Nano-multilayered ZrN‒Ag/Mo‒S‒N film design for stable anti-frictional performance at a wide range of temperatures

A multilayer film,composed by ZrN‒Ag(20 nm)and Mo‒S‒N(10 nm)layers,combining the intrinsic lubricant characteristics of each layer was deposited using DC magnetron sputtering system,to promote lubrication in a wide-range of temperatures.The results showed that the ZrN‒Ag/Mo‒S‒N multilayer film exhibited a sharp interface between the different layers.A face-centered cubic(fcc)dual-phases of ZrN and Ag co-existed in the ZrN‒Ag layers,whilst the Mo‒S‒N layers displayed a mixture of hexagonal close-packed MoS_(2)(hcp-MoS_(2))nano-particles and an amorphous phase.The multilayer film exhibited excellent room temperature(RT)triblogical behavior,as compared to the individual monolayer film,due to the combination of a relative high hardness with the low friction properties of both layers.The reorientation of MoS_(2)parallel to the sliding direction also contributed to the enhanced anti-frictional performance at RT.At 400℃,the reorientation of MoS_(2)as well as the formation of MoO_(3)phase were responsible for the lubrication,whilst the hard t-ZrO_(2)phase promoted abrasion and,consequently,led to increasing wear rate.At 600℃,the Ag_(2)MoO_(4)double-metal oxide was the responsible for the low friction and wear-resistance;furthermore,the observed transformation from t-ZrO_(2)to m-ZrO_(2),could also have contributed to the better tribological performance.

Insights into the oxidation resistance mechanism and tribological behaviors of multilayered TiSiN/CrVxN hard coatings

In the last decades,vanadium alloyed coatings have been introduced as potential candidates for self-lubrication due to their perfect tribological properties.In this work,the influence of V incorporation on the wear performance and oxidation resistance of TiSiN/CrN film coatings deposited by direct current(DC)reactive magnetron sputtering is investigated.The results show that vanadium incorporation significantly decreases the oxidation resistance of the coatings.In general,two layers are formed during the oxidation process:i)Ti(V)O_(2) on top,followed by a protective layer,which is subdivided into two layers,Cr_(2)O_(3) and Si-O.ii)The diffusion of V controls the oxidation of V-containing coatings.The addition of vanadium improves the wear resistance of coatings,and the wear rate decreases with increasing V content in the coatings;however,the friction coefficient is independent of the chemical composition of the coatings.The wear of the V-containing coatings is driven by polishing wear.

Tribological performance under different environments of Ti-C-N composite films for marine wear-resistant parts

The need for reducing the wear in mechanical parts used in the industry makes self-lubricant films one of the sustainable solutions to achieve long-term protection under different environmental conditions.The purpose of this work is to study the influence of C additions on the tribological behavior of a magnetron-sputtered TiN film in air,water,and seawater.The results show that the addition of C into the TiN binary film induced a new amorphous phase,and the films exhibited a dual phase of fcc(face-centered cubic)-TiN and amorphous carbon.The antifriction and wear-resistance properties were enhanced in air and water by adding 19.1at%C.However,a further increase in the C concentration improved anti-frictional properties but also led to higher wear rates.Although the amorphous phase induced microbatteries and accelerated the corrosion of TiN phases in seawater,the negative abrasion state was detected for all Ti-C-N films due to the adhesion of the tribocorrosion debris on the wear track.

Sirt5 desuccinylates Cdc42 to mediate osteoclastogenesis and bone remodeling in mice

Post-translational modifications(PTMs)play a critical role in bone remodeling,with phosphorylation and acetylation being particularly well characterized.Recently,succinylation,a relatively uncommon PTM on lysine,has received considerable research attention for its influence on several physiological and pathological processes and conditions.1 Several substrates involved in mitochondrial pathways have been validated as substrates for the desuccinylase sirtuin 5(Sirt5),a key regulator of succinylation.2 Bone is one of the most metabolically active organs,but the role of succinylation during bone remodeling is not well characterized.

Predictably synthesizing a library of white-light-emitting perovskites

The low-dimensional organic-inorganic halide perovskites with self-trapped exciton emission have promising prospects for single-phase white-light emitters. However, so far, these broadband white-light-emitting(BWLE) perovskites were synthesized by trial-and-error testing spacing molecules. Here, we developed a steric hindrance regulation strategy to predictably synthesize BWLE perovskites. The molecules containing C–C(–NH_(2))–C groups were introduced into low-dimensional perovskites, which brings a large steric hindrance in-plane orientation. The bigger C–C(–NH_(2))–C bond angle would induce larger structural distortion in perovskites, which leads to the higher rate of self-trapping of excitons and the deeper self-trapping depth. The photoluminescence spectra of the synthesized perovskites can cover the cool-to-warm white light region. Overall, we fabricated a material library consisting of 40 kinds of BWLE compounds according to this strategy. Our findings develop a general strategy to synthesize BWLE perovskites and offer a material platform for optoelectronic applications.

A Novel Small Deletion in the A TP2A2 Gene in a Patient with Sporadic Darier's Disease and Concomitant Depression: A Case Report

Introduction:Darier's disease is a rare autosomal dominant skin disorder caused by mutations in ATP2A2.Recently,the high prevalence of neuropsychiatric symptoms is frequently reported in Darier's disease patients.We present a case of patient with concurrence of Darier's disease and depression and detected the mutations in Case presentation:A 29-year-old man presented with a 15-year history of brown,harsh keratotic papules on his scalp,face,neck,trunk,axilla,ingunia and upper limbs.Meanwhile,he had persistent depression.He was diagnosed as Darier's disease according to clinical manifestations and result of histological examination.We sequenced all coding regions of ATP2A2.The mutation c.2993_2994del(p.Val998Alafs*33)in exon 20 of ATP2A2 was detected.Discussion:Darier's disease has been associated with several extracutaneous manifestations,in particular neuropsychiatric morbidity.Likely gene disrupting mutations in ATP2A2 was reported to have a close relationship to Darier's disease cases with reported co-occurring neuropsychiatric features.Consistent with the previous reports,an likely gene disrupting mutations was detected in our patient with concurrence of DD end depression.Conclusion:The psychiatric disorders in patients with Darier's disease should be well appreciated.The underlying mechanism in correlation between the mutation in ATP2A2 and neuropsychiatric phenotypes in Darier's disease remain unclarified and warrants further investigation.