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1.
Emulsification of Surfactant on Oil Droplets by Molecular Dynamics Simulation.
Cheng, Y, Yuan, S
Molecules (Basel, Switzerland). 2020;(13)
Abstract
Heavy oil in crude oil flooding is extremely difficult to extract due to its high viscosity and poor fluidity. In this paper, molecular dynamics simulation was used to study the emulsification behavior of sodium dodecyl sulfonate (SDSn) micelles on heavy oil droplets composed of asphaltenes (ASP) at the molecular level. Some analyzed techniques were used including root mean square displacement, hydrophile-hydrophobic area of an oil droplet, potential of mean force, and the number of hydrogen bonds between oil droplet and water phase. The simulated results showed that the asphaltene with carboxylate groups significantly enhances the hydration layer on the surface of oil droplets, and SDSn molecules can change the strength of the hydration layer around the surface of the oil droplets. The water bridge structure between both polar heads of the surfactant was commonly formed around the hydration layer of the emulsified oil droplet. During the emulsification of heavy oil, the ratio of hydrophilic hydrophobic surface area around an oil droplet is essential. Molecular dynamics method can be considered as a helpful tool for experimental techniques at the molecular level.
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2.
Reductive decolorization of azo dyes via in situ generation of green tea extract-iron chelate.
Yu, L, Qiu, Y, Yu, Y, Wang, S
Environmental science and pollution research international. 2018;(18):17300-17309
Abstract
In this study, rapid decolorization of azo dyes was achieved by in situ-generated green tea extract-iron (GTE-Fe) chelate for the first time. When changing reaction conditions from the aerobic condition to the anaerobic condition, the decolorization efficiencies of two azo dyes, i.e., acid orange 7 (AO7) and acid black 1 (AB1), increased from 46.38 and 83.17 to 90.13 and 95.37%, respectively. The recalcitrant AO7 was then selected as the targeting pollutant in subsequent optimization and mechanism studies. Experimental evidences showed that the initial concentrations of AO7, Fe(III), and GTE are the key factors to optimize the decolorization efficiency. Further characterization studies by spectroscopic analysis, including FESEM, FTIR, and XPS, suggested that the major mechanism of AO7 decolorization is the nucleophilic attack of the oxygen in green tea polyphenols (GTP), and this attack could be facilitated by the organometal chelation. This study provided an efficient and environmental friendly strategy to decolorize azo dyes via in situ generation of the GTE-Fe chelate, as well as its mechanistic insights, shedding lights on in situ remediation of azo dye pollution. Graphical abstract ᅟ.
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3.
Comparative study of Cu-based bimetallic oxides for Fenton-like degradation of organic pollutants.
Wang, Q, Ma, Y, Xing, S
Chemosphere. 2018;:450-456
Abstract
In order to provide useful information for the rational design of effective Fenton-like catalyst, a series of Cu-based bimetallic oxides were synthesized and their Fenton-like performances for the degradation of Orange II and ciprofloxacin were compared. The structure, chemical oxidation state, surface charge property and redox ability of the catalysts were also investigated by different characterization techniques. Among them, NiCu exhibited the highest adsorption capacity towards Orange II and the highest activity for the production of OH from H2O2 decomposition, which could be attributed to its high surface area and highly positively charged surface. However, FeCu exhibited the highest activity for the degradation of Orange II. The reason might be that FeCu has more unpaired electrons and higher redox ability, thus promoting the activation of adsorbed Orange II through the electron transfer process. By contrast, NiCu exhibited the highest activity for the removal of ciprofloxacin because ciprofloxacin was mainly degraded by OH. Finally, the main degradation intermediates of Orange II and ciprofloxacin were determined by liquid chromatography-mass spectrometry.
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4.
Degradation of Acid Orange 7 by peroxymonosulfate activated with the recyclable nanocomposites of g-C3N4 modified magnetic carbon.
Guo, F, Lu, J, Liu, Q, Zhang, P, Zhang, A, Cai, Y, Wang, Q
Chemosphere. 2018;:297-307
Abstract
Carbon-based catalysts have attracted high attention since they are greener and cheaper, while magnetic nanomaterials are very useful in environmental application because of the easy recovery and operation given by the magnetic separability. Therefore, graphitic carbon nitride modified magnetic carbon nanocomposites Fe3O4@C/g-C3N4 was prepared herein for the first time as a new carbon-based catalyst for the activation of peroxymonosulfate (PMS). The catalytic properties of Fe3O4@C/g-C3N4 in activating PMS for the degradation of Acid Orange 7 (AO 7), a model organic pollutant, were investigated. AO 7 degradation efficiency was significantly enhanced after modification of Fe3O4@C with g-C3N4, and the composite Fe3O4@C/g-C3N4 from loading of 5 wt% g-C3N4 and calcined at 300 °C for 30 min exhibited the best performance. AO 7 could be efficiently decolorized using the "Fe3O4@C/C3N4 (5%) + PSM" system within the pH range of 2-6, and 97% of AO 7 could be removed in 20 min without pH adjustment (pH = 4). Radical quenching and EPR studies confirmed that both sulfate and hydroxyl radicals produced from PMS activation were the active species responsible for the oxidation of AO 7. The degradation mechanism was suggested based on the experimental results and XPS analyses. It was proposed that the CO groups on the carbon surface of Fe3O4@C rather than the CO in g-C3N4 played a key role as the active sites for PMS activation. The catalyst was magnetically separable and displayed good stability and reusability, thus providing a potentially green catalyst for sustainable remediation of organic pollutants.
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5.
Biodegradation of phenol, salicylic acid, benzenesulfonic acid, and iomeprol by Pseudomonas fluorescens in the capillary fringe.
Hack, N, Reinwand, C, Abbt-Braun, G, Horn, H, Frimmel, FH
Journal of contaminant hydrology. 2015;:40-54
Abstract
Mass transfer and biological transformation phenomena in the capillary fringe were studied using phenol, salicylic acid, benzenesulfonic acid, and the iodinated X-ray contrast agent iomeprol as model organic compounds and the microorganism strain Pseudomonas fluorescens. Three experimental approaches were used: Batch experiments (uniform water saturation and transport by diffusion), in static columns (with a gradient of water saturation and advective transport in the capillaries) and in a flow-through cell (with a gradient of water saturation and transport by horizontal and vertical flow: 2-dimension flow-through microcosm). The reactors employed for the experiments were filled with quartz sand of defined particle size distribution (dp=200...600 μm, porosity ε=0.42). Batch experiments showed that phenol and salicylic acid have a high, whereas benzenesulfonic acid and iomeprol have a quite low potential for biodegradation under aerobic conditions and in a matrix nearly close to water saturation. Batch experiments under anoxic conditions with nitrate as electron acceptor revealed that the biodegradation of the model compounds was lower than under aerobic conditions. Nevertheless, the experiments showed that the moisture content was also responsible for an optimized transport in the liquid phase of a porous medium. Biodegradation in the capillary fringe was found to be influenced by both the moisture content and availability of the dissolved substrate, as seen in static column experiments. The gas-liquid mass transfer of oxygen also played an important role for the biological activity. In static column experiments under aerobic conditions, the highest biodegradation was found in the capillary fringe (e.g. βt/β0 (phenol)=0 after t=6 d) relative to the zone below the water table and unsaturated zone. The highest biodegradation occurred in the flow-through cell experiment where the height of the capillary fringe was largest.
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6.
Removal of methyl orange on modified ostrich bone waste--a novel organic-inorganic biocomposite.
Arshadi, M, Faraji, AR, Amiri, MJ, Mehravar, M, Gil, A
Journal of colloid and interface science. 2015;:11-23
Abstract
The synthesis and growth behavior of the chemically modified ostrich bone wastes as bioadsorbents for the removal of methyl orange from aqueous solutions have been investigated. The ostrich bone wastes were treated with cetyltrimethylammonium bromide (CTABr) and sodium dodecyl benzene sulfonate (SDBS). The synthesized biomaterials were characterized by several physicochemical techniques. The modified ostrich bone with CTABr was found to be effective as adsorbent for the removal of methyl orange (MO) from aqueous solutions. The effect of the experimental conditions on the adsorption behavior was studied by varying the contact time, initial MO concentration, temperature, initial pH, chemical modification process, and amount of adsorbent. The contact time to attain equilibrium for maximum adsorption (90%) was found to be 50 min. The adsorption kinetics of MO has been studied in terms of pseudo-first- and -second-order kinetics, and the Freundlich, Langmuir and Langmuir-Freundlich isotherm models have also been applied to the equilibrium adsorption data. The adsorption process was spontaneous and endothermic in nature and followed pseudo-second-order kinetic model.
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7.
MRI assessment of early tumor response in metastatic renal cell carcinoma patients treated with sorafenib.
Kang, HC, Tan, KS, Keefe, SM, Heitjan, DF, Siegelman, ES, Flaherty, KT, O'Dwyer, PJ, Rosen, MA
AJR. American journal of roentgenology. 2013;(1):120-6
Abstract
OBJECTIVE The purpose of this study was to examine early MRI changes in renal cell carcinoma (RCC) treated with the antiangiogenic agent sorafenib and to identify MRI biomarkers of RCC response to sorafenib. MATERIALS AND METHODS Sixteen patients with RCC were evaluated by MRI before and 3-12 weeks after commencing treatment with sorafenib. Two experienced MR radiologists, blinded to treatment status, independently graded tumor appearance on T1-weighted, T2-weighted, and gadolinium-enhanced images. The proportional odds mixed model was used to compare qualitative appearance of tumors before and after therapy. Time-to-progression was correlated with Response Evaluation Criteria in Solid Tumors (RECIST) 1.0 and MR-modified Choi criteria, incorporating changes in both tumor enhancement and size. RESULTS After sorafenib therapy, there was a significant increase in T1 signal intensity of tumors (p < 0.0001) and a significant decrease in degree of tumor enhancement (p < 0.0001). The sum of unidimensional tumor diameters decreased significantly after therapy (p = 0.005). However, the average decrease in size at early follow-up was 13%, and all patients except one had stable disease by RECIST 1.0. Early responders defined by MR-modified Choi criteria had increased time-to-progression compared with nonresponders, whereas early RECIST evaluation did not predict clinical outcome. CONCLUSION Decreased enhancement and T1 shortening of tumors on MRI may be useful biomarkers of RCC response to angiogenesis inhibitors. Response criteria combining early changes in size and enhancement lead to better correlation with clinical outcome compared with size decrease alone.
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8.
Phase 2 Southwest Oncology Group-directed intergroup trial (S0505) of sorafenib in advanced soft tissue sarcomas.
von Mehren, M, Rankin, C, Goldblum, JR, Demetri, GD, Bramwell, V, Ryan, CW, Borden, E
Cancer. 2012;(3):770-6
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Abstract
BACKGROUND Patients with advanced soft tissue sarcomas (STS) have limited therapeutic options. Sorafenib (BAY 43-9006) is a multitargeted tyrosine kinase inhibitor of raf, vascular endothelial growth factor receptors 1 (VEGFR1) through 3, platelet-derived growth factor B, fms-like tyrosine kinase 3, and c-kit, and some of these may be relevant in STS. METHODS The authors tested sorafenib at a dose of 400 mg twice daily in patients with advanced vascular sarcoma (VS), high-grade liposarcomas, and leiomyosarcomas who had received 0 or 1 previous regimens for advanced disease. RESULTS Fifty-one patients were accrued to the study, and 37 were evaluable for toxicity and response. There were no unexpected side effects and no confirmed responses. The median progression-free survival was 3 months, and the median overall survival was 17 months. Six of 8 patients in the VS cohort had prolonged clinical benefit (stable disease or better), resulting in a median progression-free survival of 5 months compared with 2 to 3 months for the patients who had liposarcoma and leiomyosarcomas. CONCLUSIONS Sorafenib at the dose and schedule studied did not result in any responses in the VS, liposarcoma, or leiomyosarcoma cohort according to Response Evaluation Criteria in Solid Tumors.
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9.
The efficacy of hepatic arterial infusion chemotherapy as an alternative to sorafenib in advanced hepatocellular carcinoma.
Jeong, SW, Jang, JY, Lee, JE, Lee, SH, Kim, SG, Cha, SW, Kim, YS, Cho, YD, Kim, HS, Kim, BS, et al
Asia-Pacific journal of clinical oncology. 2012;(2):164-71
Abstract
AIMS: Sorafenib is the only systemic treatment shown to be effective against advanced hepatocellular carcinoma (HCC). Hepatic arterial infusion chemotherapy (HAIC) has been selected as an alternative therapeutic option for advanced HCC. We investigated the efficacy and safety of HAIC as an alternative treatment for sorafenib in advanced HCC. METHODS Between May 2008 and March 2011, 20 consecutive patients were treated with sorafenib monotherapy as a first-line treatment and 21 consecutive patients who could not take sorafenib because of cost were treated with HAIC monotherapy as an alternative. Sorafenib was administered in 400 mg b.i.d. doses. For HAIC, daily cisplatin (7 mg/m(2) on days 1-5) and 5-FU (170 mg/m(2) on days 1-5) were infused every 4 weeks. We assessed overall survival (OS), progression-free survival (PFS), objective response rate (ORR) and toxicity. RESULTS Median OS was 4.9 months (95% CI, 3.4-6.4) for sorafenib and 7.3 months (95% CI, 4.5-10.2) for HAIC (P = 0.599). Median PFS was 2.0 months (95% CI, 1.96-2.05) versus 3.0 months (95% CI, 1.98-4.02) for sorafenib and HAIC, respectively (P = 0.303). ORR and disease control rate (DCR) for sorafenib were 10.0 and 35.0% versus 19.0 and 38.1% for HAIC (ORR, P = 0.413; DCR, P = 0.837). Patients treated with HAIC more frequently exhibited grade 3/4 neutropenia (23.8 vs 0% for sorafenib), whereas sorafenib therapy showed grade 3/4 hand-foot skin reaction in 10% of patients. CONCLUSION HAIC is a useful alternative treatment for advanced HCC and further prospective investigations are required.
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10.
A phase II trial of sorafenib in relapsed and unresectable high-grade osteosarcoma after failure of standard multimodal therapy: an Italian Sarcoma Group study.
Grignani, G, Palmerini, E, Dileo, P, Asaftei, SD, D'Ambrosio, L, Pignochino, Y, Mercuri, M, Picci, P, Fagioli, F, Casali, PG, et al
Annals of oncology : official journal of the European Society for Medical Oncology. 2012;(2):508-16
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Abstract
PURPOSE After standard multimodal therapy, the prognosis of relapsed and unresectable high-grade osteosarcoma is dismal and unchanged over the last decades. Recently, mitogen-activated protein kinases were shown to be activated in osteosarcoma specimens, suggesting, therefore, they are suitable targets for the multikinase inhibitor sorafenib. Thus, we explored sorafenib activity in patients with relapsed and unresectable osteosarcoma. EXPERIMENTAL DESIGN Patients > 14 years, progressing after standard treatment, were eligible to receive 400 mg of sorafenib twice daily until progression or unacceptable toxicity. The primary end point was progression-free survival (PFS) at 4 months. Secondary objectives were PFS, overall survival (OS), clinical benefit rate (CBR), defined as no progression at 6 months and safety. This nonrandomized phase II study used a Simon two-stage design. PFS and OS at 95% confidence intervals (95% CIs) were calculated by the Kaplan-Meier method. All tests were two sided. RESULTS Thirty-five patients were enrolled. PFS at 4 months was 46% (95% CI 28% to 63%). Median PFS and OS were 4 (95% CI 2-5) and 7 (95% CI 7-8) months, respectively. The CBR was 29% (95% CI 13% to 44%). We observed 3 (8%) partial responses (PRs), 2 (6%) minor responses (< 30% tumor shrinkage) and 12 (34%) stable diseases (SDs). For six patients (17%), PR/SD lasted ≥ 6 months. Noteworthy, tumor density reduction and [(18)F]2-fluoro-2-deoxy-d-glucose-positron emission tomography responses were observed among SD patients. Sorafenib was reduced or briefly interrupted in 16 (46%) patients and permanently discontinued in one (3%) case due to toxicity. CONCLUSIONS Sorafenib demonstrated activity as a second- or third-line treatment in terms of PFS at 4 months with some unprecedented long-lasting responses. Sorafenib, the first targeted therapy showing activity in osteosarcoma patients, deserves further investigations.