bluuebunny/crossref_metadata_2025_split huggingface dataset:
Organocatalytic and Scalable Syntheses of Unsymmetrical 1,2,4,5‐Tetrazines by Thiol‐Containing Promotors
Authors: Mao Wuyu , Shi Wei , Li Jie , Su Dunyan , Wang Xiaomeng , Zhang Lyuye , Pan Lili , Wu Xiaoai , Wu Haoxing 
Published: November 2018

AbstractDespite the growing application of tetrazine bioorthogonal chemistry, it is still challenging to access tetrazines conveniently from easily available materials. Described here is the de novo formation of tetrazine from nitriles and hydrazine hydrate using a broad array of thiol‐containing catalysts, including peptides. Using this facile methodology, the syntheses of 14 unsymmetric tetrazines, containing a range of reactive functional groups, on the gram scale were achieved with satisfactory yields. Using tetrazine methylphosphonate as a building block, a highly efficient Horner–Wadsworth–Emmons reaction was developed for further derivatization under mild reaction conditions. Tetrazine probes with diverse functions can be scalably produced in yields of 87–93 %. This methodology may facilitate the widespread application of tetrazine bioorthogonal chemistry.
Early detection of cervical cancer based on high‐risk HPV DNA‐based genosensors: A systematic review
Authors: Mahmoodi Pegah , Fani Mona , Rezayi Majid , Avan Amir , Pasdar Zahra , Karimi Ehsan , Amiri Iraj S. , Ghayour‐Mobarhan Majid 
Published: November 2018

AbstractHuman papillomavirus type (HPV) is a common cause of sexually transmitted disease (STD) in humans. HPV types 16 and 18 as the highest risk types are related with gynecologic malignancy and cervical cancer (CC) among women worldwide. Recently, considerable development of genosensors, which allows dynamic monitoring of hybridization events for HPV‐16 and 18, has been a topic of focus by many researchers. In this systematic review, we highlight the route of development of DNA‐based genosensory detection methods for diagnosis of high risk of HPV precancer. Biosensor detection methods of HPV‐16 and 18 was investigated from 1994 to 2018 using several databases including PubMed, Cochrane Library, Scopus, Google Scholar, SID, and Scientific Information Database. Manual search of references of retrieved articles were also performed. A total of 50 studies were reviewed. By analyzing the most recent developed electrochemical biosensors for the identification of HPV, we observed that the sensor platform fabricated by Wang et al. holds the lowest detection limit reported in the literature for the DNA of HPV‐16. Up to this date, optical, electrochemical, and piezoelectric systems are the main transducers used in the development of biosensors. Among the most sensitive techniques available to study the biorecognition activity of the sensors, we highlight the biosensors based fluorescent, EIS, and QCM. The current systematic review focuses on the sensory diagnostic methods that are being used to detect HPV‐16 and 18 worldwide. Special emphasis is given on the sensory techniques that can diagnosis the individuals with CC. © 2018 BioFactors, 45(2):101–117, 2019
Vicenin‐2 acts as a radiosensitizer of the non‐small cell lung cancer by lowering Akt expression
Authors: Baruah Taranga Jyoti , Kma Lakhon 
Published: November 2018

AbstractNon‐small cell lung cancer (NSCLC) has a very high rate of incidence and is resistant to chemo‐ and radiotherapy. Vicenin‐2 (VCN‐2) is a flavonoid obtained from Ocimum sanctum L. and it has been reported to have radioprotective, anticancer, and radiosensitizing properties. We have conducted this study to check the effect of VCN‐2 on the cell viability and the effect on PTEN (Phosphatase and tensin homolog), PI3KCA (Phosphatidylinositol 4, 5‐biphosphate 3‐kinase catalytic subunit alpha isoform/PI3K 110α subunit), and Akt1 when VCN‐2 was used alone and in combination with radiation in the NSCLC cell line NCI‐H23 (H23). We have also checked the effect of VCN‐2 on various pro‐ and anti‐apoptotic genes and the ultra‐morphological changes that occurred in the cells when VCN‐2 is used alone and in combination with radiation. VCN‐2 was able to lower cancer cell survival and phosphorylated Akt while promoting the expression of pro‐apoptotic genes and down‐regulating anti‐apoptotic genes. We also observed the apoptosis‐associated ultra‐morphological changes in the VCN‐2‐treated cells. Our study have demonstrated that VCN‐2 can be a potential chemotherapeutic and radiosensitizing agent in NSCLC. © 2018 BioFactors, 45(2):200–210, 2019
Parametric optimization of polycaprolactone synthesis catalysed by Candida antarctica lipase B using response surface methodology
Authors: Pakalapati Harshini , Arumugasamy Senthil Kumar , Jewaratnam Jegalakshimi , Wong Yong Jie , Khalid Mohammad 
Published: November 2018

AbstractA statistical approach with D‐optimal design was used to optimize the process parameters for polycaprolactone (PCL) synthesis. The variables selected were temperature (50°C‐110°C), time (1‐7 h), mixing speed (50‐500 rpm) and monomer/solvent ratio (1:1‐1:6). Molecular weight was chosen as response and was determined using matrix‐assisted laser desorption/ionization time of flight (MALDI TOF). Using the D‐optimal method in design of experiments, the interactions between parameters and responses were analysed and validated. The results show a good agreement with a minimum error between the actual and predicted values.
Downregulation of lncRNA NEAT1_2 radiosensitizes hepatocellular carcinoma cells through regulation of miR‐101‐3p/WEE1 axis
Authors: Chen Xin , Zhang Nuobei 
Published: November 2018

AbstractRadioresistance is a major obstacle in hepatocellular carcinoma (HCC) radiotherapy. Aberrant expression of long non‐coding RNA (lncRNA) has been postulated to be implicated in the development of HCC radioresistance. We investigated the role of lncRNA nuclear enriched abundant transcript 1_2 (NEAT1_2) in radioresistance of HCC and its molecular mechanism in this study. We found that NEAT1_2 and WEE1 were upregulated, and miR‐101‐3p was downregulated in HCC tissues, as well as HCC cell lines. Downregulation of WEE1 sensitized the radiosensitivity of HCC cells, as evidenced by decreased survival fractions of Huh7 and PLC5 cells and increased percentage of apoptotic cells. Also, knockdown of NEAT1_2 exerted a reinforcing effect on the radiosensitivity of HCC cells. In addition, WEE1 was confirmed as a direct target of miR‐101‐3p. Upregulation of miR‐101‐3p obviously decreased the mRNA and protein levels of WEE1 compared with that in the miR‐NC group, while transfection of anta‐miR‐101‐3p presented the opposite effects. In parallel, NEAT1_2 was identified to interact with miR‐101‐3p, and NEAT1_2 upregulated the expression of WEE1 in Huh7 cells through sponging miR‐101‐3p. Besides, the reinforcing effect of NEAT1_2 silencing could be attenuated by downregulation of miR‐101‐3p. To conclude, our results support the concept that downregulation of lncRNA NEAT1_2 radiosensitizes hepatocellular carcinoma cells through regulation of miR‐101‐3p/WEE1 axis.
Icosahedral Carbaboranes with Peripheral Hydrogen–Chalcogenide Groups: Structures from Gas Electron Diffraction and Chemical Shielding in Solution
Authors: Baše Tomáš , Holub Josef , Fanfrlík Jindřich , Hnyk Drahomír , Lane Paul D. , Wann Derek A. , Vishnevskiy Yury V. , Tikhonov Denis , Reuter Christian G. , Mitzel Norbert W. 
Published: November 2018

AbstractCarbaboranes 1,2‐(EH)2‐closo‐1,2‐C2B10H10 (E=S, Se) were prepared, in the case of E=Se for the first time. Their semi‐experimental equilibrium molecular structures were established by the concerted use of quantum‐chemical calculations and gas electron diffraction. A method was developed and implemented to quantify the contribution of experimental data to each refined structural parameter. The accuracy of the experimental structures and those calculated at the MP2 level of theory were gauged by comparison of experimental 11B NMR chemical shifts with quantum‐chemically computed values; the inclusion of electron correlation (GIAO‐MP2) provided superior results. For the purpose of geometrical prediction, the remaining group 16 elements were considered, and the icosahedral structures for E=O and Te were also computed; for E=O the same theoretical approach was used as for E=S, and for E=Te a description similar to that for E=Se was employed.
Quantification of Cellular Proteostasis in Live Cells by Fluorogenic Assay Using the AgHalo Sensor
Authors: Fares Matthew , Zhang Xin 
Published: November 2018

AbstractProper cellular proteostasis is essential to cellular fitness and viability. Exogenous stress conditions compromise proteostasis and cause aggregation of cellular proteins. We have developed a fluorogenic sensor (AgHalo) to quantify stress‐induced proteostasis deficiency. The AgHalo sensor uses a destabilized HaloTag variant to represent aggregation‐prone cellular proteins and is equipped with a series of fluorogenic probes that exhibit a fluorescence increase when the sensor forms either soluble oligomers or insoluble aggregates. Herein, we present protocols that describe how the AgHalo sensor can be employed to visualize and quantify proteome stress in live cells using a direct fluorescence read‐out and visualization with a fluorescence microplate reader and a microscope. Additionally, protocols for using the AgHalo sensor in combination with fluorogenic probes and commercially available HaloTag probes to enable two‐color imaging experiments are described. These protocols will enable use of the AgHalo sensor to visualize and quantify proteostasis in live cells, a task that is difficult to accomplish using previous, always‐fluorescent methods. © 2018 by John Wiley & Sons, Inc.
A knowledge‐based approach to manage configurable business processes
Authors: Benallal Wehbi , Barhamgi Mahmoud , Benslimane Djamal , Maamar Zakaria , Faci Noura , Bellaaj Ameni 
Published: November 2018

SummaryThis paper stresses out the struggle of organizations when managing multiple variants of the same business process. Each variant constitutes a response to structural and/or functional needs that overtime become unsustainable due to the multiplicity and complexity of these needs. To mitigate this struggle, a knowledge‐based approach for capturing these versions into a single configurable business process and splitting this process into fragments is discussed in the paper. The approach builds a configuration knowledge base to track the business process variability (ie, particularities of each business process variant). Variants are represented as a new configurable process structure tree resulting from fragmenting a business process. Implementation of the approach is, also, reported in this paper.
Three‐phase step‐up/step‐down isolated dc‐dc converter with wide‐range duty cycle for low dc renewable energy sources applications
Authors: Mayer Robson , Berrehil El Kattel Menaouar , Vidal Garcia Oliveira Sérgio 
Published: November 2018

SummaryRenewable sources of low voltage are an important resource in power generation systems. Many provide high output current at low voltage, as the photovoltaic modules and fuel cells systems, therefore, become more popular considering the safety requirements. In this paper, a novel current‐fed three‐phase dc‐dc converter with high‐frequency isolation transformer is proposed. This one has the main features as high dc voltage gain, reduced switches count, minimize the volume of the output/input filters, the frequency ripple of the input current and output voltage are three times higher than the switching frequency, best losses distribution and reduced stresses in the circuit. Moreover, it operates with wide‐range duty cycle, the soft‐start can be used, which allows the input current and the output voltage to be started gradually. Operating with a duty cycle of 1/3 and 2/3, the input current ripple is canceled. The proposed converter is studied qualitatively and quantitatively, being presented the operation principle in continuous and discontinuous conduction mode, dc voltage gain in each operation mode, and the voltage and current stresses for the power components sizing. To validate the operation of the proposed converter, the laboratory design example and experimental results are presented to demonstrate the performance and validate the claims of the converter for wide load variation. Experimental results are presented for a 4‐kW prototype, operating in R2 region for continuous conduction mode. Additionally, experimental results in R1 and R3 regions are obtained.
Shaking table tests of a reinforced concrete bridge pier with a low‐cost sliding pendulum system
Authors: Brito Miguel B. , Ishibashi Hiroki , Akiyama Mitsuyoshi 
Published: November 2018

SummaryAfter the occurrence of various destructive earthquakes in Japan, extensive efforts have been made to improve the seismic performance of bridges. Although improvements to the ductile capacities of reinforced concrete (RC) bridge piers have been developed over the past few decades, seismic resilience has not been adequately ensured. Simple ductile structures are not robust and exhibit a certain level of damage under extremely strong earthquakes, leading to large residual displacements and higher repair costs, which incur in societies with less‐effective disaster response and recovery measures. To ensure the seismic resilience of bridges, it is necessary to continue developing the seismic design methodology of RC bridges by exploring new concepts while avoiding the use of expensive materials. Therefore, to maximize the postevent operability, a novel RC bridge pier with a low‐cost sliding pendulum system is proposed. The seismic force is reduced as the upper component moves along a concave sliding surface atop the lower component of the RC bridge pier. No replaceable seismic devices are included to lengthen the natural period; only conventional concrete and steel are used to achieve low‐cost design solutions. The seismic performance was evaluated through unidirectional shaking table tests. The experimental results demonstrated a reduction in the shear force transmitted to the substructure, and the residual displacement decreased by establishing an adequate radius of the sliding surface. Finally, a nonlinear dynamic analysis was performed to estimate the seismic response of the proposed RC bridge pier.
An edge‐based pressure stabilization technique for finite elements on arbitrarily anisotropic meshes
Authors: Frei Stefan 
Published: November 2018

SummaryIn this paper, we analyze a stabilized equal‐order finite element approximation for the Stokes equations on anisotropic meshes. In particular, we allow arbitrary anisotropies in a subdomain, for example, along the boundary of the domain, with the only condition that a maximum angle is fulfilled in each element. This discretization is motivated by applications on moving domains as arising, for example, in fluid‐structure interaction or multiphase‐flow problems. To deal with the anisotropies, we define a modification of the original continuous interior penalty stabilization approach. We show analytically the discrete stability of the method and convergence of order
in the energy norm and
in the L2‐norm of the velocities. We present numerical examples for a linear Stokes problem and for a nonlinear fluid‐structure interaction problem, which substantiate the analytical results and show the capabilities of the approach.
Long‐term streamflow forecasting using artificial neural network based on preprocessing technique
Authors: Li Fang‐Fang , Wang Zhi‐Yu , Qiu Jun 
Published: November 2018

AbstractArtificial neural network (ANN) combined with signal decomposing methods is effective for long‐term streamflow time series forecasting. ANN is a kind of machine learning method utilized widely for streamflow time series, and which performs well in forecasting nonstationary time series without the need of physical analysis for complex and dynamic hydrological processes. Most studies take multiple factors determining the streamflow as inputs such as rainfall. In this study, a long‐term streamflow forecasting model depending only on the historical streamflow data is proposed. Various preprocessing techniques, including empirical mode decomposition (EMD), ensemble empirical mode decomposition (EEMD) and discrete wavelet transform (DWT), are first used to decompose the streamflow time series into simple components with different timescale characteristics, and the relation between these components and the original streamflow at the next time step is analyzed by ANN. Hybrid models EMD‐ANN, EEMD‐ANN and DWT‐ANN are developed in this study for long‐term daily streamflow forecasting, and performance measures root mean square error (RMSE), mean absolute percentage error (MAPE) and Nash–Sutcliffe efficiency (NSE) indicate that the proposed EEMD‐ANN method performs better than EMD‐ANN and DWT‐ANN models, especially in high flow forecasting.
Distribution of brain iron accrual in adolescence: Evidence from cross‐sectional and longitudinal analysis
Authors: Peterson Eric T. , Kwon Dongjin , Luna Beatriz , Larsen Bart , Prouty Devin , De Bellis Michael D. , Voyvodic James , Liu Chunlei , Li Wei , Pohl Kilian M. , Sullivan Edith V. , Pfefferbaum Adolf 
Published: November 2018

AbstractTo track iron accumulation and location in the brain across adolescence, we repurposed diffusion tensor imaging (DTI) and functional magnetic resonance imaging (fMRI) data acquired in 513 adolescents and validated iron estimates with quantitative susceptibility mapping (QSM) in 104 of these subjects. DTI and fMRI data were acquired longitudinally over 1 year in 245 male and 268 female, no‐to‐low alcohol‐consuming adolescents (12–21 years at baseline) from the National Consortium on Alcohol and NeuroDevelopment in Adolescence (NCANDA) study. Brain region average signal values were calculated for susceptibility to nonheme iron deposition: pallidum, putamen, dentate nucleus, red nucleus, and substantia nigra. To estimate nonheme iron, the corpus callosum signal (robust to iron effects) was divided by regional signals to generate estimated R2 (edwR2 for DTI) and R2* (eR2* for fMRI). Longitudinal iron deposition was measured using the normalized signal change across time for each subject. Validation using baseline QSM, derived from susceptibility‐weighted imaging, was performed on 46 male and 58 female participants. Normalized iron deposition estimates from DTI and fMRI correlated with age in most regions; both estimates indicated less iron in boys than girls. QSM results correlated highly with DTI and fMRI results (adjusted R2 = 0.643 for DTI, 0.578 for fMRI). Cross‐sectional and longitudinal analyses indicated an initial rapid increase in iron, notably in the putamen and red nucleus, that slowed with age. DTI and fMRI data can be repurposed for identifying regional brain iron deposition in developing adolescents as validated with high correspondence with QSM.
Protective effect of microRNA‐224 on acute lower extremity ischemia through activation of the mTOR signaling pathway via CHOP in mice
Authors: Chen Yang‐Xi 
Published: November 2018

AbstractAcute lower extremity ischemia (ALEXI) is known worldwide as an urgent condition, occurring when there is an abrupt interruption in blood flow into an extremity. This study aims to investigate whether microRNA‐224 (miR‐224) affects the ALEXI mice and the underlying mechanism. The miR‐224 expression and C/EBP homologous protein (CHOP), mammalian target of rapamycin (mTOR), translation initiation factor 4E‐binding protein 1 (4E‐BP1), and phosphoprotein 70 ribosomal protein S6 kinase (p70S6K) messenger RNA (mRNA), as well as protein expressions, were determined. The target gene of miR‐224 was also verified by using a luciferase reporter gene assay. The vascular endothelial cells from the ALEXI mice were transfected with miR‐224 mimics, miR‐224 inhibitors, or small‐interfering RNA against CHOP. Cell proliferation was assessed using a 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) assay. The cell cycle distribution along with the cell apoptosis were both evaluated by using a flow cytometry. The muscle fibers of the lower extremities found in the ALEXI mice were evidently swollen and rounded, presenting with a remarkably narrowed gap. The positive CHOP expression increased in ALEXI mice than normal mice, while the miR‐224 expression and mTOR, 4E‐BP1, and p70S6K mRNA, as well as the protein expression, decreased. Luciferase reporter gene assay validated that the miR‐224 gene directly targeted CHOP. MiR‐224 facilitated cell proliferation but inhibited cell apoptosis; by contrast, CHOP increased cell apoptosis. Moreover, the cells transfected along with miR‐224 mimic exhibited a lower CHOP expression as well as increased mTOR, 4E‐BP1, and p70S6K expression. Our study provided evidence that miR‐224 could alleviate the occurrence and development of ALEXI in mice through activation of the mTOR signaling pathway by downregulating CHOP.
Novel effects of sphingosylphosphorylcholine on the apoptosis of breast cancer via autophagy/AKT/p38 and JNK signaling
Authors: Ge Di , Gao Jia , Han Lina , Li Ying , Liu Hong‐Hong , Yang Wan‐Cheng , Chang Fen , Liu Jing , Yu Mei , Zhao Jing 
Published: November 2018

AbstractSphingosylphosphorylcholine (SPC), an important lipid mediator in blood, inhibits the proliferation and migration of various cancer cells. However, its effect as a cell‐specific sphingolipid in breast cancer cells is still unknown. Here, we showed that SPC promoted autophagy and apoptosis in triple‐negative breast cancer MDA‐MB‐231 cells. Autophagy worked as a negative regulator of apoptosis‐induced by SPC. Mechanistically, SPC mediated apoptosis via activating c‐Jun N‐terminal kinase (JNK). Meanwhile, p38MAPK (p38) and protein kinase B (PKB or AKT) signaling pathways were also activated to inhibit apoptosis, suggesting that SPC could evoke multiple signaling pathways to modulate cell apoptosis. In addition, the crosstalk between autophagy, p38, AKT and JNK is that autophagy, p38, and AKT attenuated the JNK. AKT and p38 were in the downstream of autophagy, which is autophagy/AKT/p38 signaling evoked by SPC to antagonize JNK signaling and subsequent apoptosis. Although the pathways that antagonize apoptosis were evoked, the cells eventually reached apoptosis by SPC. Therefore, the combination with pharmacological autophagy inhibitors would be a more effective therapeutic strategy for eliminating breast cancer cells by SPC.