14 research outputs found
In vitro and in vivo evaluation of a single chain antibody fragment generated in planta with potent rabies neutralisation activity.
Rabies causes more than 60,000 human deaths annually in areas where the virus is endemic. Importantly, rabies is one of the few pathogens for which there is no treatment following the onset of clinical disease with the outcome of infection being death in almost 100% of cases. Whilst vaccination, and the combination of vaccine and rabies immunoglobulin treatment for post-exposure administration are available, no tools have been identified that can reduce or prevent rabies virus replication once clinical disease has initiated. The search for effective antiviral molecules to treat those that have already developed clinical disease associated with rabies virus infection is considered one of the most important goals in rabies research. The current study assesses a single chain antibody molecule (ScFv) based on a monoclonal antibody that potently neutralises rabies in vitro as a potential therapeutic candidate. The recombinant ScFv was generated in Nicotiana benthamiana by transient expression, and was chemically conjugated (ScFv/RVG) to a 29 amino acid peptide, specific for nicotinic acetylcholine receptor (nAchR) binding in the CNS. This conjugated molecule was able to bind nAchR in vitro and enter neuronal cells more efficiently than ScFv. The ability of the ScFv/RVG to neutralise virus in vivo was assessed using a staggered administration where the molecule was inoculated either four hours before, two days after or four days after infection. The ScFv/RVG conjugate was evaluated in direct comparison with HRIG and a potential antiviral molecule, Favipiravir (also known as T-705) to indicate whether there was greater bioavailability of the ScFv in the brains of treated mice. The study indicated that the approach taken with the ScFv/RVG conjugate may have utility in the design and implementation of novel tools targetting rabies virus infection in the brain
Inference on the Gamma Distribution
<p>This study develops inferential procedures for a gamma distribution. Based on the Cornish–Fisher expansion and pivoting the cumulative distribution function, an approximate confidence interval for the gamma shape parameter is derived. The generalized confidence intervals for the rate parameter and other quantities such as mean are explored. The proposed generalized inferential procedures are extended to construct prediction limits for a single future measurement and for at least <i>p</i> of <i>m</i> measurements at each of <i>r</i> locations. The performance of the proposed procedures is evaluated using Monte Carlo simulation. The simulation results show that the proposed procedures are very satisfactory. Finally, three real examples are used to illustrate the proposed procedures. Supplementary materials for this article are available online.</p
Experimental Study on Gas Transport in Shale Matrix with Real Gas and Klinkenberg Effects
Gas transport in shale matrix is complex due to multiple mechanisms and is difficult to be investigated by macroscopic experiment. For Gas Research Institute (GRI) method, which is the most accepted one for gas transport investigation in shale matrix, the apparatus was modified by adding an automatic gas supplement and pressurization (AGSP) system, and a numerical model considering the variation of real gas property and the Klinkenberg effect was established for data interpretation. Then, the intrinsic permeability and Klinkenberg coefficient were effectively obtained by maintaining high expanding speed of gas in apparatus and eliminating the negative effect of low filling degree of sample. By analysis, the ideal gas transports faster than real gas due to the viscosity difference at low pressure and the deviation factor difference at high pressure. For Wufeng-Longmaxi shale matrix, the positive influence of Klinkenberg effect on gas transport would attenuate with increasing pressure and is more powerful than bulk shale sample with fractures. Therefore, the gas transport in real shale matrix could be well known, which is meaningful to production forecast and evaluation in oil and gas fields
Green synthesized clavate-shaped ZnO modified silk fabric with aging resistance and outstanding antibacterial and UV-shielding properties
Silk, a popular luxury textile with many years of history, is easy to embrittle and adsorb bacteria when stored for a long time or exposed to sunlight, which affects its service life. To improve the silk fabrics with excellent antibacterial activity, washing and aging durability, and UV shielding, multifunctional silk fabrics were designed and fabricated via a green finishing approach. Here, we proposed a simple strategy to fabricate silk fabrics with multi-functions via coating clavate-shaped ZnO nanoparticles (ZF-silk fabrics) by dipping and pressing for cycles. The scanning electron microscope (SEM), fourier transform infrared (FTIR), ultraviolet visible spectrophotometry (UV–Vis), and X-ray diffraction (XRD) were used to analyze the structure and properties of fabricated ZF-silk fabrics. Compared with raw silk fabric, the fabricated ZF-silk fabrics represented excellent UV shielding, good tensile strength, and superior antibacterial activity. Notably, the ZF-silk fabrics had good washing stability and aging resistance. In addition, the ZF-silk fabrics possessed superior antibacterial activity before and after aging treatment (under UV radiation for 72 h). Therefore, the durable and multifunctional ZF-silk fabrics indicate great potential for achieving to realize a long service life of the fabrics
Effects of Nitrogen Additions on Soil Respiration in an Asian Tropical Montane Rainforest
Understanding the impacts of nitrogen (N) addition on soil respiration (RS) and its temperature sensitivity (Q10) in tropical forests is very important for the global carbon cycle in a changing environment. Here, we investigated how RS respond to N addition in a tropical montane rainforest in Southern China. Four levels of N treatments (0, 25, 50, and 100 kg N ha−1 a−1 as control (CK), low N (N25), moderate N (N50), and high N (N100), respectively) were established in September 2010. Based on a static chamber-gas chromatography method, RS was measured from January 2015 to December 2018. RS exhibited significant seasonal variability, with low RS rates appeared in the dry season and high rates appeared in the wet season regardless of treatment. RS was significantly related to the measured soil temperature and moisture. Our results showed that soil RS increased after N additions, the mean annual RS was 7% higher in N25 plots, 8% higher in N50 plots, and 11% higher in N100 plots than that in the CK plots. However, the overall impacts of N additions on RS were statistically insignificant. For the entire study period, the CK, N25, N50, and N100 treatments yielded Q10 values of 2.27, 3.45, 4.11, and 2.94, respectively. N addition increased the temperature sensitivity (Q10) of RS. Our results suggest that increasing atmospheric N deposition may have a large impact on the stimulation of soil CO2 emissions from tropical rainforests in China
Effect of Chemical Treatment on Rice Straw Fiber Surface and Properties of Straw/Polylactic Acid Composites
In this work, rice straw fibers were modified using NaOH, KBM-403, and tetraethyl orthosilicate (TEOS), and the changes in the surface groups of the straw fibers before and after the modification were analyzed by infrared testing. Straw/polylactic composite were prepared by hot pressing, and the effects of the modifiers used on the properties of these blends were studied by conducting mechanical and thermal performance tests. The results showed that the tensile strength of the straw fiber composites modified by NaOH and KBM-403 increased by 20% and 21.2%, respectively, compared with that of the unmodified composite, whereas the tensile strength of the TEOS-modified fiber did not increase significantly. The flexural strengths of the composites increased by 10.2%, 11.1%, and 13.2%. The impact strength increased by 38.5%, 7.6%, and 7.6%. The results of thermal analysis show that initial and maximum thermal decomposition temperatures of the composite materials increased, indicating that the modified composite materials had a higher thermal stability. These blends are a kind of potential material for structural applications such as interiors, drywell and partitions for furniture
Quantification of Ecosystem-Scale Methane Sinks Observed in a Tropical Rainforest in Hainan, China
Tropical rainforest ecosystems are important when considering the global methane (CH4) budget and in climate change mitigation. However, there is a lack of direct and year-round observations of ecosystem-scale CH4 fluxes from tropical rainforest ecosystems. In this study, we examined the temporal variations in CH4 flux at the ecosystem scale and its annual budget and environmental controlling factors in a tropical rainforest of Hainan Island, China, using 3 years of continuous eddy covariance measurements from 2016 to 2018. Our results show that CH4 uptake generally occurred in this tropical rainforest, where strong CH4 uptake occurred in the daytime, and a weak CH4 uptake occurred at night with a mean daily CH4 flux of −4.5 nmol m−2 s−1. In this rainforest, the mean annual budget of CH4 for the 3 years was −1260 mg CH4 m−2 year−1. Furthermore, the daily averaged CH4 flux was not distinctly different between the dry season and wet season. Sixty-nine percent of the total variance in the daily CH4 flux could be explained by the artificial neural network (ANN) model, with a combination of air temperature (Tair), latent heat flux (LE), soil volumetric water content (VWC), atmospheric pressure (Pa), and soil temperature at −10 cm (Tsoil), although the linear correlation between the daily CH4 flux and any of these individual variables was relatively low. This indicates that CH4 uptake in tropical rainforests is controlled by multiple environmental factors and that their relationships are nonlinear. Our findings also suggest that tropical rainforests in China acted as a CH4 sink during 2016–2018, helping to counteract global warming
Quantification of Ecosystem-Scale Methane Sinks Observed in a Tropical Rainforest in Hainan, China
Tropical rainforest ecosystems are important when considering the global methane (CH4) budget and in climate change mitigation. However, there is a lack of direct and year-round observations of ecosystem-scale CH4 fluxes from tropical rainforest ecosystems. In this study, we examined the temporal variations in CH4 flux at the ecosystem scale and its annual budget and environmental controlling factors in a tropical rainforest of Hainan Island, China, using 3 years of continuous eddy covariance measurements from 2016 to 2018. Our results show that CH4 uptake generally occurred in this tropical rainforest, where strong CH4 uptake occurred in the daytime, and a weak CH4 uptake occurred at night with a mean daily CH4 flux of −4.5 nmol m−2 s−1. In this rainforest, the mean annual budget of CH4 for the 3 years was −1260 mg CH4 m−2 year−1. Furthermore, the daily averaged CH4 flux was not distinctly different between the dry season and wet season. Sixty-nine percent of the total variance in the daily CH4 flux could be explained by the artificial neural network (ANN) model, with a combination of air temperature (Tair), latent heat flux (LE), soil volumetric water content (VWC), atmospheric pressure (Pa), and soil temperature at −10 cm (Tsoil), although the linear correlation between the daily CH4 flux and any of these individual variables was relatively low. This indicates that CH4 uptake in tropical rainforests is controlled by multiple environmental factors and that their relationships are nonlinear. Our findings also suggest that tropical rainforests in China acted as a CH4 sink during 2016–2018, helping to counteract global warming