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The widely available crop oil is an effective alternative to the increasingly scarce marine fish oil. However, simple alternative strategies have led to declining growth and the edible value of farmed fish. It is worthwhile to explore the effects of micro supplements in diets to improve the tolerance of fish to different dietary lipid sources, which finally optimizes the feeding strategies. This study aimed to investigate the regulation of L-carnitine and dietary oil conditions on nutrient composition, lipid metabolism, and glucose regulation of Rhynchocypris lagowskii. Four diets were prepared according to fish oil, fish oil supplemented with L-carnitine, corn oil, and corn oil supplemented with L-carnitine, and FO, LCFO, CO, and LCCO were labeled, respectively. R. lagowskii was fed experimental diets for 8 weeks, and the glucose tolerance test was performed. The CO diet significantly resulted in higher crude lipid content in muscle but a lower level of serum lipid parameters of R. lagowskii than the FO diet. However, dietary L-carnitine supplementation significantly reduced the crude lipid content in the hepatopancreas and muscle of the fish fed with the CO diet yet increased the serum lipid parameters. Additionally, the crude lipid content of muscle was reduced in the fish fed with an FO diet supplemented with L-carnitine. Compared with the FO diet, the CO diet significantly reduced the ratio of n3/n6 polyunsaturated fatty acid in the hepatopancreas and muscle of R.lagowskii. Dietary L-carnitine supplementation significantly reduced the contents of total saturated fatty acids and total monounsaturated fatty acids in hepatopancreas under both dietary lipid sources. The CO diet significantly up-regulated the expression of genes related to lipid uptake and adipogenesis in hepatopancreas, including lipoprotein lipase (lpl), acetyl-coenzyme A carboxylase alpha (accα), and sterol regulatory element binding protein-1 (srebp1), compared with the FO diet. While dietary L-carnitine supplementation significantly down-regulated the expressions of lpl, accα, srebp1, and fatty acid synthase in hepatopancreas and muscle of fish under both dietary lipid sources, along with up-regulated expression of carnitine palmitoyltransferase 1 in hepatopancreas. Moreover, the fish fed with a CO diet significantly increased the expression of glucose uptake and clearance and significantly down-regulated the expressions of glucose regulation-related genes, including glucose transporter 1, glycogen synthase 1, and phosphofructokinase in hepatopancreas and muscle, resulting in slower glucose uptake and clearance than fish fed with FO diet. Nevertheless, dietary L-carnitine supplementation up-regulated the expression of gluconeogenesis-related genes, including glucose-6-phosphatase and phosphoenolpyruvate carboxykinase in the hepatopancreas of R. lagowskii under both dietary lipid sources. In conclusion, a higher dietary n6 PUFA resulted in lipid deposition, decreased serum lipid parameters, and limited serum glucose utilization of R. lagowskii. While the regulatory effect of L-carnitine on lipid metabolism and glucose utilization of R. lagowskii varies with dietary lipid sources and tissues.
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Ácidos Grasos Omega-3 , Metabolismo de los Lípidos , Animales , Aceite de Maíz , Carnitina/farmacología , Glucosa , Grasas de la Dieta , Dieta/veterinaria , Aceites de Pescado , Suplementos DietéticosRESUMEN
As spent batteries can be considered as alternative raw sources of electrode materials; the development of regeneration techniques for spent graphite becomes key to realizing economic and environmental sustainability. Herein, the reutilization of small spent graphite particles is domonstrated due to their special structural characteristics, which may directly contribute to the improvement of lithiation kinetics and high-rate charging during long-term cycling. Such intrinsic defects and external cracked channels may be introduced by the aging of intrinsic bulk structure and exfoliation of surface structure. On account of these potential advantages, a carbonized polypyrrole layer on sieved small graphite particles is developed to obtain superior rate performance. The coated amorphous/graphitic layer could repair the exposed edge and basal plane, and significantly facilitate Li ion diffusion during fast charging. Moreover, the enhanced performance may favor the improved homogeneity of current density distribution during fast charging, which is confirmed by a porous electrode model. The regenerated graphite with a disorder/order coating layer could effectively regulate the Li+ transport channel, exhibiting a high specific capacity at high-rate charging (102.7 mAh g-1 at 4 C after 500 cycles) without severe Li plating. This work provides an opportunity to utilize spent graphite in fast-charging batteries.
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Research was conducted on the growth performance and nutritional quality of Chinese mitten crabs (Eriocheir sinensis) during a 62-day growing period in a symbiotic coculture comprising rice and crab. Culture experiments were conducted in three rice fields of equal size (996 m2). On days 0 (July 15, D0), 15 (July 30, D15), 31 (August 15, D31), 46 (August 30, D46), and 62 (September 2, D62), tissue samples of 50 female E. sinensis were collected randomly from each rice field. The results showed that the serum growth hormone (GH) content and muscle ecdysone receptor (EcR) mRNA expression levels were higher in the D31 and D46 groups; the content of serum 20-hydroxyecdysone (20-HE) and the mRNA expression levels of retinoid X receptor (RXR), insulin-like growth factor 2 (IGF2), and chitinase (CHI) reached the maximum in the D31 group. Muscle crude protein content gradually increased; hepatopancreas crude protein and crude lipid content began to decrease after reaching the maximum value in the D0 and D15 groups, respectively; the contents of crude protein and crude lipid in the ovary significantly increased in the D46 and D62 groups (P < 0.05). The content of muscle essential amino acids (EAA) reached the maximum in the D46 group; the hepatopancreas EAA content began to decrease significantly in the D31 group (P < 0.05); and the EAA content of the ovary decreased significantly after reaching the maximum value in the D46 group (P < 0.05). The muscle contents of eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), docosahexaenoic acid (DHA), polyunsaturated fatty acids (PUFA), and n-3 polyunsaturated fatty acids (n-3PUFA) and the ratio of n-3 polyunsaturated fatty acids/n-6 polyunsaturated fatty acids (n3/n6) decreased significantly in the D31 group (P < 0.05); the hepatopancreas contents of EPA, PUFA, n-3PUFA, and n-6 polyunsaturated fatty acids (n-6PUFA) and the ratio of n3/n6 began to decrease after reaching the maximum value in the D31 group, ethyl behenate (21:0), tetracosanoic acid (24:0), DPA, and DHA contents were detected for the first time in the D31 group; the ovary PUFA, n-3PUFA contents, and n3/n6 ratio of the D46 and D62 groups were significantly lower than those of the D31 group (P < 0.05). During the experimental conditions described here, female E. sinensis raised in rice fields reached rapid growth from August 15 to August 30. Additionally, the nutritional quality of the female E. sinensis edible tissues (muscle, hepatopancreas, and ovary) began to decline after August 15, when sufficient nutrients such as protein, lipid, EAA, and PUFA should be provided to the female E. sinensis.
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Multi-user multiple-input multiple-output (MU-MIMO) technology can significantly improve the spectral and energy efficiencies of wireless networks. In the uplink MU-MIMO systems, the optimal precoder design at the base station utilizes the Lagrange multipliers method and the centralized iterative algorithm to minimize the mean squared error (MSE) of all users under the power constraint. The precoding matrices need to be fed back to the user equipment to explore the potential benefits of the joint transceiver design. We propose a CNN-based compression network named PCQNet to minimize the feedback overhead. We first illustrate the effect of the trainable compression ratios and feedback bits on the MSE between the original precoding matrices and the recovered ones. We then evaluate the block error rates as the performance measure of the centralized implementation with an optimal minimum mean-squared error (MMSE) transceiver. Numerical results show that the proposed PCQNet achieves near-optimal performance compared with other quantized feedback schemes and significantly reduces the feedback overhead with negligible performance degradation.
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High-surface-area mesoporous CeO2 (hsmCeO2 ) was prepared by a facile organic-template-induced homogeneous precipitation process and showed excellent catalytic activity in imine synthesis in the absence of base from primary alcohols and amines in air atmosphere at low temperature. For comparison, ordinary CeO2 and hsmCeO2 after different thermal treatments were also investigated. XRD, N2 physisorption, UV-Raman, H2 temperature-programmed reduction, O2 temperature-programmed desorption, EPR spectroscopy, and X-ray photoelectron spectroscopy were used to unravel the structural and redox properties. The hsmCeO2 calcined at 400 °C shows the highest specific surface area (158â m2 g-1 ), the highest fraction of surface coordinatively unsaturated Ce3+ ions (18.2 %), and the highest concentration of reactive oxygen vacancies (2.4×1015 â spins g-1 ). In the model reaction of oxidative coupling of benzyl alcohol and aniline, such an exceptional redox property of the hsmCeO2 catalyst can boost benzylideneaniline formation (2.75 and 5.55â mmol g ceria - 1 h-1 based on >99 % yield at 60 and 80 °C, respectively) in air with no base additives. It can also work effectively at a temperature of 30 °C and in gram-scale synthesis. These are among the best results for all benchmark ceria catalysts in the literature. Moreover, the hsmCeO2 catalyst shows a wide scope towards primary alcohols and amines with good to excellent yield of imines. The influence of reaction parameters, the reusability of the catalyst, and the reaction mechanism were investigated.
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Polar motion (PM) has a close relation to the Earth's structure and composition, seasonal changes of the atmosphere and oceans, storage of waters, etc. As one of the four major space geodetic techniques, doppler orbitography and radiopositioning integrated by satellite (DORIS) is a mature technique that can monitor PM through precise ground station positioning. There are few articles that have analyzed the PM series derived by the DORIS solution in detail. The aim of this research was to assess the PM time-series based on the DORIS solution, to better capture the time-series. In this paper, Fourier fast transform (FFT) and singular spectrum analysis (SSA) were applied to analyze the 25 years of PM time-series solved by DORIS observation from January 1993 to January 2018, then accurately separate the trend terms and periodic signals, and finally precisely reconstruct the main components. To evaluate the PM time-series derived from DORIS, they were compared with those obtained from EOP 14 C04 (IAU2000). The results showed that the RMSs of the differences in PM between them were 1.594 mas and 1.465 mas in the X and Y directions, respectively. Spectrum analysis using FFT showed that the period of annual wobble was 0.998 years and that of the Chandler wobble was 1.181 years. During the SSA process, after singular value decomposition (SVD), the time-series was reconstructed using the eigenvalues and corresponding eigenvectors, and the results indicated that the trend term, annual wobble, and Chandler wobble components were accurately decomposed and reconstructed, and the component reconstruction results had a precision of 3.858 and 2.387 mas in the X and Y directions, respectively. In addition, the tests also gave reasonable explanations of the phenomena of peaks of differences between the PM parameters derived from DORIS and EOP 14 C04, trend terms, the Chandler wobble, and other signals detected by the SSA and FFT. This research will help the assessment and explanation of PM time-series and will offer a good method for the prediction of pole shifts.
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BACKGROUND: Male androgenetic alopecia (MAA) is a multifactorial disease, with patients presenting at a younger age, which is a risk factor for many metabolic diseases. AIMS: To explore the risk factors associated with early-onset of MAA and its metabolic characteristics. METHODS: Forty patients with MAA and 45 healthy controls were collected. The serum levels of fasting blood glucose (FBG), total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), total testosterone (TT), uric acid (UA), and 25-hydroxyvitamin D (25(OH)D) were measured. Meanwhile, lipid metabolites were detected by ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). RESULTS: 37.50% MAA patients had metabolic syndrome, compared to 17.78% in control group (p < 0.05). The levels of HDL-C, UA, and 25(OH)D were decreased in patients with MAA compared to healthy controls (p < 0.05). However, there was no significant difference in the level of TT between the two groups. Additionally, there were no significant differences in the levels of HDL-C, UA, 25(OH)D, and TT among different grades of hair loss (p > 0.05). The lipid profile of early-onset MAA differed significantly from healthy controls. In early-onset MAA, the levels of ceramide (Cer) and sphingomyelin (SM) were significantly lower. Cer(d38:5) and TG(15:0/18:1/18:1) may be the biomarkers. CONCLUSION: Low HDL-C, UA, and 25(OH)D may be the independent risk factors for early-onset MAA. Abnormal lipid metabolism was observed in early-onset MAA, wherein Cer and SM may serve as protective factors.
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Edad de Inicio , Alopecia , Metabolismo de los Lípidos , Humanos , Masculino , Alopecia/sangre , Alopecia/diagnóstico , Proyectos Piloto , Adulto , Factores de Riesgo , Estudios de Casos y Controles , Adulto Joven , Síndrome Metabólico/sangre , Síndrome Metabólico/diagnóstico , Síndrome Metabólico/metabolismo , Lípidos/sangre , Vitamina D/sangre , Vitamina D/análogos & derivados , Persona de Mediana EdadRESUMEN
Sludge resource utilization is one of the important routines for transmitting fecal pollution to water and soil, and sludge dewatering is a crucial step for sludge resource utilization. However, it remains unclear the decay characteristics and persistence of fecal pollution indicators after sludge dewatering. In this study, the persistence of six fecal pollution indicators, namely E. coli (EC), human-specific HF183 Bacteroides (HF183), human adenovirus (HAdV), human JC and BK polyomavirus (JCPyV and BKPyV), and crAssphage, in dewatered sludge cake and dewatering filtrate deriving from raw sewage sludge, as well as three types of sludge conditioned with polyacrylamide (PAM), Fenton's reagent, or Fe[III] and CaO were analyzed. The quantitative polymerase chain reaction (qPCR) and viability-qPCR methods were used to analyze the variation in abundances and infectivity of fecal pollution indicators in dewatered sludge cake or dewatering filtrate over the storage time, respectively. Decay predications of fecal pollution indicators over time were modeled using either the first-order or the biphasic decay model. The qPCR results revealed that fecal pollution indicators in dewatered sludge cake persisted longer than those in dewatering filtrate at the same temperature. Increasing temperature can accelerate the decay of fecal pollution indicators in both dewatered sludge cake and dewatering filtrate. Notably, sludge conditioning treatment may prolong the persistence of fecal pollution indicators in both dewatered sludge cake and dewatering filtrate. Viability-qPCR results indicated that the fecal pollution indicators (except HAdV) in dewatered sludge cakes deriving from both raw sewage sludge and conditioned sludges remained infectious for up to 30 days. After a storage period of 40 days, the abundances of fecal pollution indicators (except for EC) in sludge conditioned with Fenton's reagent were effectively decreased and meanwhile the infectivity of EC was reduced, exhibiting the lowest levels of fecal pollution. Therefore, both ambient temperature and conditioning treatment greatly impacted the decay characteristics and persistence of fecal pollution indicators in dewatered sludge cake and dewatering filtrate, and selecting suitable conditioning method can minimize environmental risks associated with fecal pollution in sewage sludge.
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Visual question generation aims to focus on some target objects in an image to generate questions with certain questioning purposes. Existing studies mainly utilize an answer to extract the target object corresponding to the questioning purpose for questioning. However, answers fail to accurately and completely map to every target object, such as the objects corresponding to the answer are ambiguous or the answers are the relationship between multiple objects. To address this problem, we propose a content-controlled question generation model, which generates questions based on a given target object set specified from an image. Considering that the target objects have different contributions during the generation process, we design a recurrent generative architecture to explicitly control attention to different objects and their corresponding image information at each generative stage. Extensive experiments on the VQA v2.0 dataset and the Visual7w dataset show that the proposed model outperforms the state-of-the-art models and can controllably generate questions with specified content.
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Sludge reuse and utilization is one of important routines of disseminating fecal pollution to surface water and groundwater. However, it remains unclear the spatial distribution of fecal pollution indicators in sludge flocs and their reductions during sludge treatment processes. In this study, the abundances of fecal pollution indicators including cross-assembly phage (crAssphage), JC and BK polyomavirus (JCPyV, BKPyV), human adenovirus (HAdV), the human-specific HF183 Bacteroides (HF183) and Escherichia coli (EC) in soluble extracellular polymeric substances (S-EPS), loosely-bound EPS (LB-EPS), tightly-bound EPS (TB-EPS), and pellets of sludge flocs were determined, and the effect of potassium ferrate (PF) treatment on their removal and inactivation was investigated by using both qPCR and viability-qPCR. Results showed that all investigated indicators were detected in each fraction of sludge flocs. The PF treatment led to a great migration of indicators from sludge pellets to sludge EPS and some extent of their inactivation in each fraction of sludge flocs. The overall reductions of human fecal indicators in sludge determined by qPCR were 0-1.30 logs, which were 0-2 orders of magnitude lower than those of 0.69-2.39 logs detected by viability-qPCR, implying their inactivation by PF treatment to potentially alleviate the associated human health risks.
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Compuestos de Hierro , Aguas del Alcantarillado , Humanos , Compuestos de Potasio , AguaRESUMEN
OBJECTIVE: The aim of this study was to investigate the association of serum carcinoembryonic antigen (CEA), nerve-specific enolase (NSE), cytokeratin 19 fragment (CYFRA21-1), squamous cell carcinoma antigen (SCC-Ag), and pro-gastrin-releasing peptide (ProGRP) with the clinicopathological characteristics and chemotherapeutic outcomes of patients with lung cancer. METHODS: A total of 189 patients with lung cancer (lung cancer group) diagnosed at the Fourth Affiliated Hospital of Anhui Medical University from January 2020 to December 2021 were included. During the same period, 199 patients with benign lung disorders were included as the benign lung disease group and 75 healthy people were selected as the control group. The serum concentrations of CEA, NSE, CYFRA21-1, SCC-Ag, and ProGRP in all the 3 groups were analyzed and compared in patients with different lung cancer tumor-node-metastasis (TNM) stages and pathological classifications. A total of 11 patients with small cell lung cancer (SCLC) and 18 patients with lung adenocarcinoma (LAC) were further evaluated for the dynamic changes of CEA, NSE, CYFRA21-1, SCC-Ag, and ProGRP before chemotherapy and during the 6 courses of chemotherapy, and the outcome of chemotherapy was evaluated every 2 courses. RESULTS: The serum concentrations of CEA, NSE, CYFRA21-1, SCC-Ag, and ProGRP in the lung cancer group were significantly higher than those in the control group (Pâ <â .05). We found statistically significant differences in serum CEA, NSE, CYFRA 21-1, SCC-Ag, and ProGRP among patients with different pathological types (LAC, squamous cell carcinoma, or SCLC) and different stages (I-IV). The ProGRP and NSE had the highest expression in SCLC, CEA showed the highest expression in LAC, whereas CYFRA21-1 and SCC-Ag showed the highest expression in lung squamous cell carcinoma (LSCC). The concentrations of all the markers were elevated in the advanced pathological stages. The receiver operating characteristic curve analysis showed that the diagnostic value of the combined detection of CEA, NSE, CYFRA 21-1, SCC-Ag, and ProGRP for lung cancer was significantly higher than using a single biomarker (Pâ <â .05). Our dynamic monitoring results show that ProGRP progressively decreased in remission cases of SCLC and CEA progressively decreased in LAC remission cases. CONCLUSION: CEA, NSE, CYFRA 21-1, SCC-Ag, and ProGRP have good clinical value in the early diagnosis, differential diagnosis, and progression monitoring of lung cancer. The ProGRP and CEA concentrations are beneficial for evaluating the outcome of chemotherapy in SCLC and LAC. The combined detection of multiple biomarkers shows improved clinical value in the early diagnosis of lung cancer.
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Carcinoma de Células Escamosas , Enfermedades Pulmonares , Neoplasias Pulmonares , Humanos , Queratina-19 , Antígeno Carcinoembrionario , Biomarcadores de Tumor , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/tratamiento farmacológico , Antígenos de Neoplasias , Fosfopiruvato Hidratasa , Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/tratamiento farmacológicoRESUMEN
We synthesize a Sn-modified MIL-101(Fe), which can confine Pt to the single-atom scale. This novel Pt@MIL(FeSn) catalyst efficiently hydrogenates levulinic acid to γ-valerolactone (TOF: 1386 h-1, yield: >99%) at only 100 °C and 1 MPa of H2via α-angelica lactone as an intermediate. This could be the first report on switching the reaction path from 4-hydroxypentanoic acid to α-angelica lactone under very mild conditions. Incorporating Sn into MIL-101(Fe) enables the creation of abundant micro-pores less than 1 nm and Lewis acidic sites that stabilize Pt0 atoms. The ensemble of active Pt atoms and a Lewis acid can synergistically enhance adsorption of the CîO bond and facilitate dehydrative cyclization of levulinic acid.
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Gold nanoparticles with uniform mean sizes (≈3 nm) loaded onto various supports have been prepared and studied for the oxidant-free dehydrogenation of benzyl alcohol to benzaldehyde and hydrogen. The use of hydrotalcite (HT), which possesses both strong acidity and strong basicity, provides the best catalytic performance. Au/HT catalysts with various mean Au particle sizes (2.1-21 nm) have been successfully prepared by a deposition-precipitation method under controlled conditions. Detailed catalytic reaction studies with these catalysts demonstrate that the Au-catalyzed dehydrogenation of benzyl alcohol is a structure-sensitive reaction. The turnover frequency (TOF) increases with decreasing Au mean particle size (from 12 to 2.1 nm). A steep rise in TOF occurs when the mean Au particle size becomes smaller than 4 nm. Our present work suggests that the acid-base properties of the support and the size of Au nanoparticles are two key factors controlling the alcohol dehydrogenation catalysis. A reaction mechanism is proposed to rationalize these results. It is assumed that the activation of the ß-C-H bond of alcohol, which requires the coordinatively unsaturated Au atoms, is the rate-determining step.
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Activated charcoal-dispersed Ru-Ir alloy nanoparticles (ca. 2.2 nm) are a selective and reusable hydrogenation catalyst for the conversion of 5-hydroxymethylfurfural to valuable liquid biofuel. A 99% yield to 2,5-dimethylfuran is achieved at only 120 °C. An acceleration in the reduction of substrate and intermediates is observed due to the synergistic effect between the Ru and Ir species.
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A one-pot synthesized CoRu-CoOX nanocomposite was reported as a magnetically recoverable catalyst for selective hydrogenation of furfural to furfuryl alcohol in water at ambient H2 pressure.
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Liver cancer (LC), which is one of the most common types of cancer worldwide, is notorious for its high morbidity and mortality rates. Interleukin-8 (IL-8), an important member of the CXC chemokine family that was originally classified as a potent neutrophil chemoattractant, has been shown to serve an important role in inflammation, tumor growth, invasion and metastasis through interactions with its receptors. However, the expression and functional roles of IL-8 and its receptors, CXC chemokine receptor (CXCR) 1 and CXCR2 in the progression of liver cancer remain to be fully elucidated. In the present study, it was shown that the mRNA levels of IL-8, CXCR1 and CXCR2 were increased in peripheral blood mononuclear cells from patients with liver cancer compared with those from patients with cirrhosis or normal controls (P<0.05). Higher levels of CXCR1, CXCR2 and IL-8 were associated with advanced tumor stage and increased risk of lymph node or distant metastasis. Immunohistochemistry showed that the IL-8, CXCR1 and CXCR2 proteins were expressed in the cytoplasm of hepatoma cells at higher intensities than those of normal controls (P<0.05). The semi-quantitative analysis revealed that the relative mean density of hepatic IL-8, CXCR1 and CXCR2 staining in liver cancer was significantly increased compared with that in normal liver tissues (P<0.05). The analysis revealed that the mRNA expression of IL-8 was positively associated with that of CXCR1 (r=0.618; P<0.05) and CXCR2 (r=0.569; P<0.05). The mRNA levels of CXCR1 and CXCR2 gradually increased with elevated expression of IL-8 in liver cancer. Experiments were performed using human Huh-7 and HepG2 cell lines, incubating cells with IL-8 and conducting in vitro migration and invasion assays. The results showed that the wound healing activity and migration of Huh-7 and HepG2 cells were increased by IL-8. Pretreatment of the cells with anti-CXCR1 or anti-CXCR2 (5 µM) for 30 min markedly inhibited IL-8-directed cell migration. Taken together, these results indicated that IL-8 promotes liver cancer cell migration via CXCR1 and CXCR2 and that targeting the CXCR1/2 may be a potential strategy for liver cancer treatment.
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A hydrotalcite-supported gold catalyst has been found to be efficient for both oxidative and non-oxidative conversions of benzyl alcohol into benzaldehyde. In both cases, the reaction rates were dependent on the size of the Au particles, but the size dependence for the non-oxidative reaction was more pronounced. Our analyses on the intrinsic rates of different sites suggested that all of the atoms on the Au surfaces participated in the oxidative reaction, whereas the edge and corner Au atoms predominantly contributed to the non-oxidative reaction, and that the terrace atoms were at least two orders of magnitude less active than the edge or corner atoms. In both cases, the rate-determining step was CH bond cleavage. The presence of oxygen significantly enhanced the reaction rate. Herein, we propose that the non-oxidative reaction proceeds through a ß-H elimination step by the low-coordination-number edge and corner Au atoms, whereas the active oxygen species, which are even generated on the terrace Au atoms, might assist CH bond cleavage under oxidative conditions.
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Hydrotalcite-supported gold nanoparticles with sizes of less than 5 nm are highly efficient and reusable catalysts for the oxidant-free dehydrogenation of alcohols to carbonyl compounds and hydrogen.