Use Of Excessive Amounts Research Articles

GENERATING NITROGEN RECOMMENDATIONS FOR MAIZE: ECONOMIC CONSIDERATIONS

The use of excessive amounts of nitrogen fertilizers in crops usually results in nitrogen (N) losses, increasing environmental pollution and contributing to climate change, while also elevating crop production costs. This study aimed to determine in maize (Zea mays L.): (1) the economic optimal nitrogen rate (EONR), economic optimal yield (EOY), and N use efficiency (NUE) utilizing the current N/maize (grain) price ratio (N/MPR) for attainable yield levels; and (2) the effect of an increase in the N/MPR on the EONR, EOY, net income (NI), NUE, and the loss of N. Data from 140 maize response experiments to increasing rates of N, conducted between 2010 and 2019 across 18 states in Mexico under rainfed and irrigated conditions, were analyzed. In these experiments, the average maximum yields were 4.971 ± 2.716 Mg ha-1 under rainfed conditions and 11.776 ± 2.366 Mg ha-1 under irrigated conditions. The EONR, EOY, and NUE were determined with the current N/MPR for attainable yield levels. At these levels, both the EONR and NUE increased with higher EOY and decreased with increased yield without N treatment. An increase in N/MPR reduced EONR and its associated costs without significantly affecting EOY and NI. The reduction in EONR resulted in higher NUE and, consequently, lower N losses. By utilizing N/MRP in economic optimization, recommended N rates for maize can be reduced, leading to decreased N losses and environmental pollution.

Epidemiological characteristics of New Delhi Metallo-β-Lactamase-producing Enterobacteriaceae in the Fourth hospital of Hebei Medical University

The epidemiological characteristics of New Delhi Metallo-β-Lactamase-Producing (NDM) Enterobacteriaceae were analyzed to provide theoretical support for clarifying the distribution characteristics of carbapenem-resistant Enterobacteriaceae (CRE) in the hospital environment and early identification of susceptible patients. From January 2017 to December 2021,42 strains of NDM-producing Enterobacteriaceae were gathered from the Fourth Hospital of Hebei Medical University, primarily Escherichia coli, Klebsiella pneumoniae, and Enterobacter cloacae. The micro broth dilution method combined with the Kirby-Bauer method was used to determine the minimal inhibitory concentrations (MICs) of antibiotics. The carbapenem phenotype was detected by the modified carbapenem inactivation method (mCIM) and EDTA carbapenem inactivation method (eCIM). Carbapenem genotypes were detected by colloidal gold immunochromatography and real-time fluorescence PCR. The results of antimicrobial susceptibility testing showed that all NDM-producing Enterobacteriaceae were multiple antibiotic resistant, but the sensitivity rate to amikacin was high. Invasive surgery prior to culture, the use of excessive amounts of different antibiotics, the use of glucocorticoids, and ICU hospitalization were clinical characteristics of NDM-producing Enterobacteriaceae infection. Molecular typing of NDM-producing Escherichia coli and Klebsiella pneumoniae was carried out by Multilocus Sequence Typing (MLST), and the phylogenetic trees were constructed. Eight sequence types (STs) and two NDM variants were detected in 11 strains of Klebsiella pneumoniae, primarily ST17, and NDM-1. A total of 8 STs and 4 NDM variants were detected in 16 strains of Escherichia coli, mainly ST410, ST167, and NDM-5. For high-risk patients who have CRE infection, CRE screening should be done as soon as feasible to adopt prompt and efficient intervention measures to prevent outbreaks in the hospital.

Hyperbranched additive into a high solid acrylate coating for automotive application: impact on performance and emission of volatile organic content

PurposeAutomotive coating materials are very important items for this industry. However, their performance is limited by the use of excessive amounts of solvents in their formulations, whereas the emission of volatile organic solvents is against the widely ascending principle of green chemistry. Thus, this study aims to overcome this global problem to save the environment without affecting the properties and performance of the coating.Design/methodology/approachHigh solid content paint formulation for automotive applications has been designed with low amount of volatile organic solvents with the aid of a functionalized hyperbranched modifier.FindingsIt was found that the presence of a hyperbranched additive allows a high solid content to be designed and facilitate the processing, which indicates its liability to compensate the role played by excessive solvents amounts. In addition, the mechanical properties and physical characteristics of the modified coatings showed outstanding performance and preservation of clarity in comparison with the commercial counterparts.Practical implicationsA high solid content coating with facile processing and improved performance leads to cheaper price beside the positive impact on the environment considering the limited emission of volatile organic contents.Social implicationsLimitation of the used volatile organic compounds in any industry helps to save the health of humans and keep the environment unaffected.Originality/valueThe use of functionalized hyperbranched additive to automotive coatings is a very promising additive for automotive coatings with optimized characteristics.

Access to 10‐Phenanthrenols via Electrochemical C−H/C−H Arylation

AbstractA protocol for the synthesis of 10‐phenanthrenol from 1‐biphenyl‐2‐ylethanone bearing an electron‐withdrawing group through metal‐ and oxidant‐free C−H/C−H arylation has been established. The electrochemical intramolecular cycloaromatization avoids the use of excess amounts of chemical oxidizing agents, and provides concise and regio‐selective access to a variety of valuable 10‐phenanthrenol derivatives.magnified image

Global greenhouse vegetable production systems are hotspots of soil N2O emissions and nitrogen leaching: A meta-analysis.

Vegetable production in greenhouses is often associated with the use of excessive amounts of nitrogen (N) fertilizers, low NUE (15-35%), and high N losses along gaseous and hydrological pathways. In this meta-analysis, we assess the effects of application rate, fertilizer type, irrigation, and soil properties on soil N2O emissions and nitrogen leaching from greenhouse vegetable systems on the basis of 75 studies. Mean±standard error (SE) N2O emissions from unfertilized control plots (N2Ocontrol) and N leaching (NLcontrol) of greenhouse vegetable systems were 3.2±0.4 and 91±20kgN ha-1 yr-1, respectively, indicating legacy effects due to fertilization in preceding crop seasons. Soil organic carbon concentrations (SOC) and irrigation were significantly positively correlated with NLcontrol losses, while other soil properties did not significantly affect N2Ocontrol or NLcontrol. The annual mean soil N2O emission from fertilized greenhouse vegetable systems was 12.0±1.0kg N2O-N ha-1 yr-1 (global: 0.067Tg N2O-N yr-1), with N2O emissions increasing exponentially with fertilization. The mean EFN2O was 0.85%. The mean annual nitrogen leaching (NL) was 297±22kgN ha-1 yr-1 (global: 1.66TgN yr-1), with fertilization, irrigation, and SOC explaining 65% of the observed variation. The mean leaching factor across all fertilizer types was 11.9%, but 18.7% for chemical fertilizer. Crop NUE was highest, while N2O emissions and N leaching were lowest, at fertilizer rates <500kgN ha-1 year-1. Yield-scaled N2O emissions (0.05±0.01kg N2O-N Mg-1 yr-1) and nitrogen leaching (0.79±0.08kgN Mg-1 yr-1) were lowest at fertilizer rates <1000kgN ha-1 yr-1. Vegetables are increasingly produced in greenhouses, often under management schemes of extreme fertilization (>1500kgN ha-1 yr-1) and irrigation (>1200mm yr-1). Our study indicates that high environmental N2O and N leaching losses can be mitigated by reducing fertilization rates to 500-1000kgN ha-1 yr-1 (mean: ∼762kgN ha-1 yr-1) without jeopardizing yields.

Investigations of the effect of the amount of biochar on soil porosity and aggregation and crop yields on fertilized black soil in northern China.

The combination of chemical fertilizer and biochar is regarded as a useful soil supplement for improving the properties of soil and crop yields, and this study describes how the biochar of maize straw can be used to improve the quality of the degraded black soil. This has been achieved by examining the effects of combining different amounts of biochar with chemical fertilizer on the porosities and aggregate formation of soil and exploring how these changes positively impact on crop yields. A field trial design combining different amounts of maize straw biochar [0 (NPK), 15.75 (BC1), 31.5 (BC2), and 47.25 t ha−1 (BC3)] with a chemical fertilizer (NPK) has been used to investigate changes in the formation of soil aggregate, clay content, soil organic carbon (SOC), and crop yields in Chinese black soil over a three year period from 2013 to 2015. The results of this study show that the addition of fertilizer and biochar in 2013 to black soil results in an increased soybean and maize yields from 2013 to 2015 for all the treatments, with BC1/BC2 affording improved crop yields in 2015, while BC3 gave a lower soybean yield in 2015. Total porosities and pore volumes were increased for BC1 and BC2 treatments but relatively decreased for BC3, which could be attributed to increased soil capillary caused by the presence of higher numbers of fine soil particles. The addition of biochar had a positive influence on the numbers and mean weight diameters (MWD) of soil macroaggregates (>0.25 mm) that were present, with the ratio of SOC to TN in soil macroaggregates found to be greater than in the microaggregates. The most significant amount of carbon present in macroaggregates (>2 mm and 0.25–2 mm) was observed when BC2 was applied as a soil additive. Increasing the levels of maze straw biochar to 47.25 t ha−1 led to an increase in the total organic carbon of soil, however, the overall amount of macroaggregates and MWD were decreased, which is possibly due to localized changes in microbial habitat. The supplementation of biochar increased in the amount of aromatic C present (most significant effect observed for BC2), with the ratio of aliphatic C to aromatic C found to be enhanced due to a relative reduction in the aliphatic C content with >2 mm particle fraction. These changes in organic carbon content and soil stability were analyzed using univariate quadratic equations to explain the relationship between the type of functional groups (polysaccharide C, aliphatic C, aromatic C, aliphatic C/aromatic C) present in the soil aggregates and their MWDs, which were found to vary significantly. Overall, the results of this study indicate that the use of controlled amounts of maize-straw biochar in black soil is beneficial for improving crop yields and levels of soil aggregation, however, the use of excessive amounts of biochar results in unfavorable aggregate formation which negatively impacts the yields of crop growth. The data produced suggest that aromatic C content can be used as a single independent variable to characterize the stability of soil aggregate when biochar/fertilizer mixtures are used as soil additives to boost growth yields. Analysis of soil and crop performance in black soil revealed that the application of maize-straw biochar at a rate of 15.75 and 31.5 t ha−1 had positive effects on crop yields, soil aggregation and accumulation of aromatic C in the aggregate fractions when a soybean-maize rotation system was followed over three years.

Experimental Study of Rubble Mound Behavior on the Very Soft Soil Seabed

The construction of rubble mound structures such as a breakwater or access road on a very soft seabed is essential to the development of maritime transportation. This process can result in significant settlement that causes the rock particles to sink into the seabed, leading to loss of material. In the current study, several case studies on breakwaters facing large settlements, which resulted in the use of excessive amounts of rubble, were surveyed. A series of physical models were developed to study the deformation and volume loss of rubble mound breakwaters on very soft clayey soil during construction. It was found that most deformation occurred early in construction. The primary mechanisms influencing settlement were rock penetration into the soft bed, flow of clay material into the porous body of the rubble mound, and lateral deformation of the soil beneath the breakwater, which is associated with soft bed heave at the breakwater toe. During testing of very soft beds, the ratio of material loss to the design weight of the rubble mound increased up to 27%, and the proportion of penetration to total material loss was as high as 56%. The results of the experiments and case studies were used to develop an empirical relation with which to predict settlement.

Targeted Delivery of Antibiotic Therapy to Inhibit Pseudomonas aeruginosa Using Lipid-Coated Mesoporous Silica Core-Shell Nanoassembly.

Pseudomonas aeruginosa (PA) is an opportunistic pathogen, which causes serious lung infections in immunocompromised patients. Traditional oral intake of large quantities of small-molecule antibiotics to treat bacterial infections leads to off-target toxicity and development of drug-resistant species. Improved delivery systems of antibiotics to the targeted site of bacterial infections would help reduce the need for a high intake of antibiotics. Colistin (Col), an antibacterial peptide, is considered the last resort treatment for multidrug resistant (MDR)-PA. To approach the problem of development of antibacterial resistance and off-target toxicity due to the use of excessive amounts of antibiotics, we have designed a targeted drug delivery nanoassembly, which delivers antibiotics to extracellular and intracellular bacteria. The nanoassembly is composed of (1) drug (Col)-loaded mesoporous silica (MSN) core (Col@MSN), (2) liposomal shell (Col@MSN@LL), and (3) PA-targeting LL-37 peptide (Col@MSN@LL-(LL-37)). The liposomal shell prevents premature drug release before the nanoassembly approaches the targeted bacteria. The liposome bilayer degrades upon excreted lipase present in the local environment of PA, releasing encapsulated Col. There is a significant increase in Col release (∼90% release within 40 h) in the presence of bacteria compared to the absence of bacteria (only ∼75% release after 80 h). A 6.7-fold increase in the antimicrobial efficacy of Col encapsulated in Col@MSN@LL-(LL-37) was seen compared to free Col. All studies were done using a clinical strain of PA14. Col@MSN@LL-(LL-37) successfully targets and inhibits intracellular PA14 within the lung epithelial cells. Only 7% PA14 viability is seen after treating the lung epithelial cells with Col@MSN@LL-(LL-37). No significant cytotoxicity was observed with Col@MSN@LL-(LL-37). Therefore, this discussed lipid-coated targeted nanoassembly can be considered as a successful antibiotic delivery platform.

Effect of Salinity Stress on Growth, Yield and Quality of Roses: A Review

Soil salinity is one of the most important abiotic factors that adversely effect on plant growth. In addition, nursery and greenhouse industry is under pressure to recover and recycle fertilizer solution and wastes. Most of these contains significantly higher salt concentrations that could cause harm to susceptible species of plants. Rose plants are the most attractive plants in all our world. Although, the roses face serious salt stress. Globally, soil salinity is naturally occurring or by the usage of poor quality of water and the other activities of humans or use of excessive amount of fertilizer applications. Although, the level of salts tolerance among various cultivars and species can be different in roses. In this review paper, we will discuss the responses of roses to salinity and ways to combat salinity in roses production.er.

Performance evaluation of asphalt concrete mixes under varying replacement percentages of natural sand

Frequently, load associated mode of failure, rutting and fatigue, are the main failure types found in some newly constructed roads within Baghdad, the capital of Iraq, and some suburban areas. The use of excessive amount of natural sand in asphalt concrete mixes which is attractive to local contractors could be one of the possible causes to the lack of strength properties of the mixes resulting in frustration in the pavement performance. In this study, the performance properties of asphalt concrete mixes with two natural sand types, desert and river sands, were evaluated. Moreover, five replacement rates of 0, 25, 50, 75, and 100% by weight of the fine aggregate finer than 4.75 mm were used. The performance properties including moisture susceptibility, resilient modulus, permanent deformation, and fatigue characteristics were evaluated using indirect tensile strength, uniaxial repeated loading and repeated flexural beam tests. Also, as a part of the research objective, the laboratory tests result were used to predict the performance using VESYS computer software. Results showed that mixes with high natural sand content (NSC) are more susceptible to moisture damage and rutting, lower resilient modulus and some improvement in fatigue resistance. Based on the obtained results, the necessity has rise to revise the current local specification for asphalt concrete which specifies the limits of natural sand content in the mixes of wearing and binder courses with 25% whereas for base course mixes no limit exist yet.

Comparative analysis of calculation method of adsorption isosteric heat: Case study of CO2 capture using MOFs

The isosteric heat of adsorption ( q st ) is a critical parameter to describe the CO 2 adsorption separation system for the determination of energy consumption of regeneration. The q st could be easily determined using the ensemble fluctuation approach as well as indirect approaches, including the isosteric and analytic ones; however the obtained q st values could be affected by the method used to determine them. To date, only a few studies compared these approaches using the same criteria, leading to challenges in identifying the proper approach for calculating q st . In this study, detailed comparisons of the indirect approaches and ensemble fluctuation approach were performed. The adsorption isotherms and q st values of Cu-BTC, MIL-47(V), MIL-100(Cr), and MIL-101(Cr), were obtained using the grand canonical Monte Carlo simulation. Then, q st was calculated using indirect approaches and the effect of the fitting equation was discussed. The results indicated that the ensemble fluctuation approach significantly depended on the force field. The simulated q st values of MIL-100(Cr) and MIL-101(Cr) were consistent with the calorimetric data; however, the simulated q st values of Cu-BTC and MIL-47(V) were not. For the indirect approaches, the Padè equation, combined with the isosteric approach, provided the most accurate q st values, and the relative deviation was approximately 1% under most conditions. This indicated the Padè equation could emerge as a universal fitting equation. Moreover, for the pressure or temperature swing adsorption processes, using excess variables to directly determine q st was not recommended, because the “isoexcess heat” could deviate from the isosteric heat by up to 10%. • Detailed overview of theory on isosteric heat. • Comprehensive comparison of various approaches for determination of isosteric heat. • GCMC simulation study of CO 2 gas adsorption on Cu-BTC, MIL-47(V), MIL-100(Cr), and MIL-101(Cr). • Effect of fitting formula on calculation of isosteric heat. • Effect of use of excess amounts on calculated isosteric heat of TSA and PSA.

Sonoelectrochemical Synthesis of Proton Exchange Membrane Water Electrolyzer (PEMWE) Electrocatalysts

The publication of ‘The use of ultrasound for the fabrication of fuel cell materials’ in the International Journal of Hydrogen Energy in 2010 [1] triggered an international interest in the use of power ultrasound (20 kHz – 1 MHz), sonochemistry (the use of ultrasound in chemistry) and sonoelectrochemistry (the use of ultrasound in electrochemistry) [2-4] for the synthesis of energy materials and useful gases [5]. This is due to the fact that these techniques allow the generation of nano-energy materials of controlled sizes, shapes and morphologies in a one-pot synthetic approach [6]. Furthermore, these methods do not require intensive labour and the use of excess amounts of toxic and environmentally hazardous solvents that are often used in conventional chemical methods. In 2009, Zin, Pollet and Dabalà published the first paper in the literature highlighting the synthesis of platinum (Pt) nanoparticles from aqueous solutions using sonoelectrochemistry [7]. Recently, Karousos et al. [8] showed that the high surface area Vulcan XC-72 carbon black (CB) substrate can be decorated with sonoelectrochemically produced Pt in a one-pot-one-step process by combining galvanostatic pulsed electrodeposition and power ultrasound (20 kHz). In this present study, IrO2 nanoparticles were synthesized sonochemically and sonoelectrochemically at room temperature in a three-electrode set up using a ultrasonicating GC (glassy carbon) working electrode or sonoelectrode generating very short applied current pulses (a few ms) triggered and followed immediately by short ultrasonic pulses (a few ms at 24 kHz). The Oxygen Evolution Reaction (OER) activity of the IrO2 electrocatalyst nanoparticles were evaluated ex-situ via cyclic voltammetry (CV) and linear sweep voltammetry (LSV), and the physical properties of the IrO2 electrocatalyst nanoparticles were evaluated via X-ray diffraction (XRD), transmission electron microscopy (TEM), and energy dispersive spectroscopy (EDS). The data were compared to commercial catalysts and those obtained by other methods [9]. B.G. Pollet. The use of ultrasound for the fabrication of fuel cell materials, Int. J. Hydrogen Energy 22 (2010) 1039–1059.B.G. Pollet, M. Ashokkumar (Eds), B.G. Pollet, M. Ashokkumar, Introduction to ultrasound, Sonochemistry and Sonoelectrochemistry, SpringerBriefs: Berlin, Germany (2019) in press.B.G. Pollet (Ed), Power ultrasound in electrochemistry: from versatile laboratory tool to engineering solution, John Wiley & Sons, Hoboken, NJ, USA (2012) ISBN: 978-0-470-97424-7.B.G. Pollet, A short introduction to Sonoelectrochemistry. Electrochem. Soc. Interface 27 (2018) 41–4.Md.H. Islam, O.S. Burheim, B.G. Pollet, Sonochemical and sonoelectrochemical production of hydrogen, Ultras. Sonochem. 51 (2019) 533-555.M.T.Y. Paul, Md.H. Islam, O.S. Burheim, B.G. Pollet, Recent development in sonoelectrochemical synthesis of nanomaterials, Ultrason. Sonochem., submitted (2019).V. Zin, B.G. Pollet, M. Dabalà. Sonoelectrochemical (20kHz) production of platinum nanoparticles from aqueous solutions, Electrochim. Acta 54(28) (2009) 7201-7206.D.S. Karousos, K.I. Desdenakis, P.M. Sakkas, G. Sourkouni, B.G. Pollet, C. Argirusis. Sonoelectrochemical one-pot synthesis of Pt–carbon black nanocomposite PEMFC electrocatalyst. Ultrason. Sonochem. 35(B) (2017) 591-597.C.Felix, B.J. Bladergroen, V. Linkov, B.G. Pollet, S. Pasupathi, Ex-situ electrochemical characterization of IrO2 synthesized by a modified Adams Fusion method for the oxygen evolution reaction, Catalysts 2019, 9, 318; doi:10.3390/catal9040318

Biosynthetically Inspired Transformation of Iboga to Monomeric Post-iboga Alkaloids

Summary Organisms have evolved to produce various natural products from a common precursor as a means of maximizing the number of secondary metabolites, thus acquiring selectional advantages. By adopting nature's divergent biosynthetic strategy, we transformed (+)-catharanthine to various iboga and post-iboga alkaloids, including (−)-conodusine A, (+)-conodusines B and C, (−)-voatinggine, (−)-tabertinggine, and (+)-dippinine B. Well-orchestrated oxidations and reorganizations of catharanthine derivatives enabled chemical access to these natural products.

Atom- and Mass-economical Continuous Flow Production of 3-Chloropropionyl Chloride and its Subsequent Amidation.

3-Chloropropionyl chloride is a chemically versatile building block with applications in the field of adhesives, pharmaceuticals, herbicides and fungicides. Its current production entails problems concerning safety, prolonged reaction times and the use of excessive amounts of chlorinating reagents. We developed a continuous flow procedure for acid chloride formation from acrylic acid and a consecutive 1,4-addition of hydrogen chloride generating 3-chloropropionyl chloride, as presented in this paper. Up to 94 % conversion was reached in 25 minutes at mild temperatures and pressures. This continuous flow method offers a safer alternative and is highly efficient in terms of consumption of starting product and shorter residence time. Valorization of this building block is exemplified by the synthesis of beclamide, a compound with sedative and anticonvulsant properties. Over 80 % conversion towards this drug was achieved in 1 minute in a continuous flow setup. Further research is needed to telescope the synthesis of 3-chloropropionyl chloride and subsequent beclamide formation without intermediate purification.

Chemical treatment of wood fibers to enhance the sound absorption coefficient of flexible polyurethane composite foams

Polyurethane foams are commonly used as sound absorption materials in the automobile industry because their well-defined structure allows for effective absorption of sound waves through air friction and the structural vibration of cell walls. In this study, chemically treated wood fibers were incorporated into the polyurethane foams to improve their sound absorption coefficient by enhancing the compatibility between the wood fibers and the polyurethane matrix. The open porosity of the composite foams was strongly dependent on the chemical treatments of wood fibers as well as the wood fiber contents in the composites, and it was related to the air-flow resistivity and tortuosity of the foam materials. Model calculations revealed that high air-flow resistivity led to a high sound absorption coefficient, which agreed well with experimental observations. Therefore, for achieving high sound absorption performance in composite foams, no more than the optimum amount of a coupling agent must be used to improve the interfacial compatibility between the wood fibers and the polyurethane matrix. The use of excessive amount of the silane coupling agent led to intramolecular agglomeration, thus negatively affecting the sound absorption behavior.

Enhancing the Rheological Performance of Wheat Flour Dough with Glucose Oxidase, Transglutaminase or Supplementary Gluten

The enzymes glucose oxidase and transglutaminase are frequently used to improve the breadmaking performance of wheat flours, as they have the ability to considerably alter the viscoelastic nature of the gluten network. To evaluate a flour’s breadmaking performance, rheological tests offer an attractive framework. In this study, the rheological impact of adding glucose oxidase or transglutaminase to wheat flour dough is investigated by means of linear oscillatory shear tests, creep-recovery shear tests and startup extensional tests. The former tests reveal that the enzymes render the dough stiffer and enhance its elastic character, until saturation is reached. In the breadmaking process, the use of excessive amounts of enzyme is known to be counterproductive. The strain-hardening index clearly reveals this overcross-linking effect. Besides enzymes, the gluten network can also be reinforced by adding supplementary gluten, which was indeed found to enhance the extent of strain-hardening.

Solvent bar micro-extraction (SBME) based determination of PAHs in seawater samples

Measuring the impact of PAHs in seawater samples is often difficult due to the low concentrations in which they appear and the complexity of the sample matrix. Traditional methods for sample preparation such as liquid-liquid extraction and solid phase extraction require the use of excessive amounts of solvents and reagents, and sample handling. In this work, hollow fiber liquid phase micro-extraction (HFLPME), in the configuration of solvent bar micro-extraction (SBME), was proposed as an environmentally friendly and more effective tool, for the extraction of the 16 priority PAHs from seawater samples. Extraction was conducted using hexane as a solvent. Enrichment factors from 45 to 163 were obtained after 60min at a stirring rate of 500rpm in the sample. Moreover, a negative linear relationship was observed between the enrichment factor and the molecular weight of the PAHs. Under optimized conditions, the limits of detection were in the range from 0.21 to 0.82ngL−1, the method showed a linear response up to 500μgL−1, and the average relative standard deviation for seawater samples spiked with 5ngL−1 was 11.6%. After calibration, the SBME was applied to extract PAHs in seawater samples from the Bay of Cadiz (SW Spain), showing an average recovery of 99%. In conclusion, the SBME is an environmentally friendly, one-step alternative for sample preparation in the determination of PAHs in seawater samples.

Deposition of zeolite nanoparticles onto porous silica monolith

A facile and effective method of deposition of ZSM-5 (MFI framework topology) zeolite nanoparticles (nanocrystals) onto macro-/mesoporous silica monolith is demonstrated in this paper. The electrostatic interaction between zeolite and silica monolith was controlled by cationic polyelectrolytes, which were adsorbed onto either silica monolith or zeolite nanocrystals. The effects of time, concentration of zeolite nanocrystals, type of polyelectrolyte and ultrasound treatment were examined. It was found that deposition of nanocrystals on silica monolith modified with polyelectrolyte resulted in a monolayer coverage. Adsorption of nanocrystals modified with polyelectrolyte resulted in a multilayer coverage on the silica monolith due to the agglomeration of particles. On the other hand, the use of excess amounts of polyelectrolyte in the modification of nanoparticles leads to a low coverage of silica monolith by zeolite nanoparticles and is the result of the competition between polyelectrolyte and modified nanocrystals on the silica monolith surface.

The Synergistic Impact of Excessive Alcohol Drinking and Cigarette Smoking upon Prospective Memory.

The independent use of excessive amounts of alcohol or persistent cigarette smoking have been found to have a deleterious impact upon Prospective Memory (PM: remembering future intentions and activities), although to date, the effect of their concurrent use upon PM is yet to be explored. The present study investigated the impact of the concurrent use of drinking excessive amounts of alcohol and smoking cigarettes (a “Polydrug” group) in comparison to the combined effect of the single use of these substances upon PM. The study adopted a single factorial independent groups design. The Cambridge Prospective Memory Test (CAMPROMPT) is a test of both time-based and event-based PM and was used here to measure PM. The CAMPROMPT was administered to 125 adults; an excessive alcohol user group (n = 40), a group of smokers who drink very little alcohol (n = 20), a combined user group (the “Polydrug” group) who drink excessively and smoke cigarettes (n = 40) and a non-drinker/low alcohol consumption control group (n = 25). The main findings revealed that the Polydrug users recalled significantly fewer time-based PM tasks than both excessive alcohol users p < 0.001 and smokers p = 0.013. Polydrug users (mean = 11.47) also remembered significantly fewer event-based PM tasks than excessive alcohol users p < 0.001 and smokers p = 0.013. With regards to the main aim of the study, the polydrug users exhibited significantly greater impaired time-based PM than the combined effect of single excessive alcohol users and cigarette smokers p = 0.033. However, no difference was observed between polydrug users and the combined effect of single excessive alcohol users and cigarette smokers in event-based PM p = 0.757. These results provide evidence that concurrent (polydrug) use of these two substances has a synergistic effect in terms of deficits upon time-based PM. The observation that combined excessive drinking and cigarette smoking leads to a greater impairment in time-based PM may be of paramount importance, given the key role PM plays in everyday independent living.

Comparative Study on Organoleptic, Microbiological and Chemical Qualities of Dried Fish, Goldstripe Sardinella(Sardinella Gibbosa) with Low Salt Levels and Spices

Dried fish is very important component in Sri Lankan fishery productswhile current domestic production is estimated at around 40,000 tons per year. Generally, dried fish production in Sri Lanka is based on traditional methodology where 30% of salt is used averagely. Use of excess amount of salt can have negative health effects. Therefore production of dried fish with low salt is very important.Accordingly, partial substitution of salt with alternative substances can be done. Current study aimed at evaluating the effect of low levels of salt and combined effect of low salt and spices on quality of dried fish. The study was carried out using eviscerated and cleaned up GoldstripeSardinella with 0% (T1), 5% (T2), 10% (T3) salt levels and two different combinations of salt and spices (1%salt with 0.2%turmeric, 0.5%chlli, 0.5%pepper (T4) and 2%salt with 0.2%turmeric, 0.2%chlli, 0.2%pepper (T5)). Hot air dehydrator (65-70°C) was used for fish drying. Chemical (moisture, water activity (aw), Total volatile nitrogen (TVN), and sodium chloride), physical (texture and rehydration), microbiological (APC, mould and yeast count and coliform count) properties and sensory attributes of experimentally prepared dried fish were investigated. The chemical parameters for all treatments were significantly different (p<0.05) while physical parameters were not (p>0.05). T2 indicated the best chemical quality. The values for moisture, aw, sodium chloride, TVN, texture and rehydration for T2, were 11.6584±0.03, 0.591±0.002, 12.43±0.15, 59.43mg/100g±12.86, 1.54kg±0.14 and 12.70±3.54 respectively. T2 and T3 had least microbial counts while T1 and T5 had highest microbial count. But T5 had highest scores for all sensory attributes indicating consumer preference for low salt and spicy taste regardless of high TVN content and poor microbial quality.Therefore it is essential to improve the methodology to enhance the quality of low salt and spices added dried fish.