Rural Development and Restructuring in Central China’s Rural Areas: A Case Study of Eco-Urban Agglomeration around Poyang Lake, China

This study aims to provide a scientific reference for rural reconstruction and revitalization in the areas covered by Eco-Urban Agglomeration Around Poyang Lake. Rural development and restructuring is a comprehensive process involving multiple elements and a long-time sequence. Accordingly, scientific knowledge concerning the evolution and characteristics of the spatial and temporal patterns of rural development and reconstruction is crucial for successively facilitating rural revitalization and ensuring the sustainable development of rural areas. In this study, a framework of rural development and restructuring was constructed for areas around Poyang Lake Eco-Urban Agglomeration based on the data regarding population, land, and industrial elements in the rural regional system, as well as the data of counties covered by Poyang Lake Eco-Urban Agglomeration. For this purpose, the entropy value and other research methods were used to analyze the level of rural development and the degree of rural reconstruction, as well as to identify the characteristics of rural reconstruction types. The study results revealed the following: (1) Rural Comprehensive Development Level has increased from 0.218 to 0.347, and the geographical development gap of the countryside has narrowed; however, the development level of each region and each factor continues to remain uneven. (2) The results demonstrated a wave-like advancement in the Rural Comprehensive Restructuring Degree, with a decreased Rural Population Restructuring Degree, an increased Rural Industry Restructuring Degree, and a decreased Rural Land Restructuring Degree. (3) Rural restructuring in the study area can be divided into six zones according to the level of rural development and the degree of rural restructuring, with Type I and Type III being the main types. Based on the above results, this research proposes optimizations for different rural development and reconstruction type zones

Cellular delivery of quantum dot-bound hybridization probe for detection of intracellular pre-microRNA using chitosan/poly(γ-glutamic acid) complex as a carrier.

A quantum dot (QD)-bound hybridization probe was designed for detection of intracellular pre-miRNA using chitosan (CS)/poly(γ-glutamic acid) (γ-PGA) complex as a gene vector. The probe was prepared by assembling thiolated RNA to gold nanoparticle (Au NP) via Au-S bond and then binding 3'-end amine of the RNA to the carboxy group capped on quantum dot surface. The QD-RNA-Au NP probe was assembled on the vector by mixing with aqueous γ-PGA solution and then CS solution to construct a gene delivery system for highly effective cellular uptake and delivery. After the probe was released from CS/γ-PGA complex to the cytoplasm by electrostatic repulsion at intracellular pH, it hybridized with pre-miRNA precursor as target. The formed product was then cleaved by RNase III Dicer, leading to the separation of QDs from Au NPs and fluorescence emission of QDs, which could be detected by confocal microscopic imaging to monitor the amount of the intracellular pre-miRNA precursor. The in vitro assays revealed that the QD-RNA-Au NP was a robust, sensitive and selective probe for quantitative detection of target pre-miRNA. Using MDA-MB231 and MCF-7 breast cancer cells as models, the relative amount of pre-miRNA let-7a could be successfully compared. Since the amount of miRNA is related to the progress and prognosis of cancer, this strategy could be expected to hold promising application potential in medical research and clinical diagnostics

Ag@Au Core–Shell Porous Nanocages with Outstanding SERS Activity for Highly Sensitive SERS Immunoassay

A highly sensitive immunoassay of biomarkers has been achieved using 4-mercaptobenzoic acid-labeled Ag@Au core–shell porous nanocage tags and α-fetoprotein immuno-sensing chips. The Ag@Au porous nanocages were uniquely synthesized by using an Ag core as a self-sacrificial template and reducing agent, where the slow reaction process led to the formation of a porous Au layer. The size of the remaining Ag core and surface roughness of the Au shell were controlled by adjusting the chloroauric acid concentration. The porous cage exhibited excellent surface-enhanced Raman spectroscopy (SERS) activity, presumably due to a synergetic interaction between newly generated hot spots in the rough Au shell and the retained SERS activity of the Ag core. Using α-fetoprotein as a model analyte for immunoassay, the SERS signal had a wide linear range of 0.20 ng mL−1 to 500.0 ng mL−1 with a detection limit of 0.12 ng mL−1. Without the need of further signal amplification, the as-prepared Ag@Au bimetallic nanocages can be directly used for highly sensitive SERS assays of other biomarkers in biomedical research, diagnostics, etc

Real-time PCR detection of pre-micRNA let-7a expression.

<p>(a) normal human vascular endothelial cells, (b) MCF-7 and (c) MDA-MB-231 breast cancer cells.</p

In vitro fluorescent detection of pre-microRNA.

<p>(A) Fluorescence spectra of (a) QD-RNA-Au NP and (b) QD-control RNA-Au NP probe loaded CS/γ-PGA complex in presence of target pre-miRNA. (B) Fluorescence spectra of QD-RNA-Au NP probe loaded CS/γ-PGA complex at different amounts of pre-miRNA and (C) linear plot of fluorescence intensity vs pre-miRNA amount. (D) Fluorescence spectra of the mixtures of QD-RNA-Au NP probe loaded CS/γ-PGA complex and 50 ng of total RNAs extracted from MCF-7 and MDA-MB-231 cells, 100 µl DEPC-treated water was used as control.</p

Gel retardation assay of NP probe complex.

<p>(a) QD-RNA-Au NP probe, (b) QD-RNA-Au NP probe loaded CS, and (c) QD-RNA-Au NP probe loaded CS/γ-PGA complex.</p

Cytotoxicity induced by QD-RNA-Au NP probe loaded CS, CS/γ-PGA complex and liposome in MCF-7 cells.

<p>Cytotoxicity induced by QD-RNA-Au NP probe loaded CS, CS/γ-PGA complex and liposome in MCF-7 cells.</p

Flow cytometric analysis.

<p>(A) MCF-7 and (B)MDA-MB-231 cells after transfected with probe loaded complex.</p