Wearable sweat sensors have spearheaded the thrust toward personalized health monitoring with continuous, real-time, and molecular-level insight in a noninvasive manner. However, effective sweat sampling still remains a huge challenge. Here, we introduce an intelligent Janus textile band that bridges the gap between self-pumping sweat collection, comfortable epidemic microclimate, and sensitive electrochemical biosensing via an integrated wearable platform. The dominant sweat sampling configuration is a textile with Janus wettability, which is fabricated by electrospinning a hydrophobic polyurethane (PU) nanofiber array onto superhydrophilic gauze. Based on a contact-pumping model, the Janus textile can unidirectionally and thoroughly transport sweat from skin (hydrophobic side) to embedded electrode surface (hydrophilic side) with epidemic comfort. On-body experimentation reveals that the sensitive detection of multiple biomarkers including glucose, lactate, K + , and Na + is achieved in the pumped sweat. Such smart Janus textile bands can effectively drain epidermal sweat to targeted assay sites via interface modifications, representing a reinforced and controlled biofluids analysis pathway with physiological comfort.

A novel method for determination of diphenylamine (DPA) and its nitrated derivatives, which are considered as characteristic components in smokeless powder and gunshot residues, is described. A tandem mass spectrometric method is established and mass spectrometer parameters optimized for each compound to obtain higher sensitivity. Under optimum conditions, quantitative analysis was carried out. The linear ranges are 5.0-200.0, 2.0-200.0 and 5.0-250.0 ng ml-1 and the detection limits are 1.0, 0.5 and 2.5 ng ml-1 for diphenylamine (DPA), N-NO-diphenylamine (N-NO-DPA) and 4-NO2-diphenylamine (4-NO2-DPA), respectively. Intra-assay and inter-assay precision and accuracy of analysis of these three samples were investigated. Based on the regression lines obtained above, smokeless samples were analyzed. It was found that there are 0.952% DPA, 0.384% N-NO-DPA and 0.128% 4-NO2-DPA in smokeless powder. Recovery tests showed that using cotton swabs, 80.3 +/- 4.9% DPA, 79.6 +/- 3.1% N-NO-DPA and 83.1 +/- 5.4% 4-NO2-DPA could be recovered from human hands.

Sodium sulfinates, sulfinic acids, sulfonyl chlorides and sulfonyl hydrazides as readily available and efficient sulfonylation reagents have been extensively explored in recent years. Sulfonyl radical can be generated from these sulfonyl reagents via different methods, then the sulfonyl radical could react with various substrates via different pathways to afford the corresponding products. In this review, we will summarize the progress in sulfonylation via radical reaction using sodium sulfinates, sulfinic acids, sulfonyl chlorides and sulfonyl hydrazides in recent three years. In terms of the different sulfonylation reagents, we classify these sulfonylation reactions into four types: 1.

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A kind of semiaromatic polyamide, poly(dodecamethylene terephthalamide) (PA12T) was synthesized via a polycondensation reaction of terephthalic acid and 1,12-dodecanediamine. The structure of prepared PA12T was characterized by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance ( 1 H-NMR), and elemental analysis. The mechanical properties of PA12T were also studied. The thermal behavior of PA12T was determined by differential scanning calorimetry, thermogravimetric analysis, and dynamic mechanical analysis. Pyrolysis products and thermal decomposition mechanism of PA12T were analyzed by pyrolysis-gas chromatography/ mass spectrometry (Py-GC/MS). Melting temperature (T m ), glass transition temperature (T g ), and decomposition temperature (T d ) of PA12T are 310 C, 144 C, and 429 C, respectively. The Py-GC/MS results showed that the pyrolysis products were mainly composed of 32 kinds of compounds, such as benzonitrile, 1,4-benzenedicarbonitrile, N-methylbenzamide, N-hexylbenzamide, and aromatic compounds. The major pyrolysis mechanisms were b-CH hydrogen transfer process, main-chain random scission, and hydrolytic decomposition.

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Abstract.A novel engineering plastic, poly(decamethylene 2,6-naphthalamide) (PA10N) was prepared via a reaction of 2,6-naphthalene dicarboxylic acid and 1,10-decanediamine. The structure of synthesized PA10N was characterized by elemental analysis, Fourier transform infrared (FT-IR) spectroscopy and proton nuclear magnetic resonance ( 1 H-NMR). The thermal behavior was determined by differential scanning calorimetry (DSC), thermo-gravimetric analysis (TGA) and dynamic mechanical analysis (DMA). Melting temperature (Tm), glass transition temperature (Tg) and decomposition temperature (Td) of PA10N are 320, 144 and 495°C, respectively. The solubility, water-absorbing capacity, and mechanical properties of PA10N have also been investigated. Pyrolysis products and thermal decomposition mechanism of PA10N were analyzed by flash pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The results show that the heat resistance and mechanical properties of PA10N are near to those of poly(nonamethylene terephthalamide) (PA9T), and PA10N is a promising heat-resistant and processable engineering plastic.

We studied the transport of graphene electrons through lateral magnetic barriers. The relativistic electrons experience resonant tunneling through two adjacent but opposite magnetic field regions. For a periodic structure fabricated with such magnetic barriers, the resonant tunneling peak further splits into several sharp spikes. The conductance also shows oscillation with the Fermi energy.