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881.
Ikram Ullah Munam Ali Shah Abdul Wahid Amjad Mehmood Houbing Song 《Telecommunication Systems》2018,67(4):553-575
The Internet of Things (IoT) means connecting everything with every other thing through the Internet. In IoT, millions of devices communicate to exchange data and information with each other. During communication, security and privacy issues arise which need to be addressed. To protect information about users’ location, an efficient technique should be devised. Several techniques have already been proposed for preserving location privacy in IoT. However, the existing research lags in preserving location privacy in IoT and has highlighted several issues such as being specific or being restricted to a certain location. In this paper, we propose a new location privacy technique called the enhanced semantic obfuscation technique (ESOT) to preserve the location information of a user. Experimental results show that ESOT achieves improved location privacy and service utility when compared with a well-known existing approach, the semantic obfuscation technique. 相似文献
882.
Kha KM Perveen S Ayattollahi SA Saba N Rashid A Firdous S Haider SM Ullah Z Rahat S Khan Z 《Natural product letters》2002,16(4):283-290
Three glycosides and a long chain alcohol were isolated from the bulbs of Polianthes tuberosa, these were identified as 3,29-dihydroxystigmast-5-ene-3-O-beta-D-galactopyranoside (1), ethyl beta-D-galactopyranoside (2), ethyl-alpha-D-galactopyranoside (3), and 1-tricosanol (4). The structures were determined by extensive spectroscopic and chemical methods. All four isolated compounds were screened for their cytotoxicity, antibacterial and antifungal activities, none of the compounds showed any significant activity. 相似文献
883.
Nurul ’I. Abdul Karim Wan A. Wan Ibrahim Mohd M. Sanagi Aemi S. Abdul Keyon 《Electrophoresis》2016,37(20):2649-2656
Online preconcentration using electrokinetic supercharging (EKS) was proposed to enhance the sensitivity of separation for endocrine disrupting chemical (methylparaben (MP)) and phenolic pollutants (2‐nitrophenol (NP) and 4‐chlorophenol (CP)) in water sample. Important EKS and separation conditions such as the concentration of BGE; the choice of terminating electrolyte (TE); and the injection time of leading electrolyte (LE), sample, and TE were optimized. The optimum EKS‐CE conditions were as follows: BGE comprising of 12 mM sodium tetraborate pH 10.1, 100 mM sodium chloride as LE hydrodynamically injected at 50 mbar for 30 s, electrokinetic injection (EKI) of sample at –3 kV for 200 s, and 100 mM CHES as TE hydrodynamically injected at 50 mbar for 40 s. The separation was conducted at negative polarity mode and UV detection at 214 nm. Under these conditions, the sensitivity of analytes was enhanced from 100‐ to 737‐fold as compared to normal CZE with hydrodynamic injection, giving LOD of 4.89, 5.29, and 53 μg/L for MP, NP and CP, respectively. The LODs were adequate for the analysis of NP and CP in environmental water sample having concentration at or lower than their maximum admissible concentration limit (240 and 2000 μg/L for NP and CP). The LOD of MP can be suitable for the analysis of MP exists at mid‐microgram per liter level, even though the LOD was slightly higher than the concentration usually found in water samples (from ng/L to 1 μg/L). The method repeatabilities (%RSD) were in the range of 1.07–2.39% (migration time) and 8.28–14.0% (peak area). 相似文献
884.
A mass sensitive quartz crystal microbalance (QCM) based genosensor has been developed using breast cancer 1 (BRCA1) gene as a model gene. We modified the traditional sandwich assay by conjugating reporter probe DNA (DNA-r) with an assembly of gold nanoparticles leading to an increased mass on the surface, which enhanced the sensitivity to few orders of magnitude. The unique cleavage function of endonuclease is used for achieving the selectivity to complementary DNA over mismatched DNA. With this combination, the sensor exhibited excellent sensitivity with a detection limit of 10 aM BRCA1 gene and it showed good selectivity for even single base mismatch DNA targets. This ultrasensitive and cost-effective DNA detection protocol can be extended to the direct analysis of any non-amplified genomic DNA. 相似文献
885.
Adnan Ahmed Kamalrulnizam Abu Bakar Muhammad Ibrahim Channa Abdul Waheed Khan 《Mobile Networks and Applications》2016,21(2):272-285
Nodes in most of the deployments of Wireless Sensor Networks (WSNs) remain un-administered and exposed to variety of security attacks. Characterized by constrained resources and dynamically changing behavior of sensor nodes, reliable data delivery in WSNs is nontrivial. To counter node misbehavior attacks, traditional cryptographic and authentication based solutions have proved to be inappropriate due to high cost and incapability factors. Recently, trust based solutions have appeared to be viable solutions to address nodes’ misbehavior attacks. However, the existing trust based solutions incur high cost in trust estimation and network-wide dissemination which significantly increases traffic congestion and undermines network lifetime. This paper presents a Trust and Energy aware Secure Routing Protocol (TESRP) for WSN that exploits a distributed trust model for discovering and isolating misbehaving nodes. TESRP employs a multi-facet routing strategy that takes into consideration the trust level, residual energy, and hop-counts of neighboring nodes while making routing decisions. This strategy not only ensures data dissemination via trusted nodes but also balances out energy consumption among trusted nodes while traversing through shorter paths. Demonstrated by simulation results in NS-2, TESRP achieves improved performance in terms of energy consumption, throughput and network lifetime as compared to existing solutions. 相似文献
886.
Ba-Abbad Muneer M. Takriff Mohd S. Benamor Abdelbaki Mohammad Abdul Wahab 《Journal of Sol-Gel Science and Technology》2017,81(3):880-893
Journal of Sol-Gel Science and Technology - Haematite (α-Fe2O3) nanoparticles (NPs) of different sizes and morphologies were prepared from two different iron precursors (iron acetate (A) and... 相似文献
887.
888.
Fawad Kaleem Ghulam Shabir Kashif Aslam Sumaira Rasul Hamid Manzoor Shahid Masood Shah Abdul Rehman Khan 《Applied biochemistry and biotechnology》2018,186(2):306-334
Salinity is one of the major threats faced by the modern agriculture today. It causes multidimensional effects on plants. These effects depend upon the plant growth stage, intensity, and duration of the stress. All these lead to stunted growth and reduced yield, ultimately inducing economic loss to the farming community in particular and to the country in general. The soil conditions of agricultural land are deteriorating at an alarming rate. Plants assess the stress conditions, transmit the specific stress signals, and then initiate the response against that stress. A more complete understanding of plant response mechanisms and their practical incorporation in crop improvement is an essential step towards achieving the goal of sustainable agricultural development. Literature survey shows that investigations of plant stresses response mechanism are the focus area of research for plant scientists. Although these efforts lead to reveal different plant response mechanisms against salt stress, yet many questions still need to be answered to get a clear picture of plant strategy to cope with salt stress. Moreover, these studies have indicated the presence of a complicated network of different integrated pathways. In order to work in a progressive way, a review of current knowledge is critical. Therefore, this review aims to provide an overview of our understanding of plant response to salt stress and to indicate some important yet unexplored dynamics to improve our knowledge that could ultimately lead towards crop improvement. 相似文献
889.
890.
Lewis Acid Guests in a {P8W48} Archetypal Polyoxotungstate Host: Enhanced Proton Conductivity via Metal‐Oxo Cluster within Cluster Assemblies
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Dr. Peng Yang Maryam Alsufyani Abdul‐Hamid Emwas Chaoqin Chen Prof. Niveen M. Khashab 《Angewandte Chemie (International ed. in English)》2018,57(40):13046-13051
Complexes made by hosts that completely surround their guests provide a means to stabilize reactive chemical intermediates, transfer biologically active cargo to a diseased cell, and construct molecular‐scale devices. By the virtue of inorganic host–guest self‐assembly, nucleation processes in the cavity of a {P8W48}‐archetype phosphotungstate has afforded a nanoscale 16‐AlIII‐32‐oxo cluster and its GaIII analogue that contain the largest number of AlIII/GaIII ions yet found in polyoxometalate (POM) chemistry. Interestingly, the rich Lewis acid AlIII centers within the Lewis base POM support shows an exceptional proton conductivity of 4.5×10?2 S cm?1 (85 °C, 70 % RH; RH: relative humidity), which is by far the highest conductivity reported among POM‐based single‐crystal proton conductors. 相似文献