bluuebunny/crossref_metadata_2025_split huggingface dataset:
Solids Go Bio: Inorganic Nanoparticles as Enzyme Mimics
Authors: Ragg Ruben , Tahir Muhammad N. , Tremel Wolfgang 
Published: December 2015

AbstractA longstanding goal of biomimetic chemistry is the design and synthesis of functional enzyme mimics. The past three decades have seen a wide variety of materials, including metal complexes, polymers and other biomolecules, that mimic the structures and functions of naturally occurring enzymes. Among these, inorganic nanoparticles offer huge potential, because they are more stable than their natural counterparts, while having large surface areas and sizes comparable to those of natural enzymes. Therefore, a considerable number of “artificial enzymes” derived from inorganic nanomaterials have been reported. This microreview highlights the recent progress in the field of enzymatically active inorganic nanomaterials, including mimics of peroxidases, haloperoxidases, superoxide dismutases and sulfite oxidases, along with selected biotechnological applications and their future prospects.
Thermal and Light‐Induced Spin Transitions of FeII Complexes with 4‐ and 5‐(Phenylazo)‐2,2′‐bipyridine Ligands: Intra‐ vs. Intermolecular Effects
Authors: Schmidt Sven Olaf , Naggert Holger , Buchholz Axel , Brandenburg Hannah , Bannwarth Alexander , Plass Winfried , Tuczek Felix 
Published: December 2015

AbstractFive new spin crossover complexes with 4‐ and 5‐(phenylazo)‐2,2‐bipyridine (4‐/5‐PAbipy) ligands were synthesized and investigated with respect to their spin crossover (SCO) behavior. The results are compared to the thermal and light‐induced spin transition properties of the parent SCO complexes [Fe(bpz)2(bipy)] (1) and [Fe(bipy)2(NCS)2] (2). [Fe(bpz)2(4‐PAbipy)] (1a) undergoes a stepwise spin transition whereas [Fe(bpz)2(5‐PAbipy)] (1b) exhibits a one‐step transition with a 6 K‐wide hysteresis. For [Fe(bpz)2(tBu5‐PAbipy)] (1c) the spin transition to the low‐spin state is incomplete. Qualitatively similar changes of the SCO behavior are observed for the complexes [Fe(4‐PAbipy)2(NCS)2] (2a) and [Fe(5‐PAbipy)2(NCS)2] (2b). In comparison to the parent system 2, a strengthening of intermolecular interactions leads to a stabilization of the low‐spin state. Evidence for the LIESST behavior could be obtained for all new compounds by means of magnetic susceptibility measurements as well as UV/Vis and resonance Raman spectroscopy.
Xanthones with pancreatic lipase inhibitory activity from the pericarps of Garcinia mangostana L. (Guttiferae)
Authors: Chae Hee‐Sung , Kim Eun‐Young , Han Ling , Kim Na‐Rae , Lam Bunthoeun , Paik Jin Hyub , Yoon Kee Dong , Choi Young Hee , Chin Young‐Won 
Published: December 2015

Bioactivity‐guided isolation of natural compounds from the pericarps of Garcinia mangostana, using a pancreatic lipase assay, led to the identification of 13 xanthones including α‐mangostin (1), β‐mangostin (2), γ‐mangostin (3), 1‐isomangostin (4), gartanin (5), garcinone D (6), 9‐hydroxycalabaxanthone (7), smeathxanthone A (8), tovophyllin A (9), 8‐ deoxygartanin (10), mangostanin (11), calocalabaxanthone (12), and 1,7‐dihydroxy‐3‐methoxy‐2‐(3‐methylbut‐2‐enyl) xanthen‐9‐one (13). The inhibitory activities of the isolated xanthones against pancreatic lipase were evaluated and α‐mangostin (1) was found to possess the most potent inhibitory activity (IC50 5.0 µM) in a non‐competitive manner, compared with the positive control, orlistat (IC50 3.9 µM).Practical applications: Pancreatic lipase is a key enzyme in lipid absorption. A total of 13 compounds were isolated from the pericarps of G. mangostana. Their structures were characterized by HRESI‐MS, and 1D and 2D‐NMR spectroscopic data. Our results show that all the isolates exhibited inhibitory activity against pancreatic lipase. Of the active xanthones, α‐mangostin displayed the most potent lipase inhibition, with an IC50 value of 5.0 μM. Furthermore, kinetic analysis of α‐mangostin was carried out. In the Lineweaver–Burk plot, the apparent Vmax values in the presence of 1, 2, 4, and 10 µM α‐mangostin were decreased compared with those without α‐mangostin, whereas the Km values of 4‐MU oleate with and without α‐mangostin were both close to 3.22 μM. Finally, it is evident that xanthone derivatives isolated from G. mangostana possess pancreatic lipase inhibitory activities.A total of 13 compounds are isolated from the pericarps of Garcinia mangostana. α‐Mangostin is found to possess the most potent lipase inhibitory activity.
Mechanism of Ylide Transfer to ­Carbonyl Compounds: Density Functional Calculations
Authors: Patil Mahendra , Thiel Walter 
Published: December 2015

AbstractWe report a computational study on the mechanism of the reaction of ethyl acetoacetate (1) with two sulfur reagents: Martin's sulfurane (Ra) and a mixture of diphenyl sulfide and triflic anhydride (Rb). These reagents are able to provide a sulfonium ion [Ph2S‐OX]+ and an anionic nucleophile –OX as active species [X = C(CF3)2Ph for Ra and X = SO2CF3 for Rb] in the reaction. Experimentally, the reaction of Ra with carbonyl compounds provides an S‐ylide as the only product whereas a low yield of S‐ylide is obtained in the case of Rb. To elucidate the mechanism of these reactions with prototype substrate 1, different plausible pathways have been investigated using density functional theory (DFT), mostly at the B3LYP‐D/6‐31+G** level. According to DFT calculations, initial deprotonation of 1 may furnish either an enolate (with Ra) or an O‐sulfenylated enolate (with Rb). Subsequent nucleophilic addition of the enolate to the sulfonium ion provides the simplest route to S‐ylide product, which is favored when using reagent Ra. In the case of reagent Rb, the preferentially formed O‐sulfenylated enolate may undergo either a series of nucleophilic displacements or a [1,3] sigmatropic shift or a [3,3] sigmatropic rearrangement, all followed by a final deprotonation to yield the product. These conversions are highly exothermic and involve thermodynamically stable products. The [3,3] sigmatropic rearrangement that directly produces an arylated carbonyl compound is computed to be the kinetically most facile reaction with Rb. Overall, the computational results unveil detailed mechanistic scenarios detailing possible transformations and providing qualitative explanations for some of the experimental findings.
Starburst Triphenylamine‐Based Donor–Acceptor‐Type Small Molecules for Solution‐Processed Organic Solar Cells
Authors: Tan Hua , Peng Wenhong , Xiao Manjun , Xu Chao , Nie Kaixuan , Yu Junting , Wang Yafei , Liu Yu , Zhu Weiguo 
Published: December 2015

AbstractA class of the donor–acceptor (D–A)‐type organic small molecules that includes TPA‐DPP, DTPA‐DPP, and TTPA‐DPP [TPA = triphenylamine, DPP = diketopyrrolopyrrole, DTPA = bis(triphenylamine), TTPA = tris(triphenylamine)] was synthesized; these compounds contain TPA as a donor unit and DPP as an acceptor unit. Solution‐processed organic solar cells (OSCs) with these compounds as donors and [6,6]‐phenyl‐C71‐butyric acid methyl ester (PC71BM) as an acceptor were fabricated. The starburst OSCs prepared from DTPA‐DPP and TTPA‐DPP with two and three TPA units, respectively, exhibited better photovoltaic performance than the OSC prepared with one TPA unit, because DTPA‐DPP and TTPA‐DPP have better light‐harvesting properties and charge‐transport properties. The DTPA‐DPP‐based OSCs delivered a power conversion efficiency (PCE) of 2.26 % and the TTPA‐DPP‐based OSCs exhibited a higher PCE of 2.47 %. The PCE level is 1.15 and 1.25 times higher than that in the TPA‐DPP‐based OSCs, respectively. Our work indicates that a starburst configuration can improve the photovoltaic properties of D–A‐type organic small molecules in OSCs.
Electrocatalytic Determination of Hydrazine and Phenol Using a Carbon Paste Electrode Modified with Ionic Liquids and Magnetic Core‐shell Fe3O4@SiO2/MWCNT Nanocomposite
Authors: Beitollahi Hadi , Tajik Somayeh , Jahani Shohreh 
Published: December 2015

AbstractA carbon paste electrode was modified with 2‐(4‐Oxo‐3‐phenyl‐3,4‐dihydroquinazolinyl)‐N′‐phenyl‐hydrazinecarbothioamide, magnetic coreshell Fe3O4@SiO2/MWCNT nanocomposite and ionic liquid (n‐hexyl‐3‐methylimidazolium hexafluoro phosphate). The electro‐oxidation of hydrazine at the surface of the modified electrode was studied using electrochemical approaches. This modified electrode offers a considerable improvement in voltammetric sensitivity toward hydrazine, compared to the bare electrode. Square wave voltammetry (SWV) exhibits a linear dynamic range from 7.0×10−8 to 5.0×10−4 M and a detection limit of 40.0 nM for hydrazine. The diffusion coefficient and kinetic parameters (such as electron transfer coefficient and the heterogeneous rate constant) for hydrazine oxidation were also determined. The prepared modified electrode exhibits a very good resolution between the voltammetric peaks of hydrazine and phenol that makes it suitable for the detection of hydrazine in the presence of phenol in real samples.
Cognitive Function in Adolescent Patients with Anorexia Nervosa and Unipolar Affective Disorders
Authors: Sarrar Lea , Holzhausen Martin , Warschburger Petra , Pfeiffer Ernst , Lehmkuhl Ulrike , Schneider Nora 
Published: December 2015

AbstractStudies have shown impairments in cognitive function among adult patients with anorexia nervosa (AN) and affective disorders (AD). The association between cognitive dysfunctions, AN and AD as well as the specificity for these psychiatric diagnoses remains unclear. Therefore, we examined cognitive flexibility and processing speed in 47 female adolescent patients with AN, 21 female adolescent patients with unipolar affective disorders and 48 female healthy adolescents. All participants completed a neuropsychological test battery.There were no significant group differences regarding cognitive function, except for psychomotor processing speed with poorer performance in patients with AN. A further analysis revealed that all groups performed with the normal range, although patients with AN were over represented in the poorest performing quartile.We found no severe cognitive impairments in either patient group. Nevertheless, belonging to the AN group contributed significantly to poor performances in neuropsychological tasks. Therefore, we conclude that the risk for cognitive impairments is slightly higher for patients with AN. Copyright © 2015 John Wiley & Sons, Ltd and Eating Disorders Association.
Factors contributing to nitrate contamination in a groundwater recharge area of the North China Plain
Authors: Wang Shiqin , Tang Changyuan , Song Xianfang , Yuan Ruiqiang , Han Zhiwei , Pan Yun 
Published: December 2015

AbstractNitrate contamination is a common problem in groundwater of the North China Plain (NCP) owing to overuse of fertilizers and discharge of wastewater. Accordingly, it is important to investigate nitrate contamination in recharge areas to understand the fate of nitrate in the plains area. In this study, the spatial and temporal distribution characteristics of nitrate and factors contributing to its sources and transformation in shallow groundwater of the Beiyishui River watershed, NCP, were analysed by a combination of multiple regression and multi‐tracer methods. The nitrate concentration of 79% of the samples exceeded the natural environmental standard of 13.3 mg l−1, while that of 23% of the samples exceeded the World Health Organization (WHO) drinking water standard of 50 mg l−1. Groundwater age estimation of the hill regions based on chlorofluorocarbons (CFCs) revealed a mix of young water from 1982 to 1990 and old, low CFC water. The analysis based on the variations in land use in past years revealed that part of the grassland was converted into woodland between 1980 and 1995; therefore, the land use at the recharge time was used to determine which surface conditions influence groundwater nitrate concentrations. Multiple regression analysis showed that point source pollution contributed to the high concentration of nitrate in the hill region. Fertilizer application associated with land use change from grassland to woodland was also related to the present nitrate concentration. In the plains area, the contribution of fresh water from fault fractures and denitrification led to 31 to 72% and 6 to 51% reductions in nitrate concentrations, respectively. Our results suggested that controlling point source contamination and fertilizer input to hilly regions of the study will prevent groundwater of the plains area from deterioration in future years by mixing fresh water into the aquifers and decreasing denitrification, and therefore nitrate concentrations. Copyright © 2015 John Wiley & Sons, Ltd.
Diverse impacts of ENSO on wintertime rainfall over the Maritime Continent
Authors: Jia XiaoJing , Ge JingWen , Wang Su 
Published: December 2015

ABSTRACTThe diverse influences of the El Niño Southern Oscillation (ENSO) on wintertime precipitation over the Maritime Continent are herein investigated using observational data. The ENSO events are divided into four categories—strong El Niño, strong La Niña, moderate El Niño and moderate La Niña—according to their amplitudes. Significant negative Maritime Continent precipitation anomalies are observed during strong El Niño events, whereas wet conditions occur during strong La Niña events. In the case of moderate La Niña events, the Maritime Continent rainfall anomalies are similar in spatial structure and comparable in amplitude to strong La Niña events, whereas almost no significant rainfall anomalies are observed in moderate El Niño years. Further analysis shows that strong El Niño (strong/moderate La Niña) events are associated with a significant anticyclone (cyclone) surface response over the western tropical Pacific and related to a significant descending (ascending) branch of the Walker circulation around the Philippines. However, during moderate El Niño events, both the central‐eastern and the western tropical sea surface temperature anomalies (SSTA) are weak and cannot significantly change the Walker circulation over the tropical Pacific. Therefore, the descending branch anomalies of the Walker circulation associated with moderate El Niño events around the Philippines are quite weak and cannot cause significant negative precipitation anomalies in that location. In addition, there is large case‐to‐case variance in the tropical Pacific SSTA associated with moderate El Niño events, which also contributes to the weak Maritime Continent rainfall response in the composite analysis.
Mechanism for occurrence of precipitation over the southern slope of the Tibetan Plateau without local surface heating
Authors: Wang Ziqian , Duan Anmin , Wu Guoxiong , Yang Song 
Published: December 2015

ABSTRACTPrevious studies have indicated that the sucking and pumping effects induced by surface sensible heating (SH) lead to vigorous ascent and moisture convergence over the southern Tibetan Plateau (TP), which is the primary cause of local precipitation formation. Numerical simulations with the Weather Research and Forecasting (WRF) model show that weak ascending motion and precipitation still exist over the southern slope of the TP when local surface SH is suppressed and that this precipitation is associated with microphysical processes. Suppressed surface heating induces a significant cold anomaly near the surface, which reduces the saturation‐specific humidity but increases relative humidity. The process of the phase change of moisture results in the formation of obvious microphysical large‐scale precipitation. Moreover, latent heating is released due to microphysical condensation corresponding with the phase change process, which further leads to a weak ascending and convective precipitation over the southern slope of the TP. Thus, local precipitation over the slope when surface heating is suppressed results directly from large‐scale condensation precipitation and indirectly from the convective precipitation induced by the microphysical processes of moisture phase change, instead of the sucking and pumping effects due to the surface heating of the TP.
Contrast‐enhanced CT using a cationic contrast agent enables non‐destructive assessment of the biochemical and biomechanical properties of mouse tibial plateau cartilage
Authors: Lakin Benjamin A. , Patel Harsh , Holland Conor , Freedman Jonathan D. , Shelofsky Joshua S. , Snyder Brian D. , Stok Kathryn S. , Grinstaff Mark W. 
Published: December 2015

ABSTRACTMouse models of osteoarthritis (OA) are commonly used to study the disease's pathogenesis and efficacy of potential treatments. However, measuring the biochemical and mechanical properties of articular cartilage in these models currently requires destructive and time‐consuming histology and mechanical testing. Therefore, we examined the feasibility of using contrast‐enhanced CT (CECT) to rapidly and non‐destructively image and assess the glycosaminoglycan (GAG) content. Using three ex vivo C57BL/6 mouse tibial plateaus, we determined the time required for the cationic contrast agent CA4+ to equilibrate in the cartilage. The whole‐joint coefficient of friction (μ) of 10 mouse knees (some digested with Chondroitenase ABC to introduce variation in GAG) was evaluated using a modified Stanton pendulum. For both the medial and lateral tibial plateau cartilage of these knees, linear regression was used to compare the equilibrium CECT attenuations to μ, as well as each side's indentation equilibrium modulus (E) and Safranin‐O determined GAG content. CA4+ equilibrated in the cartilage in 30.9 ± 0.95 min (mean ± SD, tau value of 6.17 ± 0.19 min). The mean medial and lateral CECT attenuation was correlated with μ (R2 = 0.69,p < 0.05), and the individual medial and lateral CECT attenuations correlated with their respective GAG contents (R2 ≥ 0.63,p < 0.05) and E (R2 ≥ 0.63,p < 0.05). In conclusion, CECT using CA4+ is a simple, non‐destructive technique for three‐dimensional imaging of ex vivo mouse cartilage, and significant correlations between CECT attenuation and GAG, E, and μ are observed. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1130–1138, 2016.
Impacts of ridge–furrow rainfall concentration systems and mulches on corn growth and yield in the semiarid region of China
Authors: Ren Xiao‐Long , Zhang Peng , Chen Xiao‐Li , Jia Zhi‐Kuan 
Published: December 2015

AbstractBACKGROUNDPlastic‐covered ridge–furrow farming systems for rainfall concentration (RC) improve the water availability for crops and increase the water use efficiency (WUE), thereby stabilizing high yields. In this study, we optimized the mulching patterns forRCplanting to mitigate the risks of drought during crop production in semiarid agricultural areas. We conducted a 4‐year field study to determine theRCeffects on corn production of mulching in furrows with 8% biodegradable films (RCSB), liquid film (RCSL), bare furrow (RCSN) and conventional flat (CF) farming.RESULTSWe found thatRCsignificantly (P> 0.05) increased the soil moisture in the top 0–100 cm layer and the topsoil temperature (0–20 cm) during the corn‐growing period. Mulching with different materials in planting furrows further improved the rain‐harvesting, moisture‐retaining and yield‐increasing effects ofRCplanting. Compared withCF, the 4‐year average total dry matter amount per plant forRCSB,RCSLandRCSNtreatments increased by 42.1%, 30.8% and 17.2%, respectively. The grain yield increased by 59.7%, 53.4% and 32.6%, respectively.CONCLUSIONPlastic‐covered ridge and furrow mulched with biodegradable film and liquid film is recommended for use in the semiarid Loess Plateau of China to alleviate the effects of drought on crop production. © 2015 Society of Chemical Industry
Circulating triglycerides and bile acids are reduced by a soluble wheat arabinoxylan via modulation of bile concentration and lipid digestion rates in a pig model
Authors: Gunness Purnima , Williams Barbara A. , Gerrits Walter J.J. , Bird Anthony R. , Kravchuk Olena , Gidley Michael J. 
Published: December 2015

ScopeSoluble dietary fibres have shown to have lipid reducing properties. However, their mechanisms of action are still unclear. The present study investigated how a soluble wheat arabinoxylan‐rich fraction (AXRF) fed to pigs used as a human model reduced blood triglycerides.Methods and resultsAfter 4 weeks on the experimental diets, blood from the jugular (JV) and hepatic portal (HPV) veins, bile from the gall bladder, and digesta samples from four sites of the small intestine (SI) and cecum were collected. The results showed that the AXRF significantly decreased the concentrations of total bile acid (BA) in the HPV (p < 0.01), JV (p < 0.01), bile (p < 0.05) and SI (p < 0.05), but with no effect on ileal BAs excretion flux. Furthermore, blood triglyceride (TAG) levels were also lower with AXRF (p < 0.01) but with no significant effects on LDL‐, HDL‐ or total cholesterol levels. The lower plasma TAG concentration was consistent with the reduced/delayed digestion and absorption of TAG with the AXRF (total fatty acid and MUFA p < 0.01; unsaturated fatty acid p < 0.05).ConclusionThe results suggest that AXRF reduced the levels of circulating BAs which slowed down the digestion of TAG and absorption of free fatty acids, with consequent reduction in blood TAG. Reduction in circulating bile acids by arabinoxylan causes reduction in lipids digestion and absorption.
Pencil Beam Scanning Proton Therapy for Pediatric Parameningeal Rhabdomyosarcomas: Clinical Outcome of Patients Treated at the Paul Scherrer Institute
Authors: Weber Damien C. , Ares Carmen , Albertini Francesca , Frei‐Welte Martina , Niggli Felix K. , Schneider Ralf , Lomax Antony J 
Published: December 2015

BackgroundParameningeal rhabdomyosarcomas (PM‐RMSs) represent approximately 25% of all rhabdomyosarcoma (RMS) cases. These tumors are associated with early recurrence and poor prognosis. This study assessed the clinical outcome and late toxicity of pencil beam scanning (PBS) proton therapy (PT) in the treatment of children with PM‐RMS.ProceduresThirty‐nine children with PM‐RMS received neoadjuvant chemotherapy followed by PBS‐PT at the Paul Scherrer Institute, with concomitant chemotherapy. The median age was 5.8 years (range, 1.2–16.1). Due to young age, 25 patients (64%) required general anesthesia during PT. The median time from the start of chemotherapy to PT was 13 weeks (range, 3–23 weeks). Median prescription dose was 54 Gy (relative biologic effectiveness, RBE).ResultsWith a mean follow‐up of 41 months (range, 9–106 months), 10 patients failed. The actuarial 5‐year progression‐free survival (PFS) was 72% (95% CI, 67–94%) and the 5‐year overall survival was 73% (95% CI, 69–96%). On univariate analysis, a delay in the initiation of PT (>13 weeks) was a significant detrimental factor for PFS. Three (8%) patients presented with grade 3 radiation‐induced toxicity. The estimated actuarial 5‐year toxicity ≥grade 3 free survival was 95% (95% CI, 94–96%).ConclusionsOur data contribute to the growing body of evidence demonstrating the safety and effectiveness of PT for pediatric patients with PM‐RMS. These preliminary results are encouraging and in line with other combined proton–photon and photons series; observed toxicity was acceptable.