bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bis‐tridentate IrIII Phosphors Bearing Two Fused Five‐Six‐Membered Metallacycles: A Strategy to Improved Photostability of Blue Emitters
Authors: Hsu Ling‐Yang , Liang Qiumin , Wang Zhiheng , Kuo Hsin‐Hung , Tai Wun‐Shan , Su Shi‐Jian , Zhou Xiuwen , Yuan Yi , Chi Yun 
Published: October 2019

AbstractIridium complexes bearing chelating cyclometalates are popular choices as dopant emitters in the fabrication of organic light‐emitting diodes (OLEDs). In this contribution, we report a series of blue‐emitting, bis‐tridentate IrIII complexes bearing chelates with two fused five‐six‐membered metallacycles, which are in sharp contrast to the traditional designs of tridentate chelates that form the alternative, fused five‐five metallacycles. Five IrIII complexes, Px‐21–23, Cz‐4, and Cz‐5, have been synthesized that contain a coordinated dicarbene pincer chelate incorporating a methylene spacer and a dianionic chromophoric chelate possessing either a phenoxy or carbazolyl appendage to tune the coordination arrangement. All these tridentate chelates afford peripheral ligand–metal–ligand bite angles of 166–170°, which are larger than the typical bite angle of 153–155° observed for their five‐five‐coordinated tridentate counterparts, thereby leading to reduced geometrical distortion in the octahedral frameworks. Photophysical measurements and TD‐DFT studies verified the inherent transition characteristics that give rise to high emission efficiency, and photodegradation experiments confirmed the improved stability in comparison with the benchmark fac‐[Ir(ppy)3] in degassed toluene at room temperature. Phosphorescent OLED devices were also fabricated, among which the carbazolyl‐functionalized emitter Cz‐5 exhibited the best performance among all the studied bis‐tridentate phosphors, showing a maximum external quantum efficiency (EQEmax) of 18.7 % and CIEx,y coordinates of (0.145, 0.218), with a slightly reduced EQE of 13.7 % at 100 cd m−2 due to efficiency roll‐off.
Atomically Dispersed Pt on Screw‐like Pd/Au Core‐shell Nanowires for Enhanced Electrocatalysis
Authors: Chao Tingting , Zhang Yida , Hu Yanmin , Zheng Xusheng , Qu Yunteng , Xu Quan , Hong Xun 
Published: October 2019

AbstractEngineering noble metal nanostructures at the atomic level can significantly optimize their electrocatalytic performance and remarkably reduce their usage. We report the synthesis of atomically dispersed Pt on screw‐like Pd/Au nanowires by using ultrafine Pd nanowires as seeds. Au can selectively grow on the surface of Pd nanowires by an island growth pattern to fabricate surface defect sites to load atomically dispersed Pt, which can be confirmed by X‐ray absorption fine structure measurements and aberration corrected HRTEM images. The nanowires with 2.74 at % Pt exhibit superior HER properties in acidic solution with an overpotential of 20.6 mV at 10 mA cm−2 and enhanced alkaline ORR performance with a mass activity over 15 times greater than the commercial platinum/carbon (Pt/C) catalysts.
Backbone Reactivity of Lithium β‐Diketiminate (NacNac) Complexes with CO2, tBuNCO and iPrNCO
Authors: Gauld Richard M. , McLellan Ross , Kennedy Alan R. , Barker Jim , Reid Jacqueline , Mulvey Robert E. 
Published: October 2019

AbstractThough alkali metal NacNac (β‐diketiminate) complexes have been utilised in synthesis as NacNac‐transfer agents, studies of them in their own right with small molecules are exceptionally rare. Here, the lithium compound of the common 2,6‐diisopropylphenyl‐β‐methyldiketiminate [NacNac(Dipp, Me)] ligand is investigated with carbon dioxide and isocyanates. In all four cases reaction occurs at the backbone γ‐C atom of the NacNac ligand, which redistributes electronically into a diimine. Insertion of CO2 gives an eight‐atom carboxylate (Li2O4C2) ring at the γ‐C site in a dimer. Insertion of tBuNCO gives a secondary amide at the γ‐C site in a monomer with TMEDA chelating lithium. Double insertion of tBuNCO and (adventitious) oxygen gives a dimer with a (LiO)2 central core involving the latter source. Insertion of less bulky (iPrNCO) gives a dimer with dimerisation through the C=O bonds of the emergent secondary amide function.
Exfoliation and Sensitization of 2D Carbon Nitride for Photoelectrochemical Biosensing under Red Light
Authors: Zhao Lufang , Ji Jingjing , Shen Yanfei , Wu Kaiqing , Zhao Tingting , Yang Hong , Lv Yanqin , Liu Songqin , Zhang Yuanjian 
Published: October 2019

AbstractTwo‐dimensional carbon nitride (CN) has drawn increasing attention as a conjugated metal‐free polymer for photoelectrochemical (PEC) biosensing. However, CN only absorbs ultraviolet and very limited visible light (λ<460 nm), which poses potential risks for biomolecules and also cannot pass through tissue for in vivo detection. Herein, simultaneous exfoliation and functionalization of CN nanosheets (CNNS) with copper phthalocyanine (TsCuPc) simply by mechanical milling, thanks to the delicate π–π interaction between them, is reported. Moreover, due to energy‐level matching, an effective donor–acceptor (D‐A) interaction with much‐improved photocurrent under irradiation with red light (λ>630 nm) was observed for the as‐prepared CNNS‐TsCuPc. As an example, dopamine in blood was detected by using red light by a CNNS‐TsCuPc photoelectrode with uncompromised linear range and detection limit, as well high selectivity. As one of the few successful demonstrations of red‐light‐responsive PEC sensing systems, this work takes a first step toward future in vivo applications by enriching the optoelectronic properties of CN with task‐specific antenna molecules via D‐A interaction.
Formal Synthesis of Indolizidine and Quinolizidine Alkaloids from Vinyl Cyclic Carbonates
Authors: Cristòfol Àlex , Böhmer Christian , Kleij Arjan W. 
Published: October 2019

AbstractCyclic carbonates have long been considered relatively inert molecules acting as protecting groups in complex multistep synthetic routes. This study shows that a concise, yet modular synthesis of indolizidine and quinolizidine alkaloids can be developed from vinyl‐substituted cyclic carbonate (VCC) intermediates. Through a highly stereoselective palladium‐catalyzed allylic alkylation reaction, these alkaloid motifs can be assembled in four synthetic and only two column purification steps. The combined results help to further advance functionalized cyclic carbonates as useful and reactive intermediates in natural product synthesis.
Efficient Synthesis of Cyclic Sulfoximines from N‐Propargylsulfinamides through Sulfur–Carbon Bond Formation
Authors: Aota Yusuke , Maeda Yoshiaki , Kano Taichi , Maruoka Keiji 
Published: October 2019

AbstractCyclic sulfoximines were readily synthesized by the cyclization of N‐propargylsulfinamides without using expensive and toxic metal catalysts. This cyclization proceeded without loss of optical purity of chiral sulfinamides through the unusual sulfur–carbon bond formation promoted by an inexpensive inorganic base. This stereospecific cyclization offers a general approach to the asymmetric synthesis of chiral cyclic sulfoximines as an emerging heterocycle in medicinal chemistry.
Cardiovascular risk factors among Ghanaian patients with HIV: A cross‐sectional study
Authors: Appiah Lambert T. , Sarfo Fred S. , Huffman Mark D. , Nguah Samuel B. , Stiles Jonathan K. 
Published: October 2019

AbstractBackgroundCardiovascular disease (CVD) poses a significant cause of morbidity and mortality among people living with human immunodeficiency virus (HIV). However, data are limited on CVD risk burden among HIV patients in Ghana. We describe the age‐ and sex‐adjusted prevalence of CVD risk factors among HIV patients in Ghana.MethodsFrom January 2013 to May 2014, we identified eligible HIV patients 18 years and older, as well as uninfected adult blood donors presenting to the Komfo Anokye Teaching Hospital as controls. Using a standardized protocol, we collected demographic, clinical, laboratory, and electrocardiographic data. We created multivariable logistic regression models to compare the prevalence of abnormal risk factors between the two groups.ResultsWe recruited 345 patients with HIV (n = 173 on HAART, n = 172 not on HAART) and 161 uninfected adult blood donors. Patients with HIV were older (mean [SD] age: 41 [11] vs 32 [11] years) and were more likely to be female (72% vs 28%) than blood donors. Among patients on HAART, median (interquartile range) treatment duration was 17 (4‐52) months. The prevalence of hypertension, hypercholesterolemia, and diabetes mellitus among HIV patients was 9%, 29%, and 5%, respectively, compared with 5%, 15%, and 0.6% among uninfected blood donors. Smoking was the least prevalent CVD risk factor (1%‐2%). After adjustment for age, sex, and body mass index, HIV patients had a 10‐fold higher odds of prevalent diabetes compared with controls, (adjusted OR = 10.3 [95% CI: 1.2, 86.7]).ConclusionCVD risk factors are common among HIV patients in Ghana, demonstrating the urgent need for creation and implementation of strategic CVD interventions.
Charcot–Marie–Tooth disease Type 2E/1F mutant neurofilament proteins assemble into neurofilaments
Authors: Stone Elizabeth J. , Uchida Atsuko , Brown Anthony 
Published: October 2019

AbstractCharcot–Marie–Tooth disease Type 2E/1F (CMT2E/1F) is a peripheral neuropathy caused by mutations in neurofilament protein L (NFL), which is one of five neurofilament subunit proteins that co‐assemble to form neurofilaments in vivo. Prior studies on cultured cells have shown that CMT2E/1F mutations disrupt neurofilament assembly and lead to protein aggregation, suggesting a possible disease mechanism. However, electron microscopy of axons in peripheral nerve biopsies from patients has revealed accumulations of neurofilament polymers of normal appearance and no evidence of protein aggregates. To reconcile these observations, we reexamined the assembly of seven CMT2E/1F NFL mutants in cultured cells. None of the mutants assembled into homopolymers in SW13vim‐ cells, but P8R, P22S, L268/269P, and P440/441L mutant NFL assembled into heteropolymers in the presence of neurofilament protein M (NFM) alone, and N98S, Q332/333P, and E396/397K mutant NFL assembled in the presence of NFM and peripherin. P8R, P22S, N98S, L268/269P, E396/397K, and P440/441L mutant NFL co‐assembled into neurofilaments with endogenous NFL, NFM, and α‐internexin in cultured neurons, although the N98S and E396/397K mutants showed reduced filament incorporation, and the Q332/333P mutant showed limited incorporation. We conclude that all the mutants are capable of assembling into neurofilaments, but for some of the mutants this was dependent on the identity of the other neurofilament proteins available for co‐assembly, and most likely also their relative expression level. Thus, caution should be exercised when drawing conclusions about the assembly capacity of CMT2E/1F mutants based on transient transfections in cultured cells.
Dose‐dependent effect of aerobic exercise on inflammatory biomarkers in a randomized controlled trial of women at high risk of breast cancer
Authors: Haley Jeremy S. , Hibler Elizabeth A. , Zhou Shouhao , Schmitz Kathryn H. , Sturgeon Kathleen M. 
Published: October 2019

BackgroundIncreased levels of inflammation are associated with many diseases, including cancer. Physical activity can lower breast cancer risk as well as levels of inflammation. The Women In Steady Exercise Research (WISER) Sister trial was a randomized controlled trial that investigated the effects of a dosed, moderate to vigorous, aerobic exercise intervention on levels of inflammation in premenopausal women who were at high risk of developing breast cancer.MethodsParticipants were randomized to control (<75 minutes per week; 41 patients), low‐dose exercise (150 minutes per week; 38 patients), or high‐dose exercise (300 minutes per week; 37 patients) groups. The 5‐menstrual cycles–long, home‐based treadmill exercise intervention gradually increased in minutes per week and intensity up to a maximum of 80% of the age‐predicted maximum heart rate. Blood was collected at baseline and at follow‐up and assayed for chemokine (C‐C motif) ligand 2 (CCL2), interleukin 10 (IL‐10), interleukin 12 (IL‐12), and tumor necrosis factor α (TNF‐α).ResultsA linear dose‐response relationship was observed for the proinflammatory biomarkers CCL2 (%Δ of −5.44% in the control group, −0.03% in the low‐dose exercise group, and 1.54% in the high‐dose exercise group), IL‐12 (%Δ of −21.5% in the control group, 38.2% in the low‐dose exercise group, and 25.8% in the high‐dose exercise group,) and TNF‐α (%Δ of −4.69% in the control group, 9.51% in the low‐dose exercise group, and 15.7% in the high‐dose exercise group) but not for the anti‐inflammatory biomarker IL‐10 (%Δ of 5.05% in the control group, 6.05% in the low‐dose exercise group, and 10.6% in the high‐dose exercise group). For IL‐12 and TNF‐α, the percentage change was significantly higher in the low‐dose (IL‐12: P < .001; and TNF‐α: P = .01) and high‐dose (IL‐12: P < .001; and TNF‐α: P < .001) exercise groups compared with the control group.ConclusionsModerate to vigorous aerobic exercise appeared to increase levels of proinflammatory biomarkers in a dose‐dependent manner in a population of healthy women at high risk of developing breast cancer. The results of the current study suggest that for healthy premenopausal women, the mechanism of reduced breast cancer risk observed in physically active individuals may not be a result of reduced levels of inflammation.
Evaluation of the use of a guided bur during preclinical teaching of tooth preparation: A pilot study
Authors: Yee Soho , Richert Raphaël , Viguie Gilbert , Couraud Sébastien , Dehurtevent Marion , Fages Michel , Corne Pascale , Ducret Maxime 
Published: October 2019

AbstractObjectivesAn innovative calibrated bur, aiming to improve precision during reduction of the incisal edge, was recently proposed to guide practitioners during tooth preparation. However, limited information is available concerning its usefulness in dental preclinical education. The aim of this study was to evaluate whether using this innovative guided bur improves learning experience quality and the performance of students during tooth preparation.Material and methodsAfter having provided written consent, 60 second‐year students were divided into two groups. One group used a 1‐mm rounded bur to perform depth grooves, whereas the second group used the innovative guided bur, consisting in a 2‐mm‐depth marker with a stopping surface. Once the grooves were obtained, they were then connected using the same wheel bur in both groups. The aim was to obtain a final 2‐mm reduction of the incisal edge. Quality of the learning experience (stress level, motivation to restart, self‐evaluation of the preparation, and difficulty) was quantified using a visual analog scale. Duration of the procedure was also measured in both groups. 3D measurements for each tooth were performed using an STL comparison software.ResultsThere were no significant differences between groups in terms of stress and self‐evaluation of the preparation. Students in the guided bur group reported significantly lower perception of exercise difficulty (p < .001) and significantly higher motivation to restart the procedure (p < .001). The guided bur group performed the procedure in 16.4% less time than the rounded bur group. The use of the guided bur led to a 23% over‐reduction, whereas the use of the rounded bur led to a 10% under‐reduction.ConclusionsOverall, the present study shows that the guided bur provides significant improvement in the student's learning experience with increased motivation and decreased perception of difficulty. It shortens the duration of procedure performance, but it also induces a reduction in preparation accuracy.
A note on mutually beneficial exchange and discrimination
Authors: Duncan Thomas K. , Farhat Daniel 
Published: October 2019

AbstractWe use Hammond and Axelrod's (Hammond, R. A. & Axelrod, R. (2006). The evolution of ethnocentrism. Journal of Conflict Resolution, 50, 6: 926–936) agent‐based model of ethnocentrism to show how people's willingness to cooperate with outsiders is affected by mutually beneficial exchange. In environments where one person gains at the expense of others (“charity economies”), we find discrimination to be a dominant behavior. However, non‐discrimination becomes the dominant behavior when an environment contains productive investment and mutually beneficial exchange (“investment economies”). These results point to market‐improving policy prescriptions to reduce racial/ethnic tension and the conflict that arise from it.
Estimation of the commercial height of trees with laser meter: a viable alternative for forest management in the Brazilian Amazon
Authors: Sales Agust , Antonio Siviero Marco , Cezar Gomes Pereira Paulo , Benmuyal Vieira Sabrina , Alves Berberian Ghaby , Maia Miranda Bárbara 
Published: October 2019

AbstractCommercial height of the tree is a key variable for estimating the wood stock in tropical forests managed for timber production purposes. Most available measurement devices suffer limitations in this type of forest, promoting low precision measurements with high variation errors. The laser meter device appears as a viable alternative, as in addition to using trigonometric principles, it is not necessary that the device is close to the eyes of the meter to carry out the measurement. The device can be used to measure commercial height of trees on flat or sloping terrain, at different distances from the tree. However, there are no studies evaluating the precision of this device. The objective of this study was to determine the precision of the laser meter method for estimating the commercial height of trees, as compared to the actual measurement in a tropical forest in the Brazilian Amazon. Measurements were made on 300 trees with commercial height between 7 and 14 m. Actual commercial heights were measured with graduated ruler. Applied tests were paired t test, graphical analysis of residuals and calculations of bias statistics, mean absolute deviation, standard deviation of differences, and coefficient of determination (R2). Paired t test indicated that the mean of the heights measured by the laser meter is statistically equal to that of the graduated ruler. Measurements with laser meter did not show bias and had mean error of 0.0745. The standard deviation of the differences indicated dispersion of errors of 0.97, equal to that shown in the graduated rule. Laser meter presents an alternative method for estimating the commercial height of trees in tropical forest in the Brazilian Amazon. There was no tendency to underestimate or overestimate the commercial heights of trees. Use of the laser meter is potentially of use for measuring the commercial height of trees in tropical forests.
Population structure, connectivity, and demographic history of an apex marine predator, the bull shark Carcharhinus leucas
Authors: Pirog Agathe , Ravigné Virginie , Fontaine Michaël C. , Rieux Adrien , Gilabert Aude , Cliff Geremy , Clua Eric , Daly Ryan , Heithaus Michael R. , Kiszka Jeremy J. , Matich Philip , Nevill John E. G. , Smoothey Amy F. , Temple Andrew J. , Berggren Per , Jaquemet Sébastien , Magalon Hélène 
Published: October 2019

AbstractKnowledge of population structure, connectivity, and effective population size remains limited for many marine apex predators, including the bull shark Carcharhinus leucas. This large‐bodied coastal shark is distributed worldwide in warm temperate and tropical waters, and uses estuaries and rivers as nurseries. As an apex predator, the bull shark likely plays a vital ecological role within marine food webs, but is at risk due to inshore habitat degradation and various fishing pressures. We investigated the bull shark's global population structure and demographic history by analyzing the genetic diversity of 370 individuals from 11 different locations using 25 microsatellite loci and three mitochondrial genes (CR, nd4, and cytb). Both types of markers revealed clustering between sharks from the Western Atlantic and those from the Western Pacific and the Western Indian Ocean, with no contemporary gene flow. Microsatellite data suggested low differentiation between the Western Indian Ocean and the Western Pacific, but substantial differentiation was found using mitochondrial DNA. Integrating information from both types of markers and using Bayesian computation with a random forest procedure (ABC‐RF), this discordance was found to be due to a complete lack of contemporary gene flow. High genetic connectivity was found both within the Western Indian Ocean and within the Western Pacific. In conclusion, these results suggest important structuring of bull shark populations globally with important gene flow occurring along coastlines, highlighting the need for management and conservation plans on regional scales rather than oceanic basin scale.
Multiple freshwater invasions of the tapertail anchovy (Clupeiformes: Engraulidae) of the Yangtze River
Authors: Cheng Fangyuan , Wang Qian , Maisano Delser Pierpaolo , Li Chenhong 
Published: October 2019

AbstractFreshwater fish evolved from anadromous ancestors can be found in almost all continents. The roles of paleogeographic events and nature selection in speciation process often are under focus of research. We studied genetic diversity of anadromous and resident tapertail anchovies (Coilia nasus species complex) in the Yangtze River Basin using 4,434 nuclear loci, and tested the history of freshwater invasion of C. nasus. We found that both C. brachygnathus and C. nasus were valid species, but the resident C. nasus taihuensis and the anadromous C. nasus were not different genetically based on Bayes factor species delimitation (BFD*). Maximum likelihood tree, Network, PCA and STRUCTURE analyses all corroborated the results of BFD*. Two independent freshwater invasion events of C. nasus were supported, with the first event occurring around 4.07 Ma and the second happened around 3.2 Ka. The time of the two freshwater invasions is consistent with different paleogeographic events. Estimation showed that gene flow was higher within ecotypes than between different ecotypes. F‐DIST analyses identified 120 disruptive outliers by comparing C. brachygnathus to anadromous C. nasus, and 21 disruptive outliers by comparing resident C. nasus to anadromous C. nasus. Nine outliers were found to be common between the two comparisons, indicating that independent freshwater invasion of C. nasus might involve similar molecular pathways. The results of this study suggest that adaptation to landlocked freshwater environment of migratory fish can evolve multiple times independently, and morphology of landlocked ecotypes may cause confusion in their taxonomy.
Dinuclear Copper Complexes Triply Bridged by a Tetraphosphane, rac‐Ph2PCH2P(Ph)CH2P(Ph)CH2PPh2
Authors: Tanase Tomoaki , Otaki Risa , Okue Ayumi , Nakamae Kanako , Nakajima Takayuki 
Published: October 2019

AbstractInvited for the cover of this issue is the group of Tomoaki Tanase at Nara Women's University, Japan. The cover image shows a dinuclear copper(I) complex triply bridged by rac‐dpmppm with a series of diimino ligands as a “dicopper firefly” that switches its luminescence mechanisms to emit rapid fluorescence in dichloromethane solution and 3MLCT phosphorescence in the solid state.