This article provides a timely exploration of the relationship between hospitality employee service sabotage and customer deviant behaviors in Taiwan. The authors also examine the mediating role of ...relational quality and the moderating role of corporate reputation. The proposed research framework was tested using data from 226 customers of casual dining restaurants who responded to a questionnaire-based survey that was administered in northern Taiwan. The results indicate that employee service sabotage is positively related to customer deviant behaviors and potentially increases the incidence of the latter. Moreover, the relationship between employee service sabotage and customer deviant behaviors is mediated by relational quality, including satisfaction and commitment. It was found that the relationship between employee service sabotage and customer deviant behaviors is negatively moderated by corporate reputation. Employee service sabotage has less effect on customer deviant behaviors when customers perceive corporate reputation more positively. The study contributes to knowledge by proposing an empirically developed and tested conceptual model that offers an enhanced understanding of the relationship between employee service sabotage and customer deviant behaviors.
A recurrence of hepatocellular carcinoma (HCC) after living donor liver transplantation (LDLT) is one of the major concerns reflecting the higher mortality of HCC. This study aimed to explore the ...impact of circulating exosomes on HCC development and recurrence. One‐shot transfusion of hepatoma serum to naïve rats induced liver cancer development with gradual elevation of alpha‐fetoprotein (AFP), but exosome‐free hepatoma serum failed to induce AFP elevation. The microarray analysis revealed miR‐92b as one of the highly expressing microribonucleic acids in hepatoma serum exosomes. Overexpression of miR‐92b enhanced the migration ability of liver cancer cell lines with active release of exosomal miR‐92b. The hepatoma‐derived exosomal miR‐92b transferred to natural killer (NK) cells, resulting in the downregulation of CD69 and NK cell‐mediated cytotoxicity. Furthermore, higher expression of miR‐92b in serum exosomes was confirmed in HCC patients before LDLT, and its value at 1 month after LDLT was maintained at a higher level in the patients with posttransplant HCC recurrence. In summary, we demonstrated the impact of circulating exosomes on liver cancer development, partly through the suppression of CD69 on NK cells by hepatoma‐derived exosomal miR‐92b. The value of circulating exosomal miR‐92b may predict the risk of posttransplant HCC recurrence.
This study demonstrates the impact of circulating exosomes on liver cancer development in rats, explores functional roles of exosomal miR‐92b in the tumor microenvironment, and verifies its clinical value for early prediction of posttransplant hepatocellular carcinoma recurrence.
The transition form factors for doubly heavy baryons into a spin-1/2 or spin-3/2 ground-state baryon induced by both the charged current and the flavor changing neutral current are systematically ...studied within the light-front quark model. In the transition the two spectator quarks have two spin configurations and both are considered in this calculation. We use an updated vertex functions, and inspired by the flavor SU(3) symmetry, we also provide a new approach to derive the flavor-spin factors. With the obtained transition form factors, we perform a phenomenological study of the corresponding semi-leptonic decays of doubly heavy baryons induced by the
c
→
d
/
s
ℓ
+
ν
,
b
→
c
/
u
ℓ
-
ν
¯
and
b
→
d
/
s
ℓ
+
ℓ
-
. Results for partial decay widths, branching ratios and the polarization ratios
Γ
L
/
Γ
T
s are given. We find that most branching ratios for the semi-leptonic decays induced by the
c
→
d
,
s
transitions are at the order of
10
-
3
∼
10
-
2
, which might be useful for the search of other doubly-heavy baryons. Uncertainties in form factors, the flavor SU(3) symmetry and sources of symmetry breaking effects are discussed. We find that the SU(3) symmetry breaking effects could be sizable in charmed baryon decays while in the bottomed case, the SU(3) symmetry breaking effects are less significant. Our results can be examined at the experimental facilities in the future.
Fabricating high‐efficient electron transporting interfacial layers (ETLs) with isotropic features is highly desired for all‐directional electron transfer/collection from an anisotropic active layer, ...achieving excellent power conversion efficiency (PCEs) on nonfullerene acceptor (NFA) organic solar cells (OSCs). The complicated synthesis and cost‐consumption in exploring versatile materials arouse great interest in the development of binary‐doping interlayers without phase separation and flexible manipulation. Herein, for the first time, a novel cathode interfacial layer based on biomass‐derived demethylated kraft lignin (DMeKL) is proposed. Features of multiple phenolic‐hydroxyl (PhOH) and uniform‐distributed render DMeKL to exhibit an excellent bonding capacity with amino terminal substituted perylene diiminde (PDIN), and successfully form a high‐efficient isotropic electron transfer 3D network. Synchronously, secondary bonds completely modify conjugate‐blocked linkages of DMeKL, significantly enhance the electron transporting performance on cross‐section and vertical‐sections, and repair the contact of PDIN with active layer. The DMeKL/PDIN‐based 3D‐network exhibits well‐matched work function (WF) (–4.34 eV) with cathode (–4.30 eV) and energy level of electron acceptor (–4.11 eV). DMeKL/PDIN‐based NFAs‐OSC shows excellent short‐circuit current density (26.61 mA cm–2) and PCE (16.02%) beyond the classic PDIN‐based NFA‐OSC (25.64 mA cm–2, 15.41%), which is the highest PCEs among biomaterials interlayers. The results supply a novel method to achieve high‐efficient cathode interlayer for NFAs‐OSCs.
A secondary bond‐constructed isotropic electron transfer 3D‐network is fabricated based on biomass‐derived demethylated kraft lignin (DMeKL). Secondary bonds successfully modify the contact of the perylene diiminde/active layer and conjugate‐blocked linkages in DMeKL, to overcome anisotropy‐aroused electron transfer barriers at the cathode interface. The enhancement of cross/vertical‐sectional electron transfer performance and well‐matched energy levels yields the highest power conversion efficiency reported among biomaterial‐based organic solar cells.
Increased lipogenesis has been linked to an increased cancer risk and poor prognosis; however, the underlying mechanisms remain obscure. Here we show that phosphatidic acid phosphatase (PAP) lipin-1, ...which generates diglyceride precursors necessary for the synthesis of glycerolipids, interacts with and is a direct substrate of the Src proto-oncogenic tyrosine kinase. Obesity-associated microenvironmental factors and other Src-activating growth factors, including the epidermal growth factor, activate Src and promote Src-mediated lipin-1 phosphorylation on Tyr398, Tyr413 and Tyr795 residues. The tyrosine phosphorylation of lipin-1 markedly increases its PAP activity, accelerating the synthesis of glycerophospholipids and triglyceride. Alteration of the three tyrosine residues to phenylalanine (3YF-lipin-1) disables lipin-1 from mediating Src-enhanced glycerolipid synthesis, cell proliferation and xenograft growth. Re-expression of 3YF-lipin-1 in PyVT;Lpin1
mice fails to promote progression and metastasis of mammary tumours. Human breast tumours exhibit increased p-Tyr-lipin-1 levels compared to the adjacent tissues. Importantly, statistical analyses show that levels of p-Tyr-lipin-1 correlate with tumour sizes, lymph node metastasis, time to recurrence and survival of the patients. These results illustrate a direct lipogenesis-promoting role of the pro-oncogenic Src, providing a mechanistic link between obesity-associated mitogenic signaling and breast cancer malignancy.
•Density functional theory was applied to investigate the ReO4− adsorption mechanism.•The interaction of ReO4− and basic oxygen-containing groups was considered firstly.•Basic oxygen-containing ...groups possess stronger affinity toward ReO4−.
Biochar has a good adsorption ability for perrhenate (ReO4−), which can be attributed to its abundant oxygen-containing groups, yet the effects of oxygen-containing groups on ReO4− adsorption are still unclear. Here, the interaction of ReO4− and acidic/basic oxygen-containing groups (hydroxyl, carboxyl, pyrone and chromene) on biochar were investigated by density functional theory (DFT) calculation with conductor-like screening model (COSMO). According to the calculated results, it was evidenced that the adsorption of oxygen-containing group functionalized BC towards ReO4− was gradually strengthened as decreased pH, and the protonated positively charged oxygen-containing groups presented stronger chemisorption to ReO4− mainly through electrostatic interaction, complexation and atomic orbital hybridization. The protonated hydroxyl and carboxyl and the protonated etheric oxygen of pyrone and chromene can offer favorable binding sites to ReO4−. Compared with the acidic oxygen-containing groups, the higher adsorption energy values, and the larger Mayer bond order indexes of interacting atoms identified that the basic oxygen-containing groups have stronger affinity with ReO4−. Pyrone had the strongest adsorption stability toward ReO4−. Our results can provide new ideas into the design and preparation of separation materials for ReO4− or the other anions capture from the aqueous solution.
•Thermal effects of AC-DBD plasma actuation for icing mitigation were investigated.•Heat transfer mechanisms in DBD plasma actuation and electro-heating were revealed.•Anti-icing performances of DBD ...plasma actuator and electro-heater were compared.•Equivalent anti-icing results were achieved by DBD plasma actuator and electro-heater.•Duty-cycled DBD plasma actuation promoted a better anti-icing performance.
A comparison study of a novel method of utilizing thermal effects induced by Dielectric-Barrier-Discharge (DBD) plasma actuation (i.e., DBD plasma-based method) and a conventional electrical heating method for aircraft icing mitigation was performed in an Icing Research Tunnel available at Iowa State University (i.e., ISU-IRT). A NACA0012 airfoil/wing model embedded with an AC-DBD plasma actuator and a conventional electrical film heater over the airfoil surface was tested under a typical aircraft icing condition. While a high-speed imaging system was used to record the dynamic ice accretion and transient surface water transport processes over the airfoil surface, an infrared (IR) thermal imaging system was also utilized to map the corresponding surface temperature distributions over the airfoil surface simultaneously to quantify the unsteady heat transfer and phase changing process over the ice accreting airfoil surface. It was found that, with the same power input, the DBD plasma-based method showed at least equivalent effectiveness, if not better, in preventing ice accretion over the airfoil surface, in comparison to the conventional electrical heating method. Further optimization of the DBD plasma-based method with a duty-cycle modulation was found to have a much better anti-/de-icing performance, in comparison to the conventional electrical heating method. The findings derived from the present study demonstrated the potential of a new class of anti-/de-icing strategy by leveraging the thermal effects induced by DBD plasma actuation for aircraft in-flight icing mitigation.
The recently discovered superconductivity in Nd_{1−x}Sr_{x}NiO_{2} provides a new opportunity for studying strongly correlated unconventional superconductivity. The single-hole Ni^{+} (3d^{9}) ...configuration in the parent compound NdNiO_{2} is similar to that of Cu^{2+} in cuprates. We suggest that after doping, the intraorbital spin-singlet and interorbital spin-triplet double-hole (doublon) configurations of Ni^{2+} are competing, and we construct a two-band Hubbard model by including both the 3d_{x^{2}−y^{2}} and 3d_{xy} orbitals. The effective spin-orbital superexchange model in the undoped case is a variant of the SU(4) Kugel-Khomskii model augmented by symmetry-breaking terms. Upon doping, the effective exchange interactions between spin-1/2 single holes, spin-1 (triplet) doublons, and singlet doublons are derived. Possible superconducting pairing symmetries are classified in accordance to the D_{4h} crystalline symmetry, and their connections to the superexchange interactions are analyzed.
•A Barchan-dune-shaped-ramp (BDSR) film cooling concept was explored experimentally.•PSP technique was used to quantify cooling effectiveness based on mass transfer analog.•50–100% improvement in ...film cooling effectiveness was achieved with the BDA design.•Down-wash flow induced by BDSR was found to enhance film cooling effectiveness.•Both the location and height of the BDSR would affect the cooling performance.
In the present study, an experimental investigation was conducted to explore a novel film cooling design with Barchan-dune-shaped-ramp (BDSR) concept to augment the effectiveness of film cooling injection from discrete holes. Inspired by the unique shape of Barchan dunes commonly seen in deserts to prevent sand particles on the ground from being blown away by the oncoming airflow, the BDSR concept was proposed to enable the coolant streams exhausted from coolant injection holes to stay more firmly on the surface of interest for improved film cooling performance. During the experiments, while coolant streams were injected from discrete circular holes on a flat test plate at an injection angle of 35°, a row of BDSRs were mounted on the test plate at either downstream or upstream of the coolant injection holes for improved film cooling effectiveness. While a high-resolution Particle Image Velocimetry (PIV) system was used to conduct detailed flow field measurements to quantify the dynamic mixing process between the coolant jet streams and the mainstream flows over the test plate, a Pressure Sensitive Paint (PSP) technique was used to map the corresponding adiabatic film cooling effectiveness on the surface of interest based on a mass-flux analog to traditional temperature-based cooling effectiveness measurements. The cooling effectiveness data of the BDSR design were compared quantitatively against those of a conventional film cooling design without BDSR (i.e., baseline case) under the same test conditions in order to evaluate the effects of the BDSRs on the film cooling effectiveness over the surface of interest. The effects of the locations and height of the BDSRs in relation to the coolant injection holes on the film cooling effectiveness at different blowing ratios (i.e., the coolant-to-mainstream mass flux ratios) were examined quantitatively based on the PIV and PSP measurements. The detailed flow field measurements were correlated with the measured film cooling effectiveness distributions to elucidate the underlying physics in order to explore/optimize design paradigms for better film cooling protection of turbine blades from harsh environments.
NiSe@NiOOH core–shell hyacinth-like nanostructures supported on nickel foam (NF) have been successfully synthesized by a facile solvothermal selenization and subsequent in situ electrochemical ...oxidation (ISEO). First, the unique NiSe/NF nanopillar arrays were prepared in N,N-dimethylformamide (DMF) as a precursor template that can provide a large surface area, excellent conductivity, and robust support. Next, amorphous NiOOH covering the surface of NiSe nanopillars was fabricated by ISEO, as confirmed by XPS andEDX spectroscopy. SEM images revealed the hyacinth-like morphology of NiSe@NiOOH/NF with NiOOH as the shell and NiSe as the core. The electrochemical performance of NiSe@NiOOH/NF for the oxygen evolution reaction (OER) was investigated. NiSe@NiOOH/NF demonstrates an obviously enhanced OER activity with much lower overpotential of 332 mV at 50 mA cm–2 compared to other Ni-based electrocatalysts. The low charge-transfer resistance (R ct), large electrochemical double-layer capacitance (C dl) of electrochemically active surface areas (ECSAs), and excellent long-term stability of NiSe@NiOOH/NF confirm the enhancement of its electrochemical performance for the OER, which can be ascribed to the large amount of active sites derived from the amorphous NiOOH shell and the good conductivity and stability derived from the NiSe core. In addition, the synergistic effect between the NiSe core and NiOOH shell could serve for a highly efficient OER electrocatalyst.
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