Preparation of Carbon-Based Solid Acid Catalyst from High-Sulfur Petroleum Coke with Nitric Acid and Ball Milling, and a Computational Evaluation of Inherent Sulfur Conversion Pathways.

A series of petroleum coke (petcoke)-derived solid acid catalysts were prepared via nitric acid treatment with or without ball milling pretreatment. The inherent sulfur in petcoke was converted to sulfonic groups, which were active sites for the esterification of octanoic acid and methanol at 60 °C, with ester yields of 14-43%. More specifically, samples without ball milling treated at 120 °C for 3 h had a total acidity of 4.67 mmol/g, which was 1.6 times that of the samples treated at 80 °C, despite their -SO3H acidities being similar (~0.08 mmol/g). The samples treated for 24 h had higher -SO3H (0.10 mmol/g) and total acidity (5.25 mmol/g) but not increased catalytic activity. Ball milling increased the defects and exposed aromatic hydrogen groups on petcoke, which facilitated further acid oxidation (0.12 mmol -SO3H/g for both materials and total acidity of 5.18 mmol/g and 5.01 mmol/g for BP-N-3/120 and BP-N-8/90, respectively) and an increased ester yield. DFT calculations were used to analyze the pathways of sulfonic acid group formation, and the reaction pathway with NO2• was the most thermodynamically and kinetically favourable. The activities of the prepared catalysts were related to the number of -SO3H acid sites, the total acidity, and the oxygen content, with the latter two factors having a negative impact.

Patient-centredness in primary care walk-in clinics for refugees in Hamburg.

BACKGROUND: The huge increase of refugees to Germany caused a great challenge to the health system. We aimed to examine the level of patient-centredness in medical consultations with refugee patients, aided by video interpreters in primary care walk-in clinics (PCWC) in Hamburg. METHODS: Videotaped consultations (N = 92) of 83 patients from 2017 to 2018 were analysed. Two raters used the Measure of Patient-Centered Communication (MPCC) and the International Classification of primary care (ICPC-2). MPCC scores with regard to patients' reason for seeking medical care and the procedures taken were explored using variance analyses adjusted for age, gender, and the duration of the consultation. The duration was further explored by Pearson correlations. RESULTS: Patient-centredness of all consultations on average was 64% (95% CI 60-67) according to MPCC, with health-related issues affecting the results. The highest level of patient-centredness was achieved in psychological health issues with 79% (65-94), the lowest in respiratory ones with 55% (49-61). Longer consultations resulted in higher MPCC scores. CONCLUSIONS: The level of patient-centredness varied in the addressed health issues as well as in the duration of the consultation. Despite the variation, video interpreting in consultations supports a solid patient-centredness. PRACTICE IMPLICATIONS: We recommend the use of remote video interpreting services for outpatient healthcare to support patient-centred communication and to fill the gap of underrepresentation of qualified interpreters on site, regarding a high diversity of spoken languages.

Sulphur retention and in-situ preparation of metal sulphide catalysts during activation of petroleum coke.

Petroleum coke (petcoke) containing sulphur has limited direct applications, but stockpiling the material creates an environmental issue. Although chemical activation can be used to valorise the petcoke to activated carbon, sulphur is released creating alternative environmental problems. In this study, a new activation method for high sulphur content (∼6.5 wt%) petcoke was developed to retain sulphur and prepare transition metal sulphide catalysts simultaneously. Petcoke was mixed with tungsten and nickel precursors and then activated by KOH at 600 °C in the presence of steam. After washing, the activated petcoke had a sulphur content of 5.1 wt%, which was much higher than that in the absence of steam during activation (0.4 wt%). Sulphur was also retained (>4 wt% of sulphur) when other transition metals including molybdenum and cobalt were used. Characterization by XRD, XPS, and SEM-EDS suggested that sulphur was retained on the activated petcoke in the form of metal sulphides. Further thermodynamic analysis of the system revealed that in the presence of steam an H2S/H2 mixture was generated, and this mixture promoted the formation of the metal sulphide species when metal precursors were introduced. The prepared metal sulphide catalysts were active for several reactions including the photoreduction of CO2. Overall, this study provided an effective method to prepare metal sulphide catalysts from sulphur containing carbonaceous waste.

Regeneration of dye-saturated activated carbon through advanced oxidative processes: A review.

Activated carbon (AC) is a porous carbon-rich material that is widely used to remove pollutants, such as synthetic dyes, from contaminated water. Although quite efficient, the use of this technology is limited to the ability of the AC to be regenerated and/or reused. Conventional regeneration procedures are inefficient, requiring the development and/or implementation of new approaches. Advanced Oxidative Processes (AOP) have unique properties that result in high efficiency in wastewater treatment. The use of these technologies in the regeneration of AC has gained considerable prominence due to the ability to remove organic pollutants concentrated in the AC. During this process, the oxidizing species produced interact with the substrates adsorbed on the AC, in a non-selective way, mineralizing them and/or reducing their recalcitrance. Although widely used in wastewater treatment, few reviews focus on the use of AOP as AC regeneration technology, causing an insufficient exchange of information and ideas for strategic development in this area. Therefore, in this review, the authors present an overview of the use of some AOP (Photolysis, Peroxidation, Fenton reaction and Advanced electrochemical oxidative processes) when applied in regeneration of dye-saturated AC, including the mechanisms involved in the different processes, the general aspects that affect individual processes and the different methods established to quantify the effectiveness of regeneration.

Empowerment in cancer patients: Does peer support make a difference? A systematic review.

OBJECTIVE: Empowerment is critical for cancer patients to make informed choices, to manage medication, and to navigate through the oncological care system. Cancer peer support provides patients with information, emotional relief and may promote empowerment. This paper provides a systematic review of the literature examining the impact of cancer peer support interventions on psychological empowerment. METHODS: PubMed, Web of Science, CINAHL, Cochrane Library, PsycINFO and PSYNDEX databases were systematically searched from inception until December 2020. We included quantitative studies, published in English or German, which examined peer-led cancer support interventions and their impact on the three components of psychological empowerment (intrapersonal, interactional and behavioural) among participating cancer patients. RESULTS: Database searches and screening of relevant reference lists identified 2336 potentially relevant articles. A total of 29 studies were included in the review. Active coping, self-efficacy and knowledge were the most prominent dimensions of empowerment in these studies. The majority of studies revealed that peer support led to a small to medium, significant increase in psychological empowerment, and was associated with further patient-reported benefits. CONCLUSIONS: The existing evidence suggests a weak to moderate, positive association between cancer peer support and the three components of psychological empowerment among cancer patients. Peer support groups should be seen as an important element in cancer care and clinical practice and, thus, be more systematically involved in cancer care.

Solid acid catalysts produced by sulfonation of petroleum coke: Dominant role of aromatic hydrogen.

Carbon based solid waste materials have been intensively investigated for the preparation of solid acid catalysts through sulfonation, but the acidity varies significantly depending on the material. In this study, the role of aromatic hydrogen in sulfonation with concentrated H2SO4 was investigated using petroleum coke (petcoke), graphite, and biochar as the carbon materials. Through ball milling and calcination, the amount of aromatic hydrogen on the petcoke could be increased or decreased, respectively. After sulfonation at 80 °C with concentrated H2SO4, the produced acidity (i.e., -SO3H groups) increased as the amount of aromatic hydrogen increased from essentially no acidity on graphite to 0.55 mmol/g on biochar and 1.25 mmol/g on petcoke (particle sizes of 45-90 µm) indicating the importance of aromatic hydrogen during sulfonation. Calcination (350 °C for 1 h) of the petcoke before sulfonation decreased the acidity to 0.59 mmol/g, while ball milling (with isopropanol and silica for 24 h) increased the acidity to 3.73 mmol/g. The sulfonated petcoke samples were used as catalysts for the esterification reaction between octanoic acid and methanol at 60 °C and the turnover frequencies were 48-85 h-1. The results give insights on the preparation of solid acid catalysts from carbon materials and highlight the application of petcoke without activation as a feedstock for esterification catalysts.

Phosphonium-enhanced chitosan for Cr(VI) adsorption in wastewater treatment.

Adsorption is a commonly used method for industrial wastewater treatment because of its low-cost, easy operation and high efficiency. In this work, chitosan was crosslinked and functionalized with a low-cost phosphonium salt, tetrakis(hydroxymethyl)phosphonium sulfate (THPS), to enhance its adsorption capacity for Cr(VI). The novel phosphonium-crosslinked chitosan (PCC) was characterized using elemental analysis, XRF, FTIR, NMR and SEM-EDX. At pH 6, PCC had a higher Langmuir equilibrium constant than the unmodified chitosan (0.19 ± 0.02 L mg-1 versus 0.0044 ± 0.0005 L mg-1) and PCC demonstrated higher adsorption capacity than chitosan at equilibrium Cr(VI) concentrations below 120 mg L-1. Additionally, magnesium sulfate or magnesium chloride was shown to desorb Cr(VI) and recycle PCC. When treated with THPS, chitosan is activated for Cr(VI) adsorption at pH 6; therefore, PCC can be used in wastewater treatment over a wider pH range than chitosan.

Mechanistic insights for the electro-Fenton regeneration of carbon materials saturated with methyl orange: Dominance of electrodesorption.

Adsorption followed by regeneration of the adsorbent is a sustainable way to remove pollutants from water systems. In this study, the electro-Fenton regeneration of activated carbon and mesoporous carbon loaded with magnetic γ-Fe2O3 and then saturated with an anionic adsorbate, methyl orange, has been studied. The saturated adsorbents were regenerated and the influence of several factors on the regeneration efficiency and pore structure recovery was systematically investigated. Regeneration was improved with a higher cathodic potential, better contact with the cathode, and larger pores. The addition of an electrochemical potential improved the regeneration of adsorption sites within micropores. A mathematical model based on electrostatic, solvation, and dispersion interaction energies was developed to explain the regeneration process. Cationic (methylene blue) and neutral (benzoic acid) adsorbates were also tested to further test the model predictions. Overall, the results support electro-desorption being the dominant pathway during electro-Fenton regeneration of the carbon materials, with cathodic reduction and electro-Fenton oxidation contributing a minor part to the regeneration via degradation of the desorbed methyl orange.

Benefit of Hydrophilicity for Adsorption of Methyl Orange and Electro-Fenton Regeneration of Activated Carbon-Polytetrafluoroethylene Electrodes.

Activated carbon (AC)-polytetrafluoroethylene (PTFE) electrodes were prepared and applied for methyl orange (MO) adsorption and electro-Fenton regeneration. The addition of PTFE to AC significantly decreased the hydrophilicity, which in turn, decreased both the amount of MO adsorbed and the regeneration efficiency. With the minimum amount of binder (a 7:1 mass ratio of AC to binder), the MO adsorption was 176 mg g-1. The amount adsorbed decreased to 23 mg g-1 for the electrode with a 1:1 mass ratio of AC to binder. For these ratios, the regeneration efficiencies were 81% and 49%, respectively. The adsorption kinetics were well fit by a Weber-Morris model. The diffusion rate constants obtained from this model were linearly related to the hydrophilicity of the electrode, i.e., the higher the hydrophilicity the higher the adsorption rate. Based on the results, an adsorption capacity >50 mg g-1 in 8 h with a regeneration efficiency of >70% at cathodic potential of -0.8 V (vs Ag/AgCl) can be obtained if the contact angle of water on the electrodes is lower than 90°.

Impact of Pore Size on Fenton Oxidation of Methyl Orange Adsorbed on Magnetic Carbon Materials: Trade-Off between Capacity and Regenerability.

The economic cleanup of wastewater continues to be an active area of research. In this study, the influence of pore size on regeneration by Fenton oxidation for carbon materials with adsorbed methyl orange (MO) was investigated. More specifically three carbon supports, with pore sizes ranging from mainly microporous to half microporous-half mesoporous to mainly mesoporous, were impregnated with γ-Fe2O3 to make them magnetic and easy to separate from solution. The carbon samples were characterized before adsorption and after regeneration with hydrogen peroxide at 20 °C. In addition, adsorption kinetics and isotherms were collected, and the Weber-Morris intraparticle diffusion model and Freundlich isotherm model fit to the data. The adsorption capacity increased with increasing microporosity while the regeneration efficiency increased with increasing mesoporosity. Further experiments with varying regeneration and adsorption conditions suggested that the regeneration process may be kinetically limited. The MO adsorbed in the micropores was strongly adsorbed and difficult to remove unlike the MO adsorbed in the mesopores, which could be reacted under relatively mild conditions. Thus, there was a trade-off between adsorption capacity and regeneration.

Adsorption of acid-extractable organics from oil sands process-affected water onto biomass-based biochar: Metal content matters.

The impact of biochar properties on acid-extractable organics (AEO) adsorption from oil sands process-affected water (OSPW) was studied. Biochar from wheat straw with the highest ash content (14%) had the highest adsorption capacity (0.59 mg/g) followed by biochar from pulp mill sludge, switchgrass, mountain pine, hemp shives, and aspen wood. The adsorption capacity had no obvious trend with surface area, total pore volume, bulk polarity and aromaticity. The large impact of metal content was consistent with the carboxylates (i.e., naphthenate species) in the OSPW binding to the metals (mainly Al and Fe) on the carbon substrate. Although the capacity of biochar is still approximately two orders of magnitude lower than that of a commercial activated carbon, confirming the property (i.e., metal content) that most influenced AEO adsorption, may allow biochar to become competitive with activated carbon after normalizing for cost, especially if this cost includes environmental impacts.

Removal and biodegradation of naphthenic acids by biochar and attached environmental biofilms in the presence of co-contaminating metals.

This study evaluated the efficacy of using a combined biofilm-biochar approach to remove organic (naphthenic acids (NAs)) and inorganic (metals) contaminants from process water (OSPW) generated by Canada's oil sands mining operations. A microbial community sourced from an OSPW sample was cultured as biofilms on several carbonaceous materials. Two biochar samples, from softwood bark (SB) and Aspen wood (N3), facilitated the most microbial growth (measured by protein assays) and were used for NA removal studies performed with and without biofilms, and in the presence and absence of contaminating metals. Similar NA removal was seen in 6-day sterile N3 and SB assays (>30%), while biodegradation by SB-associated biofilms increased NA removal to 87% in the presence of metals. Metal sorption was also observed, with up to four times more immobilization of Fe, Al, and As on biofilm-associated biochar. These results suggest this combined approach may be a promising treatment for OSPW.

Activation of Aspen Wood with Carbon Dioxide and Phosphoric Acid for Removal of Total Organic Carbon from Oil Sands Produced Water: Increasing the Yield with Bio-Oil Recycling.

Several samples of activated carbon were prepared by physical (CO2) and chemical (H3PO4) activation of aspen wood and tested for the adsorption of organic compounds from water generated during the recovery of bitumen using steam assisted gravity drainage. Total organic carbon removal by the carbon samples increased proportionally with total pore volume as determined from N2 adsorption isotherms at -196 °C. The activated carbon produced by CO2 activation had similar removal levels for total organic carbon from the water (up to 70%) to those samples activated with H3PO4, but lower yields, due to losses during pyrolysis and activation. A method to increase the yield when using CO2 activation was proposed and consisted of recycling bio-oil produced from previous runs to the aspen wood feed, followed by either KOH addition (0.48%) or air pretreatment (220 °C for 3 h) before pyrolysis and activation. By recycling the bio-oil, the yield of CO2 activated carbon (after air pretreatment of the mixture) was increased by a factor of 1.3. Due to the higher carbon yield, the corresponding total organic carbon removal, per mass of wood feed, increased by a factor of 1.2 thus improving the overall process efficiency.

Enhancing biochar yield by co-pyrolysis of bio-oil with biomass: impacts of potassium hydroxide addition and air pretreatment prior to co-pyrolysis.

The influence of KOH addition and air pretreatment on co-pyrolysis (600 °C) of a mixture of bio-oil and biomass (aspen wood) was investigated with the goal of increasing biochar yield. The bio-oil was produced as a byproduct of the pyrolysis of biomass and recycled in subsequent runs. Co-pyrolysis of the biomass with the recycled bio-oil resulted in a 16% mass increase in produced biochar. The yields were further increased by either air pretreatment or KOH addition prior to co-pyrolysis. Air pretreatment at 220 °C for 3 h resulted in the highest mass increase (32%) compared to the base case of pyrolysis of biomass only. No synergistic benefit was observed by combining KOH addition with air pretreatment. In fact, KOH catalyzed reactions that increased the bed temperature resulting in carbon loss via formation of CO and CO2.

Disease-associated QT-shortage versus quinine associated QT-prolongation: age dependent ECG-effects in Ghanaian children with severe malaria.

BACKGROUND: While several anti-malarials are known to affect the electric conduction system of the heart, less is known on the direct effects of Plasmodium falciparum infection. Some earlier studies point to a direct impact of Plasmodium falciparum infection on the electric conduction system of the heart. The aim of this study was to analyse infection- and drug-induced effects on the electric conduction system. METHODS: Children aged 12 months to 108 months with severe malaria were included in Kumasi, Ghana. In addition to basic demographic, clinical, biochemical and parasitological, biochemical data were measured data upon hospitalization (day 0) and 12-lead electrocardiograms were recorded before (day 0) and after (day 1) initiation of quinine therapy as well as after 42 (±3) days. RESULTS: A total of 180 children were included. Most children were tachycardic on day 0 but heart rate declined on day 1 and during follow up. The corrected QT intervals were longest on day 1 and shortest on day 0. Comparison of QT intervals with day 42 (healthy status) after stratification for age demonstrated that in the youngest (<24 months) this was mainly due to a QT shortage on day 0 while a QT prolongation on day 1 was most pronounced in the oldest (≥48 months). Nearly one third of the participating children had measurable 4-aminoquinoline levels upon admission, but no direct effect on the corrected QT intervals could be shown. CONCLUSION: Severe P. falciparum infection itself can provoke changes in the electrophysiology of the heart, independent of anti-malarial therapy. Especially in young - thus non immune - children the effect of acute disease associated pre-treatment QT-shortage is more pronounced than quinine associated QT-prolongation after therapy. Nevertheless, neither malaria nor anti-malarial induced effects on the electrophysiology of the heart were associated with clinically relevant arrhythmias in the present study population.

Pyrolysis of wood to biochar: increasing yield while maintaining microporosity.

The objective of this study was to determine if biochar yield could be increased by the deposition of volatile pyrolysis species within the bed during production, without negatively influencing the microporosity and adsorption properties. Aspen (Populus tremuloides) wood chips were loaded into three vertically stacked zones within a reactor and heated in nitrogen to temperatures between 420 and 650°C (i.e., pyrolyzed). The yield did increase from the zone at the reactor inlet to the subsequent zones as volatile species deposited and carbonized, and importantly, the carbonized deposits had a similar microporous structure and organic vapor uptake (1,1,1,2-tetrafluoroethane) to that of the primary biochar. Based on these results, bio-oil from previous runs at 600°C was recycled to the bed, which further increased the yield while maintaining the desirable adsorption properties of the biochar.

IFT80, which encodes a conserved intraflagellar transport protein, is mutated in Jeune asphyxiating thoracic dystrophy.

Jeune asphyxiating thoracic dystrophy, an autosomal recessive chondrodysplasia, often leads to death in infancy because of a severely constricted thoracic cage and respiratory insufficiency; retinal degeneration, cystic renal disease and polydactyly may be complicating features. We show that IFT80 mutations underlie a subset of Jeune asphyxiating thoracic dystrophy cases, establishing the first association of a defective intraflagellar transport (IFT) protein with human disease. Knockdown of ift80 in zebrafish resulted in cystic kidneys, and knockdown in Tetrahymena thermophila produced shortened or absent cilia.

Molecular motors implicated in the axonal transport of tau and alpha-synuclein.

Tau and alpha-synuclein are both proteins implicated in the pathology of neurodegenerative disease. Here we have investigated the mechanisms of axonal transport of tau and alpha-synuclein, because failure of axonal transport has been implicated in the development of several neurodegenerative disorders. We found that the transport of both of these proteins depend on an intact microtubule- but not actin-cytoskeleton, and that tau and alpha-synuclein both move at overall slow rates of transport. We used time-lapse video microscopy to obtain images of live neurons that had been transfected with plasmids expressing proteins tagged with enhanced green fluorescent protein. We found that particulate structures containing tau or alpha-synuclein travel rapidly when moving along axons but spend the majority of the time paused, and these structures have similar characteristics to those previously observed for neurofilaments. The motile particles containing tau or alpha-synuclein colocalise with the fast-transporting molecular motor kinesin-1 in neurons. Co-immunoprecipitation experiments demonstrate that tau and alpha-synuclein are each associated with complexes containing kinesin-1, whereas only alpha-synuclein appears to interact with dynein-containing complexes. In vitro glutathione S-transferase-binding assays using rat brain homogenate or recombinant protein as bait reveals a direct interaction of kinesin-1 light chains 1 and 2 with tau, but not with alpha-synuclein. Our findings suggest that the axonal transport of tau occurs via a mechanism utilising fast transport motors, including the kinesin family of proteins, and that alpha-synuclein transport in neurons may involve both kinesin and dynein motor proteins.

Disruption of Bardet-Biedl syndrome ciliary proteins perturbs planar cell polarity in vertebrates.

The evolutionarily conserved planar cell polarity (PCP) pathway (or noncanonical Wnt pathway) drives several important cellular processes, including epithelial cell polarization, cell migration and mitotic spindle orientation. In vertebrates, PCP genes have a vital role in polarized convergent extension movements during gastrulation and neurulation. Here we show that mice with mutations in genes involved in Bardet-Biedl syndrome (BBS), a disorder associated with ciliary dysfunction, share phenotypes with PCP mutants including open eyelids, neural tube defects and disrupted cochlear stereociliary bundles. Furthermore, we identify genetic interactions between BBS genes and a PCP gene in both mouse (Ltap, also called Vangl2) and zebrafish (vangl2). In zebrafish, the augmented phenotype results from enhanced defective convergent extension movements. We also show that Vangl2 localizes to the basal body and axoneme of ciliated cells, a pattern reminiscent of that of the BBS proteins. These data suggest that cilia are intrinsically involved in PCP processes.