Effective identification of terrain positions from gridded DEM data using multimodal classification integration

Terrain positions are widely used to describe the Earth’s topographic features and play an important role in the studies of landform evolution, soil erosion and hydrological modeling. This work develops a new multimodal classification system with enhanced classification performance by integrating different approaches for terrain position identification. The adopted classification approaches include local terrain attribute (LA)-based and regional terrain attribute (RA)-based, rule-based and supervised, and pixel-based and object-oriented methods. Firstly, a double-level definition scheme is presented for terrain positions. Then, utilizing a hierarchical framework, a multimodal approach is developed by integrating different classification techniques. Finally, an assessment method is established to evaluate the new classification system from different aspects. The experimental results, obtained at a Loess Plateau region in northern China on a 5 m digital elevation model (DEM), show reasonably positional relationship, and larger inter-class and smaller intra-class variances. This indicates that identified terrain positions are consistent with the actual topography from both overall and local perspectives, and have relatively good integrity and rationality. This study demonstrates that the current multimodal classification system, developed by taking advantage of various classification methods, can reflect the geographic meanings and topographic features of terrain positions from different levels

Preparation of Dual Functionalized Surfaces for Covalent Immobilization of BMP-6 and Adhesive Ligands for Biological Applications

The median age of our population causes osteoporosis, bone fractures and disorders, which are also caused by multiple myeloma. In the past 25 years, regenerative medicine had gained in importance, especially for regeneration and renewal of bone tissue, which consists of different cell types composed in a very complex architecture. The growth factor bone morphogenetic protein 6 (BMP-6) belongs to the transforming growth factor β (TGF- β) superfamily and it induces the differentiation of mesenchymal stem cells into mature osteoblasts in bone leading to new bone formation. Besides induction of osteogenic differentiation, BMP-6 is also known to induce cell death in multiple myeloma cells in high concentrations. However, a systemic application is not practicable, since uncontrolled diffusion causes a wide range of side-effects. Immobilization of growth factors allows local treatment of bone fractures and defects, while it prevents uncontrolled release of growth factors. Furthermore, the required amount of growth factors can be reduced tremendously. The objective of this work was the covalent immobilization of BMP-6 co-presented with clicked integrin ligands on a structured gold nanoparticle (AuNP) platform, using blockcopolymer micellar nanolithography (BCMN) developed by Prof. Spatz and co-workers, to study integrin signaling in connection with growth factor responses. BMP-6 was selectively bound to gold nanoparticles organized in a hexagonal structure on the surface allowing to control the amount and density on the surface. I showed that surface co-presentation of BMP-6 and RGD or α5β1 integrin selective ligand promotes SMAD1/5 phosphorylation and osteogenic differentiation of the standard model system C2C12, even at amounts as low as 1 ng, whereas soluble BMP-6 application is significantly less effective. Additionally, BMP-6 was immobilized on gold nanostructured polyethylene glycol diacrylamide (PEG-DA) hydrogels containing different concentrations of cRGD in order to study the influence of the stiffness on the cell signaling. Furthermore, this approach was used to investigate the effect of immobilized BMP-6 in low doses on the multiple myeloma cell line OPM-2 to induce cell death. This approach provides for the first time the successful presentation of BMP-6 in small and defined amounts on surfaces in combination with adhesive ligands. Furthermore, covalent immobilization hinders protein release while maintaining the biological activity of the growth factor

Online_Supplement – Supplemental material for Assessing Item-Level Fit for Higher Order Item Response Theory Models

<p>Supplemental material, Online_Supplement for Assessing Item-Level Fit for Higher Order Item Response Theory Models by Xue Zhang, Chun Wang and Jian Tao in Applied Psychological Measurement</p

Facile Synthesis of Biocompatible Fluorescent Nanoparticles for Cellular Imaging and Targeted Detection of Cancer Cells

In this work, we report the facile synthesis of functional core–shell structured nanoparticles with fluorescence enhancement, which show specific targeting of cancer cells. Biopolymer poly-l-lysine was used to coat the silver core with various shell thicknesses. Then, the nanoparticles were functionalized with folic acid as a targeting agent for folic acid receptor. The metal-enhanced fluorescence effect was observed when the fluorophore (5-(and-6)-carboxyfluorescein-succinimidyl ester) was conjugated to the modified nanoparticle surface. Cellular imaging assay of the nanoparticles in folic acid receptor-positive cancer cells showed their excellent biocompatibility and selectivity. The as-prepared functional nanoparticles demonstrate the efficiency of the metal-enhanced fluorescence effect and provide an alternative approach for the cellular imaging and targeting of cancer cells

Water-Soluble Conjugated Polymer as a Platform for Adenosine Deaminase Sensing Based on Fluorescence Resonance Energy Transfer Technique

We report a new biosensor for adenosine deaminase (ADA) sensing based on water-soluble conjugated poly­(9,9-bis­(6′-<i>N</i>,<i>N</i>,<i>N</i>-trimethylammonium)­hexyl)­fluorine phenylene (PFP) and fluorescence resonance energy transfer technique. In this biosensor, PFP, DNAc-FI labeled with fluorescein (FAM), and ethidium bromide (EB) were used as the fluorescence energy donor, resonance gate, and the final fluorescence energy acceptor, respectively. In the absence of ADA, the adenosine aptamer forms a hairpin-like conformation with adenosine, which is far from its complementary single-stranded DNA (DNAc-FI). When PFP is excited at 380 nm, fluorescein emits strong green fluorescence via one-step FRET while EB has no fluorescence. After addition of ADA, adenosine is hydrolyzed to inosine and then double-stranded DNA (dsDNA) is formed between the aptamer and DNAc-FI, followed by EB intercalating into dsDNA. Once PFP is excited, EB will emit strong yellow fluorescence after two-step FRET from PFP to fluorescein and from fluorescein to EB. The sensitive ADA detection then is realized with a low detection limit of 0.5 U/L by measuring the FRET ratio of EB to fluorescein. Most importantly, the assay is accomplished homogeneously in 25 min without further treatments, which is much more simple and rapid than that reported in literature. Hence, this method demonstrates the sensitive, cost-effective, and rapid detection of ADA activity. It also opens an opportunity for designing promising sensors for other enzymes

Covalent Bonding of Metal–Organic Framework-5/Graphene Oxide Hybrid Composite to Stainless Steel Fiber for Solid-Phase Microextraction of Triazole Fungicides from Fruit and Vegetable Samples

A hybrid material of the zinc-based metal–organic framework-5 and graphene oxide (metal–organic framework-5/graphene oxide) was prepared as a novel fiber coating material for solid-phase microextraction (SPME). The SPME fibers were fabricated by covalent bonding via chemical cross-linking between the coating material metal–organic framework-5/graphene oxide and stainless steel wire. The prepared fiber was used for the extraction of five triazole fungicides from fruit and vegetable samples. Gas chromatography coupled with microelectron capture detector (GC-μECD) was used for quantification. The developed method gave a low limit of detection (0.05–1.58 ng g^–1) and good linearity (0.17–100 ng g^–1) for the determination of the triazole fungicides in fruit and vegetable samples. The relative standard deviations (RSDs) for five replicate extractions of the triazole fungicides ranged from 3.7 to 8.9%. The method recoveries for spiked fungicides (5, 20, and 50 ng g^–1) in grape, apple, cucumber, celery cabbage, pear, cabbage, and tomato samples were in the range of 85.6–105.8% with the RSDs ranging from 3.6 to 11.4%, respectively, depending on both the analytes and samples. The metal–organic framework-5/graphene oxide coated fiber was stable enough for 120 extraction cycles without a significant loss of extraction efficiency. The method was suitable for the determination of triazole fungicides in fruit and vegetable samples

Pharmacokinetic comparisons of Paeoniflorin and Paeoniflorin-6'O-benzene sulfonate in rats via different routes of administration

<p>1. The pharmacokinetics study of Paeoniflorin (Pae) and its acylated derivative (CP-25) was performed.</p> <p>2. The structure of CP-25 was identified by mass spectrometry (MS) and nuclear magnetic resonance spectroscopy (NMR). The rats were injected with CP-25(6, 12, 24 mg/kg) and orally treated with CP-25 (32, 64, 128 mg/kg), respectively. An high-performance liquid chromatography (HPLC) assay was developed to determine the plasma concentrations of Pae and CP-25.</p> <p>3. The results of MS and NMR showed that the acylated product was Pae-6'O-benzene sulfonate (CP-25). The plasma levels in oral CP-25 groups were detectable, whereas those of Pae in the oral groups (25 and 50 mg/kg) were undetectable. More specifically, the <i>C</i>_max values of oral CP-25 were 0.12, 0.19 and 0.44 μg/ml, and the corresponding <i>t</i>_1/2β of CP-25 were 1.44, 2.12 and 2.11 h, respectively. In addition, the <i>t</i>_1/2β values of intravenous CP-25 were 161.99, 152.81 and 153.76 min, respectively.</p> <p>4. Compared with the venous pharmacokinetics parameters of Pae, those of the <i>t</i>_1/2β, <i>MRT, Vd</i> and <i>CL/F</i> in the CP-25 groups increased noticeably. As expected, compared with oral parameters of Pae, those of <i>t</i>_1/2a, <i>t</i>_1/2β, <i>AUC, MRT</i> and <i>Vd</i> in the CP-25 group increased obviously. Finally, the absolute bioavailability of Pae and CP-25 were 3.6 and 10.6%, respectively.</p> <p>5. Our results indicate that CP-25 is characterized by improved absorption, well distribution, lower clearance, long mean residence time, and moderate bioavailability in rats.</p

Differentiating between simple and complex cells.

<p><b>A</b> Examples of peristimulus time histograms (PSTH) of responses to optimized (orientation, direction of movement, spatial and temporal frequencies, size) achromatic grating patches presented via dominant or non-dominant eyes. Histograms in <b>Ai</b> and <b>Aii</b> illustrate excellent interocular ‘matching’ of F1/F0 spike-response ratios to high-contrast grating patches optimized for each eye. Histograms in <b>Aiii</b> illustrates poor interocular matching of F1/F0 spike-response ratios. <b>B</b> Frequency histogram of F1/F0 spike-response ratios for the current sample of binocular parastriate cells to optimized grating patches presented via the dominant eyes. Note that the majority of cells that were identified as simple or complex on the basis of their F1/F0 spike-response ratios were also identified as simple or complex on the basis of Hubel and Wiesel's (1962) criteria. <b>Ci</b> Scatter plot of the magnitudes of peak discharge rates for the current sample of cells to optimized grating patches presented via the dominant vs. those to the optimized grating patches presented via the non-dominant eyes. <b>Cii</b> Histogram of the mean peak discharge rates of simple and complex cells to optimized drifting gratings presented via the dominant and the non-dominant eyes. Error bars indicate SEM. <b>Di</b> Scatter plot of F1/F0 spike-response ratios for optimized stimuli presented via the dominant eyes vs. those for optimized stimuli presented via the non-dominant eyes. <b>Dii</b> The frequency histogram illustrates the range of interocular differences in phase-sensitivity (F1/F0 spike-response ratios) elicited individually by optimized grating patches presented via the dominant and non-dominant eyes.</p

Spatial frequency cut-offs and temporal frequency tuning.

<p><b>Ai</b> Scatter plot illustrating the interocular matching of spatial frequency bandwidths; black line indicates linear regression line. <b>Aii</b> Frequency histogram of the interocular matching of SF bandwidths for simple and complex cells. <b>B</b> Histogram of the mean spatial frequency bandwidths of simple and complex cells for stimuli presented via dominant and non-dominant eyes. ** Indicates significant (P<0.01 Mann-Whitney test) difference; *** indicates significant (P<0.0005, Wilcoxon test) difference. <b>C</b> Examples of temporal frequency tuning curves for optimized (orientation, spatial frequency, size) gratings presented via dominant and non-dominant eyes. Note that in case of cell whose responses are illustrated in <b>Ci</b> there is an excellent interocular match of both optimal and high cut-off temporal frequencies. However, in case of cell whose responses are illustrated in <b>Cii</b> there are clear interocular differences in both optimal and high cut-off temporal frequencies. <b>D</b> Scatter plot showing the interocular matching of optimal temporal frequencies for the present sample of area 18 cells. <b>E</b> Histograms in <b>i</b> and <b>ii</b> illustrate respectively the optimal and high cut-off temporal frequencies for stimuli presented via the dominant and non-dominant eyes. Error bars indicate SEM.</p

Contrast sensitivity and comparison of high vs. low eye dominance.

<p><b>A</b> Examples of contrast response functions for optimized grating patches presented via the dominant and non-dominant eyes. Note that in some cells (<b>Ai</b>) irrespective of the contrast, the response to stimuli presented via non-dominant eye is much weaker than that to stimuli presented via dominant eye. In other cells however, at low contrasts the response to stimuli presented via the dominant eye is not much stronger than that to stimuli presented via the non-dominant eye (<b>Aii</b>) or the eye dominance is reversed (<b>Aiii</b>). The C₅₀ contrasts, that is, the contrasts at which the magnitude of response to optimized stimuli confined to the sRF reached 50% of maximum response are indicted by the dashed lines. <b>B</b> Histogram showing the mean C₅₀ values of the contrast response functions of the current sample of cells when stimulated via the dominant or non-dominant eyes. <b>C</b> Frequency histograms of cells with high eye dominance indices (HEDI) and cells with low eye dominance indices (LEDI). Also shown is the equation by which eye dominance index has been determined. <b>D</b> Mean SI of HEDI and LEDI cells for stimuli presented via the dominant or non-dominant eyes. Error bars indicate SEM; ** indicate significant (P<0.01, Wilcoxon test) differences. <b>Ei</b> Scatter plot of the peak discharge rates for optimized grating patches presented via the dominant vs. optimized grating patches presented via the non-dominant eyes. <b>Eii</b> Mean peak discharges rates of HEDI and LEDI cells for stimuli presented via the dominant or non-dominant eyes. Error bars indicate SEM; # indicates marginally significant (P<0.05, Mann-Whitney test, one-tailed criterion) difference.</p