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Immune-mediated inflammatory diseases (IMIDs) represent a diverse group of diseases and challenges remain for the current medications. Herein, we present an activatable and targeted nanosystem for detecting and imaging IMIDs foci and treating them through blocking NF-κB/NLRP3 pathways. A ROS-activatable prodrug BH-EGCG is synthesized by coupling a near-infrared chromophore with the NF-κB/NLRP3 inhibitor epigallocatechin-3-gallate (EGCG) through boronate bond which serves as both the fluorescence quencher and ROS-responsive moiety. BH-EGCG molecules readily form stable nanoparticles in aqueous medium, which are then coated with macrophage membrane to ensure the actively-targeting capability toward inflammation sites. Additionally, an antioxidant precursor N-acetylcysteine is co-encapsulated into the coated nanoparticles to afford the nanosystem BH-EGCG&NAC@MM to further improve the anti-inflammatory efficacy. Benefiting from the inflammation-homing effect of the macrophage membrane, the nanosystem delivers payloads (diagnostic probe and therapeutic drugs) to inflammatory lesions more efficiently and releases a chromophore and two drugs upon being triggered by the overexpressed in-situ ROS, thus exhibiting better theranostic performance in the autoimmune hepatitis and hind paw edema mouse models, including more salient imaging signals and better therapeutic efficacy via inhibiting NF-κB pathway and suppressing NLRP3 inflammasome activation. This work may provide perceptions for designing other actively-targeting theranostic nanosystems for various inflammatory diseases., Graphical abstract Image 1, Highlights • A multifunctional nanosystem has been developed for targeting, imaging and treating immune-mediated inflammatory diseases. • Once activated the nanosystem generates fluorescent/optoacoustic signals for diagnosis and evaluating therapeutic efficacy. • The released drugs EGCG and NAC in inflammation site treat the diseases via inhibiting NF-κB/NLRP3 pathways.

Heterogeneous bubble nucleation is one of the most fundamental interfacial processes ranging from nature to technology. There is excellent evidence that surface topology is important in directing heterogeneous nucleation; however, deep understanding of the energetics by which nanoscale architectures promote nucleation is still challenging. Herein, we report a direct and quantitative measurement of single-bubble nucleation on a single silica nanoparticle within a microsized droplet using scanning electrochemical cell microscopy. Local gas concentration at nucleation is determined from finite element simulation at the corresponding faradaic current of the peak-featured voltammogram. It is demonstrated that the criteria gas concentration for nucleation first drops and then rises with increasing nanoparticle radius. An optimum nanoparticle radius around 10 nm prominently expedites the nucleation by facilitating the special topological nanoconfinements that consequently catalyze the nucleation. Moreover, the experimental result is corroborated by our theoretical calculations of free energy change based on the classic nucleation theory. This study offers insights into the impact of surface topology on heterogenous nucleation that have not been previously observed.

Depression has a growing impact on public health. Accumulating evidence supports an association between depression and increased immune system activity. IL-10 is a key cytokine that inhibits excessive inflammatory responses and is related to the anti-inflammatory and protective functions of the central nervous system (CNS). Cx3cr1CreERIL-10-/- mice were used in our study. We aimed to identify the role of IL-10 in microglia in depression and anxiety-like behavior. We performed a series of behavioral tests on the mice; the Cx3cr1CreERIL-10-/- male mice showed depression- and anxiety-like behavior compared with the littermates. The expression of transient receptor potential canonical 5 (TRPC5) decreased in both the medial prefrontal cortex (mPFC) and amygdala regions. The cytokines IL-1β and IL-6 increased, and IL-10 was decreased by western blotting. The knockout mice showed different trends in the effects of synaptic proteins. In the mPFC, IL-10 knockout induced a decrease in NR2B and synaptophysin; in the amygdala region, there was a significant increase in NR2B and PSD95. IL-10 knockout from microglia induced a decrease in GAD67 and parvalbumin (Pv) in the mPFC, but not in the amygdala. Our results showed enhanced depression and anxiety-like behavior in the Cx3cr1CreER IL-10-/- mice, which could be related to an imbalance in local excitatory and inhibitory transmission, as well as neuroinflammation in the mPFC and amygdala. This imbalance was associated with increased local inflammation. Although many studies have demonstrated the role of TRPC channels in emotional responses, our study showed that TRPC was not involved in this process in Cx3cr1CreERIL-10-/- mice.

Systemic sclerosis (SSc) is a heterogeneous disease with skin fibrosis. Yes-associated protein (YAP)/transcriptional coactivator with PDZ-binding motif (TAZ) is associated with fibrotic response. This work attempted to determine the precise mechanism of YAP/TAZ in SSc. Single-cell sequencing (scRNA-seq) was used to analyse the differential gene expression between SSc patients and healthy volunteers, showing that the YAP/TAZ signalling pathway was enriched in the fibroblasts of SSc patients. Subsequently, enzyme-linked immunosorbent assay and immunohistochemical analyses were conducted to examine the levels of YAP and TAZ in mild and severe SSc patients. YAP and TAZ were highly expressed in the serum and skin tissues of mild and severe SSc patients, especially severe SSc patients. Additionally, an SSc mouse model was induced by bleomycin, and the impacts of YAP/TAZ knockdown on the pathological changes in skin and lung tissues were detected by haematoxylin and eosin staining and Masson staining. Knockdown of YAP and TAZ inhibited α-SMA mRNA and protein expression in skin and lung tissues of SSc mice. Inhibition of YAP and TAZ reduced skin inflammation and thickness and repressed lung inflammation and fibrosis in SSc mice. Importantly, knockdown of YAP and TAZ synergistically inhibited inflammation and fibrosis in skin and lung tissues in SSc mice. In conclusion, this work demonstrated that knockdown of YAP and TAZ exerted a synergistic effect on alleviating SSc in mice. Thus, this work suggests that YAP/TAZ is a potential target for SSc treatment.

Deconjugation of bile salts in vivo not only promotes the cholesterol metabolism of the host, but also provides cellular carbon, nitrogen and sulphur for some probiotics. In this study, the gene of BSH from Bifidobacterium bifidum (ATCC 29521) was amplified and expressed using glutathione S-transferase (GST) Gene Fusion System. The enzyme was purified in a mild conditions without denaturation and renaturation, and the molecular mass was estimated to be 35 kDa. The optimum pH for the enzyme catalysis was 5.5. The BSH enzyme was stable from 37 to 57 °C. In addition, this enzyme was completely inhibited by Cu2+, while many other metal ions only gave moderate inhibition. Hydrolysis efficiency of BSH was quantified in two ways: ninhydrin colouration method and high-performance liquid chromatography coupled with evaporative light scattering detector (HPLC-ELSD). The hydrolysis process was clearly observed through real-time picture monitoring. The activity of BSH on glycine-conjugated bile salts was better than on taurine-conjugated bile salts. The proportion of hydrolysis for both sodium glycochenodeoxycholate (GCDCA) and sodium glycoursodeoxycholate (GUDCA) were more than 90% in 60 min. However, the proportion of hydrolysis for sodium taurochenodeoxycholate (TCDCA) and sodium tauroursodeoxycholate (TUDCA) were only 68% and 43% at the same condition. The study of this paper provides a better choice for hydrolysis of glycine-conjugated bile salts.HighlightsThe specificity of BSH was high for glycine-conjugated bile salts.Hydrolysis process of bile acid was obtained through real-time picture monitoring.Hydrolysis efficiency of BSH was quantified in two ways: ninhydrin colouration method and HPLC-ELSD. The specificity of BSH was high for glycine-conjugated bile salts. Hydrolysis process of bile acid was obtained through real-time picture monitoring. Hydrolysis efficiency of BSH was quantified in two ways: ninhydrin colouration method and HPLC-ELSD.

2020 is the decisive year of poverty alleviation. China has made remarkable achievements in poverty alleviation, but how to prevent the phenomenon that poor households return to poverty after poverty alleviation is a very urgent research topic at this stage. Under the theory of evolutionary game, this paper establishes a game model between the governments and the families out of poverty, and solves the evolutionary stability strategy. The results show that: without constraints, the outcome of the evolutionary game will evolve in two different directions. One is the rational state we desire, that is, governments are incentive and poor households are positive, the other is an unreasonable state, that is, the governments are non-incentive and poor households are negative. Finally, suitable suggestions are put forward to make the game evolve to a reasonable result by analyzing the relevant parameters.

Sleep deprivation, which is a common problem in modern society, impairs memory function and emotional behavior. TRPV1, a subfamily of transient receptor potential cation channels, is abundantly expressed in the central nervous system and is associated with animal behavior. In this article, we report that TRPV1 deficiency in mice alleviates sleep deprivation-induced abnormal behaviors. We found that in the sleep-deprived mice, TRPV1 knockout increased the duration and visits in the central area in the open field task and increased visits to the open arms in the elevated plus maze. The TRPV1

This study examined the mediating role of children's executive function (EF) in the relation between parental rejection and children's externalizing behavior problems and whether this mediation varies depending on their callous-unemotional (CU) trait levels. Two hundred and eighty-four Chinese school-aged children and their fathers and mothers participated. Both fathers and mothers reported on parental rejection, children's externalizing behavior problems, EF, and CU traits. The results showed that EF mediated the association between parental rejection and externalizing behavior problems. Moreover, the negative link between EF and externalizing behavior problems was moderated by CU traits; in particular, the combination of higher-level CU traits and lower-level EF predicted more externalizing behavior problems. Our findings point to the importance of considering family context and multiple personal factors simultaneously to decrease children's behavior problems.

Members of the transient receptor potential canonical (TRPC) protein family are widely distributed in the hippocampus of mammals and exert respective and cooperative influences on the functions of neurons. The relationship between specific TRPC subtypes and neuroinflammation is receiving increasing attention. Here, using Cx3cr1CreER IL-10−/−transgenic mice and their littermates, we demonstrated that Cx3cr1CreER IL-10−/− mice displayed spatial memory deficits in object location recognition (OLR) and Morris water maze (MWM) tasks. The decreased levels of TRPC4 and TRPC5 in the hippocampal regions were verified via reverse transcription polymerase chain reaction, western blotting, and immunofluorescence tests. The expression of postsynaptic density protein 95 (PSD95) and synaptophysin in the hippocampus decreased with an imbalance in the local inflammatory environment in the hippocampus. The number of cells positive for ionized calcium binding adaptor molecule 1 (Iba1), a glial fibrillary acidic protein (GFAP), increased with the high expression of interleukin 6 (IL-6) in Cx3cr1CreER IL-10−/− mice. The nod-like receptor protein 3 (NLRP3) inflammasome was also involved in this process, and the cytokines IL-1β and IL-18 activated by NLRP3 were also elevated by western blotting. The colocalization of TRPC5 and calmodulin-dependent protein kinase IIα (CaMKIIα) significantly decreased TRPC5 expression in excitatory neurons. AAV9-CaMKIIα-TRPC5 was used to upregulate TRPC5 in excitatory neurons in the hippocampus. The results showed that the upregulation of TRPC5 improved the memory performance of Cx3cr1CreER IL-10−/− mice by inhibiting NLRP3 inflammasome-associated inflammatory activity.

Gas bubbles are ubiquitous in electrochemical processes, particularly in water electrolysis. Due to the development of gas-evolving electrocatalysis and energy conversion technology, a deep understanding of gas bubble behaviors at the electrode surface is highly desirable. In this work, by combining theoretical analysis and molecular simulations, we study the behaviors of a single nanobubble electrogenerated at a nanoelectrode. With the dynamic equilibrium model, the stability criteria for stationary surface nanobubbles are established. We show theoretically that a slight change in either the gas solubility or solute concentration results in various nanobubble dynamic states at a nanoelectrode: contact line pinning in aqueous and ethylene glycol solutions, oscillation of pinning states in dimethyl sulfoxide, and mobile nanobubbles in methanol. The above complex nanobubble behavior at the electrode/electrolyte interface is explained by the competition between gas influx into the nanobubble and outflux from the nanobubble.

Background Acetabular orientation changes after periacetabular osteotomy (PAO) lead to technical change when performing subsequent total hip arthroplasty (THA). There is no unified consensus regarding the solution for acetabular component installation after PAO. In the current study, we performed computed tomography (CT)-based simulation of acetabular component installation and compared the acetabular defect and component position following THA after PAO and the same patient before PAO. Methods From January 2014 to December 2018, pelvic models of 28 patients (28 hips) underwent PAO and with the risk factors to develop secondary osteoarthritis. The acetabular reconstruction process was simulated using 3D models from CT data, and the acetabular component coverage was calculated in 3D space based on the measurement and algorithm we proposed. We evaluated the anterior, posterior, superior, inferior acetabular sector angle (ASA), the medial wall thickness (MWT), and the distance from the hip center to the plane of pubic symphysis and ossa sedentarium in the study group (post-PAO group) and control group (pre-PAO group). In addition, we investigated the changes in the acetabular component covering and size between the two groups. Results A-ASA and I-ASA values were significantly smaller in the post-PAO group than in the pre-PAO group. The S-ASA and distance values were significantly bigger in the post-PAO group. Compared to the pre-PAO group, the post-PAO group has a bone defect in the anterior and inferior medial. However, the post-PAO group has to elevate the cup to improved component coverings. Conclusion Acetabular defection following simulation of cup installation after PAO was significantly changed compared to those without PAO. Elevation of hip joint centers as much as 4 mm and increase acetabular cup anteversion were therapeutic options for DDH patients following THA after PAO

The effects of Walmart closure on households’ demand for consumer-packaged goods categories are analysed. The investigation involves two stages. In the first stage, Walmart closure effects on household demand for these categories are estimated using a two-way linear fixed effects regression. In the second stage, the estimated Walmart closure effects are regressed on category characteristics using the weighted least squares regression. The empirical results indicate that Walmart closure tends to exert differential impacts on household volume purchase across consumer-packaged goods categories. These variations exist because categories differ in their types and the roles they play in retailers’ portfolios. After Walmart’s exit, consumers shop more at channels that have a stronger association with certain category types and roles, resulting in more purchases in these categories than others.

Whilte herbal medicines are widely used for health promotion and therapy for chronic conditions, inappropriate use of them may cause adverse effects like liver injury, and accurately evaluating their hepatotoxicity is of great significance for public health. Herein, an activatable probe QY-N for diagnosing herbal-medicine-induced liver injury by detecting hepatic NO with NIR-II fluorescence and multispectral optoacoustic tomography (MSOT) imaging is demonstrated. The probe includes a bismethoxyphenyl-amine-containing dihydroxanthene serving as electron donor, a quinolinium as electron acceptor, and a butylamine as recognition group and fluorescence quencher. The hepatic level of NO reacts with butylamine, thereby generating the activated probe QY-NO which exhibits a red-shifted absorption band (700-850 nm) for optoacoustic imaging and generates strong emission (910-1110 nm) for NIR-II fluorescence imaging. QY-NO is aggregation-induced-emission (AIE) active, which ensures strong emission in aggregated state. QY-N is utilized in the triptolide-induced liver injury mouse model, and experimental results demonstrate the QY-N can be activated by hepatic NO and thus be used in detecting herbal-medicine-induced liver injury. The temporal and spatial information provided by three-dimensional MSOT images well delineates the site and size of liver injury. Moreover, QY-N has also been employed to monitor rehabilitation of liver injury during treatment process.

Aim Previous research has shown that adiponectin (AD) induces severe insulin resistance (IR) and exhibits pro-inflammatory effect, so it could serve as a useful risk biomarker in rheumatoid arthritis (RA). The present study aims to evaluate the effect of AD on IR and anti-arthritis in collagen-induced arthritic (CIA) rats. Method After immunization with bovine type II collagen (CII), Wistar rats were administered with AD (60 μg/kg/day) or saline into the ankle joint cavity of the left hind leg for 15 days. The severity of arthritis was clinically and histologically assessed. Arthritis score was recorded every other day for each paw. Paw volume was measured on alternate days to monitor the progression of the disease in the arthritic control group. Tumor necrosis factor (TNF)-α, interleukin (IL)-1, AD, insulin and fasting glucose were measured in sera. Histopathology of joint synovial tissues was also examined. Results Treatment with AD resulted in significantly delayed onset of arthritis as well as decreased clinical arthritis and histopathological severity scores. AD reduced both serum fasting glucose, TNF-α, IL-1 and IR. Histological analysis confirmed treatment with AD suppressed joint synovial inflammation and immunohistochemical expression of TNF-α compared to the CIA group. Surprisingly, adiponectin levels measured by enzyme-linked immunosorbent assay in serum were significantly increased in CIA rats compared to the normal group. Conclusions Adiponectin might display anti-inflammatory effects. These results suggest that AD may be a potential immunosuppressant for the treatment of RA linked to metabolic disease.

Purpose: Although retinoblastoma is rare but can be deadly in some severe cases. To find novel therapeutic targets for retinoblastoma, we explored the potential role of lncRNA NKILA in retinoblastoma. Results: We found that, comparing to healthy controls, NKILA was downregulated, while lncRNA XIST was upregulated in plasma of retinoblastoma patients and they were inversely correlated. Downregulation of NKILA distinguished early-stage patients from healthy controls. Overexpression of lncRNA NKILA mediated the downregulation of XIST in retinoblastoma cells, while XIST overexpression failed to significantly affect NKILA. Overexpression of NKILA resulted in decreased, while XIST overexpression resulted in increased proliferation, migration and invasion rates of retinoblastoma cells. In addition, rescue experiment showed that XIST overexpression attenuated the effects of NKILA overexpression on cancer cell behaviors. Conclusions: Therefore, NKILA inhibits retinoblastoma possibly by downregulating XIST, but the causality has not been fully validated.

Although many organic molecules found commonly in the atmosphere are known to be surface-active in aqueous solutions, their effects on the mechanisms underlying haze formation remain unclear. In this paper, based on a simple thermodynamic analysis, we report that the adsorption of amphiphilic organics alone not only lowers the surface tension, but also unexpectedly stabilizes nanodroplets of specific size under water vapor supersaturation. Then we determine how various factors, including relative humidity, water activity effect due to dissolution of inorganic components as well as surface tension effect due to surface adsorption of organic components, cooperatively induce the stability of nanodroplets. The nanodroplet stability behaviors not captured in the current theory would change the formation mechanism of haze droplets, from the hygroscopic growth pathway to a nonclassical two-step nucleation pathway.

PURPOSE OF REVIEW Systemic sclerosis (SSc) is a complex autoimmune disorder that occurs in a genetically susceptible host. Genetic studies of SSc in recent years have defined or suggested a number of new genes with polymorphisms conferring susceptibility to or protection against SSc. RECENT FINDINGS Although not all genes fall neatly into one functional category, the major genes with polymorphisms associated with SSc are those involved in immune regulation and inflammation, especially T-cell differentiation, proliferation, activation, B-cell signaling, and innate immunity. SUMMARY Understanding the functions of SSc-associated genes will provide important new insights in future studies to explore the pathogenesis of SSc, as well as to develop targeted therapies for SSc.

A large number of genetic variants have been associated with human diseases. However, the lack of a genetic diversification approach has impeded our ability to interrogate functions of genetic variants in mammalian cells. Current screening methods can only be used to disrupt a gene or alter its expression. Here we report the fusion of activation-induced cytidine deaminase (AID) with nuclease-inactive clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein 9 (dCas9) for efficient genetic diversification, which enabled high-throughput screening of functional variants. Guided by single guide (sg)RNAs, dCas9-AID-P182X (AIDx) directly changed cytidines or guanines to the other three bases independent of AID hotspot motifs, generating a large repertoire of variants at desired loci. Coupled with a uracil-DNA glycosylase inhibitor, dCas9-AIDx converted targeted cytidines specifically to thymines, creating specific point mutations. By targeting BCR-ABL with dCas9-AIDx, we efficiently identified known and new mutations conferring imatinib resistance in chronic myeloid leukemia cells. Thus, targeted AID-mediated mutagenesis (TAM) provides a forward genetic tool to screen for gain-of-function variants at base resolution.

The dysregulation of microRNAs (miRNAs/miRs) has become increasingly recognized as a primary feature of retinoblastoma (RB). Furthermore, miRNAs have been demonstrated to be involved in the occurrence and development of RB. Therefore, it is crucial to investigate the expression profile and roles of miRNAs in RB in order to identify potential therapeutic targets to treat patients with RB. The expression profile and biological roles of miRNA‑504 (miR‑504) have been reported in numerous types of human cancer; however, the roles of miR‑504 in RB remain unknown. In the present study, it was demonstrated that miR‑504 expression was significantly decreased in RB tissues and cell lines. Functional analysis identified that resumption of miR‑504 expression suppressed cell proliferation and invasion in RB. Furthermore, astrocyte elevated gene‑1 (AEG‑1) was determined to be a direct target of miR‑504 in RB, and a negative correlation between miR‑504 and AEG‑1 mRNA expression levels was observed in RB tissues. Additionally, the tumor‑suppressing effects of miR‑504 overexpression in RB cells could be rescued by AEG‑1 upregulation. In conclusion, these results indicated a significant role of the miR‑504/AEG‑1 pathway in inhibiting the aggressiveness of RB, suggesting that this miRNA may be employed as a therapeutic target for the treatment of patients with this disease.

RNA splicing is a critical mechanism by which to modify transcriptome, and its dysregulation is the underlying cause of many human diseases. It remains challenging, however, to genetically modulate a splicing event in its native context. Here, we demonstrate that a CRISPR-guided cytidine deaminase (i.e., targeted-AID mediated mutagenesis [TAM]) can efficiently modulate various forms of mRNA splicing. By converting invariant guanines to adenines at either 5' or 3' splice sites (SS), TAM induces exon skipping, activation of alternative SS, switching between mutually exclusive exons, or targeted intron retention. Conversely, TAM promotes downstream exon inclusion by mutating cytidines into thymines at the polypyrimidine tract. Applying this approach, we genetically restored the open reading frame and dystrophin function of a mutant DMD gene in patient-derived induced pluripotent stem cells (iPSCs). Thus, the CRISPR-guided cytidine deaminase provides a versatile genetic platform to modulate RNA splicing and to correct mutations associated with aberrant splicing in human diseases.

Metallic bone implants face interfacial concerns, such as infection and insufficient bone formation. Combination of drug-loaded microparticles with the implant surface is a promising approach to reducing the concerns. The present study reports a simple method for this purpose. Drug-loaded chitosan and alginate microparticles were separately prepared by emulsion methods. Dry microparticles were introduced into porous titanium (Ti) coatings on Ti discs, and induced to agglomerate in pores by wetting with water. Agglomerates were stably entrapped in the pores: 77-82% retained in the coating after immersion in a water bath for 7 d. Discs carrying drug-loaded microparticles showed a rapid release within 6 h and a subsequent slow release up to 1 d. After coculture with Staphylococcus epidermidis for 24 h, the discs formed inhibition zones, confirming antibacterial properties. These suggest that the microparticle entrapment-based method is a promising method for reducing some of the bone-implant interfacial concerns.

WTX is a tumor suppressor gene expressed during embryonic development and inactivated in 20-30% of cases of Wilms tumor, the most common pediatric kidney cancer. WTX has been implicated in several cellular processes including Wnt signaling, WT1 transcription, NRF2 degradation, and p53 function. Given that WTX is widely expressed during embryonic development and has been recently shown to regulate mesenchymal precursor cells in several organs, we tested for the potential involvement of WTX in a panel of pediatric tumors and adult sarcomas. A total of 353 tumors were screened for WTX deletions by fluorescence in situ hybridization (FISH). Discrete somatic WTX deletions were identified in two cases, one hepatoblastoma and one embryonal rhabdomyosarcoma, and confirmed by array comparative genomic hybridization. Direct sequencing of the full WTX open reading frame in 24 hepatoblastomas and 21 embryonal rhabdomyosarcomas did not identify additional mutations in these tumor types. The presence of WTX mRNA was confirmed in hepatoblastomas and embryonal rhabdomyosarcomas without WTX deletions by RNA-in situ hybridization. Notably, tumors with evidence of WTX inactivation, Wilms tumor, hepatoblastoma and rhabdomyosarcoma, are primitive tumors that resemble undifferentiated precursor cells and are linked to overgrowth syndromes. These results indicate that WTX inactivation occurs in a wider variety of tumor types than previously appreciated and point to shared pathogenic mechanisms between a subset of pediatric malignancies.

National Natural Science Foundation of China [51131002, 50772018]; Program for New Century Excellent Talents in Universities of China [NCET-07-0139]; NSERC; CRC

The effects of trace boron on microstructure and mechanical properties of β type Ti-9V-3Al-3Cr-3Zr-3.5Mo (wt. %) alloy have been investigated in this study. Upon the addition of 0.02 wt. % boron, the grain size of the B-modified alloy was almost four times smaller than that of the B-free alloy. Accordingly, the tensile strength and elongation of B-modified alloy increased from 712 MPa and 14.6 % to 813 MPa and 17.9 %, respectively, mainly due to the effect of grain refinement.

The effects of Nb addition on microstructures, Young’s moduli, tensile properties of Ti-30Ta-xNb (x = 21, 24, 27, 30, wt. %) alloys were investigated in this study. The results show that dual phases containing β phase and a little α" martensite were observed when x = 21 and 24, whereas single β phase is present when x = 27 and 30. A minimum Young’s modulus of 52.13 GPa was obtained in Ti-30Ta-21Nb alloy. Ti-30Ta-xNb alloys exhibit high strength-to-modulus ratios, showing their great potentials to develop as new candidates for biomedical applications.

Natural Science Foundation of China [50771086]; Program for New Century Excellent Talents in University [NCET-09-0676]; Program for New Century Excellent Talents in Fujian Province University (NCETFJ); Fujian Provincial Department of Science and Technolog

通讯作者地址: Ma, YQ (通讯作者), Xiamen Univ, Coll Mat, Dept Mat Sci & Engn, Xiamen 361005, Peoples R China 地址: 1. Xiamen Univ, Coll Mat, Dept Mat Sci & Engn, Xiamen 361005, Peoples R China

The phase equilibria at 900 °C and B2/L21 order-disorder transition in the Ni-Mn-Ga ternary system were investigated by analyzing the equilibrated alloys and diffusion couples using a combination of techniques. It was confirmed that a bcc single phase region exists in a wide composition range at 900 °C, and the critical temperatures of B2/L21 order-disorder transition were determined in Ni-50 at.% section, which exhibits a maximal ordering transition temperature of 796 at Mn content of 25 at.%. The obtained results will be helpful for the preparation and annealing of Ni-Mn-Ga alloys in the specific temperature.

The rare earth element Gd is added to Ni53Mn22Co6Ga19 high-temperature shape memory alloy to refine the grain size and adjust the distribution of γ phase, and their microstructure, martensitic transformation behaviors, mechanical and shape memory properties were investigated. The results show that the grain size is obviously decreased and the γ phase tends to segregate at grain boundaries with increasing Gd content. Small amounts of Gd-rich phase were formed with 0.1 at.% Gd addition. The martensitic transformation temperature abruptly increases with 0.1 at.% Gd addition, then almost keeps constant with further increasing Gd content. The addition of 0.1 at.% Gd is proved to be beneficial to both tensile stress and strain before fracture, but negative to the shape-memory effect.

National Natural Science Foundation of China [50921003]; Beijing Nova Program (BNP); New Century Excellent Talents in University (NCET)

Ni–Mn–Co–Ga alloys with Ni/Mn or Ni and Mn substituted by Co were investigated as candidates for high-temperature shape-memory alloys. Ni 56− x Co x Mn 25 Ga 19 alloys with x 56− x Co x Mn 25 Ga 19 ( x ⩾ 8), Ni 56 Mn 25− y Co y Ga 19 ( y = 4, 8) and Ni 56− z /2 Mn 25− z /2 Co z Ga 19 ( z = 4, 6) alloys consist of a two-phase mixture of martensite and γ phase. The mechanical and shape-memory properties of Ni 56 Mn 25− y Co y Ga 19 and Ni 56− z /2 Mn 25− z /2 Co z Ga 19 alloys, which were hot-rolled into 0.5 mm thin plates by conventional hot rolling process, were investigated. The ductility and hot-workability of Ni–Mn–Co–Ga alloys were greatly improved by increasing the amount of ductile γ phase. Dynamic tensile tests and scanning electron microscopy observations of fracture surfaces confirm that the existence of γ phase plays a key role in improving the ductility of Ni–Mn–Co–Ga alloys.

通讯作者地址: Ma, YQ (通讯作者), Xiamen Univ, Coll Mat, Dept Mat Sci & Engn, Xiamen 361005, Peoples R China 地址: 1. Xiamen Univ, Coll Mat, Dept Mat Sci & Engn, Xiamen 361005, Peoples R China 电子邮件地址: myq@xmu.edu.cn