bluuebunny/crossref_metadata_2025_split huggingface dataset:
LPMOs in cellulase mixtures affect fermentation strategies for lactic acid production from lignocellulosic biomass
Authors: Müller Gerdt , Kalyani Dayanand Chandrahas , Horn Svein Jarle 
Published: September 2016

ABSTRACTEnzymatic catalysis plays a key role in the conversion of lignocellulosic biomass to fuels and chemicals such as lactic acid. In the last decade, the efficiency of commercial cellulase cocktails has increased significantly, in part due to the inclusion of lytic polysaccharide monooxygenases (LPMOs). However, the LPMOs’ need for molecular oxygen to break down cellulose demands reinvestigations of process conditions. In this study, we evaluate the efficiency of lactic acid production from steam‐exploded birch using an LPMO‐containing cellulase cocktail in combination with lactic acid bacteria, investigating both separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF). While the SSF set up generally has been considered to be more efficient because it avoids sugar accumulation which may inhibit the cellulases, the SHF set up in our study yielded 26–32% more lactic acid than the SSF. This was mainly due to competition for oxygen between LPMOs and the fermenting organisms in the SSF process, which resulted in reduced LPMO activity and thus less efficient saccharification of the lignocellulosic substrate. By means of aeration it was possible to activate the LPMOs in the SSF, but less lactic acid was produced due to a shift in metabolic pathways toward production of acetic acid. Overall, this study shows that lactic acid can be produced efficiently from lignocellulosic biomass, but that the use of LPMO‐containing cellulase cocktails in fermentation processes demands re‐thinking of traditional process set ups due to the requirement of oxygen in the saccharification step. Biotechnol. Bioeng. 2017;114: 552–559. © 2016 Wiley Periodicals, Inc.
A synthetic microbial consortium of Shewanella and Bacillus for enhanced generation of bioelectricity
Authors: Liu Ting , Yu Yang‐Yang , Chen Tao , Chen Wei Ning 
Published: September 2016

ABSTRACTIn this study, a synthetic microbial consortium containing exoelectrogen Shewanella oneidensis MR‐1 and riboflavin‐producing strain, Bacillus subtilis RH33, was rationally designed and successfully constructed, enabling a stable, multiple cycles of microbial fuel cells (MFCs) operation for more than 500 h. The maximum power density of MFCs with this synthetic microbial consortium was 277.4 mW/m2, which was 4.9 times of that with MR‐1 (56.9 mW/m2) and 40.2 times of RH33 (6.9 mW/m2), separately. At the same time, the Coulombic efficiency of the synthetic microbial consortium (5.6%) was higher than MR‐1 (4.1%) and RH33 (2.3%). Regardless the high concentration of riboflavin produced by RH33, the power density of RH33 was rather low. The low bioelectricity generation can be ascribed to the low efficiency of RH33 in utilizing riboflavin for extracellular electron transfer (EET). In the synthetic microbial consortium of MR‐1 and RH33, it was found that both mediated and direct electron transfer efficiencies were enhanced. By exchanging the anolyte of MR‐1 and RH33, it was confirmed that the improved MFC performance with the synthetic microbial consortium was because MR‐1 could efficiently utilize the high concentration of riboflavin produced by RH33. Biotechnol. Bioeng. 2017;114: 526–532. © 2016 Wiley Periodicals, Inc.
Screening for inherited metabolic diseases using gas chromatography–tandem mass spectrometry (GC–MS/MS) in Sichuan, China
Authors: Wang Hong , Wang Xia , Li Yingying , Dai Wei , Jiang Dongmei , Zhang Xiaodong , Cui Yali 
Published: September 2016

AbstractThe aim of this study was to retrospectively diagnose and confirm inherited metabolic diseases (IMD), from a small population of IMD high‐risk patients, with the aid of gas chromatography–tandem mass spectrometry (GC–MS/MS), technologies yet to be popularized in Sichuan, China. Using GC–MS/MS coupled with clinical diagnosis, we retrospectively analyzed samples of dried blood spots and urine specimen from 183 IMD high‐risk infant patients, who visited the West China Second Hospital of Sichuan University between June 2013 and October 2015. Four out of 183 IMD high‐risk infant patients were finally diagnosed to be IMD positive, among which two patients were identified with phenylketonuria, one with maple syrup urine disease, and 1 with methylmalonic academia. Restrictive diets and other symptomatic treatments were employed to treat the confirmed infant patients whose conditions are still under tracking and there are zero cases of death so far. GC–MS/MS was found to be an efficient and reliable way to detect IMD. It is necessary to apply GC–MS/MS, in addition to other clinical approaches, for diagnosing candidate IMD patients so that the confirmed patients can get medical intervention and timely treatment.
Constraining an Irregular Peptide Secondary Structure through Ring‐Closing Alkyne Metathesis
Authors: Cromm Philipp M. , Wallraven Kerstin , Glas Adrian , Bier David , Fürstner Alois , Ottmann Christian , Grossmann Tom N. 
Published: September 2016

AbstractMacrocyclization can be used to constrain peptides in their bioactive conformations, thereby supporting target affinity and bioactivity. In particular, for the targeting of challenging protein–protein interactions, macrocyclic peptides have proven to be very useful. Available approaches focus on the stabilization of α‐helices, which limits their general applicability. Here we report for the first time on the use of ring‐closing alkyne metathesis for the stabilization of an irregular peptide secondary structure. A small library of alkyne‐crosslinked peptides provided a number of derivatives with improved target affinity relative to the linear parent peptide. In addition, we report the crystal structure of the highest‐affinity derivative in a complex with its protein target 14‐3‐3ζ. It can be expected that the alkyne‐based macrocyclization of irregular binding epitopes should give rise to new scaffolds suitable for targeting of currently intractable proteins.
The Importance of Methyl Positioning and Tautomeric Equilibria for Imidazole Nucleophilicity
Authors: Campos Renan B. , Menezes Leociley R. A. , Barison Andersson , Tantillo Dean J. , Orth Elisa S. 
Published: September 2016

AbstractImidazole (IMZ) rings catalyze many biological dephosphorylation processes. The methyl positioning effect on IMZs reactivity has long intrigued scientists and its full understanding comprises a promising tool for designing highly efficient IMZ‐based catalysts. We evaluated all monosubstituted methylimidazoles (xMEI) in the reaction with diethyl 2,4‐dinitrophenyl phosphate by kinetics studies, NMR analysis and DFT calculations. All xMEI showed remarkable rate enhancements, up to 1.9×105 fold, compared with spontaneous hydrolysis. Unexpectedly, the electron‐donating methyl group acts to decrease the reactivity of the xMEI compared to IMZ, except for 4(5)methylimidazole, (4(5)MEI). This behavior was attributed to both electronic and steric effects. Moreover, reaction intermediates were monitored by NMR and surprisingly, the reactivity of the two different 4(5)MEI tautomers was distinguished.
Evaluation of Performance of Periodically Operated Reactors for Single Input Modulations of General Waveforms
Authors: Nikolić Daliborka , Petkovska Menka 
Published: September 2016

AbstractThe nonlinear frequency response (NFR) method is used for evaluating the time‐average performance of a chemical reactor subjected to single input modulations of general waveforms, by using Fourier series for representing the input and Volterra series for representing the output. Both the input and the output are approximated by finite sums. The obtained results are applied for the case of a square‐wave input modulation. As a case study, the improvement of an isothermal continuous stirred‐tank reactor with simple reaction mechanism with modulation of the inlet reactant concentration is used and the results are tested on a numerical example.
Relationship Among Risk Score Systems and Coronary Atherosclerosis Determined by Multislice Computed Tomography
Authors: García‐Lledó Alberto , Moya‐Mur José L. , Ponz‐Mir Virginia , Novo‐Aparicio Susana , Sanz‐Barrio Azucena , Álvarez‐Sanz Concepción , de Santiago‐Nocito Ana 
Published: September 2016

BackgroundRisk score systems (RSS) were designed to estimate the risk of cardiac events. Their ability to predict coronary atherosclerosis (CA) has not been established.HypothesisRisk score systems can predict presence of CA in patients without typical symptoms or ischemia. Because design of each RSS is different, their predictive value could also differ.MethodsA retrospective analysis was done on patients from a low‐risk region referred for cardiac multislice computed tomography (MSCT). The sample included low‐ to intermediate‐risk patients with nontypical chest pain and asymptomatic high‐risk patients. Patients with documented ischemia were excluded. Three RSS were determined: Framingham Risk Score (FRS), Regicor (FRS calibrated for Spanish population), and Systematic Coronary Risk Evaluation (SCORE). Coronary arteries were investigated to determine calcium score and presence of protruding atheromas.ResultsWe analyzed 582 patients (53.8% male; mean age 51 ± 11.5 years). Their mean estimated risk was intermediate: 15.6 ± 10.4 by FRS, 6.3 ± 4.3 by Regicor, and 3.9 ± 4.1 by SCORE. The MSCT showed no CA in 38.8%, nonobstructive plaques in 28.7%, and obstructive ones in 32.5%. The ability of the RSS to predict CA was not significantly different, with moderate diagnostic value (areas under ROC curves, 0.72–0.65). The prevalence of CA was high in low‐risk patients: 40%, 47%, and 53% in FRS, Regicor, and SCORE low‐risk patients, respectively.ConclusionsRisk score systems have only moderate diagnostic value to predict presence of CA, without significant differences among them. Coronary artery disease is highly prevalent in patients considered low risk.
Oral Administration of Peptide‐Based Drugs: Beyond Lipinski's Rule
Authors: Santos Gabriela B. , Ganesan A. , Emery Flavio S. 
Published: September 2016

AbstractThe use of peptides in therapy presents several limitations, from physicochemical characteristics to inadequate pharmacokinetic profiles for oral absorption. As peptides are gaining importance in the therapeutic arsenal, there is an increasing need to rationalize the main characteristics of this compound class in the market. Therefore, we performed an extensive analysis of all known peptide drugs and clinical candidates based on their peptide features, physicochemical and structural properties, and correlated these with their administration route and therapeutic classes. Peptide drugs are widely distributed across drug and pharmacological space, covering several therapeutic areas with structural diversity and complexity, distributed between groups of cyclic and linear compounds. Although structural and physicochemical properties are clear within these groups, we counter the consensus that cyclic peptides have better oral availability than linear peptides, as most of the orally administrated peptides have linear structures. This study and review furnishes information that could support peptide drug design, with a new cutoff of known descriptors that go beyond the Rule of Five.
Computational virtual evaluation of the effect of annuloplasty ring shape
Authors: Choi Ahnryul , McPherson David D. , Kim Hyunggun 
Published: September 2016

AbstractMitral regurgitation (MR) is a result of mitral valve (MV) pathology. Its etiology can be categorized as degenerative or functional MR. Ring annuloplasty aims to reconfigure a dilated mitral annulus to its normal size and shape. We investigated the effect of annuloplasty ring shape on MR outcome using our established 3‐dimensional (3‐D) echocardiography‐based computational MV evaluation protocols. Virtual patient MV models were created from 3‐D transesophageal echocardiographic data in patients with MR because of mitral annular dilation. Two distinct annuloplasty rings (Physio II and GeoForm) were designed and virtually implanted to the patient MVs. Dynamic finite element simulations of MV function were performed for each MV after virtual ring annuloplasty of either ring, and physiologic and biomechanical characteristics of MV function were compared. Excessive stress values appeared primarily in the midanterior and midposterior regions, and lack of leaflet coaptation was found in pre‐annuloplasty patient MVs. Both rings demonstrated marked reduction of stresses and efficient leaflet coaptation. The Physio II ring demonstrated more evenly distributed stress reduction across the leaflets and annulus compared with the GeoForm ring. Conversely, the highly nonplanar curvature of the GeoForm ring more effectively increased leaflet coaptation compared with the Physio II ring. This indicates that the shape of annuloplasty ring affects post‐annuloplasty physiologic and biomechanical conditions, which can lead to tissue alteration over a longer period after ring annuloplasty. This virtual ring annuloplasty simulation strategy provides detailed physiologic and biomechanical information and may help better plan the optimal ring selection and improved patient‐specific MV repairs.
Single cell analysis of human tissues and solid tumors with mass cytometry
Authors: Leelatian Nalin , Doxie Deon B. , Greenplate Allison R. , Mobley Bret C. , Lehman Jonathan M. , Sinnaeve Justine , Kauffmann Rondi M. , Werkhaven Jay A. , Mistry Akshitkumar M. , Weaver Kyle D. , Thompson Reid C. , Massion Pierre P. , Hooks Mary A. , Kelley Mark C. , Chambless Lola B. , Ihrie Rebecca A. , Irish Jonathan M. 
Published: September 2016

BackgroundMass cytometry measures 36 or more markers per cell and is an appealing platform for comprehensive phenotyping of cells in human tissue and tumor biopsies. While tissue disaggregation and fluorescence cytometry protocols were pioneered decades ago, it is not known whether established protocols will be effective for mass cytometry and maintain cancer and stromal cell diversity.MethodsTissue preparation techniques were systematically compared for gliomas and melanomas, patient derived xenografts of small cell lung cancer, and tonsil tissue as a control. Enzymes assessed included DNase, HyQTase, TrypLE, collagenase (Col) II, Col IV, Col V, and Col XI. Fluorescence and mass cytometry were used to track cell subset abundance following different enzyme combinations and treatment times.ResultsMechanical disaggregation paired with enzymatic dissociation by Col II, Col IV, Col V, or Col XI plus DNase for 1 h produced the highest yield of viable cells per gram of tissue. Longer dissociation times led to increasing cell death and disproportionate loss of cell subsets. Key markers for establishing cell identity included CD45, CD3, CD4, CD8, CD19, CD64, HLA‐DR, CD11c, CD56, CD44, GFAP, S100B, SOX2, nestin, vimentin, cytokeratin, and CD31. Mass and fluorescence cytometry identified comparable frequencies of cancer cell subsets, leukocytes, and endothelial cells in glioma (R = 0.97), and tonsil (R = 0.98).ConclusionsThis investigation establishes standard procedures for preparing viable single cell suspensions that preserve the cellular diversity of human tissue microenvironments. © 2016 International Clinical Cytometry Society
Performance study of hybrid decode–amplify–forward (HDAF) relaying scheme for physical layer security in wireless cooperative network
Authors: Gurrala Kiran Kumar , Das Susmita 
Published: September 2016

SummaryIn this paper, the secrecy performance and power allocation of the signal‐to‐noise ratio‐based hybrid decode–amplify–forward (HDAF) relaying protocol in wireless cooperative network are investigated to get security at physical layer. The performance metrics considered are secrecy rate and intercept probability. The Ergodic secrecy rate is approximated theoretically. The effect of relay and eavesdropper locations on the secrecy performance of the system is analyzed. It is found that maximum secrecy rate is obtained for the relay close‐to‐destination case and minimum for the relay close‐to‐eavesdropper case. Jamming schemes are superior in secrecy rate performance than without jamming schemes. To enhance the secrecy rate further with the optimized relay and jammer powers, invasive weed optimization (IWO) algorithm‐based power allocation is proposed. Here, maximizing the secrecy rate is defined as the cost function for the proposed IWO algorithm‐based power allocation. Comparative study is done over the conventional equal and proposed power allocation schemes for validation. The proposed power allocation scheme proved to be superior. Copyright © 2016 John Wiley & Sons, Ltd.
Evaluating mountain meadow groundwater response to Pinyon‐Juniper and temperature in a great basin watershed
Authors: Carroll Rosemary W.H. , Huntington Justin L. , Snyder Keirith A. , Niswonger Richard G. , Morton Charles , Stringham Tamzen K. 
Published: September 2016

AbstractThis research highlights development and application of an integrated hydrologic model (GSFLOW) to a semiarid, snow‐dominated watershed in the Great Basin to evaluate Pinyon‐Juniper (PJ) and temperature controls on mountain meadow shallow groundwater. The work used Google Earth Engine Landsat satellite and gridded climate archives for model evaluation. Model simulations across three decades indicated that the watershed operates on a threshold response to precipitation (P) >400 mm/y to produce a positive yield (P‐ET; 9%) resulting in stream discharge and a rebound in meadow groundwater levels during these wetter years. Observed and simulated meadow groundwater response to large P correlates with above average predicted soil moisture and with a normalized difference vegetation index threshold value >0.3. A return to assumed pre‐expansion PJ conditions or an increase in temperature to mid‐21st century shifts yielded by only ±1% during the multi‐decade simulation period; but changes of approximately ±4% occurred during wet years. Changes in annual yield were largely dampened by the spatial and temporal redistribution of evapotranspiration across the watershed: Yet the influence of this redistribution and vegetation structural controls on snowmelt altered recharge to control water table depth in the meadow. Even a small‐scale removal of PJ (0.5 km2) proximal to the meadow will promote a stable, shallow groundwater system resilient to droughts, while modest increases in temperature will produce a meadow susceptible to declining water levels and a community structure likely to move toward dry and degraded conditions.
Sustainable development and anthropogenic induced geomorphic hazards in subsiding areas
Authors: Abou Karaki Najib , Fiaschi Simone , Closson Damien 
Published: September 2016

AbstractIn many areas of the world, subsidence related to the lowering of the water table is modifying the landscape and provoking costly environmental hazards.We consider the Dead Sea (the Earth's lowest lake) as a model. Its water level was 395 m bMSL in the 1960s. Due to water diversions in the catchment area, as of 2016, the level has dropped to about 430 m bMSL. Here, as in other parts of the Anthropocene world, from China, to Iran, to Turkey, to Canada and the United States, consequences of human interventions are rapidly modifying the environment. Aggressive geomorphic processes leading to accelerated degradations are taking place and affecting landforms and infrastructures.In Tectonic terms, the lake is a pull‐apart basin resulting from the motion of the Dead Sea Transform fault. Since the 1960s, a slice of brine of about 35 km3 has been lost. The water table is dropping more rapidly in the lake than in the coastal zone creating an ever‐increasing head difference. Consequently, groundwater moves towards the sea to compensate for the imbalance, provoking the reactivation of the area's paleo‐channels with subsidence, sinkholes, and landslides.Since the 1980s, industrial‐touristic infrastructure has covered newly emerging lands in geomorphic hazards‐prone areas of the coastal zone.Time series analysis of high to very high resolution visible/radar satellite images acquired from the 1970s to present, revealed major landscape evolution. Such dynamic systems prevailing in recent decades permitted the study of human/environment interactions to help minimize their effects.Major deformations of an industrial dike were analysed and quantified. The results underline the necessity in the Anthropocene of careful analysis of relevant data sources acquired before and during subsidence, particularly in karst topography zones and prior to the development of major human activities in economically appealing environments around the world. Copyright © 2016 John Wiley & Sons, Ltd.
High Ratio Non‐Isolated DC–DC Converter for Hydrogen Battery Using a 50 kW PEM Fuel Cell
Authors: Videau N. , Fontes G. , Flumian D. , Gateau G. , Meynard T. , da Silva J. L. , Verdu O. 
Published: September 2016

AbstractThis paper proposes a DC–DC converter dedicated to high efficiency and high voltage conversion ratio, which is well suited for fuel cell applications. At high voltage conversion ratio the proposed converter, named here mirror boost converter, has a better ratio of active/freewheeling times which, compared with conventional structures, reduces the penalty on efficiency induced by the high conversion ratio. This converter also uses eight interleaved coupled‐inductors, which reduces the current and voltage ripple and makes possible to use of smaller passive components. Coupling all phases with an inter‐cell transformer (ICT) also improves the power density, volume and losses of the magnetic component compared to separate inductors. A comparison with a classical double boost converter is realized using the same material. The proposed converter reaches a peak efficiency of 96.5% at 17 kW and 95.3% at 42 kW for a voltage conversion ratio around 10. The mirror boost converter has about half the losses of the double boost converter at same fuel cell power and delivers 69% more power at the maximum measured current phase.
Berechnung des Erdruhedrucks – verschiedene analytische Ansätze für beliebige Neigungen von Gelände und Wand
Authors: Goldscheider Michael 
Published: September 2016

AbstractDer Erdruhedruck wird als ein statisch unbestimmtes Spannungs‐Verformungs‐Problem definiert. Die gewöhnlich angewendeten und in DIN 4085 empfohlenen Gleichungen zur Abschätzung des Erdruhedruckbeiwerts für normalkonsolidierte und für vorbelastete Böden werden aufgrund von übergeordnetem, in Versuchen beobachtetem Materialverhalten begründet. Die Gleichungen zur Berechnung des Erdruhedrucks bei horizontaler Geländeoberfläche an einer beliebig geneigten Wand werden aus den Gesetzmäßigkeiten der Spannungstransformation abgeleitet. Bei gleichmäßig geneigter Geländeoberfläche werden die Gleichungen des Spannungsfelds unter Verwendung eines charakteristischen Koordinatensystems mit den Achsen parallel und senkrecht zur Geländeoberfläche formuliert. Dadurch reduzieren sich die Gleichgewichtsgleichungen von einem Paar partieller auf zwei gewöhnliche, einfach lösbare Differenzialgleichungen, die es ermöglichen, den vom Geländeneigungswinkel β abhängigen Erdruhedruckbeiwert einzuführen. Dieser Beiwert wird durch Interpolation zwischen dem Wert für β = 0 und dem Grenzwert bei β = φ (Reibungswinkel) bestimmt. Die Interpolationsformel ist die einzige Annahme bei dieser Berechnung. Auf der Grundlage dieser Gleichungen wird der Erdruhedruck an einer Wand mit beliebiger Neigung in geneigtem Gelände analog zum Fall mit horizontalem Gelände durch Spannungstransformation bestimmt. Berechnungsbeispiele werden vorgeführt. Ein in der Praxis übliches vereinfachtes Berechnungsverfahren wird erklärt und diskutiert; für seine Anwendung auf geneigte Wände in geneigtem Gelände wird ein Korrekturfaktor aus dem genaueren Verfahren entwickelt.