Two-dimensional crystals are emerging materials for nanoelectronics. Development of the field requires candidate systems with both a high carrier mobility and, in contrast to graphene, a sufficiently ...large electronic bandgap. Here we present a detailed theoretical investigation of the atomic and electronic structure of few-layer black phosphorus (BP) to predict its electrical and optical properties. This system has a direct bandgap, tunable from 1.51 eV for a monolayer to 0.59 eV for a five-layer sample. We predict that the mobilities are hole-dominated, rather high and highly anisotropic. The monolayer is exceptional in having an extremely high hole mobility (of order 10,000 cm(2) V(-1) s(-1)) and anomalous elastic properties which reverse the anisotropy. Light absorption spectra indicate linear dichroism between perpendicular in-plane directions, which allows optical determination of the crystalline orientation and optical activation of the anisotropic transport properties. These results make few-layer BP a promising candidate for future electronics.
Two colorless and transparent polyimide (CPI) films with enhanced high‐temperature dimensional stability and solution‐processability were prepared from the methyl‐substituted benzanilide containing ...organo‐soluble polyimide (PI) resins. For this target, a new aromatic diamine, 2,3′‐dimethyl‐4,4′‐diaminobenzanilide (MMDABA) was synthesized. The methyl substituents were expected to endow the derived PI resins good solubility and rigid‐rod benzanilide units can efficiently reduce the coefficients of thermal expansion (CTE) of the derived CPI films. CPI‐a and CPI‐b were prepared by the one‐step thermal polycondensation from MMDABA with hydrogenated pyromellitic dianhydride for CPI‐a and hydrogenated 3,3′,4,4′‐biphenyltetracarboxylic dianhydride for CPI‐b, respectively. The derived PI resins were soluble in polar aprotic solvents. Colorless and transparent CPI‐a and CPI‐b films were prepared from the PI solutions and the subsequent 280°C curing. The CPI films showed good transparency in visible light and transmittances higher than 80% at 450 nm and yellowness index (b*) below 2.0. More importantly, the derived CPI‐a film showed the glass transition temperature (Tg) of 417.5°C and the CTE value of 46.9 × 10−6/K in the range of 50–250°C. Apparently, incorporation of alkyl‐substituted benzanilide units achieved good balance among solution‐processability, high‐temperature dimensional stability, and optical properties.
Ultrafast‐response (20 μs) UV detectors, which are visible‐blind and self‐powered, in devices where an n‐type ZnO nanowire partially lies on a p‐type GaN film, are demonstrated. Moreover, a ...CdSe‐nanowire red‐light detector powered by a nanoscale ZnO/GaN photovoltaic cell is also demonstrated, which extends the device function to a selective multiwavelength photodetector and shows the function of an optical logical AND gate.
Background and Aims
Hepatic macrophages can be activated by many factors such as gut‐derived bacterial components and factors released from damaged hepatocytes. Macrophage polarization toward a ...proinflammatory phenotype (M1) represents an important event in the disease progression of nonalcoholic fatty liver disease (NAFLD). However, the underlying molecular mechanisms remain incompletely understood. Exosomes have been identified as important mediators for cell–cell communication by transferring various biological components such as microRNAs (miRs), proteins, and lipids. The role of exosomes in crosstalk between hepatocytes and macrophages in disease progression of NAFLD is yet to be explored.
Approach and Results
In the present study, we reported that lipotoxic injury–induced release of hepatocyte exosomes enriched with miR‐192‐5p played a critical role in the activation of M1 macrophages and hepatic inflammation. Serum miR‐192‐5p levels in patients with NAFLD positively correlated with hepatic inflammatory activity score and disease progression. Similarly, the serum miR‐192‐5p level and the number of M1 macrophages, as well as the expression levels of the hepatic proinflammatory mediators, were correlated with disease progression in high‐fat high‐cholesterol diet–fed rat models. Lipotoxic hepatocytes released more miR‐192‐5p‐enriched exosomes than controls, which induced M1 macrophage (cluster of differentiation 11b–positive CD11b+/CD86+) activation and increase of inducible nitric oxide synthase, interleukin 6, and tumor necrosis factor alpha expression. Furthermore, hepatocyte‐derived exosomal miR‐192‐5p inhibited the protein expression of the rapamycin‐insensitive companion of mammalian target of rapamycin (Rictor), which further inhibited the phosphorylation levels of Akt and forkhead box transcription factor O1 (FoxO1) and resulted in activation of FoxO1 and subsequent induction of the inflammatory response.
Conclusions
Hepatocyte‐derived exosomal miR‐192‐5p plays a critical role in the activation of proinflammatory macrophages and disease progression of NAFLD through modulating Rictor/Akt/FoxO1 signaling. Serum exosomal miR‐192‐5p represents a potential noninvasive biomarker and therapeutic target for nonalcoholic steatohepatitis.
In practical applications, particularly in flexible manufacturing systems, there is a high level of uncertainty. A type-2 fuzzy logic system (T2FS) has several parameters and an enhanced ability to ...handle high levels of uncertainty. This article proposes an improved artificial immune system (IAIS) algorithm to solve a special case of the flexible job shop scheduling problem (FJSP), where the processing time of each job is a nonsymmetric triangular interval T2FS (IT2FS) value. First, a novel affinity calculation method considering the IT2FS values is developed. Then, four problem-specific initialization heuristics are designed to enhance both quality and diversity. To enhance the exploitation abilities, six local search approaches are conducted for the routing and scheduling vectors, respectively. Next, a simulated annealing method is embedded to accept antibodies with low affinity, which can enhance the exploration abilities of the algorithm. Moreover, a novel population diversity heuristic is presented to eliminate antibodies with high crowding values. Five efficient algorithms are selected for a detailed comparison, and the simulation results demonstrate that the proposed IAIS algorithm is effective for IT2FS FJSPs.
Few-layer bismuthene is an emerging two-dimensional material in the fields of physics, chemistry, and material science. However, its nonlinear optical property and the related photonics device have ...been seldom studied so far. Here, we demonstrate a sub-200 fs soliton mode-locked erbium-doped fiber laser (EDFL) using a microfiber-based bismuthene saturable absorber for the first time, to the best of our knowledge. The bismuthene nanosheets are synthesized by the sonochemical exfoliation method and transferred onto the taper region of a microfiber by the optical deposition method. Stable soliton pulses centered at 1561 nm with the shortest pulse duration of about 193 fs were obtained. Our findings unambiguously imply that apart from its fantastic electric and thermal properties, few-layer bismuthene may also possess attractive optoelectronic properties for nonlinear photonics, such as mode-lockers, Q-switchers, optical modulators and so on.
AIM To investigate whether gut microbiota metabolite sodium butyrate(Na B)is an effective substance for attenuating non-alcoholic fatty liver disease(NAFLD)and the internal mechanisms.METHODS Male ...C57BL/6J mice were divided into three groups,normal control were fed standard chow and model group were fed a high-fat diet(HFD)for 16 wk,the intervention group were fed HFD for 16 wk and treated with Na B for 8 wk.Gut microbiota from each group were detected at baseline and at 16 wk,liver histology were evaluated and gastrointestinal barrier indicator such as zonula occluden-1(ZO-1)were detected by immunohistochemistry and realtime-PCR,further serum or liver endotoxin were determined by ELISA and inflammation-or metabolism-associated genes were quantified by real-time PCR.RESULTS Na B corrected the HFD-induced gut microbiota imbalance in mice,while it considerably elevated the abundances of the beneficial bacteria Christensenellaceae,Blautia and Lactobacil us.These bacteria can produce butyric acid in what seems like a virtuous circle.And butyrate restored HFD induced intestinal mucosa damage,increased the expression of ZO-1 in small intestine,further decreased the levels of gut endotoxin in serum and liver compared with HF group.Endotoxin-associated genes such as TLR4 and Myd88,pro-inflammation genes such as MCP-1,TNF-α,IL-1,IL-2,IL-6 and IFN-γin liver or epididymal fat were obviously downregulated after Na B intervention.Liver inflammation and fat accumulation were ameliorated,the levels of TG and cholesterol in liver were decreased after Na B intervention,NAS score was significantly decreased,metabolic indices such as FBG and HOMA-IR and liver function indicators ALT and AST were improved compared with HF group.CONCLUSION Na B may restore the dysbiosis of gut microbiota to attenuate steatohepatitis,which is suggested to be a potential gut microbiota modulator and therapeutic substance for NAFLD.
Colloidal quantum dots (QDs) consisting of precious‐metal‐free elements show attractive potentials towards solar‐driven CO2 reduction. However, the inhibition of hydrogen (H2) production in aqueous ...solution remains a challenge. Here, we describe the first example of a carbon–carbon (C−C) coupling reaction to block the competing H2 evolution in photocatalytic CO2 reduction in water. In a specific system taking ZnSe QDs as photocatalysts, the introduction of furfural can significantly suppress H2 evolution leading to CO evolution with a rate of ≈5.3 mmol g−1 h−1 and a turnover number (TON) of >7500 under 24 h visible light. Meanwhile, furfural is upgraded to the self‐coupling product with a yield of 99.8 % based on the consumption of furfural. Mechanistic insights show that the reductive furfural coupling reaction occurs on surface Zn‐sites to consume electrons and protons originally used for H2 production, while the CO formation pathway at surface anion vacancies from CO2 remains.
Reductive carbon–carbon coupling was used to block H2 evolution in CO2 photoreduction in water. Furfural, one of the biomass platform molecules, adsorbs on Zn‐sites consuming electrons and protons originally used for H2 production, but the CO formation pathway at surface anion vacancies remains. Therefore, CO was evolved with a CO/H2 ratio of 265 : 1 in the gas phase and furfural was upgraded to value‐added hydrofuroin.
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•The optimal chiller loading problem by minimizing energy consumption is investigated.•The strategy of local search around the elite weed of IWO algorithm is developed.•Detailed ...experiments have been conducted for the parameter tuning.•The experimental results show that the EIWO algorithm can find optimal solution.•The convergence ability, stability and robustness of EIWO algorithm are verified.
In this study, an improved invasive weed optimization (EIWO) algorithm is investigated to solve the optimal chiller loading (OCL) problem for minimization of the power consumption. In the proposed algorithm, several components are developed, such as decimal-based representation, reproduction approach, spatial dispersal method, and competitive selection mechanism. Then, the local search strategy for elite weed is proposed, which can improve the searching ability of the algorithm. To verify the efficiency and effectiveness of the proposed algorithm, three well-known instances based on the OCL problem in air-conditioning systems are tested with the comparison with other recently published algorithms. The experimental results show that the EIWO algorithm can find equal or better optimal solution compared with other algorithms. The convergence ability, stability and robustness are also verified after the detailed comparisons.
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