Effects of temperature, ammonium and glucose concentrations on yeast growth in a model wine system

In enology, alcoholic fermentation is a complex process involving several mechanisms. Slow and incomplete alcoholic fermentation is a chronic problem for the wine industry and factors leading to sluggish and stuck fermentations have been extensively studied and reviewed. The most studied cause of sluggish and stuck fermentation is the nitrogen content limitation. Nevertheless, other factors, such as temperature of fermentation and sugar concentration can affect the growth of yeasts. In this study we modelled the yeast growth‐cycle in wine model system as a function of temperature, sugar and ammonium concentrations; the individual effects and the interaction of these factors were analysed by means of a quadratic response surface methodology. Cell concentrations and weight loss were monitored in the whole wine fermentation process. The results of central composite design show that lower is the availability of nitrogen, higher is the cell growth rate; moreover, initial nitrogen concentration also influences survival time of Saccharomyces cerevisiae.     

Perceived interactivity leading to e-loyalty: Development of a model for cognitive–affective user responses

Novel applications of website interactivity are important to attract and retain online users. In this empirical study five designs for interactivity are examined using different web-poll interfaces. The goal of the investigation is to examine perceived interactivity in a model which includes most commonly tested cognitive elements such as efficiency and effectiveness, but augments this model with the inclusion of a cognitive–affective element for trust, and an affective element of enjoyment. More specifically, a model is created to validate the relationship of perceived interactivity (comprised of user control, user connectedness, and responsiveness of the web-poll application) to efficiency, effectiveness, trust and enjoyment, of the website. In turn, efficiency, effectiveness, trust, and enjoyment are tested for their influence on user behavioral intentions for e-loyalty. All relationships in the model are supported. In addition, exploratory evaluation of qualitative comments is conducted to investigate additional insights between the five web-poll treatments in this investigation. The research confirms the complexity of a model in which cognitive, cognitive–affective and affective elements are present, and advances knowledge on the consequences of perceived interactivity. In additional to theoretical advancements, the research has merit for web designers and online marketers regarding how to enhance interactive online web applications.     

A Novel Neurofilament Light Chain ELISA Validated in Patients with Alzheimer’s Disease,Frontotemporal Dementia,and Subjective Cognitive Decline,and the Evaluation of Candidate Proteins for Immunoassay Calibration

Neurofilament light chain (Nf-L) is a well-known biomarker for axonal damage; however, the corresponding circulating Nf-L analyte in cerebrospinal fluid (CSF) is poorly characterized. We therefore isolated new monoclonal antibodies against synthetic peptides, and these monoclonals were characterized for their specificity on brain-specific intermediate filament proteins. Two highly specific antibodies, ADx206 and ADx209, were analytically validated for CSF applications according to well-established criteria. Interestingly, using three different sources of purified Nf-L proteins, a significant impact on interpolated concentrations was observed. With a lower limit of analytical sensitivity of 100 pg/mL using bovine Nf-L as the calibrator, we were able to quantify the Nf-L analyte in each sample, and these Nf-L concentrations were highly correlated to the Uman diagnostics assay (Spearman rho = 0.97, p < 0.001). In the clinical diagnostic groups, the new Nf-L ELISA could discriminate patients with Alzheimer’s disease (AD, n = 20) from those with frontotemporal lobe dementia (FTD, n = 20) and control samples with subjective cognitive decline (SCD, n = 20). Henceforth, this novel Nf-L ELISA with well-defined specificity and epitopes can be used to enhance our understanding of harmonizing the use of Nf-L as a clinically relevant marker for neurodegeneration in CSF.     

Preparation and characterization of a macroporous agarose monolith as a stationary phase in IMAC chromatography

A macroporous monolith used as stationary phase for the separation of biomolecules by immobilized metal ion affinity chromatography (IMAC), based on D5 agarose (D5) chemically modified was proposed. The characterization of physical properties was studied. Pressure drop was <0.4?MPa, being a very low value compared to other similar chromatographic supports. The adsorption/desorption process was carried out using bovine serum albumin (BSA) at pH 7.4 as a target protein. The monolith was re-used for 20 adsorption/desorption cycles and it was possible to verify that the average percentage of adsorption in all cycles was 89.65%. It was also possible to apply a model in order to obtain the kinetic adsorption constant (k_a), desorption constant (k_d) and equilibrium constant (K_e) by the proposed system. These results indicate that this system is governed by the adsorption process.     

Teucrium plant species as natural sources of novel anticancer compounds: antiproliferative, proapoptotic and antioxidant properties

This study deals with total phenolic content, antiproliferative and proapoptotic activity of methanolic extracts from different Teucrium species and the effect on the prooxidant/antioxidant status in HCT-116 cells. The total phenolic content of the extracts was measured spectrophotometricaly and the obtained results ranged from 56.62 mg/g to 172.50 mg GA/g. The antiproliferative activity of methanolic extracts from different Teucrium species was determined using MTT cell viability assay, where IC(50) value was used as a parameter for cytotoxicity. The type of cell death was explored by fluorescence microscopy using the acridin orange/ethidium bromide method. MTT assay showed that all extracts significantly reduced cell viability in a dose-dependent manner, with very low IC(50) values. The highest content of phenolic compounds and the best cytotoxic activity on HCT-116 cells after 24 h of exposure was in T. chamaedrys extract, with IC(50) values of 5.48 × 10(-9) μg/mL. After 72 h, methanolic extract of T. arduini appeared to have the best cytotoxic activity on HCT-116, with IC(50) values of 0.37 μg/mL. Treatments caused typical apoptotic morphological changes in HCT-116 cells and showed a high percentage of apoptotic cells. The results of the presented research indicate that some Teucrium extracts are a very rich source of phenols, which may directly contribute to high antiproliferative and proapoptotic activity.     

Synthesis, structural and magnetic properties of nanostructured Ca0.9Gd0.1MnO3 obtained by modified glycine nitrate procedure (MGNP)

Ca_0.9Gd_0.1MnO₃ nanopowders with perovskite type crystal structure were synthesized by modified glycine nitrate procedure. Nanopowders were prepared by combining glycine with metal nitrates and/or metal acetates in their appropriate stoichiometric ratios. Modification of the procedure was performed by partial replacement of nitrates by acetates, in order to control the burn-up reaction. Obtained Ca_0.9Gd_0.1MnO₃ powders were calcinated in the temperature interval from 850 °C to 950 °C for 10 min. Properties such as phase evolution, lattice parameters, chemical composition and magnetic properties were monitored by DTA, X-ray diffraction, SEM/EDS and magnetic measurements. Magnetic measurements performed at the sample with the smallest crystallite size showed that a 10% of Gd³⁺ substituted Ca²⁺ ions changes antiferromagnetic properties of CaMnO₃ by the introduction of ferromagnetic interaction due to a double exchange between Mn³⁺ and Mn⁴⁺ ions. Presence of competing interactions and their randomness lead to a formation of a spin glass state below Neel temperature T_N = 110 K. From the high temperature magnetic susceptibility measurements effective magnetic moment of manganese ions is determined which lies between the values for Mn³⁺ and Mn⁴⁺ ions.     

A comparative study of photocatalytically active nanocrystalline tetragonal zyrcon-type and monoclinic scheelite-type bismuth vanadate

Monoclinic scheelite-type BiVO₄ is currently considered as one of the most promising non-titania photocatalysts, wheras tetragonal zircon-type BiVO₄ is still poorly understood. Herein, a new and simple synthetic approach was applied and nanostructured single-phase zircon-type BiVO₄ was successfully prepared by a controllable ethylene-glycol colloidal route. In addition, nanostructured monoclinic scheelite-type BiVO₄ powders were also fabricated through annealing of the as-prepared samples. A comparative study of the two BiVO₄ polymorphs was conducted and it turned out that the novel synthetic approach had a significant impact on porosity and photocatalytic performance of zircon-structured BiVO₄. All the prepared materials, as-prepared and annealed, were mesoporous, while measured values of specific surface area of some zircon-structured samples (～34?m²/g) were ～7 times higher than those reported thus far for this phase. Interestingly, for the first time, zircon-type BiVO₄, previously considered to be a poor photocatalyst, exhibited a better overall performance in degradation of methyl orange compared to monoclinic scheelite-type BiVO₄. Hence, it could be expected that the here-presented synthesis and observations will both arouse interest in scarcely studied tetragonal zircon-type BiVO₄ and facilitate as well as speed up further research of its properties.     

Antiproliferative and Proapoptotic Activities of Methanolic Extracts from Ligustrum vulgare L. as an Individual Treatment and in Combination with Palladium Complex

The aim of this study is to examine the growth inhibitory effects of methanolic leaf and fruit extracts of L. vulgare on HCT-116 cells over different time periods and their synergistic effect with a Pd(apox) complex. The antiproliferative activity of plant extracts alone or in combination with the Pd(apox) complex was determined using MTT cell viability assay, where the IC(50) value was used as a parameter of cytotoxicity. Results show that antiproliferative effects of L. vulgare extracts increase with extension of exposure time, with decreasing IC(50) values, except for 72 h where the IC(50) values for methanolic leaf extract were lower than for the fruit extract. The Pd(apox) complex alone had a weak antiproliferative effect, but combination with L. vulgare extracts caused stronger effects with lower IC(50) values than with L. vulgare extracts alone. The type of cell death was explored by fluorescence microscopy using the acridin orange/ethidium bromide method. Treatments with plant extracts caused typical apoptotic morphological changes in HCT-116 cells and co-treatments with Pd(apox) complex caused higher levels of apoptotic cells than treatment with plant extracts alone. The results indicate that L. vulgare is a considerable source of natural bioactive substances with antiproliferative activity on HCT-116 cells and which have a substantial synergistic effect with the Pd(apox) complex.