation. Traditional geometry images have difficulties in achieving optimal reconstruction errors and preserving manually selected geometric details, due to the limitations of parametrization methods. To solve two issues, we propose two adaptive geometry images for remeshing triangular meshes. The first scheme produces geometry images with the minimum Hausdorff error by finding the optimization direction for sampling points based on the Hausdorff distance between the original mesh and the reconstructed mesh. The second scheme produces geometry images with higher reconstruction precision over the manually selected region-of-interest of the input mesh, by increasing the number of sampling points over the region-of-interest. Experimental results show that both schemes give promising results compared with traditional parametrization-based geometry images
Novel peptide–dendrimer conjugates as drug carriers for targeting nonsmall cell lung cancer
Phage display technology has been demonstrated to be a powerful tool for
screening useful ligands that are capable of specifically binding to biomarkers
on the surface of tumor cells. The ligands found by this technique, such as
peptides, have been successfully applied in the fields of early cancer
diagnostics and chemotherapy. In this study, a novel nonsmall cell lung
cancer-targeting peptide (LCTP, sequence RCPLSHSLICY) was screened in vivo using
a Ph.D.-C7C™ phage display library. In order to develop a
universal tumor-targeting drug carrier, the LCTP and fluorescence-labeled
molecule (FITC) were conjugated to an acetylated polyamidoamine (PAMAM)
dendrimer of generation 4 (G4) to form a
PAMAM–Ac–FITC–LCTP conjugate. The
performance of the conjugate was first tested in vitro. In vitro results of cell
experiments analyzed by flow cytometry and inverted fluorescence microscopy
indicated that PAMAM–Ac–FITC–LCTP was
enriched more in NCI-H460 cells than in 293T cells, and cellular uptake was both
time- and dose-dependent. The tissue distribution of the conjugate in athymic
mice with lung cancer xenografts was also investigated to test the targeting
efficiency of PAMAM–Ac–FITC–LCTP in vivo.
The results showed that LCTP can effectively facilitate the targeting of
PAMAM–Ac–FITC–LCTP to nonsmall cell lung
cancer cells and tumors. These results suggest that the LCTP-conjugated PAMAM
dendrimer might be a promising drug carrier for targeted cancer diagnosis and
treatment
Annexins in Influenza Virus Replication and Pathogenesis
Influenza A viruses (IAVs) are important human respiratory pathogens which cause seasonal or periodic endemic infections. IAV can result in severe or fatal clinical complications including pneumonia and respiratory distress syndrome. Treatment of IAV infections is complicated because the virus can evade host immunity through antigenic drifts and antigenic shifts, to establish infections making new treatment options desirable. Annexins (ANXs) are a family of calcium and phospholipid binding proteins with immunomodulatory roles in viral infections, lung injury, and inflammation. A current understanding of the role of ANXs in modulating IAV infection and host responses will enable the future development of more effective antiviral therapies. This review presents a comprehensive understanding of the advances made in the field of ANXs, in particular, ANXA1 and IAV research and highlights the importance of ANXs as a suitable target for IAV therapy
Ultralow thermal conductivity of single crystalline porous silicon nanowires
Porous materials provide a large surface to volume ratio, thereby providing a
knob to alter fundamental properties in unprecedented ways. In thermal
transport, porous nanomaterials can reduce thermal conductivity by not only
enhancing phonon scattering from the boundaries of the pores and therefore
decreasing the phonon mean free path, but also by reducing the phonon group
velocity. Here we establish a structure-property relationship by measuring the
porosity and thermal conductivity of individual electrolessly etched single
crystalline silicon nanowires using a novel electron beam heating technique.
Such porous silicon nanowires exhibit extremely low diffusive thermal
conductivity (as low as 0.33 Wm-1K-1 at 300K for 43% porosity), even lower than
that of amorphous silicon. The origin of such ultralow thermal conductivity is
understood as a reduction in the phonon group velocity, experimentally verified
by measuring the Young modulus, as well as the smallest structural size ever
reported in crystalline Silicon (less than 5nm). Molecular dynamics simulations
support the observation of a drastic reduction in thermal conductivity of
silicon nanowires as a function of porosity. Such porous materials provide an
intriguing platform to tune phonon transport, which can be useful in the design
of functional materials towards electronics and nano-electromechanical systems
Exposure to Urban Air Pollution and Bone Health in Clinically Healthy Six-year-old Children
Air pollution induces systemic inflammation, as well as respiratory, myocardial and brain inflammation in children. Peak bone mass is influenced by environmental factors. We tested the hypothesis that six-year-olds with lifetime exposures to urban air pollution will have alterations in inflammatory markers and bone mineral density (BMD) as opposed to low-polluted city residents when matched for BMI, breast feeding history, skin phototype, age, sex and socioeconomic status. This pilot study included 20 children from Mexico City (MC) (6.17 years ± 0.63 years) and 15 controls (6.27 years ± 0.76 years). We performed full paediatric examinations, a history of outdoor exposures, seven-day dietary recalls, serum inflammatory markers and dual-energy X-ray absorptiometry (DXA). Children in MC had significantly higher concentrations of IL-6 (p=0.001), marked reductions in total blood neutrophils (p= 0.0002) and an increase in monocytes (p=0.005). MC children also had an insufficient Vitamin D intake and spent less time outdoors than controls (p\u3c0.001) in an environment characterized by decreased UV light, with ozone and fine particulates concentrations above standard values. There were no significant differences between the cohorts in DXA Z scores. The impact of systemic inflammation, vitamin D insufficiency, air pollution, urban violence and poverty may have long-term bone detrimental outcomes in exposed paediatric populations as they grow older, increasing the risk of low bone mass and osteoporosis. The selection of reference populations for DXA must take into account air pollution exposures
Mst1-Mediated Phosphorylation of Nur77 Improves the Endometrial Receptivity in Human and Mice
Background: Successful embryo implantation requires the attachment of a blastocyst to the receptive endometrial epithelium, which was disturbed in the women with recurrent implantation failure (RIF). Endometrial β3-integrin was the most important adhesion molecule contributing to endometrial receptivity in both humans and mice. Nur77 has been proven indispensable for fertility in mice, here we explore the role of Nur77 on embryo-epithelial adhesion and potential treatment to embryo implantation failure.
Methods: The expression and location of Mst1 and Nur77 in endometrium from fertile women and RIF patients were examined by IHC, qRT-PCR and Western blotting. In vitro kinase assay following with LC-MS/MS were used to identify the phosphorylation site of Nur77 activated by Mst1. The phosphorylated Nur77 was detected by phos-tag SDS-PAGE assay and specific antibody against phospho-Nur77-Thr366. The effect of embryo-epithelium interaction was determined in the BeWo spheroid or mouse embryo adhesion assay, and delayed implantation mouse model. RNA-seq was used to explore the mechanism by which Nur77 derived peptide promotes endometrial receptivity.
Findings: Endometrial Mammalian sterile 20 (STE20)-like kinase 1 (Mst1) expression level was decreased in the women with RIF than that in the fertile control group, while Mst1 activation in the epithelial cells promoted trophoblast-uterine epithelium adhesion. The effect of Nur77 mediated trophoblast-uterine epithelium adhesion was facilitated by active Mst1. Mechanistically, mst1 promotes the transcription activity of Nur77 by phosphorylating Nur77 at threonine 366 (T366), and consequently increased downstream target β3-integrin expression. Furthermore, a Nur77-derived peptide containing phosphorylated T366 markedly promoted mouse embryo attachment to Ishikawa cells ([4 (2-4)] vs [3 (2-4)]) and increased the embryo implantation rate (4 vs 1.4) in a delayed implantation mouse model by regulating integrin signalling. Finally, it is observed that the endometrial phospho-Nur77 (T366) level is decreased by 80% in the women with RIF.
Interpretation: In addition to uncovering a potential regulatory mechanism of Mst1/Nur77/β3-integrin signal axis involved in the regulation of embryo-epithelium interaction, our finding provides a novel marker of endometrial receptivity and a potential therapeutic agent for embryo implantation failure.
Funding: National Key Research and Development Program of China (2018YFC1004400), the National Natural Science Foundation of China (82171653, 82271698, 82030040, 81971387 and 30900727), and National Institutes of Health grants (R01HL103869)
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