Validation of a high performance liquid chromatographic method for quantitative determination of boldine in fluid extract of boldo

A simple and specific method was validated for quantification of boldine in fluid extract of boldo (Peumus boldus Mol.) using high-performance liquid chromatography. A reversed-phase C18 , Phenomenex® (150 x 4.6 mm, 4 µm) column was employed. The mobile phase consisted of 0.1 % trifluoroacetic acid and acetonitrile (78:22, v/v) at a flow rate of 0.8 mL/min. The column was maintained at 30 °C and the boldine peak detection was performed at a wavelength of 281 nm. The parameters used in the validation process were: linearity, specificity, precision, accuracy, limit of detection, limit of quantification and robustness. The validated method was selective and linear (r≥0.9991) for boldine concentration considering 5.0, 10.0, 15.0, 20.0 and 25.0 micro;g/mL. The recovery ranged from 90.93 % to 96.24 % and the limit of quantification was 2.41 micro;g/mL. The precision determined was reported as RSD (1.73 %). The method can be successfully applied to measure boldine concentrations in Boldo extract and be included in routine analysis of quality control.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Validation of a high performance liquid chromatographic method for quantitative determination of boldine in fluid extract of boldo

A simple and specific method was validated for quantification of boldine in fluid extract of boldo (Peumus boldus Mol.) using high-performance liquid chromatography. A reversed-phase C18 , Phenomenex® (150 x 4.6 mm, 4 µm) column was employed. The mobile phase consisted of 0.1 % trifluoroacetic acid and acetonitrile (78:22, v/v) at a flow rate of 0.8 mL/min. The column was maintained at 30 °C and the boldine peak detection was performed at a wavelength of 281 nm. The parameters used in the validation process were: linearity, specificity, precision, accuracy, limit of detection, limit of quantification and robustness. The validated method was selective and linear (r≥0.9991) for boldine concentration considering 5.0, 10.0, 15.0, 20.0 and 25.0 micro;g/mL. The recovery ranged from 90.93 % to 96.24 % and the limit of quantification was 2.41 micro;g/mL. The precision determined was reported as RSD (1.73 %). The method can be successfully applied to measure boldine concentrations in Boldo extract and be included in routine analysis of quality control.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Axisymmetric equilibria of a gravitating plasma with incompressible flows

It is found that the ideal magnetohydrodynamic equilibrium of an axisymmetric gravitating magnetically confined plasma with incompressible flows is governed by a second-order elliptic differential equation for the poloidal magnetic flux function containing five flux functions coupled with a Poisson equation for the gravitation potential, and an algebraic relation for the pressure. This set of equations is amenable to analytic solutions. As an application, the magnetic-dipole static axisymmetric equilibria with vanishing poloidal plasma currents derived recently by Krasheninnikov, Catto, and Hazeltine [Phys. Rev. Lett. {\bf 82}, 2689 (1999)] are extended to plasmas with finite poloidal currents, subject to gravitating forces from a massive body (a star or black hole) and inertial forces due to incompressible sheared flows. Explicit solutions are obtained in two regimes: (a) in the low-energy regime $\beta_0\approx \gamma_0\approx \delta_0 \approx\epsilon_0\ll 1$, where $\beta_0$, $\gamma_0$, $\delta_0$, and $\epsilon_0$ are related to the thermal, poloidal-current, flow and gravitating energies normalized to the poloidal-magnetic-field energy, respectively, and (b) in the high-energy regime $\beta_0\approx \gamma_0\approx \delta_0 \approx\epsilon_0\gg 1$. It turns out that in the high-energy regime all four forces, pressure-gradient, toroidal-magnetic-field, inertial, and gravitating contribute equally to the formation of magnetic surfaces very extended and localized about the symmetry plane such that the resulting equilibria resemble the accretion disks in astrophysics.Comment: 12 pages, latex, to be published in Geophys. Astrophys. Fluid Dynamic

Resources and users in the tagging process: approaches and case studies

In this contribution we propose a comparison between two distinct approaches to the annotation of digital resources. The former, top-down, is rooted in the cathedral model and is based on an authoritative, centralized definition of the adopted mark-up language; the latter, bottom-up, refers to the bazaar model and is based on the contributions of a community of users. These two approaches are analyzed taking into account both their descriptive potential and the constraints they impose on the reasoning process of recommender systems, with special reference to user profiling. Three case studies are described, with reference to research projects that apply these approaches in the contexts of e-learning and knowledge management

Web conversations about complementary and alternative medicines and cancer: Content and sentiment analysis

Background: The use of complementary and alternative medicine (CAM) among cancer patients is widespread and mostly self-administrated. Today, one of the most relevant topics is the nondisclosure of CAM use to doctors. This general lack of communication exposes patients to dangerous behaviors and to less reliable information channels, such as the Web. The Italian context scarcely differs from this trend. Today, we are able to mine and analyze systematically the unstructured information available in the Web, to get an insight of people's opinions, beliefs, and rumors concerning health topics. Objective: Our aim was to analyze Italian Web conversations about CAM, identifying the most relevant Web sources, therapies, and diseases and measure the related sentiment. Methods: Data have been collected using the Web Intelligence tool ifMONITOR. The workflow consisted of 6 phases: (1) eligibility criteria definition for the ifMONITOR search profile; (2) creation of a CAM terminology database; (3) generic Web search and automatic filtering, the results have been manually revised to refine the search profile, and stored in the ifMONITOR database; (4) automatic classification using the CAM database terms; (5) selection of the final sample and manual sentiment analysis using a 1-5 score range; (6) manual indexing of the Web sources and CAM therapies type retrieved. Descriptive univariate statistics were computed for each item: absolute frequency, percentage, central tendency (mean sentiment score [MSS]), and variability (standard variation Ò). Results: Overall, 212 Web sources, 423 Web documents, and 868 opinions have been retrieved. The overall sentiment measured tends to a good score (3.6 of 5). Quite a high polarization in the opinions of the conversation partaking emerged from standard variation analysis (δ≥1). In total, 126 of 212 (59.4%) Web sources retrieved were nonhealth-related. Facebook (89; 21%) and Yahoo Answers (41; 9.7%) were the most relevant. In total, 94 CAM therapies have been retrieved. Most belong to the "biologically based therapies or nutrition" category: 339 of 868 opinions (39.1%), showing an MSS of 3.9 (δ=0.83). Within nutrition, "diets" collected 154 opinions (18.4%) with an MSS of 3.8 (δ=0.87); "food as CAM" overall collected 112 opinions (12.8%) with a MSS of 4 (δ=0.68). Excluding diets and food, the most discussed CAM therapy is the controversial Italian "Di Bella multitherapy" with 102 opinions (11.8%) with an MSS of 3.4 (δ=1.21). Breast cancer was the most mentioned disease: 81 opinions of 868. Conclusions: Conversations about CAM and cancer are ubiquitous. There is a great concern about the biologically based therapies, perceived as harmless and useful, under-rating all risks related to dangerous interactions or malnutrition. Our results can be useful to doctors to be aware of the implications of these beliefs for the clinical practice. Web conversation exploitation could be a strategy to gain insights of people's perspective for other controversial topics

HPLC method for assessment of in vitro and in vivo recovery of gatifloxacin using microdialysis

A simple and sensitive HPLC method was validated for assessment of in vitro and in vivo recovery of gatifloxacin using microdialysis. The validation parameters of linearity, precision, accuracy and limit of detection were studied as well as stability. Correlation coefficient (r2) obtained was > 0.999 for all calibration curves (20-600 ng.mL-1). Intra- and inter-day precision, expressed as the relative standard deviation (RSD) were less than 1.59 % and 1.33 %, respectively. Acceptable accuracy was achieved for all concentrations (99.17-101.35 %). The limit of quantification of the method was 20 ng.mL-1. The method showed the stability of gatifloxacin when submitted to different conditions. The validated method was applied to study calibration of microdialysis probes. The probe recovery was determined by no net flux experiment in vitro and in vivo. The in vitro and in vivo recovery for gatifloxacin was 30.9 ± 2.9 % and 28.9 ± 0.8 %, respectively. No differences were found between the two approaches. The HPLC method offers advantages because it has no extra sample handling steps; it is sensitive and can be used to determine free concentrations of gatifloxacin in tissues.Colegio de Farmacéuticos de la Provincia de Buenos Aire

X-rays investigations for the characterization of two 17th century brass instruments from Nuremberg

A recent finding at the Castello Sforzesco in Milan of two brass natural horns from the end of the 17th century and assigned to the Haas family from Nuremberg brought to light new information about this class of objects. The instruments were heavily damaged, but their historical value was great. In this study, a multidisciplinary approach mainly based on non-invasive analytical techniques and including X-rays investigations (X-ray radiography, X-ray fluorescence and X-ray diffraction) was used. The present study was aimed at: i) pointing out the executive techniques for archaeometric purposes; ii) characterizing the morphological and the chemical features of materials; and iii) identifying and mapping the damages of the structure and the alterations of the surface

A bacterial formula with native strains as alternative to chemical fertiliser for tomato crop

Global tomato productivity is threatened by biotic and abiotic stressors. To support and guarantee an adequate yield of tomato crops, agricultural practices have been based on the intensive use of fertilisers with negative impacts on the environment. This study presents a simple and effective strategy of functional bioaugmentation, suitable for different varieties, to replace chemical fertilisation. A tailored microbial formula composed by eight indigenous strains (including the genera Delftia, Pseudomonas, Paenarthrobacter, Phyllobacterium, Bacillus, and Acinetobacter) was developed as biofertilizer. Strains were selected from native soil for their plant growth-promoting (PGP) functions, and combined respecting the taxonomic composition of the original PGP heterotrophic community structure. The effect of the bio-fertilisation vs chemical fertilisation was tested in three successive field trials in the company greenhouse, with different tomato varieties (Camone, Oblungo, Cherry). When bio-fertilisation was applied only twice during the Camone's life cycle, tomato yield was significantly reduced (0.8 vs 2.1 kg per plant, p = 0.0003). However, monthly inoculation during plant growth led to a fruit yield comparable to that obtained with chemical fertilisers (about 1.5 kg per plant for Oblungo, and about 2 kg per plant for Cherry variety, p = 0.9999). Bio-fertilization did not significantly affect plant height; only during the last growing period of the Cherry variety, a significantly higher average plant height (p < 0.0001) was observed with chemical fertiliser. The results indicate that a knowledge-based bacterial formula and monthly inoculation during the plant growth can be a successful bio-fertilisation strategy. These findings may pave the way towards more sustainable tomato production, since farming practices are becoming increasingly crucial, in accordance with Agenda 2030 and the UE "Farm to Fork" strategy.[GRAPHICS]

COVID-19 Vaccine Hesitancy in Italy: Predictors of Acceptance, Fence Sitting and Refusal of the COVID-19 Vaccination

Background: The hesitancy in taking the COVID-19 vaccine is a global challenge. The need to identify predictors of COVID-19 vaccine reluctance is critical. Our objectives were to evaluate sociodemographic, psychological, and behavioral factors, as well as attitudes and beliefs that influence COVID-19 vaccination hesitancy in the general population of Italy. Methods: A total of 2,015 people were assessed in two waves (March, April and May, 2021). Participants were divided into three groups: (1) individuals who accepted the vaccination (“accepters”); (2) individuals who refused the vaccination (“rejecters”); and (3) individuals who were uncertain about their attitudes toward the vaccination (“fence sitters”). Group comparisons were performed using ANOVA, the Kruskal-Wallis test and chi-square tests. The strength of the association between the groups and the participants' characteristics was analyzed using a series of multinomial logistic regression models with bootstrap internal validation (one for each factor). Results: The “fence sitters” group, when compared to the others, included individuals of younger age, lower educational level, and worsening economic situation in the previous 3 months. After controlling for sociodemographic factors, the following features emerged as the main risk factors for being “fence sitters” (compared with vaccine “accepters”): reporting lower levels of protective behaviors, trust in institutions and informational sources, frequency of use of informational sources, agreement with restrictions and higher conspirative mentality. Higher levels of COVID-19 perceived risk, trust in institutions and informational sources, frequency of use of informational sources, agreement with restrictions and protective behaviors were associated with a higher likelihood of becoming “fence sitters” rather than vaccine “rejecters.” Conclusions: The “fence sitters” profile revealed by this study is intriguing and should be the focus of public programmes aimed at improving adherence to the COVID-19 vaccination campaign

Chandra Detections of Two Quiescent Black Hole X-Ray Transients

Using the Chandra X-ray Observatory, we have detected the black hole transients V4641 Sgr and XTE J1859+226 in their low luminosity, quiescent states. The 0.3-8 keV luminosities are (4.0^(+3.3)_(-2.4))E31 (d/7 kpc)^2 erg/s and (4.2^(+4.8)_(-2.2))E31 (d/11 kpc)^2 erg/s for V4641 Sgr and XTE J1859+226, respectively. With the addition of these 2 systems, 14 out of the 15 transients with confirmed black holes (via compact object mass measurements) now have measured quiescent luminosities or sensitive upper limits. The only exception is GRS 1915+105, which has not been in quiescence since its discovery in 1992. The luminosities for V4641 Sgr and XTE J1859+226 are consistent with the median luminosity of 2E31 erg/s for the systems with previous detections. Our analysis suggests that the quiescent X-ray spectrum of V4641 Sgr is harder than for the other systems in this group, but, due to the low statistical quality of the spectrum, it is not clear if V4641 Sgr is intrinsically hard or if the column density is higher than the interstellar value. Focusing on V4641 Sgr, we compare our results to theoretical models for X-ray emission from black holes in quiescence. Also, we obtain precise X-ray positions for V4641 Sgr and XTE J1859+226 via cross-correlation of the X-ray sources detected near our targets with IR sources in the 2 Micron All-Sky Survey catalog.Comment: 4 pages, Accepted by ApJ Letter