Nanocomposites of Carbon Nanotube (CNTs)/CuO with High Sensitivity to Organic Volatiles at Room Temperature

AbstractIn order to enhance the sensitivity of carbon nanotube based chemical sensors at room temperature operation, CNTs/CuO nanocomposite was prepared under hydrothermal reaction condition. The resulted-product was characterized with TEM (transmission electron microscopy), XRD (X-ray diffraction) and so on. A chemical prototype sensor was constructed based on CNTs/CuO nanocomposite and an interdigital electrode on flexible polymer substrate. The gas-sensing behavior of the sensor to some typical organic volatiles was investigated at room temperature operation. The results indicated that the carbon nanotube was dispersed well in CuO matrix, the CuO was uniformly coated on the surface of carbon nanotube, and the tubular structure of carbon nanotube was clearly observed. From morphology of TEM images, it can also be observed that a good interfacial adhesion between CNT and CuO matrix was formed, which maybe due to the results of strong interaction between CNTs with carboxyl groups and CuO containing some hydroxy groups. The CNTs/CuO nanocomposite showed dramatically enhanced sensitivity to some typical organic volatiles. This study would provide a simple, low-cost and general approach to functionalize the carbon nanotube. It is also in favor of developing chemical sensors with high sensitivity or catalysts with high activity to organic volatiles at low temperature

A Metal-Ion-Incorporated Mussel-Inspired Poly(Vinyl Alcohol)-Based Polymer Coating Offers Improved Antibacterial Activity and Cellular Mechanoresponse Manipulation

Cobalt (CoII) ions have been an attractive candidate for the biomedical modification of orthopedic implants for decades. However, limited research has been performed into how immobilized CoII ions affect the physical properties of implant devices and how these changes regulate cellular behavior. In this study we modified biocompatible poly(vinyl alcohol) with terpyridine and catechol groups (PVA-TP-CA) to create a stable surface coating in which bioactive metal ions could be anchored, endowing the coating with improved broad-spectrum antibacterial activity against Escherichia coli and Staphylococcus aureus, as well as enhanced surface stiffness and cellular mechanoresponse manipulation. Strengthened by the addition of these metal ions, the coating elicited enhanced mechanosensing from adjacent cells, facilitating cell adhesion, spreading, proliferation, and osteogenic differentiation on the surface coating. This dual-functional PVA-TP-CA/Co surface coating offers a promising approach for improving clinical implantation outcomes

Spatial and temporal variability in net primary production (NPP) of alpine grassland on Tibetan Plateau from 1982 to 2009

Abstract HKT-ISTP 2013 B

A CRISPR/Cas9-Based Mutagenesis Protocol for Brachypodium distachyon and Its Allopolyploid Relative, Brachypodium hybridum

The CRISPR/Cas9 system enables precise genome editing and is a useful tool for functional genomic studies. Here we report a detailed protocol for targeted genome editing in the model grass Brachypodium distachyon and its allotetraploid relative B. hybridum, describing gRNA design, a transient protoplast assay to test gRNA efficiency, Agrobacterium-mediated transformation and the selection and analysis of regenerated plants. In B. distachyon, we targeted the gene encoding phytoene desaturase (PDS), which is a crucial enzyme in the chlorophyll biosynthesis pathway. The albino phenotype of mutants obtained confirmed the effectiveness of the protocol for functional gene analysis. Additionally, we targeted two genes related to cell wall maintenance, encoding a fasciclin-like arabinogalactan protein (FLA) and a pectin methylesterase (PME), also in B. distachyon. Two genes encoding cyclin-dependent kinases (CDKG1 and CDKG2), which may be involved in DNA recombination were targeted in both B. distachyon and B. hybridum. Cas9 activity induces mainly insertions or deletions, resulting in frameshift mutations that, may lead to premature stop codons. Because of the close phylogenetic relationship between Brachypodium species and key temperate cereals and forage grasses, this protocol should be easily adapted to target genes underpinning agronomically important traits

A CRISPR/Cas9-Based Mutagenesis Protocol for Brachypodium distachyon and Its Allopolyploid Relative, Brachypodium hybridum

The CRISPR/Cas9 system enables precise genome editing and is a useful tool for functional genomic studies. Here we report a detailed protocol for targeted genome editing in the model grass Brachypodium distachyon and its allotetraploid relative B. hybridum, describing gRNA design, a transient protoplast assay to test gRNA efficiency, Agrobacterium-mediated transformation and the selection and analysis of regenerated plants. In B. distachyon, we targeted the gene encoding phytoene desaturase (PDS), which is a crucial enzyme in the chlorophyll biosynthesis pathway. The albino phenotype of mutants obtained confirmed the effectiveness of the protocol for functional gene analysis. Additionally, we targeted two genes related to cell wall maintenance, encoding a fasciclin-like arabinogalactan protein (FLA) and a pectin methylesterase (PME), also in B. distachyon. Two genes encoding cyclin-dependent kinases (CDKG1 and CDKG2), which may be involved in DNA recombination were targeted in both B. distachyon and B. hybridum. Cas9 activity induces mainly insertions or deletions, resulting in frameshift mutations that, may lead to premature stop codons. Because of the close phylogenetic relationship between Brachypodium species and key temperate cereals and forage grasses, this protocol should be easily adapted to target genes underpinning agronomically important traits

Optimization design of a new hybrid magnetic circuit motor

The combination of permanent magnets and electrically excited windings creates an air gap magnetic field. The development of a hybrid magnetic circuit motor with an adjustable magnetic field is of great significance. This article introduces a hybrid magnetic circuit motor design that combines salient pole electromagnetic and permanent magnets. A tubular magnetic barrier has been designed to reduce inter-pole leakage and enhance the usage rate of permanent magnets in the hybrid magnetic circuit motor. The optimum eccentricity of the rotor has been accurately designed, resulting in an improved sinusoidal distribution of the air gap magnetic density waveform. An analysis of the static composite magnetic field under various excitation currents has been conducted, showcasing the capability of the hybrid magnetic circuit motor to stably adjust the air gap flux density level and output torque. A prototype has undergone comprehensive trial production and testing, conclusively confirming the machine’s superior output performance

Abnormal network homogeneity of default-mode network and its relationships with clinical symptoms in antipsychotic-naïve first-diagnosis schizophrenia

Schizophrenia is a severe mental disorder affecting around 0.5–1% of the global population. A few studies have shown the functional disconnection in the default-mode network (DMN) of schizophrenia patients. However, the findings remain discrepant. In the current study, we compared the intrinsic network organization of DMN of 57 first-diagnosis drug-naïve schizophrenia patients with 50 healthy controls (HCs) using a homogeneity network (NH) and explored the relationships of DMN with clinical characteristics of schizophrenia patients. Receiver operating characteristic (ROC) curves analysis and support vector machine (SVM) analysis were applied to calculate the accuracy of distinguishing schizophrenia patients from HCs. Our results showed that the NH values of patients were significantly higher in the left superior medial frontal gyrus (SMFG) and right cerebellum Crus I/Crus II and significantly lower in the right inferior temporal gyrus (ITG) and bilateral posterior cingulate cortex (PCC) compared to those of HCs. Additionally, negative correlations were shown between aberrant NH values in the right cerebellum Crus I/Crus II and general psychopathology scores, between NH values in the left SMFG and negative symptom scores, and between the NH values in the right ITG and speed of processing. Also, patients’ age and the NH values in the right cerebellum Crus I/Crus II and the right ITG were the predictors of performance in the social cognition test. ROC curves analysis and SVM analysis showed that a combination of NH values in the left SMFG, right ITG, and right cerebellum Crus I/Crus II could distinguish schizophrenia patients from HCs with high accuracy. The results emphasized the vital role of DMN in the neuropathological mechanisms underlying schizophrenia