bluuebunny/crossref_metadata_2025_split huggingface dataset:
Anwendung von Mediumeffekten in Aktivierungs‐ und Deaktivierungsstrategien zur selektiven Funktionalisierung aliphatischer C‐H‐Bindungen
Authors: Bietti Massimo 
Published: June 2018

AbstractDie selektive Funktionalisierung nichtaktivierter aliphatischer C‐H‐Bindungen ist ein wichtiges Ziel der modernen Synthesechemie. Jedoch stellt die hochselektive Unterscheidung zwischen Bindungen in organischen Molekülen eine entscheidende Herausforderung dar, und ein tiefgreifendes Verständnis der selbst geringsten Reaktivitätstrends ist unerlässlich. Von den dafür entwickelten Methoden fanden Ansätze basierend auf Wasserstoffatomtransfer (HAT) besonderes Interesse. Dabei wurden Effekte von Reaktionsmedien erfolgreich zur Veränderung der Reaktivität und Regioselektivität in synthetisch bedeutenden C‐H‐Funktionalisierungreaktionen genutzt. In diesem Aufsatz werden die mechanistischen Besonderheiten dieser verfügbaren Strategien diskutiert. Es wird gezeigt, dass Wasserstoffbrücken und Säure‐Base‐Wechselwirkungen die Aktivierung oder Deaktivierung von C‐H‐Bindungen für HAT‐Reagenzien begünstigen und damit zur Feineinstellung von Regioselektivität und Chemoselektivität sowie als Orientierung für zukünftige Entwicklungen und Anwendungen genutzt werden können.
A Ratiometric Two‐Photon Fluorescent Probe for Tracking Lysosomal ATP: Direct In Cellulo Observation of Lysosomal Membrane Fusion Processes
Authors: Jun Yong Woong , Wang Taejun , Hwang Sekyu , Kim Dokyoung , Ma Donghee , Kim Ki Hean , Kim Sungjee , Jung Junyang , Ahn Kyo Han 
Published: June 2018

AbstractVesicles exchange their contents through membrane fusion processes, kiss‐and‐run and full‐collapse fusion. Indirect observation of these fusion processes using artificial vesicles enhanced our understanding on the molecular mechanisms involved. Direct observation of the fusion processes in a real biological system, however, remains a challenge owing to many technical obstacles. We report a ratiometric two‐photon probe offering real‐time tracking of lysosomal ATP with quantitative information for the first time. By applying the probe to two‐photon live‐cell imaging, the lysosomal membrane fusion process in cells has been directly observed and the concentration of its content, lysosomal ATP, has been measured. Results show that the kiss‐and‐run process between lysosomes proceeds through repeated transient interactions with gradual content mixing, whereas the full‐fusion process occurs at once. Furthermore, it is confirmed that both the fusion processes proceed with conservation of the content. Such a small‐molecule probe exerts minimal disturbance and hence has potential for studying various biological processes associated with lysosomal ATP.
An Unusual Intramolecular Halogen Bond Guides Conformational Selection
Authors: Tesch Roberta , Becker Christian , Müller Matthias Philipp , Beck Michael Edmund , Quambusch Lena , Getlik Matthäus , Lategahn Jonas , Uhlenbrock Niklas , Costa Fanny Nascimento , Polêto Marcelo D. , Pinheiro Pedro de Sena Murteira , Rodrigues Daniel Alencar , Sant'Anna Carlos Mauricio R. , Ferreira Fabio Furlan , Verli Hugo , Fraga Carlos Alberto Manssour , Rauh Daniel 
Published: June 2018

AbstractPIK‐75 is a phosphoinositide‐3‐kinase (PI3K) α‐isoform‐selective inhibitor with high potency. Although published structure–activity relationship data show the importance of the NO2 and the Br substituents in PIK‐75, none of the published studies could correctly determine the underlying reason for their importance. In this publication, we report the first X‐ray crystal structure of PIK‐75 in complex with the kinase GSK‐3β. The structure shows an unusual U‐shaped conformation of PIK‐75 within the active site of GSK‐3β that is likely stabilized by an atypical intramolecular Br⋅⋅⋅NO2 halogen bond. NMR and MD simulations show that this conformation presumably also exists in solution and leads to a binding‐competent preorganization of the PIK‐75 molecule, thus explaining its high potency. We therefore suggest that the site‐specific incorporation of halogen bonds could be generally used to design conformationally restricted bioactive substances with increased potencies.
Investigation of the Effects of Virgin Olive Oil Cleaning Systems on the Secoiridoid Aglycone Content Using High Performance Liquid Chromatography–Mass Spectrometry
Authors: Pascale Raffaella , Bianco Giuliana , Cataldi Tommaso R. I. , Buchicchio Alessandro , Losito Ilario , Altieri Giuseppe , Genovese Francesco , Tauriello Antonella , Di Renzo Giovanni C. , Lafiosca Maria C. 
Published: June 2018

AbstractPhenolic compounds are useful markers to control olive oil technological processes, including the virgin olive oil (VOO)/water separation after olive oil extraction. In this investigation, VOO extracted from olives of cv. Coratina using a mild oil/water separator called the hydrocyclone sedimentation system (Hydroil) was compared with VOO obtained using a conventional vertical centrifuge separator (Cenoil), which is mostly used in the modern olive oil industry. Secoiridoid aglycones were selected, among phenolic compounds, as markers and analyzed using reversed‐phase liquid chromatography coupled to linear quadrupole ion‐trap mass spectrometry with electrospray ionization in the negative mode. VOO samples obtained using the Hydroil system were found to contain significantly higher levels of secoiridoid aglycones, compared to the Cenoyl‐type samples. In particular, the total content of the aglycones of decarboxymethyl oleuropein, decarboxymethyl ligstroside, ligstroside, and oleuropein, expressed in terms of oleuropein, was estimated as 35.40 ± 0.80 mg kg−1, compared to 8.06 ± 0.41 mg kg−1 in the Cenoil samples (n = 3). Since no significant difference in residual water (P < 0.05) was found between the two types of VOO samples, the higher amount of secoiridoids obtained for Hydroil‐type ones was explained by the lower extent of oxidation occurring during the mild oil/water separation achieved using the Hydroil system.
Molecular characterization of a typical 2‐Cys thioredoxin peroxidase from the Asiatic rice borer Chilo suppressalis and its role in oxidative stress
Authors: Cao Ye , Yang Qing , Tu Xiao‐Hui , Li Shi‐Guang , Liu Su 
Published: June 2018

AbstractIn insects, thioredoxin peroxidase (TPX) plays an important role in protecting against oxidative damage. However, studies on the molecular characteristics of TPXs in the Asiatic rice borer, Chilo suppressalis, are limited. In this work, a cDNA sequence (CsTpx3) encoding a TPX was identified from C. suppressalis. The deduced CsTPX3 protein shares high sequence identity and two positionally conserved cysteines with orthologs from other insect species, and was classified as a typical 2‐Cys TPX. CsTpx3 was expressed most highly during the fifth‐instar larval stage, and transcripts were most abundant in the midgut. Recombinant CsTPX3 protein expressed in Escherichia coli displayed the expected peroxidase activity by removing H2O2. Furthermore, CsTPX3 protected DNA from oxidative damage, and E. coli cells overexpressing CsTPX3 exhibited long‐term resistance to oxidative stress. Exposure to various oxidative stressors, such as cold (8°C), heat (35°C), bacteria (E. coli), and two insecticides (chlorpyrifos and lambda‐cyhalothrin), significantly upregulated transcription of CsTpx3. However, exposure to abamectin had no such effect. Our results provide valuable information for future studies on the antioxidant mechanism in this insect species.
Modeling vehicle traffic loads by the 2D compound Poisson process
Authors: Liu Yang , Li Deru , Li Yingqiu , Zhang Haiping 
Published: June 2018

AbstractVehicular loads are an important factor in the fatigue and deterioration of bridges. In this paper, using weight‐in‐motion data from the Nanxi Yangtze river bridge, we propose a novel two‐dimensional (2D) compound Poisson process model of vehicle loads. This model considers the relations between vehicle loads, including vehicle speed and weight, whereby the relationships between these two marginal processes are described by a 2D Lévy copula function. Vehicle loads simulated by the proposed model were then compared with measured vehicle loads. The results show that histograms for vehicle loads simulated by the proposed model are similar to those generated for the measured vehicle loads. Moreover, the theoretical probabilities of vehicle loads are close in value to the empirical probabilities of vehicle loads. In addition, a two‐sample Kolmogorov‐Smirnov test at the significance level of 1% is given, which yields asymptotic p‐values of 3.2966 × 10−4 for vehicle speed and 3.0489 × 10−10 for vehicle weight. These values confirm that the proposed 2D compound Poisson process model is suitable for estimating vehicle loads.
Reconstruction of 24 Penicillium genome‐scale metabolic models shows diversity based on their secondary metabolism
Authors: Prigent Sylvain , Nielsen Jens C. , Frisvad Jens C. , Nielsen Jens 
Published: June 2018

AbstractModeling of metabolism at the genome‐scale has proved to be an efficient method for explaining the phenotypic traits observed in living organisms. Further, it can be used as a means of predicting the effect of genetic modifications for example, development of microbial cell factories. With the increasing amount of genome sequencing data available, there exists a need to accurately and efficiently generate such genome‐scale metabolic models (GEMs) of nonmodel organisms, for which data is sparse. In this study, we present an automatic reconstruction approach applied to 24 Penicillium species, which have potential for production of pharmaceutical secondary metabolites or use in the manufacturing of food products, such as cheeses. The models were based on the MetaCyc database and a previously published Penicillium GEM and gave rise to comprehensive genome‐scale metabolic descriptions. The models proved that while central carbon metabolism is highly conserved, secondary metabolic pathways represent the main diversity among species. The automatic reconstruction approach presented in this study can be applied to generate GEMs of other understudied organisms, and the developed GEMs are a useful resource for the study of Penicillium metabolism, for example, for the scope of developing novel cell factories.
Milligram scale production of potent recombinant small interfering RNAs in Escherichia coli
Authors: Kaur Guneet , Cheung Hung‐Chi , Xu Wei , Wong Jun Vic , Chan For Fan , Li Yingxue , McReynolds Larry , Huang Linfeng 
Published: June 2018

AbstractSmall interfering RNAs (siRNAs) are invaluable research tools for studying gene functions in mammalian cells. siRNAs are mainly produced by chemical synthesis or by enzymatic digestion of double‐stranded RNA (dsRNA) produced in vitro. Recently, bacterial cells, engineered with ectopic plant viral siRNA binding protein p19, have enabled the production of “recombinant” siRNAs (pro‐siRNAs). Here, we describe an optimized methodology for the production of milligram amount of highly potent recombinant pro‐siRNAs from Escherichia coli cells. We first optimized bacterial culture medium and tested new designs of pro‐siRNA production plasmid. Through the exploration of multiple pro‐siRNA related factors, including the expression of p19 protein, (dsRNA) generation method, and the level of RNase III, we developed an optimal pro‐siRNA production plasmid. Together with a high–cell density fed‐batch fermentation method in a bioreactor, we have achieved a yield of ~10 mg purified pro‐siRNA per liter of bacterial culture. The pro‐siRNAs produced by the optimized method can achieve high efficiency of gene silencing when used at low nanomolar concentrations. This new method enables fast, economical, and renewable production of pure and highly potent bioengineered pro‐siRNAs at the milligram level. Our study also provides important insights into the strategies for optimizing the production of RNA products in bacteria, which is an under‐explored field.
Evaluation of encapsulating and microporous nondegradable hydrogel scaffold designs on islet engraftment in rodent models of diabetes
Authors: Rios Peter D. , Skoumal Michael , Liu Jeffrey , Youngblood Richard , Kniazeva Ekaterina , Garcia Andrés J. , Shea Lonnie D. 
Published: June 2018

AbstractIslet transplantation is a promising therapeutic option for type 1 diabetes mellitus, yet the current delivery into the hepatic portal vasculature is limited by poor engraftment. Biomaterials have been used as a means to promote engraftment and function at extrahepatic sites, with strategies being categorized as encapsulation or microporous scaffolds that can either isolate or integrate islets with the host tissue, respectively. Although these approaches are typically studied separately using distinct material platforms, herein, we developed nondegradable polyethylene glycol (PEG)‐based hydrogels for islet encapsulation or as microporous scaffolds for islet seeding to compare the initial engraftment and function of islets in syngeneic diabetic mice. Normoglycemia was restored with transplantation of islets within either encapsulating or microporous hydrogels containing 700 islet equivalents (IEQ), with transplantation on microporous hydrogels producing lower blood glucose levels at earlier times. A glucose challenge test at 1 month after transplant indicated that encapsulated islets had a delay in glucose‐stimulated insulin secretion, whereas microporous hydrogels restored normoglycemia in times consistent with native pancreata. Encapsulated islets remained isolated from the host tissue, whereas the microporous scaffolds allowed for revascularization of the islets after transplant. Finally, we compared the inflammatory response after transplantation for the two systems and noted that microporous hydrogels had a substantially increased presence of neutrophils. Collectively, these findings suggest that both encapsulation and microporous PEG scaffold designs allow for stable engraftment of syngeneic islets and the ability to restore normoglycemia, yet the architecture influences islet function and responsiveness after transplantation.
Meta-analysis of the oncological safety of autologous fat transfer after breast cancer
Authors: Krastev T K , Schop S J , Hommes J , Piatkowski A A , Heuts E M , van der Hulst R R W J 
Published: June 2018

Abstract

Background
Autologous fat transfer, also known as lipofilling, is a minimally invasive technique that uses the patient's own fat to correct disfiguring sequelae after breast cancer surgery. Despite its obvious clinical benefits, experimental research has demonstrated that autologous fat transfer inherently stimulates angiogenesis and tissue regeneration, which is feared to increase the risk of locoregional recurrence of breast cancer. This meta-analysis is founded on recently completed large cohort studies on this highly relevant topic.

Methods
A literature search was performed in PubMed, Embase and the Cochrane Library on 1 September 2017, adhering to the PRISMA guidelines, to identify all relevant studies of patients with breast cancer exposed to autologous fat transfer. The difference in incidence rate of locoregional recurrence between patients who had autologous fat transfer and controls was the primary outcome in the meta-analysis.

Results
Fifty-nine studies and a total of 4292 patients were included. These consisted of seven matched cohorts, 12 cohorts and 40 case series. Mean follow-up was 5·7 years from the date of primary cancer surgery and 2·7 years after autologous fat transfer. Meta-analysis of matched cohorts revealed an incidence rate difference of –0·15 (95 per cent c.i. –0·36 to 0·07) per cent per year, which was not statistically significant (P = 0·419). This finding was confirmed in the pooled results of the remaining cohorts and case series.

Conclusion
This meta-analysis of all oncological data from the published literature demonstrated that autologous fat transfer did not result in an increased rate of locoregional recurrence in patients with breast cancer. Autologous fat transfer can therefore be performed safely in breast reconstruction after breast cancer.
Hippocampal involvement in nonpathological déjà vu: Subfield vulnerability rather than temporal lobe epilepsy equivalent
Authors: Pešlová Eva , Mareček Radek , Shaw Daniel J. , Kašpárek Tomáš , Pail Martin , Brázdil Milan 
Published: June 2018

AbstractIntroductionMorphological correlates of nonpathological déjà vu (DV) have been identified recently within the human brain. Significantly reduced gray matter volume (GMV) within a set of cortical and subcortical regions reported in subjects experiencing DV seems to mirror the distribution of GMV reduction in mesial temporal lobe epilepsy (MTLE) patients but vary in terms of the hippocampus. Another condition associated with hippocampal GMV reduction and DV alike disturbance in memory processing is schizophrenia (SCH). Here, we tested the hypothesis that hippocampal involvement in nonpathological DV resembles more closely the pattern of GMV decrease observed in MTLE compared with that occurring in SCH.MethodsUsing automated segmentation of the MRI data we compared the medians of GMV within 12 specific hippocampal subfields in healthy individuals that do (DV+; N = 87) and do not report déjà vu experience (DV−; N = 26), and patients with MTLE (N = 47) and SCH (N = 29). By Pearson correlation, we then evaluated the similarity of MTLE and SCH groups to DV+ group with respect to spatial distribution of GMV deviation from DV− group.ResultsSignificant GMV decrease was found in MTLE group in most of the subfields. There were just trends in the hippocampal GMV decrease found in DV+ or SCH groups. Concerning the spatial distribution of GMV decrease, we revealed statistically significant correlation for the left hippocampus for SCH vs DV+. Otherwise there was no statistically significant correlation.ConclusionsOur findings reveal structural features of hippocampal involvement in nonpathological DV, MTLE, and SCH. Despite our expectations, the pattern of GMV reduction in the DV+ relative to the DV− group does not resemble the pattern observed in MTLE any more than that observed in SCH. The highly similar patterns of the three clinical groups rather suggest an increased vulnerability of certain hippocampal subfields; namely, Cornu Ammonis (CA)4, CA3, dentate gyrus granular cell layer (GC‐DG), hippocampal–amygdaloid transition area (HATA) and subiculum.
Phytochemical, Free Radical Scavenging and Antifungal Profile of Cuscuta campestrisYunck. Seeds
Authors: Jakovljević Violeta D. , Vrvić Miroslav M. , Vrbničanin Sava , Sarić‐Krsmanović Marija 
Published: June 2018

This work was conceptualized with the goal to investigate the phytochemical, free radical scavenging and antifungal profile of Cuscuta campestrisYunck. seeds. Total phenolics, amino acid and carbohydrate contents were evaluated in ethanolic, acetone and chloroform extract. Effective antioxidant activity was evaluated throughout seven antioxidant methods. The antifungal activity was assessed against eight fungal strains and Candida albicans. The results showed total phenol, flavonoid, flavonols and phenolic acids contents in amount of 1.51 – 6.35 mg GAE/mL, 78 – 425 μg RU/mL, 1.04 – 2.98 mg QU/g and 12.01 – 30.58 μg CAE/mL, respectively. The total amino acids and carbohydrates content ranged from 8.29 to 185.45 μg Gly/mL and from 0.05 to 0.12 μg Glu/mL. The ethanolic extract showed the best antioxidant activity in phosphomolybdenum, DPPH free radical scavenging, ferric reducing power and lipid peroxidation assays. The best activity in ferrous ion chelating and H2O2 assays had the acetone extract, whereas the best hydroxyl radical scavenging activity was observed with the chloroform extract. The ethanolic extract at a concentration of 6 mg/mL proved to be the most effective antimycotic, since it inhibited the growth of all tested fungi except Penicillium verrucosum. The obtained results indicate that C. campestris seeds could be attributed to a potential source of natural antioxidants in food and pharmaceutical products.
Understanding faculty training in competency‐based curriculum development
Authors: Echols Diana Gilmer , Neely Patricia W. , Dusick Diane 
Published: June 2018

BackgroundCompetency‐based (CBE) programs have increased significantly over the past decade in response to a changing higher education environment. This dramatic increase in CBE programs has been supported by faculty tasked with developing curriculum composed of competency statements, assessment strategies, and learning content. Yet, little is known about the types of training and support provided to faculty and faculty‐perceived levels of competence in CBE curriculum development.MethodsThis study used a convenience sample to gather survey data from 70 faculty members who had developed CBE curriculum. Participants provided information on the CBE components developed, types of training received, and hours spent in training. Each faculty member also identified his or her perceived level of competence in content development, assessment development, collaboration skills, technical skills, and communication skills. A correlation analysis was used to compare training histories with perceived levels of competence in the five skill areas identified.FindingsResults suggest that the type of training a faculty member receives affects his or her perceived levels of confidence in CBE curriculum development skills. A significant relationship between total hours of training and level of competence was indicated with four types of training: one‐on‐one training with an expert, webinars, phone conferences, and self‐study.ConclusionThe most important conclusion is the result of the final hypothesis: there is a significant positive relationship between motivating students (faculty) to engage and level of competence. Both student (faculty) retention and success are related to higher levels of engagement (Tools for teaching, 2nd ed. San Francisco, CA: John Wiley & Sons, Inc; 2009).
Cobalt/Carbon Nanocomposite as Oxygen Evolution Reaction Electrocatalyst
Authors: Biegun Marcin , Chen Xuecheng , Mijowska Ewa 
Published: June 2018

AbstractElectrocatalysts based on cobalt are promising catalytic materials for water electrolysis. In this work, We reported a catalyst composed of cobalt nanoparticles embeded in a carbon lattice through synthesis with a cationic polymer (PEI) and carbonization process at three temperatures (800, 900 and 1000 °C). The material obtained at 1000 °C showed the highest activity towards the oxygen evolution reaction (OER) in an alkaline medium (1 M KOH). Moreover, the OER overpotential required to reach 10 mA cm−2 of 296 mV, was lower than for the commercial RuO2 catalyst. Further, the material also exhibited very good stability in a long‐term stability test at 10 mA cm−2.
Surface Adsorption of Polyethylene Glycol to Suppress Dendrite Formation on Zinc Anodes in Rechargeable Aqueous Batteries
Authors: Mitha Aly , Yazdi Alireza Z. , Ahmed Moin , Chen Pu 
Published: June 2018

AbstractAqueous metal batteries routinely suffer from the dendritic growth at the anode, leading to significant capacity fading and ultimately, battery failure from short‐circuit. Herein, we utilize polyethylene glycol to regulate dendrite growth and improve the long‐term cycling stability of an aqueous rechargeable lithium/zinc battery. PEG200 in the electrolyte decreases the corrosion and chronoamperometric current densities of the zinc electrode up to four‐fold. Batteries with pre‐grown dendrites also perform significantly better when PEG is present in the electrolyte (41.4 mAh g−1 vs. 7.9 mAh g−1 after 1000 cycles). X‐ray diffraction and electron microscopy studies show that dendrites in the PEG‐containing electrolyte have been inhibited, leading to much smaller/smoother surface features than those of the control. The facile preparation process of the aqueous electrolyte combined with low cost and vast performance improvement in batteries of all sizes indicates high upscaling viability.