Purpose Digital technologies over time are becoming increasingly pervasive and relatively affordable, finding a large diffusion in Small and Medium Enterprises (SMEs) also for internationalization ...purposes. However, less is known about the specific mechanisms by which this can be achieved. Specifically, we focus on how SMEs can face the international environment, leveraging digital technologies and thanks to their intellectual capital (IC). Design/methodology/approach We analyze the relationship between digital technologies and the internationalization of SMEs, exploring the mediating role of IC in its three dimensions: human, relational and innovation capital, and assessing the possible moderating effects posed by international institutional conditions, specifically the Sino-US trade frictions. The relationships are tested using a sample of companies listed on China’s A-share Growth Enterprise Market (GEM) from 2010 to 2021. Findings Digital technologies help to internationalize SMEs. However, this positive relationship is affected (mediated) by the presence of an already consolidated IC. In addition, the institutional conditions of the international market, such as the Sino-US trade friction, moderate the components of IC differently. Specifically, the overall mediating effect of human and relational capital is boosted, while this does not happen for innovation capital. Originality/value First, this study contributes to the literature on organizational resilience, especially digital resilience, confirming its validity in the context of internationalization and, in particular, those processes adopted by SMEs. Second, we clarify the mechanisms through which digital technologies exert their impact on the process of internationalization and in particular the prominent necessity of having IC. Third, our conclusions enrich the understanding of how IC components react to turbulence in international markets.
In order to investigate the phonon scattering mechanisms in double-filled skutterudites, the low-temperature lattice thermal conductivities of Ino.lYbyCO4Sb12 were measured and analyzed based on the ...Debye model. The eingenmode frequencies of In and Yb were obtained from low-temperature specific heat capacity analysis. It is found that filling these two types of guest atoms with different eingenmode frequencies into the voids in skutterudites could introduce strong point defect and resonant scattering to lattice phonons, thus lead to significant decrease in the lattice thermal conductivity.
Wearable device based human activity recognition, as an important field of ubiquitous and mobile computing, is drawing more and more attention. Compared with simple human activity (SHA) recognition, ...complex human activity (CHA) recognition faces more challenges, e.g., various modalities of input and long sequential information. In this paper, we propose a deep learning model named DEBONAIR (Deep lEarning Based multimodal cOmplex humaN Activity Recognition) to address these problems, which is an end-to-end model extracting features systematically. We design specific sub-network architectures for different sensor data and merge the outputs of all sub-networks to extract fusion features. Then, a LSTM network is utilized to learn the sequential information of CHAs. We evaluate the model on two multimodal CHA datasets. The experiment results show that DEBONAIR is significantly better than the state-of-the-art CHA recognition models.
Elevated serum uric acid (sUA) is associated with increasing risk of coronary heart disease (CHD). However, existing research is limited by potential confounders. Herein, our study aims to probe the ...association between sUA levels and the morphological characteristics of coronary plaque by a propensity score matching (PSM) analysis.All 420 patients with CHD who had undergone optical coherence tomography of culprit lesions were included. Eligible patients were assigned into 2 groups according to sUA level: high-sUA group (sUA ≥ 6.0 mg/dL) and low-sUA group (sUA < 6.0 mg/dL). PSM was applied to control the balance of baseline characteristics.After PSM, a total of 112 patients were included in our study (56 in each group). The high-sUA group showed a higher prevalence of TCFA (35.7% versus 16.1%, P = 0.03) and macrophage infiltration (33.9% versus 14.3%, P = 0.026) compared with the low-sUA group. Plaques in the high-sUA group had a wider maximum lipid arc (166.51° (115.77°, 224.14°) versus 142.29° (93.95°, 169.06°), P = 0.048), longer calcification length (6.77 (3.90, 20.55) mm versus 4.20 (1.95, 7.45) mm, P = 0.040), and thinner minimum fibrous cap thickness (43.81 (28.17, 62.26) μm versus 92.57 (46.25, 135.37) μm, P = 0.003). Correlation analysis indicated that the sUA value was inversely associated with the minimum fibrous cap thickness (r = −0.332, P = 0.015) and positively associated with the maximum lipid arc (r = 0.399, P = 0.003), average lipid arc (r = 0.347, P = 0.011), and calcification length (r = 0.386, P = 0.006).The relationship between high-sUA levels and typical vulnerable features of plaques persisted after balancing the traditional risk factors.
Due to prominent attenuation of travelling waves, double-end fault location method produces considerable errors when applied to ultra-high voltage AC half-wavelength transmission (UAHT) lines. In ...order to address this problem, this study presents a novel fault location scheme based on the attenuation, refraction and reflection principles of aerial-mode voltage travelling waves (AVTWs). In the scheme, the faulted section of an UAHT line is first determined according to the accumulated amplitude ratio of the pre-determined frequency components of AVTWs asynchronously sampled at both terminals of the line. Then, the Teager energy of the first two wavefronts of the AVTW – measured at the terminal in the faulted section – is used to define two factors for selecting the appropriate accurate fault location method. Finally, the single-end travelling wave method is adopted for locating the faults near the line terminal. The presented double-end method utilises the amplitude ratio of AVTWs to locate the faults far from the line terminal. A 1000 kV UAHT line model is considered with various fault conditions in PSCAD/EMTDC simulations. The simulation results and analysis demonstrate that the proposed fault location scheme is accurate and immune to fault distances, fault types, fault impedances and fault inception angles.
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•A pilot-scale process of VFA production from FW was established under acid condition.•The highest VFA production yield was 0.79 mgCOD/mgCOD at pH of 6.5.•Higher pH resulted in an ...increase in the proportion of butyric acid.•Dominant microbial function group promoted the conversion of acetic to butyric acid.
Here, a pilot-scale volatile fatty acids (VFAs) production system was established using food waste (FW) as feedstock under acidic conditions. The effects of pH (uncontrolled, 4.5, 5.5, and 6.5) on the FW acidification system were investigated. The results showed that VFAs concentration increased from 8419 to 15048 mg COD/L with pH level increasing from 4.5 to 6.5, and the highest VFA production yield (0.79 mgCOD/mgCOD) was obtained at a pH of 6.5. A larger proportion of butyric acid (52.9%) was observed, accompanied by a 23% decrease of acetic acid when pH was elevated to 6.5. Microbial analysis showed that Clostridium sensu stricto 1, Sporanaerobacter, and Proteiniphilum were dominant, which not only positively influence the hydrolysis and acidogenesis processes but also play an essential role in the conversion of acetic acid to butyric acid. In summary, this study provides a valuable reference for large-scale FW treatment to recover valuable resources.
An effective and recoverable CuFe2O4@GO catalyst for PMS activation was synthesized and the underlying catalytic mechanism was revealed in this study.
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Recently, heterogeneous ...activation of peroxymonosulfate (PMS) to oxidatively degrade organic pollutants has been a hotspot. In the present work, copper ferrite-graphite oxide hybrid (CuFe2O4@GO) was prepared and used as catalyst to activate PMS for degradation of methylene blue (MB) in aqueous solution. A high degradation efficiency (93.3%) was achieved at the experimental conditions of 20 mg/L MB, 200 mg/L CuFe2O4@GO, 0.8 mmol/L PMS, and 25 °C temperature. Moreover, CuFe2O4@GO showed an excellent reusability and stability. The effects of various operational parameters including pollutant type, solution pH, catalyst dosage, PMS dosage, pollutant concentration, temperature, natural organic matter (NOM), and inorganic anions on the catalytic degradation process were comprehensively investigated and elucidated. The further mechanistic study revealed the Cu(II)/Cu(I) redox couple on CuFe2O4@GO played the dominant role in PMS activation, where both hydroxyl and sulfate radicals were generated and proceeded the degradation of pollutants. In general, CuFe2O4@GO is a promising heterocatalyst for PMS-based advanced oxidation processes (AOPs) in wastewater treatment.
The development of a powerful nanoplatform to realize the simultaneous therapy and diagnosis of cancer using a similar element for theranostics remains a critical challenge. Herein, we report such a ...theranostic nanoplatform based on pyridine (Pyr)-functionalized generation 5 (G5) poly(amidoamine) dendrimers complexed with copper(II) (Cu(II)) for radiotherapy-enhanced T 1-weighted magnetic resonance (MR) imaging and the synergistic radio-chemotherapy of both tumors and tumor metastasis. In this study, amine-terminated G5 dendrimers were covalently linked with 2-pyridinecarboxylic acid, acetylated to neutralize their remaining terminal amines, and complexed with Cu(II) through both the internal tertiary amines and the surface Pyr groups to form the G5.NHAc-Pyr/Cu(II) complexes. We show that the complexes are able to inhibit the proliferation of different cancer cell lines with half-maximal inhibitory concentrations ranging from 4 to 10 μM and induce significant cancer cell apoptosis. Due to the presence of Cu(II), the G5.NHAc-Pyr/Cu(II) complexes display an r 1 relaxivity of 0.7024 mM–1 s–1, enabling effective in vivo MR imaging of tumor xenografts and lung metastatic nodules. Further, under radiotherapy (RT) conditions, the tumor MR imaging sensitivity can be significantly enhanced, and the G5.NHAc-Pyr/Cu(II) complexes enable the enhanced chemotherapy of both a xenografted tumor model and a blood-vessel metastasis model. With the demonstrated theranostic potential of the dendrimer-Cu(II) nanocomplexes without additional agents or elements for RT-enhanced MR imaging and chemotherapy of tumor and tumor metastasis, this novel Cu(II)-based nanohybrids may hold great promise for the theranostics of different cancer types and metastases.
Heavy metals are non-biodegradable and carcinogenic pollutants with great bio-accumulation potential. Their ubiquitous occurrence in water and soils has caused serious environmental concerns. ...Effective strategies that can eliminate the heavy metal pollution are urgently needed. Here the adsorption potential of seven heavy metal cations (Cd2+, Cu2+, Fe3+, Hg2+, Mn2+, Ni2+ and Zn2+) with 20 amino acids was systematically investigated with Density Functional Theory method. The binding energies calculated at B3LYP-D3/def2TZVP level showed that the contribution order of amino acid side chains to the binding affinity was carboxyl > benzene ring > hydroxyl > sulfhydryl > amino group. The affinity order was inversely proportional to the radius and charge transfer of heavy metal cations, approximately following the order of: Ni2+ > Fe3+ > Cu2+ > Hg2+ > Zn2+ > Cd2+ > Mn2+. Compared to the gas-phase in other researches, the water environment has a significant influence on structures and binding energies of the heavy metal and amino acid binary complexes. Collectively, the present results will provide a basis for the design of a chelating agent (e.g., adding carboxyl or a benzene ring) to effectively remove heavy metals from the environment.
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•The highest production of MCFA was achieved with sludge and pit mud as inoculum.•The proportion of SCFA and MCFA with mixed inoculum accounted for 59.2% of the ...SCOD.•Clostridium-related bacteria was key microorganism related to the production of MCFA.•Mixed inoculum has the ability of hydrolytic metabolism and fatty acid biosynthesis.
In this study, medium-chain fatty acids (MCFA) production from food waste with ethanol as electron donor using three different inoculants (active sludge, pit mud and mixture of sludge and pit mud). The results showed that the R3 (mixed inoculum of sludge and pit mud) produced 8539.1 mg COD/L of MCFA, which was significantly higher than that produced by R1 (active sludge, 2712.6 mg COD/L) and R2 (pit mud, 3585.9 mg COD/L). The major MCFA was caproate and heptanoate, and the short-chain fatty acids (SCFA) and MCFA selectivity reaches 69.2%. Microbial community analysis revealed that the relative abundance levels of Clostridium_sensu_stricto_1, Clostridium_sensu_stricto_12 and Oscibacter were positively correlated with MCFA production. Further analysis of the enzymes related genes involved in the MCFA biosynthesis indicates that they were mainly related to enzymes of Clostridium, Oscibacter and Ruminiclostridium. These were the key genera involved in the chain elongation process. Metagenomic analysis revealed that fatty acid biosynthesis (FAB) pathway was the main pathway of MCFA synthesis in all three fermentation reactors. The abundance levels of all FAB pathway related-genes and MCFA functional microorganisms were higher in R3. Additionally, the enrichment of the main gene abundance of metabolic pathway revealing that the mixed inoculum of sludge and pit mud combined the ability of fatty acid biosynthesis and carbohydrate metabolism, with higher fermentation potential. Overall, this study provides new strategies and insights for MCFA production.
