Effect of energy density and virginiamycin supplementation in diets on growth performance and digestive function of finishing steers

Navarrete, Juan D.,Montano, Martin F.,Raymundo, Constantino,Salinas-Chavira, Jaime,Torrentera, Noemi,Zinn, Richard A. Asian Australasian Association of Animal Productio 2017 Animal Bioscience Vol.30 No.10

Objective: This study was determined the influence of virginiamycin supplementation on growth-performance and characteristics of digestion of cattle with decreasing dietary net energy value of the diet for maintenance ($NE_m$) from 2.22 to 2.10 Mcal/kg. Methods: Eighty crossbred beef steers ($298.2{\pm}6.3kg$) were used in a 152-d performance evaluation consisting of a 28-d adaptation period followed by a 124-d growing-finishing period. During the 124-d period steers were fed either a lesser energy dense (LED, $2.10Mcal/kg\;NE_m$) or higher energy dense (HED, $2.22Mcal/kg\;NE_m$) diet. Diets were fed with or without 28 mg/kg (dry matter [DM] basis) virginiamycin in a $2{\times}2$ factorial arrangement. Four Holstein steers ($170.4{\pm}5.6kg$) with cannulas in the rumen (3.8 cm internal diameter) and proximal duodenum were used in $4{\times}4$ Latin square experiment to study treatment effects on characteristics of digestion. Results: Neither diet energy density nor virginiamycin affected average daily gain (p>0.10). As expected, dry matter intake and gain efficiency were greater (p<0.01) for LED- than for HED-fed steers. Virginiamycin did not affect estimated net energy value of the LED diet. Virginiamycin increased estimated NE of the HED diet. During daylight hours when the temperature humidity index averaged $81.3{\pm}2.7$, virginiamycin decreased (p<0.05) ruminal temperature. Virginiamycin did not influence (p>0.10) ruminal or total tract digestion. Ruminal (p = 0.02) and total tract digestion (p<0.01) of organic matter, and digestible energy (p<0.01) were greater for HED vs LED. Ruminal microbial efficiency was lower (p<0.01) for HED vs LED diets. Conclusion: The positive effect of virginiamycin on growth performance of cattle is due to increased efficiency of energy utilization, as effects of virginiamycin on characteristics of digestion were not appreciable. Under conditions of high ambient temperature virginiamycin may reduce body temperature.

Synthesis and characterization of Rh/Al2O3-CeO2 catalysts: effect of the Ce4+/Ce3+ ratio on the MTBE removal

Ignacio Cuauhtémoc,Gilberto Torres,Juan Navarrete,Carlos Angeles-Chavez,Juan Manuel Padilla,Gloria Del Angel 한양대학교 세라믹연구소 2009 Journal of Ceramic Processing Research Vol.10 No.4

Rhodium supported catalysts were prepared by impregnating γ-Al2O-Ce supports, which were prepared from boehmite and cerium nitrate with different cerium contents (1, 5, 10 and 20 Ce wt%). High specific surface areas, which diminish with the cerium content, were obtained. At high cerium contents the X-ray Diffraction (XRD) patterns showed the characteristic peaks of cerium oxide. X-ray photoelectron Spectroscopy (XPS) identified the presence of Rho and Rhδ+ on the catalysts. The analysis of the Ce 3d region showed the presence of Ce3+ and Ce4+ where their relative abundance depends on the cerium content. Small rhodium particle sizes were determined by High Angle Annular Dark Field (HAADF) Scanning Transmission Electron Microscopy (STEM). It has been found that the conversion for the wet oxidation of methyl tert-butyl ether (MTBE) depends on the cerium content; conversion ranging from 73 to 96% were reached. A correlation between the total mineralization of MTBE and the relative abundance of the Ce4+/Ce3+ ratio was observed. A total mineralization, as high as 87%, was obtained in the catalyst with the highest Ce4+/Ce3+ ratio. Rhodium supported catalysts were prepared by impregnating γ-Al2O-Ce supports, which were prepared from boehmite and cerium nitrate with different cerium contents (1, 5, 10 and 20 Ce wt%). High specific surface areas, which diminish with the cerium content, were obtained. At high cerium contents the X-ray Diffraction (XRD) patterns showed the characteristic peaks of cerium oxide. X-ray photoelectron Spectroscopy (XPS) identified the presence of Rho and Rhδ+ on the catalysts. The analysis of the Ce 3d region showed the presence of Ce3+ and Ce4+ where their relative abundance depends on the cerium content. Small rhodium particle sizes were determined by High Angle Annular Dark Field (HAADF) Scanning Transmission Electron Microscopy (STEM). It has been found that the conversion for the wet oxidation of methyl tert-butyl ether (MTBE) depends on the cerium content; conversion ranging from 73 to 96% were reached. A correlation between the total mineralization of MTBE and the relative abundance of the Ce4+/Ce3+ ratio was observed. A total mineralization, as high as 87%, was obtained in the catalyst with the highest Ce4+/Ce3+ ratio.

Push–Pull Type Oligo(<i>N</i>-annulated perylene)quinodimethanes: Chain Length and Solvent-Dependent Ground States and Physical Properties

Zeng, Zebing,Lee, Sangsu,Son, Minjung,Fukuda, Kotaro,Burrezo, Paula Mayorga,Zhu, Xiaojian,Qi, Qingbiao,Li, Run-Wei,Navarrete, Juan T. Ló,pez,Ding, Jun,Casado, Juan,Nakano, Masayoshi,Kim, Dongho American Chemical Society 2015 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.137 No.26

<P>Research on stable open-shell singlet diradicaloids recently became a hot topic because of their unique optical, electronic, and magnetic properties and promising applications in materials science. So far, most reported singlet diradicaloid molecules have a symmetric structure, while asymmetric diradicaloids with an additional contribution of a dipolar zwitterionic form to the ground state were rarely studied. In this Article, a series of new push pull type oligo(N-annulated perylene)quinodimethanes were synthesized. Their chain length and solvent-dependent ground states and physical properties were systematically investigated by various experimental methods such as steady-state and transient absorption, two-photon absorption, X-ray crystallographic analysis, electron spin resonance, superconducting quantum interference device, Raman spectroscopy, and electrochemistry. It was found that with extension of the chain length, the diradical character increases while the contribution of the zwitterionic form to the ground state becomes smaller. Because of the intramolecular charge transfer character, the physical properties of this push pull system showed solvent dependence. In addition, density functional theory calculations on the diradical character and Hirshfeld charge were conducted to understand the chain length and solvent dependence of both symmetric and asymmetric systems. Our studies provided a comprehensive understanding on the fundamental structure and environment property relationships in the new asymmetric diradicaloid systems.</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>

Benzo-thia-fused [ <i>n</i> ]thienoacenequinodimethanes with small to moderate diradical characters: the role of pro-aromaticity <i>versus</i> anti-aromaticity

Shi, Xueliang,Quintero, Estefaní,a,Lee, Sangsu,Jing, Linzhi,Herng, Tun Seng,Zheng, Bin,Huang, Kuo-Wei,Ló,pez Navarrete, Juan T.,Ding, Jun,Kim, Dongho,Casado, Juan,Chi, Chunyan Royal Society of Chemistry 2016 Chemical Science Vol.7 No.5

<▼1><P>Pro-aromatic <B>Th<I>n</I>-TIPS</B> exhibits distinctly different physical properties from anti-aromatic <B>S<I>n</I>-TIPS</B>.</P></▼1><▼2><P>Open-shell singlet diradicaloids have recently received much attention due to their unique optical, electronic and magnetic properties and promising applications in materials science. Among various diradicaloids, quinoidal π-conjugated molecules have become the prevailing design. However, the need for a fundamental understanding on how the fusion mode and pro-aromaticity/anti-aromaticity affect their diradical character and physical properties remains unaddressed. In this work, a series of pro-aromatic benzo-thia-fused [<I>n</I>]thienoacenequinodimethanes (<B>Th<I>n</I>-TIPS</B> (<I>n</I> = 1–3) and <B>BDTh-TIPS</B>) were synthesized and compared with the previously reported anti-aromatic bisindeno-[<I>n</I>]thienoacenes (<B>S<I>n</I>-TIPS</B>, <I>n</I> = 1–4). The ground-state geometric and electronic structures of these new quinoidal molecules were systematically investigated by X-ray crystallographic analysis, variable temperature NMR, ESR, SQUID, Raman, and electronic absorption spectroscopy, assisted by DFT calculations. It was found that the diradical character index (<I>y</I><SUB>0</SUB>) increased from nearly zero for <B>Th1-TIPS</B> to 2.4% for <B>Th2-TIPS</B>, 18.2% for <B>Th3-TIPS</B>, and 38.2% for <B>BDTh-TIPS</B>, due to the enhanced aromatic stabilization. Consequently, with the extension of molecular size, the one-photon absorption spectra are gradually red-shifted, the two-photon absorption (TPA) cross section values increase, and the singlet excited state lifetimes decrease. By comparison with the corresponding anti-aromatic analogues <B>S<I>n</I>-TIPS</B> (<I>n</I> = 1–3), the pro-aromatic <B>Th<I>n</I>-TIPS</B> (<I>n</I> = 1–3) exhibit larger diradical character, longer singlet excited state lifetime and larger TPA cross section value. At the same time, they display distinctively different electronic absorption spectra and improved electrochemical amphotericity. Spectroelectrochemical studies revealed a good linear relationship between the optical energy gaps and the molecular length in the neutral, radical cationic and dicationic forms. Our research work discloses a significant difference between the pro-aromatic and anti-aromatic quinoidal compounds and provides guidance for the design of new diradicaloids with desirable properties.</P></▼2>

(Semi)ladder-Type Bithiophene Imide-Based All-Acceptor Semiconductors: Synthesis, Structure-Property Correlations, and Unipolar n-Type Transistor Performance

Wang, Yingfeng,Guo, Han,Harbuzaru, Alexandra,Uddin, Mohammad Afsar,Arrechea-Marcos, Iratxe,Ling, Shaohua,Yu, Jianwei,Tang, Yumin,Sun, Huiliang,Ló,pez Navarrete, Juan Teodomiro,Ortiz, Rocio Ponce American Chemical Society 2018 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.140 No.19

<P>Development of high-performance unipolar n-type organic semiconductors still remains as a great challenge. In this work, all-acceptor bithiophene imide-based ladder-type small molecules BTI<I>n</I> and semiladder-type homopolymers PBTI<I>n</I> (<I>n</I> = 1-5) were synthesized, and their structure-property correlations were studied in depth. It was found that Pd-catalyzed Stille coupling is superior to Ni-mediated Yamamoto coupling to produce polymers with higher molecular weight and improved polymer quality, thus leading to greatly increased electron mobility (μ<SUB>e</SUB>). Due to their all-acceptor backbone, these polymers all exhibit unipolar n-type transport in organic thin-film transistors, accompanied by low off-currents (10<SUP>-10</SUP>-10<SUP>-9</SUP> A), large on/off current ratios (10<SUP>6</SUP>), and small threshold voltages (∼15-25 V). The highest μ<SUB>e</SUB>, up to 3.71 cm<SUP>2</SUP> V<SUP>-1</SUP> s<SUP>-1</SUP>, is attained from PBTI1 with the shortest monomer unit. As the monomer size is extended, the μ<SUB>e</SUB> drops by 2 orders to 0.014 cm<SUP>2</SUP> V<SUP>-1</SUP> s<SUP>-1</SUP> for PBTI5. This monotonic decrease of μ<SUB>e</SUB> was also observed in their homologous BTI<I>n</I> small molecules. This trend of mobility decrease is in good agreement with the evolvement of disordered phases within the film, as revealed by Raman spectroscopy and X-ray diffraction measurements. The extension of the ladder-type building blocks appears to have a large impact on the motion freedom of the building blocks and the polymer chains during film formation, thus negatively affecting film morphology and charge carrier mobility. The result indicates that synthesizing building blocks with more extended ladder-type backbone does not necessarily lead to improved mobilities. This study marks a significant advance in the performance of all-acceptor-type polymers as unipolar electron transporting materials and provides useful guidelines for further development of (semi)ladder-type molecular and polymeric semiconductors for applications in organic electronics.</P> [FIG OMISSION]</BR>

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>

Kinetically Blocked Stable Heptazethrene and Octazethrene: Closed-Shell or Open-Shell in the Ground State?

Li, Yuan,Heng, Wee-Kuan,Lee, Byung Sun,Aratani, Naoki,Zafra, José,L.,Bao, Nina,Lee, Richmond,Sung, Young Mo,Sun, Zhe,Huang, Kuo-Wei,Webster, Richard D.,Ló,pez Navarrete, Juan T.,Kim, Dongh American Chemical Society 2012 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.134 No.36

<P>Polycyclic aromatic hydrocarbons with an open-shell singlet biradical ground state are of fundamental interest and have potential applications in materials science. However, the inherent high reactivity makes their synthesis and characterization very challenging. In this work, a convenient synthetic route was developed to synthesize two kinetically blocked heptazethrene (<B>HZ-TIPS</B>) and octazethrene (<B>OZ-TIPS</B>) compounds with good stability. Their ground-state electronic structures were systematically investigated by a combination of different experimental methods, including steady-state and transient absorption spectroscopy, variable temperature NMR, electron spin resonance (ESR), superconducting quantum interfering device (SQUID), FT Raman, and X-ray crystallographic analysis, assisted by unrestricted symmetry-broken density functional theory (DFT) calculations. All these demonstrated that the heptazethrene derivative <B>HZ-TIPS</B> has a closed-shell ground state while its octazethrene analogue <B>OZ-TIPS</B> with a smaller energy gap exists as an open-shell singlet biradical with a large measured biradical character (<I>y</I> = 0.56). Large two-photon absorption (TPA) cross sections (σ<SUP>(2)</SUP>) were determined for <B>HZ-TIPS</B> (σ<SUP>(2)</SUP><SUB>max</SUB> = 920 GM at 1250 nm) and <B>OZ-TIPS</B> (σ<SUP>(2)</SUP><SUB>max</SUB> = 1200 GM at 1250 nm). In addition, <B>HZ-TIPS</B> and <B>OZ-TIPS</B> show a closely stacked 1D polymer chain in single crystals.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/2012/jacsat.2012.134.issue-36/ja304618v/production/images/medium/ja-2012-04618v_0015.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja304618v'>ACS Electronic Supporting Info</A></P>