MBE growth and characterization of Zn1-xCrxTe diluted magnetic semiconductor

Master'sMASTER OF ENGINEERIN

Comparative Proteomic Analysis of Panax ginseng C. A. Meyer × Panax quinquefolius L. Leaves and Parental Lines

Heterosis refers to the superior performance of heterozygous F1 hybrid plants with respect to those of their genetically distinct parents. Despite its wide use in crops, heterosis is seldom applied in the Panax genus, and its molecular basis remains unclear. Thus, this study is aimed to obtain hybrid F1s and identify the proteins associated with heterosis. Hybrid F1 plants and parental inbred lines were obtained using the embryo rescue technique, and the proteomes of their leaves were analyzed using two‐dimensional gel electrophoresis. A total of 236 differentially expressed proteins were found, among which 84 nonadditive proteins indicated a heterosis pattern in the hybrid. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes analysis revealed that photosynthesis, carbohydrate metabolism, and protein and amino acid synthesis were the most abundant classes of nonadditive proteins. Of the proteins in these categories, 10, 6, and 4 proteins, respectively, showed above high parent expression in the hybrid leaves. These results imply that the increment in photosynthetic capacity, carbohydrate decomposition, and nitrogen fixation might be related to the heterosis of the hybrid biomass and ginsenoside production in the hybrid leaves. This study could provide a basis for hybrid breeding of the Panax genus

Biocontrol potential and action mechanism of Bacillus amyloliquefaciens DB2 on Bipolaris sorokiniana

IntroductionBipolaris sorokiniana is the popular pathogenic fungi fungus which lead to common root rot and leaf spot on wheat. Generally, chemical fungicides are used to control diseases. However, the environmental pollution resulting from fungicides should not be ignored. It is important to study the mode of antagonistic action between biocontrol microbes and plant pathogens to design efficient biocontrol strategies.ResultsAn antagonistic bacterium DB2 was isolated and identified as Bacillus amyloliquefaciens. The inhibition rate of cell-free culture filtrate (CF, 20%, v/v) of DB2 against B. sorokiniana reached 92.67%. Light microscopy and scanning electron microscopy (SEM) showed that the CF significantly altered the mycelial morphology of B. sorokiniana and disrupted cellular integrity. Fluorescence microscopy showed that culture filtrate destroyed mycelial cell membrane integrity, decreased the mitochondrial transmembrane potential, induced reactive oxygen species (ROS) accumulation, and nuclear damage which caused cell death in B. sorokiniana. Moreover, the strain exhibited considerable production of protease and amylase, and showed a significant siderophore and indole-3-acetic acid (IAA) production. In the detached leaves and potted plants control assay, B. amyloliquefacien DB2 had remarkable inhibition activity against B. sorokiniana and the pot control efficacy was 75.22%. Furthermore, DB2 suspension had a significant promotion for wheat seedlings growth.ConclusionB. amyloliquefaciens DB2 can be taken as a potential biocontrol agent to inhibit B. sorokiniana on wheat and promote wheat growth

RANKL/RANK promotes the migration of gastric cancer cells by interacting with EGFR

BACKGROUND: The incidence and mortality rates of gastric cancer (GC) rank in top five among all malignant tumors. Chemokines and their receptor-signaling pathways reportedly play key roles in the metastasis of malignant tumor cells. Receptor activator of nuclear factor κB ligand (RANKL) is a member of the tumor necrosis factor family, with strong chemokine-like effects. Some studies have pointed out that the RANKL/RANK pathway is vital for the metastasis of cancer cells, but the specific mechanisms in GC remain poorly understood. RESULTS: This study reports original findings in cell culture models and in patients with GC. Flow cytometry and western blotting analyses showed that RANK was expressed in BGC-823 and SGC-7901 cells in particular. Chemotaxis experiments and wound healing assay suggested that RANKL spurred the migration of GC cells. This effect was offset by osteoprotegerin (OPG), a decoy receptor for RANKL. RANKL contributed to the activation of human epidermal growth factor receptor (HER) family pathways. The lipid raft core protein, caveolin 1 (Cav-1), interacted with both RANK and human epidermal growth factor receptor-1(EGFR). Knockdown of Cav-1 blocked the activation of EGFR and cell migration induced by RANKL. Moreover, RANK-positive GC patients who displayed higher levels of EGFR expression had poor overall survival. CONCLUSIONS: In summary, we confirmed that with the promotion of RANKL, RANK and EGFR can form complexes with the lipid raft core protein Cav-1, which together promote GC cell migration. The formation of the RANK-Cav-1-EGFR complex provides a novel mechanism for the metastasis of GC. These observations warrant confirmation in independent studies, in vitro and in vivo. They also inform future drug target discovery research and innovation in the treatment of GC progression

β-Elemene-induced autophagy protects human gastric cancer cells from undergoing apoptosis

<p>Abstract</p> <p>Background</p> <p>β-Elemene, a compound found in an herb used in traditional Chinese medicine, has shown promising anti-cancer effects against a broad spectrum of tumors. The mechanism by which β-elemene kills cells remains unclear. The aim of the present study is to investigate the anti-tumor effect of β-elemene on human gastric cancer cells and the molecular mechanism involved.</p> <p>Results</p> <p>β-Elemene inhibited the viability of human gastric cancer MGC803 and SGC7901 cells in a dose-dependent manner. The suppression of cell viability was due to the induction of apoptosis. A robust autophagy was observed in the cells treated with β-elemene; it was characterized by the increase of punctate LC3 dots, the cellular morphology, and the increased levels of LC3-II protein. Further study showed that β-elemene treatment up-regulated Atg5-Atg12 conjugated protein but had little effect on other autophagy-related proteins. PI3K/Akt/mTOR/p70S6K1 activity was inhibited by β-elemene. Knockdown of Beclin 1 with small interfering RNA, or co-treatment with the autophagy inhibitor, 3-methyladenine or chlorochine enhanced significantly the antitumor effects of β-elemene.</p> <p>Conclusions</p> <p>Our data provides the first evidence that β-elemene induces protective autophagy and prevents human gastric cancer cells from undergoing apoptosis. A combination of β-elemene with autophagy inhibitor might thus be a useful therapeutic option for advanced gastric cancer.</p

Market simulation of traceable food in China based on conjoint-value analysis: a traceable case of pork

The food-traceability system is considered to be one of the main measures to fundamentally prevent food-safety problems. It is of great value to study consumer demand for traceable food and market simulations that can adjust the production and supply structure of traceable food and promote traceable market development. Having sampled and interviewed 2,121 consumers in China, consumer preferences for traceable pork with different levels of safety information, and the respective market share of traceable pork with different product profiles were investigated using conjoint value analysis and the randomized first choice method. Results showed that Chinese consumers prioritized the certification of a traceable-pork safety-information attribute. Furthermore, consumers were willing to pay extra costs in order to obtain traceable safety information. However, this additional expenditure should account for no more than 30% of the price of ordinary pork, or consumer demand for safe pork decreases. Results of a market simulation also identified a type of traceable pork that had an optimal combination of attributes and met the needs of Chinese consumers. Consequently, the government should gradually promote a multilevel traceable-food market system in China by developing a combination of a certification mechanism and traceability system, and increasing financial subsidies for the construction of the traceability system

Biostratigraphy, sedimentology and sequence stratigraphy of the Tournaisian-Visean transitional strata in South China (Guangxi)

The biostratigraphy and sedimentological evolution of the Tournaisian-Visean (T-V) transitional strata in South China (Guangxi) have been investigated. The sediments were deposited on a carbonate platform and in slope and basinal environments. In the T-V transitional strata, six foraminiferal associations have been distinguished which allow correlation between the shallow and deep water deposits. A careful examination of the evolutionary stages of the foraminifer Eoparastaffella provides a more accurate criterion for the definition of the T-V boundary, but does not significantly modify the historical one. The distinction of two morphotypes is based on the elevation of the last whorl and the peripheral outline. Tournaisian specimens of Eoparastaffella have a well rounded periphery (morphotype 1) contrasting with the subangular periphery of younger Visean specimens (morphotype 2). A coefficient can be deduced from simple biometric measurements for more precisely defining the T-V boundary.status: publishe

Effect of pad and slurry on fixed abrasive polishing of gallium oxide crystal

Gallium oxide crystal is one of the most representative fourth generation semiconductor materials with the advantages of high band gap, high voltage resistance and short absorption cutoff edge. It has broad application prospects. Micro-cracks, scratches and other surface defects are prone to appear in the polishing process of Gallium oxide crystal, which is difficult to achieve high-quality surface processing and cannot meet the requirements of corresponding devices. Moreover, the existing polishing process of gallium oxide crystal is complex and inefficient. Fixed abrasive polishing technology has the advantages of controllable abrasive distribution and depth of cut, and high utilization rate of abrasive. In this study, fixed abrasive polishing of gallium oxide crystal was adopted, and the effect of matrix hardness, abrasive concentration of polishing pad, the additives of polishing slurry on material removal rate and surface quality were investigated. The results show that when the hardness of the polishing pad is moderate II, the abrasive concentration is 100%, and the slurry additive is oxalic acid, the material removal rate is 68 nm/min and the surface roughness Sa value is 3.17 nm in fixed abrasive polishing of gallium oxide crystal. Fixed abrasive polishing technology can achieve high-efficient and high-quality polishing of gallium oxide crystal

Status and Prospect of Islanding Detection in Active Distribution Network

A large number of distributed power sources are injected to the distribution network, which can cause island operation in planned or unplanned situations. The islanded operation caused by the fault will cause the inverter to go off the grid in serious fault conditions such as short circuit between phases and disconnection. After the island is formed, if the common connection point before the island exchanges more power, a sudden change in the voltage within the island occurs. The frequency and phase angle changes of the voltage in the island are closely related to the characteristics of the inverter phase-locked loop, and the frequency mutation generally does not cause sudden changes in frequency due to a certain inertia of the phase-locked loop. Due to sudden changes in load power angle, input fault ride-through, etc., sudden changes in the phase angle of voltage in islands may occur. In order to solve the possible problems of power quality deterioration in islands, passive, active, and remote islanding detection schemes can be adopted, and the three schemes have their own advantages and disadvantages. In actual operation, it is necessary to consider the cooperation relationship between island detection, protection, safe automatic control and fault ride through

A Routing Protocol Based on Received Signal Strength for Underwater Wireless Sensor Networks (UWSNs)

Underwater wireless sensor networks (UWSNs) are featured by long propagation delay, limited energy, narrow bandwidth, high BER (Bit Error Rate) and variable topology structure. These features make it very difficult to design a short delay and high energy-efficiency routing protocol for UWSNs. In this paper, a routing protocol independent of location information is proposed based on received signal strength (RSS), which is called RRSS. In RRSS, a sensor node firstly establishes a vector from the node to a sink node; the length of the vector indicates the RSS of the beacon signal (RSSB) from the sink node. A node selects the next-hop along the vector according to RSSB and the RSS of a hello packet (RSSH). The node nearer to the vector has higher priority to be a candidate next-hop. To avoid data packets being delivered to the neighbor nodes in a void area, a void-avoiding algorithm is introduced. In addition, residual energy is considered when selecting the next-hop. Meanwhile, we establish mathematic models to analyze the robustness and energy efficiency of RRSS. Lastly, we conduct extensive simulations, and the simulation results show RRSS can save energy consumption and decrease end-to-end delay