Protein Based Localized Surface Plasmon Resonance Gas Sensing

We apply the localized surface plasrnon resonance （LSPR） of gold nanoparticles （GNPs） covalently coupled with cytochrorne c （cyt c） to create a nanobiosensor for detecting hydrogen sulfide （H2S） in the range of 15 lOOppb. Monolayer formation of GNPs on glass surface functionalized with 3-aminopropyltrirnethoxysilane （APTMS） is performed for fabricating a chip-based format of the optical transducer. By chemical introduction of short-chain thiol derivatives on cyt c protein shell via its lysine residues, a very fast self-assembled rnonolayer （SAM） of cyt c is formed on the GNPs. Significant shifts in the LSPR peak （△λLSPR） are observed by reacting H2S with cyt c. Results show a linear relationship between △λLSPR and H2S concentration. Furthermore, shifts in the LSPR peak are reversible and the peak positions return to their pre-exposure values once the H2S is removed. The experirnental results strongly indicate that the protein based LSPR chip can be successfully used as a simple, fast, sensitive and quantitative sensor for H2S detection.

Resource Allocation for Uplink CSI Sensing Report in Multi-User WLAN Sensing

Sensing in wireless local area network(WLAN) gains great interests recently. In this paper we focus on the multi-user WLAN sensing problem under the existing 802.11 standards. Multiple stations perform sensing with the access point and transmit channel state information(CSI)report simultaneously on the basis of uplink-orthogonal frequency division multiple access(OFDMA). Considering the transmission resource consumed in CSI report and the padding wastage in OFDMA based CSI report, we optimize the CSI simplification and uplink resource unit(RU)allocation jointly, aiming to balance the sensing accuracy and padding wastage performances in WLAN sensing. We propose the minimize padding maximize efficiency(MPME) algorithm to solve the problem and evaluate the performance of the proposed algorithm through extensive simulations.

An Indoor Environment Sensing and Localization System via mmWave Phased Array

In this paper,an indoor layout sensing and localization system with testbed in the 60-GHz millimeter wave(mmWave)band,named mmReality,is elaborated.The mmReality system consists of one transmitter and one mobile receiver,both with a phased array and a single radio frequency(RF)chain.To reconstruct the room layout,the pilot signal is delivered from the transmitter to the receiver via different pairs of transmission and receiving beams,so that multipath signals in all directions can be captured.Then spatial smoothing and the two-dimensional multiple signal classification(MUSIC)algorithm are applied to detect the angle-of-departures(AoDs)and angle-of-arrivals(AoAs)of propagation paths.Moreover,the technique of multi-carrier ranging is adopted to measure the path lengths.Therefore,with the measurements of the receiver in different locations of the room,the receiver and virtual transmitters can be pinpointed to reconstruct the room layout.Experiments show that the reconstructed room layout can be utilized to localize a mobile device via the AoA spectrum.

Gold nanorods conjugated upconversion nanoparticles nanocomposites for simultaneous bioimaging,local temperature sensing and photothermal therapy of OML-1 oral cancer cells

The major challenge in photothermal therapy(PTT)is to develop nanocomposites that simultaneously exhibit bioimaging and PTT under a single near-infrared(NIR)irradiation with high therapeutic efficiency.Herein,we present a multifunctional nanocomposite synthesized by linking NaYF_(4):Yb^(3+),Er^(3+)upconversion nanoparticles(UCNPs)with gold nanorods(AuNR)to exhibit fluorescence label-ing,local temperature sensing and photothermal functions simul-taneously with a single NIR laser excitation.The AuNR-NaYF_(4):Yb^(3+),Er^(3+)nanocomposite particles displayed better photothermal prop-erties compared with pure AuNRs or a blend of AuNRs and NaYF_(4):Yb^(3+),Er^(3+)UCNPs.The temperature-dependent upconversion lumi-nescence(UCL)property was used to determine local temperature at the nanocomposite particles,which is useful for selecting appro-priate irradiation dosage for PTT.The therapeutic performance of the nanocomposites in PTT for OML-1 oral cancer cells was deter-mined.For cell labeling,we successfully labeled streptavidin-linked nanocomposite particles on the surface of OML-1 oral cancer using anti-human epidermal growth factor receptor 2(anti-Her2)anti-body.Finally,the nanocomposite particles caused exceptional destruction of cancer cells up to 70%dead cells under 976 nm laser irradiation for only one min at 0.3 W/cm^(2)which is below the maximal permissible exposure of human skin.

Molecular mechanisms underlying phosphate sensing, signaling, and adaptation in plants

As an essential plant macronutrient, the low availability of phosphorus （P） in most soils imposes serious limitation on crop production. Plants have evolved complex responsive and adaptive mechanisms for acquisition, remobilization and recycling of phosphate （Pi） to maintain P homeostasis. Spatio-temporal molecular, physiological, and biochemical Pi deficiency responses developed by plants are the consequence of local and systemic sensing and signaling pathways. Pi deficiency is sensed locally by the root system where hormones serve as important signaling components in terms of developmental reprogramming, leading to changes in root system architecture. Root-to-shoot and shoot-to-root signals, delivered through the xylem and phloem, respectively, involving Pi itself, hormones, miRNAs, mRNAs, and sucrose, serve to coordinate Pi deficiency responses at the whole-plant level. A combination of chromatin remodeling, transcriptional and posttranslational events contribute to globally regulating a wide range of Pi deficiency responses. In this review, recent advances are evaluated in terms of progress toward developing a comprehen- sive understanding of the molecular events underlying control over P homeostasis. Application of this knowledge, in terms of developing crop plants having enhanced attributes for P use efficiency, is discussed from the perspective of agricultural sustainability in the face of diminishing global P supplies.

Sensorless Sensing with WiFi

Can WiFi signals be used for sensing purpose？ The growing PHY layer capabilities of WiFi has made it possible to reuse WiFi signals for both communication and sensing. Sensing via WiFi would enable remote sensing without wearable sensors, simultaneous perception and data transmission without extra communication infrastructure, and contactless sensing in privacy-preserving mode. Due to the popularity of WiFi devices and the ubiquitous deployment of WiFi networks, WiFi-based sensing networks, if fully connected, would potentially rank as one of the world＇s largest wireless sensor networks. Yet the concept of wireless and sensorless sensing is not the simple combination of WiFi and radar. It seeks breakthroughs from dedicated radar systems, and aims to balance between low cost and high accuracy, to meet the rising demand for pervasive environment perception in everyday life. Despite increasing research interest, wireless sensing is still in its infancy. Through introductions on basic principles and working prototypes, we review the feasibilities and limitations of wireless, sensorless, and contactless sensing via WiFi. We envision this article as a brief primer on wireless sensing for interested readers to explore this open and largely unexplored field and create next-generation wireless and mobile computing applications.