Sol-Gel Synthesis of Inorganic Mesostructured Composite Photocatalyst for Water Purification: An Insight Into the Synthesis Fundamentals, Reaction, and Binding Mechanisms, Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry

The paper discusses the sol-gel synthesis of an inorganic mesostructured composite photocatalyst for application in water purification. The fundamentals for each synthesis step on the final Ti-content, anatase-to-rutile composition, bonding structure and mechanism to kaolinite, shape, surface area, and size control were described. In addition, various advanced microscopic techniques were used to characterize and validate the physical and chemical properties of the composite photocatalyst. A hypothetical schematic for the fabrication of mesostructured composite photocatalyst was also presented to better illustrate the overall reaction and binding mechanism. The photocatalytic degradation of an aqueous dye solution was also investigated

Exploration of a novel Type II 1D-ZnO nanorods/BiVO 4 heterojunction photocatalyst for water depollution

Abstract(#br)In this study, we reported on the successful fabrication of a novel heterojunction photocatalyst (in particulate system) with a Type II band alignment between 1D-ZnO nanorods and BiVO 4 nanocrystals. Pristine 1D-ZnO nanorods and BiVO 4 nanocrystals were first fabricated through hydrothermal reaction followed by heterojunction formation via the wet chemical reaction. The 1D-ZnO/ x BiVO 4 heterojunction photocatalyst (

Purification and Characterization of Enterovirus 71 Viral Particles Produced from Vero Cells Grown in a Serum-Free Microcarrier Bioreactor System

[[abstract]]Background: Enterovirus 71 (EV71) infections manifest most commonly as a childhood exanthema known as hand-foot-and-mouth disease (HFMD) and can cause neurological disease during acute infection. Principal Finding: In this study, we describe the production, purification and characterization of EV71 virus produced from Vero cells grown in a five-liter serum-free bioreactor system containing 5 g/L Cytodex 1 microcarrier. The viral titer was >106 TCID50/mL by 6 days post infection when a MOI of 10?5 was used at the initial infection. Two EV71 virus fractions were separated and detected when the harvested EV71 virus concentrate was purified by sucrose gradient zonal ultracentrifugation. The EV71 viral particles detected in the 24–28% sucrose fractions had an icosahedral structure 30–31 nm in diameter and had low viral infectivity and RNA content. Three major viral proteins (VP0, VP1 and VP3) were observed by SDS-PAGE. The EV71 viral particles detected in the fractions containing 35–38% sucrose were 33–35 nm in size, had high viral infectivity and RNA content, and were composed of four viral proteins (VP1, VP2, VP3 and VP4), as shown by SDS-PAGE analyses. The two virus fractions were formalin-inactivated and induced high virus neutralizing antibody responses in mouse immunogenicity studies. Both mouse antisera recognized the immunodominant linear neutralization epitope of VP1 (residues 211–225). Conclusion:These results provide important information for cell-based EV71 vaccine development, particularly for the preparation of working standards for viral antigen quantification

Processing and characterization of free standing highly oriented ferroelectric polymer films with remarkably low coercive field and high remnant polarization

Nan Meng would like to thank the China Scholarship Council (CSC No.: 201306630008) for the financial support. Prof. M.J. Reece would like to acknowledge the support of Sunchon National University, South Korea, through the BK21þ programme

Women with endometriosis have higher comorbidities: Analysis of domestic data in Taiwan

AbstractEndometriosis, defined by the presence of viable extrauterine endometrial glands and stroma, can grow or bleed cyclically, and possesses characteristics including a destructive, invasive, and metastatic nature. Since endometriosis may result in pelvic inflammation, adhesion, chronic pain, and infertility, and can progress to biologically malignant tumors, it is a long-term major health issue in women of reproductive age. In this review, we analyze the Taiwan domestic research addressing associations between endometriosis and other diseases. Concerning malignant tumors, we identified four studies on the links between endometriosis and ovarian cancer, one on breast cancer, two on endometrial cancer, one on colorectal cancer, and one on other malignancies, as well as one on associations between endometriosis and irritable bowel syndrome, one on links with migraine headache, three on links with pelvic inflammatory diseases, four on links with infertility, four on links with obesity, four on links with chronic liver disease, four on links with rheumatoid arthritis, four on links with chronic renal disease, five on links with diabetes mellitus, and five on links with cardiovascular diseases (hypertension, hyperlipidemia, etc.). The data available to date support that women with endometriosis might be at risk of some chronic illnesses and certain malignancies, although we consider the evidence for some comorbidities to be of low quality, for example, the association between colon cancer and adenomyosis/endometriosis. We still believe that the risk of comorbidity might be higher in women with endometriosis than that we supposed before. More research is needed to determine whether women with endometriosis are really at risk of these comorbidities

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Nano-photocatalytic mineralization and disinfection for water reclamation: from catalyst engineering to process optimization and modelling.

In this thesis, a feasible photocatalytic technology for water treatment was explored using a bottom-up approach in four separate research and developmental stages. These include (1) the synthesis, characterizations and photocatalytic activity (PCI) evaluation of a thin nanocrystals layer of titanium dioxide (TiO₂) immobilised onto modified mesoporous kaolin clay; (2) optimization and kinetics study of the photocatalytic reaction with recalcitrant organic dye Congo red (CR); (3) optimization and kinetics study of the photocatalytic disinfection with surrogate Escherichia coli and (4) assessment of a sequential batch reactor (SBR) mode for semi-continuous removal of dissolved pharmaceutical organic matters from secondary municipal wastewater. A modified two step sol-gel approach was used to immobilise layered of TiO₂ nanocrystals onto structurally stable kaolin (TiO₂-K) particles for enhanced physical properties. The TiO₂-K demonstrated a superior settling ability, adsorption capacity, PCI and stability compared to other conventional TiO₂ particles. Microscopic characterizations revealed that the modified kaolin provides a delaminated sandwich silica structure which minimizes chemical intercalation and further promotes high external surface area for heterocoagulation with microporous TiO₂ nanocrystals. Thermal regeneration cycles for the photocatalysts lifespan study examines that the PCI of TiO₂-K was improved over six treatment cycles, as a result of the change in average TiO₂ nanocrystals size and porosity. The real operational performances of the TiO₂-K photocatalysts for the organic degradation in water were investigated in a self-designed laboratory scale annular slurry photoreactor (ASP) system. The effect of key operational factors for the ASP system, such as TiO₂-K loading, pH, aeration rate and CR concentration were investigated. Results show that pH was the most significant factor that affects the adsorption and photocatalytic reactions in the ASP system. The point of zero charge (PZC) for the TiO₂-K particles was found to shift towards more basic extent of 9.5, resulting in a detrimental PCI when the ASP was operated at pH > PZC (TiO₂-K). The optimum operating conditions of the ASP was found to be 6.0 g L⁻¹ TiO₂-K loading, pH 7.0, 7.5 L min⁻¹ aeration rate and 40 mg L⁻¹ CR concentration. Under these optimum ASP conditions, the CR was completely photo-degraded in 4 h along with 80% reduction in chemical oxygen demand (COD) of the LC/MS-identified intermediates species. Owing to the lack of understanding and predictive in the singular optimum ASP condition, the Taguchi method was employed to collectively optimise the operating factor; determine the synergistic factor interactions and key influential factors, and further develop an empirical response surface model for the PCI prediction. From the Taguchi experiments, the photo-oxidation kinetics of CR exhibited saturation kinetics and thus, the Langmuir-Hinshelwood (L-H) model was applied. The Taguchi method predicted the optimum L-H apparent first order rate constant of 3.46 x 10⁻² min⁻¹ under the ASP operating conditions of 8.0 g L⁻¹ TiO₂-K, pH 5.0, 7.5 L min⁻¹ aeration rate and 40 mg L⁻¹ CR. Analysis of variance revealed that the CR concentration is the most significant factor, while pH appears to be the least significant one. The aeration rate in ASP was determined to have a significant synergistic effect on the TiO₂-K loading from the 3-D response surface plot. When the photo-oxidation of CR was referenced to the anatase titanate nanofiber (TNC) with PZC of 4.6, it was observed that the ASP operation was constrained by a narrow functional pH range. The optimum ASP operating conditions with slurry TNC were 4.0 g L⁻¹ TNC loading, pH 3.0, 5 L min⁻¹ aeration rate and 60 mg L⁻¹ CR, resulting in a degradation rate of 3.47 x 10⁻² mol L⁻¹ min⁻¹. Subsequent Taguchi analysis found that the low PZC (TNC) has a profound effect on the synergistic interaction with its loading concentrations. The 3D response plots showed that the low PZC (TNC) could be compensated with a high TNC loading at pH >PZC (TNC) and low aeration rate for optimal conditions. The Taguchi method predicted that the optimum ASP operating conditions were 6.0 g L⁻¹ TNC, pH 9, 5.0 L min⁻¹ aeration rate and 20 mg L⁻¹ CR. Analysis of variance shows that the pH, aeration rate and CR concentration were the significant factors, while TNC loading is the least significant one. The PCI for both photocatalysts were also tested against the photo-disinfection of Escherichia coli (ATCC 11775) as the surrogate indicator in the batch ASP system. In both investigations, the photocatalytic inactivation kinetics was found to exhibit non-linearity in the enumerated bacteria against irradiation time. The modified Hom model was used to fit a sigmoidal-shape bacterial survivor curve with strong shoulder and tailing characteristics. Using the TNC, the dissolved oxygen level in the open ASP system was found to be constantly replenished and further affects the photocatalytic inactivation kinetics. An L-H mechanistic model was proposed to determine oxygen transfer limitation in the photocatalytic disinfection process at different TNC loadings. A Fe²⁺ up to 1.0 mg L⁻¹ could initiate the residual disinfecting effect (RDE) of the photocatalytic reaction in the ASP, with constant dissociation of hydrogen peroxide (H₂O₂) to hydroxyl radicals (OH•). The RDE was diminished with increasing COD values. To effectively suppress the bacterial regrowth, the dissolved organic carbon should be well suppressed below 16 mg COD L⁻¹. Finally, the ASP system was operated as a SBR mode to allow semi-continuous treatment of the secondary municipal wastewater spiked with pharmaceutical Carbamazepine (CBZ) compound. A microfiltration module of 0.2 μm in porosity was fitted parallel to the reactor light source. The effects of key factors such as SBR cycles, nitrate (NO₃⁻), phosphate (PO₄³⁻), COD and photocatalysts on the effective photocatalytic CBZ removal were investigated. When the CBZ was degraded in the presence of high molecular weight effluent organic matter (EOM) in wastewater, the photocatalytic reaction appeared to have a preferential attack on the EOM that subsequently lower the degradation efficiency of CBZ. Other than this, the PO₄³⁻ in the wastewater showed a detrimental effect of photocatalyst fouling and deactivation on both TiO₂ catalysts used, resulting in a strong catalyst deactivation, and fouling of the catalysts. The deactivation and fouling are site specific and do not completely retard the photoactivity of the catalysts used. The sequential batch-annular slurry photoreactor (SB-ASP) was effectively operated up to two SBR cycles at catalyst loading (1 gL⁻¹) without any photocatalyst replacement, as the semi-continuous operation allows simultaneous water discharge and UV photocatalyst reactivation phase.Thesis (Ph.D.) -- University of Adelaide, School of Chemical Engineering, 201