100 research outputs found
A Global Characterization and Identification of Multifunctional Enzymes
Multi-functional enzymes are enzymes that perform multiple physiological functions. Characterization and identification of multi-functional enzymes are critical for communication and cooperation between different functions and pathways within a complex cellular system or between cells. In present study, we collected literature-reported 6,799 multi-functional enzymes and systematically characterized them in structural, functional, and evolutionary aspects. It was found that four physiochemical properties, that is, charge, polarizability, hydrophobicity, and solvent accessibility, are important for characterization of multi-functional enzymes. Accordingly, a combinational model of support vector machine and random forest model was constructed, based on which 6,956 potential novel multi-functional enzymes were successfully identified from the ENZYME database. Moreover, it was observed that multi-functional enzymes are non-evenly distributed in species, and that Bacteria have relatively more multi-functional enzymes than Archaebacteria and Eukaryota. Comparative analysis indicated that the multi-functional enzymes experienced a fluctuation of gene gain and loss during the evolution from S. cerevisiae to H. sapiens. Further pathway analyses indicated that a majority of multi-functional enzymes were well preserved in catalyzing several essential cellular processes, for example, metabolisms of carbohydrates, nucleotides, and amino acids. What’s more, a database of known multi-functional enzymes and a server for novel multi-functional enzyme prediction were also constructed for free access at http://bioinf.xmu.edu.cn/databases/MFEs/index.htm
High-order harmonic generation spectroscopy by recolliding electron caustics
open12Spectral focusing of the recolliding electron in high-order harmonic generation driven by two-color fields is shown to be a powerful tool for isolating and enhancing hidden spectral features of the target under study. In previous works we used this technique for probing multi-electron effects in xenon and we compared our experimental results with time-dependent configuration-interaction singles calculations. We demonstrate here that this technique can be exploited for reconstructing the enhancement factor of the xenon giant dipole resonance and we discuss the sensitivity of this method to macroscopic effects. We then extend the technique to argon in order to test the applicability of this procedure to other targets.openFaccialà, D.; Pabst, S.; Bruner, B.D.; Ciriolo, A.G.; Devetta, M.; Negro, M.; Geetha, P Prasannan; Pusala, A.; Soifer, H.; Dudovich, N.; Stagira, S.; Vozzi, C.Faccialà, D.; Pabst, S.; Bruner, B. D.; Ciriolo, A. G.; Devetta, M.; Negro, M.; PRASANNAN GEETHA, Prabhash; Pusala, Aditya; Soifer, H.; Dudovich, N.; Stagira, S.; Vozzi, C
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Familial hypercholesterolaemia: identification and management. Evidence reviews for case-finding, diagnosis and statin monotherapy
This guideline covers identifying and managing familial hypercholesterolaemia (FH), a specific type of high cholesterol that runs in the family, in children, young people and adults. It aims to help identify people at increased risk of coronary heart disease as a result of having FH.
In November 2017, we reviewed the evidence for case finding and diagnosis, identification using cascade testing, and management using statins. We amended recommendations in sections 1.1, 1.2 and 1.3
Uphold the nuclear weapons test moratorium
The Trump administration is considering renewing nuclear weapons testing (1), a move that could increase the risk of another nuclear arms race as well as an inadvertent or intentional nuclear war. Following in the long tradition of scientists opposing nuclear weapons due to their harmful effects on both humanity and the planet (2), we ask the U.S. government to desist from plans to conduct nuclear tests.
During the Cold War, the United States conducted 1030 nuclear weapons tests, more than all other nuclear-armed nations combined (3). In 1996, the United States signed the Comprehensive Nuclear Test Ban Treaty (CTBT), agreeing not to conduct a nuclear weapons test of any yield (4). The United States has not yet ratified the CTBT but did spearhead the 2016 adoption of UN Security Council Resolution 2310, which calls upon all countries to uphold the object and purpose of the CTBT by not conducting nuclear tests (5).
Eight of the nine nuclear-armed states, including the five permanent members of the UN Security Council, have observed a moratorium on nuclear testing since 1998 (3, 4). The ninth, North Korea, responding to international pressure, stopped testing warhead detonations (as opposed to missile flights) in 2017 (6). If the United States ratified the CTBT, joining the 168 countries who have already done so (4), there is a good chance that the other holdout countries would ratify the treaty as well (7)
Uphold the nuclear weapons test moratorium
The Trump administration is considering renewing nuclear weapons testing (1), a move that could increase the risk of another nuclear arms race as well as an inadvertent or intentional nuclear war. Following in the long tradition of scientists opposing nuclear weapons due to their harmful effects on both humanity and the planet (2), we ask the U.S. government to desist from plans to conduct nuclear tests.
During the Cold War, the United States conducted 1030 nuclear weapons tests, more than all other nuclear-armed nations combined (3). In 1996, the United States signed the Comprehensive Nuclear Test Ban Treaty (CTBT), agreeing not to conduct a nuclear weapons test of any yield (4). The United States has not yet ratified the CTBT but did spearhead the 2016 adoption of UN Security Council Resolution 2310, which calls upon all countries to uphold the object and purpose of the CTBT by not conducting nuclear tests (5).
Eight of the nine nuclear-armed states, including the five permanent members of the UN Security Council, have observed a moratorium on nuclear testing since 1998 (3, 4). The ninth, North Korea, responding to international pressure, stopped testing warhead detonations (as opposed to missile flights) in 2017 (6). If the United States ratified the CTBT, joining the 168 countries who have already done so (4), there is a good chance that the other holdout countries would ratify the treaty as well (7)
Large Scale Association Analysis Identifies Three Susceptibility Loci for Coronary Artery Disease
Genome wide association studies (GWAS) and their replications that have associated DNA variants with myocardial infarction (MI) and/or coronary artery disease (CAD) are predominantly based on populations of European or Eastern Asian descent. Replication of the most significantly associated polymorphisms in multiple populations with distinctive genetic backgrounds and lifestyles is crucial to the understanding of the pathophysiology of a multifactorial disease like CAD. We have used our Lebanese cohort to perform a replication study of nine previously identified CAD/MI susceptibility loci (LTA, CDKN2A-CDKN2B, CELSR2-PSRC1-SORT1, CXCL12, MTHFD1L, WDR12, PCSK9, SH2B3, and SLC22A3), and 88 genes in related phenotypes. The study was conducted on 2,002 patients with detailed demographic, clinical characteristics, and cardiac catheterization results. One marker, rs6922269, in MTHFD1L was significantly protective against MI (OR = 0.68, p = 0.0035), while the variant rs4977574 in CDKN2A-CDKN2B was significantly associated with MI (OR = 1.33, p = 0.0086). Associations were detected after adjustment for family history of CAD, gender, hypertension, hyperlipidemia, diabetes, and smoking. The parallel study of 88 previously published genes in related phenotypes encompassed 20,225 markers, three quarters of which with imputed genotypes The study was based on our genome-wide genotype data set, with imputation across the whole genome to HapMap II release 22 using HapMap CEU population as a reference. Analysis was conducted on both the genotyped and imputed variants in the 88 regions covering selected genes. This approach replicated HNRNPA3P1-CXCL12 association with CAD and identified new significant associations of CDKAL1, ST6GAL1, and PTPRD with CAD. Our study provides evidence for the importance of the multifactorial aspect of CAD/MI and describes genes predisposing to their etiology
Carburization of steels-An overview
221-228<span style="font-size:11.0pt;line-height:115%;
font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:"times="" roman";mso-ansi-language:en-us;="" mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">A high carbon upper layer
is produced by diffusing carbon and the carburized steel is used in gears,
crankshafts where high ware and tare occurs. The thermodynamic, kinetic and
transport phenomenon occurring during carburization is studied. Importance of
thermochemical phase diagrams to determine the stability region of the oxides and
carbides is illustrated. The relationship between the composition of the
carburizing atmosphere and the carbon content of the steel is brought out
Development of a suitable heat treating environment for obtaining the correct
penetration depth is attempted. Mechanism of carburization, kinetic and
reaction mechanism of decomposition of gas mixture on the steel surface is
described. Models for predicting carburization depth are reviewed. A diffusion model
is proposed which is applicable to any diffusion-cum-reaction process.
Application and hazards of carburization are explained.</span
Gas-solid reactions: experimental evaluation of the zone model
Zinc sulfide pellets sintered at 1200°C, 1000°C, 800°C and 600°C were partially oxidized in a single pellet reactor. Sulfur profiles of these samples were measured using Auger electron spectroscopy (AES) and electron probe microanalysis (EPMA). These profiles showed the coexistence of three zones: ash layer, reaction zone, and unreacted core. The zone thickness was found to be approximately the same for samples of comparable porosities. The effective diffusivities of sintered zinc sulfide pellets calculated by using the values of zone thickness measured in the present study compare well with the literature values reported from kinetic studies
Gas-solid reactions: a method of direct solution for solid conversion profiles
A new solution technique for non-catalytic gas-solid reactions, which are first order in gas concentration but are represented by any general rate form with respect to the solid, has been proposed. An equation for the variation in conversion with position in the pellet has been derived, the solution of which yields the conversion profiles and the average conversion directly. The method has been illustrated by application to a number of models, such as the particle pellet model with and without structural changes, the volume reaction model, and reactions with significant nucleation effects
A model for gas-solid reactions with structural changes in the presence of inert solids
A mathematical model is developed to account for the effect of inert material present in the solid in noncatalytic gas-solid reactions accompanied by significant structural changes. This model finds application in the desulfurization of flue gases using dolomite, chlorination of ilmenite, etc. where the naturally occurring ores contain inert materials in the solid matrix. The results show that the asymptotic conversion is increased by the presence of inerts and an optimum inert content exists for which the gas uptake and the utilization of the active solid material are maximum
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