bluuebunny/crossref_metadata_2025_split huggingface dataset:
Habitat‐specific differences in plasticity of foliar δ13C in temperate steppe grasses
Authors: Liu Yanjie , Zhang Lirong , Niu Haishan , Sun Yue , Xu Xingliang 
Published: February 2014

AbstractA decrease in foliar δ13C with increasing precipitation is a common tendency in steppe plants. However, the rate of decrease has been reported to differ between different species or populations. We here hypothesized that plant populations in the same habitat of temperate steppes may not differ in foliar δ13C response patterns to precipitation, but could differ in the levels of plasticity of foliar δ13C across different habitats. In order to test this hypothesis, we conducted controlled watering experiments in northeast China at five sites along a west–east transect at latitude 44°N, which show substantial interannual fluctuations and intra‐annual changes in precipitation among them. In 2001, watering treatment (six levels, three replicates) was assigned to 18 plots at each site. The responses of foliar δ13C to precipitation (i.e., the sum of watering and rainfall) were determined in populations of several grass species that were common across all sites. Although similar linear regression slopes were observed for populations of different species growing at the same site, significantly different slopes were obtained for populations of the same species growing at different sites. Further, the slope of the line progressively decreased from Site I to Site V for all species in this study. These results suggest habitat‐specific differences in plasticity of foliar δ13C in temperate steppe grasses. This indicates that species' δ13C response to precipitation is conservative at the same site due to their long‐term acclimation, but the mechanism responsible behind this needs further investigations.
Clinical features, management, and short‐ and long‐term outcomes of patients with acute decompensated heart failure: phase I results of the HEARTS database
Authors: AlHabib Khalid F. , Elasfar Abdelfatah A. , Alfaleh Hussam , Kashour Tarek , Hersi Ahmad , AlBackr Hanan , Alshaer Fayez , AlNemer Khalid , Hussein Gamal A. , Mimish Layth , Almasood Ali , AlHabeeb Waleed , AlGhamdi Saleh , Alsharari Mubrouk , Chakra Esmail , Malik Asif , Soomro Raza , Ghabashi Abdullah , Al‐Murayeh Mushabab , Abuosa Ahmed 
Published: February 2014

AimsThe HEart function Assessment Registry Trial in Saudi Arabia (HEARTS) is a national multicentre project, studying clinical features, management, short‐ and long‐term outcomes, and mortality predictors in patients admitted with acute decompensated heart failure (ADHF).Methods and resultsOur prospective registry enrolled 2610 ADHF patients admitted to 18 hospitals in Saudi Arabia between October 2009 and December 2010, and followed mortality rates until January 2013. The patients included 66% men and 85.5% Saudis, with a median age (interquartile range) of 61.4 (15) years; 64% had acute on chronic heart failure (HF), 64.1% diabetes mellitus, 70.6% hypertension, and 55.7% CAD. Exacerbating factors for hospital admission included acute coronary syndromes (37.8%), infections (20.6%), non‐compliance with low‐salt diet (25.2%), and non‐compliance with HF medications (20%). An LVEF <40% was found in 73%. In‐hospital use of evidence‐based medications was high. All‐cause cumulative mortality rates at 30 days, 6 months, 1 year, 2 years, and 3 years were 8.3, 13.7, 19.5, 23.5, and 24.3%, respectively. Important independent predictors of mortality were history of stroke, acute on chronic HF, systolic blood pressure <90 mmHg upon presentation, estimated glomerular filtration rate <60 mL/min, and haemoglobin <10 g/dL.ConclusionPatients with ADHF in Saudi Arabia presented at a younger age and had higher rates of CAD risk factors compared with those in developed countries. Most patients had reduced LV systolic function, mostly due to ischaemic aetiology, and had poor long‐term prognosis. These findings indicate a need for nationwide primary prevention and HF disease management programmes.
Boron Macrocycles Based on Multicomponent Assemblies using (3‐Aminophenyl)boronic Acid and Pentaerythritol as Common Reagents; Molecular Receptors toward Lewis Bases
Authors: Celis Norma A. , Godoy‐Alcántar Carolina , Guerrero‐Álvarez Jorge , Barba Victor 
Published: February 2014

AbstractFour cyclic boronate esters were synthesized by using a multicomponent reaction from (3‐aminophenyl)boronic acid, pentaerythritol, and aldehyde derivatives [isophthalaldehyde (1), dialdehyde A (2), (3‐formylphenyl)boronic acid (3), and (2,4‐difluoro‐3‐formylphenyl)boronic acid (4)]. All four reactions lead to the formation of macrocyclic compounds in good yields of more than 70 %. The cavities of the compounds consist of 29‐, 30‐ and 40‐membered rings, and the macrocyclic structures contain two (2) and four (1 and 3–4) boron atoms as Lewis acids. Additionally, the molecules contain eight (1) and six (2–4) donor atoms (N,O) within the macrocyclic structure, thus constituting a ditopic cavity. X‐ray analysis of 2 and 3 revealed the whole conformation within the trigonal planar geometry for the boron atoms and the inclusion of neutral guest molecules, chloroform for 2 and benzene for 3. Titration of the receptors with triethylamine, pyridine, and tetrabutylammonium fluoride show that the Lewis acids are available for interaction with Lewis bases. The interaction was follow by 11B NMR and UV/Vis spectroscopy.
Reaction Mechanisms of a Tungsten–Germylyne Complex with One or Two Molecules of Alcohols and Arylaldehydes: A DFT Study
Authors: Ye Xinchen , Yang Liu , Li Yang , Huang Jianying , Zhou Li , Lei Qunfang , Fang Wenjun , Xie Hujun 
Published: February 2014

AbstractThe mechanisms for the reactions of a tungsten–germylyne complex with one or two molecules of alcohols and arylaldehydes have been investigated with the aid of density functional theory (DFT). The calculation results show that a germylyne complex 1a [Cp*(CO)2W≡GeC(SiH3)3] (Cp* = pentamethylcyclopentadienyl) reacts with only one molecule of alcohol to give hydrido(alkoxygermylene) complexes through coordination of the alcohol oxygen atom to the electron‐deficient germylyne germanium atom followed by hydrogen‐atom transfer from the oxygen atom to the tungsten atom, whereas 1a reacts with two molecules of arylaldehydes consecutively to lead to base‐stabilized alkoxy(germylene) complexes through C–H bond activation followed by hydrogermylation. In addition, two diastereomers can be formed from the reaction of a tungsten–germylyne complex with benzaldehyde. The interconversion of two diastereomers is involved in the consecutive decoordination of the C(O)Ph ligand, rotation of the germylene ligand, and recoordination of the C(O)Ph ligand to the germanium center. Our calculations are consistent with experimental observations and could provide new insights into the reactivity of the germylyne complex.
Efficient Synthesis of Aluminium‐Terminated Polyethylene by Means of Irreversible Coordinative Chain‐Transfer Polymerisation Using a Guanidinatotitanium Catalyst
Authors: Obenauf Johannes , Kretschmer Winfried P. , Kempe Rhett 
Published: February 2014

AbstractA series of guanidinato‐ligand‐stabilised titanium complexes has been synthesised and characterised. These compounds can be prepared by carbodiimide insertion into titanium–amide bonds. Reaction of carbodiimides N,N′‐bis(2,6‐diisopropylphenyl)carbodiimide, N,N′‐bis(2,6‐dimethylphenyl)carbodiimide and N‐tert‐butyl‐N′‐(2,6‐diisopropylphenyl)carbodiimide (2a–2c, respectively) with [(Et2N)TiCl3] led to mono(guanidinato)trichloridotitanium(IV) complexes (3a–3c). Subsequent conversion with methylmagnesium chloride gave the corresponding trimethyl complexes (4a and 4b). Single‐crystal X‐ray diffraction analyses were carried out for all complexes. Compound 4a showed very high activities in the polymerisation of ethylene in the presence of very high amounts of triethylaluminium and undergoes polymeryl chain transfer to aluminium. Irreversible coordinative chain‐transfer polymerisation and a unique combination of catalyst economy and high activity were observed. In the presence of 1000 equivalents of aluminium, a chain elongation of 83.3 % could be achieved with an activity of 9900 kgPE molcat–1 h–1 bar–1. The influence of the steric demand of the ligand on the polymerisation capability is significant and was investigated too.
Synthesis of N‐Glycosyl Conjugates through a Multicomponent Domino Process
Authors: Bellucci Maria Cristina , Volonterio Alessandro 
Published: February 2014

AbstractThe development of efficient methods for the combinatorial synthesis of N‐glycosyl conjugates is vital for many fields of modern synthetic organic chemistry. Herein, we report a multicomponent domino process for the regioselective synthesis of a large array N‐glycosyl‐Asp‐urea conjugates, which could be further functionalized in a chemoselective way, starting from easily accessible reactants such as N‐glycosylamines, fumaric acid monoesters, azides, and isocyanates. The process occurs under very mild conditions, does not require the use of strong bases/acids or high temperature, and is highly versatile, working efficiently with a range of protecting groups and substituents.
Synthesis of (S)‐ and (R)‐Harmicine from Proline: An Approach Toward Tetrahydro‐β‐carbolines
Authors: Lood Christopher S. , Koskinen Ari M. P. 
Published: February 2014

Abstract(S)‐ and (R)‐Harmicine were synthesized from L‐ and D‐proline, respectively. This chiral pool synthesis constitutes a new approach towards C1 substituted tetrahydro‐β‐carbolines. The developed route makes use of the 9‐phenyl‐9‐fluorenyl protecting group strategy of amino acids to prevent racemization of the vulnerable α‐amino carbonyl stereocenter. Enantiopure harmicine (> 99 % ee) was obtained in nine steps from commercially available starting material. The synthesis was performed without the use of any silica gel flash chromatography.
Importance models of the physical self: Improved methodology supports a normative‐cultural importance model but not the individual importance model
Authors: Scalas L. Francesca , Morin Alexandre J. S. , Marsh Herbert W. , Nagengast Benjamin 
Published: February 2014

AbstractWe examine theoretical and methodological issues associated with the roles of individual and group‐normative importance in self‐esteem determination. Critical issues include multicollinearity among the physical self‐subdomains, which may have affected previous results, and the need for a multidimensional perspective on importance models. We apply state‐of‐the‐art methodologies, including exploratory structural equation modelling and the product‐of‐indicators approach to latent interactions. Positive interactions would be required to support the individually importance‐weighted average model, but none were observed in the multidimensional model estimated on the full sample. Nonetheless, some interaction effects were found in the country‐specific version of the model. Rather, we found support for the alternative group importance‐weighted average model. We conclude that domain‐specific self‐concepts are weighted differently and thus differentially affect self‐esteem, but these weights do not seem to depend on individual differences in importance. Although awaiting confirmation from further studies, our results suggest the idea that individuals use mainly normative importance processes based on cultural factors in weighting each domain‐specific component of self‐concept. Copyright © 2014 John Wiley & Sons, Ltd.
Inelastic displacement ratios for soil–structure systems allowed to uplift
Authors: Ghannad Mohammad Ali , Jafarieh Amir Hossein 
Published: February 2014

SUMMARYThe simultaneous effects of soil–structure interaction, foundation uplift and inelastic behavior of the superstructure on total displacement response of soil–structure systems are investigated. The superstructure is modeled as an equivalent single‐degree‐of‐freedom system with bilinear behavior mounted on a rigid foundation resting on distributed tensionless Winkler springs and dampers. It is well known that the behavior of soil–structure systems can be well described using a limited number of nondimensional parameters. Here, by introducing two new parameters, the concept is extended to inelastic soil–structure systems in which the foundation is allowed to uplift. An extensive parametric study is conducted for a wide range of the key parameters through nonlinear time history analyses. It is shown that while uplifting soil–structure systems experience excessive displacements, in comparison with systems that are not allowed to uplift, ductility demand in the superstructure generally decreases owing to foundation uplift. A new inelastic displacement ratio (IDR) is proposed in conjunction with a nonlinear static analysis of uplifting soil–structure systems. Simplified expressions are also provided to estimate the proposed IDR. Copyright © 2014 John Wiley & Sons, Ltd.
Seismic health monitoring of an instrumented multistory building using the interpolation method
Authors: Limongelli M. P. 
Published: February 2014

SUMMARYIn this paper, a new approach to structural damage localization is presented using as damage feature the interpolation error related to the use of a spline function in modeling the operational deformed shapes of the structure. Statistically significant variations of the interpolation error between the undamaged and the inspection phase indicate the onset of damage. A threshold value of the damage feature is defined in terms of the tolerable probability of false alarm to select variations of the interpolation error because of damage from those due to random sources. The method is successfully applied to a calibrated model of the factor building a real densely instrumented building at the University of California, Los Angeles. Results show that the method is effective for damage localization for both single and multiple locations of damage also in case of responses corrupted by noise. Copyright © 2014 John Wiley & Sons, Ltd.
Network‐turbo‐coding‐based cooperation with distributed space‐time block codes
Authors: Chen Bin , Flanagan Mark F. 
Published: February 2014

AbstractIn this paper, we propose a scheme to improve the performance of turbo‐coded two‐user cooperative uplink transmission. In the proposed scheme, each user transmits its partner's second parity frame in addition to its own, using a network‐coded combination, which is further protected by a space‐time block code. The proposed system is simulated in slow and fast fading environments. Numerical simulation results indicate that for slow fading, the proposed scheme can yield up to 20% increase in data throughput compared to the traditional distributed turbo coding, while simultaneously providing a gain of 0.7 dB in bit error rate. This latter gain rises to approximately 2.5 dB when a fast fading environment is considered. Furthermore, an outage probability analysis is conducted, which corroborates the simulated performance results.Copyright © 2014 John Wiley & Sons, Ltd.
Experimental study of horizontal flame spread over rigid polyurethane foam on a plateau: effects of sample width and ambient pressure
Authors: Zhou Y. , Xiao H. H. , Sun J. H. , Zhang X. N. , Yan W. G. , Huang X. J. 
Published: February 2014

SummaryThe effects of sample width and ambient pressure on horizontal flame spread over horizontal rigid polyurethane foams are experimentally studied. A series of comparative experiments are conducted at two places with different altitudes in China. The sample surface temperature, spread rate, and height of flame are measured over a range of sample widths from 4 to 16 cm. Experimental results show that the horizontal flame spread rate decreases as the sample width increases in a negative power law at both two altitudes and the flame spread rate in the Hefei plain (at an altitude of 30 m) is larger than that on the Tibetan plateau (at an altitude of 3658 m) of the same width. The horizontal flame spread mechanism on the rigid polyurethane foam is analyzed qualitatively in comparison with the results of the flame spread rate of expanded polystyrene foams. The relationship between the dimensionless flame height (Hf/W) and the sample width (W) is obtained by using Froude number similarity. It is found based on the experimental data under two different ambient pressures that the average value of the exponent of the ambient pressure in the power law for the horizontal flame spread rate is about 1.9, which is in good agreement with the theoretical value 2.0. Copyright © 2014 John Wiley & Sons, Ltd.
Laryngeal replacement with an artificial larynx after total laryngectomy: The possibility of restoring larynx functionality in the future
Authors: Debry Christian , Dupret–Bories Agnes , Vrana Nihal E. , Hemar Patrick , Lavalle Philippe , Schultz Philippe 
Published: February 2014

AbstractBackgroundMost patients perceive total laryngectomy as a mutilation carrying with it a loss of physical and psychological integrity. Thus, an artificial larynx system that can replace the laryngeal functions would significantly improve the quality of life for the afflicted patients.MethodsThis report, with accompanying video, presents the first case in an ongoing clinical trial of laryngeal rehabilitation using an artificial larynx after total laryngectomy for squamous cell carcinoma, for an 8‐month follow‐up period. We depict the prosthesis' features, our 2‐step surgical procedure, and the outcome. The prosthesis is formed of 2 parts: (1) a tracheal prosthesis with a porous titanium junction with trachea, which was implanted in the first step to ensure its colonization, and (2) a removable part composed of concentric valves that enable inhalation and exhalation. The second part was implanted endoscopically. The implant was monitored with a retrograde nasofibroscopy of the tracheal prosthesis lumen and CT scans over a course of 8 months.ResultsThe patient's functioning in the relevant postoperative problem areas, such as swallowing, breathing, and smelling, has significantly improved. The patient was able to talk in a whispering fashion while the tracheostomy was temporarily closed. The implant's porous part was in the process of being colonized by the surrounding tissue and no fistulas were observed as evidenced by barium swallow.ConclusionAs the current case shows, tracheotomy closure can be performed, and laryngeal functions are restored, by means of an implant. With further improvements, this system can alleviate the need for a permanent tracheostomy after total laryngectomy, while maintaining important larynx functions intact. © 2014 Wiley Periodicals, Inc. Head Neck 36: 1669–1673, 2014
Increase in hippocampal theta oscillations during spatial decision making
Authors: Belchior Hindiael , Lopes‐dos‐Santos Vítor , Tort Adriano B.L. , Ribeiro Sidarta 
Published: February 2014

ABSTRACTThe processing of spatial and mnemonic information is believed to depend on hippocampal theta oscillations (5–12 Hz). However, in rats both the power and the frequency of the theta rhythm are modulated by locomotor activity, which is a major confounding factor when estimating its cognitive correlates. Previous studies have suggested that hippocampal theta oscillations support decision‐making processes. In this study, we investigated to what extent spatial decision making modulates hippocampal theta oscillations when controlling for variations in locomotion speed. We recorded local field potentials from the CA1 region of rats while animals had to choose one arm to enter for reward (goal) in a four‐arm radial maze. We observed prominent theta oscillations during the decision‐making period of the task, which occurred in the center of the maze before animals deliberately ran through an arm toward goal location. In speed‐controlled analyses, theta power and frequency were higher during the decision period when compared to either an intertrial delay period (also at the maze center), or to the period of running toward goal location. In addition, theta activity was higher during decision periods preceding correct choices than during decision periods preceding incorrect choices. Altogether, our data support a cognitive function for the hippocampal theta rhythm in spatial decision making. © 2014 The Authors Hippocampus Published by Wiley Periodicals, Inc.
Spatial memory in sedentary and trained diabetic rats: Molecular mechanisms
Authors: Diegues João Carlos , Pauli José Rodrigo , Luciano Eliete , de Almeida Leme José Alexandre Curiacos , de Moura Leandro Pereira , Dalia Rodrigo Augusto , de Araújo Michel Barbosa , Sibuya Clarice Yoshiko , de Mello Maria Alice Rostom , Gomes Ricardo José 
Published: February 2014

ABSTRACTDiabetes mellitus is a chronic disease that has been associated with memory loss, neurological disorders, and Alzheimer's disease. Some studies show the importance of physical exercise to prevent and minimize various neurological disorders. It is believed that the positive effects of exercise on brain functions are mediated by brain insulin and insulin‐like growth factor‐1 (IGF‐1) signaling. In this study, we investigate the role of swimming exercise training on hippocampus proteins related to insulin/IGF‐1 signaling pathway in Type 1 diabetic rats and its effects on spatial memory. Wistar rats were divided into four groups namely sedentary control, trained control, sedentary diabetic (SD), and trained diabetic (TD). Diabetes was induced by Alloxan (ALX) (32 mg/kg b.w.). The training program consisted in swimming 5 days/week, 1 h/day, per 6 weeks, supporting an overload corresponding to 90% of the anaerobic threshold. We employed ALX‐induced diabetic rats to explore learning and memory abilities using Morris water maze test. At the end of the training period, the rats were sacrificed 48 h after their last exercise bout when blood samples were collected for serum glucose, insulin, and IGF‐1 determinations. Hippocampus was extracted to determinate protein expression (IR, IGF‐1R, and APP) and phosphorylation (AKT‐1, AKT‐2, Tau, and β‐amyloide proteins) by Western Blot analysis. All dependent variables were analyzed by two‐way analysis of variance with significance level of 5%. Diabetes resulted in hyperglycemia and hypoinsulinemia in both SD and TD groups (P < 0.05); however, in the training‐induced group, there was a reduction in blood glucose in TD. The average frequency in finding the platform decreased in SD rats; however, exercise training improved this parameter in TD rats. Aerobic exercise decreased Tau phosphorylation and APP expression, and increased some proteins related to insulin/IGF‐1 pathway in hippocampus of diabetic rats. Thus, these molecular adaptations from exercise training might contribute to improved spatial learning and memory in diabetic organisms. © 2014 Wiley Periodicals, Inc.