Methanation of CO over Ni catalyst: A theoretical study

Theoretical methods (generalized valence‐bond calculations) were used to examine the bond energies and geometries of numerous species chemisorbed onto Ni clusters representing Ni surface. These results were used to obtain thermochemical information and to examine various mechanisms for the methanation of CO over Ni: CO+3H^(→)_(2(Ni)) CH_4+H_2O. It is found that chemisorbed formyl radicals (Ni–CHO) lead to a favorably appearing chain reaction that is consistent with current experimental results. In addition, we find a chemisorbed C_2 species that may be the catalytically active C_(ad) formed from dissociation of CO

Theoretical studies of nickel clusters and chemisorption of hydrogen

First principles calculations of high- and low-symmetry clusters (up to Ni87) are reported. Macroscopic properties [ionization potential (IP), electron affinity (EA), and bandwidth] are not sensitive to cluster symmetry and, except for EA, are converged to bulk values by Ni87. Even for Ni87 the EA is over 2.5 eV smaller than the IP; the origin of this effect is discussed. The chemisorption of hydrogen is considered on the low-symmetry clusters, where it is found that threefold and fourfold sites are most favored with bond energies of [angle]3 eV for both types of sites. Geometries are not cluster sensitive with R (NiH) values of 1.57, 1.62, and 1.78 Å for twofold, threefold, and fourfold sites, respectively. Vibrational frequencies for these sites are 1420, 1212, and 592 cm^–1, respectively

A guide to the South Plains of Texas

A compilation of essays and articles covering history, agriculture, educational institutions, and legends of the historic South Plains of Texas.[139] leaves ; 152 pdf pages.November 1935.Pictorial illustrations by Bess Hubbard.Mimeographed copy reproduced by the students of Lubbock High School with permission and assistance of the Texas Highway Dept.Plains of Texas / A.W. Evans -- The rock house on Blanco Canyon / R.B. Smith -- The story of the famous Old Yellow House Ranch / Lamb county news -- The T-Bar Ranch / R.B. Smith -- U-Lazy-S Ranch / E. Taylor -- The old Mackenzie Trail / W.L Chittenden -- Mackenzie's Indian campaigns on the Staked Plains / M.L. Cox -- Horse bones / R.G. Carter -- Old Man Singer's store / W.C. Holden -- Letter of long ago describes living conditions in days of first settles / M. Witt -- Shanties and dugouts / The Cattleman -- The legend of the sand hills / J. Mitchell -- Three notable landmarks in Lynn County / F.P. Hill -- Descriptions of South Plains cities and towns / V. Upton -- Elevation, population, and highway mileage maps / M.W. Hobbs -- Roadside divertissement / V. Upton

Mycobacterium tuberculosis WhiB3 Maintains Redox Homeostasis by Regulating Virulence Lipid Anabolism to Modulate Macrophage Response

The metabolic events associated with maintaining redox homeostasis in Mycobacterium tuberculosis (Mtb) during infection are poorly understood. Here, we discovered a novel redox switching mechanism by which Mtb WhiB3 under defined oxidizing and reducing conditions differentially modulates the assimilation of propionate into the complex virulence polyketides polyacyltrehaloses (PAT), sulfolipids (SL-1), phthiocerol dimycocerosates (PDIM), and the storage lipid triacylglycerol (TAG) that is under control of the DosR/S/T dormancy system. We developed an in vivo radio-labeling technique and demonstrated for the first time the lipid profile changes of Mtb residing in macrophages, and identified WhiB3 as a physiological regulator of virulence lipid anabolism. Importantly, MtbΔwhiB3 shows enhanced growth on medium containing toxic levels of propionate, thereby implicating WhiB3 in detoxifying excess propionate. Strikingly, the accumulation of reducing equivalents in MtbΔwhiB3 isolated from macrophages suggests that WhiB3 maintains intracellular redox homeostasis upon infection, and that intrabacterial lipid anabolism functions as a reductant sink. MtbΔwhiB3 infected macrophages produce higher levels of pro- and anti-inflammatory cytokines, indicating that WhiB3-mediated regulation of lipids is required for controlling the innate immune response. Lastly, WhiB3 binds to pks2 and pks3 promoter DNA independent of the presence or redox state of its [4Fe-4S] cluster. Interestingly, reduction of the apo-WhiB3 Cys thiols abolished DNA binding, whereas oxidation stimulated DNA binding. These results confirmed that WhiB3 DNA binding is reversibly regulated by a thiol-disulfide redox switch. These results introduce a new paradigmatic mechanism that describes how WhiB3 facilitates metabolic switching to fatty acids by regulating Mtb lipid anabolism in response to oxido-reductive stress associated with infection, for maintaining redox balance. The link between the WhiB3 virulence pathway and DosR/S/T signaling pathway conceptually advances our understanding of the metabolic adaptation and redox-based signaling events exploited by Mtb to maintain long-term persistence

Health-related quality-of-life measures for long-term follow-up in children after major trauma

Objective: Our objective was to review measures of health-related quality of life (HRQL) for long-term follow up in children after major trauma and to determine the measures that are suitable for a large age range, reliable and valid, and cover a substantial amount of the domains of functioning using the International Classification of Functioning, Disability, and Health (ICF) of the World Health Organization (WHO). Methods: The Medline and EMBASE databases were searched in all years up to October 2007 for generic HRQL measures suitable for children aged 5-18 years old and validated in English or Dutch. Measures were reviewed with respect to the age range for which the measure was suitable and reliability, validity, and content related to the ICF. Results: The search resulted in 1,235 hits and 21 related articles. Seventy-nine papers met the inclusion criteria, describing in total 14 measures: Child Health and Illness Profile Adolescent and Child Edition (CHIP-AE/CE), Child Health Questionnaire Child and Parent Forms (CHQCF87/PF50/PF28), DISABKIDS, Functional Status II (FS II)(R), Health Utilities Index Mark 2 (HUI 2), KIDSCREEN 52/27, KINDL, Pediatric Quality of Life Inventory (PedsQL), TNO Institute of Prevention and Health and the Leiden University Hospital (TNO-AZL), TNO-AZL Children’s Quality Of Life (TACQOL), and Youth Quality of Life Instrument-Research Version (YQOL-R). Measures that were suitable for a large age range were CHQ-PF50/PF28, DISABKIDS, FS II(R), HUI 2, KIDSCREEN, PedsQL, and TACQOL. All measures had moderate to good psychometric properties, except for CHQ-PF50/PF28, KINDL, and TACQOL, which had either low internal consistency or bad test-retest reliability. The measures that covered more than six chapters of the ICF domains were CHIP-AE/CE, CHQ-CF87/PF50, DISABKIDS, KIDSCREEN-52, PedsQL, and TACQOL. Conclusions: DISABKIDS, KIDSCREEN 52, and Peds-QL are suitable for long-term follow-up measurement of HRQL in children after major trauma. They cover a large age range, have good psychometric properties, and cover the ICF substantially

Waste, Industry and Romantic Leisure: Veblen's Theory of Recognition

types: ArticleVeblen’s work contains a neglected, since for the most part implicit, theory of recognition centred on his concepts of waste and workmanship. This article tries to develop this theory in order to shed new light on the theorem of conspicuous leisure and consumption. The legitimacy of violence at the ‘predatory stage’ of culture has been partly superseded by a legitimacy of industrial efficiency, so that the leisure classes need to disguise their conspicuous waste as socially useful productive endeavours. At the same time waste remains a powerful symbol of legitimate status, so that even the industrial classes turn to it in order to assert their social worth and demand social recognition. Waste - which is far more central in Veblen’s theory than is emulation - becomes an ambiguous symbol which can stand for both unproductive privilege and industrial efficiency. The utilitarian urge for efficiency and the meaninglessness of a struggle for recognition through conspicuous waste produce a desire for a romantic escape, also acknowledged by Veblen, but often overlooked in his sharp criticism of consumerism

Molecular mechanisms of cell death: recommendations of the Nomenclature Committee on Cell Death 2018.

Over the past decade, the Nomenclature Committee on Cell Death (NCCD) has formulated guidelines for the definition and interpretation of cell death from morphological, biochemical, and functional perspectives. Since the field continues to expand and novel mechanisms that orchestrate multiple cell death pathways are unveiled, we propose an updated classification of cell death subroutines focusing on mechanistic and essential (as opposed to correlative and dispensable) aspects of the process. As we provide molecularly oriented definitions of terms including intrinsic apoptosis, extrinsic apoptosis, mitochondrial permeability transition (MPT)-driven necrosis, necroptosis, ferroptosis, pyroptosis, parthanatos, entotic cell death, NETotic cell death, lysosome-dependent cell death, autophagy-dependent cell death, immunogenic cell death, cellular senescence, and mitotic catastrophe, we discuss the utility of neologisms that refer to highly specialized instances of these processes. The mission of the NCCD is to provide a widely accepted nomenclature on cell death in support of the continued development of the field