116 research outputs found

    Rats Sniff Off Toxic Air

    No full text
    Breathing air is a fundamental human need, yet its safety, when challenged by various harmful or lethal substances, is often not properly guarded. For example, air toxicity is currently monitored only for a single or a limited number of known toxicants, thus failing to warn against possible hazardous air fully. Here, we discovered that, within minutes, living rats emitted distinctive profiles of volatile organic compounds (VOCs) via breath when exposed to various airborne toxicants such as endotoxin, O3, ricin, and CO2. Compared to background indoor air, when exposed to ricin or endotoxin aerosols, breath-borne VOC levels, especially that of carbon disulfide, were shown to decrease, while their elevated levels were observed for exposure to O3 and CO2. A clear contrast in breath-borne VOC profiles of rats exposed to different toxicants was observed with a statistical significance. Differences in microRNA regulations such as miR-33, miR-146a, and miR-155 from rats’ blood samples revealed different mechanisms used by rats in combating different air toxicant challenges. Similar to dogs, rats were found here to be able to sniff off toxic air by releasing a specific breath-borne VOC profile. The discovered science opens a new arena for online monitoring of air toxicity and health effects of pollutants

    Deposit Insurance and Bank Liquidity Creation: Evidence from a Natural Experiment in China*

    No full text
    In this paper, we examine how the implementation of deposit insurance influences the impact of bank capital, excess lending, banking competition and monetary policy on liquidity creation of banks. Our examination uses China’s introduction of deposit insurance in 2015 as a natural experiment. We find that deposit insurance positively reinforces the effect of capital but weakens that of monetary policy on liquidity creation. We do not find that deposit insurance has a significant influence on the effects of excess lending and competition on the liquidity creation of banks. We also show that the implementation of deposit insurance has heterogenous effects on the liquidity creation of large and small banks.</p

    Nanopore Identification of N‑Acetylation by Hydroxylamine Deacetylation (NINAHD)

    No full text
    N-Acetyl modification, a chemical modification commonly found on biomacromolecules, plays a crucial role in the regulation of cell activities and is related to a variety of diseases. However, due to the instability of N-acetyl modification, accurate and rapid identification of N-acetyl modification with a low measurement cost is still technically challenging. Here, based on hydroxylamine deacetylation and nanopore single molecule chemistry, a universal sensing strategy for N-acetyl modification has been developed. Acetohydroxamic acid (AHA), which is produced by the hydroxylamine deacetylation reaction and serves as a reporter for N-acetylation identification, is specifically sensed by a phenylboronic acid (PBA)-modified Mycobacterium smegmatis porin A (MspA). With this strategy, N-acetyl modifications on RNA, DNA, proteins, and glycans were identified, demonstrating its generality. Specifically, histones can be treated with hydroxylamine deacetylation, from which the generated AHA can represent the amount of N-acetyl modification detected by a nanopore sensor. The unique event features of AHA also demonstrate the robustness of sensing against other interfering analytes in the environment

    Automated in Vivo Nanosensing of Breath-Borne Protein Biomarkers

    No full text
    Toxicology and bedside medical condition monitoring is often desired to be both ultrasensitive and noninvasive. However, current biomarker analyses for these purposes are mostly offline and fail to detect low marker quantities. Here, we report a system called dLABer (detection of living animal’s exhaled breath biomarker) that integrates living rats, breath sampling, microfluidics, and biosensors for the automated tracking of breath-borne biomarkers. Our data show that dLABer could selectively detect (online) and report differences (of up to 103-fold) in the levels of inflammation agent interleukin-6 (IL-6) exhaled by rats injected with different ambient particulate matter (PM). The dLABer system was further shown to have an up to 104 higher signal-to-noise ratio than that of the enzyme-linked immunosorbent assay (ELISA) when analyzing the same breath samples. In addition, both blood-borne IL-6 levels analyzed via ELISA in rats injected with different PM extracts and PM toxicity determined by a dithiothreitol (DTT) assay agreed well with those determined by the dLABer system. Video recordings further verified that rats exposed to PM with higher toxicity (according to a DTT assay and as revealed by dLABer) appeared to be less physically active. All the data presented here suggest that the dLABer system is capable of real-time, noninvasive monitoring of breath-borne biomarkers with ultrasensitivity. The dLABer system is expected to revolutionize pollutant health effect studies and bedside disease diagnosis as well as physiological condition monitoring at the single-protein level

    Ce-Doped NiFe Layered Double Hydroxide/NiFe<sub>2</sub>O<sub>4</sub> Nanosheet Catalysts for Water Oxidation

    No full text
    It is imperative to develop electrocatalysts with excellent activity and robust stability for the oxygen evolution reaction (OER) through simple, energy-saving methods. In this work, a Ce-doped NiFe layered double hydroxide/NiFe2O4 nanosheet hybrid electrocatalyst (labeled as Ce-NiFe LDH/NiFe2O4) was deposited on a nickel foam substrate through a simple one-pot hydrothermal route. Electrochemical investigations showed that the as-synthesized catalyst possessed 187 mV of low overpotential at 10 mA cm–2 with a reverse scan mode in 1 M KOH solution along with superb durability of 316 h at a current density of 500 mA cm–2, exhibiting excellent electrocatalytic performances. Experiments revealed that the introduction of NaCl and Ce3+ during the preparation could markedly promote the electrocatalytic property of the catalyst. Also, the as-prepared catalyst still presented outstanding OER electrocatalytic performances under harsh conditions, such as seawater and strong alkaline solutions, suggesting that the present catalyst bears great potential in practical applications

    Additional file 1 of Association between light at night and the risk of child death in sub-saharan Africa: a cross-sectional analysis based on DHS data

    No full text
    Supplementary Material 1: Figure S1. Flow diagram of the country selection progress in the analysis. Figure S2. Distribution of LAN in Africa in 2005. Figure S3. Changes in annual mean LAN in the 15 countries included in this study from 2005 to 2013. Figure S4. Correlation between household wealth quantile and LAN in the 15 countries included in this study. Table S1. Distribution of Under 5 mortality rate and LAN level for the study population in urban and rural areas in 15 African countries. Table S2. Stratified analysis of LAN and risk of child mortality in Afric

    DataSheet1_Rational Synthesis of Freestanding NaxV2O5-rGO Paper as the Stable Cathode for Sodium Ion Batteries.PDF

    No full text
    Flexible NaxV2O5/rGO papers were successfully prepared via hydrothermal method followed by vacuum filtration as a high-performance cathode for SIBs. The as-prepared NaxV2O5/rGO combined flexibility and high conductivity that can buffer stress and facilitate the fast transportation of electrons during the charge-discharge process. As a result, the as-prepared NaxV2O5-rGO paper can exhibit a reversible Na-ion storage capacity of ∼197 mA h g−1 at 100 mA g−1 and a good cycling performance with 81% capacity retention for 400 cycles at a high current density of 500 mA g−1, showing great potential in flexible energy storage devices.</p

    Novel Detection Method for Evaluating the Activity of an Alkaline Serine Protease from Bacillus clausii

    No full text
    Until now, the detection methods for serine proteases have been quite time-consuming or cannot indicate the “real” protease activity. Here, a rapid and simple method for determining the “real” activity of serine proteases toward AAPX (a kind of mixed polypeptide substrates, with X representing 20 standard amino acids) was developed. This AAPX method has high reliability, sensitivity, and repeatability and can be used for detecting the serine protease activity spectrophotometrically. Additionally, the site-directed saturation mutagenesis library of alkaline serine protease PRO (BcPRO) from Bacillus clausii was screened with this AAPX method. Three beneficial mutants S99R, S99H, and S99W were identified, and S99W displayed the highest activity. In comparison to wild-type BcPRO, S99W exhibited enhanced catalytic performance toward eight AAPX monomers, and the molecular dynamics simulation revealed the mechanism responsible for its improved activity toward AAPM. Consequently, this work provides an efficient method for detecting, characterizing, mining, and high-throughput screening of serine proteases
    corecore