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Microbes use signaling factors for intraspecies and interspecies communications. While many intraspecies signaling factors have been found and characterized, discovery of factors for interspecies communication is lagging behind. To facilitate the discovery of such factors, we explored the potential of a mixed microbial culture (MMC) derived from wheatgrass, in which heterogeneity of this microbial community might elicit signaling factors for interspecies communication. The stability of Wheatgrass MMC in terms of community structure and metabolic output was first characterized by 16S ribosomal RNA amplicon sequencing and liquid chromatography/mass spectrometry (LC/MS), respectively. In addition, detailed MS analyses led to the identification of 12-hydroxystearic acid (12-HSA) as one of the major metabolites produced by Wheatgrass MMC. Stereochemical analysis revealed that Wheatgrass MMC produces mostly the (R)-isomer, although a small amount of the (S)-isomer was also observed. Furthermore, 12-HSA was found to modulate planktonic growth and biofilm formation of various marine bacterial strains. The current study suggests that naturally derived MMCs could serve as a simple and reproducible platform to discover potential signaling factors for interspecies communication. In addition, the study indicates that hydroxylated long-chain fatty acids, such as 12-HSA, may constitute a new class of interspecies signaling factors., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

To develop a robust quantitative calibration model for spectroscopy, different sources of variability that are not directly related to the components of interest should be included in the calibration samples; this variability should be similar to that which is anticipated during validation and routine operation. Moisture content of pharmaceutical samples can vary as a function of supplier, storage conditions, geographic origin or seasonal variation. Additionally, some pharmaceutical operations (e. g., wet granulation) cause exposure of excipients and API to water. Although water is a weak Raman scatterer, moisture variability has an indirect effect on analytical model performance. Because many pharmaceutical components have intrinsic fluorescent characteristics (with broad spectral features), moisture variability may cause spectral artifacts in the form of baseline variation associated with fluorescence quenching. This work investigates the deleterious effects of water quenching on quantitative prediction accuracy of a multivariate calibration algorithm for Raman spectroscopy. To demonstrate this, a formulation composed of acetaminophen, lactose, microcrystalline cellulose, HPMC and magnesium stearate was used. Tablets were manufactured using laboratory scale equipment. A full-factorial design was used to vary acetaminophen (5 levels), and excipient ratios (3 levels) to generate tablets for calibration and testing. Tablet moisture variation was introduced by placing samples in different humidity chambers. Significant spectral effects arising from fluorescence were identified in the Raman spectra and due to moisture variation: the fluorescence related spectral variability caused substantial degradation of the prediction performance for API. The work demonstrated that accounting for moisture variation during method development reduced the prediction error of the multivariate prediction model., (Copyright © 2018 Elsevier B.V. All rights reserved.)

There is a strong need in the medical device industry to decrease failure rates of biomedical devices by reducing the incidence of defect structures and contaminants during the production process. The detection and identification of defect structures and contaminants is crucial for many industrial applications. The present study exploits reference-free X-ray fluorescence (XRF) analysis as an analytical tool for the traceable characterization of surface contaminants of medical devices, in particular N,N'-ethylene-bis (stearamide), an ubiquitous compound used in many industrial applications as a release agent or friction reduction additive. Reference-free XRF analysis as primary method has been proven to be capable of underpinning all other applied methods since it yields the absolute mass deposition of the selected N,N'-ethylene-bis (stearamide) contaminant whilst X-ray absorption fine structure analysis determines the chemical species. Ambient vibrational spectroscopy and mass spectroscopy methodologies such as Fourier transform infrared, Raman, and secondary ion mass spectroscopy have been used in this systematic procedure providing an extensive range of complementary analyses. The calibration procedure described in this paper was developed using specially designed and fabricated model systems varying in thickness and substrate material. Furthermore, typical real medical devices such as both a polyethylene hip liner and a silver-coated wound dressing have been contaminated and investigated by these diverse methods, enabling testing of this developed procedure. These well-characterized samples may be used as calibration standards for bench top instrumentation from the perspective of providing traceable analysis of biomaterials and surface treatments. These findings demonstrate the potential importance and usefulness of combining complementary methods for a better understanding of the relevant organic materials., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Obesity is a major health crisis worldwide and new treatments are needed to fight this epidemic. Using the swine model, we recently reported that dietary L-arginine (Arg) supplementation promotes muscle gain and reduces body-fat accretion. The present study tested the hypothesis that Arg regulates expression of key genes involved in lipid metabolism in skeletal muscle and white adipose tissue. Sixteen 110-day-old barrows were fed for 60 days a corn- and soybean-meal-based diet supplemented with 1.0% Arg or 2.05% L-alanine (isonitrogenous control). Blood samples, longissimus dorsi muscle and overlying subcutaneous adipose tissue were obtained from 170-day-old pigs for biochemical studies. Serum concentrations of leptin, alanine and glutamine were lower, but those for Arg and proline were higher in Arg-supplemented pigs than in control pigs. The percentage of oleic acid was higher but that of stearic acid and linoleic acid was lower in muscle of Arg-supplemented pigs, compared with control pigs. Dietary Arg supplementation increased mRNA levels for fatty acid synthase in muscle, while decreasing those for lipoprotein lipase, glucose transporter-4, and acetyl-coenzyme A carboxylase-α in adipose tissue. Additionally, mRNA levels for hormone sensitive lipase were higher in adipose tissue of Arg-supplemented pigs compared with control pigs. These results indicate that Arg differentially regulates expression of fat-metabolic genes in skeletal muscle and white adipose tissue, therefore favoring lipogenesis in muscle but lipolysis in adipose tissue. Our novel findings provide a biochemical basis for explaining the beneficial effect of Arg in improving the metabolic profile in mammals (including obese humans)., (Copyright © 2011 Elsevier Inc. All rights reserved.)

The distribution of magnesium stearate (MgSt) in tablet granule has a significant impact on the compression process. A rapid quantitative method for evaluating magnesium stearate content by atomic absorption was established. The MgSt was extracted from the granule in 0.1 mol/L nitric acid and the resulting free magnesium ion quantitated by atomic absorption. The total analysis time was significantly shortened in comparison to the previously used sample ignition method. This newly established method was evaluated with several drug products and several types of blender. The analytical method was also applied to tablets with poor compression (rough tablet surface). The MgSt content in these rough surface tablets was significantly lower than in tablets with smooth surfaces from the same batch. From these results, this atomic absorption method is considered to be an accurate and useful method for evaluating MgSt distribution and can be applied to tablet manufacturing process validation.

The aim of this study was to compare the contents of the main biochemical compounds and the antioxidant capacity of five Spanish olive oils by four different antioxidant tests and to find out the most valuable oil for disease preventing diets. Fatty acids, sterols and individual antioxidant compounds in Arbequina, Hojiblanca, Extra Virgin, Picual and Lampante Spanish olive oils were determined. Antioxidant activities were done as well using different radical scavenging activities: total radical-trapping antioxidative potential by ABAP (TRAP-ABAP), radical scavenging activity by DPPH (RSA-DPPH), antioxidant assay by beta-carotene-linoleate model system (AA-beta-carotene) and total antioxidant status by ABTS (TAA-ABTS). The highest content of all studied antioxidant compounds (353; 329; 4.6 and 2.7 mg/kg for tocopherols, tocotrienols, polyphenols and o-diphenols, respectively) was found in Extra Virgin oil. Also the highest antioxidant capacity was observed in Extra Virgin oil (668 nM/ml; 29.4%; 40.4% and 2.64 mM TE/kg for TRAP-ABAP, RSA-DPPH, AA- beta-carotene and TAA-ABTS, respectively). The correlation between total phenols and antioxidant capacities measured by four methods was very high, but the highest for the beta-carotene (R = 0.9958). In conclusion, the best method for determination of the antioxidant capacity of olive oils is the beta-carotene test. Extra Virgin olive oil has high organoleptic properties and the highest antioxidant activity. The above-mentioned makes this oil a preferable choice for diseases preventing diets.

We have evaluated the fatty acid composition of high density lipoprotein (HDL) cholesteryl esters in serum specimens of 83 male subjects, divided into 2 groups: one with a mean HDL cholesterol of 0.75 mmol/L and the other with 1.25 mmol/L. The specimens with low HDL cholesterol concentrations had an increase in the proportion of palmitic acid (6%) and stearic acid (67%) compared with specimens and high HDL cholesterol concentration. When the fatty acid composition of the same specimens was evaluated in groups corresponding to the four major phenotypes (normolipidemic, hypercholesterolemic, hypertriglyceridemic and hyperlipidemic), we found statistically no significant differences between these groups in the HDL cholesteryl ester fraction. There were, however, statistically significant differences between the hyperlipidemic group and the other three groups in the proportions of palmitoleic, oleic and stearic acids, and in the ratio of oleic/linoleic acids of total cholesteryl esters.