RESUMEN

The effect of Fe3O4 nanoparticles (Fe3O4 NPs) on the electron transfer process in aerobic composting systems remains unexplored. In this study, we compared the electron transfer characteristics of DOM in sludge composting without additives (group CK) and with the addition of 50 mg/kg Fe3O4 NPs additive (group Fe). It was demonstrated that the electron transfer capacity (ETC) and electron donating capacity (EDC) of compost-derived DOM increased by 13%-29% and 40%-47%, respectively, with the addition of Fe3O4 NPs during sludge composting. Analyzing the composition and structure of DOM revealed that Fe3O4 NPs promoted the formation of humic acid-like substances and enhanced the aromatic condensation degree of DOM. Correlation analysis indicated that the increase in EDC of DOM was closely associated with the phenolic group in DOM and influenced by quinone groups and the degree of aromatization of DOM. The higher EDC and the structural evolution of DOM in group Fe reduced the bioaccessibility of Cu, Cr, Ni, Zn. This study contributes to a deeper understanding of the redox evolutionary mechanism of DOM in sludge composting and broadens the application of iron oxides additives.

Asunto(s)

RESUMEN

This paper analyzes the green production efficiency (GPE) and spatial divergence of the hog breeding industry, with the aim of providing a foundation for the rational layout of hog breeding and promoting the industry's high-quality development. The paper uses the SBM model to estimate GPE in 29 provinces, cities, and districts of China from 2006 to 2019. Furthermore, it analyzes the spatial divergence of GPE and its driving factors using divergence indexes and the Geodetector. The results show that China's GPE of the hog breeding industry increased from 0.409 to 0.496 between 2006 and 2019. The highest efficiency occurred during the I-period, while the lowest efficiency was observed during the II-period. The highest efficiency was in the key development region, and the lowest efficiency was in the potential growth region. The spatial divergence of GPE in the hog breeding industry expanded, with labor input, non-point source pollution, resource endowment, and environmental load bearing being the main driving factors for the expansion in each period. The potential growth region had the largest spatial divergence, mainly affected by resource endowment. In contrast, the constrained development region had the smallest spatial divergence, mainly affected by resource endowment and pollutant emissions. The spatial divergence of moderate and key development regions was considerable, mainly affected by environmental investment, environmental load bearing, and pollutant emissions. Therefore, the key to improving the GPE of the hog breeding industry is to promote the adoption of advanced technology, such as labor-saving, material-saving, and emission reduction technologies. Moreover, several actions should be taken to reduce the spatial divergence among different regions, such as integrated breeding, clean standards, large-scale breeding, and high-end boutique.

Asunto(s)

RESUMEN

OBJECTIVE: Transarterial chemoembolization (TACE) is a common therapy for hepatocellular carcinoma (HCC), while TACE-induced tumor angiogenesis would increase progression and metastasis risk. Besides, apatinib possesses the capability of inhibiting tumor angiogenesis. Thus, this study aimed to explore the efficacy and safety of TACE plus apatinib compared to TACE alone in HCC patients. METHODS: Ninety-six intermediate-advanced HCC patients were retrospectively enrolled and classified into TACE plus apatinib group (N = 45) and TACE group (N = 51) based on the treatment. RESULTS: Objective response rate (68.9% vs. 47.1%) was increased in TACE plus apatinib group than in TACE group (P = 0.031). However, no difference was found in disease-control rate between groups (95.6% vs. 86.3%) (P = 0.167). Progression-free survival (PFS) (median PFS (95% confidence interval (CI)): 20.0 (13.2-26.8) vs. 14.0 (8.3-19.7) months) was enhanced in TACE plus apatinib group compared with TACE group (P = 0.030), while no difference was found in overall survival between groups (P = 0.060). Additionally, multivariate Cox's analysis presented that TACE plus apatinib (vs. TACE alone) independently associated with prolonged PFS (P = 0.043, hazard ratio = 0.617). Regarding safety profile, no difference in liver function indexes (albumin, total bilirubin, alanine aminotransferase and aspartate aminotransferase) was found after treatment between two groups; meanwhile, only the incidence of hand-foot skin reaction (24.4% vs. 7.8%) was higher in TACE plus apatinib group compared to TACE group (P = 0.025), while no difference was found in other adverse events between two groups (all P > 0.05). CONCLUSION: TACE plus apatinib illustrates a superior efficacy with tolerable safety than TACE alone in intermediate-advanced HCC patients.

Asunto(s)

RESUMEN

OBJECTIVE: To compare the efficacy of percutaneous ethanol injection (PEI) and radiofrequency ablation (RFA) for patients with hepatocellular carcinoma (HCC) of no larger than 5 cm. METHODS: The data used in this study were retrieved from the SEER database. In total, 3510 patients diagnosed with HCC of no larger than 5 cm who received PEI or RFA were included. RESULTS: The median overall survival (mOS) and median cancer-specific survival (mCSS) of RFA-treated patients were not significantly longer than those of PEI-treated patients either before or after propensity score matching (PSM). The subgroup analysis showed that patients with HCC of no larger than 2 cm, HCC of larger than 2 cm, American Joint Committee on Cancer (AJCC) stage I and II, and AJCC stage III and IV who received RFA had mOS and mCSS similar to those of patients who received PEI after PSM. Multivariable regression analysis showed that PEI did not increase the all-cause mortality risk or cancer-specific mortality risk after PSM. CONCLUSION: RFA is still the better choice for patients with a single HCC of no more than 5 cm. However, PEI might be a good choice for these patients who cannot be treated with RFA.

Asunto(s)

RESUMEN

Three medicinal fungi were used to carry out solid-state fermentation (SSF) of wheat bran. The results showed that the use of these fungi for SSF significantly improved wheat bran's nutritional properties including the extraction yield of soluble dietary fiber (SDF), total phenolic content (TPC), total flavonoid content (TFC), physical properties containing swelling capacity (SC) and oil absorption capacity (OAC), as well as antioxidant activities. Electronic nose and GC-MS analyses showed that fermented wheat bran had different volatiles profiles compared to unfermented wheat bran. The results suggest that SSF by medicinal fungi is a promising way for the high-value utilization of wheat bran.

RESUMEN

BACKGROUND: Apatinib, a tyrosine kinase inhibitor, inhibits angiogenesis under the tumor hypoxic environment induced by drug-eluting bead transarterial chemoembolization (DEB-TACE), which is hypothesized to have synergic effect with DEB-TACE in treating hepatocellular carcinoma (HCC) patients. This study aimed to evaluate the efficacy and safety of DEB-TACE plus apatinib in treating huge HCC patients. METHODS: Totally, 73 huge HCC patients (tumor size > 10 cm) were screened and divided into DEB-TACE plus apatinib group (N = 34) or DEB-TACE group (N = 39) based on the treatment they received. Their clinical response and adverse events were retrieved. The progression-free survival (PFS) and overall survival (OS) were calculated. RESULTS: DEB-TACE plus apatinib achieved a trend of higher objective response rate (64.7% vs. 43.6%, P = 0.071), but similar disease control rate (88.2% vs. 79.5%, P = 0.314) than DEB-TACE alone. Moreover, DEB-TACE plus apatinib reached an improved PFS (median (95%CI): 19.0 months (15.5-22.5) vs. 10.9 months (8.0-13.8), P = 0.025) and OS (median (95%CI): 25.1 months (20.3-29.9) vs. 13.7 months (9.8-17.6), P = 0.042) than DEB-TACE alone. After adjustment by multivariate Cox's regression analyses, DEB-TACE plus apatinib (vs. DEB-TACE alone) was independently correlated with better PFS (HR: 0.420, P = 0.004) and OS (HR: 0.477, P = 0.022). Regarding safety, adverse events were mostly mild and manageable; also, they were of no difference between DEB-TACE plus apatinib and DEB-TACE alone (all P > 0.05). CONCLUSION: DEB-TACE plus apatinib achieves prolonged PFS and OS, while similar adverse events occurrence compared to DEB-TACE alone in huge HCC treatment.

Asunto(s)

RESUMEN

Soluble microbial products (SMP), a type of polymers released from microbial metabolism and decay, show great potential for wastewater treatment as bioflocculants; however, biogenic flocculant utilization is currently limited to bacterial SMP. In this study, SMP produced by Phanerochaete chrysosporium BKMF-1767 (SMP-P) was investigated to determine the application potential of fungal SMP. SMP-P exhibited high flocculation activity in kaolin suspension at a dosage range of 0.67-0.84 mg/L with Ca2+ assistance, comparable to that of commercial polyacrylamide. The high molecular weight polysaccharides (2.0 × 106-4.7 × 107 Da) in SMP-P, which enabled flocculation via the bridging mechanism and served as the dominant active constituent, were composed of glucose and arabinose at a molar ratio of 1: 0.03, with (1 â†’ 4, 6)-linked glucose as the main backbone and a small proportion of branched structures. They contained hydroxyl and carboxyl, effective functional groups for the flocculation process, and displayed parallel self-orientation behavior in water. Efficient chemical oxygen demand removal was achieved during municipal wastewater treatment using SMP-P as the bioflocculant. This study demonstrates the feasibility of utilizing fugal SMP as bioflocculants and provides guidance for their practical application.

Asunto(s)

RESUMEN

The distribution, characteristics of extracellular polymeric substances (EPS) of Phanerochaete chrysosporium under Pb2+ stress and the influence on Pb removal were investigated. Polysaccharides was found to be the main composition in both soluble EPS (SEPS) and bounded EPS (BEPS). More polysaccharides and protein in BEPS were detected with the increased Pb2+ concentration. The ratio of Pb amount distributed in BEPS to the total Pb removed by the fungal biomass gradually decreased from 91.66 to 61.27% in group with 50 mg/L of initial Pb2+, but kept at about 35% or 25% in groups with higher Pb2+. It implies that BEPS played a certain role in the lead removal process, and the role of BEPS was relatively more important in the removal of lower concentration of Pb2+ and in the initial period of Pb removal. With FTIR analysis and Pb2+ adsorption experiment, more effective functional groups and better Pb2+ adsorption capacity was demonstrated in BEPS than in SEPS. SEM-EDS analysis demonstrated that part of Pb immobilized in BEPS was in the form of Pb precipitation. The increased molecular weight in SEPS and more polysaccharides in BEPS were probably beneficial for the adhesion of Pb precipitation.

Asunto(s)

RESUMEN

As signal molecules, auxins play an important role in mediating plant growth. Due to serious interfering substances in plants, it is difficult to accurately detect auxins with traditional solid-phase extraction methods. To improve the selectivity of sample pretreatment, a novel molecularly imprinted polymer -coated solid-phase microextraction fiber, which could be coupled directly to high-performance liquid chromatography, was prepared with indole acetic acid as template molecule for the selective extraction of auxins. The factors influencing the polymer formation, such as polymerization solvent, cross-linker, and polymerization time, were investigated in detail to enhance the performance of indole acetic acid-molecularly imprinted polymer coating. The morphological and chemical stability of this molecularly imprinted polymer-coated fiber was characterized by scanning electron microscopy, infrared spectrometry, and thermal analysis. The extraction capacity of the molecularly imprinted polymer-coated solid-phase microextraction fiber was evaluated for the selective extraction of indole acetic acid and indole-3-pyruvic acid followed by high-performance liquid chromatography analysis. The linear range for indole acetic acid and indole-3-pyruvic acid was 1-100 µg/L and their detection limit was 0.5 µg/L. The method was applied to the simultaneous determination of two auxins in two kinds of tobacco (Nicotiana tabacum L and Nicotiana rustica L) samples, with recoveries range from 82.1 to 120.6%.

Asunto(s)

RESUMEN

Translation and bend of the spine in the sagittal plane during high-speed quadruped running were investigated. The effect of the two spine motions on slip between the foot and the ground was also explored. First, three simplified sagittal plane models of quadruped mammals were studied in symmetric bounding. The first model's trunk allowed no relative motion, the second model allowed only trunk bend, and the third model allowed both bend and translation. Next, torque was introduced to equivalently replace spine motion and the possibility of foot slip of the three models was analyzed theoretically. The results indicate that the third model has the least possibility of slip. This conclusion was further confirmed by simulation experiments. Finally, the conclusion was verified by the reductive model crawling robot.

RESUMEN

White rot fungi have been extensively reported to have strong adsorption capacity to heavy metal ions, whereas the knowledge of extracellular polymeric substances (EPS) from the fungus has been rarely involved. In this study, the contribution characteristics of 'the in situ EPS in Phanerochaete chrysosporium to Pb immobilization were investigated. First of all, the component and amount of EPS were investigated. It was found that the main component of EPS was carbohydrates, and highest EPS amount was produced at 5 days. In the Pb2+ immobilization experiments, EPS was demonstrated to play a more important role in immobilizing Pb2+ at lower initial Pb concentration. pH increase was beneficial for EPS to immobilize Pb. Higher EPS amount increased the Pb removal efficiency at a certain extent, while the specific uptake decreased. The Pb2+ immobilization by EPS produced at 7 days was most successful.

Asunto(s)

RESUMEN

When exposed to higher Pb(2+) concentration, Phanerochaete chrysosporium secreted higher content of oxalate and thiol compounds. An earlier and faster increase in oxalate was observed after short-term exposure, comparing with a gentle increase in the thiol compounds. In the extracellular polymeric substances (EPS) extract, more oxalate and T-SH were detected when the initial Pb(2+) was higher, and the variations were different from the situation in the culture medium. In EPS solution, the oxalate amount was more closely related with Pb than that of thiol compounds. pH condition in the whole Pb removal process by P. chrysosporium ranged from 4 to 6.5 and was more beneficial for the binding of Pb(2+) to carboxylic groups in the oxalic acid. More Pb(2+) induced more EPS amount, and the increase of EPS amount influenced the immobilized oxalate more seriously. The present study can supply more comprehensive information about the metal passivation mechanism in white-rot fungi and provide meaningful references for an enhanced removal of heavy metals.

Asunto(s)

RESUMEN

The aim of this study was to develop a low-cost and environmental friendly treatment method for the removal of cationic dye from wastewater. Rice straw powder combined with the white rot fungus Phanerochaete chrysosporium (P. chrysosporium) were used to remove methylene blue (MB) from wastewater at varied operational conditions. Results demonstrated that this combined biodegradation and adsorption method was effective for the removal of MB from aqueous solutions; a maximum removal efficiency of 88 % was achieved for an initial dye concentration of 400 mg/L. Of the total removed MB, 28.4 % was biodegraded by P. chrysosporium, and the rest was adsorbed on the biodegraded rice straw and the fungal cells. The amount of total adsorbed MB in the treatment group (400 mg/L) is almost three times of that in the control without P. chrysosporium group. This significant improvement in the adsorption capacity is mainly because P. chrysosporium increased the specific surface area of the straw and produced more functional groups on it. Besides, P. chrysosporium also affect the pH in a positive way for the adsorption.

Asunto(s)

RESUMEN

The degradation of methylene blue (MB) by semi-solid-state fermentation of agricultural residues rice straw with Phanerochaete chrysosporium and the reutilization of fermented residues was investigated. A maximum decolorization of 84.8% for an initial dye concentration of 0.4 g/L was observed at the optimal operating conditions (temperature 35 °C, pH 5). As compared to the previous results obtained using synthetic materials as substrate, the results in the present study revealed an excellent performance of the bioreactor in decolorizing the wastewater containing MB, which is due to this type of cultivation reproducing the natural living conditions of the white rot fungi. Among the two ligninolytic enzymes that are responsible to the decolorization, manganese peroxidase (MnP) activity was found better correlated with decoloration percentage. Our results also provide a first step to recycling the fermented residues for the removal of MB from aqueous solutions, the maximum adsorption capacity of the fermented residues reached 51.4 mg/g.

Asunto(s)

RESUMEN

Extensive studies have been operated on the biosorption of heavy metal using white-rot fungi, whereas information on the stability of the sorbed metal species has never been taken into consideration, which is important for the later disposal of the used biomass. In this study, the growing cells of Phanerochaete chrysosporium were used to remove Pb from the fungal living environment. The bioremoval of Pb proceeded continually until 121 h. The bioremoved Pb was found to be stabilized at the first time P. chrysosporium was exposed to Pb ions. The extractable rate of removed Pb decreased constantly and kept at a stable level around 20 % after 121 h. The results indicated that the growing biomass is efficient for the stabilization of Pb, and the used biomass was suitable to be separated for further disposal at 121 h. With environment scanning electron microscopy coupled with energy-dispersive X-ray analysis (ESEM-EDAX) and X-ray powder diffraction (XRD) analysis, the stabilized Pb species were identified to be lead oxalate and lead chloride phosphate. Further, it is found that the stabilization of Pb by growing P. chrysosporium is not strictly limited in the aspect of pH when pH in the environment is in the range of 4-6.

Asunto(s)

RESUMEN

Among the technologies for heavy metal remediation, bioremediation technology has gained extensive attention because of its low processing costs and high efficiency. The white-rot fungus Phanerochaete chrysosporium (P. chrysosporium) which has a good tolerance to heavy metals has been widely used in the heavy metal bioremediation. In order to figure out the molecular mechanisms involved in the oxidative stress of P. chrysosporium against metal toxicity, we examined the effect of Pb(2+) on the levels of reactive oxygen species and the production of malondialdehyde. Results showed that P. chrysosporium could adjust Pb-stressed condition by regulating the unique oxidation-antioxidation process in cells and kept a balance between oxidation and antioxidation when it was threatened by a different dose of Pb(2+). Investigations into the oxidative stress of P. chrysosporium to lead could not only provide a better understanding of the relationship between lead and oxidative stress in P. chrysosporium, but also offer important informations on the development of fungal-based remediation technologies to reduce the toxic effects of lead.

Asunto(s)

RESUMEN

This study examines the role of oxalic acid in the uptake of Cd and participation in detoxification process in Phanerochaete chrysosporium. Cd-induced oxalic acid secretion was observed with growth inhibition and enzyme inactivation (LiP and MnP) of P. chrysosporium. The peak value of oxalic acid concentration was 16.6 mM at initial Cd concentration of 100 mg L(-1). During the short-term uptake experiments, the uptake of Cd was enhanced and accelerated in the presence of oxalic acid and resulted in alleviated growth and enzyme inhibition ratios. The formation of a metal-oxalate complex therefore may provide a detoxification mechanism via effect on metal bioavailability, whereby many fungi can survive and grow in environments containing high concentrations of toxic metals. The present findings will advance the understanding of fungal resistance to metal stress, which could show promise for a more useful application of microbial technology in the treatment of metal-polluted waste.

Asunto(s)

RESUMEN

Gold-cellobiose nanocomposites (GCNCs) were synthesized by reducing gold salt with a polysaccharide, cellobiose. Here, cellobiose acted as a controller of nucleation or stabilizer in the formation of gold nanoparticles. The obtained GCNCs were characterized with UV-visible spectroscopy; Zetasizer and Fourier transform infrared (FT-IR) spectrophotometer. Moreover, 6-Mercapto-1-hexanol (MCH) was modified on GCNCs, and the MCH-GCNCs were used to determine the cellobiase activity in compost extracts based on the surface plasmon resonance (SPR) property of MCH-GCNCs. The degradation of cellobiose on MCH-GCNCs by cellobiase could induce the aggregation, and the SPR absorption wavelength of MCH-GCNCs correspondingly red shifted. Thus, the absorbance ratio of treated MCH-GCNCs (A650/A520) could be used to estimate the cellobiase activity, and the probe exhibited highly sensitive and selective detection of the cellobiase activity with a wide linear from 3.0 to 100.0U L(-1) within 20 min. Meanwhile, a good linear relationship with correlation coefficient of R2=0.9976 was obtained. This approach successfully showed the suitability of gold nanocomposites as a colorimetric sensor for the sensitive and specific enzyme activity detection.

Asunto(s)

RESUMEN

Phanerochaete chrysosporium are known to be vital hyperaccumulation species for heavy metal removal with admirable intracellular bioaccumulation capacity. This study analyzes the heavy metal-induced glutathione (GSH) accumulation and the regulation at the intracellular heavy metal level in P. chrysosporium. P. chrysosporium accumulated high levels of GSH, accompanied with high intracellular concentrations of Pb and Cd. Pb bioaccumulation lead to a narrow range of fluctuation in GSH accumulation (0.72-0.84 µmol), while GSH plummeted under Cd exposure at the maximum value of 0.37 µmol. Good correlations between time-course GSH depletion and Cd bioaccumulation were determined (R (2) > 0.87), while no significant correlations have been found between GSH variation and Pb bioaccumulation (R (2) < 0.38). Significantly, concentration-dependent molar ratios of Pb/GSH ranging from 0.10 to 0.18 were observed, while molar ratios of Cd/GSH were at the scope of 1.53-3.32, confirming the dominant role of GSH in Cd chelation. The study also demonstrated that P. chrysosporium showed considerable hypertolerance to Pb ions, accompanied with demand-driven stimulation in GSH synthesis and unconspicuous generation of reactive oxygen stress. GSH plummeted dramatically response to Cd exposure, due to the strong affinity of GSH to Cd and the involvement of GSH in Cd detoxification mechanism mainly as Cd chelators. Investigations into GSH metabolism and its role in ameliorating metal toxicity can offer important information on the application of the microorganism for wastewater treatment.

Asunto(s)

RESUMEN

The production of oxalate at different initial Pb(2+) concentrations during solid-state fermentation of straw with Phanerochaete chrysosporium was investigated. It was found that the maximal peak value of oxalate concentration (22.84 mM) was detected at the initial Pb(2+) concentration of 200 mg kg(-1) dry straw, while the minimum (15.89 mM) at the concentration of 600 mg Pb(2+)kg(-1) dry straw, and at moderate concentration of Pb(2+) the capability of oxalic acid secretion was enhanced. In addition, it was also found that more oxalic acid accumulation went together with better Pb(2+) passivation effect and higher manganese peroxidase (MnP) activity. The present findings will improve the understandings of the interactions of heavy metals with white-rot fungi and the role of oxalate in lignin degradation system, which could provide useful references for more efficient treatment of Pb-contaminated lignocellulosic waste.

Asunto(s)