Search

PbS films grown on quartz substrates by the chemical bath deposition method were annealed in an O2 atmosphere to investigate the role of oxygen in the sensitization process at different annealing temperatures. The average grain size of the PbS films gradually increased as the annealing temperature increased from 400 °C to 700 °C. At an annealing temperature of 650 °C, the photoresponsivity and detectivity reached 1.67 A W−1 and 1.22 × 1010 cm Hz1/2 W−1, respectively. The role of oxides in the sensitization process was analyzed in combination with X-ray diffraction and scanning electron microscopy results, and a three-dimensional network model of the sensitization mechanism of PbS films was proposed. During the annealing process, O functioned as a p-type impurity, forming p+-type PbS layers with high hole concentrations on the surface and between the PbS grains. As annealing proceeds, the p+-type PbS layers at the grain boundaries interconnect to form a three-dimensional network structure of hole transport channels, while the unoxidized p-type PbS layers act as electron transport channels. Under bias, photogenerated electron–hole pairs were efficiently separated by the formed p+-p charge separation junction, thereby reducing electron–hole recombination and facilitating a higher infrared response. [ABSTRACT FROM AUTHOR]

Blockchain technology, as a revolutionary technology that has emerged in recent years, holds significant potential for application in supply chain operations. This paper provides a systematic review of blockchain-based supply chain case studies. The existing literature primarily focuses on the food, agriculture, and pharmaceutical sectors, highlighting the advantages of blockchain technology in terms of traceability and transparency. However, there is a limited number of studies addressing the improvement of collaboration efficiency in supply chains, particularly within the realm of information technology enterprises. By conducting semi-structured interviews, we present a case study of Lenovo, a leading enterprise utilizing blockchain technology, to elucidate the advantages of using blockchain technology. Subsequently, it proposes a conceptual model for a blockchain-based information collaboration system and discusses the potential applications of blockchain technology in supply chain collaboration. Our study contributes to the existing work on blockchain applications to enhance supply chain collaboration. [ABSTRACT FROM AUTHOR]

Wheat yield is greatly reduced because of the occurrence of leaf spot diseases. Bipolaris sorokiniana is the main pathogenic fungus in leaf spot disease. In this study, B. sorokiniana from wheat leaf (W-B. sorokiniana) showed much stronger pathogenicity toward wheat than endophytic B. sorokiniana from Pogostemon cablin (P-B. sorokiniana). The transcriptomes and metabolomics of the two B. sorokiniana strains and transcriptomes of B. sorokiniana-infected wheat leaves were comparatively analyzed. In addition, the expression levels of unigenes related to pathogenicity, toxicity, and cell wall degradation were predicted and validated by quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis. Results indicated that pathogenicity-related genes, especially the gene encoding loss-of-pathogenicity B (LopB) protein, cell wall-degrading enzymes (particularly glycosyl hydrolase-related genes), and killer and Ptr necrosis toxin-producing related unigenes in the W-B. sorokiniana played important roles in the pathogenicity of W-B. sorokiniana toward wheat. The down-regulation of cell wall protein, photosystem peptide, and rubisco protein suggested impairment of the phytosynthetic system and cell wall of B. sorokiniana-infected wheat. The up-regulation of hydrolase inhibitor, NAC (including NAM, ATAF1 and CUC2) transcriptional factor, and peroxidase in infected wheat tissues suggests their important roles in the defensive response of wheat to W-B. sorokiniana. This is the first report providing a comparison of the transcriptome and metabolome between the pathogenic and endophytic B. sorokiniana strains, thus providing a molecular clue for the pathogenic mechanism of W-B. sorokiniana toward wheat and wheat's defensive response mechanism to W-B. sorokiniana. Our study could offer molecular clues for controlling the hazard of leaf spot and root rot diseases in wheat, thus improving wheat yield in the future. [ABSTRACT FROM AUTHOR]

In this paper, we report on achieving the hybridization effect in a Mie-based dielectric metamolecule and provide its physically intuitive picture. Hybridization results in the splitting of the initial overlapping resonance dips, thus leading to two new collective resonance modes. It was observed via the simulated displacement field distribution that the two modes behave as the in-phase and out-of-phase oscillation of two meta-atoms, thus enhancing and suppressing the intensity of the electric field at the gap between two meta-atoms. Moreover, since the two hybridized modes are caused by the interaction effect, the intensities of the electric field can be adjusted by several external factors, like applied forces and temperature. Taking advantage of this easy-equipped dielectric meta-device, certain zones in it can be applied to receive amplified signals and shielded noises of different frequencies in microwave communication fields. Moreover, due to the function of enhancing electric field intensities, it is also promising in wireless charging technology. [ABSTRACT FROM AUTHOR]

Chiral metamaterials with asymmetric transmission can be applied as polarization-controlled devices. Here, a Mie-based dielectric metamaterial with a spacer exhibiting asymmetric transmission of linearly polarized waves at microwave frequencies was designed and demonstrated numerically. The unidirectional characteristic is attributed to the chirality of the metamolecule and the mutual excitation of the Mie resonances. Field distributions are simulated to investigate the underlying physical mechanism. Fano-type resonances emerge near the Mie resonances of the constituents and come from the destructive interference inside the structure. The near-field coupling further contributes to the asymmetric transmission. The influences of the lattice constant and the spacer thickness on the asymmetric characteristics were also analyzed by parameter sweeps. The proposed Mie-based metamaterial is of a simple structure, and it has the potential for applications in dielectric metadevices, such as high-performance polarization rotators. [ABSTRACT FROM AUTHOR]

Hybridized metamaterials with collective mode resonance are usually applied as sensors. In this paper, we make use of one Mie-based hybridized metamolecule comprising of dielectric meta-atoms and an elastic bonding layer in order to detect the distances and applied forces. The hybridization induced splitting results in two new collective resonance modes, of which the red-shifted mode behaves as the in-phase oscillation of two meta-atoms. Owing to the synergy of the oscillation, the in-phase resonance appears as a deep dip with a relatively high Q-factor and figure of merit (FoM). By exerting an external force, namely by adjusting the thickness of the bonding layer, the coupling strength of the metamolecule is changed. As the coupling strength increases, the first collective mode dip red-shifts increasingly toward lower frequencies. By fitting the relationship of the distance–frequency shift and the force–frequency shift, the metamolecule can be used as a sensor to characterize tiny displacement and a relatively wide range of applied force in civil engineering and biological engineering. [ABSTRACT FROM AUTHOR]

Gliotoxin, produced by fungi, is an epipolythiodioxopiperazine (ETP) toxin with bioactivities such as anti-liver fibrosis, antitumor, antifungus, antivirus, antioxidation, and immunoregulation. Recently, cytotoxic gliotoxins were isolated from a deep-sea-derived fungus, Dichotomomyces cejpii . However, the biosynthetic pathway for gliotoxins in D. cejpii remains unclear. In this study, the transcriptome of D. cejpii was sequenced using an Illumina Hiseq 2000. A total of 19,125 unigenes for D. cejpii were obtained from 9.73 GB of clean reads. Ten genes related to gliotoxin biosynthesis were annotated. The expression levels of gliotoxin-related genes were detected through quantitative real-time polymerase chain reaction (qRT-PCR). The GliG gene, encoding a glutathione S -transferase (DC-GST); GliI , encoding an aminotransferase (DC-AI); and GliO , encoding an aldehyde reductase (DC-AR), were cloned and expressed, purified, and characterized. The results suggested the important roles of DC-GST, DC-AT, and DC-AR in the biosynthesis of gliotoxins. Our study on the genes related to gliotoxin biosynthesis establishes a molecular foundation for the wider application of gliotoxins from D. cejpii in the biomedical industry in the future., Competing Interests: The authors declare no conflict of interest.

Myrothecium roridum is a plant pathogenic fungus that infects different crops and decreases the yield of economical crops, including soybean, cotton, corn, pepper, and tomato. Until now, the pathogenic mechanism of M. roridum has remained unclear. Different types of trichothecene mycotoxins were isolated from M. roridum , and trichothecene was considered as a plant pathogenic factor of M. roridum . In this study, the transcriptome of M. roridum in different incubation durations was sequenced using an Illumina Hiseq 2000. A total of 35,485 transcripts and 25,996 unigenes for M. roridum were obtained from 8.0 Gb clean reads. The protein-protein network of the M. roridum transcriptome indicated that the mitogen-activated protein kinases signal pathway also played an important role in the pathogenicity of M. roridum. The genes related to trichothecene biosynthesis were annotated. The expression levels of these genes were also predicted and validated through quantitative real-time polymerase chain reaction. Tri5 gene encoding trichodiene synthase was cloned and expressed, and the purified trichodiene synthase was able to catalyze farnesyl pyrophosphate into different kinds of sesquiterpenoids. Tri4 and Tri11 genes were expressed in Escherichia coli , and their corresponding enzymatic properties were characterized. The phylogenetic tree of trichodiene synthase showed a great discrepancy between the trichodiene synthase from M. roridum and other species. Our study on the genes related to trichothecene biosynthesis establishes a foundation for the M. roridum hazard prevention, thus improving the yields of economical crops.

Trichothecene mycotoxins are a type of sesquiterpenoid produced by various kinds of plantpathogenic fungi. In this study, two trichothecene toxins, namely, a novel cytotoxic epiroridin acid and a known trichothecene, mytoxin B, were isolated from the endophytic fungus Myrothecium roridum derived from the medicinal plant Pogostemon cablin. The two trichothecene mytoxins were confirmed to induce the apoptosis of HepG-2 cells by cytomorphology inspection, DNA fragmentation detection, and flow cytometry assay. The cytotoxic mechanisms of the two mycotoxins were investigated by quantitative real time polymerase chain reaction, western blot, and detection of mitochondrial membrane potential. The results showed that the two trichothecene mycotoxins induced the apoptosis of cancer cell HepG-2 via activation of caspase-9 and caspase-3, up-regulation of bax gene expression, down-regulation of bcl-2 gene expression, and disruption of the mitochondrial membrane potential of the HepG-2 cell. This study is the first to report on the cytotoxic mechanism of trichothecene mycotoxins from M. roridum. This study provides new clues for the development of attenuated trichothecene toxins in future treatment of liver cancer.