bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Glowing Trajectory between Bio‐ and Chemiluminescence: From Luciferin‐Based Probes to Triggerable Dioxetanes
Authors: Hananya Nir , Shabat Doron 
Published: October 2017

AbstractBioluminescent and chemiluminescent probes are widely used for noninvasive imaging applications because of their high sensitivity and the simplicity of the equipment required to perform the measurement. Synthetic luciferin‐analogue probes with in vivo imaging performance better than that of luciferin are now available. In addition, caged luciferin‐based bioluminogenic probes have been emerged as a general tool for the visualization of different enzymes and analytes in vivo. Recent discoveries have led to development of highly efficient chemiluminescent probes that are extremely bright under physiological conditions. As discussed in this Minireview, chemiluminescence is ready to realize its potential as a valuable tool for imaging in living systems.
Catalytic Asymmetric [8+2] Annulation Reactions Promoted by a Recyclable Immobilized Isothiourea
Authors: Wang Shoulei , Rodríguez‐Escrich Carles , Pericàs Miquel A. 
Published: October 2017

AbstractHigher‐order cycloaddition reactions constitute an efficient approach towards the construction of medium to large ring systems. However, enantioselective versions of these transformations remain scarce, which hampers their deployment in medicinal chemistry, or any other discipline in which homochirality is deemed crucial. Herein, we report a novel method for the production of enantiomerically enriched cycloheptatrienes fused to a pyrrolidone ring on the basis of an isothiourea‐catalyzed periselective [8+2] cycloaddition reaction between chiral ammonium enolates (generated in situ from carboxylic acids) and azaheptafulvenes. The resulting bicyclic compounds can be hydrogenated, but, most remarkably, they can also undergo completely regioselective [4+2] cycloaddition with active dienophiles to give architecturally complex polycyclic compounds in a straightforward manner.
Synthesis of Arylamines via Aminium Radicals
Authors: Svejstrup Thomas D. , Ruffoni Alessandro , Juliá Fabio , Aubert Valentin M. , Leonori Daniele 
Published: October 2017

AbstractArylamines constitute the core structure of many therapeutic agents, agrochemicals, and organic materials. The development of methods for the efficient and selective construction of these structural motifs from simple building blocks is desirable but still challenging. We demonstrate that protonated electron‐poor O‐aryl hydroxylamines give aminium radicals in the presence of Ru(bpy)3Cl2. These highly electrophilic species undergo polarized radical addition to aromatic compounds in high yield and selectivity. We successfully applied this method to the late‐stage modification of chiral catalyst templates, therapeutic agents, and natural products.
Synthesis of C3‐Methyl‐Substituted Pyrroloindolines and Furoindolines via Cascade Dearomatization of Indole Derivatives with Methyl Iodide
Authors: Yi Ji‐Cheng , Liu Chuan , Dai Li‐Xin , You Shu‐Li 
Published: October 2017

AbstractA highly efficient method for constructing C3‐methyl‐substituted pyrroloindolines and furoindolines via cascade dearomatization reaction of indole derivatives with methyl iodide was developed. This protocol offers a direct approach to a wide range of C3 methyl substituted pyrroloindolines under mild conditions. The utility of this method was further demonstrated in the concise synthesis of (±)‐esermethol.
Application of quinone‐based fluorophore and native fluorescence for the spectrofluorimetric determination of agomelatine in dosage form: Identification of acidic and alkaline‐ induced degradation products by LC–MS/TOF
Authors: Ibrahim Fawzia , El‐Deen Asmaa Kamal , Shimizu Kuniyoshi 
Published: October 2017

AbstractThree spectrofluorimetric methods were developed for agomelatine (AGM) determination in commercial tablets. Method A is based on measuring the native fluorescence of AGM aqueous solution at 230/360 nm. Methods B and C are based on the formation of a charge transfer complex between AGM and 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ) and 7,7,8,8‐tetracyanoquinodimethane (TCNQ) with measurement of the formed fluorophore at 365/475 nm and 250/304 nm, respectively. The relative fluorescence intensity (RFI) of AGM–DDQ complex was greatly enhanced in the presence of methyl‐β‐cyclodextrin (CD). The methods were linear over the concentration ranges of 0.015–0.5, 0.5–8.0, 0.09–6.0 and 0.05–0.2 μg/ml for AGM‐native fluorescence, AGM–DDQ, AGM–DDQ–CD and AGM–TCNQ complexes, respectively with excellent correlation coefficients (r = 0.9999). The methods were validated as per the International Conference on Harmonization (ICH) guidelines and all validation requirements were satisfied. The developed methods were extended to the analysis of AGM in commercial tablets. Furthermore, the stability of AGM was studied under different stress conditions (alkaline, acidic, oxidative and photolytic). The potential alkaline and acidic degradation products were identified by LC–MS/TOF.
Differential expression of microRNAs in TM3 Leydig cells of mice treated with brain‐derived neurotrophic factor
Authors: Gao Shan , Li Chunjin , Xu Ying , Chen Shuxiong , Zhao Yun , Chen Lu , Jiang Yanwen , Liu Zhuo , Fan Rong , Sun Liting , Wang Fengge , Zhu Xiaoling , Zhang Jing , Zhou Xu 
Published: October 2017

Brain‐derived neurotrophic factor (BDNF) is a neurotrophin that can promote the development and proliferation of neurons. BDNF has been found to be involved in male reproduction. Leydig cells in testicular interstitial tissues can secrete testosterone in a luteinizing hormone‐dependent manner. We showed that BDNF and its receptor TrkB were expressed in mice TM3 Leydig cells in the present study. Furthermore, BDNF can promote proliferation of mouse TM3 Leydig cells in vitro. Results of microRNA (miRNA) deep sequencing showed that BDNF can alter the expression profile of miRNAs in TM3 Leydig cells. Eighty‐three miRNAs were significantly different in the BDNF‐treated and control groups (fold change of >2.0 or <0.5, P < 0.05) wherein 40 were upregulated and 43 were downregulated. The expression levels of miR‐125a‐5p, miR‐22‐5p, miR‐342‐59, miR‐451a, miR‐148a‐5p, miR‐29b‐3p, miR‐199b‐5p, and miR‐145a‐5p were further confirmed by quantitative real‐time polymerase chain reaction. Bioinformatic analysis revealed that miRNAs regulated a large number of genes with different functions. Pathway analysis indicated that miRNAs participate in the pathways involved in signal transduction, cancer, metabolism, endocrine system, immune system, and nerve system. This study indicated that miRNAs might be involved in the BDNF‐regulated cellular functions of Leydig cells.
Synthesis and Structure Determination of Large‐Pore Zeolite SCM‐14
Authors: Luo Yi , Smeets Stef , Peng Fei , Etman Ahmed S. , Wang Zhendong , Sun Junliang , Yang Weimin 
Published: October 2017

AbstractSCM‐14 (Sinopec Composite Material No. 14), a new stable germanosilicate zeolite with a 12×8×8‐ring channel system, was synthesized using commercially available 4‐pyrrolidinopyridine as organic structure‐directing agents (OSDAs) in fluoride medium. The framework structure of SCM‐14 was determined using rotation electron diffraction (RED), and refined against synchrotron X‐ray powder diffraction (SXPD) data for both as‐made and calcined materials. The framework structure of SCM‐14 is closely related to that of three known zeolites: mordenite (MOR), GUS‐1 (GON), and IM‐16 (UOS). SCM‐14 has the same projection as that of mordenite and GUS‐1 when viewed along the 12‐ring channels, and possesses two more straight 8‐ring channels running perpendicular to the 12‐ring channels. The structure of SCM‐14 can be constructed by either the same layers as that of GUS‐1 or the same columns as that of IM‐16. Based on their structural relationship, three topologically reasonable hypothetical zeolites were predicted.
Unprecedented One‐Pot Reaction towards Chiral, Non‐Racemic Copper(I) Complexes of [2.2]Paracyclophane‐Based P,N‐Ligands
Authors: Braun Carolin , Nieger Martin , Bräse Stefan 
Published: October 2017

AbstractHerein, we report a simple one‐pot route to enantiopure copper(I) complexes featuring a unique [2.2]paracyclophane‐based P,N‐ligand system. Phosphine and pyridine moieties can be varied allowing the modular synthesis of these rigid and stable [2.2]paracyclophane‐based P,N‐ligands. These P,N‐ligands are a new ligand class for different transition‐metal complexes, which is shown exemplarily for palladium(II).
Deciphering Structure–Activity Relationships in a Series of 2,2‐Dimethylchromans Acting as Inhibitors of Insulin Release and Smooth Muscle Relaxants
Authors: Pirotte Bernard , Florence Xavier , Goffin Eric , Lebrun Philippe 
Published: October 2017

Abstract4,6‐Disubstituted 2,2‐dimethylchromans are reported as pharmacologically active compounds that mainly target the ATP‐sensitive potassium channels. The present study is an attempt to characterize the impact of the nature of substituents introduced at the 4‐ and 6‐positions of 2,2‐dimethylchromans on their capacities to inhibit insulin release from pancreatic β‐cells or to relax vascular smooth muscle cells, both biological responses that are supposed to reflect interaction with specific ion channels. From the core structure 4‐amino‐2,2‐dimethylchroman, a progressive increase in the steric hindrance of the chemical functionalities introduced at the 4‐position (amino, formamido, acetamido, arylureido/thioureido) and at the 6‐position (amino, formamido, acetamido, alkoxycarbonylamino) led to a progressive magnification of the inhibitory effect on the insulin release process and, to a lesser extent, of the vasorelaxant activity. Moreover, the dextrorotatory enantiomer of 2,2‐dimethylchroman compound 29 was more potent than its levorotatory counterpart for inhibiting the insulin secretory process. Additional pharmacological investigations suggested, however, that the myorelaxant activity of 11 and 15 resulted from a direct Ca2+ entry blockade.
Enhanced Photocatalytic Hydrogen Evolution of NiCoP/g‐C3N4 with Improved Separation Efficiency and Charge Transfer Efficiency
Authors: Bi Lingling , Gao Xupeng , Zhang Lijing , Wang Dejun , Zou Xiaoxin , Xie Tengfeng 
Published: October 2017

AbstractAlthough NiCoP has attracted much attention in the field of electrocatalysis, the study of its photocatalytic activity and mechanism have been somewhat limited. NiCoP/g‐C3N4, synthesized by simple one‐pot method, is a highly efficient photocatalyst for hydrogen production from water. NiCoP/g‐C3N4 exhibits a hydrogen evolution rate of 1643 μmol h−1 g−1, which is 21 times higher than that of bare g‐C3N4. The excellent performance is due to a combination of improved separation efficiency and effective charge transfer efficiency. The photogenerated charge behavior is characterized by the surface photovoltage (SPV), transient photovoltage (TPV), and photoluminescence spectroscopy. The photogenerated charge transport is investigated by electrochemical impedance spectroscopy and polarization curve. Moreover, the effective charge transfer efficiency was measured according to the mimetic apparent quantum yield. SPV and TPV measurements, whereby 10 vol % of a triethanolamine–water mixture was added into the testing system, were taken to simulate the real atmosphere for photocatalytic reaction, which can give rise to the photogenerated charge transfer process. A possible photocatalytic mechanism was also proposed. This study may provide an efficient theoretical basis to design transition metal phosphide cocatalyst‐modified photocatalysts.
LC–MS/MS method for quantification of baclofen in hair: A useful tool to assess compliance in alcohol dependent patients?
Authors: Larabi I.A. , Fabresse N. , Knapp A. , Forcet M. , Baud F.J. , Lorin de la Grandmaison G. , Alvarez J.C. 
Published: October 2017

AbstractTo evaluate adherence to treatment, we developed and validated a novel liquid chromatography–tandem mass spectrometry (LC–MS/MS) method for baclofen quantification in hair.Twenty mg was washed twice with dichloromethane, incubated in phosphate buffer (pH 5) for 10 minutes at 95°C, then extracted by liquid‐liquid extraction in alkaline condition. Baclofen‐d4 was used as the internal standard. This method was applied to assess compliance in4 treated alcohol‐dependent patients (3 dead and one living). Blood quantification of baclofen and ethanol were performed in the 4 cases. Hair ethylglucuronide (ethanol metabolite, EtG) measurement (2x3 cm) was associated in 1 patient. Baclofen quantification in hair was validated over the range 10–5000 pg/mg. The accuracy was within 96.0%–110.9% and the precision was less than 9.3%. Baclofen segmental (3x2cm) hair concentrations found in the living patient were 4420, 4260, and 4380 pg/mg, reflecting a regular exposure over the last 6 months and suggesting patient compliance. However, the high EtG level found in this patient in the analyzed segments (225 pg/mg and 215 pg/mg) showed excessive alcohol consumption during the same period, suggesting therapeutic failure. In the 3 deceased patients, the non‐segmental analysis of hair showed baclofen concentrations of 15, 545, and 2475 pg/mg. The low concentrations in the 2 first cases are compatible either with a poor compliance or to a beginning of a treatment. This is the first measurement of baclofen in hair of alcohol dependent patients. It could be used as a monitoring biomarker to assess patient's compliance.
The association between high‐dose loop diuretic use at discharge and cardiovascular mortality in patients with heart failure
Authors: Okabe Toshitaka , Yakushiji Tadayuki , Kido Takehiko , Oyama Yuji , Igawa Wataru , Ono Morio , Ebara Seitaro , Yamashita Kennosuke , Yamamoto Myong Hwa , Saito Shigeo , Amemiya Kisaki , Isomura Naoei , Ochiai Masahiko 
Published: October 2017

AbstractAimsFew studies have reported the impact of high‐dose loop diuretics at discharge on prognosis in Japanese patients with heart failure (HF). Our purpose was to assess the relationship between the dose of loop diuretics at discharge and cardiovascular mortality in patients with HF.Methods and resultsWe enrolled decompensated HF patients who were admitted to our hospital between March 2010 and March 2015, and compared HF patients who received high‐dose loop diuretics at discharge (HD group) with low‐dose loop diuretics at discharge (LD group) with regard to risk of cardiovascular mortality, and all‐cause mortality. High‐dose loop diuretic was defined as ≥40 mg/day of oral furosemide at discharge. A total of 215 patients were enrolled to the study. The median follow‐up duration was 641 days. All‐cause and cardiovascular mortality were significantly lower in the LD group than in the HD group (10.4% vs. 31.6%, P < 0.001; 2.2% vs. 24.6%, P < 0.001, respectively). High‐dose loop diuretics were associated with cardiovascular mortality in multivariate Cox proportional hazards model (hazard ratio, 16.06, 95% confidence interval 3.457 to 116.8; P < 0.001). The largest area under the receiver operating characteristic curve (0.85) for cardiovascular death was obtained with a threshold of 40 mg furosemide.ConclusionsHigh‐dose loop diuretic use at discharge was one of the predictors of cardiovascular mortality in patients with HF. An oral furosemide dose of 40 mg daily may be defined as ‘high‐dose’ loop diuretics in Japanese patients with chronic HF.
Circulating proteins as predictors of incident heart failure in the elderly
Authors: Stenemo Markus , Nowak Christoph , Byberg Liisa , Sundström Johan , Giedraitis Vilmantas , Lind Lars , Ingelsson Erik , Fall Tove , Ärnlöv Johan 
Published: October 2017

AimsTo identify novel risk markers for incident heart failure using proteomic profiling of 80 proteins previously associated with cardiovascular pathology.Methods and resultsProteomic profiling (proximity extension assay) was performed in two community‐based prospective cohorts of elderly individuals without heart failure at baseline: the Prospective Investigation of the Vasculature in Uppsala Seniors [PIVUS, n = 901, median age 70.2 (interquartile range 70.0–70.3) years, 80 events]; and the Uppsala Longitudinal Study of Adult Men [ULSAM, n = 685, median age 77.8 (interquartile range 76.9–78.1) years, 90 events]. Twenty‐nine proteins were associated with incident heart failure in the discovery cohort PIVUS after adjustment for age and sex, and correction for multiple testing. Eighteen associations replicated in ULSAM. In pooled analysis of both cohorts, higher levels of nine proteins were associated with incident heart failure after adjustment for established risk factors: growth differentiation factor 15 (GDF‐15), T‐cell immunoglobulin and mucin domain 1 (TIM‐1), tumour necrosis factor‐related apoptosis‐inducing ligand receptor 2 (TRAIL‐R2), spondin‐1 (SPON1), matrix metalloproteinase‐12 (MMP‐12), follistatin (FS), urokinase‐type plasminogen activator surface receptor (U‐PAR), osteoprotegerin (OPG), and suppression of tumorigenicity 2 (ST2). Of these, GDF‐15, U‐PAR, MMP‐12, TRAIL‐R2, SPON1 and FS were associated with worsened echocardiographic left ventricular systolic function at baseline, while only TIM‐1 was positively associated with worsened diastolic function (P < 0.02 for all).ConclusionProteomic profiling identified several novel associations between proteins involved in apoptosis, inflammation, matrix remodelling, and fibrinolysis with incident heart failure in elderly individuals. Our results encourage additional studies investigating the underlying mechanisms and the clinical utility of our findings.
Antioxidant Capacity and Total Phenol Content in Hop and Malt Commercial Samples
Authors: Oliveira Neto Jerônimo Raimundo , Lopes de Macêdo Isaac Yves , Lopes de Oliveira Naiara Raica , de Queiroz Ferreira Rafael , de Souza Gil Eric 
Published: October 2017

AbstractThe antioxidant properties of commercial hops and malted barley were evaluated by electroanalytical methods and compared with spectrophotometric methods. Hop group showed better antioxidant capacity and total phenols content (TPC) values than malt group. The highest electrochemical Index (EI) was observed for HCO hop sample. Electrochemical Index (EI) showed a good Pearson correlation with ABTS (2,2′‐azino‐bis (3‐ethylbenzothiazoline‐6‐sulphonic acid)), DPPH (2,2‐diphenyl‐1‐picrylhydrazyl), and TPC, being of 0.85, 0.77 and 0.86 respectively for hop samples. While for the malt samples were 0.96, 0.69 and 0.49, respectively. The samples were compared to each other within each group and statistical differences can be observed, p<0.05. Therefore, the electroanalytical tools showed to be practical and easy to evaluate the antioxidant properties of hop and malt samples. The results may contribute to the selection of raw material for brewing and therefore with the quality of one of beverage one most consumed around the world.
Development of Catalyst‐Enhanced Sodium Alanate as an Advanced Hydrogen‐Storage Material for Mobile Applications
Authors: Liu Yongfeng , Ren Zhuanghe , Zhang Xin , Jian Ni , Yang Yaxiong , Gao Mingxia , Pan Hongge 
Published: October 2017

AbstractAs a prototypical high‐capacity complex hydride, sodium alanate (NaAlH4) has attracted significant attention because of its favorable thermodynamics and the potential low cost of its raw materials (NaH and Al). However, a high desorption temperature and slow kinetics preclude its practical use, particularly in mobile applications. The introduction of appropriate catalysts has been demonstrated to reduce the operating temperature and to improve the reversibility of hydrogen storage in NaAlH4 effectively. In this Review, we survey the development of various catalytic additives and their effects on the hydrogen‐storage behavior of NaAlH4. First, the basic physical and chemical characteristics of NaAlH4 and its catalyst‐doping methods are briefly summarized. Then, the catalytically enhanced hydrogen‐storage properties and the corresponding mechanistic understanding are highlighted. Finally, the remaining challenges and the directions of future research efforts are discussed.
Structural breaks and volatility forecasting in the copper futures market
Authors: Gong Xu , Lin Boqiang 
Published: October 2017

This paper examines whether structural breaks contain incremental information for forecasting the volatility of copper futures. Considering structural breaks in volatility, we develop four heterogeneous autoregressive (HAR) models based on classical or latest HAR‐type models. Subsequently, we apply these models to forecast volatility in the copper futures market. The empirical results reveal that our models exhibit better in‐sample and out‐of‐sample performances than classical or latest HAR‐type models. This suggests that structural breaks contain incremental prediction information for the volatility of copper futures. More importantly, we argue that considering structural breaks can improve the performances of most of existing HAR‐type models.Highlights

There are many structural break points in return volatility of the copper futures.
We propose 12 new heterogeneous autoregressive models.
Our models outperform the existing heterogeneous autoregressive models.
Structural breaks contain additional ex ante information for volatility forecasting.
The ex ante information is obvious in forecasting mid‐ and long‐term volatilities.
Raman mapping of the S3− chromophore in degraded ultramarine blue paints
Authors: Cato Eleanor , Scherrer Nadim , Ferreira Ester S.B. 
Published: October 2017

AbstractA specific case of degradation was observed in synthetic ultramarine paint within 3 paintings from the early 20th century, manifesting as an intricate pattern of white lines criss‐crossing the blue paint surface. Raman spectroscopy can be performed directly on untreated sample surfaces and is sensitive to the colour components in ultramarine (S3− and S2− chromophores). This method was chosen to map the chromophore intensity distribution and to relate it to the surface degradation pattern. Raman signal intensity, however, decreases when the laser is out of focus, providing a challenge when mapping signal intensity across rough or undulating surfaces. To account for this, a series of experiments was conducted to determine the laser and objective combination least sensitive to changes in surface topography. The optimal settings were found to be the 785‐nm excitation wavelength with the 50× long working distance objective (numerical aperture 0.50). This combination gave the smallest focus‐dependent signal decrease on test samples: When shifted 5 μm out of focus above or below the sample surface, the signal from the same spot showed a decrease of 7% only. Maps of the blue (S3−) chromophore signal at 548 cm−1 taken from 3 samples showed a clear decrease in intensity on the degraded white lines. Patterns of signal intensity distribution matched well with the optical degradation pattern. From this observation, in conjunction with previous surface characterisation reported elsewhere, it was concluded that the surface phenomenon was indeed a discolouration of the ultramarine pigment, caused by a reduction in the concentration of the chromophore.