Transparent and Flexible Actuator Based on a Hybrid Dielectric Layer of Wavy Polymer and Dielectric Fluid Mixture

Transparent and flexible vibrotactile actuators play an essential role in human-machine interaction applications by providing mechanical stimulations that can effectively convey haptic sensations. In the present study, we fabricated an electroactive, flexible, and transparent vibrotactile actuator with a dielectric layer including a dielectric elastomer and dielectric fluid mixture. The dielectric fluid mixture of propylene carbonate (PC) and acetyl tributyl citrate (ATBC) was injected to obtain a transparent dielectric layer. To further improve the haptic performance, different weight ratios of dielectric fluid (PC: ATBC) were injected. The fabricated vibrotactile actuators based on a transparent dielectric layer were investigated for their electrical and electromechanical behavior. The proposed actuators generate a large vibrational intensity (~2.5 g) in the range of 200-250 Hz. Hence, the proposed actuators open up a new class of vibrotactile actuators for possible use in various domains, including robotics, smart textiles, teleoperation, and the metaverse.

Acetyl Tributyl Citrate Exposure at Seemingly Safe Concentrations Induces Adverse Effects in Different Genders of Type 2 Diabetes Mice, Especially Brain Tissue

Acetyl tributyl citrate (ATBC) is a widely used phthalate substitute. Although ATBC is considered to be with a safe dosage of up to 1000 mg/kg/day, studies on its effects in some sensitive populations, such as diabetic patients, are relatively rare. Epidemiological studies have shown that there is a link between diabetes and nervous system diseases. However, toxicological studies have not fully confirmed this yet. In this study, glycolipid metabolism, cognitive deficits, brain tissue damage, levels of neurotransmitters, beta-amyloid plaques (Aβ), hyperphosphorylated tau protein (p-Tau), oxidative stress and inflammation, as well as glial cell homeostatic levels in the brain tissue of type 2 diabetes (T2DM) mice, were determined after ATBC exposure (0, 2, 20, and 200 mg/kg/day) for 90 days. The results confirmed that ATBC exposure aggravated the disorder of glycolipid metabolism and caused cognitive deficits in T2DM mice; induced histopathological alterations and Aβ and p-Tau accumulation, and reduced the levels of 5-hydroxytryptamine and acetylcholine in T2DM mouse brains; oxidative stress and glial cell homeostatic levels in T2DM mouse brains were also changed. Some of the adverse effects were gender-dependent. These findings support the theory that T2DM mice, especially males, are more sensitive to ATBC exposure. Although the safe dose of ATBC is high, prolonged exposure at seemingly safe concentrations has the potential to aggravate diabetes symptoms and cause brain tissue damage in T2DM mice.

Effect of Extrusion Screw Speed and Plasticizer Proportions on the Rheological, Thermal, Mechanical, Morphological and Superficial Properties of PLA

One of the critical processing parameters-the speed of the extrusion process for plasticized poly (lactic acid) (PLA)-was investigated in the presence of acetyl tributyl citrate (ATBC) as plasticizer. The mixtures were obtained by varying the content of plasticizer (ATBC, 10-30% by weight), using a twin screw extruder as a processing medium for which a temperature profile with peak was established that ended at 160 °C, two mixing zones and different screw rotation speeds (60 and 150 rpm). To evaluate the thermo-mechanical properties of the blend and hydrophilicity, the miscibility of the plasticizing and PLA matrix, Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), oscillatory rheological analysis, Dynamic Mechanical Analysis (DMA), mechanical analysis, as well as the contact angle were tested. The results derived from the oscillatory rheological analysis had a viscous behavior in the PLA samples with the presence of ATBC; the lower process speed promotes the transitions from viscous to elastic as well as higher values of loss modulus, storage modulus and complex viscosity, which means less loss of molecular weight and lower residual energy in the transition from the viscous state to the elastic state. The mechanical and thermal performance was optimized considering a greater capacity in the energy absorption and integration of the components.

Pharmacokinetic Properties of Acetyl Tributyl Citrate, a Pharmaceutical Excipient

Acetyl tributyl citrate (ATBC) is an (the Food and Drug Administration) FDA-approved substance for use as a pharmaceutical excipient. It is used in pharmaceutical coating of solid oral dosage forms such as coated tablets or capsules. However, the information of ATBC on its pharmacokinetics is limited. The aim of this study is to investigate the pharmacokinetic properties of ATBC using liquid chromatography–tandem mass spectrometric (LC–MS/MS) analysis. ATBC was rapidly absorbed and eliminated and the bioavailability was 27.4% in rats. The results of metabolic stability tests revealed that metabolic clearance may have accounted for a considerable portion of the total clearance of ATBC. These pharmacokinetic data would be useful in studies investigating the safety and toxicity of ATBC.

Effects of in vitro exposure to dibutyl phthalate, mono-butyl phthalate, and acetyl tributyl citrate on ovarian antral follicle growth and viability

Dibutyl phthalate (DBP) is present in consumer products and the coating of some oral medications. Acetyl tributyl citrate (ATBC) has been proposed as an alternative to DBP because DBP causes endocrine disruption in animal models. Following ingestion, DBP is converted to its main metabolite mono-butyl phthalate (MBP) which has been detected in >90% of human follicular fluid samples. Previous studies show that DBP reduces the number of antral follicles present in the ovaries of mice. Thus, this study was designed to evaluate the effects of DBP, MBP, and ATBC on in vitro growth and viability of mouse ovarian antral follicles. Antral follicles were isolated from CD-1 females (PND32-37) and treated with vehicle, DBP, MBP, or ATBC (starting at 0.001 and up to 1000 μg/ml for DBP; 24-72 h). Follicle diameter, ATP production, qPCR, and TUNEL were used to measure follicle growth, viability, cell cycle and apoptosis gene expression, and cell death-associated DNA fragmentation, respectively. While MBP did not cause toxicity, DBP exposure at ≥10 μg/ml resulted in growth inhibition followed by cytoxicity at ≥500 μg/ml. ATBC increased the number of nongrowing follicles at 0.01 μg/ml and did not affect ATP production, but increased TUNEL positive area in treated follicles. Gene expression results suggest that cytotoxicity in DBP-treated follicles occurs via activation of cell cycle arrest prior to follicular death. These findings suggest that concentrations of DBP ≥10 μg/ml are detrimental to antral follicles and that ATBC should be examined further as it may disrupt antral follicle function at low concentrations.

Effects of oral exposure to the phthalate substitute acetyl tributyl citrate on female reproduction in mice

Acetyl tributyl citrate (ATBC), is a phthalate substitute used in food and medical plastics, cosmetics and toys. Although systemically safe up to 1000 mg kg-1  day-1 , its ability to cause reproductive toxicity in females at levels below 50 mg kg-1  day-1 has not been examined. This study evaluated the effects of lower ATBC exposures on female reproduction using mice. Adult CD-1 females (n = 7-8 per treatment) were dosed orally with tocopherol-stripped corn oil (vehicle), 5 or 10 mg kg-1  day-1 ATBC daily for 15 days, and then bred with a proven breeder male. ATBC exposure did not alter body weights, estrous cyclicity, and gestational and litter parameters. Relative spleen weight was slightly increased in the 5 mg kg-1  day-1 group. ATBC at 10 mg kg-1  day-1 targeted ovarian follicles and decreased the number of primordial, primary and secondary follicles present in the ovary. These findings suggest that low levels of ATBC may be detrimental to ovarian function, thus, more information is needed to understand better the impact of ATBC on female reproduction. Copyright © 2016 John Wiley & Sons, Ltd.