A Classification Method Based on Principal Components of SELDI Spectra to Diagnose of Lung Adenocarcinoma

Lung cancer is the leading cause of cancer death worldwide, but techniques for effective early diagnosis are still lacking. Proteomics technology has been applied extensively to the study of the proteins involved in carcinogenesis. In this paper, a classification method was developed based on principal components of surface-enhanced laser desorption/ionization (SELDI) spectral data. This method was applied to SELDI spectral data from 71 lung adenocarcinoma patients and 24 healthy individuals. Unlike other peak-selection-based methods, this method takes each spectrum as a unity. The aim of this paper was to demonstrate that this unity-based classification method is more robust and powerful as a method of diagnosis than peak-selection-based methods.The results showed that this classification method, which is based on principal components, has outstanding performance with respect to distinguishing lung adenocarcinoma patients from normal individuals. Through leaving-one-out, 19-fold, 5-fold and 2-fold cross-validation studies, we found that this classification method based on principal components completely outperforms peak-selection-based methods, such as decision tree, classification and regression tree, support vector machine, and linear discriminant analysis.The classification method based on principal components of SELDI spectral data is a robust and powerful means of diagnosing lung adenocarcinoma. We assert that the high efficiency of this classification method renders it feasible for large-scale clinical use

Comprehensively Surveying Structure and Function of RING Domains from Drosophila melanogaster

Using a complete set of RING domains from Drosophila melanogaster, all the solved RING domains and cocrystal structures of RING-containing ubiquitin-ligases (RING-E3) and ubiquitin-conjugating enzyme (E2) pairs, we analyzed RING domains structures from their primary to quarternary structures. The results showed that: i) putative orthologs of RING domains between Drosophila melanogaster and the human largely occur (118/139, 84.9%); ii) of the 118 orthologous pairs from Drosophila melanogaster and the human, 117 pairs (117/118, 99.2%) were found to retain entirely uniform domain architectures, only Iap2/Diap2 experienced evolutionary expansion of domain architecture; iii) 4 evolutionary structurally conserved regions (SCRs) are responsible for homologous folding of RING domains at the superfamily level; iv) besides the conserved Cys/His chelating zinc ions, 6 equivalent residues (4 hydrophobic and 2 polar residues) in the SCRs possess good-consensus and conservation- these 4 SCRs function in the structural positioning of 6 equivalent residues as determinants for RING-E3 catalysis; v) members of these RING proteins located nucleus, multiple subcellular compartments, membrane protein and mitochondrion are respectively 42 (42/139, 30.2%), 71 (71/139, 51.1%), 22 (22/139, 15.8%) and 4 (4/139, 2.9%); vi) CG15104 (Topors) and CG1134 (Mul1) in C3HC4, and CG3929 (Deltex) in C3H2C3 seem to display broader E2s binding profiles than other RING-E3s; vii) analyzing intermolecular interfaces of E2/RING-E3 complexes indicate that residues directly interacting with E2s are all from the SCRs in RING domains. Of the 6 residues, 2 hydrophobic ones contribute to constructing the conserved hydrophobic core, while the 2 hydrophobic and 2 polar residues directly participate in E2/RING-E3 interactions. Based on sequence and structural data, SCRs, conserved equivalent residues and features of intermolecular interfaces were extracted, highlighting the presence of a nucleus for RING domain fold and formation of catalytic core in which related residues and regions exhibit preferential evolutionary conservation

HIGH-PRECISION DEM PRODUCTION FOR SPACEBORNE STEREO SAR IMAGES BASED ON SIFT MATCHING AND REGION-BASED LEAST SQUARES MATCHING

Generally, there are two ways to generate Digital Elevation Model (DEM) using synthetic aperture radar (SAR) data, which are Interferometer Synthetic Aperture Radar(InSAR) and radargrammetry. Considering the disadvantages of InSAR data, such as the limit of terrain and the influence of water content, the application field of InSAR is relatively limited, while radargrammetry is more widely applied since it does not have such limits. However, for high-precision stereo SAR imagery, since the terrain distortion caused by shooting angle cannot be eliminated and the speckle noises are obvious, the classical matching algorithms for optical stereo images do not have the same effect on SAR data. Based on the experience of optical stereo image matching, this paper proposes a new algorithm which combines the feature of SIFT image matching, region-based least squares matching and TIN . First, SIFT matching is used as the initial matching to obtain the sparse DEM, then by using TIN the matching points are forecast, finally the region-based least squares matching is adopted to get accurate matching points. In this paper, COSMO-SkyMed and TSX stereo images of Lanzhou area are used to validate the proposed method. Experiment results show that the algorithm can be effectively used in stereo SAR matching and high-precision DEM production

Preparation and physical properties of a Cr3Al filmwith a DO3structure

A Cr3Al compound with a DO3 structure has previously been predicted to be nearly half metal and a promising spintronics material; however, its synthesis has not been reported. Here, a Cr3Al compound with a DO3 structure is successfully prepared in thin-film form by the magnetron sputtering method. It was found that the substrate temperature is crucial to the atomic ordering, thin-film density and lattice constant. The lattice constant varies with different substrate temperatures and is smaller than the theoretical equilibrium lattice constant. Theoretical investigations on the electronic structures and magnetic properties indicate that the Cr3Al compound with a DO3 structure is a rare material with zero-gap half-metallic characteristics under an experimental lattice constant of 5.83 Å. The experimental result is in agreement with the theoretical results in magnetization, and the Cr3Al compound synthesized in this work exhibits semi-metallic-like electrical transport characteristics and positive magnetoresistance of greater than 2% in the temperature range 2-250 K

Novel bipolar magnetic semiconducting and fully compensated ferrimagnetic semiconducting characters in newly designed LiMgPdSn-type compounds: KCaCX (X = O, S, and Se)

With the first-principles calculations, the electronic structure and magnetic properties of KCaCX (X = O, S and Se) alloys with LiMgPdSn-type structure have been studied. The results show that KCaCO is a new bipolar ferrimagnetic semiconductor (BFS) with an integer magnetic moment of 3.00 μB at the equilibrium lattice parameter, while KCaCS and KCaCSe are fully compensated ferrimagnetic (antiferromagnetic) semiconductors (FCFS). The strong spin polarization mainly derives from the 2p electrons of C element in the KCaCX (X = O, S and Se) compounds. Under the effect of hydrostatic strain and tetragonal distortion, KCaCO alloy undergoes an interesting physics change from bipolar ferrimagnetic semiconductor (BFS) → ferrimagnetic spin-gapless semiconductor (FSGS) → general ferrimagnetic metal (GFM) transition, which indicates that the electronic and magnetic structure could be highly tuned by external temperature or pressure. A physics transition can also be found in KCaCS and KCaCSe compounds: undergoing FCFS → fully compensated ferrimagnetic semi-metal (FCFSM) → general fully compensated ferrimagnetic metal (FCFM) transitions under the hydrostatic strain and tetragonal distortion. Therefore, KCaCX (X = O, S and Se) compounds would be a series of potential candidates for new spintronics device