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Real-time monitoring of health threatening gases for chemical safety and human health protection requires detection and discrimination of trace gases with proper gas sensors. In many applications, costly, bulky, and power-hungry devices, normally employing optical gas sensors and electrochemical gas sensors, are used for this purpose. Using a single miniature low-power semiconductor gas sensor to achieve this goal is hardly possible, mostly due to its selectivity issue. Herein, we report a dual-mode microheater integrated nanotube array gas sensor (MINA sensor). The MINA sensor can detect hydrogen, acetone, toluene, and formaldehyde with the lowest measured limits of detection (LODs) as 40 parts-per-trillion (ppt) and the theoretical LODs of ∼7 ppt, under the continuous heating (CH) mode, owing to the nanotubular architecture with large sensing area and excellent surface catalytic activity. Intriguingly, unlike the conventional electronic noses that use arrays of gas sensors for gas discrimination, we discovered that when driven by the pulse heating (PH) mode, a single MINA sensor possesses discrimination capability of multiple gases through a transient feature extraction method. These above features of our MINA sensors make them highly attractive for distributed low-power sensor networks and battery-powered mobile sensing systems for chemical/environmental safety and healthcare applications.

Semiconductor chemiresistive gas sensors play critical roles in a smart and sustainable city where a safe and healthy environment is the foundation. However, the poor limits of detection and selectivity are the two bottleneck issues limiting their broad applications. Herein, a unique sensor design with a 3D tin oxide (SnOsub2/sub) nanotube array as the sensing layer and platinum (Pt) nanocluster decoration as the catalytic layer, is demonstrated. The Pt/SnOsub2/subsensor significantly enhances the sensitivity and selectivity of NOsub2/subdetection by strengthening the adsorption energy and lowering the activation energy toward NOsub2/sub. It not only leads to ultrahigh sensitivity to NOsub2/subwith a record limit of detection of 107 parts per trillion, but also enables selective NOsub2/subsensing while suppressing the responses to interfering gases. Furthermore, a wireless sensor system integrated with sensors, a microcontroller, and a Bluetooth unit is developed for the practical indoor and on-road NOsub2/subdetection applications. The rational design of the sensors and their successful demonstration pave the way for future real-time gas monitoring in smart home and smart city applications.

The design and synthesis of hollow-nanostructured transition metal oxide-based anodes is of great importance for long-term operation of lithium ion batteries (LIBs). Herein, a special hollow bowl-like α-Fe

The accelerated evolution of communication platforms including Internet of Things (IoT) and the fifth generation (5G) wireless communication network makes it possible to build intelligent gas sensor networks for real-time monitoring chemical safety and personal health. However, this application scenario requires a challenging combination of characteristics of gas sensors including small formfactor, low cost, ultralow power consumption, superior sensitivity, and high intelligence. Herein, self-powered integrated nanostructured-gas-sensor (SINGOR) systems and a wirelessly connected SINGOR network are demonstrated here. The room-temperature operated SINGOR system can be self-driven by indoor light with a Si solar cell, and it features ultrahigh sensitivity to H2, formaldehyde, toluene, and acetone with the record low limits of detection (LOD) of 10, 2, 1, and 1 ppb, respectively. Each SINGOR consisting of an array of nanostructured sensors has the capability of gas pattern recognition and classification. Furthermore, multiple SINGOR systems are wirelessly connected as a sensor network, which has successfully demonstrated flammable gas leakage detection and alarm function. They can also achieve gas leakage localization with satisfactory precision when deployed in one single room. These successes promote the development of using nanostructured-gas-sensor network for wide range applications including smart home/building and future smart city.

The Internet of Things (IOT) is an Internet-based network that covers everything. Message Queuing Telemetry Transport (MQTT) is one of the commonly used communication protocols for any platform in the Internet of Things. Whether it is from the perspective of overall security or device compatibility and resource consumption, the MQTT protocol has certain advantages and is the most competitive communication protocol in the current Internet of Things. However, the user password login form adopted by the MQTT protocol has a certain degree of security problems. IOTA is an encrypted currency, and the Tangle network it uses is a new distributed structure. Based on this situation, this article innovatively combines the Tangle network with the MQTT protocol, and proposes a new communication option for MQTT nodes. When a new node enters the network, start from the Broker with the help of a “walker”, by judging the connection and survival of the node, using the Markov Chain Monte Carlo (MCMC) random walk algorithm to complete the node selection, and finally realize MQTT Communication between nodes. This article puts forward the design idea of this scheme, and realizes the scheme through simulation experiment.

The Internet of things (IoT) is an expansion and extension based on the Internet, from network interconnection to the interrelationship of things. Most of the Internet of Things are using the publish/subscribe model, which stipulates the one-to-many situation of nodes in the Internet of Things’ uses a publish/subscribe model to achieve communication, using Broker as a relay and topic as a designated transmission path to deliver information to subscribers. But when a large amount of data is being transmitted, there will be node congestion. This will not only reduce the efficiency of data transmission, but also increase and waste the energy consumption of the entire Internet of Things. Therefore, this paper proposes topic logistics based on node resource status, and designs a new network data transmission algorithm. Based on the value of node resource status, it realizes the selection of possible data communication paths. It is verified through experiments that this algorithm can realize node resources. The full utilization of, thereby reducing communication energy consumption and improving transmission efficiency.

As the feature size of devices decreases and the number of transistor interconnect exceeds billions, the runtime of global router becomes a problem in very large-scale integrated circuit design. The congestion prediction in the global routing, which can cost huge time, is one of the most important and challenging problems. In this paper, we propose a density and pins peaks-based fast neural network algorithm (NNA) to predict congestion map. In order to save runtime, traditional prediction methods are replaced by a machine learning method with local density and pins as features. Furthermore, to improve the performance of proposed method, the predictive identification method to specify order of the rip-up and reroute for congested regions is also proposed. Compared with state-of-the-art router, NTHU-Route 2.0, on ISPD08 benchmarks, our method greatly improves the speed of predicting routing congestion information by 1094% in test cases, and saves runtime of the global router.

The tuberculin skin test (TST) and interferon gamma (IFN-γ) release assays (IGRAs) are used as adjunctive tests for the evaluation of suspected cases of active tuberculosis (TB). However, a positive test does not differentiate latent from active TB. We investigated whether flow cytometric measurement of novel combinations of intracellular cytokines and surface makers on CD4 T cells could differentiate between active and latent TB after stimulation withMycobacterium tuberculosis-specific proteins. Blood samples from 60 patients referred to the Singapore Tuberculosis Control Unit for evaluation for active TB or as TB contacts were stimulated with purified protein derivative (PPD), ESAT-6 and CFP-10, or heparin-binding hemagglutinin (HBHA). The CD4 T cell cytokine response (IFN-γ, interleukin-2 [IL-2], interleukin-17A [IL-17A], interleukin-22 [IL-22], granulocyte-macrophage colony-stimulating factor [GM-CSF], and tumor necrosis factor alpha [TNF-α]) and surface marker expression (CD27, CXCR3, and CD154) were then measured. We found that the proportion of PPD-specific CD4 T cells, defined as CD154+TNF-α+cells that were negative for CD27 and positive for GM-CSF, gave the strongest discrimination between subjects with latent and those with active TB (area under the receiver operator characteristic [ROC] curve of 0.9277;P< 0.0001). Also, the proportions and absolute numbers of HBHA-specific CD4 T cells were significantly higher in those with latent TB infection, particularly CD154+TNF-α+IFN-γ+IL-2+and CD154+TNF-α+CXCR3+. Finally, we found that the ratio of ESAT-6- and CFP-10-responding to HBHA-responding CD4 T cells was significantly different between the two study populations. In conclusion, we found novel markers ofM. tuberculosis-specific CD4 cells which differentiate between active and latent TB.

The most difficult field in gene therapy is that vector system should offer both a means of successful transfection and a maximum of safety for the patient. Viral vectors and plasmid vectors are traditional vectors; they may cause unwanted immunological side effects resulting from the expression of nontherapeutic genes. Our aim is to develop a new general gene therapy vector which is suggested to be called as Micro-Linear Vector. The gene expression cassette is capped by our designed cap, including promoter, enhancer, objective gene, and RNA-stabilizing sequence, so it can defend the exnuclease in the eukaryotic cell, at the same time, DNA not encoding the objective gene is reduced to a minimum. The GFP gene is separated from the pEGFP-N3 plasmid, and acts as a reporter gene to construct the Micro-Linear Vector, then both the new vector and the plasmid are transfected to cells, the results are tested by fluorescence microscope and flow cytometry. The results show that the Micro-Linear Vector has a high effective of transfection and safety in 293, 3T3, CNE2 and B95-8 cell lines, at the same time it is less toxicity than the plasmid. We can get the rudiments of conclusion that Micro-Linear Vector has high effection of the transfection and more safety than tradition plasmid in eukaryotic cell.

Phosphoribosyl pyrophosphate synthetase (PRS; EC 2.7.6.1) catalyzes the reaction of ribose-5-phosphate (R5P) with ATP to yield AMP and PRPP (5-phosphoribosyl-1-pyrophosphate), which is necessary for the de novo and salvage pathways of purine-, pyrimidine- and pyridine-nucleotide biosynthesis. PRPP is a metabolite that is required at all times in the cell and is thus central to life. In this study, human PRS1 was produced in Escherichia coli in soluble form and purified to homogeneity. Crystals in complex with Mg2+, inorganic phosphate (P(i)) and ATP were obtained by the hanging-drop vapour-diffusion method. Diffraction data were collected to 2.6 A resolution. The crystal belongs to space group R3, with unit-cell parameters a = b = 168.846, c = 61.857 angstroms, assuming two molecules in the asymmetric unit and a volume-to-weight ratio of 2.4 angstroms3 Da(-1), which was consistent with the result calculated from the self-rotation function.

3-Hydroxyanthranilic acid 3,4-dioxygenase (3HAO) is a non-heme ferrous extradiol dioxygenase in the kynurenine pathway from tryptophan. It catalyzes the conversion of 3-hydroxyanthranilate (HAA) to quinolinic acid (QUIN), an endogenous neurotoxin, via the activation of N-methyl-D-aspartate (NMDA) receptors and the precursor of NAD + biosynthesis. The crystal structure of 3HAO from S. cerevisiae at 2.4 Å resolution shows it to be a member of the functionally diverse cupin superfamily. The structure represents the first eukaryotic 3HAO to be resolved. The enzyme forms homodimers, with two nickel binding sites per molecule. One of the bound nickel atoms occupies the proposed ferrous-coordinated active site, which is located in a conserved double-strand b-helix domain. Examination of the structure reveals the participation of a series of residues in catalysis different from other extradiol dioxygenases. Together with two iron-binding residues (His49 and Glu55), Asp120, Asn51, Glu111, and Arg114 form a hydrogen-bonding network; this hydrogen-bond network is key to the catalysis of 3HAO. Residues Arg101, Gln59, and the substrate-binding hydrophobic pocket are crucial for substrate specificity. Structure comparison with 3HAO from Ralstonia metallidurans reveals similarities at the active site and suggests the same catalytic mechanism in prokaryotic and eukaryotic 3HAO. Based on sequence comparison, we suggest that bicupin of human 3HAO is the first example of evolution from a monocupin dimer to bicupin monomer in the diverse cupin superfamilies. Based on the model of the substrate HAA at the active site of Y3HAO, we propose a mechanism of catalysis for 3HAO. Copyright © 2006 The Protein Society., link_to_subscribed_fulltext