bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functionalized Contorted Polycyclic Aromatic Hydrocarbons by a One‐Step Cyclopentannulation and Regioselective Triflyloxylation
Authors: Yang Xuan , Hoffmann Marvin , Rominger Frank , Kirschbaum Tobias , Dreuw Andreas , Mastalerz Michael 
Published: May 2019

AbstractThe oxidative cyclodehydrogenation (often named the Scholl reaction) is still a powerful synthetic tool to construct even larger polycyclic aromatic hydrocarbons (PAHs) by multiple biaryl bond formations without the necessity of prior installation of reacting functional groups. Scholl‐type reactions are usually very selective although the resulting products bear sometimes some surprises, such as the formation of five‐membered instead of six‐membered rings or the unexpected migration of aryl moieties. There are a few examples, where chlorinated byproducts were found when FeCl3 was used as reagent. To our knowledge, the direct functionalization of PAHs during Scholl‐type cyclization by triflyloxylation has not been observed. Herein we describe the synthesis of functionalized PAHs by the formation of five‐membered rings and a regioselective triflyloxylation in one step. The triflyloxylated PAHs can be used as reactants for further transformation to even larger contorted PAHs.
Synthesis, characterization, molecular docking and biological activities of novel pyrazoline derivatives
Authors: Turkan Fikret , Cetin Adnan , Taslimi Parham , Karaman Halide S. , Gulçin İlhami 
Published: May 2019

AbstractIn this study, synthesis of ethyl 2‐((4‐bromophenyl)diazenyl)‐3‐oxo‐phenylpropanoate 1 was carried out and a series of new 3H‐pyrazol‐3‐ones (P1–7) were synthesized from 1 as well as various hydrazines. The obtained yields of the synthesized compounds were moderate (40–70%) and these compounds were confirmed by spectral data. These novel pyrazoline derivatives were effective inhibitor compounds of the human carbonic anhydrase I and II isozymes (hCAs I and II) and of the acetylcholinesterase (AChE) enzyme, with Ki values in the range of 17.4–40.7 nM for hCA I, 16.1–55.2 nM for hCA II, and 48.2–84.1 nM for AChE. In silico studies were performed on the compounds inhibiting hCA I, hCA II, and AChE receptors. On the basis of the findings, the inhibition profile of the new pyrazoline compounds at the receptors was determined.
State estimation for nonlinear conformable fractional‐order systems: A healthy operating case and a faulty operating case
Authors: Jmal Assaad , Elloumi Mourad , Naifar Omar , Ben Makhlouf Abdellatif , Hammami Mohamed Ali 
Published: May 2019

AbstractThe issue of estimating states for classical integer‐order nonlinear systems has been widely addressed in the literature. Yet, generalization of existing results to the fractional‐order framework represents a fertile area of research. Note that, recently, a new and advantageous type of fractional derivative, the conformable derivative, was defined. So far, the general query of designing observers for conformable fractional‐order systems has not been investigated. In addition, it has been proved in the literature that some important tools for stability analysis of fractional‐order systems are valid using the conformable derivative concept, but invalid using other fractional derivative concepts. Motivated by the cited facts, this paper presents a first‐state estimation scheme for fractional‐order systems under the conformable derivative concept. A healthy operating case and a faulty operating case are treated. In this paper, a version of Barbalat's lemma, which is invalid using the well‐known Caputo derivative, is exploited to prove the convergence of the estimation errors. In order to validate the theoretical results, a numerical example is studied in the simulation section.
Payload pendulation and position control systems for an offshore container crane with adaptive‐gain sliding mode control
Authors: Ngo Quang Hieu , Nguyen Ngo Phong , Nguyen Chi Ngon , Tran Thanh Hung , Bui Van Huu 
Published: May 2019

AbstractWhen container ports are not available for heavy ships, the offshore ship‐to‐ship transfer operation is an alternative method to an inland container terminal. This process is performed between a large container ship and a smaller ship, which is equipped with a container crane, called the mobile harbor or the ship‐mounted crane. The sea‐state condition is a crucial factor in open‐sea operations. The presence of waves, wind, and current disturbances excite the pendulum oscillations of the crane's hanging container. In this study, the problem of payload pendulation and container position for an offshore container crane using an adaptive‐gain sliding mode control (SMC) scheme is investigated. The primary control task during the loading and unloading process is to keep the container in the desired region under the harsh oceanic environment. The proposed control architecture incorporates an adaptive‐gain SMC with a compensation part and a prediction mechanism. Therein, a sliding surface is design to combine the desired sway motion of the payload with the desired trolley trajectory. Furthermore, a varying control gain is proposed in the sliding control, obtained by an adaption law that transitions the system into sliding mode. By constructing an appropriate Lyapunov function, we show that the proposed control law ensures the asymptotic stability of the ship‐mounted crane. Numerical simulations are presented to show the effectiveness and robustness of the proposed control system.
Hierarchical nonparametric survival modeling for demand forecasting with fragmented categorical covariates
Authors: Li Ta‐Hsin 
Published: May 2019

AbstractThis paper addresses the problem of data fragmentation when incorporating imbalanced categorical covariates in nonparametric survival models. The problem arises in an application of demand forecasting where certain categorical covariates are important explanatory factors for the diversity of survival patterns but are severely imbalanced in the sense that a large percentage of data segments defined by these covariates have very small sample sizes. Two general approaches, called the class‐based approach and the fusion‐based approach, are proposed to handle the problem. Both reply on judicious utilization of a data segment hierarchy defined by the covariates. The class‐based approach allows certain segments in the hierarchy to have their private survival functions and aggregates the others to share a common survival function. The fusion‐based approach allows all survival functions to borrow and share information from all segments based on their positions in the hierarchy. A nonparametric Bayesian estimator with Dirichlet process priors provides the data‐sharing mechanism in the fusion‐based approach. The hyperparameters in the priors are treated as fixed quantities and learned from data by taking advantage of the data segment hierarchy. The proposed methods are motivated and validated by a case study with real‐world data from an operation of software development service.
Dipeptidyl peptidase 4 inhibitors as novel agents in improving survival in diabetic patients with colorectal cancer and lung cancer: A Surveillance Epidemiology and Endpoint Research Medicare study
Authors: Bishnoi Rohit , Hong Young‐Rock , Shah Chintan , Ali Azka , Skelton William P. , Huo Jinhai , Dang Nam H. , Dang Long H. 
Published: May 2019

AbstractBackgroundDipeptidyl peptidase 4 (DPP4) is a cell surface protein that can act as a tumor suppressor or activator, depending upon the level of expression and interaction with the microenvironment and chemokines. DPP4 inhibitors are used to treat diabetes.MethodsWe conducted this Surveillance Epidemiology and Endpoint Research‐Medicare database study to evaluate the role of DPP4 inhibitors on the overall survival (OS) of diabetic patients diagnosed with colorectal (CRC) and lung cancers.ResultsDiabetic patients with CRC or lung cancer who were treated with DPP4 inhibitors exhibited a statistically significant survival advantage (hazard ratio [HR] of 0.89; CI: 0.82‐0.97, P = 0.007) that remained significant after controlling for all other confounders. When DPP4 inhibitors were used in combination of metformin which is known to suppress cancer, the survival advantage was even more pronounced (HR of 0.83; CI: 0.77‐0.90, P < 0.0001). Data were then analyzed separately for two cancer types. In the CRC‐only cohort, the use of DPP4 inhibitors alone had a positive trend but did not meet statistically significant threshold (HR of 0.87; CI: 0.75‐1.00, P = 0.055), while the combined use of DPP4 inhibitors and metformin was associated with statistically significant survival advantage (HR of 0.77; CI: 0.67‐0.89, P = 0.003). Similarly, for the lung cancer cohort, use of DPP4 alone was not found to be statistically significant (HR of 0.93; CI: 0.83‐1.03, P = 0.153), whereas lung cancer patients treated with the combination of DPP4 inhibitors and metformin showed statistically significant survival advantage (HR of 0.88; CI: 0.80‐0.97, P = 0.010).ConclusionsDPP4 inhibition in CRC and lung cancer is associated with improved OS, which possibly may be due to the effect of DPP4 inhibition on immunoregulation of cancer.
Suppression of epidermal growth factor receptor‐mediated β‐catenin nuclear accumulation enhances the anti‐tumor activity of phosphoinositide 3‐kinase inhibitor in breast cancer
Authors: Niu Jie , Wang Xiao , Liang Chao , Zhang Yi‐Dan , Liu Fan‐Ye , Li Hai‐Ying , Xie Song‐Qiang , Sun Hua , Fang Dong 
Published: May 2019

AbstractPhosphoinositide 3‐kinase (PI3K) signaling is frequently deregulated in breast cancer and plays a critical role in tumor progression. However, resistance to PI3K inhibitors in breast cancer has emerged, which is due to the enhanced β‐catenin nuclear accumulation. Until now, the mechanisms underlying PI3K inhibition‐induced β‐catenin nuclear accumulation remains largely unknown. In the present study, we found inhibition of PI3K with LY294002 promoted β‐catenin nuclear accumulation in MCF‐7 and MDA‐MB‐231 breast cancer cells. Combining PI3K inhibitor LY294002 with XAV‐939, an inhibitor against β‐catenin nuclear accumulation, produced an additive anti‐proliferation effect against breast cancer cells. Subsequent experiments suggested β‐catenin nuclear accumulation induced by PI3K inhibition depended on the feedback activation of epidermal growth factor receptor (EGFR) signaling pathway in breast cancer cells. Inhibition of EGFR phosphorylation with Gefitinib enhanced anti‐proliferation effect of PI3K inhibitor LY294002 in MCF‐7 and MDA‐MB‐231 cells. Taken together, our findings may elucidate a possible mechanism explaining the poor outcome of PI3K inhibitors in breast cancer treatment.
Thermal and Sensitiveness Determination of Cubanes: Towards Cubane‐Based Fuels for Infrared Countermeasures
Authors: Dallaston Madeleine A. , Brusnahan Jason S. , Wall Craig , Williams Craig M. 
Published: May 2019

AbstractAs infrared seeking technology evolves, threats are better able to distinguish defensive infrared (IR) flares from true targets. Spectrally matched flares, which generally employ carbon‐based fuels, are better able to decoy some advanced missiles by more closely mimicking the IR emission of the target. Cubane is a high‐energy carbon‐based scaffold which may be suitable for use as a fuel in spectrally matched flares. The enthalpy of formation and strain energy of a series of cubanes was predicted in silico, and their thermal and impact stability examined. All were found to undergo highly exothermic decomposition in sealed cell differential scanning calorimetry, and two cubanes subsequently underwent quantitative sensitiveness testing. Despite their F of I values being in the secondary explosive range, cubane‐1,4‐dicarboxylic acid (F of I=70) and 4‐carbamoylcubane‐1‐carboxylic acid (F of I=90) were identified as potentially useful fuels for pyrotechnic infrared countermeasure flare formulations.
Silver Nanowire‐Templated Molecular Nanopatterning and Nanoparticle Assembly for Surface‐Enhanced Raman Scattering
Authors: Li Zhuoyao , Wang Guilin , Zhang Chengyu , Wei Cong , Wang Xiang , Gao Yongqian , Li Hai , Huang Xiao , Yuan Haifeng , Lu Gang 
Published: May 2019

AbstractDeveloping simple and cost‐efficient methods for fabricating molecular patterns is of great importance in the field of nanoscience and nanotechnology. Here, a simple and convenient method was developed for fabricating nanopatterns composed of positively charged silane molecules by using silver nanowires as templates. The as‐obtained silane pattern copies the shape of the silver nanowires and is only 0.7 nm thick, which can later be used for templated assembly of small molecules and nanoparticles of opposite charges. As a proof of concept, the resultant assembly could be further used for surface‐enhanced Raman scattering.
Heck Diversification of Indole‐Based Substrates under Aqueous Conditions: From Indoles to Unprotected Halo‐tryptophans and Halo‐tryptophans in Natural Product Derivatives
Authors: Pubill‐Ulldemolins Cristina , Sharma Sunil V. , Cartmell Christopher , Zhao Jinlian , Cárdenas Paco , Goss Rebecca J. M. 
Published: May 2019

AbstractThe blending of synthetic chemistry with biosynthetic processes provides a powerful approach to synthesis. Biosynthetic halogenation and synthetic cross‐coupling have great potential to be used together, for small molecule generation, access to natural product analogues and as a tool for chemical biology. However, to enable enhanced generality of this approach, further synthetic tools are needed. Though considerable research has been invested in the diversification of phenylalanine and tyrosine, functionalisation of tryptophans thorough cross‐coupling has been largely neglected. Tryptophan is a key residue in many biologically active natural products and peptides; in proteins it is key to fluorescence and dominates protein folding. To this end, we have explored the Heck cross‐coupling of halo‐indoles and halo‐tryptophans in water, showing broad reaction scope. We have demonstrated the ability to use this methodology in the functionalisation of a brominated antibiotic (bromo‐pacidamycin), as well as a marine sponge metabolite, barettin.
Redox‐Induced Oxidative C−C Bond Cleavage of 2,2′‐Pyridil in Diruthenium Complexes
Authors: Khan Farheen Fatima , Sobottka Sebastian , Sarkar Biprajit , Lahiri Goutam Kumar 
Published: May 2019

AbstractIn the recent years, there has been an emerging research interest in the domain of C−C bond‐cleavage reactions. The present contribution deals with the redox‐mediated dioxygen activation and C−C bond cleavage in a diruthenium complex [(acac)2RuII(μ‐L1)RuII(acac)2], 1 (acac=acetylacetonate) incorporating 2,2′‐pyridil (L1) as the bridging ligand. The above process leads to a C−C‐cleaved monomeric product [(acac)2RuIII(pic−)], 2 (pic−=piconilate). Intriguingly, similar diastereomeric complexes [(acac)2RuII(μ‐L2)RuII(acac)2], meso (ΔΛ): 3 a and rac (ΔΔ/ΛΛ): 3 b, involving an analogous diimine bridge (L2=N1,N2‐diphenyl‐1,2‐di(pyridin‐2‐yl)ethane‐1,2‐diimine), were stable towards such oxidative transformations. Electrochemical and spectroelectrochemical studies, in combination, establish the potential non‐innocent feature of the 2,2′‐Pyridil (L1) and its derivative (L2) both in oxidation and reduction processes. Additionally, theoretical calculations have been employed to verify the redox states and their behavior. Furthermore, transition state (TS) calculations at the M06L/6‐31G*/LANL2DZ level of theory together with detailed kinetic studies outline a putative mechanism for the selective transformation of 1→2 involving the formation of an intermediate bearing peroxide linkage to complex 1.
Investigation of Dipicolinic Acid Isosteres for the Inhibition of Metallo‐β‐Lactamases
Authors: Chen Allie Y. , Thomas Pei W. , Cheng Zishuo , Xu Nasa Y. , Tierney David L. , Crowder Michael W. , Fast Walter , Cohen Seth M. 
Published: May 2019

AbstractNew Delhi metallo‐β‐lactamase‐1 (NDM‐1) poses an immediate threat to our most effective and widely prescribed drugs, the β‐lactam‐containing class of antibiotics. There are no clinically relevant inhibitors to combat NDM‐1, despite significant efforts toward their development. Inhibitors that use a carboxylic acid motif for binding the ZnII ions in the active site of NDM‐1 make up a large portion of the >500 inhibitors reported to date. New and structurally diverse scaffolds for inhibitor development are needed urgently. Herein we report the isosteric replacement of one carboxylate group of dipicolinic acid (DPA) to obtain DPA isosteres with good inhibitory activity against NDM‐1 (and related metallo‐β‐lactamases, IMP‐1 and VIM‐2). It was determined that the choice of carboxylate isostere influences both the potency of NDM‐1 inhibition and the mechanism of action. Additionally, we show that an isostere with a metal‐stripping mechanism can be re‐engineered into an inhibitor that favors ternary complex formation. This work provides a roadmap for future isosteric replacement of routinely used metal binding motifs (i.e., carboxylic acids) for the generation of new entities in NDM‐1 inhibitor design and development.
Disrupted network connectivity in pediatric brain tumor survivors is a signature of injury
Authors: Gauvreau Samantha , Lefebvre Jérémie , Bells Sonya , Laughlin Suzanne , Bouffet Eric , Mabbott Donald J. 
Published: May 2019

AbstractCognition is compromised in pediatric brain tumor survivors but the neurophysiological basis of this compromise remains unclear. We hypothesized that reduced neural synchronization across brain networks is involved. To test this, we evaluated group differences using a retrospective cohort comparison design between 24 pediatric brain tumor survivors [11.81 ± 3.27)] and 24 age matched healthy children [12.04 ± 3.28)] in functional connectivity within a cerebellar network to examine local effects of the tumor, a whole brain network to examine diffuse effects of treatment (i.e., chemotherapy and radiation), and across multiple intrinsic connectivity networks. Neural activity was recorded during magnetoencephalography scanning while participants were at rest and functional connectivity within networks was measured using the phase lag index. We corroborated our findings using a computational model representing the local tumor effects on neural synchrony. Compared to healthy children, pediatric brain tumor survivors show increased functional connectivity for theta and beta frequency bands within the cerebellar network and increased functional connectivity for the theta band within the whole brain network that again localized to the cerebellum. Computational modeling showed that increased synchrony in the theta bad is observed following local clustering as well as sparse interarea brain connectivity. We also observed increased functional connectivity for the alpha frequency band in the ventral attention network and decreased functional connectivity within the gamma frequency band in the motor network within paedatric brain tumor survivors versus healthy children. Notably, increased gamma functional connectivity within the motor network predicted decreased reaction time on behavioral tasks in pediatric brain tumor survivors. Disrupted network synchrony may be a signature of neurological injury and disease.
CROSA: Context‐aware cloud service ranking approach using online reviews based on sentiment analysis
Authors: Ben‐Abdallah Emna , Boukadi Khouloud , Lloret Jaime , Hammami Mohamed 
Published: May 2019

SummaryThe explosion of cloud services over the Internet has raised new challenges in cloud service selection and ranking. The existence of a great variety of offered cloud services made the users think deeply about the most appropriate services that meet their needs and at the same time are adaptable to their context. Nowadays, online reviews are used for the purpose of enhancing the effectiveness of finding useful product information, having impact on the consumers' decision‐making process. In this context, the current paper suggests a context‐aware cloud service ranking approach using online reviews and based on sentiment analysis (CROSA). Its main objective is to ease the cloud service selection. The CROSA approach analyzes sentiments associated with service measurement index (SMI)–based service properties for each alternative cloud service. Moreover, it enhances the cloud service decision‐making by supporting fuzzy sentiments through the intuitionistic fuzzy set theory and PROMETHEE II. The experimental results presented in this paper show that this approach is efficient and performing.
Improvement of the Oxidative Stability of Spray‐Dried Microencapsulated Chia Seed Oil Using Maillard Reaction Products (MRPs)
Authors: Copado Claudia N. , Diehl Bernd W. K. , Ixtaina Vanesa Y. , Tomás Mabel C. 
Published: May 2019

The present work deals with the study of the physicochemical properties of microencapsulated chia seed oil by spray‐dried method, with different oil content, using Maillard reaction products (MRPs) generated from different heat treatments (0, 60, or 100°C, 30 min) of sodium caseinate‐lactose mixture as wall material. With an absorbance at 465 nm, the color and FTIR parameters are used to follow the Maillard reaction extent. The DPPH assay is applied to analyze the antioxidant activity. The microcapsules present low moisture contents (0.02–3.00% d.b.) and water activity (0.243–0.470), and high values of microencapsulation efficiency (≈99%). The color parameters of the powders show that the microcapsules present a light color with a slight tendency toward yellow. The micrographs of powders show individual spherical microcapsules with smooth surfaces in general. The powders present a high dispersibility. The lipid oxidation analyses show that the microencapsulation process is able to protect chia oil against lipid oxidation in all treatments, with the microcapsules with the highest heat treatment being the most effective in this sense. This fact is related to the highest content of the MRPs, which further protect microencapsulated chia oil.Practical Applications: This research provides information about an alternative treatment to microencapsulate chia oil, which is very rich in omega‐3 fatty acids, to deliver these compounds for food applications. These treatments allow microencapsulating of chia seed oil with high microencapsulation efficiency and good oxidative stability to apply them in the production of omega‐3 fortified foods. The results are significant both for the scientific community and the food industry. The relevance of this study is the application of MRPs to confer spray‐dried microencapsulated chia seed oil higher protection against lipid oxidation. Besides, the obtained results contribute to the development of novel functional products for the food industry and also to satisfy a market with tendencies toward healthy eating.Microencapsulation process as protection system of chia oil against lipid oxidation are studied.
Values and adolescents' self‐esteem: The role of value content and congruence with classmates
Authors: Benish‐Weisman Maya , Daniel Ella , McDonald Kristina L. 
Published: May 2019

AbstractThe study examined the relations between adolescents’ self‐esteem and two aspects of values: content and congruence with classmates. Using a large sample of Israeli adolescents (N = 1,683; Mage = 14.36, SD = 2.24, range = 11–18, 54.31% females), we found that self‐esteem related negatively to self‐enhancement values and positively to conservation values using zero order correlations. Multilevel polynomial regressions, controlling for demographic differences, found significant quadratic associations of self‐esteem with self‐enhancement, self‐transcendence, openness‐to‐change, and conservation values. Furthermore, using Response Surface Analyses, it was found that adolescents who were congruent with their classmates’ self‐enhancement and self‐transcendence values showed the highest levels of self‐esteem. The findings point to the importance of social context for the relations between values and self‐esteem among adolescents.