Preparation of a Ni-P-nanoPTFE Composite Coating on the Surface of GCr15 Steel for Spinning Rings via a Defoamer and Transition Layer and Its Wear and Corrosion Resistance.

In this study, a method of preparing a Ni-P-nanoPTFE composite coating on the surface of GCr15 steel for spinning rings is proposed. The method incorporates a defoamer into the plating solution to inhibit the agglomeration of nano-PTFE particles and pre-deposits a Ni-P transition layer to reduce the possibility of leakage coating. Meanwhile, the effect of varying the PTFE emulsion content in the bath on the micromorphology, hardness, deposition rate, crystal structure, and PTFE content of the composite coatings was investigated. The wear and corrosion resistances of the GCr15 substrate, Ni-P coating, and Ni-P-nanoPTFE composite coating are compared. The results show that the composite coating prepared at a PTFE emulsion concentration of 8 mL/L has the highest concentration of PTFE particles (up to 2.16 wt%). Additionally, its wear resistance and corrosion resistance are improved compared with Ni-P coating. The friction and wear study shows that the nano-PTFE particles with low dynamic friction coefficient are mixed in the grinding chip, which gives the composite coating self-lubricating characteristics, and the friction coefficient decreases to 0.3 compared with 0.4 of Ni-P coating. The corrosion study shows that the corrosion potential of the composite coating has increased by 7.6% compared with that of the Ni-P coating, which shifts from -456 mV to a more positive value of -421 mV. The corrosion current reduces from 6.71 µA to 1.54 µA, which is a 77% reduction. Meanwhile, the impedance increased from 5504 Ω·cm2 to 36,440 Ω·cm2, which is an increase of 562%.

ß2-microglobulin functions as an endogenous NMDAR antagonist to impair synaptic function.

Down syndrome (DS) is a neurological disorder with multiple immune-related symptoms; however, crosstalk between the CNS and peripheral immune system remains unexplored. Using parabiosis and plasma infusion, we found that blood-borne factors drive synaptic deficits in DS. Proteomic analysis revealed elevation of ß2-microglobulin (B2M), a major histocompatibility complex class I (MHC-I) component, in human DS plasma. Systemic administration of B2M in wild-type mice led to synaptic and memory defects similar to those observed in DS mice. Moreover, genetic ablation of B2m or systemic administration of an anti-B2M antibody counteracts synaptic impairments in DS mice. Mechanistically, we demonstrate that B2M antagonizes NMDA receptor (NMDAR) function through interactions with the GluN1-S2 loop; blocking B2M-NMDAR interactions using competitive peptides restores NMDAR-dependent synaptic function. Our findings identify B2M as an endogenous NMDAR antagonist and reveal a pathophysiological role for circulating B2M in NMDAR dysfunction in DS and related cognitive disorders.

Urea/sodium hydroxide pretreatments enhance decomposition of maize straw in soils and sorption of straw residues toward herbicides.

Because of the rigid crystalline structure and recalcitrant components, maize straw returned is slowly decomposed in soils. Straw residues are substantially accumulated in soils and pose detrimental impacts to crop plantation. Here we report the pretreatments of urea and NaOH (USH) to enhance maize straw decomposition in the field. The USH reagents interacted synergistically to destruct straw, mainly through breaking the rigid hydrogen bonding network and chemically hydrolyzing recalcitrant lignin. The synergy was evident for the USH reagents containing 6-8% urea and 0.1-1% NaOH under various temperature conditions (-20 °C to 25 °C). The USH (7%/0.1%) pretreatment resulted in notable enhancement (37%) of straw decomposition in the field within 6 months, superior to current biological-based treatments (6-28%). Moreover, this pretreatment posed no influence on the adsorption of straw residues collected at the early stage of decomposition (27 days) toward five commonly used herbicides. Those straw residues collected on 67 days and later exhibited high adsorption capacity, indicated by 0.5- to 4-folded increases in Kd values. Additionally, the impacts to soil pH and bacterial/fungal community were negligible. The USH pretreatments thus have practical interests in mitigating accumulation of straw residues in straw-returned soils.