bluuebunny/crossref_metadata_2025_split huggingface dataset:
Loss of Single‐Domain Function in a Modular Assembly Line Alters the Size and Shape of a Complex Polyketide
Authors: Peng Huiyun , Ishida Keishi , Hertweck Christian 
Published: October 2019

AbstractThe structural wealth of complex polyketide metabolites produced by bacteria results from intricate, highly evolved biosynthetic programs of modular assembly lines, in which the number of modules defines the size of the backbone, and the domain composition controls the degree of functionalization. We report a remarkable case where polyketide chain length and scaffold depend on the function of a single β‐keto processing domain: A ketoreductase domain represents a switch between diverging biosynthetic pathways leading either to the antifungal aureothin or to the nematicidal luteoreticulin. By a combination of heterologous expression, mutagenesis, metabolite analyses, and in vitro biotransformation we elucidate the factors governing non‐colinear polyketide assembly involving module skipping and demonstrate that a simple point mutation in type I polyketide synthase (PKS) can have a dramatic effect on the metabolic profile. This finding sheds new light on possible evolutionary scenarios and may inspire future synthetic biology approaches.
Bioactive Peptide Brush Polymers via Photoinduced Reversible‐Deactivation Radical Polymerization
Authors: Sun Hao , Choi Wonmin , Zang Nanzhi , Battistella Claudia , Thompson Matthew P. , Cao Wei , Zhou Xuhao , Forman Christopher , Gianneschi Nathan C. 
Published: October 2019

AbstractHarnessing metal‐free photoinduced reversible‐deactivation radical polymerization (photo‐RDRP) in organic and aqueous phases, we report a synthetic approach to enzyme‐responsive and pro‐apoptotic peptide brush polymers. Thermolysin‐responsive peptide‐based polymeric amphiphiles assembled into spherical micellar nanoparticles that undergo a morphology transition to worm‐like micelles upon enzyme‐triggered cleavage of coronal peptide sidechains. Moreover, pro‐apoptotic polypeptide brushes show enhanced cell uptake over individual peptide chains of the same sequence, resulting in a significant increase in cytotoxicity to cancer cells. Critically, increased grafting density of pro‐apoptotic peptides on brush polymers correlates with increased uptake efficiency and concurrently, cytotoxicity. The mild synthetic conditions afforded by photo‐RDRP, make it possible to access well‐defined peptide‐based polymer bioconjugate structures with tunable bioactivity.
Convergent Total Syntheses of (−)‐Rubriflordilactone B and (−)‐pseudo‐Rubriflordilactone B
Authors: Mohammad Mujahid , Chintalapudi Venkaiah , Carney Jeffrey M. , Mansfield Steven J. , Sanderson Pollyanna , Christensen Kirsten E. , Anderson Edward A. 
Published: October 2019

AbstractA highly convergent strategy for the synthesis of the natural product (−)‐rubriflordilactone B, and the proposed structure of (−)‐pseudo‐rubriflordilactone B, is described. Late stage coupling of diynes containing the respective natural product FG rings with a common AB ring aldehyde precedes rhodium‐catalyzed [2+2+2] alkyne cyclotrimerization to form the natural product skeleton, with the syntheses completed in just one further operation. This work resolves the uncertainty surrounding the identity of pseudo‐rubriflordilactone B and provides a robust platform for further synthetic and biological investigations.
Umpolung Strategy for α‐Functionalization of Aldehydes for the Addition of Thiols and other Nucleophiles
Authors: Blom Jakob , Reyes‐Rodríguez Gabriel J. , Tobiesen Henriette N. , Lamhauge Johannes N. , Iversen Marc V. , Barløse Casper L. , Hammer Niels , Rusbjerg Matilde , Jørgensen Karl Anker 
Published: October 2019

AbstractNucleophile–nucleophile coupling is a challenging transformation in organic chemistry. Herein we present a novel umpolung strategy for α‐functionalization of aldehydes with nucleophiles. The strategy uses organocatalytic enamine activation and quinone‐promoted oxidation to access O‐bound quinol‐intermediates that undergo nucleophilic substitution reactions. These quinol‐intermediates react with different classes of nucleophiles. The focus is on an unprecedented organocatalytic oxidative α‐thiolation of aldehydes. The reaction scope is demonstrated for a broad range of thiols and extended to chemoselective bioconjugation, and applicable to a large variety of aldehydes. This strategy can also encompass organocatalytic enantioselective coupling of α‐branched aldehydes with thiols forming quaternary thioethers. Studies indicate a stereoselective formation of the intermediate followed by a stereospecific nucleophilic substitution reaction at a quaternary stereocenter, with inversion of configuration.
The Development of Epoxidized Hemp Oil Prepolymers for the Preparation of Thermoset Networks
Authors: Omonov Tolibjon S. , Patel Vinay , Curtis Jonathan M. 
Published: October 2019

AbstractEpoxy thermosets comprised of plant oils along with simple curing agents are sustainable and environmentally friendly polymers. The curing agent selected, and its compatibility with epoxy monomers, strongly affects the curing kinetics, the extent of curing, and the final properties of an epoxy polymers. The goal of this work is to expand the application of epoxidized oils in formulating biobased thermoset polymer systems. Epoxidized hemp oil (EHO) was produced with 8% oxirane oxygen content (OOC) after 24 hours using in situ generated performic acid. Two model curing agents—one aromatic (trimellitic anhydride, TMA) and one biobased nonaromatic (citric acid, CA)—with similar molecular weights were selected to study the cure behavior of EHO in acetone. Both curing agents are insoluble in EHO. The prepolymerization curing reaction behavior was monitored via the OOC, attenuated total reflectance Fourier transform infrared (ATR‐FTIR) spectroscopy, and gel permeation chromatography. It was demonstrated that at 50 °C, the reaction of EHO with TMA was extremely fast to form esters of TMA, while the reaction of EHO with CA was slower and followed different pathways. The cured EHO/TMA epoxy network is rigid and has a high alpha relaxation temperature (T
α) of 89 °C, which is associated with the glass transition temperature (T
g), while the cured EHO/CA network system is semirigid with a T
α of 40 °C. In addition, TGA analysis showed that the EHO/TMA resin system represents a more homogenous structure compared to the EHO/CA system, as indicated by the presence of lower‐temperature decompositions of citric acid derivatives.
Inverse identification of viscosity coefficient for Newtonian and non‐Newtonian slurries during the turbulent pipeline transportation
Authors: Zhang Ji , Yuan Han , Cheng Liang , Mei Ning , Yan Zhe 
Published: October 2019

AbstractSlurry viscosity is an important parameter that can be used for slurry characterization and pipeline design. This study proposed an inversion method to identify the viscosity coefficient of slurries in turbulent pipeline flow. An inverse heat convection problem with unknown viscosity for Newtonian and non‐Newtonian slurries was solved in a fully developed turbulent pipe flow, and a modified mixing length theory in the turbulent model was applied to improve the estimation accuracy. Through the inversion calculation, the viscosity coefficient was obtained by temperature profile at several measurement positions. An experimental setup was established, and several experiments were conducted to verify the viscosity estimations for slurry flow in this study. The results showed that the method was reliable for identifying the slurry viscosities in the turbulent state and the modified mixing length model can effectively improve the inversion accuracy. This method provided an effective way to detect the rheological properties for determining the operation mode of turbulent slurry pipelines.
Estimating and Controlling the Renewable Microgrid States Using IoT Infrastructure
Authors: Rana Md Masud , Bo Rui , Chen Haotian 
Published: October 2019

AbstractThis paper considers the optimal filter design issue for microgrid state estimation and stabilisation under packet loss conditions. The considered internet of things (IoT) technologies collect system state information from sensors and send control messages to actuators where they are connected over a lossy communication network. From signal processing point of view, this paper develops an optimal state estimation algorithm using the mean squared error principle. Then a feedback controller is designed under the condition of packet dropouts in the communication network. Finally, the convergence of the developed algorithm is numerically shown. The performance of the proposed schemes are demonstrated using the renewable microgrid.
Phase II randomized clinical trial of endosonography and PET/CT versus clinical assessment only for follow-up after surgery for upper gastrointestinal cancer (EUFURO study)
Authors: Bjerring O S , Fristrup C W , Pfeiffer P , Lundell L , Mortensen M B 
Published: October 2019

Abstract

Background
Upper gastrointestinal malignancies have a poor prognosis. There is no consensus on how patients should be followed after surgery. The authors hypothesized that a structured follow-up programme including endoscopic ultrasonography (EUS) and [18F]fluorodeoxyglucose (FDG) PET/CT would detect cancer recurrences, leading to more patients being eligible for therapy.

Methods
After surgery with curative intent for adenocarcinomas in the gastro-oesophageal junction, stomach or pancreas, patients were randomized 1 : 1 to standard clinical assessment in the outpatient clinic at 3, 6, 9, 12, 18 and 24 months after operation, or clinical assessment plus imaging including [18F]FDG PET/CT and EUS. The primary endpoint was number of patients receiving oncological treatment for recurrence. Secondary endpoints were overall and progression-free survival, survival after recurrence detection of isolated locoregional recurrences and risk factors affecting survival.

Results
In total, 183 patients were enrolled, including 93 who underwent standard follow-up and 90 who had follow-up plus imaging. A recurrence was detected in 84 patients within 2 years after surgery (42 in each group), including 33 of 42 patients in the imaging group who were asymptomatic. Some 25 of 42 patients in the imaging group and 14 of 42 in the standard group received chemotherapy (P = 0·028). Although survival after detection of recurrence in asymptomatic patients was significantly longer than that for symptomatic patients (P &lt; 0·001), overall survival from date of surgery in the two treatment groups was comparable.

Conclusion
Follow-up after surgery for upper gastrointestinal cancer with EUS and PET/CT leads to detection of more asymptomatic cancer recurrences and patients referred for treatment without prolonging overall survival. Registration number: NCT02209415 (http://www.clinicaltrials.gov).
Association of statin use with risk of Gleason score‐specific prostate cancer: A hospital‐based cohort study
Authors: Wang Kai , Gerke Travis A. , Chen Xinguang , Prosperi Mattia 
Published: October 2019

AbstractBackgroundConflicting evidence suggests that statins act chemopreventively against prostate cancer (PCa). Whether the association of statin use with PCa risk is Gleason score‐dependent, time‐, dose‐respondent is not well studied.MethodsWe conducted a cohort study at a tertiary hospital in the Southeastern US using longitudinal data of electronic medical records (EMR) from 1994 to 2016. Only cancer‐free men aged >18 years at baseline with follow‐up time of ≥12 months were included. Time‐dependent Cox proportional hazards regression was used to estimate adjusted hazard ratios (aHRs) with 95% confidence intervals (CIs).ResultsAmong 13 065 men, 2976 were diagnosed with PCa over median follow‐up of 6.6 years. Statin use was associated with lower risk of both Gleason low‐ (score <7: aHR, 0.85; 95% CI, 0.74‐0.96) and high‐grade PCa (score ≥7: aHR, 0.54; 95% CI, 0.42‐0.69). The protective association was observed only when statins had been used for a relatively longer duration (≥11 months) or higher dose (≥121 defined daily doses), and were more pronounced for PCa of higher Gleason score (<7: aHR, 0.85, 95% CI, 0.74‐0.96; 7 [3 + 4]: aHR, 0.62, 95% CI, 0.43‐0.90; 7 [4 + 3]: aHR, 0.49, 95% CI, 0.29‐0.82; 8: aHR, 0.60, 95% CI, 0.37‐0.96; 9‐10: aHR, 0.24, 95% CI, 0.11‐0.54). Lipophilic statins (aHR, 0.83; 95% CI, 0.72‐0.95) might be more protective than hydrophilic statins (aHR, 0.91, 95% CI, 0.63‐1.33) against PCa.ConclusionStatin use might be associated with reduced PCa risk only when used for a relatively longer duration, and the risk reduction was higher for PCa of higher Gleason score.
A prospective clinical trial of the second‐look procedure for transoral surgery in patients with T1 and T2 laryngeal, oropharyngeal, and hypopharyngeal cancer
Authors: Nishimura Goshi , Sano Daisuke , Arai Yasuhiro , Hatano Takashi , Takahashi Hideaki , Tanabe Teruhiko , Wada Takashi , Morishita Daiki , Oridate Nobuhiko 
Published: October 2019

AbstractBackgroundTransoral surgery (TOS) has been widely applied for early T‐stage head and neck cancer (HNC). The resection is performed with a minimum safety margin for function preservation under a limited surgical field; therefore, it is difficult to have a strong conviction about the complete resection. This study aims to evaluate the completeness of the initial TOS procedure; possibility of primary control by TOS alone; and predictive factors in patients with early T‐stage laryngeal, oropharyngeal, and hypopharyngeal cancer.MethodsPatients were treated by TOS at the primary site with or without neck dissection. The patients were divided into two groups based on the pathological evaluation of their surgical specimens: the control (observation) group, in that the resection was considered complete and the intervention (second‐look procedure) group, in that incomplete tumor resection was suspected. The predictive factors for the possibility and/or limitations of complete resection by TOS were then analyzed.ResultsThe study enrolled 26 and 25 patients in the control and intervention group, respectively. The success rate for single resection was 66% and the predictive factor was tumor depth obtained by enhanced computed tomography (CT) examination (odds ratio, 7.870, P = .0243). The success rate for definitive therapy by TOS alone was 83% and the predictive factor was poor differentiation observed on pathological examination (odds ratio, 6.800, P = .0248).ConclusionsTOS has the potential for both definitive resection and function preservation with minimal invasiveness. Identification of the risk factors for TOS is advantageous for accurate treatment selection in patients with early T‐stage HNC.
Nachweis des Feuerwiderstands von Ziegelmauerwerk – Tipps für eine effiziente Bemessung
Authors: Graubner Carl‐Alexander , Purkert Benjamin 
Published: October 2019

AbstractIn Germany, structural fire design of masonry is carried out in a simplified way using tabulated minimum wall thicknesses depending on the loading level in fire. Against this background the procedure of structural fire design is shown briefly before two approaches for a more efficient verification of the fire resistance are explained. The first possibility is to determine the reduction factor for the design value of the actions in fire more precisely and thereby reduce the loading level. Secondly, a design methodology is presented which can be applied in case of masonry walls with low vertical load but a large load eccentricity at mid‐height of the wall. Finally, the verification of the fire resistance of masonry according to national technical approval is discussed with an explanation how to obtain the same loading level in fire if the design is based on DIN EN 1996‐3/NA as when it is based on DIN EN 1996‐1‐1/NA.
Experimentelle Traglastermittlung einer teilweise bewehrten Lochfassade aus Ziegelmauerwerk
Authors: Förster Valentin , Graubner Carl‐Alexander , Proske Tilo 
Published: October 2019

AbstractFor a new multi‐storey car park over the Central Bus Station (ZOB) in Kiel, a perforated clinker brick veneer facade not conforming to standards was planned. The design and technical characteristics of the facade have already been described in the article by Medzech and Schrade in this issue [1]. This article deals with the experimental investigations carried out to obtain a project‐related one‐off approval (ZiE). These experiments contain in particular large tests on storey‐height wall sections, which were subjected to eccentric compressive loading and partly to horizontal loads representing wind action. Supplementary small tests on unreinforced and reinforced masonry served to determine the bending capacity, the anchoring capacity of the reinforcement and the load‐bearing capacity of the wall anchors in the masonry. Due to the special facade construction with special bricks for the project, wall anchors, reinforcement bar couplers and unique test set‐ups had to be developed for the specific project.
Parkhaus ZOB Kiel: Eine gelochte Mauerwerksfassade für den Zentralen Omnibusbahnhof
Authors: Medzech Jürgen , Schrade Holger 
Published: October 2019

AbstractOn the occasion of the Olympic sailing competitions in Kiel, the ZOB and the multi‐storey car park above it were built in 1972.The two‐storey multi‐storey car park, equipped for about 560 parking spaces, was originally connected to the railway station quay, the main railway station and the city centre by three pedestrian bridges. These bridges were demolished over the years. The new construction of the Atlantic Hotel in 2009 made it necessary to partially demolish the multi‐storey car park and the ZOB. At the same time, preparations began for the redesign of the remaining ZOB site.However, the original idea of renovating the building, which had been reduced in size by the construction of the new hotel, and additionally increasing it by two parking levels, was rejected.The poor structural condition and the planning of a new attractive bus station ultimately required demolition.In the new planning of the ZOB, two construction sites were defined. The design for the new multi‐storey car park on construction site 2 took into account the specifications for the number of storeys, the spacing areas, the maximum eaves height and the materials used in the neighbouring buildings as an independent building.The rounding of the facade at Stresemannplatz gives passers‐by coming from the west a clearer view of the harbour. The spindle, which is raised above the 6th floor, serves as a recognizable point visible from afar.
Microclimate predicts frost hardiness of alpineArabidopsis thalianapopulations better than elevation
Authors: Lampei Christian , Wunder Jörg , Wilhalm Thomas , Schmid Karl J. 
Published: October 2019

AbstractIn mountain regions, topological differences on the microscale can strongly affect microclimate and may counteract the average effects of elevation, such as decreasing temperatures. While these interactions are well understood, their effect on plant adaptation is understudied.We investigated winter frost hardiness ofArabidopsis thalianaaccessions originating from 13 sites along altitudinal gradients in the Southern Alps during three winters on an experimental field station on the Swabian Jura and compared levels of frost damage with the observed number of frost days and the lowest temperature in eight collection sites.We found that frost hardiness increased with elevation in a log‐linear fashion. This is consistent with adaptation to a higher frequency of frost conditions, but also indicates a decreasing rate of change in frost hardiness with increasing elevation. Moreover, the number of frost days measured with temperature loggers at the collection sites correlated much better with frost hardiness than the elevation of collection sites, suggesting that populations were adapted to their local microclimate. Notably, the variance in frost days across sites increased exponentially with elevation. Together, our results suggest that strong microclimate heterogeneity of high alpine environments can preserve functional genetic diversity among small populations.Synthesis: Here, we tested how plant populations differed in their adaptation to frost exposure along an elevation gradient and whether microsite temperatures improve the prediction of frost hardiness. We found that local temperatures, particularly the number of frost days, are a better predictor of the frost hardiness of plants than elevation. This reflects a substantial variance in frost frequency between sites at similar high elevations. We conclude that high mountain regions harbor microsites that differ in their local microclimate and thereby can preserve a high functional genetic diversity among them. Therefore, high mountain regions have the potential to function as a refugium in times of global change.
Glucose Electro‐oxidation on Graphite Electrode Modified with Nickel/Chromium Nanoparticles
Authors: Kiani Azadeh , Ghaffarinejad Ali , Abolfazl Seyedsadjadi Seyed , Mansouri Atiyeh 
Published: October 2019

AbstractIn this study, an available and inexpensive graphite substrate, was easily modified with Ni/Cr nanoparticles via electrodeposition technique in a very short time (3 min) and used as an electrocatalyst for glucose oxidation in alkaline solution. Graphite electrode modified with Ni/Cr nanoparticles demonstrated an outstanding electrocatalytic performance to glucose oxidation in comparison to examined Ni‐based electrodes or even different materials in other reports. It is noteworthy to mention that adding a little Cr led to a synergistic effect with Ni; accordingly, the presence of Cr not only resulted in a greater adsorption of glucose molecules by chromium oxide but also boosted conductivity of the nickel oxide because of the enhancement of Ni(III) amount. The electrochemical studies were performed by cyclic voltammetry and electrochemical impedance spectroscopy (EIS). The morphology and structure of catalyst layer was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X‐ray diffraction (XRD) and energy dispersive x‐ray spectroscopy (EDS). The linear range of the electrode by cyclic voltammetry was between 2–31 mM with a high sensitivity of 2094 μA cm−2 mM−1. The repeatability and reproducibility of the proposed electrode was examined in glucose solution which were 0.3 % and 4.7 %, respectively. According to the low cost, ease and fast preparation, good repeatability and high sensitivity, this electrode can be a good candidate for nonenzymatic glucose oxidation.
Pattern Recognition of Amino Acids in Wines
Authors: Cioates Negut Catalina , Stefan‐van Staden Raluca‐Ioana , Harja Florian , van Staden Jacobus Frederick 
Published: October 2019

AbstractNew synthesized fatty acid amides (N‐(2‐(piperidin‐1‐yl)ethyl)oleamide, and N‐(2‐(pyrrolidin‐1‐yl)ethyl)oleamide) were used for the design of stochastic sensors based on nanographene paste. The stochastic sensors were used for pattern recognition of four amino acids: L‐histidine, L‐tyrosine, L‐ornithine, and L‐lysine in wines. The pattern recognition was performed based on the signatures recorded for each of the amino acids. The limits of determination allow the assay of amino acids in wine at very low concentrations faster, reliable, and more cost effective than other methods proposed to date.