Porous hollow silica nanoparticles as controlled delivery system for water-soluble pesticide

Porous hollow silica nanoparticles (PHSNs) were prepared and applied as controlled delivery system of water-soluble pesticide validamycin. PHSNs were loaded with validamycin through a specially designed supercritical fluid loading method. It was demonstrated that a high loading capacity (36 wt.%) of validamycin could be achieved, which was found to be more effective than that of the simple immersing method in this study. The loaded PHSNs were characterized by TG, IR and XPS analysis. The validamycin release profile from PHSNs was investigated and showed a multi-staged release pattern probably due to the different adsorption locations of validamycin on PHSNs. This release behavior makes PHSNs a promising carrier in agriculture, especially for pesticide controlled delivery whose immediate as well as prolonged release is needed. In addition, factors influencing the validamycin release rate, including pH and temperature, were investigated.     

Seasonal fluctuations of organochlorine and triazines pesticides in the aquatic system of Ioannina basin (Greece)

For the period September 1984 to November 1985 water samples from the aquatic system of Ioannina basin were analyzed every second month for organochlorine and triazines pesticides. The detected compounds were found to follow a seasonal pattern, with an increment during summer followed by a decrease during winter and an increase again during late spring. This pattern was apparent for Ioannina lake as well as for the Kalamas river connected to it through the Lapsista's canal and tunnel. The results are discussed in terms of the amounts of the detected pesticides used for farming in the vicinity of the Ioannina basin and the seasonal rainfall.     

Is there more to email negotiation than email? The role of email affinity

Email has profoundly influenced the way we communicate personally and professionally and, for many, email negotiations have become a common, every day experience. While many studies have investigated email negotiations by relying on and discussing the characteristics of the medium, this paper focuses on the user’s attitude toward the medium and its respective influence on email negotiation. Specifically, we investigate which dimensions make up negotiators’ attitude toward email, i.e. their email affinity, and how these attitudes, in turn, influence the negotiation outcomes. In our scale development, three facets of email affinity are theoretically considered, empirically explored and validated: email preference, email comfort and email clarity. Our negotiation study contains a quasi-experimental email negotiation exercise where subjects were paired according to their email affinity. Email comfort emerged as a significant predictor of individual profit, joint gain, and different dimensions of subjective value. Theoretical implications and further research are discussed.     

Enhanced Competitive Chemiluminescent Enzyme Immunoassay for the Trace Detection of Insecticide Triazophos

Abstract: A direct competitive chemiluminescent enzyme immunoassay (CLEIA) for triazophos was developed, which was based on the anti‐THHe IgG monoclonal antibody and a heterogeneous enzyme tracer (THHu‐HRP). Several components of chemiluminescent enhanced solution (CES) were optimized. The results showed that 1 mM of p‐iodo‐phenol, 0.625 mM of luminol, and 4 mM of H₂O₂ had the best performance. Based on the study of CES, the influence of several factors (assay buffer, blocking substance, and solvent) on the immunoassay was investigated. The sensitivity for detection, IC₅₀ value was 0.87 ng/mL at a practical working concentration range between 0.04 ng/mL and 5 ng/mL and the limit of detection for triazophos was 0.063 ng/mL. The average recovery of triazophos added to lettuce, carrot, apple, water, and soil were 78.71%, 67.52%, 118.3%, 117.2%, and 122.0%, respectively. Finally, comparison between the methods of CLEIA and high‐performance liquid chromatography‐tandem mass spectrum (HPLC‐MS/MS) was performed. The results obtained from CLEIA were in agreement with those of HPLC‐MS/MS. Practical Application: The method developed in the paper could take positive or negative test of vegetable, fruit, and environmental samples for triazophos with high sensitivity and efficiency.     

Heavy metal ions retention by bi-functionalized lignin: Synthesis,applications, and adsorption mechanisms

Bi-functionalized lignin with amino and sulfonic groups (ASL) was synthesized via Mannich reaction and sulfomethylation. It was systematically characterized by FT-IR, element analysis, surface charge and XPS. Effects of initial pH, contact time and initial metal ion concentration on the adsorption of Cu(II) and Pb(II) onto ALS were studied. Results indicated that the biosorbent showed excellent performance for metals even from low pH solutions. The adsorption kinetics and isotherms could be described well with Pseudo-second-order and D–R model, respectively. Further investigation of the metal-loaded ASL by FT-IR and XPS elucidated the amino and sulfonic groups reacted with metals in different way.     

Contamination with retinoic acid receptor agonists in two rivers in the Kinki region of Japan

This study was conducted to investigate the agonistic activity against human retinoic acid receptor (RAR) α in the Lake Biwa-Yodo River and the Ina River in the Kinki region of Japan. To accomplish this, a yeast two-hybrid assay was used to elucidate the spatial and temporal variations and potential sources of RARα agonist contamination in the river basins. RARα agonistic activity was commonly detected in the surface water samples collected along two rivers at different periods, with maximum all-trans retinoic acid (atRA) equivalents of 47.6 ng-atRA/L and 23.5 ng-atRA/L being observed in Lake Biwa-Yodo River and Ina River, respectively. The results indicated that RARα agonists are always present and widespread in the rivers. Comparative investigation of RARα and estrogen receptor α agonistic activities at 20 stations along each river revealed that the spatial variation pattern of RARα agonist contamination was entirely different from that of the estrogenic compound contamination. This suggests that the effluent from municipal wastewater treatment plants, a primary source of estrogenic compounds, seemed not to be the cause of RARα agonist contamination in the rivers. Fractionation using high performance liquid chromatography (HPLC) directed by the bioassay found two bioactive fractions from river water samples, suggesting the presence of at least two RARα agonists in the rivers. Although a trial conducted to identify RARα agonists in the major bioactive fraction was not completed as part of this study, comparison of retention times in HPLC analysis and quantification with liquid chromatography-mass spectrometry analysis revealed that the major causative contaminants responsible for the RARα agonistic activity were not RAs (natural RAR ligands) and 4-oxo-RAs, while 4-oxo-RAs were identified as the major RAR agonists in sewage in Beijing, China. These findings suggest that there are unknown RARα agonists with high activity in the rivers.     

Quantitative assessment of risk associated with dietary intake of mycotoxin ochratoxin A on the adult inhabitants in Shanghai city of P.R. China

Mycotoxin ochratoxin A (OTA) is considered to be a possible risk factor for adverse effects in humans. In the present study, quantitative assessment of risk associated with dietary intake of OTA was performed based on consumption habits of the representative adult inhabitants in Shanghai city of P. R. China. Firstly, a total of 400 food samples randomly collected from different locations of Shanghai were analyzed by the previously established isotope dilution LC–MS/MS method. Then, 265 participants of 70 males and 195 females as representative inhabitants were invited to answer the designed questionnaire about the quantity and frequency of foods including four major varieties of grapes, cereals, beans and dried fruits as well as their derived products. Finally, all data were simulated by the point evaluation and model evaluation for the risk assessment of OTA contamination. Results from the point evaluation indicated that mean value of daily intake (DI) of OTA was 1.147 ng/kg body weight/day, which was lower than all the reference standards. However, DI value (8.566 ng/kg body weight/day) in the high percentile (97.5th) was obviously higher than the PTDI (5 ng/kg body weight/day) proposed by Scientific Committee on Food. Among the different groups of foods, OTA in cereals and derived products made the largest contribution to the potential healthy risk. The mean DI value and 97.5th percentile were 1.093 and 7.962 ng/kg body weight/day, respectively, indicating that more than 90% of the risk was due to the contamination of OTA in cereals and derived products. On the other hand, similar results were obtained by the Monte Carlo assessment model. Thus, from the currently available data and analyzed results on the adult inhabitants, regarding OTA contamination issues on food safety administration of Shanghai, there was no significant attention which should be paid on food consumption in Shanghai, besides cereals and derived products with very little possibility as the risk factors.     

A model for capturing and representing the engineering design process

This paper presents a Collaborative Model for capturing and representing the engineering Design process (CoMoDe). CoMoDe is a deductive object-oriented model that, in relation to an engineering design process, is able to capture the different elements that participate in a design process in an integrated fashion. In particular, it is able to represent (i) the activities, operations, and actors that have generated each design product, (ii) the imposed requirements, and (iii) the rationale behind each decision. Furthermore, it also offers an explicit mechanism to represent and trace the different model versions that have participated in the design process. On such a basis, this proposal introduces specific procedures to handle various situations appearing in cooperative environments. They are: (i) different design teams perform independent concurrent activities on “a priori” independent parts of the artefact being designed and afterwards their results need to be made consistent; (ii) distinct teams concurrently work on slightly coupled parts of the artefact being designed and conflict handling must be addressed along their “parallel” course of actions.     

Accuracy and congruency of three different digital land-use maps

For numerous model applications in the earth and environmental sciences, digital land-use data are indispensable as a source of information on the geographical distribution of the land-use/cover. Therefore, the land-use data sets ATKIS, CORINE Land Cover, and Landsat TM classifications are widely used in Germany. However, the users of these data mostly do not have information on their quality. In this study, the accuracy of the three above-mentioned digital land-use maps was evaluated a posteriori based on the results of a field inventory in two test areas with a total area of 17 km². The results show that the overall accuracy of the land-use maps varies from 0.692 to 0.876. For the individual land-use classes, the user accuracy ranged from less than 0.001 to 0.991. In this paper, the positional congruency of the land-use class polygons among the three maps was also evaluated for a larger study region of 670 km² in the state of Hessen (Germany). This region is a small structured landscape with a relatively high portion of fallow land. In the analysis, the following six land-use classes were considered: urban and traffic areas, forest, water, arable land, pastures and meadows, and fallow land (including other uses). The results showed that the congruency of the land-use classes forest and urban and traffic areas is higher than the congruency of the land-use classes of the open land (arable land, pastures and meadows, fallow).     

Alcoholic fermentation effects on malt spiked with trichothecenes

Malt contaminated with DON and T-2 toxin at levels of between 0 and 1000 ng/g was used for fermentation on a laboratorial scale in order to evaluate the decontamination caused by alcoholic fermentation using Saccharomyces cerevisiae. Fermentation was carried out over a period of 120 h at 14 °C and a reduction in the levels of contamination was detected by GC. Forty one percent of the initial quantity of DON and T-2 toxin contamination was passed on to the final liquid portion. Six percent of the initial contamination was detected in the wort, which signifies a total decontamination of 53% of DON and T-2 toxin, taking into account both the wort and the filtered sample.