100 research outputs found
Efficiency Analysis of Scientific and Technological Innovation in Grain Production Based on Improved Grey Incidence Analysis
open access articleAnalyzing and evaluating the efficiency of scientific and technological innovation in grain production is conducive to the rational allocation of resources, promoting the development of scientific and technological innovation in grain production and providing guarantee for grain security. By refining the elements of grain production and scientific and technological innovation, an evaluation system of scientific and technological innovation in grain production is constructed. Firstly, combining linear programming together with the traditional grey synthetic incidence analysis model, a incidence analysis of the scientific and technological innovation indicators of grain production is carried out, and the key and secondary indexes affecting grain outputs are screened by an improved grey incidence analysis model. Secondly, based on DEA-Malmquist index model and taking the grain production process as the research object, the scientific and technological achievement transformation indicators are divided into pre-production, in-production and post-production indicators. The key indicators and secondary indicators of scientific and technological innovation of grain production in various cities of Henan Province from 2010 to 2019 are used to analyze the efficiency of scientific and technological innovation in each stage of grain production. The results show that: (1) The type of basic ability of scientific and technological innovation indicators and the transformation ability of scientific and technological innovation achievements are the major indicators influencing grain outputs, and the investment of basic resources of scientific and technological innovation and the transformation of scientific and technological innovation achievements are the most important to improve grain outputs. (2) In addition, the study reveals that the secondary indicators of the technological innovation efficiency of grain production based on the DEA-Malmquist index model are more efficient than the key indicators in the pre-production, in-production and post-production stages. And there are gaps in the scientific and technological innovation performance of grain production among cities in Henan Province, and the index of technological progress is the leading factor for the gap
Observation of acoustic spatiotemporal vortices
Vortices in fluids and gases have piqued the interest of human for centuries.
Development of classical-wave physics and quantum mechanics highlighted wave
vortices characterized by phase singularities and topological charges. In
particular, vortex beams have found numerous applications in modern optics and
other areas. Recently, optical spatiotemporal vortex states exhibiting the
phase singularity both in space and time have been reported. Here, we report
the first generation of acoustic spatiotemporal vortex pulses. We utilize an
acoustic meta-grating with mirror-symmetry breaking as the spatiotemporal
vortex generator. In the momentum-frequency domain, we unravel that the
transmission spectrum functions exhibit a topological phase transition where
the vortices with opposite topological charges are created or annihilated in
pairs. Furthermore, with the topological textures of the nodal lines, these
vortices are robust and exploited to generate spatiotemporal vortex pulse
against structural perturbations and disorder. Our work paves the way for
studies and applications of spatiotemporal structured waves in acoustics and
other wave systems.Comment: 12 pages, 4 figure
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Blueberry leaf extracts incorporated chitosan coatings for preserving postharvest quality of fresh blueberries
The phenolic compounds in blueberry (Vaccinium spp.) fruit and leaf extracts (BLE) were determined based on HPLC analysis. Antimicrobial assays against Staphylococcus aureus, Listeria monocytogenes, Salmonella typhimurium and Escherichia coli, as well as fungi isolated from the rotting blueberry fruit were conducted. The effects of chitosan coating incorporating different concentrations of BLE on the quality of fresh fruit during postharvest storage at 2±1 °C and 95±2% relative humidity (RH) for 35 d and then at room conditions for 3 d were also investigated. Five different coating treatments were applied including 2% (w/v) chitosan coating (T1), 2% (w/v) chitosan coating containing 4% (w/v, T2), 8% (w/v, T3), or 12% (w/v, T4) BLE, and 2% (w/v) chitosan coating containing 12% BLE plus modified atmosphere packaging (MAP at 3 kPa O₂+12 kPa CO₂) (T5). A sample of blueberries dipped into distilled water was used as control (T0). BLE had a greater variety of phenolic compounds than fruit extracts with syringic acid the highest concentration (0.259±0.003 g kg⁻¹), but the total phenolic content in BLE was lower (P < 0.05) than in fruit extracts. BLE showed good antimicrobial activity against all tested microorganisms, with a minimum inhibition concentration from 25-50 g L⁻¹. The 2% chitosan coating that incorporated 8% or 12% BLE showed some degree of decreasing decay rate of fruit compared with the control, and the coating with BLE plus MAP had more effective control of fruit decay. All treated samples maintained higher total phenolic content and radical scavenging activity than the control. This study suggested that chitosan coating incorporating BLE can be employed to extend shelf-life and maintain high nutritional value of fresh blueberries during postharvest storage.Keywords: Physicochemical quality, Blueberry leaf extracts, Postharvest storage, Phytochemicals, Fresh blueberries, Chitosan coatingKeywords: Physicochemical quality, Blueberry leaf extracts, Postharvest storage, Phytochemicals, Fresh blueberries, Chitosan coatin
Enhanced {\alpha} particle generation via proton-boron fusion reactions in laser-modulated plasma
Aneutronic and nonradioactive properties make the proton-boron fusion a
prospective candidate for fusion energy production through reactions following
p+B3 (p-B). However, it is difficult to
achieve a thermal fusion ignition, since the low reaction cross-sections for
center-of-mass energy below 100 keV. To realize fusion energy gain, it is
essential to consider utilization of the maximum cross-section at the resonant
peak of p-B fusion, and explore the nuclear reactions in plasma
environment. In this work, p-B reactions triggered by interactions
between energetic proton beams and laser-ablated boron plasma have been
investigated. More than 200 times enhancement of particle emission
efficiency (number ratio of escaping particles and boron nuclei) in
plasma has been observed, compared with the cold boron. The proton beam
transport path modulated by strong electro-magnetic fields in plasma could
dominate the enhanced particle generation, due to a longer
collisional length. In addition, an particle yield up to
110 /sr has been measured via the pitcher-catcher scheme in
plasma. This work could benefit understanding of the plasma effects on nuclear
reaction dynamics, and also enable opportunities to explore physics in laser
fusion associated with advanced fusion fuels
Effect of Functional Oligosaccharides and Ordinary Dietary Fiber on Intestinal Microbiota Diversity
Functional oligosaccharides, known as prebiotics, and ordinary dietary fiber have important roles in modulating the structure of intestinal microbiota. To investigate their effects on the intestinal microecosystem, three kinds of diets containing different prebiotics were used to feed mice for 3 weeks, as follows: GI (galacto-oligosaccharides and inulin), PF (polydextrose and insoluble dietary fiber from bran), and a GI/PF mixture (GI and PF, 1:1), 16S rRNA gene sequencing and metabolic analysis of mice feces were then conducted. Compared to the control group, the different prebiotics diets had varying effects on the structure and diversity of intestinal microbiota. GI and PF supplementation led to significant changes in intestinal microbiota, including an increase of Bacteroides and a decrease of Alloprevotella in the GI-fed, but those changes were opposite in PF fed group. Intriguing, in the GI/PF mixture-fed group, intestinal microbiota had the similar structure as the control groups, and flora diversity was upregulated. Fecal metabolic profiling showed that the diversity of intestinal microbiota was helpful in maintaining the stability of fecal metabolites. Our results showed that a single type of oligosaccharides or dietary fiber caused the reduction of bacteria species, and selectively promoted the growth of Bacteroides or Alloprevotella bacteria, resulting in an increase in diamine oxidase (DAO) and/or trimethylamine N-oxide (TMAO) values which was detrimental to health. However, the flora diversity was improved and the DAO values was significantly decreased when the addition of nutritionally balanced GI/PF mixture. Thus, we suggested that maintaining microbiota diversity and the abundance of dominant bacteria in the intestine is extremely important for the health, and that the addition of a combination of oligosaccharides and dietary fiber helps maintain the health of the intestinal microecosystem
Preparation and Characterization of Stimuli-Responsive Magnetic Nanoparticles
In this work, the main attention was focused on the synthesis of stimuli-responsive magnetic nanoparticles (SR-MNPs) and the influence of glutathione concentration on its cleavage efficiency. Magnetic nanoparticles (MNPs) were first modified with activated pyridyldithio. Then, MNPs modified with activated pyridyldithio (MNPs-PDT) were conjugated with 2, 4-diamino-6-mercaptopyrimidine (DMP) to form SR-MNPs via stimuli-responsive disulfide linkage. Fourier transform infrared spectra (FTIR), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) were used to characterize MNPs-PDT. The disulfide linkage can be cleaved by reduced glutathione (GHS). The concentration of glutathione plays an important role in controlling the cleaved efficiency. The optimum concentration of GHS to release DMP is in the millimolar range. These results had provided an important insight into the design of new MNPs for biomedicine applications, such as drug delivery and bio-separation
Meta-analysis Followed by Replication Identifies Loci in or near CDKN1B, TET3, CD80, DRAM1, and ARID5B as Associated with Systemic Lupus Erythematosus in Asians
Systemic lupus erythematosus (SLE) is a prototype autoimmune disease with a strong genetic involvement and ethnic differences. Susceptibility genes identified so far only explain a small portion of the genetic heritability of SLE, suggesting that many more loci are yet to be uncovered for this disease. In this study, we performed a meta-analysis of genome-wide association studies on SLE in Chinese Han populations and followed up the findings by replication in four additional Asian cohorts with a total of 5,365 cases and 10,054 corresponding controls. We identified genetic variants in or near CDKN1B, TET3, CD80, DRAM1, and ARID5B as associated with the disease. These findings point to potential roles of cell-cycle regulation, autophagy, and DNA demethylation in SLE pathogenesis. For the region involving TET3 and that involving CDKN1B, multiple independent SNPs were identified, highlighting a phenomenon that might partially explain the missing heritability of complex diseases
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