Non–contact real–time detection of trace nitro-explosives by MOF composites visible–light chemiresistor

To create an artificial structure to remarkably surpass the sensitivity, selectivity and speed of the olfaction system of animals is still a daunting challenge. Herein, we propose a core-sheath pillar (CSP) architecture with a perfect synergistic interface that effectively integrates the advantages of metal–organic frameworks and metal oxides to tackle the above-mentioned challenge. The sheath material, NH₂-MIL-125, can concentrate target analyte, nitro-explosives, by 10¹² times from its vapour. The perfect band-matched synergistic interface enables the TiO₂ core to effectively harvest and utilize visible light. At room temperature and under visible light, CSP (TiO₂, NH₂-MIL-125) shows an unexpected self-promoting analyte-sensing behaviour. Its experimentally reached limit of detection (～0.8 ppq, hexogeon) is 10³ times lower than the lowest one achieved by a sniffer dog or all sensing techniques without analyte pre-concentration. Moreover, the sensor exhibits excellent selectivity against commonly existing interferences, with a short response time of 0.14 min

Association Between Serum Folate Levels and Caffeinated Beverage Consumption in Pregnant Women in Chiba: The Japan Environment and Children’s Study

Background: Several studies have reported the adverse effects of caffeine intake during pregnancy on fetal health. However, the effects of caffeine intake from green and oolong teas has not been investigated, despite the considerable consumption of these teas in Japan and the potential inhibitory effects of catechins—chemicals present at relatively high levels in green and oolong teas—on folic acid absorption. The potential associations of serum folate levels with caffeinated beverage consumption and catechin levels remain largely unstudied. The present study aimed to determine these associations in pregnant Japanese women. Methods: Pregnant women (n = 2,701) not receiving folate supplementation were enrolled at the Chiba Unit Center, a regional site of the Japan Environment and Children’s Study (JECS). Serum folate levels were measured using an Access folate assay kit, and nutrient and caffeine intakes were assessed using a self-administered food frequency questionnaire that was previously evaluated in Japanese populations. Results: The low and normal serum folate groups reported caffeine intakes of 42.3 mg/1,000 kcal and 34.4 mg/1,000 kcal, respectively, and tannin intakes of 40.8 mg/1,000 kcal and 36.3 mg/1,000 kcal, respectively. Multiple regression analyses revealed negative associations of serum folate levels with caffeine and tannin intakes and a positive association between serum folate levels and dietary folate intake. Conclusions: Considering the negative associations of caffeine and tannin levels with serum folate levels, pregnant women should consume caffeinated beverages, such as coffee and green/oolong teas, with caution

Sulfonic Group Functionalized Mixed Ligand Coordination Polymers: Synthesis, Characterization, Water Sorption, and Proton Conduction Studies

Five sulfonic acid group functionalized mixed ligand coordination polymers (CPs), namely, {[Zn­(bpeH)­(5-sip)­(H₂O)]·(H₂O)}_<i>n</i> (<b>1</b>), {[Cu­(pyz)­(5-Hsip)­(H₂O)₂]·(H₂O)₂}_<i>n</i> (<b>2</b>), {[Cu­(bpee)_0.5­(5-sip)­(H₂O)₂]·(H₂O)₄­(bpeeH₂)_0.5}_<i>n</i> (<b>3</b>), {[Cu­(bpy)­(5-Hsip)­(H₂O)]·(H₂O)₂}_<i>n</i> (<b>4</b>), and {[Cu­(bpy)₂­(5-H₂sip)₂]·(H₂O)₆}_<i>n</i> (<b>5</b>) [where sip^3– = 5-sulfoiso­phthalate; bpe = 4,4′-bispyridyl­ethane; pyz = pyrazine; bpee = 4,4′-bispyridyl­ethylene; bpy = 4,4′-bipyridine], have been synthesized with varying different N,N′-donor linkers using slow diffusion techniques at room temperature. The CPs possess guest water filled 1D channels and noncoordinating sulfonic acid or coordinated sulfonate groups, which are interconnected by means of extended intermolecular H-bonding interaction, which supports the humidity dependent proton conductivity of the samples. Under 95% relative humidity (% RH), the CPs exhibit the temperature dependent proton conductivity which is maximum up to in the range of ∼10^–5–10^–6 S cm^–1 at 65 °C. In most of the cases, the framework shows activation energies with the value ranging from 0.35 to 0.54 eV, suggesting mostly the contribution of the Grotthuss mechanism of the proton conductivity