First-principles study for quasi-static growth model in FeAl intermetallic based on Wulff cluster model.

In order to investigate the structure of FeAl mesoscopic crystals segregating in liquid state alloys, we have determined their equilibrium structures (Wulff shape) based on the Wulff cluster model. For non-stoichiometric surface terminations, the chemical environment is taken into account through the chemical potential of the constituents. In this case, different cluster shapes change as a function of the chemical environment. In order to model the growth process in more detail, we propose a quasi-static growth model based on the sequential addition of (sub-)monolayers in the most favorable surface directions. Thus, a sequence of different Wulff shapes results in the growth process, as illustrated for the FeAl intermetallic compound. This model is proved preliminarily by calculating the concentration trend of Al/Fe atoms on both Al-terminated and Fe-terminated surfaces, and by simulating the most stable layer adsorbed on these two surfaces. This model might be helpful in analyzing the growth processes including nucleation barriers during nucleation processes theoretically.

Fabrication of versatile lignocellulose nanofibril/polymerizable deep eutectic solvent hydrogels with anti-swelling, adhesive and low-temperature resistant properties via a one-pot strategy.

Lignocellulosic nanofibril (LCNF) is indispensable in numerous potential applications because of its unsurpassed quintessential characteristics. While it still remains a challenge to assemble LCNF in a facile and environmental economy-first manner. In this work, a simple and green one-step synthetic approach was reported to prepare a series of LCNF-containing versatile hydrogels using deep eutectic solvent (DES). In particular, the LCNF5% hydrogel (namely LCNF5%-gel) in this work perfectly integrated superior stretchability (∼643 %), and displayed a dramatically improved anti-swelling ability (25 %) compared to the control sample (neat DES hydrogel, 2252 %). Simultaneously, the LCNF5% hydrogel presented underwater adhesiveness and outstanding long-term low-temperature resistance (stable at -25 °C for a month). This novel multifunctional hydrogel, prepared by a facile and eco-friendly strategy, is potentially useful in wet adhesion or underwater applications.

The effect of secukinumab treatment for psoriasis on serum cytokines and correlation with disease severity.

OBJECTIVE: To investigate the effects of secukinumab treatment for psoriasis on different functional cytokines and inflammatory mediators in patients' serum METHODS: Enzyme-linked immunosorbent assay was used to detect interleukin (IL)-1ß and IL-1RA associated with intrinsic immunity; IL-6, IL-18, and growth regulated oncogene alpha (GROα) associated with neutrophils; IL-12, tumour necrosis factor (TNF)-α, and interferon (IFN)-γ associated with Th1; IL-23, IL-17A, and IL-22 associated with Th17; Thymus activation regulated chemokine (TARC), IL-13, and defensin beta 2 (DEFB2) associated with Th2; Vascular endothelial growth factor (VEGF)-A and IL-10 associated with angiogenesis; and IFN-γ associated with sepsis in the peripheral blood of 12 patients with common psoriasis treated with secukinumab and 15 healthy controls. IL-23, IL-17A, IL-22 associated with Th17; TARC, IL-13, DEFB2 associated with Th2; VEGF-A, IL-10 associated with angiogenesis and procalcitonin (PCT) associated with sepsis. The differences in expression of the above cytokines before and after treatment and the correlation with psoriasis disease severityï¼»Psoriasis Area Severity Index(PASI) scoreï¼½, age, and disease duration were analyzed. RESULTS: The mean PASI score of the enrolled patients with moderate to severe psoriasis was 21.6 ± 11.0 before treatment and decreased to below 1 after treatment. Serum IL-6; IL-18, GROα, IFN-γ, TNF-α, VEGF-A, and IL-17A were significantly higher than normal. And IL-17A and IFN-γ were positively correlated with disease duration and age, and IL-18 was positively correlated with PASI score. The expression levels of IL-6, GROα, VEGF-A, IFN-γ, TNF-α, IL-17A and IL-23 were significantly lower after secukinumab treatment compared with those before treatment, but the expression levels of IFN-γ, VEGF-A, TARC, IL-13, and DEFB2 were still significantly higher than those of normal subjects after treatment CONCLUSIONS: secukinumab clears skin lesions by antagonizing IL-17A and simultaneously decreasing the expression levels of IL-6, GRO α, VEGF-A, IFN-γ, TNF-α, IL-17A, and IL-23.

Microstructure and Mechanical Properties of HfC-SiC Ceramics Influenced by WC Addition.

The development of HfC-SiC has been challenging due to difficulties in achieving sintering and satisfactory mechanical properties. However, this study aims to overcome these limitations by incorporating WC as an additive. SPS was employed to process HfC-SiC and HfC-SiC doped with 5 vol.% WC. The resulting samples were then evaluated for their oxygen content, relative density, Vickers hardness, bending strength, indentation fracture toughness, and microstructure. The Vickers hardness (20.50 ± 0.20 GPa), flexural strength (600.19 ± 84.00 MPa), and indentation fracture toughness (5.76 ± 0.54 MPa·m1/2) of HfC-30 vol.% SiC-5 vol.% WC ceramics are higher than HfC-30 vol.% SiC ceramics. Doping 5 vol.% WC in HfC-30 vol.% SiC not only reduces the oxygen content of samples but also produces the (Hf,W)C solid solution and refines the microstructures, which are the main reasons for the higher mechanical properties of HfC-30 vol.% SiC-5 vol.% WC ceramics. In summary, this study successfully addresses the challenges associated with HfC-SiC by incorporating WC as an additive, leading to improved mechanical properties and microstructures.

Research about the capacitance properties of ion-induced multilayer and self-assembled monolayer Ti3C2T x.

MXenes materials are two-dimensional inorganic materials with abundant surface sites as capacitors. Better control of its morphology and expression of surface groups helps to improve the performance of capacitors. Herein, we controlled the morphology of MXenes with HF, HCl-LiF etching conditions, alkali and metal ions inducing factors. Benefiting from the nanostructures, the capacitance of HCl-LiF-prepared self-assembled monolayer Ti3C2T x soared to 370.96 F g-1 from 32.09 F g-1 of HF-etched multilaminate Ti3C2T x . As a result of the introduction of ions, the surface termination group is replaced by -OH with -F. Profit from this, the alkalized single-deck plicated Ti3C2T x exhibited a supernal capacitance up to 684.53 F g-1 because of the wrinkled morphology and more -OH terminal groups. Meanwhile, metal ion abduction brought some negative effects to electrochemical properties due to the oxidation of high-valent metal ions potentially.

New insights into segmental vitiligo: A clinical and immunological comparison with nonsegmental vitiligo.

The overlaps between segmental vitiligo (SV) and nonsegmental vitiligo (NSV) suggest the underlying features of SV, which may be helpful for treating SV. In this study, 379 vitiligo patients were recruited and divided into SV (33.2%), mild-to-moderate NSV (M-NSV, affected body affected area [BSA] ≤10%, 34.0%), and severe NSV (S-NSV, affected BSA >10%, 32.7%) groups. Demographics and clinical data were collected through in-person interviews. The disease activity, progression, and prognosis were assessed through 6 months' follow-up. Serum cytokines profile and tissue-infiltrating immune cells were measured by ELISA assay and immunofluorescence, respectively. The SV exhibited lower rates of autoimmune comorbidities and recurrence than the S-NSV, but performed similar to the M-NSV. Moreover, the disease activity, progression, serum cytokines profile, and tissue-infiltrating Th/c1 cells in the active SV and M-NSV were comparable, but differed significantly from those of the active S-NSV. The clinical and immunological similarities between SV and M-NSV presented a deeper autoimmune understanding of SV. Additionally, a classification of active vitiligo according to disease extent may be more clinically meaningful than subtypes for guiding immunomodulatory treatment.

Dysfunction of ATG7-dependent autophagy dysregulates the antioxidant response and contributes to oxidative stress-induced biological impairments in human epidermal melanocytes.

Autophagy is a process involving the self-digestion of components that participates in anti-oxidative stress responses and protects cells against oxidative damage. However, the role of autophagy in the anti-oxidative stress responses of melanocytes remains unclear. To investigate the role of autophagy in human epidermal melanocytes, we knocked down and overexpressed ATG7, the critical gene of autophagy, in normal human epidermal melanocytes. We demonstrated that ATG7-dependent autophagy could affect melanin content of melanocytes by regulating melanogenesis. Moreover, suppression of ATG7-dependent autophagy inhibits proliferation and promotes oxidative stress-induced apoptosis of melanocytes, whereas enhancement of ATG7-dependent autophagy protects melanocytes from oxidative stress-induced apoptosis. Meanwhile, deficiency of ATG7-dependent autophagy results in premature senescence of melanocytes under oxidative stress. Notably, we verified that ATG7-dependent autophagy could alter oxidative stress homeostasis by regulating reactive oxygen species (ROS) production, nuclear factor erythroid 2-related factor 2 (Nrf2) antioxidant pathway, and the activity of several antioxidant enzymes in melanocytes. In conclusion, our study suggested that ATG7-dependent autophagy is indispensable for redox homeostasis and the biological functions of melanocytes, such as melanogenesis, proliferation, apoptosis, and senescence, especially under oxidative stress.

Exogenous hydrogen sulfide inhibits human melanoma cell development via suppression of the PI3K/AKT/ mTOR pathway.

BACKGROUND: Melanoma is one of the most aggressive, therapy-resistant skin cancers in the world. Hydrogen sulfide (H2S), a newly discovered gasotransmitter, plays a crucial role in the progression and development of many types of cancers. However, the effect of H2S on human skin melanoma remains to be elucidated. OBJECTIVE: We aimed to explore the effect of exogenous H2S on melanoma cells and its underlying mechanisms. METHODS: In this study, human skin melanoma cell lines, including A375 and SK-MEL-28, were treated with a donor of H2S (NaHS). CCK-8, scratch assay, flow cytometric analysis, western blotting and transmission electron microscopy (TEM) were performed to explore the effects of H2S on cell behaviors. RESULTS: Treatment with NaHS inhibited cell proliferation, migration and division, while it could induce cell apoptosis and autophagy in melanoma cell lines. Moreover, NaHS significantly decreased the expression of p-PI3K, p-Akt and mTOR proteins. Furthermore, insulin-like growth factor-1 (IGF-1), the activator of PI3K/AKT/mTOR pathway, could reverse the cell behaviors caused by NaHS. CONCLUSION: Our results demonstrated that exogenous hydrogen sulfide could inhibit human melanoma cell development via suppression of the PI3K/AKT/mTOR pathway. Hydrogen sulfide might serve as a potential therapeutic option for melanoma.

Al-Doped Ga-Based Liquid Metal: Modification Strategy and Controllable High-Temperature Lubricity through Frictional Interface Regulation.

Ga-based liquid metal (GLM) may be a potential heat-transfer material in many industries such as electronic devices and nuclear reactors, and thus, improving its lubricity is conducive to solving the friction and corrosion problems of the motion pairs served in the GLM medium. This paper proposes a modification strategy based on the conventional and large-scale mechanical milling to prepare Al-doped GLM successfully and regulates the GLM lubricity through controlling the frictional interface properties. It is found that at room temperature (∼20 °C), the Al element in the Al-doped GLM medium has a stronger adsorption capacity on the T91 surface, so the Al-rich film is formed on the frictional interfaces and reduces the wear of the T91 disk effectively compared to that in the GLM medium. However, the doping of Al is detrimental to the wear resistance of the T91 steel significantly at 400 °C by inhibiting the formation of the protective FeGa3 film on the frictional interfaces, which readily appears at T91 frictional interfaces in the GLM medium. At 600 °C, Al atoms participate in the formation of a multilayer intermetallic film, thus improving the wear resistance again. This paper provides a new idea for preparing the metal-doped GLM and improving the lubricity of GLM, and it drives forward our understanding of the lubrication mechanisms of liquid lubricants.

Dysfunction of Autophagy: A Possible Mechanism Involved in the Pathogenesis of Vitiligo by Breaking the Redox Balance of Melanocytes.

Vitiligo is a common chronic acquired pigmentation disorder characterized by loss of functional melanocytes from the epidermis and follicular reservoir. Among multiple hypotheses which have been proposed in the pathogenesis of vitiligo, autoimmunity and oxidative stress-mediated toxicity in melanocytes remain most widely accepted. Macroautophagy is a lysosome-dependent degradation pathway which widely exists in eukaryotic cells. Autophagy participates in the oxidative stress response in many cells, which plays a protective role in preventing damage caused by oxidative stress. Recent studies have enrolled autophagy as an important regulator in limiting damage caused by UV light and lipid oxidation, keeping oxidative stress in a steady state in epidermal keratinocytes and maintaining normal proliferation and aging of melanocytes. Impairment of autophagy might disrupt the antioxidant defense system which renders melanocytes to oxidative insults. These findings provide supportive evidence to explore new ideas of the pathogenesis of vitiligo and other pigmentation disorders.

Hydrothermal synthesis and green luminescent properties of Lu2O3:Yb3+/Ho3+ nanocubes.

Uniform and dispersive Lu2O3:Yb3+/Ho3+ nanocubes have been successfully synthesized by the hydrothermal process followed by a subsequent calcination at 800 degrees C. X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), photoluminescence (PL), cathodoluminescence (CL) spectra, as well as lifetimes measurements were utilized to characterize the synthesized phosphors. The as-formed RE(3+)-doped lutetium oxide precursor via the hydrothermal process as a template could transform to RE(3+)-doped Lu2O3 with their original cubic morphology and slight shrinkage in the size after the post-annealing process. The formation mechanism for the lutetium oxide precursor cubes has been proposed. Under the excitation of UV light, 980-nm laser and low-voltage electron-beams, Lu2O3:Yb3+/Ho3+ phosphors all show the characteristic emission of the Ho3+ ion (5F4, 5S2 --> 18 transition) withgreen color, which is easily observed by naked eyes. The corresponding luminescent mechanisms have been discussed. Due to the excellent PL (including up-conversion and down-conversion) properties and CL properties of the Lu2O3:Yb3+/Ho3+ phosphors, they are potentially applicable in fluorescent lamps, up-conversion fluorescent labels and FED devices as an efficient green phosphor.