Long-term evaluation of palm oil mill effluent (POME) steam reforming over lanthanum-based perovskite oxides

To replace the obsolete ponding system, palm oil mill effluent (POME) steam reforming (SR) over net-acidic LaNiO3 and net-basic LaCoO3 were proposed as the POME primary treatments, with promising H2-rich syngas production. Herein, the long-term evaluation of POME SR was scrutinized with both catalysts under the optimal conditions (600 °C, 0.09 mL POME/min, 0.3 g catalyst, & 74–105 μm catalyst particle size) to examine the catalyst microstructure changes, transient process stability, and final effluent evaluation. Extensive characterization proved the (i) adsorption of POME vapour on catalysts before SR, (ii) deposition of carbon and minerals on spent SR catalysts, and (iii) dominance of coking deactivation over sintering deactivation at 600 °C. Despite its longer run, spent LaCoO3 (50.54 wt%) had similar carbon deposition with spent LaNiO3 (50.44 wt%), concurring with its excellent coke resistance. Spent LaCoO3 (6.12 wt%; large protruding crystals) suffered a harsher mineral deposition than spent LaNiO3 (3.71 wt%; thin film coating), confirming that lower reactivity increased residence time of reactants. Transient syngas evolution of both SR catalysts was relatively steady up to 4 h but perturbed by coking deactivation thereafter. La2O2CO3 acted as an intermediate species that hastened the coke removal via reverse Boudouard reaction upon its decarbonation. La2O2CO3 decarbonation occurred continuously in LaCoO3 system but intermittently in LaNiO3 system. LaNiO3 system only lasted for 13 h as its compact ash blocked the gas flow. LaCoO3 system lasted longer (17 h) with its porous ash, but it eventually failed because KCl crystallites blocked its active sites. Relatively, LaCoO3 system offered greater net H2 production (72.78%) and POME treatment volume (30.77%) than LaNiO3 system. SR could attain appreciable POME degradation (>97% COD, BOD5, TSS, & colour intensity). Withal, SR-treated POME should be polished to further reduce its incompliant COD and BOD5

Physicochemical, sensorial and antioxidant properties of sardine fish patties incorporated with different natural additives

Sardine fish patty is a processed seafood product that easily spoiled because of oxidation. Oregano, cloves, cinnamon, turmeric, and green tea contain antioxidant properties that could preserve the fish patty. This study aimed to incorporate these ingredients into sardine fish patties and investigate their effects on the physicochemical properties, sensory evaluation, and lipid oxidation of the patties. The fresh sardine patties were treated with 0.5% of oregano (PWO), cloves (PWC), cinnamon (PWCI), turmeric (PWT) or green tea (PWGT) before being cooked, cooled and chill-stored for 12 days. No significant effects of the treatments were observed on moisture content, cooking yield, and shrinkage of the patties. The incorporation of turmeric significantly (P<0.05) affected all colour parameters on the patties (PWT). Although PWGT showed slightly increased values in some texture profiling parameters, the PWGT also showed positive acceptability regarding sensory evaluation for most of the eating quality parameters. A significant (P<0.05) reduction in TBARS values in the patties incorporated with green tea (PWGT), while increased scavenging activity values of the PWGT and cloves (PWC) were observed. Thus, the study implied that green tea demonstrated a good effect on sardine fish patty, as compared to spices, which could be a potential natural preservative to preserve the fish product during storage

State-of-the-art of the synthesis and applications of sulfonated carbon-based catalysts for biodiesel production: a review

Sulfonated carbon-based catalysts (SCC) are favorable heterogeneous acids for acid-catalyzed reactions including esterification and transesterification for biodiesel production. They are covalently functionalized with SO3H groups via CPhSO3H or CSO3H linkages with special carbon structures. To date, the types of SCC for biodiesel production ranges from biochar (BC), activated carbon (AC), graphene, graphite oxides, multiwalled carbon nanotubes, order mesoporous carbon, and graphitic carbon nitride. Lignocellulosic and biomass wastes are important carbon precursors for low-cost BC and AC production. This review critically reviews and summarizes the most up-to-date research progress in the evolution of SCC for biodiesel production. Systematic discussions and comparisons on the different carbon materials, preparation methods, and sulfonation preparation parameters which directly affect the physicochemical attributes and catalytic performance are provided. The applications and reusability studies of these materials in biodiesel production are also included. Finally, the challenges to be addressed and future prospects of the research direction on the applications of SCC for biodiesel production are discussed

Effective removal of Pb(II) by low-cost fibrous silica KCC-1 synthesized from silica-rich rice husk ash

Rice husk ash was utilized as a low-cost silica precursor in preparing KCC-1(RHA) for Pb(II) removal. The characterization results revealed the comparable properties of KCC-1(RHA) with the conventional KCC-1. The optimum adsorption conditions were achieved at initial concentration of 322.06 mg/L, adsorbent dosage of 2.4 g/L, and time of 117 min, with Pb(II) removal of 75%. The experimental results followed the pseudo-second-order kinetic model (R2 ≥ 0.9950) and Langmuir isotherm model (R2 = 0.9934). The KCC-1(RHA) showed good performance during five cycles of adsorption-desorption, thus, affirmed great potential of RHA as silica precursor in synthesizing KCC-1(RHA) for excellent Pb(II) removal

Egg-shell Treated Oil Palm Fronds (EG-OPF) as Low-Cost Adsorbent for Methylene Blue Removal

A new adsorbent (egg-shell treated oil palm fronds (EG-OPF)) prepared from wastes was evaluated for methylene blue (MB) removal. Optimization among three significant variables (initial concentration (X1), initial pH (X2), and adsorbent dosage (X3)) were executed using response surface methodology (RSM). The most excellent performance was marked at X1 = 291.7 mg/L, X2 = pH 5, and X3 = 1.82 g/L, with MB removal of 80.26 %. The kinetic study was fitted perfectly with the pseudo-second-order model (R2 > 0.990), indicating the chemisorption process. The isotherm study was found to follow the Langmuir isotherm model (R2 = 0.999), with maximal adsorption magnitude of 714.3 mg/g, implying the monolayer adsorption on a homogenous adsorbent surface. The reusability study affirmed the feasibility of EG-OPF in MB removal, credited to its excellent performance during reusability studies. The present study successfully discovered a new low-cost adsorbent (EG-OPF) for MB removal. Copyright © 2019 BCREC Group. All rights reserve

Dynamics of HBV cccDNA expression and transcription in different cell growth phase

<p>Abstract</p> <p>Background</p> <p>The covalently closed-circular DNA (cccDNA) of hepatitis B virus (HBV) is associated with viral persistence in HBV-infected hepatocytes. However, the regulation of cccDNA and its transcription in the host cells at different growth stages is not well understood.</p> <p>Methods</p> <p>We took advantages of a stably HBV-producing cell line, 1.3ES2, and examine the dynamic changes of HBV cccDNA, viral transcripts, and viral replication intermediates in different cellular growth stages.</p> <p>Results</p> <p>In this study, we showed that cccDNA increased suddenly in the initial proliferation phase of cell growth, probably attributable to its nuclear replenishment by intracellular nucleocapsids. The amount of cccDNA then decreased dramatically in the cells during their exponential proliferation similar to the loss of extrachromosomal plasmid DNA during cell division, after which it accumulated gradually while the host cells grew to confluency. We found that cccDNA was reduced in dividing cells and could be removed when proliferating cells were subjected to long term of lamivudine (3TC) treatment. The amounts of viral replicative intermediates were rapidly reduced in these proliferating cells and were significantly increased after cells reaching confluency. The expression levels of viral transcripts were increased in parallel with the elevated expression of hepatic transcription factors (HNF4α, CEBPα, PPARα, etc.) during cell growth confluency. The HBV transcripts were transcribed from both integrated viral genome and cccDNA, however the transcriptional abilities of cccDNA was less efficient then that from integrated viral genome in all cell growth stages. We also noted increases in the accumulation of intracellular viral particles and the secretion of mature virions as the cells reached confluency and ceased to grow.</p> <p>Conclusions</p> <p>Based on the dynamics of HBV replication, we propose that HBV replication is modulated differently in the different stages of cell growth, and can be divided into three phases (initial proliferation phase, exponential proliferation phase and growth confluency phase) according to the cell growth curve. The regulation of cccDNA in different cell growth phase and its importance regarding HBV replication are discussed.</p

Regulatory T Cells: Potential Target in Anticancer Immunotherapy

SummaryThe concept of regulatory T cells was first described in the early 1970s, and regulatory T cells were called suppressive T cells at that time. Studies that followed have demonstrated that these suppressive T cells negatively regulated tumor immunity and contributed to tumor growth in mice. Despite the importance of these studies, there was extensive skepticism about the existence of these cells, and the concept of suppressive T cells left the center stage of immunologic research for decades. Interleukin-2 receptor α-chain, CD25, was first demonstrated in 1995 to serve as a phenotypic marker for CD4+ regulatory cells. Henceforth, research of regulatory T cells boomed. Regulatory T cells are involved in the pathogenesis of cancer, autoimmune disease, transplantation immunology, and immune tolerance in pregnancy. Recent evidence has demonstrated that regulatory T cellmediated immunosuppression is one of the crucial tumor immune evasion mechanisms and the main obstacle of successful cancer immunotherapy. The mechanism and the potential clinical application of regulatory T cells in cancer immunotherapy are discussed

Methylene blue adsorption onto cockle shells-treated banana pith: Optimization, isotherm, kinetic, and thermodynamic studies

Two low-cost wastes, banana pith (BP) and cockle shells (CS) were explored towards methylene blue (MB) removal. The performance of cockle shells-treated banana pith (CS-BP) in MB removal was compared with untreated BP and commercially Ca(OH)2-treated BP (Ca(OH)2-BP). The adsorption efficacy was following the order of BP 0.99) and the Langmuir isotherm (R2 = 0.999) models, demonstrating the chemisorption and naturally homogeneous process. Thermodynamics study discovered that the MB removal by CS-BP is endothermic, feasible, spontaneous and randomness growth at a solid-solute interface. It is affirmed that CS could be employed as a low-cost activation material and CS-BP as a low-cost adsorbent

Methylene blue adsorption onto cockle shells-treated banana pith: optimization, isotherm, kinetic, and thermodynamic studies

Two low-cost wastes, banana pith (BP) and cockle shells (CS) were explored towards methylene blue (MB) removal. The performance of cockle shells-treated banana pith (CS-BP) in MB removal was compared with untreated BP and commercially Ca(OH)2-treated BP (Ca(OH)2-BP). The adsorption efficacy was following the order of BP 0.99) and the Langmuir isotherm (R2 = 0.999) models, demonstrating the chemisorption and naturally homogeneous process. Thermodynamics study discovered that the MB removal by CS-BP is endothermic, feasible, spontaneous and randomness growth at a solid-solute interface. It is affirmed that CS could be employed as a low-cost activation material and CS-BP as a low-cost adsorbent