An edge-based smoothed finite element method for adaptive analysis

L. Chen,J. Zhang,K.Y. Zeng,P.G. Jiao 국제구조공학회 2011 Structural Engineering and Mechanics, An Int'l Jou Vol.39 No.6

An efficient edge-based smoothed finite element method (ES-FEM) has been recently developed for solving solid mechanics problems. The ES-FEM uses triangular elements that can be generated easily for complicated domains. In this paper, the complexity study of the ES-FEM based on triangular elements is conducted in detail, which confirms the ES-FEM produces higher computational efficiency compared to the FEM. Therefore, the ES-FEM offers an excellent platform for adaptive analysis, and this paper presents an efficient adaptive procedure based on the ES-FEM. A smoothing domain based energy (SDE) error estimate is first devised making use of the features of the ES-FEM. The present error estimate differs from the conventional approaches and evaluates error based on smoothing domains used in the ES-FEM. A local refinement technique based on the Delaunay algorithm is then implemented to achieve high efficiency in the mesh refinement. In this refinement technique, each node is assigned a scaling factor to control the local nodal density, and refinement of the neighborhood of a node is accomplished simply by adjusting its scaling factor. Intensive numerical studies, including an actual engineering problem of an automobile part, show that the proposed adaptive procedure is effective and efficient in producing solutions of desired accuracy.

Genetic Variation of H-FABP Gene and Association with Intramuscular Fat Content in Laiwu Black and Four Western Pig Breeds

Zeng, Y.Q.,Wang, G.L.,Wang, C.F.,Wei, S.D.,Wu, Y.,Wang, L.Y.,Wang, H.,Yang, H.L. Asian Australasian Association of Animal Productio 2005 Animal Bioscience Vol.18 No.1

This study was performed to detect genetic variation of the heart fatty acid-binding protein (H-FABP) gene by PCRRFLPs approach and its association with intramuscular fat (IMF) content. Data from 223 individuals, including one Chinese native pig breed and four western pig breeds, were analyzed. The results showed that for the H-FABP gene, there was one polymorphic HinfI site in the 5'-upstream region, whereas there were one HaeIII and one HinfI (marked as $HinfI^*$) polymorphic site in the second intron, respectively. The three PCR-RFLPs were present in all breeds tested. The allele frequencies, however, revealed significant differences between them (p<0.05). Furthermore, the allele frequency distribution of HinfI in the Laiwu Black and that of $HinfI^*$ in the Hampshire breed were at disequilibrium, which might be the result of selective breeding. Results also indicated that for HinfI, HaeIII and $HinfI^*$ HFABP RFLP, significant (p<0.05) contrasts of 0.78%, -0.69% and 0.72% were detected in the least square means of IMF content between the homozygous genotype HH and hh, DD and dd, BB and bb classes, respectively. It implied that the HHddBB genotype had the highest IMF content in this experimental population and these H-FABP RFLPs could serve, to some extent, as genetic markers for use in improvement of IMF content.

Identification of independent association signals and putative functional variants for breast cancer risk through fine-scale mapping of the 12p11 locus

Zeng, Chenjie,Guo, Xingyi,Long, Jirong,Kuchenbaecker, Karoline B.,Droit, Arnaud,Michailidou, Kyriaki,Ghoussaini, Maya,Kar, Siddhartha,Freeman, Adam,Hopper, John L.,Milne, Roger L.,Bolla, Manjeet K.,Wa BioMed Central 2016 Breast cancer research Vol.18 No.-

<P><B>Background</B></P><P>Multiple recent genome-wide association studies (GWAS) have identified a single nucleotide polymorphism (SNP), rs10771399, at 12p11 that is associated with breast cancer risk.</P><P><B>Method</B></P><P>We performed a fine-scale mapping study of a 700 kb region including 441 genotyped and more than 1300 imputed genetic variants in 48,155 cases and 43,612 controls of European descent, 6269 cases and 6624 controls of East Asian descent and 1116 cases and 932 controls of African descent in the Breast Cancer Association Consortium (BCAC; http://bcac.ccge.medschl.cam.ac.uk/), and in 15,252 <I>BRCA1</I> mutation carriers in the Consortium of Investigators of Modifiers of <I>BRCA1/2</I> (CIMBA). Stepwise regression analyses were performed to identify independent association signals. Data from the Encyclopedia of DNA Elements project (ENCODE) and the Cancer Genome Atlas (TCGA) were used for functional annotation.</P><P><B>Results</B></P><P>Analysis of data from European descendants found evidence for four independent association signals at 12p11, represented by rs7297051 (odds ratio (OR) = 1.09, 95 % confidence interval (CI) = 1.06–1.12; <I>P</I> = 3 × 10<SUP>-9</SUP>), rs805510 (OR = 1.08, 95 % CI = 1.04–1.12, <I>P</I> = 2 × 10<SUP>-5</SUP>), and rs1871152 (OR = 1.04, 95 % CI = 1.02–1.06; <I>P</I> = 2 × 10<SUP>-4</SUP>) identified in the general populations, and rs113824616 (<I>P</I> = 7 × 10<SUP>-5</SUP>) identified in the meta-analysis of BCAC ER-negative cases and <I>BRCA1</I> mutation carriers. SNPs rs7297051, rs805510 and rs113824616 were also associated with breast cancer risk at <I>P</I> < 0.05 in East Asians, but none of the associations were statistically significant in African descendants. Multiple candidate functional variants are located in putative enhancer sequences. Chromatin interaction data suggested that <I>PTHLH</I> was the likely target gene of these enhancers. Of the six variants with the strongest evidence of potential functionality, rs11049453 was statistically significantly associated with the expression of <I>PTHLH</I> and its nearby gene <I>CCDC91</I> at <I>P</I> < 0.05.</P><P><B>Conclusion</B></P><P>This study identified four independent association signals at 12p11 and revealed potentially functional variants, providing additional insights into the underlying biological mechanism(s) for the association observed between variants at 12p11 and breast cancer risk.</P><P><B>Electronic supplementary material</B></P><P>The online version of this article (doi:10.1186/s13058-016-0718-0) contains supplementary material, which is available to authorized users.</P>

Stable Tetrabenzo-Chichibabin’s Hydrocarbons: Tunable Ground State and Unusual Transition between Their Closed-Shell and Open-Shell Resonance Forms

Zeng, Zebing,Sung, Young Mo,Bao, Nina,Tan, Davin,Lee, Richmond,Zafra, José,L.,Lee, Byung Sun,Ishida, Masatoshi,Ding, Jun,Ló,pez Navarrete, Juan T.,Li, Yuan,Zeng, Wangdong,Kim, Dongho,Huang American Chemical Society 2012 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.134 No.35

<P>Stable open-shell polycyclic aromatic hydrocarbons (PAHs) are of fundamental interest due to their unique electronic, optical, and magnetic properties and promising applications in materials sciences. Chichibabin’s hydrocarbon as a classical open-shell PAH has been investigated for a long time. However, most of the studies are complicated by their inherent high reactivity. In this work, two new stable benzannulated Chichibabin’s hydrocarbons <B>1-CS</B> and <B>2-OS</B> were prepared, and their electronic structure and geometry in the ground state were studied by various experiments (steady-state and transient absorption spectra, NMR, electron spin resonance (ESR), superconducting quantum interference device (SQUID), FT Raman, X-ray crystallographic etc.) and density function theory (DFT) calculations. <B>1-CS</B> and <B>2-OS</B> exhibited tunable ground states, with a closed-shell quinoidal structure for <B>1-CS</B> and an open-shell biradical form for <B>2-OS</B>. Their corresponding excited-state forms <B>1-OS</B> and <B>2-CS</B> were also chemically approached and showed different decay processes. The biradical <B>1-OS</B> displayed an unusually slow decay to the ground state (<B>1-CS</B>) due to a large energy barrier (95 ± 2.5 kJ/mol) arising from severe steric hindrance during the transition from an orthogonal biradical form to a butterfly-like quinoidal form. The quick transition from the quinoidal <B>2-CS</B> (excited state) to the orthogonal biradicaloid <B>2-OS</B> (ground state) happened during the attempted synthesis of <B>2-CS</B>. Compounds <B>1-CS</B> and <B>2-OS</B> can be oxidized into stable dications by FeCl<SUB>3</SUB> and/or concentrated H<SUB>2</SUB>SO<SUB>4</SUB>. The open-shell <B>2-OS</B> also exhibited a large two-photon absorption (TPA) cross section (760 GM at 1200 nm).</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/2012/jacsat.2012.134.issue-35/ja3050579/production/images/medium/ja-2012-050579_0017.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja3050579'>ACS Electronic Supporting Info</A></P>

Effects of Dietary Lysine Levels on Apparent Nutrient Digestibility and Serum Amino Acid Absorption Mode in Growing Pigs

Zeng, P.L.,Yan, H.C.,Wang, X.Q.,Zhang, C.M.,Zhu, C.,Shu, G.,Jiang, Q.Y. Asian Australasian Association of Animal Productio 2013 Animal Bioscience Vol.26 No.7

Two experiments were conducted to determine the effects of different dietary lysine levels on the apparent nutrient digestibility, the serum amino acid (AA) concentration, and the biochemical parameters of the precaval and portal vein blood in growing pigs. In Experiment 1, 15 noncannulated pigs received diets with different lysine densities (0.65%, 0.95%, and 1.25% lysine) for 13 d. A total collection digestion test was performed, and blood samples were collected from the precaval vein at the end of the experiment. In Experiment 2, four cannulated pigs were fed the same diets of Experiment 1. The experiment used a self-control experimental design and was divided into three periods. On d 5 of each period, at 0.5 h before feeding and hourly up to 8 h after feeding, single blood samples were collected from catheters placed in the portal vein. In Experiment 1, some serum AAs (including lysine), serum urinary nitrogen (SUN), and total protein (TP) concentrations were significantly affected by the dietary lysine levels (p<0.05). Moreover, the 0.65% lysine treatment showed a significant lower apparent digestibility of gross energy, dry matter, crude protein, and phosphorus than the other treatments (p<0.05). In Experiment 2, serum lysine, histidine, phenylalanine, threonine, valine, isoleucine (p = 0.0588), triglyceride, and SUN (p = 0.0572) concentrations were significantly affected by the dietary lysine levels (p<0.05). Additionally, almost all of the determined serum AA and total AA concentrations reached their lowest values at 0.5 h before feeding and their highest values at 2 h after feeding (p<0.05). These findings indicate that the greatest absorption of AA occurred at 2 h after feeding and that the dynamic profile of serum AA is affected by the dietary lysine levels. Moreover, when the dietary lysine content was 0.95%, the growing pigs achieved a better nutrient digestibility and serum metabolites levels.

Hydrodynamic Effect on the Inhibition for the Flow Accelerated Corrosion of an Elbow

( L. Zeng ),( G. A. Zhang ),( X. P. Guo ) 한국부식방식학회(구 한국부식학회) 2017 Corrosion Science and Technology Vol.16 No.1

The inhibition effect of thioureido imidazoline inhibitor (TAI) for flow accelerated corrosion (FAC) at different locations for an X65 carbon steel elbow was studied by array electrode and computational fluid dynamics (CFD) simulations. The distribution of the inhibition efficiency measured by electrochemical impedance spectroscopy (EIS) is in good accordance with the distribution of the hydrodynamic parameters at the elbow. The inhibition efficiencies at the outer wall are higher than those at the inner wall meaning that the lower inhibition efficiency is associated with a higher flow velocity, shear stress, and turbulent kinetic energy at the inner wall of the elbow, as well as secondary flow at the elbow rather than the mass transport of inhibitor molecules. Compared to the static condition, the inhibition efficiency of TAI for FAC was relatively low. It is also due to a drastic turbulence flow and high wall shear stress during the FAC test, which prevents the adsorption of inhibitor and/or damages the adsorbed inhibitor film.

Effect of Microbial Phytase on Performance, Nutrient Absorption and Excretion in Weaned Pigs and Apparent Ileal Nutrient Digestibility in Growing Pigs

Zeng, Z.K.,Piao, X.S.,Wang, D.,Li, P.F.,Xue, L.F.,Salmon, Lorraine,Zhang, H.Y.,Han, X.,Liu, L. Asian Australasian Association of Animal Productio 2011 Animal Bioscience Vol.24 No.8

Two experiments were conducted to evaluate the efficacy of Trichoderma reesei derived phytase for pigs fed diets with fixed calcium to total phosphorus ratios (1.5:1). In Exp. 1, 280 weaned pigs (initial BW of $10.32{\pm}1.94$ kg) were allocated to one of five dietary treatments on the basis of weight and gender in a randomized complete block design. Treatments were the low phosphorus (0.6% Ca, 0.4% total P and 0.23% available P) diets supplemented with 0, 250, 1,000, or 2,000 FTU phytase/kg of diet and a positive control diet (PC; 0.85% Ca, 0.58% total P and 0.37% available P). The treatments were applied to seven pens with eight pigs per pen, half male and half female. In Exp. 2, six barrows fitted with ileal T-cannula (initial BW = $35.1{\pm}1.6$ kg) were assigned to three dietary treatments with a double $3{\times}3$ Latin square design. The dietary treatments were the low-phosphorus diet (0.53% Ca, 0.34% total P and 0.14% available P), the low phosphorus diet plus 1,000 FTU phytase/kg and a positive control diet (0.77% Ca, 0.50% total P and 0.30% available P). In Exp. 1, there were linear increases (p<0.01) in weight gain, phosphorus absorption, bone strength, calcium and phosphorus content of fat-free dried bone and plasma phosphorus concentrations with increasing dose rate of phytase. The performance of pigs fed the diets with 250, 1,000, or 2,000 FTU of phytase/kg did not differ from pigs fed the PC diet. Pigs fed diets with 1,000 or 2,000 FTU of phytase/kg did not differ from pigs fed the PC diet in bone characteristics. The apparent digestibility of dry matter, crude protein, ash and energy was not affected by dietary treatment. However, pigs fed the PC diet excreted more fecal phosphorus (g/d, p<0.01) and fecal phosphorus per BW gain (g/kg) than pigs fed the diets with phytase. Phytase linearly decreased (p<0.01) fecal phosphorus excreted per BW gain (g/kg), plasma calcium concentration as well as plasma and bone alkaline phosphatase activity. In Exp. 2, phytase supplementation in the low-P diet increased (p<0.05) the apparent ileal digestibility (AID) of Ca, P, leucine, lysine, phenylalanine, alanine and cysteine, tended to AID of crude protein, isoleucine, threonine, asparagine and serine. In conclusion, the novel phytase originated from Trichoderma reesei is effective in releasing Ca, P, and amino acids from corn soy based diet for pigs.

Pushing Extended <i>p</i>-Quinodimethanes to the Limit: Stable Tetracyano-oligo(<i>N</i>-annulated perylene)quinodimethanes with Tunable Ground States

Zeng, Zebing,Ishida, Masatoshi,Zafra, José,L.,Zhu, Xiaojian,Sung, Young Mo,Bao, Nina,Webster, Richard D.,Lee, Byung Sun,Li, Run-Wei,Zeng, Wangdong,Li, Yuan,Chi, Chunyan,Navarrete, Juan T. Lo American Chemical Society 2013 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.135 No.16

<P><I>p</I>-Quinodimethane (<I>p</I>-QDM) is a fundamental building block for the design of π-conjugated systems with low band gap and open-shell biradical character. However, synthesis of extended <I>p</I>-QDMs has usually suffered from their intrinsic high reactivity and poor solubility. In this work, benzannulation together with terminal cyano-substitution was demonstrated to be an efficient approach for the synthesis of a series of soluble and stable tetracyano-oligo(<I>N</I>-annulated perylene)quinodimethanes <B><I>n</I>Per-CN</B> (<I>n</I> = 1–6), with the longest molecule having 12 <I>para</I>-linked benzenoid rings! The geometry and electronic structures of these oligomers were investigated by steady-state and transient absorption spectroscopy, nuclear magnetic resonance, electron spin resonance, superconducting quantum interference device, and FT Raman spectroscopy assisted by density functional theory calculations. They showed tunable ground states, varying from a closed-shell quinoidal structure for monomer, to a singlet biradical for dimer, trimer, and tetramer, and to a triplet biradical for pentamer and hexamer. Large two-photon absorption cross-section values were observed in the near-infrared range, which also exhibited a clear chain-length dependence.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/2013/jacsat.2013.135.issue-16/ja402467y/production/images/medium/ja-2013-02467y_0010.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja402467y'>ACS Electronic Supporting Info</A></P>

An edge-based smoothed finite element method for adaptive analysis

Chen, L.,Zhang, J.,Zeng, K.Y.,Jiao, P.G. Techno-Press 2011 Structural Engineering and Mechanics, An Int'l Jou Vol.39 No.6

An efficient edge-based smoothed finite element method (ES-FEM) has been recently developed for solving solid mechanics problems. The ES-FEM uses triangular elements that can be generated easily for complicated domains. In this paper, the complexity study of the ES-FEM based on triangular elements is conducted in detail, which confirms the ES-FEM produces higher computational efficiency compared to the FEM. Therefore, the ES-FEM offers an excellent platform for adaptive analysis, and this paper presents an efficient adaptive procedure based on the ES-FEM. A smoothing domain based energy (SDE) error estimate is first devised making use of the features of the ES-FEM. The present error estimate differs from the conventional approaches and evaluates error based on smoothing domains used in the ES-FEM. A local refinement technique based on the Delaunay algorithm is then implemented to achieve high efficiency in the mesh refinement. In this refinement technique, each node is assigned a scaling factor to control the local nodal density, and refinement of the neighborhood of a node is accomplished simply by adjusting its scaling factor. Intensive numerical studies, including an actual engineering problem of an automobile part, show that the proposed adaptive procedure is effective and efficient in producing solutions of desired accuracy.

Model Based Filtered Backprojection Algorithm: A Tutorial

Gengsheng L. Zeng 대한의용생체공학회 2014 Biomedical Engineering Letters (BMEL) Vol.4 No.1

Purpose People have been wandering for a long timewhether a filtered backprojection (FBP) algorithm is able toincorporate measurement noise in image reconstruction. Thepurpose of this tutorial is to develop such an FBP algorithmthat is able to minimize an objective function with anembedded noise model. Methods An objective function is first set up to modelmeasurement noise and to enforce some constraints so thatthe resultant image has some pre-specified properties. Aniterative algorithm is used to minimize the objective function,and then the result of the iterative algorithm is converted intothe Fourier domain, which in turn leads to an FBP algorithm. The model based FBP algorithm is almost the same as theconventional FBP algorithm, except for the filtering step. Results The model based FBP algorithm has been applied tolow-dose x-ray CT, nuclear medicine, and real-time MRIapplications. Compared with the conventional FBP algorithm,the model based FBP algorithm is more effective in reducingnoise. Even though an iterative algorithm can achieve thesame noise-reducing performance, the model based FBPalgorithm is much more computationally efficient. Conclusions The model based FBP algorithm is an efficientand effective image reconstruction tool. In many applications,it can replace the state-of-the-art iterative algorithms, whichusually have a heavy computational cost. The model basedFBP algorithm is linear and it has advantages over a nonlineariterative algorithm in parametric image reconstruction andnoise analysis.