bluuebunny/crossref_metadata_2025_split huggingface dataset:
Estimation of adjusted expected excess length‐of‐stay associated with ventilation‐acquired pneumonia in intensive care: A multistate approach accounting for time‐dependent mechanical ventilation
Authors: Bluhmki Tobias , Allignol Arthur , Ruckly Stephane , Timsit Jean‐Francois , Wolkewitz Martin , Beyersmann Jan 
Published: September 2018

AbstractThe expected excess length‐of‐stay is an established concept to assess the health and economic impact of nosocomial, that is, hospital‐acquired infections such as ventilation‐acquired pneumonia in intensive care. Estimation must account for the timing of infection as in a multistate perspective, because common retrospective comparisons yield inflated estimates due to time‐dependent bias. Since occurrence of ventilation‐acquired pneumonia is closely linked to ventilation status, we suggest a multistate model incorporating time‐dependent mechanical ventilation as additional states. The appeal is that the expected excess length‐of‐stay decomposes into extra days spent under ventilation and not under ventilation. This is not only highly relevant from a patient's perspective regarding quality of life, but also from an economic point of view, because ventilation is a major cost driver. The challenge is that estimation involves complex functionals of the matrix of transition probabilities, which in turn are based on the transition hazards. To address heterogeneity between patients, which is a common phenomenon in observational hospital epidemiology, we apply pseudovalue regression to adjust the ventilation‐specific quantities for baseline confounding. The performance of our proposal is assessed by simulation and the methods are illustrated on data provided by 12 French intensive care units. Preliminary results indicate that the expected excess length‐of‐stay associated with ventilation‐acquired pneumonia is mainly triggered by extra days spent under mechanical ventilation, and that the excess is most pronounced for intensive care patients with fewer comorbidities at baseline. We also find that such a decomposition is challenging for early times. Example code is provided.
Unraveling the genetic basis of fast l‐arabinose consumption on top of recombinant xylose‐fermenting Saccharomyces cerevisiae
Authors: Wang Xin , Yang Junjie , Yang Sheng , Jiang Yu 
Published: September 2018

AbstractOne major challenge in the bioconversion of lignocelluloses into ethanol is to develop Saccharomyces cerevisiae strains that can utilize all available sugars in biomass hydrolysates, especially the d‐xylose and l‐arabinose that cannot be fermented by the S. cerevisiae strain naturally. Here, we integrated an l‐arabinose utilization cassette (AUC) into the genome of an efficient d‐xylose fermenting industrial diploid S. cerevisiae strain CIBTS0735 to make strain CIBTS1972. After evolving on arabinose, CIBTS1974 with excellent fermentation capacity was obtained. A comparison between genome sequences of strains CIBTS1974 and CIBTS1972 revealed that the copy number of the AUC had increased from 1 to 12. We then constructed the AUC null‐mutant CIBTS1975 and gradually rescued the l‐arabinose utilization defect by integrating AUC iteratively. On the other hand, the parental strain CIBTS0735 was able to acquire the same performance as CIBTS1974 by the direct introduction of 12 copies of the AUC; the performance was further improved by adding two more copies. Besides, we found that not the two transporters present in the AUC were both needed during l‐arabinose utilization, GAL2 was necessary and STP2 was not essential. We have described for the first time that a high copy number of AUC is sufficient for the strain to metabolize l‐arabinose efficiently independent of evolution.
A fully online sensor‐equipped, disposable multiphase microbioreactor as a screening platform for biotechnological applications
Authors: Lladó Maldonado Susanna , Panjan Peter , Sun Shiwen , Rasch Detlev , Sesay Adama M. , Mayr Torsten , Krull Rainer 
Published: September 2018

AbstractA new disposable, multiphase, microbioreactor (MBR; with a working volume of 550 μl) equipped with online sensors is presented for biotechnological screening research purposes owing to its high‐throughput potential. Its design and fabrication, online sensor integration, and operation are described. During aerobic cultivation, sufficient oxygen supply is the most important factor that influences growth and product formation. The MBR is a microbubble column bioreactor (μBC), and the oxygen supply was realized by active pneumatic bubble aeration, ensuring sufficient volumetric liquid‐phase mass transfer (k
L
a) and proper homogenization of the cultivation broth. The μBC was equipped with miniaturized sensors for the pH, dissolved oxygen, optical density and glucose concentration that allowed real‐time online monitoring of these process variables during cultivation. The challenge addressed here was the integration of sensors in the limited available space. The MBR was shown to be a suitable screening platform for the cultivation of biological systems. Batch cultivations of
Saccharomyces cerevisiae were performed to observe the variation in the process variables over time and to show the robustness and operability of all the online sensors in the MBR.
Analysis of competence acquisition in a flipped classroom approach
Authors: Estriegana Rosa , Medina‐Merodio José‐Amelio , Barchino Roberto 
Published: September 2018

AbstractHigher Education Institutions are interested in describing qualifications in terms of competences and abilities that prepare graduates best for their future professional and social life. This study aims to analyze students’ acquisition of competences, on one hand, inside the classroom using a flipped learning approach, on the other hand, outside the classroom through students’ self‐study using information and communication technology resources such as teaching videos, virtual labs, simulations, or game‐based learning. The study also wants to shed light on the relationship between the achieved competences and the learning outcomes. The analysis was based on the data collected from a core subject in the first year of the Computer Engineering and Information Systems degree courses. The answers to an online survey (n = 285) were examined by using a structural equation model with 13 observed and seven latent variables. The results obtained show that the learning environment created inside and outside the classroom plays a key role in the acquisition and development of the three competences analyzed: systematic, personal, and cooperative. Our findings also suggest that competence or skills acquisition, despite being considered one of the main issues in the higher education qualifications framework, does not exactly match the academic results measured during the assessment process.
New CAD/CAM course framework in digital manufacturing
Authors: Wang Xiaoqin , Bi Zhuming 
Published: September 2018

AbstractDespite the importance of manufacturing industry, its position in a nation's economy has shown its shrinking; the workforce in manufacturing industry has been continuously declined. Engineering universities are highly pressured to attract new‐generation youth to traditional engineering programs and improve their retention ratios by keeping students in engineering programs. There is an emerging need to bring some innovations in engineering curriculum design to keep up with the rapid changes in other fields, especially, information technology (IT). In this paper, we focus on our effort in developing a new computer aided design (CAD) and computer integrated manufacturing CAM) course. Literatures on CAD/CAM course designs are surveyed to identify the limitations in traditional teaching CAD/CAM, the trend of manufacturing technologies is discussed to determine the industry's expectations of their new employees. A new CAD/CAM course has been designed by incorporating the theory of Digital Manufacturing and CAD/CAM integrated tools together in teaching.
Masking the Peroxidase‐Like Activity of the Molybdenum Disulfide Nanozyme Enables Label‐Free Lipase Detection
Authors: Nandu Nidhi , Salih Hizir Mustafa , Roberston Neil M. , Ozturk Birol , Yigit Mehmet V. 
Published: September 2018

AbstractTwo‐dimensional MoS2 nanoparticles (2D‐nps) exhibit artificial enzyme properties that can be regulated at bio‐nanointerfaces. We discovered that protein lipase is able to tune the peroxidase‐like activity of MoS2 2D‐nps, offering low‐nanomolar, label‐free detection and identification in samples with unknown identity. The inhibition of the peroxidase‐like activity of the MoS2 2D‐nps was demonstrated to be concentration dependent, and as low as 5 nm lipase was detected with this approach. The results were compared with those obtained with several other proteins that did not display any significant interference with the nanozyme behavior of the MoS2 2D‐nps. This unique response of lipase was characterized and exploited for the successful identification of lipase in six unknown samples by using qualitative visual inspection and a quantitative statistical analysis method. The developed methodology in this approach is noteworthy for many aspects; MoS2 2D‐nps are neither labeled with a signaling moiety nor modified with any ligands for signal readout. Only the intrinsic nanozyme activity of the MoS2 2D‐nps is exploited for this detection approach. No analytical equipment is necessary for the visual detection of lipase. The synthesis of the water‐soluble MoS2 2D‐nps is low costing and can be performed in bulk scale. Exploring the properties of 2D‐nps and their interactions with biological materials reveals highly interesting yet instrumental features that offer the development of novel bioanalytical approaches.
Applying Le Chatelier's Principle for a Highly Efficient Catalytic Transfer Hydrogenation with Ethanol as the Hydrogen Source
Authors: Weingart Pascal , Thiel Werner R. 
Published: September 2018

AbstractWhile isopropanol or formic acid derivatives are mainly applied as hydrogen sources in catalytic transfer hydrogenation reactions, there are only a few reports on the use of primary alcohols. In the present communication we report that ecologically benign and cheap ethanol can be applied with a ruthenium(II) that is completely stable against moisture and oxygen. Catalytic transfer hydrogenation is an equilibrium reaction. Therefore, a rapid removal of acetic aldehyde being formed as the product of ethanol oxidation is the key for high conversions. The reaction shows a broad substrate scope and allows the hydrogenation of ketones, aldehydes and imines.
Simultaneous Design and Control of a Ternary Reactive Distillation Column with Inert Material
Authors: Vasudevan Aneesh , Narayanasamy Selvaraju , Paramasivan Ganesh 
Published: September 2018

AbstractProcess integration means significant challenges in operating a chemical process dynamically due to its complexity. One example is the ternary reactive distillation with inert material. Based on the heuristic approach, chemical process design and process control are performed independently one after another. This may lead to infeasible solutions either in process design and control or in both. The application of simultaneous design and control, formulated as mixed‐integer dynamic optimization (MIDO) problems, increased rapidly in the last decade. Simultaneous process design and control, including control structure selection and control parameters, is devised for the challenging benchmark problem of a ternary reactive distillation with inert material. The improved process design and control is obtained by solving the MIDO problem.
Using an AlCl3/Urea Ionic Liquid Analog Electrolyte for Improving the Lifetime of Aluminum‐Sulfur Batteries
Authors: Bian Yinghui , Li Yu , Yu Zhichao , Chen Hui , Du Kewen , Qiu Chaochao , Zhang Guoxin , Lv Zichuan , Lin Meng‐Chang 
Published: September 2018

AbstractAluminum‐sulfur (Al−S) chemistry is attractive for the development of next‐generation rechargeable battery systems. However, only a few reversible Al−S cells have been reported until now. This paper demonstrates that the use of an AlCl3/urea electrolyte in Al−S cells is a promising approach to improve the cycle life and reach a high discharge voltage plateau of ∼1.6–2.0 V. In contrast to the instability of sulfur in the conventional AlCl3/EMIC electrolyte, sulfur is chemically stable in the AlCl3/urea electrolyte, which allows better cell cycling stability. The Al−S cell delivers an initial capacity of ∼700 mAh gs−1 and maintains a capacity of up to ∼500 mAh gs−1 after 100 cycles.
Porous Carbon Hosts for Lithium–Sulfur Batteries
Authors: Wang Minya , Xia Xinhui , Zhong Yu , Wu Jianbo , Xu Ruochen , Yao Zhujun , Wang Donghuang , Tang Wangjia , Wang Xiuli , Tu Jiangping 
Published: September 2018

AbstractLithium–sulfur batteries (LSBs) are considered to be one of the most promising alternatives to the current lithium‐ion batteries (LIBs) to meet the increasing demand for energy storage owing to their high energy density, natural abundance, low cost, and environmental friendliness. Despite great success, LSBs still suffer from several problems, including undermined capacity arising from low utilization of sulfur, unsatisfactory rate performance and poor cycling life owing to the shuttle effect of polysulfides, and poor electrical conductivity of sulfur. Under such circumstances, the design/fabrication of porous carbon–sulfur composite cathodes is regarded as an effective solution to overcome the above problems. In this review, different synthetic methods of porous carbon hosts and their corresponding integration into carbon–sulfur cathodes are summarized. The pore formation mechanism of porous carbon hosts is also addressed. The pore size effect on electrochemical performance is highlighted and compared. The enhanced mechanism of the porous carbon host on the sulfur cathode is systematically reviewed and revealed. Finally, the combination of porous carbon hosts and high‐profile solid‐state electrolytes is demonstrated, and the challenges to realize large‐scale commercial application of porous carbon–sulfur cathodes is discussed and future trends are proposed.
Rare‐Earth Metal(II) Aryloxides: Structure, Synthesis, and EPR Spectroscopy of [K(2.2.2‐cryptand)][Sc(OC6H2tBu2‐2,6‐Me‐4)3]
Authors: Moehring Samuel A. , Beltrán‐Leiva María J. , Páez‐Hernández Dayán , Arratia‐Pérez Ramiro , Ziller Joseph W. , Evans William J. 
Published: September 2018

AbstractThe suitability of aryloxide ligands for stabilizing +2 oxidation states of Sc and Y has been examined and EPR evidence indicating the first O‐donor complexes of ScII and YII has been obtained, as well as an X‐ray crystal structure of a ScII aryloxide complex. The trivalent rare‐earth metal aryloxide precursors, Ln(OAr′)3, 1‐Ln (Ln=Sc, Y, Gd, Dy, Ho, Er; OAr′=OC6H2tBu2‐2,6‐Me‐4), were synthesized from the corresponding rare‐earth metal trichlorides and LiOAr′⋅OEt2. Reduction of THF solutions of 1‐Ln with potassium graphite in the presence of 2.2.2‐cryptand (crypt) yielded dark‐colored solutions, 2‐Ln, whose EPR spectra at 77 K are characteristic of the LnII ions: a two‐line spectrum (g∥=1.99, g□=1.97, Aave=154 G) for 2‐Y and an eight‐line spectrum (gave=2.01 and Aave=291 G) for 2‐Sc. Solutions of 2‐Y decompose within one minute at room temperature, wheras 2‐Sc persists up to 40 min at room temperature. 2‐Sc was identified by X‐ray crystallography as [K(crypt)][Sc(OAr′)3], which has a trigonal‐planar arrangement of oxygen‐donor atoms around ScII. Analogous reductions of 1‐Ln for Ln=Gd, Dy, Ho, and Er also gave dark solutions of limited stability. Theoretical analysis using time‐dependent density functional theory (TD‐DFT) along with complete active space self‐consistent field (CASSCF) methods, and structural analysis with the Guzei ligand solid angle G‐parameter method are presented.
Organocatalytic Regiodivergent C−C Bond Cleavage of Cyclopropenones: A Highly Efficient Cascade Approach to Enantiopure Heterocyclic Frameworks
Authors: Cao Jian , Fang Ran , Liu Jin‐Yu , Lu Hong , Luo Yong‐Chun , Xu Peng‐Fei 
Published: September 2018

AbstractHere a highly efficient cascade approach is reported that combines a cycloaddition reaction with a regioselective strain‐release process to afford diverse heterocyclic frameworks through bifunctional catalysis. The cooperation of hydrogen‐bonding network activation and a regiodivergent strain‐assisted effect is the key to promoting this complex chemical transformation, leading to the generation of two different ring systems in high yields with excellent stereoselectivities. The reaction proceeded by a mechanism involving a “spring‐loaded” intermediate with switchable C−C bond cleavages achieved by controllable ring‐strain release. This reaction was also amenable to gram scale synthesis with only 0.1 mol % catalyst loading.
Optimal Destabilization of DNA Double Strands by Single‐Nucleobase Caging
Authors: Seyfried Patrick , Heinz Marcel , Pintér György , Klötzner Dean‐Paulos , Becker Yvonne , Bolte Michael , Jonker Hendrik R. A. , Stelzl Lukas S. , Hummer Gerhard , Schwalbe Harald , Heckel Alexander 
Published: September 2018

AbstractPhotolabile protecting groups are widely used to trigger oligonucleotide activity. The ON/OFF‐amplitude is a critical parameter. An experimental setup has been developed to identify protecting group derivatives with superior caging properties. Bulky rests are attached to the cage moiety via Cu‐catalyzed azide–alkyne cycloaddition post‐synthetically on DNA. Interestingly, the decrease in melting temperature upon introducing o‐nitrobenzyl‐caged (NPBY‐) and diethylaminocoumarin‐cages (DEACM‐) in DNA duplexes reaches a limiting value. NMR spectroscopy was used to characterize individual base‐pair stabilities and determine experimental structures of a selected number of photocaged DNA molecules. The experimental structures agree well with structures predicted by MD simulations. Combined, the structural data indicate that once a sterically demanding group is added to generate a tri‐substituted carbon, the sterically less demanding cage moiety points towards the neighboring nucleoside and the bulkier substituents remain in the major groove.
The Dawn of Functional Organoarsenic Chemistry
Authors: Imoto Hiroaki , Naka Kensuke 
Published: September 2018

AbstractOrganoarsenic chemistry was actively studied until the middle of 20th century. Although various properties of organoarsenic compounds have been computationally predicted, for example, frontier orbital levels, aromaticity, and inversion energies, serious concern to the danger of their synthetic processes has restricted experimental studies. Conventional synthetic routes require volatile and toxic arsenic precursors. Recently, nonvolatile intermediate transformation (NIT) methods have been developed to safely access functional organoarsenic compounds. Important intermediates in the NIT methods are cyclooligoarsines, which are prepared from nonvolatile inorganic precursors. In particular, the new approach has realized experimental studies on conjugated arsenic compounds: arsole derivatives. The elucidation of their intrinsic properties has triggered studies on functional organoarsenic chemistry. As a result, various kinds of arsenic‐containing π‐conjugated molecules and polymers have been reported for the last few years. In this minireview, progress of this recently invigorated field is overviewed.
Absolute configurations of chiral molecules with multiple stereogenic centers without prior knowledge of the relative configurations: A case study of inuloxin C
Authors: Johnson Jordan L. , Raghavan Vijay , Cimmino Alessio , Moeini Arash , Petrovic Ana G. , Santoro Ernesto , Superchi Stefano , Berova Nina , Evidente Antonio , Polavarapu Prasad L. 
Published: September 2018

AbstractElectronic circular dichroism (ECD) and discrete wavelength resolved specific optical rotations, referred to as optical rotatory dispersion (ORD), have been remeasured for inuloxin C and analysed with corresponding quantum chemical (QC) predicted data for all diastereomers of inuloxin C. The QC‐predicted sign of ORD and of a major ECD band are found to match the experimental observations for more than one diastereomer. However, these ECD and ORD analyses combined with electronic dissymmetry factor analyses narrowed the choices of absolute configuration (AC) of inuloxin C to (5R,7S,8R,10R) and (5S,7S,8S,10S). Supplementing these analyses with corresponding analyses for acetylated inuloxin C resulted in a unique choice for the AC of inuloxin C as (5S,7S,8S,10S). This result is independent of NMR analysis. Furthermore, this AC is in full agreement with previously determined relative configuration by NMR and the AC derived therefrom using ECD and ORD. Therefore, the present study identifies a pathway for determining the ACs of chiral molecules with multiple stereogenic centers when relative configurations are not known, or when it is desired to deduce ACs independent of the known relative configurations.
Symmetrical Diamidates as a Class of Phosphate Prodrugs to Deliver the 5′‐Monophosphate Forms of Anticancer Nucleoside Analogues
Authors: Slusarczyk Magdalena , Ferrari Valentina , Serpi Michaela , Gönczy Blanka , Balzarini Jan , McGuigan Christopher 
Published: September 2018

AbstractThe application of phosphorodiamidate technology to pyrimidine and purine nucleosides with anticancer activity to potentially overcome the resistance mechanisms associated with parent nucleosides is reported. Sixteen symmetrical phosphorodiamidates were prepared from the natural amino acids l‐alanine and glycine. All the compounds were evaluated for their cytotoxic activity against a wide panel of solid and leukaemic tumour cell lines. In addition, a carboxypeptidase Y assay was performed on a representative phosphorodiamidate in order to reveal the putative bioactivation pathway for the reported phosphorodiamidate‐type prodrugs.
Inter‐ and intra‐specific differences in muscarinic acetylcholine receptor expression in the neural pathways for vocal learning in songbirds
Authors: Asogwa Norman C. , Mori Chihiro , Sánchez‐Valpuesta Miguel , Hayase Shin , Wada Kazuhiro 
Published: September 2018

AbstractAcetylcholine receptors (AChRs) abound in the central nervous system of vertebrates. Muscarinic AChRs (mAChRs), a functional subclass of AChRs, mediate neuronal responses via intracellular signal transduction. They also play roles in sensorimotor coordination and motor skill learning by enhancing cortical plasticity. Learned birdsong is a complex motor skill acquired through sensorimotor coordination during a critical period. However, the functions of AChRs in the neural circuits for vocal learning and production remain largely unexplored. Here, we report the unique expression of mAChRs subunits (chrm2–5) in the song nuclei of zebra finches. The expression of excitatory subunits (chrm3 and chrm5) was downregulated in the song nuclei compared with the surrounding brain regions. In contrast, the expression of inhibitory mAChRs (chrm2 and chrm4) was upregulated in the premotor song nucleus HVC relative to the surrounding nidopallium. Chrm4 showed developmentally different expression in HVC during the critical period. Compared with chrm4, individual differences in chrm2 expression emerged in HVC early in the critical period. These individual differences in chrm2 expression persisted despite testosterone administration or auditory deprivation, which altered the timing of song stabilization. Instead, the variability in chrm2 expression in HVC correlated with parental genetics. In addition, chrm2 expression in HVC exhibited species differences and individual variability among songbird species. These results suggest that mAChRs play an underappreciated role in the development of species and individual differences in song patterns by modulating the excitability of HVC neurons, providing a potential insight into the gating of auditory responses in HVC neurons.