bluuebunny/crossref_metadata_2025_split huggingface dataset:
Iron Complexes in Visible‐Light‐Sensitive Photoredox Catalysis: Effect of Ligands on Their Photoinitiation Efficiencies
Authors: Zhang Jing , Campolo Damien , Dumur Frederic , Xiao Pu , Fouassier Jean Pierre , Gigmes Didier , Lalevée Jacques 
Published: June 2016

AbstractThe novel role of metal‐based complexes as photoinitiator catalysts fits well into the concept of green chemistry, as it realizes the activation of polymer synthesis processes by visible light that are abundant in the solar light and allows the marked reduction of photoinitiator amount in the systems. In the present paper, a series of iron complexes (FeC_x) with various ligands have been proposed as new photoinitiator catalysts to initiate the cationic polymerization of epoxides or the free radical polymerization of acrylates upon a near‐UV or visible‐light LED exposure. The ligands play an important role on the light absorption properties and the photoinitiation ability of the iron complexes. In combination with one or two additives, FeC_x are capable to efficiently generate radicals, cations, and radical cations through an oxidative or a reductive path. Two of the newly developed FeC_x‐based photoinitiating systems exhibited comparable photoinitiation efficiency with the commercial Type I photoinitiator bis(2,4,6‐trimethylbenzoyl)‐phenylphosphineoxide (BAPO). Owing to the photocatalytic effect, remarkable photoinitiation efficiencies have been achieved by using very low concentration of iron complexes (0.02 wt %) in the systems. The involved photochemical mechanisms have been studied using electron spin resonance spin trapping, steady state photolysis, cyclic voltammetry, and laser flash photolysis techniques.
Efficient Photocatalytic Hydrogen Production over Rh‐Doped Inverse Spinel Zn2TiO4
Authors: Sun Xiaoqin , Wang Shuwei , Shen Cai , Xu Xiaoxiang 
Published: June 2016

AbstractIntroducing foreign elements is an appealing means to endow wide band gap semiconductors with visible‐light responses. Here, we investigated a series of Rh‐doped Zn2TiO4 as water reduction photocatalysts. Our results show that Rh doping is effective to improve the visible‐light response as well as surface hydrophilicity of Zn2TiO4. Efficient photocatalytic hydrogen evolution was observed after Rh doping and was found to be compositional dependent. The best performance was recorded for sample Zn2Ti0.96Rh0.04O4, with an apparent quantum efficiency of ≈0.74 % under full‐range irradiation (λ≥250 nm) and ≈0.25 % under visible‐light irradiation (λ≥420 nm). The light absorption and surface hydrophilicity are likely the controlling factors for the better activity. Theoretical calculations suggest that Rh doping is responsible for a band gap reduction and is due to a newly formed valence band composed mainly of Rh 4d orbitals at the top of the original valence band. The visible‐light activity can be attributed to the electron excitations from this new valence band to the conduction band.
High‐Performance Hybrid Supercapacitor Based on Graphene‐Wrapped Mesoporous T‐Nb2O5 Nanospheres Anode and Mesoporous Carbon‐Coated Graphene Cathode
Authors: Ma Guoqiang , Li Ke , Li Yuanyuan , Gao Biao , Ding Tianpeng , Zhong Qize , Su Jun , Gong Li , Chen Jian , Yuan Longyan , Hu Bin , Zhou Jun , Huo Kaifu 
Published: June 2016

AbstractLithium‐ion hybrid supercapacitors combining the advantages of Li‐ion batteries and supercapacitors have been the subject of extensive interest in the field of energy storage because of their high energy density at high power density. Herein, we report reduced graphene oxide (rGO) cross‐linked mesoporous T‐Nb2O5 nanospheres (T‐Nb2O5 MNSs/rGO) as high‐performance Li+ intercalation pseudocapacitive material and mesoporous carbon‐coated rGO (MC/rGO) as high‐power electric double‐layer capacitive material. The T‐Nb2O5 MNSs/rGO anode material boasts a high reversible capacity of 181 mAh g−1 at a current density of 20 mA g−1, good cycle stability, with 85 % capacity retention after 1000 cycles, as well as excellent rate capability. The MC/rGO cathode material delivers a large capacity of 110 and 86 F g−1 at a current density of 500 and 10 000 mA g−1 in organic electrolyte in the voltage range of 3–4.5 V (vs. Li/Li+). The advanced Li‐HSCs with a T‐Nb2O5 MNSs/rGO anode combined with a MC/rGO cathode show the highest power density of 25 600 W kg−1 at 21 Wh kg−1, which is much higher than that of similar Li‐HSC systems previously reported. Furthermore, the Li‐HSCs exhibit an excellent cyclability, with 82 % capacitance retention after 4000 cycles.
Patient experience and quality of urologic cancer surgery in US hospitals
Authors: Shirk Joseph D. , Tan Hung‐Jui , Hu Jim C. , Saigal Christopher S. , Litwin Mark S. 
Published: June 2016

BACKGROUNDCare interactions as perceived by patients and families are increasingly viewed as both an indicator and lever for high‐value care. To promote patient‐centeredness and motivate quality improvement, payers have begun tying reimbursement with related measures of patient experience. Accordingly, the authors sought to determine whether such data correlate with outcomes among patients undergoing surgery for genitourinary cancer.METHODSThe authors used the Nationwide Inpatient Sample and Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) data from 2009 through 2011. They identified hospital admissions for cancer‐directed prostatectomy, nephrectomy, and cystectomy, and measured mortality, hospitalization length, discharge disposition, and complications. Mixed effects models were used to compare the likelihood of selected outcomes between the top and bottom tercile hospitals adjusting for patient and hospital characteristics.RESULTSAmong a sample of 46,988 encounters, the authors found small differences in patient age, race, income, comorbidity, cancer type, receipt of minimally invasive surgery, and procedure acuity according to HCAHPS tercile (P<.001). Hospital characteristics also varied with respect to ownership, teaching status, size, and location (P<.001). Compared with patients treated in low‐performing hospitals, patients treated in high‐performing hospitals less often faced prolonged hospitalization (odds ratio, 0.77; 95% confidence interval, 0.64‐0.92) or nursing‐sensitive complications (odds ratio, 0.85; 95% confidence interval, 0.72‐0.99). No difference was found with regard to inpatient mortality, other complications, and discharge disposition (P>.05).CONCLUSIONSUsing Nationwide Inpatient Sample and HCAHPS data, the authors found a limited association between patient experience and surgical outcomes. For urologic cancer surgery, patient experience may be optimally viewed as an independent quality domain rather than a mechanism with which to improve surgical outcomes. Cancer 2016;122:2571–8. © 2016 American Cancer Society.
Impact of hypofractionated and standard fractionated chemoradiation before pancreatoduodenectomy for pancreatic ductal adenocarcinoma
Authors: Cloyd Jordan M. , Crane Christopher H. , Koay Eugene J. , Das Prajnan , Krishnan Sunil , Prakash Laura , Snyder Rebecca A. , Varadhachary Gauri R. , Wolff Robert A. , Javle Milind , Shroff Rachna T. , Fogelman David , Overman Michael , Wang Huamin , Maitra Anirban , Lee Jeffrey E. , Fleming Jason B. , Katz Matthew H. G. 
Published: May 2016

BACKGROUNDPrevious studies have suggested that preoperative chemoradiation (CRT) is associated with an improved margin‐negative resection rate among patients who undergo pancreatoduodenectomy (PD) for pancreatic ductal adenocarcinoma (PDAC). However, the optimal preoperative regimen has not been established.METHODSAll patients with PDAC who received chemotherapy and/or CRT followed by PD between 1999 and 2014 were retrospectively reviewed. The effects of 2 external‐beam radiation regimens—a standard course of 50.4 Gy in 28 fractions and a hypofractionated course of 30 Gy in 10 fractions—were compared. Differences in clinicopathologic characteristics, locoregional recurrence (LR), and overall survival (OS) were assessed.RESULTSAmong 472 patients who received preoperative therapy, 224 (47.5%) received 30 Gy, 221 (46.8%) received 50.4 Gy, and 27 (5.7%) received chemotherapy alone. Patients who received 50.4 Gy were more likely to have advanced‐stage disease and to have received induction and postoperative chemotherapy, but there was no difference in the R1 margin status, treatment effect, LR, or OS between the 2 radiation groups (all P values > .05). Patients who received preoperative CRT had a lower rate of LR than patients who received preoperative chemotherapy alone (P < .01). In a multivariate Cox proportional hazards analysis, 50.4 Gy was associated with OS and LR similar to those associated with 30 Gy, whereas the absence of preoperative radiation was associated with a higher rate of LR (odds ratio, 2.21; 95% confidence interval, 1.04‐4.70) and similar OS.CONCLUSIONSPreoperative hypofractionated CRT was associated with similar local control and OS in comparison with standard CRT in patients undergoing PD for PDAC. The use of chemotherapy alone without CRT was associated with poorer local control but similar survival. Cancer 2016. © 2016 American Cancer Society. Cancer 2016;122:2671–2679. © 2016 American Cancer Society.
Effect of particle size on pigments colour
Authors: Gueli Anna M. , Bonfiglio Guido , Pasquale Stefania , Troja Sebastiano O. 
Published: June 2016

AbstractThe historical pigments, contrary to modern ones, are not constituted by particles having all the same size and this influences the colour of the paint layers. The hiding power and colouring power of a pigment depends, in fact, on its particle size. The aim of this study was to evaluate the influence of particle size on optical characterization of paintings in terms of reflection of light and related colour specification. Starting from the qualitative observation, we have attempted to quantify the pigments colour variations induced by grinding and then attributable to granularity. Powdered pigments of principal colours have been selected in specific particle size range by mechanical sieving. The measurements were performed both on pigment pellets and on paintings realized with binder casein. All samples were characterized by an optical and colorimetric point of view through spectrophotometric analysis and for the surface morphological observation through scanning electron microscopy. © 2016 Wiley Periodicals, Inc. Col Res Appl, 42, 236–243, 2017
Pseudo‐Ligandless Click Chemistry for Oligonucleotide Conjugation
Authors: Mack Stephanie , Fouz Munira F. , Dey Sourav K. , Das Subha R. 
Published: June 2016

AbstractParticularly for its use in bioconjugations, the copper‐catalyzed (or copper‐promoted) azide‐alkyne cycloaddition (CuAAC) reaction or ‘click chemistry’, has become an essential component of the modern chemical biologist's toolbox. Click chemistry has been applied to DNA, and more recently, RNA conjugations, and the protocols presented here can be used for either. The reaction can be carried out in aqueous buffer, and uses acetonitrile as a minor co‐solvent that serves as a ligand to stabilize the copper. The method also includes details on the analysis of the reaction product. © 2016 by John Wiley & Sons, Inc.
Optimization of Norbornadiene Compounds for Solar Thermal Storage by First‐Principles Calculations
Authors: Kuisma Mikael , Lundin Angelica , Moth‐Poulsen Kasper , Hyldgaard Per , Erhart Paul 
Published: June 2016

AbstractMolecular photoswitches capable of storing solar energy are interesting candidates for future renewable energy applications. Here, using quantum mechanical calculations, we carry out a systematic screening of crucial optical (solar spectrum match) and thermal (storage energy density) properties of 64 such compounds based on the norbornadiene–quadricyclane system. Whereas a substantial number of these molecules reach the theoretical maximum solar power conversion efficiency, this requires a strong red‐shift of the absorption spectrum, which causes undesirable absorption by the photoisomer as well as reduced thermal stability. These compounds typically also have a large molecular mass, leading to low storage densities. By contrast, single‐substituted systems achieve a good compromise between efficiency and storage density, while avoiding competing absorption by the photo‐isomer. This establishes guiding principles for the future development of molecular solar thermal storage systems.
Consummatory succesive positive contrast produced by the downshift of an aversive solution in infant rats
Authors: Suárez Andrea B. , Pautassi Ricardo M. , Kamenetzky Giselle V. 
Published: June 2016

AbstractSubjects trained in successive positive contrast are usually given an appetitive stimulus of relatively low quality during a pre‐shift, followed by exposure to a significantly greater quality of the same stimulus. Enhanced responsiveness to the high‐quality stimulus during the post‐shift phase, compared to a control group that receives the superior reward in both phases, is taken as an index of successive positive contrast. Successive positive contrast reports are rare, probably due to performance limitations inherent to the experimental protocols available. We exposed infant rats (14 days old at the start of training) to .1% or .01% quinine during 4, 10 min, trials (pre‐shift phase). All animals were then given two trials of exposure to .01% quinine (post‐shift phase). During the pre‐shift the level of intake was greater in pups stimulated with the relatively less aversive .01% quinine solution. These animals also exhibited, compared to those stimulated with .1% quinine, lower emission of the aversive response paw treading. During the post‐shift phase, the group that had been exposed to .1% quinine exhibited significantly greater intake of .01% quinine, along with a reduction in the emission of paw treading and an enhancement in paw licking, an ingestive, appetitive response. Altogether, the evidence is suggestive of the emergence of consummatory successive positive contrast during the second week of life of the rat. To our knowledge, this is the first evidence of positive contrast using an aversive solution.
Dispersal by rodent caching increases seed survival in multiple ways in canopy‐fire ecosystems
Authors: Peterson N. B. , Parker V. T. 
Published: May 2016

AbstractSeed‐caching rodents have long been seen as important actors in dispersal ecology. Here, we focus on the interactions with plants in a fire‐disturbance community, specifically Arctostaphylos species (Ericaceae) in California chaparral. Although mutualistic relationships between caching rodents and plants are well studied, little is known how this type of relationship functions in a disturbance‐driven system, and more specifically to systems shaped by fire disturbance. By burying seeds in the soil, rodents inadvertently improve the probability of seed surviving high temperatures produced by fire. We test two aspects of vertical dispersal, depth of seed and multiple seeds in caches as two important dimensions of rodent‐caching behavior. We used a laboratory experimental approach to test seed survival under different heating conditions and seed bank structures. Creating a synthetic soil seed bank and synthetic fire/heating in the laboratory allowed us to have control over surface heating, depth of seed in the soil, and seed cache size. We compared the viability of Arctostaphylos viscida seeds from different treatment groups determined by these factors and found that, as expected, seeds slightly deeper in the soil had substantial increased chances of survival during a heating event. A key result was that some seeds within a cache in shallow soil could survive fire even at a depth with a killing heat pulse compared to isolated seeds; temperature measurements indicated lower temperatures immediately below caches compared to the same depth in adjacent soil. These results suggest seed caching by rodents increases seed survival during fire events in two ways, that caches disrupt heat flow or that caches are buried below the heat pulse kill zone. The context of natural disturbance drives the significance of this mutualism and further expands theory regarding mutualisms into the domain of disturbance‐driven systems.
Herbivore density mediates the indirect effect of herbivores on plants via induced resistance and apparent competition
Authors: Ramirez Ricardo A. , Eubanks Micky D. 
Published: June 2016

AbstractHerbivore‐induced plant resistance and apparent competition are two indirect ways herbivores interact. If a less damaging herbivore indirectly suppresses the abundance of a more damaging herbivore via these mechanisms, then plants may ultimately benefit. Changes in herbivore density, however, can dictate the intensity of species interactions and may play a critical role in determining the outcome of plant‐ and predator‐mediated herbivore interactions. We tested the effects of herbivore density on the strength of indirect interactions among phloem‐feeding aphids and herbivorous caterpillars and the outcome of these interactions for their shared host plant, cotton (Gossypium hirsutum). We quantified the survival of caterpillars on host plants that were infested with varying densities of aphids in the presence and absence of predators (ladybeetles). We found that aphids induced defensive proteins in cotton plants and that caterpillar survival was negatively affected by induced resistance. Likewise, we found that the presence of aphids increased predation of caterpillars by ladybeetles, but that apparent competition between aphids and caterpillars was density dependent. Ladybeetles consumed relatively high numbers of small caterpillars at low to intermediate aphid densities, but essentially became aphid specialists at high aphid densities. Aphid induced defenses and apparent competition combined such that plant damage by caterpillars was lowest when predators were present at low aphid density (induced resistance + highest level of apparent competition). This suggests that herbivores can benefit plants, but the effect on host plants is mediated by herbivore density. Indirect herbivore‐plant mutualisms may increase plant quality, plant fitness, and yield of crop plants and these interactions need to be considered in ecologically based pest management plans. In addition, these interactions likely alter arthropod community structure and natural selection on anti‐herbivore defense traits in plants in natural systems.
Environmental stress mediates trophic cascade strength and resistance to invasion
Authors: Cheng Brian S. , Grosholz Edwin D. 
Published: June 2016

AbstractAlthough much attention has focused on the drivers of trophic cascade strength among systems (e.g., habitat type, body size, predator, and prey thermy) comparatively little is known of how trophic cascades change within systems, especially with respect to gradients in environmental stress. To address this, we measured the strength of a trophic cascade across an estuarine stress gradient and tested the predictions of “consumer stress model” that suggests sensitivity to stress is greater in mobile consumers relative to sessile prey. We used field observations and experimental manipulations within a central California estuary (Tomales Bay), where higher water temperatures in summer/fall and lower salinity during winter/spring may differentially affect predators (native crabs), meso‐consumers (invasive oyster drills), and sessile prey (native oysters). Our results demonstrate that sites with high environmental stress (warmer and lower salinity waters) excluded top predators from the food web, which facilitated high densities of oyster drills and resulted in low oyster survival. In contrast, less stressful sites (cooler and higher salinity waters) had high crab densities leading to reduced oyster drill survival and high oyster survival (an indirect positive effect). Observational data from 14 field sites along both margins of Tomales Bay are consistent with the results of experimental manipulations. This study highlights the importance of environmental stress in mediating within system trophic cascade strength by altering top predator abundance. Our results support the predictions of the consumer stress model and suggest that increasing environmental stress (warming and variable salinity regimes) as a result of climate change may decouple species interactions. Furthermore, warming and extreme low salinities may indirectly intensify the negative effects of non‐native species by reducing the biotic resistance provided by native predators.
Estimation of avian species richness: biases in morning surveys and efficient sampling from acoustic recordings
Authors: La Van T. , Nudds Thomas D. 
Published: June 2016

AbstractSpecies richness estimation is an important component of ecological studies and conservation planning. Limited resources necessitate that sampling protocols be as efficient and accurate as possible. For birds, automated acoustic sampling offers potential advantages of abundant data at reduced cost for field observers, and enhanced diel coverage, but neither of which may accrue if surveys are biased and/or too costly to analyze in the lab. Here, we assessed bias in estimates of species and higher order taxonomic richness obtained from standard morning point counts, and from morning‐only acoustic recordings, relative to estimates from 72, 10‐min acoustic recordings conducted hourly over 3 d. Furthermore, we compared 10‐min subsamples of 24‐h recordings across five statistical estimators to establish which combination of number of samples, from which times of day, and with which statistical estimator, best approximated total observed species richness. Total observed species richness was the total number of species detected per site over 720 min of 10‐min recordings. Standard morning point counts and morning‐only acoustic recordings consistently underestimated both total species and higher order taxonomic richness. Species not detected were those that irregularly or nocturnally vocalize. Without statistical estimators, the greatest number of species per unit sample effort was detected from 10‐min, on‐the‐hour samples between 07:00 and 12:00, and at 21:00, over 3 d. With the jackknife estimator, three 10‐min samples (one at each of 08:00, 09:00, and 12:00, over 3 d) most efficiently estimated within 5% of total observed species richness. Researchers can subsample in combination with statistical estimators to increase analytical efficiency for species richness using acoustic recordings.