Double-Layered Conductive Network Design of Flexible Strain Sensors for High Sensitivity and Wide Working Range.

For flexible strain sensors, the optimization between sensitivity and working range is a significant challenge due to the fact that high sensitivity and high working range are usually difficult to obtain at the same time. Herein, a breathable flexible strain sensor with a double-layered conductive network structure was designed and developed, which consists of a thermoplastic polyurethane (TPU)/carbon nanotube (CNT) layer (as a substrate layer) and a Ag nanowire (AgNW) layer. The TPU/CNT layer is made of electrospinning TPU with CNTs deposited onto the surface of TPU fibers, and the flexible TPU/CNT mat guarantees the integrity of the conductive path under a large strain. The AgNW layer was prepared by depositing different amounts of AgNWs on the surface of the TPU/CNT layer, and the high-conductivity AgNWs offer a low initial resistance. Benefitting from the synergistic two-layer structure, the as-obtained flexible strain sensor exhibits a very high sensitivity (up to 1477.7) and a very wide working range (up to 150%). Besides, the fabricated sensor exhibits fast response (88 ms), excellent dynamical stability (7000 cycles), and excellent breathability. The working mechanism of the strain sensor was further investigated using various techniques (microscopy, equivalent circuit, and thermal effects of current). Furthermore, the as-fabricated flexible strain sensors accurately detect the omnidirectional human motions, including subtle and large human motions. This work provides an efficient approach to achieve the optimization between high sensitivity and large working range of strain sensors, which may have great potential applications in health monitoring, body motion detection, and human-machine interactions.

Core-Shell Structured Magnetic Carboxymethyl Cellulose-Based Hydrogel Nanosorbents for Effective Adsorption of Methylene Blue from Aqueous Solution.

This article reports effective removal of methylene blue (MB) dyes from aqueous solutions using a novel magnetic polymer nanocomposite. The core-shell structured nanosorbents was fabricated via coating Fe3O4 nanoparticles with a layer of hydrogel material, that synthesized by carboxymethyl cellulose cross-linked with poly(acrylic acid-co-acrylamide). Some physico-chemical properties of the nanosorbents were characterized by various testing methods. The nanosorbent could be easily separated from aqueous solutions by an external magnetic field and the mass fraction of outer hydrogel shell was 20.3 wt%. The adsorption performance was investigated as the effects of solution pH, adsorbent content, initial dye concentration, and contact time. The maximum adsorption capacity was obtained at neutral pH of 7 with a sorbent dose of 1.5 g L-1. The experimental data of MB adsorption were fit to Langmuir isotherm model and Pseudo-second-order kinetic model with maximum adsorption of 34.3 mg g-1. XPS technique was applied to study the mechanism of adsorption, electrostatic attraction and physically adsorption may control the adsorption behavior of the composite nanosorbents. In addition, a good reusability of 83.5% MB recovering with adsorption capacity decreasing by 16.5% over five cycles of sorption/desorption was observed.

Metabolism of liver CYP450 and ultrastructural changes after long-term administration of aspirin and ibuprofen.

Worldwide, aspirin and ibuprofen are the most commonly used non-steroidal anti-inflammatory drugs (NSAIDs). Some adverse reactions, including gastrointestinal reactions, have been concerned extensively. Nevertheless, the mechanism of liver injury remains unclear. In the present study, we focused on the metabolism of liver cytochrome P450 (CYP450) and ultrastructural morphology of liver cells. A total of thirty rats were divided into three groups of 10. Rats in the aspirin and ibuprofen groups were given enteric-coated aspirin (15 mg/kg) and ibuprofen (15 mg/kg), respectively by gavage for four weeks. The body weights were recorded every two days. Liver function and metabolic capacity of CYP450 were studied on days 14 and 28. We then conducted ultrastructural examinations. Body weights in the Ibuprofen group were lower than those of the Control group, and ALT and AST levels were significantly higher (P < 0.05). There were no significant differences in terms of body weight, ALT or AST between the Aspirin and Control groups. The metabolic capacity of CYP450 was evaluated using five probe drugs, phenacetin, tolbutamide, metoprolol, midazolam, and bupropion. We found that ibuprofen and aspirin induced metabolism of the probe drugs. Moreover, according to the pharmacokinetic data, the Control, Aspirin and Ibuprofen groups could be discriminated accurately. Ultrastructural examination showed that the number of mitochondria was increased in both the Ibuprofen and Aspirin groups. Long-term administration of enteric-coated aspirin and ibuprofen induced the metabolic activity of the CYP450 enzyme. Aspirin had better tolerability than did ibuprofen, as reflected by pharmacokinetic data of probe drug metabolism.

Fisher Discrimination of Metabolic Changes in Rats Treated with Aspirin and Ibuprofen.

BACKGROUND: Aspirin and ibuprofen are the most frequently prescribed non-steroidal anti-inflammatory drugs in the world. However, both are associated with a variety of toxicities. We applied serum metabonomics and Fisher discrimination for the early diagnosis of its toxic reaction in order to help diagnose these toxicities. METHODS: A total of 45 rats were randomly divided into Control group, Aspirin group, and Ibuprofen groups. The experiment groups were given intragastric aspirin (15 mg/kg) or ibuprofen (15 mg/kg) for 3 weeks. Liver function tests were performed and blood metabonomics were analyzed by gas chromatography-mass spectrometry. RESULTS: The most important compounds altered were trihydroxybutyric acid and l-alanine in the aspirin group, and acetoacetic acid, l-alanine, and trihydroxybutyric acid in the ibuprofen group. With respect to metabolic profiles, all 3 groups were completely distinct from one another. Fisher discrimination showed that 91.1% of the original grouped cases were correctly classified by the third week. However, only 55.6% of liver function tests were able to classify grouped cases correctly. CONCLUSION: Trihydroxybutyric acid, l-alanine, and acetoacetic acid were the most significant indicators of altered serum metabolites following intragastric administration of aspirin and ibuprofen in rates. These metabolomic data may be used for classification of aspirin and ibuprofen toxicity.

Effect of ademetionine on cytochrome P450 isoforms activity in rats.

Cocktail method was used to evaluate the influence of ademetionine on the activities of CYP450 isoforms CYP1A2, CYP2D6, CYP3A4, CYP2C19, CYP2C9 and CYP2B6, which were reflected by the changes of pharmacokinetic parameters of six specific probe drugs phenacetin, metroprolol, midazolam, omeprazole, tolbutamide and bupropion, respectively. The experimental rats were randomly divided into two group, control group and ademetionine group. The ademetionine group rats were given 50 mg/kg ademetionine by continuous oral administration for 7 days. The mixture of six probes was given to rats through oral administration and the blood samples were obtained at a series of time-points through the caudal vein. The concentrations of probe drugs in rat plasma were measured by UPLC-MS/MS. In the experiment for ademetionine and control group, there was statistical pharmacokinetics difference for phenacetin, metroprolol, midazolam, omeprazole, tolbutamide and bupropion. Continuous oral administration for 7 days could induce the activities of CYP450 isoforms CYP1A2 of rats, while it may inhibit the activities of CYP2D6, CYP3A4, CYP2C19 and CYP2C9.

[The study of effects of pirfenidone on the pulmonary fibrosis induced by paraquat in mice].

OBJECTIVE: To study the curative effects of pirfenidone (PF) on pulmonary fibrosis induced by paraquat (PQ) in mice and to provide the theoretical basis for clinical treatment. METHODS: Ninety adult healthy male ICR mice were randomly divided into six groups: control group, PQ group, 2 mg/kg Dexamethasone group, 25 mg/kg PF group, 50 mg/kg PF group and 100 mg/kg PF group, there were 15 mice in each group. The corresponding volume of normal saline was given to the each mouse in control group according to the weight, after 2 h 0.1% CMC was given to the each mouse of control group one time by intragastric administration, then the CMC was administrated at regular time until sacrifice. All mice for other 5 groups were exposed to 100 mg/kg PQ by intragastric administration. At 2 h after exposure to PQ, 0.02 ml/10 g dexamethasone and 25, 50, 100 mg/kg PF were given to mice for dexamethasone group and for 3 PF groups by intragastric administration each day for 49 days, respectively. The lung coefficient was calculated and pathological changes of lung tissue were observed by HE staining for each mouse. The hydroxyproline (HYP) level in lung tissue was measured for each mouse. The mRNA level of and the protein level of TGF-ß(1) in lung tissue for each mouse were determined, and the protein level of TGF-ß(1) in the bronchus-alveolus lavage fluid (BALF) of each mouse was detected. RESULTS: The survival rates on the 3rd day in PQ group, 3 PF groups and dexamethasone group were 53.33%, 46.67%, 73.33%, 86.67% and 80%, respectively. The survival rates on the 3rd day in dexamethasone group, 50 mg/kg and 100 mg/kg PF groups were significantly higher than those of PQ group and 25 mg/kg PF group (P < 0.05). The lung coefficients of 3 PF groups were significantly lower than that of the PQ group (P < 0.05). The lung tissue HYP levels of dexamethasone group and 3 PF groups were 50.95 ± 11.65, 44.52 ± 9.48, 43.27 ± 6.01 and 40.82 ± 5.90 mg/g respectively, which were significantly lower than that (74.27 ± 3.68) of PQ group (P < 0.01). The TGF-ß(1) protein levels of BALF in dexamethasone group, 50 and 100 mg/kg PF groups were 22.03 ± 7.27, 27.75 ± 5.84 and 21.31 ± 6.82 ng/ml respectively, which were significantly lower than that (52.52 ± 15.51) ng/ml of PQ group (P < 0.01) The expression level of TGF-ß(1) mRNA in 100 mg/kg PF group decreased significantly, as compared with PQ group (P < 0.01). CONCLUSION: PF could reduce the collagen deposition and pulmonary fibrosis induced by PQ in mice lungs.