Search

This study introduces a brazing technique for joining Al0·3CoCrFeNi high-entropy alloy (HEA) utilizing a FeCoCrNiCu/Ti composite interlayer. The primary objectives of this investigation encompass an examination of the microstructure of the Al0·3CoCrFeNi joint, as well as an evaluation of the shear strength of the brazed joints under diverse brazing parameters. The characteristic microstructure of the Al0·3CoCrFeNi brazing seam is comprised of Ti (s, s), Cu (s, s) from the FeCoCrNiCu interlayer, and face-centered cubic (FCC) phases containing more than five elements. When the brazing temperature increases from 1100 °C to 1180 °C, there is a gradual augmentation in the diffusion of Ti element and subsequent reactions involving Cu, Ti, and Ni. Furthermore, the impact of holding time on the brazing seam is investigated. The findings suggest that prolonging the holding time has a relatively negligible effect on the reaction layer formed by the Ti foil. However, it does lead to a reduction of the Cu (s, s) content within the FeCoCrNiCu interlayer. Notably, the highest shear strength reaches up to 280 MPa when the joint brazed at 1160 °C for 10 min. In addition, the shear strength did not decrease below 800 °C. During the shear test, ductile fractures are observed in the joint, indicating favorable mechanical properties. Overall, this study successfully demonstrates the potential of the proposed brazing technique employing a FeCoCrNiCu/Ti composite interlayer for the effective joining of Al0·3CoCrFeNi HEA. By optimizing the brazing parameters, it is possible to achieve robust joints with exceptional mechanical characteristics.

Narrow gap oscillating laser welding with filler wire is a promising technique for joining high-strength steels in construction machinery. In order to investigate the influence of beam oscillation on the surface morphology and microstructure of weld joints of two types of commonly-used high-strength steels, a comparative study between oscillation welding and non-oscillation welding was conducted. High-speed photography technique was employed to reveal the microstructure and mechanical properties of the dissimilar joints. The results showed that laser beam oscillation produces two effects: one was to enlarge the heated surface of molten pool, while the other was to stir the liquid metal in molten pool periodically. Under the first effect, the fusion between sidewall and weld bead layers was promoted, while under the latter, coarse columnar grains ceased to appear, but finer grains were formed. The weld joints between Q355 and 35 steels exhibited excellent tensile impact bending performance, which was attributed to the grain refinement effect. The results also demonstrated that the oscillation welding with a contact angle less than 50° could avoid lack of fusion in multi-pass wire-filling laser welding. The influence of the oscillation welding process on the quality of welding was further discussed.

In recent years, new energy vehicles (NEVs) have taken the world by storm. A large number of NEV batteries have been scrapped, and research on NEV battery recycling is important for promoting the sustainable development of NEVs. Battery recycling is an important aspect of the sustainable development of NEVs. In this study, we conducted an in-depth analysis of the current status of research on NEV battery recycling from a new perspective using bibliometric methods and visualization software. This study shows that research targeting the recycling of NEV batteries is growing rapidly, and collaborative networks exist among researchers from different countries, institutions, and fields. The focus of research has shifted from lead-acid batteries to lithium batteries, and the supply chain and circular economy related to NEV battery recycling is an emerging research hotspot. Based on our analysis, we propose that the government should establish policies to improve the recycling networks at the collection stage and provide subsidies to attract consumers. Enterprises should develop low-cobalt and cobalt-free technologies, utilize green solvents, and develop new battery swap modes. The establishment of an information platform is conducive to the further development of collaborative networks.

Reactive air brazing (RAB) has been widely applied in fabricating solid oxide fuel cell stacks, gas separators, sensors, and other fields due to the joint good oxidation resistance. Nevertheless, a methodical analysis of fundamental principles, development process, and application scope has yet to be reported since RAB was proposed in 2000. Although various braze systems have been developed, a comprehensive comparison and classification are still absent, making it difficult to guide the selection of RAB braze. Besides, this technique faces several intractable issues, such as excessive interfacial reactions, large thermal mismatch, etc., seriously restricting the RAB application. Hence this review elucidates the basic information, braze systems, existing issues, and corresponding solutions of RAB. The joining mechanism, development history, and application fields are explicitly introduced. Reported braze systems are analyzed in-depth and divided into three categories according to reactivity. Further, we outline four issues of RAB: excessive interfacial reaction, excessive thermal expansion coefficient of braze, limited aging performance, and high-temperature softening of braze, and discuss the corresponding solutions. Finally, our review proposed several potential improvements and possible future research trends in the RAB technique, aiming to guide the future development of RAB and offer new insights to broaden its application range.

Vacuum brazing of TiAl alloy is achieved using TiZrNiCu fillers and BNi-2 fillers. The oxidation behavior of the two kinds of TiAl alloy joints is investigated in air at 800 °C. The influence of high-temperature oxidation on the microstructure and mechanical properties of the joints are characterized by scanning electron microscopy, X-ray diffraction, transmission electron microscopy, and shear tests. It is found that long-term oxidation does not have a large effect on the microstructure of joints. However, the fillet of the brazed joint achieved via BNi-2 fillers forms longitudinal solidification cracks, which proved that the brazed joint using TiZrNiCu fillers shows more excellent oxidation resistance.

Glass/Glass-ceramic sealing is always accompanied by issues of high porosity and brittle joints. To migrate these problems, an Ag foam was innovatively induced as an interlayer in the process of glass sealing the yttria-stabilized zirconia (YSZ) ceramic to Mn–Co spinel-coated Crofer 22 H stainless steel. Interlayer-added joints showed a significant reduction in porosity, and the shear strength was improved to 52.3 MPa, with an enhancement of 37.8 %. The influence of interlayer on the microstructure of the joint has been investigated and the formation process of the joint is illustrated. The Ag interlayer expels gases from the sealant material through expansion at high temperatures and promotes finer nucleation grains of crystallites integrating with the interlayer, reducing the porosity and alleviating the brittleness as well.

Laminated composites have been extensively researched due to their excellent mechanical properties, but their application in superwetting fields has been rarely reported. In this work, the surfaces with extreme wettability were prepared based on laminated composites. The Ti6Al4V/304 stainless steel (304 SS) micro-laminated composites were fabricated by diffusion bonding the Ti6Al4V foils and 304 SS foils with the thickness of 10–50 μm in vacuum. The typical interfacial microstructure and the effect of diffusion temperature on the microstructure were investigated. The bonded interface of joints is mainly composed of β-Ti, Ti2Ni, FeTi, Fe2Ti, Fe–Cr from the Ti6Al4V side to the 304 SS. The effect of diffusion temperature on the microstructure was researched. Based on the prepared Ti6Al4V/304 SS micro-laminated composites, an array structure with micro grooves was fabricated through the simple chemical etching. The 304 SS foils were etched to form grooves, while Ti6Al4V foils still remained as bulges. Due to surface modification and rough morphology, the etched surfaces exhibited the excellent hydrophobicity. Increasing the width and depth of grooves and decreasing the width of bulges led to the higher water contact angles and improved hydrophobicity. The highest water contact angles of 148.3° has been achieved under the conditions of grooves with a width of 50 μm, a depth of 60 μm, and the bulges with a width of 10 μm. The surfaces exhibited nearly superhydrophobicity and performed self-cleaning property. The processing method of this work could expand the application of laminated composite in extreme wettability fields.

K418 alloy was prepared by selective laser melting (SLM) at different laser powers (160∼240 W) in this paper. The influence of laser power on the densification behavior, microstructure, microhardness, and tensile properties was studied systematically. The results showed that the densities of the material increased rapidly first and then decreased slowly with the increase of laser power. When the laser power increased from 160 W to 240 W, the surface defects of the specimen decreased, the microstructure changed from columnar dendrites to cellular, and the grains grew in the direction preferentially. When the laser power is 200 W, the grain size is the smallest, the content of small-angle grain boundaries is more, the Schmidt factor is less, and then the best mechanical properties are achieved, at which the microhardness reaches 362.89 ± 5.01 HV, the tensile strength reaches 1244.35 ± 70.1 MPa, the yield strength reaches 863.89 ± 23.1 MPa, and the elongation of the material reaches a maximum of 12.53 ± 0.71 %. In addition, the fracture mode of the material is a mixed tough-brittle fracture mechanism.

Joining C/C composites to Ni-based single crystal alloy DD3 can significantly broaden their industrial application. The currently used active brazing method (ABM) may cause harmful reactions with Ni-based alloys, generating brittle compounds and deteriorating joint performance. In this work, a two-step method involving chromium carbide (Cr–C) surface modification and brazing using pure Cu filler is first developed to explore avoiding brittle compounds in joints. Surprisingly, the brazed seam of joints is mainly composed of (Cu, Ni) solid solution (s, s) without generating brittle compounds. At the DD3 interface, only (Ni, Cu) (s, s) and (Cu, Ni) (s, s) layers are formed. Besides, (W, Mo) (s, s) particles are precipitated nearby the DD3 substrate. For the C/C interface, the Cu filler is tightly joined to the Cr–C layer without forming new phases. The joint microstructure has no significant change with the variation of the Cr–C layer thickness. As increased the Cr–C layer thickness, the joint strength first increases and then decreases. The maximum shear strength of ∼32 MPa is obtained when the Cr–C layer thickness is ∼4.6 μm. The joint shear strength decreases with increased testing temperatures, which can still be maintained at ∼28 MPa at 600 °C. The surface modification and brazing strategy in this work can be further applied to the joining of other carbon materials and ceramics with poor wettability.

Testicular germ cell tumors (TGCT) are the most common reproductive system malignancies in men aged 15–44 years, accounting for 95 % of all testicular tumors. Our previous studies have been shown that long non-coding RNAs (lncRNAs), such as LINC00313, TTTY14 and RFPL3S, were associated with development of TGCT. Subgrouping TGCT according to differential expressed lncRNAs and immunological characteristics is helpful to comprehensively describe the characteristics of TGCT and implement precise treatment. In this study, the TGCT transcriptome data in The Cancer Genome Atlas Program (TCGA) database was used to perform consensus clustering analysis to construct a prognostic model for TGCT. TGCT was divided into 3 subtypes C1, C2, and C3 based on the differentially expressed lncRNAs. C1 subtype was sensitive to chemotherapy drugs, while the C2 subtype was not sensitive to chemotherapy drugs, and C3 subtype may benefit from immunotherapy. We defined the C1 subtype as epidermal progression subtype, the C2 subtype as mesenchymal progression subtype, and the C3 subtype as T cell activation subtype. Subgrouping based on differentially expressed genes (DEGs) and immunological characteristics is helpful for the precise treatment of TGCT.

A high-strength and anti-intergranular corrosion (IGC) Al-6.8Zn-2.2 Mg-Sc-Zr alloy (AS alloy) was designed, and the effects of Sc addition and Cu removal on the microstructure, mechanical properties and corrosion behavior were systematically investigated. Based on transmission electron microscopy (TEM) and Kelvin probe force microscopy (KPFM) techniques, the underlying causes of IGC and exfoliation corrosion (EXCO) of the AS alloy were investigated, and the corrosion mechanism of AS alloy was finally obtained. The AS alloy exhibits excellent mechanical properties with a tensile strength of 601 MPa in the peak-ageing condition at 120 °C, which comes from the pinning effect of Al3(Sc, Zr) dispersions. Moreover, AS alloys of T6 and T74 conditions show outstanding IGC and EXCO resistance. On the one hand, the fine, near-ellipsoidal grains in AS alloy alleviate the peeling stress caused by IGC products by blocking the formation of wedge-shaped gaps along GBs, which then bring about improved EXCO resistance. On the other hand, the removal of Cu from the traditional Al-Zn-Mg-Cu alloy avoids the segregation of Cu into GBs and thereafter reduces the fluctuations of the potential and the electron work function (EWF) across the GBs; the addition of Sc induces the high fraction of LAGBs and thus weakens the solutes' segregation at GBs, which can be beneficial for smoothing the fluctuation of corrosion potential (Ecorr) to enhance the IGC resistance.

Hydrogenation and nanocrystallization of Ti6Al4V alloy were achieved by electrolytic hydrogenation and SMAT processing. The hydride δ phase appeared when the hydrogenation time reached 4 h. The grain size of Ti6Al4V alloy after surface nanocrystallization reached below 35 nm when the SMAT processing time was 2 h. Surface morphology and roughness were characterized by AFM. The diffusion bonding between Ti6Al4V alloys at low temperature was achieved under different parameters. It is demonstrated that the porosity at the interface decreased correspondingly when the hydrogenation time or nanocrystallization time was extended. The porosity of the joint reached 0 when the hydrogenation time was 24 h or the nanocrystallization time was 4 h. Then hydrogenation and nanocrystallization treatments were combined. It is found that there are more bonding defects in both hydrogenation-nanocrystallization and nanocrystallization-hydrogenation joints than in joints with single hydrogenation or nanocrystallization treatment. It can be concluded that the porosity of the joints with nanocrystallization first is lower than that with hydrogenation first.

A finite element method (FEM) combined with subroutines was established and used for tracing the evolution of stresses in M50 steel in quenching. The constitutive relation and thermal physical properties of M50 steel were tested and integrated into the modeling. The finite element analysis, taking into account of thermal stresses and martensitic phase transformation, predicts accurately the high-velocity nitrogen (HNQ) induced residual stresses in the M50 steel bulk. The simulation results suggested that the residual stresses in M50 steel is compressive at the surface while tensive at the center, along with very strong residual stresses at edges. The residual stress reaches to the high level of −810.3 MPa and −1436 MPa in the case of HNQ and water quenching, respectively. The evolution of stress is found to be jointly driven by the thermal stress and phase transformation stress. The thermal stress dominates the evolution at the initial stage while the phase transformation stress becomes dominating once the martensite transformation begins.

Additive friction stir deposition (AFSD) is a relatively new additive manufacturing technique to fabricate parts in solid state below the melting temperature. Due to the solid-state nature, AFSD benefits from lower residual stresses as well as significantly lower susceptibility to porosity, hot-cracking, and other defects compared to conventional fusion-based metallic additive manufacturing. These unique features make AFSD a promising alternative to conventional forging for fabricating large structures for aerospace, naval, nuclear, and automotive applications. This review comprehensively summarizes the advances in AFSD, as well as the microstructure and properties of the final part. Given the rapidly growing research in AFSD, we focus on fundamental questions and issues, with a particular emphasis on the underlying relationship between AFSD-based processing, microstructure, and mechanical properties. The implications of the experimental and modeling research in AFSD will be discussed in detail. Unlike the columnar structure in fusion-based additive manufacturing, fully dense material with a fine, fully-equiaxed microstructure can be fabricated in AFSD. The as-wrought structure brings the as-printed parts with comparable properties to wrought parts. The fundamental difference between AFSD and fusion-based metallic additive manufacturing will be summarized. Furthermore, the existing challenges and possible future research directions are explored.

The effects of different test parameters on the creep of axially compressed concrete members were investigated under standard test conditions, considering loading ages of 7, 14 and 28 days and mineral powder admixtures of 0, 15%, 25% and 35%, respectively. The test results show that the creep of concrete decreases with the increase of mineral powder content when the loading age was fixed. When the content of mineral powder was unchanged, the creep of concrete would decrease with the increase of loading age. Based on the CEB-FIP MC 1990 concrete creep calculation model, the creep correction coefficient of mineral powder concrete considering the strength of mineral powder concrete, mineral powder content and loading age was proposed. The formula for the concrete creep correction coefficient which considers the loading age and mineral powder content was established by combining the existing creep test data and the test results of mineral powder concrete strength with the different loading ages and mineral powder contents in this paper. The comparison of the CEB-FIP MC 1978 and experiment values shows that the proposed formula in this paper can predict the development of creep of mineral powder concrete better. Finally, using the creep coefficient formula of mineral powder concrete, the creep coefficient values of concrete under different loading ages and mineral powder contents in CEB-FIP MC 1990 code were modified.

One of the critical challenges for the protonic ceramic fuel cell stack is sealing electrolytes and interconnects. However, the traditional AgCuO sealant will aggravate the oxidation along the interconnect surface and result in brittle compound layers at the BaZr0.1Ce0.7Y0.1Yb0.1O3-δ (BZCYYb) electrolyte interface. The present work demonstrates that a silver particle interlayer with high dislocation density can be adopted to join BZCYYb electrolyte to the interconnect (AISI 441 stainless) in air instead of traditional AgCuO sealant. Elevating temperatures result in a sufficient bonding at the Ag/BZCYYb interface, and a defect-free joint is obtained at 950 °C. Atomic bonding at Ag/BZCYYb interface is confirmed by TEM. Also, a dense and thin oxide layer (2–3 μm) is formed along the AISI 441 interface. Ag particles in the interlayer provide the main driving force for the sintering joining. The massive dislocations promote the recovery and recrystallization of the Ag interlayer, as well as the interdiffusion of BZCYYb/Ag. After aging in the wet oxidizing atmosphere at 600 °C for 300 h, joints remain intact and dense, indicating superior oxidation resistance and aging performance. Besides, the joint shear strength (25.3 MPa) is 59 % higher than that of the joint brazed by traditional AgCuO.

Testicular germ cell tumors (TGCTs) commonly occur in males between the ages of 15 and 34, accounting for 98% of testicular malignancies. Long non-coding RNAs (LncRNAs) have been reported to play important roles in TGCT proliferation, invasion, and functioned as prognostic biomarkers. Testis-specific transcript, Y-linked 14 (TTTY14), a long non-coding RNA localized on Chr Y q11.222, has been found to be a potential prognostic biomarker for laryngeal squamous cell carcinoma, gastric cancer, and osteosarcoma. The biological role of TTTY14 in TGCT is not well understood. In this study, we aim to clarify the biological role of TTTY14 in TGCT, as well as its role in TGCT survival prognosis and immunotherapy efficacy prediction through the deep mining of public data combined with the verification of cell biological experiments. We found that high TTTY14 expression was a poor survival prognostic factor in TGCT patients and the expression of TTTY14 might be regulated by copy number variation and DNA methylation. TTTY14 knockdown significantly inhibited the proliferation of TGCT in vitro. TTTY14 expression was positively correlated with immune cell dysfunction, and significantly negatively correlated with B cells, CD8+ T cells, and macrophages, suggesting that TTTY14 may also affect the drug sensitivity by regulating the tumor immune microenvironment. In conclusion, we revealed that lncRNA TTTY14 was a novel oncogene and a biomarker in TGCT. TTTY14 may influence the drugs sensitivity through regulating the tumor immune microenvironment.

Background: Anoikis, a form of apoptosis induced by cell detachment, plays a key role in cancer metastasis. However, the potential roles of anoikis-related genes (ARGs) in assessing the prognosis of skin cutaneous melanoma (SKCM) and the tumor microenvironment (TME) remain unclear. Methods: The data from TCGA corresponding to transcriptomic expression patterns for patients with SKCM were downloaded and utilized to screen distinct molecular subtypes by a non-negative matrix factorization algorithm. The prognostic signature was constructed by least absolute shrinkage and selection operator (LASSO) Cox regression and was validated in SKCM patients from the GEO cohort. Moreover, the relationship of the ARG_score with prognosis, tumor-infiltrating immune cells, gene mutation, microsatellite instability (MSI), and immunotherapy efficacy. Results: We screened 100 anoikis-related differentially expressed genes between SKCM tissues and normal skin tissues, which could divide all patients into three different subtypes with significantly distinct prognosis and immune cell infiltration. Then, an anoikis-related signature was developed based on subtype-related DEGs, which could classify all SKCM patients into low and high ARG_score groups with differing overall survival (OS) rates. ARG_score was confirmed to be a strong independent prognostic indicator for SKCM patients. By combining ARG_score with clinicopathological features, a nomogram was constructed, which could accurately predict the individual OS of patients with SKCM. Moreover, low ARG_score patients presented with higher levels of immune cell infiltration, TME score, higher tumor mutation burden, and better immunotherapy responses. Conclusions: Our comprehensive analysis of ARGs in SKCM provides important insights into the immunological microenvironment within the tumor of SKCM patients and helps to forecast prognosis and the response to immunotherapy in SKCM patients, thereby making it easier to tailor more effective treatment strategies to individual patients.

The exploration towards cost-effective filler metal for ceramics joining has always been the key issues for ceramics joining. Herein, we reveal that the Al metal prefers to spread on the ZrO2 based ceramic under the air heating condition, due to the geometric limit effects by in-situ formed dense Al2O3 surface. Inspired by this, the joining of ZrO2 based ceramics was realized in air with Al metal as filler, through the diffusion of Al towards ceramic side. The Al element can induce obvious interfacial bonding effect on Al2O3 layer and ZrO2 ceramic, where the hybridization among the Al-p, Zr-d and O-p orbitals plays a key role. The in-situ formed Al2O3 layer on Al filler surface is vital for forming the fine interface (shear strength of ∼36 MPa), which results in the relief of lattice mismatch and peak stress at ceramic-filler metal transition interface.

In this work, the Mn–Co spinel coating is successfully employed to control adverse reactions at the Crofer 22 APU interconnect/Ag–CuO braze interface through blocking their direct contact. The Mn–Co spinel coating is fabricated on the Crofer 22 APU before reactive air brazing (RAB). Wetting of Ag–CuO braze on the Mn–Co spinel coated Crofer 22 APU is studied. Ag-8mol%CuO braze is used to successfully braze the Mn–Co spinel coated Crofer 22 APU and YSZ at 1050 °C for 30 min in air. The Crofer 22 APU is protected well by the Mn–Co spinel coating during RAB, avoiding its oxidation and the outward diffusion of Fe and Cr. The long-term stability of joints is also evaluated in air at 800 °C for 200 h. The Mn–Co spinel coating effectively mitigates further degradation of the joint caused by oxidation at the interconnect/braze interface.

DNA sensing through the cGAS-STING pathway plays an important role in cancer immunosurveillance. Pharmaceutical activation of STING in the tumor environment is considered an attractive approach to induce anti-tumor immunity, but had limited efficacy in the clinic. Several studies have found that STING is epigenetically silenced in many tumors, including colon cancer. This suggests that STING silencing in tumor cells contributes to immune escape and may limit the application of STING agonists. We previously found that inhibition of the KDM5 family histone demethylases restored STING expression in human breast cancer cells and activated the cGAS-STING pathway. In this study, we used MC38 and CT26 syngeneic mouse colorectal cancer models to show that loss of STING in tumor cells accelerates tumor growth. KDM5 inhibitors activate STING expression in mouse colorectal cancer cells and suppress colon cancer growth in immune competent mice in a STING-dependent manner. This study highlights KDM5 inhibitors as novel immune modulators in cancer therapies.

A novel method to measure cooling rates during solidification in Directed Energy Deposition (DED) using on-axis photodiode-based Planck thermometry (PDPT) was developed. The proposed method can monitor the average in-situ melt pool temperature at a 100 kHz acquisition rate. This is much faster than other thermal imaging methods, such as an IR (50∼200 Hz) or melt pool camera (25∼100 Hz), due to the use of photodiode single-pixel measurements. PDPT measures the average melt pool temperature by detecting two visible wavelengths from a coaxial, top-down field of view (FOV) of the melt pool through the cladding nozzle. To investigate the viability of the proposed method, single clads of Inconel 718 were manufactured with various energy densities (20∼90 J/mm2) and characterized in terms of cooling rates and dimensions. Cooling rates measured from an off-axis IR camera as well as FEM simulations were compared with the cooling rates from the proposed method to verify the method. The measured solidification cooling rate values from PDPT were consistent with the reported values in the literature (800 °C/s∼5000 °C/s), which validated the proposed approach. Furthermore, the developed method can measure rapid solidification cooling rates over 5000 °C/s, beyond the current limit of IR cameras in industrial applications and at a fraction of the cost. The findings indicate that solidification cooling rates can be monitored with respect to processing conditions, ultimately enabling a connection between process parameters and the resulting local microstructure. This opens possibilities for effective certification or for tailoring desired mechanical properties through closed-loop control.

Introduction: As an important advanced functional material, the memory effect of nitinol shape memory alloy (SMA) is the focus of research. According to the current research, the memory function of the alloy decreases after welding, and there is no sufficient explanation for the phenomenon. Objectives: For the problem, this research is to explore the underlying causes of the decrease of shape memory function after welding by analyzing the microstructure and micro defects. Methods: The vacuum electron beam welding tests of 1 mm thick Ni50Ti50 alloy plate was carried out to determine the appropriate welding process parameter. And the shape memory function of the welded joint was compared with that of the base metal to analyze the change of memory function. Results: It was found that the shape memory function of the welded joint decreased significantly under different strain variables. And the phase transition temperature also changed. Conclusions: This was due to the micro stress field produced by non-equilibrium solidification in molten pool promoted the formation and propagation of dislocations, increasing the dislocation density in the martensite. Dislocations entangled with each other in the martensite, showing a grid-like distribution, which destroyed the integrity of martensite substructure. At the same time, the twin substructure of martensite was often accompanied by vacancies, dislocations, stacking faults, and a consequently large stress field formed between twin planes due to lattice distortion. Secondary twin was identified inside martensite under micro shear stress, where the martensite showed the bending state. The habitual relationship between martensite phase and parent phase was destroyed, resulting in the decrease of shape memory function.

Traumatic spinal cord injury is a fatal acute event without effective clinical therapies. Following the trauma, immediate neural protection and microenvironment mitigation are vitally important for nerve tissue repair, where stem cell-based therapies could be eclipsed by the deficiency of cells due to the hostile microenvironment as well as the transport and preservation processes. Effective emergency strategies are required to be convenient, biocompatible, and stable. Herein, we assess an emergency cell-free treatment using mesenchymal stem cell-derived exosomes, which have proven capable of comprehensive mitigation of the inhibitory lesion microenvironment. The clinically validated fibrin glue is utilized to encapsulate the exosomes and in-situ gelates in transected rat spinal cords to provide a substrate for exosome delivery as well as nerve tissue growth. The emergency treatment alleviates the inflammatory and oxidative microenvironment, inducing effective nerve tissue repair and functional recovery. The therapy presents a promising strategy for effective emergency treatment of central nervous system trauma.

As the decision-makers and implementers of a firm’s financial strategy, executives play a critical role in cash holding activities, and their psychological characteristics have a major impact on cash holdings. This paper investigates the association between CEO organizational identification and firm cash holdings. The empirical results show that CEO organizational identification is negatively associated with firm cash holdings, and the negative association is more pronounced when the level of financial development is higher and economic uncertainty is lower. Further analysis reveals that the higher a CEO’s organizational identification, the higher the firm’s R&D investment and capital expenditure, and high CEO organizational identification can increase the value of firm cash holdings. Overall, our findings supplement the literature on organizational identification and cash holdings, and on the effect of executives’ psychological characteristics on corporate financial decision-making.

Background: The congenital oligodontia in maxilla could result in a significant skeletal jaw malformation such as atrophic maxilla and severe skeletal class III malocclusion. Since there is no referable dentition in anterior maxilla, the orthognathic surgery and oral rehabilitation for those patients becomes more challenging and less predictable. Materials and methods: We hereby present a new sequencing of interdisciplinary treatments, including calvarial bone grafting, installation of implant-supported provisional prosthesis, bimaxillary orthognathic surgery, and the final installation of dental implants and the fixed prosthesis. Results: The facial esthetics and function of the permanent prosthesis were satisfactory, with a remarkable improvement in the maxillomandibular relation, adequate horizontal and vertical repositioning of the maxilla, and appropriate incisor exposure. Conclusion: Although more surgeries and longer treatment period may be required due to the interdisciplinary treatment plan, better aesthetic and functional outcomes may be acquired by this reported procedure in the long-term for young patients.

Background: Poultry farms and LPMs are a reservoir of antimicrobial resistant bacteria and resistance genes from feces. The LPM is an important interface between humans, farm animals, and environments in a typical urban environment, and it is considered a reservoir for ARGs and viruses. However, the antibiotic resistomes shared between chicken farms and LPMs, and that of LPM workers and people who have no contact with the LPMs remains unknown. Methods: We characterized the resistome and bacterial microbiome of farm chickens and LPMs and LPM workers and control subjects. The mobile ARGs identified in chickens and the distribution of the mcr-family genes in publicly bacterial genomes and chicken gut metagenomes was analyzed, respectively. In addition, the prevalence of mcr-1 in LPMs following the ban on colistin-positive additives in China was explored. Results: By profiling the microbiomes and resistomes in chicken farms, LPMs, LPM workers, and LPM environments, we found that the bacterial community composition and resistomes were significantly different between the farms and the LPMs, and the LPM samples possessed more diversified ARGs (59 types) than the farms. Some mobile ARGs, such as mcr-1 and tet(X3), identified in chicken farms, LPMs, LPM workers, and LPM environments were also harbored by human clinical pathogens. Moreover, we found that the resistomes were significantly different between the LPM workers and those who have no contact with the LPMs, and more diversified ARGs (188 types) were observed in the LPM workers. It is also worth noting that mcr-10 was identified in both human (5.2%, 96/1,859) and chicken (1.5%, 14/910) gut microbiomes. Although mcr-1 prevalence decreased significantly in the LPMs across the eight provinces in China, from 190/333 (57.1%) samples in September 2016-March 2017 to 208/544 (38.2%) samples in August 2018-May 2019, it is widespread and continuous in the LPMs. Conclusion: Live poultry trade has a significant effect on the diversity of ARGs in LPM workers, chickens, and environments in China, driven by human selection with the live poultry trade. Our findings highlight the live poultry trade as ARG disseminators into LPMs, which serve as an interface of LPM environments even LPM workers, and that could urge Government to have better control of LPMs in China. Further studies on the factors that promote antibiotic resistance exchange between LPM environments, human commensals, and pathogens, are warranted.

Summary: Although tumor-infiltrating lymphocytes (TILs) maintain their ability to proliferate, persist, and eradicate tumors, they are frequently dysfunctional in situ. By performing both whole-genome CRISPR and metabolic inhibitor screens, we identify that nicotinamide phosphoribosyltransferase (NAMPT) is required for T cell activation. NAMPT is low in TILs, and its expression is controlled by the transcriptional factor Tubby (TUB), whose activity depends on the T cell receptor-phospholipase C gamma (TCR-PLCγ) signaling axis. The intracellular level of NAD+, whose synthesis is dependent on the NAMPT-mediated salvage pathway, is also decreased in TILs. Liquid chromatography-mass spectrometry (LC-MS) and isotopic labeling studies confirm that NAD+ depletion led to suppressed glycolysis, disrupted mitochondrial function, and dampened ATP synthesis. Excitingly, both adoptive CAR-T and anti-PD1 immune checkpoint blockade mouse models demonstrate that NAD+ supplementation enhanced the tumor-killing efficacy of T cells. Collectively, this study reveals that an impaired TCR-TUB-NAMPT-NAD+ axis leads to T cell dysfunction in the tumor microenvironment, and an over-the-counter nutrient supplement of NAD+ could boost T-cell-based immunotherapy.

The emergence of mobile Tigecycline-resistant tet(X3) and tet(X4) is believed to be a global threat to public health. Here, we investigated the prevalence of tet(X3) and tet(X4) in our metagenomic data of migratory birds. While tet(X4) was not identified in our samples, tet(X3) was found in two gut microbiomes of bird fecal samples, with 100% amino acid identity of sites 150–387. These results suggest that tet(X3) has been spreading into the environment for a long period of time and that there is an urgent need to control its further transmission.

To design microstructure and microhardness in the additive manufacturing (AM) of nickel (Ni)-based superalloys, the present work develops a novel data-driven approach that combines physics-based models, experimental measurements, and a data-mining method. The simulation is based on a computational thermal-fluid dynamics (CtFD) model, which can obtain thermal behavior, solidification parameters such as cooling rate, and the dilution of solidified clad. Based on the computed thermal information, dendrite arm spacing and microhardness are estimated using well-tested mechanistic models. Experimental microstructure and microhardness are determined and compared with the simulated values for validation. To visualize process–structure–properties (PSPs) linkages, the simulation and experimental datasets are input to a data-mining model—a self-organizing map (SOM). The design windows of the process parameters under multiple objectives can be obtained from the visualized maps. The proposed approaches can be utilized in AM and other data-intensive processes. Data-driven linkages between process, structure, and properties have the potential to benefit online process monitoring control in order to derive an ideal microstructure and mechanical properties. Keywords: Additive manufacturing, Data science, Multiphysics modeling, Self-organizing map, Microstructure, Microhardness, Ni-based superalloy

Micro friction stir welding (μFSW) was successfully performed to join the ultra-thin 6061-T4 sheet with the thickness of 0.5 mm. The optimum plunging depth of 0.05 mm was obtained and reduction ratio was lower than 0.2%. Based on better dynamic flow induced by the triflat pin, the good surface appearance at the wider process window was obtained, while the grain size at the nugget zone was finer than that by the taper pin. Increasing welding speed caused that tensile property increased firstly and then decreased with high welding speed than 500 mm/min. The maximum values of tensile strength and elongation of the μFSW joint using the triflat pin reached 220.3 MPa and 11.7%, which were 91.9% and 54.4% of base material, respectively. Keywords: Micro friction stir welding, Ultra-thin sheet, 6061-T4 alloy, Microstructure, Mechanical property

Changes in gravity and buoyancy of a Full Ocean Depth Autonomous Underwater Vehicle (FOD-AUV) during its descending and ascending process must be considered very carefully compared with a Human Occupied Vehicle (HOV) or a Remotely Pperated Vehicle (ROV) whose activities rely on human decision. We firstly designed a two-step weight dropping pattern to achieve a high descending and ascending efficiency and a gravity-buoyancy balance at designed depth. The static equations showed that gravity acceleration, seawater density and displacement are three key aspects affecting the balance. Secondly, we try our best to analysis the gravity and buoyancy changing according to the previous known scientific information, such as anomaly of gravity acceleration, changing of seawater states. Finally, we drew conclusion that gravity changes little (no more than 0.1kgf, it is impossible to give a accurate value). A density-depth relationship at the Challenger Deep was acquired and the displacement changing of the FOD-AUV was calculated preciously. Keywords: Autonomous underwater vehicle, Full ocean depth, Statics variation analysis, Challenger deep, Gravity and buoyancy

Summary: Major depression is a prevalent and long-lasting psychiatric illness with severe functional impairment and high suicide rate. We have previously shown that the ventrolateral orbital cortex (VLO) plays a key role in the stress responses in mice, but the underlying mechanisms remains unclear. Here, we used proteomic method to identify differentially expressed proteins in VLO of chronic unpredictable mild stress (CUMS) mice. Of 4,953 quantified proteins, 45 proteins were differentially expressed following CUMS. The integrated pathway analyses identified 14-3-3ε and TrkB signaling as differentially downregulated in association with stress-induced depressive-like behaviors. 14-3-3ε overexpression in VLO relieved the depressive-like behaviors by rescue of Bad-mediated apoptosis. Moreover, treatment with the 14-3-3ε stabilizer FC-A precluded neuronal apoptotic signaling in VLO of depressed mice. Because 14-3-3ε provides significant protection against chronic stress, boosting 14-3-3ε expression, pharmacological stabilization of 14-3-3s (e.g. with FC-A) is identified as an exciting therapeutic target for major depression.

Gut microbiota is a reservoir of antibiotic resistance genes (ARGs). Yet, limited information is available regarding the presence (metagenomic DNA level) and expression profiles (metatranscriptomic RNA level) of ARGs in gut microbiota. Here, we used both metagenomic and metatranscriptomic approaches to comprehensively reveal the abundance, diversity, and expression of ARGs in human, chicken, and pig gut microbiomes in China. Based on deep sequencing data and ARG databases, a total of 330 ARGs associated with 21 antibiotic classes were identified in 18 human, chicken, and pig fecal samples. Metatranscriptomic analysis revealed that 49.4, 66.5, and 56.6% of ARGs identified in human, chicken, and pig gut microbiota, respectively, were expressed, indicating that a large proportion of ARGs were not transcriptionally active. Further analysis demonstrated that transcript abundance of tetracycline, aminoglycoside, and beta-lactam resistance genes was mainly contributed by acquired ARGs. We also found that various biocide, chemical, and metal resistance genes were actively transcribed in human and animal guts. The combination of metagenomic and metatranscriptomic analysis in this study allowed us to specifically link ARGs to their transcripts, providing a comprehensive view of the prevalence and expression of ARGs in gut microbiota. Taken together, these data deepen our understanding of the distribution, evolution, and dissemination of ARGs and metal resistance genes in human, chicken, and pig gut microbiota. Keywords: Metagenomics, Metatranscriptomics, Gut resistome, Acquired ARGs, Mcr-1

Metabolic syndrome (MS) is a combination of symptoms characterized by central obesity, hypertension, hyperglycemia, and hyperlipidemia, which together increase the risk of heart disease, stroke and diabetes. In our study, we hypothesized that an EET-agonist (AUDA) would increase expression of PGC 1α and improve mitochondrial and endothelial functions, resulting in improved heart function in a rat model of MS. To investigate this, rats were randomly divided into four groups: 1) Control; 2) MS + ABCT; 3) MS + AUDA; and 4) MS + AUDA + SnMP. MS rats were fed a high-fructose diet for 16 weeks and developed elevated inflammatory mediators, oxidative stress, and significant decreases in fractional shortening and hemodynamic parameters, indicating cardiac dysfunction. Histology revealed myocardial fibrosis and myocyte hypertrophy. AUDA improves mitochondrial function proven by increase in mt copy number and ATP production and significantly increased expression of PGC-1α and HO-1 in the rats and normalization of inflammatory cytokines, oxidative stress, and improves in cardiac function and myocardial fibrosis. These benefits were reversed by SnMP. Furthermore, AUDA increases eNOS but decreases iNOS expression which improved endothelial function. We therefore demonstrate that endogenous EET upregulation plays a novel role in protecting the heart from MS by regulating mitochondrial and endothelial function. Keywords: Epoxyeicoastrienoic acids, PGC-1α, Heme oxygenase-1, Mitochondrial function, Metabolic syndrome

Abstract Background Cardiac impairment is associated with high morbidity and mortality in immunoglobulin light chain (AL) type amyloidosis, for which early identification and risk stratification is vital. For myocardial tissue characterization, late gadolinium enhancement (LGE) is a classic and most commonly performed cardiovascular magnetic resonance (CMR) parameter. T1 mapping with native T1 and extracellular volume (ECV) are recently developed quantitative parameters. We aimed to investigate the prognostic value of native T1, ECV and LGE in patients with AL amyloidosis. Methods Eighty-two patients (55.5 ± 8.5 years; 52 M) and 20 healthy subjects (53.2 ± 11.7 years; 10 M) were prospectively recruited. All subjects underwent CMR with LGE imaging and T1 mapping using a Modified Look-Locker Inversion-recovery (MOLLI) sequence on a 3 T scanner. Native T1 and ECV were measured semi-automatically using a dedicated CMR software. The left ventricular (LV) LGE pattern was classified as none, patchy, and global groups. Global LGE was considered when there was diffuse, transmural LGE in more than half of the short axis images. Follow-up was performed for all-cause mortality using Cox proportional hazards regression analysis and Kaplan-Meier survival curves. Results The patients demonstrated an increase in native T1 (1438 ± 120 ms vs. 1283 ± 46 ms, P = 0.001) and ECV (43.9 ± 10.9% vs. 27.0 ± 1.7%, P = 0.001) compared to healthy controls. Native T1, ECV and LGE showed significant correlation with Mayo Stage, and ECV and LGE showed significant correlation with echocardiographic E/E’ and LV ejection fraction. During the follow-up for a median time of 8 months, 21 deaths occurred. ECV ≥ 44.0% (hazard ratio [HR] 7.249, 95% confidence interval (CI) 1.751–13.179, P = 0.002) and global LGE (HR 4.804, 95% CI 1.971–12.926, P = 0.001) were independently prognostic for mortality over other clinical and imaging parameters. In subgroups with the same LGE pattern, ECV ≥ 44.0% remained prognostic (log rank P = 0.029). Median native T1 (1456 ms) was not prognostic for mortality (Tarone-Ware, P = 0.069). Conclusions During a short-term follow-up, both ECV and LGE are independently prognostic for mortality in AL amyloidosis. In patients with a similar LGE pattern, ECV remained prognostic. Native T1 was not found to be a prognostic factor.

Summary: Ceramides and their metabolites are important for the homeostasis of the epidermis, but much remains unknown about the roles of specific pathways of ceramide metabolism in skin biology. With a mouse model deficient in the alkaline ceramidase (Acer1) gene, we demonstrate that ACER1 plays a key role in the homeostasis of the epidermis and its appendages by controlling the metabolism of ceramides. Loss of Acer1 elevated the levels of various ceramides and sphingoid bases in the skin and caused progressive hair loss in mice. Mechanistic studies revealed that loss of Acer1 widened follicular infundibulum and caused progressive loss of hair follicle stem cells (HFSCs) due to reduced survival and stemness. These results suggest that ACER1 plays a key role in maintaining the homeostasis of HFSCs, and thereby the hair follicle structure and function, by regulating the metabolism of ceramides in the epidermis. : Acer1 is a skin-specific ceramidase that controls the catabolism of ceramides. Lin et al. show that Acer1 plays a key role in maintaining the homeostasis of the hair follicle stem cell and the hair follicle structure and function by regulating the metabolism of ceramides in the epidermis. Keywords: alkaline ceramidase, alopecia, epidermal keratinocyte, hair follicle stem cell, ceramide, sphingosine, sphingolipid, stem cell quiescence, stemness

Lower Cretaceous black shales in coastal southeastern China are of significance to the geological study of the Tethys and Pacific realms and to hydrocarbon exploration of southeastern China and East China Sea. However, the stratigraphic correlation, distribution patterns and hydrocarbon potential of the black shales have not been well constrained so far. In this study, the zircon U–Pb ages, organic petrologic and geochemical analyses were performed for representative outcrop sections in the region. Zircon U–Pb ages demonstrate that the Lower Cretaceous black shales in coastal southeastern China can be divided into two regional-scale sets. The first set was deposited during the early stage of the Early Cretaceous (K11, Berriasian–Hauterivian). The second set was deposited during the late stage of the Early Cretaceous (K12), and might extend to the Taiwan Strait. Detailed organic geochemical analyses including organic matter abundance, type and maturity of the Lower Cretaceous black shales demonstrate that the organic matter abundance of the sources reached medium to good quality by the hydrocarbon source rock standards, and the average TOC values and the chloroform bitumen “A” of the K11 black shales are higher. The type of organic matter is mainly type III, type II can also be found from the K12 black shales. The thermal maturity of most samples is high to overmature. A relatively comprehensive hydrocarbon resource evaluation indicates that favorable regions are in the northern Guangdong Province for the K11 and in the coastal region of Zhejiang Province and the western Fujian Province for the K12. Sedimentology studies on the Shipu section for the K11 black shales illuminated that the K12 black shales in coastal southeastern China were mainly deposited during transgressive period. The relative sea level changes controlled the sequential development pattern of the K12 black shales.

Metastasis is a major clinical challenge for cancer treatment. Emerging evidence suggests that aberrant epigenetic modifications contribute significantly to tumor formation and progression. However, the drivers and roles of such epigenetic changes in tumor metastasis are still poorly understood. Using bioinformatic analysis of human breast cancer gene-expression data sets, we identified histone demethylase RBP2 as a putative mediator of metastatic progression. By using both human breast cancer cells and genetically engineered mice, we demonstrated that RBP2 is critical for breast cancer metastasis to the lung in multiple in vivo models. Mechanistically, RBP2 promotes metastasis as a pleiotropic positive regulator of many metastasis genes, including TNC. In addition, RBP2 loss suppresses tumor formation in MMTV-neu transgenic mice. These results suggest that therapeutic targeting of RBP2 is a potential strategy for inhibition of tumor progression and metastasis.

Lipoprotein-associated phospholipase A2 (Lp-PLA2), specifically Group VIIA PLA2, is a member of the phospholipase A2 superfamily and is found mainly associated with LDL and HDL in human plasma. Lp-PLA2 is considered as a risk factor, a potential biomarker, a target for therapy in the treatment of cardiovascular disease, and evidence suggests that the level of Lp-PLA2 in plasma is associated with the risk of future cardiovascular and stroke events. The differential location of the enzyme in LDL/HDL lipoproteins has been suggested to affect Lp-PLA2 function and/or its physiological role and an abnormal distribution of the enzyme may correlate with diseases. Although a mutagenesis study suggested that a surface helix (residues 362–369) mediates the association between Lp-PLA2 and HDL, the molecular details and mechanism of association has remained unknown. We have now employed hydrogen deuterium exchange mass spectrometry to characterize the interaction between recombinant human Lp-PLA2 and human HDL. We have found that specific residues 113–120, 192–204, and 360–368 likely mediate HDL binding. In a previous study, we showed that residues 113–120 are important for Lp-PLA2-liposome interactions. We now find that residues 192–204 show a decreased deuteration level when Lp-PLA2 is exposed to apoA-I, but not apoA-II, the most abundant apoproteins in HDL, and additionally, residues 360–368 are only affected by HDL.The results suggest that apoA-I and phospholipid membranes play crucial roles in Lp-PLA2 localization to HDL.

Cytoskeleton disorganization is an early step in the activation process of matrix metalloproteinase 2 (MMP-2) by membrane type 1 MMP (MTi-MMP) but is also associated with endoplasmic reticulum (ER) dysfunction and subsequent cell death. Given evidence that the ER-embedded glucose-6-phosphate transporter (G6PT) regulates glioblastoma cell survival and that MT1MMP is a key enzyme in the cancer cell invasive phenotype, we explored the molecular link between G6PT and MTi-MMP. Cytoskeleton-disrupting agents such as concanavalin A (ConA) and cytochalasin D triggered proMMP-2 activation and cell death in U87 glioma cells. ConA decreased G6PT gene expression, an event that was also observed in cells overexpressing the fulllength recombinant MTi-MMP protein. Overexpression of a membrane-bound catalytically active but cytoplasmic domain-deleted MTi-MMP was unable to downregulate G6PT gene expression or to trigger necrosis. Gene silencing of MTi-MMP with small interfering RNA prevented proMMP-2 activation and induced G6PT gene expression. ConA inhibited Akt phosphorylation, whereas overexpression of recombinant G6PT rescued the cells from ConA-induced proMMP-2 activation and increased Akt phosphorylation. Altogether, new functions of MTi-MMP in cell death signaling may be linked to those of G6PT. Our study indicates a molecular signaling axis regulating the invasive phenotype of brain tumor cells and highlights a new “bioswitch” function for G6PT in cell survival.