The Research and Simulation of CSMA/CA Mechanism of ZigBee Protocol

AbstractIn order to improve the performance of star-topology ZigBee network with fewer nodes, modified the CSMA/CA channel access mechanism of ZigBee protocol, and proposed an improved channel access mechanism - Circular Queue access mechanism. Described and realized Circular Queue mechanism; showed the beacon frame format of Circular-Queued. Finally, gave the simulation results, compared and analyzed the network performance of CSMA / CA mechanism before and after the modification from network response time, throughput, packet loss rate

Naringenin prevents TGF-β1 secretion from breast cancer and suppresses pulmonary metastasis by inhibiting PKC activation

Presenting the incidence of pulmonary metastasis (mice with metastasis/total mice). Tumor-bearing mice treated with naringenin or 1D11 were imaged on day 24 using bags to avoid the bioluminescence from primary tumor. The mice with pulmonary metastases were numbered based on the bioluminescence signal. (TIF 26 kb

Changing Soil Water Content: Main Trigger of the Multi-Phase Mobilization and Transformation of Petroleum Pollution Components—Insights from the Batch Experiments

Soil moisture content continuously alters the types and forms of petroleum organic pollutants in the soil through processes such as dissolution, convection, and dilution, forming complex migration and transformation in a water–air–soil–NAPL system. Field investigations and traditional indoor simulation experiments have difficulty in terms of accurately diagnosing the state of different petroleum pollutants due to the influence of environmental factors and the difficulty of controlling single factors. Batch experiments were conducted to simulate the mobilization and differentiation processes of petroleum pollutants under the influence of soil water content. The results show that (1) the residual content of components is the lowest in coarse sand and the highest in clay, which is mainly affected by soil particles; meanwhile, the residual saturation value of octanoic acid is the largest, and that of toluene is the smallest, as determined in terms of their viscosity and volatility. (2) The infiltration processes of the components are affected by their properties and medium characteristics. Due to its small particle size and strong adsorption, clay has the highest residual saturation of petroleum pollutants (28.8%). This can even be more than twice that of coarse sand (13.3%). For different components, the residual saturations of octanoic acid and toluene are the highest and lowest, respectively (taking fine sand as an example: 25.3% and 13.2%), with a relatively large difference, as determined in terms of viscosity and solubility. (3) As the free phase can migrate freely, it is transformed most rapidly in the pores. The changes in the dissolved phase of each component are relatively small and tend to be gentle. The changes in the residual phase are mainly affected by volatility, viscosity, soil particles, and pore and cosmid content; the degree of change is ordered as follows: toluene > cyclohexane > hexadecane > octanoic acid

Numerical Simulations and the Design of Magnetic Field-Enhanced Electron Impact Ion Source with Hollow Cylinder Structure

An electron impact ion source-adopted magnetic field-enhanced technology has been designed for enhancing the electron intensity and the ionization efficiency. Based on the ion optic focus mechanism, an electron impact ionization source was designed, and the electron entrance into the ionization chamber was designed with a hollow cylinder structure to improve the ion extraction efficiency. Numerical simulation and optimal geometry were optimized by SIMION 8.0 to provide higher electron intensity and ion transmission efficiency. To improve the electron intensity, the influence of the filament potential and magnetic intensity was investigated, and the values of 70 eV and 150 Gs were chosen in our apparatus. Based on the optimal parameters, the air in the lab and oxygen gas was detected by the homemade apparatus, and the ion intensity was detected in the positive and negative ion modes, respectively. The homemade electron impact ion source apparatus has the potential to enhance ionization efficiency applied in the mass spectrometer ionization source

Carbazoles via AuCl₃‑Catalyzed Cyclization of 1‑(Indol-2-yl)-3-alkyn-1-ols

AuCl₃-catalyzed reaction of 1-(indol-2-yl)-3-alkyn-1-ols occurred smoothly in toluene at room temperature to form a benzene ring leading to a series of carbazole derivatives efficiently. A possible mechanism has been proposed for the formation of carbazoles

Carbazoles via AuCl₃‑Catalyzed Cyclization of 1‑(Indol-2-yl)-3-alkyn-1-ols

AuCl₃-catalyzed reaction of 1-(indol-2-yl)-3-alkyn-1-ols occurred smoothly in toluene at room temperature to form a benzene ring leading to a series of carbazole derivatives efficiently. A possible mechanism has been proposed for the formation of carbazoles

A Habitable Earth and Carbon Neutrality: Mission and Challenges Facing Resources and the Environment in China—An Overview

Since the Industrial Revolution, the impacts of human activities have changed the global climate system, and climate warming has had rapid and widespread effects on the planet. At present, the world is experiencing a series of natural disasters, such as climate change, environmental pollution, biodiversity loss, and sea level rise, which pose a serious threat to the livability of the Earth. An international consensus has been reached that achieving carbon neutrality is the key to tackling climate change; it is also crucial to building a livable planet. To achieve carbon neutrality, energy is the main aspect, for which technology regarding resources and the environment is essential. In this context, we collected data, performed an in-depth analysis of the basic and structural characteristics of the development of the coal industry and environmental remediation, studied and judged the trends in regional economic development and demand growth, and closely examined the requirements of China’s development strategy, which focuses on the ideas of carbon peak and carbon neutralization in line with local development trends and economic system characteristics. We must build a livable Earth, promote the green and low-carbon transformation of regional energy, promote high-quality economic development, and ensure the safe supply of energy

Mitofusin1 in oocyte is essential for female fertility

Mitofusins (Mfn) are the important regulators of mitochondrial organization in mammalian cells; however, their roles during oocyte development remain unknown. In the present study, we generated mice with oocyte-specific knockout of Mfn1 or Mfn2 (Mfn1fl/fl;Zp3-Cre or Mfn2fl/fl;Zp3-Cre). We report that deletion of Mfn1, but not Mfn2, in oocytes leads to female mice sterility, associated with the defective folliculogenesis and impaired oocyte quality. In specific, follicles are arrested at secondary stage in Mfn1fl/fl;Zp3-Cre mice, accompanying with the reduced proliferation of granulosa cells. Moreover, alterations of mitochondrial structure and distribution pattern are readily observed in Mfn1-null oocytes. Consistent with this, mitochondrial activity and function are severely disrupted in oocytes from Mfn1fl/fl;Zp3-Cre mice. In addition, the differentially expressed genes in Mfn1-deleted oocytes are also identified by whole-transcriptome sequencing. In sum, these results demonstrate that Mfn1-modulated mitochondrial function is essential for oocyte development and folliculogenesis, providing a novel mechanism determining female fertility. Keywords: Mitochondria, Folliculogenesis, Oocyte, Fertility, Reproductio