bluuebunny/crossref_metadata_2025_split huggingface dataset:
Controlling Conformations in Alternating Dialkylsilylene‐Spaced Donor–Acceptor Copolymers by a Cooperative Thorpe–Ingold Effect and Polymer Folding
Authors: Chen Chih‐Hsien , Huang Yen‐Chin , Liao Wei‐Chih , Lim Tsong‐Shin , Liu Kuan‐Lin , Chen I‐Chia , Luh Tien‐Yau 
Published: December 2011

AbstractA series of dialkylsilylene‐spaced copolymers 6 and 7, which contain Me2Si and iPr2Si spacer groups, respectively, and have alternating donor and acceptor chromophores, have been designed and regioselectively synthesized by hydrosilylation. The ratio of the donor and acceptor chromophores for each repeat unit is 2:1, and the two donor chromophores are linked by a trimethylene bridge. A 4‐aminostyrene moiety is used as the donor and a series of acceptor chromophores with different reduction potentials are employed. Both steady‐state and kinetic measurements reveal that the photoinduced electron transfer (PET) in 6 obeyed the Marcus theory in which normal and inverted regions are observed. On the other hand, the iPr2Si‐spaced copolymers 7 exhibit absorption and emission from the charge‐transfer complexes exclusively due to ground‐state interactions between the donor and acceptor chromophores. The discrepancy in photophysical behavior may have arisen from the difference in distance between the adjacent donor and acceptor chromophores. The bulkiness of the substituents on the silicon atom (i.e., Me versus iPr) may exert the Thorpe–Ingold effect on the local conformation around the silicon atom. The differences in the small energetic barriers for each of the conformational states may be amplified by extending the distance of the folding structure, which results in perturbing the conformation of the polymers. These results suggest that the electronic interactions between adjacent donor–acceptor pairs in these copolymers are controlled by the synchronization of the substitution effect and corresponding polymeric structures.
The Bivalency effect in task switching: Event‐related potentials
Authors: Grundy John G. , Benarroch Miriam F.F. , Woodward Todd S. , Metzak Paul D. , Whitman Jennifer C. , Shedden Judith M. 
Published: December 2011

AbstractDuring task switching, if we occasionally encounter stimuli that cue more than one task (i.e., bivalent stimuli), response slowing is observed on all univalent trials within that block, even when no features overlap with the bivalent stimuli. This observation is known as the bivalency effect. Previous fMRI work (Woodward et al., 2008) clearly suggests a role for the dorsal anterior cingulate cortex (dACC) in the bivalency effect, but the time course remains uncertain. Here, we present the first high‐temporal resolution account for the bivalency effect using stimulus‐locked event‐related potentials. Participants alternated among three simple tasks in six experimental blocks, with bivalent stimuli appearing occasionally in bivalent blocks (blocks 2, 4, and 6). The increased reaction times for univalent stimuli in bivalent blocks demonstrate that these stimuli are being processed differently from univalent stimuli in purely univalent blocks. Frontal electrode sites captured significant amplitude differences associated with the bivalency effect within time windows 100–120 ms, 375–450 ms, and 500–550 ms, which may reflect additional extraction of visual features present in bivalent stimuli (100–120 ms) and suppression of processing carried over from irrelevant cues (375–450 ms and 500–550 ms). Our results support the fMRI findings and provide additional evidence for involvement of the dACC. Furthermore, the bivalency effect dissipated with extended practice both behaviorally and electrophysiologically. These findings are discussed in relation to the differential processing involved in a controlled response style. Hum Brain Mapp, 2013. © 2011 Wiley Periodicals, Inc.
Hippocampal activity is associated with self‐descriptiveness effect in memory, whereas self‐reference effect in memory depends on medial prefrontal activity
Authors: Zhu Lei , Guo Xiuyan , Li Jianqi , Zheng Li , Wang Qianfeng , Yang Zhiliang 
Published: December 2011

AbstractThe self has long been regarded as a unique cognitive structure by virtue of its superior mnemonic abilities. Two separate effects result from this self memory facilitation: self‐reference effect and self‐descriptiveness effect in memory. Self‐reference effect denotes that information processed with reference to the self is better remembered than information processed with reference to others, whereas self‐descriptiveness effect indicates that items judged to be self‐relevant is remembered better than items judged not to be relevant to self during self‐reference task. Although there is a compelling connection between self‐reference effect in memory and self mentalization processes indexed by the medial prefrontal activity, the underlying mechanisms of the self‐descriptiveness effect in memory have remained underspecified. In the present fMRI study, we used a subsequent memory paradigm to examine the neural correlates of self‐descriptiveness and self‐reference effect in memory. Participants encoded personality traits while performing self‐reference and other‐reference task (judged the descriptiveness of the traits to themselves or a famous person “Bruce Lee”), and then were given a test of recognition memory outside the scanner. It is revealed that the hippocampal activity corresponded with self‐descriptiveness effect in memory, but the activity of the medial prefrontal cortex and perirhinal cortex related to self‐reference effect in memory. These findings suggested that the memory boost for self‐relevant items relies on the enhanced relational binding mechanisms employed during self‐relevant items. © Wiley Periodicals, Inc.
Three New E‐Secoursane Triterpenoid Saponins from the Leaves of Ilex dunniana
Authors: Zhang Yue , Li Lu‐Jun , Zhang Peng , Pi Hui‐Fang , Ruan Han‐Li , Wu Ji‐Zhou 
Published: December 2011

AbstractThree new triterpenoid saponins with an 18,19‐secours‐13(18)‐ene skeleton, dunnianaolactones A–C (1–3, resp.), together with nine known compounds i.e., the ursane‐type triterpene saponin 4, the two benzofuran lignans 5 and 6, five flavonoid glycosides, and 4‐hydroxybenzoic acid, were isolated from the leaves of Ilex dunniana Levl. (Aquifoliaceae). Their structures were elucidated by means of spectroscopic and chemical methods. The configuration of dunnianaolactone A (1) was further confirmed by X‐ray crystal‐structure analysis.
Kinetics and Mechanism of Certain Acetylation Reactions with Acetamide/Oxychloride in Acetonitrile under VilsmeierHaack Conditions
Authors: Venkateswarlu Marri , Satish Kumar Mukka , Ramgopal Soma , Rajanna Kamatala Chinna , Umesh Kumar Utkoor , Uppalaiah Kusampally , Saiprakash Pondichery Kuppuswamy 
Published: December 2011

AbstractVilsmeierHaack (VH) acetylation reactions with benzaldehydes or acetophenones in MeCN followed second‐order kinetics and afforded acetyl derivatives under kinetic conditions, irrespective of the nature of the oxychloride (SOCl2 or POCl3) used for the preparation of the VH reagent along with acetamide. The present finding contributes to the understanding of the nature of the reactive species of the VH reagent as well as of the acetylation mechanism.
Photo‐Cross‐Linking of Polymethacrylates with Stilbene Chromophores in the Side Chains
Authors: Jahnke Angelika , Beile Bernhard , Meier Herbert 
Published: December 2011

AbstractMethacrylates (=2‐methylpropenoates) 5 with (E)‐stilbene (=(E)‐1,2‐diphenylethene) building blocks on tethers of variable length were prepared (Scheme 2) and polymerized (i.e., 5→6; Scheme 3) in the presence of AIBN (=2,2′‐azobis(2‐methylpropanenitrile). 4‐[(E)‐2‐Phenylethenyl]phenyl acetate (7) as model compound established the cyclodimerization as a single irreversible photoreaction. i.e., (7→8–11; Scheme 4) in the absence of oxygen. The solution photolysis of the polymers 6 provided a similar result, whereby [2π+2π] cycloadditions of stilbene units of neighboring tethers predominated. On the contrary, the desired photo‐cross‐linking of chaines occurred in the irradiation of polymer films.
Respirable rifampicin‐based microspheres containing isoniazid for tuberculosis treatment
Authors: Cassano Roberta , Trombino Sonia , Ferrarelli Teresa , Mauro Maria Vittoria , Giraldi Cristina , Manconi Maria , Fadda Anna Maria , Picci Nevio 
Published: December 2011

AbstractThe purpose of this investigation was to develop small microspheres for delivering antimycobacterial drugs to infected host macrophages. Rifampicin‐based microparticles were prepared. The drug was covalently linked to acrylic moieties to obtain a polymerizable derivative for the preparation of materials useful as drug delivery systems that then were loaded with isoniazid acting in synergy with rifampicin. Their antitubercular activity was determined in vitro. Fourier transform infrared spectroscopy confirmed hydrogel structure. Morphological analysis showed microparticles with spherical shape and homogeneous surface. In vitro release studies were performed in media simulating physiologic pH (7.4) and endosomal of alveolar macrophages pH (5.2). A similar amount of isoniazid was delivered within the first 6 h at both pHs, while a smaller amount of the drug was delivered at pH 7.4 in the last phase of the study. In vitro antitubercular activity showed a behavior comparable to that of rifampicin and isoniazid free. Bioactive swelling matrices, showing a high swelling degree into a medium miming intra alveolar environment, were obtained. They could be applied for their antitubercular activity. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.
A Comparative Analysis between Ultrasonometry and Computer‐Aided Tomography to Evaluate Bone Healing
Authors: Barbieri Giuliano , Mazzer Nilton , Ribeiro Eduardo Alvarez , Nogueira‐Barbosa Marcello Henrique , Barbieri Cláudio Henrique 
Published: December 2011

AbstractAn ultrasonometric and computed‐tomographic study of bone healing was undertaken using a model of a transverse mid‐shaft osteotomy of sheep tibiae fixed with a semi‐flexible external fixator. Fourteen sheep were operated and divided into two groups of seven according to osteotomy type, either regular or by segmental resection. The animals were killed on the 90th postoperative day and the tibiae resected for the in vitro direct contact transverse and axial measurement of ultrasound propagation velocity (UV) followed by quantitative computer‐aided tomography (callus density and volume) through the osteotomy site. The intact left tibiae were used for control, being examined in a symmetrical diaphyseal segment. Regular osteotomies healed with a smaller and more mature callus than resection osteotomies. Axial UV was consistently and significantly higher (p ≤ 0.01) than transverse UV and both transverse and axial UV were significantly higher for the regular than for the segmental resection osteotomy. Transverse UV did not differ significantly between the intact and operated tibiae (p = 0.20 for regular osteotomy; p = 0.02 for resection osteotomy), but axial UV was significantly higher for the intact tibiae. Tomographic callus density was significantly higher for the regular than for the resection osteotomy and higher than both for the intact tibiae, presenting a strong positive correlation with UV. Callus volume presented an opposite behavior, with a negative correlation with UV. We conclude that UV is at least as precise as quantitative tomography for providing information about the healing state of both regular and resection osteotomy. © 2011 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1076–1082, 2012
Development of a polar lipid profiling method by supercritical fluid chromatography/mass spectrometry
Authors: Lee Jae W. , Yamamoto Takashi , Uchikata Takato , Matsubara Atsuki , Fukusaki Eiichiro , Bamba Takeshi 
Published: December 2011

AbstractWe established a high‐throughput and high‐resolution analytical method based on supercritical fluid chromatography (SFC) coupled with mass spectrometry (MS) for the simultaneous profiling of diverse polar lipids in a mixture. Trimethylsilyl (TMS) derivatization was used for the analysis of ten polar lipids: phosphatidylglycerol (PG), phosphatidic acid (PA), phosphatidylinositol (PI), lysophosphatidylcholine (LPC), lysophosphatidylethanolamine (LPE), lysophosphatidylglycerol (LPG), lysophosphatidic acid (LPA), lysophosphatidylinositol (LPI), sphingomyeline (SM), and sphingosine‐1‐phosphate (S1P). Using the developed method, the peak tailings of PA, PI, LPA, LPI, and S1P improved, and the limit of detection of PG, PI, LPA, LPI, and S1P was enhanced by 12‐, 40‐, 510‐, 39‐, and 1490‐fold, respectively. Next, in the analysis of sheep plasma, 20 minor species of PI, LPC, LPE, and SM, and 7 molecular species of LPA, LPI, and S1P were additionally analyzed. The relative ratio of the molecular species in each polar lipid was also found by quantification. Finally, the simultaneous and detail profiling of ten polar lipids was successfully performed by SFC/MS applying TMS derivatization. This developed method is particularly applicable to metabolomics, especially for targeting polar lipids.
Deprotection‐free preparation of propargyl ether‐containing phosphinated benzoxazine and the structure–property relationship of the resulting thermosets
Authors: Chang Hou Chien , Lin Ching Hsuan , Lin Hung Tse , Dai Shenghong A. 
Published: December 2011

AbstractGenerally, protection and deprotection procedures of amino groups are required in preparing propargyl ether‐containing benzoxazines. In this study, we report a facile, deprotection‐free preparation of a propargyl ether‐containing phosphinated benzoxazine (2) from the nucleophilic substitution of a phenolic OH‐containing phosphinated benzoxazine (1) and propargyl bromide in the catalysis of potassium carbonate. The structure of (2) was characterized and confirmed by a high‐resolution mass spectrum, 1H, 13C, 1H‐1H, 1H‐13C nuclear magnetic resonance (NMR) spectra, and X‐ray single crystal diffractogram. infrared (IR) and differential scanning calorimetry were used to monitor the ring‐opening of benzoxazine and crosslinking of propargyl ether. The microstructure and the structure–property relationship of the resulting homopolymers and copolymers are discussed. The Tg of homopolymer of (2) is 208 °C by dynamic mechanical analysis, the coefficient of thermal expansion is 43 ppm/°C, and Td 5% (N2) is 393 °C, respectively, which are higher than those of the homopolymer of (1). Similar trends were observed in the copolymerization system. The results demonstrate the beneficial effect of crosslinking afforded by the propargyl ether group is higher than that by the phenolic OH group. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Root branching: mechanisms, robustness, and plasticity
Authors: Dastidar Mouli Ghosh , Jouannet Virginie , Maizel Alexis 
Published: December 2011

AbstractPlants are sessile organisms that must efficiently exploit their habitat for water and nutrients. The degree of root branching impacts the efficiency of water uptake, acquisition of nutrients, and anchorage. The root system of plants is a dynamic structure whose architecture is determined by modulation of primary root growth and root branching. This plasticity relies on the continuous integration of environmental inputs and endogenous developmental programs controlling root branching. This review focuses on the cellular and molecular mechanisms involved in the regulation of lateral root distribution, initiation, and organogenesis with the main focus on the root system of Arabidopsis thaliana. We also examine the mechanisms linking environmental changes to the developmental pathways controlling root branching. Recent progress that emphasizes the parallels to the formation of root branches in other species is discussed. WIREs Dev Biol 2012, 1:329–343. doi: 10.1002/wdev.17This article is categorized under:

Plant Development > Root Development
The Koshrabad granite massif in Uzbekistan: petrogenesis, metallogeny, and geodynamic setting
Authors: Konopelko D.L. , Biske Yu S. , Kullerud K. , Seltmann R. , Divaev F.K. 
Published: December 2011

Abstract
The Koshrabad massif, referred to as the Hercynian postcollisional intrusions of the Tien Shan, is composed of two rock series: (1) mafic and quartz monzonites and (2) granites of the main phase. Porphyritic granitoids of the main phase contain ovoids of alkali feldspar, often rimmed with plagioclase. Mafic rocks developed locally in the massif core resulted from the injections of mafic magma into the still unconsolidated rocks of the main phase, which produced hybrid rocks and various dike series. All rocks of the massif are characterized by high f (Fe/(Fe + Mg)) values and contain fayalite, which points to the reducing conditions of their formation. Mafic rocks are the product of fractional crystallization of alkali-basaltic mantle melt, and granitoids of the main phase show signs of crustal-substance contamination. In high f values and HFSE contents the massif rocks are similar to A-type granites. Data on the geochemical evolution of the massif rocks confirm the genetic relationship of the massif gold deposits with magmatic processes and suggest the accumulation of gold in residual acid melts and the rapid formation of ore quartz veins in the same structures that controlled the intrusion of late dikes. The simultaneous intrusion of compositionally different postcollisional granitoids of the North Nuratau Ridge, including the Koshrabad granitoids, is due to the synchronous melting of different crustal protoliths in the zone of transcrustal shear, which was caused by the ascent of the hot asthenospheric matter in the dilatation setting. The resulting circulation of fluids led to the mobilization of ore elements from the crustal rocks and their accumulation in commercial concentrations.
Clinical risk assessment rating and all-cause mortality in secondary mental healthcare: the South London and Maudsley NHS Foundation Trust Biomedical Research Centre (SLAM BRC) Case Register
Authors: Wu C.-Y. , Chang C.-K. , Hayes R. D. , Broadbent M. , Hotopf M. , Stewart R. 
Published: December 2011

BackgroundMental disorders are widely recognized to be associated with increased risk of all-cause mortality. However, the extent to which highest-risk groups for mortality overlap with those viewed with highest concern by mental health services is less clear. The aim of the study was to investigate clinical risk assessment ratings for suicide, violence and self-neglect in relation to all-cause mortality among people receiving secondary mental healthcare.MethodA total of 9234 subjects over the age of 15 years were identified from the South London and Maudsley Biomedical Research Centre Case Register who had received a second tier structured risk assessment in the course of their clinical care. A cohort analysis was carried out. Total scores for three risk assessment clusters (suicide, violence and self-neglect) were calculated and Cox regression models used to assess survival from first assessment.ResultsA total of 234 deaths had occurred over an average 9.4-month follow-up period. Mortality was relatively high for the cohort overall in relation to national norms [standardized mortality ratio 3.23, 95% confidence interval (CI) 2.83–3.67] but not in relation to other mental health service users with similar diagnoses. Only the score for the self-neglect cluster predicted mortality [hazard ratio (HR) per unit increase 1.14, 95% CI 1.04–1.24] with null findings for assessed risk of suicide or violence (HRs per unit increase 1.00 and 1.06 respectively).ConclusionsLevel of clinician-appraised risk of self-neglect, but not of suicide or violence, predicted all-cause mortality among people receiving specific assessment of risk in a secondary mental health service.
Impaired neural response to internal but not external feedback in schizophrenia
Authors: Horan W. P. , Foti D. , Hajcak G. , Wynn J. K. , Green M. F. 
Published: December 2011

BackgroundAccurate monitoring and integration of both internal and external feedback is crucial for guiding current and future behavior. These aspects of performance monitoring are commonly indexed by two event-related potential (ERP) components: error-related negativity (ERN) and feedback negativity (FN). The ERN indexes internal response monitoring and is sensitive to the commission of erroneous versus correct responses, and the FN indexes external feedback monitoring of positive versus negative outcomes. Although individuals with schizophrenia consistently demonstrate a diminished ERN, the integrity of the FN has received minimal consideration.MethodThe current research sought to clarify the scope of feedback processing impairments in schizophrenia in two studies: study 1 examined the ERN elicited in a flanker task in 16 out-patients and 14 healthy controls; study 2 examined the FN on a simple monetary gambling task in expanded samples of 35 out-patients and 33 healthy controls.ResultsStudy 1 replicated prior reports of an impaired ERN in schizophrenia. By contrast, patients and controls demonstrated comparable FN differentiation between reward and non-reward feedback in study 2.ConclusionsThe differential pattern across tasks suggests that basic sensitivity to external feedback indicating reward versus non-reward is intact in schizophrenia, at least under the relatively simple task conditions used in this study. Further efforts to specify intact and impaired reward-processing subcomponents in schizophrenia may help to shed light on the diminished motivation and goal-seeking behavior that are commonly seen in this disorder.
Neuro-fuzzy-based skill learning for robots
Authors: Lin Hsien-I. , Lee C. S. George 
Published: December 2011

SUMMARYEndowing robots with the ability of skill learning enables them to be versatile and skillful in performing various tasks. This paper proposes a neuro-fuzzy-based, self-organizing skill-learning framework, which differs from previous work in its capability of decomposing a skill by self-categorizing it into significant stimulus-response units (SRU, a fundamental unit of our skill representation), and self-organizing learned skills into a new skill. The proposed neuro-fuzzy-based, self-organizing skill-learning framework can be realized by skill decomposition and skill synthesis. Skill decomposition aims at representing a skill and acquiring it by SRUs, and is implemented by stages with a five-layer neuro-fuzzy network with supervised learning, resolution control, and reinforcement learning to enable robots to identify a sufficient number of significant SRUs for accomplishing a given task without extraneous actions. Skill synthesis aims at organizing a new skill by sequentially planning learned skills composed of SRUs, and is realized by stages, which establish common SRUs between two similar skills and self-organize a new skill from these common SRUs and additional new SRUs by reinforcement learning. Computer simulations and experiments with a Pioneer 3-DX mobile robot were conducted to validate the self-organizing capability of the proposed skill-learning framework in identifying significant SRUs from task examples and in common SRUs between similar skills and learning new skills from learned skills.