Contributions of photosynthetic organs to the seed yield of hybrid rice: The effects of gibberellin application examined by carbon isotope technology

The Author(s), 2018. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Contributions of photosynthetic organs to the seed yield of hybrid rice: The effects of gibberellin application examined by carbon isotope technology. Seed Science and Technology, 46(3), (2018): 533-546, doi:10.15258/sst.2018.46.3.10.Changes in the structure and quality of a hybrid combination population have been observed after the application of gibberellins. Such changes would affect the accumulation and distribution of photosynthetic products, which would subsequently affect the yield during hybrid rice seed production. In this study, photosynthetic physiological characteristics and the distribution of photosynthetic products were evaluated in a field experiment. The transport of panicle photosynthetic products to grain was demonstrated using a 14C isotope tracer technique.The contribution ratios of the panicle and leaf to yield in the hybrid rice seed production were 32.3 and 42.1%, respectively. Through isotope tracing technology, it was determined that about 90% of the photosynthetic products of the panicle and 50% of those of the leaf were delivered to the panicle. During the filling period, the contribution of panicle to yield was concentrated in the early period (0–10 days after pollination), and the contribution of leaf to yield was more significant in the late period (10 days after pollination to maturity). These results suggest that the panicle makes an important photosynthetic contribution (equivalent to that of the flag leaf) during the process of grain filling, especially at 0–5 days after the heading stage.We are thankful to anonymous reviewers and editors for their helpful comments and suggestions. This research was part of the project for the National Natural Science Foundation of China (No. 31271666), “12th 5-year plan” Agro-Scientific Research in the Public Interest (Grant No. 201303002) and the Earmarked Fund for China Agriculture Research System (Grant No. CARS-01-26)

Quantifying the impact of aerosol scattering on the retrieval of methane from airborne remote sensing measurements

As a greenhouse gas with strong global warming potential, atmospheric methane (CH₄) emissions have attracted a great deal of attention. Although remote sensing measurements can provide information about CH₄ sources and emissions, accurate retrieval is challenging due to the influence of atmospheric aerosol scattering. In this study, imaging spectroscopic measurements from the Airborne Visible/Infrared Imaging Spectrometer – Next Generation (AVIRIS-NG) in the shortwave infrared are used to compare two retrieval techniques – the traditional matched filter (MF) method and the optimal estimation (OE) method, which is a popular approach for trace gas retrievals. Using a numerically efficient radiative transfer model with an exact single-scattering component and a two-stream multiple-scattering component, we also simulate AVIRIS-NG measurements for different scenarios and quantify the impact of aerosol scattering in the two retrieval schemes by including aerosols in the simulations but not in the retrievals. The presence of aerosols causes an underestimation of CH₄ in both the MF and OE retrievals; the biases increase with increasing surface albedo and aerosol optical depth (AOD). Aerosol types with high single-scattering albedo and low asymmetry parameter (such as water-soluble aerosols) induce large biases in the retrieval. When scattering effects are neglected, the MF method exhibits lower fractional retrieval bias compared to the OE method at high CH₄ concentrations (2–5 times typical background values) and is suitable for detecting strong CH₄ emissions. For an AOD value of 0.3, the fractional biases of the MF retrievals are between 1.3 % and 4.5 %, while the corresponding values for OE retrievals are in the 2.8 %–5.6 % range. On the other hand, the OE method is an optimal technique for diffuse sources (<1.5 times typical background values), showing up to 5 times smaller fractional retrieval bias (8.6 %) than the MF method (42.6 %) for the same AOD scenario. However, when aerosol scattering is significant, the OE method is superior since it provides a means to reduce biases by simultaneously retrieving AOD, surface albedo, and CH₄. The results indicate that, while the MF method is good for plume detection, the OE method should be employed to quantify CH₄ concentrations, especially in the presence of aerosol scattering

Influence of polyethylene glycol density and surface lipid on pharmacokinetics and biodistribution of lipid-calcium-phosphate nanoparticles

The pharmacokinetics (PK) and biodistribution of nanoparticles (NPs) are controlled by a complex array of interrelated, physicochemical and biological factors of NPs. The lipid-bilayer core structure of the Lipid-Calcium-Phosphate (LCP) NPs allows us to examine the effects of the density of polyethylene glycol (PEG) and the incorporation of various lipids onto the surface on their fate in vivo. Fluorescence quantification estimated that up to 20% (molar percent of outer leaflet lipids) could be grafted on the surface of LCP NPs. Contrary to the common belief that high level of PEGylation could prevent the uptake of NPs by the reticuloendothelial system (RES) organs such as liver and spleen, a significant amount of the injected dose was observed in the liver. Confocal microscopy revealed that LCP NPs were largely localized in hepatocytes not Kupffer cells. It was further demonstrated that the delivery to hepatocytes was dependent on both the concentration of PEG and the surface lipids. LCP NPs could be directed from hepatocytes to Kupffer cells by decreasing PEG concentration on the particle surface. In addition, LCP NPs with 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) exhibited higher accumulation in the hepatocytes than LCP NPs with dioleoylphosphatidylcholine (DOPC). Analysis of the proteins bound to NPs suggested that apolipoprotein E (apoE) might serve as an endogenous targeting ligand for LCP-DOTAP NPs, but not LCP-DOPC NPs. The significant uptake of NPs by the hepatocytes is of great interest to formulation design for oncologic and hepatic drug deliveries

Observation analysis of "5.22" extreme rainfall event in Guilin

An extreme heavy rainfall event struck the northern part of the Guilin urban area in the early morning of May 22, 2023, breaking local historical records for both hourly and three-hourly precipitation, resulting in severe urban waterlogging. Analysis was conducted using data from routine observation, ground-based dense automatic stations, Doppler weather radar, and ERA5 reanalysis. The results are as follows. (1) This event occurred on the edge of the subtropical high-pressure system, with the continuous strengthening of the southwest jet stream providing abundant moisture and energy for the extreme rainfall under the influence of the low-level shear line and the southward movement of the surface cold front. (2) The echoes of heavy rainfall evolved into a linear convection, which changed the direction and shape when timely met with the surface cold air. Meanwhile, the continuously developing new individual cells on its western side joined to form a "train effect," leading to extreme rainfall. The echo exhibited characteristics of low core and high efficiency. (3) The timely intrusion of weak cold air intensified convective rainfall and enhanced cold pool outflow, triggering new convection in the warm and moist region ahead of it, which favored the development and persistence of heavy rainfall. (4) During the eastward movement of individual convective cells, they merged through cloud bridges and expanded through cloud development, forming new cloud clusters and rapidly intensifying precipitation. The interaction and merging of convective cells were the main mechanisms for the prolonged and intensified heavy rainfall. (5) Various numerical models underestimated the intensity of this event, with biases in forecasting the rainfall center mainly due to deviations in the timing of forecasting the influence of surface cold air

A Highly Efficient Synthetic Vector: Nonhydrodynamic Delivery of DNA to Hepatocyte Nuclei in Vivo

Multifunctional membrane-core nanoparticles, composed of calcium phosphate cores, arginine-rich peptides, cationic and PEGylated lipid membranes, and galactose targeting ligands, have been developed as synthetic vectors for efficient nuclear delivery of plasmid DNA and subsequent gene expression in hepatocytes in vivo. Targeted particles exhibited rapid and extensive hepatic accumulation and were predominantly internalized by hepatocytes, while the inclusion of such peptides in LCP was sufficient to elicit high degrees of nuclear translocation of plasmid DNA. Monocyclic CR8C significantly enhanced in vivo gene expression over ten-fold more than linear CR8C, likely due to a release-favoring mechanism of the DNA/peptide complex. Though 100-fold lower in activity than that achieved via hydrodynamic injection, this formulation presents as a much less invasive alternative. To our knowledge, this is the most effective synthetic vector for liver gene transfer

Nanoparticle Delivery of Pooled siRNA for Effective Treatment of Non-Small Cell Lung Caner

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related death. To explore the potential of small interfering RNA (siRNA) therapy for NSCLC, we have developed anisamide-targeted LCP to efficiently deliver siRNA into the cytoplasm of sigma receptor-expressing NSCLC cells. Targeted LCP demonstrated a 9-fold higher siRNA delivery efficiency compared to non-targeted LCP in A549 cells in vitro. To simultaneously target multiple oncogenic mechanisms, we co-formulated three siRNA sequences targeting HDM2, c-myc and VEGF oncogenes, and investigated their efficacy of cell-killing in A549 and H460 cells in vitro. The results indicated that the pooled siRNA co-delivered by the targeted LCP could effectively and simultaneously knock down HDM2, c-myc and VEGF expressions and significantly inhibit tumor cell growth. After i.v. injection of mice bearing A549 xenografted tumor with Texas Red-labeled siRNA formulated in the targeted LCP, siRNA was successfully delivered to and concentrated in the tumor cells. Repeated intravenous injections of mice with pooled siRNA formulated in the targeted LCP significantly impaired NSCLC growth in vivo (p < 0.01) for both A549 and H460 tumors, demonstrating an ED50 for the treatment of ~0.2 mg/kg in A549 tumors. The enhanced anti-tumor activity is due to the fact that the silencing of HDM2/c-myc/VEGF could inhibit tumor proliferation and angiogenesis and also simultaneously induce tumor apoptosis. Our results demonstrate that the targeted LCP is a promising vector to deliver pooled siRNA into tumors and to achieve multiple target blocking. This is potentially a valid therapeutic modality in the gene therapy of human NSCLC

Enhancing the Spin–Orbit Coupling in Fe3O4 Epitaxial Thin Films by Interface Engineering

10.1021/acsami.6b0947884027353-2735