oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 161 )

2018 ( 1208 )

2017 ( 1073 )

2016 ( 1098 )

Custom range...

Search Results: 1 - 10 of 78289 matches for " Xiaoxiang Chen "
All listed articles are free for downloading (OA Articles)
Page 1 /78289
Display every page Item
Study on Quantitative Model of Karst Drainage Basin Water-Holding Based on Principal Component Analysis: A Case Study of Guizhou, China  [PDF]
Zhonghua He, Xiaoxiang Chen, Hong Liang, Fasu Huang, Fang Zhao
Advances in Remote Sensing (ARS) , 2013, DOI: 10.4236/ars.2013.23023
Abstract:

In Karst drainage basins, there are the ground water and underground water exchanging frequently, and the shortage of water resources due to having the special double aquifer mediums and unique surface and subsurface river systematic structure. This paper is to select 20 research sampling areas coming fromGuizhouProvince, and according to the spectral characteristics of the catchment water-holding mediums and vegetations, and using the remote sensing technique, extract the watershed vegetation index. According to the principle of principal component analysis, using the software of Spss and Matlab is to analyze the impacts of watershed vegetation type on the catchment water-holding ability, and establish the principal component analysis function. Studies have shown that: 1) the watershed vegetation coverage rate plays an important role in Karst basin water-holding ability; 2) the catchment water-holding ability is the comprehensive reflection and manifestation of the Catchment Water-storing Capacity (CWC); 3) it is much better effects and higher accuracy to monitor/forecast the catchment water-holding volume by using the vegetation indices.

A Novel Low RCS Design Method for X-Band Vivaldi Antenna
XiaoXiang He,Teng Chen,Xin Wang
International Journal of Antennas and Propagation , 2012, DOI: 10.1155/2012/218681
Abstract: A novel low radar cross-section (RCS) design method is proposed, and its application on Vivaldi antenna that covers the entire X band is investigated. According to the difference of the current distribution on the radiator when the antenna radiates or scatters, the shape of the metal radiator is modified, so that maximally 19.2 dBsm RCS reduction is achieved which satisfied radiation performance. Simulated and measured results about gain, S11, and RCS are presented. As a result, the effectiveness of the presented low RCS design method is validated.
New characterizations for core inverses in rings with involution
Sanzhang Xu,Jianlong Chen,Xiaoxiang Zhang
Mathematics , 2015,
Abstract: The core inverse for a complex matrix was introduced by Baksalary and Trenkler. Raki\'c, Din\v{c}i\'c and Djordjevi\'c generalized the core inverse of a complex matrix to the case of an element in a ring. They also proved that the core inverse of an element in a ring can be characterized by five equations and every core invertible element is group invertible. It is natural to ask when a group invertible element is core invertible, in this paper, we will answer this question. We will use three equations to characterize the core inverse of an element. That is, let $a, b\in R$, then $a\in R^{\tiny\textcircled{\tiny\#}}$ with $a^{\tiny\textcircled{\tiny\#}}=b$ if and only if $(ab)^{\ast}=ab$, $ba^{2}=a$ and $ab^{2}=b$. Finally, we investigate the additive property of two core invertible elements. Moreover, the formulae of the sum of two core invertible elements are presented.
Hyper-IgE Syndrome with STAT3 Mutation: A Case Report in Mainland China
Lixin Xie,Xiaoxiang Hu,Yang Li,Weihua Zhang,Liang'an Chen
Clinical and Developmental Immunology , 2010, DOI: 10.1155/2010/289873
Abstract: Hyper-immunoglobulin E syndromes (HIES) including compound primary immunodeficiency and nonimmunological abnormalities are characterized by extremely high serum IgE levels, eosinophilia, eczema, susceptibility to infections, distinctive facial appearance, retention of deciduous teeth, cyst-forming pneumonias, and skeletal abnormalities. Itis reported that some cases of familial HIES are relative to autosomal dominant or recessive inheritance, but most cases are sporadic, and result from mutations in the human signal transducer and activator of transcription 3 (STAT3) gene. In this paper, we firstly report a young man diagnosed of Hyper-IgE syndrome with STAT3 mutation in Mainland China, and investigate the autosomal dominant trait of his family members.
Hyper-IgE Syndrome with STAT3 Mutation: A Case Report in Mainland China
Lixin Xie,Xiaoxiang Hu,Yang Li,Weihua Zhang,Liang'an Chen
Journal of Immunology Research , 2010, DOI: 10.1155/2010/289873
Abstract: Hyper-immunoglobulin E syndromes (HIES) including compound primary immunodeficiency and nonimmunological abnormalities are characterized by extremely high serum IgE levels, eosinophilia, eczema, susceptibility to infections, distinctive facial appearance, retention of deciduous teeth, cyst-forming pneumonias, and skeletal abnormalities. Itis reported that some cases of familial HIES are relative to autosomal dominant or recessive inheritance, but most cases are sporadic, and result from mutations in the human signal transducer and activator of transcription 3 (STAT3) gene. In this paper, we firstly report a young man diagnosed of Hyper-IgE syndrome with STAT3 mutation in Mainland China, and investigate the autosomal dominant trait of his family members. 1. Introduction The hyper-IgE syndromes (HIES) are rare primary immune deficiencies characterized by elevated serum IgE, dermatitis, and recurrent skin and lung infections. There are two forms of HIES: a dominant form caused by mutations in STAT3, and a recessive form, for which a genetic cause is unclear. These two different syndromes have distinct presentations, courses, and outcomes and share very little in terms of pathogenesis other than the IgE elevation. In this paper, we firstly report a young man diagnosed of Hyper-IgE syndrome with STAT3 mutation in Mainland China, and investigate the autosomal dominant trait of his family members. Our patient, a 20-year-old man in mainland China, was suffering from eczema, lung cyst, skeletal and dental abnormalities, and so forth, which are the characteristics of type 1 HIES. He has extremely high serum IgE level is 200 times than that of normal person. Then, we sequenced the STAT3 gene by complementary DNA (cDNA) and genomic DNA, and we found a mutation locus, in which his parents and sister are normal. 2. Patient and Diagnosis A 20-year-old man was found to presented with over ten-years history of cough with yellow-colored sputum and one year history of bloody sputum. He also reported universal boils on the face and limbs and recurrent pneumonias. In 1998, he received right upper lung cyst surgical therapy. His medical history was significant for eczema since newborn period and recurrent pustular and eczematoid rashes on the face and scalp in the childhood. Several primary teeth arrachement surgeries were performed in 13 years old on account of failure of the primary teeth to exfoliate. On physical examination, the vital signs were normal, clubbed fingers and toes; the characteristic facial appearance was noted with broad nose, deep-set eyes with a
Ladder Arrangement Method for Stealth Design of Vivaldi Antenna Array
XiaoXiang He,SaiSai Huang,Teng Chen,Yang Yang
International Journal of Antennas and Propagation , 2013, DOI: 10.1155/2013/295767
Abstract: A novel stealth design method for X-band Vivaldi antenna arrays is proposed in this paper by ladder arrangement along radiation direction. Two-element array, eight-element array, and 3 × 7-element array are investigated in this paper. S parameters, RCSs, and radiation patterns are studied, respectively. According to the ladder arrangement of Vivaldi antennas presented, 16.3?dBsm maximal RCS reduction is achieved with satisfied radiation performance. As simulated and measured, results demonstrate that the effectiveness of the presented low RCS design method is validated. 1. Introduction Generally speaking, RCS reduction of antenna will affect the radiation performance and increase the antenna system complexity. Li and Liu [1] reduced RCS maximally by 27?dBsm at a specific frequency with two short-circuit pins loaded in each microstrip unit and cut two H-shape slots.However, this method reduces the RCS only at a relatively narrow frequency band and angle range. ??Another powerful method, investigated by Jang et al. [2], is to use the EBG structure, and about 10?dBsm RCS reduction is obtained outside of the operating band, which also can be acquired with frequency selective surface (FSS) on radome. In the operating band, the RCS with EBG structure is almost unchanged. Liu et al. [3] use fractal slot on microstrip patch antenna and the RCS can be reduced and the radiation characteristics can be maintained. There are still some other methods such as holly-leaf-shaped [4] design or using a phase-switched screen (PSS) [5] boundary, which can reduce RCS in operating band. Vivaldi antennas are widely used in fire control system, radar, communication, and electronic countermeasures (ECM) [6] fields due to their high gain, less physical dimension, and broad bandwidth. Therefore, the stealth design of Vivaldi antennas [6–11] is widely investigated. Based on the difference of antenna current distribution in the radiating and scattering status, He et al. [12] proposed a novel stealthy X-band Vivaldi antenna with maximally 19.2?dBsm RCS reduction. 2. Stealth Design Scheme The stealth design method proposed in this paper is to decrease RCS of an antenna array while maintaining the antenna’s radiating performance. For the array element is an end-fire Vivaldi antenna, we give two schematic diagrams in which ladder arrangement is employed with a quarter wavelength step in radiation direction (see Figure 1). Figure 1: The path of scattering and radiating wave with ladder arranged array. As we can see from Figure 1(a), when the antenna radiates, the electromagnetic waves
Moore-Penrose Invertibility of Differences and Products of Projections in Rings with Involution
Xiaoxiang Zhang,Shuangshuang Zhang,Jianlong Chen,Long Wang
Mathematics , 2013,
Abstract: This article concerns the MP inverse of the differences and the products of projections in a ring $R$ with involution. Some equivalent conditions are obtained. As applications, the MP invertibility of the commutator $pq-qp$ and the anti-commutator $pq+qp$ are characterized, where $p$ and $q$ are projections in $R$. Some related known results in $C^*$-algebra are generalized.
Projections and Idempotents in star-reducing Rings Involving the Moore-Penrose Inverse
Xiaoxiang Zhang,Shuangshuang Zhang,Jianlong Chen,Long Wang
Mathematics , 2013,
Abstract: In [Comput. Math. Appl. 59 (2010) 764-778], Baksalary and Trenkler characterized some complex idempotent matrices of the form $(I-PQ)^{\dag}P(I-Q)$, $(I-QP)^{\dag}(I-Q)$ and $P(P+Q-QP)^{\dag}$ in terms of the column spaces and null spaces of $P$ and $Q$, where $P, Q\in \mathbb{C}^{\textsf{OP}}_n = \{L\in \mathbb{C}_{n,n}\ |\ L^2 = L = L^*\}$. We generalize these results from $\mathbb{C}_{n,n}$ to any *-reducing rings.
Relative Derived Category with respect to a Subcategory
Zhenxing Di,Xiaoxiang Zhang,Wei Ren,Jianlong Chen
Mathematics , 2014,
Abstract: The notion of relative derived category with respect to a subcategory is introduced. A triangle-equivalence, which extends a theorem of Gao and Zhang [Gorenstein derived categories, \emph{J. Algebra} \textbf{323} (2010) 2041-2057] to the bounded below case, is obtained. Moreover, we interpret the relative derived functor $\mathrm{Ext}_{\mathcal{X}\mathcal {A}}(-,-)$ as the morphisms in such derived category and give two applications.
The Impact of Chemotherapy on EGFR Mutation Status in Non-Small-Cell Lung Cancer: A Meta-Analysis  [PDF]
Xiaoshun Shi, Fuxi Huang, Allen M. Chen, Zhuolin Wu, Qianqian Huang, Ying Liang, Qipeng Zhou, Haiyun Mo, Xiaoxiang Li, Jiexia Zhang
Open Journal of Genetics (OJGen) , 2017, DOI: 10.4236/ojgen.2017.74010
Abstract: Background: Emerging evidence indicates that chemotherapy for lung cancer may alter EGFR mutation status. However, whether chemotherapy as a firstline treatment may increase or reduce the frequency of EGFR mutations in NSCLC remains uncertain. Therefore, we conducted a meta-analysis to evaluate whether chemotherapy leads to altered EGFR mutation status. Methods: A systematic literature search was performed using the PubMed, OVID, Science Direct, Cochrane Library, and CNKI databases for studies on pre- and post-chemotherapy EGFR mutation status. Relevant studies documenting perichemotherapy EGFR mutation ratios were included. Analyses of pooled odds ratios (OR) were performed. Results: Six studies involving 656 patients were included in this meta-analysis. It was found that chemotherapy may alter EGFR status (OR = 1.93, 95% CI 1.05 - 3.56; p < 0.0001). No significant differences in EGFR mutation alterations were observed in terms of gender, smoking history, EGFR loci, or chemotherapy response in NSCLC patients. Conclusions: Chemotherapy may contribute to altered EGFR status. NSCLC patients with EGFR mutations might need to be considered for EGFR status redeterminations prior to second-line EGFR-TKI treatment or upon tumor recurrence after chemotherapy. Further randomized clinical trials should investigate the impact of neoadjuvant or first-line chemotherapy on EGFR mutation status in NSCLC patients.
Page 1 /78289
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.