Magnetic Carbon Nanotubes for Protein Separation

Magnetic separation is a promising strategy in protein separation. Owing to their unique one-dimensional structures and desired magnetic properties, stacked-cup carbon nanotubes (CSCNTs) with magnetic nanoparticles trapped in their tips can serve as train-like systems for protein separation. In this study, we functionalized the magnetic CSCNTs with high density of carboxyl groups by radical addition and then anchored 3-aminophenylboronic acid (APBA) through amidation reaction to achieve oriented conjunction of antibodies (IgG). It was also demonstrated that the obtained magnetic CSCNTs-APBA-IgG conjugates could readily react with target antigens through specific antigen-antibody reaction and be used as new magnetic systems for protein separation

Carbon in Chinese grasslands : meta-analysis and theory of grazing effects

Unidad de excelencia María de Maeztu CEX2019-000940-MGlobally, livestock grazing is an important management factor influencing soil degradation, soil health and carbon (C) stocks of grassland ecosystems. However, the effects of grassland types, grazing intensity and grazing duration on C stocks are unclear across large geographic scales. To provide a more comprehensive assessment of how grazing drives ecosystem C stocks in grasslands, we compiled and analyzed data from 306 studies featuring four grassland types across China: desert steppes, typical steppes, meadow steppes and alpine steppes. Light grazing was the best management practice for desert steppes (< 2 sheep ha−1) and typical steppes (3 to 4 sheep ha−1), whereas medium grazing pressure was optimal for meadow steppes (5 to 6 sheep ha−1) and alpine steppes (7 to 8 sheep ha−1) leading to the highest ecosystem C stocks under grazing. Plant biomass (desert steppes) and soil C stocks (meadow steppes) increased under light or medium grazing, confirming the 'intermediate disturbance hypothesis'. Heavy grazing decreased all C stocks regardless of grassland ecosystem types, approximately 1.4 Mg ha−1 per year for the whole ecosystem. The regrowth and regeneration of grasslands in response to grazing intensity (i.e., grazing optimization) depended on grassland types and grazing duration. In conclusion, grassland grazing is a double-edged sword. On the one hand, proper management (light or medium grazing) can maintain and even increase C stocks above- and belowground, and increase the harvested livestock products from grasslands. On the other hand, human-induced overgrazing can lead to rapid degradation of vegetation and soils, resulting in significant carbon loss and requiring long-term recovery. Grazing regimes (i.e., intensity and duration applied) must consider specific grassland characteristics to ensure stable productivity rates and optimal impacts on ecosystem C stocks

An invasive podosome-like structure promotes fusion pore formation during myoblast fusion

An F-actin–enriched protrusion resembling an invasive podosome promotes fusion pore formation between muscle founder cells and fusion-competent myoblasts

Anomalous overland flow on hillslopes: A fractional kinematic wave model, its solutions and verification with data from laboratory observations

This paper analyses a fractional kinematic wave equation (fKWE) for overland flow and evaluates its solutions for applications using data from overland flow flumes with simulated rainfall in the laboratory. Solutions of fKWE presented have been derived for large time or when the Laplace transform variable s→0, which is one of the most important situations for overland flow. The solutions include expressions for the depth, velocity, and unit discharge, of overland flow. Fitting the approximate solution for the depth of overland flow to the data yields the values of the order of space-fractional derivatives, ρ , which is around slope gradient and the rainfall intensity. The approximate order of ρ ρ =1.5. It is found that ρ increases with the =1.5, which is about the average of order 1 for the advection equation and 2 for the diffusion equation, implies that diffusive mechanisms manifest in the overland flow. The findings mean that either an fKWE is used or a diffusion term is needed to account for dynamic forces in overland flow as the fKWE captures more physical mechanisms

A Precision Machining of Gears : Slow-Scanning Field Controlled Electrochemical Honing

This paper presents a new working method of controllable Electro-Chemical Honing (ECH) of gears as follows. A gear shaped cathode which is meshing with a workpiece gear during machining is exposed as cathode pole only on a strip on the tooth dank. By varying the center distance between the cathode and the gear slowly, the electrolysis zone sweeps over the tooth flank from root to tip (slow scanning as we call it). Since the center distance is varied by a step motor, so the time of dwelling of the pole, and hence the amount of metal removal on different spots of the profile can be controlled by programming. An on-line profile error measuring device is provided. The computer calculates the required discharging time which has a relationship with dwelling time, and sends out the programming to control the metal. removing rate so as to cancel the error or to produce profile correction needed by silent transmission. A mathematical model is built for calculating the required discharging time. Several ground gears with typical profile errors are subjected to trial machining on this working principle. It cancels the profile errors very efficiently. The experiment demonstrates that the machining method can step up the profile accuracy to very high order on the basis of the general accuracy guaranteed by the proceeding operationgear grinding

Beryllium-7 activity concentration in plants on the Loess Plateau, China

The activity concentration of beryllium-7 ((7)Be), a naturally occurring cosmogenic radionuclide produced in the upper atmosphere, was measured in plants on the Loess plateau of China during the growing season of 2005. The (7)Be mass activity concentration on July 27 ranged from 34.8 to 147.1 Bq kg(-1) in herbaceous plants, from 47.6 to 116.1 Bq kg(-1) in subshrubs, and from 15.7 to 56.8 Bq kg(-1) in crop plants. The (7)Be mass and areal activity concentrations of a mixture of herbaceous plants increased from 66.8 to 288.7 Bq kg(-1) and from 0.7 to 46.5 Bq m(-2), respectively, during the growing season. On an areal basis, the fraction of (7)Be in plants in the soil-plant system increased from 0.4 to 8.4% during the growing season. Positive linear correlations were found between the increases of (7)Be mass and areal activity concentrations in the inter-sampling intervals and the amount of precipitation

Sediment source analysis using the fingerprinting method in a small catchment of the Loess Plateau, China

Purpose This paper aims to use the composite fingerprinting method to reconstruct the environmental history after the Grain-for-Green Project and to provide effective sediment management and soil erosion-control strategies. Materials and methods This study used a composite fingerprinting method based on 45 geochemical properties and a mixing model to investigate sediment core changes in the sediment source in an agricultural catchment with little native vegetation. The samples consisted of 77 source samples (i.e., gully, grassland, forest, cropland, and fallow land) and five sediment cores. Genetic algorithm (GA) optimization has been recently used to find the best optimum source contribution to sediments. Results and discussion The results demonstrate that gully is the main sediment source in this catchment, constituting 34.7 %, followed by cropland (28.2 %), forest (21.5 %), grassland (12.7 %), and fallow land (2.9 %). However, the relative contribution of each source type was variable in all five sediment cores. The sediment that derived from grassland was relatively stable in the five cores. The relative contribution of forest was higher in the downstream portion of the check dam and lower in the upstream portion and gradually increased in the direction of the runoff pathway. As the forest matured, the sediment that derived from the forest gradually decreased. Changes in the hydro-ecological environment would lead to the leaf litter and understory being poorly developed and the soil being bare in the forest, making it more vulnerable to erosion. Conclusions Reforestation and fallow are the key ecological strategies for reducing soil erosion. However, at the beginning of the Grain-for-Green Project, the young forest contributed 21.5 % of the sediment, indicating that natural fallow may be a better-designed sediment management and soil erosion-control strategy.<br style=" font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; " /