Cobalt-containing spherical glass nanoparticles for therapeutic ion release

Bioactive glass nanoparticles (BGNPs) can be internalized by cells, allowing the intracellular release of dissolution products with therapeutic benefit. Different therapeutic ions can be incorporated into the glass network that can promote angiogenesis via simulation of hypoxia conditions and consequent activation of pro-angiogenic genes. Here, novel monodispersed spherical dense BGNPs were obtained by a modified Stöber method with the SiO₂–CaO–CoO composition, with diameters of 92 ± 1 nm, with cobalt as the pro-angiogenic ion. The presence of Co²⁺ species and the role of Co and Ca as network modifiers in the silica glass were confirmed by X-ray photoelectron spectroscopy and ²⁹Si solid-state magic-angle spinning nuclear magnetic resonance, respectively. Controlled Co²⁺ ion release was observed in culture media, and no cytotoxicity was observed by (4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide cell viability assay on human osteosarcoma cells in direct contact with the nanoparticles. This study demonstrated that Co²⁺ ions can be incorporated into dense and spherical BGNPs, and these materials exhibit great potential as intracellular ion delivery systems with therapeutic properties.     

CoCo 2019: report on the eighth confluence competition

We report on the 2019 edition of the Confluence Competition, a competition of software tools that aim to prove or disprove confluence and related (undecidable) properties of rewrite systems automatically.

     

A fully verified container library

The comprehensive functionality and nontrivial design of realistic general-purpose container libraries pose challenges to formal verification that go beyond those of individual benchmark problems mainly targeted by the state of the art. We present our experience verifying the full functional correctness of EiffelBase2: a container library offering all the features customary in modern language frameworks, such as external iterators, and hash tables with generic mutable keys and load balancing. Verification uses the automated deductive verifier AutoProof, which we extended as part of the present work. Our results indicate that verification of a realistic container library (135 public methods, 8400 LOC) is possible with moderate annotation overhead (1.4 lines of specification per LOC) and good performance (0.2 s per method on average).     

A new strategy for predicting short-term wind speed using soft computing models

Wind power prediction is a widely used tool for the large-scale integration of intermittent wind-powered generators into power systems. Given the cubic relationship between wind speed and wind power, accurate forecasting of wind speed is imperative for the estimation of future wind power generation output. This paper presents a performance analysis of short-term wind speed prediction techniques based on soft computing models (SCMs) formulated on a backpropagation neural network (BPNN), a radial basis function neural network (RBFNN), and an adaptive neuro-fuzzy inference system (ANFIS). The forecasting performance of the SCMs is augmented by a similar days (SD) method, which considers similar historical weather information corresponding to the forecasting day in order to determine similar wind speed days for processing. The test results demonstrate that all evaluated SCMs incur some level of performance improvement with the addition of SD pre-processing. As an example, the SD+ANFIS model can provide up to 48% improvement in forecasting accuracy when compared to the individual ANFIS model alone.     

Fabrication of ultrafine edible emulsions: Comparison of high-energy and low-energy homogenization methods

Emulsions containing ultrafine droplets (r < 100 nm) have a number of potential advantages over conventional emulsions for the encapsulation and delivery of lipophilic substances in foods and beverages: high optical clarity; high physical stability; increased bioavailability. These ultrafine emulsions can be fabricated from high-energy or low-energy homogenization methods, which each have advantages and limitations. In this study, we compared a high-energy method (microfluidization) with a low-energy method (spontaneous emulsification) for forming oil-in-water emulsions from food-grade ingredients (medium chain triglycerides and Tweens). The influence of surfactant type (Tween 80, Tween 85, and Tween 80/Tween 85) and surfactant-to-oil ratio (SOR = 0.1–5) on the formation of emulsions was examined. Both the low- and high-energy methods were able to produce emulsions with ultrafine droplets (r < 100 nm). The microfluidization method required high-energy inputs and dedicated equipment, but could produce ultrafine emulsions at much lower surfactant-to-oil ratio (SOR < 0.1). On the other hand, the spontaneous emulsification method only required simple mixing, but it needed much higher surfactant-to-oil ratios (SOR > 0.5) to produce droplets with r < 100 nm. This study has important implications for the development of food-grade delivery systems to encapsulate lipophilic substances, such as flavors, colors, vitamins, and nutraceuticals.     

Indoor visible mold and mold odor are associated with new‐onset childhood wheeze in a dose‐dependent manner

Evidence is accumulating that indoor dampness and mold are associated with the development of asthma. The underlying mechanisms remain unknown. New Zealand has high rates of both asthma and indoor mold and is ideally placed to investigate this. We conducted an incident case‐control study involving 150 children with new‐onset wheeze, aged between 1 and 7 years, each matched to two control children with no history of wheezing. Each participant's home was assessed for moisture damage, condensation, and mold growth by researchers, an independent building assessor and parents. Repeated measures of temperature and humidity were made, and electrostatic dust cloths were used to collect airborne microbes. Cloths were analyzed using qPCR. Children were skin prick tested for aeroallergens to establish atopy. Strong positive associations were found between observations of visible mold and new‐onset wheezing in children (adjusted odds ratios ranged between 1.30 and 3.56; P ≤ .05). Visible mold and mold odor were consistently associated with new‐onset wheezing in a dose‐dependent manner. Measurements of qPCR microbial levels, temperature, and humidity were not associated with new‐onset wheezing. The association between mold and new‐onset wheeze was not modified by atopic status, suggesting a non‐allergic association.     

Dissociative Bioorthogonal Reactions

Bioorthogonal reactions that proceed readily under physiological conditions without interference from biomolecules have found widespread application in the life sciences. Complementary to the bioorthogonal reactions that ligate two molecules, reactions that release a molecule or cleave a linker are increasingly attracting interest. Such dissociative bioorthogonal reactions have a broad spectrum of uses, for example, in controlling bio-macromolecule activity, in drug delivery, and in diagnostic assays. This review article summarizes the developed bioorthogonal reactions linked to a release step, outlines representative areas of the applications of such reactions, and discusses aspects that require further improvement.