Distribution of aflatoxin M1 during Grana Padano cheese production from naturally contaminated milk

The distribution of aflatoxin M₁ (AFM₁) has been investigated in samples of whey, curd and a typical hard and long maturing cheese like Grana Padano (ripened for twelve months), produced with naturally contaminated milk in a range of 30–98 ng AFM₁/kg. AFM₁ determinations were carried out on 25 samples of each product by reverse-phase HPLC and fluorescence detection with post-column derivatisation, after a preliminary C18-SPE clean-up. Experimental results show that, in comparison to milk, AFM₁ concentration levels increased both in curd (3-fold) and in long maturing cheese (4.5-fold), while AFM₁ occurrence in whey decreased by 40%.     

Laboratory methods for assessing API sensitivity to mechanical stress during agitated drying

Two distinct laboratory methods have been developed to assess the propensity of active pharmaceutical ingredients to undergo particle breakage during agitated drying operations. In the first method, mechanical stress is applied to particles by mechanical agitation of powders compressed under an applied normal force. For the second, particles experience stresses as they are carried within a pressurized gas stream. These methods are simple, relatively compound-sparing, and are used to rank materials according to a quantitative breakage classification scale as hard, medium, or easy to break. Based on the results obtained using these methods at laboratory scale, recommendations and precautions for processing at larger scale are made. In this paper, these methods are described in detail, and the results, obtained for several pharmaceutical compounds, are presented.     

Method for rapid high-frequency seismogram calculation

We present a method for rapid, high-frequency seismogram calculation that makes use of an algorithm to automatically generate an exhaustive set of seismic phases with an appreciable amplitude on the seismogram. The method uses a hierarchical order of ray and seismic-phase generation, taking into account some existing constraints for ray paths and some physical constraints. To compute synthetic seismograms, the COMRAD code (from the Italian: “COdice Multifase per il RAy-tracing Dinamico”) uses as core a dynamic ray-tracing code. To validate the code, we have computed in a layered medium synthetic seismograms using both COMRAD and a code that computes the complete wave field by the discrete wave number method. The seismograms are compared according to a time–frequency misfit criteria based on the continuous wavelet transform of the signals. Although the number of phases is considerably reduced by the selection criteria, the results show that the loss in amplitude on the whole seismogram is negligible. Moreover, the time for the computing of the synthetics using the COMRAD code (truncating the ray series at the 10th generation) is 3–4-fold less than that needed for the AXITRA code (up to a frequency of 25 Hz).     

Principal component analysis in fast atom bombardment-mass spectrometry of triacylglycerols in edible oils

Positive-ion fast atom bombardment-mass spectrometry, withm-nitrobenzyl alcohol as matrix and a methanolic sodium iodide (Nal) solution, was used to characterize edible oils by their triacylglycerol composition. Cationized triacylglycerols gave characteristic spectra for olive (57 samples), sunflower (9 samples), soybean (9 samples), corn (12 samples), and peanut (10 samples) oils. Relative abundance of [M + Na]⁺ ions showed relevant differences among the oils. The obtained data were analyzed with the aid of chemometrics by using principal component analysis (PCA) to evaluate the differentiation. Twelve variables were reduced to two principal components, accounting for 82% of the total variance. A two-dimensional plot of 97 PCA scores allowed the separation of the edible oils. The analysis is both fast and reproducible.     

利用带电源管理的多路输出电源实现ATE系统的最大灵活性和经济性

ATE系统设计师经常要同时面对降低系统成本和提高系统灵活性的挑战。本文讲述ATE系统电源新的独特性能和如何帮助ATE系统设计师从容应对这些挑战。     

Combined spectroscopic characterization of electron transfer at hybrid CuPcF(16)/GaAs semiconductor interfaces

We characterize photoinduced charge injection at the interface between a fluorinated copper phthalocyanine (CuPcF(16)) film deposited over a GaAs(100) wafer by means of pump-probe spectroscopy combined with ultraviolet photoemission spectroscopy (UPS) and electromodulated transmission spectroscopy. UPS characterization of the hybrid interface demonstrates that the CuPcF(16) 's lowest unoccupied molecular level (LUMO) is almost aligned with the GaAs conduction band. Upon photoexcitation of the hybrid interface with 150 fs pulses we observe an efficient photoinduced electron transfer from CuPcF(16) to GaAs. The evolution of interfacial CuPcF(16) charges appear to be strongly influenced by energy level alignment at the GaAs/CuPcF(16) heterojunction.     

User Interaction and Data Management for Large Scale Grid Applications

In this paper we present a model that combines the X3DMMS application with the G3CPie execution framework, that enables the user to perform large scale computations on distributed computing environments. Such an approach facilitates the management and the preparation of the data required to define the input files for DL_POLY, a popular Molecular Dynamics (MD) package used for the study of molecular systems. The researcher can define in a intuitive way the initial configuration of the molecular system, making use of the X3DMMS virtual reality environment, and prepares the related MD package oriented input files. After having defined the initial conditions of the system, the researcher can carry out the required computations by using the G3CPie workflow environment, which controls the execution of the calculation on a distributed computing infrastructure. To test the validity of the developed model, implemented in the EGI infrastructure, we present the results carried out for a propane bulk system, where the solvation process of propane inside the bulk has been investigated. The presented approach provides a reusable example for other laboratories or groups interested both in acting through virtual representation of the molecular systems and porting their applications to distributed computing infrastructures.     

Developing software beyond customer needs and plans: an exploratory study of its forms and individual-level drivers

Excessive software development is the tendency to develop new software above and beyond the requirements of the market and/or planned specifications. It is a widespread phenomenon involving both risks and flexibility advantages. As it represents a challenging dilemma for software developers, it is important to study its human origins. Drawing on the tripartite model of individual attitudes, this study investigates the influence of developers’s cognitive (intuitive and rational thinking styles), affective (emotional attachment) and behavioural (reliance on past experiences) traits on two forms of excess, beyond needs and beyond plans. Using survey data on 307 software developers, this study shows that different manifestations of excess are associated with distinct traits of software developers. Emotional attachment drives beyond needs excess. A positive (negative) association is found between relying on past experiences and beyond needs excess (beyond plans excess). An intuitive cognitive style fosters the inclusion of extra features in the new product scope, whereas a rational style might lead to developing one-size-fits-all software that targets the needs of a broad user base. These findings contribute to research on the development of digital new products and production technologies by offering a comprehensive yet fine-grained picture of excessive software development’s nature and drivers.