Determination of carbendazim, thiophanate, thiophanate-methyl and benomyl residues in agricultural products by liquid chromatography-tandem mass spectrometry

A simple and reliable liquid chromatographic-tandem mass spectrometric (LC-MS/MS) method was developed for carbendazim (MBC), thiophanate (TE), thiophanate-methyl (TM) and benomyl (BM) in agricultural products. These compounds were extracted from agricultural products with methanol after addition of sodium L-ascorbate. BM was hydrolyzed to MBC during the extraction with methanol. TE and TM were cyclized to ethyl 2-benzimidazole carbamate (EBC) and MBC by refluxing at 120 °C for 30 min with copper acetate in 50% acetic acid. MBC and EBC were cleaned up by an n-hexane wash and extraction with ethyl acetate and determined by LC-MS/MS. The mean recoveries from 10 agricultural products were in the range of 75.8-100.0%, and the relative standard deviations of 5 experiments were in the range of 1.5-9.2% at concentrations equal to the maximum residue limits (MRLs). The calibration curves were made by using commercial MBC and EBC as reference analytical standards without refluxing. The quantification limits were 0.01 mg/kg (as MBC), which is the uniform limit in the positive list system for agricultural chemical residues in foods in Japan.     

Dissemination of Enterococcus faecalis and Enterococcus faecium in a Ricotta Processing Plant and Evaluation of Pathogenic and Antibiotic Resistance Profiles

In this work, the sources of contamination by Enterococcus spp. in a ricotta processing line were evaluated. The isolated strains were tested for virulence genes (gelE, cylA,B, M, esp, agg, ace, efaA, vanB), expression of virulence factors (hemolysin and gelatinase), and the resistance to 10 different antibiotics. Enterococcus faecium and Enterococcus faecalis were subjected to discriminatory identification by intergenic spacer region (ITS)‐polymerase chain reaction and sequencing of the ITS region. The results showed that Enterococcus spp. was detected in the raw materials, environment samples and the final product. None of the 107 Enterococcus isolates were completely free from all virulence genes considered. A fraction of 21.5% of the isolates containing all of the genes of the cylA, B, M operon also expressed β‐hemolysis. Most of the isolates showed the gelE gene, but only 9.3% were able to hydrolyze gelatin. In addition, 23.5% of the observed Enterococcus isolates had the vanB gene but were susceptible to vancomycin in vitro. The dissemination of antibiotic‐resistant enterococci was revealed in this study: 19.3% of the E. faecium samples and 78.0% of the E. faecalis samples were resistant to at least one of the antibiotics tested. Sequencing of region discriminated 5 and 7 distinct groups among E. faecalis and E. faecium, respectively. Although some similarity was observed among some of the isolates, all E. faecalis and E. faecium isolates had genetic differences both in the ITS region and in the virulence profile, which makes them different from each other.     

Using the spatial dilemma strategies to model agents’ commitments for a coalition formation

In spatial strategies of a spatial prisoner’s dilemma (Ishida and Mori (2005) Artif Life Robotics 9:139–143), it is possible to involve not only the geographical configuration of countries, but also many other relations such as economic relations, historical relations, military relations, and so on if they can be expressed by a network. This article explores the possibility of modeling an agent’s commitments using spatial strategies. Several types of spatiotemporal strategy are discussed in a context of coalition formation in international communities.     

An example of fault site localization on a 0.18 μm CMOS device with combination of front and backside techniques

This paper describes a failure analysis on a 0.18 μm CMOS device. To find out fault mechanism, combination of several fault localization techniques that are both front and backside were utilized. Fault mechanism is discussed, including the relation between the results of these techniques and physical layout with circuit information. In this case, the failure device had these features: multi-metallization process with dummy fill metals, low supply voltage, and non-function with high I_DD leakage. These features made verifying the fault mechanism very difficult. We provide an approach of voltage contrast method with FIB milling techniques. This approach enabled to probe inner nodes in the multi-metallization device and to verify the fault mechanism. We also discuss the verification with circuit simulation and the root cause in detail.     

Donor-Linked Fullerenes: Photoinduced electron transfer and its potential application

Redox-active fullerenes can be covalently bound to a variety of donors, their photophysical properties have been investigated. Their photochemical processes. Including electron transfer and energy transfer, are varied, depending on the donor, linkage between the donor and C₆₀, and solvent. Regardless of the solvent and linkage, the charge-separated state is produced efficiently in zinc porphyrin-C₆₀ systems, showing that C_6o is a good electron acceptor. The most intriguing characteristic of C₆₀ in electron transfer is that C₆₀ accelerates photoinduced charge separation and retards charge recombination in the dark. The long-lived charge-transfer state: of the C₆₀–porphyrin dyad was successfully converted to photocurrent using a self-assembled monolayer technique. These findings will provide a new strategy for the design and synthesis of artificial photosynthetic systems and photoactive materials using C₆₀ as a building block.     

Evaluation and Control of Iron and Steelmaking Slags through Electrochemical FeO Sensor

One of the greatest obstacles to the application of physical chemistry principles to the elucidation of slag‐metal reactions is a lack of knowledge of activities of the reacting species. To a large extent, oxygen potential of the slag phase governs iron and steelmaking practice. Without oxygen control by means of appropriate sensors, the behaviour of the other elements cannot be managed. In this paper, measurements of the FeO activity with various types of electrochemical FeO sensors will be described together with examples of their applications for improved strategies toward better practice for ladle metallurgy and sulphur and manganese distributions between slag and metal phases during steelmaking. Measurements of FeO activity have also been made in order to improve dephosphorization reactions. This type of work has led to significant reduction in volume of slag generated within the steelmaking vessel, which in turn, has important implications for refractory wear, metal yield, alloy recovery and improved productivity. Finally an on‐line sensor is described which permits the oxygen potential to be determined for both the metal phase and the slag phase during steelmaking in the BOF.     

Formation and structure of zinc-substituted calcium hydroxyapatite

Zn-substituted Ca hydroxyapatites were synthesized by precipitation method under the specific conditions (pH 8, 90 °C) and their structural properties were investigated. The substituting limit of Zn was estimated at about 15 mol%. The lattice parameter a decreased up to 5 mol% Zn, and started to increase over 5 mol% Zn. The lattice parameter c monotonously decreased with increase in Zn fraction. The increase in lattice parameter a for higher Zn fraction was ascribed to increasing amount of lattice H₂O which substituted for OH sites in the apatite structure. The lattice H₂O in the Zn-substituted apatites was lost by the heat treatment at 400 °C. As a result, both the lattice parameters a and c of the heat-treated apatites decreased with increasing Zn fraction. Only the difference in ionic radius between Zn²⁺ (0.074 nm) and Ca²⁺ (0.099 nm) was decisive to the change in both lattice parameters after the heat treatment at 400 °C.     

Evaluations for immunity-based anomaly detection with dynamic updating of profiles

This article presents evaluations of an immunity-based anomaly detection method with dynamic updating of profiles. Our experiments showed that the updating of both self and nonself profiles markedly decreased both the false alarm and missed alarm rates in masquerader detection. In computer worm detection, all the random-scanning worms and simulated metaserver worms examined were detected. The detection accuracy of the simulated passive worm was markedly improved.     

Sonochemical synthesis of gold nanoparticles on chitosan

Au nanoparticles deposited on chitosan were readily prepared from aqueous solution of NaAuCl₄ containing chitosan powder by the reaction with sonochemically formed reducing species. The average size of the formed Au particles was measured to be 22 nm with a relatively narrow size distribution, although there was no specific stabilizer for Au nanoparticles.     

Evaluation of risk and benefit in thermal effusivity sensor for monitoring lubrication process in pharmaceutical product manufacturing

In the process design of tablet manufacturing, understanding and control of the lubrication process is important from various viewpoints. A detailed analysis of thermal effusivity data in the lubrication process was conducted in this study. In addition, we evaluated the risk and benefit in the lubrication process by a detailed investigation. It was found that monitoring of thermal effusivity detected mainly the physical change of bulk density, which was changed by dispersal of the lubricant and the coating powder particle by the lubricant. The monitoring of thermal effusivity was almost the monitoring of bulk density, thermal effusivity could have a high correlation with tablet hardness. Moreover, as thermal effusivity sensor could detect not only the change of the conventional bulk density but also the fractional change of thermal conductivity and thermal capacity, two-phase progress of lubrication process could be revealed. However, each contribution of density, thermal conductivity, or heat capacity to thermal effusivity has the risk of fluctuation by formulation. After carefully considering the change factor with the risk to be changed by formulation, thermal effusivity sensor can be a useful tool for monitoring as process analytical technology, estimating tablet hardness and investigating the detailed mechanism of the lubrication process.