Geographic origin of southern Brazilian wines by carbon and oxygen isotope analyses

We present a method that can differentiate between the varieties of grapes and the vintages of wines and show the relationship between the grapes, the wine and the geographic location. The place of origin and its geographic and climatic characteristics were determined by the isotopic ratios, ¹³C/¹²C of the ethanol and ¹⁸O/¹⁶O of the water content of wine (wine water), for southern Brazil wines. The producing subregions of Pinto Bandeira, Vale dos Vinhedos and Nova Pádua showed differences in the temperature, rainfall and humidity conditions used for the production under microvinification conditions of Merlot and Cabernet Sauvignon varieties, in the harvests of 2005 and 2006. An isotope ratio mass spectrometer coupled to an elemental analyzer was used to measure the ¹³C/¹²C of ethanol and the ¹⁸O/¹⁶O of wine water. Regardless of the grape variety used, it was possible to determine the subregion through measurement of the δ¹⁸O values in both harvests. The altitudes of the different subregions led to statistical differences and demonstrated an influence mainly on the δ¹⁸O values of wine water. The δ¹⁸O value of wine water was determined to be more selective for the determination of the cultivation subregions than the δ¹³C value of the ethanol. The altitude and latitude influenced mainly the δ ¹⁸O values of wine water and the ethanol. The climatic influences are more noteworthy in distinguishing the year of the harvest than the cultivation subregion. Copyright © 2010 John Wiley & Sons, Ltd.     

Seasonal Chemical Evaluation of Miconia chamissois Naudin from Brazilian Savanna

Miconia chamissois Naudin is a species from the Cerrado, which is being increasingly researched for its therapeutic potential. The aim of this study was to obtain a standardized extract and to evaluate seasonal chemical variations. Seven batches of aqueous extracts from leaves were produced for the standardization. These extracts were evaluated for total solids, polyphenol (TPC) and flavonoid content (TFC), vitexin derivative content, antioxidant activity; thin-layer chromatography (TLC), and high-performance liquid chromatography (HPLC) profiles were generated. For the seasonal study, leaves were collected from five different periods (May 2017 to August 2018). The results were correlated with meteorological data (global radiation, temperature, and rainfall index). Using chromatographic and spectroscopic techniques, apigenin C-glycosides (vitexin/isovitexin) and derivatives, luteolin C-glycosides (orientin/isoorientin) and derivatives, a quercetin glycoside, miconioside B, matteucinol-7-O-β-apiofuranosyl (1 → 6) -β-glucopyranoside, and farrerol were identified. Quality parameters, including chemical marker quantification by HPLC, and biological activity, are described. In the extract standardization process, all the evaluated parameters showed low variability. The seasonality study revealed no significant correlations (p < 0.05) between TPC or TFC content and meteorological data. These results showed that it is possible to obtain extracts from M. chamissois at any time of the year without significant differences in composition.     

The preparation and reactions of protected glyphosate imidate,thioimidate, and thiono esters from N-[diphenoxyphosphinylmethyl]glycinonitrile: Comparative reactivities of activated carboxylate versus phosphonate esters

The highly efficient syntheses of novel protected glyphosate imidate, thioimidate, and thiono ester derivatives are described starting from N-[diphenoxyphosphinylmethyl]glycinonitrile 3b . The scope, utility and limitations in using each of these activated carboxylate functionalities for further transformations to new “masked” heterocyclic derivatives are defined. While the solution stability of the imidate and thioimidate series limited the synthetic application of these species, the corresponding thiono ester derivatives were valuable synthetic intermediates, providing a short, efficient route to the first glyphosate derivatives containing 1,3,4-oxadiazole and 1,2,4-triazole ring systems in place of the carboxylate group. These thiono esters thus undergo selective nucleophilic addition at this activated carboxylate center, while retaining the reactive diphenyl phosphonate moiety.     

Generation of digital elevation models by using SIR-C/X-SARmultifrequency two-pass interferometry: the Etna case study

The authors exploit the interferometric multifrequency potentiality of the SIR-C/X-SAR system which is equipped with an L-, C-, and X-band sensor. They present a solution to improve the unwrapping performance of the C- and X-band data by considering the L-band unwrapped pattern. A new algorithm for the generation of a single digital elevation model (DEM) combining L-, C-, and X-band information is presented. This solution is based on the fusion of the unwrapped phase patterns by using a Kalman filter. The proposed fusion operation also accounts for the coherence characteristics of the three data sets. The selected test site is the Mt. Etna region in Italy which is very interesting from the volcanological and geological point of view. Numerical assessments of the achieved results are provided by evaluating the height accuracy with respect to a reference DEM     

Crystal growth kinetics in cordierite and diopside glasses in wide temperature ranges

We measured and collected literature data for the crystal growth rate, u(T), of μ-cordierite (2MgO · 2Al₂O₃ · 5SiO₂) and diopside (CaO · MgO · 2SiO₂) in their isochemical glass forming melts. The data cover exceptionally wide temperature ranges, i.e. 800–1350 °C for cordierite and 750–1378 °C for diopside. The maximum of u(T) occurs at about 1250 °C for both systems. A smooth shoulder is observed around 970 °C for μ-cordierite. Based on measured and collected viscosity data, we fitted u(T) using standard crystal growth models. For diopside, the experimental u(T) fits well to the 2D surface nucleation model and also to the screw dislocation growth mechanism. However, the screw dislocation model yields parameters of more significant physical meaning. For cordierite, these two models also describe the experimental growth rates. However, the best fittings of u(T) including the observed shoulder, were attained for a combined mechanism, assuming that the melt/crystal interface growing from screw dislocations is additionally roughened by superimposed 2D surface nucleation at large undercoolings, starting at a temperature around the shoulder. The good fittings indicate that viscosity can be used to assess the transport mechanism that determines crystal growth in these two systems, from the melting point T_m down to about T_g, with no sign of a breakdown of the Stokes–Einstein/Eyring equation.     

Structural Aspects of the Fermion-Boson Mapping in Two-Dimensional Gauge and Anomalous Gauge Theories with Massive Fermions

Using a synthesis of the functional integral and operator approaches we discuss the fermion-boson mapping and the role played by the Bose field algebra in the Hilbert space of two-dimensional gauge and anomalous gauge field theories with massive fermions. In QED₂ with quartic self-interaction among massive fermions, the use of an auxiliary vector field introduces a redundant Bose field algebra that should not be considered as an element of the intrinsic algebraic structure defining the model. In anomalous chiral QED₂ with massive fermions the effect of the chiral anomaly leads to the appearance in the mass operator of a spurious Bose field combination. This phase factor carries no fermion selection rule and the expected absence of Θ-vacuum in the anomalous model is displayed from the operator solution. Even in the anomalous model with massive Fermi fields, the introduction of the Wess-Zumino field replicates the theory, changing neither its algebraic content nor its physical content.     

Real-World Scenarios With Negative Interest Rates Based on the LIBOR Market Model

ABSTRACT

In this article, we present a methodology to simulate the evolution of interest rates under real-world probability measure. More precisely, using the multidimensional Shifted Lognormal LIBOR market model and a specification of the market price of risk vector process, we explain how to perform simulations of the real-world forward rates in the future, using the Euler?Maruyama scheme with a predictor?corrector strategy. The proposed methodology allows for the presence of negative interest rates as currently observed in the markets.     

Use of bacterial cellulose in the textile industry and the wettability challenge—a review

Bacterial cellulose (BC) has been studied as an alternative material in several segments of the food, pharmaceutical, materials and textile industries. The importance of BC is linked to sustainability goals, since it is an easily degradable biomaterial of low toxicity to the environment and is a renewable raw material. For use in the textile area, bacterial cellulose has attracted great interest from researchers, but it presents some challenges notably to its hydrophilic structure. This integrative review article brings together studies and methods related to minimizing the hydrophilicity of bacterial cellulose, in order to expand its applicability in the textile industry in its dry state. The databases consulted were Scopus, ScienceDirect, ProQuest and Web of Science, the documents investigated were scientific articles and the time period investigated was between 2015 and 2021. The results showed that although there are methods to make the BC membrane more hydrophobic, future studies in this regard and on other properties must continue so that bacterial cellulose can be commercially introduced in the textile sector.

     

Chemical composition and antioxidant, antimicrobial, and larvicidal activities of the essential oils of Annona salzmannii and A. pickelii (Annonaceae)

The essential oils from the leaves of Annona salzmannii and A. pickelii (Annonaceae) growing in Sergipe, northeastern region of Brazil, were obtained by hydrodistillation using a Clevenger-type apparatus, and analyzed by GC/MS and GC/FID. Thirty-four compounds were identified in the essential oil of A. salzmannii and twenty-seven in that of A. pickelii; sesquiterpenes predominated in both essential oils. Bicyclogermacrene (20.3%), (E)-caryophyllene (19.9%), delta-cadinene (15.3%), alpha-copaene (10.0%), and allo-aromadendrene (5.7%) were the main components of A. salzmannii, and bicyclogermacrene (45.4%), (E)-caryophyllene (14.6%), and alpha-copaene (10.6%) of A. pickelii. The essential oils showed significant antioxidant capacity in the ORAC(FL) and DPPH assays. The antimicrobial activity of these essential oils was also evaluated against bacteria and fungi, as well as the larvicidal activity against Aedes aegypti larvae.