Synthesis and characterization of metals doped on fibrous silica zeolites for benzene alkylation with methanol

Benzene alkylation with methanol (benzene methylation) offers an alternative process to produce toluene, which is an important chemical intermediate in petrochemical industries. However, the existing catalysts have low performance for toluene yield due to their intrinsic micropores and high acidity. In this research, zeolite catalysts (ZSM-5, Y and Beta) with fibrous morphology (HFZ, HFY and HFB) were prepared to study their properties and catalytic activity’s relationship with benzene methylation. The fibrous ZSM-5 (HFZ) was further modified using different concentrations of silica source, tetraethylorthosilicate (TEOS). Then, different transition metals (TMs) such as cobalt (Co), titanium (Ti) and manganese (Mn), as well as various Mn loading (1-10 wt%) were loaded on HFZ catalyst using impregnation method to enhance the benzene methylation performance. The catalysts were characterized using X-ray diffraction, nitrogen physisorption, field emission scanning electron microscopy, transmission electron microscopy, Fourier transform infrared (FTIR) spectroscopy, pyridine adsorbed FTIR, 2,6-lutidine adsorbed FTIR, Raman spectroscopy and thermogravimetric analysis. The catalytic testing was conducted at 300 – 400 ºC under atmospheric pressure. The toluene yield for different fibrous zeolite catalysts and concentration of TEOS was found in the order: 1.0HFZ (63.1 %) > 0.5HFZ (57.5 %) > 1.5HFZ (55.7 %) > HFBEA (50.9 %) > HFY (50.4 %) at 300 ºC. This result could be attributed to the adequate mesoporosity and Brönsted acid sites of the 1.0HFZ, thus decreasing the diffusion limitation and side reactions. For different TMs loaded on HFZ, the Mn/HFZ outperformed Co/HFZ and Ti/HFZ. Among the Mn loadings (1 – 10 wt%), the 5Mn/HFZ reached the highest toluene yield of 69.6 % at 350 ºC, carrier gas flowrate of 20 cm3s-1 and benzene: methanol ratio of 1. In addition, the 5Mn/HFZ possessed outstanding stability over 72 h time on stream, as compared to pristine HFZ with activity loss of 10.8 % for toluene yield. The in-situ FTIR study corroborated that Lewis acid sites originated from Mn are beneficial for toluene formation by enhancing the benzene ring stabilization and adsorption during the alkylation reaction and inhibit the side reaction. The optimum toluene yield predicted by response surface methodology was 68.8 % at reaction temperature of 361 ºC, carrier gas flowrate of 19.0 cm3s-1 and benzene:methanol ratio of 1.45. Based on the above observations, this study highlights the potential role of fibrous silica ZSM-5 and Mn catalysts in the benzene methylation reaction, particularly in the production of toluene

Synthesis of titanium dioxide supported on mesostructured silica nanoparticles for photocatalytic decolourization of congo red

Various dyes that had been widely used in industries may produce harmful effects to the living organisms and the environment if not treated properly before being discharged into water bodies. Photocatalytic decolourization is one of the promising techniques to degrade dyes due to its mild operating conditions and green technology process. In this study, the effects of titanium dioxide (TiO2) supported on mesostructured silica nanoparticles (MSN) under different preparation methods were investigated for photocatalytic decolourization of congo red (CR). The microwave-synthesized mesoporous titania nanoparticles (MTN) supported on MSN were prepared by impregnation method (MTN/MSN), while electrogenerated TiO2 was supported on MSN by in-situ electrochemical (TiO2/MSN-E) and impregnation (TiO2/MSN-I) methods, respectively. The properties of the catalysts were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Nitrogen adsorption-desorption, electron spin resonance (ESR) analysis and 29Si magic angle spin nuclear magnetic resonance (29Si MAS NMR). The results indicated that the introduction of MTN and TiO2 did not change the lattice structure of MSN but decreased the surface area and pore volume of the catalysts as a consequence of pore blockage. The photocatalytic activity of the catalysts towards decolourization of 10 mg L-1 CR at pH 5 with 1.0 gL-1 catalyst after 5 h was in the following order: TiO2/MSN-E > MTN/MSN > TiO2/MSN-I. The TiO2/MSN-E (94 %) showed the best performance compared to other catalysts, probably due to the presence of abundant Si-O-Ti bonds oxygen vacancies and titanium site defect in MSN frameworks. The kinetics study of the catalysts indicated that decolourization of CR followed the pseudo first order Langmuir-Hinshelwood model. The response surface methodology study for TiO2/MSN-E catalyst demonstrated good significance of model with a high coefficient of determination (R2 = 0.9698) and a regenerated study showed that the catalysts were still stable after 5 cycles. The employment of the catalyst on decolourization of simulated dyes revealed remarkable performance, suggesting the potential use of the catalysts for textile wastewater treatment

Efficacy of a locally produced microbial phytase from Enterobacter sakazakii ASUIA273 on body weight and hemato-biochemical constituents in broiler chickens

An experiment was carried out in broiler chicks fed different doses of locally produced microbial phytase supplementation to observe their growth performance as health status, and to investigate the changes of hematological and biochemical values. A total of 144 chicks (Cobb) at one-day old were allocated to 4 treatment (T) groups with 12 cages comprising 3 replicates, each cage containing to 12 birds. Experimental formulating diets arranged with 4 levels of 0, 500, 1000 and 1500 phytase enzyme unit (FTU/kg-I) as considered as Th T2, T3, T4 respectively. They were maintained formulating diet on these dietary treatments from 1 to 42 d of age with feed and water made available for ad libitum consumption. At 1 week interval 2 birds from each treatment were weight through out experimental period for assessing the growth performance. For determining the changes of hematological (RBC, Hb, PCV, MCV, MCHC, WBC, Heterophil, Eosinophil, Basophil, Lymphocyte, Monocyte, Thrombocyte and Icterus Index) and biochemical (Albumin, Total Protein, ALT, ALP, AST, GGT, LDH, Cholesterol, Triglyceride, Glucose, Ca, P, Na, K, Cl, Urea, Creatine and Uric acid) values at the age of 6 weeks randomly selected 2 birds were slaughtered and blood were collected. Data were subjected to analysis of variance (ANOVA) using the least significant difference (LSD) by PC-SAS software (SAS Institute, 2009). Data showed that body weight was not affected at periods of 1si and 2nd weeks of age among different treatment groups. But, at ages from 3rd to 6th weeks, weight gains at four treatment gIZ.Qupwsere increased almost sequentially and consistantly, and had been showed more different and significant (p:s 0.05) increased at 4th and 5th weeks of age from the control. No significant and constant treatments effects were observed on blood and biochemical parameters except eosinophil: Accordingly, it can be recommended to use an uncentrifuged microbial phytase in broiler diet during the period from 4th - 5th weeks of age, to achieve increased weight gain without changing hemato-biochemical parameters

Effects of locally produced bacterial phytase on humoral immunity, live body weight and blood characteristics in broilers vaccinated against Newcastle disease

Immune responses in association with body weight performance and hemato-biochemical constituents might influence the Newcastle disease (ND) vaccination by dietary phytase supplementation (Enterobacter sakazakii ASUA273). The objective of the study was to determine the effects of bacterial phytase supplementation on humoral immunity in association with live body weight and blood characteristics of broilers. Male-day-old Cobb broilers (n=180) were assigned into four phytase treatments (0, 500, 1000 and 1500 FTU/kg-1 of diet) with 12 cages comprised of 3 replicates and each cage contained 15 birds. Birds were maintained on formulated basal diet based with available phosphorus (0.19%) that lasted up to six weeks in feed. Birds were vaccinated with a live ND vaccine at day-old and 21 day-old. Two birds were randomly selected from each treatment weekly. Specific antibody to ND, non-specific immunoglobins (IgM, IgG, and IgA) and live body weight were measured weekly. At the end of experiment, the complete haemato-biochemical constituents were determined. Data of humoral immunity with live body weight and haemato- biochemical values were analysed based on factorial arrangement (treatments×weeks) of completely randomized design (CRD), respectively. Response of the humoral immunity shown that although serum-antibody of ND, IgM, and IgG levels were not improved, the mucosal IgA contents were increased with the increasing phytase doses. The live body weights of broilers were significantly increased (P<0.05) to the graded levels of phytase supplementation throughout the experimental period. Cumulative effects of mucosal IgA contents and live body weights of broilers showed significant (P<0.05) interaction between the effects of phytase levels and effects of weeks. Overall, phytase dose at 1500 FTU/kg-1 of diet over the age of 6 weeks-old showed the best performance. Conversely, no significant, sequential, and consistent treatment effects were observed on hemato-biochemical constituents in broiler chickens. It is therefore, concluded that the efficacy of this local phytase was flourished in respective to mucosal IgA contents and live body weights of broilers

Minimum CO2 Miscibility Pressure Evaluation using Interfacial Tension (IFT) and Slim-tube Hybrid Tests

The effectiveness of CO2-enhanced oil recovery (EOR) is strongly dependent on the CO2−oil minimum miscible pressure (MMP) value, which can be estimated using various methods. In this study, interfacial tension (IFT) and slim-tube tests were used to estimate the MMP value. Experimental results indicated that the IFT test had a higher MMP value than the slim-tube test. Particularly, the outcomes of IFT and the slim-tube tests differed slightly, i.e., 0.7% and 4.3% at 60 and 66 °C, respectively. Furthermore, the current work also compares MMP data gathered using visual observation and equation of state (EOS) simulation. The MMP estimated by EOS is higher but close to the IFT and slim-tube recovery factor method, where all results are within the 1650− 1700 psi and 1700−1800 psi visual observation ranges at 60 and 66 °C, respectively. However, MMP deviations concerning the slim-tube test and EOS were consistent at different temperatures. This study offers an alternative to estimate and evaluate CO2−oil MMP for EOR applications accurately and efficiently

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication

Enhanced reactive CO2 species formation via V2O5-promoted NI/KCC-1 for low temperature activation of CO2 methanation

Application of CO2 methanation, especially in CO2-rich gas fields, could potentially provide additional value to the synthetic natural gas production. In this study, highly active vanadium (V2O5)-promoted Ni/KCC-1 catalysts with 5% nickel content were prepared using a co-impregnation method for CO2 methanation reaction. The influence of V2O5 on the textural properties, basicity and reducibility of the 5Ni/KCC-1 catalysts was systematically investigated. It was found that addition of V2O5 enhances the basicity of the catalysts; however, it decreases the surface area and pore volume. The amphoteric properties of V2O5 provide additional adsorption sites of CO2 producing more reactive unidentate CO2 adsorbed species. The presence of V2O5 also improved the dispersion and exposed more Ni species. This leads to an increased amount of reducible NiO species. Compared to 5Ni/KCC-1, the V2O5-Ni/KCC-1 series were active at lower temperature. The light off temperature for V2O5-Ni/KCC-1 was 423 K compared to 473 K for 5Ni/KCC-1. At 623 K, the 7.5V2O5-Ni/KCC-1 reaches 94.4% CO2 conversion, 15% higher than 5Ni/KCC-1. The presence of O2 negatively affects the catalytic activity as O2 interferes with the CO2 adsorption sites. The analysis of variance (ANOVA) indicates that the reaction temperature heavily influences the CH4 yield followed by the reduction temperature and H2:CO2 ratio. The optimized conditions by the RSM are a reduction temperature of 696.9 K, a reaction temperature of 766.5 K and a H2:CO2 ratio of 5.1

Evaluation of humoral immune response, body weight and blood constituents of broilers supplemented with phytase on infectious bursal disease vaccination

Phytase inclusion in phosphorus (P) deficient diet increases the bioavailability of nutrients and plays, indirectly, a role in biological function of many metabolic processes. The possibility of using phytase in diet might influence immune, growth and blood performances of animals. The objective of the study was to assess the effect of local bacterial phytase on humoral immunity in association with weight and blood characteristics of infectious bursal disease (IBD) vaccinated broilers. Male-day-old Cobb-broilers were assigned into four groups based on phytase treatments (0, 500, 1,000 and 1,500 fitase units per kg of diet) with 12 cages comprising three replicates per treatment, each treatment containing 15 birds. They were vaccinated with an IBD vaccine (IBD UPM93) and were fed formulating P (0.19%) deficient diet from 1 to 42 day of age. Results indicated that although serum IBD antibody, IgM, and IgG were not increased, mucosal IgA contents were increased with increasing phytase doses. Data on bird's growth performance revealed that cumulative live weights were increased significantly (p < 0.05) to graded levels of phytase and the highest enzyme level commenced best performance. Results suggest that the local phytase supplementation in low phosphorus diet will improve mucosal IgA contents and body weights of birds

Strategies for introducing titania onto mesostructured silica nanoparticles targeting enhanced photocatalytic activity of visible-light-responsive Ti-MSN catalysts

Titanium-mesostructured silica nanoparticles (Ti-MSN) catalysts which are excellent photocatalytic materials for the environment were prepared by supporting mesostructured silica nanoparticles (MSNs) with titanium species synthesized by three different approaches: microwave and in situ and ex situ electrochemical methods, denoted as Ti-MSN-M, Ti-MSN-I, and Ti-MSN-E, respectively. The physicochemical properties of the catalysts were investigated via XRD, 29Si NMR, N2 adsorption-desorption, FTIR, ESR, and UV-DRS analyses. Characterization results revealed that the introduction of mesoporous titania nanoparticles (MTNs) prepared by the microwave method onto MSNs (Ti-MSN-M) did not significantly affect the silica framework. However, the silica network in the Ti-MSN-I and Ti-MSN-E was rather disrupted, particularly for the former catalyst, due to the desilication accompanied by isomorphous substitution of Ti in the MSN framework to form Si[sbnd]O[sbnd]Ti bonds. Ti was also found to be exchanged with the terminal hydroxyl groups of all catalysts to form the Si[sbnd]O[sbnd]Ti bonds. The addition of Ti species onto MSNs also increased the number of oxygen vacancies (Vo) and metal defect sites. Photocatalytic testing on the decolorization of Congo red (CR) resulted in the following order: Ti-MSN-I (94%) > Ti-MSN-M (90%) > Ti-MSN-E (34%). The Vo and metal defect sites were responsible in lowering the band gap of catalysts and decreasing the electron–hole recombination, while the great numbers of Si[sbnd]O[sbnd]Ti bonds as well as large surface area and pore volume increased the active sites and offered a good surface contact with light to enhance the activity of catalysts. A kinetic study demonstrated that the photodegradation followed the pseudo-first-order Langmuir-Hinshelwood model. Ti-MSN-I and Ti-MSN-M maintained their activities for up to five runs without serious catalyst deactivation, indicating their potential for the degradation of dye in wastewater. Mineralization measurements of CR by TOC and BOD5 analyses after 3 h of contact time were 85.7% and 87.6% using Ti-MSN-M, while 83.7% and 80.3% using Ti-MSN-I, respectively. Optimization by response surface methodology showed that the catalyst dosage, pH, and TiO2 loading were the significant factors in the decolorization of CR. This study demonstrated that these two green technologies; electrochemical and MW have a great potential to be used in synthesis of various advanced materials for greener and more sustainable processes