Use of Lactobacillus plantarum fermentation products in bread-making to prevent Bacillus subtilis ropy spoilage

Four fermentation products (FPs) of the lactic acid bacterium Lactobacillus plantarum ITM21B were screened for their anti-Bacillus activity in vitro and in bread-making trials. Results of the storage tests performed with loaves prepared with an FP or calcium propionate demonstrated that after 3 days at 30 degrees C, gross spoilage was evident in only the control loaves, which contained Bacillus subtilis at numbers of about 10(9) cfu/g. The highest inhibitory activity was shown by DM-FP obtained by growing L. plantarum in a defined medium (DM). Significantly, this medium contained an amino acceptor of the aminoacid transamination, namely alpha-ketoglutaric acid, and an aminoacid pool. With loaves prepared using the DM-acid mixture which simulated the DM-FP composition, the same reduction of ropy spoilage as with DM-FP was obtained after 3 days, while the efficacy of the mixture decreased after 7 days. This result suggests the potential involvement of some unknown metabolites in the inhibitory activity of DM-FP. In baked products made with flour based media (M1-FP, M2-FP, M3-FP), no ropy symptoms were noticeable after 3 days storage although a considerable Bacillus count was detected. DM-FP was as effective as calcium propionate (0.3% w/w, based on flour mass) in prolonging the Bacillus free-shelf life of yeast-leavened bread for 7 days.     

Application of capillary electrophoresis to determine metal cations,anions, organic acids,and carbohydrates in some Pinot Noir red wines

Capillary electrophoresis was used for determination of inorganic alkali and alkali earth metal cations, inorganic anions, anions of organic acids, and carbohydrates in six Pinot Noir grape red wines. Spectrum analysis was applied to evaluate the possible chemical differences between the wines from different geographic origin. In addition, sensory evaluation was used to reveal differences between wines from the end user point of view. Both chemical analyses and the sensory evaluation revealed clear differences among the wine samples. The total concentrations of inorganic ions, carboxylate anions, and carbohydrates varied 1.9–3.1 g L⁻¹, 4.3–5.5 g L⁻¹, and 1.5–7.5 g L⁻¹, respectively. Although the grape was same in all samples, the results show considerable variations in chemical composition, the red wine from Tasmanian being the most different among samples.     

1,2,4-Oxadiazole Topsentin Analogs with Antiproliferative Activity against Pancreatic Cancer Cells,Targeting GSK3β Kinase

A new series of topsentin analogs, in which the central imidazole ring of the natural lead was replaced by a 1,2,4-oxadiazole moiety, was efficiently synthesized. All derivatives were pre-screened for antiproliferative activity against the National Cancer Institute (NCI-60) cell lines panel. The five most potent compounds were further investigated in various pancreatic ductal adenocarcinoma (PDAC) cell lines, including SUIT-2, Capan-1, and Panc-1 cells, eliciting EC₅₀ values in the micromolar and sub-micromolar range, associated with significant reduction of cell migration. These remarkable results might be explained by the effects of these new topsentin analogues on epithelial-to-mesenchymal transition markers, including SNAIL-1/2 and metalloproteinase-9. Moreover, flow cytometric analysis after Annexin V-FITC and propidium iodide staining demonstrated that these derivatives enhanced apoptosis of PDAC cells. Keeping with these data, the PathScan intracellular signaling and ELISA array revealed cleavage of caspase-3 and PARP and a significant inhibition of GSK3β phosphorylation, suggesting this kinase as a potential downstream target of our novel compounds. This was further supported by a specific assay for the evaluation of GSK3β activity, showing IC₅₀ values for the most active compounds against this enzyme in the micromolar range.     

Prospective Analysis of Artisanal Mining in the Santa Rita Village: Municipality of Andes,Antioquia

Mine Water and the Environment - Artisanal and small-scale mining (ASM) of gold has adversely affected the environment and human health for decades, mostly due to excessive use of mercury. With the...     

Reentrant Interface Depinning from Rough Walls

Depinning of an interface from a rough self-affine wall delimiting an attractive substrate is described in terms of directed paths on a square lattice. Short range interactions are assumed and the phase diagram is determined by transfer matrix methods for several values of _W, the roughness exponent of the wall. For all _W the following scenario is observed. At a very low temperature T, the interface is not pinned for wall attraction energies below a certain _W-dependent, nonzero threshold. This contrasts with the case of smooth walls, for which the threshold is zero. In a range of attraction energies just below the threshold, a pinning transition first occurs, as T increases, followed by a depinning one (reentrant depinning). This unusual reentrance phenomenon, in which, upon increasing T, dewetting is followed by wetting, is peculiar of self-affine roughness and does not occur, e.g., with a periodic substrate corrugation. The nature of both wetting and dewetting transitions is determined by the value of _W. As found in related work, the two transitions are both continuous or both first-order, according to whether _W;l/2, or _W>l/2, respectively. The border value ₀=1/2 coincides with the intrinsic roughness of the interface in the bulk.     

Regional flood frequency analysis in the central‐western river basins of Argentina

Knowing the probability of occurrence of a flood event is an important issue for water resources planning. At‐site probability models require a long extension of hydrological data for robust estimation of low‐frequency events. As the mean record length of 25 gauge stations in western river basins of Argentina is 49 years (until 2010), regional models are an interesting tool to determine mountain rivers system dynamics. This study aims to estimate low‐frequency quantiles of annual maximum flow in Argentinean western river basins (28°S–37°S) applying regional frequency analysis based on the L‐moments method. Besides, mean annual maximum flow of 75 gauge stations (22°S–52°S) was analysed. First, an exploratory data analysis was performed; normality, independence, and randomness were accepted in the 27%, 87%, and 91% of cases, respectively. Increasing trends in annual maximum flows in the north‐western and central‐western rivers of Argentina were detected, whereas decreasing trends in annual maximum flow in the Patagonian Andes were identified. Base on at‐site characteristics and at‐site statistics, a homogeneous region of 12 stations with a record period of 568 years was formed. General extreme value was the most appropriate distribution for this homogeneous study region. Estimation accuracy using Monte Carlo simulations was performed. The error bounds were set at 90%, the mean square error was 9.23%, and the relative bias was 1.6%. The regional method performed better than the at‐site estimation.     

Wafer-Scale Fabrication of Hierarchically Porous Silicon and Silica by Active Nanoparticle-Assisted Chemical Etching and Pseudomorphic Thermal Oxidation (Small 22/2023)

Many biological materials exhibit a multiscale porosity with small, mostly nanoscale pores as well as large, macroscopic capillaries to simultaneously achieve optimized mass transport capabilities and lightweight structures with large inner surfaces. Realizing such a hierarchical porosity in artificial materials necessitates often sophisticated and expensive top-down processing that limits scalability. Here, an approach that combines self-organized porosity based on metal-assisted chemical etching (MACE) with photolithographically induced macroporosity for the synthesis of single-crystalline silicon with a bimodal pore-size distribution is presented, i.e., hexagonally arranged cylindrical macropores with 1 µm diameter separated by walls that are traversed by pores 60 nm across. The MACE process is mainly guided by a metal-catalyzed reduction–oxidation reaction, where silver nanoparticles (AgNPs) serve as the catalyst. In this process, the AgNPs act as self-propelled particles that are constantly removing silicon along their trajectories. High-resolution X-ray imaging and electron tomography reveal a resulting large open porosity and inner surface for potential applications in high-performance energy storage, harvesting and conversion or for on-chip sensorics and actuorics. Finally, the hierarchically porous silicon membranes can be transformed structure-conserving by thermal oxidation into hierarchically porous amorphous silica, a material that could be of particular interest for opto-fluidic and (bio-)photonic applications due to its multiscale artificial vascularization.