Robust Detection of Moving Human Target Behind Wall via Impulse through-Wall Radar

Through-wall human target detection is highly desired in military applications. We have developed an impulse through-wall radar (TWR) to address this problem. In order to obtain a robust detection performance, firstly we adopt the exponential average background subtraction (EABS) method to mitigate clutters and improve the signal-to-clutter ratio (SCR). Then, different from the conventional constant false alarm rate (CFAR) methods that are applied along the fast-time dimension, we propose a new CFAR method along the slow-time dimension to resist the residual clutters in the clutter mitigation output because of timing jitters, based on the presence of a larger relative variation of human target moving in and out in comparison with that of residual clutters in the slow-time dimension. The proposed method effectively solves the false alarm issue caused by residual clutters in the conventional CFAR methods, and obtains robust detection performance. Finally, different through-wall experiments are provided to verify the proposed method.Defence Science Journal, 2013, 63(6), pp.636-642, DOI:http://dx.doi.org/10.14429/dsj.63.576

Wafer-scale fabrication of high-density nanoslit arrays for surface-enhanced Raman spectroscopy

Surfaces with a periodic nanostructure and controllable feature size are sought after for optical applications, and the fabrication of such surfaces in large areas with high reproducibility, good stability and low deviation is very important. We present a strategy to fabricate large-area nanoslit arrays with controllable pitches and gaps. Au nanoslit arrays with gaps down to around 10 nm and a high gap density of 2.0 ×104 cm-1 have been fabricated, which can greatly enhance the near-field electromagnetic field to achieve localized surface plasmon resonance (LSPR). An averaged surface-enhanced Raman scattering analytical enhancement factor of 8.0 ×107 has been achieved on the substrate using a 633 nm laser source and the 'coupling effect' of LSPR of the nanoslits

A novel image fusion algorithm based on bandelet transform

A novel image fusion algorithm based on bandelet transform is proposed. Bandelet transform can take advantage of the geometrical regularity of image structure and represent sharp image transitions such as edges efficiently in image fusion. For reconstructing the fused image, the maximum rule is used to select source images’ geometric flow and bandelet coefficients. Experimental results indicate that the bandelet-based fusion algorithm represents the edge and detailed information well and outperforms the wavelet-based and Laplacian pyramid-based fusion algorithms, especially when the abundant texture and edges are contained in the source images.Navigation Science Foundation (No. 05F07001) and the National Natural Science Foundation of China (No. 60472081)

Serum YKL-40 in coronary heart disease: linkage with inflammatory cytokines, artery stenosis, and optimal cut-off value for estimating major adverse cardiovascular events

ObjectiveYKL-40, previously known as chitinase-3-like protein 1 (CHI3L1), is an inflammation-related glycoprotein that promotes atherosclerosis, but its application and optimal cut-off value as a prognostic biomarker in coronary heart disease (CHD) require more clinical evidence. Thus, this prospective study aimed to evaluate the linkage of serum YKL-40 with disease features, inflammatory cytokines, and major adverse cardiovascular events (MACEs) in CHD patients.MethodsA total of 410 CHD patients were enrolled for serum YKL-40 determination via enzyme-linked immunosorbent assay. Meanwhile, serum YKL-40 levels in 100 healthy controls (HCs) were also quantified.ResultsYKL-40 level was higher in CHD patients compared with that in HCs (P < 0.001). YKL-40 was positively linked with hyperlipidemia (P = 0.014), diabetes mellitus (P = 0.001), fasting blood glucose (P = 0.045), C-reactive protein (P < 0.001), the Gensini score (P < 0.001), and stenosis degree (graded by the Gensini score) (P < 0.001) in CHD patients. In addition, an elevated YKL-40 level was associated with increased levels of tumor necrosis factor alpha (P = 0.001), interleukin (IL)-1β (P = 0.001), IL-6 (P < 0.001), and IL-17A (P = 0.002) in CHD patients. The 1-/2-/3-year cumulative MACE rates of CHD patients were 5.5%, 14.4%, and 25.0%, respectively. Regarding the prognostic capability, YKL-40 ≥100 ng/ml (the median cut-off value) (P = 0.003) and YKL-40 ≥150 ng/ml (the third interquartile cut-off value) (P = 0.021) reflected an elevated accumulating MACE rate, whereas accumulating MACE was not different between CHD patients with YKL-40 ≥80 and <80 ng/ml (the first interquartile cut-off value) (P = 0.083).ConclusionSerum YKL-40 is positively linked with inflammatory cytokines and the Gensini score, whose high expression cut-off by 100 and 150 ng/ml estimates a higher MACE risk in CHD patients

Microbial community composition and metabolic potential during a succession of algal blooms from Skeletonema sp. to Phaeocystis sp.

Elucidating the interactions between algal and microbial communities is essential for understanding the dynamic mechanisms regulating algal blooms in the marine environment. Shifts in bacterial communities when a single species dominates algal blooms have been extensively investigated. However, bacterioplankton community dynamics during bloom succession when one algal species shift to another is still poorly understood. In this study, we used metagenomic analysis to investigate the bacterial community composition and function during algal bloom succession from Skeletonema sp. to Phaeocystis sp. The results revealed that bacterial community structure and function shifted with bloom succession. The dominant group in the Skeletonema bloom was Alphaproteobacteria, while Bacteroidia and Gammaproteobacteria dominated the Phaeocystis bloom. The most noticeable feature during the successions was the change from Rhodobacteraceae to Flavobacteriaceae in the bacterial communities. The Shannon diversity indices were significantly higher in the transitional phase of the two blooms. Metabolic reconstruction of the metagenome-assembled genomes (MAGs) showed that dominant bacteria exhibited some environmental adaptability in both blooms, capable of metabolizing the main organic compounds, and possibly providing inorganic sulfur to the host algae. Moreover, we identified specific metabolic capabilities of cofactor biosynthesis (e.g., B vitamins) in MAGs in the two algal blooms. In the Skeletonema bloom, Rhodobacteraceae family members might participate in synthesizing vitamin B1 and B12 to the host, whereas in the Phaeocystis bloom, Flavobacteriaceae was the potential contributor for synthesizing vitamin B7 to the host. In addition, signal communication (quorum sensing and indole-3-acetic acid molecules) might have also participated in the bacterial response to bloom succession. Bloom-associated microorganisms showed a noticeable response in composition and function to algal succession. The changes in bacterial community structure and function might be an internal driving factor for the bloom succession