Showing papers by "Nanjing University published in 2004"

Effect on left ventricular function of intracoronary transplantation of autologous bone marrow mesenchymal stem cell in patients with acute myocardial infarction.

Abstract: Sixty-nine patients who underwent primary percutaneous coronary intervention within 12 hours after onset of acute myocardial infarction were randomized to receive intracoronary injection of autologous bone marrow mesenchymal stem cell or standard saline. Several imagining techniques demonstrated that bone marrow mesenchymal stem cells significantly improved left ventricular function.

Robust image segmentation using FCM with spatial constraints based on new kernel-induced distance measure

Abstract: Fuzzy c-means clustering (FCM) with spatial constraints (FCM/spl I.bar/S) is an effective algorithm suitable for image segmentation. Its effectiveness contributes not only to the introduction of fuzziness for belongingness of each pixel but also to exploitation of spatial contextual information. Although the contextual information can raise its insensitivity to noise to some extent, FCM/spl I.bar/S still lacks enough robustness to noise and outliers and is not suitable for revealing non-Euclidean structure of the input data due to the use of Euclidean distance (L/sub 2/ norm). In this paper, to overcome the above problems, we first propose two variants, FCM/spl I.bar/S/sub 1/ and FCM/spl I.bar/S/sub 2/, of FCM/spl I.bar/S to aim at simplifying its computation and then extend them, including FCM/spl I.bar/S, to corresponding robust kernelized versions KFCM/spl I.bar/S, KFCM/spl I.bar/S/sub 1/ and KFCM/spl I.bar/S/sub 2/ by the kernel methods. Our main motives of using the kernel methods consist in: inducing a class of robust non-Euclidean distance measures for the original data space to derive new objective functions and thus clustering the non-Euclidean structures in data; enhancing robustness of the original clustering algorithms to noise and outliers, and still retaining computational simplicity. The experiments on the artificial and real-world datasets show that our proposed algorithms, especially with spatial constraints, are more effective.

State feedback controller design of networked control systems

Abstract: This paper is concerned with the controller design of networked control systems (NCS). A new model of the NCSs is provided under consideration of both the network-induced delay and the data packet dropout in the transmission. In terms of the given model, a controller design method is proposed based on a delay-dependent approach. The feedback gain of a memoryless controller and the maximum allowable value of the network-induced delay can be derived by solving a set of linear matrix inequalities. Two examples are given to show the effectiveness of our method.

Photocatalytic decomposition of organic contaminants by Bi2WO6 under visible light irradiation

Abstract: An oxide photocatalyst Bi2WO6 with corner-shared WO6 octahedral layered structure was synthesized. Its band gap was determined to be 2.69 eV from UV–vis diffuse reflectance spectra. The photocatalyst showed not only the activity for photocatalytic O2 evolution with the initial evolution rate of 2.0 μmol/h but also the activity of mineralizing both CHCl3 and CH3CHO contaminants under visible light irradiation. Meanwhile, wavelength dependence of CH3CHO decomposition was observed, which indicated that the photocatalytic activity of the photocatalyst was in good agreement with its light-absorption ability.

Genome-wide identification of NBS genes in japonica rice reveals significant expansion of divergent non-TIR NBS-LRR genes

Abstract: A complete set of candidate disease resistance ( R) genes encoding nucleotide-binding sites (NBSs) was identified in the genome sequence of japonica rice ( Oryza sativa L. var. Nipponbare). These putative R genes were characterized with respect to structural diversity, phylogenetic relationships and chromosomal distribution, and compared with those in Arabidopsis thaliana. We found 535 NBS-coding sequences, including 480 non-TIR (Toll/IL-1 receptor) NBS-LRR (Leucine Rich Repeat) genes. TIR NBS-LRR genes, which are common in A. thaliana, have not been identified in the rice genome. The number of non-TIR NBS-LRR genes in rice is 8.7 times higher than that in A. thaliana, and they account for about 1% of all of predicted ORFs in the rice genome. Some 76% of the NBS genes were located in 44 gene clusters or in 57 tandem arrays, and 16 apparent gene duplications were detected in these regions. Phylogenetic analyses based both NBS and N-terminal regions classified the genes into about 200 groups, but no deep clades were detected, in contrast to the two distinct clusters found in A. thaliana. The structural and genetic diversity that exists among NBS-LRR proteins in rice is remarkable, and suggests that diversifying selection has played an important role in the evolution of R genes in this agronomically important species. (Supplemental material is available online at http://gattaca.nju.edu.cn .)

Single-crystal hexagonal disks and rings of ZnO: Low-temperature, large-scale synthesis and growth mechanism

Abstract: [*] Dr. F. Li Department of Chemistry University of New Orleans New Orleans, LA 70148 (USA) Fax: (+1)504-280-6860 E-mail: fli@uno.edu Dr. Y. Ding, P. Gao, Prof. Dr. Z. L. Wang School of Materials Science and Engineering Georgia Institute of Technology Atlanta, GA 30332-0245 (USA) Fax: (+1)404-894-9140 E-mail: zhong.wang@mse.gatech.edu Prof. X. Xin Department of Chemistry Nanjing University Nanjing 20093 (P. R. China) [**] The authors gratefully acknowledge the financial support of the National Science Foundation of China (No.90101028) and the National Science Foundation. Zuschriften

State feedback controller design of networked control systems

Abstract: This work is concerned with the controller design of networked control systems (NCSs). A new model of NCSs is provided under consideration of both the network-induced delay and the data packet dropout in the transmission. In terms of the given model, a controller design method is proposed based on a delay dependent approach. The feedback gain of a memoryless controller and the maximum allowable value of the network-induced delay can be derived by solving a set of linear matrix inequalities. Two examples are given to show the effectiveness of our method.

The star formation history of Seyfert 2 nuclei

Abstract: We present a study of the stellar populations in the central ∼200 pc of a large and homogeneous sample comprising 79 nearby galaxies, most of which are Seyfert 2s. The star formation history of these nuclei is reconstructed by means of state-of-the-art population synthesis modelling of their spectra in the 3500‐5200 A interval. A quasar-like featureless continuum (FC) is added to the models to account for possible scattered light from a hidden active galactic nucleus (AGN). We find the following. (1) The star formation history of Seyfert 2 nuclei is remarkably heterogeneous: young starbursts, intermediate-age and old stellar populations all appear in significant and widely varying proportions. (2) A significant fraction of the nuclei show a strong FC component, but this FC is not always an indication of a hidden AGN: it can also betray the presence of a young, dusty starburst. (3) We detect weak broad Hβ emission in several Seyfert 2s after cleaning the observed spectrum by subtracting the synthesis model. These are most likely the weak scattered lines from the hidden broad-line region envisaged in the unified model, given that in most of these cases independent spectropolarimetry data find a hidden Seyfert 1. (4) The FC strengths obtained by the spectral decomposition are substantially larger for the Seyfert 2s which present evidence of broad lines, implying that the scattered nonstellar continuum is also detected. (5) There is no correlation between the star formation in the nucleus and either the central or overall morphology of the parent galaxies. Ke yw ords: galaxies: active ‐ galaxies: Seyfert ‐ galaxies: statistics ‐ galaxies: stellar content.

Electrogenerated Chemiluminescence from a CdSe Nanocrystal Film and Its Sensing Application in Aqueous Solution

Abstract: Electrogenerated chemiluminescence (ECL) of semiconductor quantum dots in aqueous solutions and its first sensing application were studied by depositing CdSe nanocrystals (NCs) on a paraffin-impregnated graphite electrode (PIGE). The CdSe nanocrystal thin film exhibited two ECL peaks at −1.20 (ECL-1) and −1.50 V (ECL-2) in pH 9.3, 0.1 M PBS during the cyclic sweep between 0 and −1.8 V at 20 mV s-1. The electron-transfer reaction between individual electrochemically reduced nanocrystal species and oxidant coreactants such as H2O2 and reduced dissolved oxygen led to ECL-1. When mass NCs packed densely in the film were reduced electrochemically, assembly of reduced nanocrystal species could react with coreactants to produce another ECL signal, ECL-2. ECL-1 showed higher sensitivity to the concentration of oxidant coreactants than ECL-2 and thus was used for ECL detection of coreactant, H2O2. A linear response of ECL-1 to H2O2 was observed in the concentration range of 2.5 × 10-7−6 × 10-5 M with a detection l...

NF-kappaB and its regulation on the immune system.

Abstract: NF-kappaB is a transcription factor of eukaryote, whose family comprises five members in mammals and three in drosophila. Transcription factors of the NF-kappaB family are activated in response to signals that lead to cell growth, differentiation, apoptosis and other events. NF-kappaB takes part in expression of numerous cytokines and adhesion molecules which are critical elements involved in the regulation of immune responses. In this review, we focus on our current understanding of NF-kappaB signal pathway and its role in the innate and adaptive immune responses in which these transcription factors have a key regulatory function. Furthermore we review what is currently known about their effects associated with apoptosis.

Modeling greenhouse gas emissions from rice‐based production systems: Sensitivity and upscaling

Abstract: [1] A biogeochemical model, Denitrification-Decomposition (DNDC), was modified to enhance its capacity of predicting greenhouse gas (GHG) emissions from paddy rice ecosystems. The major modifications focused on simulations of anaerobic biogeochemistry and rice growth as well as parameterization of paddy rice management. The new model was tested for its sensitivities to management alternatives and variations in natural conditions including weather and soil properties. The test results indicated that (1) varying management practices could substantially affect carbon dioxide (CO2), methane (CH4), or nitrous oxide (N2O) emissions from rice paddies; (2) soil properties affected the impacts of management alternatives on GHG emissions; and (3) the most sensitive management practices or soil factors varied for different GHGs. For estimating GHG emissions under certain management conditions at regional scale, the spatial heterogeneity of soil properties (e.g., texture, SOC content, pH) are the major source of uncertainty. An approach, the most sensitive factor (MSF) method, was developed for DNDC to bring the uncertainty under control. According to the approach, DNDC was run twice for each grid cell with the maximum and minimum values of the most sensitive soil factors commonly observed in the grid cell. The simulated two fluxes formed a range, which was wide enough to include the “real” flux from the grid cell with a high probability. This approach was verified against a traditional statistical approach, the Monte Carlo analysis, for three selected counties or provinces in China, Thailand, and United States. Comparison between the results from the two methods indicated that 61-99% of the Monte Carlo-produced GHG fluxes were located within the MSA-produced flux ranges. The result implies that the MSF method is feasible and reliable to quantify the uncertainties produced in the upscaling processes. Equipped with the MSF method, DNDC modeled emissions of CO2, CH4, and N2O from all of the rice paddies in China with two different water management practices, i.e., continuous flooding and midseason drainage, which were the dominant practices before 1980 and in 2000, respectively. The modeled results indicated that total CH4 flux from the simulated 30 million ha of Chinese rice fields ranged from 6.4 to 12.0 Tg CH4-C per year under the continuous flooding conditions. With the midseason drainage scenario, the national CH4 flux from rice agriculture reduced to 1.7–7.9 Tg CH4-C. It implied that the water management change in China reduced CH4 fluxes by 4.2–4.7 Tg CH4-C per year. Shifting the water management from continuous flooding to midseason drainage increased N2O fluxes by 0.13–0.20 Tg N2O-N/yr, although CO2 fluxes were only slightly altered. Since N2O possesses a radiative forcing more than 10 times higher than CH4, the increase in N2O offset about 65% of the benefit gained by the decrease in CH4 emissions.

A general projection neural network for solving monotone variational inequalities and related optimization problems

Abstract: Recently, a projection neural network for solving monotone variational inequalities and constrained optimization problems was developed. In this paper, we propose a general projection neural network for solving a wider class of variational inequalities and related optimization problems. In addition to its simple structure and low complexity, the proposed neural network includes existing neural networks for optimization, such as the projection neural network, the primal-dual neural network, and the dual neural network, as special cases. Under various mild conditions, the proposed general projection neural network is shown to be globally convergent, globally asymptotically stable, and globally exponentially stable. Furthermore, several improved stability criteria on two special cases of the general projection neural network are obtained under weaker conditions. Simulation results demonstrate the effectiveness and characteristics of the proposed neural network.

Ultrasonic-assisted synthesis of monodisperse single-crystalline silver nanoplates and gold nanorings.

Abstract: A simple sonochemical route was developed for the crystal growth of uniform silver nanoplates and ringlike gold nanocrystals in a N,N-dimethylformamide solution. The platelike structures were generated from the selective growth on different crystal planes in the presence of poly(vinylpyrrolidone) and the ultrasonic-assisted Ostwald ripening processes. The silver nanoplates in solution served as the templates for the synthesis of ringlike gold crystals via a displacement reaction. Both the silver nanoplates and gold nanorings were highly oriented single crystals with (111) planes as the basal planes.

The observation of superparamagnetic behavior in molecular nanowires

Abstract: Using the anionic precursor [(Tp)Fe(CN)3]-, a new one-dimensional Ising cyanide-bridged chain, [(Tp)2FeIII2(CN)6Cu(CH3OH).2CH3OH]n, has been prepared. The crystal structure and magnetic studies demonstrate that it is a single-chain magnet and the blocking temperature is ca. 6 K.

Constraining ΩM and Dark Energy with Gamma-Ray Bursts

Abstract: An E-gamma,E-jet proportional to E-p'(1.5) relationship with a small scatter for current gamma-ray burst (GRB) data was recently reported, where E-gamma,E-jet is the beaming-corrected gamma-ray energy and E'(p) is the nuF(nu) peak energy in the local observer frame. By considering this relationship for a sample of 12 GRBs with known redshift, peak energy, and break time of afterglow light curves, we constrain the mass density of the universe and the nature of dark energy. We find that the mass density Omega(M) = 0.35(-0.15)(+0.15) (at the 1 sigma confidence level) for a flat universe with a cosmological constant, and the w parameter of an assumed static dark energy equation of state w = -0.84(-0.83)(+0.57) ( 1 sigma). Our results are consistent with those from Type Ia supernovae. A larger sample established by the upcoming Swift satellite is expected to provide further constraints.