40 research outputs found

    Synthesis of cuprous oxide nanocubes combined with chitosan nanoparticles and its application to p-nitrophenol degradation

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    For the first time, cuprous oxide nanocubes (Cu2O NCBs) were successfully combined with chitosan nanoparticles (CS NPs) to generate Cu2O NCBs/CS NPs composites material with highly optical property and photocatalytic activity using a simple and eco-friendly synthetic approach at room temperature for 30 min. The synthesized Cu2O NCBs NPs/CS NPs were determined characterizations by Ultraviolet-visible spectroscopy (UV-vis), Fourier transform infrared spectroscopy (FTIR), X – ray Diffraction (XRD),  Transmission Electron Microscope (TEM) and Energy-dispersive X-ray spectroscopy (EDX). Results show that the Cu2O NCBs/CS NPs composites have an average particle size of ~3-5 nm; in which, Cu2O has the form of nanocubes (Cu2O NCBs) with size ~3-4 nm and chitosan nanoparticles with spherical shape (CS NPs) with size ~4-5 nm. In addition, the percent (%) composition of elements present in Cu2O NCBs/CS NPs composites material have been obtained respective: Cu (23.99%), O (38.18%), and C (33.61%). Moreover, Cu2O NCBs/CS NPs composites material was also investigated for photocatalytic activity applied in p-nitrophenol degradation. The obtained results showed that the catalytic capability of Cu2O NCBs/CS NPs for p-nitrophenol reduction reached the highest efficiency >55% in the treatment time of 25 min, and this efficiency was higher than that result of using ZnO@chitosan nanoparticles (ZnO@CS NPs) catalyst under the same conditions for comparison

    The Anatomical Numerical Measurement of Posterior Cruciate Ligament: A Vietnamese Cadaveric Study

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    BACKGROUND: The posterior cruciate ligament (PCL) is crucial to restrain the posterior translation of the tibia. Its anatomical structure is complex. A proper understanding of PCL anatomy may assist surgeon in reconstructing anatomically native PCL. AIM: To describe the anatomical numerical measurement of the PCL in Vietnamese adults. METHODS: Twenty-one fresh cadaveric knees were examined. The macroscopic details of the intra-articular PCL, the attachment of the anterolateral bundle (ALB), posteromedial bundles (PMB) to the femur and tibia were analysed. We used a digital camera to photograph the cadaveric specimens and used the ImageJ software to analyse the collected images. RESULTS: The ALB and PMB length were 35.5 ± 2.78 and 32.6 ± 2.28 mm, respectively. The smallest and the biggest diameter of middle third of the PCL were 5.9 ± 0.71 and 10.0 ± 1.39 mm, respectively. The area of cross section of middle third of the PCL was 53.6 ± 12.37 mm2. The femoral insertion area of ALB and PMB were 88.4 ± 16.89 and 43.5 ± 8.83 mm2, respectively. The distance from the central point of femoral ALB, PMB, and total PCL insertion to the Blumensaat line were 5.5 ± 0.91, 11.5 ± 1.98, and 7.6 ± 1.42 mm, respectively. The shortest distance from medial femoral cartilage rim to the central point of femoral ALB, PMB, and total PCL insertion were 7.0 ± 0.79, 7.3 ± 0.95, and 7.8 ± 1.73 mm, respectively. The tibial insertion area of ALB and PMB were 84.5 ± 12.52 and 47.8 ± 6.20 mm2 respectively. The shortest distance from the posterior cartilage corner of the medial tibial plateau to the central point of ALB, PMB, and total PCL insertion to tibia were 8.5 ± 1.02, 9.4 ± 1.11, and 8.3 ± 1.1 mm, respectively. The central point of tibial PCL insertion was 9.7±1.08 mm below cartilage plane of the medial tibial plateau. CONCLUSION: This study describes the detailed anatomical measurement of the PCL and its bundles in adults

    A Pathogen Secreted Protein as a Detection Marker for Citrus Huanglongbing.

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    The citrus industry is facing an unprecedented crisis due to Huanglongbing (HLB, aka citrus greening disease), a bacterial disease associated with the pathogen Candidatus Liberibacter asiaticus (CLas) that affects all commercial varieties. Transmitted by the Asian citrus psyllid (ACP), CLas colonizes citrus phloem, leading to reduced yield and fruit quality, and eventually tree decline and death. Since adequate curative measures are not available, a key step in HLB management is to restrict the spread of the disease by identifying infected trees and removing them in a timely manner. However, uneven distribution of CLas cells in infected trees and the long latency for disease symptom development makes sampling of trees for CLas detection challenging. Here, we report that a CLas secreted protein can be used as a biomarker for detecting HLB infected citrus. Proteins secreted from CLas cells can presumably move along the phloem, beyond the site of ACP inoculation and CLas colonized plant cells, thereby increasing the chance of detecting infected trees. We generated a polyclonal antibody that effectively binds to the secreted protein and developed serological assays that can successfully detect CLas infection. This work demonstrates that antibody-based diagnosis using a CLas secreted protein as the detection marker for infected trees offers a high-throughput and economic approach that complements the approved quantitative polymerase chain reaction-based methods to enhance HLB management programs

    Carbon Nanomaterial-Based Chemiresistive Biosensors for Detection of Secretory Protein Biomarkers of Citrus Greening Disease

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    Citrus greening disease, also known as Huanglongbing (HLB), is posing a worldwide threat to the multi-billion dollars citrus industry. Currently, there are no cures for infected plants while containment of the spread of disease is heavily dependent on early detection of infected hosts for quarantine. The pathogen responsible for causing the disease is the bacteria Candidatus Liberibacter asiaticus (CLas). Thus, it is imperative that disease management strategies address current demands for accurate, timely, and robust disease detection and diagnosis minimize the spread of disease. By adopting a novel detection strategy targeting a recently discovered secreted protein biomarker, SDE1, which is unique to CLas, we hope to overcome the challenges faced by current detection methods, such as nucleic acid-based and symptom-based which have been found prone to false negatives and mis-diagnoses, respectively. To do this, we have worked to procure and characterize the antibodies specific for the novel HLB biomarker. In the process of characterizing the anti-SDE1 antibodies, we have also developed a specific and sensitive enzyme-linked immunosorbent assay (ELISA) for high-throughput and point-of-laboratory analysis of citrus plant samples. With the final goal of using the anti-SDE1 antibodies to develop sensitive, facile, and specific HLB detection method, we have integrated these antibodies into nanoscale electrical biosensor platforms. Using the novel semiconducting carbon nanomaterials, reduced graphene oxide (RGO) and single-walled carbon nanotubes (SWNTs), as the electrical transducer element for our biosensors, we have developed chemiresistive biosensors that demonstrate specificity and sensitivity to the SDE1 biomarker in simple phosphate buffer and in plant extracts

    Uniaxially oriented nickel aluminum superalloy films sputtered with in situ heating

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    We report uniaxially oriented nickel aluminum (NiAl) films grown by DC magnetron sputtering under in situ heating. The films self-organize in (110) orientation with relatively low surface roughness and tight grain boundaries in columnar structure. The electrical carrier concentration and resistivity are on the order of 10(21) cm(-3) and 10(-5) omega center dot cm, respectively. The plasmonic performance, as indicated by the dielectric function, is comparable to that of a NiAl single crystal and exceeds those of conventional refractory materials (molybdenum, tungsten, titanium nitride) at visible to NIR wavelengths. This work paves the way to superalloy-based plasmonic nanostructures for photothermal energy applications

    Detection of a secreted protein biomarker for citrus Huanglongbing using a single-walled carbon nanotubes-based chemiresistive biosensor

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    Citrus greening, or Huanglongbing (HLB), is currently the most devasting disease of citrus, creating unprecedented crisis for the multibillion-dollar global citrus industry. To-date, there is no effective cure and disease management relies on early detection and removal of infected trees. Thus, it is imperative that accurate, timely, and robust disease detection and diagnosis technologies are available to minimize the spread of disease. This study reports a sensitive and selective label-free biosensor that combines the physical and chemical advantages of carbon nanomaterials like single-walled carbon nanotubes (SWNTs) in a field-effect transistor (FET)/chemiresistor architecture with selective antibodies against Sec-delivered effector 1 (SDE1), a secreted protein biomarker, for the detection of HLB. The biosensor detected SDE1 biomarkers for citrus greening in plant tissue extracts with the dynamic range over three orders of magnitude in the low nanomolar to micromolar concentration range and limit of detection of 5 nM. The study also demonstrated the use of the standard additions assay method with the biosensor to attain a 90-percent signal recovery in concentrated plant tissue extract, allowing for quantitative detection without an external calibration. Adopting the novel detection strategy targeting the secreted protein biomarker, SDE1, addresses some of the challenges faced by current methods of nucleic acid-based assays and symptom-based diagnosis, which have been found prone to false negatives and misdiagnoses, respectively
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